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Sample records for pi3k signaling pathways

  1. AKTivation of the PI3K/AKT/mTOR signaling pathway by KSHV

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    Aadra P Bhatt

    2013-01-01

    Full Text Available As an obligate intracellular parasite, the Kaposi sarcoma-associated herpesvirus (KSHV relies on host cell machinery to meet its needs for survival, viral replication, production, and dissemination of progeny virions. KSHV is a ɣ-herpesvirus that is associated with three different malignancies: Kaposi sarcoma (KS, and two B cell lymphoproliferative disorders, primary effusion lymphoma (PEL and multicentric Castleman disease (MCD. KSHV viral proteins modulate cellular phosphatidylinositol-3-kinase (PI3K/AKT/mammalian target of rapamycin (mTOR signaling pathway, which is a ubiquitous pathway that also controls B lymphocyte proliferation and development. We review the mechanisms by which KSHV manipulates the PI3K/AKT/mTOR pathway, with a specific focus on B cells.

  2. PI3K-AKT signaling pathway is involved in hypoxia/thermal-induced immunosuppression of small abalone Haliotis diversicolor.

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    Sun, Yulong; Zhang, Xin; Wang, Guodong; Lin, Shi; Zeng, Xinyang; Wang, Yilei; Zhang, Ziping

    2016-12-01

    The PI3K-AKT signal pathway has been found to be involved in many important physiological and pathological processes of the innate immune system of vertebrates and invertebrates. In this study, the AKT (HdAKT) and PI3K (HdPI3K) gene of small abalone Haliotis diversicolor were cloned and characterized for the important status of PI3K and AKT protein in PI3K-AKT signaling pathway. The full length cDNAs of HdAKT and HdPI3K are 2126 bp and 6052 bp respectively, encoding proteins of 479 amino acids and 1097 amino acids, respectively. The mRNA expression level of fourteen genes in the PI3K-AKT signaling pathway were detected by quantitative real-time PCR. The results showed that all these fourteen genes were ubiquitously expressed in seven selected tissues. Meanwhile, HdAKT was expressed in haemocytes with the highest expression level (p abalone. The mRNA expression of these genes in gills, haemocytes and hepatopancreas was significantly down-regulated after the Vibrio parahaemolyticus stimulation with environment stimulation (thermal, hypoxia and thermal & hypoxia). These results indicate that the dual/multiple stresses defeat the immune system and lead to immunosuppression in abalone. PI3K-AKT signaling pathway may be involved in hypoxia/thermal-induced immunosuppression of small abalone Haliotis diversicolor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Omentin-1 Stimulates Human Osteoblast Proliferation through PI3K/Akt Signal Pathway

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    Shan-Shan Wu

    2013-01-01

    Full Text Available It has been presumed that adipokines deriving from adipose tissue may play important roles in bone metabolism. Omentin-1, a novel adipokine, which is selectively expressed in visceral adipose tissue, has been reported to stimulate proliferation and inhibit differentiation of mouse osteoblast. However, little information refers to the effect of omentin-1 on human osteoblast (hOB proliferation. The current study examined the potential effects of omentin-1 on proliferation in hOB and the signal pathway involved. Omentin-1 promoted hOB proliferation in a dose-dependent manner as determined by [3H]thymidine incorporation. Western blot analysis revealed that omentin-1 induced activation of Akt (phosphatidylinositol-3 kinase downstream effector and such effect was impeded by transfection of hOB with Akt-siRNA. Furthermore, LY294002 (a selective PI3K inhibitor and HIMO (a selective Akt inhibitor abolished the omentin-1-induced hOB proliferation. These findings indicate that omentin-1 induces hOB proliferation via the PI3K/Akt signaling pathway and suggest that osteoblast is a direct target of omentin-1.

  4. PI-103 and Quercetin Attenuate PI3K-AKT Signaling Pathway in T- Cell Lymphoma Exposed to Hydrogen Peroxide.

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    Akhilendra Kumar Maurya

    Full Text Available Phosphatidylinositol 3 kinase-protein kinase B (PI3K-AKT pathway has been considered as major drug target site due to its frequent activation in cancer. AKT regulates the activity of various targets to promote tumorigenesis and metastasis. Accumulation of reactive oxygen species (ROS has been linked to oxidative stress and regulation of signaling pathways for metabolic adaptation of tumor microenvironment. Hydrogen peroxide (H2O2 in this context is used as ROS source for oxidative stress preconditioning. Antioxidants are commonly considered to be beneficial to reduce detrimental effects of ROS and are recommended as dietary supplements. Quercetin, a ubiquitous bioactive flavonoid is a dietary component which has attracted much of interest due to its potential health-promoting effects. Present study is aimed to analyze PI3K-AKT signaling pathway in H2O2 exposed Dalton's lymphoma ascite (DLA cells. Further, regulation of PI3K-AKT pathway by quercetin as well as PI-103, an inhibitor of PI3K was analyzed. Exposure of H2O2 (1mM H2O2 for 30min to DLA cells caused ROS accumulation and resulted in increased phosphorylation of PI3K and downstream proteins PDK1 and AKT (Ser-473 and Thr-308, cell survival factors BAD and ERK1/2, as well as TNFR1. However, level of tumor suppressor PTEN was declined. Both PI-103 & quercetin suppressed the enhanced level of ROS and significantly down-regulated phosphorylation of AKT, PDK1, BAD and level of TNFR1 as well as increased the level of PTEN in H2O2 induced lymphoma cells. The overall result suggests that quercetin and PI3K inhibitor PI-103 attenuate PI3K-AKT pathway in a similar mechanism.

  5. Myrcia bella Leaf Extract Presents Hypoglycemic Activity via PI3k/Akt Insulin Signaling Pathway

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    Priscilla Maria Ponce Vareda

    2014-01-01

    Full Text Available Species of Myrcia are used by indigenous people and in traditional communities in Brazil for the treatment of Diabetes mellitus. We investigated the hypoglycemic effect of the extract of leaves of Myrcia bella in diabetic mice. The chemical fingerprinting of the 70% EtOH extract characterized as main constituents flavonoid aglycones, flavonoid-O-glycosides, and acylated flavonoid-O-glycosides derivatives of quercetin and myricetin. Mice were treated with saline or extract of M. bella (300 or 600 mg/Kg b.w. for 14 days. Body weight and water and food intake were measured every day. Fasting blood glucose was measured weekly. At the end of the treatment, blood insulin, triglycerides, total cholesterol, and protein were measured. Glycogen content and expression of proteins of the insulin signaling pathway were measured in liver. The treatment with 600 mg/Kg reduced the fasting blood glucose in diabetic mice of the 7th day as water and food intake and increased hepatic glycogen. Total cholesterol and triglycerides were reduced in diabetic treated mice. The treatment increased the expression of IRS-1, PI3-K, and AKT in the livers of diabetic treated mice. The results indicate that the extract of the leaves of Myrcia bella has hypoglycemic properties and possibly acts to regulate glucose uptake by the liver.

  6. Neuroprotective capabilities of TSA against cerebral ischemia/reperfusion injury via PI3K/Akt signaling pathway in rats.

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    Ma, Xiao-Hui; Gao, Qiang; Jia, Zhen; Zhang, Ze-Wei

    2015-02-01

    Hundreds of previous studies demonstrated the cytoprotective effect of trichostatin-A (TSA), a kind of histone deacetylases inhibitors (HDACIs), against cerebral ischemia/reperfusion insult. Meanwhile, phosphatidylinositol-3 kinase/Akt (PI3K/Akt) is a well-known, important signaling pathway that mediates neuroprotection. However, it should be remains unclear whether the neuroprotective capabilities of TSA against cerebral ischemia/reperfusion is mediated by activation of the PI3K/Akt signaling pathway. Five groups rats (n = 12 each), with middle cerebral artery occlusion (MCAO) except sham group, were used to investigate the neuroprotective effect of certain concentration (0.05 mg/kg) of TSA, and whether the neuroprotective effect of TSA is associated with activation of the PI3K/Akt signaling pathway through using of wortmannin (0.25 mg/kg). TSA significantly increased the expression of p-Akt protein, reduced infarct volume, and attenuated neurological deficit in rats with transient MCAO, wortmannin weakened such effect of TSA dramatically. TSA could significantly decrease the neurological deficit scores and reduce the cerebral infarct volume during cerebral ischemia/reperfusion injury, which was achieved partly by activation of the PI3K/Akt signaling pathway via upgrading of p-Akt protein.

  7. Association between PI3K/Akt/mTOR/p70S6K signaling pathway and hepatic fibrosis

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    WU Changhui

    2015-11-01

    Full Text Available Phosphoinositide 3-kinase (PI3K/protein kinase-B (AkT/mammalian target of rapamycin (mTOR/70-kDa ribosomal protein S6 kinase (p70S6K, PI3K/Akt/mTOR/p70S6K, is an important signaling pathway in the life activities of cells, and it plays an important role in promoting the growth, proliferation, invasion, and anti-apoptosis of cells and promoting angiogenesis. It was clarified that the PI3K/Akt/mTOR/p70S6K signaling pathway is involved in regulating the activities of hepatic stellate cell(HSC, thus influencing the development and progression of hepatic fibrosis. Analysis demonstrated that blocking any target of the PI3K/Akt/mTOR/p70S6K signaling pathway can inhibit the activation and proliferation of HSC, promote the apoptosis of HSC, inhibit the extracellular matrix secretion from HSC, and delay the progression of hepatic fibrosis. Blocking the pathway is expected to be a treatment strategy for hepatic fibrosis.

  8. The role of the PI3K-Akt signaling pathway in the developmental competence of bovine oocytes.

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    Gabriella Mamede Andrade

    Full Text Available The ovarian follicle encloses oocytes in a microenvironment throughout their growth and acquisition of competence. Evidence suggests a dynamic interplay among follicular cells and oocytes, since they are constantly exchanging "messages". We dissected bovine ovarian follicles and recovered follicular cells (FCs-granulosa and cumulus cells and cumulus-oocyte complexes (COCs to investigate whether the PI3K-Akt signaling pathway impacted oocyte quality. Following follicle rupture, COCs were individually selected for in vitro cultures to track the follicular cells based on oocyte competence to reach the blastocyst stage after parthenogenetic activation. Levels of PI3K-Akt signaling pathway components in FCs correlated with oocyte competence. This pathway is upregulated in FCs from follicles with high-quality oocytes that are able to reach the blastocyst stage, as indicated by decreased levels of PTEN and increased levels of the PTEN regulators bta-miR-494 and bta-miR-20a. Using PI3K-Akt responsive genes, we showed decreased FOXO3a levels and BAX levels in lower quality groups, indicating changes in cell cycle progression, oxidative response and apoptosis. Based on these results, the measurement of levels of PI3K-Akt pathway components in FCs from ovarian follicles carrying oocytes with distinct developmental competences is a useful tool to identify putative molecular pathways involved in the acquisition of oocyte competence.

  9. Ursolic acid increases glucose uptake through the PI3K signaling pathway in adipocytes.

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    Yonghan He

    Full Text Available BACKGROUND: Ursolic acid (UA, a triterpenoid compound, is reported to have a glucose-lowering effect. However, the mechanisms are not fully understood. Adipose tissue is one of peripheral tissues that collectively control the circulating glucose levels. OBJECTIVE: The objective of the present study was to determine the effect and further the mechanism of action of UA in adipocytes. METHODS AND RESULTS: The 3T3-L1 preadipocytes were induced to differentiate and treated with different concentrations of UA. NBD-fluorescent glucose was used as the tracer to measure glucose uptake and Western blotting used to determine the expression and activity of proteins involved in glucose transport. It was found that 2.5, 5 and 10 µM of UA promoted glucose uptake in a dose-dependent manner (17%, 29% and 35%, respectively. 10 µM UA-induced glucose uptake with insulin stimulation was completely blocked by the phosphatidylinositol (PI 3-kinase (PI3K inhibitor wortmannin (1 µM, but not by SB203580 (10 µM, the inhibitor of mitogen-activated protein kinase (MAPK, or compound C (2.5 µM, the inhibitor of AMP-activated kinase (AMPK inhibitor. Furthermore, the downstream protein activities of the PI3K pathway, phosphoinositide-dependent kinase (PDK and phosphoinositide-dependent serine/threoninekinase (AKT were increased by 10 µM of UA in the presence of insulin. Interestingly, the activity of AS160 and protein kinase C (PKC and the expression of glucose transporter 4 (GLUT4 were stimulated by 10 µM of UA under either the basal or insulin-stimulated status. Moreover, the translocation of GLUT4 from cytoplasm to cell membrane was increased by UA but decreased when the PI3K inhibitor was applied. CONCLUSIONS: Our results suggest that UA stimulates glucose uptake in 3T3-L1 adipocytes through the PI3K pathway, providing important information regarding the mechanism of action of UA for its anti-diabetic effect.

  10. Cold stress-induced brain injury regulates TRPV1 channels and the PI3K/AKT signaling pathway.

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    Liu, Ying; Liu, Yunen; Jin, Hongxu; Cong, Peifang; Zhang, Yubiao; Tong, Changci; Shi, Xiuyun; Liu, Xuelei; Tong, Zhou; Shi, Lin; Hou, Mingxiao

    2017-09-01

    Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel that interacts with several intracellular proteins in vivo, including calmodulin and Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/Akt). TRPV1 activation has been reported to exert neuroprotective effects. The aim of this study was to examine the impact of cold stress on the mouse brain and the underlying mechanisms of TRPV1 involvement. Adult male C57BL/6 mice were subjected to cold stress (4°C for 8h per day for 2weeks). The behavioral deficits of the mice were then measured using the Morris water maze. Expression levels of brain injury-related proteins and mRNA were measured by western blot, immunofluorescence or RT-PCR analysis. The mice displayed behavioral deficits, inflammation and changes in brain injury markers following cold stress. As expected, upregulated TRPV1 expression levels and changes in PI3K/Akt expression were found. The TRPV1 inhibitor reduced the levels of brain injury-related proteins and inflammation. These data suggest that cold stress can induce brain injury, possibly through TRPV1 activation and the PI3K/Akt signaling pathway. Suppression of inflammation by inhibition of TRPV1 and the PI3K/Akt pathway may be helpful to prevent cold stress-induced brain injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Non-genomic actions of retinoic acid induce pi3k signaling pathway and phosphorylation of nuclear proteins

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    Laserna Mendieta, Emilio J.; Masiá, Susana; Barettino, Domingo

    2007-01-01

    Retinoic acid (RA), the active form of vitamin A, induces neuroblastoma cells SH-SY5Y to differentiate. In addition to its classical transcriptional actions regulating the expression of specific genes, RA acts in an extra-genomic way, modulating the activity of relevant signalling cascades. In particular, RA treatment of SH-SY5Y neuroblastoma cells results in activation of phosphatidyl-inositol-3-kinase (PI3K) signaling pathway, and this activation is required for RA-induced differentiation (...

  12. Induction of cyclooxygenase-2 in macrophages by catalase: role of NF-kappaB and PI3K signaling pathways.

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    Jang, Byeong-Churl; Kim, Do-Hyun; Park, Jong-Wook; Kwon, Taeg Kyu; Kim, Sang-Pyo; Song, Dae-Kyu; Park, Jong-Gu; Bae, Jae-Hoon; Mun, Kyo-Chul; Baek, Won-Ki; Suh, Min-Ho; Hla, Timothy; Suh, Seong-Il

    2004-04-02

    Induction of COX-2 by catalase in smooth muscle cells, endothelial cells, and neuronal cells has been previously reported. However, the mechanism by which catalase up-regulates COX-2 remains poorly understood. In this study, we investigated the effect of catalase on induction of COX-2 in macrophages. The addition of catalase into Raw 264.7 macrophages induced COX-2 expression that was correlated with increased COX-2 transcription and mRNA stability. Catalase also induced activation of NF-kappaB, PI3K, ERKs, p38s, or JNKs. Catalase-induced COX-2 expression was abrogated by treatment of MG-132 (a NF-kappaB inhibitor) or LY294002 (a PI3K inhibitor), but not by treatment of PD98059 (an ERK inhibitor), SB203580 (a p38 inhibitor), or SP600125 (a JNK inhibitor). Moreover, inhibition of PI3K by LY294002 caused partial decrease of catalase-induced COX-2 transcription and steady-state COX-2 transcript levels, but not COX-2 mRNA stability. Together, these results suggest that catalase induces the expression of COX-2 in Raw 264.7 macrophages, and the induction is related with activation of NF-kappaB transcription factor and PI3K signaling pathway.

  13. [TLR2 modulates Staphylococcus aureus-induced inflammatory response and autophagy in macrophages through PI3K signaling pathway].

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    Li, Shuai; Fang, Lei; Wang, Jiong; Liu, Rongyu

    2017-09-01

    Objective To investigate the molecular mechanisms of Toll-like receptor 2 (TLR2) taking part in inflammatory response in Staphylococcus aureus (SA)-induced asthma. Methods We established the cell inflammatory response model through stimulating mouse RAW264.7 macrophages with SA. The TLR2, myeloid differentiation factor 88 (MyD88), phosphoinositide-3 kinase (PI3K), nuclear factor κBp65 (NF-κBp65), phospho-NF-κBp65, beclin-1 and microtubule-associated protein 1 light chain 3B (LC3B) were detected by Western blot analysis after treatment with TLR2 small interfering RNA (siRNA) and 3-methyladenine (3-MA), and the tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were determined by ELISA. In addition, the number of autolysosomes was observed by the laser scanning confocal microscope. Results SA-stimulated macrophages activated various signaling pathways including TLR2. TLR2 siRNA markedly repressed the expressions of PI3K, phospho-NF-κBp65, the autophagy protein beclin-1 and LC3B as well as the number of autolysosomes and the production of TNF- and IL-6. We also demonstrated that 3-MA had the same effect on autophagy and inflammation as TLR2 siRNA did. Conclusion TLR2 modulates SA-induced inflammatory response and autophagy in macrophages through PI3K signaling pathway.

  14. Insulin and the PI3K/AKT Signaling Pathway Regulate Ribonuclease 7 Expression in the Human Urinary Tract

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    Eichler, Tad; Becknell, Brian; Easterling, Robert S.; Ingraham, Susan E.; Cohen, Daniel M.; Schwaderer, Andrew; Hains, David S.; Li, Birong; Cohen, Ariel; Metheny, Jackie; Trindandapani, Susheela; Spencer, John David

    2017-01-01

    Diabetes mellitus is a systemic disease associated with a deficiency of insulin production or action. Diabetic patients have an increased susceptibility to infection with the urinary tract being the most common site of infection. Recent studies suggest that Ribonuclease 7 (RNase 7) is a potent antimicrobial peptide that plays an important role in protecting the urinary tract from bacterial insult. The impact of diabetes on RNase 7 expression and function are unknown. Here, we investigate the effects of insulin on RNase 7. Using human urine specimens, we measured urinary RNase 7 concentrations in healthy control patients and insulin-deficient type 1 diabetics before and after starting insulin therapy. Compared to controls, diabetic patients had suppressed urinary RNase 7 concentrations, which increased with insulin. Using primary human urothelial cells, we explored the mechanisms by which insulin induces RNase 7. Insulin induces RNase 7 production via the phosphatidylinositide 3-kinase signaling pathway (PI3K/AKT) to shield urothelial cells from uropathogenic E. coli. In contrast, we show that uropathogenic E. coli suppresses PI3K/AKT and RNase 7. Together, these results indicate that insulin and PI3K/AKT signaling are essential for RNase 7 expression. They also suggest that increased infection risks in diabetic patients may be secondary to suppressed RNase 7 production. These data may provide unique insight into novel UTI therapeutic strategies in at risk populations. PMID:27401534

  15. The Effect of Tianmai Xiaoke Pian on Insulin Resistance through PI3-K/AKT Signal Pathway

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    Nana Wang

    2016-01-01

    Full Text Available In the clinical setting, given the potential adverse effects of thiazolidinediones and biguanides, we often have difficulty in treatment that no other insulin sensitizers are available for use in type 2 diabetic mellitus (T2DM patients. Tianmai Xiaoke Pian (TMXKP is a traditional Chinese medicine tablet, which is comprised of chromium picolinate, Tianhuafen, Maidong, and Wuweizi. To understand its mechanism of action on insulin resistance, TMXKP (50 mg/kg orally was tested in T2DM rats (induced by a high-fat diet and streptozotocin. Eight weeks later, fasting blood glucose (FBG and oral glucose tolerance tests (OGTT were performed. Area under the curve (AUC and homeostatic model assessment of insulin resistance (HOMA-IR were calculated, and PI3-K/AKT signal pathway-related genes and proteins were tested by reverse transcription-polymerase chain reaction (RT-PCR and western blot analysis in muscle, adipose, and liver tissues, respectively. TMXKP significantly reduced FBG, OGTT, AUC, and HOMA-IR in diabetic rats P<0.05. Furthermore, we also observed that TMXKP could significantly decrease IRS-1, IRS-2, PI3-K p85α, and AKT2 gene expression and also IRS-1, IRS-2, PI3-K, AKT2, and p-AKT2 protein expression levels P<0.05 in diabetic rats. These findings confirm that TMXKP can alleviate insulin resistance in T2DM rats through the PI3K/AKT pathway. Thus TMXKP appears to be a promising insulin sensitizer.

  16. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes.

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    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-11-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.

