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Sample records for mediated hypercalcemia induced

  1. Teriparatide Induced Delayed Persistent Hypercalcemia

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    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  2. A Rare Case Report of Immobility-Induced Hypercalcemia in an Infant.

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    Vyas, Neha; Kaminski, Beth; MacLeish, Sarah

    2016-04-01

    Immobility-induced hypercalcemia is a rare cause of hypercalcemia in children, and to our knowledge it has never been reported in an infant. Infants and children are in a state of high bone turnover. Therefore, they are prone to the imbalance of osteoblastic and osteoclastic activity that occurs with prolonged immobilization, leading to hypercalcemia. Here we present the case of an infant with hypercalcemia who presented with fatigue, irritability, and failure to thrive after prolonged immobilization. Therapeutic interventions were conservative and included hydration and increased mobility leading to complete resolution. This case highlights the importance of including this rare entity in a differential diagnosis of hypercalcemia as well as screening postsurgical patients with prolonged immobility for hypercalcemia. Copyright © 2016 by the American Academy of Pediatrics.

  3. Calcitriol-mediated hypercalcemia in a patient with bilateral adrenal non-Hodgkin's B-cell lymphoma case report

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    Ana Abaroa-Salvatierra

    2016-04-01

    Full Text Available Calcitriol-mediated hypercalcemia is a frequent manifestation of hematological malignancies. However, there are a few reports of cases presenting with increased angiotensin-converting enzyme (ACE level, which suggests a possible mechanism similar to that of granulomatous diseases. We present a patient with hypercalcemia, normal parathyroid hormone, and parathyroid hormone-related protein levels but high calcitriol and ACE levels that, after further investigation, was diagnosed with bilateral adrenal non-Hodgkin's B-cell lymphoma. Primary adrenal lymphoma represents only 1% of all non-Hodgkin's lymphomas and is usually asymptomatic but should be considered by clinicians among the malignancies that cause calcitriol-mediated hypercalcemia.

  4. Immobilisation-induced hypercalcemia following spinal cord injury affecting the kidney function in two young native Greenlanders

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    Linstow, Michael V; Biering-Sørensen, Fin

    2017-01-01

    INTRODUCTION: Immobilisation-induced hypercalcemia following SCI affecting the kidney function, is a rare but potentially serious condition. We report immobilisation-induced hypercalcemia affecting the kidney function in two young native Greenlanders with spinal cord injury (SCI). CASE...... PRESENTATIONS: Two 15- and 24-year-old male native Greenlanders, both with traumatic C5 SCI were admitted to our spinal cord unit. They were non-smokers without history of daily alcohol intake pre- or immediately post-injury. No physical demanding activities pre-injury. Due to complaints of nausea/vomiting 10...... the last 20 years our spinal cord unit has only experienced immobilisation-induced hypercalcemia following SCI affecting the kidney function in two young male native Greenlanders. This finding of immobilisation-induced hypercalcemia following SCI affecting the kidney function in two young native...

  5. MANAGEMENT OF ACUTE RENAL FAILURE WITH DELAYED HYPERCALCEMIA SECONDARY TO SARCOCYSTIS NEURONA-INDUCED MYOSITIS AND RHABDOMYOLYSIS IN A CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS).

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    Alexander, Amy B; Hanley, Christopher S; Duncan, Mary C; Ulmer, Kyle; Padilla, Luis R

    2015-09-01

    A 3-yr-old captive-born California sea lion (Zalophus californianus) developed Sarcocystis neurona-induced myositis and rhabdomyolysis that led to acute renal failure. The sea lion was successfully managed with fluid therapy, antiprotozoals, antibiotics, anti-inflammatories, antiemetics, gastroprotectants, and diuretics, but developed severe delayed hypercalcemia, a syndrome identified in humans after traumatic or exertion-induced rhabdomyolysis. Treatment with calcitonin was added to the management, and the individual recovered fully. The case emphasizes that animals with rhabdomyolysis-induced renal failure risk developing delayed hypercalcemia, which may be life threatening, and calcium levels should be closely monitored past the resolution of renal failure.

  6. Can atorvastatin calcium cause asymptomatic hypercalcemia?

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    Ipekçi, Süleyman Hilmi; Baldane, Süleyman; Sözen, Mehmet; Kebapçılar, Levent

    2014-10-01

    The use of statins may have unnatural effects. A 54-year-old woman was admitted to the hospital with an incidental finding of hypercalcemia (10.8 mg/dL). There was no disease other than hyperlipidemia, and the patient had been on a course of atorvastatin calcium 10 mg for 1.5 years. A workup investigation to diagnose the cause of hypercalcemia was completed. The investigation did not reveal any pathological diseases that may have caused the hypercalcemia. The hypercalcemia resolved after atorvastatin-calcium was stopped, and the patient developed hypercalcemia shortly after the initiation of the atorvastatin calcium. Here, we report a clinical case of recurrent hypercalcemia possibly induced by atorvastatin calcium administration.

  7. Spondylometaphyseal dysplasia with hypercalcemia

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    Bagga, A.; Srivastava, R.N.; Gupta, S.; Gupta, A.

    1989-01-01

    Kozlowski's spondylometaphyseal dysplasia is characterised by short-trunk dwarfism, platyspondyly, metaphyseal dysplasia and retarded bone age. We report an association of this syndrome with asymptomatic, hypocalciuric hypercalcemia, a previously undocumented finding. (orig.)

  8. Multifactorial Hypercalcemia and Literature Review on Primary Hyperparathyroidism Associated with Lymphoma

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    Jelena Maletkovic

    2014-01-01

    Full Text Available The most common cause of hypercalcemia in hospitalized patients is malignancy. Primary hyperparathyroidism most commonly causes hypercalcemia in the outpatient setting. These two account for over 90% of all cases of hypercalcemia. Hypercalcemia can be divided into PTH-mediated and PTH-independent variants. Primary hyperparathyroidism, familial hypocalciuric hypercalcemia, familial hyperparathyroidism, and secondary hyperparathyroidism are PTH mediated. The most common PTH-independent type of hypercalcemia is malignancy related. Several mechanisms lead to hypercalcemia in malignancy-direct osteolysis by metastatic disease or, more commonly, production of humoral factors by the primary tumor also known as humoral hypercalcemia of malignancy that accounts for about 80% of malignancy-related hypercalcemia. The majority of HHM is caused by tumor-produced parathyroid hormone-related protein and less frequently production of 1,25-dihydroxyvitamin D or parathyroid hormone by the tumor. We report the rare case of a patient with hypercalcemia and diagnosed primary hyperparathyroidism. The patient had persistent hypercalcemia after surgical removal of parathyroid adenoma with recorded significant decrease in PTH level. After continued investigation it was found that the patient also had elevated 1,25-dihydroxyvitamin D and further studies confirmed a large spleen mass that was later confirmed to be a lymphoma. This is a rare example of two concomitant causes of hypercalcemia requiring therapy.

  9. Hypercalcemia in idiopathic myelofibrosis

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    Voss, A; Schmidt, K; Hasselbalch, H

    1992-01-01

    A case of idiopathic myelofibrosis (IMF) presenting with hypercalcemia and hypercalcitriolemia is reported. It is proposed that ectopic production of the active vitamin D metabolite related to ongoing clonal expansion in the bone marrow accounts for the hypercalcemic state. Consistently low level...

  10. Hypercalcemia due to Primary Hepatic Lymphoma

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    Andrew Hsu

    2016-01-01

    Full Text Available A 65-year-old female with a history of mixed connective tissue disease and pulmonary fibrosis on azathioprine, hydroxychloroquine, and prednisone (osteoporosis on teriparatide presented with a 1-month history of hypercalcemia. After discontinuation of teriparatide, the patient’s hypercalcemia persisted. Further evaluation revealed primary hepatic lymphoma as the source of her hypercalcemia.

  11. Hypercalcemia

    Science.gov (United States)

    ... located in the neck behind the thyroid gland. Vitamin D is obtained when the skin is exposed to sunlight, and from dietary sources. The most common cause of high calcium blood level is excess PTH released by the parathyroid glands. This excess ...

  12. Lithium-associated hypercalcemia and hyperparathyroidism in the elderly: what do we know?

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    Lehmann, Susan W; Lee, Janet

    2013-04-05

    Lithium has been reported to induce hypercalcemia and hyperparathyroidism, yet few studies have examined the impact on older patients. We therefore undertook this review and report our findings. We undertook a systematic review of articles on lithium-associated hypercalcemia and/or hyperparathyroidism that were identified via electronic English language database searches through PubMed. Among reported cases and case series of lithium-associated hyperparathyroidism in which ages of specific subjects were provided, 40% of affected individuals were over age 60. Mean serum calcium levels are reported to be higher in lithium treated patients over age 60 compared with younger patients. While many patients who develop lithium-associated hypercalcemia and hyperparathyroidism are asymptomatic, symptomatic complications may be more of a concern in older patients, especially in those with co-morbid renal disease. To date, all cross-sectional studies of lithium-associated hypercalcemia and hyperparathyroidism are of mixed age group cohorts and more specific studies focused on older patients have yet to be performed. Lithium-induced hypercalcemia and hyperparathyroidism are under-recognized potential complications of lithium therapy which may occur more frequently in older patients. Psychiatrists should be vigilant in screening for hypercalcemia and hyperparathyroidism in their older patients receiving lithium, both prior to starting treatment and at least annually thereafter. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Spondylometaphyseal dysplasia with hypercalcemia. [Radiological studies

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    Bagga, A.; Srivastava, R.N.; Gupta, S.; Gupta, A.

    1989-08-01

    Kozlowski's spondylometaphyseal dysplasia is characterised by short-trunk dwarfism, platyspondyly, metaphyseal dysplasia and retarded bone age. We report an association of this syndrome with asymptomatic, hypocalciuric hypercalcemia, a previously undocumented finding. (orig.).

  14. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    DEFF Research Database (Denmark)

    Mrgan, Monija; Nielsen, Sanne; Brixen, Kim

    2014-01-01

    Familial hypocalciuric hypercalcemia (FHH) is a lifelong, benign autosomal dominant disease characterized by hypercalcemia, normal to increased parathyroid hormone level, and a relatively low renal calcium excretion. Inactivation of the calcium-sensing receptor in heterozygous patients results...... in FHH, while in homozygous patients as well as in compound heterozygous or dominant negative heterozygous patients, it may result in neonatal severe hyperparathyroidism (NSHPT). Parathyroid surgery is not indicated in FHH and does not lower plasma calcium unless total parathyroidectomy is performed...

  15. Hypercalcemia Associated with a Malignant Brenner Tumor Arising from a Mature Cystic Teratoma

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    Michael C. Honigberg

    2012-11-01

    Full Text Available A 60-year-old woman presented with abdominal pain and weight loss and was found to have serum calcium of 15.0 mg/dl. Serum parathyroid hormone-related peptide (PTHrP returned elevated. Imaging suggested bilateral mature cystic teratomas. Her hypercalcemia was treated initially with intravenous saline, as well as intramuscular and subcutaneous calcitonin. She underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, and final pathology revealed malignant Brenner tumor in association with a mature cystic teratoma. Her postoperative PTHrP returned less than assay, and her total and ionized calcium fell below normal, requiring supplemental calcium and vitamin D. At follow-up one month after discharge, her calcium had normalized. We present the first reported case of hypercalcemia occurring in association with a malignant Brenner tumor. Malignancy-associated hypercalcemia occurs via four principal mechanisms: (1 tumor production of PTHrP; (2 osteolytic bone involvement by primary tumor or metastasis; (3 ectopic activation of vitamin D to 1,25-(OH2 vitamin D, and (4 ectopic production of parathyroid hormone. PTHrP-mediated hypercalcemia is the most common mechanism and was responsible in this case. In patients with paraneoplastic hypercalcemia who undergo surgical treatment, close monitoring and management of serum calcium is necessary both pre- and postoperatively.

  16. A case of isolated adrenocorticotropic hormone deficiency: a rare but possible cause of hypercalcemia

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    Harano Y

    2015-03-01

    Full Text Available Yumi Harano,1 Atsuko Kitano,2 Yurika Akiyama,1 Lisa Kotajima,1 Kazufumi Honda,1 Hiroko Arioka11Department of General Internal Medicine, 2Department of Medical Oncology, St Luke’s International Medical Center, Tokyo, JapanAbstract: A 52-year-old woman presented with an 8-month history of epigastric pain, nausea, and weight loss. One year before, she was diagnosed with breast cancer. During the postoperative chemotherapy, she developed epigastric pain and nausea. As a result, she gradually lost 12 kg of her body weight. We performed upper gastrointestinal endoscopy, which revealed mild erosive gastritis. After the treatment with a proton pump inhibitor, her symptoms persisted. Before the admission, mild hypercalcemia was pointed out. Fluid replacement didn't improve hypercalcemia. We assessed adrenocortical function, which showed that her serum cortisol and adrenocorticotropic hormone were decreased. Through loading tests, we established diagnosis of isolated adrenocorticotropic hormone deficiency. She was treated with hydrocortisone. Soon after the treatment, her serum calcium level returned to normal and her symptoms improved. In a case of hypercalcemia unresponsive to fluid replacement, we recommend ruling out adrenal insufficiency after excluding more common diseases which induce hypercalcemia.Keywords: hypercalcemia, breast cancer, chemotherapy, adrenocorticotropic hormone deficiency, adrenocortical insufficiency

  17. A rare cause of hypercalcemia presenting with high parathormone levels: Familial hypocalciuric hypercalcemia

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    Okan Bakiner

    2013-08-01

    Full Text Available Familial Hypocalciuric Hypercalcemia is a generally benign disorder caused by heterozygous inactivating mutations in the Calcium-Sensing-Receptor gene resulting in altered calcium metabolism. It should be considered in differential diagnosis of primary hyperparathyroidism. Our case whom was diagnosed as toxic nodular goitre and primary hyperparathyroidism and suggested surgical treatment in another clinical center was evaluated in our out-patient clinic. Furosemid treatment which may affect calcium metabolism was stopped and medical therapy for hyperthyroidism was given. During follow-up the patient was considered as familial hypocalciuric hypercalcemia because of mild hypercalcemia, borderline elevated parathormone levels and significantly decreased daily urinary calcium excretion. The diagnosis was confirmed with the determination of similar laboratory findings for calcium metabolism in her children. In conclusion, evaluating the calcium metabolism after correcting the other factors and keeping familial hypocalciuric hypercalcemia in mind while diagnostic approach to hypercalcemia and differentially diagnosis of primary hyperparathyroidism may prevent unnecessary surgery. [Cukurova Med J 2013; 38(4.000: 765-769

  18. Cholestasis and hypercalcemia secondary to panhypopituitarism in a newborn.

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    Dursun, Fatma; Gerenli, Nelgin; Kırmızıbekmez, Heves

    2017-01-01

    Dursun F, Gerenli N, Kırmızıbekmez H. Cholestasis and hypercalcemia secondary to panhypopituitarism in a newborn. Turk J Pediatr 2017; 59: 100-103. Cholestatic hepatitis and hypercalcemia are rare features of hypopituitarism in newborns. So diagnosis of hypopituitarism is frequently delayed. The most frequent symptoms of congenital hypopituitarism are hypoglycemia, prolonged jaundince and micropenis. A patient with congenital hypopituitarism associated with cholestasis and hypercalcemia is reported here. Newborns with hypercalcemia and cholestasis should alert pediatricians to the possibility of congenital hypopituitarism and prompt endocrinological investigation.

  19. ACUTE LYMPHOBLASTIC LEUKEMIA WITHOUT CIRCULATING BLASTS PRESENTING AS SEVERE HYPERCALCEMIA

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    Z. Oloomi

    2007-05-01

    Full Text Available Hypercalcemia complicating malignancy is a rare complication in pediatric age group. In this article, we present a case with acute lymphoblastic leukemia presenting as severe hypercalcemia. A 10 years old girl presented with an acute onset of fever, nausea, vomiting, loss of weight, costovertebral pain and frequency. She was admitted with a presumptive diagnosis of acute pyelonephritis. Her examination showed mild hepatosplenomegaly. In laboratory studies she had sever hypercalcemia. Despite the absence of circulating blast, bone marrow aspiration was diagnostic of acute lymphoblastic leukemia. The hypercalcemia was initially treated with intravenous hydration and furosemide but the serum calcium levels normalized only after the beginning of specific chemotherapy. Hypercalcemia represents an emergency in children, and acute leukemia must be considered in differential diagnosis even when there are no circulating blasts.

  20. Calcitonin produces hypercalcemia in leopard sharks.

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    Glowacki, J; O'Sullivan, J; Miller, M; Wilkie, D W; Deftos, L J

    1985-02-01

    Calcitonin was detected by RIA in sera from four marine species, leopard sharks (Triakis semifasciata), horn sharks (Heterodontus francisci), thornback rays (Platyrhinoides triseriata), and kelp bass (Paralabrax clathratus). These animals have levels of calcitonin and calcium higher than freshwater and terrestrial species have. The administration of salmon calcitonin to bass (4 micrograms/kg BW) produced hypocalcemia and hypophosphatemia as has been reported for other bony vertebrates. In marked contrast, calcitonin produced a prompt hypercalcemia in sharks; the average was 9.8% increase in serum calcium in nine animals with no attendant change in phosphorus. These findings demonstrate that calcitonin can increase serum calcium in sharks. Because shark skeleton is composed of cartilage, this hypercalcemic effect of calcitonin does not require a bony skeleton.

  1. Prolonged Hypercalcemia Following Resection of Dysgerminoma: A Case Report

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    Wald, Abigail; Narasimhan, Sumana; Nieves-Arriba, Lucybeth; Waggoner, Steven

    2009-01-01

    Background. Hypercalcemia is a rare but potentially dangerous complication of pediatric cancer. Of the dysgerminoma cases reported to date, associated hypercalcemia is corrected within 2–7 days of tumor resection. Case. A 13-year-old female with an ovarian dysgerminoma was found to be hypercalcemic on presentation. Following dysgerminoma resection, moderate hypercaclemia persisted for 7 days and calcium remained mildly elevated for an additional 7 days. PTHrP was undetectable. Immunolocalizat...

  2. Hypercalcemia in children: three cases report with unusual clinical presentations

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    Bruna Barros Garbim

    Full Text Available Abstract Hypercalcemia is a rare condition in childhood; the most common causes are primary hyperparathyroidism, malignancy, prolonged immobilisation, thyrotoxicosis, thiazide diuretic, supplements containing calcium, milk-alkali syndrome, vitamin D intoxication, infections and idiopathic. We present three cases of severe hypercalcemia of unusual causes in children. The first patient had high fever, poor general condition, weight loss and myalgia. Extensive preliminary investigation did not define the etiology, but a review of medical history revealed prolonged contact with pet bird and a positive serology for Chlamydia confirmed the diagnosis of psittacosis. The second patient had generalized lymphadenopathy and hepatosplenomegaly with fever a month ago. Paracoccidioides brasiliensis was identified in myelogram; the patient showed partial improvement with the use of co-trimoxazole, with subsequent emergence of multiple osteolytic lesions. A smear of gastric lavage was positive for Mycobacterium tuberculosis and the patient was treated with rifampicin, isoniazid, ethambutol and pyrazinamide, with improvement of clinical condition. The third patient was treated by hypercalciuria and idiopathic hypomagnesiuria with daily use of cholecalciferol; the patient had a two quilograms of weight loss in the past two months. No cause of hypercalcemia could be detected in laboratory workout. The capsules of cholecalciferol were analyzed and presented an amount of 832,000 IU of vitamin D per capsule. Acute hypercalcemia in childhood may be due to exogenous vitamin D intoxication, as well as infectious causes. The possible causal relationship between psittacosis and occurrence of hypercalcemia alert to the need for detailed investigation of the epidemiological antecedents.

  3. A randomized study evaluating cinacalcet to treat hypercalcemia in renal transplant recipients with persistent hyperparathyroidism

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    Evenepoel, P.; Cooper, K.; Holdaas, H.

    2014-01-01

    Persistent hyperparathyroidism (HPT) after kidney transplantation (KTx) is associated with hypercalcemia, hypophosphatemia and abnormally high levels of parathyroid hormone (PTH). In this randomized trial, cinacalcet was compared to placebo for the treatment of hypercalcemia in adult patients...

  4. Prolonged Hypercalcemia Following Resection of Dysgerminoma: A Case Report

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    Abigail Wald

    2009-01-01

    Full Text Available Background. Hypercalcemia is a rare but potentially dangerous complication of pediatric cancer. Of the dysgerminoma cases reported to date, associated hypercalcemia is corrected within 2–7 days of tumor resection. Case. A 13-year-old female with an ovarian dysgerminoma was found to be hypercalcemic on presentation. Following dysgerminoma resection, moderate hypercaclemia persisted for 7 days and calcium remained mildly elevated for an additional 7 days. PTHrP was undetectable. Immunolocalization studies indicated that 1-hydroxylase was expressed in dysgerminoma tissue but 1,25(OH2D3 was not elevated. Conclusion. Persistently elevated calcium levels following tumor resection suggests that this case involves a previously undescribed mechanism. Elucidation of this mechanism may offer new insights into tumor biology and opportunities for therapeutic correction of hypercalcemia in this patient population.

  5. Hypercalcemia and hypophosphatemia among preterm infants receiving aggressive parenteral nutrition.

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    Brener Dik, Pablo H; Galletti, María F; Bacigalupo, Leticia T; Fernández Jonusas, Silvia; L Mariani, Gonzalo

    2018-06-01

    Aggressive parenteral nutrition is the standard of care among very-low-birth weight preterm infants. However, in recent studies, its impact on short-term outcomes, has been evaluated. The objective was to compare the prevalence of hypercalcemia and hypophosphatemia among preterm infants receiving aggressive or standard parenteral nutrition. Observational, retrospective study comparing a group of preterm infants weighing less than 1250 grams who received aggressive parenteral nutrition with a historical control group. The prevalence of hypercalcemia was estimated and its association with aggressive parenteral nutrition was searched adjusting by confounders. The mean phosphate level was estimated for the control group by linear regression and was compared to the value in the other group. Forty patients per group were included. The prevalence of hypercalcemia was higher in the group who received aggressive parenteral nutrition (87.5% versus 35%, p= 0.001). Aggressive parenteral nutrition was associated with hypercalcemia when adjusting by birth weight, intrauterine growth restriction, amino acid, and calorie intake (adjusted odds ratio: 21.8, 95% confidence interval [CI]: 3.7-128). The mean calcium level was different between both groups (p= 0.002). Infants who received aggressive parenteral nutrition had more sepsis without reaching statistical significance and the mean phosphate level was lower than that estimated for the control group (p= 0.04). The prevalence of hypophosphatemia in this group was 90% (95% CI: 76-97%). Our data show an association between hypercalcemia/hypophosphatemia and aggressive parenteral nutrition. It is recommended to frequently monitor calcium and phosphate levels since they might be associated with adverse clinical outcomes. Sociedad Argentina de Pediatría.

  6. Chk2 mediates RITA-induced apoptosis.

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    de Lange, J; Verlaan-de Vries, M; Teunisse, A F A S; Jochemsen, A G

    2012-06-01

    Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA.

  7. Inducible nitric oxide synthase mediates bone loss in ovariectomized mice.

    NARCIS (Netherlands)

    Cuzzocrea, S.; Mazzon, E.; Dugo, L.; Genovese, T.; Paola, R. Di; Ruggeri, Z.; Vegeto, E.; Caputi, A.P.; Loo, F.A.J. van de; Puzzolo, D.; Maggi, A.

    2003-01-01

    Several clinical studies have shown that bone loss may be attributed to osteoclast recruitment induced by mediators of inflammation. In different experimental paradigms we have recently demonstrated that estrogen exhibits antiinflammatory activity by preventing the induction of inducible nitric

  8. Gallium nitrate inhibits calcium resorption from bone and is effective treatment for cancer-related hypercalcemia

    International Nuclear Information System (INIS)

    Warrell, R.P. Jr.; Bockman, R.S.; Coonley, C.J.; Isaacs, M.; Staszewski, H.

    1984-01-01

    Approximately two-thirds of patients who receive the anticancer drug gallium nitrate develop mild hypocalcemia. To evaluate the mechanism of drug-induced hypocalcemia, we tested the effects of gallium nitrate upon in vitro release of 45 Ca++ from explanted fetal rat bones. The drug significantly inhibited 45 Ca++ release in response to stimulation with both parathyroid hormone and a lymphokine preparation with osteoclast activating factor activity. The inhibitory effects on bone resorption were both time- and dose-dependent. Later, in a pilot study, we treated 10 patients who had cancer-related hypercalcemia with gallium nitrate administered by continuous infusion. All patients responded by a reduction of total serum calcium to normal or subnormal concentrations (13.8 +/- 1.05 mg/dl, mean +/- SD pretreatment, to 8.03 +/- 1.03 mg/dl, mean posttreatment nadir). Our results indicate that gallium nitrate effectively treats cancer-related hypercalcemia and that it probably acts by inhibiting calcium release from bone

  9. Vitamin D Intoxication with Hypercalcemia Due to Overuse of Supplement

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    MohammadBagher Oghazian

    2015-10-01

    Full Text Available We describe a patient with hypercalcemia associated with the injection of high doses vitamin D as supplement for a period of six months. A 76-year-old woman had been taking an intramuscular injection of vitamin D 300,000 IU every ten days for six months. She was hospitalized with symptoms of hypercalcemia: chronic constipation, unstable gait, a chronic generalized musculoskeletal pain and increased fatigue. On admission her 25 (OH vitamin D and Calcium levels were 559 nmol/L and 13.85 mg/dL respectively, and Parathyroid Hormone (PTH level was 7.1 pg/mL. Immediately she received diuresis therapy with saline and furosemide in conjunction with calcitonin and pamidronate. At discharge her serum calcium level was 11.5 mg/dL. To lower endogenous overproduction of calcitriol, prednisolone 20 mg/day for 10 days was administered at discharge time.

  10. Progressive disseminated histoplasmosis presenting with cachexia and hypercalcemia

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    Khasawneh FA

    2013-02-01

    Full Text Available Faisal A Khasawneh,1 Subhan Ahmed,2 Ruba A Halloush31Section of Infectious Diseases, Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX, 2Section of Nephrology, Department of Internal Medicine, University of Oklahoma, Tulsa, OK, 3Amarillo Pathology Group, Amarillo, TX, USAAbstract: Histoplasmosis is a common endemic mycosis. The majority of infections involving this dimorphic fungus are asymptomatic. Manifestations in symptomatic patients are diverse, ranging from flu-like illness to a more serious disseminated disease. We present here a case of chronic disseminated histoplasmosis mimicking a metastatic cancer. We reviewed the literature for cases of disseminated histoplasmosis presenting with hypercalcemia, focusing particularly on clinical presentation, risk factors predisposing for fungal infection, and outcome. We report a case of a 65-year-old diabetic male who presented with unexplained weight loss and hypercalcemia. Multiple brain space-occupying lesions and bilateral adrenal enlargement were evident on imaging studies. Biopsies showed caseating granulomas with budding yeast, consistent with histoplasmosis. The patient's symptoms resolved after liposomal amphotericin B and itraconazole therapy. Granulomatous diseases, including fungal infections, should be considered alongside malignancies, in patients with similar presentation.Keywords: disseminated histoplasmosis, hypercalcemia

  11. Using denosumab to treat immobilization hypercalcemia in a post-acute care patient.

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    Booth, Katrina A; Hays, Clare I

    2014-10-01

    Hypercalcemia in adults has several less common causes. Management in patients with chronic kidney disease (CKD) is challenging because bisphosphonates are contraindicated. This case presents an uncommon cause of hypercalcemia in a subacute rehabilitation patient who was managed with denosumab. A 79-year-old female with CKD stage 4 was admitted to a skilled nursing facility with a limited-weight-bearing status after right-hip arthroplasty. Four weeks later, she developed hypercalcemia (11.5 mg/dL; normal, 7.9-9.9 mg/dL) with serum albumin of 2.5 g/dL (corrected calcium, 12.7 mg/dL). Despite iv fluids, hypercalcemia worsened (corrected serum calcium, 14.5 mg/dL), and she was rehospitalized. Additional studies eliminated common causes of hypercalcemia, leading to the diagnosis of immobilization hypercalcemia. Due to CKD, a bisphosphonate was not given. She received 10 doses of calcitonin s.c. with mild improvement in her calcium, and she returned to the skilled nursing facility. Because hypercalcemia worsened within days, denosumab 60 mg was administered s.c., and her serum calcium level normalized. Over the next several weeks, her surgical wound worsened. Hip x-ray showed osteolysis of her residual right femoral head. In retrospect, hip x-ray during her hospitalization for hypercalcemia showed osteolysis, likely from osteomyelitis. A contribution of osteomyelitis to hypercalcemia could not be excluded. Despite resolution of hypercalcemia, she succumbed to sepsis. Immobilization hypercalcemia is underappreciated in post-acute care older adults. In this patient with CKD, denosumab reversed her hypercalcemia; however, the case highlights potential risks and limitations with this therapy and emphasizes the need for further studies in medically complex older adults.

  12. An Unusual Case of Hypercalcemia Associated with Graves’ Disease and Vitamin D Deficiency

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    Evgenia Korytnaya

    2011-01-01

    Full Text Available Objective To present a case of hypercalcemia associated with thyrotoxicosis in a patient with vitamin D deficiency and review biochemical changes during the course of treatment. Methods We report a case, describe the changes in serum calcium, phosphorus, parathyroid hormone in Graves’ disease and concomitant Vitamin D deficiency. We compare our findings to those reported in literature. Results Our patient had hypercalcemia secondary to thyrotoxicosis alone, which was confirmed by low parathyroid hormone level and resolution of hypercalcemia with treatment of thyrotoxicosis. The case was complicated by a concomitant vitamin D deficiency. Serum calcium elevation in patients with thyrotoxicosis occurs secondary to hyperthyroidism alone or due to concurrent hyperparathyroidism. Hypercalcemia from thyrotoxicosis is usually asymptomatic and is related to bone resorption. Vitamin D deficiency can be seen in patients with thyrotoxicosis because of accelerated metabolism, poor intestinal absorption and increased demand during bone restoration phase. Coexistence of hypercalcemia and Vitamin D deficiency in patients with thyrotoxicosis is rare, but possible, and 25-hydroxyvitamin D levels should be checked. The definite treatment for hypercalcemia in thyrotoxicosis is correction of thyroid function. Conclusion Hypercalcemia in thyrotoxicosis should be distinguished from concomitant hyperparathyroidism and confirmed by resolution of hypercalcemia with control of thyrotoxicosis. Patients with hypercalcemia and thyrotoxicosis may also have vitamin D deficiency and 25-OH Vitamin D levels should be checked.

  13. Recurrent hypercalcemia in a patient with acute sarcoidosis

    International Nuclear Information System (INIS)

    Saavedra Ramirez, Publio Giovanni; Ramirez Palacios, Ivan; Cardona Tapias, Alejandro

    2007-01-01

    Sarcoidosis is a chronic granulomatous disease of unknown etiology characterized by the presence of noncaseating epithelioid granulomas that can take place in every organ or system of the human body. This disease can be acute or sub acute and self limited in presentation or can have a chronic course characterized by exacerbations and remissions. Hypercalcemia can be detected in 10 to 20 percent of the patients with the disease. It is caused by the over expression of vitamin D-receptor and 25-hydroxyvitamin D 1-? hydroxylase enzyme in monocytes and activated macrophages within the granuloma in a way that is resistant to the natural inhibition driven by high serum calcium Levels. This autonomous enzymatic activity leads to the overproduction of calcitriol which increase intestinal absorption of the calcium present in the diet and also increase the activity of osteoclast with consequent high bone turnover and hypercalcemia. In this report we present the case of a 49 years old man, black race, bilateral parotid gland enlargement, bilateral hilar lymphadenopathy, severe recurrent hypercaIcemia and acute renal failure in which sarcoidosis was documented as the cause of his symptoms

  14. Norcantharidin (NCTD) induces mitochondria mediated apoptosis in ...

    African Journals Online (AJOL)

    Administrator

    2011-06-15

    Jun 15, 2011 ... cancer deaths for both sexes being attributable to hepatoma. However ..... Resveratrol induces apoptosis and cell cycle arrest of human T24 bladder cancer cells in ... involvement of the CD95 receptor/ligand. J. Cancer. Res.

  15. Case of Hypercalcemia Secondary to Hypervitaminosis A in a 6-Year-Old Boy with Autism

    Directory of Open Access Journals (Sweden)

    Arpita Kalla Vyas

    2011-01-01

    Full Text Available Vitamin A intoxication secondary to over-the-counter nutritional supplements and from its use in acne treatment has been described. However, there have been very few case reports of chronic hypervitaminosis A leading to hypercalcemia in the pediatric population. This paper describes a boy with hypercalcemia secondary to chronic vitamin A intoxication in the context of vitamin A usage for therapy of autism. In addition to discontinuation of vitamin A, hyperhydration, and furosemide, the hypercalcemia in this patient required the use of prednisone and pamidronate to normalize the calcium.

  16. Diabetes due to recurrent pancreatitis secondary to hypercalcemia due to primary hyperparathyroidism

    Directory of Open Access Journals (Sweden)

    Sumit Kumar Chakrabarti

    2013-01-01

    Full Text Available Acute pancreatitis due to hypercalcemia associated with hyperparathyroidism (HPT is not very common. We herein report a case of a 21-year-old woman, who presented with acute pancreatitis. She had a past history of recurrent nephrolithiasis. Subsequent evaluation revealed hypercalcemia (serum calcium: 12.6 mg/dL; low phosphate (2.9 mg/dL with elevated parathyroid hormone (PTH, 156.7 pg/mL and HbA1c (6.9%. Diagnosis of primary HPT (PHPT was made. Recurrent pancreatitis due to hypercalcemia may have resulted in diabetes mellitus.

  17. Non-malignant causes of hypercalcemia in cancer patients: a frequent and neglected occurrence.

    Science.gov (United States)

    Soyfoo, M S; Brenner, K; Paesmans, M; Body, J J

    2013-05-01

    Hypercalcemia is a frequent finding in cancer patients and can be observed in any type of cancer. The physician in charge of cancer patients often ignores non-malignant causes of hypercalcemia. Our objective was to review the causes of hypercalcemia in a large series of cancer patients. We have retrospectively studied in a Cancer Centre all consecutive hypercalcemic (Ca> 10.5 mg/dl) patients over an 8-year period. Of 699 evaluated patients, 642 were analyzed after exclusion of patients whose hypercalcemia resolved after rehydration or who had a normal Ca level after correction for protein concentrations. Clinical information was gathered on the type of cancer, its histology, whether the disease was active or in complete remission, and on the presence of bone metastases. Biochemical data included serum Ca, P(i), proteins in all patients, PTH in most patients, and PTHrP, 25OH-Vitamin D, 1,25(OH)(2)-Vitamin D, TSH, and T4 in selected cases. By order of decreasing frequency, the main causes of hypercalcemia were cancer (69.0 %), primary hyperparathyroidism (24.6 %), hyperthyroidism (2.2 %), milk alkali syndrome (0.9 %), and sarcoidosis (0.45 %). In cancer-related causes, bone metastases accounted for 53.0 % of the cases, humoral hypercalcemia of malignancy (HHM) for 35.3 % while there were 11.7 % of cases apparently due to both HHM and bone metastases. Hypercalcemia was not due to cancer in 97 % (84/87) of the patients who were in complete remission. Even in patients with active neoplastic disease, the number of patients whose hypercalcemia was not due to cancer remained clinically relevant (115/555 = 20.5 %). In the 158 patients with primary hyperparathyroidism, 92 patients were in complete remission and 66 patients had active neoplastic disease. In this large series of hypercalcemia in cancer patients, the cause was not due to cancer in almost one third of the cases. Most patients considered to be in complete remission had hypercalcemia due to a benign

  18. Hypercalcemia and high parathyroid hormone-related protein concentration associated with malignant melanoma in a dog.

    Science.gov (United States)

    Pressler, Barrak M; Rotstein, David S; Law, Jerry M; Rosol, Thomas J; LeRoy, Bruce; Keene, Bruce W; Jackson, Mark W

    2002-07-15

    A 12-year-old Cocker Spaniel with an oral malignant melanoma was evaluated for progressive lethargy and anorexia. No metastases were identified during antemortem evaluation, but severe hypercalcemia was evident. Antemortem diagnostic testing failed to identify a cause for the hypercalcemia. No neoplasms other than the melanoma were identified on postmortem examination. Serum parathyroid hormone-related protein concentration was markedly high, and the melanoma had moderate to marked immunostaining for this protein. Paraneoplastic syndromes are rare in dogs with malignant melanoma.

  19. Pamidronate Rescue Therapy for Hypercalcemia in a Child With Williams Syndrome

    Directory of Open Access Journals (Sweden)

    Sami A. Sanjad

    2018-05-01

    Full Text Available A 15-month-old male infant diagnosed with Williams Syndrome (WS was admitted with severe hypercalcemia and nephrocalcinosis. Intravenous hydration and furosemide failed to yield an appreciable and sustainable fall in serum calcium, while the injection of pamidronate achieved a significant decrease in serum calcium in a short period of time. This bisphosphonate could be considered as a second-line treatment for refractory hypercalcemia in WS.

  20. Lupeol induces S-phase arrest and mitochondria-mediated ...

    Indian Academy of Sciences (India)

    48

    Lupeol induces S-phase arrest and mitochondria-mediated apoptosis in cervical cancer cells. Nupoor Prasad1, Akash Sabarwal2, Umesh C. S. Yadav1, Rana P. Singh2,*. 1School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India. 2Cancer Biology Laboratory, School of Life Sciences, Jawaharlal ...

  1. Humoral Hypercalcemia of Malignancy with a Parathyroid Hormone-Related Peptide-Secreting Intrahepatic Cholangiocarcinoma Accompanied by a Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Katsushi Takeda

    2017-01-01

    Full Text Available Humoral hypercalcemia of malignancy (HHM is caused by the oversecretion of parathyroid hormone-related peptide (PTHrP from malignant tumors. Although any tumor may cause HHM, that induced by intrahepatic cholangiocarcinoma (ICC or gastric cancer (GC is rare. We report here a 74-year-old male who displayed HHM with both ICC and GC and showed an elevated serum PTHrP level. Treatment of the hypercalcemia with saline, furosemide, elcatonin, and zoledronic acid corrected his serum calcium level and improved symptoms. Because treatment of ICC should precede that of GC, we chose chemotherapy with cisplatin (CDDP and gemcitabine (GEM. Chemotherapy reduced the size of the ICC and decreased the serum PTHrP level. One year after diagnosis, the patient was alive in the face of a poor prognosis for an ICC that produced PTHrP. Immunohistochemical staining for PTHrP was positive for the ICC and negative for the GC, leading us to believe that the cause of the HHM was a PTHrP-secreting ICC. In conclusion, immunohistochemical staining for PTHrP may be useful in discovering the cause of HHM in the case of two cancers accompanied by an elevated serum PHTrP level. Chemotherapy with CDDP and GEM may be the most appropriate treatment for a PTHrP-secreting ICC.

  2. Maternal and infantile hypercalcemia caused by vitamin-D-hydroxylase mutations and vitamin D intake.

    Science.gov (United States)

    Dinour, Dganit; Davidovits, Miriam; Aviner, Shraga; Ganon, Liat; Michael, Leonid; Modan-Moses, Dalit; Vered, Iris; Bibi, Haim; Frishberg, Yaacov; Holtzman, Eli J

    2015-01-01

    Hypercalcemia is caused by many different conditions and may lead to severe complications. Loss-of-function mutations of CYP24A1, encoding vitamin D-24-hydroxylase, have recently been identified in idiopathic infantile hypercalcemia and in adult kidney stone disease. The aim of this study was to investigate the genetics and clinical features of both infantile and maternal hypercalcemia. We studied members of four unrelated Israeli families with hypercalcemia, namely, one woman during pregnancy and after delivery and three infants. Clinical and biochemical data were obtained from probands' medical charts. Genomic DNA was isolated from peripheral blood and CYP24A1 was sequenced. Typical symptoms of hypercalcemia associated with the intake of recommended doses of vitamin D developed in the infants and pregnant woman. Four different loss-of-function CYP24A1 mutations were identified, two of which are reported here for the first time (p.Trp134Gly and p.Glu315*). The infants from families 1 and 2, respectively, were found to be compound heterozygotes, and the infant from family 3 and the pregnant woman were found to be homozygous. This is the first report of maternal hypercalcemia caused by a CYP24A1 mutation, showing that not only infants are at risk for this complication. Our findings emphasize the importance of recognition, genetic diagnosis and proper treatment of this recently identified hypercalcemic disorder in this era of widespread vitamin D supplements.

  3. Hypercalcemia, hypervitaminosis A and 3-epi-25-OH-D3 levels after consumption of an "over the counter" vitamin D remedy. a case report.

    Science.gov (United States)

    Granado-Lorencio, F; Rubio, E; Blanco-Navarro, I; Pérez-Sacristán, B; Rodríguez-Pena, R; García López, F J

    2012-06-01

    Intoxication from vitamin D supplements has been rarely reported but, nowadays, it occurs more frequently. 3-epi-25-OH-D(3) is highly prevalent in adults and it is considered of biological relevance. We report a case of vitamin D toxicity with hypercalcemia, acute renal failure and hypervitaminosis A after consuming an over-the-counter vitamin D supplement. Our data suggest that the contribution of 3-epi-25-OH-D(3) is not altered during vitamin D toxicity, although the serum levels of 25-OH-D(3) and 3-epi-25-OH-D(3) may display a different rate of clearance. The patient also displayed hypervitaminosis A unrelated to diet, possibly caused by renal failure related to the hypercalcemia induced by vitamin D toxicity. Because of the increasing use of over-the-counter vitamin D supplements and the potential iatrogenic hypercalcemia related to hypervitaminosis A, the present case highlights the importance of evaluating both the use of (non-) prescribed medication and vitamin A status during vitamin D toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Malignancy-Induced Hypercalcemia—Diagnostic Challenges

    Directory of Open Access Journals (Sweden)

    Claire Hoyoux

    2017-11-01

    Full Text Available Hypercalcemia in children is a rare metabolic finding. The clinical picture is usually non-specific, and the etiology includes several entities (metabolic, nutritional, drug-induced, inflammatory, cancer-associated, or genetic depending on the age at presentation, but severe hypercalcemia is associated mainly with malignancy in childhood and sepsis in neonates. Severe parathyroid hormone (PTH-suppressed hypercalcemia is challenging and requires multidisciplinary diagnostic and therapeutic approaches to (i confirm or rule out a malignant cause, (ii treat it and its potentially dangerous complications. We report a case of severe and complicated PTH-independent hypercalcemia in a symptomatic 3-year-old boy. His age, severity of hypercalcemia and its complicated course, and the first imaging reports were suggestive of malignancy. The first bone and kidney biopsies and bone marrow aspiration were normal. The definitive diagnosis was a malignant-induced hypercalcemia, and we needed 4 weeks to assess other differential diagnoses and to confirm, on histopathological and immunochemical base, the malignant origin of hypercalcemia. Using this case as an illustrative example, we suggest a diagnostic approach that underlines the importance of repeated histology if the clinical suspicion is malignancy-induced hypercalcemia. Effective treatment is required acutely to restore calcium levels and to avoid complications.

  5. Molecular Signaling Pathways Mediating Osteoclastogenesis Induced by Prostate Cancer Cells

    International Nuclear Information System (INIS)

    Rafiei, Shahrzad; Komarova, Svetlana V

    2013-01-01

    Advanced prostate cancer commonly metastasizes to bone leading to osteoblastic and osteolytic lesions. Although an osteolytic component governed by activation of bone resorbing osteoclasts is prominent in prostate cancer metastasis, the molecular mechanisms of prostate cancer-induced osteoclastogenesis are not well-understood. We studied the effect of soluble mediators released from human prostate carcinoma cells on osteoclast formation from mouse bone marrow and RAW 264.7 monocytes. Soluble factors released from human prostate carcinoma cells significantly increased viability of naïve bone marrow monocytes, as well as osteoclastogenesis from precursors primed with receptor activator of nuclear factor κ-B ligand (RANKL). The prostate cancer-induced osteoclastogenesis was not mediated by RANKL as it was not inhibited by osteoprotegerin (OPG). However inhibition of TGFβ receptor I (TβRI), or macrophage-colony stimulating factor (MCSF) resulted in attenuation of prostate cancer-induced osteoclastogenesis. We characterized the signaling pathways induced in osteoclast precursors by soluble mediators released from human prostate carcinoma cells. Prostate cancer factors increased basal calcium levels and calcium fluctuations, induced nuclear localization of nuclear factor of activated t-cells (NFAT)c1, and activated prolonged phosphorylation of ERK1/2 in RANKL-primed osteoclast precursors. Inhibition of calcium signaling, NFATc1 activation, and ERK1/2 phosphorylation significantly reduced the ability of prostate cancer mediators to stimulate osteoclastogenesis. This study reveals the molecular mechanisms underlying the direct osteoclastogenic effect of prostate cancer derived factors, which may be beneficial in developing novel osteoclast-targeting therapeutic approaches

  6. Moduli mediation without moduli-induced gravitino problem

    Energy Technology Data Exchange (ETDEWEB)

    Akita, Kensuke [Department of Physics, Waseda University, Tokyo, 169-8555 (Japan); Kobayashi, Tatsuo [Department of Physics, Hokkaido University,Sapporo, 060-0810 (Japan); Oikawa, Akane; Otsuka, Hajime [Department of Physics, Waseda University, Tokyo, 169-8555 (Japan)

    2016-05-30

    We study the moduli-induced gravitino problem within the framework of the phenomenologically attractive mirage mediations. The huge amount of gravitino generated by the moduli decay can be successfully diluted by introducing an extra light modulus field which does not induce the supersymmetry breaking. Since the lifetime of extra modulus field becomes longer than usually considered modulus field, our proposed mechanism is applied to both the low- and high-scale supersymmetry breaking scenarios. We also point out that such an extra modulus field appears in the flux compactification of type II string theory.

  7. CLCA2 as a p53-Inducible Senescence Mediator

    Directory of Open Access Journals (Sweden)

    Chizu Tanikawa

    2012-02-01

    Full Text Available p53 is a tumor suppressor gene that is frequently mutated in multiple cancer tissues. Activated p53 protein regulates its downstream genes and subsequently inhibits malignant transformation by inducing cell cycle arrest, apoptosis, DNA repair, and senescence. However, genes involved in the p53-mediated senescence pathway are not yet fully elucidated. Through the screening of two genome-wide expression profile data sets, one for cells in which exogenous p53 was introduced and the other for senescent fibroblasts, we have identified chloride channel accessory 2 (CLCA2 as a p53-inducible senescence-associated gene. CLCA2 was remarkably induced by replicative senescence as well as oxidative stress in a p53-dependent manner. We also found that ectopically expressed CLCA2 induced cellular senescence, and the down-regulation of CLCA2 by small interfering RNA caused inhibition of oxidative stress-induced senescence. Interestingly, the reduced expression of CLCA2 was frequently observed in various kinds of cancers including prostate cancer, whereas its expression was not affected in precancerous prostatic intraepithelial neoplasia. Thus, our findings suggest a crucial role of p53/CLCA2-mediated senescence induction as a barrier for malignant transformation.

  8. Heme oxygenase-1 mediates BAY 11-7085 induced ferroptosis.

    Science.gov (United States)

    Chang, Ling-Chu; Chiang, Shih-Kai; Chen, Shuen-Ei; Yu, Yung-Luen; Chou, Ruey-Hwang; Chang, Wei-Chao

    2018-03-01

    Ferroptosis is a form of oxidative cell death and has become a chemotherapeutic target for cancer treatment. BAY 11-7085 (BAY), which is a well-known IκBα inhibitor, suppressed viability in cancer cells via induction of ferroptotic death in an NF-κB-independent manner. Reactive oxygen species scavenging, relief of lipid peroxidation, replenishment of glutathione and thiol-containing agents, as well as iron chelation, rescued BAY-induced cell death. BAY upregulated a variety of Nrf2 target genes related to redox regulation, particularly heme oxygenase-1 (HO-1). Studies with specific inhibitors and shRNA interventions suggested that the hierarchy of induction is Nrf2-SLC7A11-HO-1. SLC7A11 inhibition by erastin, sulfasalazine, or shRNA interference sensitizes BAY-induced cell death. Overexperession of SLC7A11 attenuated BAY-inhibited cell viability. The ferroptotic process induced by hHO-1 overexpression further indicated that HO-1 is a key mediator of BAY-induced ferroptosis that operates through cellular redox regulation and iron accumulation. BAY causes compartmentalization of HO-1 into the nucleus and mitochondrion, and followed mitochondrial dysfunctions, leading to lysosome targeting for mitophagy. In this study, we first discovered that BAY induced ferroptosis via Nrf2-SLC7A11-HO-1 pathway and HO-1 is a key mediator by responding to the cellular redox status. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Necroptosis Mediates TNF-Induced Toxicity of Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Shan Liu

    2014-01-01

    Full Text Available Tumor necrosis factor-α (TNF-α is a critical proinflammatory cytokine regulating neuroinflammation. Elevated levels of TNF-α have been associated with various neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. However, the signaling events that lead to TNF-α-initiated neurotoxicity are still unclear. Here, we report that RIP3-mediated necroptosis, a form of regulated necrosis, is activated in the mouse hippocampus after intracerebroventricular injection of TNF-α. RIP3 deficiency attenuates TNF-α-initiated loss of hippocampal neurons. Furthermore, we characterized the molecular mechanism of TNF-α-induced neurotoxicity in HT-22 hippocampal neuronal cells. HT-22 cells are sensitive to TNF-α only upon caspase blockage and subsequently undergo necrosis. The cell death is suppressed by knockdown of CYLD or RIP1 or RIP3 or MLKL, suggesting that this necrosis is necroptosis and mediated by CYLD-RIP1-RIP3-MLKL signaling pathway. TNF-α-induced necroptosis of HT-22 cells is largely independent of both ROS accumulation and calcium influx although these events have been shown to be critical for necroptosis in certain cell lines. Taken together, these data not only provide the first in vivo evidence for a role of RIP3 in TNF-α-induced toxicity of hippocampal neurons, but also demonstrate that TNF-α promotes CYLD-RIP1-RIP3-MLKL-mediated necroptosis of hippocampal neurons largely bypassing ROS accumulation and calcium influx.

  10. Life-Threatening Hypercalcemia During Prodrome of Pneumocystis jiroveci Pneumonia in an Immunocompetent Infant

    Directory of Open Access Journals (Sweden)

    Judith Sebestyen VanSickle MD

    2017-04-01

    Full Text Available Severe hypercalcemia in infants is usually attributed to genetic etiologies and less commonly to acquired ones. An 8-week-old girl presented with failure to thrive, mild respiratory distress, and life-threatening hypercalcemia (23.5 mg/dL. Serum 1,25(OH2-vitamin D (1,25(OH2-D level was elevated and parathyroid hormone undetectable. Evaluation for genetic mutations and malignant etiologies of hypercalcemia was negative. Treatment with intravenous hydration, loop diuretic, and calcitonin failed to correct the hypercalcemia, which was subsequently controlled with bisphosphonate therapy. Due to progressive respiratory deterioration, a bronchopulmonary lavage was done on day 17 of her hospitalization disclosing Pneumocystis jiroveci infection. The subsequent immunological investigation showed no abnormalities. She was treated with trimethoprim/sulfamethoxazole resulting in gradual clearing of her lungs and normalization of serum 1,25(OH2-D level. A year later, she remains healthy with normal biochemical parameters of mineral metabolism. We conclude that in a child with hypercalcemia with suppressed parathyroid hormone and elevated 1,25(OH2-D, once the genetic etiology for elevated 1,25(OH2-D and malignancy are ruled out, one should investigate closely for a chronic granulomatous disease. Among the latter Pneumocystis jiroveci pneumonia infection should be considered even in an immunocompetent child.

  11. Hypercalcemia in Upper Urinary Tract Urothelial Carcinoma: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Keiko Asao

    2013-01-01

    Full Text Available Objective. We here report a patient with upper urinary tract urothelial carcinoma with hypercalcemia likely due to elevated 1,25-dihydroxyvitamin D. Methods. We present a clinical case and a summary of literature search. Results. A 57-year-old man, recently diagnosed with a left renal mass, for which a core biopsy showed renal cell carcinoma, was admitted for hypercalcemia of 11.0 mg/mL He also had five small right lung nodules with a negative bone scan. Both intact parathyroid hormone and parathyroid hormone-related peptide were appropriately low, and 1,25-dihydroxyvitamin D was elevated at 118 pg/dL. The patient’s calcium was normalized after hydration, and he underwent radical nephrectomy. On the postoperative day 6, a repeat 1,25-dihydroxyvitamin D was 24 pg/mL with a calcium of 8.1 mg/dL. Pathology showed a 6 cm high-grade urothelial carcinoma with divergent differentiation. We identified a total of 27 previously reported cases with hypercalcemia and upper tract urothelial carcinoma in English. No cases have a documented elevated 1,25-dihydroxyvitamin D level. Conclusion. This clinical course suggests that hypercalcemia in this case is from the patient’s tumor, which was likely producing 1,25-dihydroxyvitamin D. Considering the therapeutic implications, hypercalcemia in patients with upper urinary tract urothelial carcinoma should be evaluated with 1,25-dihydroxyvitamin D.

  12. Pathophysiological aspects and therapeutic approaches of tumoral osteolysis and hypercalcemia.

    Science.gov (United States)

    Bonjour, J P; Rizzoli, R

    1989-01-01

    Malignant tumors can affect the integrity of the skeletal tissue and the homeostasis of the two main components of bone mineral, calcium (Ca) and inorganic phosphate (Pi). Various tumoral cell products can increase bone resorption by influencing the number of osteoclasts and/or their activity. These tumoral products could act either directly on bone cells of the osteoblastic or osteoclastic lineages, or indirectly by influencing cells secreting osteotropic factors, such as interleukin-1, tumor necrosis factors, transforming growth factors, and colony-stimulating factor. Among the classical calciotropic hormones, 1,25-dihydroxyvitamin D3 could be implicated in lymphoma. In hypercalcemia of malignancy, an increase in bone resorption is observed in most patients. However, in many cases an increased tubular reabsorption of Ca has been documented as well. This phenomenon when present after adequate rehydration is probably due to the secretion by the tumoral cells of a parathyroid hormone-related peptide (PTHrP). This factor has been recently identified as a protein containing 141 amino acids. This protein or some very close analogs have been shown to be secreted by lung, kidney and also breast carcinoma. Besides increasing bone resorption and stimulating tubular reabsorption of Ca, PTHrP also selectively decreases the tubular reabsorption of Pi, an action that may explain the hypophosphatemia observed in some types of neoplasm. Therapeutically, administration of antiresorbing agents such as clodronate or other bisphosphonates can normalize the increased osteolysis and, if present, the associated elevation in the plasma level of Ca in most cancer patients. However in some cases, wherein the prevailing hypercalcemic mechanism is due to an enhancement in the tubular reabsorption of Ca, other therapeutic means should be associated with the antiosteolytic bisphosphonate therapy.

  13. Girl with idiopathic childhood hypercalcemia reveals new disease-causing CYP24A1 mutation

    DEFF Research Database (Denmark)

    Madsen, Jens Otto Broby; Sauer, Sabrina; Beck, Bodo

    2018-01-01

    of a 21 months old girl initially hospitalized due to excessive consumption of water and behavioral difficulties. Blood tests showed hypercalcemia, borderline high vitamin-D levels, and renal ultrasound revealed medullary nephrocalcinosis. An abnormality within the vitamin-D metabolism was suspected......CONTEXT: Idiopathic Infantile Hypercalcemia (IHH) was associated with vitamin-D supplementation in the 1950's. 50 years later mutations in the CYP241A gene, involved in the degradation of vitamin-D, have been identified as being a part of the etiology. CASE DESCRIPTION: We hereby report a case...... and genetic testing was performed. This revealed the patient to be compound heterozygous for a common (p.E143del) and a novel (likely) disease-causing mutation (p.H83D) in the CYP24A1 gene. The hypercalcemia normalized after calcium depleted diet and discontinuation of vitamin-D supplementation. CONCLUSIONS...

  14. A novel mutation in the calcium-sensing receptor gene in an Irish pedigree showing familial hypocalciuric hypercalcemia: a case report.

    LENUS (Irish Health Repository)

    Elamin, Wael F

    2010-01-01

    Familial hypocalciuric hypercalcemia is a rare autosomal dominant disorder characterized by asymptomatic and non-progressive hypercalcemia due to mutations of the calcium-sensing receptor gene. Disorders of calcium metabolism are very common in the elderly, and they can coexist with familial hypocalciuric hypercalcemia in affected families.

  15. IB4(+) nociceptors mediate persistent muscle pain induced by GDNF.

    Science.gov (United States)

    Alvarez, Pedro; Chen, Xiaojie; Bogen, Oliver; Green, Paul G; Levine, Jon D

    2012-11-01

    Skeletal muscle is a well-known source of glial cell line-derived neurotrophic factor (GDNF), which can produce mechanical hyperalgesia. Since some neuromuscular diseases are associated with both increased release of GDNF and intense muscle pain, we explored the role of GDNF as an endogenous mediator in muscle pain. Intramuscularly injected GDNF induced a dose-dependent (0.1-10 ng/20 μl) persistent (up to 3 wk) mechanical hyperalgesia in the rat. Once hyperalgesia subsided, injection of prostaglandin E(2) at the site induced a prolonged mechanical hyperalgesia (>72 h) compared with naïve rats (vibration increased muscle GDNF levels at 24 h, a time point where rats also exhibited marked muscle hyperalgesia. Intrathecal antisense oligodeoxynucleotides to mRNA encoding GFRα1, the canonical binding receptor for GDNF, reversibly inhibited eccentric exercise- and mechanical vibration-induced muscle hyperalgesia. Finally, electrophysiological recordings from nociceptors innervating the gastrocnemius muscle in anesthetized rats, revealed significant increase in response to sustained mechanical stimulation after local GDNF injection. In conclusion, these data indicate that GDNF plays a role as an endogenous mediator in acute and induction of chronic muscle pain, an effect likely to be produced by GDNF action at GFRα1 receptors located in IB4(+) nociceptors.

  16. Ultimobranchial body and parathyroid gland of the parrot Psittacula psittacula in response to experimental hypercalcemia.

    Science.gov (United States)

    Swarup, K; Tewari, N P; Srivastav, A K

    Psittacula psittacula when subjected to long term hypercalcemia by intramuscular injections of vitamin D2 (20,000 I.U.) on alternate days and by increasing dietary calcium, exhibit a rise in the serum calcium level after 10, 20 and 30 days of treatment as compared to their corresponding controls. The ultimobranchial cells show progressive hypertrophy up to 20th day of the treatment. From 20th day till the end of the experiment (30 days) these cells show feeble staining response. The parathyroid glands suffer from degenerative changes due to its inactivity under chronic hypercalcemia.

  17. Slight hypercalcemia is not associated with positive responses in the Comet Assay in male rat liver.

    Science.gov (United States)

    Thiel, Anette; Hamel, Annie; Schaefer, Katrien; Cardoso, Renato; Beilstein, Paul

    2017-08-01

    Maintenance of physiological levels of intracellular and extracellular calcium is essential for life. Increased intracellular calcium levels are involved in cell death (apoptosis and necrosis) and are associated with positive responses in the Comet assay in vitro. In addition, high calcium and vitamin D intakes were reported to induce apoptosis in adipose tissue in obese mice and to increase DNA-migration in the Comet assay. To investigate increased serum concentration of calcium as a potential confounding factor in the regulatory Comet assay in vivo, we induced mild hypercalcemia in male Wistar rats by 3-day continuous intravenous infusion of calcium gluconate and performed the Comet assay in the liver in line with regulatory guidelines. The results of the study showed that mild increases in serum calcium concentration (up to 1.4 times above the concurrent control) and increased urinary calcium concentration (up to 27.8 times above the concurrent control) results in clinical signs like mild tremor, faster respiration rate and decreased activity in a few animals. However, under the conditions of the study, no increase in the %Tail DNA in the Comet assay and no indication of liver damage as determined by histopathological means were observed. Thus, mild increases in plasma calcium did not lead to positive results in a genotoxicity assessment by the Comet assay in the rat liver. This result is important as it confirms the reliability of this assay for regulatory evaluation of safety. Copyright © 2017 DSM Nutritional Products AG. Published by Elsevier B.V. All rights reserved.

  18. Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Claire [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); Lafosse, Jean-Michel [CHU Toulouse, Hopital Rangueil, Service d' orthopedie et Traumatologie, Toulouse F-31000 (France); Malavaud, Bernard [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); CHU Toulouse, Hopital Rangueil, Service d' Urologie et de Transplantation Renale, Toulouse F-31000 (France); Cuvillier, Olivier, E-mail: olivier.cuvillier@ipbs.fr [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France)

    2010-01-01

    Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

  19. Sulfite induces release of lipid mediators by alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Beck-Speier, I.; Dayal, N.; Maier, L. [GSF - National Research Center for Environment and Health, Neuherberg (Germany). Inst. for Inhalation Biology; Denzlinger, C. [Tuebingen Univ. (Germany). Dept. II, Medical Clinic; Haberl, C. [Tuebingen Univ. (Germany). Dept. III, Medical Clinic

    1998-03-01

    Air pollutants are supposed to modulate physiological responses of alveolar macrophages (AM). This study was addressed to the question whether at neutral pH sulfur(IV) species in comparison to sulfur(VI) species cause AM to release proinflammatory mediators and which pathways are involved in their generation. Supernatants obtained from canine AM treated with sulfite (0.1 mM to 2 mM) enhanced the respiratory burst of canine neutrophils, measured by lucigenin-dependent chemiluminescence, whereas supernatants derived from AM treated with sulfate (1 mM) did not. The neutrophil-stimulating activity released by sulfite-treated AM consisted of platelet-activating factor (PAF) and leukotriene B{sub 4} (LTB{sub 4}) as shown by desensitization of the platelet-activating factor (PAF) and leukotriene B{sub 4} (LTB{sub 4}) as shown by desensitization of the corresponding receptors. Inhibitors of phospholipase A{sub 2} substantially suppressed release of neutrophil-stimulating activity by sulfite-treated AM. Inhibition of 5-lipoxygenase in sulfite-treated AM also reduced neutrophil-stimulating activity, while inhibition of cyclooxygenase had no effect. In conclusion, sulfite induces AM to release lipid mediators via phospholipase A{sub 2}- and 5-lipoxygenase-dependent pathways. These mediators activate neutrophils via the receptors for PAF and LTB{sub 4}. (orig.)

  20. Hyperglycemia-induced diaphragm weakness is mediated by oxidative stress

    Science.gov (United States)

    2014-01-01

    Introduction A major consequence of ICU-acquired weakness (ICUAW) is diaphragm weakness, which prolongs the duration of mechanical ventilation. Hyperglycemia (HG) is a risk factor for ICUAW. However, the mechanisms underlying HG-induced respiratory muscle weakness are not known. Excessive reactive oxygen species (ROS) injure multiple tissues during HG, but only one study suggests that excessive ROS generation may be linked to HG-induced diaphragm weakness. We hypothesized that HG-induced diaphragm dysfunction is mediated by excessive superoxide generation and that administration of a specific superoxide scavenger, polyethylene glycol superoxide dismutase (PEG-SOD), would ameliorate these effects. Methods HG was induced in rats using streptozotocin (60 mg/kg intravenously) and the following groups assessed at two weeks: controls, HG, HG + PEG-SOD (2,000U/kg/d intraperitoneally for seven days), and HG + denatured (dn)PEG-SOD (2000U/kg/d intraperitoneally for seven days). PEG-SOD and dnPEG-SOD were administered on day 8, we measured diaphragm specific force generation in muscle strips, force-pCa relationships in single permeabilized fibers, contractile protein content and indices of oxidative stress. Results HG reduced diaphragm specific force generation, altered single fiber force-pCa relationships, depleted troponin T, and increased oxidative stress. PEG-SOD prevented HG-induced reductions in diaphragm specific force generation (for example 80 Hz force was 26.4 ± 0.9, 15.4 ± 0.9, 24.0 ± 1.5 and 14.9 ± 0.9 N/cm2 for control, HG, HG + PEG-SOD, and HG + dnPEG-SOD groups, respectively, P hyperglycemia-induced diaphragm dysfunction. This new mechanistic information could explain how HG alters diaphragm function during critical illness. PMID:24886999

  1. Astrocytes mediate in vivo cholinergic-induced synaptic plasticity.

    Directory of Open Access Journals (Sweden)

    Marta Navarrete

    2012-02-01

    Full Text Available Long-term potentiation (LTP of synaptic transmission represents the cellular basis of learning and memory. Astrocytes have been shown to regulate synaptic transmission and plasticity. However, their involvement in specific physiological processes that induce LTP in vivo remains unknown. Here we show that in vivo cholinergic activity evoked by sensory stimulation or electrical stimulation of the septal nucleus increases Ca²⁺ in hippocampal astrocytes and induces LTP of CA3-CA1 synapses, which requires cholinergic muscarinic (mAChR and metabotropic glutamate receptor (mGluR activation. Stimulation of cholinergic pathways in hippocampal slices evokes astrocyte Ca²⁺ elevations, postsynaptic depolarizations of CA1 pyramidal neurons, and LTP of transmitter release at single CA3-CA1 synapses. Like in vivo, these effects are mediated by mAChRs, and this cholinergic-induced LTP (c-LTP also involves mGluR activation. Astrocyte Ca²⁺ elevations and LTP are absent in IP₃R2 knock-out mice. Downregulating astrocyte Ca²⁺ signal by loading astrocytes with BAPTA or GDPβS also prevents LTP, which is restored by simultaneous astrocyte Ca²⁺ uncaging and postsynaptic depolarization. Therefore, cholinergic-induced LTP requires astrocyte Ca²⁺ elevations, which stimulate astrocyte glutamate release that activates mGluRs. The cholinergic-induced LTP results from the temporal coincidence of the postsynaptic activity and the astrocyte Ca²⁺ signal simultaneously evoked by cholinergic activity. Therefore, the astrocyte Ca²⁺ signal is necessary for cholinergic-induced synaptic plasticity, indicating that astrocytes are directly involved in brain storage information.

  2. Hypercalcemia and acute renal insufficiency following use of a veterinary supplement

    Directory of Open Access Journals (Sweden)

    Marcelo Fernando Ronsoni

    Full Text Available Abstract A previously healthy 24 yo male presented with a two-month history of epigastric pain, nausea, vomiting, fatigue and malaise. He reported abuse of different substances, including an injectable veterinary vitamin compound, which contains high doses of vitamin A, D and E, and an oily vehicle that induces local edema and enhances muscle volume. Serum creatinine was 3.1 mg/dL, alanine transaminase 160 mg/dL, aspartate transaminase 11 mg/dL, total testosterone 23 ng/dL, 25-OH-vitamin D >150 ng/mL (toxicity >100, 1,25-OH-vitamin D 80 pg/mL, vitamin A 0.7 mg/dL, parathormone <3 pg/mL, total calcium 13.6 mg/dL, 24-hour urinary calcium 635 mg/24h (RV 42-353. A urinary tract ultrasound demonstrated signs of parenchymal nephropathy. The diagnosis was hypercalcemia and acute renal failure secondary to vitamin D intoxication. He was initially treated with intravenous hydration, furosemide and prednisone. On the fifth day of hospitalization a dose of pamidronate disodium was added. The patient evolved with serum calcium and renal function normalization. Thirty days later he presented normal clinical and laboratory tests, except 25-OH-vitamin D that was persistently increased (107 ng/mL, as it may take several months to normalize. This case report is a warning of the risks related to the use of veterinary substances for aesthetics purposes.

  3. Iatrogenic acute pancreatitis due to hypercalcemia in a child with pseudohypoparathyroidism.

    Science.gov (United States)

    Feyles, Francesca; Mussa, Alessandro; Peiretti, Valentina; Tessaris, Daniele; Santanera, Arianna; Corrias, Andrea; de Sanctis, Luisa; Calvo, Luigi

    2014-01-01

    Pancreatitis due to hypercalcemia is very rare in children, and its pathogenetic role is still debated. The following report describes a case of acute pancreatitis secondary to hypercalcemia in a 6-year-old boy with pseudohypoparathyroidism treated with calcium and vitamin D. Pseudohypoparathyroidism is characterized by parathormone (PTH) resistance, high PTH levels and hypocalcemia which need to be corrected with calcium and vitamin D supplementation. The patient was admitted for severe abdominal pain and vomiting associated with high plasma amylase, lipase and calcium levels. Hypercalcemia due to vitamin D and calcium overtreatment was probably responsible for the acute pancreatitis in this case. High serum calcium levels seem to sensitize patients to pancreatitis, even if the mechanism through which it happens is not completely understood. Moreover, the importance of concomitant predisposing factors, either acquired or especially genetic, needs to be further defined. Even though a rare occurance in childhood, hypercalcemia should be considered as a cause of pancreatitis and it should be examined together with the other etiologies that may contribute to the development of this disease.

  4. Mutations Affecting G-Protein Subunit α11 in Hypercalcemia and Hypocalcemia

    Science.gov (United States)

    Babinsky, Valerie N.; Head, Rosie A.; Cranston, Treena; Rust, Nigel; Hobbs, Maurine R.; Heath, Hunter; Thakker, Rajesh V.

    2013-01-01

    BACKGROUND Familial hypocalciuric hypercalcemia is a genetically heterogeneous disorder with three variants: types 1, 2, and 3. Type 1 is due to loss-of-function mutations of the calcium-sensing receptor, a guanine nucleotide–binding protein (G-protein)–coupled receptor that signals through the G-protein subunit α11 (Gα11). Type 3 is associated with adaptor-related protein complex 2, sigma 1 subunit (AP2S1) mutations, which result in altered calcium-sensing receptor endocytosis. We hypothesized that type 2 is due to mutations effecting Gα11 loss of function, since Gα11 is involved in calcium-sensing receptor signaling, and its gene (GNA11) and the type 2 locus are colocalized on chromosome 19p13.3. We also postulated that mutations effecting Gα11 gain of function, like the mutations effecting calcium-sensing receptor gain of function that cause autosomal dominant hypocalcemia type 1, may lead to hypocalcemia. METHODS We performed GNA11 mutational analysis in a kindred with familial hypocalciuric hypercalcemia type 2 and in nine unrelated patients with familial hypocalciuric hypercalcemia who did not have mutations in the gene encoding the calcium-sensing receptor (CASR) or AP2S1. We also performed this analysis in eight unrelated patients with hypocalcemia who did not have CASR mutations. In addition, we studied the effects of GNA11 mutations on Gα11 protein structure and calcium-sensing receptor signaling in human embryonic kidney 293 (HEK293) cells. RESULTS The kindred with familial hypocalciuric hypercalcemia type 2 had an in-frame deletion of a conserved Gα11 isoleucine (Ile200del), and one of the nine unrelated patients with familial hypocalciuric hypercalcemia had a missense GNA11 mutation (Leu135Gln). Missense GNA11 mutations (Arg181Gln and Phe341Leu) were detected in two unrelated patients with hypocalcemia; they were therefore identified as having autosomal dominant hypocalcemia type 2. All four GNA11 mutations predicted disrupted protein

  5. [Severe hypercalcemia of unusual cause, looking for the culprit: Case report and review of the literature].