  17. Layered double hydroxide nanoparticles promote self-renewal of mouse embryonic stem cells through the PI3K signaling pathway

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    Wu, Youjun; Zhu, Rongrong; Zhou, Yang; Zhang, Jun; Wang, Wenrui; Sun, Xiaoyu; Wu, Xianzheng; Cheng, Liming; Zhang, Jing; Wang, Shilong

    2015-06-01

    Embryonic stem cells (ESCs) hold great potential for regenerative medicine due to their two unique characteristics: self-renewal and pluripotency. Several groups of nanoparticles have shown promising applications in directing the stem cell fate. Herein, we investigated the cellular effects of layered double hydroxide nanoparticles (LDH NPs) on mouse ESCs (mESCs) and the associated molecular mechanisms. Mg-Al-LDH NPs with an average diameter of ~100 nm were prepared by hydrothermal methods. To determine the influences of LDH NPs on mESCs, cellular cytotoxicity, self-renewal, differentiation potential, and the possible signaling pathways were explored. Evaluation of cell viability, lactate dehydrogenase release, ROS generation and apoptosis demonstrated the low cytotoxicity of LDH NPs. The alkaline phosphatase activity and the expression of pluripotency genes in mESCs were examined, which indicated that exposure to LDH NPs could support self-renewal and inhibit spontaneous differentiation of mESCs under feeder-free culture conditions. The self-renewal promotion was further proved to be independent of the leukemia inhibitory factor (LIF). Furthermore, cells treated with LDH NPs maintained the potential to differentiate into all three germ layers both in vitro and in vivo through formation of embryoid bodies and teratomas. In addition, we observed that LDH NPs initiated the activation of the PI3K/Akt pathway, while treatment with the PI3K inhibitor LY294002 could block the effects of LDH NPs on mESCs. The results confirmed that the promotion of self-renewal by LDH NPs was associated with activation of the PI3K/Akt signaling pathway. Altogether, our studies identified a new role of LDH NPs in maintaining self-renewal of mouse ES cells which could potentially be applied in stem cell research.Embryonic stem cells (ESCs) hold great potential for regenerative medicine due to their two unique characteristics: self-renewal and pluripotency. Several groups of nanoparticles

  18. Acacetin protects against cardiac remodeling after myocardial infarction by mediating MAPK and PI3K/Akt signal pathway

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    Wei Chang

    2017-12-01

    Full Text Available Since inhibiting cardiac remodeling is a critical treatment goal after myocardial infarction (MI, many drugs have been evaluated for this purpose. Acacetin is a flavonoid compound that has been shown to have anti-cancer, anti-mutagenic, anti-inflammatory and anti-peroxidative effects. In this study, we investigated whether acacetin is able to exert a protective effect against MI. One week after anterior wall standard MI surgeries or sham surgeries were performed in mice, acacetin was administered via gavage for two weeks. The results of echocardiographic and hemodynamic evaluation revealed that cardiac dysfunction significantly improved after acacetin treatment. H&E staining indicated that the ratio of the infarct size and the cardiomyocyte cross-sectional area was decreased by acacetin. Masson's staining detected that the fibrotic area ratio was evidently lower in the acacetin-treated MI group. TUNEL assays showed that acacetin ameliorated cardiomyocyte apoptosis after MI. RT-qPCR analysis showed that levels of hypertrophic and fibrotic markers were significantly decreased after acacetin treatment. Western blot analysis of various signaling pathway proteins showed that acacetin targets the MAPK and PI3K/Akt signaling pathways. Collectively, acacetin improves mouse left ventricular function and attenuates cardiac remodeling by inhibiting of the MAPK and PI3K/Akt signaling pathway.

  19. Cryptotanshinone exhibits therapeutical effects on cerebral stroke through the PI3K/AKT‑eNOS signaling pathway.

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    Zhu, Weixin; Qiu, Weihong; Lu, Ailan

    2017-12-01

    Cerebral stroke is a kind of acute cerebrovascular disease with high incidence, morbidity and disability. Treatments against various types of cerebral stroke are limited at preventive measurements due to the lack of effective therapeutic method. The present study aimed to investigate the protective effect of cryptotanshinone (CPT) on cerebral stroke, and investigate the possible mechanism involved in order to develop a novel therapy against stoke. The phosphoinositide 3‑kinase membrane translocation of cerebral stroke rats pretreated with CPT at various concentrations were measured, as well as the phosphorylation of protein kinase B (AKT) and endothelial nitric oxide synthase (eNOS). Additionally, the expression level of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax) and vascular endothelial growth factor were also assessed using western blotting and reverse transcription‑quantitative polymerase chain reaction. Furthermore, biochemical tests were used to measure the activity of superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) in both the cerebral cortex and peripheral blood. As a result, CPT‑pretreated rats presented declined phosphoinositide 3‑kinase (PI3K) and AKT expression levels, indicating that the PI3K/AKT signaling pathway was inhibited. Increased Bcl‑2 and NO levels in both the cerebral cortex and peripheral blood demonstrated the anti‑apoptosis and blood vessel protection effect of CPT. Furthermore, increased SOD activity and declined MDA levels demonstrated suppressed lipid peroxidation. In conclusion, CPT exhibited a protective effect against cerebral stroke through inhibition of the PI3K/AKT‑eNOS signaling pathway. These results suggested the potential of CPT as a promising agent in the treatment of cerebral stroke.

  20. The role of the PI3K-Akt signal transduction pathway in Autographa californica multiple nucleopolyhedrovirus infection of Spodoptera frugiperda cells

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    Xiao Wei; Yang Yi; Weng Qingbei; Lin Tiehao; Yuan Meijin; Yang Kai; Pang Yi

    2009-01-01

    Many viruses activate the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway, thereby modulating diverse downstream signaling pathways associated with antiapoptosis, proliferation, cell cycling, protein synthesis and glucose metabolism, in order to augment their replication. To date, the role of the PI3K-Akt pathway in Baculovirus replication has not been defined. In the present study, we demonstrate that infection of Sf9 cells with Autographa californica multiple nucleopolyhedrovirus (AcMNPV) elevated cellular Akt phosphorylation at 1 h post-infection. The maximum Akt phosphorylation occurred at 6 h post-infection and remained unchanged until 18 h post-infection. The PI3K-specific inhibitor, LY294002, suppressed Akt phosphorylation in a dose-dependent manner, suggesting that AcMNPV-induced Akt phosphorylation is PI3K-dependent. The inhibition of PI3K-Akt activation by LY294002 significantly reduced the viral yield, including a reduction in budded viruses and occlusion bodies. The virus production was reduced only when the inhibitor was added within 24 h of infection, implying that activation of PI3K occurred early in infection. Correspondingly, both viral DNA replication and late (VP39) and very late (POLH) viral protein expression were impaired by LY294002 treatment; LY294002 had no effect on immediate-early (IE1) and early-late (GP64) protein expression. These results demonstrate that the PI3K-Akt pathway is required for efficient Baculovirus replication.

  1. Isorhynchophylline Protects PC12 Cells Against Beta-Amyloid-Induced Apoptosis via PI3K/Akt Signaling Pathway

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    Xian, Yan-Fang; Lin, Zhi-Xiu; Mao, Qing-Qiu; Chen, Jian-Nan; Su, Zi-Ren; Lai, Xiao-Ping; Ip, Paul Siu-Po

    2013-01-01

    The neurotoxicity of amyloid-β (Aβ) has been implicated as a critical cause of Alzheimer's disease. Isorhynchophylline (IRN), an oxindole alkaloid isolated from Uncaria rhynchophylla, exerts neuroprotective effect against Aβ 25–35-induced neurotoxicity in vitro. However, the exact mechanism for its neuroprotective effect is not well understood. The present study aimed to investigate the molecular mechanisms underlying the protective action of IRN against Aβ 25–35-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. Pretreatment with IRN significantly increased the cell viability, inhibited the release of lactate dehydrogenase and the extent of DNA fragmentation in Aβ 25–35-treated cells. IRN treatment was able to enhance the protein levels of phosphorylated Akt (p-Akt) and glycogen synthase kinase-3β (p-GSK-3β). Lithium chloride blocked Aβ 25–35-induced cellular apoptosis in a similar manner as IRN, suggesting that GSK-3β inhibition was involved in neuroprotective action of IRN. Pretreatment with LY294002 completely abolished the protective effects of IRN. Furthermore, IRN reversed Aβ 25–35-induced attenuation in the level of phosphorylated cyclic AMP response element binding protein (p-CREB) and the effect of IRN could be blocked by the PI3K inhibitor. These experimental findings unambiguously suggested that the protective effect of IRN against Aβ 25–35-induced apoptosis in PC12 cells was associated with the enhancement of p-CREB expression via PI3K/Akt/GSK-3β signaling pathway. PMID:24319473

  2. Expression of factors and key components associated with the PI3K signaling pathway in colon cancer.

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    Chen, Hua; Gao, Junyi; Du, Zhenhua; Zhang, Xuequn; Yang, Fei; Gao, Wei

    2018-04-01

    The pathophysiology of colorectal cancer (CRC) has not been fully elucidated. The dysregulation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway frequently contributes to the tumorigenesis and progression of human cancer. The aim of the present study was to explore the expression and clinical significance of a number of associated factors and key components of the PI3K signaling pathway, including phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (p110α), phosphorylated protein kinase B (p-Akt) Ser473, p-mammalian target of rapamycin (mTOR) Ser2448, cyclin D1, cyclin dependent kinase (CDK)4, RELA proto-oncogene, nuclear factor-κβ subunit (p65), Ras and extracellular signal-regulated kinase (ERK)1/2 in human CRC. The expression of target proteins was detected using immunohistochemistry (IHC) in 65 CRC cases and 15 colonic adenoma cases. The association between the expression of target proteins and clinical pathological parameters was analyzed using a χ 2 test. IHC results revealed that the expression of all target proteins was significantly increased in CRC tissues compared with in colonic adenoma tissues (P0.05). Cyclin D1, CDK4 and Ras were revealed to be expressed significantly higher in poorly differentiated CRC compared with moderately differentiated CRC (Pcancer tissues with lymph node metastasis compared with cancer tissues without lymph node metastasis (P<0.05). These results suggest that the target proteins may all participate in the tumorigenesis of CRC. Furthermore, cyclin D1, CDK4, Ras, p65 and ERK1/2 may be important in the progression of CRC. The results of the present study may provide novel predictive factors and therapeutic targets for CRC.

  3. Glucose-induced lipid deposition in goose primary hepatocytes is dependent on the PI3K-Akt-mTOR signaling pathway

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    Han Chunchun

    2016-01-01

    Full Text Available Previously we showed that fatty liver formation in overfed geese was accompanied by PI3K-Akt-mTOR pathway activation and changes in plasma glucose concentrations. Here, we show that glucose acts in goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway. We observed that glucose increased lipogenesis, decreased fatty acid oxidation and increased very low density lipoprotein triglyceride (VLDL-TG assembly and secretion. Co-treatment with glucose and inhibitors of the PI3K-Akt-mTOR pathway (LY294002, rapamycin, NVP-BEZ235 decreased the levels of factors involved in lipogenesis and increased the levels of factors involved in fatty acid oxidation and VLDL-TG assembly and secretion. These findings show that inhibition of the PI3K-Akt-mTOR pathway decreased glucose-induced lipogenesis, inhibited the downregulation of fatty acid oxidation by glucose and increased the upregulation of VLDL-TG assembly and secretion by glucose. The results presented herein provide further support for the role of the PI3K-Akt-mTOR pathway in lipid metabolism as we showed that in goose primary hepatocytes, glucose acts through the PI3K-Akt-mTOR-dependent pathway to stimulate lipid deposition by increasing lipogenesis and decreasing fatty acid oxidation and VLDL-TG assembly and secretion.

  4. nm23 regulates decidualization through the PI3K-Akt-mTOR signaling pathways in mice and humans.

    Science.gov (United States)

    Zhang, Xue; Fu, Li-Juan; Liu, Xue-Qing; Hu, Zhuo-Ying; Jiang, Yu; Gao, Ru-Fei; Feng, Qian; Lan, Xi; Geng, Yan-Qing; Chen, Xue-Mei; He, Jun-Lin; Wang, Ying-Xiong; Ding, Yu-Bin

    2016-10-01

    Does nm23 have functional significance in decidualization in mice and humans? nm23 affects decidualization via the phosphoinositide 3 kinase/mammalian target of rapamycin (PI3K-Akt-mTOR) signaling pathways in mouse endometrial stromal cells (ESCs; mESCs) and human ESCs. The function of nm23 in suppressing metastasis has been demonstrated in a variety of cancer types. nm23 also participates in the control of DNA replication and cell proliferation and differentiation. We first analyzed the expression profile of nm23 in mice during early pregnancy (n = 6/group), pseudopregnancy (n = 6/group) and artificial decidualization (n = 6/group) and in humans during the menstrual cycle phases and the first trimester. We then used primary cultured mESCs and a human ESC line, T-HESC, to explore the hormonal regulation of nm23 and the roles of nm23 in in vitro decidualization, and as a possible mediator of downstream PI3K-Akt-mTOR signaling pathways. We evaluated the dynamic expression of nm23 in mice and humans using immunohistochemistry, western blot and real-time quantitative RT-PCR (RT-qPCR). Regulation of nm23 by steroid hormones was investigated in isolated primary mESCs and T-HESCs by western blot. The effect of nm23 knockdown (using siRNA) on ESC proliferation was analyzed by 5-ethynyl-2'-deoxyuridine staining (EdU) and proliferating cell nuclear antigen protein (PCNA) expression. The influence of nm23 expression on the differentiation of ESCs was determined by RT-qPCR using the mouse differentiation markers decidual/trophoblast PRL-related protein (dtprp, also named prl8a2) and prolactin family 3 subfamily c member 1 (prl3c1) and the human differentiation markers insulin-like growth factor binding protein 1 (IGFBP1) and prolactin (PRL). The effects of nm23 siRNA (si-nm23) and the PI3K inhibitor LY294002 on the downstream effects of nm23 on the PI3K-Akt-mTOR signaling pathway were estimated by western blot. NM23-M1 was specifically expressed in the decidual zone

  5. Study on the relationship between PI3K/AKT signaling pathway and apoptosis in cartilage tissue of rats with osteoarthritis

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    Xiao-Yan Li

    2017-05-01

    Full Text Available Objective: To study the relationship between PI3K/AKT signaling pathway and apoptosis in cartilage tissue of rats with osteoarthritis (OA. Methods: The clean male Wistar rats were selected as experimental animals and randomly divided into OA model group and control group. The OA model was established by intra-articular injection of papain solution and L-cysteine. Fourth weeks and eighth weeks after model establishment, the expression of PI3K/AKT signaling molecules, inflammatory mediators, apoptosis marker molecules and autophagy marker molecules in articular cartilage were determined. Results: p-PI3K and p-AKT expression in articular cartilage of OA group were significantly lower than those of control group; IL-1β, IL-6, IL-17, IL-18, eIF4E, Bax, Caspase-3, mTOR, Beclin1, Atg5 and Atg7 expression in articular cartilage of OA group were significantly higher than those of control group and negatively correlated with p-PI3K and p-AKT expression while Bcl-2 expression in articular cartilage of OA group was significantly lower than that of control group and positively correlated with p-PI3K and p-AKT expression. Conclusion: The inhibition of PI3K/AKT signaling pathway in cartilage tissue of OA rat model can promote chondrocyte apoptosis and autophagy.

  6. Isorhynchophylline Protects PC12 Cells Against Beta-Amyloid-Induced Apoptosis via PI3K/Akt Signaling Pathway

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    Yan-Fang Xian

    2013-01-01

    Full Text Available The neurotoxicity of amyloid-β (Aβ has been implicated as a critical cause of Alzheimer’s disease. Isorhynchophylline (IRN, an oxindole alkaloid isolated from Uncaria rhynchophylla, exerts neuroprotective effect against Aβ25–35-induced neurotoxicity in vitro. However, the exact mechanism for its neuroprotective effect is not well understood. The present study aimed to investigate the molecular mechanisms underlying the protective action of IRN against Aβ25–35-induced neurotoxicity in cultured rat pheochromocytoma (PC12 cells. Pretreatment with IRN significantly increased the cell viability, inhibited the release of lactate dehydrogenase and the extent of DNA fragmentation in Aβ25–35-treated cells. IRN treatment was able to enhance the protein levels of phosphorylated Akt (p-Akt and glycogen synthase kinase-3β (p-GSK-3β. Lithium chloride blocked Aβ25–35-induced cellular apoptosis in a similar manner as IRN, suggesting that GSK-3β inhibition was involved in neuroprotective action of IRN. Pretreatment with LY294002 completely abolished the protective effects of IRN. Furthermore, IRN reversed Aβ25–35-induced attenuation in the level of phosphorylated cyclic AMP response element binding protein (p-CREB and the effect of IRN could be blocked by the PI3K inhibitor. These experimental findings unambiguously suggested that the protective effect of IRN against Aβ25–35-induced apoptosis in PC12 cells was associated with the enhancement of p-CREB expression via PI3K/Akt/GSK-3β signaling pathway.

  7. Signaling through the PI 3-K, Akt and SGK Pathway in Breast Cancer Progression

    Science.gov (United States)

    2013-12-01

    Moritz A, Li Y, Guo A, Villen J, Wang Y, MacNeill J, et al. Akt-RSK-S6 Kinase 552 Signaling Networks Activated by Oncogenic Receptor Tyrosine Kinases. Sci...polarity by afadin during the formation of embryoid bodies. Genes Cells. 2008;13:79– 570 90. 571 23. Su L, Hattori M, Moriyama M, Murata N, Harazaki M

  8. The effect of Liuwei Dihuang decoction on PI3K/Akt signaling pathway in liver of type 2 diabetes mellitus (T2DM) rats with insulin resistance.

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    Dai, Bing; Wu, Qinxuan; Zeng, Chengxi; Zhang, Jiani; Cao, Luting; Xiao, Zizeng; Yang, Menglin

    2016-11-04

    Liuwei Dihaung decoction (LWDHT) is a well-known classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch.(family: Scrophulariaceae), Cornus officinalis Sieb.(family: Cornaceae), Dioscorea opposite Thunb.(family: Dioscoreaceae), Alisma orientale(G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys in China clinically. This study is aimed at investigating the effect of Liuwei dihuang decoction on PI3K/Akt signaling pathway in liver of T2DM rats with insulin resistance. T2DM model was induced in male Sprague-Dawley (SD) rats by high sugar and high fat diets combined with small dose of streptozocin (STZ) injection. The successful T2DM rats were randomly allocated three group--vehicle group, positive control group and Liuwei Dihuang decoction group. After 12-weeks treatment with distilled water, rosiglitazone and LWDHT by intragastric administration respectively, the rats were put to death in batches. The variance of fasting blood glucose (FBG) and fasting insulin (FINS) in serum were determined, the pathological changes of each rats' liver were observed by hematoxylin-eosin (HE) staining, the expression of insulin receptor substrate 2(IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinas B (Akt) involving the canonical PI3K/Akt signaling pathway were detected by Real-time fluorescent quantitative PCR (RT-PCR), and the expression level of IRS2, PI3K, Akt protein and phosphorylated IRS2, PI3K, Akt protein were evaluated by Western Blot. All the data were analyzed by SPSS 17.0. Four weeks of treatment with LWDHT could significantly decrease the level of FBG and FINS in serum, improve the cellular morphology of liver, kidney, pancreas tissue, and the expression of IRS2, PI3K, Akt mRNA and phosphorylated IRS2, PI3K, Akt

  9. Combinatorial therapy with adenoviral-mediated PTEN and a PI3K inhibitor suppresses malignant glioma cell growth in vitro and in vivo by regulating the PI3K/AKT signaling pathway.

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    Nan, Yang; Guo, Liyun; Song, Yunpeng; Wang, Le; Yu, Kai; Huang, Qiang; Zhong, Yue

    2017-08-01

    Glioblastoma is a highly invasive and challenging tumor of the central nervous system. The mutation/deletion of the tumor suppressor phosphatase and tensin homolog (PTEN) gene is the main genetic change identified in glioblastomas. PTEN plays a critical role in tumorigenesis and has been shown to be an important therapeutic target. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 is commonly used to inhibit glioma cell growth via regulation of the PI3K/AKT signaling pathway. In this study, we examined the growth inhibitory effects of a combinatorial therapy of adenoviral-mediated PTEN (Ad-PTEN) and LY294002 on LN229 and U251 glioma cells in vitro and on tumor xenografts in vivo. In vitro, LN229 and U251 glioma cells were treated by combinatorial therapy with Ad-PTEN and LY294002. The growth ability was determined by MTT assay. The cell cycle distribution was analyzed by flow cytometry. Cell invasive ability was analyzed by transwell invasion assay and cell apoptosis analysis via FITC-Annexin V analysis. In vivo, U251 subcutaneous glioblastoma xenograft was used to assay anti-tumor effect of combinatorial therapy with Ad-PTEN and LY294002 by mean volume of tumors, immunohistochemistry and TUNEL method. The combinatorial treatment clearly suppressed cell proliferation, arrested the cell cycle, reduced cell invasion and promoted cell apoptosis compared with the Ad-PTEN or LY294002 treatment alone. The treatment worked by inhibiting the PI3K/AKT pathway. In addition, the growth of U251 glioma xenografts treated with the combination of Ad-PTEN and LY294002 was significantly inhibited compared with those treated with Ad-PTEN or LY294002 alone. Our data indicated that the combination of Ad-PTEN and LY294002 effectively suppressed the malignant growth of human glioma cells in vitro and in tumor xenografts, suggesting a promising new approach for glioma gene therapy that warrants further investigation.