    Science.gov (United States)

    Jalbert, M; Mignot, A; Gauchez, A-S; Dobrokhotov, A-C; Fourcade, J

    2018-04-27

    Hypercalcemia is not a rare event and can lead to severe consequences. Its main etiologies are primary hyperparathyroidism and neoplasic conditions. The iatrogenic etiology by vitamin D intoxication is more rarely found. A 76-year-old finish woman comes to the emergency room for chest pain. Her medical history is impossible to specify due to the language barrier and initial confusion. She has severe hypercalcaemia (4.14mmol/L), renal insufficiency, cardiac arrhythmia later complicated by an ischemic cardiac episode. Clinic and biologic examinations initially guided the research towards a hematological and neoplasic pathology. The iatrogenic etiology will be permitted by the contribution of details on its medical history and treatment learnt secondly. She was treated for post-surgical hypoparathyroidism by dihydrotachysterol, a vitamin D derivative. The cessation of substitution, treatment with hydration and biphosphonates allowed the rapid correction of hypercalcemia. Dihydrotachysterol intoxication is a rare etiology of hypercalcemia. Because of the longer half-life of this molecule, the risk of hypercalcemia seems to be greater than with other vitamin D derivatives. This molecule, withdrawn from the French market in 1982, is not detected by the dosage of 25 and 1.25 OH vitamin D. We report an original case of intoxication by dihydrotachysterol. The risk of hypercalcemia encountered with this molecule must be known. The close medical follow-up recommended in case of hypoparathyroidism seems to be particularly necessary in case of supplementation by this molecule. Copyright © 2018 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.

  6. Important hypercalcemia due to subcutaneous fat necrosis treated with pamidronate in an infant with severe hypoxic-ischemic encephalopathy

    Directory of Open Access Journals (Sweden)

    Pasqua Anna Quitadamo

    2016-08-01

    Full Text Available Subcutaneous fat necrosis (SCFN of the newborn is an uncommon form of panniculitis that occurs after fetal distress and involves fatty areas during the first weeks of life. This rare disorder is generally self-limiting and undergoes complete regression. However, it can be complicated with a potentially life-threatening hypercalcemia. We report a case of severe hypercalcemia due to SCFN occurring after serious perinatal hypoxic injury, which resolved by intravenous administration of pamidronate. This treatment was rapidly effective and well tolerated. We suggest that pamidronate could be the first-line therapy for severe hypercalcemia in SCFN.

  7. A case report of a thyroid papillary cancer that manifested leukocytosis and hypercalcemia after radiotherapy for bone metastasis

    International Nuclear Information System (INIS)

    Kobayashi, Hisataka; Endo, Keigo; Nishimura, Kazumasa; Kasagi, Kanji; Yamamoto, Itsuo; Konishi, Junji; Abe, Mitsuyuki; Shimizu, Yoshihiko.

    1989-01-01

    Bone metastasis from a thyroid papillary cancer of a 59-year-old woman had been successfully treated with radiotherapy (6,000 rad) and iodine-131 (120 mCi). One year later, the patient developed leukocytosis (maximum 143,000/mm 3 ) and hypercalcemia (16.0 mg/dl). A colony stimulating factor (CSF) was detectable in her plasma, and nude mice that had been given metastatic tissues sinilarly developed leukocytosis and hypercalcemia. Leukocytosis and hypercalcemia seemed to have been caused by the CSF produced in the bone metastasized tissues of this thyroid cancer. (author)

  8. CFTR mediates noradrenaline-induced ATP efflux from DRG neurons.

    Science.gov (United States)

    Kanno, Takeshi; Nishizaki, Tomoyuki

    2011-09-24

    In our earlier study, noradrenaline (NA) stimulated ATP release from dorsal root ganglion (DRG) neurons as mediated via β(3) adrenoceptors linked to G(s) protein involving protein kinase A (PKA) activation, to cause allodynia. The present study was conducted to understand how ATP is released from DRG neurons. In an outside-out patch-clamp configuration from acutely dissociated rat DRG neurons, single-channel currents, sensitive to the P2X receptor inhibitor PPADS, were evoked by approaching the patch-electrode tip close to a neuron, indicating that ATP is released from DRG neurons, to activate P2X receptor. NA increased the frequency of the single-channel events, but such NA effect was not found for DRG neurons transfected with the siRNA to silence the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In the immunocytochemical study using acutely dissociated rat DRG cells, CFTR was expressed in neurons alone, but not satellite cells, fibroblasts, or Schwann cells. It is concluded from these results that CFTR mediates NA-induced ATP efflux from DRG neurons as an ATP channel.

  9. Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Muzaffar, Suhail; Chattoo, Bharat B

    2017-03-01

    Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

  10. Notch-1 mediates hypoxia-induced angiogenesis in rheumatoid arthritis.

    Science.gov (United States)

    Gao, Wei; Sweeney, Catherine; Connolly, Mary; Kennedy, Aisling; Ng, Chin Teck; McCormick, Jennifer; Veale, Douglas J; Fearon, Ursula

    2012-07-01

    findings indicate that Notch-1 is expressed in synovial tissue and that increased NICD expression is associated with low in vivo tissue PO2. Furthermore, Notch-1/HIF-1α interactions mediate hypoxia-induced angiogenesis and invasion in inflammatory arthritis. Copyright © 2012 by the American College of Rheumatology.

  11. Oxytocin mediates copulation-induced hypoalgesia of male rats.

    Science.gov (United States)

    Futagami, Hiroko; Sakuma, Yasuo; Kondo, Yasuhiko

    2016-04-08

    Copulatory behavior has been reported to raise the pain threshold in male rats. In this study, we examined the effect of copulatory behavior with or without ejaculation on pain threshold measured by electrical shock via an electrode attached to the tail. It was demonstrated that ejaculation is not necessary to raise the pain threshold in male rats. In addition, we examined whether oxytocin, a hypothalamic neuropeptide, was involved in copulation-induced hypoalgesia. Sexually experienced males were subjected to stereotaxic implantation of a guide cannula targeting the lateral ventricle. After the recovery period, half of the males were intracerebroventricularly treated with an oxytocin antagonist (OTA, 100ng d(CH2)51,Tyr(Me)2,Thr4, Orn8,Tyr-NH29]-vasotocin/1μL saline) and the remaining half were administered saline without anesthesia. Fifteen minutes later, half of each group were given sexual behavior with receptive females. We found no effect of OTA on sexual activity. Immediately after ejaculation, pain threshold was measured. While raised pain threshold was observed after sexual behavior in saline-treated males, no change in pain threshold was found in OTA-treated males even after copulation. The results suggest that central oxytocin mediates copulation-induced hypoalgesia in male rats. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Important hypercalcemia due to subcutaneous fat necrosis treated with pamidronate in an infant with severe hypoxic-ischemic encephalopathy

    OpenAIRE

    Pasqua Anna Quitadamo; Antonio Villani; Piero Paolo Cristalli; Marina Marinelli; Anita Riganti; Michele Bisceglia; Alberto Gatta

    2016-01-01

    Subcutaneous fat necrosis (SCFN) of the newborn is an uncommon form of panniculitis that occurs after fetal distress and involves fatty areas during the first weeks of life. This rare disorder is generally self-limiting and undergoes complete regression. However, it can be complicated with a potentially life-threatening hypercalcemia. We report a case of severe hypercalcemia due to SCFN occurring after serious perinatal hypoxic injury, which resolved by intravenous administration of pamidrona...

  13. Glutamate decarboxylase and. gamma. -aminobutyric acid transaminase activity in brain structures during action of high concentrated sulfide gas on a background of hypo- and hypercalcemia

    Energy Technology Data Exchange (ETDEWEB)

    Kadyrov, G.K.; Aliyev, A.M.

    Activity of the following enzymes was studied on the background of hypo- and hypercalcemia and exposure to high concentration of sulfide gas: glutamate decarboxylase (GDC) and {gamma}-aminobutyric acid transaminase (GABA-T). These enzymes regulate metabolism of GABA. The results showed that a 3.5 hr exposure to sulfide gas at a concentration of 0.3 mg/1 led to significantly increased activity of GDC in cerebral hemispheres, cerebellum and in brain stem. Activity of GABA-T dropped correspondingly. On the background of hypercalcemia induced by im. injection of 10% calcium gluconate (0.6 m1/200 g body weight of experimental rats) the negative effect caused by the exposure to sulfide gas was diminished. Under conditions of hypocalcemia (im. injection of 10 mg/200 g body weight of sodium oxalate), exposure to sulfide gas led to a significantly decreased activity of GDC and GABA-T in the hemispheres and in the brain stem, but in the cerebellum the activity of GDC increased sharply while that of GABA-T decreased correspondingly. 8 refs.

  14. Hypercalcemia and huge splenomegaly presenting in an elderly patient with B-cell non-Hodgkin's lymphoma: a case report

    Directory of Open Access Journals (Sweden)

    Tirgari Farrokh

    2010-10-01

    Full Text Available Abstract Introduction Hypercalcemia is the major electrolyte abnormality in patients with malignant tumors. It can be due to localized osteolytic hypercalcemia or elaboration of humoral substances such as parathyroid hormone-related protein from tumoral cells. In hematological malignancies, a third mechanism of uncontrolled synthesis and secretion of 1-25(OH2D3 from tumoral cells or neighboring macrophages may contribute to the problem. However, hypercalcemia is quite unusual in patients with B-cell non-Hodgkin's lymphoma. Case presentation An 85-year-old Caucasian woman presented with low grade fever, anorexia, abdominal discomfort and fullness in her left abdomen for the last six months. She was mildly anemic and complained of fatigability. She had huge splenomegaly and was hypercalcemic. After correction of her hypercalcemia, she had a splenectomy. Microscopic evaluation revealed a malignant lymphoma. Her immunohistochemistry was positive for leukocyte common antigen, CD20 and parathyroid hormone-related peptide. Conclusion Immunopositivity for parathyroid hormone-related peptide clearly demonstrates that hypersecretion of a parathyroid hormone-like substance from the tumor had led to hypercalcemia in this case. High serum calcium is seen in only seven to eight percent of patients with B-cell non-Hodgkin's lymphoma, apparently due to different mechanisms. Evaluation of serum parathyroid hormone-related protein and 1-25(OH2D3 can be helpful in diagnosis and management. It should be noted that presentation with hypercalcemia has a serious impact on prognosis and survival.

  15. Hyperparathyroidism-jaw Tumor Syndrome: An Overlooked Cause of Severe Hypercalcemia.

    Science.gov (United States)

    Mathews, Joseph Wolfgang; Winchester, Rhonda; Alsaygh, Nebras; Bartlett, Anne M; Luttrell, Louis

    2016-09-01

    Ossifying fibromas of the maxillofacial bones are an uncommon form of benign neoplasm usually treated by surgical excision. Up to 30% of patients with hyperparathyroidism-jaw tumor syndrome, a rare form of multiple endocrine neoplasia resulting from autosomal dominant inactivating mutation of the Hrpt2 tumor suppressor gene, initially present with ossifying fibromas. Coincident hypercalcemia because of the presence of parathyroid adenoma is common in these patients, of whom 15% may have or may develop parathyroid carcinoma. The authors present a case of severe postsurgical hypercalcemia after removal of a large maxillary ossifying fibroma in a patient with previously unrecognized hyperparathyroidism-jaw tumor AU3 syndrome. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  16. Necrotizing pancreatitis due to hypercalcemia in a hemodialysis patient with pica

    OpenAIRE

    Brener, Zachary Z.; Bergman, Michael

    2014-01-01

    Pica refers to the persistent, compulsive craving for and ingestion of nonfood items and certain food items. Pica is quite common among dialysis patients. The nutrient composition of some of the substances ingested may contribute to severe metabolic and mineral disturbances and other serious medical complications. We report the first case of a hemodialysis patient with chalk pica associated hypercalcemia who developed acute necrotizing pancreatitis. Hydration, nutritional support and hemodial...

  17. RNase L mediated protection from virus induced demyelination.

    Directory of Open Access Journals (Sweden)

    Derek D C Ireland

    2009-10-01

    Full Text Available IFN-alpha/beta plays a critical role in limiting viral spread, restricting viral tropism and protecting mice from neurotropic coronavirus infection. However, the IFN-alpha/beta dependent mechanisms underlying innate anti-viral functions within the CNS are poorly understood. The role of RNase L in viral encephalomyelitis was explored based on its functions in inhibiting translation, inducing apoptosis, and propagating the IFN-alpha/beta pathway through RNA degradation intermediates. Infection of RNase L deficient (RL(-/- mice with a sub-lethal, demyelinating mouse hepatitis virus variant revealed that the majority of mice succumbed to infection by day 12 p.i. However, RNase L deficiency did not affect overall control of infectious virus, or diminish IFN-alpha/beta expression in the CNS. Furthermore, increased morbidity and mortality could not be attributed to altered proinflammatory signals or composition of cells infiltrating the CNS. The unique phenotype of infected RL(-/- mice was rather manifested in earlier onset and increased severity of demyelination and axonal damage in brain stem and spinal cord without evidence for enhanced neuronal infection. Increased tissue damage coincided with sustained brain stem infection, foci of microglia infection in grey matter, and increased apoptotic cells. These data demonstrate a novel protective role for RNase L in viral induced CNS encephalomyelitis, which is not reflected in overall viral control or propagation of IFN-alpha/beta mediated signals. Protective function is rather associated with cell type specific and regional restriction of viral replication in grey matter and ameliorated neurodegeneration and demyelination.

  18. Reduced platelet-mediated and enhanced leukocyte-mediated fibrinolysis in experimentally induced diabetes in rats

    International Nuclear Information System (INIS)

    Winocour, P.D.; Colwell, J.A.

    1985-01-01

    Studies of fibrinolytic activity in diabetes mellitus have produced conflicting results. This may be a result of methodologic insensitivity or of variable contributions of the different blood components to whole blood fibrinolysis. To explore these two possibilities, the authors used a sensitive solid-phase radiometric assay to examine the fibrinolytic activity of whole blood, platelet-rich plasma, leukocytes, and platelet- and leukocyte-poor plasma prepared from control rats and rats with streptozocin-induced diabetes at various times after induction of diabetes. Fibrinolytic activity of whole blood from diabetic rats after 7 days was significantly reduced, and remained reduced after longer durations of diabetes up to 28 days. Platelet-rich plasma from diabetic rats had decreased fibrinolytic activity, which followed the same time course of changes as in whole blood. The platelet contribution to whole blood fibrinolysis was further reduced in vivo after 14 days of diabetes by a reduced whole blood platelet count. In contrast, fibrinolytic activity of leukocytes from diabetic rats became enhanced after 7 days of diabetes. After 49 days of diabetes, the whole blood leukocyte count was reduced, and in vivo would offset the enhanced activity. Plasma fibrinolytic activity was small compared with that of whole blood and was unaltered in diabetic rats. The authors conclude that altered platelet function contributes to decreased fibrinolytic activity of whole blood in diabetic rats, and that this may be partially offset by enhanced leukocyte-mediated fibrinolysis

  19. Collider study on the loop-induced dark matter mediation

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Yuhsin, E-mail: yhtsai@umd.edu [Maryland Center for Fundamental Physics, University of Maryland, College Park, MD 20742 (United States)

    2016-06-21

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For DM couplings involving light mediators, especially for the loop-mediated interactions, a meaningful interpretation of the results requires to go beyond effective field theory. In this note we discuss the study of the magnetic dipole interacting DM, focusing on a model with anarchic dark flavor structure. By including the momentum-dependent form factors that mediate the coupling – given by the Dark Penguin – in collider processes, we study bounds from monophoton, diphoton, and non-pointing photon searches at the LHC. We also compare our results to constraints from the direct detection experiments.

  20. Collider study on the loop-induced dark matter mediation

    International Nuclear Information System (INIS)

    Tsai, Yuhsin

    2016-01-01

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For DM couplings involving light mediators, especially for the loop-mediated interactions, a meaningful interpretation of the results requires to go beyond effective field theory. In this note we discuss the study of the magnetic dipole interacting DM, focusing on a model with anarchic dark flavor structure. By including the momentum-dependent form factors that mediate the coupling – given by the Dark Penguin – in collider processes, we study bounds from monophoton, diphoton, and non-pointing photon searches at the LHC. We also compare our results to constraints from the direct detection experiments.

  1. Neutrophils and the calcium-binding protein MRP-14 mediate carrageenan-induced antinociception in mice

    Directory of Open Access Journals (Sweden)

    Rosana L. Pagano

    2002-01-01

    Full Text Available Background: We have previously shown that the calcium-binding protein MRP-14 secreted by neutrophils mediates the antinociceptive response in an acute inflammatory model induced by the intraperitoneal injection of glycogen in mice.

  2. β3-adrenoceptor mediates β3-selective agonist-induced effects on ...

    African Journals Online (AJOL)

    β3-adrenoceptor mediates β3-selective agonist-induced effects on energy expenditure, insulin secrtion and food ... Journal of the Ghana Science Association ... is usually associated with obesity, also involves defective energy expenditure, ...

  3. Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0615 TITLE: Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy PRINCIPAL...29 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Targeting Neutrophil Protease-Mediated Degradation of Tsp-1 to Induce Metastatic Dormancy...infection or cigarette smoke enhanced pulmonary metastasis from breast cancer in humans and mice. Similarly, autoimmune arthritis, characterized by

  4. Multi-organ dysfunction in bodybuilding possibly caused by prolonged hypercalcemia due to multi-substance abuse: case report and review of literature.

    Science.gov (United States)

    Schäfer, C N; Guldager, H; Jørgensen, H L

    2011-01-01

    A 26-year-old male bodybuilder was admitted to the surgical department of a Danish community hospital for hematemesis. During the clinical interview, he revealed that he had recently finished a course of anabolic steroids and erythropoietin. The patient also had a previous history of infections and chronic ulcers due to paraffin-oil injections in both upper arms one year before. Over the course of the next few hours, the patient developed signs of multi-organ dysfunction, including pancreatitis, hemorrhagic gastritis, nephropathy with temporary anuria, and respiratory insufficiency, and was transferred to the ICU. After manometric monitoring on the patient's upper arms proved difficult, invasive blood pressure monitoring was used and revealed that the patient was in a state of hypertensive crisis. This case of multi-organ dysfunction was possibly caused by multi-substance-induced hypercalcemia. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Non-parathyroid hypercalcemia associated with paraffin oil injection in 12 younger male bodybuilders

    DEFF Research Database (Denmark)

    Sølling, Anne Sophie Koldkjær; Tougaard, Birgitte G; Harsløf, Torben

    2018-01-01

    INTRODUCTION: Injection of paraffin oil to augment muscles size is a troubling phenomenon known to cause a foreign body reaction with formation of granulomas. In a few case reports, long-term side effects have been reported in terms of hypercalcemia and renal failure. METHODS: We identified a case...... the normal range or slightly elevated. Follow-up measurements showed marked hypercalciuria with nearly normal levels of bone turnover markers. A correlation was found between levels of peptidyl dipeptidase and calcitriol (R = 0.812, P = 0.050). Treatment with antiresorptive agents seemed less effective than...

  6. Hypercalcemia and acute pancreatitis in a male patient with acute promyelocytic leukemia and pulmonary tuberculosis.

    Science.gov (United States)

    Abdullah, Ali S; Adel, Ahmad M; Hussein, Radwa M; Abdullah, Mohammed Aj; Yousaf, Anil; Mudawi, Deena; Mohamed, Shehab F; Nashwan, Abdulqadir J; Soliman, Dina; Ibrahim, Feryal; Yassin, Mohamed A

    2018-04-03

    We report a rare case of hypercalcemia and acute pancreatitis in a subject with acute promyelocytic leukemia (APL) and pulmonary tuberculosis, during all-trans-retinoic acid (ATRA) treatment. Both associated complications were potentially due to several causes. A careful monitoring and exclusion of all causative factors must be addressed. Further research is necessary to improve our understanding of risk factors for these complications in patients with (APL). Studying these patterns may help us to improve outcomes for all children and young adults with hematologic malignancies.

  7. Dihydroartemisinin induces apoptosis preferentially via a Bim-mediated intrinsic pathway in hepatocarcinoma cells.

    Science.gov (United States)

    Qin, Guiqi; Zhao, ChuBiao; Zhang, Lili; Liu, Hongyu; Quan, Yingyao; Chai, Liuying; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

    2015-08-01

    This report is designed to dissect the detail molecular mechanism by which dihydroartemisinin (DHA), a derivative of artemisinin, induces apoptosis in human hepatocellular carcinoma (HCC) cells. DHA induced a loss of the mitochondrial transmemberane potential (ΔΨm), release of cytochrome c, activation of caspases, and externalization of phosphatidylserine indicative of apoptosis induction. Compared with the modest inhibitory effects of silencing Bax, silencing Bak largely prevented DHA-induced ΔΨm collapse and apoptosis though DHA induced a commensurable activation of Bax and Bak, demonstrating a key role of the Bak-mediated intrinsic apoptosis pathway. DHA did not induce Bid cleavage and translocation from cytoplasm to mitochondria and had little effects on the expressions of Puma and Noxa, but did increase Bim and Bak expressions and decrease Mcl-1 expression. Furthermore, the cytotoxicity of DHA was remarkably reduced by silencing Bim, and modestly but significantly reduced by silencing Puma or Noxa. Silencing Bim or Noxa preferentially reduced DHA-induced Bak activation, while silencing Puma preferentially reduced DHA-induced Bax activation, demonstrating that Bim and to a lesser extent Noxa act as upstream mediators to trigger the Bak-mediated intrinsic apoptosis pathway. In addition, silencing Mcl-1 enhanced DHA-induced Bak activation and apoptosis. Taken together, our data demonstrate a crucial role of Bim in preferentially regulating the Bak/Mcl-1 rheostat to mediate DHA-induced apoptosis in HCC cells.

  8. [Femoral osteolytic lesions with soft tissue tumors and hypercalcemia as presentation form of a B-cell lymphoma].

    Science.gov (United States)

    Hernández Hernández, J L; Olmos Martínez, J M; Figols Ladrón de Guevara, J; Riancho Moral, J A; González Macías, J

    2000-05-01

    Hypercalcemia associated with haematological neoplasms account for 15 to 20% of hipercalcemia in malignancy, and occurs usually in patients with multiple myeloma. However, its incidence in patients with linfoma is low, and it is observed usually in T-cell linfomas. Bone affectation is also uncommon in patients with non-Hodgkin linfoma. It usually is seen as a late manifestation of the disease, and its occurrence as the form of presentation is exceptional. We hereby report a patient with a B-cell non-Hodgkin linfoma presenting with hypercalcemia and femoral osteolytic lesions.

  9. Redox-Mediated and Ionizing-Radiation-Induced Inflammatory Mediators in Prostate Cancer Development and Treatment

    Science.gov (United States)

    Miao, Lu; Holley, Aaron K.; Zhao, Yanming; St. Clair, William H.

    2014-01-01

    Abstract Significance: Radiation therapy is widely used for treatment of prostate cancer. Radiation can directly damage biologically important molecules; however, most effects of radiation-mediated cell killing are derived from the generated free radicals that alter cellular redox status. Multiple proinflammatory mediators can also influence redox status in irradiated cells and the surrounding microenvironment, thereby affecting prostate cancer progression and radiotherapy efficiency. Recent Advances: Ionizing radiation (IR)–generated oxidative stress can regulate and be regulated by the production of proinflammatory mediators. Depending on the type and stage of the prostate cancer cells, these proinflammatory mediators may lead to different biological consequences ranging from cell death to development of radioresistance. Critical Issues: Tumors are heterogeneous and dynamic communication occurs between stromal and prostate cancer cells, and complicated redox-regulated mechanisms exist in the tumor microenvironment. Thus, antioxidant and anti-inflammatory strategies should be carefully evaluated for each patient at different stages of the disease to maximize therapeutic benefits while minimizing unintended side effects. Future Directions: Compared with normal cells, tumor cells are usually under higher oxidative stress and secrete more proinflammatory mediators. Thus, redox status is often less adaptive in tumor cells than in their normal counterparts. This difference can be exploited in a search for new cancer therapeutics and treatment regimes that selectively activate cell death pathways in tumor cells with minimal unintended consequences in terms of chemo- and radio-resistance in tumor cells and toxicity in normal tissues. Antioxid. Redox Signal. 20, 1481–1500. PMID:24093432

  10. IgE-mediated basophil tumour necrosis factor alpha induces matrix metalloproteinase-9 from monocytes

    DEFF Research Database (Denmark)

    Falkencrone, Sidsel; Poulsen, Lars K.; Bindslev-Jensen, Carsten

    2013-01-01

    IgE-mediated activation of mast cells has been reported to induce the release of tumour necrosis alpha (TNF-α), which may display autocrine effects on these cells by inducing the generation of the tissue remodelling protease matrix metalloproteinase-9 (MMP-9). While mast cells and basophils have...

  11. Vitamin-D toxicity and other non-malignant causes of hypercalcemia: a retrospective study at a tertiary care hospital in pakistan

    International Nuclear Information System (INIS)

    Khan, M.N.

    2017-01-01

    Background: Hypercalcemia is a common clinical problem; primary hyperparathyroidism and malignancy is commonest causes of hypercalcemia. Aetiology of hypercalcemia are changing, causes that were diseases of the past like Vitamin-D toxicity and milk alkali syndrome are observed more often. Vitamin-D deficiency is an important problem and overzealous replacement of Vitamin-D has been observed, suspected to cause toxicity. Method: This was a retrospective review of patients admitted at the Aga Khan University Hospital from January 2008 to December 2013 with hypercalcemia. We reviewed the electronic health records for laboratory and radiological studies, and discharge summaries to establish the cause of hypercalcemia. Patients with solid tumour malignancy were excluded from the analysis. The treatment records and hospital course of patients diagnosed with Vitamin-D toxicity were also reviewed. Results: Primary hyperparathyroidism was the most common cause of hypercalcemia comprising 41 (28.2 %) patients. Vitamin-D toxicity was present in 25 (17.3%) and probable Vitamin-D toxicity 11 (7.6 %) in patients. Vitamin-D toxicity and probable Vitamin-D toxicity together comprised 36 (24.8%) cases. Other causes of hypercalcemia included multiple myeloma 18 (12.4%) patients, tuberculosis 6 (4.1%) patients, chronic kidney disease 6 (4.1%) cases, sarcoidosis 4 (2.7%) and lymphoma 3 (2.0%) patients. In 29(20%) patients a cause of hypercalcemia could not be determined and were labelled as undiagnosed cases. Conclusion: Vitamin-D toxicity was the second commonest cause of hypercalcemia after primary hyperparathyroidism. Knowledge of the prevalent and emerging causes of hypercalcemia is important for prompt diagnosis and treatment. (author)

  12. A Rare Case of Gestational Gigantomastia with Hypercalcemia: The Challenges of Management and Follow up

    Science.gov (United States)

    Moazzami, Bahram; Chaichian, Shahla; Farahvash, Mohammad Reza; Taheri, Saeedeh; Ahmadi, Seyed Ali; Mokhtari, Majid; Sheibani, Kourosh

    2016-01-01

    Background: Gigantomastia is a breast disorder marked by exaggerated rapid growth of the breasts, generally bilaterally. Since this disorder is very rare and has been reported only in sparse case reports its etiology has yet to be fully established. Treatment is aimed at improving the clinical and psychological symptoms and reducing the treatment side effects; however, the best therapeutic option varies from case to case. Case Presentation: The present report described a case of gestational gigantomastia in a 30-year-old woman, gravida 2, parity 1, 17 week pregnant admitted to Pars Hospital, Tehran, Iran, on May 2014. The patient was admitted to hospital at week 17 of pregnancy, although her breasts initially had begun to enlarge from the first trimester. The patient developed hypercalcemia in her 32nd week of pregnancy. The present report followed this patient from diagnosis until the completion of treatment. Conclusion: Although gestational gigantomastia is a rare condition, its timely prognosis and careful examination of some conditions like hyperprolactinemia and hypercalcemia is essential in successful management of this condition. PMID:27921004

  13. Multiple endocrine neoplasia phenocopy revealed as a co-occurring neuroendocrine tumor and familial hypocalciuric hypercalcemia type 3

    DEFF Research Database (Denmark)

    Hovden, Silje; Jespersen, Marie Louise; Nissen, Peter H

    2016-01-01

    Familial hypocalciuric hypercalcemia type 3 should be considered as differential diagnosis in patients with suspected primary hyperparathyroidism and/or suspected multiple neoplasia syndrome, as correct diagnosis will spare the patients for going through multiple futile parathyroidectomies...... and for the worry of being diagnosed with a cancer susceptibility syndrome....

  14. Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

    Science.gov (United States)

    Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M

    2013-01-01

    Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.

  15. Hypercalcemia in hyperthyroidism: patterns of serum calcium, parathyroid hormone, and 1,25-dihydroxyvitamin D3 levels during management of thyrotoxicosis.

    Science.gov (United States)

    Iqbal, Ayesha A; Burgess, Elizabeth H; Gallina, Daniel L; Nanes, Mark S; Cook, Curtiss B

    2003-01-01

    To present two cases of hypercalcemia associated with thyrotoxicosis and to describe serial biochemical findings during the course of treatment of hyperthyroidism. We report two cases, illustrate the changes in serum calcium, parathyroid hormone, and 1,25-dihydroxyvitamin D3 levels during management of thyrotoxicosis, and compare our findings with those in previous studies. Hypercalcemia attributable to thyrotoxicosis is well documented, but the mechanism for the hypercalcemia is incompletely understood. Our first patient had a complicated medical history and several potential causes of hypercalcemia, including recurrent hyperparathyroidism, metastatic breast cancer, and relapse of previously treated thyrotoxicosis. A suppressed parathyroid hormone level and negative bone and computed tomographic scans excluded the first two factors. After thyroid ablation with 131I, the serum calcium and thyroxine levels decreased, and the parathyroid hormone and 1,25-dihydroxyvitamin D3 levels normalized. Our second patient, who was referred to our institution with a preliminary diagnosis of hypercalcemia associated with malignant disease and who had no symptoms of hyperthyroidism, was found to have a high free thyroxine level, diffuse enlargement of the thyroid, and high uptake (58%) of 123I on a thyroid scan. After thyroid ablation, the serum calcium, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone levels normalized, and the free thyroxine level declined. The probable pathogenesis of hypercalcemia in thyrotoxicosis is reviewed with respect to thyroid hormone and its effect on bone turnover. Physicians should consider thyrotoxicosis in the differential diagnosis of hypercalcemia.

  16. Nitric oxide mediated bystander responses induced by microbeam targeted cells

    International Nuclear Information System (INIS)

    Shao, C.; Prise, K.M.; Folkard, M.; Michael, B.D.

    2003-01-01

    Considerable evidence has recently been accumulated in support of the existence of a 'bystander effect', which cells having received no irradiation show biological consequences from their vicinal irradiated cells. The application of microbeams is providing new insights into the radiation-induced bystander effect. The present study found that when a fraction of radioresistant human glioblastoma cells were individually targeted with a precise number of helium ions generated from the Gray Cancer Institute Charged Particle Microbeam, micronucleus (MN) induction significantly exceeded the expected value that was calculated from the number of MN observed when all of the cells were targeted assuming no bystander effect occurring. Even when only a single cell within a population was hit by one helium ion, the MN induction in the population could be increased by 16%. These results provide direct evidence of radiation-induced bystander effect. Moreover, MN was effectively induced in the unirradiated primary human fibroblasts and glioblastoma cells either co-cultured with irradiated cells or treated with the medium harvested from irradiated cells, indicating a signal molecule was produced from the irradiated cells. However, when c-PTIO, a nitric oxide (NO)-specific scavenger, was present in the medium during and after irradiation until MN analysis, the production of MN in all of the above cases was reduced to low levels. Consequently, NO plays an important role in the radiation-induced bystander effect

  17. Gastric vagus mediates immobilization-induced hypocalcemia in rats.

    Science.gov (United States)

    Ma, J; Aou, S; Matsui, H; Hori, T

    1993-09-01

    The involvement of the parasympathetic nervous system in the etiology of stress-induced hypocalcemia was investigated in the rat. Atropine methyl bromide (0.1 and 0.6 mg/kg ip) given 20 min before immobilization (IMB) was observed to suppress the induction of hypocalcemia in a dose-dependent manner. A vagotomy of the bilateral cervical trunks also abolished the IMB-induced hypocalcemia. A vagotomy on either the thyroid/parathyroid branches or the celiac branches had no effect on the IMB-induced hypocalcemia, but a vagotomy on the gastric branches completely abolished it. Pretreatment with either secretin (2 and 6 micrograms/kg ip), an inhibitor of gastrin release, or cimetidine (5 and 10 mg/kg ip), a histamine H2-receptor antagonist, diminished the IMB-induced hypocalcemia. The concentration of serum gastrin increased significantly during IMB. It is thus concluded that the decreased levels of plasma calcium caused by IMB are due to the activation of the vagus innervating the stomach. Gastrin and histamine are also involved as a consequence of the activation of the vagus.

  18. ROS Mediates Radiation-Induced Differentiation in Human Lung Fibroblast

    International Nuclear Information System (INIS)

    Park, Sa Rah; Ahn, Ji Yeon; Kim, Mi Hyeung; Lim, Min Jin; Yun, Yeon Sook; Song, Jie Young

    2009-01-01

    One of the most common tumors worldwide is lung cancer and the number of patients with lung cancer received radiotherapy is increasing rapidly. Although radiotherapy may have lots of advantages, it can also induce serious adverse effects such as acute radiation pneumonitis and pulmonary fibrosis. Pulmonary fibrosis is characterized by excessive production of smooth muscle actin-alpha (a-SMA) and accumulation of extracellular matrix (ECM) such as collagen and fibronectin. There has been a great amount of research about fibrosis but the exact mechanism causing the reaction is not elucidated especially in radiation-induced fibrosis. Until now it has been known that several factors such as transforming growth factor (TGF-b), tumor necrosis factor (TNF), IL-6, platelet-derived growth factor (PDGF) and reactive oxygen species are related to fibrosis. It is also reported that reactive oxygen species (ROS) can be induced by radiation and can act as a second messenger in various signaling pathways. Therefore we focused on the role of ROS in radiation induced fibrosis. Here, we suggest that irradiation generate ROS mainly through NOX4, result in differentiation of lung fibroblast into myofibroblast

  19. Dexras1 mediates glucocorticoid-associated adipogenesis and diet-induced obesity

    Science.gov (United States)

    Cha, Jiyoung Y.; Kim, Hyo Jung; Yu, Jung Hwan; Xu, Jing; Kim, Daham; Paul, Bindu D.; Choi, Hyeonjin; Kim, Seyun; Lee, Yoo Jeong; Ho, Gary P.; Rao, Feng; Snyder, Solomon H.; Kim, Jae-woo

    2013-01-01

    Adipogenesis, the conversion of precursor cells into adipocytes, is associated with obesity and is mediated by glucocorticoids acting via hitherto poorly characterized mechanisms. Dexras1 is a small G protein of the Ras family discovered on the basis of its marked induction by the synthetic glucocorticoid dexamethasone. We show that Dexras1 mediates adipogenesis and diet-induced obesity. Adipogenic differentiation of 3T3-L1 cells is abolished with Dexras1 depletion, whereas overexpression of Dexras1 elicits adipogenesis. Adipogenesis is markedly reduced in mouse embryonic fibroblasts from Dexras1-deleted mice, whereas adiposity and diet-induced weight gain are diminished in the mutant mice. PMID:24297897

  20. Mediatization

    DEFF Research Database (Denmark)

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exposed to media content, i.e. effects are seen as an outcome of mediated communication. Mediatization...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction...

  1. Adrenaline-induced colonic K+ secretion is mediated by KCa1.1 (BK) channels

    DEFF Research Database (Denmark)

    Sørensen, Mads Vaarby; Sausbier, Matthias; Ruth, Peter

    2010-01-01

    . However, the secretory K(+) channel responsible for cAMP-induced K(+) secretion remains to be defined. In this study we used the Ussing chamber to identify adrenaline-induced electrogenic K(+) secretion. We found that the adrenaline-induced electrogenic ion secretion is a compound effect dominated...... variants in colonic enterocytes (STREX and ZERO). Importantly, the ZERO variant known to be activated by cAMP is differentially up-regulated in enterocytes from animals on a high K(+) diet. In summary, these results strongly suggest that the adrenaline-induced distal colonic K(+) secretion is mediated...

  2. Ceramide Production Mediates Aldosterone-Induced Human Umbilical Vein Endothelial Cell (HUVEC Damages.

    Directory of Open Access Journals (Sweden)

    Yumei Zhang

    Full Text Available Here, we studied the underlying mechanism of aldosterone (Aldo-induced vascular endothelial cell damages by focusing on ceramide. We confirmed that Aldo (at nmol/L inhibited human umbilical vein endothelial cells (HUVEC survival, and induced considerable cell apoptosis. We propose that ceramide (mainly C18 production might be responsible for Aldo-mediated damages in HUVECs. Sphingosine-1-phosphate (S1P, an anti-ceramide lipid, attenuated Aldo-induced ceramide production and following HUVEC damages. On the other hand, the glucosylceramide synthase (GCS inhibitor PDMP or the ceramide (C6 potentiated Aldo-induced HUVEC apoptosis. Eplerenone, a mineralocorticoid receptor (MR antagonist, almost completely blocked Aldo-induced C18 ceramide production and HUVEC damages. Molecularly, ceramide synthase 1 (CerS-1 is required for C18 ceramide production by Aldo. Knockdown of CerS-1 by targeted-shRNA inhibited Aldo-induced C18 ceramide production, and protected HUVECs from Aldo. Reversely, CerS-1 overexpression facilitated Aldo-induced C18 ceramide production, and potentiated HUVEC damages. Together, these results suggest that C18 ceramide production mediates Aldo-mediated HUVEC damages. MR and CerS-1 could be the two signaling molecule regulating C18 ceramide production by Aldo.

  3. Fructokinase activity mediates dehydration-induced renal injury.

    Science.gov (United States)

    Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

    2014-08-01

    The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

  4. Cocaine induces astrocytosis through ER stress-mediated activation of autophagy

    Science.gov (United States)

    Periyasamy, Palsamy; Guo, Ming-Lei; Buch, Shilpa

    2016-01-01

    ABSTRACT Cocaine is known to induce inflammation, thereby contributing in part, to the pathogenesis of neurodegeneration. A recent study from our lab has revealed a link between macroautophagy/autophagy and microglial activation. The current study was aimed at investigating whether cocaine could also mediate activation of astrocytes and, whether this process involved induction of autophagy. Our findings demonstrated that cocaine mediated the activation of astrocytes by altering the levels of autophagy markers, such as BECN1, ATG5, MAP1LC3B-II, and SQSTM1 in both human A172 astrocytoma cells and primary human astrocytes. Furthermore, cocaine treatment resulted in increased formation of endogenous MAP1LC3B puncta in human astrocytes. Additionally, astrocytes transfected with the GFP-MAP1LC3B plasmid also demonstrated cocaine-mediated upregulation of the green fluorescent MAP1LC3B puncta. Cocaine-mediated induction of autophagy involved upstream activation of ER stress proteins such as EIF2AK3, ERN1, ATF6 since blockage of autophagy using either pharmacological or gene-silencing approaches, had no effect on cocaine-mediated induction of ER stress. Using both pharmacological and gene-silencing approaches to block either ER stress or autophagy, our findings demonstrated that cocaine-induced activation of astrocytes (measured by increased levels of GFAP) involved sequential activation of ER stress and autophagy. Cocaine-mediated-increased upregulation of GFAP correlated with increased expression of proinflammatory mediators such as TNF, IL1B, and IL6. In conclusion, these findings reveal an association between ER stress-mediated autophagy and astrogliosis in cocaine-treated astrocytes. Intervention of ER stress and/or autophagy signaling would thus be promising therapeutic targets for abrogating cocaine-mediated neuroinflammation. PMID:27337297

  5. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    International Nuclear Information System (INIS)

    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun; Shin, Ki Soon; Kang, Shin Jung

    2013-01-01

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD

  6. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of); Shin, Ki Soon [Department of Biology, Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kang, Shin Jung, E-mail: sjkang@sejong.ac.kr [Department of Molecular Biology, Sejong University, Seoul 143-747 (Korea, Republic of)

    2013-08-09

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD.

  7. Hypercalcemia and renal function impairment associated with vitamin D toxicity: case report

    Directory of Open Access Journals (Sweden)

    Vanessa Guerra

    Full Text Available Abstract Nowadays vitamin D (25-OHD deficiency is supposed to be a global epidemic condition. Expectedly, vitamin D measurement and intake exponentially increased in Brazil in this decade. Although the benefit of vitamin D to general health is still in debate, its indiscriminate use potentially may lead to enhance the incidence of vitamin D intoxication, which is considered a rare disorder. We report a case of a 70 year old diabetic male with chronic renal disease (blood creatinine of 1.6 mg/dL who progressed suddenly to acute kidney injury (blood creatinine of 5.7 mg/dL associated with hypercalcemia and high blood levels of vitamin D. Vitamin D and calcitriol were discontinued and hypercalcemia was managed by hydration followed by furosemide. Thereafter, disodium pamidronate was administered and the patient did not undergo on dialysis. It took approximately 14 months to normalize 25-OHD levels and blood creatinine returned to basal levels only after 24 months. The indicated labeling dosage was 2000 IU, but most likely the vitamin D manipulated preparation was higher as the vitamin D blood levels were very high. Although rare, vitamin D intoxication is becoming more frequent as the patients use frequently manipulated preparations that could be subject to errors in the manufacturing and labeling of the tablets or capsules. The present report alerts to the potential increase in the incidence of severe vitamin D intoxication due to the frequent use of this secosteroid as a nutritional supplement. At the same time, it is necessary to improve regulation on the nutrient supplement market.

  8. Anaphylatoxin C3a induced mediator release from mast cells

    International Nuclear Information System (INIS)

    Herrscher, R.; Hugli, T.E.; Sullivan, T.J.

    1986-01-01

    The authors investigated the biochemical and functional consequences of the binding of highly purified human C3a to isolated rat serosal mast cells. C3a caused a dose-dependent (1-30 μM), noncytotoxic release of up to 64% (+/- 7 SEM) of the mast cell histamine content. C3a (10μM) increased 45 Ca ++ uptake 8.2- fold (+/- 2.2 SEM) above unstimulated control values within 10 minutes. Arachidonyl-diacylglycerol and arachidonyl-monoacylglycerol levels increased significantly within 2 minutes after C3a (10 μM) stimulation. Turnover of phosphatidylinositol, phosphatidic acid, and phosphatidylcholine were increased within 15 minutes. In contrast to antigen, C3a stimulation (10 μM) was not enhanced by exogenous phosphatidylserine, and was not inhibited by ethanol (100 μmM). C3a suppressed arachidonic acid (AA) release to 38% (+/- 9 SEM) below baseline, and did not cause PGD 2 formation. C3a and the desarginine form of C3a caused identical responses in all experiments. These studies indicate that C3a stimulation activates mast cell preformed mediator release in a manner very similar to antigen-IgE stimulation, but C3a suppresses free AA levels and does not stimulate PGD 2 synthesis

  9. Ultraviolet Radiation and the Slug Transcription Factor Induce Proinflammatory and Immunomodulatory Mediator Expression in Melanocytes

    Directory of Open Access Journals (Sweden)

    Stephanie H. Shirley

    2012-01-01

    Full Text Available Despite extensive investigation, the precise contribution of the ultraviolet radiation (UVR component of sunlight to melanoma etiology remains unclear. UVR induces keratinocytes to secrete proinflammatory and immunomodulatory mediators that promote inflammation and skin tumor development; expression of the slug transcription factor in keratinocytes is required for maximal production of these mediators. In the present studies we examined the possibility that UVR-exposed melanocytes also produce proinflammatory mediators and that Slug is important in this process. Microarray studies revealed that both UVR exposure and Slug overexpression altered transcription of a variety of proinflammatory mediators by normal human melanocytes; some of these mediators are also known to stimulate melanocyte growth and migration. There was little overlap in the spectra of cytokines produced by the two stimuli. However IL-20 was similarly induced by both stimuli and the NFκB pathway appeared to be important in both circumstances. Further exploration of UVR-induced and Slug-dependent pathways of cytokine induction in melanocytes may reveal novel targets for melanoma therapy.

  10. Ultraviolet Radiation and the Slug Transcription Factor Induce Pro inflammatory and Immunomodulatory Mediator Expression in Melanocytes

    International Nuclear Information System (INIS)

    Shirley, S. H.; Kusewitt, D. F.; Grimm, E. A.

    2012-01-01

    Despite extensive investigation, the precise contribution of the ultraviolet radiation (UVR) component of sunlight to melanoma etiology remains unclear. UVR induces keratinocytes to secrete pro inflammatory and immunomodulatory mediators that promote inflammation and skin tumor development; expression of the slug transcription factor in keratinocytes is required for maximal production of these mediators. In the present studies we examined the possibility that UVR-exposed melanocytes also produce pro inflammatory mediators and that Slug is important in this process. Micro array studies revealed that both UVR exposure and Slug overexpression altered transcription of a variety of pro inflammatory mediators by normal human melanocytes; some of these mediators are also known to stimulate melanocyte growth and migration. There was little overlap in the spectra of cytokines produced by the two stimuli. However IL-20 was similarly induced by both stimuli and the NFκB pathway appeared to be important in both circumstances. Further exploration of UVR-induced and Slug-dependent pathways of cytokine induction in melanocytes may reveal novel targets for melanoma therapy.

  11. Fiber-Mediated Nourishment of Gut Microbiota Protects against Diet-Induced Obesity by Restoring IL-22-Mediated Colonic Health.

    Science.gov (United States)

    Zou, Jun; Chassaing, Benoit; Singh, Vishal; Pellizzon, Michael; Ricci, Matthew; Fythe, Michael D; Kumar, Matam Vijay; Gewirtz, Andrew T

    2018-01-10

    Dietary supplementation with fermentable fiber suppresses adiposity and the associated parameters of metabolic syndrome. Microbiota-generated fiber-derived short-chain fatty acids (SCFAs) and free fatty acid receptors including GPR43 are thought to mediate these effects. We find that while fermentable (inulin), but not insoluble (cellulose), fiber markedly protected mice against high-fat diet (HFD)-induced metabolic syndrome, the effect was not significantly impaired by either inhibiting SCFA production or genetic ablation of GPR43. Rather, HFD decimates gut microbiota, resulting in loss of enterocyte proliferation, leading to microbiota encroachment, low-grade inflammation (LGI), and metabolic syndrome. Enriching HFD with inulin restored microbiota loads, interleukin-22 (IL-22) production, enterocyte proliferation, and antimicrobial gene expression in a microbiota-dependent manner, as assessed by antibiotic and germ-free approaches. Inulin-induced IL-22 expression, which required innate lymphoid cells, prevented microbiota encroachment and protected against LGI and metabolic syndrome. Thus, fermentable fiber protects against metabolic syndrome by nourishing microbiota to restore IL-22-mediated enterocyte function. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  13. Nuclear receptors and myokines : mediators of exercise-induced skeletal muscle metabolism

    NARCIS (Netherlands)

    van Gogh, IJA

    2016-01-01

    Skeletal muscle is a crucial organ in mediating (exercise-induced) beneficial health effects. In this thesis we gained important knowledge on the molecular biology of the muscle. With our focus on the muscle, we investigated the crosstalk with other organs, the regulation of myokines and the role of

  14. GENETIC INFLUENCES ON IN VTIRO PARTICULATE MATTER-INDUCED AIRWAY EPITHELIAL INJURY AND INFLAMMATORY MEDIATOR RELEASE

    Science.gov (United States)

    GENETIC INFLUENCES ON IN VITRO PARTICULATE MATTER-INDUCED AIRWAY EPITHELIAL INJURY AND INFLAMMATORY MEDIATOR RELEASE. JA Dye, JH Richards, DA Andrews, UP Kodavanti. US EPA, RTP, NC, USA.Particulate matter (PM) air pollution is capable of damaging the airway epitheli...

  15. Interleukin-12 induces sustained activation of multiple host inflammatory mediator systems in chimpanzees

    NARCIS (Netherlands)

    Lauw, F. N.; Dekkers, P. E.; te Velde, A. A.; Speelman, P.; Levi, M. [=Marcel M.; Kurimoto, M.; Hack, C. E.; van Deventer, S. J.; van der Poll, T.

    1999-01-01

    To determine in vivo effects of interleukin (IL)-12 on host inflammatory mediator systems, 4 healthy chimpanzees received recombinant human IL-12 (1 microg/kg) by intravenous injection. IL-12 induced increases in plasma concentrations of IL-15, IL-18, and interferon-gamma (IFN-gamma), plus a marked

  16. Role of oxidative stress in methamphetamine-induced dopaminergic toxicity mediated by protein kinase Cδ.

    Science.gov (United States)

    Shin, Eun-Joo; Duong, Chu Xuan; Nguyen, Xuan-Khanh Thi; Li, Zhengyi; Bing, Guoying; Bach, Jae-Hyung; Park, Dae Hun; Nakayama, Keiichi; Ali, Syed F; Kanthasamy, Anumantha G; Cadet, Jean Lud; Nabeshima, Toshitaka; Kim, Hyoung-Chun

    2012-06-15

    This study examined the role of protein kinase C (PKC) isozymes in methamphetamine (MA)-induced dopaminergic toxicity. Multiple-dose administration of MA did not significantly alter PKCα, PKCβI, PKCβII, or PKCζ expression in the striatum, but did significantly increase PKCδ expression. Gö6976 (a co-inhibitor of PKCα and -β), hispidin (PKCβ inhibitor), and PKCζ pseudosubstrate inhibitor (PKCζ inhibitor) did not significantly alter MA-induced behavioral impairments. However, rottlerin (PKCδ inhibitor) significantly attenuated behavioral impairments in a dose-dependent manner. In addition, MA-induced behavioral impairments were not apparent in PKCδ knockout (-/-) mice. MA-induced oxidative stress (i.e., lipid peroxidation and protein oxidation) was significantly attenuated in rottlerin-treated mice and was not apparent in PKCδ (-/-) mice. Consistent with this, MA-induced apoptosis (i.e., terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive apoptotic cells) was significantly attenuated in rottlerin-treated mice. Furthermore, MA-induced increases in the dopamine (DA) turnover rate and decreases in tyrosine hydroxylase (TH) activity and the expression of TH, dopamine transporter (DAT), and vesicular monoamine transporter 2 (VMAT2) were not significantly observed in rottlerin-treated or PKCδ (-/-) mice. Our results suggest that PKCδ gene expression is a key mediator of oxidative stress and dopaminergic damage induced by MA. Thus, inhibition of PKCδ may be a useful target for protection against MA-induced neurotoxicity. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. STAT3 mediates regorafenib-induced apoptosis in hepatocellular carcinoma.

    Science.gov (United States)

    Tai, Wei-Tien; Chu, Pei-Yi; Shiau, Chung-Wai; Chen, Yao-Li; Li, Yong-Shi; Hung, Man-Hsin; Chen, Li-Ju; Chen, Pei-Lung; Su, Jung-Chen; Lin, Ping-Yi; Yu, Hui-Chuan; Chen, Kuen-Feng

    2014-11-15

    Here, we aim to investigate the molecular mechanism of regorafenib and verify the potential druggable target for the treatment of hepatocellular carcinoma (HCC). HCC cell lines (PLC5, HepG2, Hep3B, SK-Hep1, and HA59T) were used to investigate the in vitro effect of regorafenib. Phosphatase activity was analyzed in HCC cells and purified SHP-1 proteins. PLC5-bearing mice were used to test the therapeutic efficiency of 20 and 40 mg/kg/d treatment with regorafenib ([Formula: see text] mice). The clinical relevance of STAT3 signaling was investigated with 142 tumor samples from different patients with HCC. Descriptive statistical analysis was used to compare the baseline characteristics of patients and the expression of p-STAT3. Regorafenib inhibited STAT3-related signaling in a dose-dependent manner and was a more potent inhibitor of STAT3 than sorafenib. Regorafenib increased SHP-1 phosphatase activity in purified SHP-1 protein directly. N-SH2 domain deletion and D61A mutants mimicking open-form SHP-1 partially abolished regorafenib-induced STAT3 inhibition and apoptosis. Importantly, a higher level of expression of STAT3 was found in patients with advanced clinical stages (P = 0.009) and poorly differentiated tumors (P = 0.035). Regorafenib induced significant tumor inhibition by relieving the autoinhibited N-SH2 domain of SHP-1 directly and inhibiting p-STAT3 signals. STAT3 may be suitable as a prognostic marker of HCC development, and may be a druggable target for HCC-targeted therapy using regorafenib. ©2014 American Association for Cancer Research.

  18. ABCB4 mediates diet-induced hypercholesterolemia in laboratory opossums.

    Science.gov (United States)

    Chan, Jeannie; Mahaney, Michael C; Kushwaha, Rampratap S; VandeBerg, Jane F; VandeBerg, John L

    2010-10-01

    High-responding opossums are susceptible to developing hypercholesterolemia on a high-cholesterol diet, but low-responding opossums are resistant. The observation of low biliary cholesterol and low biliary phospholipids in high responders suggested that the ABCB4 gene affects response to dietary cholesterol. Two missense mutations (Arg29Gly and Ile235Leu) were found in the ABCB4 gene of high responders. High responders (ATHH strain) were bred with low responders (ATHE or ATHL strain) to produce F1 and F2 progeny in two different genetic crosses (KUSH6 and JCX) to determine the effect of ABCB4 allelic variants on plasma cholesterol concentrations after a dietary challenge. Pedigree-based genetic association analyses consistently implicated a variant in ABCB4 or a closely linked locus as a major, but not the sole, genetic contributor to variation in the plasma cholesterol response to dietary cholesterol. High responders, but not low responders, developed liver injury as indicated by elevated plasma biomarkers of liver function, probably reflecting damage to the canalicular membrane by bile salts because of impaired phospholipid secretion. Our results implicate ABCB4 as a major determinant of diet-induced hypercholesterolemia in high-responding opossums and suggest that other genes interact with ABCB4 to regulate lipemic response to dietary cholesterol.

  19. Exosome-mediated microRNA transfer plays a role in radiation-induced bystander effect.

    Science.gov (United States)

    Xu, Shuai; Wang, Jufang; Ding, Nan; Hu, Wentao; Zhang, Xurui; Wang, Bing; Hua, Junrui; Wei, Wenjun; Zhu, Qiyun

    2015-01-01

    Bystander effects can be induced through cellular communication between irradiated cells and non-irradiated cells. The signals that mediate this cellular communication, such as cytokines, reactive oxygen species, nitric oxide and even microRNAs, can be transferred between cells via gap junctions or extracellular medium. We have previously reported that miR-21, a well described DDR (DNA damage response) microRNA, is involved in radiation-induced bystander effects through a medium-mediated way. However, the mechanisms of the microRNA transfer have not been elucidated in details. In the present study, it was found that exosomes isolated from irradiated conditioned medium could induce bystander effects. Furthermore, we demonstrated plenty of evidences that miR-21, which is up-regulated as a result of mimic transfection or irradiation, can be transferred from donor or irradiated cells into extracellular medium and subsequently get access to the recipient or bystander cells through exosomes to induce bystander effects. Inhibiting the miR-21 expression in advance can offset the bystander effects to some extent. From all of these results, it can be concluded that the exosome-mediated microRNA transfer plays an important role in the radiation-induced bystander effects. These findings provide new insights into the functions of microRNAs and the cellular communication between the directly irradiated cells and the non-irradiated cells.

  20. Resolution of hypercalcemia of malignancy following radical cystectomy in a patient with paraneoplastic syndrome associated with urothelial carcinoma of the bladder

    Directory of Open Access Journals (Sweden)

    Alfredo Harb-De La Rosa

    2015-01-01

    Full Text Available Hypercalcemia of malignancy is a common finding associated with different types of cancers; however, its association with urothelial carcinoma of the bladder is rare. We report a case of a 69-year-old male with nonmetastatic urothelial carcinoma of the bladder who developed hypercalcemia that failed to respond to medical management, but resolved completely after undergoing resection of the tumor through radical cystectomy.

  1. SET mediates TCE-induced liver cell apoptosis through dephosphorylation and upregulation of nucleolin.

    Science.gov (United States)

    Ren, Xiaohu; Huang, Xinfeng; Yang, Xifei; Liu, Yungang; Liu, Wei; Huang, Haiyan; Wu, Desheng; Zou, Fei; Liu, Jianjun

    2017-06-20

    Trichloroethylene (TCE) is an occupational and environmental chemical that can cause severe hepatotoxicity. While our previous studies showed that the phosphatase inhibitor SET is a key mediator of TCE-induced liver cell apoptosis, the molecular mechanisms remain elusive. Using quantitative phosphoproteomic analysis, we report here that nucleolin is a SET-regulated phosphoprotein in human liver HL-7702 cells. Functional analysis suggested that SET promoted dephosphorylation of nucleolin, decreased its binding to its transcriptional activator, c-myc, and upregulated nucleolin expression in TCE-treated cells. Importantly, TCE-induced hepatocyte apoptosis was significantly attenuated when nucleolin was downregulated with specific siRNAs. These findings indicate that TCE may induce hepatocyte apoptosis via SET-mediated dephosphorylation and overexpression of nucleolin.

  2. Polyphosphate induces matrix metalloproteinase-3-mediated proliferation of odontoblast-like cells derived from induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Hase, Naoko; Yamaguchi, Hideyuki; Hiyama, Taiki; Kawai, Rie [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 464-8651 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 464-8651 (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan)

    2015-05-01

    Inorganic polyphosphate [Poly(P)] may represent a physiological source of phosphate and has the ability to induce bone differentiation in osteoblasts. We previously reported that cytokine-induced matrix metalloproteinase (MMP)-3 accelerates the proliferation of purified odontoblast-like cells. In this study, MMP-3 small interfering RNA (siRNA) was transfected into odontoblast-like cells derived from induced pluripotent stem cells to investigate whether MMP-3 activity is induced by Poly(P) and/or is associated with cell proliferation and differentiation into odontoblast-like cells. Treatment with Poly(P) led to an increase in both cell proliferation and additional odontoblastic differentiation. Poly(P)-treated cells showed a small but significant increase in dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1) mRNA expression, which are markers of mature odontoblasts. The cells also acquired additional odontoblast-specific properties including adoption of an odontoblastic phenotype typified by high alkaline phosphatase (ALP) activity and a calcification capacity. In addition, Poly(P) induced expression of MMP-3 mRNA and protein, and increased MMP-3 activity. MMP-3 siRNA-mediated disruption of the expression of these effectors potently suppressed the expression of odontoblastic biomarkers ALP, DSPP, and DMP-1, and blocked calcification. Interestingly, upon siRNA-mediated silencing of MMP-3, we noted a potent and significant decrease in cell proliferation. Using specific siRNAs, we revealed that a unique signaling cascade, Poly(P)→MMP-3→DSPP and/or DMP-1, was intimately involved in the proliferation of odontoblast-like cells. - Highlights: • Polyphosphate increases proliferation of iPS cell-derived odontoblast-like cells. • Polyphosphate-induced MMP-3 results in an increase of cell proliferation. • Induced cell proliferation involves MMP-3, DSPP, and/or DMP-1 sequentially. • Induced MMP-3 also results in an increase of odontoblastic

  3. Effect decomposition in the presence of an exposure-induced mediator-outcome confounder

    Science.gov (United States)

    VanderWeele, Tyler J.; Vansteelandt, Stijn; Robins, James M.

    2014-01-01

    Methods from causal mediation analysis have generalized the traditional approach to direct and indirect effects in the epidemiologic and social science literature by allowing for interaction and non-linearities. However, the methods from the causal inference literature have themselves been subject to a major limitation in that the so-called natural direct and indirect effects that are employed are not identified from data whenever there is a variable that is affected by the exposure, which also confounds the relationship between the mediator and the outcome. In this paper we describe three alternative approaches to effect decomposition that give quantities that can be interpreted as direct and indirect effects, and that can be identified from data even in the presence of an exposure-induced mediator-outcome confounder. We describe a simple weighting-based estimation method for each of these three approaches, illustrated with data from perinatal epidemiology. The methods described here can shed insight into pathways and questions of mediation even when an exposure-induced mediator-outcome confounder is present. PMID:24487213

  4. Identification of a cDNA encoding a parathyroid hormone-like peptide from a human tumor associated with humoral hypercalcemia of malignancy

    International Nuclear Information System (INIS)

    Mangin, M.; Webb, A.C.; Dreyer, B.E.

    1988-01-01

    Humoral hypercalcemia of malignancy is a common paraneoplastic syndrome that appears to be mediated in many instances by a parathyroid hormone-like peptide. Poly(A) + RNA from a human renal carcinoma associated with this syndrome was enriched by preparative electrophoresis and used to construct an enriched cDNA library in phage λgt10. The library was screened with a codon-preference oligonucleotide synthesized on the basis of a partial N-terminal amino acid sequence from a human tumor-derived peptide, and a 2.0 kilo-base cDNA was identified. The cDNA encodes a 177 amino acid protein consisting of a 36 amino acid leader sequence and a 141 amino acid mature peptide. The first 13 amino acids of the deduced sequence of the mature peptide display strong homology to human PTH, with complete divergence thereafter. RNA blot-hybridization analysis revealed multiple transcripts in mRNA from tumors associated with the humor syndrome and also in mRNA from normal human keratinocytes. Southern blot analysis of genomic DNA from humans and rodents revealed a simple pattern compatible with a single-copy gene. The gene has been mapped to chromosome 12

  5. IgG4-Related Disease Combined with Autoimmune Hemolytic Anemia and Steroid-Responsive Transient Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Sho Hasegawa

    2015-01-01

    Full Text Available A 67-year-old man with elevated serum immunoglobulin G4 (IgG4 levels, systemic lymphadenopathy infiltrated by IgG4-positive plasma cells, and Coombs-positive autoimmune hemolytic anemia (AIHA showed marked hypercalcemia. Although the intact parathyroid hormone (PTH level was elevated, 99mTc-MIBI scintigraphy and thyroid ultrasonography revealed no evidence of primary hyperparathyroidism. Liver biopsy showed marked infiltration of IgG4-positive plasma cells, which confirmed the diagnosis of IgG4-related disease (IgG4-RD. Corticosteroid therapy was initiated, and subsequently, intact PTH and serum calcium levels gradually normalized. Transient hypercalcemia in a patient with AIHA may therefore be associated with IgG4-RD.

  6. Osteonecrosis of the Jaw and Rebound Hypercalcemia in Young People Treated With Denosumab for Giant Cell Tumor of Bone.

    Science.gov (United States)

    Uday, Suma; Gaston, Czar Louie; Rogers, Luke; Parry, Michael; Joffe, Johnathan; Pearson, John; Sutton, David; Grimer, Robert; Högler, Wolfgang

    2018-02-01

    Denosumab, an inhibitor of receptor activator of nuclear factor κ-B ligand, is an approved treatment of giant cell tumor of bone (GCTB) in adults and "skeletally mature" adolescents. Safety concerns include oversuppression of bone remodelling, with risk of osteonecrosis of the jaw (ONJ) and atypical femur fractures during treatment in adults and rebound hypercalcemia after treatment cessation in children. To date, ONJ has never been reported in children or adolescents. To describe serious adverse effects during and following high-dose denosumab therapy in GCTB patients. Two adolescents (14 and 15 years) and a young adult (40 years) received fixed-dose denosumab for GCTB for 1.3 to 4 years (cumulative dose, 47 to 98 mg/kg), which was stopped because of development of ONJ in one adolescent and bilateral femoral cortical stress reactions in the young adult. All three patients developed rebound hypercalcemia with acute kidney injury 5.5 to 7 months after denosumab cessation. The ONJ necessitated surgical debridement. Rebound hypercalcemia (serum calcium, 3.1 to 4.3 mmol/L) was unresponsive to hyperhydration alone, requiring repeated doses of calcitonin or intravenous bisphosphonate treatment. Hypercalcemia recurred in two patients within 4 weeks, with normal serum calcium profiles thereafter. All patients were naive to chemotherapy, radiotherapy, bisphosphonates, and corticosteroids and were metastases free, confirming the causative role of denosumab in these complications. These suppression-release effects of high-dose denosumab on bone remodeling raise questions about safety of fixed dosing and treatment duration. In young people, weight-adjusted dosing and safety monitoring during and after antiresorptive therapy is required. Copyright © 2017 Endocrine Society

  7. Transient Receptor Potential Vanilloid 1 Expression Mediates Capsaicin-Induced Cell Death

    Directory of Open Access Journals (Sweden)

    Ricardo Ramírez-Barrantes

    2018-06-01

    Full Text Available The transient receptor potential (TRP ion channel family consists of a broad variety of non-selective cation channels that integrate environmental physicochemical signals for dynamic homeostatic control. Involved in a variety of cellular physiological processes, TRP channels are fundamental to the control of the cell life cycle. TRP channels from the vanilloid (TRPV family have been directly implicated in cell death. TRPV1 is activated by pain-inducing stimuli, including inflammatory endovanilloids and pungent exovanilloids, such as capsaicin (CAP. TRPV1 activation by high doses of CAP (>10 μM leads to necrosis, but also exhibits apoptotic characteristics. However, CAP dose–response studies are lacking in order to determine whether CAP-induced cell death occurs preferentially via necrosis or apoptosis. In addition, it is not known whether cytosolic Ca2+ and mitochondrial dysfunction participates in CAP-induced TRPV1-mediated cell death. By using TRPV1-transfected HeLa cells, we investigated the underlying mechanisms involved in CAP-induced TRPV1-mediated cell death, the dependence of CAP dose, and the participation of mitochondrial dysfunction and cytosolic Ca2+ increase. Together, our results contribute to elucidate the pathophysiological steps that follow after TRPV1 stimulation with CAP. Low concentrations of CAP (1 μM induce cell death by a mechanism involving a TRPV1-mediated rapid and transient intracellular Ca2+ increase that stimulates plasma membrane depolarization, thereby compromising plasma membrane integrity and ultimately leading to cell death. Meanwhile, higher doses of CAP induce cell death via a TRPV1-independent mechanism, involving a slow and persistent intracellular Ca2+ increase that induces mitochondrial dysfunction, plasma membrane depolarization, plasma membrane loss of integrity, and ultimately, cell death.

  8. Membrane fusion inducers, chloroquine and spermidine increase lipoplex-mediated gene transfection

    International Nuclear Information System (INIS)

    Wong-Baeza, Carlos; Bustos, Israel; Serna, Manuel; Tescucano, Alonso; Alcantara-Farfan, Veronica; Ibanez, Miguel; Montanez, Cecilia; Wong, Carlos; Baeza, Isabel

    2010-01-01

    Gene transfection into mammalian cells can be achieved with viral and non-viral vectors. Non-viral vectors, such as cationic lipids that form lipoplexes with DNA, are safer and more stable than viral vectors, but their transfection efficiencies are lower. Here we describe that the simultaneous treatment with a membrane fusion inducer (chlorpromazine or procainamide) plus the lysosomotropic agent chloroquine increases lipoplex-mediated gene transfection in human (HEK293 and C-33 A) and rat (PC12) cell lines (up to 9.2-fold), as well as in situ in BALB/c mice spleens and livers (up to 6-fold); and that the polyamine spermidine increases lipoplex-mediated gene transfection and expression in cell cultures. The use of these four drugs provides a novel, safe and relatively inexpensive way to considerably increase lipoplex-mediated gene transfection efficiency.

  9. Rimonabant induced anorexia in rodents is not mediated by vagal or sympathetic gut afferents

    DEFF Research Database (Denmark)

    Madsen, Andreas Nygaard; Jelsing, Jacob; van de Wall, Esther H E M

    2009-01-01

    The selective CB1 receptor antagonist rimonabant is a novel weight control agent. Although CB1 receptors and binding sites are present in both the rodent central and peripheral nervous systems, including the afferent vagus nerve, the role of gut afferents in mediating anorexia following CB1R...... blockade is still debated. In the present study we examined rimonabant-induced anorexia in male C57BL/6J mice with subdiaphragmatic vagotomy (VGX) as well as in male Sprague-Dawley rats subjected to either subdiaphragmatic vagal deafferentation (SDA) alone or in combination with a complete celiac...... system, are required for rimonabant to inhibit food intake leading to the hypothesis that centrally located CB1 receptors are the prime mediators of rimonabant-induced anorexia....

  10. Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

    Science.gov (United States)

    Matsumoto, H.; Ohnishi, T.

    There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

  11. Sialyl-Tn vaccine induces antibody-mediated tumour protection in a relevant murine model

    DEFF Research Database (Denmark)

    Julien, S; Picco, G; Sewell, R

    2009-01-01

    challenge. We show that synthetic STn coupled to keyhole limpet haemocyanin (Theratope), induced antibodies to STn that recognised the glycan carried on a number of glycoproteins and in these mice a significant delay in tumour growth was observed. The protection was dependent on STn being expressed...... by the tumour and was antibody mediated. Affinity chromatography of the STn-expressing tumour cell line, followed by mass spectrometry, identified osteopontin as a novel STn-carrying glycoprotein which was highly expressed by the tumours. These results suggest that if antibodies can be induced to a number...

  12. Functional analysis of molecular mechanisms of radiation induced apoptosis, that are not mediated by DNA damages

    International Nuclear Information System (INIS)

    Angermeier, Marita; Moertl, Simone

    2012-01-01

    The effects of low-dose irradiation pose new challenges on the radiation protection efforts. Enhanced cellular radiation sensitivity is displayed by disturbed cellular reactions and resulting damage like cell cycle arrest, DNA repair and apoptosis. Apoptosis serves as genetically determinate parameter for the individual radiation sensitivity. In the frame of the project the radiation-induced apoptosis was mechanistically investigated. Since ionizing radiation induced direct DNA damage and generates a reactive oxygen species, the main focus of the research was the differentiation and weighting of DNA damage mediated apoptosis and apoptosis caused by the reactive oxygen species (ROS).

  13. Protective effect of chlorpromazine on TNF-mediated hapten-induced irritant reaction.

    Science.gov (United States)

    Erroi, A; Fantuzzi, G; Demitri, M T; Echtenacher, B; Gnocchi, P; Isetta, A; Ghezzi, P

    1995-01-01

    Picryl chloride-induced irritant reaction (IR) was shown to be mediated by tumor necrosis factor (TNF). Anti-TNF monoclonal antibodies, but not interleukin 1 receptor antagonist (IL-1 Ra), had a protective effect. Chlorpromazine (CPZ), an inhibitor of TNF synthesis, protected against IR and inhibited the IR-associated TNF induction in ear homogenates. Investigation of the role of polymorphonuclear leukocyte (PMN) in neutropenic mice showed that neutropenia did not prevent the development of the IR.

  14. A Mitochondria-Dependent Pathway Mediates the Apoptosis of GSE-Induced Yeast

    OpenAIRE

    Cao, Sishuo; Xu, Wentao; Zhang, Nan; Wang, Yan; Luo, YunBo; He, Xiaoyun; Huang, Kunlun

    2012-01-01

    Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) ...

  15. Electroacupuncture preconditioning-induced neuroprotection may be mediated by glutamate transporter type 2

    OpenAIRE

    Zhu, Xiaoling; Yin, Jinbo; Li, Liaoliao; Ma, Lei; Tan, Hongying; Deng, Jiao; Chen, Shaoyang; Zuo, Zhiyi

    2013-01-01

    Electroacupuncture has been shown to induce a preconditioning effect in the brain. The mechanisms for this protection are not fully elucidated. We hypothesize that this protection is mediated by excitatory amino acid transporters (EAATs) that have been shown to be neuroprotective. To test this hypothesis, two-month old male Sprague-Dawley rats and EAAT type 3 (EAAT3) knockout mice received or did not receive 30-min electroacupuncture once a day for 5 consecutive days. They were subjected to a...

  16. Hindbrain GLP-1 receptor mediation of cisplatin-induced anorexia and nausea.

    Science.gov (United States)

    De Jonghe, Bart C; Holland, Ruby A; Olivos, Diana R; Rupprecht, Laura E; Kanoski, Scott E; Hayes, Matthew R

    2016-01-01

    While chemotherapy-induced nausea and vomiting are clinically controlled in the acute (anorexia, nausea, fatigue, and other illness-type behaviors during the delayed phase (>24 h) of chemotherapy are largely uncontrolled. As the hindbrain glucagon-like peptide-1 (GLP-1) system contributes to energy balance and mediates aversive and stressful stimuli, here we examine the hypothesis that hindbrain GLP-1 signaling mediates aspects of chemotherapy-induced nausea and reductions in feeding behavior in rats. Specifically, hindbrain GLP-1 receptor (GLP-1R) blockade, via 4th intracerebroventricular (ICV) exendin-(9-39) injections, attenuates the anorexia, body weight reduction, and pica (nausea-induced ingestion of kaolin clay) elicited by cisplatin chemotherapy during the delayed phase (48 h) of chemotherapy-induced nausea. Additionally, the present data provide evidence that the central GLP-1-producing preproglucagon neurons in the nucleus tractus solitarius (NTS) of the caudal brainstem are activated by cisplatin during the delayed phase of chemotherapy-induced nausea, as cisplatin led to a significant increase in c-Fos immunoreactivity in NTS GLP-1-immunoreactive neurons. These data support a growing body of literature suggesting that the central GLP-1 system may be a potential pharmaceutical target for adjunct anti-emetics used to treat the delayed-phase of nausea and emesis, anorexia, and body weight loss that accompany chemotherapy treatments. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. GPBAR1/TGR5 mediates bile acid-induced cytokine expression in murine Kupffer cells.

    Directory of Open Access Journals (Sweden)

    Guiyu Lou

    Full Text Available GPBAR1/TGR5 is a novel plasma membrane-bound G protein-coupled bile acid (BA receptor. BAs are known to induce the expression of inflammatory cytokines in the liver with unknown mechanism. Here we show that without other external stimuli, TGR5 activation alone induced the expression of interleukin 1β (IL-1β and tumor necrosis factor-α (TNF-α in murine macrophage cell line RAW264.7 or murine Kupffer cells. The TGR5-mediated increase of pro-inflammatory cytokine expression was suppressed by JNK inhibition. Moreover, the induced pro-inflammatory cytokine expression in mouse liver by 1% cholic acid (CA diet was blunted in JNK-/- mice. TGR5 activation by its ligands enhanced the phosphorylation levels, DNA-binding and trans-activities of c-Jun and ATF2 transcription factors. Finally, the induced pro-inflammatory cytokine expression in Kupffer cells by TGR5 activation correlated with the suppression of Cholesterol 7α-hydroxylase (Cyp7a1 expression in murine hepatocytes. These results suggest that TGR5 mediates the BA-induced pro-inflammatory cytokine production in murine Kupffer cells through JNK-dependent pathway. This novel role of TGR5 may correlate to the suppression of Cyp7a1 expression in hepatocytes and contribute to the delicate BA feedback regulation.

  18. The role of inducer cells in mediating in vitro suppression of feline immunodeficiency virus replication

    International Nuclear Information System (INIS)

    Phadke, Anagha P.; Choi, In-Soo; Li Zhongxia; Weaver, Eric; Collisson, Ellen W.

    2004-01-01

    CD8 + T-cell-mediated suppression of feline immunodeficiency virus (FIV) replication has been described by several groups, although the mechanisms of activation and conditions for viral suppression vary with the methodologies. We have previously reported that CD8 + T-cell-mediated suppression of FIV replication required inducer cell stimulation of the effector cells. The focus of the present study was to examine the essential role of inducer cells required for the induction of this soluble anti-FIV activity. Both FIV-PPR-infected T cells and feline skin fibroblasts (FSF) infected with an alphavirus vector expressing FIV capsid or the irrelevant antigen lacZ, stimulated autologous or heterologous effector cells to produce supernatants that suppressed FIV replication. Thus, induction of this suppression of FIV replication did not strictly require autologous inducer cells and did not require the presence of FIV antigen. Anti-viral activity correlated with the presence of CD8 + T cells. Suppression was maximal when the inducer cells and the effector cells were in contact with each other, because separation of the inducer and effector cells by a 0.45-μm membrane reduced FIV suppression by approximately 50%. These findings emphasize the importance for membrane antigen interactions and cytokines in the optimal induction of effector cell synthesis of the soluble anti-FIV activity

  19. FOXO3-mediated up-regulation of Bim contributes to rhein-induced cancer cell apoptosis.

    Science.gov (United States)

    Wang, Jiao; Liu, Shu; Yin, Yancun; Li, Mingjin; Wang, Bo; Yang, Li; Jiang, Yangfu

    2015-03-01

    The anthraquinone compound rhein is a natural agent in the traditional Chinese medicine rhubarb. Preclinical studies demonstrate that rhein has anticancer activity. Treatment of a variety of cancer cells with rhein may induce apoptosis. Here, we report that rhein induces atypical unfolded protein response in breast cancer MCF-7 cells and hepatoma HepG2 cells. Rhein induces CHOP expression, eIF2α phosphorylation and caspase cleavage, while it does not induce glucose-regulated protein 78 (GRP78) expression in both MCF-7 and HepG2 cells. Meanwhile, rhein inhibits thapsigargin-induced GRP78 expression and X box-binding protein 1 splicing. In addition, rhein inhibits Akt phosphorylation and stimulates FOXO transactivation activity. Rhein induces Bim expression in MCF-7 and HepG2 cells, which can be abrogated by FOXO3a knockdown. Knockdown of FOXO3a or Bim abrogates rhein-induced caspase cleavage and apoptosis. The chemical chaperone 4-phenylbutyrate acid antagonizes the induction of FOXO activation, Bim expression and caspase cleavage by rhein, indicating that protein misfolding may be involved in triggering these deleterious effects. We conclude that FOXO3a-mediated up-regulation of Bim is a key mechanism underlying rhein-induced cancer cells apoptosis.

  20. Neurogenic mediators contribute to local edema induced by Micrurus lemniscatus venom

    Science.gov (United States)

    2017-01-01

    Background/Aims Micrurus is one of the four snake genera of medical importance in Brazil. Coral snakes have a broad geographic distribution from the southern United States to Argentina. Micrurine envenomation is characterized by neurotoxic symptoms leading to dyspnea and death. Moreover, various local manifestations, including edema formation, have been described in patients bitten by different species of Micrurus. Thus, we investigated the ability of Micrurus lemniscatus venom (MLV) to induce local edema. We also explored mechanisms underlying this effect, focusing on participation of neuropeptides and mast cells. Methodology/Principal findings Intraplantar injection of MLV (1–10 μg/paw) in rats caused dose- and time-dependent edema with a peak between 15 min and 1 h after injection. MLV also induced degranulation of peritoneal mast cells (MCs). MC depletion by compound 48/80 markedly reduced MLV-induced edema. Pre-treatment (30 min) of rats with either promethazine a histamine H1 receptor antagonist or methysergide, a nonselective 5-HT receptor antagonist, reduced MLV-induced edema. However, neither thioperamide, a histamine H3/H4 receptor antagonist, nor co-injection of MLV with HOE-140, a BK2 receptor antagonist, altered the response. Depletion of neuropeptides by capsaicin or treatment of animals with NK1- and NK2-receptor antagonists (SR 140333 and SR 48968, respectively) markedly reduced MLV-induced edema. Conclusions/Significance In conclusion, MLV induces paw edema in rats by mechanisms involving activation of mast cells and substance P-releasing sensory C-fibers. Tachykinins NKA and NKB, histamine, and serotonin are major mediators of the MLV-induced edematogenic response. Targeting mast cell- and sensory C-fiber-derived mediators should be considered as potential therapeutic approaches to interrupt development of local edema induced by Micrurus venoms. PMID:29161255

  1. Neurogenic mediators contribute to local edema induced by Micrurus lemniscatus venom.

    Directory of Open Access Journals (Sweden)

    Luciana Lyra Casais-E-Silva

    2017-11-01

    Full Text Available Micrurus is one of the four snake genera of medical importance in Brazil. Coral snakes have a broad geographic distribution from the southern United States to Argentina. Micrurine envenomation is characterized by neurotoxic symptoms leading to dyspnea and death. Moreover, various local manifestations, including edema formation, have been described in patients bitten by different species of Micrurus. Thus, we investigated the ability of Micrurus lemniscatus venom (MLV to induce local edema. We also explored mechanisms underlying this effect, focusing on participation of neuropeptides and mast cells.Intraplantar injection of MLV (1-10 μg/paw in rats caused dose- and time-dependent edema with a peak between 15 min and 1 h after injection. MLV also induced degranulation of peritoneal mast cells (MCs. MC depletion by compound 48/80 markedly reduced MLV-induced edema. Pre-treatment (30 min of rats with either promethazine a histamine H1 receptor antagonist or methysergide, a nonselective 5-HT receptor antagonist, reduced MLV-induced edema. However, neither thioperamide, a histamine H3/H4 receptor antagonist, nor co-injection of MLV with HOE-140, a BK2 receptor antagonist, altered the response. Depletion of neuropeptides by capsaicin or treatment of animals with NK1- and NK2-receptor antagonists (SR 140333 and SR 48968, respectively markedly reduced MLV-induced edema.In conclusion, MLV induces paw edema in rats by mechanisms involving activation of mast cells and substance P-releasing sensory C-fibers. Tachykinins NKA and NKB, histamine, and serotonin are major mediators of the MLV-induced edematogenic response. Targeting mast cell- and sensory C-fiber-derived mediators should be considered as potential therapeutic approaches to interrupt development of local edema induced by Micrurus venoms.

  2. Parathyroid carcinoma and persistent hypercalcemia: A case report and review of therapeutic options

    Directory of Open Access Journals (Sweden)

    Subhodip Pramanik

    2018-01-01

    Full Text Available Parathyroid carcinomas are very uncommon, accounting for 0.1% to 5% of all causes of primary hyperparathyroidism. Parathyroid–jaw tumor syndrome, with a mutation in HRPT2 that encodes parafibromin, is the most common genetic association. Unique features include aggressive clinical course and a lack of preoperative definitive diagnostic criteria. The authors report a case of a 33-year-old male with bilateral nephrocalcinosis, a left-sided neck mass, high calcium, very high parathormone level and a history of parathyroid adenectomy. Computed tomography and 99m-technetium methoxyisobutylisonitrile scan revealed a localized tumor in the left inferior parathyroid region. The patient underwent radical surgery, and histopathology revealed characteristic features of parathyroid carcinoma. Preoperative identification with clinical clues is very important to plan a more radical surgical approach, as both radiotherapy and chemotherapy are ineffective. Recurrence is common and mostly occurs within 2–3 years after surgery. Patient's age, histology and tumor DNA aneuploidy are predictors of survival. Hypercalcemia is controlled with calcimimetics, bisphosphonates and denosumab in inoperable cases. Furthermore, biologic therapy with parafibromin and telomerase inhibitors is under development.

  3. Allergen-Induced Dermatitis Causes Alterations in Cutaneous Retinoid-Mediated Signaling in Mice

    Science.gov (United States)

    Gericke, Janine; Ittensohn, Jan; Mihály, Johanna; Dubrac, Sandrine; Rühl, Ralph

    2013-01-01

    Nuclear receptor-mediated signaling via RARs and PPARδ is involved in the regulation of skin homeostasis. Moreover, activation of both RAR and PPARδ was shown to alter skin inflammation. Endogenous all-trans retinoic acid (ATRA) can activate both receptors depending on specific transport proteins: Fabp5 initiates PPARδ signaling whereas Crabp2 promotes RAR signaling. Repetitive topical applications of ovalbumin (OVA) in combination with intraperitoneal injections of OVA or only intraperitoneal OVA applications were used to induce allergic dermatitis. In our mouse model, expression of IL-4, and Hbegf increased whereas expression of involucrin, Abca12 and Spink5 decreased in inflamed skin, demonstrating altered immune response and epidermal barrier homeostasis. Comprehensive gene expression analysis showed alterations of the cutaneous retinoid metabolism and retinoid-mediated signaling in allergic skin immune response. Notably, ATRA synthesis was increased as indicated by the elevated expression of retinaldehyde dehydrogenases and increased levels of ATRA. Consequently, the expression pattern of genes downstream to RAR was altered. Furthermore, the increased ratio of Fabp5 vs. Crabp2 may indicate an up-regulation of the PPARδ pathway in allergen-induced dermatitis in addition to the altered RAR signaling. Thus, our findings suggest that ATRA levels, RAR-mediated signaling and signaling involved in PPARδ pathways are mainly increased in allergen-induced dermatitis and may contribute to the development and/or maintenance of allergic skin diseases. PMID:23977003

  4. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    International Nuclear Information System (INIS)

    Li, Ruizhao; Zhang, Li; Shi, Wei; Zhang, Bin; Liang, Xinling; Liu, Shuangxin; Wang, Wenjian

    2013-01-01

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca 2+ was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca 2+ ]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway, which may

  5. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruizhao, E-mail: liruizhao1979@126.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Li, E-mail: Zhanglichangde@163.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Southern Medical University, Guangzhou, Guangdong (China); Shi, Wei, E-mail: shiwei.gd@139.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Bin, E-mail: zhangbinyes@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liang, Xinling, E-mail: xinlingliang@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liu, Shuangxin, E-mail: mplsxi@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Wang, Wenjian, E-mail: wwjph@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China)

    2013-04-15

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca{sup 2+} was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca{sup 2+}]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway

  6. Delayed brain ischemia tolerance induced by electroacupuncture pretreatment is mediated via MCP-induced protein 1

    Science.gov (United States)

    2013-01-01

    Background Emerging studies have demonstrated that pretreatment with electroacupuncture (EA) induces significant tolerance to focal cerebral ischemia. The present study seeks to determine the involvement of monocyte chemotactic protein-induced protein 1 (MCPIP1), a recently identified novel modulator of inflammatory reactions, in the cerebral neuroprotection conferred by EA pretreatment in the animal model of focal cerebral ischemia and to elucidate the mechanisms of EA pretreatment-induced ischemic brain tolerance. Methods Twenty-four hours after the end of the last EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 90 minutes in male C57BL/6 mice and MCPIP1 knockout mice. Transcription and expression of MCPIP1 gene was monitored by qRT-PCR, Western blot and immunohistochemistry. The neurobehavioral scores, infarction volumes, proinflammatory cytokines and leukocyte infiltration in brain and NF-κB signaling were evaluated after ischemia/reperfusion. Results MCPIP1 protein and mRNA levels significantly increased specifically in mouse brain undergoing EA pretreatment. EA pretreatment significantly attenuated the infarct volume, neurological deficits, upregulation of proinflammatory cytokines and leukocyte infiltration in the brain of wild-type mice after MCAO compared with that of the non-EA group. MCPIP1-deficient mice failed to evoke EA pretreatment-induced tolerance compared with that of the control MCPIP1 knockout group without EA treatment. Furthermore, the activation of NF-κB signaling was significantly reduced in EA-pretreated wild-type mice after MCAO compared to that of the non-EA control group and MCPIP1-deficient mice failed to confer the EA pretreatment-induced inhibition of NF-κB signaling after MCAO. Conclusions Our data demonstrated that MCPIP1 deficiency caused significant lack of EA pretreatment-induced cerebral protective effects after MCAO compared with the control group and that MCPIP1 is

  7. Cadmium-induced teratogenicity: Association with ROS-mediated endoplasmic reticulum stress in placenta

    International Nuclear Information System (INIS)

    Wang, Zhen; Wang, Hua; Xu, Zhong Mei; Ji, Yan-Li; Chen, Yuan-Hua; Zhang, Zhi-Hui; Zhang, Cheng; Meng, Xiu-Hong; Zhao, Mei; Xu, De-Xiang

    2012-01-01

    The placenta is essential for sustaining the growth of the fetus. An increased endoplasmic reticulum (ER) stress has been associated with the impaired placental and fetal development. Cadmium (Cd) is a potent teratogen that caused fetal malformation and growth restriction. The present study investigated the effects of maternal Cd exposure on placental and fetal development. The pregnant mice were intraperitoneally injected with CdCl 2 (4.5 mg/kg) on gestational day 9. As expected, maternal Cd exposure during early limb development significantly increased the incidences of forelimb ectrodactyly in fetuses. An obvious impairment in the labyrinth, a highly developed tissue of blood vessels, was observed in placenta of mice treated with CdCl 2 . In addition, maternal Cd exposure markedly repressed cell proliferation and increased apoptosis in placenta. An additional experiment showed that maternal Cd exposure significantly upregulated the expression of GRP78, an ER chaperone. Moreover, maternal Cd exposure induced the phosphorylation of placental eIF2α, a downstream molecule of PERK signaling. In addition, maternal Cd exposure significantly increased the level of placental CHOP, another target of PERK signaling, indicating that the unfolded protein response (UPR) signaling was activated in placenta of mice treated with CdCl 2 . Interestingly, alpha-phenyl-N-t-butylnitrone, a free radical spin-trapping agent, significantly alleviated Cd-induced placental ER stress and UPR. Taken together, these results suggest that reactive oxygen species (ROS)-mediated ER stress might be involved in Cd-induced impairment on placental and fetal development. Antioxidants may be used as pharmacological agents to protect against Cd-induced fetal malformation and growth restriction. -- Highlights: ► Cd induces fetal malformation and growth restriction. ► Cd induced placental ER stress and UPR. ► PBN alleviates Cd-induced ER stress and UPR in placenta. ► ROS-mediated ER stress might

  8. Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lili; Yang, Min; Ding, Wei [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Zhang, Minmin [Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China); Niu, Jianying [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Qiao, Zhongdong [School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200240 (China); Gu, Yong, E-mail: yonggu@vip.163.com [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China)

    2016-08-01

    Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangial cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.

  9. Transcription regulator TRIP-Br2 mediates ER stress-induced brown adipocytes dysfunction.

    Science.gov (United States)

    Qiang, Guifen; Whang Kong, Hyerim; Gil, Victoria; Liew, Chong Wee

    2017-01-09

    In contrast to white adipose tissue, brown adipose tissue (BAT) is known to play critical roles for both basal and inducible energy expenditure. Obesity is associated with reduction of BAT function; however, it is not well understood how obesity promotes BAT dysfunction, especially at the molecular level. Here we show that the transcription regulator TRIP-Br2 mediates ER stress-induced inhibition of lipolysis and thermogenesis in BAT. Using in vitro, ex vivo, and in vivo approaches, we demonstrate that obesity-induced inflammation upregulates brown adipocytes TRIP-Br2 expression via the ER stress pathway and amelioration of ER stress in mice completely abolishes high fat diet-induced upregulation of TRIP-Br2 in BAT. We find that increased TRIP-Br2 significantly inhibits brown adipocytes thermogenesis. Finally, we show that ablation of TRIP-Br2 ameliorates ER stress-induced inhibition on lipolysis, fatty acid oxidation, oxidative metabolism, and thermogenesis in brown adipocytes. Taken together, our current study demonstrates a role for TRIP-Br2 in ER stress-induced BAT dysfunction, and inhibiting TRIP-Br2 could be a potential approach for counteracting obesity-induced BAT dysfunction.

  10. HCV-induced autophagosomes are generated via homotypic fusion of phagophores that mediate HCV RNA replication.

    Directory of Open Access Journals (Sweden)

    Linya Wang

    2017-09-01

    Full Text Available Hepatitis C virus (HCV induces autophagy to promote its replication, including its RNA replication, which can take place on double-membrane vesicles known as autophagosomes. However, how HCV induces the biogenesis of autophagosomes and how HCV RNA replication complex may be assembled on autophagosomes were largely unknown. During autophagy, crescent membrane structures known as phagophores first appear in the cytoplasm, which then progress to become autophagosomes. By conducting electron microscopy and in vitro membrane fusion assay, we found that phagophores induced by HCV underwent homotypic fusion to generate autophagosomes in a process dependent on the SNARE protein syntaxin 7 (STX7. Further analyses by live-cell imaging and fluorescence microscopy indicated that HCV-induced phagophores originated from the endoplasmic reticulum (ER. Interestingly, comparing with autophagy induced by nutrient starvation, the progression of phagophores to autophagosomes induced by HCV took significantly longer time, indicating fundamental differences in the biogenesis of autophagosomes induced by these two different stimuli. As the knockdown of STX7 to inhibit the formation of autophagosomes did not affect HCV RNA replication, and purified phagophores could mediate HCV RNA replication, the assembly of the HCV RNA replication complex on autophagosomes apparently took place during the formative stage of phagophores. These findings provided important information for understanding how HCV controlled and modified this important cellular pathway for its own replication.

  11. 2'-Hydroxycinnamaldehyde induces apoptosis through HSF1-mediated BAG3 expression.

    Science.gov (United States)

    Nguyen, Hai-Anh; Kim, Soo-A

    2017-01-01

    BAG3, a member of BAG co-chaperone family, is induced by stressful stimuli such as heat shock and heavy metals. Through interaction with various binding partners, BAG3 is thought to play a role in cellular adaptive responses against stressful conditions in normal and neoplastic cells. 2'-Hydroxycinnamaldehyde (HCA) is a natural derivative of cinnamaldehyde and has antitumor activity in various cancer cells. In the present study, for the first time, we identified that HCA induced BAG3 expression and BAG3-mediated apoptosis in cancer cells. The apoptotic cell death induced by HCA was demonstrated by caspase-7, -9 and PARP activation, and confirmed by Annexin V staining in both SW480 and SW620 colon cancer cells. Notably, both the mRNA and protein levels of BAG3 were largely induced by HCA in a dose- and time-dependent manner. By showing transcription factor HSF1 activation, we demonstrated that HCA induces the expression of BAG3 through HSF1 activation. More importantly, knockdown of BAG3 expression using siRNA largely inhibited HCA-induced apoptosis, suggesting that BAG3 is actively involved in HCA-induced cancer cell death. Considering the importance of the stress response mechanism in cancer progression, our results strongly suggest that BAG3 could be a potential target for anticancer therapy.

  12. Maresin 1, a Proresolving Lipid Mediator, Mitigates Carbon Tetrachloride-Induced Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Ruidong Li

    2016-01-01

    Full Text Available Maresin 1 (MaR 1 was recently reported to have protective properties in several different animal models of acute inflammation by inhibiting inflammatory response. However, its function in acute liver injury is still unknown. To address this question, we induced liver injury in BALB/c mice with intraperitoneal injection of carbon tetrachloride with or without treatment of MaR 1. Our data showed that MaR 1 attenuated hepatic injury, oxidative stress, and lipid peroxidation induced by carbon tetrachloride, as evidenced by increased thiobarbituric acid reactive substances and reactive oxygen species levels were inhibited by treatment of MaR 1. Furthermore, MaR 1 increased activities of antioxidative mediators in carbon tetrachloride-treated mice liver. MaR 1 decreased indices of inflammatory mediators such as tumor necrosis factor-α, interleukin-6, interleukin-1β, monocyte chemotactic protein 1, myeloperoxidase, cyclooxygenase-2, and inducible nitric oxide synthase. Administration of MaR 1 inhibited activation of nuclear factor kappa B (NF-κb and mitogen-activated protein kinases (MAPKs in the liver of CCl4 treated mice. In conclusion, these results suggested the antioxidative, anti-inflammatory properties of MaR 1 in CCl4 induced liver injury. The possible mechanism is partly implicated in its abilities to inhibit ROS generation and activation of NF-κb and MAPK pathway.

  13. Carvedilol-mediated antioxidant protection against doxorubicin-induced cardiac mitochondrial toxicity

    International Nuclear Information System (INIS)

    Oliveira, Paulo J.; Bjork, James A.; Santos, Maria S.; Leino, Richard L.; Froberg, M. Kent; Moreno, Antonio J.; Wallace, Kendall B.

    2004-01-01

    The cardiotoxicity associated with doxorubicin (DOX) therapy limits the total cumulative dose and therapeutic success of active anticancer chemotherapy. Cardiac mitochondria are implicated as primary targets for DOX toxicity, which is believed to be mediated by the generation of highly reactive free radical species of oxygen from complex I of the mitochondrial electron transport chain. The objective of this study was to determine if the protection demonstrated by carvedilol (CV), a β-adrenergic receptor antagonist with strong antioxidant properties, against DOX-induced mitochondrial-mediated cardiomyopathy [Toxicol. Appl. Pharmacol. 185 (2002) 218] is attributable to its antioxidant properties or its β-adrenergic receptor antagonism. Our results confirm that DOX induces oxidative stress, mitochondrial dysfunction, and histopathological lesions in the cardiac tissue, all of which are inhibited by carvedilol. In contrast, atenolol (AT), a β-adrenergic receptor antagonist lacking antioxidant properties, preserved phosphate energy charge but failed to protect against any of the indexes of DOX-induced oxidative mitochondrial toxicity. We therefore conclude that the cardioprotective effects of carvedilol against DOX-induced mitochondrial cardiotoxicity are due to its inherent antioxidant activity and not to its β-adrenergic receptor antagonism

  14. Ghrelin mediates stress-induced food-reward behavior in mice.

    Science.gov (United States)

    Chuang, Jen-Chieh; Perello, Mario; Sakata, Ichiro; Osborne-Lawrence, Sherri; Savitt, Joseph M; Lutter, Michael; Zigman, Jeffrey M

    2011-07-01

    The popular media and personal anecdotes are rich with examples of stress-induced eating of calorically dense "comfort foods." Such behavioral reactions likely contribute to the increased prevalence of obesity in humans experiencing chronic stress or atypical depression. However, the molecular substrates and neurocircuits controlling the complex behaviors responsible for stress-based eating remain mostly unknown, and few animal models have been described for probing the mechanisms orchestrating this response. Here, we describe a system in which food-reward behavior, assessed using a conditioned place preference (CPP) task, is monitored in mice after exposure to chronic social defeat stress (CSDS), a model of prolonged psychosocial stress, featuring aspects of major depression and posttraumatic stress disorder. Under this regime, CSDS increased both CPP for and intake of high-fat diet, and stress-induced food-reward behavior was dependent on signaling by the peptide hormone ghrelin. Also, signaling specifically in catecholaminergic neurons mediated not only ghrelin's orexigenic, antidepressant-like, and food-reward behavioral effects, but also was sufficient to mediate stress-induced food-reward behavior. Thus, this mouse model has allowed us to ascribe a role for ghrelin-engaged catecholaminergic neurons in stress-induced eating.

  15. Mechanisms and mediators of hypertension induced by erythropoietin and related molecules.

    Science.gov (United States)

    Agarwal, Rajiv

    2017-12-08

    Hypertension is a common but frequently overlooked adverse effect of erythropoietin (EPO) therapy. Underreporting of hypertension with EPO is likely due to either more aggressively managing hypertension through the prescription of antihypertensive drugs or closer attention to dry weight. The purpose and focus of this review is to critically evaluate the mechanisms of EPO-induced hypertension. Preclinical data are considered first, followed by clinical data where available. Mediated by a variety of molecules, there is an imbalance in the vascular tone favoring net vasoconstriction that mediates EPO-induced hypertension. Animal studies show the primary importance of chronic kidney disease in the genesis of EPO-induced hypertension. Preclinical studies show deranged regulation of the nitric oxide, endothelins and porstanoids and the sympathoadrenal and renin-angiotensin pathways as causes of EPO-induced hypertension. Human studies suggest that EPO administration is also associated with increased responsiveness to catecholamines and angiotensin II on vascular tissue; in addition, hypoxia-induced vasodilation may be impaired in those with EPO-induced hypertension. There is little evidence for EPO as a direct vasoconstrictor or its effect on blood viscosity as a mechanism of EPO-induced hypertension. EPO-induced hypertension, at least in part, appears to be independent of an increase in hemoglobin, because experiments show that hemoglobin may be increased by EPO without an increase in blood pressure (BP) by simply treating the animals with EPO-binding protein and that treatment with EPO in the setting of iron deficiency may not increase hemoglobin but may still increase BP. However, experimental data are not consistent across studies and better mechanistic designs are needed, especially in patients with chronic kidney disease, to dissect the precise mechanism of EPO-induced hypertension. Animal studies suggest that hypoxia-inducible factor stablizers may induce

  16. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-08-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  17. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    International Nuclear Information System (INIS)

    Nagata, Yosuke; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-01-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  18. Flavonoids-induced accumulation of hypoxia-inducible factor (HIF)-1alpha/2alpha is mediated through chelation of iron.

    Science.gov (United States)

    Park, Sung-Soo; Bae, Insoo; Lee, Yong J

    2008-04-15

    Hypoxia-inducible factor-1 alpha (HIF-1alpha) is the regulatory subunit of the heterodimeric transcription factor HIF-1 that is the key regulator of cellular response to low oxygen tension. Under normoxic conditions, HIF-1alpha is continuously degraded by the ubiquitin-proteasome pathway through pVHL (von Hippel-Lindau tumor suppressor protein). Under hypoxic conditions, HIF-1alpha is stabilized and induces the transcription of HIF-1 target genes. Quercetin, a flavonoid with anti-oxidant, anti-inflammatory, and kinase modulating properties, has been found to induce HIF-1alpha accumulation and VEGF secretion in normoxia. In this study, the molecular mechanisms of quercetin-mediated HIF-1alpha accumulation were investigated. Previous studies have shown that, in addition to being induced by hypoxia, HIF-1alpha can be induced through the phosphatidylinositol 3-kinase (PI3K)/Akt and p53 signaling pathways. But our study revealed, through p53 mutant-type as well as p53 null cell lines, that neither the PI3K/Akt nor the p53 signaling pathway is required for quercetin-induced HIF-1alpha accumulation. And we observed that HIF-1alpha accumulated by quercetin is not ubiquitinated and the interaction of HIF-1alpha with pVHL is reduced, compared with HIF-1alpha accumulated by the proteasome inhibitor MG132. The use of quercetin's analogues showed that only quercetin and galangin induce HIF-1/2alpha accumulation and this effect is completely reversed by additional iron ions. This is because quercetin and galangin are able to chelate cellular iron ions that are cofactors of HIF-1/2alpha proline hydroxylase (PHD). These data suggest that quercetin inhibits the ubiquitination of HIF-1/2alpha in normoxia by hindering PHD through chelating iron ions.

  19. Phenolic acids potentiate colistin-mediated killing of Acinetobacter baumannii by inducing redox imbalance.

    Science.gov (United States)

    Ajiboye, Taofeek O; Skiebe, Evelyn; Wilharm, Gottfried

    2018-05-01

    Phenolic acids with catechol groups are good prooxidants because of their low redox potential. In this study, we provided data showing that phenolic acids, caffeic acid, gallic acid and protocatechuic acid, enhanced colistin-mediated bacterial death by inducing redox imbalance. The minimum inhibitory concentrations of these phenolic acids against Acinetobacter baumannii AB5075 were considerably lowered for ΔsodB and ΔkatG mutants. Checkerboard assay shows synergistic interactions between colistin and phenolic acids. The phenolic acids exacerbated colistin-induced oxidative stress in A. baumannii AB5075 through increased superoxide anion generation, NAD + /NADH and ADP/ATP ratio. In parallel, the level of reduced glutathione was significantly lowered. We conclude that phenolic acids potentiate colistin-induced oxidative stress in A. baumannii AB5075 by increasing ROS generation, energy metabolism and electron transport chain activity with a concomitant decrease in glutathione. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  20. Contraction induced secretion of VEGF from skeletal muscle cells is mediated by adenosine

    DEFF Research Database (Denmark)

    Høier, Birgitte; Olsen, Karina; Nyberg, Michael Permin

    2010-01-01

    and that the contraction induced secretion of VEGF is partially mediated via adenosine acting on A(2B) adenosine receptors. Moreover, the contraction induced secretion of VEGF protein from muscle is dependent on both PKA and MAPK activation, but only the MAPK pathway appears to be adenosine dependent.......The role of adenosine and contraction for secretion of VEGF in skeletal muscle was investigated in human subjects and rat primary skeletal muscle cells. Microdialysis probes were inserted into the thigh muscle of seven male subjects and dialysate was collected at rest, during infusion of adenosine...... and contraction caused secretion of VEGF (pcontraction induced secretion of VEGF protein was abolished by the A(2B) antagonist enprofyllin and markedly reduced by inhibition of PKA or MAPK. The results demonstrate that adenosine causes secretion of VEGF from human skeletal muscle cells...

  1. Hepcidin mediates transcriptional changes that modulate acute cytokine-induced inflammatory responses in mice.

    Science.gov (United States)

    De Domenico, Ivana; Zhang, Tian Y; Koening, Curry L; Branch, Ryan W; London, Nyall; Lo, Eric; Daynes, Raymond A; Kushner, James P; Li, Dean; Ward, Diane M; Kaplan, Jerry

    2010-07-01

    Hepcidin is a peptide hormone that regulates iron homeostasis and acts as an antimicrobial peptide. It is expressed and secreted by a variety of cell types in response to iron loading and inflammation. Hepcidin mediates iron homeostasis by binding to the iron exporter ferroportin, inducing its internalization and degradation via activation of the protein kinase Jak2 and the subsequent phosphorylation of ferroportin. Here we have shown that hepcidin-activated Jak2 also phosphorylates the transcription factor Stat3, resulting in a transcriptional response. Hepcidin treatment of ferroportin-expressing mouse macrophages showed changes in mRNA expression levels of a wide variety of genes. The changes in transcript levels for half of these genes were a direct effect of hepcidin, as shown by cycloheximide insensitivity, and dependent on the presence of Stat3. Hepcidin-mediated transcriptional changes modulated LPS-induced transcription in both cultured macrophages and in vivo mouse models, as demonstrated by suppression of IL-6 and TNF-alpha transcript and secreted protein. Hepcidin-mediated transcription in mice also suppressed toxicity and morbidity due to single doses of LPS, poly(I:C), and turpentine, which is used to model chronic inflammatory disease. Most notably, we demonstrated that hepcidin pretreatment protected mice from a lethal dose of LPS and that hepcidin-knockout mice could be rescued from LPS toxicity by injection of hepcidin. The results of our study suggest a new function for hepcidin in modulating acute inflammatory responses.

  2. Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

    Science.gov (United States)

    Zhu, Bing; Li, Yinghua; Lin, Zhengfang; Zhao, Mingqi; Xu, Tiantian; Wang, Changbing; Deng, Ning

    2016-04-01

    Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

  3. Muscarinic receptors mediate cold stress-induced detrusor overactivity in type 2 diabetes mellitus rats.

    Science.gov (United States)

    Imamura, Tetsuya; Ishizuka, Osamu; Ogawa, Teruyuki; Yamagishi, Takahiro; Yokoyama, Hitoshi; Minagawa, Tomonori; Nakazawa, Masaki; Gautam, Sudha Silwal; Nishizawa, Osamu

    2014-10-01

    This study determined if muscarinic receptors could mediate the cold stress-induced detrusor overactivity induced in type 2 diabetes mellitus rats. Ten-week-old female Goto-Kakizaki diabetic rats (n = 12) and Wister Kyoto non-diabetic rats (n = 12) were maintained on a high-fat diet for 4 weeks. Cystometric investigations of the unanesthetized rats were carried out at room temperature (27 ± 2°C) for 20 min. They were intravenously administered imidafenacin (0.3 mg/kg, n = 6) or vehicle (n = 6). After 5 min, the rats were transferred to a low temperature (4 ± 2°C) for 40 min where the cystometry was continued. The rats were then returned to room temperature for the final cystometric measurements. Afterwards, expressions of bladder muscarinic receptor M3 and M2 messenger ribonucleic acids and proteins were assessed by reverse transcription polymerase chain reaction and immunohistochemistry. In non-diabetic Wister Kyoto rats, imidafenacin did not reduce cold stress-induced detrusor overactivity. In diabetic Goto-Kakizaki rats, just after transfer to a low temperature, the cold stress-induced detrusor overactivity in imidafenacin-treated rats was reduced compared with vehicle-treated rats. Within the urinary bladders, the ratio of M3 to M2 receptor messenger ribonucleic acid in the diabetic Goto-Kakizaki rats was significantly higher than that of the non-diabetic Wister Kyoto rats. The proportion of muscarinic M3 receptor-positive area within the detrusor in diabetic Goto-Kakizaki rats was also significantly higher than that in non-diabetic Wister Kyoto rats. Imidafenacin partially inhibits cold stress-induced detrusor overactivity in diabetic Goto-Kakizaki rats. In this animal model, muscarinic M3 receptors partially mediate cold stress-induced detrusor overactivity. © 2014 The Japanese Urological Association.

  4. Failure to Diagnose Hyperparathyroidism in 10,432 Patients With Hypercalcemia: Opportunities for System-level Intervention to Increase Surgical Referrals and Cure.

    Science.gov (United States)

    Balentine, Courtney J; Xie, Rongbing; Kirklin, James K; Chen, Herbert

    2017-10-01

    To determine whether a significant number of patients with hyperparathyroidism remain undiagnosed and untreated. Failure to diagnose primary hyperparathyroidism and refer patients to surgeons leads to impaired quality of life and increased costs. We hypothesized that many patients with hyperparathyroidism would be untreated due to not considering the diagnosis, inadequate evaluation of hypercalcemia, and under-referral to surgeons. We reviewed administrative data on 682,704 patients from a tertiary referral center between 2011 and 2015, and identified hypercalcemia (>10.5 mg/dL) in 10,432 patients. We evaluated whether hypercalcemic patients underwent measurement of parathyroid hormone (PTH), had documentation of hypercalcemia/hyperparathyroidism, or were referred to surgeons. The mean age of our cohort was 54 years, with 61% females, and 56% whites. Only 3200 (31%) hypercalcemic patients had PTH levels measured, 2914 (28%) had a documented diagnosis of hypercalcemia, and 880 (8%) had a diagnosis of hyperparathyroidism in the medical record. Only 592 (22%) out of 2666 patients with classic hyperparathyroidism (abnormal calcium and PTH) were referred to surgeons. A significant proportion of patients with hyperparathyroidism do not undergo appropriate evaluation and surgical referral. System-level interventions which prompt further evaluation of hypercalcemia and raise physician awareness about hyperparathyroidism could improve outcomes and produce long-term cost savings.

  5. The obesity-induced transcriptional regulator TRIP-Br2 mediates visceral fat endoplasmic reticulum stress-induced inflammation.

    Science.gov (United States)

    Qiang, Guifen; Kong, Hyerim Whang; Fang, Difeng; McCann, Maximilian; Yang, Xiuying; Du, Guanhua; Blüher, Matthias; Zhu, Jinfang; Liew, Chong Wee

    2016-04-25

    The intimate link between location of fat accumulation and metabolic disease risk and depot-specific differences is well established, but how these differences between depots are regulated at the molecular level remains largely unclear. Here we show that TRIP-Br2 mediates endoplasmic reticulum (ER) stress-induced inflammatory responses in visceral fat. Using in vitro, ex vivo and in vivo approaches, we demonstrate that obesity-induced circulating factors upregulate TRIP-Br2 specifically in visceral fat via the ER stress pathway. We find that ablation of TRIP-Br2 ameliorates both chemical and physiological ER stress-induced inflammatory and acute phase response in adipocytes, leading to lower circulating levels of inflammatory cytokines. Using promoter assays, as well as molecular and pharmacological experiments, we show that the transcription factor GATA3 is responsible for the ER stress-induced TRIP-Br2 expression in visceral fat. Taken together, our study identifies molecular regulators of inflammatory response in visceral fat that-given that these pathways are conserved in humans-might serve as potential therapeutic targets in obesity.

  6. Swimming Motility Mediates the Formation of Neutrophil Extracellular Traps Induced by Flagellated Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Madison Floyd

    2016-11-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections often characterized by robust neutrophilic infiltration. Neutrophils provide the first line of defense against P. aeruginosa. Aside from their defense conferred by phagocytic activity, neutrophils also release neutrophil extracellular traps (NETs to immobilize bacteria. Although NET formation is an important antimicrobial process, the details of its mechanism are largely unknown. The identity of the main components of P. aeruginosa responsible for triggering NET formation is unclear. In this study, our focus was to identify the main bacterial factors mediating NET formation and to gain insight into the underlying mechanism. We found that P. aeruginosa in its exponential growth phase promoted strong NET formation in human neutrophils while its NET-inducing ability dramatically decreased at later stages of bacterial growth. We identified the flagellum as the primary component of P. aeruginosa responsible for inducing NET extrusion as flagellum-deficient bacteria remained seriously impaired in triggering NET formation. Purified P. aeruginosa flagellin, the monomeric component of the flagellum, does not stimulate NET formation in human neutrophils. P. aeruginosa-induced NET formation is independent of the flagellum-sensing receptors TLR5 and NLRC4 in both human and mouse neutrophils. Interestingly, we found that flagellar motility, not flagellum binding to neutrophils per se, mediates NET release induced by flagellated bacteria. Immotile, flagellar motor-deficient bacterial strains producing paralyzed flagella did not induce NET formation. Forced contact between immotile P. aeruginosa and neutrophils restored their NET-inducing ability. Both the motAB and motCD genetic loci encoding flagellar motor genes contribute to maximal NET release; however the motCD genes play a more important role. Phagocytosis of P. aeruginosa and superoxide production by neutrophils were also

  7. Prevalence of incidental thyroid nodules in ultrasound studies of dogs with hypercalcemia (2008-2013).

    Science.gov (United States)

    Pollard, Rachel E; Bohannon, Laurie K; Feldman, Edward C

    2015-01-01

    Ultrasound is commonly used to evaluate the cervical region in dogs with hypercalcemia due to suspected hyperparathyroidism. Incidental thyroid nodules may be detected during these studies, however little information has been published to guide clinical decision-making when this occurs. The purpose of this cross-sectional study was to determine the prevalence of incidental thyroid nodules in hypercalcemic dogs undergoing cervical ultrasound at our hospital during the period of 2008-2013. Dogs with a palpable neck mass were excluded. Cervical ultrasound images for each dog were retrieved and reviewed by a board certified veterinary radiologist who was unaware of patient outcome. Presence, number, and dimensions of thyroid nodules were recorded. Results of thyroid nodule aspirate, biopsy or necropsy were recorded from medical records when available. Ninety-one dogs met inclusion criteria. Of these, 14/91 (15%) dogs had at least one thyroid nodule. Mean (± standard deviation) thyroid gland nodule length, width, and height were 1.51 ± 0.74, 0.96 ± 0.73, and 0.75 ± 0.36 cm, respectively. A histologic diagnosis was available for the incidental thyroid lesions in eight dogs, including one dog with two nodules. Confirmed diagnoses for these nodules were thyroid cyst (3/9, 33%), thyroid adenoma (3/9, 33%), thyroid adenocarcinoma (2/9, 22%) and nodular hyperplasia (1/9, 11%). Findings indicated that incidental thyroid nodules may be present in hypercalcemic dogs with no palpable neck mass and no clinical signs of thyroid disease. Some of these nodules may be malignant and therefore a recommendation for cytology or biopsy may be justified. © 2014 American College of Veterinary Radiology.

  8. Diet-induced obesity mediated by the JNK/DIO2 signal transduction pathway

    Science.gov (United States)

    Vernia, Santiago; Cavanagh-Kyros, Julie; Barrett, Tamera; Jung, Dae Young; Kim, Jason K.; Davis, Roger J.

    2013-01-01

    The cJun N-terminal kinase (JNK) signaling pathway is a key mediator of metabolic stress responses caused by consuming a high-fat diet, including the development of obesity. To test the role of JNK, we examined diet-induced obesity in mice with targeted ablation of Jnk genes in the anterior pituitary gland. These mice exhibited an increase in the pituitary expression of thyroid-stimulating hormone (TSH), an increase in the blood concentration of thyroid hormone (T4), increased energy expenditure, and markedly reduced obesity compared with control mice. The increased amount of pituitary TSH was caused by reduced expression of type 2 iodothyronine deiodinase (Dio2), a gene that is required for T4-mediated negative feedback regulation of TSH expression. These data establish a molecular mechanism that accounts for the regulation of energy expenditure and the development of obesity by the JNK signaling pathway. PMID:24186979

  9. Biogenic selenium nanoparticles induce ROS-mediated necroptosis in PC-3 cancer cells through TNF activation.

    Science.gov (United States)

    Sonkusre, Praveen; Cameotra, Swaranjit Singh

    2017-06-07

    Selenium is well documented to inhibit cancer at higher doses; however, the mechanism behind this inhibition varies widely depending on the cell type and selenium species. Previously, we have demonstrated that Bacillus licheniformis JS2 derived biogenic selenium nanoparticles (SeNPs) induce non-apoptotic cell death in prostate adenocarcinoma cell line, PC-3, at a minimal concentration of 2 µg Se/ml, without causing toxicity to the primary cells. However, the mechanism behind its anticancer activity was elusive. Our results have shown that these SeNPs at a concentration of 2 µg Se/ml were able to induce reactive oxygen species (ROS) mediated necroptosis in PC-3 cells by gaining cellular internalization. Real-time qPCR analysis showed increased expression of necroptosis associated tumor necrotic factor (TNF) and interferon regulatory factor 1 (IRF1). An increased expression of RIP1 protein was also observed at the translational level upon SeNP treatment. Moreover, the cell viability was significantly increased in the presence of necroptosis inhibitor, Necrostatin-1. Data suggest that our biogenic SeNPs induce cell death in PC-3 cells by the ROS-mediated activation of necroptosis, independent to RIP3 and MLKL, regulated by a RIP1 kinase.

  10. p18(Hamlet) mediates different p53-dependent responses to DNA-damage inducing agents.

    Science.gov (United States)

    Lafarga, Vanesa; Cuadrado, Ana; Nebreda, Angel R

    2007-10-01

    Cells organize appropriate responses to environmental cues by activating specific signaling networks. Two proteins that play key roles in coordinating stress responses are the kinase p38alpha (MAPK14) and the transcription factor p53 (TP53). Depending on the nature and the extent of the stress-induced damage, cells may respond by arresting the cell cycle or by undergoing cell death, and these responses are usually associated with the phosphorylation of particular substrates by p38alpha as well as the activation of specific target genes by p53. We recently characterized a new p38alpha substrate, named p18(Hamlet) (ZNHIT1), which mediates p53-dependent responses to different genotoxic stresses. Thus, cisplatin or UV light induce stabilization of the p18(Hamlet) protein, which then enhances the ability of p53 to bind to and activate the promoters of pro-apoptotic genes such as NOXA and PUMA leading to apoptosis induction. In a similar way, we report here that p18(Hamlet) can also mediate the cell cycle arrest induced in response to gamma-irradiation, by participating in the p53-dependent upregulation of the cell cycle inhibitor p21(Cip1) (CDKN1A).

  11. Maternal immunity enhances Mycoplasma hyopneumoniae vaccination induced cell-mediated immune responses in piglets.

    Science.gov (United States)

    Bandrick, Meggan; Theis, Kara; Molitor, Thomas W

    2014-06-05

    Passively acquired maternal derived immunity (MDI) is a double-edged sword. Maternal derived antibody-mediated immunity (AMI) and cell-mediated immunity (CMI) are critical immediate defenses for the neonate; however, MDI may interfere with the induction of active immunity in the neonate, i.e. passive interference. The effect of antigen-specific MDI on vaccine-induced AMI and CMI responses to Mycoplasma hyopneumoniae (M. hyopneumoniae) was assessed in neonatal piglets. To determine whether CMI and AMI responses could be induced in piglets with MDI, piglets with high and low levels of maternal M. hyopneumoniae-specific immunity were vaccinated against M. hyopneumoniae at 7 d of age. Piglet M. hyopneumoniae-specific antibody, lymphoproliferation, and delayed type hypersensitivity (DTH) responses were measured 7 d and 14 d post vaccination. Piglets with M. hyopneumoniae-specific MDI failed to show vaccine-induced AMI responses; there was no rise in M. hyopneumoniae antibody levels following vaccination of piglets in the presence of M. hyopneumoniae-specific MDI. However, piglets with M. hyopneumoniae-specific MDI had primary (antigen-specific lymphoproliferation) and secondary (DTH) M. hyopneumoniae-specific CMI responses following vaccination. In this study neonatal M. hyopneumoniae-specific CMI was not subject to passive interference by MDI. Further, it appears that both maternal derived and endogenous CMI contribute to M. hyopneumoniae-specific CMI responses in piglets vaccinated in the face of MDI.

  12. Regulation of apoptosis-inducing factor-mediated, cisplatin-induced apoptosis by Akt

    OpenAIRE

    Yang, X; Fraser, M; Abedini, M R; Bai, T; Tsang, B K

    2008-01-01

    Cisplatin is a first-line chemotherapeutic for ovarian cancer, although chemoresistance limits treatment success. Apoptosis, an important determinant of cisplatin sensitivity, occurs via caspase-dependent and -independent mechanisms. Activation of the protein kinase Akt, commonly observed in ovarian tumours, confers resistance to ovarian cancer cells via inhibition of caspase-dependent apoptosis. However, the effect of Akt on cisplatin-induced, caspase-independent apoptosis remains unclear. W...

  13. Endothelin‐1 mediates natriuresis but not polyuria during vitamin D‐induced acute hypercalcaemia

    Science.gov (United States)

    Tokonami, Natsuko; Cheval, Lydie; Monnay, Isabelle; Meurice, Guillaume; Loffing, Johannes; Feraille, Eric

    2017-01-01

    Key points Hypercalcaemia can occur under various pathological conditions, such as primary hyperparathyroidism, malignancy or granulomatosis, and it induces natriuresis and polyuria in various species via an unknown mechanism.A previous study demonstrated that hypercalcaemia induced by vitamin D in rats increased endothelin (ET)‐1 expression in the distal nephron, which suggests the involvement of the ET system in hypercalcaemia‐induced effects.In the present study, we demonstrate that, during vitamin D‐induced hypercalcaemia, the activation of ET system by increased ET‐1 is responsible for natriuresis but not for polyuria.Vitamin D‐treated hypercalcaemic mice showed a blunted response to amiloride, suggesting that epithelial sodium channel function is inhibited.We have identified an original pathway that specifically mediates the effects of vitamin D‐induced hypercalcaemia on sodium handling in the distal nephron without affecting water handling. Abstract Acute hypercalcaemia increases urinary sodium and water excretion; however, the underlying molecular mechanism remains unclear. Because vitamin D‐induced hypercalcaemia increases the renal expression of endothelin (ET)‐1, we hypothesized that ET‐1 mediates the effects of hypercalcaemia on renal sodium and water handling. Hypercalcaemia was induced in 8‐week‐old, parathyroid hormone‐supplemented, male mice by oral administration of dihydrotachysterol (DHT) for 3 days. DHT‐treated mice became hypercalcaemic and displayed increased urinary water and sodium excretion compared to controls. mRNA levels of ET‐1 and the transcription factors CCAAT‐enhancer binding protein β and δ were specifically increased in the distal convoluted tubule and downstream segments in DHT‐treated mice. To examine the role of the ET system in hypercalcaemia‐induced natriuresis and polyuria, mice were treated with the ET‐1 receptor antagonist macitentan, with or without DHT. Mice treated with both

  14. Endothelin-1 mediates natriuresis but not polyuria during vitamin D-induced acute hypercalcaemia.

    Science.gov (United States)

    Tokonami, Natsuko; Cheval, Lydie; Monnay, Isabelle; Meurice, Guillaume; Loffing, Johannes; Feraille, Eric; Houillier, Pascal

    2017-04-15

    Hypercalcaemia can occur under various pathological conditions, such as primary hyperparathyroidism, malignancy or granulomatosis, and it induces natriuresis and polyuria in various species via an unknown mechanism. A previous study demonstrated that hypercalcaemia induced by vitamin D in rats increased endothelin (ET)-1 expression in the distal nephron, which suggests the involvement of the ET system in hypercalcaemia-induced effects. In the present study, we demonstrate that, during vitamin D-induced hypercalcaemia, the activation of ET system by increased ET-1 is responsible for natriuresis but not for polyuria. Vitamin D-treated hypercalcaemic mice showed a blunted response to amiloride, suggesting that epithelial sodium channel function is inhibited. We have identified an original pathway that specifically mediates the effects of vitamin D-induced hypercalcaemia on sodium handling in the distal nephron without affecting water handling. Acute hypercalcaemia increases urinary sodium and water excretion; however, the underlying molecular mechanism remains unclear. Because vitamin D-induced hypercalcaemia increases the renal expression of endothelin (ET)-1, we hypothesized that ET-1 mediates the effects of hypercalcaemia on renal sodium and water handling. Hypercalcaemia was induced in 8-week-old, parathyroid hormone-supplemented, male mice by oral administration of dihydrotachysterol (DHT) for 3 days. DHT-treated mice became hypercalcaemic and displayed increased urinary water and sodium excretion compared to controls. mRNA levels of ET-1 and the transcription factors CCAAT-enhancer binding protein β and δ were specifically increased in the distal convoluted tubule and downstream segments in DHT-treated mice. To examine the role of the ET system in hypercalcaemia-induced natriuresis and polyuria, mice were treated with the ET-1 receptor antagonist macitentan, with or without DHT. Mice treated with both macitentan and DHT displayed hypercalcaemia and polyuria

  15. Apoptosis inducing factor (AIF) mediates lethal redox stress induced by menadione.

    Science.gov (United States)

    Wiraswati, Hesti Lina; Hangen, Emilie; Sanz, Ana Belén; Lam, Ngoc-Vy; Reinhardt, Camille; Sauvat, Allan; Mogha, Ariane; Ortiz, Alberto; Kroemer, Guido; Modjtahedi, Nazanine

    2016-11-22

    Mitochondrial apoptosis inducing factor (AIF) is a redox-active enzyme that participates to the biogenesis/maintenance of complex I of the respiratory chain, yet also contributes to catabolic reactions in the context of regulated cell death when AIF translocates to the cytosol and to the nucleus. Here we explore the contribution of AIF to cell death induced by menadione (2-methyl-1,4-naphtoquinone; also called vitamin K3) in conditions in which this pro-oxidant does not cause the mitochondrial release of AIF, yet causes caspase-independent cell killing. Depletion of AIF from human cancer cells reduced the cytotoxicity of menadione. This cytoprotective effect was accompanied by the maintenance of high levels of reduced glutathione (GSH), which are normally depleted by menadione. In addition, AIF depletion reduced the arylation of cellular proteins induced by menadione. This menadione-triggered arylation, which can be measured by a fluorescence assay, is completely suppressed by addition of exogenous glutathione or N-acetyl cysteine. Complex I inhibition by Rotenone did not mimic the cytoprotective action of AIF depletion. Altogether, these results are compatible with the hypothesis that mitochondrion-sessile AIF facilitates lethal redox cycling of menadione, thereby precipitating protein arylation and glutathione depletion.

  16. Radiotherapy-Induced Skin Reactions Induce Fibrosis Mediated by TGF-β1 Cytokine

    Directory of Open Access Journals (Sweden)

    Cherley Borba Vieira de Andrade

    2017-04-01

    Full Text Available Purpose: This study aimed to investigate radiation-induced lesions on the skin in an experimental animal model. Methods and Materials: Cutaneous wounds were induced in Wistar rats by 4 MeV energy electron beam irradiation, using a dose rate of 240 cGy/min, for 3 different doses (10 Gy, 40 Gy, and 60 Gy. The skin was observed 5, 10, and 25 days (D after ionizing radiation exposition. Results: Infiltrate inflammatory process was observed in D5 and D10, for the 40 Gy and 60 Gy groups, and a progressive increase of transforming growth factor β1 is associated with this process. It could also be noted a mischaracterization of collagen fibers at the high-dose groups. Conclusion: It was observed that the lesions caused by ionizing radiation in rats were very similar to radiodermatitis in patients under radiotherapy treatment. Advances in Knowledge: This study is important to develop strategies to prevent radiation-induced skin reactions.

  17. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    International Nuclear Information System (INIS)

    Das, Suvarthi; Kumar, Ashutosh; Seth, Ratanesh Kumar; Tokar, Erik J.; Kadiiska, Maria B.; Waalkes, Michael P.; Mason, Ronald P.; Chatterjee, Saurabh

    2013-01-01

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates protein

  18. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    Energy Technology Data Exchange (ETDEWEB)

    Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Seth, Ratanesh Kumar [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Tokar, Erik J. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Waalkes, Michael P. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Mason, Ronald P. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

    2013-06-15

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates

  19. The Agricultural Antibiotic Carbadox Induces Phage-mediated Gene Transfer in Salmonella

    Directory of Open Access Journals (Sweden)

    Bradley L. Bearson

    2014-02-01

    Full Text Available Antibiotics are used for disease therapeutic or preventative effects in humans and animals, as well as for enhanced feed conversion efficiency in livestock. Antibiotics can also cause undesirable effects in microbial populations, including selection for antibiotic resistance, enhanced pathogen invasion, and stimulation of horizontal gene transfer. Carbadox is a veterinary antibiotic used in the U.S. during the starter phase of swine production for improved feed efficiency and control of swine dysentery and bacterial swine enteritis. Carbadox has been shown in vitro to induce phage-encoded Shiga toxin in Shiga toxin-producing Escherichia coli and a phage-like element transferring antibiotic resistance genes in Brachyspira hyodysenteriae, but the effect of carbadox on prophages in other bacteria is unknown. This study examined carbadox exposure on prophage induction and genetic transfer in Salmonella enterica serovar Typhimurium, a human foodborne pathogen that frequently colonizes swine without causing disease. S. Typhimurium LT2 exposed to carbadox induced prophage production, resulting in bacterial cell lysis and release of virions that were visible by electron microscopy. Carbadox induction of phage-mediated gene transfer was confirmed by monitoring the transduction of a sodCIII::neo cassette in the Fels-1 prophage from LT2 to a recipient Salmonella strain. Furthermore, carbadox frequently induced generalized transducing phages in multidrug-resistant phage type DT104 and DT120 isolates, resulting in the transfer of chromosomal and plasmid DNA that included antibiotic resistance genes. Our research indicates that exposure of Salmonella to carbadox induces prophages that can transfer virulence and antibiotic resistance genes to susceptible bacterial hosts. Carbadox-induced, phage-mediated gene transfer could serve as a contributing factor in bacterial evolution during animal production, with prophages being a reservoir for bacterial fitness

  20. Hypoxia-inducible factor 1-mediated human GATA1 induction promotes erythroid differentiation under hypoxic conditions.

    Science.gov (United States)

    Zhang, Feng-Lin; Shen, Guo-Min; Liu, Xiao-Ling; Wang, Fang; Zhao, Ying-Ze; Zhang, Jun-Wu

    2012-08-01

    Hypoxia-inducible factor promotes erythropoiesis through coordinated cell type-specific hypoxia responses. GATA1 is essential to normal erythropoiesis and plays a crucial role in erythroid differentiation. In this study, we show that hypoxia-induced GATA1 expression is mediated by HIF1 in erythroid cells. Under hypoxic conditions, significantly increased GATA1 mRNA and protein levels were detected in K562 cells and erythroid induction cultures of CD34(+) haematopoietic stem/progenitor cells. Enforced HIF1α expression increased GATA1 expression, while HIF1α knockdown by RNA interference decreased GATA1 expression. In silico analysis revealed one potential hypoxia response element (HRE). The results from reporter gene and mutation analysis suggested that this element is necessary for hypoxic response. Chromatin immunoprecipitation (ChIP)-PCR showed that the putative HRE was recognized and bound by HIF1 in vivo. These results demonstrate that the up-regulation of GATA1 during hypoxia is directly mediated by HIF1.The mRNA expression of some erythroid differentiation markers was increased under hypoxic conditions, but decreased with RNA interference of HIF1α or GATA1. Flow cytometry analysis also indicated that hypoxia, desferrioxamine or CoCl(2) induced expression of erythroid surface markers CD71 and CD235a, while expression repression of HIF1α or GATA1 by RNA interference led to a decreased expression of CD235a. These results suggested that HIF1-mediated GATA1 up-regulation promotes erythropoiesis in order to satisfy the needs of an organism under hypoxic conditions. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  1. Lentiviral-mediated administration of IL-25 in the CNS induces alternative activation of microglia

    DEFF Research Database (Denmark)

    Maiorino, C; Khorooshi, R; Ruffini, F

    2013-01-01

    Interleukin-25 (IL-25) is the only anti-inflammatory cytokine of the IL-17 family, and it has been shown to be efficacious in inhibiting neuroinflammation. Known for its effects on cells of the adaptive immune system, it has been more recently described to be effective also on cells of the innate...... was partly inhibited and the CNS protected from immune-mediated damage. To our knowledge, this is the first example of M2 shift (alternative activation) induced in vivo on CNS-resident myeloid cells by gene therapy, and may constitute a promising strategy to investigate the potential role of protective...

  2. Surface grafting via photo-induced copper-mediated radical polymerization at extremely low catalyst concentrations

    Czech Academy of Sciences Publication Activity Database

    Laun, J.; Vorobii, Mariia; de los Santos Pereira, Andres; Pop-Georgievski, Ognen; Trouillet, V.; Welle, A.; Barner-Kowollik, C.; Rodriguez-Emmenegger, Cesar; Junkers, T.

    2015-01-01

    Roč. 36, č. 18 (2015), s. 1681-1686 ISSN 1022-1336 R&D Projects: GA ČR(CZ) GJ15-09368Y; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : copper-mediated polymerization * photo-induced polymerization * polymer brushes Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.638, year: 2015

  3. Caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress.

    Science.gov (United States)

    Zhang, Qiang; Liu, Jianing; Chen, Shulan; Liu, Jing; Liu, Lijuan; Liu, Guirong; Wang, Fang; Jiang, Wenxin; Zhang, Caixia; Wang, Shuangyu; Yuan, Xiao

    2016-04-01

    It is well recognized that mandibular growth, which is caused by a variety of functional appliances, is considered to be the result of both neuromuscular and skeletal adaptations. Accumulating evidence has demonstrated that apoptosis plays an important role in the adaptation of skeletal muscle function. However, the underlying mechanism of apoptosis that is induced by stretch continues to be incompletely understood. Endoplasmic reticulum stress (ERS), a newly defined signaling pathway, initiates apoptosis. This study seeks to determine if caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress in myoblast and its underlying mechanism. Apoptosis was assessed by Hochest staining, DAPI staining and annexin V binding and PI staining. ER chaperones, such as GRP78, CHOP and caspase-12, were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Furthermore, caspase-12 inhibitor was used to value the mechanism of the caspase-12 pathway. Apoptosis of myoblast, which is subjected to cyclic stretch, was observed in a time-dependent manner. We found that GRP78 mRNA and protein were significantly increased and CHOP and caspase-12 were activated in myoblast that was exposed to cyclic stretch. Caspase-12 inhibition reduced stretch-induced apoptosis, and caspase-12 activated caspase-3 to induce apoptosis. We concluded that caspase-12 played an important role in stretch-induced apoptosis that is associated by endoplasmic reticulum stress by activating caspase-3.

  4. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  5. Role of inducers in detection of blaPDC-mediated oxyimino-cephalosporin resistance in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Birson Ingti

    2017-01-01

    Interpretation & conclusions: P. aeruginosa harbouring inducible (chromosomal and plasmid-mediated AmpC β-lactamase is a matter of concern as it may limit therapeutic option. Using cefoxitin-ceftazidime-based test is simple and may be used for detecting inducible AmpC β-lactamase amongst P. aeruginosa.

  6. CD36 Mediated Fatty Acid-Induced Podocyte Apoptosis via Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Wei Hua

    Full Text Available Hyperlipidemia-induced apoptosis mediated by fatty acid translocase CD36 is associated with increased uptake of ox-LDL or fatty acid in macrophages, hepatocytes and proximal tubular epithelial cells, leading to atherosclerosis, liver damage and fibrosis in obese patients, and diabetic nephropathy (DN, respectively. However, the specific role of CD36 in podocyte apoptosis in DN with hyperlipidemia remains poorly investigated.The expression of CD36 was measured in paraffin-embedded kidney tissue samples (Ctr = 18, DN = 20 by immunohistochemistry and immunofluorescence staining. We cultured conditionally immortalized mouse podocytes (MPC5 and treated cells with palmitic acid, and measured CD36 expression by real-time PCR, Western blot analysis and immunofluorescence; lipid uptake by Oil red O staining and BODIPY staining; apoptosis by flow cytometry assay, TUNEL assay and Western blot analysis; and ROS production by DCFH-DA fluorescence staining. All statistical analyses were performed using SPSS 21.0 statistical software.CD36 expression was increased in kidney tissue from DN patients with hyperlipidemia. Palmitic acid upregulated CD36 expression and promoted its translocation from cytoplasm to plasma membrane in podocytes. Furthermore, palmitic acid increased lipid uptake, ROS production and apoptosis in podocytes, Sulfo-N-succinimidyloleate (SSO, the specific inhibitor of the fatty acid binding site on CD36, decreased palmitic acid-induced fatty acid accumulation, ROS production, and apoptosis in podocytes. Antioxidant 4-hydroxy-2,2,6,6- tetramethylpiperidine -1-oxyl (tempol inhibited the overproduction of ROS and apoptosis in podocytes induced by palmitic acid.CD36 mediated fatty acid-induced podocyte apoptosis via oxidative stress might participate in the process of DN.

  7. Hypothalamic CaMKKβ mediates glucagon anorectic effect and its diet-induced resistance

    Science.gov (United States)

    Quiñones, Mar; Al-Massadi, Omar; Gallego, Rosalía; Fernø, Johan; Diéguez, Carlos; López, Miguel; Nogueiras, Ruben

    2015-01-01

    Objective Glucagon receptor antagonists and humanized glucagon antibodies are currently studied as promising therapies for obesity and type II diabetes. Among its variety of actions, glucagon reduces food intake, but the molecular mechanisms mediating this effect as well as glucagon resistance are totally unknown. Methods Glucagon and adenoviral vectors were administered in specific hypothalamic nuclei of lean and diet-induced obese rats. The expression of neuropeptides controlling food intake was performed by in situ hybridization. The regulation of factors of the glucagon signaling pathway was assessed by western blot. Results The central injection of glucagon decreased feeding through a hypothalamic pathway involving protein kinase A (PKA)/Ca2+-calmodulin-dependent protein kinase kinase β (CaMKKβ)/AMP-activated protein kinase (AMPK)-dependent mechanism. More specifically, the central injection of glucagon increases PKA activity and reduces protein levels of CaMKKβ and its downstream target phosphorylated AMPK in the hypothalamic arcuate nucleus (ARC). Consistently, central glucagon significantly decreased AgRP expression. Inhibition of PKA and genetic activation of AMPK in the ARC blocked glucagon-induced anorexia in lean rats. Genetic down-regulation of glucagon receptors in the ARC stimulates fasting-induced hyperphagia. Although glucagon was unable to decrease food intake in DIO rats, glucagon sensitivity was restored after inactivation of CaMKKβ, specifically in the ARC. Thus, glucagon decreases food intake acutely via PKA/CaMKKβ/AMPK dependent pathways in the ARC, and CaMKKβ mediates its obesity-induced hypothalamic resistance. Conclusions This work reveals the molecular underpinnings by which glucagon controls feeding that may lead to a better understanding of disease states linked to anorexia and cachexia. PMID:26909312

  8. Mast cell mediators in citric acid-induced airway constriction of guinea pigs

    International Nuclear Information System (INIS)

    Lin, C.-H.; Lai, Y.-L.

    2005-01-01

    We demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. In this study, we further investigated the underlying mediator(s) for this type of airway constriction. At first, to examine effects caused by blocking agents, 67 young Hartley guinea pigs were divided into 7 groups: saline + CA; methysergide (serotonin receptor antagonist) + CA; MK-886 (leukotriene synthesis inhibitor) + CA; mepyramine (histamine H 1 receptor antagonist) + CA; indomethacin (cyclooxygenase inhibitor) + CA; cromolyn sodium (mast cell stabilizer) + CA; and compound 48/80 (mast cell degranulating agent) + CA. Then, we tested whether leukotriene C 4 (LTC 4 ) or histamine enhances CA-induced airway constriction in compound 48/80-pretreated guinea pigs. We measured dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV 0.1 ) during either baseline or recovery period. In addition, we detected histamine level, an index of pulmonary mast cell degranulation, in bronchoalveolar lavage (BAL) samples. Citric acid aerosol inhalation caused decreases in Crs and FEV 0.1 , indicating airway constriction in the control group. This airway constriction was significantly attenuated by MK-886, mepyramine, cromolyn sodium, and compound 48/80, but not by either methysergide or indomethacin. Both LTC 4 and histamine infusion significantly increased the magnitude of CA-induced airway constriction in compound 48/80-pretreated guinea pigs. Citric acid inhalation caused significant increase in histamine level in the BAL sample, which was significantly suppressed by compound 48/80. These results suggest that leukotrienes and histamine originating from mast cells play an important role in CA inhalation-induced noncholinergic airway constriction

  9. IL-27 induces a pro-inflammatory response in human fetal membranes mediating preterm birth.

    Science.gov (United States)

    Yin, Nanlin; Wang, Hanbing; Zhang, Hua; Ge, Huisheng; Tan, Bing; Yuan, Yu; Luo, Xiaofang; Olson, David M; Baker, Philip N; Qi, Hongbo

    2017-09-01

    Inflammation at the maternal-fetal interface has been shown to be involved in the pathogenesis of preterm birth. Interleukin 27 (IL-27), a heterodimeric cytokine, is known to mediate an inflammatory response in some pregnancy complications. In this study, we aimed to determine whether IL-27 could induce an inflammatory reaction at the maternal-fetal interface that would mediate the onset of preterm birth. We found elevated expression of IL-27 in human peripheral serum and elevated expression of its specific receptor (wsx-1) on fetal membranes in cases of preterm birth. Moreover, the release of inflammatory markers (CXCL10, IFN-γ, MCP-1, IL-6, IL-1β and TNF-α), especially CXCL10, was markedly augmented upon stimulation of IL-27 in the fetal membranes. Additionally, IL-27 and IFN-γ cooperated to amplify the expression of CXCL10 in the fetal membranes. Moreover, the production of CXCL10 was increased in IL-27-treated fetal membrane through JNK, PI3K or Erk signaling pathways. Finally, MMP2 and MMP9 were activated by IL-27 in human fetal membranes, which may be related to the onset of preterm premature rupture of membranes (pPROM). In conclusion, for the first time, we reported that the aberrant expression of IL-27 could mediate an excessive inflammatory response in fetal membranes through the JNK, PI3K or Erk signaling pathways, which contributes to preterm birth. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Attenuated RANKL-induced cytotoxicity by Portulaca oleracea ethanol extract enhances RANKL-mediated osteoclastogenesis.

    Science.gov (United States)

    Erkhembaatar, Munkhsoyol; Choi, Eun-Joo; Lee, Hak-Yong; Lee, Choong Hun; Lee, Young-Rae; Kim, Min Seuk

    2015-07-14

    Portulaca oleracea (PO) has been widely used as traditional medicine because of its pharmacological activities. However, the effects of PO on osteoclasts that modulate bone homeostasis are still elusive. In this study, we examined the effects of PO ethanol extract (POEE) on receptor activator of nuclear factor-κB ligand (RANKL)-mediated Ca(2+) mobilization, nuclear factor of activated T-cell c1 (NFATc1) amplification, tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cell (MNC) formation, and cytotoxicity. Our results demonstrated that POEE suppressed RANKL-induced Ca(2+) oscillations by inhibition of Ca(2+) release from internal Ca(2+) stores, resulting in reduction of NFATc1 amplification. Notably, POEE attenuated RANKL-mediated cytotoxicity and cleavage of polyadenosine 5'-diphosphate-ribose polymerase (PARP), resulted in enhanced formation of TRAP+ MNCs. These results present in vitro effects of POEE on RANKL-mediated osteoclastogenesis and suggest the possible use of PO in treating bone disorders, such as osteopetrosis.