  10. Protective Effect of Tempol on Acute Kidney Injury Through PI3K/Akt/Nrf2 Signaling Pathway

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    Gensheng Zhang

    2016-02-01

    Full Text Available Background/Aims: Tempol is a protective antioxidant against ischemic injury in many animal models. The molecular mechanisms are not well understood. Nuclear factor erythroid 2-related factor (Nrf2 is a master transcription factor during oxidative stress, which is enhanced by activation of protein kinase C (PKC pathway. Another factor, tubular epithelial apoptosis, is mediated by activation of phosphoinositide 3-kinase (PI3K/protein kinase B (PKB, Akt signaling pathway during renal ischemic injury. We tested the hypothesis that tempol activates PKC or PI3K/Akt/Nrf2 pathways to transcribe many genes that coordinate endogenous antioxidant defense. Methods: The right renal pedicle was clamped for 45 minutes and the left kidney was removed to study renal ischemia/reperfusion (I/R injury in C57BL/6 mice. The response was assessed from serum parameters, renal morphology and renal expression of PKC, phosphorylated-PKC (p-PKC, Nrf2, heme oxygenase-1 (HO-1, Akt, phosphorylated-Akt (p-Akt, pro-caspase-3 and cleaved caspase-3 in groups of sham and I/R mice given vehicle, or tempol (50 or 100 mg/kg, intraperitoneal injection. Results: The serum malondialdehyde (MDA, marker of reactive oxygen species doubled and the BUN and creatinine increased 5- to 10-fold after I/R injury. Tempol (50 or 100 mg/kg prevented the increases in MDA but only tempol (50 mg/kg lessened the increases in BUN and creatinine and moderated the acute tubular necrosis. I/R did not change expression of PKC or p-PKC but reduced renal expression of Nrf2, p-Akt, HO-1 and pro-caspase-3 and increased cleaved caspase-3. Tempol (50 mg/kg prevented these changes produced by I/R whereas tempol (100 mg/kg had lesser or inconsistent effects. Conclusion: Tempol (50 mg/kg prevents lipid peroxidation and attenuates renal damage after I/R injury. The beneficial pathway apparently is not dependent on upregulation or phosphorylation of PKC, at lower tempol doses, does implicate upregulation of Akt with

  11. BMI-1 suppression increases the radiosensitivity of oesophageal carcinoma via the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Yang, Xing-Xiao; Ma, Ming; Sang, Mei-Xiang; Zhang, Xue-Yuan; Liu, Zhi-Kun; Song, Heng; Zhu, Shu-Chai

    2018-02-01

    BMI-1 knockdown, while the kinase agonist IGF-1 reversed the effects of BMI-1 knockdown on cell viability and radiosensitivity. Taken together, BMI-1 knockdown induces radiosensitivity in ESCC and significantly inhibits cell viability, which may contribute to an increased proportion of cells in the G0/G1 phase and cell apoptosis via suppression of the PI3K/Akt signalling pathway.

  12. PDGF Promotes the Warburg Effect in Pulmonary Arterial Smooth Muscle Cells via Activation of the PI3K/AKT/mTOR/HIF-1α Signaling Pathway

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    Yunbin Xiao

    2017-07-01

    Full Text Available Background/Aims: The enhanced proliferation of pulmonary arterial smooth muscle cells (PASMCs is a central pathological component in pulmonary arterial hypertension (PAH. Both the Warburg effect and platelet-derived growth factor (PDGF are involved in the proliferation of PASMCs. However, the mechanism underlying the crosstalk between the Warburg effect and PDGF during PASMC proliferation is still unknown. We hypothesized that PDGF promotes the Warburg effect via activating the phosphatidylinositol 3-kinase (PI3K signaling pathway and hypoxia-inducible factor 1-α (HIF-1α in proliferative PASMCs. Methods: PASMCs were derived from pulmonary arteries of SD rats; cell viability, the presence of metabolites, and metabolic enzyme activities assay were determined by MTT assays, kit assays and western blot analysis, respectively. Results: PDGF promoted PASMC proliferation in a dose- and time-dependent manner, accompanied by an enhanced Warburg effect. Treatment with PDGFR antagonists, Warburg effect inhibitor and PDK1 inhibitor significantly inhibited PI3K signaling activation, HIF-1α expression and PASMC proliferation induced by PDGF, respectively. Furthermore, treatment with PI3K signaling pathway inhibitors remarkably suppressed PDGF-induced PASMC proliferation and the Warburg effect. Conclusion: microplate reader (Biotek, Winooski The Warburg effect plays a critical role in PDGF-induced PASMC proliferation and is mediated by activation of the PI3K signaling pathway and HIF-1α.

  13. Effect of Qufengtongluo Decoction on PI3K/Akt Signaling Pathway in the Kidney of Type 2 Diabetes Mellitus Rat (GK Rat with Diabetic Nephropathy

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    Wei-Jun Huang

    2018-01-01

    Full Text Available Qufengtongluo (QFTL decoction is an effective treatment for diabetic nephropathy (DN. However, the underlying molecular mechanism is still unclear. In this study, we try to investigate whether QFTL decoction acts via inhibiting PI3K/Akt signaling pathway. Twenty-four GK rats were randomly divided into 3 groups: blank group, sham-operated group, and QFTL group. After model establishment, rats in QFTL group were given QFTL decoction by gavage, while the rest were given pure water. During the 8-week intervention, 24 hr urinal protein was measured every 2-3 weeks. After intervention, kidneys were removed for pathological smear, quantitative real-time PCR, and western blotting to detect expression levels of p-PI3K, p-Akt, PTEN, TGF-β, PI3K mRNA, Akt mRNA, PTEN mRNA, and TGF-β mRNA. QFTL group showed a slighter degree of renal fibrosis in Masson and PASM staining and a greater reduction of 24 hr urinal protein than blank group. Compared to blank group, expression levels of p-PI3K, p-Akt, PI3K mRNA, and Akt mRNA were lower in QFTL group, while expression levels of PTEN and PTEN mRNA were higher. Besides, TGF-β was downregulated by QFTL decoction. In conclusion, this study suggests that QFTL decoction might inhibit PI3K/Akt signaling pathway via activating PTEN and inhibiting TGF-β.

  14. TRIM24 promotes glioma progression and enhances chemoresistance through activation of the PI3K/Akt signaling pathway.

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    Zhang, L-H; Yin, A-A; Cheng, J-X; Huang, H-Y; Li, X-M; Zhang, Y-Q; Han, N; Zhang, X

    2015-01-29

    The tripartite motif protein TRIM24 (tripartite motif-containing 24) has been found to play distinct roles in tumor development and progression, according to different tumor contexts. However, it remains elusive whether TRIM24 plays a role in malignant gliomas that are the most common and deadly primary brain tumors in adults. We report here that TRIM24 expression is positively correlated with glioma malignancy and is negatively associated with prognosis of patients with newly diagnosed glioblastoma, which is the most malignant form of gliomas but displays highly heterogeneous clinical outcome. The multivariate Cox regression analysis demonstrates the independent predictive value of TRIM24 expression level for overall and progression-free survival. Knockdown of TRIM24 suppresses cell proliferation, cell cycle progression, clone formation and in vivo tumor development, whereas overexpression of TRIM24 promotes cell growth. Chromatin immunoprecipitation, real-time reverse transcription-PCR and mutation analyses demonstrate that TRIM24 binds to the PIK3CA promoter via its PHD-Bromo domain to activate the transcription of PIK3CA gene, thus enhancing phosphatidylinositide 3-kinase (PI3K)/Akt signaling. The pan-PI3K inhibitor LY294002 and small interfering RNA targeting PIK3CA both abrogate the growth-promoting effect of TRIM24. Moreover, TRIM24 regulates the expression of DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) through PI3K/Akt/nuclear factor-κB signaling transduction and enhances resistance to temozolomide, the standard chemotherapeutic agent for glioblastoma. Finally, glioblastoma patients with low TRIM24 expression benefit from chemotherapy, whereas those with high TRIM24 expression do not have such benefit. Our results suggest that TRIM24 might serve as a potential prognostic marker and therapeutic target for the management of malignant gliomas.

  15. Endothelium-Dependent Relaxation Effect of Apocynum venetum Leaf Extract via Src/PI3K/Akt Signalling Pathway

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    Yeh Siang Lau

    2015-06-01

    Full Text Available Botanical herbs are consumed globally not only as an essential diet but also as medicines or as functional/recreational food supplements. The extract of the Apocynum venetum leaves (AVLE, also known as Luobuma, exerts its antihypertensive effect via dilating the blood vessels in an endothelium- and concentration-dependent manner with optimal effect seen at as low as 10 µg/mL. A commercial Luoboma “antihypertensive tea” is available commercially in the western province of China. The present study seeks to investigate the underlying cellular mechanisms of the nitric oxide (NO-releasing property of AVLE in rat aortas and human umbilical vein endothelial cells (HUVECs. Endothelium-dependent relaxation induced by AVLE was assessed in organ chambers in the presence or absence of polyethyleneglycol catalase (PP2, 20 µM; inhibitor of Src kinase, wortmannin (30 nM and LY294002 (20 µM; PI3 (phosphatidylinositol3-Kinase inhibitor, NG-nitro-l-arginine (L-NAME, 100 µM; endothelial NO synthase inhibitor (eNOS and ODQ (1 µM; soluble guanylyl cyclase inhibitor. Total nitrite and nitrate (NOx level and protein expression of p-Akt and p-eNOS were measured. AVLE-induced endothelium-dependent relaxation was reduced by PP2, wortmannin and LY294002 and abolished by L-NAME and ODQ. AVLE significantly increased total NOx level in rat aortas and in HUVECs compared to control. It also instigated phosphorylation of Akt and eNOS in cultured HUVECs in a concentration-dependent manner and this was markedly suppressed by PP2, wortmannin and LY294002. AVLE also inhibited superoxide generated from both NADPH oxidase and xanthine/xanthine oxidase system. Taken together, AVLE causes endothelium-dependent NO mediated relaxations of rat aortas through Src/PI3K/Akt dependent NO signalling pathway and possesses superoxide scavenging activity.

  16. Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes

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    Jae Kyoung Chae

    2017-02-01

    Full Text Available Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R, adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways.

  17. The Effect of Sanggua Drink Extract on Insulin Resistance through the PI3K/AKT Signaling Pathway

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    Yu Cai

    2018-01-01

    Full Text Available Treating type 2 diabetes mellitus (T2DM using thiazolidinediones and biguanides can present several challenges for patients. Sanggua Drink (SGD is a commonly used agent in traditional Chinese medicine, and it consists of Folium Mori, Fructus Momordicae Charantiae, Radix Puerariae Lobatae, and Rhizoma Dioscorea. The hypoglycemic effects and mechanisms of SGD extracts on insulin resistance in diabetic rats were investigated. SGD (1.24 g/kg orally was verified in T2DM rats induced by a high-fat diet and streptozotocin. The results showed that SGD treatment was observed to reduce fasting blood glucose, water and food intake, total cholesterol triglycerides, and LDL, OGTT, FINS, HOMA-IR, GHb, and MDA and increase hepatic glycogen, HDL, SOD, CAT, and GSH-Px in diabetic rats. Simultaneously, SGD treatment by T2DM showed significantly ameliorated pathological changes and reduced inflammation in the pancreas. Treatment was also observed to increase gene and protein expressions of InsR, IRS-2, PI3K, AKT, and Glut4 in the livers of diabetic treated rats. These results suggest that SGD extracts have hypoglycemic properties and may alleviate insulin resistance in T2DM rats through the PI3K/AKT pathway. Therefore, SGD appears to be a promising insulin sensitizer.

  18. Nephroprotective Effects of Polydatin against Ischemia/Reperfusion Injury: A Role for the PI3K/Akt Signal Pathway

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    Hong-Bao Liu

    2015-01-01

    Full Text Available Oxidative stress and inflammation are involved in the pathogenesis in renal ischemia/reperfusion (I/R injury. It has been demonstrated that polydatin processed the antioxidative, anti-inflammatory, and nephroprotective properties. However, whether it has beneficial effects and the possible mechanisms on renal I/R injury remain unclear. In our present study I/R models were simulated both in vitro and in vivo. Compared with vehicle control, the administration of polydatin significantly improved the renal function, accelerated the mitogenic response and reduced cell apoptosis in renal I/R injury models, strongly suppressed the I/R-induced upregulation of the expression of tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, inducible nitric oxide synthase, prostaglandin E-2, and nitric oxide levels, and dramatically decreased contents of malondialdehyde, but it increased the activity of superoxide dismutase, glutathione transferase, glutathione peroxidase and catalase, and the level of glutathione. Further investigation showed that polydatin upregulated the phosphorylation of Akt in kidneys of I/R injury dose-dependently. However, all beneficial effects of polydatin mentioned above were counteracted when we inhibited PI3K/Akt pathway with its specific inhibitor, wortmannin. Taken together, the present findings provide the first evidence demonstrating that PD exhibited prominent nephroprotective effects against renal I/R injury by antioxidative stress and inflammation through PI3-K/Akt-dependent molecular mechanisms.

  19. Lauric Acid Stimulates Mammary Gland Development of Pubertal Mice through Activation of GPR84 and PI3K/Akt Signaling Pathway.

    Science.gov (United States)

    Meng, Yingying; Zhang, Jing; Zhang, Fenglin; Ai, Wei; Zhu, Xiaotong; Shu, Gang; Wang, Lina; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Liang, Xingwei; Jiang, Qingyan; Wang, Songbo

    2017-01-11

    It has been demonstrated that dietary fat affects pubertal mammary gland development. However, the role of lauric acid (LA) in this process remains unclear. Thus, this study aimed to investigate the effects of LA on mammary gland development in pubertal mice and to explore the underlying mechanism. In vitro, 100 μM LA significantly promoted proliferation of mouse mammary epithelial cell line HC11 by regulating expression of proliferative markers (cyclin D1/3, p21, PCNA). Meanwhile, LA activated the G protein-coupled receptor 84 (GPR84) and PI3K/Akt signaling pathway. In agreement, dietary 1% LA enhanced mammary duct development, increased the expression of GPR84 and cyclin D1, and activated PI3K/Akt in mammary gland of pubertal mice. Furthermore, knockdown of GPR84 or inhibition of PI3K/Akt totally abolished the promotion of HC11 proliferation induced by LA. These results showed that LA stimulated mammary gland development of pubertal mice through activation of GPR84 and PI3K/Akt signaling pathway.

  20. Crocin prevents retinal ischaemia/reperfusion injury-induced apoptosis in retinal ganglion cells through the PI3K/AKT signalling pathway.

    Science.gov (United States)

    Qi, Yun; Chen, Li; Zhang, Lei; Liu, Wen-Bo; Chen, Xiao-Yan; Yang, Xin-Guang

    2013-02-01

    Crocin is a pharmacologically active component of Crocus sativus L. (saffron) and has been reported to be useful in the treatment of neuronal damage. In the present study, we investigated the neuroprotective effect of crocin on retinal ganglion cells (RGCs) after retinal ischaemia/reperfusion (IR) injury, and our results show that crocin acts through the PI3K/AKT signalling pathway. Retinal IR injury was induced by raising the intraocular pressure of Sprague-Dawley rats to 110 mmHg for 60 min. The neuroprotective effect of crocin was determined by quantifying the surviving RGCs and apoptotic RGCs following IR injury by means of retrograde labelling and TUNEL staining, respectively. The phosphorylated AKT protein level was determined by western blot and immunohistochemical analysis. To determine the extent to which the PI3K/AKT pathway contributes to the neuroprotective effect of crocin, experiments were also performed using the PI3K inhibitor LY294002. Compared with the IR + vehicle group, crocin (50 mg/kg) treatment enhanced RGC survival by approximately 36% and decreased RGC apoptosis by 44% after retinal IR injury. Western blot and immunohistochemical analysis demonstrated that the PI3K/AKT pathway was activated by crocin in the ganglion cell layer after retinal IR injury. Intravitreal injection of LY294002 blocked the neuroprotective effect of crocin on IR-induced RGC death. In conclusion, crocin prevents retinal IR-induced apoptosis of RGCs by activating the PI3K/AKT signalling pathway. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Dietary Lycium barbarum Polysaccharide Induces Nrf2/ARE Pathway and Ameliorates Insulin Resistance Induced by High-Fat via Activation of PI3K/AKT Signaling

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    Yi Yang

    2014-01-01

    Full Text Available Lycium barbarum polysaccharide (LBP, an antioxidant from wolfberry, displays the antioxidative and anti-inflammatory effects on experimental models of insulin resistance in vivo. However, the effective mechanism of LBP on high-fat diet-induced insulin resistance is still unknown. The objective of the study was to investigate the mechanism involved in LBP-mediated phosphatidylinositol 3-kinase (PI3K/AKT/Nrf2 axis against high-fat-induced insulin resistance. HepG2 cells were incubated with LBP for 12 hrs in the presence of palmitate. C57BL/6J mice were fed a high-fat diet supplemented with LBP for 24 weeks. We analyzed the expression of nuclear factor-E2-related factor 2 (Nrf2, Jun N-terminal kinases (JNK, and glycogen synthase kinase 3β (GSK3β involved in insulin signaling pathway in vivo and in vitro. First, LBP significantly induced phosphorylation of Nrf2 through PI3K/AKT signaling. Second, LBP obviously increased detoxification and antioxidant enzymes expression and reduced reactive oxygen species (ROS levels via PI3K/AKT/Nrf2 axis. Third, LBP also regulated phosphorylation levels of GSK3β and JNK through PI3K/AKT signaling. Finally, LBP significantly reversed glycolytic and gluconeogenic genes expression via the activation of Nrf2-mediated cytoprotective effects. In summary, LBP is novel antioxidant against insulin resistance induced by high-fat diet via activation of PI3K/AKT/Nrf2 pathway.

  2. Amentoflavone protects dopaminergic neurons in MPTP-induced Parkinson's disease model mice through PI3K/Akt and ERK signaling pathways

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    Cao, Qin; Qin, Liyue; Huang, Fei, E-mail: Fei_H@hotmail.com; Wang, Xiaoshuang; Yang, Liu; Shi, Hailian; Wu, Hui; Zhang, Beibei; Chen, Ziyu; Wu, Xiaojun, E-mail: xiaojunwu320@126.com

    2017-03-15

    Parkinson's disease (PD) is characterized by the progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc). Mitochondrial dysfunction and cell apoptosis are suggested to be actively involved in the pathogenesis of PD. In the present study, the neuroprotective effect of amentoflavone (AF), a naturally occurring biflavonoid from Selaginella tamariscina, was examined in PD models both in vitro and in vivo. On SH-SY5Y cells, AF treatment dose-dependently reduced 1-methyl-4-phenylpyridinium (MPP{sup +})-induced nuclear condensation and loss of cell viability without obvious cytotoxicity. It inhibited the activation of caspase-3 and p21 but increased the Bcl-2/Bax ratio. Further study disclosed that AF enhanced the phosphorylation of PI3K, Akt and ERK1/2 down-regulated by MPP{sup +} in SH-SY5Y cells, the effect of which could be blocked by LY294002, the inhibitor of PI3K. Consistently, AF alleviated the behavioral deterioration in pole and traction tests and rescued the loss of dopaminergic neurons in SNpc and fibers in striatum in methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced mice. It also could enhance the activation of PI3K and Akt as well as Bcl-2/Bax ratio in SN. Moreover, AF alleviated gliosis as well as the gene expression levels of IL-1β and iNOS in SN. Collectively, these results suggested that AF protected dopaminergic neurons against MPTP/MPP{sup +}-induced neurotoxicity, which might be mediated through activation of PI3K/Akt and ERK signaling pathways in dopaminergic neurons and attenuation of neuroinflammation. - Highlights: • AF protected dopaminergic neurons against MPTP/MPP{sup +}-induced neurotoxicity. • AF modulated PI3K/Akt and ERK signaling pathways. • AF could alleviate neuroinflammation in SN.

  3. Amentoflavone protects dopaminergic neurons in MPTP-induced Parkinson's disease model mice through PI3K/Akt and ERK signaling pathways

    International Nuclear Information System (INIS)

    Cao, Qin; Qin, Liyue; Huang, Fei; Wang, Xiaoshuang; Yang, Liu; Shi, Hailian; Wu, Hui; Zhang, Beibei; Chen, Ziyu; Wu, Xiaojun

    2017-01-01

    Parkinson's disease (PD) is characterized by the progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc). Mitochondrial dysfunction and cell apoptosis are suggested to be actively involved in the pathogenesis of PD. In the present study, the neuroprotective effect of amentoflavone (AF), a naturally occurring biflavonoid from Selaginella tamariscina, was examined in PD models both in vitro and in vivo. On SH-SY5Y cells, AF treatment dose-dependently reduced 1-methyl-4-phenylpyridinium (MPP + )-induced nuclear condensation and loss of cell viability without obvious cytotoxicity. It inhibited the activation of caspase-3 and p21 but increased the Bcl-2/Bax ratio. Further study disclosed that AF enhanced the phosphorylation of PI3K, Akt and ERK1/2 down-regulated by MPP + in SH-SY5Y cells, the effect of which could be blocked by LY294002, the inhibitor of PI3K. Consistently, AF alleviated the behavioral deterioration in pole and traction tests and rescued the loss of dopaminergic neurons in SNpc and fibers in striatum in methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced mice. It also could enhance the activation of PI3K and Akt as well as Bcl-2/Bax ratio in SN. Moreover, AF alleviated gliosis as well as the gene expression levels of IL-1β and iNOS in SN. Collectively, these results suggested that AF protected dopaminergic neurons against MPTP/MPP + -induced neurotoxicity, which might be mediated through activation of PI3K/Akt and ERK signaling pathways in dopaminergic neurons and attenuation of neuroinflammation. - Highlights: • AF protected dopaminergic neurons against MPTP/MPP + -induced neurotoxicity. • AF modulated PI3K/Akt and ERK signaling pathways. • AF could alleviate neuroinflammation in SN.