  11. AAV-mediated knock-down of HRC exacerbates transverse aorta constriction-induced heart failure.

    Directory of Open Access Journals (Sweden)

    Chang Sik Park

    Full Text Available Histidine-rich calcium binding protein (HRC is located in the lumen of sarcoplasmic reticulum (SR that binds to both triadin (TRN and SERCA affecting Ca(2+ cycling in the SR. Chronic overexpression of HRC that may disrupt intracellular Ca(2+ homeostasis is implicated in pathogenesis of cardiac hypertrophy. Ablation of HRC showed relatively normal phenotypes under basal condition, but exhibited a significantly increased susceptibility to isoproterenol-induced cardiac hypertrophy. In the present study, we characterized the functions of HRC related to Ca(2+ cycling and pathogenesis of cardiac hypertrophy using the in vitro siRNA- and the in vivo adeno-associated virus (AAV-mediated HRC knock-down (KD systems, respectively.AAV-mediated HRC-KD system was used with or without C57BL/6 mouse model of transverse aortic constriction-induced failing heart (TAC-FH to examine whether HRC-KD could enhance cardiac function in failing heart (FH. Initially we expected that HRC-KD could elicit cardiac functional recovery in failing heart (FH, since predesigned siRNA-mediated HRC-KD enhanced Ca(2+ cycling and increased activities of RyR2 and SERCA2 without change in SR Ca(2+ load in neonatal rat ventricular cells (NRVCs and HL-1 cells. However, AAV9-mediated HRC-KD in TAC-FH was associated with decreased fractional shortening and increased cardiac fibrosis compared with control. We found that phospho-RyR2, phospho-CaMKII, phospho-p38 MAPK, and phospho-PLB were significantly upregulated by HRC-KD in TAC-FH. A significantly increased level of cleaved caspase-3, a cardiac cell death marker was also found, consistent with the result of TUNEL assay.Increased Ca(2+ leak and cytosolic Ca(2+ concentration due to a partial KD of HRC could enhance activity of CaMKII and phosphorylation of p38 MAPK, causing the mitochondrial death pathway observed in TAC-FH. Our results present evidence that down-regulation of HRC could deteriorate cardiac function in TAC-FH through

  12. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Science.gov (United States)

    Calvo, Jennifer A; Moroski-Erkul, Catherine A; Lake, Annabelle; Eichinger, Lindsey W; Shah, Dharini; Jhun, Iny; Limsirichai, Prajit; Bronson, Roderick T; Christiani, David C; Meira, Lisiane B; Samson, Leona D

    2013-04-01

    Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER) is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG) mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  13. CISH is induced during DC development and regulates DC-mediated CTL activation.

    Science.gov (United States)

    Miah, Mohammad Alam; Yoon, Cheol-Hee; Kim, Joonoh; Jang, Jinah; Seong, Young-Rim; Bae, Yong-Soo

    2012-01-01

    The cytokine inducible SH2-domain protein (CISH) is a well-known STAT5 target gene, but its role in the immune system remains uncertain. In this study, we found that CISH is predominantly induced during dendritic cell (DC) development from mouse bone marrow (BM) cells and plays a crucial role in type 1 DC development and DC-mediated CTL activation. CISH knockdown reduced the expression of MHC class I, co-stimulatory molecules and pro-inflammatory cytokines in BMDCs. Meanwhile, the DC yield was markedly enhanced by CISH knockdown via cell-cycle activation and reduction of cell apoptosis. Down-regulation of cell proliferation at the later stage of DC development was found to be associated with CISH-mediated negative feedback regulation of STAT5 activation. In T-cell immunity, OT-1 T-cell proliferation was significantly reduced by CISH knockdown in DCs, whereas OT-2 T-cell proliferation was not affected by CISH knockdown. CTLs generated by DC vaccination were also markedly reduced by CISH knockdown, followed by significant impairment of DC-based tumor immunotherapy. Taken together, our data suggest that CISH expression at the later stage of DC development triggers the shutdown of DC progenitor cell proliferation and facilitates DC differentiation into a potent stimulator of CTLs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Directory of Open Access Journals (Sweden)

    Jennifer A Calvo

    2013-04-01

    Full Text Available Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  15. Intercellular and intracellular signaling pathways mediating ionizing radiation-induced bystander effects

    International Nuclear Information System (INIS)

    Hamada, Nobuyuki; Hara, Takamitsu; Kobayashi, Yasuhiko; Matsumoto, Hideki

    2007-01-01

    A rapidly growing body of experimental evidence indicates that ionizing radiation induces biological effects in non-irradiated bystander cells that have received signals from adjacent or distant irradiated cells. This phenomenon, which has been termed the ionizing radiation-induced bystander effect, challenges the long-standing paradigm that radiation traversal through the nucleus of a cell is a prerequisite to elicit genetic damage or a biological response. Bystander effects have been observed in a number of experimental systems, and cells whose nucleus or cytoplasm is irradiated exert bystander responses. Bystander cells manifest a multitude of biological consequences, such as genetic and epigenetic changes, alterations in gene expression, activation of signal transduction pathways, and delayed effects in their progeny. Several mediating mechanisms have been proposed. These involve gap junction-mediated intercellular communication, secreted soluble factors, oxidative metabolism, plasma membrane-bound lipid rafts, and calcium fluxes. This paper reviews briefly the current knowledge of the bystander effect with a focus on proposed mechanisms. The potential benefit of bystander effects to cancer radiotherapy will also be discussed. (author)

  16. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    International Nuclear Information System (INIS)

    Souza, C.F.; Carneiro, A.B.; Silveira, A.B.; Laranja, G.A.T.; Silva-Neto, M.A.C.; Costa, S.C. Goncalves da; Paes, M.C.

    2009-01-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  17. Electroacupuncture preconditioning-induced neuroprotection may be mediated by glutamate transporter type 2.

    Science.gov (United States)

    Zhu, Xiaoling; Yin, Jinbo; Li, Liaoliao; Ma, Lei; Tan, Hongying; Deng, Jiao; Chen, Shaoyang; Zuo, Zhiyi

    2013-10-01

    Electroacupuncture has been shown to induce a preconditioning effect in the brain. The mechanisms for this protection are not fully elucidated. We hypothesize that this protection is mediated by excitatory amino acid transporters (EAATs) that have been shown to be neuroprotective. To test this hypothesis, two-month old male Sprague-Dawley rats and EAAT type 3 (EAAT3) knockout mice received or did not receive 30-min electroacupuncture once a day for five consecutive days. They were subjected to a 120-min middle cerebral arterial occlusion (MCAO) at 24h after the last electroacupuncture. Neurological outcome was assessed 2days after the MCAO. Brain tissues were harvested at 24h after the last electroacupuncture for Western blotting. Rats subjected to electroacupuncture at the Baihui acupoint had smaller brain infarct volumes and better neurological deficit scores than control rats. Electroacupuncture increased EAAT type 2 (EAAT2) in the cerebral cortex, tended to increase EAAT3 in the hippocampus, and had no effect on EAAT type 1 expression. Dihydrokainate, an EAAT2 inhibitor, worsened the neurological outcome of rats with electroacupuncture pretreatment. Electroacupuncture pretreatment at the Baihui acupoint increased EAAT2 in the cerebral cortex and improved the neurological outcome of EAAT3 knockout mice. Together, our results suggest that EAAT2 may mediate the electroacupuncture preconditioning-induced neuroprotection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    Energy Technology Data Exchange (ETDEWEB)

    Souza, C.F. [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Carneiro, A.B.; Silveira, A.B. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); Laranja, G.A.T. [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); Silva-Neto, M.A.C. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); INCT, Entomologia Molecular (Brazil); Costa, S.C. Goncalves da [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Paes, M.C., E-mail: mcpaes@uerj.br [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); INCT, Entomologia Molecular (Brazil)

    2009-12-18

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  19. Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

    Science.gov (United States)

    Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

    2018-01-01

    Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

  20. Reactive oxygen species mediates homocysteine-induced mitochondrial biogenesis in human endothelial cells: Modulation by antioxidants

    International Nuclear Information System (INIS)

    Perez-de-Arce, Karen; Foncea, Rocio; Leighton, Federico

    2005-01-01

    It has been proposed that homocysteine (Hcy)-induces endothelial dysfunction and atherosclerosis by generation of reactive oxygen species (ROS). A previous report has shown that Hcy promotes mitochondrial damage. Considering that oxidative stress can affect mitochondrial biogenesis, we hypothesized that Hcy-induced ROS in endothelial cells may lead to increased mitochondrial biogenesis. We found that Hcy-induced ROS (1.85-fold), leading to a NF-κB activation and increase the formation of 3-nitrotyrosine. Furthermore, expression of the mitochondrial biogenesis factors, nuclear respiratory factor-1 and mitochondrial transcription factor A, was significantly elevated in Hcy-treated cells. These changes were accompanied by increase in mitochondrial mass and higher mRNA and protein expression of the subunit III of cytochrome c oxidase. These effects were significantly prevented by pretreatment with the antioxidants, catechin and trolox. Taken together, our results suggest that ROS is an important mediator of mitochondrial biogenesis induced by Hcy, and that modulation of oxidative stress by antioxidants may protect against the adverse vascular effects of Hcy

  1. Is there a role for leukotrienes as mediators of ethanol-induced gastric mucosal damage?

    International Nuclear Information System (INIS)

    Wallace, J.L.; Beck, P.L.; Morris, G.P.

    1988-01-01

    The role of leukotriene (LT) C 4 as a mediator of ethanol-induced gastric mucosal damage was investigated. Rats were pretreated with a number of compounds, including inhibitors of leukotriene biosynthesis and agents that have previously been shown to reduce ethanol-induced damage prior to oral administration of absolute ethanol. Ethanol administration resulted in a fourfold increase in LTC 4 synthesis. LTC 4 synthesis could be reduced significantly by pretreatment with L651,392 or dexamethosone without altering the susceptibility of the gastric mucosa to ethanol-induced damage. Furthermore, changes in LBT 4 synthesis paralleled the changes in LTC 4 synthesis observed after ethanol administration. The effects of ethanol on gastric eicosanoid synthesis were further examined using an ex vivo gastric chamber preparation that allowed for application of ethanol to only one side of the stomach. These studies confirm that ethanol can stimulate gastric leukotriene synthesis independent of the production of hemorrhagic damage. Inhibition of LTC 4 synthesis does not confer protection to the mucosa, suggesting that LTC 4 does not play an important role in the etiology of ethanol-induced gastric damage

  2. The mitochondrial pyruvate carrier mediates high fat diet-induced increases in hepatic TCA cycle capacity.

    Science.gov (United States)

    Rauckhorst, Adam J; Gray, Lawrence R; Sheldon, Ryan D; Fu, Xiaorong; Pewa, Alvin D; Feddersen, Charlotte R; Dupuy, Adam J; Gibson-Corley, Katherine N; Cox, James E; Burgess, Shawn C; Taylor, Eric B

    2017-11-01

    Excessive hepatic gluconeogenesis is a defining feature of type 2 diabetes (T2D). Most gluconeogenic flux is routed through mitochondria. The mitochondrial pyruvate carrier (MPC) transports pyruvate from the cytosol into the mitochondrial matrix, thereby gating pyruvate-driven gluconeogenesis. Disruption of the hepatocyte MPC attenuates hyperglycemia in mice during high fat diet (HFD)-induced obesity but exerts minimal effects on glycemia in normal chow diet (NCD)-fed conditions. The goal of this investigation was to test whether hepatocyte MPC disruption provides sustained protection from hyperglycemia during long-term HFD and the differential effects of hepatocyte MPC disruption on TCA cycle metabolism in NCD versus HFD conditions. We utilized long-term high fat feeding, serial measurements of postabsorptive blood glucose and metabolomic profiling and 13 C-lactate/ 13 C-pyruvate tracing to investigate the contribution of the MPC to hyperglycemia and altered hepatic TCA cycle metabolism during HFD-induced obesity. Hepatocyte MPC disruption resulted in long-term attenuation of hyperglycemia induced by HFD. HFD increased hepatic mitochondrial pyruvate utilization and TCA cycle capacity in an MPC-dependent manner. Furthermore, MPC disruption decreased progression of fibrosis and levels of transcript markers of inflammation. By contributing to chronic hyperglycemia, fibrosis, and TCA cycle expansion, the hepatocyte MPC is a key mediator of the pathophysiology induced in the HFD model of T2D. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  3. UV-B Radiation Induces Root Bending Through the Flavonoid-Mediated Auxin Pathway in Arabidopsis.

    Science.gov (United States)

    Wan, Jinpeng; Zhang, Ping; Wang, Ruling; Sun, Liangliang; Wang, Wenying; Zhou, Huakun; Xu, Jin

    2018-01-01

    Ultraviolet (UV)-B radiation-induced root bending has been reported; however, the underlying mechanisms largely remain unclear. Here, we investigate whether and how auxin and flavonoids are involved in UV-B radiation-induced root bending in Arabidopsis using physiological, pharmacological, and genetic approaches. UV-B radiation modulated the direction of root growth by decreasing IAA biosynthesis and affecting auxin distribution in the root tips, where reduced auxin accumulation and asymmetric auxin distribution were observed. UV-B radiation increased the distribution of auxin on the nonradiated side of the root tips, promoting growth and causing root bending. Further analysis indicated that UV-B induced an asymmetric accumulation of flavonoids; this pathway is involved in modulating the accumulation and asymmetric distribution of auxin in root tips and the subsequent redirection of root growth by altering the distribution of auxin carriers in response to UV-B radiation. Taken together, our results indicate that UV-B radiation-induced root bending occurred through a flavonoid-mediated phototropic response to UV-B radiation.

  4. Artemisinin induces ROS-mediated caspase3 activation in ASTC-a-1 cells

    Science.gov (United States)

    Xiao, Feng-Lian; Chen, Tong-Sheng; Qu, Jun-Le; Liu, Cheng-Yi

    2010-02-01

    Artemisinin (ART), an antimalarial phytochemical from the sweet wormwood plant or a naturally occurring component of Artemisia annua, has been shown a potential anticancer activity by apoptotic pathways. In our report, cell counting kit (CCK-8) assay showed that treatment of human lung adenocarcinoma (ASTC-a-1) cells with ART effectively increase cell death by inducing apoptosis in a time- and dose-dependent fashion. Hoechst 33258 staining was used to detect apoptosis as well. Reactive oxygen species (ROS) generation was observed in cells exposed to ART at concentrations of 400 μM for 48 h. N-acetyl-L-cysteine (NAC), an oxygen radical scavenger, suppressed the rate of ROS generation and inhibited the ART-induced apoptosis. Moreover, AFC assay (Fluorometric assay for Caspase3 activity) showed that ROS was involved in ART-induced caspase3 acitvation. Taken together, our data indicate that ART induces ROS-mediated caspase3 activation in a time-and dose-dependent way in ASCT-a-1 cells.

  5. BIM is the primary mediator of MYC-induced apoptosis in multiple solid tissues.

    Science.gov (United States)

    Muthalagu, Nathiya; Junttila, Melissa R; Wiese, Katrin E; Wolf, Elmar; Morton, Jennifer; Bauer, Barbara; Evan, Gerard I; Eilers, Martin; Murphy, Daniel J

    2014-09-11

    MYC is one of the most frequently overexpressed oncogenes in human cancer, and even modestly deregulated MYC can initiate ectopic proliferation in many postmitotic cell types in vivo. Sensitization of cells to apoptosis limits MYC's oncogenic potential. However, the mechanism through which MYC induces apoptosis is controversial. Some studies implicate p19ARF-mediated stabilization of p53, followed by induction of proapoptotic BH3 proteins NOXA and PUMA, whereas others argue for direct regulation of BH3 proteins, especially BIM. Here, we use a single experimental system to systematically evaluate the roles of p19ARF and BIM during MYC-induced apoptosis, in vitro, in vivo, and in combination with a widely used chemotherapeutic, doxorubicin. We find a common specific requirement for BIM during MYC-induced apoptosis in multiple settings, which does not extend to the p53-responsive BH3 family member PUMA, and find no evidence of a role for p19ARF during MYC-induced apoptosis in the tissues examined. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  6. BAK overexpression mediates p53-independent apoptosis inducing effects on human gastric cancer cells

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2004-07-01

    Full Text Available Abstract Background BAK (Bcl-2 homologous antagonist/killer is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Methods Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53 and MKN-28 (mutant-type p53. RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. Results BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G0/G1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45, or in p53 mutant-type (MKN-28 gastric cancer cells. Conclusions The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies.

  7. BAK overexpression mediates p53-independent apoptosis inducing effects on human gastric cancer cells

    International Nuclear Information System (INIS)

    Tong, Qiang-Song; Zheng, Li-Duan; Wang, Liang; Liu, Jun; Qian, Wei

    2004-01-01

    BAK (Bcl-2 homologous antagonist/killer) is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G 0 /G 1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45), or in p53 mutant-type (MKN-28) gastric cancer cells. The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies

  8. Mast cell chymase induces smooth muscle cell apoptosis by disrupting NF-κB-mediated survival signaling

    International Nuclear Information System (INIS)

    Leskinen, Markus J.; Heikkilae, Hanna M.; Speer, Mei Y.; Hakala, Jukka K.; Laine, Mika; Kovanen, Petri T.; Lindstedt, Ken A.

    2006-01-01

    Chymase released from activated mast cells induces apoptosis of vascular smooth muscle cells (SMCs) in vitro by degrading the pericellular matrix component fibronectin, so causing disruption of focal adhesion complexes and Akt dephosphorylation, which are necessary for cell adhesion and survival. However, the molecular mechanisms of chymase-mediated apoptosis downstream of Akt have remained elusive. Here, we show by means of RT-PCR, Western blotting, EMSA, immunocytochemistry and confocal microscopy, that chymase induces SMC apoptosis by disrupting NF-κB-mediated survival signaling. Following chymase treatment, the translocation of active NF-κB/p65 to the nucleus was partly abolished and the amount of nuclear p65 was reduced. Pretreatment of SMCs with chymase also inhibited LPS- and IL-1β-induced nuclear translocation of p65. The chymase-induced degradation of p65 was mediated by active caspases. Loss of NF-κB-mediated transactivation resulted in downregulation of bcl-2 mRNA and protein expression, leading to mitochondrial swelling and release of cytochrome c. The apoptotic process involved activation of both caspase 9 and caspase 8. The results reveal that, by disrupting the NF-κB-mediated survival-signaling pathway, activated chymase-secreting mast cells can mediate apoptosis of cultured arterial SMCs. Since activated mast cells colocalize with apoptotic SMCs in vulnerable areas of human atherosclerotic plaques, they may participate in the weakening and rupture of atherosclerotic plaques

  9. Amphiregulin mediates hCG-induced StAR expression and progesterone production in human granulosa cells

    OpenAIRE

    Fang, Lanlan; Yu, Yiping; Zhang, Ruizhe; He, Jingyan; Sun, Ying-Pu

    2016-01-01

    Progesterone plays critical roles in maintaining a successful pregnancy at the early embryonic stage. Human chorionic gonadotropin (hCG) rapidly induces amphiregulin (AREG) expression. However, it remains unknown whether AREG mediates hCG-induced progesterone production. Thus, the objective of this study was to investigate the role of AREG in hCG-induced progesterone production and the underlying molecular mechanism in human granulosa cells; primary cells were used as the experimental model. ...

  10. Light-induced, GTP-binding protein mediated membrane currents of Xenopus oocytes injected with rhodopsin of cephalopods.

    Science.gov (United States)

    Ando, H; Seidou, M; Kito, Y

    1991-01-01

    Xenopus oocytes that were injected with rhabdomeric membranes of squid and octopus photoreceptors acquired light sensitivity. The injected oocytes showed a light-induced current having characteristics similar to other G-protein-mediated Cl- currents induced by the activation of other membrane receptors. Pretreatment of the oocytes with pertussis toxin before the injection suppressed the generation of the light-induced current, indicating an ability of cephalopod rhodopsin to cross-react with an endogenous G-protein of Xenopus oocytes.

  11. Telomere-mediated chromosomal instability triggers TLR4 induced inflammation and death in mice.

    Directory of Open Access Journals (Sweden)

    Rabindra N Bhattacharjee

    Full Text Available BACKGROUND: Telomeres are essential to maintain chromosomal stability. Cells derived from mice lacking telomerase RNA component (mTERC-/- mice display elevated telomere-mediated chromosome instability. Age-dependent telomere shortening and associated chromosome instability reduce the capacity to respond to cellular stress occurring during inflammation and cancer. Inflammation is one of the important risk factors in cancer progression. Controlled innate immune responses mediated by Toll-like receptors (TLR are required for host defense against infection. Our aim was to understand the role of chromosome/genome instability in the initiation and maintenance of inflammation. METHODOLOGY/PRINCIPAL FINDINGS: We examined the function of TLR4 in telomerase deficient mTERC-/- mice harbouring chromosome instability which did not develop any overt immunological disorder in pathogen-free condition or any form of cancers at this stage. Chromosome instability was measured in metaphase spreads prepared from wildtype (mTERC+/+, mTERC+/- and mTERC-/- mouse splenocytes. Peritoneal and/or bone marrow-derived macrophages were used to examine the responses of TLR4 by their ability to produce inflammatory mediators TNFalpha and IL6. Our results demonstrate that TLR4 is highly up-regulated in the immune cells derived from telomerase-null (mTERC-/- mice and lipopolysaccharide, a natural ligand for TLR4 stabilises NF-kappaB binding to its promoter by down-regulating ATF-3 in mTERC-/- macrophages. CONCLUSIONS/SIGNIFICANCE: Our findings implied that background chromosome instability in the cellular level stabilises the action of TLR4-induced NF-kappaB action and sensitises cells to produce excess pro-inflammatory mediators. Chromosome/genomic instability data raises optimism for controlling inflammation by non-toxic TLR antagonists among high-risk groups.

  12. Hypoxia-inducible factor-dependent production of profibrotic mediators by hypoxic hepatocytes.

    Science.gov (United States)

    Copple, Bryan L; Bustamante, Juan J; Welch, Timothy P; Kim, Nam Deuk; Moon, Jeon-Ok

    2009-08-01

    During the development of liver fibrosis, mediators are produced that stimulate cells in the liver to differentiate into myofibroblasts and to produce collagen. Recent studies demonstrated that the transcription factor, hypoxia-inducible factor-1alpha (HIF-1alpha), is critical for upregulation of profibrotic mediators, such as platelet-derived growth factor-A (PDGF-A), PDGF-B and plasminogen activator inhibitor-1 (PAI-1) in the liver, during the development of fibrosis. What remains unknown is the cell type-specific regulation of these genes by HIF-1alpha in liver cell types. Accordingly, the hypothesis was tested that HIF-1alpha is activated in hypoxic hepatocytes and regulates the production of profibrotic mediators by these cells. In this study, hepatocytes were isolated from the livers of control and HIF-1alpha- or HIF-1beta-deficient mice and exposed to hypoxia. Exposure of primary mouse hepatocytes to 1% oxygen stimulated nuclear accumulation of HIF-1alpha and upregulated PAI-1, vascular endothelial cell growth factor and the vasoactive peptides adrenomedullin-1 (ADM-1) and ADM-2. In contrast, the levels of PDGF-A and PDGF-B mRNAs were unaffected in these cells by hypoxia. Exposure of HIF-1alpha-deficient hepatocytes to 1% oxygen only partially prevented upregulation of these genes, suggesting that other hypoxia-regulated transcription factors, such as HIF-2alpha, may also regulate these genes. In support of this, HIF-2alpha was activated in hypoxic hepatocytes, and exposure of HIF-1beta-deficient hepatocytes to 1% oxygen completely prevented upregulation of PAI-1, vascular endothelial cell growth factor and ADM-1, suggesting that HIF-2alpha may also contribute to upregulation of these genes in hypoxic hepatocytes. Collectively, our results suggest that HIFs may be important regulators of profibrotic and vasoactive mediators by hypoxic hepatocytes.

  13. Endoplasmic reticulum (ER) stress and cAMP/PKA pathway mediated Zn-induced hepatic lipolysis.

    Science.gov (United States)

    Song, Yu-Feng; Hogstrand, Christer; Wei, Chuan-Chuan; Wu, Kun; Pan, Ya-Xiong; Luo, Zhi

    2017-09-01

    The present study was performed to determine the effect of Zn exposure influencing endoplasmic reticulum (ER) stress, explore the underlying molecular mechanism of Zn-induced hepatic lipolysis in a fish species of significance for aquaculture, yellow catfish Pelteobagrus fulvidraco. We found that waterborne Zn exposure evoked ER stress and unfolded protein response (UPR), and activated cAMP/PKA pathway, and up-regulated hepatic lipolysis. The increase in ER stress and lipolysis were associated with activation of cAMP/PKA signaling pathway. Zn also induced an increase in intracellular Ca 2+ level, which could be partially prevented by dantrolene (RyR receptor inhibitor) and 2-APB (IP3 receptor inhibitor), demonstrating that the disturbed Ca 2+ homeostasis in ER contributed to ER stress and dysregulation of lipolysis. Inhibition of ER stress by PBA attenuated UPR, inhibited the activation of cAMP/PKA pathway and resulted in down-regulation of lipolysis. Inhibition of protein kinase RNA-activated-like ER kinase (PERK) by GSK2656157 and inositol-requiring enzyme (IRE) by STF-083010 differentially influenced Zn-induced changes of lipid metabolism, indicating that PERK and IRE pathways played different regulatory roles in Zn-induced lipolysis. Inhibition of PKA by H89 blocked the Zn-induced activation of cAMP/PKA pathway with a concomitant inhibition of ER stress-mediated lipolysis. Taken together, our findings highlight the importance of the ER stress-cAMP/PKA axis in Zn-induced lipolysis, which provides new insights into Zn toxicology in fish and probably in other vertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. PGE2-induced colon cancer growth is mediated by mTORC1

    International Nuclear Information System (INIS)

    Dufour, Marc; Faes, Seraina; Dormond-Meuwly, Anne; Demartines, Nicolas; Dormond, Olivier

    2014-01-01

    Highlights: • PGE 2 activates mTORC1 in colon cancer cells. • Inhibition of mTORC1 blocks PGE 2 induced colon cancer cell growth. • mTORC1 is a signaling intermediary in PGE 2 induced colon cancer cell responses. - Abstract: The inflammatory prostaglandin E 2 (PGE 2 ) cytokine plays a key role in the development of colon cancer. Several studies have shown that PGE 2 directly induces the growth of colon cancer cells and furthermore promotes tumor angiogenesis by increasing the production of the vascular endothelial growth factor (VEGF). The signaling intermediaries implicated in these processes have however not been fully characterized. In this report, we show that the mechanistic target of rapamycin complex 1 (mTORC1) plays an important role in PGE 2 -induced colon cancer cell responses. Indeed, stimulation of LS174T cells with PGE 2 increased mTORC1 activity as observed by the augmentation of S6 ribosomal protein phosphorylation, a downstream effector of mTORC1. The PGE 2 EP 4 receptor was responsible for transducing the signal to mTORC1. Moreover, PGE 2 increased colon cancer cell proliferation as well as the growth of colon cancer cell colonies grown in matrigel and blocking mTORC1 by rapamycin or ATP-competitive inhibitors of mTOR abrogated these effects. Similarly, the inhibition of mTORC1 by downregulation of its component raptor using RNA interference blocked PGE 2 -induced LS174T cell growth. Finally, stimulation of LS174T cells with PGE 2 increased VEGF production which was also prevented by mTORC1 inhibition. Taken together, these results show that mTORC1 is an important signaling intermediary in PGE 2 mediated colon cancer cell growth and VEGF production. They further support a role for mTORC1 in inflammation induced tumor growth

  15. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    International Nuclear Information System (INIS)

    Nguyen Ngoc, Tam Dan; Son, Young-Ok; Lim, Shin-Saeng; Shi, Xianglin; Kim, Jong-Ghee; Heo, Jung Sun; Choe, Youngji; Jeon, Young-Mi; Lee, Jeong-Chae

    2012-01-01

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G 2 /M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  16. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  17. Pseudomonas-derived ceramidase induces production of inflammatory mediators from human keratinocytes via sphingosine-1-phosphate.

    Directory of Open Access Journals (Sweden)

    Ami Oizumi

    Full Text Available Ceramide is important for water retention and permeability barrier functions in the stratum corneum, and plays a key role in the pathogenesis of atopic dermatitis (AD. A Pseudomonas aeruginosa-derived neutral ceramidase (PaCDase isolated from a patient with AD was shown to effectively degrade ceramide in the presence of Staphylococcus aureus-derived lipids or neutral detergents. However, the effect of ceramide metabolites on the functions of differentiating keratinocytes is poorly understood. We found that the ceramide metabolite sphingosine-1-phosphate (S1P stimulated the production of inflammatory mediators such as TNF-α and IL-8 from three-dimensionally cultured human primary keratinocytes (termed "3D keratinocytes", which form a stratum corneum. PaCDase alone did not affect TNF-α gene expression in 3D keratinocytes. In the presence of the detergent Triton X-100, which damages stratum corneum structure, PaCDase, but not heat-inactivated PaCDase or PaCDase-inactive mutant, induced the production of TNF-α, endothelin-1, and IL-8, indicating that this production was dependent on ceramidase activity. Among various ceramide metabolites, sphingosine and S1P enhanced the gene expression of TNF-α, endothelin-1, and IL-8. The PaCDase-enhanced expression of these genes was inhibited by a sphingosine kinase inhibitor and by an S1P receptor antagonist VPC 23019. The TNF-α-binding antibody infliximab suppressed the PaCDase-induced upregulation of IL-8, but not TNF-α, mRNA. PaCDase induced NF-κB p65 phosphorylation. The NF-κB inhibitor curcumin significantly inhibited PaCDase-induced expression of IL-8 and endothelin-1. VPC 23019 and infliximab inhibited PaCDase-induced NF-κB p65 phosphorylation and reduction in the protein level of the NF-κB inhibitor IκBα. Collectively, these findings suggest that (i 3D keratinocytes produce S1P from sphingosine, which is produced through the hydrolysis of ceramide by PaCDase, (ii S1P induces the production

  18. Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

    International Nuclear Information System (INIS)

    Yano, Hiroyuki; Hamanaka, Ryoji; Nakamura, Miki; Sumiyoshi, Hideaki; Matsuo, Noritaka; Yoshioka, Hidekatsu

    2012-01-01

    Highlights: ► We examine how radiation affects the expression level and signal pathway of collagen. ► TGF-β1 mRNA is elevated earlier than those of collagen genes after irradiation. ► Smad pathway mediates the expression of collagen in radiation induced fibrosis. ► MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both α1and α2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-β1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-β receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of α2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

  19. Hypoxia-induced hypothermia mediated by GABA in the rostral parapyramidal area of the medulla oblongata.

    Science.gov (United States)

    Osaka, T

    2014-05-16

    Hypoxia evokes a regulated decrease in the body core temperature (Tc) in a variety of animals. The neuronal mechanisms of this response include, at least in part, glutamatergic activation in the lateral preoptic area (LPO) of the hypothalamus. As the sympathetic premotor neurons in the medulla oblongata constitute a cardinal relay station in the descending neuronal pathway from the hypothalamus for thermoregulation, their inhibition can also be critically involved in the mechanisms of the hypoxia-induced hypothermia. Here, I examined the hypothesis that hypoxia-induced hypothermia is mediated by glutamate-responsive neurons in the LPO that activate GABAergic transmission in the rostral raphe pallidus (rRPa) and neighboring parapyramidal region (PPy) of the medulla oblongata in urethane-chloralose-anesthetized, neuromuscularly blocked, artificially ventilated rats. Unilateral microinjection of GABA (15nmol) into the rRPa and PPy regions elicited a prompt increase in tail skin temperature (Ts) and decreases in Tc, oxygen consumption rate (VO2), and heart rate. Next, when the GABAA receptor blocker bicuculline methiodide (bicuculline methiodide (BMI), 10pmol) alone was microinjected into the rRPa, it elicited unexpected contradictory responses: simultaneous increases in Ts, VO2 and heart rate and a decrease in Tc. Then, when BMI was microinjected bilaterally into the PPy, no direct effect on Ts was seen; and thermogenic and tachycardic responses were slight. However, pretreatment of the PPy with BMI, but not vehicle saline, greatly attenuated the hypothermic responses evoked by hypoxic (10%O2-90%N2, 5min) ventilation or bilateral microinjections of glutamate (5nmol, each side) into the LPO. The results suggest that hypoxia-induced hypothermia was mediated, at least in part, by the activation of GABAA receptors in the PPy. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Eosinophil Resistance to Glucocorticoid-Induced Apoptosis is Mediated by the Transcription Factor NFIL3

    Science.gov (United States)

    Pazdrak, Konrad; Moon, Young; Straub, Christof; Stafford, Susan; Kurosky, Alexander

    2016-01-01

    The mainstay of asthma therapy, glucocorticoids (GCs) exert their therapeutic effects through the inhibition of inflammatory signaling and induction of eosinophil apoptosis. However, laboratory and clinical observations of GC-resistant asthma suggest that GCs' effects on eosinophil viability may depend on the state of eosinophil activation. In the present study we demonstrate that eosinophils stimulated with IL-5 show impaired prop-aptoptotic response to GCs. We sought to determine the contribution of GC-mediated transactivating (TA) and transrepressing (TR) pathways in modulation of activated eosinophils' response to GC by comparing their response to the selective GC receptor (GR) agonist Compound A (CpdA) devoid of TA activity to that upon treatment with Dexamethasone (Dex). IL-5-activated eosinophils showed contrasting responses to CpdA and Dex, as IL-5-treated eosinophils showed no increase in apoptosis compared to cells treated with Dex alone, while CpdA elicited an apoptotic response regardless of IL-5 stimulation. Proteomic analysis revealed that both Nuclear Factor IL-3 (NFIL3) and Map Kinase Phosphatase 1 (MKP1) were inducible by IL-5 and enhanced by Dex; however, CpdA had no effect on NFIL3 and MKP1 expression. We found that inhibiting NFIL3 with specific siRNA or by blocking the IL-5-inducible Pim-1 kinase abrogated the protective effect of IL-5 on Dex-induced apoptosis, indicating crosstalk between IL-5 anti-apoptotic pathways and GR-mediated TA signaling occurring via the NFIL3 molecule. Collectively, these results indicate that 1) GCs' TA pathway may support eosinophil viability in IL-5-stimulated cells through synergistic upregulation of NFIL3; and 2) functional inhibition of IL-5 signaling (anti-Pim1) or the use of selective GR agonists that don't upregulate NFIL3 may be effective strategies for the restoring pro-apoptotic effect of GCs on IL-5-activated eosinophils. PMID:26880402

  1. Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Hiroyuki [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Division of Radioisotope Research, Department of Research Support, Research Promotion Project, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Hamanaka, Ryoji; Nakamura, Miki [Cell Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Sumiyoshi, Hideaki; Matsuo, Noritaka [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Yoshioka, Hidekatsu, E-mail: hidey@oita-u.ac.jp [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer We examine how radiation affects the expression level and signal pathway of collagen. Black-Right-Pointing-Pointer TGF-{beta}1 mRNA is elevated earlier than those of collagen genes after irradiation. Black-Right-Pointing-Pointer Smad pathway mediates the expression of collagen in radiation induced fibrosis. Black-Right-Pointing-Pointer MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both {alpha}1and {alpha}2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-{beta}1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-{beta} receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of {alpha}2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

  2. GSK-3 Inhibition Sensitizes Acute Myeloid Leukemia Cells to 1,25D-Mediated Differentiation

    Science.gov (United States)

    Gupta, Kalpana; Stefan, Tammy; Ignatz-Hoover, James; Moreton, Stephen; Parizher, Gary; Saunthararajah, Yogen; Wald, David N.

    2017-01-01

    1,25-dihydroxyvitamin D3 (1,25D), the biologically active form of vitamin D, is widely considered a promising therapy for acute myeloid leukemia (AML) based on its ability to drive differentiation of leukemic cells. However, clinical trials have been disappointing in part to dose-limiting hypercalcemia. Here we show how inhibiting glycogen synthase kinase 3 (GSK3) can improve the differentiation response of AML cells to 1,25D-mediated differentiation. GSK3 inhibition in AML cells enhanced the differentiating effects of low concentrations of 1,25D. In addition, GSK3 inhibition augmented the ability of 1,25D to induce irreversible growth inhibition and slow the progression of AML in mouse models. Mechanistic studies revealed that GSK3 inhibition led to the hyperphosphorylation of the vitamin D receptor (VDR), enabling an interaction between VDR and the coactivator, SRC-3 (NCOA3), thereby increasing transcriptional activity. We also found that activation of JNK-mediated pathways in response to GSK3 inhibition contributed to the potentiation of 1,25D-induced differentiation. Taken together, our findings offer a preclinical rationale to explore the repositioning of GSK3 inhibitors to enhance differentiation-based therapy for AML treatment. PMID:26964622

  3. Generation of induced pluripotent stem cells (iPSCs) stably expressing CRISPR-based synergistic activation mediator (SAM)

    DEFF Research Database (Denmark)

    Xiong, Kai; Zhou, Yan; Hyttel, Poul

    2016-01-01

    Human fibroblasts were engineered to express the CRISPR-based synergistic activation mediator (SAM) complex: dCas9-VP64 and MS2-P65-HSF1. Two induced pluripotent stem cells (iPSCs) clones expressing SAM were established by transducing these fibroblasts with lentivirus expressing OCT4, SOX2, KLF4...... a novel, useful tool to investigate genetic regulation of stem cell proliferation and differentiation through CRISPR-mediated activation of endogenous genes....

  4. Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

    Science.gov (United States)

    Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

    2013-12-01

    Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

  5. Methadone induces CAD degradation and AIF-mediated necrotic-like cell death in neuroblastoma cells.

    Science.gov (United States)

    Perez-Alvarez, Sergio; Iglesias-Guimarais, Victoria; Solesio, María E; Melero-Fernandez de Mera, Raquel María; Yuste, Víctor J; Galindo, María F; Jordán, Joaquín

    2011-04-01

    Methadone (d,l-methadone hydrochloride) is a full-opioid agonist, originally developed as a substitution for heroin or other opiates abusers. Nowadays methadone is also being applied as long-lasting analgesics in cancer, and it is proposed as a promising agent for leukemia therapy. Previously, we have demonstrated that high concentrations of methadone (0.5mM) induced necrotic-like cell death in SH-SY5Y cells. The pathway involved is caspase-independent but involves impairment of mitochondrial ATP synthesis and mitochondrial cytochrome c release. However, the downstream mitochondrial pathways remained unclear. Here, we studied the participation of apoptosis inducing factor (AIF) in methadone-induced cell death. Methadone resulted in a translocation of AIF from mitochondria to the nucleus. Translocation was inhibited by cyclosporine A, but not by lack of Bax protein. Therefore the effect seems mediated by the formation of the mitochondrial transition pore, but is apparently independent of Bax. Furthermore, methadone-treated SH-SY5Y nuclei show characteristics that are typical for stage I nuclear condensation. Methadone did not induce degradation of DNA into oligonucleosomal fragments or into high molecular weight DNA fragments. Absence of DNA fragmentation coincided with a considerable decrease in the levels of the caspase-actived endonuclase DNase and its chaperone-inhibitor ICAD. In conclusion, our results provide mechanistic insights into the molecular mechanisms that underlie methadone-induced cell death. This knowledge may prove useful to develop novel strategies to prevent toxic side-effects of methadone thereby sustaining its use as therapeutical agent against tumors. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. TMEM16A mediates the hypersecretion of mucus induced by Interleukin-13

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jiachen; Jiang, Youfan; Li, Li; Liu, Yanan; Tang, Hui; Jiang, Depeng, E-mail: depengjiang@163.com

    2015-06-10

    Previous studies showed that the Ca{sup 2+}-activated Cl{sup −} channel (CaCC) was involved in the pathogenesis of mucus hypersecretion induced by Interleukin-13 (IL-13). However, the mechanisms underlying the process were unknown. Recently, transmembrane protein 16A (TMEM16A) was identified as the channel underlying the CaCC current. The aim of the current study was to investigate whether the TMEM16A channel is part of the mechanism underlying IL-13-induced mucus hypersecretion. We observed that both TMEM16A mRNA and protein expression were significantly up-regulated after treatment with IL-13 in human bronchial epithelial 16 (HBE 16) cells, which correlated with an increase in mucus production. Additionally, mucus hypersecretion in rat airways was induced by intratracheal instillation of IL-13 and similar increases were observed in the expression of TMEM16A mRNA and protein in the bronchial epithelium. Niflumic acid (NA), a selective antagonist of CaCC, markedly blocked IL-13-induced mucin (MUC) 5AC mRNA and protein production in vivo and in vitro. Further investigation with HBE16 cells revealed that TMEM16A overexpression clearly promoted mucus production, IκBα phosphorylation, and p65 accumulation in the nucleus. The loss of TMEM16A resulted in inhibition of mucus production, and the TMEM16A-mediated production of MUC5AC was significantly blocked by a nuclear factor-kappa B (NF-κB) inhibitor. Therefore, the TMEM16A channel acts upstream of NF-κB in the regulation of mucus production. This is the first demonstration that the TMEM16A-NF-κB pathway is positively involved in IL-13-induced mucus production, which provides novel insight into the molecular mechanism of mucin overproduction. - Highlights: • TMEM16A acts as downstream events of IL-13 signaling pathway. • Established the link between TMEM16A and mucus hypersecretion. • NF-κB activation might be responsible for TMEM16A mediated mucus secretion.

  7. Sensitivity analysis for direct and indirect effects in the presence of exposure-induced mediator-outcome confounders

    Science.gov (United States)

    Chiba, Yasutaka

    2014-01-01

    Questions of mediation are often of interest in reasoning about mechanisms, and methods have been developed to address these questions. However, these methods make strong assumptions about the absence of confounding. Even if exposure is randomized, there may be mediator-outcome confounding variables. Inference about direct and indirect effects is particularly challenging if these mediator-outcome confounders are affected by the exposure because in this case these effects are not identified irrespective of whether data is available on these exposure-induced mediator-outcome confounders. In this paper, we provide a sensitivity analysis technique for natural direct and indirect effects that is applicable even if there are mediator-outcome confounders affected by the exposure. We give techniques for both the difference and risk ratio scales and compare the technique to other possible approaches. PMID:25580387

  8. Changes in colonic motility induced by sennosides in dogs: evidence of a prostaglandin mediation.

    Science.gov (United States)

    Staumont, G; Fioramonti, J; Frexinos, J; Bueno, L

    1988-01-01

    The effects of sennosides on colonic motility were investigated in eight conscious dogs chronically fitted with two strain gauge transducers in the proximal colon, an intracolonic silicone catheter and a polyethylene catheter implanted in a branch of the right colonic artery. Oral sennosides (30 mg/kg) inhibited colonic motility for 12 to 18 h after a three to six hours delay, and associated with giant contractions and diarrhoea. The minimal oral dose of sennosides to produce such changes varied from 5 to 15 mg/kg. Intracolonic sennosides at the minimal effective dose and at 30 mg/kg reproduced the effects of oral sennosides, but with a shorter latency (0.5-1.5 h). Intracolonic PGE2 (100 micrograms/kg) in viscous gel medium or intra-arterial PGE2 (10 micrograms/h) inhibited colonic motility and induced giant contractions often associated with defecation. The colonic motor changes induced by intracolonic sennosides at the minimal effective dose, but not those induced by intracolonic PGE2, were blocked by intra-arterial indomethacin (10 micrograms/h) or piroxicam (5 micrograms/h). These results suggest that colonic motor actions of sennosides are mediated through a local prostaglandins synthesis, as they were blocked by cyclooxygenase inhibitor and reproduced by PGE2. PMID:3197991

  9. Geldanamycin-induced degradation of Chk1 is mediated by proteasome

    International Nuclear Information System (INIS)

    Nomura, M.; Nomura, N.; Yamashita, J.

    2005-01-01

    Checkpoint kinase 1 (Chk1) is a cell cycle regulator and a heat shock protein 90 (Hsp90) client. It is essential for cell proliferation and survival. In this report, we analyzed the mechanisms of Chk1 regulation in U87MG glioblastoma cells using Geldanamycin (GA), which interferes with the function of Hsp90. GA reduced Chk1 protein level but not its mRNA level in glioblastoma cells. Co-treatment with GA and cycloheximide (CHX), a protein synthesis inhibitor, induced a decrease of half-life of the Chk1 protein to 3 h and resulted in Chk1 down-regulation. CHX alone induced only 32% reduction of Chk1 protein even after 24 h. These findings indicated that reduction of Chk1 by GA was due to destabilization and degradation of the protein. In addition, GA-induced down-regulation of Chk1 was reversed by MG132, a specific proteasome inhibitor. And it was revealed that Chk1 was ubiquitinated by GA. These results have indicated that degradation of Chk1 by GA was mediated by the ubiquitin-proteasome pathway in U87MG glioblastoma cells

  10. The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Juan Pablo; Collao, Andres; Chiong, Mario; Maldonado, Carola; Adasme, Tatiana; Carrasco, Loreto; Ocaranza, Paula; Bravo, Roberto; Gonzalez, Leticia; Diaz-Araya, Guillermo [Centro FONDAP Estudios Moleculares de la Celula, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Facultad de Ciencias Quimicas y Farmaceuticas, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Hidalgo, Cecilia [Centro FONDAP Estudios Moleculares de la Celula, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Instituto de Ciencias Biomedicas, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Lavandero, Sergio, E-mail: slavander@uchile.cl [Centro FONDAP Estudios Moleculares de la Celula, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Facultad de Ciencias Quimicas y Farmaceuticas, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile); Instituto de Ciencias Biomedicas, Facultad de Medicina, Universidad de Chile, Santiago 8380492 (Chile)

    2009-10-09

    Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-induced MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal {alpha}-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression.

  11. Hapten-Induced Contact Hypersensitivity, Autoimmune Reactions, and Tumor Regression: Plausibility of Mediating Antitumor Immunity

    Directory of Open Access Journals (Sweden)

    Dan A. Erkes

    2014-01-01

    Full Text Available Haptens are small molecule irritants that bind to proteins and elicit an immune response. Haptens have been commonly used to study allergic contact dermatitis (ACD using animal contact hypersensitivity (CHS models. However, extensive research into contact hypersensitivity has offered a confusing and intriguing mechanism of allergic reactions occurring in the skin. The abilities of haptens to induce such reactions have been frequently utilized to study the mechanisms of inflammatory bowel disease (IBD to induce autoimmune-like responses such as autoimmune hemolytic anemia and to elicit viral wart and tumor regression. Hapten-induced tumor regression has been studied since the mid-1900s and relies on four major concepts: (1 ex vivo haptenation, (2 in situ haptenation, (3 epifocal hapten application, and (4 antigen-hapten conjugate injection. Each of these approaches elicits unique responses in mice and humans. The present review attempts to provide a critical appraisal of the hapten-mediated tumor treatments and offers insights for future development of the field.

  12. The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling

    International Nuclear Information System (INIS)

    Munoz, Juan Pablo; Collao, Andres; Chiong, Mario; Maldonado, Carola; Adasme, Tatiana; Carrasco, Loreto; Ocaranza, Paula; Bravo, Roberto; Gonzalez, Leticia; Diaz-Araya, Guillermo; Hidalgo, Cecilia; Lavandero, Sergio

    2009-01-01

    Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-induced MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal α-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression.

  13. IFN-gamma-inducible Irga6 mediates host resistance against Chlamydia trachomatis via autophagy.

    Directory of Open Access Journals (Sweden)

    Munir A Al-Zeer

    Full Text Available Chlamydial infection of the host cell induces Gamma interferon (IFNgamma, a central immunoprotector for humans and mice. The primary defense against Chlamydia infection in the mouse involves the IFNgamma-inducible family of IRG proteins; however, the precise mechanisms mediating the pathogen's elimination are unknown. In this study, we identify Irga6 as an important resistance factor against C. trachomatis, but not C. muridarum, infection in IFNgamma-stimulated mouse embryonic fibroblasts (MEFs. We show that Irga6, Irgd, Irgm2 and Irgm3 accumulate at bacterial inclusions in MEFs upon stimulation with IFNgamma, whereas Irgb6 colocalized in the presence or absence of the cytokine. This accumulation triggers a rerouting of bacterial inclusions to autophagosomes that subsequently fuse to lysosomes for elimination. Autophagy-deficient Atg5-/- MEFs and lysosomal acidification impaired cells surrender to infection. Irgm2, Irgm3 and Irgd still localize to inclusions in IFNgamma-induced Atg5-/- cells, but Irga6 localization is disrupted indicating its pivotal role in pathogen resistance. Irga6-deficient (Irga6-/- MEFs, in which chlamydial growth is enhanced, do not respond to IFNgamma even though Irgb6, Irgd, Irgm2 and Irgm3 still localize to inclusions. Taken together, we identify Irga6 as a necessary factor in conferring host resistance by remodelling a classically nonfusogenic intracellular pathogen to stimulate fusion with autophagosomes, thereby rerouting the intruder to the lysosomal compartment for destruction.

  14. Mipu1, a novel direct target gene, is involved in hypoxia inducible factor 1-mediated cytoprotection.

    Directory of Open Access Journals (Sweden)

    Kangkai Wang

    Full Text Available Mipu1 (myocardial ischemic preconditioning up-regulated protein 1, recently identified in our lab, is a novel zinc-finger transcription factor which is up-regulated during ischemic preconditioning. However, it is not clear what transcription factor contributes to its inducible expression. In the present study, we reported that HIF-1 regulates the inducible expression of Mipu1 which is involved in the cytoprotection of HIF-1α against oxidative stress by inhibiting Bax expression. Our results showed that the inducible expression of Mipu1 was associated with the expression and activation of transcription factor HIF-1 as indicated by cobalt chloride (CoCl2 treatment, HIF-1α overexpression and knockdown assays. EMSA and luciferase reporter gene assays showed that HIF-1α bound to the hypoxia response element (HRE within Mipu1 promoter region and promoted its transcription. Moreover, our results revealed that Mipu1 inhibited the expression of Bax, an important pro-apoptosis protein associated with the intrinsic pathway of apoptosis, elevating the cytoprotection of HIF-1 against hydrogen peroxide (H2O2-mediated injury in H9C2 cells. Our findings implied that Bax may be a potential target gene of transcription factor Mipu1, and provided a novel insight for understanding the cytoprotection of HIF-1 and new clues for further elucidating the mechanisms by which Mipu1 protects cell against pathological stress.

  15. Investigating Gene Function in Cereal Rust Fungi by Plant-Mediated Virus-Induced Gene Silencing.

    Science.gov (United States)

    Panwar, Vinay; Bakkeren, Guus

    2017-01-01

    Cereal rust fungi are destructive pathogens, threatening grain production worldwide. Targeted breeding for resistance utilizing host resistance genes has been effective. However, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to expand the range of available resistance genes. Whole genome sequencing, transcriptomic and proteomic studies followed by genome-wide computational and comparative analyses have identified large repertoire of genes in rust fungi among which are candidates predicted to code for pathogenicity and virulence factors. Some of these genes represent defence triggering avirulence effectors. However, functions of most genes still needs to be assessed to understand the biology of these obligate biotrophic pathogens. Since genetic manipulations such as gene deletion and genetic transformation are not yet feasible in rust fungi, performing functional gene studies is challenging. Recently, Host-induced gene silencing (HIGS) has emerged as a useful tool to characterize gene function in rust fungi while infecting and growing in host plants. We utilized Barley stripe mosaic virus-mediated virus induced gene silencing (BSMV-VIGS) to induce HIGS of candidate rust fungal genes in the wheat host to determine their role in plant-fungal interactions. Here, we describe the methods for using BSMV-VIGS in wheat for functional genomics study in cereal rust fungi.

  16. Nitrogen mediates CO2-induced changes in rhizosphere priming effects in an aggrading forest (Invited)

    Science.gov (United States)

    Phillips, R.; Bernhardt, E. S.; Finzi, A.

    2009-12-01

    Root-induced changes in soil organic matter (SOM) decomposition are likely to provide an important feedback to carbon storage in terrestrial ecosystems but to date, there have been few measurements of such “priming effects” in forest soils. Our goal was to estimate the potential magnitude of SOM priming in a 28 year-old loblolly pine stand exposed to elevated atmospheric CO2 (ambient + 200 ppm) and nitrogen fertilization (11 g m-2 yr-1) at the Duke Forest FACE site, NC. We hypothesized that CO2- and nitrogen-induced changes in carbon supply to soil via root exudation would mediate the magnitude and timing of priming effects. Over a two-year period, trees exposed to CO2 enrichment increased dissolved carbon supply to soil by ~50% in nutrient-poor soils, resulting in a doubling of microbial biomass in the rhizosphere in the upper 10 cm of mineral soil (p proteolytic extracellular enzymes involved in SOM depolymerization, with the greatest changes occurring in non-fertilized soils. We interpret the enhanced microbial and enzyme activities in the rhizosphere as evidence of root-induced priming effects. Collectively, our results suggest that although increased carbon flux from to roots to soil may provide a mechanism for trees to accelerate soil nitrogen cycling under elevated CO2, such inputs may also accelerate SOM decomposition and thus reduce storage in the longest lived, most stable pools of carbon in aggrading forests.

  17. Sporothrix schenckii Immunization, but Not Infection, Induces Protective Th17 Responses Mediated by Circulating Memory CD4+ T Cells

    Directory of Open Access Journals (Sweden)

    Alberto García-Lozano

    2018-06-01

    Full Text Available Sporotrichosis is a chronic subcutaneous mycosis caused by the Sporothrix schenckii species complex and it is considered an emerging opportunistic infection in countries with tropical and subtropical climates. The host’s immune response has a main role in the development of this disease. However, it is unknown the features of the memory cellular immune response that could protect against the infection. Our results show that i.d. immunization in the ears of mice with inactivated S. schenckii conidia (iC combined with the cholera toxin (CT induces a cellular immune response mediated by circulating memory CD4+ T cells, which mainly produce interleukin 17 (IL-17. These cells mediate a strong delayed-type hypersensitivity (DTH reaction. Systemic and local protection against S. schenckii was mediated by circulating CD4+ T cells. In contrast, the infection induces a potent immune response in the skin mediated by CD4+ T cells, which have an effector phenotype that preferentially produce interferon gamma (IFN-γ and mediate a transitory DTH reaction. Our findings prove the potential value of the CT as a potent skin adjuvant when combined with fungal antigens, and they also have important implications for our better understanding of the differences between the memory immune response induced by the skin immunization and those induced by the infection; this knowledge enhances our understanding of how a protective immune response against a S. schenckii infection is developed.

  18. Combination therapies in adjuvant with topical ALA-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premalignant lesions

    Science.gov (United States)

    Yang, Deng-Fu; Hsu, Yih-Chih

    2012-03-01

    In Taiwan, oral cancer has becomes the fastest growth male cancer disease due to the betel nut chewing habit combing with smoking and alcohol-drinking lifestyle of people. In order to eliminate the systemic phototoxic effect of 5-aminolevulinic acid (ALA), this study was designed to use a topical ALA-mediated PDT for treatment of DMBA-induced hamster buccal pouch precancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 10 to 12 weeks. Cancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical ALA-mediated PDT. Before PDT, fluorescence spectroscopy was used to determine when ALA reached its peak level in the lesional epithelial cells after topical application of ALA gel. We found that ALA reached its peak level in precancerous lesions about 2.5 hrs after topical application of ALA gel. The cancerous lesions in hamsters were then treated with topical ALA -mediated PDT with light exposure dose of 150 J/cm2 using LED 635 nm fiber-guided light device. Visual examination demonstrated that adjuvant topical ALA -mediated PDT group has shown better therapeutic results in compared to those of non-adjuvant topical ALA-mediated PDT group for DMBA-induced hamster buccal pouch precancerous lesions.

  19. CXCR7 is induced by hypoxia and mediates glioma cell migration towards SDF-1α

    International Nuclear Information System (INIS)

    Esencay, Mine; Sarfraz, Yasmeen; Zagzag, David

    2013-01-01

    Glioblastomas, the most common and malignant brain tumors of the central nervous system, exhibit high invasive capacity, which hinders effective therapy. Therefore, intense efforts aimed at improved therapeutics are ongoing to delineate the molecular mechanisms governing glioma cell migration and invasion. In order to perform the studies, we employed optimal cell culture methods and hypoxic conditions, lentivirus-mediated knockdown of protein expression, Western Blot analysis, migration assays and immunoprecipitation. We determined statistical significance by unpaired t-test. In this report, we show that U87MG, LN229 and LN308 glioma cells express CXCR7 and that exposure to hypoxia upregulates CXCR7 protein expression in these cell lines. CXCR7-expressing U87MG, LN229 and LN308 glioma cells migrated towards stromal-derived factor (SDF)-1α/CXCL12 in hypoxic conditions in the Boyden chamber assays. While shRNA-mediated knockdown of CXCR7 expression did not affect the migration of any of the three cell lines in normoxic conditions, we observed a reduction in the migration of LN229 and LN308, but not U87MG, glioma cells towards SDF-1α in hypoxic conditions. In addition, knockdown of CXCR7 expression in LN229 and LN308 glioma cells decreased levels of SDF-1α-induced phosphorylation of ERK1/2 and Akt. Inhibiting CXCR4 in LN229 and LN308 glioma cells that were knocked down for CXCR7 did not further reduce migration towards SDF-1α in hypoxic conditions and did not affect the levels of phosphorylated ERK1/2 and Akt. Analysis of immunoprecipitated CXCR4 from LN229 and LN308 glioma cells revealed co-precipitated CXCR7. Taken together, our findings indicate that both CXCR4 and CXCR7 mediate glioma cell migration towards SDF-1α in hypoxic conditions and support the development of therapeutic agents targeting these receptors

  20. Transcriptome signature identifies distinct cervical pathways induced in lipopolysaccharide-mediated preterm birth.

    Science.gov (United States)

    Willcockson, Alexandra R; Nandu, Tulip; Liu, Cheuk-Lun; Nallasamy, Shanmugasundaram; Kraus, W Lee; Mahendroo, Mala

    2018-03-01

    With half a million babies born preterm each year in the USA and about 15 million worldwide, preterm birth (PTB) remains a global health issue. Preterm birth is a primary cause of infant morbidity and mortality and can impact lives long past infancy. The fact that there are numerous, and many currently unidentified, etiologies of PTB has hindered development of tools for risk evaluation and preventative therapies. Infection is estimated to be involved in nearly 40% of PTBs of known etiology; therefore, understanding how infection-mediated inflammation alters the cervical milieu and leads to preterm tissue biomechanical changes are questions of interest. Using RNA-seq, we identified enrichment of components involved in inflammasome activation and unique proteases in the mouse cervix during lipopolysaccharide (LPS)-mediated PTB and not physiologically at term before labor. Despite transcriptional induction of inflammasome components, there was no evidence of functional activation based on assessment of mature IL1B and IL18 proteins. The increased transcription of proteases that target both elastic fibers and collagen and concentration of myeloid-derived cells capable of protease synthesis in the cervical stroma support the structural disruption of elastic fibers as a functional output of protease activity. The recent demonstration that elastic fibers contribute to the biomechanical function of the pregnant cervix suggests their protease-induced disruption in the infection model of LPS-mediated PTB and may contribute to premature loss of mechanical competency and preterm delivery. Collectively, the transcriptomics and ultrastructural data provide new insights into the distinct mechanisms of premature cervical remodeling in response to infection.

  1. Cytokine-mediated deployment of SDF-1 induces revascularization through recruitment of CXCR4+ hemangiocytes

    Science.gov (United States)

    Jin, David K; Shido, Koji; Kopp, Hans-Georg; Petit, Isabelle; Shmelkov, Sergey V; Young, Lauren M; Hooper, Andrea T; Amano, Hideki; Avecilla, Scott T; Heissig, Beate; Hattori, Koichi; Zhang, Fan; Hicklin, Daniel J; Wu, Yan; Zhu, Zhenping; Dunn, Ashley; Salari, Hassan; Werb, Zena; Hackett, Neil R; Crystal, Ronald G; Lyden, David; Rafii, Shahin

    2009-01-01

    The mechanisms through which hematopoietic cytokines accelerate revascularization are unknown. Here, we show that the magnitude of cytokine-mediated release of SDF-1 from platelets and the recruitment of nonendothelial CXCR4+VEGFR1+ hematopoietic progenitors, ‘hemangiocytes,’ constitute the major determinant of revascularization. Soluble Kit-ligand (sKitL), thrombopoietin (TPO, encoded by Thpo) and, to a lesser extent, erythropoietin (EPO) and granulocyte-macrophage colony-stimulating factor (GM-CSF) induced the release of SDF-1 from platelets, enhancing neovascularization through mobilization of CXCR4+VEGFR1+ hemangiocytes. Although revascularization of ischemic hindlimbs was partially diminished in mice deficient in both GM-CSF and G-CSF (Csf2−/−Csf3−/−), profound impairment in neovascularization was detected in sKitL-deficient Mmp9−/− as well as thrombocytopenic Thpo−/− and TPO receptor–deficient (Mpl−/−) mice. SDF-1–mediated mobilization and incorporation of hemangiocytes into ischemic limbs were impaired in Thpo−/−, Mpl−/− and Mmp9−/− mice. Transplantation of CXCR4+VEGFR1+ hemangiocytes into Mmp9−/− mice restored revascularization, whereas inhibition of CXCR4 abrogated cytokine- and VEGF-A–mediated mobilization of CXCR4+VEGFR1+ cells and suppressed angiogenesis. In conclusion, hematopoietic cytokines, through graded deployment of SDF-1 from platelets, support mobilization and recruitment of CXCR4+VEGFR1+ hemangiocytes, whereas VEGFR1 is essential for their angiogenic competency for augmenting revascularization. Delivery of SDF-1 may be effective in restoring angiogenesis in individuals with vasculopathies. PMID:16648859

  2. Cancer-induced anorexia and malaise are mediated by CGRP neurons in the parabrachial nucleus.

    Science.gov (United States)

    Campos, Carlos A; Bowen, Anna J; Han, Sung; Wisse, Brent E; Palmiter, Richard D; Schwartz, Michael W

    2017-07-01

    Anorexia is a common manifestation of chronic diseases, including cancer. Here we investigate the contribution to cancer anorexia made by calcitonin gene-related peptide (CGRP) neurons in the parabrachial nucleus (PBN) that transmit anorexic signals. We show that CGRP PBN neurons are activated in mice implanted with Lewis lung carcinoma cells. Inactivation of CGRP PBN neurons before tumor implantation prevents anorexia and loss of lean mass, and their inhibition after symptom onset reverses anorexia. CGRP PBN neurons are also activated in Apc min/+ mice, which develop intestinal cancer and lose weight despite the absence of reduced food intake. Inactivation of CGRP PBN neurons in Apc min/+ mice permits hyperphagia that counteracts weight loss, revealing a role for these neurons in a 'nonanorexic' cancer model. We also demonstrate that inactivation of CGRP PBN neurons prevents lethargy, anxiety and malaise associated with cancer. These findings establish CGRP PBN neurons as key mediators of cancer-induced appetite suppression and associated behavioral changes.

  3. RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions.

    Science.gov (United States)

    Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

    2018-01-01

    SHLI-induced hypersensitivity reactions in both endothelial cells and mice indicating its protective effect. SHLI-induced pseudo-allergic reactions were mediated by the activation of the RhoA/ROCK signaling pathway. Conclusion : This study presents a novel mechanism of SHLI-induced immediate hypersensitivity reactions and suggests a potential therapeutic strategy to prevent the associated adverse reactions.

  4. Structural Insights into Triglyceride Storage Mediated by Fat Storage-Inducing Transmembrane (FIT) Protein 2

    Science.gov (United States)

    Gross, David A.; Snapp, Erik L.; Silver, David L.

    2010-01-01

    Fat storage-Inducing Transmembrane proteins 1 & 2 (FIT1/FITM1 and FIT2/FITM2) belong to a unique family of evolutionarily conserved proteins localized to the endoplasmic reticulum that are involved in triglyceride lipid droplet formation. FIT proteins have been shown to mediate the partitioning of cellular triglyceride into lipid droplets, but not triglyceride biosynthesis. FIT proteins do not share primary sequence homology with known proteins and no structural information is available to inform on the mechanism by which FIT proteins function. Here, we present the experimentally-solved topological models for FIT1 and FIT2 using N-glycosylation site mapping and indirect immunofluorescence techniques. These methods indicate that both proteins have six-transmembrane-domains with both N- and C-termini localized to the cytosol. Utilizing this model for structure-function analysis, we identified and characterized a gain-of-function mutant of FIT2 (FLL(157-9)AAA) in transmembrane domain 4 that markedly augmented the total number and mean size of lipid droplets. Using limited-trypsin proteolysis we determined that the FLL(157-9)AAA mutant has enhanced trypsin cleavage at K86 relative to wild-type FIT2, indicating a conformational change. Taken together, these studies indicate that FIT2 is a 6 transmembrane domain-containing protein whose conformation likely regulates its activity in mediating lipid droplet formation. PMID:20520733

  5. Medullary Reticular Neurons Mediate Neuropeptide Y-Induced Metabolic Inhibition and Mastication.

    Science.gov (United States)

    Nakamura, Yoshiko; Yanagawa, Yuchio; Morrison, Shaun F; Nakamura, Kazuhiro

    2017-02-07

    Hypothalamic neuropeptide Y (NPY) elicits hunger responses to increase the chances of surviving starvation: an inhibition of metabolism and an increase in feeding. Here we elucidate a key central circuit mechanism through which hypothalamic NPY signals drive these hunger responses. GABAergic neurons in the intermediate and parvicellular reticular nuclei (IRt/PCRt) of the medulla oblongata, which are activated by NPY-triggered neural signaling from the hypothalamus, potentially through the nucleus tractus solitarius, mediate the NPY-induced inhibition of metabolic thermogenesis in brown adipose tissue (BAT) via their innervation of BAT sympathetic premotor neurons. Intriguingly, the GABAergic IRt/PCRt neurons innervating the BAT sympathetic premotor region also innervate the masticatory motor region, and stimulation of the IRt/PCRt elicits mastication and increases feeding as well as inhibits BAT thermogenesis. These results indicate that GABAergic IRt/PCRt neurons mediate hypothalamus-derived hunger signaling by coordinating both autonomic and feeding motor systems to reduce energy expenditure and to promote feeding. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Structural insights into triglyceride storage mediated by fat storage-inducing transmembrane (FIT protein 2.

    Directory of Open Access Journals (Sweden)

    David A Gross

    2010-05-01

    Full Text Available Fat storage-Inducing Transmembrane proteins 1 & 2 (FIT1/FITM1 and FIT2/FITM2 belong to a unique family of evolutionarily conserved proteins localized to the endoplasmic reticulum that are involved in triglyceride lipid droplet formation. FIT proteins have been shown to mediate the partitioning of cellular triglyceride into lipid droplets, but not triglyceride biosynthesis. FIT proteins do not share primary sequence homology with known proteins and no structural information is available to inform on the mechanism by which FIT proteins function. Here, we present the experimentally-solved topological models for FIT1 and FIT2 using N-glycosylation site mapping and indirect immunofluorescence techniques. These methods indicate that both proteins have six-transmembrane-domains with both N- and C-termini localized to the cytosol. Utilizing this model for structure-function analysis, we identified and characterized a gain-of-function mutant of FIT2 (FLL(157-9AAA in transmembrane domain 4 that markedly augmented the total number and mean size of lipid droplets. Using limited-trypsin proteolysis we determined that the FLL(157-9AAA mutant has enhanced trypsin cleavage at K86 relative to wild-type FIT2, indicating a conformational change. Taken together, these studies indicate that FIT2 is a 6 transmembrane domain-containing protein whose conformation likely regulates its activity in mediating lipid droplet formation.

  7. Tannic Acid Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in Prostate Cancer.

    Science.gov (United States)

    Nagesh, Prashanth K B; Hatami, Elham; Chowdhury, Pallabita; Kashyap, Vivek K; Khan, Sheema; Hafeez, Bilal B; Chauhan, Subhash C; Jaggi, Meena; Yallapu, Murali M

    2018-03-07

    Endoplasmic reticulum (ER) stress is an intriguing target with significant clinical importance in chemotherapy. Interference with ER functions can lead to the accumulation of unfolded proteins, as detected by transmembrane sensors that instigate the unfolded protein response (UPR). Therefore, controlling induced UPR via ER stress with natural compounds could be a novel therapeutic strategy for the management of prostate cancer. Tannic acid (a naturally occurring polyphenol) was used to examine the ER stress mediated UPR pathway in prostate cancer cells. Tannic acid treatment inhibited the growth, clonogenic, invasive, and migratory potential of prostate cancer cells. Tannic acid demonstrated activation of ER stress response (Protein kinase R-like endoplasmic reticulum kinase (PERK) and inositol requiring enzyme 1 (IRE1)) and altered its regulatory proteins (ATF4, Bip, and PDI) expression. Tannic acid treatment affirmed upregulation of apoptosis-associated markers (Bak, Bim, cleaved caspase 3, and cleaved PARP), while downregulation of pro-survival proteins (Bcl-2 and Bcl-xL). Tannic acid exhibited elevated G₁ population, due to increase in p18 INK4C and p21 WAF1/CIP1 expression, while cyclin D1 expression was inhibited. Reduction of MMP2 and MMP9, and reinstated E-cadherin signifies the anti-metastatic potential of this compound. Altogether, these results demonstrate that tannic acid can promote apoptosis via the ER stress mediated UPR pathway, indicating a potential candidate for cancer treatment.

  8. Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

    International Nuclear Information System (INIS)

    Pattani, Varun P.; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W.

    2015-01-01

    Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm 2 laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue

  9. Hypoxia-Inducible Factors: Mediators of Cancer Progression; Prognostic and Therapeutic Targets in Soft Tissue Sarcomas

    International Nuclear Information System (INIS)

    Sadri, Navid; Zhang, Paul J.

    2013-01-01

    Soft-tissue sarcomas remain aggressive tumors that result in death in greater than a third of patients due to either loco-regional recurrence or distant metastasis. Surgical resection remains the main choice of treatment for soft tissue sarcomas with pre- and/or post-operational radiation and neoadjuvant chemotherapy employed in more advanced stage disease. However, in recent decades, there has been little progress in the average five-year survival for the majority of patients with high-grade soft tissue sarcomas, highlighting the need for improved targeted therapeutic agents. Clinical and preclinical studies demonstrate that tumor hypoxia and up-regulation of hypoxia-inducible factors (HIFs) is associated with decreased survival, increased metastasis, and resistance to therapy in soft tissue sarcomas. HIF-mediated gene expression regulates many critical aspects of tumor biology, including cell survival, metabolic programming, angiogenesis, metastasis, and therapy resistance. In this review, we discuss HIFs and HIF-mediated genes as potential prognostic markers and therapeutic targets in sarcomas. Many pharmacological agents targeting hypoxia-related pathways are in development that may hold therapeutic potential for treating both primary and metastatic sarcomas that demonstrate increased HIF expression

  10. Role of apoptosis and necrosis in cell death induced by nanoparticle-mediated photothermal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pattani, Varun P., E-mail: varun.pattani@utexas.edu; Shah, Jay; Atalis, Alexandra; Sharma, Anirudh; Tunnell, James W. [The University of Texas at Austin, Department of Biomedical Engineering (United States)

    2015-01-15

    Current cancer therapies can cause significant collateral damage due to a lack of specificity and sensitivity. Therefore, we explored the cell death pathway response to gold nanorod (GNR)-mediated photothermal therapy as a highly specific cancer therapeutic to understand the role of apoptosis and necrosis during intense localized heating. By developing this, we can optimize photothermal therapy to induce a maximum of ‘clean’ cell death pathways, namely apoptosis, thereby reducing external damage. GNRs were targeted to several subcellular localizations within colorectal tumor cells in vitro, and the cell death pathways were quantitatively analyzed after photothermal therapy using flow cytometry. In this study, we found that the cell death response to photothermal therapy was dependent on the GNR localization. Furthermore, we demonstrated that nanorods targeted to the perinuclear region irradiated at 37.5 W/cm{sup 2} laser fluence rate led to maximum cell destruction with the ‘cleaner’ method of apoptosis, at similar percentages as other anti-cancer targeted therapies. We believe that this indicates the therapeutic potential for GNR-mediated photothermal therapy to treat cancer effectively without causing damage to surrounding tissue.

  11. Nickel nanowires induced and reactive oxygen species mediated apoptosis in human pancreatic adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Kleve MG

    2011-07-01

    Full Text Available Md. Zakir Hossain1, Maurice G Kleve21Applied Biosciences (Bionanotechnology Research, Department of Applied Science, 2Molecular Biotechnology and Microscopy Laboratory, Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, USABackground: The ability to evade apoptosis is one of the key properties of cancer. The apoptogenic effect of nickel nanowires (Ni NWs on cancer cell lines has never been adequately addressed. Due to the unique physicochemical characteristics of Ni NWs, we envision the development of a novel anticancer therapeutics specifically for pancreatic cancer. Thus, we investigated whether Ni NWs induce ROS-mediated apoptosis in human pancreatic adenocarcinoma (Panc-1 cells. Methods: In this study Ni NWs were fabricated using the electrodeposition method. Synthesized Ni NWs were physically characterized by energy dispersive X-ray analysis, UV-Vis spectroscopy of NanoDrop 2000 (UV-Vis, magnetization study, scanning electron microscopy, and transmission electron microscopy. Assessment of morphological apoptotic characteristics by phase contrast microscopy (PCM, Ni-NWs-induced apoptosis staining with ethidium bromide (EB and acridine orange (AO followed by fluorescence microscopy (FM was performed. For molecular biological and biochemical characterization, Panc-1 cell culture and cytotoxic effect of Ni NWs were determined by using 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT assay. Quantitative apoptosis was analyzed by flow cytometry staining with propidium iodide through cell cycle arrest and generation of ROS using 2', 7'-dichlorofluorescein diacetate fluorescence intensity. In all experiments, Panc-1 cancer cells without any treatment were used as the negative controls.Results: The intracellular uptake of Ni NWs through endocytosis by Panc-1 cells was observed by PCM. EB and AO staining of FM and MTT assay qualitatively and quantitatively confirmed the extent of apoptosis. Flow

  12. HMGB1 mediates depressive behavior induced by chronic stress through activating the kynurenine pathway.

    Science.gov (United States)

    Wang, Bo; Lian, Yong-Jie; Su, Wen-Jun; Peng, Wei; Dong, Xin; Liu, Lin-Lin; Gong, Hong; Zhang, Ting; Jiang, Chun-Lei; Wang, Yun-Xia

    2017-11-28

    Our previous study has reported that the proactive secretion and role of central high mobility group box 1 (HMGB1) in lipopolysaccharide-induced depressive behavior. Here, the potential mechanism of HMGB1 mediating chronic-stress-induced depression through the kynurenine pathway (KP) was further explored both in vivo and in vitro. Depression model was established with the 4-week chronic unpredictable mild stress (CUMS). Sucrose preference and Barnes maze test were performed to reflect depressive behaviors. The ratio of kynurenine (KYN)/tryptophan (Trp) represented the enzyme activity of indoleamine-2,3-dioxygenase (IDO). Gene transcription and protein expression were assayed by real-time RT-PCR and western-blot or ELISA kit respectively. Along with depressive behaviors, HMGB1 concentrations in the hippocampus and serum substantially increased post 4-week CUMS exposure. Concurrent with the upregulated HMGB1 protein, the regulator of translocation of HMGB1, sirtuin 1 (SIRT1) concentration in the hippocampus remarkably increased. In addition to HMGB1 and SIRT1, IDO, the rate limiting enzyme of KP, was upregulated at the level of mRNA expression and enzyme activity in stressed hippocampi and LPS/HMGB1-treated hippocampal slices. The gene transcription of kynurenine monooxygenase (KMO) and kynureninase (KYNU) in the downstream of KP also increased both in vivo and in vitro. Mice treated with ethyl pyruvate (EP), the inhibitor of HMGB1 releasing, were observed with lower tendency of developing depressive behaviors and reduced activation of enzymes in KP. All of these experiments demonstrate that the role of HMGB1 on the induction of depressive behavior is mediated by KP activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Synthesis of lipid mediators during UVB-induced inflammatory hyperalgesia in rats and mice.

    Directory of Open Access Journals (Sweden)

    Marco Sisignano

    Full Text Available Peripheral sensitization during inflammatory pain is mediated by a variety of endogenous proalgesic mediators including a number of oxidized lipids, some of which serve endogenous modulators of sensory TRP-channels. These lipids are eicosanoids of the arachidonic acid and linoleic acid pathway, as well as lysophophatidic acids (LPAs. However, their regulation pattern during inflammatory pain and their contribution to peripheral sensitization is still unclear. Here, we used the UVB-model for inflammatory pain to investigate alterations of lipid concentrations at the site of inflammation, the dorsal root ganglia (DRGs as well as the spinal dorsal horn and quantified 21 lipid species from five different lipid families at the peak of inflammation 48 hours post irradiation. We found that known proinflammatory lipids as well as lipids with unknown roles in inflammatory pain to be strongly increased in the skin, whereas surprisingly little changes of lipid levels were seen in DRGs or the dorsal horn. Importantly, although there are profound differences between the number of cytochrome (CYP genes between mice and rats, CYP-derived lipids were regulated similarly in both species. Since TRPV1 agonists such as LPA 18∶1, 9- and 13-HODE, 5- and 12-HETE were elevated in the skin, they may contribute to thermal hyperalgesia and mechanical allodynia during UVB-induced inflammatory pain. These results may explain why some studies show relatively weak analgesic effects of cyclooxygenase inhibitors in UVB-induced skin inflammation, as they do not inhibit synthesis of other proalgesic lipids such as LPA 18∶1, 9-and 13-HODE and HETEs.

  14. Calcium-mediated signaling and calmodulin-dependent kinase regulate hepatocyte-inducible nitric oxide synthase expression.

    Science.gov (United States)

    Zhang, Baochun; Crankshaw, Will; Nesemeier, Ryan; Patel, Jay; Nweze, Ikenna; Lakshmanan, Jaganathan; Harbrecht, Brian G

    2015-02-01

    Induced nitric oxide synthase (iNOS) is induced in hepatocytes by shock and inflammatory stimuli. Excessive NO from iNOS mediates shock-induced hepatic injury and death, so understanding the regulation of iNOS will help elucidate the pathophysiology of septic shock. In vitro, cytokines induce iNOS expression through activation of signaling pathways including mitogen-activated protein kinases and nuclear factor κB. Cytokines also induce calcium (Ca(2+)) mobilization and activate calcium-mediated intracellular signaling pathways, typically through activation of calmodulin-dependent kinases (CaMK). Calcium regulates NO production in macrophages but the role of calcium and calcium-mediated signaling in hepatocyte iNOS expression has not been defined. Primary rat hepatocytes were isolated, cultured, and induced to produce NO with proinflammatory cytokines. Calcium mobilization and Ca(2+)-mediated signaling were altered with ionophore, Ca(2+) channel blockers, and inhibitors of CaMK. The Ca(2+) ionophore A23187 suppressed cytokine-stimulated NO production, whereas Ethylene glycol tetraacetic acid and nifedipine increased NO production, iNOS messenger RNA, and iNOS protein expression. Inhibition of CaMK with KN93 and CBD increased NO production but the calcineurin inhibitor FK 506 decreased iNOS expression. These data demonstrate that calcium-mediated signaling regulates hepatocyte iNOS expression and does so through a mechanism independent of calcineurin. Changes in intracellular calcium levels may regulate iNOS expression during hepatic inflammation induced by proinflammatory cytokines. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. MDMA-Induced Dissociative State not Mediated by the 5-HT2A Receptor

    Directory of Open Access Journals (Sweden)

    Drew J. Puxty

    2017-07-01

    Full Text Available Previous research has shown that a single dose of MDMA induce a dissociative state, by elevating feelings of depersonalization and derealization. Typically, it is assumed that action on the 5-HT2A receptor is the mechanism underlying these psychedelic experiences. In addition, other studies have shown associations between dissociative states and biological parameters (heart rate, cortisol, which are elevated by MDMA. In order to investigate the role of the 5-HT2 receptor in the MDMA-induced dissociative state and the association with biological parameters, a placebo-controlled within-subject study was conducted including a single oral dose of MDMA (75 mg, combined with placebo or a single oral dose of the 5-HT2 receptor blocker ketanserin (40 mg. Twenty healthy recreational MDMA users filled out a dissociative states scale (CADSS 90 min after treatments, which was preceded and followed by assessment of a number of biological parameters (cortisol levels, heart rate, MDMA blood concentrations. Findings showed that MDMA induced a dissociative state but this effect was not counteracted by pre-treatment with ketanserin. Heart rate was the only biological parameter that correlated with the MDMA-induced dissociative state, but an absence of correlation between these measures when participants were pretreated with ketanserin suggests an absence of directional effects of heart rate on dissociative state. It is suggested that the 5-HT2 receptor does not mediate the dissociative effects caused by a single dose of MDMA. Further research is needed to determine the exact neurobiology underlying this effect and whether these effects contribute to the therapeutic potential of MDMA.

  16. MicroRNAs as Potential Mediators for Cigarette Smoking Induced Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Yuka Yokoyama

    2018-04-01

    Full Text Available Smoking increases the risk of atherosclerosis-related events, such as myocardial infarction and ischemic stroke. Recent studies have examined the expression levels of altered microRNAs (miRNAs in various diseases. The profiles of tissue miRNAs can be potentially used in diagnosis or prognosis. However, there are limited studies on miRNAs following exposure to cigarette smoke (CS. The present study was designed to dissect the effects and cellular/molecular mechanisms of CS-induced atherosclerogenesis. Apolipoprotein E knockout (ApoE KO mice were exposed to CS for five days a week for two months at low (two puffs/min for 40 min/day or high dose (two puffs/min for 120 min/day. We measured the area of atherosclerotic plaques in the aorta, representing the expression of miRNAs after the exposure period. Two-month exposure to the high dose of CS significantly increased the plaque area in aortic arch, and significantly upregulated the expression of atherosclerotic markers (VCAM-1, ICAM-1, MCP1, p22phox, and gp91phox. Exposure to the high dose of CS also significantly upregulated the miRNA-155 level in the aortic tissues of ApoE KO mice. Moreover, the expression level of miR-126 tended to be downregulated and that of miR-21 tended to be upregulated in ApoE KO mice exposed to the high dose of CS, albeit statistically insignificant. The results suggest that CS induces atherosclerosis through increased vascular inflammation and NADPH oxidase expression and also emphasize the importance of miRNAs in the pathogenesis of CS-induced atherosclerosis. Our findings provide evidence for miRNAs as potential mediators of inflammation and atherosclerosis induced by CS.

  17. Wnt/β-catenin signalling pathway mediated aberrant hippocampal neurogenesis in kainic acid-induced epilepsy.

    Science.gov (United States)

    Qu, Zhengyi; Su, Fang; Qi, Xueting; Sun, Jianbo; Wang, Hongcai; Qiao, Zhenkui; Zhao, Hong; Zhu, Yulan

    2017-10-01

    Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/β-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of β-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down β-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/β-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/β-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Copyright © 2017 John Wiley & Sons, Ltd.

  18. DHEA-induced ovarian hyperfibrosis is mediated by TGF-β signaling pathway.

    Science.gov (United States)

    Wang, Daojuan; Wang, Wenqing; Liang, Qiao; He, Xuan; Xia, Yanjie; Shen, Shanmei; Wang, Hongwei; Gao, Qian; Wang, Yong

    2018-01-10

    The polycystic ovary syndrome (PCOS) is a common metabolic and endocrine disorder with pathological mechanisms remain unclear. The following study investigates the ovarian hyperfibrosis forming via transforming growth factor-β (TGF-β) signaling pathway in Dehydroepiandrosterone (DHEA)- induced polycystic ovary syndrome (PCOS) rat model. We furthermore explored whether TGF-βRI inhibitor (SB431542) decreases ovarian fibrosis by counterbalancing the expression of fibrotic biomarkers. Thirty female Sprague-Dawley rats were randomly divided into Blank group (n = 6), Oil group (n = 6), and Oil + DHEA-induced model group (n = 6 + 12). The model groups were established by subcutaneous injection of DHEA for 35 consecutive days. The 12 successful model rats were additionally divided in vehicle group (n = 6) and SB431542-treated group (n = 6). Vehicle group and SB431542-treated group, served as administration group and were intraperitoneally injected with DMSO and SB431542 for additional 14 consecutive days. Ovarian morphology, fibrin and collagen localization and expression in ovaries were detected using H&E staining, immunohistochemistry and Sirius red staining. The ovarian protein and RNA were examined using Western blot and RT-PCR. In DHEA-induced ovary in rat, fibrin and collagen had significantly higher levels, while the main fibrosis markers (TGF-β, CTGF, fibronectin, a-SMA) were obviously upregulated. SB431542 significantly reduced the expression of pro-fibrotic molecules (TGF-β, Smad3, Smad2, a-SMA) and increased anti-fibrotic factor MMP2. TGF-βRI inhibitor (SB431542) inhibits the downstream signaling molecules of TGF-β and upregulates MMP2, which in turn prevent collagen deposition. Moreover, ovarian hyperfibrosis in DHEA-induced PCOS rat model could be improved by TGF-βRI inhibitor (SB431542) restraining the transcription of accelerating fibrosis genes and modulating EMT mediator.

  19. DHA suppresses Prevotella intermedia lipopolysaccharide-induced production of proinflammatory mediators in murine macrophages.

    Science.gov (United States)

    Choi, Eun-Young; Jin, Ji-Young; Choi, Jeom-Il; Choi, In Soon; Kim, Sung-Jo

    2014-04-14

    Several reports have indicated that dietary intake of DHA is associated with lower prevalence of periodontitis. In the present study, we investigated the effect of DHA on the production of proinflammatory mediators in murine macrophage-like RAW264.7 cells stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen implicated in inflammatory periodontal disease, and its mechanisms of action. LPS was isolated from lyophilised P. intermedia ATCC 25,611 cells using the standard hot-phenol-water protocol. Culture supernatants were collected and assayed for NO, IL-1β and IL-6. Real-time PCR analysis was carried out to detect the expression of inducible NO synthase (iNOS), IL-1β, IL-6 and haeme oxygenase-1 (HO-1) mRNA. Immunoblot analysis was carried out to quantify the expression of iNOS and HO-1 protein and concentrations of signalling proteins. DNA-binding activities of NF-κB subunits were determined using an ELISA-based assay kit. DHA significantly attenuated the production of NO, IL-1β and IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW264.7 cells. DHA induced the expression of HO-1 in cells treated with P. intermedia LPS. Selective inhibition of HO-1 activity by tin protoporphyrin IX significantly mitigated the inhibitory effects of DHA on LPS-induced NO production. DHA significantly attenuated the phosphorylation of c-Jun N-terminal kinase induced by LPS. In addition, DHA suppressed the transcriptional activity of NF-κB by regulating the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and inhibited the phosphorylation of signal transducer and activator of transcription 1. Further in vivo studies are needed to better evaluate the potential of DHA in humans as a therapeutic agent to treat periodontal disease.

  20. Repetitive Transient Ischemia-Induced Cardiac Angiogenesis is Mediated by Camkii Activation

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    Zhuobin Chen

    2018-05-01

    Full Text Available Background/Aims: Coronary angiogenesis is an important protective mechanism in response to myocardial ischemia in coronary artery disease. However, the underlying mechanisms remain largely unclear. Here, we investigated the role of CaMKII activation in ischemia-induced cardiac angiogenesis. Methods: Repetitive transient ischemia model was established in C57/BL6 mice by daily multiple episodes (3 times/day of short time (5 min occlusion of the left anterior descending coronary artery for 7 days. Coronary angiogenesis was detected by immunofluorescent staining. RT-qPCR and Western blot analyses were used to detect the mRNA and protein levels of CaMKII, p-CaMKII and VEGF. Primary cardiac microvascular endothelial cells (CMECs were isolated to investigate the effects of KN93 on cell proliferation and migration in hypoxic condition. Results: We found that angiogenesis was induced in the ischemic myocardium and suppressed by chronic intraperitoneal injection of CaMKII inhibitor KN93. RT-qPCR and Western blot analyses showed that myocardial ischemia induced an increased expression and autophosphorylation of CaMKII. VEGF expression was increased in the ischemia model but blunted by KN93. Moreover, KN93 suppressed the proliferation and migration of cardiac endothelial cells in hypoxic condition in which the protein expression of CaMKII, p-CaMKII and VEGF was increased. Conclusion: CaMKII is an important mediator for the ischemia-induced coronary angiogenesis, in which CaMKII-triggered VEGF expression plays a key role.

  1. Ionotropic glutamate receptors mediate inducible defense in the water flea Daphnia pulex.

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    Hitoshi Miyakawa

    Full Text Available Phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. It seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. Inducible defenses, in which prey animals alter their morphology, behavior and/or other traits to help protect against direct or latent predation threats, are among the most striking examples of phenotypic plasticity. The freshwater microcrustacean Daphnia pulex forms tooth-like defensive structures, "neckteeth," in response to chemical cues or signals, referred to as "kairomones," in this case released from phantom midge larvae, a predator of D. pulex. To identify factors involved in the reception and/or transmission of a kairomone, we used microarray analysis to identify genes up-regulated following a short period of exposure to the midge kairomone. In addition to identifying differentially expressed genes of unknown function, we also found significant up-regulation of genes encoding ionotropic glutamate receptors, which are known to be involved in neurotransmission in many animal species. Specific antagonists of these receptors strongly inhibit the formation of neckteeth in D. pulex, although agonists did not induce neckteeth by themselves, indicating that ionotropic glutamate receptors are necessary but not sufficient for early steps of neckteeth formation in D. pulex. Moreover, using co-exposure of D. pulex to antagonists and juvenile hormone (JH, which physiologically mediates neckteeth formation, we found evidence suggesting that the inhibitory effect of antagonists is not due to direct inhibition of JH synthesis/secretion. Our findings not only provide a candidate molecule required for the inducible defense response in D. pulex, but also will contribute to the understanding of complex mechanisms

  2. Differential activation of airway eosinophils induces IL-13-mediated allergic Th2 pulmonary responses in mice.

    Science.gov (United States)

    Jacobsen, E A; Doyle, A D; Colbert, D C; Zellner, K R; Protheroe, C A; LeSuer, W E; Lee, N A; Lee, J J

    2015-09-01

    Eosinophils are hallmark cells of allergic Th2 respiratory inflammation. However, the relative importance of eosinophil activation and the induction of effector functions such as the expression of IL-13 to allergic Th2 pulmonary disease remain to be defined. Wild-type or cytokine-deficient (IL-13(-/-) or IL-4(-/-) ) eosinophils treated with cytokines (GM-CSF, IL-4, IL-33) were adoptively transferred into eosinophil-deficient recipient mice subjected to allergen provocation using established models of respiratory inflammation. Allergen-induced pulmonary changes were assessed. In contrast to the transfer of untreated blood eosinophils to the lungs of recipient eosinophil deficient mice, which induced no immune/inflammatory changes either in the lung or in the lung draining lymph nodes (LDLN), pretreatment of blood eosinophils with GM-CSF prior to transfer elicited trafficking of these eosinophils to LDLN. In turn, these LDLN eosinophils elicited the accumulation of dendritic cells and CD4(+) T cells to these same LDLNs without inducing pulmonary inflammation. However, exposure of eosinophils to GM-CSF, IL-4, and IL-33 prior to transfer induced not only immune events in the LDLN, but also allergen-mediated increases in airway Th2 cytokine/chemokine levels, the subsequent accumulation of CD4(+) T cells as well as alternatively activated (M2) macrophages, and the induction of pulmonary histopathologies. Significantly, this allergic respiratory inflammation was dependent on eosinophil-derived IL-13, whereas IL-4 expression by eosinophils had no significant role. The data demonstrate the differential activation of eosinophils as a function of cytokine exposure and suggest that eosinophil-specific IL-13 expression by activated cells is a necessary component of the subsequent allergic Th2 pulmonary pathologies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Differential Activation of Airway Eosinophils Induces IL-13 Mediated Allergic Th2 Pulmonary Responses in Mice

    Science.gov (United States)

    Jacobsen, EA; Doyle, AD; Colbert, DC; Zellner, KR; Protheroe, CA; LeSuer, WE; Lee, NA.; Lee, JJ

    2015-01-01

    Background Eosinophils are hallmark cells of allergic Th2 respiratory inflammation. However, the relative importance of eosinophil activation and the induction of effector functions such as the expression of IL-13 to allergic Th2 pulmonary disease remain to be defined. Methods Wild type or cytokine deficient (IL-13−/− or IL-4−/−) eosinophils treated with cytokines (GM-CSF, IL-4, IL-33) were adoptively transferred into eosinophil-deficient recipient mice subjected to allergen provocation using established models of respiratory inflammation. Allergen-induced pulmonary changes were assessed. Results In contrast to the transfer of untreated blood eosinophils to the lungs of recipient eosinophildeficient mice, which induced no immune/inflammatory changes either in the lung or lung draining lymph nodes (LDLNs), pretreatment of blood eosinophils with GM-CSF prior to transfer elicited trafficking of these eosinophils to LDLNs. In turn, these LDLN eosinophils elicited the accumulation of dendritic cells and CD4+ T cells to these same LDLNs without inducing pulmonary inflammation. However, exposure of eosinophils to GM-CSF, IL-4 and IL-33 prior to transfer induced not only immune events in the LDLN, but also allergen-mediated increases in airway Th2 cytokine/chemokine levels, the subsequent accumulation of CD4+ T cells as well as alternatively activated (M2) macrophages, and the induction of pulmonary histopathologies. Significantly, this allergic respiratory inflammation was dependent on eosinophil-derived IL-13 whereas IL-4 expression by eosinophils had no significant role. Conclusion The data demonstrate the differential activation of eosinophils as a function of cytokine exposure and suggest that eosinophil-specific IL-13 expression by activated cells is a necessary component of the subsequent allergic Th2 pulmonary pathologies. PMID:26009788

  4. Silibinin induces mitochondrial NOX4-mediated endoplasmic reticulum stress response and its subsequent apoptosis

    International Nuclear Information System (INIS)

    Kim, Sang-Hun; Kim, Kwang-Youn; Yu, Sun-Nyoung; Seo, Young-Kyo; Chun, Sung-Sik; Yu, Hak-Sun; Ahn, Soon-Cheol

    2016-01-01

    Silibinin, a biologically active compound of milk thistle, has chemopreventive effects on cancer cell lines. Recently it was reported that silibinin inhibited tumor growth through activation of the apoptotic signaling pathway. Although various evidences showed multiple signaling pathways of silibinin in apoptosis, there were no reports to address the clear mechanism of ROS-mediated pathway in prostate cancer PC-3 cells. Several studies suggested that reactive oxygen species (ROS) play an important role in various signaling cascades, but the primary source of ROS was currently unclear. The effect of silibinin was investigated on cell growth of prostate cell lines by MTT assay. We examined whether silibinin induced apoptosis through production of ROS using flow cytometry. Expression of apoptosis-, endoplasmic reticulum (ER)-related protein and gene were determined by western blotting and RT-PCR, respectively. Results showed that silibinin triggered mitochondrial ROS production through NOX4 expression and finally led to induce apoptosis. In addition, mitochondrial ROS caused ER stress through disruption of Ca 2+ homeostasis. Co-treatment of ROS inhibitor reduced the silibinin-induced apoptosis through the inhibition of NOX4 expression, resulting in reduction of both Ca 2+ level and ER stress response. Taken together, silibinin induced mitochondrial ROS-dependent apoptosis through NOX4, which is associated with disruption of Ca 2+ homeostasis and ER stress response. Therefore, the regulation of NOX4, mitochondrial ROS producer, could be a potential target for the treatment of prostate cancer. The online version of this article (doi:10.1186/s12885-016-2516-6) contains supplementary material, which is available to authorized users

  5. Cr(VI) induces mitochondrial-mediated and caspase-dependent apoptosis through reactive oxygen species-mediated p53 activation in JB6 Cl41 cells

    International Nuclear Information System (INIS)

    Son, Young-Ok; Hitron, J. Andrew; Wang Xin; Chang Qingshan; Pan Jingju; Zhang Zhuo; Liu Jiankang; Wang Shuxia; Lee, Jeong-Chae; Shi Xianglin

    2010-01-01

    Cr(VI) compounds are known to cause serious toxic and carcinogenic effects. Cr(VI) exposure can lead to a severe damage to the skin, but the mechanisms involved in the Cr(VI)-mediated toxicity in the skin are unclear. The present study examined whether Cr(VI) induces cell death by apoptosis or necrosis using mouse skin epidermal cell line, JB6 Cl41 cells. We also investigated the cellular mechanisms of Cr(VI)-induced cell death. This study showed that Cr(VI) induced apoptotic cell death in a dose-dependent manner, as demonstrated by the appearance of cell shrinkage, the migration of cells into the sub-G1 phase, the increase of Annexin V positively stained cells, and the formation of nuclear DNA ladders. Cr(VI) treatment resulted in the increases of mitochondrial membrane depolarization and caspases activation. Electron spin resonance (ESR) and fluorescence analysis revealed that Cr(VI) increased intracellular levels of reactive oxygen species (ROS) such as hydrogen peroxide and superoxide anion radical in dose-dependent manner. Blockage of p53 by si-RNA transfection suppressed mitochondrial changes of Bcl-2 family composition, mitochondrial membrane depolarization, caspase activation and PARP cleavage, leading to the inhibition of Cr(VI)-induced apoptosis. Further, catalase treatment prevented p53 phosphorylation stimulated by Cr(VI) with the concomitant inhibition of caspase activation. These results suggest that Cr(VI) induced a mitochondrial-mediated and caspase-dependent apoptosis in skin epidermal cells through activation of p53, which are mainly mediated by reactive oxidants generated by the chemical.

  6. Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

    International Nuclear Information System (INIS)

    Gandhi, Adarsh; Guo, Tao; Shah, Pranav; Moorthy, Bhagavatula; Ghose, Romi

    2013-01-01

    Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP +/+ and TIRAP −/− mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP +/+ mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP −/− mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies provide novel mechanistic

  7. Chlorpromazine-induced hepatotoxicity during inflammation is mediated by TIRAP-dependent signaling pathway in mice

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Adarsh, E-mail: adarsh.gandhi@nih.gov [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Guo, Tao, E-mail: tguo4@jhu.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Shah, Pranav [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States); Moorthy, Bhagavatula [Baylor College of Medicine, Department of Pediatrics, 1102 Bates Avenue, Suite 530, Houston, TX 77030 (United States); Ghose, Romi, E-mail: rghose@uh.edu [University of Houston, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, 1441 Moursund Street, Room 517, Houston, TX 77030 (United States)

    2013-02-01

    Inflammation is a major component of idiosyncratic adverse drug reactions (IADRs). To understand the molecular mechanism of inflammation-mediated IADRs, we determined the role of the Toll-like receptor (TLR) signaling pathway in idiosyncratic hepatotoxicity of the anti-psychotic drug, chlorpromazine (CPZ). Activation of TLRs recruits the first adaptor protein, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to the TIR domain of TLRs leading to the activation of the downstream kinase, c-Jun-N-terminal kinase (JNK). Prolonged activation of JNK leads to cell-death. We hypothesized that activation of TLR2 by lipoteichoic acid (LTA) or TLR4 by lipopolysaccharide (LPS) will augment the hepatotoxicity of CPZ by TIRAP-dependent mechanism involving prolonged activation of JNK. Adult male C57BL/6, TIRAP{sup +/+} and TIRAP{sup −/−} mice were pretreated with saline, LPS (2 mg/kg) or LTA (6 mg/kg) for 30 min or 16 h followed by CPZ (5 mg/kg) or saline (vehicle) up to 24 h. We found that treatment of mice with CPZ in presence of LPS or LTA leads to ∼ 3–4 fold increase in serum ALT levels, a marked reduction in hepatic glycogen content, significant induction of serum tumor necrosis factor (TNF) α and prolonged JNK activation, compared to LPS or LTA alone. Similar results were observed in TIRAP{sup +/+} mice, whereas the effects of LPS or LTA on CPZ-induced hepatotoxicity were attenuated in TIRAP{sup −/−} mice. For the first time, we show that inflammation-mediated hepatotoxicity of CPZ is dependent on TIRAP, and involves prolonged JNK activation in vivo. Thus, TIRAP-dependent pathways may be targeted to predict and prevent inflammation-mediated IADRs. -- Highlights: ► Inflammation augments the toxicity of an idiosyncratic hepatotoxin chlorpromazine. ► Activation of Toll-like receptors by LPS or LTA induces chlorpromazine toxicity. ► Sustained stress kinase (JNK) activation is associated with chlorpromazine toxicity. ► These studies

  8. PGE{sub 2}-induced colon cancer growth is mediated by mTORC1

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, Marc, E-mail: Marc.dufour@chuv.ch; Faes, Seraina, E-mail: Seraina.faes@chuv.ch; Dormond-Meuwly, Anne, E-mail: Anne.meuwly-Dormond@chuv.ch; Demartines, Nicolas, E-mail: Demartines@chuv.ch; Dormond, Olivier, E-mail: Olivier.dormond@chuv.ch

    2014-09-05

    Highlights: • PGE{sub 2} activates mTORC1 in colon cancer cells. • Inhibition of mTORC1 blocks PGE{sub 2} induced colon cancer cell growth. • mTORC1 is a signaling intermediary in PGE{sub 2} induced colon cancer cell responses. - Abstract: The inflammatory prostaglandin E{sub 2} (PGE{sub 2}) cytokine plays a key role in the development of colon cancer. Several studies have shown that PGE{sub 2} directly induces the growth of colon cancer cells and furthermore promotes tumor angiogenesis by increasing the production of the vascular endothelial growth factor (VEGF). The signaling intermediaries implicated in these processes have however not been fully characterized. In this report, we show that the mechanistic target of rapamycin complex 1 (mTORC1) plays an important role in PGE{sub 2}-induced colon cancer cell responses. Indeed, stimulation of LS174T cells with PGE{sub 2} increased mTORC1 activity as observed by the augmentation of S6 ribosomal protein phosphorylation, a downstream effector of mTORC1. The PGE{sub 2} EP{sub 4} receptor was responsible for transducing the signal to mTORC1. Moreover, PGE{sub 2} increased colon cancer cell proliferation as well as the growth of colon cancer cell colonies grown in matrigel and blocking mTORC1 by rapamycin or ATP-competitive inhibitors of mTOR abrogated these effects. Similarly, the inhibition of mTORC1 by downregulation of its component raptor using RNA interference blocked PGE{sub 2}-induced LS174T cell growth. Finally, stimulation of LS174T cells with PGE{sub 2} increased VEGF production which was also prevented by mTORC1 inhibition. Taken together, these results show that mTORC1 is an important signaling intermediary in PGE{sub 2} mediated colon cancer cell growth and VEGF production. They further support a role for mTORC1 in inflammation induced tumor growth.

  9. Menadione induces the formation of reactive oxygen species and depletion of GSH-mediated apoptosis and inhibits the FAK-mediated cell invasion.

    Science.gov (United States)

    Kim, Yun Jeong; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Chung Soo

    2014-09-01

    Menadione induces apoptosis in tumor cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to menadione is not clear. In addition, it is unclear whether menadione-induced apoptosis is mediated by the depletion of glutathione (GSH) contents that is associated with the formation of reactive oxygen species. Furthermore, the effect of menadione on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of menadione exposure on apoptosis, cell adhesion, and cell migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that menadione may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of menadione appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Menadione inhibited fetal-bovine-serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase (FAK)-dependent activation of cytoskeletal-associated components. Therefore, menadione might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

  10. Adhesion Regulating Molecule 1 Mediates HAP40 Overexpression-Induced Mitochondrial Defects

    Science.gov (United States)

    Huang, Zih-Ning; Chung, Her Min; Fang, Su-Chiung; Her, Lu-Shiun

    2017-01-01

    Striatal neuron death in Huntington's disease is associated with abnormal mitochondrial dynamics and functions. However, the mechanisms for this mitochondrial dysregulation remain elusive. Increased accumulation of Huntingtin-associated protein 40 (HAP40) has been shown to be associated with Huntington's disease. However, the link between increased HAP40 and Huntington's disease remains largely unknown. Here we show that HAP40 overexpression causes mitochondrial dysfunction and reduces cell viability in the immortalized mouse striatal neurons. HAP40-associated mitochondrial dysfunction is associated with reduction of adhesion regulating molecule 1 (ADRM1) protein. Consistently, depletion of ADRM1 by shRNAs impaired mitochondrial functions and increased mitochondrial fragmentation in mouse striatal cells. Moreover, reducing ADRM1 levels enhanced activity of fission factor dynamin-related GTPase protein 1 (Drp1) via increased phosphorylation at serine 616 of Drp1 (Drp1Ser616). Restoring ADRM1 protein levels was able to reduce HAP40-induced ROS levels and mitochondrial fragmentation and improved mitochondrial functions and cell viability. Moreover, reducing Drp1 activity by Drp1 inhibitor, Mdivi-1, ameliorates both HAP40 overexpression- and ADRM1 depletion-induced mitochondrial dysfunction. Taken together, our studies suggest that HAP40-mediated reduction of ADRM1 alters the mitochondrial fission activity and results in mitochondrial fragmentation and mitochondrial dysfunction. PMID:29209146

  11. Ultradian hormone stimulation induces glucocorticoid receptor-mediated pulses of gene transcription.

    Science.gov (United States)

    Stavreva, Diana A; Wiench, Malgorzata; John, Sam; Conway-Campbell, Becky L; McKenna, Mervyn A; Pooley, John R; Johnson, Thomas A; Voss, Ty C; Lightman, Stafford L; Hager, Gordon L

    2009-09-01

    Studies on glucocorticoid receptor (GR) action typically assess gene responses by long-term stimulation with synthetic hormones. As corticosteroids are released from adrenal glands in a circadian and high-frequency (ultradian) mode, such treatments may not provide an accurate assessment of physiological hormone action. Here we demonstrate that ultradian hormone stimulation induces cyclic GR-mediated transcriptional regulation, or gene pulsing, both in cultured cells and in animal models. Equilibrium receptor-occupancy of regulatory elements precisely tracks the ligand pulses. Nascent RNA transcripts from GR-regulated genes are released in distinct quanta, demonstrating a profound difference between the transcriptional programs induced by ultradian and constant stimulation. Gene pulsing is driven by rapid GR exchange with response elements and by GR recycling through the chaperone machinery, which promotes GR activation and reactivation in response to the ultradian hormone release, thus coupling promoter activity to the naturally occurring fluctuations in hormone levels. The GR signalling pathway has been optimized for a prompt and timely response to fluctuations in hormone levels, indicating that biologically accurate regulation of gene targets by GR requires an ultradian mode of hormone stimulation.

  12. Hypoxia-inducible factor directs POMC gene to mediate hypothalamic glucose sensing and energy balance regulation.

    Directory of Open Access Journals (Sweden)

    Hai Zhang

    2011-07-01

    Full Text Available Hypoxia-inducible factor (HIF is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance.

  13. Adrenal hormones mediate melatonin-induced increases in aggression in male Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Demas, Gregory E; Polacek, Kelly M; Durazzo, Alfredo; Jasnow, Aaron M

    2004-12-01

    Among the suite of seasonal adaptations displayed by nontropical rodents, some species demonstrate increased territorial aggression in short compared with long day lengths despite basal levels of testosterone. The precise physiological mechanisms mediating seasonal changes in aggression, however, remain largely unknown. The goal of the present study was to examine the role of melatonin, as well as adrenal hormones, in the regulation of seasonal aggression in male Siberian hamsters (Phodopus sungorus). In Experiment 1, male Siberian hamsters received either daily (s.c.) injections of melatonin (15 microg/day) or saline 2 h before lights out for 10 consecutive days. In Experiment 2, hamsters received adrenal demedullations (ADMEDx), whereas in Experiment 3 animals received adrenalectomies (ADx); control animals in both experiments received sham surgeries. Animals in both experiments subsequently received daily injections of melatonin or vehicle as in Experiment 1. Animals in all experiments were tested using a resident-intruder model of aggression. In Experiment 1, exogenous melatonin treatment increased aggression compared with control hamsters. In Experiment 2, ADMEDx had no effect on melatonin-induced aggression. In Experiment 3, the melatonin-induced increase in aggression was significantly attenuated by ADx. Collectively, the results of the present study demonstrate that short day-like patterns of melatonin increase aggression in male Siberian hamsters and suggest that increased aggression is due, in part, to changes in adrenocortical steroids.

  14. Immune-relevant thrombocytes of common carp undergo parasite-induced nitric oxide-mediated apoptosis.

    Science.gov (United States)

    Fink, Inge R; Ribeiro, Carla M S; Forlenza, Maria; Taverne-Thiele, Anja; Rombout, Jan H W M; Savelkoul, Huub F J; Wiegertjes, Geert F

    2015-06-01

    Common carp thrombocytes account for 30-40% of peripheral blood leukocytes and are abundant in the healthy animals' spleen, the thrombopoietic organ. We show that, ex vivo, thrombocytes from healthy carp express a large number of immune-relevant genes, among which several cytokines and Toll-like receptors, clearly pointing at immune functions of carp thrombocytes. Few studies have described the role of fish thrombocytes during infection. Carp are natural host to two different but related protozoan parasites, Trypanoplasma borreli and Trypanosoma carassii, which reside in the blood and tissue fluids. We used the two parasites to undertake controlled studies on the role of fish thrombocytes during these infections. In vivo, but only during infection with T. borreli, thrombocytes were massively depleted from the blood and spleen leading to severe thrombocytopenia. Ex vivo, addition of nitric oxide induced a clear and rapid apoptosis of thrombocytes from healthy carp, supporting a role for nitric oxide-mediated control of immune-relevant thrombocytes during infection with T. borreli. The potential advantage for parasites to selectively deplete the host of thrombocytes via nitric oxide-induced apoptosis is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Hypoxia-Inducible Factor Directs POMC Gene to Mediate Hypothalamic Glucose Sensing and Energy Balance Regulation

    Science.gov (United States)

    Zhang, Hai; Zhang, Guo; Gonzalez, Frank J.; Park, Sung-min; Cai, Dongsheng

    2011-01-01

    Hypoxia-inducible factor (HIF) is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance. PMID:21814490

  16. GABA(A) receptors mediate orexin-A induced stimulation of food intake.

    Science.gov (United States)

    Kokare, Dadasaheb M; Patole, Angad M; Carta, Anna; Chopde, Chandrabhan T; Subhedar, Nishikant K

    2006-01-01

    Although the role of orexins in sleep/wake cycle and feeding behavior is well established, underlying mechanisms have not been fully understood. An attempt has been made to investigate the role of GABA(A) receptors and their benzodiazepine site on the orexin-A induced response to feeding. Different groups of rats were food deprived overnight and next day injected intracerebroventricularly (icv) with vehicle (artificial CSF; 5 microl/rat) or orexin-A (20-50 nM/rat) and the animals were given free access to food. Cumulative food intake was measured during light phase of light/dark cycle at 1-, 2-, 4- and 6-h post-injection time points. Orexin-A (30-50 nM/rat, icv) stimulated food intake at all the time points (P GABA(A) receptor agonists muscimol (25 ng/rat, icv) and diazepam (0.5 mg/kg, ip) at subeffective doses significantly potentiated the hyperphagic effect of orexin-A (30 nM/rat, icv). However, the effect was negated by the GABA(A) receptor antagonist bicuculline (1 mg/kg, ip). Interestingly, benzodiazepine receptor antagonist flumazenil (5 ng/rat, icv), augmented the orexin-A (30 nM/rat, icv) induced hyperphagia; the effect may be attributed to the intrinsic activity of the agent. The results suggest that the hyperphagic effect of orexin-A, at least in part, is mediated by enhanced GABA(A) receptor activity.

  17. A mitochondria-dependent pathway mediates the apoptosis of GSE-induced yeast.

    Directory of Open Access Journals (Sweden)

    Sishuo Cao

    Full Text Available Grapefruit seed extract (GSE, which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL and 4,6'-diaminidino-2-phenylindole (DAPI staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential and ROS (reactive oxygen species indicated that the mitochondria took part in the apoptotic process. Changes in this process detected by metabonomics and proteomics revealed that the yeast cells tenaciously resisted adversity. Proteins related to redox, cellular structure, membrane, energy and DNA repair were significantly increased. In this study, the relative changes in the levels of proteins and metabolites showed the tenacious resistance of yeast cells. However, GSE induced apoptosis in the yeast cells by destruction of the mitochondrial 60 S ribosomal protein, L14-A, and prevented the conversion of pantothenic acid to coenzyme A (CoA. The relationship between the proteins and metabolites was analyzed by orthogonal projections to latent structures (OPLS. We found that the changes of the metabolites and the protein changes had relevant consistency.

  18. Mediator profiles in tears during the conjunctival response induced by allergic reaction in the nasal mucosa.

    Science.gov (United States)

    Pelikan, Zdenek

    2013-01-01

    The allergic reaction occurring primarily in the nasal mucosa can induce a secondary conjunctival response of an immediate (SICR), late (SLCR), or delayed (SDYCR) type in some patients with allergic conjunctivitis (AC). To investigate the concentration changes of histamine, tryptase, eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN), leukotrienes (LTB 4, LTC4, LTE4), myeloperoxidase (MPO), interferon-γ (IFN-γ), and interleukins (IL-2, IL-4, IL-5) in tears during the SICR, SLCR, and SDYCR. In 32 patients with AC, 11 SICR (ptears. The SICRs were associated with significant concentration changes in tears (ptears (ptears during the 32 PBS controls (p>0.1) or in the ten control patients (p>0.1). These results provide evidence for causal involvement of nasal allergy in some patients with AC, inducing secondary conjunctival response of immediate (SICR), late SLCR, or delayed SDYCR type, associated with different mediator, cytokine, and cellular profiles in the tears, suggesting involvement of different hypersensitivity mechanisms. These results also emphasize the diagnostic value of nasal allergen challenge combined with monitoring of the conjunctival response in some patients with AC.

  19. Inflammatory mediator profiles in tears accompanying keratoconjunctival responses induced by nasal allergy.

    Science.gov (United States)

    Pelikan, Zdenek

    2013-07-01

    The allergic reaction taking place in the nasal mucosa can induce a secondary ocular (keratoconjunctival) response of an immediate (SIOR), late (SLOR) or delayed (SDYOR) type in some patients with keratoconjunctivitis (KC). To investigate the concentration changes of histamine, tryptase, eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP), eosinophilic peroxidase (EPO), leucotrienes (LTB₄, LTC₄, LTE₄), prostaglandins (PGD₂, PGE₂ and PGF₂α), thromboxane B₂ (TXB₂), myeloperoxidase (MPO), interferon-γ (IFN-γ) and interleukins (IL-2, IL-4 and IL-5) in tears during the SIOR, SLOR and SDYOR. 19 SIORs (ptears. The ocular response types were associated with significant changes (ptears as follows: (1) SIORs: histamine, tryptase, ECP, LTC₄, PGD₂, PGF₂α, IL-4 and IL-5; (2) SLORs: histamine, ECP, EDN, LTB₄, LTC₄, PGE₂, MPO, IL-4 and IL-5; (3) SDYORs: LTB4, TXB₂, MPO, IFN-γ and IL-2. No significant changes of these factors were measured in tears during the 57 PBS controls (p>0.1). These results demonstrate a causal involvement of nasal allergy in some KC patients, inducing a secondary keratoconjunctival response of an immediate (SIOR), late (SLOR) or delayed (SDYOR) type, associated with different inflammatory mediator profiles in the tears, suggesting participation of different hypersensitivity mechanisms. These results also emphasise the diagnostic value of nasal challenge with allergen combined with monitoring of ocular response in KC patients, responding insufficiently to the usual ophthalmologic therapy.

  20. ROS-mediated abiotic stress-induced programmed cell death in plants

    Directory of Open Access Journals (Sweden)

    Veselin ePetrov

    2015-02-01

    Full Text Available During the course of their ontogenesis, plants are continuously exposed to a large variety of abiotic stress factors which can damage tissues and jeopardize the survival of the organism unless properly countered. While animals can simply escape and thus evade stressors, plants as sessile organisms have developed complex strategies to withstand them. When the intensity of a detrimental factor is high, one of the defense programs employed by plants is the induction of programmed cell death (PCD. This is an active, genetically controlled process which is initiated to isolate and remove damaged tissues thereby ensuring the survival of the organism. The mechanism of PCD induction usually includes an increase in the levels of reactive oxygen species (ROS which are utilized as mediators of the stress signal. Abiotic stress-induced PCD is not only a process of fundamental biological importance, but also of considerable interest to agricultural practice as it has the potential to significantly influence crop yield. Therefore, numerous scientific enterprises have focused on elucidating the mechanisms leading to and controlling PCD in response to adverse conditions in plants. This knowledge may help to develop novel strategies to obtain more resilient crop varieties with improved tolerance and enhanced productivity. The aim of the present review is to summarize the recent advances in research on ROS-induced PCD related to abiotic stress and the role of the organelles in the process.

  1. Tribbles 3 Mediates Endoplasmic Reticulum Stress-Induced Insulin Resistance in Skeletal Muscle

    Science.gov (United States)

    Koh, Ho-Jin; Toyoda, Taro; Didesch, Michelle M.; Lee, Min-Young; Sleeman, Mark W.; Kulkarni, Rohit N.; Musi, Nicolas; Hirshman, Michael F.; Goodyear, Laurie J.

    2013-01-01

    Endoplasmic Reticulum (ER) stress has been linked to insulin resistance in multiple tissues but the role of ER stress in skeletal muscle has not been explored. ER stress has also been reported to increase tribbles 3 (TRB3) expression in multiple cell lines. Here, we report that high fat feeding in mice, and obesity and type 2 diabetes in humans significantly increases TRB3 and ER stress markers in skeletal muscle. Overexpression of TRB3 in C2C12 myotubes and mouse tibialis anterior muscles significantly impairs insulin signaling. Incubation of C2C12 cells and mouse skeletal muscle with ER stressors thapsigargin and tunicamycin increases TRB3 and impairs insulin signaling and glucose uptake, effects reversed in cells overexpressing RNAi for TRB3 and in muscles from TRB3 knockout mice. Furthermore, TRB3 knockout mice are protected from high fat diet-induced insulin resistance in skeletal muscle. These data demonstrate that TRB3 mediates ER stress-induced insulin resistance in skeletal muscle. PMID:23695665

  2. The OXI1 kinase pathway mediates Piriformospora indica-induced growth promotion in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Iris Camehl

    2011-05-01

    Full Text Available Piriformospora indica is an endophytic fungus that colonizes roots of many plant species and promotes growth and resistance to certain plant pathogens. Despite its potential use in agriculture, little is known on the molecular basis of this beneficial plant-fungal interaction. In a genetic screen for plants, which do not show a P. indica- induced growth response, we isolated an Arabidopsis mutant in the OXI1 (Oxidative Signal Inducible1 gene. OXI1 has been characterized as a protein kinase which plays a role in pathogen response and is regulated by H₂O₂ and PDK1 (3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1. A genetic analysis showed that double mutants of the two closely related PDK1.1 and PDK1.2 genes are defective in the growth response to P. indica. While OXI1 and PDK1 gene expression is upregulated in P. indica-colonized roots, defense genes are downregulated, indicating that the fungus suppresses plant defense reactions. PDK1 is activated by phosphatidic acid (PA and P. indica triggers PA synthesis in Arabidopsis plants. Under beneficial co-cultivation conditions, H₂O₂ formation is even reduced by the fungus. Importantly, phospholipase D (PLDα1 or PLDδ mutants, which are impaired in PA synthesis do not show growth promotion in response to fungal infection. These data establish that the P. indica-stimulated growth response is mediated by a pathway consisting of the PLD-PDK1-OXI1 cascade.

  3. Phonon-mediated decay of an atom in a surface-induced potential

    International Nuclear Information System (INIS)

    Kien, Fam Le; Hakuta, K.; Dutta Gupta, S.

    2007-01-01

    We study phonon-mediated transitions between translational levels of an atom in a surface-induced potential. We present a general master equation governing the dynamics of the translational states of the atom. In the framework of the Debye model, we derive compact expressions for the rates for both upward and downward transitions. Numerical calculations for the transition rates are performed for a deep silica-induced potential allowing for a large number of bound levels as well as free states of a cesium atom. The total absorption rate is shown to be determined mainly by the bound-to-bound transitions for deep bound levels and by bound-to-free transitions for shallow bound levels. Moreover, the phonon emission and absorption processes can be orders of magnitude larger for deep bound levels as compared to the shallow bound ones. We also study various types of transitions from free states. We show that, for thermal atomic cesium with a temperature in the range from 100 μK to 400 μK in the vicinity of a silica surface with a temperature of 300 K, the adsorption (free-to-bound decay) rate is about two times larger than the heating (free-to-free upward decay) rate, while the cooling (free-to-free downward decay) rate is negligible

  4. Hypoxia-inducible factor 1–mediated characteristic features of cancer cells for tumor radioresistance

    International Nuclear Information System (INIS)

    Harada, Hiroshi

    2016-01-01

    Tumor hypoxia has been attracting increasing attention in the fields of radiation biology and oncology since Thomlinson and Gray detected hypoxic cells in malignant solid tumors and showed that they exert a negative impact on the outcome of radiation therapy. This unfavorable influence has, at least partly, been attributed to cancer cells acquiring a radioresistant phenotype through the activation of the transcription factor, hypoxia-inducible factor 1 (HIF-1). On the other hand, accumulating evidence has recently revealed that, even though HIF-1 is recognized as an important regulator of cellular adaptive responses to hypoxia, it may not become active and induce tumor radioresistance under hypoxic conditions only. The mechanisms by which HIF-1 is activated in cancer cells not only under hypoxic conditions, but also under normoxic conditions, through cancer-specific genetic alterations and the resultant imbalance in intermediate metabolites have been summarized herein. The relevance of the HIF-1–mediated characteristic features of cancer cells, such as the production of antioxidants through reprogramming of the glucose metabolic pathway and cell cycle regulation, for tumor radioresistance has also been reviewed

  5. A mitochondria-dependent pathway mediates the apoptosis of GSE-induced yeast.

    Science.gov (United States)

    Cao, Sishuo; Xu, Wentao; Zhang, Nan; Wang, Yan; Luo, YunBo; He, Xiaoyun; Huang, Kunlun

    2012-01-01

    Grapefruit seed extract (GSE), which has powerful anti-fungal activity, can induce apoptosis in S. cerevisiae. The yeast cells underwent apoptosis as determined by testing for apoptotic markers of DNA cleavage and typical chromatin condensation by Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) and 4,6'-diaminidino-2-phenylindole (DAPI) staining and electron microscopy. The changes of ΔΨmt (mitochondrial transmembrane potential) and ROS (reactive oxygen species) indicated that the mitochondria took part in the apoptotic process. Changes in this process detected by metabonomics and proteomics revealed that the yeast cells tenaciously resisted adversity. Proteins related to redox, cellular structure, membrane, energy and DNA repair were significantly increased. In this study, the relative changes in the levels of proteins and metabolites showed the tenacious resistance of yeast cells. However, GSE induced apoptosis in the yeast cells by destruction of the mitochondrial 60 S ribosomal protein, L14-A, and prevented the conversion of pantothenic acid to coenzyme A (CoA). The relationship between the proteins and metabolites was analyzed by orthogonal projections to latent structures (OPLS). We found that the changes of the metabolites and the protein changes had relevant consistency.

  6. Hypothalamic mTOR pathway mediates thyroid hormone-induced hyperphagia in hyperthyroidism.

    Science.gov (United States)

    Varela, Luis; Martínez-Sánchez, Noelia; Gallego, Rosalía; Vázquez, María J; Roa, Juan; Gándara, Marina; Schoenmakers, Erik; Nogueiras, Rubén; Chatterjee, Krishna; Tena-Sempere, Manuel; Diéguez, Carlos; López, Miguel

    2012-06-01

    Hyperthyroidism is characterized in rats by increased energy expenditure and marked hyperphagia. Alterations of thermogenesis linked to hyperthyroidism are associated with dysregulation of hypothalamic AMPK and fatty acid metabolism; however, the central mechanisms mediating hyperthyroidism-induced hyperphagia remain largely unclear. Here, we demonstrate that hyperthyroid rats exhibit marked up-regulation of the hypothalamic mammalian target of rapamycin (mTOR) signalling pathway associated with increased mRNA levels of agouti-related protein (AgRP) and neuropeptide Y (NPY), and decreased mRNA levels of pro-opiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC), an area where mTOR co-localizes with thyroid hormone receptor-α (TRα). Central administration of thyroid hormone (T3) or genetic activation of thyroid hormone signalling in the ARC recapitulated hyperthyroidism effects on feeding and the mTOR pathway. In turn, central inhibition of mTOR signalling with rapamycin in hyperthyroid rats reversed hyperphagia and normalized the expression of ARC-derived neuropeptides, resulting in substantial body weight loss. The data indicate that in the hyperthyroid state, increased feeding is associated with thyroid hormone-induced up-regulation of mTOR signalling. Furthermore, our findings that different neuronal modulations influence food intake and energy expenditure in hyperthyroidism pave the way for a more rational design of specific and selective therapeutic compounds aimed at reversing the metabolic consequences of this disease. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  7. Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats.

    Science.gov (United States)

    Song, J; Yin, J; Sallam, H S; Bai, T; Chen, Y; Chen, J D Z

    2013-10-01

    Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns. Male rats (intact and vagotomized) were implanted with gastric electrodes, chest and abdominal wall electrodes for investigating the effects of EA at ST-36 (stomach-36 or Zusanli) on GE, gastric slow waves, autonomic functions, and plasma interleukin 6 (IL-6) 6 and 24 h post severe burns. (i) Burn delayed GE (P Electroacupuncture improved GE 6 and 24 h post burn (P Electroacupuncture improved burn-induced gastric dysrhythmia. The percentage of normal slow waves was increased with EA 6 and 24 h post burn (P = 0.02). (iii) Electroacupuncture increased vagal activity assessed by the spectral analysis of heart rate variability (HRV). The high-frequency component reflecting vagal component was increased with EA 6 (P = 0.004) and 24 h post burn (P = 0.03, vs sham-EA). (iv) Electroacupuncture attenuated burn-induced increase in plasma IL-6 at both 6 (P = 0.03) and 24 h post burn (P = 0.003). Electroacupuncture at ST-36 improves gastric dysrhythmia and accelerates GE in rats with burns. The improvement seems to be mediated via the vagal pathway involving the inflammatory cytokine IL-6. © 2013 John Wiley & Sons Ltd.

  8. Calpain: a molecule to induce AIF-mediated necroptosis in RGC-5 following elevated hydrostatic pressure

    Science.gov (United States)

    2014-01-01

    Background RIP3 (Receptor-interacting protein 3) pathway was mainly described as the molecular mechanism of necroptosis (programmed necrosis). But recently, non-RIP3 pathways were found to mediate necroptosis. We deliberate to investigate the effect of calpain, a molecule to induce necroptosis as reported (Cell Death Differ 19:245–256, 2012), in RGC-5 following elevated hydrostatic pressure. Results First, we identified the existence of necroptosis of RGC-5 after insult by using necrostatin-1 (Nec-1, necroptosis inhibitor) detected by flow cytometry. Immunofluorescence staining and western blot were used to detect the expression of calpain. Western blot analysis was carried out to describe the truncated AIF (tAIF) expression with or without pretreatment of ALLN (calpain activity inhibitor). Following elevated hydrostatic pressure, necroptotic cells pretreated with or without ALLN was stained by Annexin V/PI, The activity of calpain was also examined to confirm the inhibition effect of ALLN. The results showed that after cell injury there was an upregulation of calpain expression. Upon adding ALLN, the calpain activity was inhibited, and tAIF production was reduced upon injury along with the decreased number of necroptosis cells. Conclusion Our study found that calpain may induce necroptosis via tAIF-modulation in RGC-5 following elevated hydrostatic pressure. PMID:24884644

  9. Investigations on UCS-CS mediation in radiation-induced conditioned taste aversion

    International Nuclear Information System (INIS)

    Burns, T.C.

    1974-01-01

    Groups of 8 male Sprague-Dawley rats were used in an investigation of procaine and dimenhydrinate effects on radiation-induced taste aversion learning. Neither the local anesthetic procaine, administered intraperitoneally, nor the antinausea drug dimenhydrinate, administered intramuscularly, blocked acquisition of aversion to saccharin flavored water. Control animals confirmed that saccharin preferences appeared normally in non-irradiated animals, and that the drugs produced no aversion in the absence of radiation. Another investigation, using groups of 5 female Sprague-Dawley rats, showed a failure of dimenhydrinate in blocking the acquisition of a rotation-induced conditioned taste aversion. Two dose levels of the drug were used, 1 mg/kg and 2 mg/kg. At the dimenhydrinate dosage used in the study involving radiation (1.75 mg/kg) and at the higher dosage used in the study involving rotation, there appeared to be a potentiation of the effects of radiation and rotation, respectively. Results of these studies seem to favor a model for UCS-CS mediation as being diffuse and perhaps redundant. The possibility that nausea-producing stimuli may work synergistically was also discussed. (U.S.)

  10. Glucocorticoids mediate stress-induced impairment of retrieval of stimulus-response memory.

    Science.gov (United States)

    Atsak, Piray; Guenzel, Friederike M; Kantar-Gok, Deniz; Zalachoras, Ioannis; Yargicoglu, Piraye; Meijer, Onno C; Quirarte, Gina L; Wolf, Oliver T; Schwabe, Lars; Roozendaal, Benno

    2016-05-01

    Acute stress and elevated glucocorticoid hormone levels are well known to impair the retrieval of hippocampus-dependent 'declarative' memory. Recent findings suggest that stress might also impair the retrieval of non-hippocampal memories. In particular, stress shortly before retention testing was shown to impair the retrieval of striatal stimulus-response associations in humans. However, the mechanism underlying this stress-induced retrieval impairment of non-hippocampal stimulus-response memory remains elusive. In the present study, we investigated whether an acute elevation in glucocorticoid levels mediates the impairing effects of stress on retrieval of stimulus-response memory. Male Sprague-Dawley rats were trained on a stimulus-response task in an eight-arm radial maze until they learned to associate a stimulus, i.e., cue, with a food reward in one of the arms. Twenty-four hours after successful acquisition, they received a systemic injection of vehicle, corticosterone (1mg/kg), the corticosterone-synthesis inhibitor metyrapone (35mg/kg) or were left untreated 1h before retention testing. We found that the corticosterone injection impaired the retrieval of stimulus-response memory. We further found that the systemic injection procedure per se was stressful as the vehicle administration also increased plasma corticosterone levels and impaired the retrieval of stimulus-response memory. However, memory retrieval was not impaired when rats were tested 2min after the systemic vehicle injection, before any stress-induced elevation in corticosterone levels had occurred. Moreover, metyrapone treatment blocked the effect of injection stress on both plasma corticosterone levels and memory retrieval impairment, indicating that the endogenous corticosterone response mediates the stress-induced memory retrieval impairment. None of the treatments affected rats' locomotor activity or motivation to search for the food reward within the maze. These findings show that stress

  11. TRPV4 activation mediates flow-induced nitric oxide production in the rat thick ascending limb

    Science.gov (United States)

    Garvin, Jeffrey L.

    2014-01-01

    Nitric oxide (NO) regulates renal function. Luminal flow stimulates NO production in the thick ascending limb (TAL). Transient receptor potential vanilloid 4 (TRPV4) is a mechano-sensitive channel activated by luminal flow in different types of cells. We hypothesized that TRPV4 mediates flow-induced NO production in the rat TAL. We measured NO production in isolated, perfused rat TALs using the fluorescent dye DAF FM. Increasing luminal flow from 0 to 20 nl/min stimulated NO from 8 ± 3 to 45 ± 12 arbitrary units (AU)/min (n = 5; P < 0.05). The TRPV4 antagonists, ruthenium red (15 μmol/l) and RN 1734 (10 μmol/l), blocked flow-induced NO production. Also, luminal flow did not increase NO production in the absence of extracellular calcium. We also studied the effect of luminal flow on NO production in TALs transduced with a TRPV4shRNA. In nontransduced TALs luminal flow increased NO production by 47 ± 17 AU/min (P < 0.05; n = 5). Similar to nontransduced TALs, luminal flow increased NO production by 39 ± 11 AU/min (P < 0.03; n = 5) in TALs transduced with a control negative sequence-shRNA while in TRPV4shRNA-transduced TALs, luminal flow did not increase NO production (Δ10 ± 15 AU/min; n = 5). We then tested the effect of two different TRPV4 agonists on NO production in the absence of luminal flow. 4α-Phorbol 12,13-didecanoate (1 μmol/l) enhanced NO production by 60 ± 11 AU/min (P < 0.002; n = 7) and GSK1016790A (10 ηmol/l) increased NO production by 52 ± 15 AU/min (P < 0.03; n = 5). GSK1016790A (10 ηmol/l) did not stimulate NO production in TRPV4shRNA-transduced TALs. We conclude that activation of TRPV4 channels mediates flow-induced NO production in the rat TAL. PMID:24966090

  12. Cyclic ADP-ribose and IP3 mediate abscisic acid-induced isoflavone accumulation in soybean sprouts

    International Nuclear Information System (INIS)

    Jiao, Caifeng; Yang, Runqiang; Gu, Zhenxin

    2016-01-01

    In this study, the roles of ABA-cADPR-Ca 2+ and ABA-IP3-Ca 2+ signaling pathways in UV-B-induced isoflavone accumulation in soybean sprouts were investigated. Results showed that abscisic acid (ABA) up regulated cyclic ADP-ribose (cADPR) and inositol 1,4,5-trisphosphate (IP3) levels in soybean sprouts under UV-B radiation. Furthermore, cADPR and IP3, as second messengers of UV-B-triggered ABA, induced isoflavone accumulation by up-regulating proteins and genes expression and activity of isoflavone biosynthetic-enzymes (chalcone synthase, CHS; isoflavone synthase, IFS). After Ca 2+ was chelated by EGTA, isoflavone content decreased. Overall, ABA-induced cADPR and IP3 up regulated isoflavone accumulation which was mediated by Ca 2+ signaling via enhancing the expression of proteins and genes participating in isoflavone biosynthesis in soybean sprouts under UV-B radiation. - Highlights: • UV-B-induced cADPR and IP3 synthesis was mediated by ABA. • cADPR and IP3 were involved in UV-B-ABA-induced isoflavone accumulation. • cADPR and IP3-induced isoflavone accumulation may be mediated by Ca 2+ . • ABA, cADPR, IP3 and Ca 2+ could activate proteins expression of CHS and IFS.

  13. Glycogen Synthase Kinase 3 Inactivation Induces Cell Senescence through Sterol Regulatory Element Binding Protein 1-Mediated Lipogenesis in Chang Cells.

    Science.gov (United States)

    Kim, You-Mie; Song, Insun; Seo, Yong-Hak; Yoon, Gyesoon

    2013-12-01

    Enhanced lipogenesis plays a critical role in cell senescence via induction of expression of the mature form of sterol regulatory element binding protein 1 (SREBP1), which contributes to an increase in organellar mass, one of the indicators of senescence. We investigated the molecular mechanisms by which signaling molecules control SREBP1-mediated lipogenesis and senescence. We developed cellular models for stress-induced senescence, by exposing Chang cells, which are immortalized human liver cells, to subcytotoxic concentrations (200 µM) of deferoxamine (DFO) and H2O2. In this model of stress-induced cell senescence using DFO and H2O2, the phosphorylation profile of glycogen synthase kinase 3α (GSK3α) and β corresponded closely to the expression profile of the mature form of SREBP-1 protein. Inhibition of GSK3 with a subcytotoxic concentration of the selective GSK3 inhibitor SB415286 significantly increased mature SREBP1 expression, as well as lipogenesis and organellar mass. In addition, GSK3 inhibition was sufficient to induce senescence in Chang cells. Suppression of GSK3 expression with siRNAs specific to GSK3α and β also increased mature SREBP1 expression and induced senescence. Finally, blocking lipogenesis with fatty acid synthase inhibitors (cerulenin and C75) and siRNA-mediated silencing of SREBP1 and ATP citrate lyase (ACL) significantly attenuated GSK3 inhibition-induced senescence. GSK3 inactivation is an important upstream event that induces SREBP1-mediated lipogenesis and consequent cell senescence.

  14. Prevalence of hypercalcemia of malignancy among pediatric cancer patients in the UK Clinical Practice Research Datalink database

    Directory of Open Access Journals (Sweden)

    Jick S

    2017-06-01

    Full Text Available Susan Jick,1 Lin Li,1 Victor M Gastanaga,2 Alexander Liede,2 Rohini K Hernandez2 1Boston Collaborative Drug Surveillance Program, Boston University School of Public Health, Lexington, MA, USA; 2Center for Observational Research, Amgen Inc., Thousand Oaks and South San Francisco, CA, USA Background: The reported proportion of cancer patients who experience hypercalcemia of malignancy (HCM is low, particularly in the pediatric population, ranging between <1% and 5%. HCM can be observed with any type of tumor in children and occurs most commonly with leukemia. While HCM is a potentially fatal condition, the prevalence of HCM is not well understood in pediatric cancer patients. Methods: Using the UK Clinical Practice Research Datalink, we identified pediatric cancer patients with recorded corrected serum calcium (CSC from 2003 through 2014. Hypercalcemic patients (CSC ≥10.8 mg/dL were classified into 4 CSC levels. We estimated the annual prevalence of HCM using Byar’s method. Results: Among 517 pediatric cancer patients, leukemia, lymphoma, and brain tumors were the most frequent cancer types. The prevalence of HCM overall (grade 1 or higher ranged from 0.24% to 0.81% between 2003 and 2014. There were too few cases to compare prevalence by type of cancer. Conclusion: We provide the first systematic analysis using a UK population-based data source to estimate the number of pediatric cancer patients affected with HCM by grade. Our findings showed that the prevalence of pediatric HCM was very low (0.24%–0.81% over the 12-year study period, which is consistent with previous study of adult cancer patients in the UK (0.20%–0.67%. Keywords: hypercalcemia, pediatric, cancer, prevalence, Clinical Practice Research Datalink

  15. Endogenous Opiates in the Nucleus Tractus Solitarius Mediate Electroacupuncture-Induced Sleep Activities in Rats

    Directory of Open Access Journals (Sweden)

    Chiung-Hsiang Cheng

    2011-01-01

    Full Text Available Electroacupuncture (EA possesses various therapeutic effects, including alleviation of pain, reduction of inflammation and improvement of sleep disturbance. The mechanisms of EA on sleep improvement, however, remain to be determined. It has been stated in ancient Chinese literature that the Anmian (EX17 acupoint is one of the trigger points that alleviates insomnia. We previously demonstrated that EA stimulation of Anmian acupoints in rats during the dark period enhances non-rapid eye movement (NREM sleep, which involves the induction of cholinergic activity in the nucleus tractus solitarius (NTS. In addition to cholinergic activation of the NTS, activation of the endogenous opioidergic system may also be a mechanism by which acupuncture affects sleep. Therefore, this study was designed to investigate the involvement of the NTS opioidergic system in EA-induced alterations in sleep. Our present results indicate that EA of Anmian acupoints increased NREM sleep, but not rapid eye movement sleep, during the dark period in rats. This enhancement in NREM sleep was dose-dependently blocked by microinjection of opioid receptor antagonist, naloxone, and the μ-opioid receptor antagonist, naloxonazine, into the NTS; administrations of δ-receptor antagonist, natrindole, and the κ-receptor antagonist, nor-binaltrophimine, however, did not affect EA-induced alterations in sleep. Furthermore, β-endorphin was significantly increased in both the brainstem and hippocampus after the EA stimuli, an effect blocked by administration of the muscarinic antagonist scopolamine into the NTS. Our findings suggest that mechanisms of EA-induced NREM sleep enhancement may be mediated, in part, by cholinergic activation, stimulation of the opiodergic neurons to increase the concentrations of β-endorphin and the involvement of the μ-opioid receptors.

  16. Lipotoxicity induces hepatic protein inclusions through TBK1-mediated p62/SQSTM1 phosphorylation.

    Science.gov (United States)

    Cho, Chun-Seok; Park, Hwan-Woo; Ho, Allison; Semple, Ian A; Kim, Boyoung; Jang, Insook; Park, Haeli; Reilly, Shannon; Saltiel, Alan R; Lee, Jun Hee

    2017-12-18

    Obesity commonly leads to hepatic steatosis, which often provokes lipotoxic injuries to hepatocytes that cause non-alcoholic steatohepatitis (NASH). NASH in turn is associated with the accumulation of insoluble protein aggregates that are composed of ubiquitinated proteins and ubiquitin adaptor p62/sequestosome 1 (SQSTM1). The formation of p62 inclusions in hepatocytes is the critical marker that distinguishes simple fatty liver from NASH and predicts a poor prognostic outcome for subsequent liver carcinogenesis. However, the molecular mechanism by which lipotoxicity induces protein aggregation is currently unknown. Here we show that upon saturated fatty acid-induced lipotoxicity, Tank-binding protein kinase 1 (TBK1) is activated and phosphorylates p62. The TBK1-mediated p62 phosphorylation is important for lipotoxicity-induced aggregation of ubiquitinated proteins and the formation of large protein inclusions in hepatocytes. In addition, cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING), upstream regulators of TBK1, are involved in the lipotoxic activation of TBK1 and subsequent p62 phosphorylation in hepatocytes. Furthermore, TBK1 inhibition prevented formation of the ubiquitin-p62 aggregates, not only in cultured hepatocytes, but also in mouse models of obesity and NASH. These results suggest that lipotoxic activation of TBK1 and subsequent p62 phosphorylation are critical steps in the NASH pathology of protein inclusion accumulation in hepatocytes. This mechanism can provide an explanation for how hypernutrition and obesity promote the development of severe liver pathologies, such as steatohepatitis and liver cancer, by facilitating the formation of p62 inclusions. This article is protected by copyright. All rights reserved. © 2017 by the American Association for the Study of Liver Diseases.

  17. Tissue inhibitor of matrix metalloproteinase-1 mediates erythropoietin-induced neuroprotection in hypoxia ischemia.

    Science.gov (United States)

    Souvenir, Rhonda; Fathali, Nancy; Ostrowski, Robert P; Lekic, Tim; Zhang, John H; Tang, Jiping

    2011-10-01

    Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However these studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice-Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2h with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48 h after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2 and STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO's protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Polychlorinated biphenyls exposure-induced insulin resistance is mediated by lipid droplet enlargement through Fsp27.

    Science.gov (United States)

    Kim, Hye Young; Kwon, Woo Young; Kim, Yeon A; Oh, Yoo Jin; Yoo, Seung Hee; Lee, Mi Hwa; Bae, Ju Yong; Kim, Jong-Min; Yoo, Young Hyun

    2017-06-01

    Although epidemiological and experimental studies demonstrated that polychlorinated biphenyls (PCBs) lead to insulin resistance, the mechanism underlying PCBs-induced insulin resistance has remained unsolved. In this study, we examined in vitro and in vivo effects of PCB-118 (dioxin-like PCB) and PCB-138 (non-dioxin-like PCB) on adipocyte differentiation, lipid droplet growth, and insulin action. 3T3-L1 adipocytes were incubated with PCB-118 or PCB-138 during adipocyte differentiation. For in vivo studies, C57BL/6 mice were administered PCB-118 or PCB-138 (37.5 mg/kg) by intraperitoneal injection and we examined adiposity and whole-body insulin action. PCB-118 and PCB-138 significantly promoted adipocyte differentiation and increased the lipid droplet (LD) size in 3T3-L1 adipocytes. In mice, both PCBs increased adipose mass and adipocyte size. Furthermore, both PCBs induced insulin resistance in vitro and in vivo. Expression of fat-specific protein 27 (Fsp27), which is localized to LD contact sites, was increased in PCB-treated 3T3-L1 adipocytes and mice. Depletion of Fsp27 by siRNA resulted in the inhibition of LD enlargement and attenuation of insulin resistance in PCB-treated 3T3-L1 adipocytes. An anti-diabetic drug, metformin, attenuated insulin resistance in PCB-treated 3T3-L1 adipocytes through the reduced expression of Fsp27 protein and LD size. This study suggests that PCB exposure-induced insulin resistance is mediated by LD enlargement through Fsp27.