  4. Biphasic activation of PI3K/Akt and MAPK/Erk1/2 signaling pathways in bovine herpesvirus type 1 infection of MDBK cells

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    Zhu Liqian

    2011-04-01

    Full Text Available Abstract Many viruses have been known to control key cellular signaling pathways to facilitate the virus infection. The possible involvement of signaling pathways in bovine herpesvirus type 1 (BoHV-1 infection is unknown. This study indicated that infection of MDBK cells with BoHV-1 induced an early-stage transient and a late-stage sustained activation of both phosphatidylinositol 3-kinase (PI3K/Akt and mitogen activated protein kinases/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2 signaling pathways. Analysis with the stimulation of UV-irradiated virus indicated that the virus binding and/or entry process was enough to trigger the early phase activations, while the late phase activations were viral protein expression dependent. Biphasic activation of both pathways was suppressed by the selective inhibitor, Ly294002 for PI3K and U0126 for MAPK kinase (MEK1/2, respectively. Furthermore, treatment of MDBK cells with Ly294002 caused a 1.5-log reduction in virus titer, while U0126 had little effect on the virus production. In addition, the inhibition effect of Ly294002 mainly occurred at the post-entry stage of the virus replication cycle. This revealed for the first time that BoHV-1 actively induced both PI3K/Akt and MAPK/Erk1/2 signaling pathways, and the activation of PI3K was important for fully efficient replication, especially for the post-entry stage.

  5. ApoA-I/SR-BI modulates S1P/S1PR2-mediated inflammation through the PI3K/Akt signaling pathway in HUVECs.

    Science.gov (United States)

    Ren, Kun; Lu, Yan-Ju; Mo, Zhong-Cheng; -Liu, Xing; Tang, Zhen-Li; Jiang, Yue; Peng, Xiao-Shan; Li, Li; Zhang, Qing-Hai; Yi, Guang-Hui

    2017-05-01

    Endothelial dysfunction plays a vital role during the initial stage of atherosclerosis. Oxidized low-density lipoprotein (ox-LDL) induces vascular endothelial injury and vessel wall inflammation. Sphingosine-1-phosphate (S1P) exerts numerous vasoprotective effects by binding to diverse S1P receptors (S1PRs; S1PR1-5). A number of studies have shown that in endothelial cells (ECs), S1PR2 acts as a pro-atherosclerotic mediator by stimulating vessel wall inflammation through the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Scavenger receptor class B member I (SR-BI), a high-affinity receptor for apolipoprotein A-I (apoA-I)/high-density lipoprotein (HDL), inhibits nuclear factor-κB (NF-κB) translocation and decreases the plasma levels of inflammatory mediators via the PI3K/Akt pathway. We hypothesized that the inflammatory effects of S1P/S1PR2 on ECs may be regulated by apoA-I/SR-BI. The results showed that ox-LDL, a pro-inflammatory factor, augmented the S1PR2 level in human umbilical vein endothelial cells (HUVECs) in a dose- and time-dependent manner. In addition, S1P/S1PR2 signaling influenced the levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-10, aggravating inflammation in HUVECs. Moreover, the pro-inflammatory effects induced by S1P/S1PR2 were attenuated by SR-BI overexpression and enhanced by an SR-BI inhibitor, BLT-1. Further experiments showed that the PI3K/Akt signaling pathway was involved in this process. Taken together, these results demonstrate that apoA-I/SR-BI negatively regulates S1P/S1PR2-mediated inflammation in HUVECs by activating the PI3K/Akt signaling pathway.

  6. 20(S-Protopanaxadiol-Induced Apoptosis in MCF-7 Breast Cancer Cell Line through the Inhibition of PI3K/AKT/mTOR Signaling Pathway

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    Hong Zhang

    2018-04-01

    Full Text Available 20(S-Protopanaxadiol (PPD is one of the major active metabolites of ginseng. It has been reported that 20(S-PPD shows a broad spectrum of antitumor effects. Our research study aims were to investigate whether apoptosis of human breast cancer MCF-7 cells could be induced by 20(S-PPD by targeting the Phosphatidylinositol 3-kinase/Protein kinase B/Mammalian target of rapamycin (PI3K/AKT/mTOR signal pathway in vitro and in vivo. Cell cycle analysis was performed by Propidium Iodide (PI staining. To overexpress and knock down the expression of mTOR, pcDNA3.1-mTOR and mTOR small interfering RNA (siRNA transient transfection assays were used, respectively. Cell viability and apoptosis were evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT-test and Annexin V /PI double-staining after transfection. The antitumor effect in vivo was determined by the nude mice xenograft assay. After 24 h of incubation, treatment with 20(S-PPD could upregulate phosphorylated-Phosphatase and tensin homologue deleted on chromosome 10 (p-PTEN expression and downregulate PI3K/AKT/mTOR-pathway protein expression. Moreover, G0/G1 cell cycle arrest in MCF-7 cells could be induced by 20(S-PPD treatment at high concentrations. Furthermore, overexpression or knockdown of mTOR could inhibit or promote the apoptotic effects of 20(S-PPD. In addition, tumor volumes were partially reduced by 20(S-PPD at 100 mg/kg in a MCF-7 xenograft model. Immunohistochemical staining indicated a close relationship between the inhibition of tumor growth and the PI3K/AKT/mTOR signal pathway. PI3K/AKT/mTOR pathway-mediated apoptosis may be one of the potential mechanisms of 20(S-PPD treatment.

  7. TGF-beta induces connexin43 gene expression in normal murine mammary gland epithelial cells via activation of p38 and PI3K/AKT signaling pathways.

    Science.gov (United States)

    Tacheau, Charlotte; Fontaine, Juliette; Loy, Jennifer; Mauviel, Alain; Verrecchia, Franck

    2008-12-01

    One of the shared physiological roles between TGF-beta and connexin family members is to inhibit epithelial cell cycle progression and consequently, to provide protection against malignant transformation. Herein, we demonstrated that TGF-beta1 induces the expression of connexin43 (Cx43) in normal murine mammary gland (NMuMG) cell lines at the protein and mRNA levels, and transcriptionally. Using overexpression of a truncated dominant-negative form of Cx43, we determined that the modulation of gap junctional communication by TGF-beta1 plays a key role in the control of NMuMG cells proliferation by TGF-beta1. In addition, using overexpression of truncated dominant-negative forms of either Smad2 or Smad3, and MDA-MB-468 human breast carcinoma cells deficient for Smad4, we determined that the Smad cascade is not implicated in TGF-beta1 effect on Cx43 expression. Using specific pharmacologic inhibitors for JNK, ERK, p38, and PI3K/AKT signaling pathways, we demonstrated the cooperative role of p38 and PI3K/AKT signaling in TGF-beta1-induced Cx43 expression and gap junctional communication. Furthermore, transfection of a c-jun antisense expression vector significantly prevented TGF-beta1-induced Cx43 gene expression demonstrating the involvement of c-Jun/AP-1 pathway together with p38 and PI3K/AKT pathways in mediating TGF-beta1-induced Cx43 gene expression.

  8. Skin Aging-Dependent Activation of the PI3K Signaling Pathway via Downregulation of PTEN Increases Intracellular ROS in Human Dermal Fibroblasts

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    Eun-Mi Noh

    2016-01-01

    Full Text Available Reactive oxygen species (ROS play a major role in both chronological aging and photoaging. ROS induce skin aging through their damaging effect on cellular constituents. However, the origins of ROS have not been fully elucidated. We investigated that ROS generation of replicative senescent fibroblasts is generated by the modulation of phosphatidylinositol 3,4,5-triphosphate (PIP3 metabolism. Reduction of the PTEN protein, which dephosphorylates PIP3, was responsible for maintaining a high level of PIP3 in replicative cells and consequently mediated the activation of the phosphatidylinositol-3-OH kinase (PI3K/Akt pathway. Increased ROS production was blocked by inhibition of PI3K or protein kinase C (PKC or by NADPH oxidase activating in replicative senescent cells. These data indicate that the signal pathway to ROS generation in replicative aged skin cells can be stimulated by reduced PTEN level. Our results provide new insights into skin aging-associated modification of the PI3K/NADPH oxidase signaling pathway and its relationship with a skin aging-dependent increase of ROS in human dermal fibroblasts.

  9. Icariin stimulates angiogenesis by activating the MEK/ERK- and PI3K/Akt/eNOS-dependent signal pathways in human endothelial cells

    International Nuclear Information System (INIS)

    Chung, Byung-Hee; Kim, Jong-Dai; Kim, Chun-Ki; Kim, Jung Huan; Won, Moo-Ho; Lee, Han-Soo; Dong, Mi-Sook; Ha, Kwon-Soo; Kwon, Young-Geun; Kim, Young-Myeong

    2008-01-01

    We investigated the molecular effect and signal pathway of icariin, a major flavonoid of Epimedium koreanum Nakai, on angiogenesis. Icariin stimulated in vitro endothelial cell proliferation, migration, and tubulogenesis, which are typical phenomena of angiogenesis, as well as increased in vivo angiogenesis. Icariin activated the angiogenic signal modulators, ERK, phosphatidylinositol 3-kinase (PI3K), Akt, and endothelial nitric oxide synthase (eNOS), and increased NO production, without affecting VEGF expression, indicating that icariin may directly stimulate angiogenesis. Icariin-induced ERK activation and angiogenic events were significantly inhibited by the MEK inhibitor PD98059, without affecting Akt and eNOS phosphorylation. The PI3K inhibitor Wortmannin suppressed icariin-mediated angiogenesis and Akt and eNOS activation without affecting ERK phosphorylation. Moreover, the NOS inhibitor NMA partially reduced the angiogenic activity of icariin. These results suggest that icariin stimulated angiogenesis by activating the MEK/ERK- and PI3K/Akt/eNOS-dependent signal pathways and may be a useful drug for angiogenic therapy

  10. BIG1, a brefeldin A-inhibited guanine nucleotide-exchange protein regulates neurite development via PI3K-AKT and ERK signaling pathways.

    Science.gov (United States)

    Zhou, C; Li, C; Li, D; Wang, Y; Shao, W; You, Y; Peng, J; Zhang, X; Lu, L; Shen, X

    2013-12-19

    The elongation of neuron is highly dependent on membrane trafficking. Brefeldin A (BFA)-inhibited guanine nucleotide-exchange protein 1 (BIG1) functions in the membrane trafficking between the Golgi apparatus and the plasma membrane. BFA, an uncompetitive inhibitor of BIG1 can inhibit neurite outgrowth and polarity development. In this study, we aimed to define the possible role of BIG1 in neurite development and to further investigate the potential mechanism. By immunostaining, we found that BIG1 was extensively colocalized with synaptophysin, a marker for synaptic vesicles in soma and partly in neurites. The amount of both protein and mRNA of BIG1 were up-regulated during rat brain development. BIG1 depletion significantly decreased the neurite length and inhibited the phosphorylation of phosphatidylinositide 3-kinase (PI3K) and protein kinase B (AKT). Inhibition of BIG1 guanine nucleotide-exchange factor (GEF) activity by BFA or overexpression of the dominant-negative BIG1 reduced PI3K and AKT phosphorylation, indicating regulatory effects of BIG1 on PI3K-AKT signaling pathway is dependent on its GEF activity. BIG1 siRNA or BFA treatment also significantly reduced extracellular signal-regulated kinase (ERK) phosphorylation. Overexpression of wild-type BIG1 significantly increased ERK phosphorylation, but the dominant-negative BIG1 had no effect on ERK phosphorylation, indicating the involvement of BIG1 in ERK signaling regulation may not be dependent on its GEF activity. Our result identified a novel function of BIG1 in neurite development. The newly recognized function integrates the function of BIG1 in membrane trafficking with the activation of PI3K-AKT and ERK signaling pathways which are critical in neurite development. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Li, Yumei; Zhang, Chunmei; Cai, Danfeng; Chen, Congde; Mu, Dongmei

    2017-12-01

    Rhabdoid tumors, which tend to occur prior to the age of 2 years, are one of the most aggressive malignancies and have a poor prognosis due to the frequency of metastasis. Silibinin, a natural extract, has been approved as a potential tumor suppressor in various studies, however, whether or not it also exerts its antitumor capacity in rhabdoid tumors, particularly with regards to tumor migration and invasion, is unclear. The rhabdoid tumor G401 cell line was used in the present in vitro study. An MTT assay was used to assess the cytotoxicity of silibinin on G401 cells, cell migration was studied using a wound healing assay and a Transwell migration assay, and cell invasion was determined using a Transwell invasion assay. The underlying mechanism in silibinin inhibited cell migration and invasion was investigated by western blot analysis and further confirmed using a specific inhibitor. Experimental results demonstrated that high doses of silibinin suppressed cell viability, and that low doses of silibinin inhibited cell migration and invasion without affecting cell proliferation. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway was involved in the silibinin-induced inhibition of metastasis. Silibinin inactivated the PI3K/Akt pathway, and inhibited cell migration and invasion, an effect that was further enhanced when LY294002, a classic PI3K inhibitor, was used concurrently. In general, silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway and may be a potential chemotherapeutic drug to combat rhabdoid tumors in the future.

  12. CXCL12 gene silencing down-regulates metastatic potential via blockage of MAPK/PI3K/AP-1 signaling pathway in colon cancer.

    Science.gov (United States)

    Ma, J; Su, H; Yu, B; Guo, T; Gong, Z; Qi, J; Zhao, X; Du, J

    2018-01-05

    To investigate the effect of CXCL12 gene silencing on proliferation,invasion, angiogenesis and the relationship of MAPK/PI3K/AP-1 signaling pathway in colon cancer cells. RT-PCR and Western-blot were used to detect the expression of CXCL12 mRNA and protein in four colon cancer cell lines. Human colon cancer cells were transfected with CXCL12 siRNA carrying by Lipofectamine 2000. The expression of CXCL12 protein was confirmed by immunoblotting. WST-1, invasion and angiogenesis assay were used to examine the effect on proliferation, invasion and angiogenesis in colon cancer cells after CXCL12 siRNA silence, respectively. The phosphorylation of MAPK/PI3K/AP-1 protein levels was detected by Western blotting in CXCL12 siRNA suppression DLD-1 cell. CXCL12 mRNA and proteins were only expressed in DLD-1 colon cancer cell lines. CXCL12 siRNA were transfected into DLD-1 cells, the expression CXCL12 proteins was significantly inhibited (P colon cancer cell. The silencing CXCL12 gene significantly inhibits the proliferation, invasion and angiogenesis ability of some types colon carcinoma cells through down-regulation of MAPK/PI3K/AP-1 signaling pathway.

  13. RIP2 Is a Critical Regulator for NLRs Signaling and MHC Antigen Presentation but Not for MAPK and PI3K/Akt Pathways.

    Science.gov (United States)

    Wu, Xiao Man; Chen, Wen Qin; Hu, Yi Wei; Cao, Lu; Nie, Pin; Chang, Ming Xian

    2018-01-01

    RIP2 is an adaptor protein which is essential for the activation of NF-κB and NOD1- and NOD2-dependent signaling. Although NOD-RIP2 axis conservatively existed in the teleost, the function of RIP2 was only reported in zebrafish, goldfish, and rainbow trout in vitro . Very little is known about the role and mechanisms of piscine NOD-RIP2 axis in vivo . Our previous study showed the protective role of zebrafish NOD1 in larval survival through CD44a-mediated activation of PI3K-Akt signaling. In this study, we examined whether RIP2 was required for larval survival with or without pathogen infection, and determined the signaling pathways modulated by RIP2. Based on our previous report and the present study, our data demonstrated that NOD1-RIP2 axis was important for larval survival in the early ontogenesis. Similar to NOD1, RIP2 deficiency significantly affected immune system processes. The significantly enriched pathways were mainly involved in immune system, such as "Antigen processing and presentation" and "NOD-like receptor signaling pathway" and so on. Furthermore, both transcriptome analysis and qRT-PCR revealed that RIP2 was a critical regulator for expression of NLRs (NOD-like receptors) and those genes involved in MHC antigen presentation. Different from NOD1, the present study showed that NOD1, but not RIP2 deficiency significantly impaired protein levels of MAPK pathways. Although RIP2 deficiency also significantly impaired the expression of CD44a, the downstream signaling of CD44a-Lck-PI3K-Akt pathway remained unchanged. Collectively, our works highlight the similarity and discrepancy of NOD1 and RIP2 in the regulation of immune signaling pathways in the zebrafish early ontogenesis, and confirm the crucial role of RIP2 in NLRs signaling and MHC antigen presentation, but not for MAPK and PI3K/Akt pathways.

  14. Roquin Suppresses the PI3K-mTOR Signaling Pathway to Inhibit T Helper Cell Differentiation and Conversion of Treg to Tfr Cells.

    Science.gov (United States)

    Essig, Katharina; Hu, Desheng; Guimaraes, Joao C; Alterauge, Dominik; Edelmann, Stephanie; Raj, Timsse; Kranich, Jan; Behrens, Gesine; Heiseke, Alexander; Floess, Stefan; Klein, Juliane; Maiser, Andreas; Marschall, Susan; Hrabĕ de Angelis, Martin; Leonhardt, Heinrich; Calkhoven, Cornelis F; Noessner, Elfriede; Brocker, Thomas; Huehn, Jochen; Krug, Anne B; Zavolan, Mihaela; Baumjohann, Dirk; Heissmeyer, Vigo

    2017-12-19

    Roquin proteins preclude spontaneous T cell activation and aberrant differentiation of T follicular helper (Tfh) or T helper 17 (Th17) cells. Here we showed that deletion of Roquin-encoding alleles specifically in regulatory T (Treg) cells also caused the activation of conventional T cells. Roquin-deficient Treg cells downregulated CD25, acquired a follicular Treg (Tfr) cell phenotype, and suppressed germinal center reactions but could not protect from colitis. Roquin inhibited the PI3K-mTOR signaling pathway by upregulation of Pten through interfering with miR-17∼92 binding to an overlapping cis-element in the Pten 3' UTR, and downregulated the Foxo1-specific E3 ubiquitin ligase Itch. Loss of Roquin enhanced Akt-mTOR signaling and protein synthesis, whereas inhibition of PI3K or mTOR in Roquin-deficient T cells corrected enhanced Tfh and Th17 or reduced iTreg cell differentiation. Thereby, Roquin-mediated control of PI3K-mTOR signaling prevents autoimmunity by restraining activation and differentiation of conventional T cells and specialization of Treg cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. MiR-20a Induces Cell Radioresistance by Activating the PTEN/PI3K/Akt Signaling Pathway in Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Zhang, Yuqin; Zheng, Lin; Ding, Yi; Li, Qi; Wang, Rong; Liu, Tongxin; Sun, Quanquan; Yang, Hua; Peng, Shunli; Wang, Wei; Chen, Longhua

    2015-01-01

    Purpose: To investigate the role of miR-20a in hepatocellular carcinoma (HCC) cell radioresistance, which may reveal potential strategies to improve treatment. Methods and Materials: The expression of miR-20a and PTEN were detected in HCC cell lines and paired primary tissues by quantitative real-time polymerase chain reaction. Cell radiation combined with colony formation assays was administrated to discover the effect of miR-20a on radiosensitivity. Bioinformatics prediction and luciferase assay were used to identify the target of miR-20a. The phosphatidylinositol 3-kinase inhibitor LY294002 was used to inhibit phosphorylation of Akt, to verify whether miR-20a affects HCC cell radioresistance through activating the PTEN/PI3K/Akt pathway. Results: MiR-20a levels were increased in HCC cell lines and tissues, whereas PTEN was inversely correlated with it. Overexpression of miR-20a in Bel-7402 and SMMC-7721 cells enhances their resistance to the effect of ionizing radiation, and the inhibition of miR-20a in HCCLM3 and QGY-7701 cells sensitizes them to it. PTEN was identified as a direct functional target of miR-20a for the induction of radioresistance. Overexpression of miR-20a activated the PTEN/PI3K/Akt signaling pathway. Additionally, the kinase inhibitor LY294002 could reverse the effect of miR-20a–induced radioresistance. Conclusion: MiR-20a induces HCC cell radioresistance by activating the PTEN/PI3K/Akt pathway, which suggests that miR-20a/PTEN/PI3K/Akt might represent a target of investigation for developing effective therapeutic strategies against HCC

  16. DNA Synthesis during Endomitosis Is Stimulated by Insulin via the PI3K/Akt and TOR Signaling Pathways in the Silk Gland Cells of Bombyx mori

    Directory of Open Access Journals (Sweden)

    Yaofeng Li

    2015-03-01

    Full Text Available Silk gland cells undergo multiple endomitotic cell cycles during silkworm larval ontogeny. Our previous study demonstrated that feeding is required for continued endomitosis in the silk gland cells of silkworm larvae. Furthermore, the insulin signaling pathway is closely related to nutritional signals. To investigate whether the insulin signaling pathway is involved in endomitosis in silk gland cells, in this study, we initially analyzed the effects of bovine insulin on DNA synthesis in endomitotic silk gland cells using 5-bromo-2'-deoxyuridine (BrdU labeling technology, and found that bovine insulin can stimulate DNA synthesis. Insulin signal transduction is mainly mediated via phosphoinositide 3-kinase (PI3K/Akt, the target of rapamycin (TOR and the extracellular signal-regulated kinase (ERK pathways in vertebrates. We ascertained that these three pathways are involved in DNA synthesis in endomitotic silk gland cells using specific inhibitors against each pathway. Moreover, we investigated whether these three pathways are involved in insulin-stimulated DNA synthesis in endomitotic silk gland cells, and found that the PI3K/Akt and TOR pathways, but not the ERK pathway, are involved in this process. These results provide an important theoretical foundation for the further investigations of the mechanism underlying efficient endomitosis in silk gland cells.