  19. Valproic acid potentiates curcumin-mediated neuroprotection in Lipopolysaccharide induced rats

    Directory of Open Access Journals (Sweden)

    Amira eZaky

    2014-10-01

    Full Text Available The etiology of neuroinflammation is complex and comprises multifactorial, involving both genetic and environmental factors during which diverse genetic and epigenetic modulations are implicated. Curcumin (Cur, and valproic acid (VPA, histone deacetylase 1 inhibitor, have neuroprotective effects. The present study was designed with an aim to investigate the ability of co-treatment of both compounds (Cur or VPA (200mg/kg for four weeks to augment neuroprotection and enhance brain recovery from intra-peritoneal (IP injection of (250 µg/kg lipopolysaccharide (LPS-stimulated neuroinflammatory condition on rat brain cortex. Cortex activation and the effects of combined treatment and production of proinflammatory mediators, COX-2, APE1 and nitric oxide/iNOS were investigated. Neuroinflammation development was assessed by histological analyses and by investigating associated indices (BACE1, APP, PSEN-1 and PSEN-2. Furthermore we measured the expression profile of let-7 miRNAs members a, b, c, e and f in all groups, a highly abundant regulator of gene expression in the CNS. Protein and mRNA levels of neuroinflammation markers COX-2, BACE1, APP and iNOS were also attenuated by combined therapy. On the other hand, assessment of the indicated five let-7 members, showed distinct expression profile pattern in the different groups. Let-7 a, b and c disappeared in the induced group, an effect that was partially suppressed by co-addition of either Cur or VPA. These data suggest that the combined treatment induced significantly the expression of the five members when compared to rats treated with Cur or VPA only as well as to self-recovery group, which indicates a possible benefit from the synergistic effect of Cur-VPA combination as therapeutic agents for neuroinflammation and its associated disorders. The mechanism elucidated here highlights the particular drug-induced expression profile of let-7 family as new targets for future pharmacological development.

  20. Intense pseudotransport of a cationic drug mediated by vacuolar ATPase: Procainamide-induced autophagic cell vacuolization

    International Nuclear Information System (INIS)

    Morissette, Guillaume; Lodge, Robert; Marceau, Francois

    2008-01-01

    Cationic drugs frequently exhibit large apparent volumes of distribution, consistent with various forms of cellular sequestration. The contributions of organelles and metabolic processes that may mimic drug transport were defined in human vascular smooth muscle cells. We hypothesized that procainamide-induced vacuolar cytopathology is driven by intense pseudotransport mediated by the vacuolar (V)-ATPase and pursued the characterization of vesicular trafficking alterations in this model. Large amounts of procainamide were taken up by intact cells (maximal in 2 h, reversible upon washout, apparent K M 4.69 mM; fluorometric determination of cell-associated drug). Procainamide uptake was extensively prevented or reversed by pharmacological inhibition of the V-ATPase with bafilomycin A1 or FR 167356, decreased at low extracellular pH and preceded vacuolar cell morphology. However, the uptake of procainamide was unaffected by mitochondrial poisons that reduced the uptake of rhodamine 6G. Large vacuoles induced by millimolar procainamide were labeled with the late endosome/lysosome markers Rab7 and CD63 and the autophagy effector LC3; their osmotic formation (but not procainamide uptake) was reduced by extracellular mannitol and parallel to LC3 II formation. Procainamide-induced vacuolization is associated with defective endocytosis of fluorophore-labeled bovine serum albumin, but not with induction of the unfolded protein response. The contents of a vacuole subset slowly (≥ 24 h) become positive for Nile red staining (phospholipidosis-like response). V-ATPase-driven ion trapping is a form of intense cation pseudotransport that concerns the uncharged form of the drugs, and is associated with a vacuolar, autophagic and evolutive cytopathology and profound effects on vesicular trafficking

  1. Botulinum neurotoxin type A induces TLR2-mediated inflammatory responses in macrophages.

    Directory of Open Access Journals (Sweden)

    Yun Jeong Kim

    Full Text Available Botulinum neurotoxin type A (BoNT/A is the most potent protein toxin and causes fatal flaccid muscle paralysis by blocking neurotransmission. Application of BoNT/A has been extended to the fields of therapeutics and biodefense. Nevertheless, the global response of host immune cells to authentic BoNT/A has not been reported. Employing microarray analysis, we performed global transcriptional profiling of RAW264.7 cells, a murine alveolar macrophage cell line. We identified 70 genes that were modulated following 1 nM BoNT/A treatment. The altered genes were mainly involved in signal transduction, immunity and defense, protein metabolism and modification, neuronal activities, intracellular protein trafficking, and muscle contraction. Microarray data were validated with real-time RT-PCR for seven selected genes including tlr2, tnf, inos, ccl4, slpi, stx11, and irg1. Proinflammatory mediators such as nitric oxide (NO and tumor necrosis factor alpha (TNFα were induced in a dose-dependent manner in BoNT/A-stimulated RAW264.7 cells. Increased expression of these factors was inhibited by monoclonal anti-Toll-like receptor 2 (TLR2 and inhibitors specific to intracellular proteins such as c-Jun N-terminal kinase (JNK, extracellular signal-regulated kinase (ERK, and p38 mitogen-activated protein kinase (MAPK. BoNT/A also suppressed lipopolysaccharide-induced NO and TNFα production from RAW264.7 macrophages at the transcription level by blocking activation of JNK, ERK, and p38 MAPK. As confirmed by TLR2-/- knock out experiments, these results suggest that BoNT/A induces global gene expression changes in host immune cells and that host responses to BoNT/A proceed through a TLR2-dependent pathway, which is modulated by JNK, ERK, and p38 MAPK.

  2. USP22 Induces Cisplatin Resistance in Lung Adenocarcinoma by Regulating γH2AX-Mediated DNA Damage Repair and Ku70/Bax-Mediated Apoptosis

    Directory of Open Access Journals (Sweden)

    Aman Wang

    2017-05-01

    Full Text Available Resistance to platinum-based chemotherapy is one of the most important reasons for treatment failure in advanced non-small cell lung cancer, but the underlying mechanism is extremely complex and unclear. The present study aimed to investigate the correlation of ubiquitin-specific peptidase 22 (USP22 with acquired resistance to cisplatin in lung adenocarcinoma. In this study, we found that overexpression of USP22 could lead to cisplatin resistance in A549 cells. USP22 and its downstream proteins γH2AX and Sirt1 levels are upregulated in the cisplatin- resistant A549/CDDP cell line. USP22 enhances DNA damage repair and induce cisplatin resistance by promoting the phosphorylation of histone H2AX via deubiquitinating histone H2A. In addition, USP22 decreases the acetylation of Ku70 by stabilizing Sirt1, thus inhibiting Bax-mediated apoptosis and inducing cisplatin resistance. The cisplatin sensitivity in cisplatin-resistant A549/CDDP cells was restored by USP22 inhibition in vivo and vitro. In summary, our findings reveal the dual mechanism of USP22 involvement in cisplatin resistance that USP22 can regulate γH2AX-mediated DNA damage repair and Ku70/Bax-mediated apoptosis. USP22 is a potential target in cisplatin-resistant lung adenocarcinoma and should be considered in future therapeutic practice.

  3. Dopamine mediated iron release from ferritin is enhanced at higher temperatures: Possible implications for fever-induced Parkinson's disease

    International Nuclear Information System (INIS)

    Babincova, Melania; Babinec, Peter

    2005-01-01

    A new molecular mechanism is proposed to explain the pathogenesis of fever-induced Parkinson's disease. This proposal is based on dopamine and 6-hydroxydopamine-mediated free iron release from ferritin magnetic nanoparticles, which is enhanced at higher temperatures, and which may lead to substantial peroxidation and injury of lipid biomembranes of the substantia nigra in the brain

  4. Topical photosan-mediated photodynamic therapy for DMBA-induced hamster buccal pouch early cancer lesions: an in vivo study

    Science.gov (United States)

    Hsu, Yih-Chih; Chang, Walter Hong-Shong; Chang, Junn-Liang; Liu, Kuang-Ting; Chiang, Chun-Pin; Liu, Chung-Ji; Chen, Chih-Ping

    2011-03-01

    Oral cancer has becomes the most prominent cancer disease in recent years in Taiwan. The reason is the betel nut chewing habit combing with smoking and alcohol-drinking lifestyle of people results in oral cancer becomes the fastest growth incident cancer amongst other major cancer diseases. In previous studies showed that photosan, haematoporphyrin derivative (HPD), has demonstrated effective PDT results on human head and neck disease studies. To avoid the systemic phototoxic effect of photosan, this study was designed to use a topical photosan-mediated PDT for treatment of DMBA-induced hamster buccal pouch cancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 10 to 12 weeks. Cancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical photosan-mediated PDT. Before PDT, fluorescence spectroscopy was used to determine when photosan reached its peak level in the lesional epithelial cells after topical application of photosan gel. We found that photosan reached its peak level in cancerous lesions about 13.5 min after topical application of photosan gel. The cancerous lesions in hamsters were then treated with topical photosan-mediated PDT (fluence rate: 600 mW/cm2; light exposure dose 200 J/cm2) using the portable Lumacare 635 nm fiber-guided light device. Visual examination demonstrated that topical photosan-mediated PDT was an applicable treatment modality for DMBA-induced hamster buccal pouch cancerous lesions.

  5. Connective tissue growth factor mediates TGF-β1-induced low-grade serous ovarian tumor cell apoptosis.

    Science.gov (United States)

    Cheng, Jung-Chien; Chang, Hsun-Ming; Leung, Peter C K

    2017-10-17

    Ovarian low-grade serous carcinoma (LGSC) is a rare disease and is now considered to be a distinct entity from high-grade serous carcinoma (HGSC), which is the most common and malignant form of epithelial ovarian cancer. Connective tissue growth factor (CTGF) is a secreted matricellular protein that has been shown to modulate many biological functions by interacting with multiple molecules in the microenvironment. Increasing evidence indicates that aberrant expression of CTGF is associated with cancer development and progression. Transforming growth factor-β1 (TGF-β1) is a well-known molecule that can strongly up-regulate CTGF expression in different types of normal and cancer cells. Our previous study demonstrated that TGF-β1 induces apoptosis of LGSC cells. However, the effect of TGF-β1 on CTGF expression in LGSC needs to be defined. In addition, whether CTGF mediates TGF-β1-induced LGSC cell apoptosis remains unknown. In the present study, we show that TGF-β1 treatment up-regulates CTGF expression by activating SMAD3 signaling in two human LGSC cell lines. Additionally, siRNA-mediated CTGF knockdown attenuates TGF-β1-induced cell apoptosis. Moreover, our results show that the inhibitory effect of the CTGF knockdown on TGF-β1-induced cell apoptosis is mediated by down-regulating SMAD3 expression. This study demonstrates an important role for CTGF in mediating the pro-apoptotic effects of TGF-β1 on LGCS.

  6. ZINC-INDUCED EGF RECEPTOR SIGNALING REQUIRES SRC-MEDIATED PHOSPHORYLATION OF THE EGF RECEPTOR ON TYROSINE 845 (Y845)

    Science.gov (United States)

    ZINC-INDUCED EGF RECEPTOR SIGNALING REQUIRES Src-MEDIATED PHOSPHORYLATION OF THE EGF RECEPTOR ON TYROSINE 845 (Y845)Weidong Wu1, Lee M. Graves2, Gordon N. Gill3 and James M. Samet4 1Center for Environmental Medicine and Lung Biology; 2Department of Pharmacology, University o...

  7. An Indirect Defence Trait Mediated through Egg-Induced Maize Volatiles from Neighbouring Plants.

    Directory of Open Access Journals (Sweden)

    Daniel M Mutyambai

    Full Text Available Attack of plants by herbivorous arthropods may result in considerable changes to the plant's chemical phenotype with respect to emission of herbivore-induced plant volatiles (HIPVs. These HIPVs have been shown to act as repellents to the attacking insects as well as attractants for the insects antagonistic to these herbivores. Plants can also respond to HIPV signals from other plants that warn them of impending attack. Recent investigations have shown that certain maize varieties are able to emit volatiles following stemborer egg deposition. These volatiles attract the herbivore's parasitoids and directly deter further oviposition. However, it was not known whether these oviposition-induced maize (Zea mays, L. volatiles can mediate chemical phenotypic changes in neighbouring unattacked maize plants. Therefore, this study sought to investigate the effect of oviposition-induced maize volatiles on intact neighbouring maize plants in 'Nyamula', a landrace known to respond to oviposition, and a standard commercial hybrid, HB515, that did not. Headspace volatile samples were collected from maize plants exposed to Chilo partellus (Swinhoe (Lepidoptera: Crambidae egg deposition and unoviposited neighbouring plants as well as from control plants kept away from the volatile emitting ones. Behavioural bioassays were carried out in a four-arm olfactometer using egg (Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae and larval (Cotesia sesamiae Cameron (Hymenoptera: Braconidae parasitoids. Coupled Gas Chromatography-Mass Spectrometry (GC-MS was used for volatile analysis. For the 'Nyamula' landrace, GC-MS analysis revealed HIPV production not only in the oviposited plants but also in neighbouring plants not exposed to insect eggs. Higher amounts of EAG-active biogenic volatiles such as (E-4,8-dimethyl-1,3,7-nonatriene were emitted from these plants compared to control plants. Subsequent behavioural assays with female T. bournieri and

  8. DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

    International Nuclear Information System (INIS)

    Chen, Rui; Wang, Bin; Chen, Ling; Cai, Dunpeng; Li, Bing; Chen, Chuanxiang; Huang, Enping; Liu, Chao; Lin, Zhoumeng; Xie, Wei-Bing; Wang, Huijun

    2016-01-01

    Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes. - Highlights: • METH exposure increases DDIT4 expression in cardiomyocytes. • DDIT4 mediates METH-induced autophagy and apoptosis in cardiomyocytes. • DDIT4 silencing protects cardiomyocytes against METH-caused autophagy and apoptosis.

  9. DNA damage-inducible transcript 4 (DDIT4) mediates methamphetamine-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Rui [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Department of Forensic Medicine, Guangdong Medical University, Dongguan 523808 (China); Wang, Bin; Chen, Ling; Cai, Dunpeng; Li, Bing; Chen, Chuanxiang; Huang, Enping [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Liu, Chao [Guangzhou Forensic Science Institute, Guangzhou 510030 (China); Lin, Zhoumeng [Institute of Computational Comparative Medicine and Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506 (United States); Xie, Wei-Bing, E-mail: xieweib@126.com [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China); Wang, Huijun, E-mail: hjwang711@yahoo.cn [Department of Forensic Medicine, School of Basic Medical Science, Southern Medical University, Guangzhou 510515 (China)

    2016-03-15

    Methamphetamine (METH) is an amphetamine-like psychostimulant that is commonly abused. Previous studies have shown that METH can induce damages to the nervous system and recent studies suggest that METH can also cause adverse and potentially lethal effects on the cardiovascular system. Recently, we demonstrated that DNA damage-inducible transcript 4 (DDIT4) regulates METH-induced neurotoxicity. However, the role of DDIT4 in METH-induced cardiotoxicity remains unknown. We hypothesized that DDIT4 may mediate METH-induced autophagy and apoptosis in cardiomyocytes. To test the hypothesis, we examined DDIT4 protein expression in cardiomyocytes and in heart tissues of rats exposed to METH with Western blotting. We also determined the effects on METH-induced autophagy and apoptosis after silencing DDIT4 expression with synthetic siRNA with or without pretreatment of a mTOR inhibitor rapamycin in cardiomyocytes using Western blot analysis, fluorescence microscopy and TUNEL staining. Our results showed that METH exposure increased DDIT4 expression and decreased phosphorylation of mTOR that was accompanied with increased autophagy and apoptosis both in vitro and in vivo. These effects were normalized after silencing DDIT4. On the other hand, rapamycin promoted METH-induced autophagy and apoptosis in DDIT4 knockdown cardiomyocytes. These results suggest that DDIT4 mediates METH-induced autophagy and apoptosis through mTOR signaling pathway in cardiomyocytes. - Highlights: • METH exposure increases DDIT4 expression in cardiomyocytes. • DDIT4 mediates METH-induced autophagy and apoptosis in cardiomyocytes. • DDIT4 silencing protects cardiomyocytes against METH-caused autophagy and apoptosis.

  10. Hypoxia-Induced Autophagy Is Mediated through Hypoxia-Inducible Factor Induction of BNIP3 and BNIP3L via Their BH3 Domains▿ †

    OpenAIRE

    Bellot, Grégory; Garcia-Medina, Raquel; Gounon, Pierre; Chiche, Johanna; Roux, Danièle; Pouysségur, Jacques; Mazure, Nathalie M.

    2009-01-01

    While hypoxia-inducible factor (HIF) is a major actor in the cell survival response to hypoxia, HIF also is associated with cell death. Several studies implicate the HIF-induced putative BH3-only proapoptotic genes bnip3 and bnip3l in hypoxia-mediated cell death. We, like others, do not support this assertion. Here, we clearly demonstrate that the hypoxic microenvironment contributes to survival rather than cell death by inducing autophagy. The ablation of Beclin1, a major actor of autophagy,...

  11. Mulberry Leaf Extract Attenuates Oxidative Stress-Mediated Testosterone Depletion in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hajizadeh

    2014-03-01

    Full Text Available Background: It has been proposed that oxidative stress may contribute to the development of testicular abnormalities in diabetes. Morus alba leaf extract (MAE has hypoglycemic and antioxidant properties. We, therefore, explored the impact of the administration of MAE on steroidogenesis in diabetic rats. Methods: To address this hypothesis, we measured the serum level of glucose, insulin, and free testosterone (Ts as well as oxidative stress parameters (including glutathione peroxidase, glutathione reductase, total antioxidant capacity, and malondialdehyde in the testis of control, untreated and MAE-treated (1 g/day/kg diabetic rats. In order to determine the likely mechanism of MAE action on Ts levels, we analyzed the quantitative mRNA expression level of the two key steroidogenic proteins, namely steroid acute regulatory protein (StAR and P450 cholesterol side-chain cleavage enzyme (P450scc, by real-time PCR. Results: The MAE-treated diabetic rats had significantly decreased glucose levels and on the other hand increased insulin and free Ts levels than the untreated diabetic rats. In addition, the administration of MAE to the diabetic rats restored the oxidative stress parameters toward control. Induction of diabetes decreased testicular StAR mRNA expression by 66% and MAE treatment enhanced mRNA expression to the same level of the control group. However, the expression of P540scc was not significantly decreased in the diabetic group as compared to the control group. Conclusion: Our findings indicated that MAE significantly increased Ts production in the diabetic rats, probably through the induction of StAR mRNA expression levels. Administration of MAE to experimental models of diabetes can effectively attenuate oxidative stress-mediated testosterone depletion. Please cite this article as: Hajizadeh MR, Eftekhar E, Zal F, Jaffarian A, Mostafavi-Pour Z. Mulberry Leaf Extract Attenuates Oxidative Stress-Mediated Testosterone Depletion in

  12. Inducible nitric-oxide synthase plays a minimal role in lymphocytic choriomeningitis virus-induced, T cell-mediated protective immunity and immunopathology

    DEFF Research Database (Denmark)

    Bartholdy, C; Nansen, A; Christensen, Jeanette Erbo

    1999-01-01

    -mediated immune response was found to be unaltered in iNOS-deficient mice compared with wild-type C57BL/6 mice, and LCMV- induced general immunosuppression was equally pronounced in both strains. In vivo analysis revealed identical kinetics of virus clearance, as well as unaltered clinical severity of systemic......By using mice with a targetted disruption in the gene encoding inducible nitric-oxide synthase (iNOS), we have studied the role of nitric oxide (NO) in lymphocytic choriomeningitis virus (LCMV)-induced, T cell-mediated protective immunity and immunopathology. The afferent phase of the T cell...... LCMV infection in both strains. Concerning the outcome of intracerebral infection, no significant differences were found between iNOS-deficient and wild-type mice in the number or composition of mononuclear cells found in the cerebrospinal fluid on day 6 post-infection. Likewise, NO did not influence...

  13. Peripheral and central mediators of lipopolysaccharide induced suppression of defensive rage behavior in the cat.

    Science.gov (United States)

    Bhatt, S; Bhatt, R S; Zalcman, S S; Siegel, A

    2009-11-10

    LPS induced suppression of defensive rage. The results demonstrate that LPS suppresses defensive rage by acting through peripheral TNF-alpha in periphery and that central effects of LPS suppression of defensive rage are mediated through PGE(2) and 5-HT(1A) receptors in the medial hypothalamus.

  14. Notch1 Mediates Preconditioning Protection Induced by GPER in Normotensive and Hypertensive Female Rat Hearts

    Directory of Open Access Journals (Sweden)

    Carmine Rocca

    2018-05-01

    Full Text Available G protein-coupled estrogen receptor (GPER is an estrogen receptor expressed in the cardiovascular system. G1, a selective GPER ligand, exerts cardiovascular effects through activation of the PI3K-Akt pathway and Notch signaling in normotensive animals. Here, we investigated whether the G1/GPER interaction is involved in the limitation of infarct size, and improvement of post-ischemic contractile function in female spontaneous hypertensive rat (SHR hearts. In this model, we also studied Notch signaling and key components of survival pathway, namely PI3K-Akt, nitric oxide synthase (NOS and mitochondrial K+-ATP (MitoKATP channels. Rat hearts isolated from female SHR underwent 30 min of global, normothermic ischemia and 120 min of reperfusion. G1 (10 nM alone or specific inhibitors of GPER, PI3K/NOS and MitoKATP channels co-infused with G1, just before I/R, were studied. The involvement of Notch1 was studied by Western blotting. Infarct size and left ventricular pressure were measured. To confirm endothelial-independent G1-induced protection by Notch signaling, H9c2 cells were studied with specific inhibitor, N-[N-(3,5 difluorophenacetyl-L-alanyl]-S-phenylglycine t-butyl ester (DAPT, 5 μM, of this signaling. Using DAPT, we confirmed the involvement of G1/Notch signaling in limiting infarct size in heart of normotensive animals. In the hypertensive model, G1-induced reduction in infarct size and improvement of cardiac function were prevented by the inhibition of GPER, PI3K/NOS, and MitoKATP channels. The involvement of Notch was confirmed by western blot in the hypertensive model and by the specific inhibitor in the normotensive model and cardiac cell line. Our results suggest that GPERs play a pivotal role in mediating preconditioning cardioprotection in normotensive and hypertensive conditions. The G1-induced protection involves Notch1 and is able to activate the survival pathway in the presence of comorbidity. Several pathological conditions

  15. Inhibition of mitochondria- and endoplasmic reticulum stress-mediated autophagy augments temozolomide-induced apoptosis in glioma cells.

    Directory of Open Access Journals (Sweden)

    Chien-Ju Lin

    Full Text Available Autophagy is a crucial process for cells to maintain homeostasis and survival through degradation of cellular proteins and organelles, including mitochondria and endoplasmic reticula (ER. We previously demonstrated that temozolomide (TMZ, an alkylating agent for brain tumor chemotherapy, induced reactive oxygen species (ROS/extracellular signal-regulated kinase (ERK-mediated autophagy to protect glioma cells from apoptosis. In this study, we investigated the role of mitochondrial damage and ER stress in TMZ-induced cytotoxicity. Mitochondrial depolarization and mitochondrial permeability transition pore (MPTP opening were observed as a prelude to TMZ-induced autophagy, and these were followed by the loss of mitochondrial mass. Electron transport chain (ETC inhibitors, such as rotenone (a complex I inhibitor, sodium azide (a complex IV inhibitor, and oligomycin (a complex V inhibitor, or the MPTP inhibitor, cyclosporine A, decreased mitochondrial damage-mediated autophagy, and therefore increased TMZ-induced apoptosis. TMZ treatment triggered ER stress with increased expression of GADD153 and GRP78 proteins, and deceased pro-caspase 12 protein. ER stress consequently induced autophagy through c-Jun N-terminal kinases (JNK and Ca(2+ signaling pathways. Combination of TMZ with 4-phenylbutyrate (4-PBA, an ER stress inhibitor, augmented TMZ-induced cytotoxicity by inhibiting autophagy. Taken together, our data indicate that TMZ induced autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. This study provides evidence that agents targeting mitochondria or ER may be potential anticancer strategies.

  16. Nitric oxide mediates angiogenesis induced in vivo by platelet-activating factor and tumor necrosis factor-alpha.

    Science.gov (United States)

    Montrucchio, G.; Lupia, E.; de Martino, A.; Battaglia, E.; Arese, M.; Tizzani, A.; Bussolino, F.; Camussi, G.

    1997-01-01

    We evaluated the role of an endogenous production of nitric oxide (NO) in the in vitro migration of endothelial cells and in the in vivo angiogenic response elicited by platelet-activating factor (PAF), tumor necrosis factor-alpha (TNF), and basic fibroblast growth factor (bFGF). The NO synthase inhibitor, N omega-nitro-L-arginine-methyl ester (L-NAME), but not its enantiomer D-NAME, prevented chemotaxis of endothelial cells induced in vitro by PAF and by TNF. The motogenic activity of TNF was also inhibited by WEB 2170, a specific PAF-receptor antagonist. In contrast, chemotaxis induced by bFGF was not prevented by L-NAME or by WEB 2170. Angiogenesis was studied in vivo in a murine model in which Matrigel was used as a vehicle for the delivery of mediators. In this model, the angiogenesis induced by PAF and TNF was inhibited by WEB 2170 and L-NAME but not by D-NAME. In contrast, angiogenesis induced by bFGF was not affected by L-NAME or by WEB 2170. TNF, but not bFGF, induced PAF synthesis within Matrigel. These results suggest that NO mediates the angiogenesis induced by PAF as well as that induced by TNF, which is dependent on the production of PAF. In contrast, the angiogenic effect of bFGF appears to be both PAF and NO independent. Images Figure 3 Figure 4 PMID:9250168

  17. Identification of RIP1 as a critical mediator of Smac mimetic-mediated sensitization of glioblastoma cells for Drozitumab-induced apoptosis.

    Science.gov (United States)

    Cristofanon, S; Abhari, B A; Krueger, M; Tchoghandjian, A; Momma, S; Calaminus, C; Vucic, D; Pichler, B J; Fulda, S

    2015-04-16

    This study aims at evaluating the combination of the tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL)-receptor 2 (TRAIL-R2)-specific antibody Drozitumab and the Smac mimetic BV6 in preclinical glioblastoma models. To this end, the effect of BV6 and/or Drozitumab on apoptosis induction and signaling pathways was analyzed in glioblastoma cell lines, primary glioblastoma cultures and glioblastoma stem-like cells. Here, we report that BV6 and Drozitumab synergistically induce apoptosis and reduce colony formation in several glioblastoma cell lines (combination indextrigger the formation of a cytosolic receptor-interacting protein (RIP) 1/Fas-associated via death domain (FADD)/caspase-8-containing complex and subsequent activation of caspase-8 and -3. BV6- and Drozitumab-induced apoptosis is blocked by the caspase inhibitor zVAD.fmk, pointing to caspase-dependent apoptosis. RNA interference-mediated silencing of RIP1 almost completely abolishes the BV6-conferred sensitization to Drozitumab-induced apoptosis, indicating that the synergism critically depends on RIP1 expression. In contrast, both necrostatin-1, a RIP1 kinase inhibitor, and Enbrel, a TNFα-blocking antibody, do not interfere with BV6/Drozitumab-induced apoptosis, demonstrating that apoptosis occurs independently of RIP1 kinase activity or an autocrine TNFα loop. In conclusion, the rational combination of BV6 and Drozitumab presents a promising approach to trigger apoptosis in glioblastoma, which warrants further investigation.

  18. E2f1 mediates high glucose-induced neuronal death in cultured mouse retinal explants.

    Science.gov (United States)

    Wang, Yujiao; Zhou, Yi; Xiao, Lirong; Zheng, Shijie; Yan, Naihong; Chen, Danian

    2017-10-02

    Diabetic retinopathy (DR) is the most common complication of diabetes and remains one of the major causes of blindness in the world; infants born to diabetic mothers have higher risk of developing retinopathy of prematurity (ROP). While hyperglycemia is a major risk factor, the molecular and cellular mechanisms underlying DR and diabetic ROP are poorly understood. To explore the consequences of retinal cells under high glucose, we cultured wild type or E2f1 -/- mouse retinal explants from postnatal day 8 with normal glucose, high osmotic or high glucose media. Explants were also incubated with cobalt chloride (CoCl 2 ) to mimic the hypoxic condition. We showed that, at 7 days post exposure to high glucose, retinal explants displayed elevated cell death, ectopic cell division and intact retinal vascular plexus. Cell death mainly occurred in excitatory neurons, such as ganglion and bipolar cells, which were also ectopically dividing. Many Müller glial cells reentered the cell cycle; some had irregular morphology or migrated to other layers. High glucose inhibited the hyperoxia-induced blood vessel regression of retinal explants. Moreover, inactivation of E2f1 rescued high glucose-induced ectopic division and cell death of retinal neurons, but not ectopic cell division of Müller glial cells and vascular phenotypes. This suggests that high glucose has direct but distinct effects on retinal neurons, glial cells and blood vessels, and that E2f1 mediates its effects on retinal neurons. These findings shed new light onto mechanisms of DR and the fetal retinal abnormalities associated with maternal diabetes, and suggest possible new therapeutic strategies.

  19. Corticosterone mediates some but not other behavioural changes induced by prenatal stress in rats.

    Science.gov (United States)

    Salomon, S; Bejar, C; Schorer-Apelbaum, D; Weinstock, M

    2011-02-01

    The effect of daily varied stress from days 13-21 of gestation in Wistar rats was investigated by tests of learning and memory and anxiogenic behaviour in the 60-day-old offspring of both sexes. Prenatal stress decreased the anogenital distance in males at 1 day of age. Anxiogenic behaviour in the elevated plus maze was seen in prenatally-stressed rats of both genders. There was no significant gender difference in the rate of spatial learning in the Morris water maze but prenatal stress only slowed that of males. In the object recognition test with an inter-trial interval of 40 min, females but not males, discriminated between a familiar and novel object. Prenatal stress did not affect object discrimination in females but feminised that in males. Maternal adrenalectomy with replacement of basal corticosterone levels in the drinking fluid prevented all of the above effects of prenatal stress in the offspring. To mimic the peak corticosterone levels and time course of elevation in response to stress, corticosterone (3 mg/kg) was injected twice (0 and 30 min) on days 13-16 and once on days 17-20 of gestation to adrenalectomised mothers. This treatment re-instated anxiogenic behaviour similar to that induced by prenatal stress, indicating that it is mediated by exposure of the foetal brain to raised levels of corticosterone. However, steroid administration to adrenalectomised dams did not decrease anogenital distance, feminise object recognition memory or slow spatial learning in their male offspring. The findings indicate that other adrenal hormones are necessary to induce these effects of prenatal stress. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

  20. Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells

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    Owa C

    2013-09-01

    Full Text Available Chie Owa, Michael E Messina Jr, Reginald HalabyDepartment of Biology, Montclair State University, Montclair, NJ, USABackground: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3.Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells.Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability.Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.Keywords: triptolide, MCF-7 breast cancer cells, apoptosis, lysosomes, lysosomal membrane permeabilization (LMP

  1. The double-stranded RNA-activated protein kinase mediates viral-induced encephalitis

    International Nuclear Information System (INIS)

    Scheuner, Donalyn; Gromeier, Matthias; Davies, Monique V.; Dorner, Andrew J.; Song Benbo; Patel, Rupali V.; Wimmer, Eckard J.; McLendon, Roger E.; Kaufman, Randal J.

    2003-01-01

    The double-stranded (ds) RNA-activated protein kinase (PKR) plays an important role in control of viral infections and cell growth. We have studied the role of PKR in viral infection in mice that are defective in the PKR signaling pathway. Transgenic mice were derived that constitutively express a trans-dominant-negative kinase-defective mutant PKR under control of the β-actin promoter. The trans-dominant-negative PKR mutant expressing transgenic mice do not have a detectable phenotype, similar to observations with PKR knock-out mice. The requirement for PKR in viral pathogenesis was studied by intracerebral infection of mice with a mouse-adapted poliovirus. Histopathological analysis revealed diffuse encephalomyelitis with severe inflammatory lesions throughout the central nervous system (CNS) in infected wild-type mice. In contrast, histopathological evaluation of virus-injected trans-dominant-negative PKR transgenic mice as well as PKR knock-out mice yielded no signs of tissue damage associated with inflammatory host responses. However, the virus did replicate in both models of PKR-deficient mice at a level equal to that observed in wild-type infected mice. Although the results indicate a clear difference in susceptibility to poliovirus-induced encephalitis, this difference manifests clinically as a slight delay in fatal neuropathy in trans-dominant-negative PKR transgenic and PKR knock-out animals. Our observations support the finding that viral-induced PKR activation may play a significant role in pathogenesis by mediating the host response to viral CNS infection. They support PKR to be an effective target to control tissue damage due to deleterious host responses to viral infection

  2. Carboxylesterase-mediated insecticide resistance: Quantitative increase induces broader metabolic resistance than qualitative change.

    Science.gov (United States)

    Cui, Feng; Li, Mei-Xia; Chang, Hai-Jing; Mao, Yun; Zhang, Han-Ying; Lu, Li-Xia; Yan, Shuai-Guo; Lang, Ming-Lin; Liu, Li; Qiao, Chuan-Ling

    2015-06-01

    Carboxylesterases are mainly involved in the mediation of metabolic resistance of many insects to organophosphate (OP) insecticides. Carboxylesterases underwent two divergent evolutionary events: (1) quantitative mechanism characterized by the overproduction of carboxylesterase protein; and (2) qualitative mechanism caused by changes in enzymatic properties because of mutation from glycine/alanine to aspartate at the 151 site (G/A151D) or from tryptophan to leucine at the 271 site (W271L), following the numbering of Drosophila melanogaster AChE. Qualitative mechanism has been observed in few species. However, whether this carboxylesterase mutation mechanism is prevalent in insects remains unclear. In this study, wild-type, G/A151D and W271L mutant carboxylesterases from Culex pipiens and Aphis gossypii were subjected to germline transformation and then transferred to D. melanogaster. These germlines were ubiquitously expressed as induced by tub-Gal4. In carboxylesterase activity assay, the introduced mutant carboxylesterase did not enhance the overall carboxylesterase activity of flies. This result indicated that G/A151D or W271L mutation disrupted the original activities of the enzyme. Less than 1.5-fold OP resistance was only observed in flies expressing A. gossypii mutant carboxylesterases compared with those expressing A. gossypii wild-type carboxylesterase. However, transgenic flies universally showed low resistance to OP insecticides compared with non-transgenic flies. The flies expressing A. gossypii W271L mutant esterase exhibited 1.5-fold resistance to deltamethrin, a pyrethroid insecticide compared with non-transgenic flies. The present transgenic Drosophila system potentially showed that a quantitative increase in carboxylesterases induced broader resistance of insects to insecticides than a qualitative change. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Genistein inhibited ammonia induced astrocyte swelling by inhibiting NF-κB activation-mediated nitric oxide formation.

    Science.gov (United States)

    Dai, Hongliang; Jia, Guizhi; Wang, Wei; Liang, Chunguang; Han, Siyu; Chu, Minghui; Mei, Xifan

    2017-06-01

    Our previous study has indicated the involvement of epidermal growth factor receptor (EGFR) transactivation in ammonia-induced astrocyte swelling, which represents a major pathogenesis of brain edema in hepatic encephalopathy. In this study, we examined the effect of genistein, a naturally occurred broad-spectrum protein tyrosine kinase (PTK) inhibitor, on ammonia-induced cell swelling. We found that genistein pretreatment significantly prevented ammonia-induced astrocyte swelling. Mechanistically, ammonia triggered EGFR/extracellular signal-regulated kinase (ERK) association and subsequent ERK phosphorylation were alleviated by genistein pretreatment. Moreover, ammonia-induced NF-κB nuclear location, iNOS expression, and consequent NO production were all prevented by AG1478 and genistein pretreatment. This study suggested that genistein could alleviate ammonia-induced astrocyte swelling, which may be, at least partly, related to its PTK-inhibiting activity and repression of NF-κB mediated iNOS-derived NO accumulation.

  4. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells

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    Kyoung-jin Min

    2017-08-01

    Full Text Available Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose polymerase (PARP, which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5 expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  5. Fisetin Induces Apoptosis Through p53-Mediated Up-Regulation of DR5 Expression in Human Renal Carcinoma Caki Cells.

    Science.gov (United States)

    Min, Kyoung-Jin; Nam, Ju-Ock; Kwon, Taeg Kyu

    2017-08-02

    Fisetin is a natural compound found in fruits and vegetables such as strawberries, apples, cucumbers, and onions. Since fisetin can elicit anti-cancer effects, including anti-proliferation and anti-migration, we investigated whether fisetin induced apoptosis in human renal carcinoma (Caki) cells. Fisetin markedly induced sub-G1 population and cleavage of poly (ADP-ribose) polymerase (PARP), which is a marker of apoptosis, and increased caspase activation. We found that pan-caspase inhibitor (z-VAD-fmk) inhibited fisetin-induced apoptosis. In addition, fisetin induced death receptor 5 (DR5) expression at the transcriptional level, and down-regulation of DR5 by siRNA blocked fisetin-induced apoptosis. Furthermore, fisetin induced p53 protein expression through up-regulation of protein stability, whereas down-regulation of p53 by siRNA markedly inhibited fisetin-induced DR5 expression. In contrast, fisetin induced up-regulation of CHOP expression and reactive oxygen species production, which had no effect on fisetin-induced apoptosis. Taken together, our study demonstrates that fisetin induced apoptosis through p53 mediated up-regulation of DR5 expression at the transcriptional level.

  6. Dark-matter production through loop-induced processes at the LHC: the s-channel mediator case.

    Science.gov (United States)

    Mattelaer, Olivier; Vryonidou, Eleni

    We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s -channel mediator can be performed within the MadGraph5_aMC@NLO framework. We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark. Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons ([Formula: see text]), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower.

  7. LncRNA H19 and Target Gene-mediated Cleft Palate Induced by TCDD.

    Science.gov (United States)

    Gao, Li Yun; Zhang, Feng Quan; Zhao, Wei Hui; Han, Guang Liang; Wang, Xiao; Li, Qiang; Gao, Shan Shan; Wu, Wei Dong

    2017-09-01

    This study investigated the role of long non-coding RNAs (lncRNAs) in the development of the palatal tissues. Cleft palates in mice were induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Expression levels of long non-coding RNA H19 (lncRNA H19) and insulin-like growth factor 2 (IGF2) gene were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The rate of occurrence of cleft palate was found to be 100% by TCDD exposure, and TCDD could cause short upper limb, cerebral fissure, webbed neck, and short neck. The expression levels of lncRNA H19 and IGF2 gene specifically showed embryo age-related differences on E13, E14, and E15 in the palatal tissues. The expression levels of lncRNA H19 and IGF2 gene showed an inverse relationship on E13, E14, and E15. These findings demonstrated that lncRNA H19 and IGF2 can mediate the development of mouse cleft palate. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  8. Feeding induced by cannabinoids is mediated independently of the melanocortin system.

    Directory of Open Access Journals (Sweden)

    Puspha Sinnayah

    2008-05-01

    Full Text Available Cannabinoids, the active components of marijuana, stimulate appetite, and cannabinoid receptor-1 (CB1-R antagonists suppress appetite and promote weight loss. Little is known about how CB1-R antagonists affect the central neurocircuitry, specifically the melanocortin system that regulates energy balance.Here, we show that peripherally administered CB1-R antagonist (AM251 or agonist equally suppressed or stimulated feeding respectively in A(y , which lack a functional melanocortin system, and wildtype mice, demonstrating that cannabinoid effects on feeding do not require melanocortin circuitry. CB1-R antagonist or agonist administered into the ventral tegmental area (VTA equally suppressed or stimulated feeding respectively, in both genotypes. In addition, peripheral and central cannabinoid administration similarly induced c-Fos activation in brain sites suggesting mediation via motivational dopaminergic circuitry. Amperometry-detected increases in evoked dopamine (DA release by the CB1-R antagonist in nucleus accumbens slices indicates that AM251 modulates DA release from VTA terminals.Our results demonstrate that the effects of cannabinoids on energy balance are independent of hypothalamic melanocortin circuitry and is primarily driven by the reward system.

  9. A gonad-expressed opsin mediates light-induced spawning in the jellyfish Clytia

    Science.gov (United States)

    Quiroga Artigas, Gonzalo; Lapébie, Pascal; Leclère, Lucas; Takeda, Noriyo; Deguchi, Ryusaku; Jékely, Gáspár

    2018-01-01

    Across the animal kingdom, environmental light cues are widely involved in regulating gamete release, but the molecular and cellular bases of the photoresponsive mechanisms are poorly understood. In hydrozoan jellyfish, spawning is triggered by dark-light or light-dark transitions acting on the gonad, and is mediated by oocyte maturation-inducing neuropeptide hormones (MIHs) released from the ectoderm. We determined in Clytia hemisphaerica that blue-cyan light triggers spawning in isolated gonads. A candidate opsin (Opsin9) was found co-expressed with MIH within specialised ectodermal cells. Opsin9 knockout jellyfish generated by CRISPR/Cas9 failed to undergo oocyte maturation and spawning, a phenotype reversible by synthetic MIH. Gamete maturation and release in Clytia is thus regulated by gonadal photosensory-neurosecretory cells that secrete MIH in response to light via Opsin9. Similar cells in ancestral eumetazoans may have allowed tissue-level photo-regulation of diverse behaviours, a feature elaborated in cnidarians in parallel with expansion of the opsin gene family. PMID:29303477

  10. Recombinase-mediated reprogramming and dystrophin gene addition in mdx mouse induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Chunli Zhao

    Full Text Available A cell therapy strategy utilizing genetically-corrected induced pluripotent stem cells (iPSC may be an attractive approach for genetic disorders such as muscular dystrophies. Methods for genetic engineering of iPSC that emphasize precision and minimize random integration would be beneficial. We demonstrate here an approach in the mdx mouse model of Duchenne muscular dystrophy that focuses on the use of site-specific recombinases to achieve genetic engineering. We employed non-viral, plasmid-mediated methods to reprogram mdx fibroblasts, using phiC31 integrase to insert a single copy of the reprogramming genes at a safe location in the genome. We next used Bxb1 integrase to add the therapeutic full-length dystrophin cDNA to the iPSC in a site-specific manner. Unwanted DNA sequences, including the reprogramming genes, were then precisely deleted with Cre resolvase. Pluripotency of the iPSC was analyzed before and after gene addition, and ability of the genetically corrected iPSC to differentiate into myogenic precursors was evaluated by morphology, immunohistochemistry, qRT-PCR, FACS analysis, and intramuscular engraftment. These data demonstrate a non-viral, reprogramming-plus-gene addition genetic engineering strategy utilizing site-specific recombinases that can be applied easily to mouse cells. This work introduces a significant level of precision in the genetic engineering of iPSC that can be built upon in future studies.

  11. Dasatinib-Induced T-Cell-Mediated Colitis: A Case Report and Review of the Literature.

    Science.gov (United States)

    Shanshal, Mohamed; Shakespeare, Andrew; Thirumala, Seshadri; Fenton, Boyd; Quick, Donald P

    2016-01-01

    Dasatinib is a potent inhibitor of the altered tyrosine kinase activity in disease states associated with BCR/ABL1. This agent has been shown to exhibit broad off-target kinase inhibition and immunomodulating properties. These effects may be responsible for dasatinib's unique side effects including a distinctive form of hemorrhagic colitis. We report a case of hemorrhagic colitis associated with dasatinib use in a patient with chronic myelogenous leukemia. Colon biopsies at the time of symptomatic colitis confirmed CD3+CD8+ T cell infiltration. The process rapidly resolved following drug discontinuation, but relapsed when rechallenged with a reduced dose of dasatinib. Colitis did not recur when the patient was treated with an alternative agent. A literature review of prior cases involving dasatinib-induced T-cell mediated colitis provides insight into commonalities that may facilitate the recognition and management of this entity. Most incidences occurred after a 3-month drug exposure and may be accompanied by large granular lymphocytes. The process uniformly resolves within a few days following drug discontinuation and will generally recur in a shorter period of time if the drug is reintroduced. Most patients will require an alternative agent, although select patients could be continued on dasatinib if other options are limited. © 2016 S. Karger AG, Basel.

  12. Acoustic stimulation can induce a selective neural network response mediated by piezoelectric nanoparticles

    Science.gov (United States)

    Rojas, Camilo; Tedesco, Mariateresa; Massobrio, Paolo; Marino, Attilio; Ciofani, Gianni; Martinoia, Sergio; Raiteri, Roberto

    2018-06-01

    Objective. We aim to develop a novel non-invasive or minimally invasive method for neural stimulation to be applied in the study and treatment of brain (dys)functions and neurological disorders. Approach. We investigate the electrophysiological response of in vitro neuronal networks when subjected to low-intensity pulsed acoustic stimulation, mediated by piezoelectric nanoparticles adsorbed on the neuronal membrane. Main results. We show that the presence of piezoelectric barium titanate nanoparticles induces, in a reproducible way, an increase in network activity when excited by stationary ultrasound waves in the MHz regime. Such a response can be fully recovered when switching the ultrasound pulse off, depending on the generated pressure field amplitude, whilst it is insensitive to the duration of the ultrasound pulse in the range 0.5 s–1.5 s. We demonstrate that the presence of piezoelectric nanoparticles is necessary, and when applying the same acoustic stimulation to neuronal cultures without nanoparticles or with non-piezoelectric nanoparticles with the same size distribution, no network response is observed. Significance. We believe that our results open up an extremely interesting approach when coupled with suitable functionalization strategies of the nanoparticles in order to address specific neurons and/or brain areas and applied in vivo, thus enabling remote, non-invasive, and highly selective modulation of the activity of neuronal subpopulations of the central nervous system of mammalians.

  13. The Neuron-Specific Protein TMEM59L Mediates Oxidative Stress-Induced Cell Death.

    Science.gov (United States)

    Zheng, Qiuyang; Zheng, Xiaoyuan; Zhang, Lishan; Luo, Hong; Qian, Lingzhi; Fu, Xing; Liu, Yiqian; Gao, Yuehong; Niu, Mengxi; Meng, Jian; Zhang, Muxian; Bu, Guojun; Xu, Huaxi; Zhang, Yun-Wu

    2017-08-01

    TMEM59L is a newly identified brain-specific membrane-anchored protein with unknown functions. Herein we found that both TMEM59L and its homolog, TMEM59, are localized in Golgi and endosomes. However, in contrast to a ubiquitous and relatively stable temporal expression of TMEM59, TMEM59L expression was limited in neurons and increased during development. We also found that both TMEM59L and TMEM59 interacted with ATG5 and ATG16L1, and that overexpression of them triggered cell autophagy. However, overexpression of TMEM59L induced intrinsic caspase-dependent apoptosis more dramatically than TMEM59. In addition, downregulation of TMEM59L prevented neuronal cell death and caspase-3 activation caused by hydrogen peroxide insults and reduced the lipidation of LC3B. Finally, we found that AAV-mediated knockdown of TMEM59L in mice significantly ameliorated caspase-3 activation, increased mouse duration in the open arm during elevated plus maze test, reduced mouse immobility time during forced swim test, and enhanced mouse memory during Y-maze and Morris water maze tests. Together, our study indicates that TMEM59L is a pro-apoptotic neuronal protein involved in animal behaviors such as anxiety, depression, and memory, and that TMEM59L downregulation protects neurons against oxidative stress.

  14. Pulmonary stromal cells induce the generation of regulatory DC attenuating T-cell-mediated lung inflammation.

    Science.gov (United States)

    Li, Qian; Guo, Zhenhong; Xu, Xiongfei; Xia, Sheng; Cao, Xuetao

    2008-10-01

    The tissue microenvironment may affect the development and function of immune cells such as DC. Whether and how the pulmonary stromal microenvironment can affect the development and function of lung DC need to be investigated. Regulatory DC (DCreg) can regulate T-cell response. We wondered whether such regulatory DC exist in the lung and what is the effect of the pulmonary stromal microenvironment on the generation of DCreg. Here we demonstrate that murine pulmonary stromal cells can drive immature DC, which are regarded as being widely distributed in the lung, to proliferate and differentiate into a distinct subset of DCreg, which express high levels of CD11b but low levels of MHC class II (I-A), CD11c, secrete high amounts of IL-10, NO and prostaglandin E2 (PGE2) and suppress T-cell proliferation. The natural counterpart of DCreg in the lung with similar phenotype and regulatory function has been identified. Pulmonary stroma-derived TGF-beta is responsible for the differentiation of immature DC to DCreg, and DCreg-derived PGE2 contributes to their suppression of T-cell proliferation. Moreover, DCreg can induce the generation of CD4+CD25+Foxp3+ Treg. Importantly, infusion with DCreg attenuates T-cell-mediated eosinophilic airway inflammation in vivo. Therefore, the pulmonary microenvironment may drive the generation of DCreg, thus contributing to the maintenance of immune homoeostasis and the control of inflammation in the lung.

  15. IκBα mediates prostate cancer cell death induced by combinatorial targeting of the androgen receptor

    International Nuclear Information System (INIS)

    Carter, Sarah Louise; Centenera, Margaret Mary; Tilley, Wayne Desmond; Selth, Luke Ashton; Butler, Lisa Maree

    2016-01-01

    Combining different clinical agents to target multiple pathways in prostate cancer cells, including androgen receptor (AR) signaling, is potentially an effective strategy to improve outcomes for men with metastatic disease. We have previously demonstrated that sub-effective concentrations of an AR antagonist, bicalutamide, and the histone deacetylase inhibitor, vorinostat, act synergistically when combined to cause death of AR-dependent prostate cancer cells. In this study, expression profiling of human prostate cancer cells treated with bicalutamide or vorinostat, alone or in combination, was employed to determine the molecular mechanisms underlying this synergistic action. Cell viability assays and quantitative real time PCR were used to validate identified candidate genes. A substantial proportion of the genes modulated by the combination of bicalutamide and vorinostat were androgen regulated. Independent pathway analysis identified further pathways and genes, most notably NFKBIA (encoding IκBα, an inhibitor of NF-κB and p53 signaling), as targets of this combinatorial treatment. Depletion of IκBα by siRNA knockdown enhanced apoptosis of prostate cancer cells, while ectopic overexpression of IκBα markedly suppressed cell death induced by the combination of bicalutamide and vorinostat. These findings implicate IκBα as a key mediator of the apoptotic action of this combinatorial AR targeting strategy and a promising new therapeutic target for prostate cancer. The online version of this article (doi:10.1186/s12885-016-2188-2) contains supplementary material, which is available to authorized users

  16. Shanxi Aged Vinegar Protects against Alcohol-Induced Liver Injury via Activating Nrf2-Mediated Antioxidant and Inhibiting TLR4-Induced Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Ting Xia

    2018-06-01

    Full Text Available Shanxi aged vinegar (SAV is a typical fermented and antioxidant food, which has various health-promoting effects. This work aimed to explore the effects of SAV on alcohol-induced liver injury. A mice model of alcoholic liver injury was established to illuminate its potential mechanisms. All mice pretreated with SAV and then received an ethanol solution (50% w/v, 4.8 g/kg b.w.. The results showed that SAV ameliorated alcohol-induced histological changes and elevation of liver enzymes. SAV attenuated alcohol-induced oxidative stress by declining levels of hepatic oxidants, and restoring depletion of antioxidant enzyme activities in mice livers. Moreover, SAV alleviated alcohol-induced oxidative damage by activating nuclear factor erythroid-2-related factor 2 (Nrf2-mediated signal pathway. In addition, SAV prevented alcohol-induced inflammation by suppressing lipopolysaccharide (LPS level and activities of pro-inflammatory enzymes, and regulating inflammatory cytokines. SAV inhibited alcohol-induced inflammation through down-regulating the expression of Toll-like receptor 4 (TLR4-mediated inflammatory response. The findings provide crucial evidence for elucidating the hepatoprotective mechanisms of SAV and encourage the future application of SAV as a functional food for liver protection.

  17. Lack of TXNIP protects against mitochondria-mediated apoptosis but not against fatty acid-induced ER stress-mediated beta-cell death.

    Science.gov (United States)

    Chen, Junqin; Fontes, Ghislaine; Saxena, Geetu; Poitout, Vincent; Shalev, Anath

    2010-02-01

    We have previously shown that lack of thioredoxin-interacting protein (TXNIP) protects against diabetes and glucotoxicity-induced beta-cell apoptosis. Because the role of TXNIP in lipotoxicity is unknown, the goal of the present study was to determine whether TXNIP expression is regulated by fatty acids and whether TXNIP deficiency also protects beta-cells against lipoapoptosis. RESARCH DESIGN AND METHODS: To determine the effects of fatty acids on beta-cell TXNIP expression, INS-1 cells and isolated islets were incubated with/without palmitate and rats underwent cyclic infusions of glucose and/or Intralipid prior to islet isolation and analysis by quantitative real-time RT-PCR and immunoblotting. Using primary wild-type and TXNIP-deficient islets, we then assessed the effects of palmitate on apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]), mitochondrial death pathway (cytochrome c release), and endoplasmic reticulum (ER) stress (binding protein [BiP], C/EBP homologous protein [CHOP]). Effects of TXNIP deficiency were also tested in the context of staurosporine (mitochondrial damage) or thapsigargin (ER stress). Glucose elicited a dramatic increase in islet TXNIP expression both in vitro and in vivo, whereas fatty acids had no such effect and, when combined with glucose, even abolished the glucose effect. We also found that TXNIP deficiency does not effectively protect against palmitate or thapsigargin-induced beta-cell apoptosis, but specifically prevents staurosporine- or glucose-induced toxicity. Our results demonstrate that unlike glucose, fatty acids do not induce beta-cell expression of proapoptotic TXNIP. They further reveal that TXNIP deficiency specifically inhibits the mitochondrial death pathway underlying beta-cell glucotoxicity, whereas it has very few protective effects against ER stress-mediated lipoapoptosis.

  18. β-Adrenergic induced SR Ca2+ leak is mediated by an Epac-NOS pathway.

    Science.gov (United States)

    Pereira, Laëtitia; Bare, Dan J; Galice, Samuel; Shannon, Thomas R; Bers, Donald M

    2017-07-01

    Cardiac β-adrenergic receptors (β-AR) and Ca 2+ -Calmodulin dependent protein kinase (CaMKII) regulate both physiological and pathophysiological Ca 2+ signaling. Elevated diastolic Ca 2+ leak from the sarcoplasmic reticulum (SR) contributes to contractile dysfunction in heart failure and to arrhythmogenesis. β-AR activation is known to increase SR Ca 2+ leak via CaMKII-dependent phosphorylation of the ryanodine receptor. Two independent and reportedly parallel pathways have been implicated in this β-AR-CaMKII cascade, one involving exchange protein directly activated by cAMP (Epac2) and another involving nitric oxide synthase 1 (NOS1). Here we tested whether Epac and NOS function in a single series pathway to increase β-AR induced and CaMKII-dependent SR Ca 2+ leak. Leak was measured as both Ca 2+ spark frequency and tetracaine-induced shifts in SR Ca 2+ , in mouse and rabbit ventricular myocytes. Direct Epac activation by 8-CPT (8-(4-chlorophenylthio)-2'-O-methyl-cAMP) mimicked β-AR-induced SR Ca 2+ leak, and both were blocked by NOS inhibition. The same was true for myocyte CaMKII activation (assessed via a FRET-based reporter) and ryanodine receptor phosphorylation. Inhibitor and phosphorylation studies also implicated phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) downstream of Epac and above NOS activation in this pathway. We conclude that these two independently characterized parallel pathways function mainly via a single series arrangement (β-AR-cAMP-Epac-PI3K-Akt-NOS1-CaMKII) to mediate increased SR Ca 2+ leak. Thus, for β-AR activation the cAMP-PKA branch effects inotropy and lusitropy (by effects on Ca 2+ current and SR Ca 2+ -ATPase), this cAMP-Epac-NOS pathway increases pathological diastolic SR Ca 2+ leak. This pathway distinction may allow novel SR Ca 2+ leak therapeutic targeting in treatment of arrhythmias in heart failure that spare the inotropic and lusitropic effects of the PKA branch. Copyright © 2017 Elsevier Ltd. All

  19. Radiation induced, raft mediated grafting of styrene onto poly(ethylene-alt-tetrafluoroethylene) (ETFE)

    International Nuclear Information System (INIS)

    Celik, G.; Barsbay, M.; Gueven, O.

    2011-01-01

    Complete text of publication follows. The development of cost-effective proton exchange membranes to replace the state-of-the-art and expensive perfluorinated membranes such as Nafion, Flemion, and Aciplex is one of the main challenges for commercialization of polymer electrolyte fuel cell technology. Recently, partially fluorinated poly(ethlyene-alt-tetrafluoroethylene) (ETFE) has been identified as a promising alternative base polymer film to prepare low-cost polymer electrolyte membranes because of its advantageous characters like superior mechanical properties and high resistance to radiation-induced damage. The radiation-induced grafting technique, based on the utilization of a polymer material such as ETFE in combination with further chemical modification steps (sulfonation) allows the functionalization of the base material and the introduction of the desired property (proton conductivity) for preparing a fuel cell membrane. However this simple conventional method suffers from one simple flaw: The molecular weight and the polydispersity of the grafted chains cannot be controlled. Predetermined molecular weights and low dispersities as well as homogeneous composition and desired architecture can be achieved by grafting of monomer onto base polymer under living/controlled free radical polymerization (CRP) conditions. Among the CRP methods, Reversible Addition Fragmentation-Chain Transfer (RAFT) is of particular interest as a very wide range of functional monomers can be polymerized in a controlled manner under non-demanding reaction conditions (e.g., tolerance to oxygen and low temperatures). The present study deals with the RAFT mediated radiation-induced (0.032 kGyh -1 , 60 Co) grafting of styrene on ETFE films followed by the sulfonation of the polystyrene grafts. The effect of monomer concentration, absorbed dose and RAFT agent concentration on the grafting were investigated. The synthesized films were characterized by ATR-FTIR, XPS, DSC and TGA methods

  20. Hepatitis C virus infection induces apoptosis through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway.

    Science.gov (United States)

    Deng, Lin; Adachi, Tetsuya; Kitayama, Kikumi; Bungyoku, Yasuaki; Kitazawa, Sohei; Ishido, Satoshi; Shoji, Ikuo; Hotta, Hak

    2008-11-01

    We previously reported that cells harboring the hepatitis C virus (HCV) RNA replicon as well as those expressing HCV NS3/4A exhibited increased sensitivity to suboptimal doses of apoptotic stimuli to undergo mitochondrion-mediated apoptosis (Y. Nomura-Takigawa, et al., J. Gen. Virol. 87:1935-1945, 2006). Little is known, however, about whether or not HCV infection induces apoptosis of the virus-infected cells. In this study, by using the chimeric J6/JFH1 strain of HCV genotype 2a, we demonstrated that HCV infection induced cell death in Huh7.5 cells. The cell death was associated with activation of caspase 3, nuclear translocation of activated caspase 3, and cleavage of DNA repair enzyme poly(ADP-ribose) polymerase, which is known to be an important substrate for activated caspase 3. These results suggest that HCV-induced cell death is, in fact, apoptosis. Moreover, HCV infection activated Bax, a proapoptotic member of the Bcl-2 family, as revealed by its conformational change and its increased accumulation on mitochondrial membranes. Concomitantly, HCV infection induced disruption of mitochondrial transmembrane potential, followed by mitochondrial swelling and release of cytochrome c from mitochondria. HCV infection also caused oxidative stress via increased production of mitochondrial superoxide. On the other hand, HCV infection did not mediate increased expression of glucose-regulated protein 78 (GRP78) or GRP94, which are known as endoplasmic reticulum (ER) stress-induced proteins; this result suggests that ER stress is not primarily involved in HCV-induced apoptosis in our experimental system. Taken together, our present results suggest that HCV infection induces apoptosis of the host cell through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway(s).

  1. Amphiregulin mediates hCG-induced StAR expression and progesterone production in human granulosa cells.

    Science.gov (United States)

    Fang, Lanlan; Yu, Yiping; Zhang, Ruizhe; He, Jingyan; Sun, Ying-Pu

    2016-04-26

    Progesterone plays critical roles in maintaining a successful pregnancy at the early embryonic stage. Human chorionic gonadotropin (hCG) rapidly induces amphiregulin (AREG) expression. However, it remains unknown whether AREG mediates hCG-induced progesterone production. Thus, the objective of this study was to investigate the role of AREG in hCG-induced progesterone production and the underlying molecular mechanism in human granulosa cells; primary cells were used as the experimental model. We demonstrated that the inhibition of EGFR and the knockdown of AREG abolished hCG-induced steroidogenic acute regulatory protein (StAR) expression and progesterone production. Importantly, follicular fluid AREG levels were positively correlated with progesterone levels in the follicular fluid and serum. Treatment with AREG increased StAR expression and progesterone production, and these stimulatory effects were abolished by EGFR inhibition. Moreover, activation of ERK1/2, but not PI3K/Akt, signaling was required for the AREG-induced up-regulation of StAR expression and progesterone production. Our results demonstrate that AREG mediates hCG-induced StAR expression and progesterone production in human granulosa cells, providing novel evidence for the role of AREG in the regulation of steroidogenesis.

  2. Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population

    DEFF Research Database (Denmark)

    Nissen, Peter H; Christensen, Signe E; Heickendorff, Lene

    2007-01-01

    CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary...... hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS...

  3. Acute pancreatitis associated with hypercalcemia: A report of two cases Pancreatitis aguda asociada a hipercalcemia: Presentación de dos casos

    Directory of Open Access Journals (Sweden)

    J. Egea Valenzuela

    2009-01-01

    Full Text Available Hypercalcemia due to hyperparathyroidism is a rare etiology for acute pancreatitis, oscillating between 1.5 and 7% in the different series. Although the cause-effect relationship and the pathophysiology of the condition are not clear, it seems that the association among them is not incidental, and serum calcium could be a major risk factor, so that pancreatitis would come to occur during severe hypercalcemia attacks. Mutations in different genes have been proposed as well to justify why only some patients with primary hyperparathyroidism and hypercalcemia develop acute pancreatitis. References to cases like these ones are rare in the literature. We report two patients with acute pancreatitis associated with hyperparathyroidism and hypercalcemia, one of them with a fatal outcome.La hipercalcemia secundaria a hiperparatiroidismo es una causa rara de pancreatitis aguda, variando entre el 1,5-7% según las series consultadas. Aunque la relación causal y la fisiopatología del proceso no están totalmente aclaradas, parece claro que la asociación no es incidental y que los niveles de calcio sérico serían un factor de riesgo mayor, desencadenándose los cuadros de pancreatitis durante las crisis de hipercalcemia. También se han descrito alteraciones en diversos genes que podrían estar implicados, justificando por qué sólo unos pocos pacientes con hiperparatiroidismo primario e hipercalcemia sufren pancreatitis aguda. Existen muy pocas referencias en la literatura a casos como los que nos ocupan. Presentamos a continuación dos pacientes con cuadros de pancreatitis aguda asociados a hiperparatiroidismo e hipercalcemia, uno de ellos con desenlace fatal.

  4. IL-13-induced proliferation of airway epithelial cells: mediation by intracellular growth factor mobilization and ADAM17

    Directory of Open Access Journals (Sweden)

    Sandifer Tracy

    2007-07-01

    Full Text Available Abstract Background The pleiotrophic cytokine interleukin (IL-13 features prominently in allergic and inflammatory diseases. In allergic asthma, IL-13 is well established as an inducer of airway inflammation and tissue remodeling. We demonstrated previously that IL-13 induces release of transforming growth factor-α (TGFα from human bronchial epithelial cells, with proliferation of these cells mediated by the autocrine/paracrine action of this growth factor. TGFα exists as an integral membrane protein and requires proteolytic processing to its mature form, with a disintegrin and metalloproteinase (ADAM17 responsible for this processing in a variety of tissues. Methods In this study, normal human bronchial epithelial (NHBE cells grown in air/liquid interface (ALI culture were used to examine the mechanisms whereby IL-13 induces release of TGFα and cellular proliferation. Inhibitors and antisense RNA were used to examine the role of ADAM17 in these processes, while IL-13-induced changes in the intracellular expression of TGFα and ADAM17 were visualized by confocal microscopy. Results IL-13 was found to induce proliferation of NHBE cells, and release of TGFα, in an ADAM17-dependent manner; however, this IL-13-induced proliferation did not appear to result solely from ADAM17 activation. Rather, IL-13 induced a change in the location of TGFα expression from intracellular to apical regions of the NHBE cells. The apical region was also found to be a site of significant ADAM17 expression, even prior to IL-13 stimulation. Conclusion Results from this study indicate that ADAM17 mediates IL-13-induced proliferation and TGFα shedding in NHBE cells. Furthermore, they provide the first example wherein a cytokine (IL-13 induces a change in the intracellular expression pattern of a growth factor, apparently inducing redistribution of intracellular stores of TGFα to the apical region of NHBE cells where expression of ADAM17 is prominent. Thus, IL-13

  5. The Role of Hedgehog Signaling in Tumor Induced Bone Disease

    Directory of Open Access Journals (Sweden)

    Shellese A. Cannonier

    2015-08-01

    Full Text Available Despite significant progress in cancer treatments, tumor induced bone disease continues to cause significant morbidities. While tumors show distinct mutations and clinical characteristics, they behave similarly once they establish in bone. Tumors can metastasize to bone from distant sites (breast, prostate, lung, directly invade into bone (head and neck or originate from the bone (melanoma, chondrosarcoma where they cause pain, fractures, hypercalcemia, and ultimately, poor prognoses and outcomes. Tumors in bone secrete factors (interleukins and parathyroid hormone-related protein that induce RANKL expression from osteoblasts, causing an increase in osteoclast mediated bone resorption. While the mechanisms involved varies slightly between tumor types, many tumors display an increase in Hedgehog signaling components that lead to increased tumor growth, therapy failure, and metastasis. The work of multiple laboratories has detailed Hh signaling in several tumor types and revealed that tumor establishment in bone can be controlled by both canonical and non-canonical Hh signaling in a cell type specific manner. This review will explore the role of Hh signaling in the modulation of tumor induced bone disease, and will shed insight into possible therapeutic interventions for blocking Hh signaling in these tumors.

  6. The Role of Hedgehog Signaling in Tumor Induced Bone Disease

    Energy Technology Data Exchange (ETDEWEB)

    Cannonier, Shellese A.; Sterling, Julie A., E-mail: Julie.sterling@vanderbilt.edu [Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN 37235 (United States); Vanderbilt Center for Bone Biology, Department of Medicine, Division of Clinical Pharmacology Vanderbilt University, Nashville, TN 372335 (United States); Department of Cancer Biology, Vanderbilt University, Nashville, TN 37235 (United States)

    2015-08-26

    Despite significant progress in cancer treatments, tumor induced bone disease continues to cause significant morbidities. While tumors show distinct mutations and clinical characteristics, they behave similarly once they establish in bone. Tumors can metastasize to bone from distant sites (breast, prostate, lung), directly invade into bone (head and neck) or originate from the bone (melanoma, chondrosarcoma) where they cause pain, fractures, hypercalcemia, and ultimately, poor prognoses and outcomes. Tumors in bone secrete factors (interleukins and parathyroid hormone-related protein) that induce RANKL expression from osteoblasts, causing an increase in osteoclast mediated bone resorption. While the mechanisms involved varies slightly between tumor types, many tumors display an increase in Hedgehog signaling components that lead to increased tumor growth, therapy failure, and metastasis. The work of multiple laboratories has detailed Hh signaling in several tumor types and revealed that tumor establishment in bone can be controlled by both canonical and non-canonical Hh signaling in a cell type specific manner. This review will explore the role of Hh signaling in the modulation of tumor induced bone disease, and will shed insight into possible therapeutic interventions for blocking Hh signaling in these tumors.

  7. The Role of Hedgehog Signaling in Tumor Induced Bone Disease

    International Nuclear Information System (INIS)

    Cannonier, Shellese A.; Sterling, Julie A.

    2015-01-01

    Despite significant progress in cancer treatments, tumor induced bone disease continues to cause significant morbidities. While tumors show distinct mutations and clinical characteristics, they behave similarly once they establish in bone. Tumors can metastasize to bone from distant sites (breast, prostate, lung), directly invade into bone (head and neck) or originate from the bone (melanoma, chondrosarcoma) where they cause pain, fractures, hypercalcemia, and ultimately, poor prognoses and outcomes. Tumors in bone secrete factors (interleukins and parathyroid hormone-related protein) that induce RANKL expression from osteoblasts, causing an increase in osteoclast mediated bone resorption. While the mechanisms involved varies slightly between tumor types, many tumors display an increase in Hedgehog signaling components that lead to increased tumor growth, therapy failure, and metastasis. The work of multiple laboratories has detailed Hh signaling in several tumor types and revealed that tumor establishment in bone can be controlled by both canonical and non-canonical Hh signaling in a cell type specific manner. This review will explore the role of Hh signaling in the modulation of tumor induced bone disease, and will shed insight into possible therapeutic interventions for blocking Hh signaling in these tumors

  8. Andrographolide induces apoptotic and non-apoptotic death and enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in gastric cancer cells.

    Science.gov (United States)

    Lim, Sung-Chul; Jeon, Ho Jong; Kee, Keun Hong; Lee, Mi Ja; Hong, Ran; Han, Song Iy

    2017-05-01

    Andrographolide, a natural compound isolated from Andrographis paniculata , has been reported to possess antitumor activity. In the present study, the effect of andrographolide in human gastric cancer (GC) cells was investigated. Andrographolide induced cell death with apoptotic and non-apoptotic features. At a low concentration, andrographolide potentiated apoptosis and reduction of clonogenicity triggered by recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL). Exposure of GC cells to andrographolide altered the expression level of several growth-inhibiting and apoptosis-regulating proteins, including death receptors. It was demonstrated that activity of the TRAIL-R2 (DR5) pathway was critical in the development of andrographolide-mediated rhTRAIL sensitization, since its inhibition significantly reduced the extent of apoptosis induced by the combination of rhTRAIL and andrographolide. In addition, andrographolide increased reactive oxygen species (ROS) generation in a dose-dependent manner. N-acetyl cysteine prevented andrographolide-mediated DR5 induction and the apoptotic effect induced by the combination of rhTRAIL and andrographolide. Collectively, the present study demonstrated that andrographolide enhances TRAIL-induced apoptosis through induction of DR5 expression. This effect appears to involve ROS generation in GCs.

  9. C-X-C Chemokine Receptor Type 4 Plays a Crucial Role in Mediating Oxidative Stress-Induced Podocyte Injury.

    Science.gov (United States)

    Mo, Hongyan; Wu, Qinyu; Miao, Jinhua; Luo, Congwei; Hong, Xue; Wang, Yongping; Tang, Lan; Hou, Fan Fan; Liu, Youhua; Zhou, Lili

    2017-08-20

    Oxidative stress plays a role in mediating podocyte injury and proteinuria. However, the underlying mechanism remains poorly understood. In this study, we investigated the potential role of C-X-C chemokine receptor type 4 (CXCR4), the receptor for stromal cell-derived factor 1α (SDF-1α), in mediating oxidative stress-induced podocyte injury. In mouse model of adriamycin nephropathy (ADR), CXCR4 expression was significantly induced in podocytes as early as 3 days. This was accompanied by an increased upregulation of oxidative stress in podocyte, as demonstrated by malondialdehyde assay, nitrotyrosine staining and secretion of 8-hydroxy-2'-deoxyguanosine in urine, and induction of NOX2 and NOX4, major subunits of NADPH oxidase. CXCR4 was also induced in human kidney biopsies with proteinuric kidney diseases and colocalized with advanced oxidation protein products (AOPPs), an established oxidative stress trigger. Using cultured podocytes and mouse model, we found that AOPPs induced significant loss of podocyte marker Wilms tumor 1 (WT1), nephrin, and podocalyxin, accompanied by upregulation of desmin both in vitro and in vivo. Furthermore, AOPPs worsened proteinuria and aggravated glomerulosclerosis in ADR. These effects were associated with marked activation of SDF-1α/CXCR4 axis in podocytes. Administration of AMD3100, a specific inhibitor of CXCR4, reduced proteinuria and ameliorated podocyte dysfunction and renal fibrosis triggered by AOPPs in mice. In glomerular miniorgan culture, AOPPs also induced CXCR4 expression and downregulated nephrin and WT1. Innovation and Conclusion: These results suggest that chemokine receptor CXCR4 plays a crucial role in mediating oxidative stress-induced podocyte injury, proteinuria, and renal fibrosis. CXCR4 could be a new target for mitigating podocyte injury, proteinuria, and glomerular sclerosis in proteinuric chronic kidney disease. Antioxid. Redox Signal. 27, 345-362.

  10. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    International Nuclear Information System (INIS)

    Sun, Hengwen; Yang, Shana; Li, Jianhua; Zhang, Yajie; Gao, Dongsheng; Zhao, Shenting

    2016-01-01

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  11. Oxidative stress induced by palytoxin in human keratinocytes is mediated by a H+-dependent mitochondrial pathway

    International Nuclear Information System (INIS)

    Pelin, Marco; Ponti, Cristina; Sosa, Silvio; Gibellini, Davide; Florio, Chiara; Tubaro, Aurelia

    2013-01-01

    In the last decades, massive blooms of palytoxin (PLTX)-producing Ostreopsis cf. ovata have been observed along Mediterranean coasts, usually associated to human respiratory and cutaneous problems. At the molecular level, PLTX induces a massive intracellular Na + influx due to the transformation of Na + /K + ATPase in a cationic channel. Recently, we have demonstrated that Na + overload is the crucial step in mediating overproduction of reactive oxygen species (ROS) and cell death in human HaCaT keratinocytes, tentatively explaining PLTX-induced skin irritant effects. In the present study the molecular mechanisms of ROS production induced by PLTX-mediated Na + intracellular overload have been investigated. In HaCaT cells, PLTX exposure caused accumulation of superoxide anion, but not of nitric oxide or peroxynitrite/hydroxyl radicals. Even if RT-PCR and western blot analysis revealed an early NOX-2 and iNOS gene and protein over-expressions, their active involvement seemed to be only partial since selective inhibitors did not completely reduce O 2 − production. A significant role of other enzymes (COX-1, COX-2, XO) was not evidenced. Nigericin, that counteracts Na + -mediated H + -imbalance, dissipating ΔpH across mitochondrial inner membrane, and the uncouplers DNP significantly reduced O 2 − production. These inhibitions were synergistic when co-exposed with complex-I inhibitor rotenone. These results suggest a novel mechanism of O 2 − production induced by PLTX-mediated ionic imbalance. Indeed, the H + intracellular overload that follows PLTX-induced intracellular Na + accumulation, could enhance ΔpH across mitochondrial inner membrane, that seems to be the driving force for O 2 − production by reversing mitochondrial electron transport. Highlights: ► PLTX induces superoxide (O 2 − ) production by reversing mitochondrial transport chain. ► The mechanism of O 2 − production is dependent on PLTX-induced ionic imbalance. ► The results led to the

  12. Oxidative stress induced by palytoxin in human keratinocytes is mediated by a H{sup +}-dependent mitochondrial pathway

    Energy Technology Data Exchange (ETDEWEB)

    Pelin, Marco, E-mail: marco.pelin@phd.units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Ponti, Cristina, E-mail: cponti@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Sosa, Silvio, E-mail: silvio.sosa@econ.units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Gibellini, Davide, E-mail: davide.gibellini@unibo.it [Department of Haematology and Oncological Sciences, University of Bologna, Via Massarenti 9, 40138 Bologna (Italy); Florio, Chiara, E-mail: florioc@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy); Tubaro, Aurelia, E-mail: tubaro@units.it [Department of Life Science, University of Trieste, Via L. Giorgieri 7/9, 34127 Trieste (Italy)

    2013-01-01

    In the last decades, massive blooms of palytoxin (PLTX)-producing Ostreopsis cf. ovata have been observed along Mediterranean coasts, usually associated to human respiratory and cutaneous problems. At the molecular level, PLTX induces a massive intracellular Na{sup +} influx due to the transformation of Na{sup +}/K{sup +} ATPase in a cationic channel. Recently, we have demonstrated that Na{sup +} overload is the crucial step in mediating overproduction of reactive oxygen species (ROS) and cell death in human HaCaT keratinocytes, tentatively explaining PLTX-induced skin irritant effects. In the present study the molecular mechanisms of ROS production induced by PLTX-mediated Na{sup +} intracellular overload have been investigated. In HaCaT cells, PLTX exposure caused accumulation of superoxide anion, but not of nitric oxide or peroxynitrite/hydroxyl radicals. Even if RT-PCR and western blot analysis revealed an early NOX-2 and iNOS gene and protein over-expressions, their active involvement seemed to be only partial since selective inhibitors did not completely reduce O{sub 2}{sup −} production. A significant role of other enzymes (COX-1, COX-2, XO) was not evidenced. Nigericin, that counteracts Na{sup +}-mediated H{sup +}-imbalance, dissipating ΔpH across mitochondrial inner membrane, and the uncouplers DNP significantly reduced O{sub 2}{sup −} production. These inhibitions were synergistic when co-exposed with complex-I inhibitor rotenone. These results suggest a novel mechanism of O{sub 2}{sup −} production induced by PLTX-mediated ionic imbalance. Indeed, the H{sup +} intracellular overload that follows PLTX-induced intracellular Na{sup +} accumulation, could enhance ΔpH across mitochondrial inner membrane, that seems to be the driving force for O{sub 2}{sup −} production by reversing mitochondrial electron transport. Highlights: ► PLTX induces superoxide (O{sub 2}{sup −}) production by reversing mitochondrial transport chain. ► The mechanism of

  13. Anthocyanins protect against LPS-induced oxidative stress-mediated neuroinflammation and neurodegeneration in the adult mouse cortex.

    Science.gov (United States)

    Khan, Muhammad Sohail; Ali, Tahir; Kim, Min Woo; Jo, Myeung Hoon; Jo, Min Gi; Badshah, Haroon; Kim, Myeong Ok

    2016-11-01

    Several studies provide evidence that reactive oxygen species (ROS) are key mediators of various neurological disorders. Anthocyanins are polyphenolic compounds and are well known for their anti-oxidant and neuroprotective effects. In this study, we investigated the neuroprotective effects of anthocyanins (extracted from black soybean) against lipopolysaccharide (LPS)-induced ROS-mediated neuroinflammation and neurodegeneration in the adult mouse cortex. Intraperitoneal injection of LPS (250 μg/kg) for 7 days triggers elevated ROS and oxidative stress, which induces neuroinflammation and neurodegeneration in the adult mouse cortex. Treatment with 24 mg/kg/day of anthocyanins for 14 days in LPS-injected mice (7 days before and 7 days co-treated with LPS) attenuated elevated ROS and oxidative stress compared to mice that received LPS-injection alone. The immunoblotting results showed that anthocyanins reduced the level of the oxidative stress kinase phospho-c-Jun N-terminal Kinase 1 (p-JNK). The immunoblotting and morphological results showed that anthocyanins treatment significantly reduced LPS-induced-ROS-mediated neuroinflammation through inhibition of various inflammatory mediators, such as IL-1β, TNF-α and the transcription factor NF- k B. Anthocyanins treatment also reduced activated astrocytes and microglia in the cortex of LPS-injected mice, as indicated by reductions in GFAP and Iba-1, respectively. Anthocyanins also prevent overexpression of various apoptotic markers, i.e., Bax, cytosolic cytochrome C, cleaved caspase-3 and PARP-1. Immunohistochemical fluoro-jade B (FJB) and Nissl staining indicated that anthocyanins prevent LPS-induced neurodegeneration in the mouse cortex. Our results suggest that dietary flavonoids, such as anthocyanins, have antioxidant and neuroprotective activities that could be beneficial to various neurological disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Down-regulation of inflammatory mediator synthesis and infiltration of inflammatory cells by MMP-3 in experimentally induced rat pulpitis.

    Science.gov (United States)

    Takimoto, Koyo; Kawashima, Nobuyuki; Suzuki, Noriyuki; Koizumi, Yu; Yamamoto, Mioko; Nakashima, Misako; Suda, Hideaki

    2014-09-01

    Matrix metalloproteinase (MMP)-3 is a member of the MMP family that degrades the extracellular matrix. Application of MMP-3 to injured pulp tissue induces angiogenesis and wound healing, but its anti-inflammatory effects are still unclear. Here, we evaluated the anti-inflammatory functions of MMP-3 in vitro and in vivo. Nitric oxide and inflammatory mediator synthesis in macrophages activated by lipopolysaccharide (LPS) was measured in the presence or absence of MMP-3. The mouse Mmp3 (mMmp3) expression vector containing full length cDNA sequence of mMmp3 or cDNA sequence of mMmp3 missing the signal peptide and pro-peptide regions was transfected to RAW264, a mouse macrophage cell line, and NO synthesis and inflammatory mediator expression were evaluated. Pulpal inflammation was histologically and immunohistochemically evaluated in a rat model of incisor pulpitis induced by the application of LPS for 9 hours in the presence or absence of MMP-3. NO and pro-inflammatory mediator synthesis promoted by LPS was significantly down-regulated by MMP-3 in vitro. The full length of mMmp3 down-regulated the LPS-induced NO synthesis and chemical mediator mRNA expression, however the mMmp3 missing the signal peptide failed to block the NO synthesis induced by LPS. The numbers of major histocompatibility complex class II+ and CD68+ cells, which infiltrated into the rat incisor pulp tissues in response to the topical application of LPS, were significantly decreased by the application of MMP-3 in vivo. These results indicate that MMP-3 possesses anti-inflammatory functions, suggesting its potential utility as an anti-inflammatory agent for pulpal inflammation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Downregulation of β1,4-galactosyltransferase 1 inhibits CDK11p58-mediated apoptosis induced by cycloheximide

    International Nuclear Information System (INIS)

    Li Zejuan; Wang Hanzhou; Zong Hongliang; Sun Qing; Kong Xiangfei; Jiang Jianhai; Gu Jianxin

    2005-01-01

    Cyclin-dependent kinase 11 (CDK11; also named PITSLRE) is part of the large family of p34 cdc2 -related kinases whose functions appear to be linked with cell cycle progression, tumorigenesis, and apoptotic signaling. The mechanism that CDK11 p58 induces apoptosis is not clear. Some evidences suggested β1,4-galactosyltransferase 1 (β1,4-GT 1) might participate in apoptosis induced by CDK11 p58 . In this study, we demonstrated that ectopically expressed β1,4-GT 1 increased CDK11 p58 -mediated apoptosis induced by cycloheximide (CHX). In contrast, RNAi-mediated knockdown of β1,4-GT 1 effectively inhibited apoptosis induced by CHX in CDK11 p58 -overexpressing cells. For example, the cell morphological and nuclear changes were reduced; the loss of cell viability was prevented and the number of cells in sub-G1 phase was decreased. Knock down of β1,4-GT 1 also inhibited the release of cytochrome c from mitochondria and caspase-3 processing. Therefore, the cleavage of CDK11 p58 by caspase-3 was reduced. We proposed that β1,4-GT 1 might contribute to the pro-apoptotic effect of CDK11 p58 . This may represent a new mechanism of β1,4-GT 1 in CHX-induced apoptosis of CDK11 p58 -overexpressing cells

  16. DNaseI Protects against Paraquat-Induced Acute Lung Injury and Pulmonary Fibrosis Mediated by Mitochondrial DNA

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    Guo Li

    2015-01-01

    Full Text Available Background. Paraquat (PQ poisoning is a lethal toxicological challenge that served as a disease model of acute lung injury and pulmonary fibrosis, but the mechanism is undetermined and no effective treatment has been discovered. Methods and Findings. We demonstrated that PQ injures mitochondria and leads to mtDNA release. The mtDNA mediated PBMC recruitment and stimulated the alveolar epithelial cell production of TGF-β1 in vitro. The levels of mtDNA in circulation and bronchial alveolar lavage fluid (BALF were elevated in a mouse of PQ-induced lung injury. DNaseI could protect PQ-induced lung injury and significantly improved survival. Acute lung injury markers, such as TNFα, IL-1β, and IL-6, and marker of fibrosis, collagen I, were downregulated in parallel with the elimination of mtDNA by DNaseI. These data indicate a possible mechanism for PQ-induced, mtDNA-mediated lung injury, which may be shared by other causes of lung injury, as suggested by the same protective effect of DNaseI in bleomycin-induced lung injury model. Interestingly, increased mtDNA in the BALF of patients with amyopathic dermatomyositis-interstitial lung disease can be appreciated. Conclusions. DNaseI targeting mtDNA may be a promising approach for the treatment of PQ-induced acute lung injury and pulmonary fibrosis that merits fast tracking through clinical trials.

  17. TLR4-NOX4-AP-1 signaling mediates lipopolysaccharide-induced CXCR6 expression in human aortic smooth muscle cells

    International Nuclear Information System (INIS)

    Patel, Devang N.; Bailey, Steven R.; Gresham, John K.; Schuchman, David B.; Shelhamer, James H.; Goldstein, Barry J.; Foxwell, Brian M.; Stemerman, Michael B.; Maranchie, Jodi K.; Valente, Anthony J.; Mummidi, Srinivas; Chandrasekar, Bysani

    2006-01-01

    CXCL16 is a transmembrane non-ELR CXC chemokine that signals via CXCR6 to induce aortic smooth muscle cell (ASMC) proliferation. While bacterial lipopolysaccharide (LPS) has been shown to stimulate CXCL16 expression in SMC, its effects on CXCR6 are not known. Here, we demonstrate that LPS upregulates CXCR6 mRNA, protein, and surface expression in human ASMC. Inhibition of TLR4 with neutralizing antibodies or specific siRNA interference blocked LPS-mediated CXCR6 expression. LPS stimulated both AP-1 (c-Fos, c-Jun) and NF-κB (p50 and p65) activation, but only inhibition of AP-1 attenuated LPS-induced CXCR6 expression. Using dominant negative expression vectors and siRNA interference, we demonstrate that LPS induces AP-1 activation via MyD88, TRAF6, ERK1/2, and JNK signaling pathways. Furthermore, the flavoprotein inhibitor diphenyleniodonium chloride significantly attenuated LPS-mediated AP-1-dependent CXCR6 expression, as did inhibition of NOX4 NADPH oxidase by siRNA. Finally, CXCR6 knockdown inhibited CXCL16-induced ASMC proliferation. These results demonstrate that LPS-TLR4-NOX4-AP-1 signaling can induce CXCR6 expression in ASMC, and suggest that the CXCL16-CXCR6 axis may be an important proinflammatory pathway in the pathogenesis of atherosclerosis

  18. Non-thermal plasma induces mitochondria-mediated apoptotic signaling pathway via ROS generation in HeLa cells.

    Science.gov (United States)

    Li, Wei; Yu, K N; Ma, Jie; Shen, Jie; Cheng, Cheng; Zhou, Fangjian; Cai, Zhiming; Han, Wei

    2017-11-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. Although increasing evidence suggests that NTP selectively induces apoptosis in some types of tumor cells, the molecular mechanisms underlying this phenomenon remain unclear. In this study, we further investigated possible molecular mechanisms for NTP-induced apoptosis of HeLa cells. The results showed that NTP exposure significantly inhibited the growth and viability of HeLa cells. Morphological observation and flow cytometry analysis demonstrated that NTP exposure induced HeLa cell apoptosis. NTP exposure also activated caspase-9 and caspase-3, which subsequently cleaved poly (ADP- ribose) polymerase. Furthermore, NTP exposure suppressed Bcl-2 expression, enhanced Bax expression and translocation to mitochondria, activated mitochondria-mediated apoptotic pathway, followed by the release of cytochrome c. Further studies showed that NTP treatment led to ROS generation, whereas blockade of ROS generation by N-acetyl-l-cysteine (NAC, ROS scavengers) significantly prevented NTP-induced mitochondrial alteration and subsequent apoptosis of HeLa cells via suppressing Bax translocation, cytochrome c and caspase-3 activation. Taken together, our results indicated that NTP exposure induced mitochondria-mediated intrinsic apoptosis of HeLa cells was activated by ROS generation. These findings provide insights to the therapeutic potential and clinical research of NTP as a novel tool in cervical cancer treatment. Copyright © 2017. Published by Elsevier Inc.

  19. Acute stress-induced cortisol elevations mediate reward system activity during subconscious processing of sexual stimuli.

    Science.gov (United States)

    Oei, Nicole Y L; Both, Stephanie; van Heemst, Diana; van der Grond, Jeroen

    2014-01-01

    Stress is thought to alter motivational processes by increasing dopamine (DA) secretion in the brain's "reward system", and its key region, the nucleus accumbens (NAcc). However, stress studies using functional magnetic resonance imaging (fMRI), mainly found evidence for stress-induced decreases in NAcc responsiveness toward reward cues. Results from both animal and human PET studies indicate that the stress hormone cortisol may be crucial in the interaction between stress and dopaminergic actions. In the present study we therefore investigated whether cortisol mediated the effect of stress on DA-related responses to -subliminal-presentation of reward cues using the Trier Social Stress Test (TSST), which is known to reliably enhance cortisol levels. Young healthy males (n = 37) were randomly assigned to the TSST or control condition. After stress induction, brain activation was assessed using fMRI during a backward-masking paradigm in which potentially rewarding (sexual), emotionally negative and neutral stimuli were presented subliminally, masked by pictures of inanimate objects. A region of interest analysis showed that stress decreased activation in the NAcc in response to masked sexual cues (voxel-corrected, pcortisol levels were related to stronger NAcc activation, showing that cortisol acted as a suppressor variable in the negative relation between stress and NAcc activation. The present findings indicate that cortisol is crucially involved in the relation between stress and the responsiveness of the reward system. Although generally stress decreases activation in the NAcc in response to rewarding stimuli, high stress-induced cortisol levels suppress this relation, and are associated with stronger NAcc activation. Individuals with a high cortisol response to stress might on one hand be protected against reductions in reward sensitivity, which has been linked to anhedonia and depression, but they may ultimately be more vulnerable to increased reward

  20. Cyclin D2 is a critical mediator of exercise-induced cardiac hypertrophy.

    Science.gov (United States)

    Luckey, Stephen W; Haines, Chris D; Konhilas, John P; Luczak, Elizabeth D; Messmer-Kratzsch, Antke; Leinwand, Leslie A

    2017-12-01

    induced cardiac growth in all of the transgenic mice except for the mice deficient in cyclin D2. In the cyclin D2 null mice, cardiac function was not impacted even though the hypertrophic response was blunted and a number of signaling pathways are differentially regulated by exercise. These data provide the field with an understanding that cyclin D2 is a key mediator of physiological hypertrophy.

  1. Hematoporphyrin monomethyl ether-mediated photodynamic therapy selectively kills sarcomas by inducing apoptosis.

    Directory of Open Access Journals (Sweden)

    Hui Zeng

    Full Text Available We investigated the antitumor effect and mechanism of hematoporphyrin monomethyl ether-mediated photodynamic therapy (HMME-PDT in sarcomas. Intracellular uptake of HMME by osteosarcoma cells (LM8 and K7 was time- and dose-dependent, while this was not observed for myoblast cells (C2C12 and fibroblast cells (NIH/3T3. HMME-PDT markedly inhibited the proliferation of sarcoma cell lines (LM8, MG63, Saos-2, SW1353, TC71, and RD (P<0.05, and the killing effect was improved with increased HMME concentration and energy intensity. Flow cytometry analysis revealed that LM8, MG63, and Saos-2 cells underwent apoptosis after treatment with HMME-PDT. Additionally, apoptosis was induced after HMME-PDT in a three-dimensional culture of osteosarcoma cells. Hoechst 33342 staining confirmed apoptosis. Cell death caused by PDT was rescued by an irreversible inhibitor (Z-VAD-FMK of caspase. However, cell viability was not markedly decreased compared with the HMME-PDT group. Expression levels of caspase-1, caspase-3, caspase-6, caspase-9, and poly (ADP-ribose polymerase (PARP proteins were markedly up-regulated in the treatment groups and increased with HMME concentration as determined by western blot analysis. In vivo, tumor volume markedly decreased at 7-16 days post-PDT. Hematoxylin and eosin staining revealed widespread necrotic and infiltrative inflammatory cells in the HMME-PDT group. Immunohistochemistry analysis also showed that caspase-1, caspase-3, caspase-6, caspase-9, and PARP proteins were significantly increased in the HMME-PDT group. These results indicate that HMME-PDT has a potent killing effect on osteosarcoma cells in vitro and significantly inhibits tumor growth in vivo, which is associated with the caspase-dependent pathway.

  2. Inhibition of calcium uptake during hypoxia in developing zebrafish is mediated by hypoxia-inducible factor.

    Science.gov (United States)

    Kwong, Raymond W M; Kumai, Yusuke; Tzaneva, Velislava; Azzi, Estelle; Hochhold, Nina; Robertson, Cayleih; Pelster, Bernd; Perry, Steve F

    2016-12-15

    The present study investigated the potential role of hypoxia-inducible factor (HIF) in calcium homeostasis in developing zebrafish (Danio rerio). It was demonstrated that zebrafish raised in hypoxic water (30 mmHg; control, 155 mmHg P O 2 ) until 4 days post-fertilization exhibited a substantial reduction in whole-body Ca 2+ levels and Ca 2+ uptake. Ca 2+ uptake in hypoxia-treated fish did not return to pre-hypoxia (control) levels within 2 h of transfer back to normoxic water. Results from real-time PCR showed that hypoxia decreased the whole-body mRNA expression levels of the epithelial Ca 2+ channel (ecac), but not plasma membrane Ca 2+ -ATPase (pmca2) or Na + /Ca 2+ -exchanger (ncx1b). Whole-mount in situ hybridization revealed that the number of ecac-expressing ionocytes was reduced in fish raised in hypoxic water. These findings suggested that hypoxic treatment suppressed the expression of ecac, thereby reducing Ca 2+ influx. To further evaluate the potential mechanisms for the effects of hypoxia on Ca 2+ regulation, a functional gene knockdown approach was employed to prevent the expression of HIF-1αb during hypoxic treatment. Consistent with a role for HIF-1αb in regulating Ca 2+ balance during hypoxia, the results demonstrated that the reduction of Ca 2+ uptake associated with hypoxic exposure was not observed in fish experiencing HIF-1αb knockdown. Additionally, the effects of hypoxia on reducing the number of ecac-expressing ionocytes was less pronounced in HIF-1αb-deficient fish. Overall, the current study revealed that hypoxic exposure inhibited Ca 2+ uptake in developing zebrafish, probably owing to HIF-1αb-mediated suppression of ecac expression. © 2016. Published by The Company of Biologists Ltd.

  3. Hyperammonemia in cirrhosis induces transcriptional regulation of myostatin by an NF-κB–mediated mechanism

    Science.gov (United States)

    Qiu, Jia; Thapaliya, Samjhana; Runkana, Ashok; Yang, Yu; Tsien, Cynthia; Mohan, Maradumane L.; Narayanan, Arvind; Eghtesad, Bijan; Mozdziak, Paul E.; McDonald, Christine; Stark, George R.; Welle, Stephen; Naga Prasad, Sathyamangla V.; Dasarathy, Srinivasan

    2013-01-01

    Loss of muscle mass, or sarcopenia, is nearly universal in cirrhosis and adversely affects patient outcome. The underlying cross-talk between the liver and skeletal muscle mediating sarcopenia is not well understood. Hyperammonemia is a consistent abnormality in cirrhosis due to impaired hepatic detoxification to urea. We observed elevated levels of ammonia in both plasma samples and skeletal muscle biopsies from cirrhotic patients compared with healthy controls. Furthermore, skeletal muscle from cirrhotics had increased expression of myostatin, a known inhibitor of skeletal muscle accretion and growth. In vivo studies in mice showed that hyperammonemia reduced muscle mass and strength and increased myostatin expression in wild-type compared with postdevelopmental myostatin knockout mice. We postulated that hyperammonemia is an underlying link between hepatic dysfunction in cirrhosis and skeletal muscle loss. Therefore, murine C2C12 myotubes were treated with ammonium acetate resulting in intracellular concentrations similar to those in cirrhotic muscle. In this system, we demonstrate that hyperammonemia stimulated myostatin expression in a NF-κB–dependent manner. This finding was also observed in primary murine muscle cell cultures. Hyperammonemia triggered activation of IκB kinase, NF-κB nuclear translocation, binding of the NF-κB p65 subunit to specific sites within the myostatin promoter, and stimulation of myostatin gene transcription. Pharmacologic inhibition or gene silencing of NF-κB abolished myostatin up-regulation under conditions of hyperammonemia. Our work provides unique insights into hyperammonemia-induced myostatin expression and suggests a mechanism by which sarcopenia develops in cirrhotic patients. PMID:24145431

  4. Src mediates cigarette smoke-induced resistance to tyrosine kinase inhibitors in NSCLC cells.

    Science.gov (United States)

    Filosto, Simone; Baston, David S; Chung, Samuel; Becker, Cathleen R; Goldkorn, Tzipora

    2013-08-01

    The EGF receptor (EGFR) is a proto-oncogene commonly dysregulated in several cancers including non-small cell lung carcinoma (NSCLC) and, thus, is targeted for treatment using tyrosine kinase inhibitors (TKI) such as erlotinib. However, despite the efficacy observed in patients with NSCLC harboring oncogenic variants of the EGFR, general ineffectiveness of TKIs in patients with NSCLC who are current and former smokers necessitates identification of novel mechanisms to overcome this phenomenon. Previously, we showed that NSCLC cells harboring either wild-type (WT) EGFR or oncogenic mutant (MT) L858R EGFR become resistant to the effects of TKIs when exposed to cigarette smoke, evidenced by their autophosphorylation and prolonged downstream signaling. Here, we present Src as a target mediating cigarette smoke-induced resistance to TKIs in both WT EGFR- and L858R MT EGFR-expressing NSCLC cells. First, we show that cigarette smoke exposure of A549 cells leads to time-dependent activation of Src, which then abnormally binds to the WT EGFR causing TKI resistance, contrasting previous observations of constitutive binding between inactive Src and TKI-sensitive L858R MT EGFR. Next, we show that Src inhibition restores TKI sensitivity in cigarette smoke-exposed NSCLC cells, preventing EGFR autophosphorylation in the presence of erlotinib. Furthermore, we show that overexpression of a dominant-negative Src (Y527F/K295R) restores TKI sensitivity to A549 exposed to cigarette smoke. Importantly, the TKI resistance that emerges even in cigarette smoke-exposed L858R EGFR-expressing NSCLC cells could be eliminated with Src inhibition. Together, these findings offer new rationale for using Src inhibitors for treating TKI-resistant NSCLC commonly observed in smokers.

  5. TAT-Mediated Delivery of Tousled Protein to Salivary Glands Protects Against Radiation-Induced Hypofunction

    Energy Technology Data Exchange (ETDEWEB)

    Sunavala-Dossabhoy, Gulshan, E-mail: gsunav@lsuhsc.edu [Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Palaniyandi, Senthilnathan; Richardson, Charles; De Benedetti, Arrigo [Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Schrott, Lisa [Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Caldito, Gloria [Department of Bioinformatics and Computational Biology, Louisiana State University Health Sciences Center, Shreveport, LA (United States)

    2012-09-01

    Purpose: Patients treated with radiotherapy for head-and-neck cancer invariably suffer its deleterious side effect, xerostomia. Salivary hypofunction ensuing from the irreversible destruction of glands is the most common and debilitating oral complication affecting patients undergoing regional radiotherapy. Given that the current management of xerostomia is palliative and ineffective, efforts are now directed toward preventive measures to preserve gland function. The human homolog of Tousled protein, TLK1B, facilitates chromatin remodeling at DNA repair sites and improves cell survival against ionizing radiation (IR). Therefore, we wanted to determine whether a direct transfer of TLK1B protein to rat salivary glands could protect against IR-induced salivary hypofunction. Methods: The cell-permeable TAT-TLK1B fusion protein was generated. Rat acinar cell line and rat salivary glands were pretreated with TAT peptide or TAT-TLK1B before IR. The acinar cell survival in vitro and salivary function in vivo were assessed after radiation. Results: We demonstrated that rat acinar cells transduced with TAT-TLK1B were more resistant to radiation (D{sub 0} = 4.13 {+-} 1.0 Gy; {alpha}/{beta} = 0 Gy) compared with cells transduced with the TAT peptide (D{sub 0} = 4.91 {+-} 1.0 Gy; {alpha}/{beta} = 20.2 Gy). Correspondingly, retroductal instillation of TAT-TLK1B in rat submandibular glands better preserved salivary flow after IR (89%) compared with animals pretreated with Opti-MEM or TAT peptide (31% and 39%, respectively; p < 0.01). Conclusions: The results demonstrate that a direct transfer of TLK1B protein to the salivary glands effectively attenuates radiation-mediated gland dysfunction. Prophylactic TLK1B-protein therapy could benefit patients undergoing radiotherapy for head-and-neck cancer.

  6. Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: Involvement of Ca2+ influx

    International Nuclear Information System (INIS)

    Moon, Dong-Oh; Kang, Chang-Hee; Kang, Sang-Hyuck; Choi, Yung-Hyun; Hyun, Jin-Won; Chang, Weon-Young; Kang, Hee-Kyoung; Koh, Young-Sang; Maeng, Young-Hee; Kim, Young-Ree; Kim, Gi-Young

    2012-01-01

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various malignant cells, several cancers including human hepatocellular carcinoma (HCC) exhibit potent resistance to TRAIL-induced cell death. The aim of this study is to evaluate the anti-cancer potential of capsaicin in TRAIL-induced cancer cell death. As indicated by assays that measure phosphatidylserine exposure, mitochondrial activity and activation of caspases, capsaicin potentiated TRAIL-resistant cells to lead to cell death. In addition, we found that capsaicin induces the cell surface expression of TRAIL receptor DR5, but not DR4 through the activation Sp1 on its promoter region. Furthermore, we investigated that capsaicin-induced DR5 expression and apoptosis are inhibited by calcium chelator or inhibitors for calmodulin-dependent protein kinase. Taken together, our data suggest that capsaicin sensitizes TRAIL-mediated HCC cell apoptosis by DR5 up-regulation via calcium influx-dependent Sp1 activation. Highlights: ► Capsaicin sensitizes TRAIL-induced apoptosis through activation of caspases. ► Capsaicin induces expression of DR5 through Sp1 activation. ► Capsaicin activates calcium signaling pathway.

  7. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen

    2015-01-01

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection

  8. Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongling; Huang, Yong; Du, Qian; Luo, Xiaomao; Zhang, Liang; Zhao, Xiaomin; Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn

    2015-01-09

    Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells in a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection.

  9. Host-Induced Gene Silencing of Rice Blast Fungus Magnaporthe oryzae Pathogenicity Genes Mediated by the Brome Mosaic Virus.

    Science.gov (United States)

    Zhu, Lin; Zhu, Jian; Liu, Zhixue; Wang, Zhengyi; Zhou, Cheng; Wang, Hong

    2017-09-26

    Magnaporthe oryzae is a devastating plant pathogen, which has a detrimental impact on rice production worldwide. Despite its agronomical importance, some newly-emerging pathotypes often overcome race-specific disease resistance rapidly. It is thus desirable to develop a novel strategy for the long-lasting resistance of rice plants to ever-changing fungal pathogens. Brome mosaic virus (BMV)-induced RNA interference (RNAi) has emerged as a useful tool to study host-resistance genes for rice blast protection. Planta-generated silencing of targeted genes inside biotrophic pathogens can be achieved by expression of M. oryzae -derived gene fragments in the BMV-mediated gene silencing system, a technique termed host-induced gene silencing (HIGS). In this study, the effectiveness of BMV-mediated HIGS in M. oryzae was examined by targeting three predicted pathogenicity genes, MoABC1, MoMAC1 and MoPMK1 . Systemic generation of fungal gene-specific small interfering RNA (siRNA) molecules induced by inoculation of BMV viral vectors inhibited disease development and reduced the transcription of targeted fungal genes after subsequent M. oryzae inoculation. Combined introduction of fungal gene sequences in sense and antisense orientation mediated by the BMV silencing vectors significantly enhanced the efficiency of this host-generated trans-specific RNAi, implying that these fungal genes played crucial roles in pathogenicity. Collectively, our results indicated that BMV-HIGS system was a great strategy for protecting host plants against the invasion of pathogenic fungi.

  10. Angiotensin-II-induced Muscle Wasting is Mediated by 25-Hydroxycholesterol via GSK3β Signaling Pathway

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    Congcong Shen

    2017-02-01

    Full Text Available While angiotensin II (ang II has been implicated in the pathogenesis of cardiac cachexia (CC, the molecules that mediate ang II's wasting effect have not been identified. It is known TNF-α level is increased in patients with CC, and TNF-α release is triggered by ang II. We therefore hypothesized that ang II induced muscle wasting is mediated by TNF-α. Ang II infusion led to skeletal muscle wasting in wild type (WT but not in TNF alpha type 1 receptor knockout (TNFR1KO mice, suggesting that ang II induced muscle loss is mediated by TNF-α through its type 1 receptor. Microarray analysis identified cholesterol 25-hydroxylase (Ch25h as the down stream target of TNF-α. Intraperitoneal injection of 25-hydroxycholesterol (25-OHC, the product of Ch25h, resulted in muscle loss in C57BL/6 mice, accompanied by increased expression of atrogin-1, MuRF1 and suppression of IGF-1/Akt signaling pathway. The identification of 25-OHC as an inducer of muscle wasting has implications for the development of specific treatment strategies in preventing muscle loss.

  11. Neuronal Orphan G-Protein Coupled Receptor Proteins Mediate Plasmalogens-Induced Activation of ERK and Akt Signaling.

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    Md Shamim Hossain

    Full Text Available The special glycerophospholipids plasmalogens (Pls are enriched in the brain and reported to prevent neuronal cell death by enhancing phosphorylation of Akt and ERK signaling in neuronal cells. Though the activation of Akt and ERK was found to be necessary for the neuronal cells survival, it was not known how Pls enhanced cellular signaling. To answer this question, we searched for neuronal specific orphan GPCR (G-protein coupled receptor proteins, since these proteins were believed to play a role in cellular signal transduction through the lipid rafts, where both Pls and some GPCRs were found to be enriched. In the present study, pan GPCR inhibitor significantly reduced Pls-induced ERK signaling in neuronal cells, suggesting that Pls could activate GPCRs to induce signaling. We then checked mRNA expression of 19 orphan GPCRs and 10 of them were found to be highly expressed in neuronal cells. The knockdown of these 10 neuronal specific GPCRs by short hairpin (sh-RNA lentiviral particles revealed that the Pls-mediated phosphorylation of ERK was inhibited in GPR1, GPR19, GPR21, GPR27 and GPR61 knockdown cells. We further found that the overexpression of these GPCRs enhanced Pls-mediated phosphorylation of ERK and Akt in cells. Most interestingly, the GPCRs-mediated cellular signaling was reduced significantly when the endogenous Pls were reduced. Our cumulative data, for the first time, suggest a possible mechanism for Pls-induced cellular signaling in the nervous system.

  12. Comparsion of light dose on topical ALA-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premalignant lesions

    Science.gov (United States)

    Yang, Deng-Fu; Tseng, Meng-Ke; Liu, Chung-Ji; Hsu, Yih-Chih

    2012-03-01

    Oral cancer has becomes the most prominent male cancer disease due to the local betel nut chewing habit combing with smoking and alcohol-drinking lifestyle. In order to minimize the systemic phototoxic effect of 5-aminolevulinic acid (ALA), this study was designed to use a topical ALA-mediated PDT for treatment of DMBA-induced hamster buccal pouch cancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 8 to 10 weeks. Precancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical ALA -mediated PDT. We found that ALA reached its peak level in cancerous lesions about 2.5 hrs after topical application of ALA gel. The precancerous lesions in hamsters were then treated with topical ALA -mediated PDT with light exposure dose of 75 and 100 J/cm2 using LED 635 nm Wonderlight device. It is suggesting that optimization of the given light dose is critical to the success of PDT results.

  13. Receptor Interacting Protein 3-Mediated Necroptosis Promotes Lipopolysaccharide-Induced Inflammation and Acute Respiratory Distress Syndrome in Mice.

    Directory of Open Access Journals (Sweden)

    Linlin Wang

    Full Text Available Necrosis amplifies inflammation and plays important roles in acute respiratory distress syndrome (ARDS. Necroptosis is a newly identified programmed necrosis that is mediated by receptor interacting protein 3 (RIP3. However, the potential involvement and impact of necroptosis in lipopolysaccharide (LPS-induced ARDS remains unknown. We therefore explored the role and mechanism of RIP3-mediated necroptosis in LPS-induced ARDS. Mice were instilled with increasing doses of LPS intratracheally to induce different degrees of ARDS. Lung tissues were harvested for histological and TUNEL staining and western blot for RIP3, p-RIP3, X-linked inhibitor of apoptosis protein (XIAP, mixed lineage kinase domain-like protein (MLKL, total and cleaved caspases-3/8. Then, wild-type and RIP3 knock-out mice were induced ARDS with 30 mg/kg LPS. Pulmonary cellular necrosis was labeled by the propidium Iodide (PI staining. Levels of TNF-a, Interleukin (IL-1β, IL-6, IL-1α, IL-10 and HMGB1, tissue myeloperoxidase (MPO activity, neutrophil counts and total protein concentration were measured. Results showed that in high dose LPS (30mg/kg and 40mg/kg -induced severe ARDS, RIP3 protein was increased significantly, accompanied by increases of p-RIP3 and MLKL, while in low dose LPS (10mg/kg and 20mg/kg -induced mild ARDS, apoptosis was remarkably increased. In LPS-induced severe ARDS, RIP3 knock-out alleviated the hypothermia symptom, increased survival rate and ameliorated the lung tissue injury RIP3 depletion also attenuated LPS-induced increase in IL-1α/β, IL-6 and HMGB1 release, decreased tissue MPO activity, and reduced neutrophil influx and total protein concentration in BALF in severe ARDS. Further, RIP3 depletion reduced the necrotic cells in the lung and decreased the expression of MLKL, but had no impact on cleaved caspase-3 in LPS-induced ARDS. It is concluded that RIP3-mediated necroptosis is a major mechanism of enhanced inflammation and lung tissue injury in

  14. Atorvastatin restores arsenic-induced vascular dysfunction in rats: Modulation of nitric oxide signaling and inflammatory mediators

    International Nuclear Information System (INIS)

    Kesavan, Manickam; Sarath, Thengumpallil Sasindran; Kannan, Kandasamy; Suresh, Subramaniyam; Gupta, Priyanka; Vijayakaran, Karunakaran; Sankar, Palanisamy; Kurade, Nitin Pandurang; Mishra, Santosh Kumar; Sarkar, Souvendra Nath

    2014-01-01

    We evaluated whether atorvastatin, an extensively prescribed statin for reducing the risks of cardiovascular diseases, can reduce the risk of arsenic-induced vascular dysfunction and inflammation in rats and whether the modulation could be linked to improvement in vascular NO signaling. Rats were exposed to sodium arsenite (100 ppm) through drinking water for 90 consecutive days. Atorvastatin (10 mg/kg bw, orally) was administered once daily during the last 30 days of arsenic exposure. On the 91 st day, blood was collected for measuring serum C-reactive protein. Thoracic aorta was isolated for assessing reactivity to phenylephrine, sodium nitroprusside and acetylcholine; evaluating eNOS and iNOS mRNA expression and measuring NO production, while abdominal aorta was used for ELISA of cytokines, chemokine and vascular cell adhesion molecules. Histopathology was done in aortic arches. Arsenic did not alter phenylephrine-elicited contraction. Atorvastatin inhibited E max of phenylephrine, but it augmented the contractile response in aortic rings from arsenic-exposed animals. Sodium nitroprusside-induced relaxation was not altered with any treatment. However, arsenic reduced acetylcholine-induced relaxation and affected aortic eNOS at the levels of mRNA expression, protein concentration, phosphorylation and NO production. Further, it increased aortic iNOS mRNA expression, iNOS-derived NO synthesis, production of pro-inflammatory mediators (IL-1β, IL-6, MCP-1, VCAM, sICAM) and serum C-reactive protein and aortic vasculopathic lesions. Atorvastatin attenuated these arsenic-mediated functional, biochemical and structural alterations. Results show that atorvastatin has the potential to ameliorate arsenic-induced vascular dysfunction and inflammation by restoring endothelial function with improvement in NO signaling and attenuating production of pro-inflammatory mediators and cell adhesion molecules. - Highlights: • We evaluated if atorvastatin reduce arsenic-induced

  15. Atorvastatin restores arsenic-induced vascular dysfunction in rats: Modulation of nitric oxide signaling and inflammatory mediators

    Energy Technology Data Exchange (ETDEWEB)

    Kesavan, Manickam; Sarath, Thengumpallil Sasindran; Kannan, Kandasamy; Suresh, Subramaniyam; Gupta, Priyanka; Vijayakaran, Karunakaran; Sankar, Palanisamy; Kurade, Nitin Pandurang; Mishra, Santosh Kumar; Sarkar, Souvendra Nath, E-mail: snsarkar1911@rediffmail.com

    2014-10-01

    We evaluated whether atorvastatin, an extensively prescribed statin for reducing the risks of cardiovascular diseases, can reduce the risk of arsenic-induced vascular dysfunction and inflammation in rats and whether the modulation could be linked to improvement in vascular NO signaling. Rats were exposed to sodium arsenite (100 ppm) through drinking water for 90 consecutive days. Atorvastatin (10 mg/kg bw, orally) was administered once daily during the last 30 days of arsenic exposure. On the 91{sup st} day, blood was collected for measuring serum C-reactive protein. Thoracic aorta was isolated for assessing reactivity to phenylephrine, sodium nitroprusside and acetylcholine; evaluating eNOS and iNOS mRNA expression and measuring NO production, while abdominal aorta was used for ELISA of cytokines, chemokine and vascular cell adhesion molecules. Histopathology was done in aortic arches. Arsenic did not alter phenylephrine-elicited contraction. Atorvastatin inhibited E{sub max} of phenylephrine, but it augmented the contractile response in aortic rings from arsenic-exposed animals. Sodium nitroprusside-induced relaxation was not altered with any treatment. However, arsenic reduced acetylcholine-induced relaxation and affected aortic eNOS at the levels of mRNA expression, protein concentration, phosphorylation and NO production. Further, it increased aortic iNOS mRNA expression, iNOS-derived NO synthesis, production of pro-inflammatory mediators (IL-1β, IL-6, MCP-1, VCAM, sICAM) and serum C-reactive protein and aortic vasculopathic lesions. Atorvastatin attenuated these arsenic-mediated functional, biochemical and structural alterations. Results show that atorvastatin has the potential to ameliorate arsenic-induced vascular dysfunction and inflammation by restoring endothelial function with improvement in NO signaling and attenuating production of pro-inflammatory mediators and cell adhesion molecules. - Highlights: • We evaluated if atorvastatin reduce arsenic-induced

  16. Cancer-induced bone loss and associated pain-related behavior is reduced by risedronate but not its phosphonocarboxylate analog NE-10790

    DEFF Research Database (Denmark)

    Hald, Andreas; Hansen, Rikke Rie; Thomsen, Mette W

    2009-01-01

    Prostate, breast and lung cancers readily develop bone metastases which lead to fractures, hypercalcemia and pain. Malignant growth in the bones depends on osteoclast-mediated bone resorption and in this regard bisphosphonate compounds, which have high-bone affinity and inhibit osteoclast activit...

  17. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK

    Science.gov (United States)

    Hill, Kayla; Yuan, Hu; Wang, Xianren

    2016-01-01

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. SIGNIFICANCE STATEMENT Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. PMID:27413159

  18. Inhibition of Drp1 protects against senecionine-induced mitochondria-mediated apoptosis in primary hepatocytes and in mice

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    Xiao Yang

    2017-08-01

    Full Text Available Pyrrolizidine alkaloids (PAs are a group of compounds found in various plants and some of them are widely consumed in the world as herbal medicines and food supplements. PAs are potent hepatotoxins that cause irreversible liver injury in animals and humans. However, the mechanisms by which PAs induce liver injury are not clear. In the present study, we determined the hepatotoxicity and molecular mechanisms of senecionine, one of the most common toxic PAs, in primary cultured mouse and human hepatocytes as well as in mice. We found that senecionine administration increased serum alanine aminotransferase levels in mice. H&E and TUNEL staining of liver tissues revealed increased hemorrhage and hepatocyte apoptosis in liver zone 2 areas. Mechanistically, senecionine induced loss of mitochondrial membrane potential, release of mitochondrial cytochrome c as well as mitochondrial JNK translocation and activation prior to the increased DNA fragmentation and caspase-3 activation in primary cultured mouse and human hepatocytes. SP600125, a specific JNK inhibitor, and ZVAD-fmk, a general caspase inhibitor, alleviated senecionine-induced apoptosis in primary hepatocytes. Interestingly, senecionine also caused marked mitochondria fragmentation in hepatocytes. Pharmacological inhibition of dynamin-related protein1 (Drp1, a protein that is critical to regulate mitochondrial fission, blocked senecionine-induced mitochondrial fragmentation and mitochondrial release of cytochrome c and apoptosis. More importantly, hepatocyte-specific Drp1 knockout mice were resistant to senecionine-induced liver injury due to decreased mitochondrial damage and apoptosis. In conclusion, our results uncovered a novel mechanism of Drp1-mediated mitochondrial fragmentation in senecionine-induced liver injury. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by PAs. Keywords: Senecionine, Drp1

  19. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi-Fen; Shyu, Huey-Wen [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chang, Yi-Chuang [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China); Tseng, Wei-Chang [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chen, Chang-Yu, E-mail: mt037@mail.fy.edu.tw [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)

    2012-03-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  20. SIRT1 Functions as an Important Regulator of Estrogen-Mediated Cardiomyocyte Protection in Angiotensin II-Induced Heart Hypertrophy

    Directory of Open Access Journals (Sweden)

    Tao Shen

    2014-01-01

    Full Text Available Background. Sirtuin 1 (SIRT1 is a member of the sirtuin family, which could activate cell survival machinery and has been shown to be protective in regulation of heart function. Here, we determined the mechanism by which SIRT1 regulates Angiotensin II- (AngII- induced cardiac hypertrophy and injury in vivo and in vitro. Methods. We analyzed SIRT1 expression in the hearts of control and AngII-induced mouse hypertrophy. Female C57BL/6 mice were ovariectomized and pretreated with 17β-estradiol to measure SIRT1 expression. Protein synthesis, cardiomyocyte surface area analysis, qRT-PCR, TUNEL staining, and Western blot were performed on AngII-induced mouse heart hypertrophy samples and cultured neonatal rat ventricular myocytes (NRVMs to investigate the function of SIRT1. Results. SIRT1 expression was slightly upregulated in AngII-induced mouse heart hypertrophy in vivo and in vitro, accompanied by elevated cardiomyocyte apoptosis. SIRT1 overexpression relieves AngII-induced cardiomyocyte hypertrophy and apoptosis. 17β-Estradiol was able to protect cardiomyocytes from AngII-induced injury with a profound upregulation of SIRT1 and activation of AMPK. Moreover, estrogen receptor inhibitor ICI 182,780 and SIRT1 inhibitor niacinamide could block SIRT1’s protective effect. Conclusions. These results indicate that SIRT1 functions as an important regulator of estrogen-mediated cardiomyocyte protection during AngII-induced heart hypertrophy and injury.

  1. Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway

    International Nuclear Information System (INIS)

    Wang, Yi-Fen; Shyu, Huey-Wen; Chang, Yi-Chuang; Tseng, Wei-Chang; Huang, Yeou-Lih; Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling; Chen, Chang-Yu

    2012-01-01

    Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

  2. Inflammatory Mediators in Induced Sputum and Airway Hyperresponsiveness in Cough Variant Asthma during Long-Term Inhaled Corticosteroid Treatment

    Directory of Open Access Journals (Sweden)

    Meixuan Liu

    2012-01-01

    Full Text Available Objective. This study aimed to investigate improvements in inflammatory mediator levels in induced sputum and airway hyperresponsiveness (AHR in cough variant asthma (CVA during long-term inhaled corticosteroid (ICS treatment. Patients and Methods. Patients with CVA (=35 and classic asthma (=26 and healthy subjects (=24 were recruited into this study. All patients were treated with budesonide (400 μg/day. Measurement of inflammatory mediators in induced sputum and PD20-FEV1 (the accumulated provocative dose resulting in a 20% decrease in FEV1 in histamine-challenged subjects was performed every three months after the start of medication. Interleukin- (IL- 5 and IL-10 were assayed by ELISA, and the percentage of eosinophils was detected with Giemsa stain. Trends during the follow-up period were analyzed using a general linear model. Results. Inflammatory mediator levels in induced sputum and PD20-FEV1 in patients with CVA and classic asthma differed from those in the control group, although no differences were found in the two asthmatic groups. PD20-FEV1 significantly increased in CVA patients after ICS treatment for 3 months, while classic asthma patients exhibited a delayed change in AHR. After ICS treatment, levels of IL-5 and IL-10 as well as the percentage of eosinophils in the CVA group were altered at 3 months and 6 months, respectively. Accordingly, the level of inflammatory mediators in classic asthma changed more slowly. Conclusion. CVA has a greater improvement in airway inflammation and airway hyperresponsiveness (AHR than classic asthma with respect to inhaled corticosteroid (ICS. Short-term ICS considerably reduces AHR although longer treatment is required for complete control of airway inflammation.

  3. Stress-induced decrease of uterine blood flow in sheep is mediated by alpha 1-adrenergic receptors.

    Science.gov (United States)

    Dreiling, Michelle; Bischoff, Sabine; Schiffner, Rene; Rupprecht, Sven; Kiehntopf, Michael; Schubert, Harald; Witte, Otto W; Nathanielsz, Peter W; Schwab, Matthias; Rakers, Florian

    2016-09-01

    Prenatal maternal stress can be transferred to the fetus via a catecholamine-dependent decrease of uterine blood flow (UBF). However, it is unclear which group of adrenergic receptors mediates this mechanism of maternal-fetal stress transfer. We hypothesized that in sheep, alpha 1-adrenergic receptors may play a key role in catecholamine mediated UBF decrease, as these receptors are mainly involved in peripheral vasoconstriction and are present in significant number in the uterine vasculature. After chronic instrumentation at 125 ± 1 days of gestation (dGA; term 150 dGA), nine pregnant sheep were exposed at 130 ± 1 dGA to acute isolation stress for one hour without visual, tactile, or auditory contact with their flockmates. UBF, blood pressure (BP), heart rate (HR), stress hormones, and blood gases were determined before and during this isolation challenge. Twenty-four hours later, experiments were repeated during alpha 1-adrenergic receptor blockage induced by a continuous intravenous infusion of urapidil. In both experiments, ewes reacted to isolation with an increase in serum norepinephrine, cortisol, BP, and HR as typical signs of activation of sympatho-adrenal and the hypothalamic-pituitary-adrenal axis. Stress-induced UBF decrease was prevented by alpha 1-adrenergic receptor blockage. We conclude that UBF decrease induced by maternal stress in sheep is mediated by alpha 1-adrenergic receptors. Future studies investigating prevention strategies of impact of prenatal maternal stress on fetal health should consider selective blockage of alpha 1-receptors to interrupt maternal-fetal stress transfer mediated by utero-placental malperfusion.

  4. Signaling dynamics of palmitate-induced ER stress responses mediated by ATF4 in HepG2 cells

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    Cho Hyunju

    2013-01-01

    Full Text Available Abstract Background Palmitic acid, the most common saturated free fatty acid, has been implicated in ER (endoplasmic reticulum stress-mediated apoptosis. This lipoapotosis is dependent, in part, on the upregulation of the activating transcription factor-4 (ATF4. To better understand the mechanisms by which palmitate upregulates the expression level of ATF4, we integrated literature information on palmitate-induced ER stress signaling into a discrete dynamic model. The model provides an in silico framework that enables simulations and predictions. The model predictions were confirmed through further experiments in human hepatocellular carcinoma (HepG2 cells and the results were used to update the model and our current understanding of the signaling induced by palmitate. Results The three key things from the in silico simulation and experimental results are: 1 palmitate induces different signaling pathways (PKR (double-stranded RNA-activated protein kinase, PERK (PKR-like ER kinase, PKA (cyclic AMP (cAMP-dependent protein kinase A in a time dependent-manner, 2 both ATF4 and CREB1 (cAMP-responsive element-binding protein 1 interact with the Atf4 promoter to contribute to a prolonged accumulation of ATF4, and 3 CREB1 is involved in ER-stress induced apoptosis upon palmitate treatment, by regulating ATF4 expression and possibly Ca2+ dependent-CaM (calmodulin signaling pathway. Conclusion The in silico model helped to delineate the essential signaling pathways in palmitate-mediated apoptosis.

  5. The therapeutic CD38 monoclonal antibody daratumumab induces programmed cell death via fcg receptor-mediated cross-linking

    DEFF Research Database (Denmark)

    Overdijk, Marije B.; Jansen, J. H. Marco; Nederend, Maaike

    2016-01-01

    RIIb as well as activating FcgRs induce DARA cross-linking-mediated PCD. In conclusion, our in vitro and in vivo data show that FcgRmediated cross-linking of DARA induces PCD of CD38-expressing multiple myeloma tumor cells, which potentially contributes to the depth of response observed in DARA......Emerging evidence suggests that FcgR-mediated cross-linking of tumor-bound mAbs may induce signaling in tumor cells that contributes to their therapeutic activity. In this study, we show that daratumumab (DARA), a therapeutic human CD38 mAb with a broad-spectrum killing activity, is able to induce...... programmed cell death (PCD) of CD38+ multiple myeloma tumor cell lines when cross-linked in vitro by secondary Abs or via an FcgR. By comparing DARA efficacy in a syngeneic in vivo tumor model using FcRg-chain knockout or NOTAM mice carrying a signaling-inactive FcRg-chain, we found that the inhibitory Fcg...

  6. Epinephrine mediates facultative carbohydrate-induced thermogenesis in human skeletal muscle

    DEFF Research Database (Denmark)

    Astrup, A; Simonsen, L; Bülow, J

    1989-01-01

    The thermic effect of carbohydrate has a component mediated by the sympathoadrenal system but of unknown anatomical localization. We have studied the contribution of skeletal muscle to the thermic effect of a carbohydrate-rich natural meal (115 g of carbohydrate, approximately 80% of energy...... postprandially and coinciding with the peak in arterial epinephrine. The present study provides evidence of a facultative thermogenic component in skeletal muscle, mediated by epinephrine via beta 2-adrenoreceptors. However, it also points to a nonmuscle component mediated through beta 1-adrenoceptors...... by norepinephrine released from the sympathetic nervous system. Consequently, the sympathoadrenal system seems to play a physiological role in the daily energy balance....

  7. Reactive Oxygen Species-Induced TXNIP Drives Fructose-Mediated Hepatic Inflammation and Lipid Accumulation Through NLRP3 Inflammasome Activation

    Science.gov (United States)

    Zhang, Xian; Zhang, Jian-Hua; Chen, Xu-Yang; Hu, Qing-Hua; Wang, Ming-Xing; Jin, Rui; Zhang, Qing-Yu; Wang, Wei; Wang, Rong; Kang, Lin-Lin; Li, Jin-Sheng; Li, Meng

    2015-01-01

    Abstract Aims: Increased fructose consumption predisposes the liver to nonalcoholic fatty liver disease (NAFLD), but the mechanisms are elusive. Thioredoxin-interacting protein (TXNIP) links oxidative stress to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation and this signaling axis may be involved in fructose-induced NAFLD. Here, we explore the role of reactive oxygen species (ROS)-induced TXNIP overexpression in fructose-mediated hepatic NLRP3 inflammasome activation, inflammation, and lipid accumulation. Results: Rats were fed a 10% fructose diet for 8 weeks and treated with allopurinol and quercetin during the last 4 weeks. Five millimolars of fructose-exposed hepatocytes (primary rat hepatocytes, rat hepatic parenchymal cells [RHPCs], HLO2, HepG2) were co-incubated with antioxidants or caspase-1 inhibitor or subjected to TXNIP or NLRP3 siRNA interference. Fructose induced NLRP3 inflammasome activation and pro-inflammatory cytokine secretion, janus-activated kinase 2/signal transducers and activators of transcription 3-mediated inflammatory signaling, and expression alteration of lipid metabolism-related genes in cultured hepatocytes and rat livers. NLRP3 silencing and caspase-1 suppression blocked these effects in primary rat hepatocytes and RHPCs, confirming that inflammasome activation alters hepatocyte lipid metabolism. Hepatocellular ROS and TXNIP were increased in animal and cell models. TXNIP silencing blocked NLRP3 inflammasome activation, inflammation, and lipid metabolism perturbations but not ROS induction in fructose-exposed hepatocytes, whereas antioxidants addition abrogated TXNIP induction and diminished the detrimental effects in fructose-exposed hepatocytes and rat livers. Innovation and Conclusions: This study provides a novel mechanism for fructose-induced NAFLD pathogenesis by which the ROS-TXNIP pathway mediates hepatocellular NLRP3 inflammasome activation, inflammation and lipid accumulation. Antioxidant

  8. Neural cell adhesion molecule-180-mediated homophilic binding induces epidermal growth factor receptor (EGFR) down-regulation and uncouples the inhibitory function of EGFR in neurite outgrowth

    DEFF Research Database (Denmark)

    Povlsen, Gro Klitgaard; Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    The neural cell adhesion molecule (NCAM) plays important roles in neuronal development, regeneration, and synaptic plasticity. NCAM homophilic binding mediates cell adhesion and induces intracellular signals, in which the fibroblast growth factor receptor plays a prominent role. Recent studies...... this NCAM-180-induced EGFR down-regulation involves increased EGFR ubiquitination and lysosomal EGFR degradation. Furthermore, NCAM-180-mediated EGFR down-regulation requires NCAM homophilic binding and interactions of the cytoplasmic domain of NCAM-180 with intracellular interaction partners, but does...

  9. Proliferating cell nuclear antigen binds DNA polymerase-β and mediates 1-methyl-4-phenylpyridinium-induced neuronal death.

    Directory of Open Access Journals (Sweden)

    Zhentao Zhang

    Full Text Available The mechanisms leading to dopaminergic neuronal loss in the substantia nigra of patients with Parkinson disease (PD remain poorly understood. We recently reported that aberrant DNA replication mediated by DNA polymerase-β (DNA pol-β plays a causal role in the death of postmitotic neurons in an in vitro model of PD. In the present study, we show that both proliferating cell nuclear antigen (PCNA and DNA pol-β are required for MPP(+-induced neuronal death. PCNA binds to the catalytic domain of DNA pol-β in MPP(+-treated neurons and in post-mortem brain tissues of PD patients. The PCNA-DNA pol-β complex is loaded into DNA replication forks and mediates DNA replication in postmitotic neurons. The aberrant DNA replication mediated by the PCNA-DNA pol-β complex induces p53-dependent neuronal cell death. Our results indicate that the interaction of PCNA and DNA pol-β contributes to neuronal death in PD.

  10. Sirt3-Mediated Autophagy Contributes to Resveratrol-Induced Protection against ER Stress in HT22 Cells

    Directory of Open Access Journals (Sweden)

    Wen-Jun Yan

    2018-02-01

    Full Text Available Endoplasmic reticulum (ER stress occurring in stringent conditions is critically involved in neuronal survival and death. Resveratrol is a non-flavonoid polyphenol that has neuroprotective effects against many neurological disorders. Here, we investigated the potential protective effects of resveratrol in an in vitro ER stress model mimicked by tunicamycin (TM treatment in neuronal HT22 cells. We found that TM dose-dependently decreased cell viability and increased apoptosis, which were both significantly attenuated by resveratrol treatment. Resveratrol markedly reduced the expression or activation of ER stress-associated factors, including GRP78, CHOP, and caspase-12. The results of immunocytochemistry and western blot showed that resveratrol promoted autophagy in TM-treated cells, as evidenced by increased LC3II puncta number, bcelin1 expression and LC3II/LC3I ratio. Pretreatment with the autophagy inhibitor chloroquine could reduce the protective effects of resveratrol. In addition, the expression of Sirt3 protein and its downstream enzyme activities were significantly increased in resveratrol-treated HT22 cells. To confirm the involvement of Sirt3-mediated mechanisms, siRNA transfection was used to knockdown Sirt3 expression in vitro. The results showed that downregulation of Sirt3 could partially prevented the autophagy and protection induced by resveratrol after TM treatment. Our study demonstrates a pivotal role of Sirt3-mediated autophagy in mediating resveratrol-induced protection against ER stress in vitro, and suggests the therapeutic values of resveratrol in ER stress-associated neuronal injury conditions.

  11. Bystander Effect Induced by Electroporation is Possibly Mediated by Microvesicles and Dependent on Pulse Amplitude, Repetition Frequency and Cell Type.

    Science.gov (United States)

    Prevc, Ajda; Bedina Zavec, Apolonija; Cemazar, Maja; Kloboves-Prevodnik, Veronika; Stimac, Monika; Todorovic, Vesna; Strojan, Primoz; Sersa, Gregor

    2016-10-01

    Bystander effect, a known phenomenon in radiation biology, where irradiated cells release signals which cause damage to nearby, unirradiated cells, has not been explored in electroporated cells yet. Therefore, our aim was to determine whether bystander effect is present in electroporated melanoma cells in vitro, by determining viability of non-electroporated cells exposed to medium from electroporated cells and by the release of microvesicles as potential indicators of the bystander effect. Here, we demonstrated that electroporation of cells induces bystander effect: Cells exposed to electric pulses mediated their damage to the non-electroporated cells, thus decreasing cell viability. We have shown that shedding microvesicles may be one of the ways used by the cells to mediate the death signals to the neighboring cells. The murine melanoma B16F1 cell line was found to be more electrosensitive and thus more prone to bystander effect than the canine melanoma CMeC-1 cell line. In B16F1 cell line, bystander effect was present above the level of electropermeabilization of the cells, with the threshold at 800 V/cm. Furthermore, with increasing electric field intensities and the number of pulses, the bystander effect also increased. In conclusion, electroporation can induce bystander effect which may be mediated by microvesicles, and depends on pulse amplitude, repetition frequency and cell type.

  12. Psychosocial Stress-Induced Analgesia: An Examination of Effects on Heat Pain Threshold and Tolerance and of Neuroendocrine Mediation.

    Science.gov (United States)

    Gaab, Jens; Jiménez, Julia; Voneschen, Livia; Oschwald, Daniel; Meyer, Andrea H; Nater, Urs M; Krummenacher, Peter

    2016-01-01

    Stress-induced analgesia (SIA) is an adaptive response of reduced nociception following demanding acute internal and external stressors. Although a psychobiological understanding of this phenomenon is of importance for stress-related psychiatric and pain conditions, comparably little is known about the psychobiological mechanisms of SIA in humans. The aim of this study was to investigate the effects of acute psychosocial stress on heat pain perception and its possible neuroendocrine mediation by salivary cortisol levels and α-amylase activity in healthy men. Employing an intra-individual assessment of heat pain parameters, acute psychosocial stress did not influence heat pain threshold but significantly, albeit slightly, increased heat pain tolerance. Using linear mixed-model analysis, this effect of psychosocial stress on heat pain tolerance was not mediated by increases of salivary cortisol and state anxiety levels or by the activity of α-amylase. These results show that while psychosocial stress is selectively analgesic for heat pain tolerance, this observed effect is not mediated by stress-induced increases of salivary cortisol and α-amylase activity, as proxies of both the hypothalamus-pituitary-adrenal axis and the autonomic nervous system activation. © 2017 S. Karger AG, Basel.

  13. Timing is critical for effective glucocorticoid receptor mediated repression of the cAMP-induced CRH gene.

    Directory of Open Access Journals (Sweden)

    Siem van der Laan

    Full Text Available Glucocorticoid negative feedback of the hypothalamus-pituitary-adrenal axis is mediated in part by direct repression of gene transcription in glucocorticoid receptor (GR expressing cells. We have investigated the cross talk between the two main signaling pathways involved in activation and repression of corticotrophin releasing hormone (CRH mRNA expression: cyclic AMP (cAMP and GR. We report that in the At-T20 cell-line the glucocorticoid-mediated repression of the cAMP-induced human CRH proximal promoter activity depends on the relative timing of activation of both signaling pathways. Activation of the GR prior to or in conjunction with cAMP signaling results in an effective repression of the cAMP-induced transcription of the CRH gene. In contrast, activation of the GR 10 minutes after onset of cAMP treatment, results in a significant loss of GR-mediated repression. In addition, translocation of ligand-activated GR to the nucleus was found as early as 10 minutes after glucocorticoid treatment. Interestingly, while both signaling cascades counteract each other on the CRH proximal promoter, they synergize on a synthetic promoter containing 'positive' response elements. Since the order of activation of both signaling pathways may vary considerably in vivo, we conclude that a critical time-window exists for effective repression of the CRH gene by glucocorticoids.

  14. Effect of glucocorticosteroid treatment on ovalbumin-induced IgE-mediated immediate and late allergic response in guinea pig.

    Science.gov (United States)

    Andersson, P; Brange, C; von Kogerer, B; Sonmark, B; Stahre, G

    1988-01-01

    The effect of glucocorticosteroid (GCS) treatment on ovalbumine-induced IgE-mediated immediate and late allergic response was studied in sensitized guinea pigs. The results show that the GCS budesonide (BUD) inhibits the allergen-induced IgE-mediated immediate and late bronchial obstruction. The effect on the early reaction is correlated to the inhibition of leukotrienes and histamine release. The importance of mediator release inhibition for the antianaphylactic effect of GCS is discussed. In examining the effect on the late reaction, it was found that BUD had to be present during the early reaction but did not inhibit the early reaction. Furthermore, the effect on the late reaction was correlated to the inhibition of vascular leakage but not to the infiltration of inflammatory cells as examined in bronchoalveolar lavage. The results indicate that some triggering factors important for the development of the late reaction are released during the early reaction. Inhibition of the release of that factor or the activation of inflammatory cells by that factor might be the mechanism behind the antiinflammatory activities of GCS.

  15. Zinc-Dependent Protection of Tobacco and Rice Cells From Aluminum-Induced Superoxide-Mediated Cytotoxicity

    Science.gov (United States)

    Lin, Cun; Hara, Ayaka; Comparini, Diego; Bouteau, François; Kawano, Tomonori

    2015-01-01

    Al3+ toxicity in growing plants is considered as one of the major factors limiting the production of crops on acidic soils worldwide. In the last 15 years, it has been proposed that Al3+ toxicity are mediated with distortion of the cellular signaling mechanisms such as calcium signaling pathways, and production of cytotoxic reactive oxygen species (ROS) causing oxidative damages. On the other hand, zinc is normally present in plants at high concentrations and its deficiency is one of the most widespread micronutrient deficiencies in plants. Earlier studies suggested that lack of zinc often results in ROS-mediated oxidative damage to plant cells. Previously, inhibitory action of Zn2+ against lanthanide-induced superoxide generation in tobacco cells have been reported, suggesting that Zn2+ interferes with the cation-induced ROS production via stimulation of NADPH oxidase. In the present study, the effect of Zn2+ on Al3+-induced superoxide generation in the cell suspension cultures of tobacco (Nicotiana tabacum L., cell-line, BY-2) and rice (Oryza sativa L., cv. Nipponbare), was examined. The Zn2+-dependent inhibition of the Al3+-induced oxidative burst was observed in both model cells selected from the monocots and dicots (rice and tobacco), suggesting that this phenomenon (Al3+/Zn2+ interaction) can be preserved in higher plants. Subsequently induced cell death in tobacco cells was analyzed by lethal cell staining with Evans blue. Obtained results indicated that presence of Zn2+ at physiological concentrations can protect the cells by preventing the Al3+-induced superoxide generation and cell death. Furthermore, the regulation of the Ca2+ signaling, i.e., change in the cytosolic Ca2+ ion concentration, and the cross-talks among the elements which participate in the pathway were further explored. PMID:26648960

  16. Quinone-induced protein handling changes: Implications for major protein handling systems in quinone-mediated toxicity

    International Nuclear Information System (INIS)

    Xiong, Rui; Siegel, David; Ross, David

    2014-01-01

    Para-quinones such as 1,4-Benzoquinone (BQ) and menadione (MD) and ortho-quinones including the oxidation products of catecholamines, are derived from xenobiotics as well as endogenous molecules. The effects of quinones on major protein handling systems in cells; the 20/26S proteasome, the ER stress response, autophagy, chaperone proteins and aggresome formation, have not been investigated in a systematic manner. Both BQ and aminochrome (AC) inhibited proteasomal activity and activated the ER stress response and autophagy in rat dopaminergic N27 cells. AC also induced aggresome formation while MD had little effect on any protein handling systems in N27 cells. The effect of NQO1 on quinone induced protein handling changes and toxicity was examined using N27 cells stably transfected with NQO1 to generate an isogenic NQO1-overexpressing line. NQO1 protected against BQ–induced apoptosis but led to a potentiation of AC- and MD-induced apoptosis. Modulation of quinone-induced apoptosis in N27 and NQO1-overexpressing cells correlated only with changes in the ER stress response and not with changes in other protein handling systems. These data suggested that NQO1 modulated the ER stress response to potentiate toxicity of AC and MD, but protected against BQ toxicity. We further demonstrated that NQO1 mediated reduction to unstable hydroquinones and subsequent redox cycling was important for the activation of the ER stress response and toxicity for both AC and MD. In summary, our data demonstrate that quinone-specific changes in protein handling are evident in N27 cells and the induction of the ER stress response is associated with quinone-mediated toxicity. - Highlights: • Unstable hydroquinones contributed to quinone-induced ER stress and toxicity

  17. Quinone-induced protein handling changes: Implications for major protein handling systems in quinone-mediated toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Rui; Siegel, David; Ross, David, E-mail: david.ross@ucdenver.edu

    2014-10-15

    Para-quinones such as 1,4-Benzoquinone (BQ) and menadione (MD) and ortho-quinones including the oxidation products of catecholamines, are derived from xenobiotics as well as endogenous molecules. The effects of quinones on major protein handling systems in cells; the 20/26S proteasome, the ER stress response, autophagy, chaperone proteins and aggresome formation, have not been investigated in a systematic manner. Both BQ and aminochrome (AC) inhibited proteasomal activity and activated the ER stress response and autophagy in rat dopaminergic N27 cells. AC also induced aggresome formation while MD had little effect on any protein handling systems in N27 cells. The effect of NQO1 on quinone induced protein handling changes and toxicity was examined using N27 cells stably transfected with NQO1 to generate an isogenic NQO1-overexpressing line. NQO1 protected against BQ–induced apoptosis but led to a potentiation of AC- and MD-induced apoptosis. Modulation of quinone-induced apoptosis in N27 and NQO1-overexpressing cells correlated only with changes in the ER stress response and not with changes in other protein handling systems. These data suggested that NQO1 modulated the ER stress response to potentiate toxicity of AC and MD, but protected against BQ toxicity. We further demonstrated that NQO1 mediated reduction to unstable hydroquinones and subsequent redox cycling was important for the activation of the ER stress response and toxicity for both AC and MD. In summary, our data demonstrate that quinone-specific changes in protein handling are evident in N27 cells and the induction of the ER stress response is associated with quinone-mediated toxicity. - Highlights: • Unstable hydroquinones contributed to quinone-induced ER stress and toxicity.