  17. CCL5 promotes VEGF-dependent angiogenesis by down-regulating miR-200b through PI3K/Akt signaling pathway in human chondrosarcoma cells

    Science.gov (United States)

    Liu, Guan-Ting; Chen, Hsien-Te; Tsou, Hsi-Kai; Tan, Tzu-Wei; Fong, Yi-Chin; Chen, Po-Chen; Yang, Wei-Hung; Wang, Shih-Wei; Chen, Jui-Chieh; Tang, Chih-Hsin

    2014-01-01

    Chondrosarcoma is the second most common primary malignant bone cancer, with potential for local invasion and distant metastasis. Chemokine CCL5 (formerly RANTES) of the CC-chemokine family plays a crucial role in metastasis. Angiogenesis is essential for the cancer metastasis. However, correlation of CCL5 with vascular endothelial growth factor (VEGF) expression and angiogenesis in human chondrosarcoma is still unknown. CCL5-mediated VEGF expression was assessed by qPCR, ELISA, and Western blotting. CCL5-induced angiogenesis was examined by migration and tube formation in endothelial progenitor cells in vitro. CCL5 increased VEGF expression and also promoted chondrosarcoma conditional medium-mediated angiogenesis in vitro and in vivo. Stimulation of chondrosarcoma with CCL5 augmented PI3K and Akt phosphorylation, while PI3K and Akt inhibitor or siRNA abolished CCL5-induced VEGF expression and angiogenesis. We also demonstrated CCL5 inhibiting miR-200b expression and miR-200b mimic reversing the CCL5-enhanced VEGF expression and angiogenesis. Moreover, in chondrosarcoma patients showed the positive correlation between CCL5 and VEGF; negative correlation between CCL5 and miR-200b. Taken together, results demonstrate CCL5 promoting VEGF-dependent angiogenesis in human chondrosarcoma cells by down-regulating miR-200b through PI3K/Akt signaling pathway. PMID:25301739

  18. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    International Nuclear Information System (INIS)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-01-01

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  19. Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi-Feng [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Yu, Hong-Wei [Department of Cardiology, Jinzhou Central Hospital, Jinzhou 121001 (China); Sun, Li-Li [Department of Ophthalmology, The Third Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); You, Lu; Tao, Gui-Zhou [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Qu, Bao-Ze, E-mail: qubaoze1971@hotmail.com [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)

    2015-12-25

    Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling. - Highlights: • Apelin-13 mediates Egr-1 upregulation in vascular smooth muscle cells via ERK1/2. • The underlying mechanisms are unknown, but exclude Jnk or p38 pathway activation. • Apelin-13 binds to Gi, activating the PI3K/Akt and PKC signaling cascades. • Consequent ERK phosphorylation results in increased Egr-1

  20. Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways

    International Nuclear Information System (INIS)

    Liu, Qi-Feng; Yu, Hong-Wei; Sun, Li-Li; You, Lu; Tao, Gui-Zhou; Qu, Bao-Ze

    2015-01-01

    Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling. - Highlights: • Apelin-13 mediates Egr-1 upregulation in vascular smooth muscle cells via ERK1/2. • The underlying mechanisms are unknown, but exclude Jnk or p38 pathway activation. • Apelin-13 binds to Gi, activating the PI3K/Akt and PKC signaling cascades. • Consequent ERK phosphorylation results in increased Egr-1

  1. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun-Seok [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kang, Shin-il [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Yoo, Kyu-dong [Hazardous Substances Analysis Division, Gwangju Regional Food and Drug Administration, Gwangju (Korea, Republic of); Lee, Mi-Yea [Department of Nursing Kyungbok University, Pocheon (Korea, Republic of); Yoo, Hwan-Soo; Hong, Jin-Tae [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Shin, Hwa-Sup [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, Bokyung [Department of Physiology, Konkuk Medical School, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Yun, Yeo-Pyo, E-mail: ypyun@chungbuk.ac.kr [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of)

    2013-04-15

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway.

  2. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

    International Nuclear Information System (INIS)

    Park, Eun-Seok; Kang, Shin-il; Yoo, Kyu-dong; Lee, Mi-Yea; Yoo, Hwan-Soo; Hong, Jin-Tae; Shin, Hwa-Sup; Kim, Bokyung; Yun, Yeo-Pyo

    2013-01-01

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway

  3. Norcantharidin inhibits tumor growth and vasculogenic mimicry of human gallbladder carcinomas by suppression of the PI3-K/MMPs/Ln-5γ2 signaling pathway

    International Nuclear Information System (INIS)

    Zhang, Jing-Tao; Sun, Wei; Zhang, Wen-Zhong; Ge, Chun-Yan; Liu, Zhong-Yan; Zhao, Ze-Ming; Lu, Xing-Sui; Fan, Yue-Zu

    2014-01-01

    Vasculogenic mimicry (VM) is a novel tumor blood supply in some highly aggressive malignant tumors. Recently, we reported VM existed in gallbladder carcinomas (GBCs) and the formation of the special passage through the activation of the PI3K/MMPs/Ln-5γ2 signaling pathway. GBC is a highly aggressive malignant tumor with disappointing treatments and a poor prognosis. Norcantharidin (NCTD) has shown to have multiple antitumor activities against GBCs, etc; however the exact mechanism is not thoroughly elucidated. In this study, we firstly investigated the anti-VM activity of NCTD as a VM inhibitor for GBCs and its underlying mechanisms. In vitro and in vivo experiments to determine the effects of NCTD on proliferation, invasion, migration, VM formation, hemodynamic and tumor growth of GBC-SD cells and xenografts were respectively done by proliferation, invasion, migration assays, H&E staining and CD31-PAS double stainings, optic/electron microscopy, tumor assay, and dynamic micro-MRA. Further, immunohistochemistry, immunofluorescence, Western blotting and RT-PCR were respectively used to examine expression of VM signaling-related markers PI3-K, MMP-2, MT1-MMP and Ln-5γ2 in GBC-SD cells and xenografts in vitro and in vivo. After treatment with NCTD, proliferation, invasion, migration of GBC-SD cells were inhibited; GBC-SD cells and xenografts were unable to form VM-like structures; tumor center-VM region of the xenografts exhibited a decreased signal in intensity; then cell or xenograft growth was inhibited. Whereas all of untreated GBC-SD cells and xenografts formed VM-like structures with the same conditions; the xenograft center-VM region exhibited a gradually increased signal; and facilitated cell or xenograft growth. Furthermore, expression of MMP-2 and MT1-MMP products from sections/supernates of 3-D matrices and the xenografts, and expression of PI3-K, MMP-2, MM1-MMP and Ln-5γ2 proteins/mRNAs of the xenografts were all decreased in NCTD or TIMP-2 group; (all P

  4. Curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway.

    Science.gov (United States)

    Tian, Binqiang; Zhao, Yingmei; Liang, Tao; Ye, Xuxiao; Li, Zuowei; Yan, Dongliang; Fu, Qiang; Li, Yonghui

    2017-08-01

    We have previously reported that curcumin inhibits urothelial tumor development in a rat bladder carcinogenesis model. In this study, we report that curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway. Curcumin inhibits IGF2 expression at the transcriptional level and decreases the phosphorylation levels of IGF1R and IRS-1 in bladder cancer cells and N-methyl-N-nitrosourea (MNU)-induced urothelial tumor tissue. Ectopic expression of IGF2 and IGF1R, but not IGF1, in bladder cancer cells restored this process, suggesting that IGF2 is a target of curcumin. Moreover, introduction of constitutively active AKT1 abolished the inhibitory effect of curcumin on cell proliferation, migration, and restored the phosphorylation levels of 4E-BP1 and S6K1, suggesting that curcumin functions via suppressing IGF2-mediated AKT/mTOR signaling pathway. In summary, our results reveal that suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway is one of the mechanisms of action of curcumin. Our findings suggest a new therapeutic strategy against human bladder cancer caused by aberrant activation of IGF2, which are useful for translational application of curcumin.

  5. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice†

    Science.gov (United States)

    Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A.; Afaq, Farrukh

    2014-01-01

    Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations, and alterations in signaling pathways eventually leading to skin cancer. In the present study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ/cm2 of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1- EP4), and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT, and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. PMID:25169110

  6. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice.

    Science.gov (United States)

    Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A; Afaq, Farrukh

    2015-01-01

    Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations and alterations in signaling pathways eventually leading to skin cancer. In this study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB-exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ cm(-2) of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB-exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1-EP4) and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB-exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. © 2014 The American Society of Photobiology.

  7. Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

    2016-05-01

    Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

  8. Involvement of PI3K/Akt Signaling Pathway and Its Downstream Intracellular Targets in the Antidepressant-Like Effect of Creatine.

    Science.gov (United States)

    Cunha, Mauricio P; Budni, Josiane; Ludka, Fabiana K; Pazini, Francis L; Rosa, Julia Macedo; Oliveira, Ágatha; Lopes, Mark W; Tasca, Carla I; Leal, Rodrigo B; Rodrigues, Ana Lúcia S

    2016-07-01

    Creatine has been proposed to exert beneficial effects in the management of depression, but the cell signaling pathways implicated in its antidepressant effects are not well established. This study investigated the involvement of PI3K/Akt signaling pathway and its downstream intracellular targets in the antidepressant-like effect of creatine. The acute treatment of mice with creatine (1 mg/kg, po) increased the Akt and P70S6K phosphorylation, and HO-1, GPx and PSD95 immunocontents. The pretreatment of mice with LY294002 (10 nmol/mouse, icv, PI3K inhibitor), wortmannin (0.1 μg/mouse, icv, PI3K inhibitor), ZnPP (10 μg/mouse, icv, HO-1 inhibitor), or rapamycin (0.2 nmol/mouse, icv, mTOR inhibitor) prevented the antidepressant-like effect of creatine (1 mg/kg, po) in the TST. In addition, the administration of subeffective dose of either the selective GSK3 inhibitor AR-A014418 (0.01 μg/mouse, icv), the nonselective GSK3 inhibitor lithium chloride (10 mg/kg, po), or the HO-1 inductor CoPP (0.01 μg/mouse, icv), in combination with a subeffective dose of creatine (0.01 mg/kg, po) reduced the immobility time in the TST as compared with either drug alone. No treatment caused significant changes in the locomotor activity of mice. These results indicate that the antidepressant-like effect of creatine in the TST depends on the activation of Akt, Nrf2/HO-1, GPx, and mTOR, and GSK3 inhibition.

  9. Minoxidil sulfate induced the increase in blood-brain tumor barrier permeability through ROS/RhoA/PI3K/PKB signaling pathway.

    Science.gov (United States)

    Gu, Yan-ting; Xue, Yi-xue; Wang, Yan-feng; Wang, Jin-hui; Chen, Xia; ShangGuan, Qian-ru; Lian, Yan; Zhong, Lei; Meng, Ying-nan

    2013-12-01

    Adenosine 5'-triphosphate-sensitive potassium channel (KATP channel) activator, minoxidil sulfate (MS), can selectively increase the permeability of the blood-tumor barrier (BTB); however, the mechanism by which this occurs is still under investigation. Using a rat brain glioma (C6) model, we first examined the expression levels of occludin and claudin-5 at different time points after intracarotid infusion of MS (30 μg/kg/min) by western blotting. Compared to MS treatment for 0 min group, the protein expression levels of occludin and claudin-5 in brain tumor tissue of rats showed no changes within 1 h and began to decrease significantly after 2 h of MS infusion. Based on these findings, we then used an in vitro BTB model and selective inhibitors of diverse signaling pathways to investigate whether reactive oxygen species (ROS)/RhoA/PI3K/PKB pathway play a key role in the process of the increase of BTB permeability induced by MS. The inhibitor of ROS or RhoA or PI3K or PKB significantly attenuated the expression of tight junction (TJ) protein and the increase of the BTB permeability after 2 h of MS treatment. In addition, the significant increases in RhoA activity and PKB phosphorylation after MS administration were observed, which were partly inhibited by N-2-mercaptopropionyl glycine (MPG) or C3 exoenzyme or LY294002 pretreatment. The present study indicates that the activation of signaling cascades involving ROS/RhoA/PI3K/PKB in BTB was required for the increase of BTB permeability induced by MS. Taken together, all of these results suggested that MS might increase BTB permeability in a time-dependent manner by down-regulating TJ protein expression and this effect could be related to ROS/RhoA/PI3K/PKB signal pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Andrographolide promotes vincristine-induced SK-NEP-1 tumor cell death via PI3K-AKT-p53 signaling pathway

    Science.gov (United States)

    Zhang, Mingsheng; Xue, Enda; Shao, Wei

    2016-01-01

    Background Nephroblastoma (Wilms’ tumor [WT]) is the most common malignant renal cancer in children. Although the outcome of WT has significantly improved as a result of the combination of surgery, chemotherapy, and radiotherapy; in some cases WT results in severe complications. Thus, novel strategies that would decrease treatment burden are required. The aim of the current study was to investigate the synergistic antitumor effect of andrographolide (AND) in combination with vincristine (VCR) on WT cells. Methods Cell Counting Kit-8 assay was used to investigate the synergistic antiproliferation effect of AND and/or VCR on SK-NEP-1 cells in vitro. Meanwhile, SK-NEP-1 xenografts were used to detect the antitumor effect in vivo. Apoptosis and autophagy were then detected by Annexin V, monodansylcadaverine staining. Finally, the underlying signaling transduction was determined with Western blotting. Results The combination of AND with VCR significantly suppressed SK-NEP-1 cell proliferation in vitro and inhibited xenograft tumor growth in vivo, compared with AND or VCR treatment alone. In addition, the synergistic antitumor effect of AND on the cells was due to an increased apoptosis, not autophagy. Moreover, PI3K-AKT-p53 signaling pathway was involved in the process of combination treatment, which was confirmed when a selective AKT activator was applied. Conclusion The combination of AND with VCR has a strong synergistic antitumor effect on WT via PI3K-AKT-p53 signaling pathway, thereby representing a potential treatment for WT in the near future. PMID:27729773

  11. Opposing effects of PI3K/Akt and Smad-dependent signaling pathways in NAG-1-induced glioblastoma cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Zhiguo Zhang

    Full Text Available Nonsteroidal anti-inflammatory drug (NSAID activated gene-1 (NAG-1 is a divergent member of the transforming growth factor-beta (TGF-β superfamily. NAG-1 plays remarkable multifunctional roles in controlling diverse physiological and pathological processes including cancer. Like other TGF-β family members, NAG-1 can play dual roles during cancer development and progression by negatively or positively modulating cancer cell behaviors. In glioblastoma brain tumors, NAG-1 appears to act as a tumor suppressor gene; however, the precise underlying mechanisms have not been well elucidated. In the present study, we discovered that overexpression of NAG-1 induced apoptosis in U87 MG, U118 MG, U251 MG, and T98G cell lines via the intrinsic mitochondrial pathway, but not in A172 and LN-229 cell lines. NAG-1 could induce the phosphorylation of PI3K/Akt and Smad2/3 in all six tested glioblastoma cell lines, except Smad3 phosphorylation in A172 and LN-229 cell lines. In fact, Smad3 expression and its phosphorylation were almost undetectable in A172 and LN-229 cells. The PI3K inhibitors promoted NAG-1-induced glioblastoma cell apoptosis, while siRNAs to Smad2 and Smad3 decreased the apoptosis rate. NAG-1 also stimulated the direct interaction between Akt and Smad3 in glioblastoma cells. Elevating the level of Smad3 restored the sensitivity to NAG-1-induced apoptosis in A172 and LN-229 cells. In conclusion, our results suggest that PI3K/Akt and Smad-dependent signaling pathways display opposing effects in NAG-1-induced glioblastoma cell apoptosis.

  12. INPP4B reverses docetaxel resistance and epithelial-to-mesenchymal transition via the PI3K/Akt signaling pathway in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Haiwen; Li, Hongliang, E-mail: honglianglity@sina.com; Chen, Qi

    2016-08-26

    Docetaxel efficiency in the therapy of prostate cancer (PCa) patients is limited due to the development of chemoresistance. Recent studies have implied a role of INPP4B in tumor chemoresistance, while the effects of INPP4B on docetaxel resistance in PCa have not been elucidated. In the present study, the docetaxel-resistant human PCa cell lines PC3-DR and DU-145-DR were established from the parental cell lines PC3 and DU-145, and the expression and role of INPP4B in docetaxel-resistant PCa cells were investigated. The results demonstrated that INPP4B expression was significantly downregulated in docetaxel-resistant cells. Overexpression of INPP4B increased the sensitivity to docetaxel and promoted cell apoptosis in PC3-DR and DU-145-DR cells. In addition, INPP4B overexpression downregulated the expression of the mesenchymal markers fibronectin, N-cadherin, and vimentin, and upregulated the expression level of the epithelial maker E-cadherin. Furthermore, INPP4B overexpression markedly inhibited the PI3K/Akt pathway. We also found that IGF-1, the inhibitor of PI3K/Akt, markedly blocked the change in EMT markers induced by overexpression of INPP4B, and reversed the resistance of PC3-DR and DU-145-DR cells to docetaxel, which is sensitized by Flag-INPP4B. In summary, the presented data indicate that INPP4B is crucial for docetaxel-resistant PCa cell survival, potentially by regulating EMT through the PI3K/Akt signaling pathway. - Highlights: • INPP4B is downregulated in docetaxel-resistant PCa cells. • INPP4B inhibits cell proliferation. • INPP4B induces cell apoptosis. • INPP4B inhibits PCa cell EMT.

  13. Adenovirus Vector E4 Gene Regulates Connexin 40 and 43 Expression in Endothelial Cells via PKA and PI3K Signal Pathways

    Science.gov (United States)

    Zhang, Fan; Cheng, Joseph; Lam, George; Jin, David K.; Vincent, Loïc; Hackett, Neil R.; Wang, Shiyang; Young, Lauren M.; Hempstead, Barbara; Crystal, Ronald G.; Rafii, Shahin

    2010-01-01

    Connexins (Cxs) provide a means for intercellular communication and play important roles in the pathophysiology of vascular cardiac diseases. Infection of endothelial cells (ECs) with first-generation E1/E3-deleted E4+ adenovirus (AdE4+) selectively modulates the survival and angiogenic potential of ECs by as of yet unrecognized mechanisms. We show here that AdE4+ vectors potentiate Cx expression in ECs in vitro and in mouse heart tissue. Infection of ECs with AdE4+, but not AdE4−, resulted in a time- and dose-dependent induction of junctional Cx40 expression and suppression of Cx43 protein and mRNA expression. Treatment of ECs with PKA inhibitor H89 or PI3K inhibitor LY294002 prevented the AdE4+-mediated regulation of Cx40 and Cx43 that was associated with diminished AdE4+-mediated survival of ECs. Moreover, both PKA activity and cAMP-response element (CRE)-binding activity were enhanced by treatment of ECs with AdE4+. However, there is no causal evidence of a cross-talk between the 2 modulatory pathways, PKA and PI3K. Remarkably, Cx40 immunostaining was markedly increased and Cx43 was decreased in the heart tissue of mice treated with intratracheal AdE4+. Taken together, these results suggest that AdE4+ may play an important role in the regulation of Cx expression in ECs, and that these effects are mediated by both the PKA/CREB and PI3K signaling pathways. PMID:15831817

  14. Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Young Hyun Yoo

    2012-11-01

    Full Text Available Diallyl disulfide (DADS, a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound's anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4 and Fas ligand (FasL proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs, including extracellular-signal regulating kinase (ERK, p38 MAPK and c-Jun N-terminal kinase (JNK. A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059 and p38 MAPK (SB203580 had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.

  15. The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways.

    Directory of Open Access Journals (Sweden)

    Bruno A Cardoso

    Full Text Available The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi, albeit with poorer tolerance. Here, we show that bone marrow (BM stromal cells (HS-5 protected MPN-derived cell lines (SET-2; HEL and UKE-1 and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN.

  16. The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways

    Science.gov (United States)

    Cardoso, Bruno A.; Belo, Hélio; Barata, João T.; Almeida, António M.

    2015-01-01

    The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN) are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi), albeit with poorer tolerance. Here, we show that bone marrow (BM) stromal cells (HS-5) protected MPN-derived cell lines (SET-2; HEL and UKE-1) and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN. PMID:26623653

  17. Piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways.

    Science.gov (United States)

    Wang, Hongfei; Wang, Yongqiang; Gao, Hongmei; Wang, Bing; Dou, Lin; Li, Yin

    2018-02-01

    Piperlongumine is an alkaloid compound extracted from Piper longum L. It is a chemical substance with various pharmacological effects and medicinal value, including anti-tumor, lipid metabolism regulatory, antiplatelet aggregation and analgesic properties. The present study aimed to understand whether piperlongumine induces the apoptosis and autophagy of leukemic cells, and to identify the mechanism involved. Cell viability and autophagy were detected using MTT, phenazine methyl sulfate and trypan blue exclusion assays. The apoptosis rate was calculated using flow cytometry. The protein expression levels of microtubule-associated protein 1A/1B-light chain 3, Akt and mechanistic target of rapamycin (mTOR) were measured using western blotting. The cell growth of leukemic cells was completely inhibited following treatment with piperlongumine, and marked apoptosis was also induced. Dead cells as a result of autophagy were stained using immunofluorescence and observed under a light microscope. Phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling was suppressed by treatment with piperlongumine, while p38 signaling and caspase-3 activity were induced by treatment with piperlongumine. It was concluded that piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways.

  18. Liraglutide Exerts Antidiabetic Effect via PTP1B and PI3K/Akt2 Signaling Pathway in Skeletal Muscle of KKAy Mice

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    Wenjun Ji

    2014-01-01

    Full Text Available Background. Liraglutide (a glucagon-like peptide 1 analog was used for the treatment of type 2 diabetes (T2DM which could produce glucose-dependent insulin secretion. Aim. The aim was to investigate whether liraglutide could improve myofibril and mitochondria injury in skeletal muscle and the mechanisms in diabetic KKAy mice. Method. We divided the male KKAy mice into 2 groups: liraglutide group (250 μg/kg/day liraglutide subcutaneous injection and model group; meanwhile, the male C57BL/6J mice were considered as the control. After 6 weeks, the ultrastructure of skeletal muscle was observed by electron microscope. The gene expressions of protein tyrosine phosphatase 1B (PTP1B, phosphatidylinositol 3-kinase (PI3K, and glucose transporter type 4 (GLUT4 were determined by real-time PCR. The protein levels of the above molecules and phospho-Akt2 (p-Akt2 were measured by Western blot. Results. Liraglutide significantly ameliorated the injury of mitochondria by increasing the number (+441% and the area (+113% of mitochondria and mitochondrial area/100 µm2 (+396% in skeletal muscle of KKAy mice. The results of real-time PCR and Western blot showed that liraglutide downregulated PTP1B while it upregulated PI3K and GLUT4 (P<0.01. The protein level of p-Akt2/Akt2 was also increased (P<0.01. Conclusion. These results revealed that liraglutide could improve myofibril and mitochondria injury in skeletal muscle against T2DM via PTP1B and PI3K/Akt2 signaling pathway.

  19. Estrogen Receptor Signaling and the PI3K/Akt Pathway Are Involved in Betulinic Acid-Induced eNOS Activation

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    Nicolas Hohmann

    2016-07-01

    Full Text Available Betulinic acid (BA is a naturally occurring pentacyclic triterpenoid with anti-inflammatory, antiviral and anti-cancer properties. Beneficial cardiovascular effects such as increased nitric oxide (NO production through enhancement of endothelial NO synthase (eNOS activity and upregulation of eNOS expression have been demonstrated for this compound. In the present study, immortalized human EA.hy 926 endothelial cells were incubated for up to 1 h with 1–100 µM BA and with the phosphatidylinositol-3-kinase (PI3K inhibitors LY294002 and wortmannin, or the estrogen receptor (ER antagonist ICI 182,780. Phosphorylation status of eNOS and total eNOS protein were analyzed by Western blotting using a serine 1177 phosphosite-specific antibody. Bioactive NO production was assessed by determination of cGMP content in rat lung fibroblasts (RFL-6 reporter cells. Short-term incubation of EA.hy 926 cells with BA resulted in eNOS phosphorylation at the serine 1177 residue in a concentration- and time-dependent manner with a half-maximal effective concentration of 0.57 µM. This was associated with an enhanced production of NO. BA-induced eNOS phosphorylation and NO production was completely blocked by pretreatment with ICI 182,780, and was attenuated by pretreatment with the PI3K inhibitors wortmannin and LY294002. These results indicate that fast non-genomic effects of ER with downstream signaling through the PI3K/Akt pathway and consecutive eNOS phosphorylation at serine 1177 are involved in BA-induced eNOS activation.

  20. Brucein D, a Naturally Occurring Tetracyclic Triterpene Quassinoid, Induces Apoptosis in Pancreatic Cancer through ROS-Associated PI3K/Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Zheng-Quan Lai

    2017-12-01

    Full Text Available Brucein D (BD, a major active quassinoid in Brucea javanica, has exhibited pronounced anticancer activities. However, the biologic mechanisms have not been fully explored. In this study, BD exhibited more potent cytotoxic effect on pancreatic cancer (PanCa cell lines, while exerted weaker cytotoxic effects on GES-1 cells (non-tumorigenic. BD was shown to elicit apoptosis through inducing both the intrinsic and extrinsic mitochondria-mediated caspase activations. Furthermore, the BD-induced apoptotic effects were dependent on the accumulated reactive oxygen species (ROS and inactivation of PI3K/Akt signaling pathway. Pretreatment with tempol completely prevented the cellular apoptosis induced by BD, and recovered the inactivation of AKT, which suggested ROS essentially involved in BD-elicited apoptosis and down-regulation of PI3K/Akt pathway. In addition, the results obtained from orthotopic xenograft in nude mice were congruent with those of the in vitro investigations. These results support the notion that BD held good potential to be further developed into an effective pharmaceutical agent for the treatment of PanCa.

  1. Downregulation of PI3K/Akt/mTOR signaling pathway in curcumin-induced autophagy in APP/PS1 double transgenic mice.

    Science.gov (United States)

    Wang, Chen; Zhang, Xiong; Teng, Zhipeng; Zhang, Tong; Li, Yu

    2014-10-05

    Autophagy is a lysosomal degradation pathway, which is essential for cell survival, proliferation, differentiation and homeostasis. It is well known that beta-amyloid (Aβ) aggregation is one of key characteristics for Alzheimer's disease (AD), which triggers a complex pathological cascade, leading to neurodegeneration. Recent studies have shown that Aβ peptide is generated from amyloid β precursor protein (APP) during autophagic turnover of APP-rich organelles by autophagy. Aβ generation during normal autophagy is subsequently degraded by lysosomes. Curcumin, a nature plant extraction, has been reported to inhibit the generation and deposition of Aβ; however, the underlying mechanisms are not fully understood yet. In the present study, we reported that curcumin treatment not only attenuated cognitive impairment detected by Morris water maze test, but also inhibited the generation of Aβ investigated by immunohistochemistry in APP/PS1 double transgenic AD mice. Moreover, curcumin induced autophagy in the mice, evidenced by LC3 immunofluorescence analysis and western blot assays on LC3. Furthermore, we found that curcumin significantly decreased the expression of Phosphatidylinositol 3-Kinase (PI3K), phosphorylated Akt and rapamycin (mTOR) at protein levels, respectively. Taken together, our data suggests that curcumin inhibits Aβ generation and induces of autophagy by downregulating PI3K/Akt/mTOR signaling pathway, and further shows a neuroprotective effect. Meanwhile curcumin might be a candidate neuroprotective agent for AD patients treatment by inducing autophagy. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Leucine Affects α-Amylase Synthesis through PI3K/Akt-mTOR Signaling Pathways in Pancreatic Acinar Cells of Dairy Calves.

    Science.gov (United States)

    Guo, Long; Liang, Ziqi; Zheng, Chen; Liu, Baolong; Yin, Qingyan; Cao, Yangchun; Yao, Junhu

    2018-05-23

    Dietary nutrient utilization, particularly starch, is potentially limited by digestion in dairy cow small intestine because of shortage of α-amylase. Leucine acts as an effective signal molecular in the mTOR signaling pathway, which regulates a series of biological processes, especially protein synthesis. It has been reported that leucine could affect α-amylase synthesis and secretion in ruminant pancreas, but mechanisms have not been elaborated. In this study, pancreatic acinar (PA) cells were used as a model to determine the cellular signal of leucine influence on α-amylase synthesis. PA cells were isolated from newborn Holstein dairy bull calves and cultured in Dulbecco's modifed Eagle's medium/nutrient mixture F12 liquid media containing four leucine treatments (0, 0.23, 0.45, and 0.90 mM, respectively), following α-amylase activity, zymogen granule, and signal pathway factor expression detection. Rapamycin, a specific inhibitor of mTOR, was also applied to PA cells. Results showed that leucine increased ( p synthesis of α-amylase as well as phosphorylation of PI3K, Akt, mTOR, and S6K1 while reduced ( p synthesis. In addition, the extracellular leucine dosage significantly influenced intracellular metabolism of isoleucine ( p synthesis through promoting the PI3K/Akt-mTOR pathway and reducing the GCN2 pathway in PA cells of dairy calves. These pathways form the signaling network that controls the protein synthesis and metabolism. It would be of great interest in future studies to explore the function of leucine in ruminant nutrition.

  3. Fisetin, a dietary flavonoid induces apoptosis via modulating the MAPK and PI3K/Akt signalling pathways in human osteosarcoma (U-2 OS cells

    Directory of Open Access Journals (Sweden)

    Jian-Ming Li

    2015-12-01

    Full Text Available Human osteosarcoma is the most prevalent primary malignant bone tumor with high frequency of invasion and metastasis. Strong resistance coupled with toxicity of the currently available chemotherapeutic drugs poses challenge in treatment. The study aimed to investigate if fisetin, a dietary flavonoid induced apoptosis in human osteosarcoma (U-2 OS cells. Fisetin at 20-100 µM effectively reduced the viability of OS cells, and induced apoptosis by significantly inducing the expression of caspases (Caspases- 3,-8 and -9 and pro-apoptotic proteins (Bax and Bad with subsequent down-regulation of Bcl-xL and Bcl-2. While fisetin inhibited PI3K/Akt pathway and ERK1/2, it caused enhanced expressions of p-JNK, p-c-Jun and p-p38. Fisetin-induced ROS generation and decrease in mitochondrial membrane potential would have also contributed to rise in apoptotic cell counts. The observations suggest that fisetin was able to effectively induce apoptosis of U-2 OS cells through ROS generation and modulation of MAPK and PI3K/Akt signalling cascades.

  4. Honokiol induces autophagic cell death in malignant glioma through reactive oxygen species-mediated regulation of the p53/PI3K/Akt/mTOR signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien-Ju [Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan (China); Comprehensive Cancer Center, Taipei Medical University, Taipei, Taiwan (China); Chen, Ta-Liang [Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan (China); Tseng, Yuan-Yun [Department of Neurosurgery, Shuang-Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Wu, Gong-Jhe [Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Hsieh, Ming-Hui [Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan (China); Lin, Yung-Wei [Brain Disease Research Center, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan (China); Chen, Ruei-Ming, E-mail: rmchen@tmu.edu.tw [Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan (China); Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Brain Disease Research Center, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan (China); Comprehensive Cancer Center, Taipei Medical University, Taipei, Taiwan (China)

    2016-08-01

    Honokiol, an active constituent extracted from the bark of Magnolia officinalis, possesses anticancer effects. Apoptosis is classified as type I programmed cell death, while autophagy is type II programmed cell death. We previously proved that honokiol induces cell cycle arrest and apoptosis of U87 MG glioma cells. Subsequently in this study, we evaluated the effect of honokiol on autophagy of glioma cells and examined the molecular mechanisms. Administration of honokiol to mice with an intracranial glioma increased expressions of cleaved caspase 3 and light chain 3 (LC3)-II. Exposure of U87 MG cells to honokiol also induced autophagy in concentration- and time-dependent manners. Results from the addition of 3-methyladenine, an autophagy inhibitor, and rapamycin, an autophagy inducer confirmed that honokiol-induced autophagy contributed to cell death. Honokiol decreased protein levels of PI3K, phosphorylated (p)-Akt, and p-mammalian target of rapamycin (mTOR) in vitro and in vivo. Pretreatment with a p53 inhibitor or transfection with p53 small interfering (si)RNA suppressed honokiol-induced autophagy by reversing downregulation of p-Akt and p-mTOR expressions. In addition, honokiol caused generation of reactive oxygen species (ROS), which was suppressed by the antioxidant, vitamin C. Vitamin C also inhibited honokiol-induced autophagic and apoptotic cell death. Concurrently, honokiol-induced alterations in levels of p-p53, p53, p-Akt, and p-mTOR were attenuated following vitamin C administration. Taken together, our data indicated that honokiol induced ROS-mediated autophagic cell death through regulating the p53/PI3K/Akt/mTOR signaling pathway. - Highlights: • Exposure of mice with intracranial gliomas to honokiol induces cell apoptosis and autophagy. • Honokiol triggers autophagy of human glioma cells via the PISK/AKT/mTOR signaling pathway. • P53 induces autophagy via regulating the AKT/mTOR pathway in honokiol-treated glioma cells. • ROS participates

  5. Reactive oxygen species via redox signaling to PI3K/AKT pathway contribute to the malignant growth of 4-hydroxy estradiol-transformed mammary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Victor O Okoh

    Full Text Available The purpose of this study was to investigate the effects of 17-β-estradiol (E2-induced reactive oxygen species (ROS on the induction of mammary tumorigenesis. We found that ROS-induced by repeated exposures to 4-hydroxy-estradiol (4-OH-E2, a predominant catechol metabolite of E2, caused transformation of normal human mammary epithelial MCF-10A cells with malignant growth in nude mice. This was evident from inhibition of estrogen-induced breast tumor formation in the xenograft model by both overexpression of catalase as well as by co-treatment with Ebselen. To understand how 4-OH-E2 induces this malignant phenotype through ROS, we investigated the effects of 4-OH-E2 on redox-sensitive signal transduction pathways. During the malignant transformation process we observed that 4-OH-E2 treatment increased AKT phosphorylation through PI3K activation. The PI3K-mediated phosphorylation of AKT in 4-OH-E2-treated cells was inhibited by ROS modifiers as well as by silencing of AKT expression. RNA interference of AKT markedly inhibited 4-OH-E2-induced in vitro tumor formation. The expression of cell cycle genes, cdc2, PRC1 and PCNA and one of transcription factors that control the expression of these genes - nuclear respiratory factor-1 (NRF-1 was significantly up-regulated during the 4-OH-E2-mediated malignant transformation process. The increased expression of these genes was inhibited by ROS modifiers as well as by silencing of AKT expression. These results indicate that 4-OH-E2-induced cell transformation may be mediated, in part, through redox-sensitive AKT signal transduction pathways by up-regulating the expression of cell cycle genes cdc2, PRC1 and PCNA, and the transcription factor - NRF-1. In summary, our study has demonstrated that: (i 4-OH-E2 is one of the main estrogen metabolites that induce mammary tumorigenesis and (ii ROS-mediated signaling leading to the activation of PI3K/AKT pathway plays an important role in the generation of 4-OH-E2

  6. PI3K/PKB signaling in Rhipicephalus (Boophilus) microplus tick embryo cell line BME26

    International Nuclear Information System (INIS)

    Abreu, L.; Fabres, A.; Logullo, C.; Esteves, E.; Daffre, S.

    2008-01-01

    Full text: Ticks are obligatory blood-sucking arthropods and important vectors of both human and animal diseases. In order to study the insulin triggered pathway and its possible roles during embryogenesis we are using a culture of embryonic Rhipicephalus (Boophilus) micro plus cells (BME26). Besides its metabolic role, insulin signaling pathway (ISP) is widely described as crucial for vertebrate and invertebrate embryogenesis and development. In such cascade Phosphatidylinositol 3-OH Kinase (PI3K) is hierarchically located upstream Protein Kinase B (PKB). Exogenous insulin is able to increase the expression level of PI3K's regulatory sub unity (p85), as determined by Real Time RT-PCR. In the presence of PI3K inhibitors (Wortmannin or LY294002) these effects were reversed. This correlates well with the activation of PKB by phosphorylation, as it appears to be PI3K-dependent. Additionally, PI3K inhibition increased the expression level of two insulin-regulated downstream targets from glycogen metabolism (GSK3b) and gluneogenesis (PEPCK) pathways. GSK3b inhibition by phosphorylation diminished in cells treated with PI3K inhibitors. These results strongly suggest the presence of an insulin sensitive PI3K-PKB axis in BME26 cells. The further study of PI3K and PKB activity in egg homogenates during embryogenesis may help us to understand the role of ISP for R. micro plus development

  7. PI3K/PKB signaling in Rhipicephalus (Boophilus) microplus tick embryo cell line BME26

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, L.; Fabres, A.; Logullo, C. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Biociencias e Biotecnologia. Lab. de Quimica e Funcao de Proteinas e Peptideos (LQFPP)]. E-mail: leoabreu@uenf.br; Esteves, E.; Daffre, S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Bioquimica

    2008-07-01

    Full text: Ticks are obligatory blood-sucking arthropods and important vectors of both human and animal diseases. In order to study the insulin triggered pathway and its possible roles during embryogenesis we are using a culture of embryonic Rhipicephalus (Boophilus) micro plus cells (BME26). Besides its metabolic role, insulin signaling pathway (ISP) is widely described as crucial for vertebrate and invertebrate embryogenesis and development. In such cascade Phosphatidylinositol 3-OH Kinase (PI3K) is hierarchically located upstream Protein Kinase B (PKB). Exogenous insulin is able to increase the expression level of PI3K's regulatory sub unity (p85), as determined by Real Time RT-PCR. In the presence of PI3K inhibitors (Wortmannin or LY294002) these effects were reversed. This correlates well with the activation of PKB by phosphorylation, as it appears to be PI3K-dependent. Additionally, PI3K inhibition increased the expression level of two insulin-regulated downstream targets from glycogen metabolism (GSK3b) and gluneogenesis (PEPCK) pathways. GSK3b inhibition by phosphorylation diminished in cells treated with PI3K inhibitors. These results strongly suggest the presence of an insulin sensitive PI3K-PKB axis in BME26 cells. The further study of PI3K and PKB activity in egg homogenates during embryogenesis may help us to understand the role of ISP for R. micro plus development.

  8. Involvement of HDAC1 and the PI3K/PKC signaling pathways in NF-κB activation by the HDAC inhibitor apicidin

    International Nuclear Information System (INIS)

    Kim, Yong Kee; Seo, Dong-Wan; Kang, Dong-Won; Lee, Hoi Young; Han, Jeung-Whan; Kim, Su-Nam

    2006-01-01

    Histone deacetylase (HDAC) inhibitors are appreciated as one of promising anticancer drugs, but they exert differential responses depending on the cell type. We recently reported the critical role of NF-κB as a modulator in determining cell fate for apoptosis in response to an HDAC inhibitor. In this study, we investigate a possible signaling pathway required for NF-κB activation in response to the HDAC inhibitor apicidin. Treatment of HeLa cells with apicidin leads to an increase in transcriptional activity of NF-κB and the expression of its target genes, IL-8 and TNF-α. TNF-α expression by apicidin is induced at earlier time points than NF-κB activation or IL-8 expression. In addition, our data show that the early expression of TNF-α does not lead to activation of NF-κB, because disruption of TNF-α activity by a neutralizing antibody does not affect nuclear translocation of NF-κB, IκBα degradation or reporter gene activation by apicidin. However, this activation of NF-κB requires the PI3K and PKC signaling pathways, but not ERK or JNK. Furthermore, apicidin activation of NF-κB seems to result from HDAC1 inhibition, as evidenced by the observation that overexpression of HDAC1, but not HDAC2, 3 or 4, dramatically inhibits NF-κB reporter gene activity. Collectively, our results suggest that activation of NF-κB signaling by apicidin requires both the PI3K/PKC signaling pathways and HDAC1, and functions as a critical modulator in determining the cellular effect of apicidin

  9. Role of GSK-3β in Regulation of Canonical Wnt/β-catenin Signaling and PI3-K/Akt Oncogenic Pathway in Colon Cancer.

    Science.gov (United States)

    Jain, Shelly; Ghanghas, Preety; Rana, Chandan; Sanyal, S N

    2017-08-09

    Non-steroidal anti-inflammatory drugs (NSAIDs) are emerging as novel chemopreventive agents because of their ability in blocking cellular proliferation, and thereby tumor development, and also by promoting apoptosis. GSK-3β, a serine threonine kinase and a negative regulator of the oncogenic Wnt/β-catenin signaling pathway, plays a critical role in the regulation of oncogenesis. Celecoxib and etoricoxib, the two cyclooxygenase-2 (COX-2) selective NSAIDs, and Diclofenac, a preferential COX-2 inhibitory NSAID, had shown uniformly the chemopreventive and anti-neoplastic effects in the early stage of colon cancer by promoting apoptosis as well as an over-expression of GSK-3β while down-regulating the PI3-K/Akt oncogenic pathway.

  10. Andrographolide promotes vincristine-induced SK-NEP-1 tumor cell death via PI3K-AKT-p53 signaling pathway

    Directory of Open Access Journals (Sweden)

    Zhang M

    2016-09-01

    Full Text Available Mingsheng Zhang, Enda Xue, Wei Shao Department of Pediatric Surgery, Liaocheng People’s Hospital, Liaocheng, Shandong Province, People’s Republic of China Background: Nephroblastoma (Wilms’ tumor [WT] is the most common malignant renal cancer in children. Although the outcome of WT has significantly improved as a result of the combination of surgery, chemotherapy, and radiotherapy; in some cases WT results in severe complications. Thus, novel strategies that would decrease treatment burden are required. The aim of the current study was to investigate the synergistic antitumor effect of andrographolide (AND in combination with vincristine (VCR on WT cells.Methods: Cell Counting Kit-8 assay was used to investigate the synergistic antiproliferation effect of AND and/or VCR on SK-NEP-1 cells in vitro. Meanwhile, SK-NEP-1 xenografts were used to detect the antitumor effect in vivo. Apoptosis and autophagy were then detected by Annexin V, monodansylcadaverine staining. Finally, the underlying signaling transduction was determined with Western blotting.Results: The combination of AND with VCR significantly suppressed SK-NEP-1 cell proliferation in vitro and inhibited xenograft tumor growth in vivo, compared with AND or VCR treatment alone. In addition, the synergistic antitumor effect of AND on the cells was due to an increased apoptosis, not autophagy. Moreover, PI3K-AKT-p53 signaling pathway was involved in the process of combination treatment, which was confirmed when a selective AKT activator was applied.Conclusion: The combination of AND with VCR has a strong synergistic antitumor effect on WT via PI3K-AKT-p53 signaling pathway, thereby representing a potential treatment for WT in the near future. Keywords: andrographolide, vincristine, p53, drug combination

  11. Marine Cyclotripeptide X-13 Promotes Angiogenesis in Zebrafish and Human Endothelial Cells via PI3K/Akt/eNOS Signaling Pathways

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    Zhong Pei

    2012-06-01

    Full Text Available Cyclotripeptide X-13 is a core of novel marine compound xyloallenoide A isolated from mangrove fungus Xylaria sp. (no. 2508. We found that X-13 dose-dependently induced angiogenesis in zebrafish embryos and in human endothelial cells, which was accompanied by increased phosphorylation of eNOS and Akt and NO release. Inhibition of PI3K/Akt/eNOS by LY294002 or l-NAME suppressed X-13-induced angiogenesis. The present work demonstrates that X-13 promotes angiogenesis via PI3K/Akt/eNOS pathways.