  18. Paraquat and maneb co-exposure induces noradrenergic locus coeruleus neurodegeneration through NADPH oxidase-mediated microglial activation

    International Nuclear Information System (INIS)

    Hou, Liyan; Zhang, Cong; Wang, Ke; Liu, Xiaofang; Wang, Hongwei; Che, Yuning; Sun, Fuqiang; Zhou, Xueying; Zhao, Xiulan; Wang, Qingshan

    2017-01-01

    Highlights: • Microglial activation induced by paraquat and maneb precedes noradrenergic neurodegeneration in locus coeruleus. • NADPH oxidase activation contributes to microglia-mediated neuroinflammation and related noradrenergic neurodegeneration. • Inhibition of NADPH oxidase by apocynin protects noradrenergic neurons against paraquat and maneb-induced toxicity. - Abstract: Co-exposure to paraquat (PQ) and maneb (Mb) has been shown to increase the risk of Parkinson’s disease (PD) and dopaminergic (DA) neurodegeneration in the substantia nigra pars compacta (SNpc) is observed in PQ and Mb-treated experimental animals. The loss of noradrenergic locus coeruleus (LC/NE) neurons in brainstem is a common feature shared by multiple neurodegenerative diseases, including PD. However, whether PQ and Mb is able to damage LC/NE neurons remains undefined. In this study, mice treated with combined PQ and Mb displayed progressive LC/NE neurodegeneration. Time course studies revealed that the activation of microglia preceded LC/NE neurodegeneration. Mechanistically, the activation of NADPH oxidase contributed to microglial activation and subsequent LC/NE neurodegeneration. We found that PQ and Mb co-exposure induced activation of NADPH oxidase as shown by increased superoxide production and membrane translocation of p47 phox , a cytosolic subunit of NADPH oxidase. Inhibition of NADPH oxidase by apocynin, a widely used NADPH oxidase inhibitor, suppressed microglial activation and gene expressions of proinflammatory factors. Furthermore, reduced activation of nuclear factor-κB (NF-κB) pathway was observed in apocynin-treated mice. More importantly, inhibition of NADPH oxidase by apocynin afforded LC/NE neuroprotection against PQ and Mb-induced neurotoxicity. Thus, our findings revealed the critical role NADPH oxidase-mediated microglial activation in driving LC/NE neurodegeneration induced by PQ and Mb, providing new insights into the pathogenesis of environmental

  19. Inflammatory cytokine tumor necrosis factor α suppresses neuroprotective endogenous erythropoietin from astrocytes mediated by hypoxia-inducible factor-2α.

    Science.gov (United States)

    Nagaya, Yoshiaki; Aoyama, Mineyoshi; Tamura, Tetsuya; Kakita, Hiroki; Kato, Shin; Hida, Hideki; Saitoh, Shinji; Asai, Kiyofumi

    2014-12-01

    Interest in erythropoietin (EPO) as a neuroprotective mediator has grown since it was found that systemically administered EPO is protective in several animal models of disease. However, given that the blood-brain barrier limits EPO entry into the brain, alternative approaches that induce endogenous EPO production in the brain may be more effective clinically and associated with fewer untoward side-effects. Astrocytes are the main source of EPO in the central nervous system. In the present study we investigated the effect of the inflammatory cytokine tumor necrosis factor α (TNFα) on hypoxia-induced upregulation of EPO in rat brain. Hypoxia significantly increased EPO mRNA expression in the brain and kidney, and this increase was suppressed by TNFα in vivo. In cultured astrocytes exposed to hypoxic conditions for 6 and 12 h, TNFα suppressed the hypoxia-induced increase in EPO mRNA expression in a concentration-dependent manner. TNFα inhibition of hypoxia-induced EPO expression was mediated primarily by hypoxia-inducible factor (HIF)-2α rather than HIF-1α. The effects of TNFα in reducing hypoxia-induced upregulation of EPO mRNA expression probably involve destabilization of HIF-2α, which is regulated by the nuclear factor (NF)-κB signaling pathway. TNFα treatment attenuated the protective effects of astrocytes on neurons under hypoxic conditions via EPO signaling. The effective blockade of TNFα signaling may contribute to the maintenance of the neuroprotective effects of EPO even under hypoxic conditions with an inflammatory response. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  20. Apoptosis and autophagy induced by pyropheophorbide-α methyl ester-mediated photodynamic therapy in human osteosarcoma MG-63 cells.

    Science.gov (United States)

    Huang, Qiu; Ou, Yun-Sheng; Tao, Yong; Yin, Hang; Tu, Ping-Hua

    2016-06-01

    Pyropheophorbide-α methyl ester (MPPa) was a second-generation photosensitizer with many potential applications. Here, we explored the impact of MPPa-mediated photodynamic therapy (MPPa-PDT) on the apoptosis and autophagy of human osteosarcoma (MG-63) cells as well as the relationships between apoptosis and autophagy of the cells, and investigated the related molecular mechanisms. We found that MPPa-PDT demonstrated the ability to inhibit MG-63 cell viability in an MPPa concentration- and light dose-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, MPPa-PDT could also induce autophagy of MG-63 cell. Meanwhile, the ROS scavenger N-acetyl-L-cysteine (NAC) and the Jnk inhibitor SP600125 were found to inhibit the MPPa-PDT-induced autophagy, and NAC could also inhibit Jnk phosphorylation. Furthermore, pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine showed the potential in reducing the apoptosis rate induced by MPPa-PDT in MG-63 cells. Our results indicated that the mitochondrial pathway was involved in MPPa-PDT-induced apoptosis of MG-63 cells. Meanwhile the ROS-Jnk signaling pathway was involved in MPPa-PDT-induced autophagy, which further promoted the apoptosis in MG-63 cells.

  1. Hepatic FGF21 mediates sex differences in high-fat high-fructose diet-induced fatty liver.

    Science.gov (United States)

    Chukijrungroat, Natsasi; Khamphaya, Tanaporn; Weerachayaphorn, Jittima; Songserm, Thaweesak; Saengsirisuwan, Vitoon

    2017-08-01

    The role of gender in the progression of fatty liver due to chronic high-fat high-fructose diet (HFFD) has not been studied. The present investigation assessed whether HFFD induced hepatic perturbations differently between the sexes and examined the potential mechanisms. Male, female, and ovariectomized (OVX) Sprague-Dawley rats were fed either a control diet or HFFD for 12 wk. Indexes of liver damage and hepatic steatosis were analyzed biochemically and histologically together with monitoring changes in hepatic gene and protein expression. HFFD induced a higher degree of hepatic steatosis in females, with significant increases in proteins involved in hepatic lipogenesis, whereas HFFD significantly induced liver injury, inflammation, and oxidative stress only in males. Interestingly, a significant increase in hepatic fibroblast growth factor 21 (FGF21) protein expression was observed in HFFD-fed males but not in HFFD-fed females. Ovarian hormone deprivation by itself led to a significant reduction in FGF21 with hepatic steatosis, and HFFD further aggravated hepatic fat accumulation in OVX rats. Importantly, estrogen replacement restored hepatic FGF21 levels and reduced hepatic steatosis in HFFD-fed OVX rats. Collectively, our results indicate that male rats are more susceptible to HFFD-induced hepatic inflammation and that the mechanism underlying this sex dimorphism is mediated through hepatic FGF21 expression. Our findings reveal sex differences in the development of HFFD-induced fatty liver and indicate the protective role of estrogen against HFFD-induced hepatic steatosis. Copyright © 2017 the American Physiological Society.

  2. Parenteral medium-chain triglyceride-induced neutrophil activation is not mediated by a Pertussis Toxin sensitive receptor.

    Science.gov (United States)

    Versleijen, Michelle W J; van Esterik, Joantine C J; Roelofs, Hennie M J; van Emst-de Vries, Sjenet E; Willems, Peter H G M; Wanten, Geert J A

    2009-02-01

    Lipid-induced immune modulation might contribute to the increased infection rate that is observed in patients using parenteral nutrition. We previously showed that emulsions containing medium-chain triglycerides (LCT/MCTs or pure MCTs), but not pure long-chain triglycerides (LCTs), impair neutrophil functions, modulate cell-signaling and induce neutrophil activation in vitro. It has recently been shown that medium-chain fatty acids are ligands for GPR84, a pertussis toxin (PT)-sensitive G-protein-coupled receptor (GPCR). This finding urged us to investigate whether MCT-induced neutrophil activation is mediated by PT-sensitive GPCRs. Neutrophils isolated from blood of healthy volunteers were pre-incubated with PT (0.5-1 microg/mL, 1.5 h) and analyzed for the effect of this pre-incubation on LCT/MCT (2.5 mmol/L)-dependent modulation of serum-treated zymosan (STZ)-induced intracellular Ca(2+) mobilization and on LCT/MCT (5 mmol/L)-induced expression of cell surface adhesion (CD11b) and degranulation (CD66b) markers and oxygen radical (ROS) production. PT did not inhibit the effects of LCT/MCT on the STZ-induced increase in cytosolic free Ca(2+) concentration. LCT/MCT increased ROS production to 146% of unstimulated cells. However, pre-incubation with PT did not inhibit the LCT/MCT-induced ROS production. Furthermore, the LCT/MCT-induced increase in CD11b and CD66b expression (196% and 235% of unstimulated cells, respectively) was not inhibited by pre-incubation with PT. LCT/MCT-induced neutrophil activation does not involve the action of a PT-sensitive G-protein-coupled receptor.

  3. Induced pluripotent stem cells inhibit bleomycin-induced pulmonary fibrosis in mice through suppressing TGF-β1/Smad-mediated epithelial to mesenchymal transition

    Directory of Open Access Journals (Sweden)

    Yan Zhou

    2016-11-01

    Full Text Available Pulmonary fibrosis is a progressive and irreversible fibrotic lung disorder with high mortality and few treatment options. Recently, induced pluripotent stem (iPS cells have been considered as an ideal resource for stem cell-based therapy. Although an earlier study demonstrated the therapeutic effect of iPS cells on pulmonary fibrosis, the exact mechanisms remain obscure. The present study investigated the effects of iPS cells on inflammatory responses, transforming growth factor (TGF-β1 signaling pathway, and epithelial to mesenchymal transition (EMT during bleomycin (BLM-induced lung fibrosis. A single intratracheal instillation of BLM (5 mg/kg was performed to induce pulmonary fibrosis in C57BL/6 mice. Then, iPS cells (c-Myc-free were administrated intravenously at 24 h following BLM instillation. Three weeks after BLM administration, pulmonary fibrosis was evaluated. As expected, treatment with iPS cells significantly limited the pathological changes, edema, and collagen deposition in lung tissues of BLM-induced mice. Mechanically, treatment with iPS cells obviously repressed the expression ratios of matrix metalloproteinase-2 (MMP-2 to its tissue inhibitor -2 (TIMP-2 and MMP-9/TIMP-1 in BLM-induced pulmonary tissues. In addition, iPS cell administration remarkably suppressed BLM-induced up-regulation of pulmonary inflammatory mediators, including tumor necrosis factor-α, interleukin (IL-1β, IL-6, inducible nitric oxide synthase, nitric oxide, cyclooxygenase-2 and prostaglandin E2. We further demonstrated that transplantation of iPS cells markedly inhibited BLM-mediated activation of TGF-β1/Mothers against decapentaplegic homolog 2/3 (Smad2/3 and EMT in lung tissues through up-regulating epithelial marker E-cadherin and down-regulating mesenchymal markers including fibronectin, vimentin and α-smooth muscle actin. Moreover, in vitro, iPS cell-conditioned medium (iPSC-CM profoundly inhibited TGF-β1-induced EMT signaling pathway in mouse

  4. Generation of induced pluripotent stem cells (iPSCs) stably expressing CRISPR-based synergistic activation mediator (SAM).

    Science.gov (United States)

    Xiong, Kai; Zhou, Yan; Hyttel, Poul; Bolund, Lars; Freude, Kristine Karla; Luo, Yonglun

    2016-11-01

    Human fibroblasts were engineered to express the CRISPR-based synergistic activation mediator (SAM) complex: dCas9-VP64 and MS2-P65-HSF1. Two induced pluripotent stem cells (iPSCs) clones expressing SAM were established by transducing these fibroblasts with lentivirus expressing OCT4, SOX2, KLF4 and C-MYC. We have validated that the reprogramming cassette is silenced in the SAM iPSC clones. Expression of pluripotency genes (OCT4, SOX2, LIN28A, NANOG, GDF3, SSEA4, and TRA-1-60), differentiation potential to all three germ layers, and normal karyotypes are validated. These SAM-iPSCs provide a novel, useful tool to investigate genetic regulation of stem cell proliferation and differentiation through CRISPR-mediated activation of endogenous genes. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

  5. ER-mediated stress induces mitochondrial-dependent caspases activation in NT2 neuron-like cells.

    Science.gov (United States)

    Arduino, Daniela M; Esteves, A Raquel; Domingues, A Filipa; Pereira, Claudia M F; Cardoso, Sandra M; Oliveira, Catarina R

    2009-11-30

    Recent studies have revealed that endoplasmic reticulum (ER) disturbance is involved in the pathophysiology of neurodegenerative disorders, contributing to the activation of the ER stress-mediated apoptotic pathway. Therefore, we investigated here the molecular mechanisms underlying the ER-mitochondria axis, focusing on calcium as a potential mediator of cell death signals. Using NT2 cells treated with brefeldin A or tunicamycin, we observed that ER stress induces changes in the mitochondrial function, impairing mitochondrial membrane potential and distressing mitochondrial respiratory chain complex Moreover, stress stimuli at ER level evoked calcium fluxes between ER and mitochondria. Under these conditions, ER stress activated the unfolded protein response by an overexpression of GRP78, and also caspase-4 and-2, both involved upstream of caspase-9. Our findings show that ER and mitochondria interconnection plays a prominent role in the induction of neuronal cell death under particular stress circumstances.

  6. Dark-matter production through loop-induced processes at the LHC: the s-channel mediator case

    Energy Technology Data Exchange (ETDEWEB)

    Mattelaer, Olivier [Durham University, Institute for Particle Physics Phenomenology (IPPP), Durham (United Kingdom); Vryonidou, Eleni [Universite catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium)

    2015-09-15

    We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5{sub a}MC rate at NLO framework. We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark. Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons (γ,Z,H), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower. (orig.)

  7. Dark-matter production through loop-induced processes at the LHC: the s-channel mediator case

    International Nuclear Information System (INIS)

    Mattelaer, Olivier; Vryonidou, Eleni

    2015-01-01

    We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5 a MC rate at NLO framework. We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark. Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons (γ,Z,H), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower. (orig.)

  8. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)

    2016-03-25

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  9. Evidence for a role of transporter-mediated currents in the depletion of brain serotonin induced by serotonin transporter substrates.

    Science.gov (United States)

    Baumann, Michael H; Bulling, Simon; Benaderet, Tova S; Saha, Kusumika; Ayestas, Mario A; Partilla, John S; Ali, Syed F; Stockner, Thomas; Rothman, Richard B; Sandtner, Walter; Sitte, Harald H

    2014-05-01

    Serotonin (5-HT) transporter (SERT) substrates like fenfluramine and 3,4-methylenedioxymethamphetamine cause long-term depletion of brain 5-HT, while certain other substrates do not. The 5-HT deficits produced by SERT substrates are dependent upon transporter proteins, but the exact mechanisms responsible are unclear. Here, we compared the pharmacology of several SERT substrates: fenfluramine, d-fenfluramine, 1-(m-chlorophenyl)piperazine (mCPP) and 1-(m-trifluoromethylphenyl)piperainze (TFMPP), to establish relationships between acute drug mechanisms and the propensity for long-term 5-HT depletions. In vivo microdialysis was carried out in rat nucleus accumbens to examine acute 5-HT release and long-term depletion in the same subjects. In vitro assays were performed to measure efflux of [(3)H]5-HT in rat brain synaptosomes and transporter-mediated ionic currents in SERT-expressing Xenopus oocytes. When administered repeatedly to rats (6 mg/kg, i.p., four doses), all drugs produce large sustained elevations in extracellular 5-HT (>5-fold) with minimal effects on dopamine. Importantly, 2 weeks after dosing, only rats exposed to fenfluramine and d-fenfluramine display depletion of brain 5-HT. All test drugs evoke fluoxetine-sensitive efflux of [(3)H]5-HT from synaptosomes, but d-fenfluramine and its bioactive metabolite d-norfenfluramine induce significantly greater SERT-mediated currents than phenylpiperazines. Our data confirm that drug-induced 5-HT release probably does not mediate 5-HT depletion. However, the magnitude of transporter-mediated inward current may be a critical factor in the cascade of events leading to 5-HT deficits. This hypothesis warrants further study, especially given the growing popularity of designer drugs that target SERT.

  10. Cytoprotective Mechanisms Mediated by Polyphenols from Chilean Native Berries against Free Radical-Induced Damage on AGS Cells

    Directory of Open Access Journals (Sweden)

    Felipe Ávila

    2017-01-01

    Full Text Available The prevalence of cytoprotective mechanisms induced by polyphenols such as activation of intracellular antioxidant responses (ICM and direct free radical scavenging was investigated in native Chilean species of strawberries, raspberries, and currants. Human gastric epithelial cells were co- and preincubated with polyphenolic-enriched extracts (PEEs from Chilean raspberries (Rubus geoides, strawberries (Fragaria chiloensis ssp. chiloensis f. chiloensis, and currants (Ribes magellanicum and challenged with peroxyl and hydroxyl radicals. Cellular protection was determined in terms of cell viability, glyoxalase I and glutathione s-transferases activities, and carboxymethyl lysine (CML and malondialdehyde levels. Our results indicate that cytoprotection induced by ICM was the prevalent mechanism for Rubus geoides and F. chiloensis. This agreed with increased levels of glyoxalase I and glutathione S-transferase activities in cells preincubated with PEEs. ORAC index indicated that F. chiloensis was the most efficient peroxyl radical scavenger. Moreover, ICM mediated by F. chiloensis was effective in protecting cells from CML accumulation in contrast to the protective effects induced by free radical scavenging. Our results indicate that although both polyphenol-mediated mechanisms can exert protective effects, ICM was the most prevalent in AGS cells. These results suggest a potential use of these native berries as functional food.

  11. Cytoprotective Mechanisms Mediated by Polyphenols from Chilean Native Berries against Free Radical-Induced Damage on AGS Cells.

    Science.gov (United States)

    Ávila, Felipe; Theoduloz, Cristina; López-Alarcón, Camilo; Dorta, Eva; Schmeda-Hirschmann, Guillermo

    2017-01-01

    The prevalence of cytoprotective mechanisms induced by polyphenols such as activation of intracellular antioxidant responses (ICM) and direct free radical scavenging was investigated in native Chilean species of strawberries, raspberries, and currants. Human gastric epithelial cells were co- and preincubated with polyphenolic-enriched extracts (PEEs) from Chilean raspberries ( Rubus geoides ), strawberries ( Fragaria chiloensis ssp. chiloensis f . chiloensis ), and currants ( Ribes magellanicum ) and challenged with peroxyl and hydroxyl radicals. Cellular protection was determined in terms of cell viability, glyoxalase I and glutathione s-transferases activities, and carboxymethyl lysine (CML) and malondialdehyde levels. Our results indicate that cytoprotection induced by ICM was the prevalent mechanism for Rubus geoides and F. chiloensis . This agreed with increased levels of glyoxalase I and glutathione S-transferase activities in cells preincubated with PEEs. ORAC index indicated that F. chiloensis was the most efficient peroxyl radical scavenger. Moreover, ICM mediated by F. chiloensis was effective in protecting cells from CML accumulation in contrast to the protective effects induced by free radical scavenging. Our results indicate that although both polyphenol-mediated mechanisms can exert protective effects, ICM was the most prevalent in AGS cells. These results suggest a potential use of these native berries as functional food.

  12. Protective role of morin, a flavonoid, against high glucose induced oxidative stress mediated apoptosis in primary rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Radhika Kapoor

    Full Text Available Apoptosis is an early event of liver damage in diabetes and oxidative stress has been linked to accelerate the apoptosis in hepatocytes. Therefore, the compounds that can scavenge ROS may confer regulatory effects on high-glucose induced apoptosis. In the present study, primary rat hepatocytes were exposed to high concentration (40 mM of glucose. At this concentration decreased cell viability and enhanced ROS generation was observed. Depleted antioxidant status of hepatocytes under high glucose stress was also observed as evident from transcriptional level and activities of antioxidant enzymes. Further, mitochondrial depolarisation was accompanied by the loss of mitochondrial integrity and altered expression of Bax and Bcl-2. Increased translocation of apoptotic proteins like AIF (Apoptosis inducing factor & Endo-G (endonuclease-G from its resident place mitochondria to nucleus was also observed. Cyt-c residing in the inter-membrane space of mitochondria also translocated to cytoplasm. These apoptotic proteins initiated caspase activation, DNA fragmentation, chromatin condensation, increased apoptotic DNA content in glucose treated hepatocytes, suggesting mitochondria mediated apoptotic mode of cell death. Morin, a dietary flavonoid from Psidium guajava was effective in increasing the cell viability and decreasing the ROS level. It maintained mitochondrial integrity, inhibited release of apoptotic proteins from mitochondria, prevented DNA fragmentation, chromatin condensation and hypodiploid DNA upon exposure to high glucose. This study confirms the capacity of dietary flavonoid Morin in regulating apoptosis induced by high glucose via mitochondrial mediated pathway through intervention of oxidative stress.

  13. Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells

    Science.gov (United States)

    HUA, YUAN-YUAN; WANG, XIAO-SHU; ZHANG, YU; YAO, CHEN-GUO; ZHANG, XI-MING; XIONG, ZHENG-AI

    2012-01-01

    The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway. PMID:22307872

  14. Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Ruo-Bing Guo

    Full Text Available Paeoniflorin (PF, the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2 and 5-LOX in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

  15. Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

    Science.gov (United States)

    Guo, Ruo-Bing; Wang, Guo-Feng; Zhao, An-Peng; Gu, Jun; Sun, Xiu-Lan; Hu, Gang

    2012-01-01

    Paeoniflorin (PF), the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO)-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2) and 5-LOX) in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

  16. Low LET radiation-induced telomerase catalytic subunit promoter activation is mediated by nuclear factor Kappa B

    International Nuclear Information System (INIS)

    Natarajan, M.; Hong, F.A.; Mohan, S.; Herman, T.S.

    2003-01-01

    Full text: The objective of this study is to understand whether low doses of low LET radiation induces survival advantage in normal cells. As an increase in telomerase activity is associated with longevity and cell proliferation, we examined the telomerase response following gamma-irradiation in normal aortic endothelial cells. Telomeric Repeat Amplification Protocol assay following low LET radiation showed an increase in telomerase enzyme activity as early as 8 h post irradiation and reaches its maximum at 24 h. Subsequent analysis revealed that the increased telomerse enzyme activity is due to increased synthesis resulting from an increased transcription. Examination of transcriptional activation of telomerase reverse transcriptase (TERT) promoter regulation showed an enhanced transcription of the telomerse gene following gamma-irradiation. In our previous reports we documented an increase in NF-kB DNA-binding property following low LET radiation (3). Therefore, to determine whether the activation of NF-kB-signaling is responsible for induced TERT promoter activation, cells transiently transfected with minimal promoter region of TERT containing wild type or mutant NF-kB binding site were examined following low LET radiation. TERT promoter activation was induced in wild type transfected cells whereas, in mutant kB binding site, the activation remained at the basal level similar to that of un-irradiated cells. More significantly, the gamma-ray mediated promoter activation of telomerase gene as well as induce telomerase enzyme activity was abrogated by ectopically expressing the IkBa mutant (IkBa (S32A/S36A)), which blocks NF-kB activation. The results thus suggest that exposure to low LET radiation could induce telomerase activity and the activation is at least, in part, mediated by the transcription factor NF-kB. Sustained activation of telomerase in these cells after low LET radiation may impart extended life span

  17. Protocatechuic aldehyde attenuates cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation

    Directory of Open Access Journals (Sweden)

    Li Gao

    2016-12-01

    Full Text Available Cisplatin is a classic chemotherapeutic agent widely used to treat different types of cancers including ovarian, head and neck, testicular and uterine cervical carcinomas. However, cisplatin induces acute kidney injury by directly triggering an excessive inflammatory response, oxidative stress and programmed cell death of renal tubular epithelial cells. All of which lead to higher mortality rates in patients. In this study we examined the protective effect of protocatechuic aldehyde (PA in vitro in cisplatin-treated tubular epithelial cells and in vivo in cisplatin nephropathy. PA is a monomer of Traditional Chinese Medicine isolated from the root of S. miltiorrhiza. Results show that PA prevented cisplatin-induced decline of renal function and histological damage, which was confirmed by attenuation of KIM1 in both mRNA and protein levels. Moreover, PA reduced renal inflammation by suppressing oxidative stress and programmed cell death in response to cisplatin, which was further evidenced by in vitro data. Of note, PA suppressed NAPDH oxidases, including Nox2 and Nox4, in a dosage-dependent manner. Moreover, silencing Nox4, but not Nox2, removed the inhibitory effect of PA on cisplatin-induced renal injury, indicating that Nox4 may play a pivotal role in mediating the protective effect of PA in cisplatin-induced acute kidney injury. Collectively, our data indicate that PA largely blocked cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation without compromising anti-tumor activity of cisplatin. These findings suggest that PA and its derivatives may serve as potential protective agents for cancer patients with cisplatin treatment.

  18. Degradation of Epidermal Growth Factor Receptor Mediates Dasatinib-Induced Apoptosis in Head and Neck Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Chin Lin

    2012-06-01

    Full Text Available Epidermal growth factor receptor (EGFR is an important oncoprotein that promotes cell growth and proliferation. Dasatinib, a bcr-abl inhibitor, has been approved clinically for the treatment of chronic myeloid leukemia and demonstrated to be effective against solid tumors in vitro through Src inhibition. Here, we disclose that EGFR degradation mediated dasatinib-induced apoptosis in head and neck squamous cell carcinoma (HNSCC cells. HNSCC cells, including Ca9-22, FaDu, HSC3, SAS, SCC-25, and UMSCC1, were treated with dasatinib, and cell viability, apoptosis, and underlying signal transduction were evaluated. Dasatinib exhibited differential sensitivities against HNSCC cells. Growth inhibition and apoptosis were correlated with its inhibition on Akt, Erk, and Bcl-2, irrespective of Src inhibition. Accordingly, we found that down-regulation of EGFR was a determinant of dasatinib sensitivity. Lysosome inhibitor reversed dasatinib-induced EGFR down-regulation, and c-cbl activity was increased by dasatinib, indicating that dasatinib-induced EGFR down-regulation might be through c-cbl-mediated lysosome degradation. Increased EGFR activation by ligand administration rescued cells from dasatinib-induced apoptosis, whereas inhibition of EGFR enhanced its apoptotic effect. Estrogen receptor α (ERα was demonstrated to play a role in Bcl-2 expression, and dasatinib inhibited ERα at the pretranslational level. ERα was associated with EGFR in dasatinib-treated HNSCC cells. Furthermore, the xenograft model showed that dasatinib inhibited HSC3 tumor growth through in vivo down-regulation of EGFR and ERα. In conclusion, degradation of EGFR is a novel mechanism responsible for dasatinib-induced apoptosis in HNSCC cells.

  19. Increased synaptophysin is involved in inflammation-induced heat hyperalgesia mediated by cyclin-dependent kinase 5 in rats.

    Directory of Open Access Journals (Sweden)

    Hong-Hai Zhang

    Full Text Available Mechanisms associated with cyclin-dependent kinase 5 (Cdk5-mediated heat hyperalgesia induced by inflammation remain undefined. This study was designed to examine whether Cdk5 mediates heat hyperalgesia resulting from peripheral injection of complete Freund's adjuvant (CFA in the spinal dorsal horns of rats by interacting with synaptophysin, a well known membrane protein mediating the endocytosis-exocytosis cycle of synaptic vesicles as a molecular marker associated with presynaptic vesicle membranes. The role of Cdk5 in mediating synaptophysin was examined through the combined use of behavioral approaches, imaging studies, and immunoprecipitation following CFA-induced inflammatory pain. Results showed that Cdk5 colocalized with both synaptophysin and soluble N-ethylmaleimide-sensitive factor (NSF attachment protein receptors (SNAREs consisting of VAMP-2, SNAP-25, and syntaxin 1A in spinal dorsal horn of rats. Increased synaptophysin expression of spinal cord horn neurons post intraplantar injection of CFA coincided with increased duration of heat hyperalgesia lasting from 6 h to 3 d. Intrathecal administration of roscovitine, a Cdk5 specific inhibitor, significantly depressed synaptophysin expression during peak heat hyperalgesia and heat hyperalgesia induced by peripheral injection of CFA. Data presented in this report indicated that calpain activity was transiently upregulated 6 h post CFA-treatment despite previous reports suggesting that calpain was capable of cleaving p35 into p25. Results from previous studies obtained by other laboratories demonstrated that significant changes in p35 expression levels within spinal cord horn neurons were not observed in the CFA-treated inflammatory pain model although significant upregulation of Cdk5 kinase was observed between 2 h to 7 d. Therefore, generation of p25 occurred in a calpain-independent fashion in a CFA-treated inflammatory pain model. Our results demonstrated that increased synaptophysin

  20. Chronically Elevated Levels of Short-Chain Fatty Acids Induce T Cell-Mediated Ureteritis and Hydronephrosis.

    Science.gov (United States)

    Park, Jeongho; Goergen, Craig J; HogenEsch, Harm; Kim, Chang H

    2016-03-01

    Short-chain fatty acids (SCFAs) are major products of gut microbial fermentation and profoundly affect host health and disease. SCFAs generate IL-10(+) regulatory T cells, which may promote immune tolerance. However, SCFAs can also induce Th1 and Th17 cells upon immunological challenges and, therefore, also have the potential to induce inflammatory responses. Because of the seemingly paradoxical SCFA activities in regulating T cells, we investigated, in depth, the impact of elevated SCFA levels on T cells and tissue inflammation in mice. Orally administered SCFAs induced effector (Th1 and Th17) and regulatory T cells in ureter and kidney tissues, and they induced T cell-mediated ureteritis, leading to kidney hydronephrosis (hereafter called acetate-induced renal disease, or C2RD). Kidney hydronephrosis in C2RD was caused by ureteral obstruction, which was, in turn, induced by SCFA-induced inflammation in the ureteropelvic junction and proximal ureter. Oral administration of all major SCFAs, such as acetate, propionate, and butyrate, induced the disease. We found that C2RD development is dependent on mammalian target of rapamycin activation, T cell-derived inflammatory cytokines such as IFN-γ and IL-17, and gut microbiota. Young or male animals were more susceptible than old or female animals, respectively. However, SCFA receptor (GPR41 or GPR43) deficiency did not affect C2RD development. Thus, SCFAs, when systemically administered at levels higher than physiological levels, cause dysregulated T cell responses and tissue inflammation in the renal system. The results provide insights into the immunological and pathological effects of chronically elevated SCFAs. Copyright © 2016 by The American Association of Immunologists, Inc.

  1. Neonatal severe hyperparathyroidism caused by homozygous mutation in CASR: A rare cause of life-threatening hypercalcemia.

    Science.gov (United States)

    Murphy, Heidi; Patrick, Jessica; Báez-Irizarry, Eileen; Lacassie, Yves; Gómez, Ricardo; Vargas, Alfonso; Barkemeyer, Brian; Kanotra, Sohit; Zambrano, Regina M

    2016-04-01

    Neonatal severe hyperparathyroidism (NSHPT) is a rare, life-threatening condition that presents with severe hypercalcemia, hyperparathyroidism, and osteopenia in the newborn period. Treatment of NSHPT traditionally includes hydration and bisphosphonates; however newer calcimimetic agents, such as cinacalcet, are now being utilized to prevent or delay parathyroidectomy which is technically difficult in the newborn. Medical treatment success is related to calcium sensing receptor (CaSR) genotype. We report a 4-day-old infant who presented with hyperbilirubinemia, poor feeding, weight loss, severe hypotonia and was ultimately diagnosed with NSHPT. The patient's total serum calcium level of 36.8 mg/dL (reference range: 8.5-10.4 mg/dL) is, to our knowledge, the highest ever documented in this setting. Exome data previously obtained on the infant's parents was re-analyzed demonstrating bi-parental heterozygosity for a mutation of the CASR gene: c.206G > A, and Sanger sequencing data confirmed the patient was a homozygote for the same mutation. Though a patient with the same CaSR gene mutation described here has responded to cinacalcet, our patient did not respond and required parathyroidectomy. Though this case has previously been published as a surgical case report, a full report of the medical management and underlying genetic etiology is warranted; this case underscores the importance of disclosing bi-parental heterozygosity for a gene causing severe neonatal disease particularly when treatment is available and illustrates the need for further in vitro studies of this CaSR mutation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. A Modified method for reducing renal injury in zoledronic acid treatment of hypercalcemia and adverse skeletal events

    Directory of Open Access Journals (Sweden)

    Jiang Liu

    2013-01-01

    Full Text Available Aims: In this paper, we have reported a previously undescribed risk factor of deterioration of renal function in zoledronic acid treatment of skeletal metastasis - high serum calcium level. Based on this consideration, a modified method of treatment of hypercalcemia (HCM with zoledronic acid is suggested in this paper. Material and Methods: Bone scan findings of 1090 cancer patients were analyzed, of which 26 had intense renal parenchymal uptake as a result of HCM or bone metastases. Subsequently, a total of 56 bone metastases patients with zoledronic acid treatment were divided into three groups: HCM group who were pre-treated to normal serum calcium level (13 patients, HCM group (19 patients, and normal serum calcium group (24 patients. Results: More patients with intense renal parenchymal uptake were hyperglycemic, statistically significantly (18/26 versus 19/1064, P = 2.1, E-78. No more patients with intense renal parenchymal uptake were associated with bone metastases (14/26 versus 438/1064, P = 0.20. Subsequently, more HCM patients receiving zoledronic acid treatment showed renal injury compared to patients with normal serum calcium level (5/15 versus 2/24, P < 0.05 and HCM patients with pre-treatment to normal serum calcium level (5/15 versus 1/17, P < 0.05. Conclusions: Intense renal parenchymal uptake of bisphosphonates is closely related to HCM rather than to bone metastases in cancer patients. The serum calcium should be measured and reduced to normal level before zoledronic acid is used in managements of adverse skeletal events in order to decrease the risk of renal injury.

  3. Distinct mechanisms of loss of IFN-gamma mediated HLA class I inducibility in two melanoma cell lines

    International Nuclear Information System (INIS)

    Rodríguez, Teresa; Méndez, Rosa; Del Campo, Ana; Jiménez, Pilar; Aptsiauri, Natalia; Garrido, Federico; Ruiz-Cabello, Francisco

    2007-01-01

    The inability of cancer cells to present antigen on the cell surface via MHC class I molecules is one of the mechanisms by which tumor cells evade anti-tumor immunity. Alterations of Jak-STAT components of interferon (IFN)-mediated signaling can contribute to the mechanism of cell resistance to IFN, leading to lack of MHC class I inducibility. Hence, the identification of IFN-γ-resistant tumors may have prognostic and/or therapeutic relevance. In the present study, we investigated a mechanism of MHC class I inducibility in response to IFN-γ treatment in human melanoma cell lines. Basal and IFN-induced expression of HLA class I antigens was analyzed by means of indirect immunofluorescence flow cytometry, Western Blot, RT-PCR, and quantitative real-time RT-PCR (TaqMan ® Gene Expression Assays). In demethylation studies cells were cultured with 5-aza-2'-deoxycytidine. Electrophoretic Mobility Shift Assay (EMSA) was used to assay whether IRF-1 promoter binding activity is induced in IFN-γ-treated cells. Altered IFN-γ mediated HLA-class I induction was observed in two melanoma cells lines (ESTDAB-004 and ESTDAB-159) out of 57 studied, while treatment of these two cell lines with IFN-α led to normal induction of HLA class I antigen expression. Examination of STAT-1 in ESTDAB-004 after IFN-γ treatment demonstrated that the STAT-1 protein was expressed but not phosphorylated. Interestingly, IFN-α treatment induced normal STAT-1 phosphorylation and HLA class I expression. In contrast, the absence of response to IFN-γ in ESTDAB-159 was found to be associated with alterations in downstream components of the IFN-γ signaling pathway. We observed two distinct mechanisms of loss of IFN-γ inducibility of HLA class I antigens in two melanoma cell lines. Our findings suggest that loss of HLA class I induction in ESTDAB-004 cells results from a defect in the earliest steps of the IFN-γ signaling pathway due to absence of STAT-1 tyrosine-phosphorylation, while absence

  4. Curcumin attenuates oxidative stress induced NFκB mediated inflammation and endoplasmic reticulum dependent apoptosis of splenocytes in diabetes.

    Science.gov (United States)

    Rashid, Kahkashan; Chowdhury, Sayantani; Ghosh, Sumit; Sil, Parames C

    2017-11-01

    The present study was aimed to determine the curative role of curcumin against diabetes induced oxidative stress and its associated splenic complications. Diabetes was induced in the experimental rats via the intraperitoneal administration of a single dose of STZ (65mgkg -1 body weight). Increased blood glucose and intracellular ROS levels along with decreased body weight, the activity of cellular antioxidant enzymes and GSH/GSSG ratio were observed in the diabetic animals. Histological assessment showed white pulp depletion and damaged spleen anatomy in these animals. Oral administration of curcumin at a dose of 100mgkg -1 body weight daily for 8weeks, however, restored these alterations. Investigation of the mechanism of hyperglycemia induced oxidative stress mediated inflammation showed upregulation of inflammatory cytokines, chemokines, adhesion molecules and increased translocation of NFκB into the nucleus. Moreover, ER stress dependent cell death showed induction of eIF2α and CHOP mediated signalling pathways as well as increment in the expression of GRP78, Caspase-12, Calpain-1, phospho JNK, phospho p38 and phospho p53 in the diabetic group. Alteration of Bax/Bcl-2 ratio; disruption of mitochondrial membrane potential, release of cytochrome-C from mitochondria and upregulation of caspase 3 along with the formation of characteristic DNA ladder in the diabetic animals suggest the involvement of mitochondria dependent apoptotic pathway in the splenic cells. Treatment with curcumin could, however, protect cells from inflammatory damage and ER as well as mitochondrial apoptotic death by restoring the alterations of these parameters. Our results suggest that curcumin has the potential to act as an anti-diabetic, anti-oxidant, anti-inflammatory and anti-apoptotic therapeutic against diabetes mediated splenic damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Transforming growth factor β-induced expression of chondroitin sulfate proteoglycans is mediated through non-Smad signaling pathways.

    Science.gov (United States)

    Jahan, Naima; Hannila, Sari S

    2015-01-01

    The expression of chondroitin sulfate proteoglycans (CSPGs) by reactive astrocytes is a major factor contributing to glial scarring and regenerative failure after spinal cord injury, but the molecular mechanisms underlying CSPG expression remain largely undefined. One contributing factor is transforming growth factor β (TGFβ), which is upregulated after injury and has been shown to induce expression of CSPGs in vitro. TGFβ typically mediates its effects through the Smad2/3 signaling pathway, and it has been suggested that this pathway is responsible for CSPG expression. However, there is evidence that TGFβ can also activate non-Smad signaling pathways. In this study, we report that TGFβ-induced expression of three different CSPGs--neurocan, brevican, and aggrecan--is mediated through non-Smad signaling pathways. We observed significant increases in TGFβ-induced expression of neurocan, brevican, and aggrecan following siRNA knockdown of Smad2 or Smad4, which indicates that Smad signaling is not required for the expression of these CSPGs. In addition, we show that neurocan, aggrecan, and brevican levels are significantly reduced when TGFβ is administered in the presence of either the PI3K inhibitor LY294002 or the mTOR inhibitor rapamycin, but not the MEK1/2 inhibitor U0126. This suggests that TGFβ mediates this effect through non-Smad-dependent activation of the PI3K-Akt-mTOR signaling pathway, and targeting this pathway may therefore be an effective means of reducing CSPG expression in the injured CNS. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Hibiscus sabdariffa polyphenols prevent palmitate-induced renal epithelial mesenchymal transition by alleviating dipeptidyl peptidase-4-mediated insulin resistance.

    Science.gov (United States)

    Huang, Chien-Ning; Wang, Chau-Jong; Yang, Yi-Sun; Lin, Chih-Li; Peng, Chiung-Huei

    2016-01-01

    Diabetic nephropathy has a significant socioeconomic impact, but its mechanism is unclear and needs to be examined. Hibiscus sabdariffa polyphenols (HPE) inhibited high glucose-induced angiotensin II receptor-1 (AT-1), thus attenuating renal epithelial mesenchymal transition (EMT). Recently, we reported HPE inhibited dipeptidyl-peptidase-4 (DPP-4, the enzyme degrades type 1 glucagon-like peptide (GLP-1)), which mediated insulin resistance signals leading to EMT. Since free fatty acids can realistically bring about insulin resistance, using the palmitate-stimulated cell model in contrast with type 2 diabetic rats, in this study we examined if insulin resistance causes renal EMT, and the preventive effect of HPE. Our findings reveal that palmitate hindered 30% of glucose uptake. Treatment with 1 mg mL(-1) of HPE and the DPP-4 inhibitor linagliptin completely recovered insulin sensitivity and palmitate-induced signal cascades. HPE inhibited DPP-4 activity without altering the levels of DPP-4 and the GLP-1 receptor (GLP-1R). HPE decreased palmitate-induced phosphorylation of Ser307 of insulin receptor substrate-1 (pIRS-1 (S307)), AT-1 and vimentin, while increasing phosphorylation of phosphatidylinositol 3-kinase (pPI3K). IRS-1 knockdown revealed its essential role in mediating downstream AT-1 and EMT. In type 2 diabetic rats, it suggests that HPE concomitantly decreased the protein levels of DPP-4, AT-1, vimentin, and fibronectin, but reversed the in vivo compensation of GLP-1R. In conclusion, HPE improves insulin sensitivity by attenuating DPP-4 and the downstream signals, thus decreasing AT-1-mediated tubular-interstitial EMT. HPE could be an adjuvant to prevent diabetic nephropathy.

  7. Skeletal Muscle TRIB3 Mediates Glucose Toxicity in Diabetes and High- Fat Diet–Induced Insulin Resistance

    Science.gov (United States)

    Wu, Mengrui; Kim, Teayoun; Jariwala, Ravi H.; Garvey, W. John; Luo, Nanlan; Kang, Minsung; Ma, Elizabeth; Tian, Ling; Steverson, Dennis; Yang, Qinglin; Fu, Yuchang

    2016-01-01

    In the current study, we used muscle-specific TRIB3 overexpressing (MOE) and knockout (MKO) mice to determine whether TRIB3 mediates glucose-induced insulin resistance in diabetes and whether alterations in TRIB3 expression as a function of nutrient availability have a regulatory role in metabolism. In streptozotocin diabetic mice, TRIB3 MOE exacerbated, whereas MKO prevented, glucose-induced insulin resistance and impaired glucose oxidation and defects in insulin signal transduction compared with wild-type (WT) mice, indicating that glucose-induced insulin resistance was dependent on TRIB3. In response to a high-fat diet, TRIB3 MOE mice exhibited greater weight gain and worse insulin resistance in vivo compared with WT mice, coupled with decreased AKT phosphorylation, increased inflammation and oxidative stress, and upregulation of lipid metabolic genes coupled with downregulation of glucose metabolic genes in skeletal muscle. These effects were prevented in the TRIB3 MKO mice relative to WT mice. In conclusion, TRIB3 has a pathophysiological role in diabetes and a physiological role in metabolism. Glucose-induced insulin resistance and insulin resistance due to diet-induced obesity both depend on muscle TRIB3. Under physiological conditions, muscle TRIB3 also influences energy expenditure and substrate metabolism, indicating that the decrease and increase in muscle TRIB3 under fasting and nutrient excess, respectively, are critical for metabolic homeostasis. PMID:27207527

  8. Evidence that shock-induced immune suppression is mediated by adrenal hormones and peripheral beta-adrenergic receptors.

    Science.gov (United States)

    Cunnick, J E; Lysle, D T; Kucinski, B J; Rabin, B S

    1990-07-01

    Our previous work has demonstrated that presentations of mild foot-shock to Lewis rats induces a suppression of splenic and peripheral blood lymphocyte responses to nonspecific T-cell mitogens. The present study demonstrated that adrenalectomy prevented the shock-induced suppression of the mitogenic response of peripheral blood T-cells but did not attenuate the suppression of splenic T-cells. Conversely, the beta-adrenergic receptor antagonists, propranolol and nadolol, attenuated the shock-induced suppression of splenic T-cells in a dose-dependent manner but did not attenuate suppression of the blood mitogen response. These data indicate that distinct mechanisms mediate the shock-induced suppression of T-cell responsiveness to mitogens in the spleen and the peripheral blood. The results indicate that the peripheral release of catecholamines is responsible for splenic immune suppression and that adrenal hormones, which do not interact with beta-adrenergic receptors, are responsible for shock-induced suppression of blood mitogenic responses.

  9. Fisetin Alleviates Lipopolysaccharide-Induced Acute Lung Injury via TLR4-Mediated NF-κB Signaling Pathway in Rats.

    Science.gov (United States)

    Feng, Guang; Jiang, Ze-Yu; Sun, Bo; Fu, Jie; Li, Tian-Zuo

    2016-02-01

    Acute lung injury (ALI), a common component of systemic inflammatory disease, is a life-threatening condition without many effective treatments. Fisetin, a natural flavonoid from fruits and vegetables, was reported to have wide pharmacological properties such as anti-inflammatory, antioxidant, and anticancer activities. The aim of this study was to detect the effects of fisetin on lipopolysaccharide (LPS)-induced acute lung injury and investigate the potential mechanism. Fisetin was injected (1, 2, and 4 mg/kg, i.v.) 30 min before LPS administration (5 mg/kg, i.v.). Our results showed that fisetin effectively reduced the inflammatory cytokine release and total protein in bronchoalveolar lavage fluids (BALF), decreased the lung wet/dry ratios, and obviously improved the pulmonary histology in LPS-induced ALI. Furthermore, fisetin inhibited LPS-induced increases of neutrophils and macrophage infiltration and attenuated MPO activity in lung tissues. Additionally, fisetin could significantly inhibit the Toll-like receptor 4 (TLR4) expression and the activation of NF-κB in lung tissues. Our data indicates that fisetin has a protective effect against LPS-induced ALI via suppression of TLR4-mediated NF-κB signaling pathways, and fisetin may be a promising candidate for LPS-induced ALI treatment.

  10. The combination of maltose-binding protein and BCG-induced Th1 activation is involved in TLR2/9-mediated upregulation of MyD88-TRAF6 and TLR4-mediated downregulation of TRIF-TRAF3.

    Science.gov (United States)

    Liu, Guomu; Zhai, Xiaoyu; Zhou, Hongyue; Yang, Xiaoyu; Zhang, Nannan; Tai, Guixiang; Ni, Weihua

    2018-03-01

    Our previous study demonstrated that maltose-binding protein (MBP) activated Th1 through the TLR2-mediated MyD88-dependent pathway and the TLR4-mediated TRIF-dependent pathway. The combination of MBP and BCG synergistically induced Th1 activation, and the TLR2/9-mediated MyD88-dependent pathway is involved in this process. To further explore this mechanism, we stimulated purified mouse CD4 + T cells with MBP and BCG in vitro. The results demonstrated that MBP combined with BCG synergistically increased IFN-γ production and TLR2/4/9 expression, suggesting the involvement of TLR2/4/9 in the combination-induced Th1 activation. Next, TLRs 2/4/9 were blocked to analyze the effects of TLRs on Th1 activation. The results demonstrated that MBP induced a low level of Th1 activation by upregulating TLR2-mediated MyD88-TRAF6 and TLR4-mediated TRIF-TRAF3 expression, whereas MBP combined with BCG induced synergistic Th1 activation, which was not only triggered by strong upregulation of TLR2/9-mediated MyD88-TRAF6 expression but also by shifting TLR4-mediated TRIF-TRAF3 into the TRIF-TRAF6 pathway. Moreover, we observed that a TLR4 antibody upregulated MyD88 expression and a TLR9 inhibitor downregulated TRIF expression, indicating that there was cross-talk between TLRs 2/4/9 in MBP combined with BCG-induced Th1 activation. Our findings may expand the knowledge regarding TLR cross-talk involved in regulating the Th1 response. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. The small GTPase, Rap1, mediates CD31-induced integrin adhesion

    NARCIS (Netherlands)

    Reedquist, K. A.; Ross, E.; Koop, E. A.; Wolthuis, R. M.; Zwartkruis, F. J.; van Kooyk, Y.; Salmon, M.; Buckley, C. D.; Bos, J. L.

    2000-01-01

    Integrin-mediated leukocyte adhesion is a critical aspect of leukocyte function that is tightly regulated by diverse stimuli, including chemokines, antigen receptors, and adhesion receptors. How cellular signals from CD31 and other adhesion amplifiers are integrated with those from classical

  12. [Ursodeoxycholic acid induced apoptosis of human hepatoma cells HepG2 and SMMC-7721 bymitochondrial-mediated pathway].

    Science.gov (United States)

    Wu, Duan; Zhou, Jianyin; Yin, Zhenyu; Liu, Pingguo; Zhao, Yilin; Liu, Jianming; Wang, Xiaomin

    2014-12-02

    To explore the effects and underlying mechanisms of ursodeoxycholic acid on human hepatoma cells. HepG2 and SMMC-7721 HCC cell lines were respectively treated with ursodeoxycholic acid. And cell proliferation, apoptosis and the expression of Bax/Bcl-2 gene were detected by methyl thiazolyl tetrazolium (MTT), inverted microscopy, fluorescent microscopy, flow cytometry and Western blot. Ursodeoxycholic acid significantly inhibited the proliferation of human hepatoma cells in a concentration- and time-dependent manner. The half maximal inhibitory concentrations (IC50) of HepG2 and SMMC-7721 were 397.3 and 387.7 µg/ml respectively after a 48-hour treatment of 400 µg /ml ursodeoxycholic acid. And it also induced the apoptosis of HepG2 and SMMC-7721 cells, up-regulated Bax gene and down-regulated Bcl-2 gene. Ursodeoxycholic acid inhibits the proliferation of hepatoma cells and induce apoptosis by mitochondrial-mediated pathway.

  13. Nitric oxide is a mediator of methamphetamine (METH)-induced neurotoxicity. In vitro evidence from primary cultures of mesencephalic cells.

    Science.gov (United States)

    Sheng, P; Cerruti, C; Ali, S; Cadet, J L

    1996-10-31

    METH is a monoaminergic toxic that destroys dopamine terminals in vivo. Oxidative mechanisms associated with DA metabolism are thought to play an important role in its toxic effects. These ideas were supported by the demonstration that CuZn-superoxide dismutase (CuZnSOD) transgenic mice were protected against the toxic effects of the drug. In the present study, we sought to determine if nitric oxide (NO) production was also involved in METH-induced neurotoxicity using primary cultures obtained from fetal rat mesencephalon. METH caused dose- and time-dependent cell death in vitro. Blockade of nitric oxide (NO) formation with several nitric oxide (NO) synthase blockers attenuated METH-mediated toxicity. Moreover, inhibition of ADP-ribosylation with nicotinamide and benzamide also provided protection against the toxicity of the drug. These results, together with our previous results in transgenic mice, support a role for free radicals in METH-induced toxic effects.

  14. Regulatory T Cells Promote β-Catenin–Mediated Epithelium-to-Mesenchyme Transition During Radiation-Induced Pulmonary Fibrosis

    International Nuclear Information System (INIS)

    Xiong, Shanshan; Pan, Xiujie; Xu, Long; Yang, Zhihua; Guo, Renfeng; Gu, Yongqing; Li, Ruoxi; Wang, Qianjun; Xiao, Fengjun; Du, Li; Zhou, Pingkun; Zhu, Maoxiang

    2015-01-01

    Purpose: Radiation-induced pulmonary fibrosis results from thoracic radiation therapy and severely limits radiation therapy approaches. CD4 + CD25 + FoxP3 + regulatory T cells (Tregs) as well as epithelium-to-mesenchyme transition (EMT) cells are involved in pulmonary fibrosis induced by multiple factors. However, the mechanisms of Tregs and EMT cells in irradiation-induced pulmonary fibrosis remain unclear. In the present study, we investigated the influence of Tregs on EMT in radiation-induced pulmonary fibrosis. Methods and Materials: Mice thoraxes were irradiated (20 Gy), and Tregs were depleted by intraperitoneal injection of a monoclonal anti-CD25 antibody 2 hours after irradiation and every 7 days thereafter. Mice were treated on days 3, 7, and 14 and 1, 3, and 6 months post irradiation. The effectiveness of Treg depletion was assayed via flow cytometry. EMT and β-catenin in lung tissues were detected by immunohistochemistry. Tregs isolated from murine spleens were cultured with mouse lung epithelial (MLE) 12 cells, and short interfering RNA (siRNA) knockdown of β-catenin in MLE 12 cells was used to explore the effects of Tregs on EMT and β-catenin via flow cytometry and Western blotting. Results: Anti-CD25 antibody treatment depleted Tregs efficiently, attenuated the process of radiation-induced pulmonary fibrosis, hindered EMT, and reduced β-catenin accumulation in lung epithelial cells in vivo. The coculture of Tregs with irradiated MLE 12 cells showed that Tregs could promote EMT in MLE 12 cells and that the effect of Tregs on EMT was partially abrogated by β-catenin knockdown in vitro. Conclusions: Tregs can promote EMT in accelerating radiation-induced pulmonary fibrosis. This process is partially mediated through β-catenin. Our study suggests a new mechanism for EMT, promoted by Tregs, that accelerates radiation-induced pulmonary fibrosis

  15. Agonist-induced internalisation of the glucagon-like peptide-1 receptor is mediated by the Gαq pathway.

    Science.gov (United States)

    Thompson, Aiysha; Kanamarlapudi, Venkateswarlu

    2015-01-01

    The glucagon-like peptide-1 receptor (GLP-1R) is a G-protein-coupled receptor (GPCR) and an important target in the treatment of type 2 diabetes mellitus (T2DM). Upon stimulation with agonist, the GLP-1R signals through both Gαs and Gαq coupled pathways to stimulate insulin secretion. The agonist-induced GLP-1R internalisation has recently been shown to be important for insulin secretion. However, the molecular mechanisms underlying GLP-1R internalisation remain unknown. The aim of this study was to determine the role of GLP-1R downstream signalling pathways in its internalisation. Agonist-induced human GLP-1R (hGLP-1R) internalisation and activity were examined using a number of techniques including immunoblotting, ELISA, immunofluorescence and luciferase assays to determine cAMP production, intracellular Ca(2+) accumulation and ERK phosphorylation. Agonist-induced hGLP-1R internalisation is dependent on caveolin-1 and dynamin. Inhibition of the Gαq pathway but not the Gαs pathway affected hGLP-1R internalisation. Consistent with this, hGLP-1R mutant T149M and small-molecule agonists (compound 2 and compound B), which activate only the Gαs pathway, failed to induce internalisation of the receptor. Chemical inhibitors of the Gαq pathway, PKC and ERK phosphorylation significantly reduced agonist-induced hGLP-1R internalisation. These inhibitors also suppressed agonist-induced ERK1/2 phosphorylation demonstrating that the phosphorylated ERK acts downstream of the Gαq pathway in the hGLP-1R internalisation. In summary, agonist-induced hGLP-1R internalisation is mediated by the Gαq pathway. The internalised hGLP-1R stimulates insulin secretion from pancreatic β-cells, indicating the importance of GLP-1 internalisation for insulin secretion. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Regulatory T Cells Promote β-Catenin–Mediated Epithelium-to-Mesenchyme Transition During Radiation-Induced Pulmonary Fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Shanshan; Pan, Xiujie; Xu, Long; Yang, Zhihua [Beijing Institute of Radiation Medicine, Beijing (China); Guo, Renfeng [Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan (United States); Gu, Yongqing; Li, Ruoxi; Wang, Qianjun; Xiao, Fengjun; Du, Li; Zhou, Pingkun [Beijing Institute of Radiation Medicine, Beijing (China); Zhu, Maoxiang, E-mail: zhumx@nic.bmi.ac.cn [Beijing Institute of Radiation Medicine, Beijing (China)

    2015-10-01

    Purpose: Radiation-induced pulmonary fibrosis results from thoracic radiation therapy and severely limits radiation therapy approaches. CD4{sup +}CD25{sup +}FoxP3{sup +} regulatory T cells (Tregs) as well as epithelium-to-mesenchyme transition (EMT) cells are involved in pulmonary fibrosis induced by multiple factors. However, the mechanisms of Tregs and EMT cells in irradiation-induced pulmonary fibrosis remain unclear. In the present study, we investigated the influence of Tregs on EMT in radiation-induced pulmonary fibrosis. Methods and Materials: Mice thoraxes were irradiated (20 Gy), and Tregs were depleted by intraperitoneal injection of a monoclonal anti-CD25 antibody 2 hours after irradiation and every 7 days thereafter. Mice were treated on days 3, 7, and 14 and 1, 3, and 6 months post irradiation. The effectiveness of Treg depletion was assayed via flow cytometry. EMT and β-catenin in lung tissues were detected by immunohistochemistry. Tregs isolated from murine spleens were cultured with mouse lung epithelial (MLE) 12 cells, and short interfering RNA (siRNA) knockdown of β-catenin in MLE 12 cells was used to explore the effects of Tregs on EMT and β-catenin via flow cytometry and Western blotting. Results: Anti-CD25 antibody treatment depleted Tregs efficiently, attenuated the process of radiation-induced pulmonary fibrosis, hindered EMT, and reduced β-catenin accumulation in lung epithelial cells in vivo. The coculture of Tregs with irradiated MLE 12 cells showed that Tregs could promote EMT in MLE 12 cells and that the effect of Tregs on EMT was partially abrogated by β-catenin knockdown in vitro. Conclusions: Tregs can promote EMT in accelerating radiation-induced pulmonary fibrosis. This process is partially mediated through β-catenin. Our study suggests a new mechanism for EMT, promoted by Tregs, that accelerates radiation-induced pulmonary fibrosis.

  17. Contact Lens-Induced Discomfort and Inflammatory Mediator Changes in Tears.

    Science.gov (United States)

    Masoudi, Simin; Zhao, Zhenjun; Stapleton, Fiona; Willcox, Mark

    2017-01-01

    Studies indicate that contact lens (CL) discontinuation mostly occurs because of dryness and discomfort symptoms. This study aimed to investigate relationships between changes in the concentration of tear inflammatory mediators with subjective comfort ratings with CL wear and no contact lens wear between morning and evening. Forty-five subjects collected tears twice daily in the morning and in the evening with or without lenses. Comfort was rated subjectively on a scale from 1 to 100 (where 100 was extremely comfortable) just before each tear collection. Tear samples were assayed for complement components (C3 and C3a), leukotriene B4 (LTB4), secretory phospholipase A2 (sPLA2), secretory immunoglobulin A (sIgA), and bradykinin using commercially available immuno-based assay kits. Comfort ratings showed a statistically significant decline from morning to evening both with CL (89.0±10.1 AM vs. 76.7±15.2 PM; P0.05). Leukotriene B4 levels were slightly higher in CL (CL 43.4±12.6 pg/ml vs. No CL 39.4±13.4 pg/mL; P=0.034), whereas the concentration of LTB4, C3, C3a, and sIgA dropped by the end of the day in the presence or absence of lens wear (Ptear levels were not correlated with comfort ratings in any of the conditions. Leukotriene B4 had a higher concentration in the evening, and when measured as a ratio to sIgA, there was a trend for increased concentration of this mediator during CL wear. Although specific mediators showed changes from morning to evening with and without lens wear, most of these were not correlated with subjective comfort ratings in lens wear. The only mediator that showed an increase in concentration during the day and during lens wear was LTB4, and further studies on this mediator are warranted.

  18. Iron mediates N-methyl-D-aspartate receptor-dependent stimulation of calcium-induced pathways and hippocampal synaptic plasticity.

    Science.gov (United States)

    Muñoz, Pablo; Humeres, Alexis; Elgueta, Claudio; Kirkwood, Alfredo; Hidalgo, Cecilia; Núñez, Marco T

    2011-04-15

    Iron deficiency hinders hippocampus-dependent learning processes and impairs cognitive performance, but current knowledge on the molecular mechanisms underlying the unique role of iron in neuronal function is sparse. Here, we investigated the participation of iron on calcium signal generation and ERK1/2 stimulation induced by the glutamate agonist N-methyl-D-aspartate (NMDA), and the effects of iron addition/chelation on hippocampal basal synaptic transmission and long-term potentiation (LTP). Addition of NMDA to primary hippocampal cultures elicited persistent calcium signals that required functional NMDA receptors and were independent of calcium influx through L-type calcium channels or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors; NMDA also promoted ERK1/2 phosphorylation and nuclear translocation. Iron chelation with desferrioxamine or inhibition of ryanodine receptor (RyR)-mediated calcium release with ryanodine-reduced calcium signal duration and prevented NMDA-induced ERK1/2 activation. Iron addition to hippocampal neurons readily increased the intracellular labile iron pool and stimulated reactive oxygen species production; the antioxidant N-acetylcysteine or the hydroxyl radical trapper MCI-186 prevented these responses. Iron addition to primary hippocampal cultures kept in calcium-free medium elicited calcium signals and stimulated ERK1/2 phosphorylation; RyR inhibition abolished these effects. Iron chelation decreased basal synaptic transmission in hippocampal slices, inhibited iron-induced synaptic stimulation, and impaired sustained LTP in hippocampal CA1 neurons induced by strong stimulation. In contrast, iron addition facilitated sustained LTP induction after suboptimal tetanic stimulation. Together, these results suggest that hippocampal neurons require iron to generate RyR-mediated calcium signals after NMDA receptor stimulation, which in turn promotes ERK1/2 activation, an essential step of sustained LTP.

  19. Keratinocyte expression of inflammatory mediators plays a crucial role in substance P-induced acute and chronic pain

    Directory of Open Access Journals (Sweden)

    Wei Tzuping

    2012-07-01

    Full Text Available Abstract Tibia fracture in rats followed by cast immobilization leads to nociceptive, trophic, vascular and bone-related changes similar to those seen in Complex Regional Pain Syndrome (CRPS. Substance P (SP mediated neurogenic inflammation may be responsible for some of the signs of CRPS in humans. We therefore hypothesized that SP acting through the SP receptor (NK1 leads to the CRPS-like changes found in the rat model. In the present study, we intradermally injected rats with SP and monitored hindpaw mechanical allodynia, temperature, and thickness as well as tissue levels of tumor necrosis factor-α (TNF-α, interleukin 1β (IL-1β, interleukin 6 (IL-6, and nerve growth factor-β (NGF for 72 h. Anti-NGF antibody was utilized to block the effects of SP-induced NGF up-regulation. Fracture rats treated with the selective NK1 receptor antagonist LY303870 prior to cast removal were assessed for BrdU, a DNA synthesis marker, incorporation in skin cells to examine cellular proliferation. Bone microarchitecture was measured using micro computed tomography (μCT. We observed that: (1 SP intraplantar injection induced mechanical allodynia, warmth and edema as well as the expression of nociceptive mediators in the hindpaw skin of normal rats, (2 LY303870 administered intraperitoneally after fracture attenuated allodynia, hindpaw unweighting, warmth, and edema, as well as cytokine and NGF expression, (3 LY303870 blocked fracture-induced epidermal thickening and BrdU incorporation after fracture, (4 anti-NGF antibody blocked SP-induced allodynia but not warmth or edema, and (5 LY303870 had no effect on bone microarchitecture. Collectively our data indicate that SP acting through NK1 receptors supports the nociceptive and vascular components of CRPS, but not the bone-related changes.

  20. Shear Stress Induces Phenotypic Modulation of Vascular Smooth Muscle Cells via AMPK/mTOR/ULK1-Mediated Autophagy.

    Science.gov (United States)

    Sun, Liqian; Zhao, Manman; Liu, Aihua; Lv, Ming; Zhang, Jingbo; Li, Youxiang; Yang, Xinjian; Wu, Zhongxue

    2018-03-01

    Phenotypic modulation of vascular smooth muscle cells (VSMCs) is involved in the pathophysiological processes of the intracranial aneurysms (IAs). Although shear stress has been implicated in the proliferation, migration, and phenotypic conversion of VSMCs, the molecular mechanisms underlying these events are currently unknown. In this study, we investigated whether shear stress(SS)-induced VSMC phenotypic modulation was mediated by autophagy involved in adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway. The results show that shear stress could inhibit the expression of key VSMC contractile genes and induce pro-inflammatory/matrix-remodeling genes levels, contributing to VSMCs phenotypic switching from a contractile to a synthetic phenotype. More importantly, Shear stress also markedly increased the levels of the autophagy marker microtubule-associated protein light chain 3-II (LC3II), Beclin-1, and p62 degradation. The autophagy inhibitor 3-methyladenine (3-MA) significantly blocked shear-induced phenotypic modulation of VSMCs. To further explore the molecular mechanism involved in shear-induced autophagy, we found that shear stress could activate AMPK/mTOR/ULK1 signaling pathway in VSMCs. Compound C, a pharmacological inhibitor of AMPK, significantly reduced the levels of p-AMPK and p-ULK, enhanced p-mTOR level, and finally decreased LC3II and Beclin-1 level, which suggested that activated AMPK/mTOR/ULK1 signaling was related to shear-mediated autophagy. These results indicate that shear stress promotes VSMC phenotypic modulation through the induction of autophagy involved in activating the AMPK/mTOR/ULK1 pathway.

  1. NOX4 mediates cytoprotective autophagy induced by the EGFR inhibitor erlotinib in head and neck cancer cells

    International Nuclear Information System (INIS)

    Sobhakumari, Arya; Schickling, Brandon M.; Love-Homan, Laurie; Raeburn, Ayanna; Fletcher, Elise V.M.; Case, Adam J.; Domann, Frederick E.; Miller, Francis J.

    2013-01-01

    Most head and neck squamous cell carcinomas (HNSCCs) overexpress epidermal growth factor receptor (EGFR) and EGFR inhibitors are routinely used in the treatment of HNSCC. However, many HNSCC tumors do not respond or become refractory to EGFR inhibitors. Autophagy, which is a stress-induced cellular self-degradation process, has been reported to reduce the efficacy of chemotherapy in various disease models. The purpose of this study is to determine if the efficacy of the EGFR inhibitor erlotinib is reduced by activation of autophagy via NOX4-mediated oxidative stress in HNSCC cells. Erlotinib induced the expression of the autophagy marker LC3B-II and autophagosome formation in FaDu and Cal-27 cells. Inhibition of autophagy by chloroquine and knockdown of autophagy pathway genes Beclin-1 and Atg5 sensitized both cell lines to erlotinib-induced cytotoxicity, suggesting that autophagy may serve as a protective mechanism. Treatment with catalase (CAT) and diphenylene iodonium (DPI) in the presence of erlotinib suppressed the increase in LC3B-II expression in FaDu and Cal-27 cells. Erlotinib increased NOX4 mRNA and protein expression by increasing its promoter activity and mRNA stability in FaDu cells. Knockdown of NOX4 using adenoviral siNOX4 partially suppressed erlotinib-induced LC3B-II expression, while overexpression of NOX4 increased expression of LC3B-II. These studies suggest that erlotinib may activate autophagy in HNSCC cells as a pro-survival mechanism, and NOX4 may play a role in mediating this effect. - Highlights: • Erlotinib increased LC3B-II and autophagosome formation in HNSCC cells. • Inhibition of autophagy sensitized HNSCC cells to erlotinib. • Erlotinib increased NOX4 promoter and 3′UTR luciferase activity. • Manipulating NOX4 decreases or increases autophagy

  2. NOX4 mediates cytoprotective autophagy induced by the EGFR inhibitor erlotinib in head and neck cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Sobhakumari, Arya [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Schickling, Brandon M. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Love-Homan, Laurie; Raeburn, Ayanna [Department of Pathology, The University of Iowa, Iowa City, IA (United States); Fletcher, Elise V.M. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Case, Adam J. [Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Domann, Frederick E. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); Miller, Francis J. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); and others

    2013-11-01

    Most head and neck squamous cell carcinomas (HNSCCs) overexpress epidermal growth factor receptor (EGFR) and EGFR inhibitors are routinely used in the treatment of HNSCC. However, many HNSCC tumors do not respond or become refractory to EGFR inhibitors. Autophagy, which is a stress-induced cellular self-degradation process, has been reported to reduce the efficacy of chemotherapy in various disease models. The purpose of this study is to determine if the efficacy of the EGFR inhibitor erlotinib is reduced by activation of autophagy via NOX4-mediated oxidative stress in HNSCC cells. Erlotinib induced the expression of the autophagy marker LC3B-II and autophagosome formation in FaDu and Cal-27 cells. Inhibition of autophagy by chloroquine and knockdown of autophagy pathway genes Beclin-1 and Atg5 sensitized both cell lines to erlotinib-induced cytotoxicity, suggesting that autophagy may serve as a protective mechanism. Treatment with catalase (CAT) and diphenylene iodonium (DPI) in the presence of erlotinib suppressed the increase in LC3B-II expression in FaDu and Cal-27 cells. Erlotinib increased NOX4 mRNA and protein expression by increasing its promoter activity and mRNA stability in FaDu cells. Knockdown of NOX4 using adenoviral siNOX4 partially suppressed erlotinib-induced LC3B-II expression, while overexpression of NOX4 increased expression of LC3B-II. These studies suggest that erlotinib may activate autophagy in HNSCC cells as a pro-survival mechanism, and NOX4 may play a role in mediating this effect. - Highlights: • Erlotinib increased LC3B-II and autophagosome formation in HNSCC cells. • Inhibition of autophagy sensitized HNSCC cells to erlotinib. • Erlotinib increased NOX4 promoter and 3′UTR luciferase activity. • Manipulating NOX4 decreases or increases autophagy.

  3. Transcriptomics and knockout mutant analysis of rhizobacteria-mediated induced systemic resistance in Arabidopsis

    NARCIS (Netherlands)

    Verhagen, B.W.M.

    2004-01-01

    A classic example of induced resistance is triggered after infection by a necrotizing pathogen, rendering uninfected,distal parts more resistant to subsequent pathogen attack, and is often referred to as systemic acquired resistance (SAR). A phenotypically comparable type of induced resistance is

  4. Allergen immunotherapy induces a suppressive memory response mediated by IL-10 in a mouse asthma model

    NARCIS (Netherlands)

    Vissers, Joost L. M.; van Esch, Betty C. A. M.; Hofman, Gerard A.; Kapsenberg, Martien L.; Weller, Frank R.; van Oosterhout, Antoon J. M.

    2004-01-01

    Background: Human studies have demonstrated that allergen immunotherapy induces memory suppressive responses and IL-10 production by allergen-specific T cells. Previously, we established a mouse model in which allergen immunotherapy was effective in the suppression of allergen-induced asthma

  5. SUCNR1-mediated chemotaxis of macrophages aggravates obesity-induced inflamm