  12. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

    Directory of Open Access Journals (Sweden)

    Demin Jiao

    2016-01-01

    Full Text Available The epithelial-mesenchymal transition (EMT and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs, we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

  13. TFII-I regulates target genes in the PI-3K and TGF-β signaling pathways through a novel DNA binding motif.

    Science.gov (United States)

    Segura-Puimedon, Maria; Borralleras, Cristina; Pérez-Jurado, Luis A; Campuzano, Victoria

    2013-09-25

    General transcription factor (TFII-I) is a multi-functional protein involved in the transcriptional regulation of critical developmental genes, encoded by the GTF2I gene located on chromosome 7q11.23. Haploinsufficiency at GTF2I has been shown to play a major role in the neurodevelopmental features of Williams-Beuren syndrome (WBS). Identification of genes regulated by TFII-I is thus critical to detect molecular determinants of WBS as well as to identify potential new targets for specific pharmacological interventions, which are currently absent. We performed a microarray screening for transcriptional targets of TFII-I in cortex and embryonic cells from Gtf2i mutant and wild-type mice. Candidate genes with altered expression were verified using real-time PCR. A novel motif shared by deregulated genes was found and chromatin immunoprecipitation assays in embryonic fibroblasts were used to document in vitro TFII-I binding to this motif in the promoter regions of deregulated genes. Interestingly, the PI3K and TGFβ signaling pathways were over-represented among TFII-I-modulated genes. In this study we have found a highly conserved DNA element, common to a set of genes regulated by TFII-I, and identified and validated novel in vivo neuronal targets of this protein affecting the PI3K and TGFβ signaling pathways. Overall, our data further contribute to unravel the complexity and variability of the different genetic programs orchestrated by TFII-I. © 2013 Elsevier B.V. All rights reserved.

  14. Inhibitor of PI3K/Akt Signaling Pathway Small Molecule Promotes Motor Neuron Differentiation of Human Endometrial Stem Cells Cultured on Electrospun Biocomposite Polycaprolactone/Collagen Scaffolds.

    Science.gov (United States)

    Ebrahimi-Barough, Somayeh; Hoveizi, Elham; Yazdankhah, Meysam; Ai, Jafar; Khakbiz, Mehrdad; Faghihi, Faezeh; Tajerian, Roksana; Bayat, Neda

    2017-05-01

    Small molecules as useful chemical tools can affect cell differentiation and even change cell fate. It is demonstrated that LY294002, a small molecule inhibitor of phosphatidylinositol 3-kinase (PI3K)/Akt signal pathway, can inhibit proliferation and promote neuronal differentiation of mesenchymal stem cells (MSCs). The purpose of this study was to investigate the differentiation effect of Ly294002 small molecule on the human endometrial stem cells (hEnSCs) into motor neuron-like cells on polycaprolactone (PCL)/collagen scaffolds. hEnSCs were cultured in a neurogenic inductive medium containing 1 μM LY294002 on the surface of PCL/collagen electrospun fibrous scaffolds. Cell attachment and viability of cells on scaffolds were characterized by scanning electron microscope (SEM) and 3-(4,5-dimethylthiazoyl-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay. The expression of neuron-specific markers was assayed by real-time PCR and immunocytochemistry analysis after 15 days post induction. Results showed that attachment and differentiation of hEnSCs into motor neuron-like cells on the scaffolds with Ly294002 small molecule were higher than that of the cells on tissue culture plates as control group. In conclusion, PCL/collagen electrospun scaffolds with Ly294002 have potential for being used in neural tissue engineering because of its bioactive and three-dimensional structure which enhances viability and differentiation of hEnSCs into neurons through inhibition of the PI3K/Akt pathway. Thus, manipulation of this pathway by small molecules can enhance neural differentiation.

  15. CXCR3 chemokine receptor-induced chemotaxis in human airway epithelial cells: role of p38 MAPK and PI3K signaling pathways.

    Science.gov (United States)

    Shahabuddin, Syed; Ji, Rong; Wang, Ping; Brailoiu, Eugene; Dun, Na; Yang, Yi; Aksoy, Mark O; Kelsen, Steven G

    2006-07-01

    Human airway epithelial cells (HAEC) constitutively express the CXC chemokine receptor CXCR3, which regulates epithelial cell movement. In diseases such as chronic obstructive pulmonary disease and asthma, characterized by denudation of the epithelial lining, epithelial cell migration may contribute to airway repair and reconstitution. This study compared the potency and efficacy of three CXCR3 ligands, I-TAC/CXCL11, IP-10/CXCL10, and Mig/CXCL9, as inducers of chemotaxis in HAEC and examined the underlying signaling pathways involved. Studies were performed in cultured HAEC from normal subjects and the 16-HBE cell line. In normal HAEC, the efficacy of I-TAC-induced chemotaxis was 349 +/- 88% (mean +/- SE) of the medium control and approximately one-half the response to epidermal growth factor, a highly potent chemoattractant. In normal HAEC, Mig, IP-10, and I-TAC induced chemotaxis with similar potency and a rank order of efficacy of I-TAC = IP-10 > Mig. Preincubation with pertussis toxin completely blocked CXCR3-induced migration. Of interest, intracellular [Ca(2+)] did not rise in response to I-TAC, IP-10, or Mig. I-TAC induced a rapid phosphorylation (5-10 min) of two of the three MAPKs, i.e., p38 and ERK1/2. Pretreatment of HAEC with the p38 inhibitor SB 20358 or the PI3K inhibitor wortmannin dose-dependently inhibited the chemotactic response to I-TAC. In contrast, the ERK1/2 inhibitor U0126 had no effect on chemotaxis. These data indicate that in HAEC, CXCR3-mediated chemotaxis involves a G protein, which activates both the p38 MAPK and PI3K pathways in a calcium-independent fashion.

  16. Chaetominine reduces MRP1-mediated drug resistance via inhibiting PI3K/Akt/Nrf2 signaling pathway in K562/Adr human leukemia cells

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    Yao, Jingyun; Wei, Xing [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China); Lu, Yanhua, E-mail: luyanhua@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China)

    2016-05-13

    Drug resistance limits leukemia treatment and chaetominine, a cytotoxic alkaloid that promotes apoptosis in a K562 human leukemia cell line via the mitochondrial pathway was studied with respect to chemoresistance in a K562/Adr human resistant leukemia cell line. Cytotoxicity assays indicated that K562/Adr resistance to adriamycin (ADR) did not occur in the presence of chaetominine and that chaetominine increased chemosensitivity of K562/Adr to ADR. Data show that chaetominine enhanced ADR-induced apoptosis and intracellular ADR accumulation in K562/Adr cells. Accordingly, chaetominine induced apoptosis by upregulating ROS, pro-apoptotic Bax and downregulating anti-apoptotic Bcl-2. RT-PCR and western-blot confirmed that chaetominine suppressed highly expressed MRP1 at mRNA and protein levels. But little obvious alternation of another drug transporter MDR1 mRNA was observed. Furthermore, inhibition of MRP1 by chaetominine relied on inhibiting Akt phosphorylation and nuclear Nrf2. In summary, chaetominine strongly reverses drug resistance by interfering with the PI3K/Akt/Nrf2 signaling, resulting in reduction of MRP1-mediated drug efflux and induction of Bax/Bcl-2-dependent apoptosis in an ADR-resistant K562/Adr leukemia cell line. - Highlights: • Chaetominine enhanced chemosensitivity of ADR against K562/Adr cells. • Chaetominine increased intracellular ADR levels via inhibiting MRP1. • Chaetominine induced apoptosis of K562/Adr cells through upregulation of ROS and modulation of Bax/Bcl-2. • Inhibition of MRP1 and Nrf2 by chaetominine treatment was correlative with blockade of PI3K/Akt signaling.

  17. A genome-wide RNAi screen identifies FOXO4 as a metastasis-suppressor through counteracting PI3K/AKT signal pathway in prostate cancer.

    Directory of Open Access Journals (Sweden)

    Bing Su

    Full Text Available Activation of the PI3K/AKT signal pathway is a known driving force for the progression to castration-recurrent prostate cancer (CR-CaP, which constitutes the major lethal phenotype of CaP. Here, we identify using a genomic shRNA screen the PI3K/AKT-inactivating downstream target, FOXO4, as a potential CaP metastasis suppressor. FOXO4 protein levels inversely correlate with the invasive potential of a panel of human CaP cell lines, with decreased mRNA levels correlating with increased incidence of clinical metastasis. Knockdown (KD of FOXO4 in human LNCaP cells causes increased invasion in vitro and lymph node (LN metastasis in vivo without affecting indices of proliferation or apoptosis. Increased Matrigel invasiveness was found by KD of FOXO1 but not FOXO3. Comparison of differentially expressed genes affected by FOXO4-KD in LNCaP cells in culture, in primary tumors and in LN metastases identified a panel of upregulated genes, including PIP, CAMK2N1, PLA2G16 and PGC, which, if knocked down by siRNA, could decrease the increased invasiveness associated with FOXO4 deficiency. Although only some of these genes encode FOXO promoter binding sites, they are all RUNX2-inducible, and RUNX2 binding to the PIP promoter is increased in FOXO4-KD cells. Indeed, the forced expression of FOXO4 reversed the increased invasiveness of LNCaP/shFOXO4 cells; the forced expression of FOXO4 did not alter RUNX2 protein levels, yet it decreased RUNX2 binding to the PIP promoter, resulting in PIP downregulation. Finally, there was a correlation between FOXO4, but not FOXO1 or FOXO3, downregulation and decreased metastasis-free survival in human CaP patients. Our data strongly suggest that increased PI3K/AKT-mediated metastatic invasiveness in CaP is associated with FOXO4 loss, and that mechanisms to induce FOXO4 re-expression might suppress CaP metastatic aggressiveness.

  18. microRNA 126 inhibits the transition of endothelial progenitor cells to mesenchymal cells via the PIK3R2-PI3K/Akt signalling pathway.

    Science.gov (United States)

    Zhang, Junfeng; Zhang, Zongqi; Zhang, David Y; Zhu, Jianbing; Zhang, Tiantian; Wang, Changqian

    2013-01-01

    Endothelial progenitor cells (EPCs) are capable of proliferating and differentiating into mature endothelial cells, and they have been considered as potential candidates for coronary heart disease therapy. However, the transition of EPCs to mesenchymal cells is not fully understood. This study aimed to explore the role of microRNA 126 (miR-126) in the endothelial-to-mesenchymal transition (EndMT) induced by transforming growth factor beta 1 (TGFβ1). EndMT of rat bone marrow-derived EPCs was induced by TGFβ1 (5 ng/mL) for 7 days. miR-126 expression was depressed in the process of EPC EndMT. The luciferase reporter assay showed that the PI3K regulatory subunit p85 beta (PIK3R2) was a direct target of miR-126 in EPCs. Overexpression of miR-126 by a lentiviral vector (lenti-miR-126) was found to downregulate the mRNA expression of mesenchymal cell markers (α-SMA, sm22-a, and myocardin) and to maintain the mRNA expression of progenitor cell markers (CD34, CD133). In the cellular process of EndMT, there was an increase in the protein expression of PIK3R2 and the nuclear transcription factors FoxO3 and Smad4; PI3K and phosphor-Akt expression decreased, a change that was reversed markedly by overexpression of miR-126. Furthermore, knockdown of PIK3R2 gene expression level showed reversed morphological changes of the EPCs treated with TGFβ1, thereby giving the evidence that PIK3R2 is the target gene of miR-126 during EndMT process. These results show that miR-126 targets PIK3R2 to inhibit EPC EndMT and that this process involves regulation of the PI3K/Akt signalling pathway. miR-126 has the potential to be used as a biomarker for the early diagnosis of intimal hyperplasia in cardiovascular disease and can even be a therapeutic tool for treating cardiovascular diseases mediated by the EndMT process.

  19. microRNA 126 inhibits the transition of endothelial progenitor cells to mesenchymal cells via the PIK3R2-PI3K/Akt signalling pathway.

    Directory of Open Access Journals (Sweden)

    Junfeng Zhang

    Full Text Available AIMS: Endothelial progenitor cells (EPCs are capable of proliferating and differentiating into mature endothelial cells, and they have been considered as potential candidates for coronary heart disease therapy. However, the transition of EPCs to mesenchymal cells is not fully understood. This study aimed to explore the role of microRNA 126 (miR-126 in the endothelial-to-mesenchymal transition (EndMT induced by transforming growth factor beta 1 (TGFβ1. METHODS AND RESULTS: EndMT of rat bone marrow-derived EPCs was induced by TGFβ1 (5 ng/mL for 7 days. miR-126 expression was depressed in the process of EPC EndMT. The luciferase reporter assay showed that the PI3K regulatory subunit p85 beta (PIK3R2 was a direct target of miR-126 in EPCs. Overexpression of miR-126 by a lentiviral vector (lenti-miR-126 was found to downregulate the mRNA expression of mesenchymal cell markers (α-SMA, sm22-a, and myocardin and to maintain the mRNA expression of progenitor cell markers (CD34, CD133. In the cellular process of EndMT, there was an increase in the protein expression of PIK3R2 and the nuclear transcription factors FoxO3 and Smad4; PI3K and phosphor-Akt expression decreased, a change that was reversed markedly by overexpression of miR-126. Furthermore, knockdown of PIK3R2 gene expression level showed reversed morphological changes of the EPCs treated with TGFβ1, thereby giving the evidence that PIK3R2 is the target gene of miR-126 during EndMT process. CONCLUSIONS: These results show that miR-126 targets PIK3R2 to inhibit EPC EndMT and that this process involves regulation of the PI3K/Akt signalling pathway. miR-126 has the potential to be used as a biomarker for the early diagnosis of intimal hyperplasia in cardiovascular disease and can even be a therapeutic tool for treating cardiovascular diseases mediated by the EndMT process.

  20. ROLE OF PI3K-AKT-mTOR AND Wnt SIGNALING PATHWAYS IN G1-S TRANSITION OF CELL CYCLE IN CANCER CELLS

    Directory of Open Access Journals (Sweden)

    LAKSHMIPATHI eVADLAKONDA

    2013-04-01

    Full Text Available The PI3K–Akt pathway together with one of its downstream targets, the mechanistic target of rapamycin (mTOR is a highly deregulated pathway in cancers. There is a reciprocal relation between the Akt phosphorylation and mTOR complexes. Akt phosphorylated at T308 activates mTORC1 by inhibition of the tuberous sclerosis complex (TSC1/2, where as mTORC2 is recognized as the kinase that phosphorylates Akt at S473. Recent developments in the research on regulatory mechanisms of autophagy places mTORC1 mediated inhibition of autophagy at the central position in activation of proliferation and survival pathways in cells. Autophagy is a negative regulator of Wnt signaling pathway and the downstream effectors of Wnt signaling pathway, cyclin D1 and the c-Myc, are the key players in initiation of cell cycle and regulation of the G1-S transition in cancer cells. Production of reaction oxygen species (ROS, a common feature of a cancer cell metabolism, activates several downstream targets like the transcription factors FoxO, which play key roles in promoting the progression of cell cycle. A model is presented on the role of PI3K -Akt - mTOR and Wnt pathways in regulation of the progression of cell cycle through Go-G1-and S phases.

  1. Protective Effect of DHT on Apoptosis Induced by U18666A via PI3K/Akt Signaling Pathway in C6 Glial Cell Lines.

    Science.gov (United States)

    Yao, Kai; Wu, Junfeng; Zhang, Jianfeng; Bo, Jimei; Hong, Zhen; Zu, Hengbing

    2016-07-01

    Various useful animal models, such as Alzheimer's disease and Niemann-Pick disease, were provided by U18666A. However, the pathogenesis of U18666A-induced diseases, including U18666A-mediated apoptosis, remains incompletely elucidated, and therapeutic strategies are still limited. Dihydrotestosterone (DHT) has been reported to contribute to the prevention and treatment of neurodegenerative disorders. Our study investigated the neuroprotective activity of DHT in U18666A-related diseases. Apoptosis of C6 cells was detected by Hoechst 33258 fluorescent staining and flow cytometry with annexin V-FITC/PI dual staining. Cell viability was assessed using Cell Counting Kit-8. Expression of apoptosis-related proteins, such as Akt, seladin-1, Bcl-2 family proteins, and caspase-3, was determined using Western blot. Our results demonstrated that the apoptotic rate of C6 cells significantly increased after U18666A addition, but was remarkably reduced after DHT treatment. Pretreatment with DHT attenuated U18666A-induced cell viability loss. PI3K inhibitor LY294002 could suppress DHT anti-apoptotic effect. Furthermore, we discovered that U18666A could significantly downregulate seladin-1 expression in a dose-dependent manner, but no significant change was observed in Bcl-xL, Bax, and P-Akt protein expressions. Compared with U18666A-treated group, the expression of P-Akt, seladin-1, and Bcl-xL significantly increased, and the expression of Bax and caspase-3 remarkably reduced after DHT treatment. However, in the presence of LY294002, the effect of DHT was reversed. In conclusion, we found that seladin-1 may take part in U18666A-induced apoptosis. DHT may inhibit U18666A-induced apoptosis by regulating downstream apoptosis-related proteins including seladin-1, caspase-3, Bcl-xL, and Bax through activation of the PI3K/Akt signal pathway.

  2. BDE-99 (2,2',4,4',5-pentabromodiphenyl ether) triggers epithelial-mesenchymal transition in colorectal cancer cells via PI3K/Akt/Snail signaling pathway.

    Science.gov (United States)

    Wang, Fei; Ruan, Xin-Jian; Zhang, Hong-Yan

    2015-01-01

    The gut is in direct contact with BDE-99 (2,2',4,4',5-pentabromodiphenyl ether), one of the most abundant PBDE congeners in the environment and in human tissues. The objective of the present study was to investigate the effects of BDE-99 on colorectal cancer (CRC) cells. The effects of BDE-99 on cell proliferation were measured by CCK-8 assay in the CRC cell line HCT-116. Wound healing and transwell migration/invasion assays were used to test the migration and invasion of CRC cells. Factors related to epithelial-to-mesenchymal transition (EMT) were measured by real-time PCR and Western blot analysis for mRNA and protein levels, respectively. BDE-99 was found to increase migration and invasion and trigger EMT in HCT-116 cells; EMT was characterized by cells acquiring mesenchymal spindle-like morphology and by increased expression of N-cadherin with a concomitant decrease in E-cadherin. BDE-99 treatment also increased the protein and mRNA levels of the transcription factor Snail, but not Slug, Twist, and ZEB1. Knockdown of Snail by siRNA significantly attenuated BDE-99-induced EMT in HCT-116 cells, suggesting that Snail plays a crucial role in BDE-99-induced EMT. The PI3K/Akt inhibitor LY294002 completely blocked BDE-99-induced Snail and invasion of HCT-116 cells. Our results revealed that BDE-99 can trigger the EMT of colon cancer cells via the PI3K/AKT/Snail signaling pathway. This study provides new insight into the tumorigenesis and metastasis of CRC stimulated by BDE-99 and possibly other PBDE congeners.

  3. Puerarin protects differentiated PC12 cells from H₂O₂-induced apoptosis through the PI3K/Akt signalling pathway.

    Science.gov (United States)

    Zhang, Qin; Huang, Wei-Dong; Lv, Xue-Ying; Yang, Yun-Mei

    2012-05-01

    Oxidative stress has been implicated as a major mechanism underlying the pathogenesis of neurodegenerative disorders. ROS (reactive oxygen species) can cause cell death via apoptosis. NGF (nerve growth factor) differentiated rat PC12 cells have been extensively used to study the differentiation and apoptosis of neurons. This study has investigated the protective effects of puerarin in H2O2-induced apoptosis of differentiated PC12 cells, and the possible molecular mechanisms involved. Differentiated PC12 cells were incubated with 700 μM H2O2 in the absence or presence of different doses of puerarin (4, 8 and 16 μM). Apoptosis was assessed by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay, TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) analysis and Annexin V-PI (propidium iodide) double staining flow cytometry. Protein levels of phospho-Akt and phospho-BAD (Bcl-2/Bcl-XL-antagonist, causing cell death) were assayed by Western blotting. After stimulation with H2O2 for 18 h, the viability of differentiated PC12 cells decreased significantly and a large number of cells underwent apoptosis. Differentiated PC12 cells were rescued from H2O2-induced apoptosis at different concentrations of puerarin in a dose-dependent manner. This was through increased production of phospho-Akt and phospho-BAD, an effect that could be reversed by wortmannin, an inhibitor of PI3K (phosphoinositide 3-kinase). The results suggest that puerarin may have neuroprotective effect through activation of the PI3K/Akt signalling pathway.

  4. Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

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    Suman, Shubhankar [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Johnson, Michael D. [Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Fornace, Albert J. [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Datta, Kamal, E-mail: kd257@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)

    2012-10-01

    Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

  5. Effects of rehabilitation training on apoptosis of nerve cells and the recovery of neural and motor functions in rats with ischemic stroke through the PI3K/Akt and Nrf2/ARE signaling pathways.

    Science.gov (United States)

    Jin, Xiao-Fei; Wang, Shan; Shen, Min; Wen, Xin; Han, Xin-Rui; Wu, Jun-Chang; Tang, Gao-Zhuo; Wu, Dong-Mei; Lu, Jun; Zheng, Yuan-Lin

    2017-09-01

    This study was designed in order to investigate the effects between rehabilitation training on the apoptosis of nerve cells and the recovery of neural and motor functions of rats with ischemic stroke by way of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and nuclear factor E2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathways. In total, 110 healthy adult male Sprague-Dawley (SD) rats were selected in order to take part in this study. Ninety SD rats were used in order to establish the middle cerebral artery occlusion (MCAO), among which 80 rats were randomly assigned as part of the natural recovery, natural recovery+Rp-PI3K (the rats injected with PI3K/Akt inhibitor LY294002), rehabilitation training, and rehabilitation training+Rp-PI3K groups. Meanwhile, 20 rats were selected as part of the sham operation group. The neural and motor functions of these rats were evaluated using a balance beam test and the Bederson score. The mRNA expressions of PI3K, Akt, Nrf2 and HO-1 were measured using an RT-qPCR. The protein expressions of PI3K, p-PI3K, Akt, p-Akt, Nrf2 and HO-1 were also detected by using western blotting and the immunohistochemistry process. The cell cycle and cell apoptosis were detected by using a flow cytometry and TUNEL assay. The sham operation group exhibited lower neural and motor function scores than other groups. At the 7, 14, and 21 d marks of this study, the neural and motor function scores were increased in the natural recovery, natural recovery+Rp-PI3K, and rehabilitation training+Rp-PI3K groups in comparison with the rehabilitation training group but found to be decreased in the natural recovery group in comparison with the natural recovery+Rp-PI3K group. In comparison with the sham operation group, expressions of PI3K, Nrf2 and HO-1, and proportions of p-PI3K/PI3K and p-Akt/Akt were all higher in the natural recovery, rehabilitation training, and rehabilitation training+Rp-PI3K groups. Same trends were

  6. Paeonia lactiflora Pall. protects against ANIT-induced cholestasis by activating Nrf2 via PI3K/Akt signaling pathway

    Directory of Open Access Journals (Sweden)

    Ma X

    2015-09-01

    Full Text Available Xiao Ma,1,2 Yan-ling Zhao,2 Yun Zhu,3 Zhe Chen,1,2 Jia-bo Wang,4 Rui-yu Li,1,4 Chang Chen,1,2 Shi-zhang Wei,1,2 Jian-yu Li,3 Bing Liu,5 Rui-lin Wang,3 Yong-gang Li,3 Li-fu Wang,3 Xiao-he Xiao4 1Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, People’s Republic of China; 2Department of Pharmacy, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 3Department of Integrative Medical Center, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 4China Military Institute of Chinese Medicine, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 5School of Chinese Medicine, The University of Hong Kong, Hong Kong Background: Paeonia lactiflora Pall. (PLP, a traditional Chinese herbal medicine, has been used for hepatic disease treatment over thousands of years. In our previous study, PLP was shown to demonstrate therapeutic effect on hepatitis with severe cholestasis. The aim of this study was to evaluate the antioxidative effect of PLP on alpha-naphthylisothiocyanate (ANIT-induced cholestasis by activating NF-E2-related factor 2 (Nrf2 via phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway. Materials and methods: Liquid chromatography-mass spectrometry (LC-MS was performed to identify the main compounds present in PLP. The mechanism of action of PLP and its therapeutic effect on cholestasis, induced by ANIT, were further investigated. Serum indices such as total bilirubin (TBIL, direct bilirubin (DBIL, aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, γ-glutamyl transpeptidase (γ-GT, and total bile acid (TBA were measured, and histopathology of liver was also performed to determine the efficacy of treatment with PLP. Moreover, in order to illustrate the underlying signaling pathway, liver glutathione (GSH content and mRNA or protein levels of glutamate

  7. E6 variants of human papillomavirus 18 differentially modulate the protein kinase B/phosphatidylinositol 3-kinase (akt/PI3K) signaling pathway

    International Nuclear Information System (INIS)

    Contreras-Paredes, Adriana; Cruz-Hernandez, Erick de la; Martinez-Ramirez, Imelda; Duenas-Gonzalez, Alfonso; Lizano, Marcela

    2009-01-01

    Intra-type genome variations of high risk Human papillomavirus (HPV) have been associated with a differential threat for cervical cancer development. In this work, the effect of HPV18 E6 isolates in Akt/PKB and Mitogen-associated protein kinase (MAPKs) signaling pathways and its implication in cell proliferation were analyzed. E6 from HPV types 16 and 18 are able to bind and promote degradation of Human disc large (hDlg). Our results show that E6 variants differentially modulate hDlg degradation, rebounding in levels of activated PTEN and PKB. HPV18 E6 variants are also able to upregulate phospho-PI3K protein, strongly correlating with activated MAPKs and cell proliferation. Data was supported by the effect of E6 silencing in HPV18-containing HeLa cells, as well as hDlg silencing in the tested cells. Results suggest that HPV18 intra-type variations may derive in differential abilities to activate cell-signaling pathways such as Akt/PKB and MAPKs, directly involved in cell survival and proliferation

  8. Mefloquine effectively targets gastric cancer cells through phosphatase-dependent inhibition of PI3K/Akt/mTOR signaling pathway

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    Liu, Yanwei [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Chen, Sen [Department of Academic Affairs, Hubei University of Medicine, Shiyan, Hubei Province (China); Xue, Rui [Department of Anesthesiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Zhao, Juan [Department of Oncology, Xiangyang Central Hospital, Shiyan, Hubei Province (China); Di, Maojun, E-mail: maoojun_di@163.com [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China)

    2016-02-05

    Deregulation of PI3K/Akt/mTOR pathway has been recently identified to play a crucial role in the progress of human gastric cancer. In this study, we show that mefloquine, a FDA-approved anti-malarial drug, effectively targets human gastric cancer cells. Mefloquine potently inhibits proliferation and induces apoptosis of a panel of human gastric cancer cell lines, with EC{sub 50} ∼0.5–0.7 μM. In two independent gastric cancer xenograft mouse models, mefloquine significantly inhibits growth of both tumors. The combination of mefloquine with paclitaxel enhances the activity of either drug alone in in vitro and in vivo. In addition, mefloquine potently decreased phosphorylation of PI3K, Akt, mTOR and rS6. Overexpression of constitutively active Akt significantly restored mefloquine-mediated inhibition of mTOR phosphorylation and growth, and induction of apoptosis, suggesting that mefloquine acts on gastric cancer cells via suppressing PI3K/Akt/mTOR pathway. We further show that mefloquine-mediated inhibition of Akt/mTOR singaling is phosphatase-dependent as pretreatment with calyculin A does-dependently reversed mefloquine-mediated inhibition of Akt/mTOR phosphorylation. Since mefloquine is already available for clinic use, these results suggest that it is a useful addition to the treatment armamentarium for gastric cancer. - Highlights: • Mefloquine targets a panel of gastric cancer cell lines in vitro and in vivo. • Combination of mefloquine and paclitaxel is synergistic. • Mefloquine acts on gastric cancer via inhibition of PI3K/Akt/mTOR pathway. • Mefloquine can be repurposed for gastric cancer treatment.

  9. Naoxintong Protects Primary Neurons from Oxygen-Glucose Deprivation/Reoxygenation Induced Injury through PI3K-Akt Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yan Ma

    2016-01-01

    Full Text Available Naoxintong capsule (NXT, developed from Buyang Huanwu Decoction, has shown the neuroprotective effects in cerebrovascular diseases, but the neuroprotection mechanisms of NXT on ischemia/reperfusion injured neurons have not yet been well known. In this study, we established the oxygen-glucose deprivation/reoxygenation (OGD/R induced neurons injury model and treat the neurons with cerebrospinal fluid containing NXT (BNC to investigate the effects of NXT on OGD/R induced neurons injury and potential mechanisms. BNC improved neuron viability and decreased apoptotic rate induced by OGD/R. BNC attenuated OGD/R induced cytosolic and mitochondrial Ca2+ overload, ROS generation, intracellular NO levels and nNOS mRNA increase, and cytochrome-c release when compared with OGD/R group. BNC significantly inhibited both mPTP opening and ΔΨm depolarization. BNC increased Bcl-2 expression and decreased Bax expression, upregulated the Bcl-2/Bax ratio, downregulated caspase-3 mRNA and caspase-9 mRNA expression, and decreased cleaved caspase-3 expression and caspase-3 activity. BNC increased phosphorylation of Akt following OGD/R, while LY294002 attenuated BNC induced increase of phosphorylated Akt expression. Our study demonstrated that NXT protected primary neurons from OGD/R induced injury by inhibiting calcium overload and ROS generation, protecting mitochondria, and inhibiting mitochondrial apoptotic pathway which was mediated partially by PI3K-Akt signaling pathway activation.

  10. Huperzine A Alleviates Oxidative Glutamate Toxicity in Hippocampal HT22 Cells via Activating BDNF/TrkB-Dependent PI3K/Akt/mTOR Signaling Pathway.

    Science.gov (United States)

    Mao, Xiao-Yuan; Zhou, Hong-Hao; Li, Xi; Liu, Zhao-Qian

    2016-08-01

    Oxidative glutamate toxicity is involved in diverse neurological disorders including epilepsy and ischemic stroke. Our present work aimed to assess protective effects of huperzine A (HupA) against oxidative glutamate toxicity in a mouse-derived hippocampal HT22 cells and explore its potential mechanisms. Cell survival and cell injury were analyzed by MTT method and LDH release assay, respectively. The production of ROS was measured by detection kits. Protein expressions of BDNF, phosphor-TrkB (p-TrkB), TrkB, phosphor-Akt (p-Akt), Akt, phosphor-mTOR (p-mTOR), mTOR, phosphor-p70s6 (p-p70s6) kinase, p70s6 kinase, Bcl-2, Bax, and β-actin were assayed via Western blot analysis. Enzyme-linked immunosorbent assay was employed to measure the contents of nerve growth factor, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). Our findings illustrated 10 μM HupA for 24 h significantly protected HT22 from cellular damage and suppressed the generation of ROS. Additionally, after treating with LY294002 or wortmannin [the selective inhibitors of phosphatidylinositol 3 kinase (PI3K)], HupA dramatically prevented the down-regulations of p-Akt, p-mTOR, and p-p70s6 kinase in HT22 cells under oxidative toxicity. Furthermore, it was observed that the protein levels of BDNF and p-TrkB were evidently enhanced after co-treatment with HupA and glutamate in HT22 cells. The elevations of p-Akt and p-mTOR were abrogated under toxic conditions after blockade of TrkB by TrkB IgG. Cellular apoptosis was significantly suppressed (decreased caspase-3 activity and enhanced Bcl-2 protein level) after HupA treatment. It was concluded that HupA attenuated oxidative glutamate toxicity in murine hippocampal HT22 cells via activating BDNF/TrkB-dependent PI3K/Akt/mTOR signaling pathway.

  11. Tamoxifen reduces P-gp-mediated multidrug resistance via inhibiting the PI3K/Akt signaling pathway in ER-negative human gastric cancer cells.

    Science.gov (United States)

    Mao, Zonglei; Zhou, Jin; Luan, Junwei; Sheng, Weihua; Shen, Xiaochun; Dong, Xiaoqiang

    2014-03-01

    Multidrug resistance (MDR), mediated by overexpression of drug efflux transporters such as P-glycoprotein (P-gp), is a major problem limiting successful chemotherapy of gastric cancer. Tamoxifen (TAM), a triphenylethylene nonsteroidal antiestrogen agent, shows broad-spectrum antitumor properties. Emerging studies demonstrated that TAM could significantly reduce the MDR in a variety of human cancers. Here we investigated the effects and possible underlying mechanisms of action of TAM on the reversion of MDR in ER-negative human gastric cancer cells. Our results demonstrated that in MDR phenotype SGC7901/CDDP gastric cancer cells TAM dramatically lowered the IC50 of CDDP, 5-FU and ADM, increased the intracellular Rhodamine123 accumulation and induced G0/G1 phase arrest, while G2/M phase decreased accordingly. Furthermore, at the molecular level, TAM substantially decreased the expression of P-gp, p-Akt and the Akt-regulated downstream effectors such as p-GSK-3β, p-BAD, Bcl-XL and cyclinD1 proteins without affecting the expression of t-Akt, t-GSK-3β, t-BAD proteins in SGC7901/CDDP cells. Thus, our findings demonstrate that TAM reverses P-gp-mediated gastric cancer cell MDR via inhibiting the PI3K/Akt signaling pathway. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  12. Cudarflavone B Provides Neuroprotection against Glutamate-Induced Mouse Hippocampal HT22 Cell Damage through the Nrf2 and PI3K/Akt Signaling Pathways

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    Dong-Sung Lee

    2014-07-01

    Full Text Available Oxidative cell damage contributes to neuronal degeneration in many central nervous system (CNS diseases such as Alzheimer’s disease, Parkinson’s disease, and ischemia. Nrf2 signaling-mediated heme oxygenase (HO-1 expression acts against oxidants that are thought to play a key role in the pathogenesis of neuronal diseases. Cudraflavone B is a prenylated flavone isolated from C. tricuspidata which has shown anti-proliferative activity, mouse brain monoamine oxidase (MAO inhibitory effects, apoptotic actions in human gastric carcinoma cells and mouse melanoma cells, and hepatoprotective activity. In this study, cudraflavone B showed neuroprotective effects and reactive oxygen species (ROS inhibition against glutamate-induced neurotoxicity by inducing the expression of HO-1 in mouse hippocampal HT22 cells. Furthermore, cudraflavone B caused the nuclear accumulation of nuclear factor-E2-related factor 2 (Nrf2 and increased the promoter activity of antioxidant response elements (ARE in mouse hippocampal HT22 cells. In addition, we found that the Nrf2-midiated HO-1 expression by cudraflavone B is involved in the cell protective response and ROS reductions, and cudraflavone B-induced expression of HO-1 was mediated through the phosphatidylinositol 3-kinase (PI3K/Akt pathway in HT22 cells. Our results demonstrated the potential application of naturally occurring cudraflavone B as a therapeutic agent from neurodegenerative disease.

  13. Si-Wu-tang extract stimulates bone formation through PI3K/Akt/NF-κB signaling pathways in osteoblasts.

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    Wu, Chi-Ming; Chen, Po-Chun; Li, Te-Mao; Fong, Yi-Chin; Tang, Chih-Hsin

    2013-10-24

    Si-Wu-Tang (SWT), a Traditional Chinese Medicine (TCM) formula, is widely used for the treatment of gynopathies diseases such as menstrual discomfort, climacteric syndrome, dysmenorrhea, and other estrogen-related diseases. Recent studies have shown that SWT can treat primary dysmenorrhea, have anti-pruritic anti-inflammatory effects, and protect against radiation-induced bone marrow damage in an animal model. It has been reported that anti-inflammatory and anti-oxidant agents have the potential to treat osteoporosis by increasing bone formation and/or suppressing bone resorption. However, the effect of SWT on bone cell function has not yet been reported. Alkaline phosphatase (ALP), bone morphogenetic proteins (BMP)-2, and osteopontin (OPN) mRNA expression was analyzed by qPCR. The mechanism of action of SWT extract was investigated using western blotting. The in vivo anti-osteoporotic effect of SWT extract was assessed in ovariectomized mice. Here, we report that SWT increases ALP, BMP-2, and OPN expression as well as bone mineralization. In addition, we show that the PI3K, Akt, and NF-κB signaling pathways may be involved in the SWT-mediated increase in gene expression and bone mineralization. Notably, treatment of mice with SWT extract prevented bone loss induced by ovariectomy in vivo. SWT may be used to stimulate bone formation for the treatment of osteoporosis.

  14. The Apoptotic Effect of Ursolic Acid on SK-Hep-1 Cells is Regulated by the PI3K/Akt, p38 and JNK MAPK Signaling Pathways

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    Wan-Ling Chuang

    2016-04-01

    Full Text Available Ursolic acid (UA is a pentacyclic triterpene acid that is present in a wide variety of medicinal herbs and edible plants. This study investigated the effect of UA on apoptosis and proliferation of hepatocellular carcinoma SK-Hep-1 cells. After treatment of SK-Hep-1 cells with different concentrations of UA, we observed that cell viability was reduced in a dose- and time-dependent manner. Furthermore, there was a dose-dependent increase in the percentage of cells in the sub-G1 and G2/M phases, with cells treated with 60 μM showing the highest percentages of cells in those phases. UA-induced chromatin condensation of nuclei was observed by using DAPI staining. The western blot results revealed that exposure to UA was associated with decreased expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, Bcl-2, and TCTP and increased expression of apoptosis-related proteins TNF-α, Fas, FADD, Bax, cleaved caspase-3, caspase-8, caspase-9, and PARP. Immunocytochemistry staining showed that treatment with UA resulted in increased expression of caspase-3. Moreover, exposure to UA resulted in the inhibition of the PI3K/Akt and p38 MAPK signaling pathways. These findings suggest that UA inhibits the proliferation of SK-Hep-1 cells and induces apoptosis.

  15. Relaxin attenuates aristolochic acid induced human tubular epithelial cell apoptosis in vitro by activation of the PI3K/Akt signaling pathway.

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    Xie, Xiang-Cheng; Zhao, Ning; Xu, Qun-Hong; Yang, Xiu; Xia, Wen-Kai; Chen, Qi; Wang, Ming; Fei, Xiao

    2017-06-01

    Aristolochic acid nephropathy remains a leading cause of chronic kidney disease (CKD), however few treatment strategies exist. Emerging evidence has shown that H2 relaxin (RLX) possesses powerful antifibrosis and anti-apoptotic properties, therefore we aimed to investigate whether H2 relaxin can be employed to reduce AA-induced cell apoptosis. Human proximal tubular epithelial (HK-2) cells exposed to AA-I were treated with or without administration of H2 RLX. Cell viability was examined using the WST-8 assay. Apoptotic morphologic alterations were observed using the Hoechst 33342 staining method. Apoptosis was detected using flow cytometry. The expression of caspase 3, caspase 8, caspase 9, ERK1/2, Bax, Bcl-2, and Akt proteins was determined by Western blot. Co-treatment with RLX reversed the increased apoptosis observed in the AA-I only treated group. RLX restored expression of phosphorylated Akt which found to be decreased in the AA-I only treated cells. RLX co-treatment led to a decrease in the Bax/Bcl-2 ratio as well as the cleaved form of caspase-3 compared to the AA-I only treated cells. This anti-apoptotic effect of RLX was attenuated by co-administration of the Akt inhibitor LY294002. The present study demonstrated H2 RLX can decrease AA-I induced apoptosis through activation of the PI3K/Akt signaling pathway.

  16. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

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    Han-Peng Kuo

    2013-01-01

    Full Text Available Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT, one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2.

  17. Smad, PI3K/Akt, and Wnt-dependent signaling pathways are involved in BMP-4-induced ESC self-renewal.

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    Lee, Min Young; Lim, Hyun Woo; Lee, Sang Hun; Han, Ho Jae

    2009-08-01

    It is known that bone morphogenetic protein 4 (BMP-4) has a diverse effect on ESCs. However, its precise mechanism in mouse ESCs is not fully understood. We evaluated the effect of BMP-4 on ESC proliferation and its related signal cascades in this study. BMP-4 significantly increased the level of [(3)H]-thymidine incorporation in time- (> or =8 hours) and dose- (> or =10 ng/ml) dependent manners. Additionally, BMP-4 increased cyclin D1 and decreased p27(kip1) expression values in a time-dependent manner. The increases in BMP-4-induced [(3)H]-thymidine incorporation and cyclin D1 expression were inhibited by the BMP-4 receptor antagonist noggin. BMP-4 increased Wnt1 expression. Wnt1 expression was attenuated by Smad4 small interfering RNA (siRNA), and BMP-4-induced cyclin D1 expression was inhibited by Smad4 and Wnt1 siRNAs. BMP-4 also activated beta-catenin, which was blocked by Smad4 and Wnt1 siRNAs. In addition, BMP-4 induced Akt phosphorylation. BMP-4-induced beta-catenin activation and cyclin D1 expression were attenuated by phosphatidyl inositol 3-kinase (PI3K) siRNA and Akt inhibitor. Additionally, downregulation of Smad4, Wnt1, and PI3K expression by siRNA decreased the levels of pluripotency marker mRNAs of ESCs, including Oct4, Sox2, and FoxD3. Our results suggested that BMP-4-induced [(3)H]-thymidine incorporation was significantly attenuated by Smad4, Wnt1, and PI3K knockdown. In conclusion, BMP-4 contributed to the maintenance of cell proliferation and the pluripotent state by Smad, PI3K/Akt, and Wnt1/beta-catenin in mouse ESCs.

  18. Dengue virus enhances thrombomodulin and ICAM-1 expression through the macrophage migration inhibitory factor induction of the MAPK and PI3K signaling pathways.

    Directory of Open Access Journals (Sweden)

    Trai-Ming Yeh

    Full Text Available Dengue virus (DV infections cause mild dengue fever (DF or severe life-threatening dengue hemorrhagic fever (DHF. The mechanisms that cause hemorrhage in DV infections remain poorly understood. Thrombomodulin (TM is a glycoprotein expressed on the surface of vascular endothelial cells that plays an important role in the thrombin-mediated activation of protein C. Prior studies have shown that the serum levels of soluble TM (sTM and macrophage migration inhibitory factor (MIF are significantly increased in DHF patients compared to levels in DF patients or normal controls. In this study, we investigated how MIF and sTM concentrations are enhanced in the plasma of DHF patients and the potential effect of MIF on coagulation through its influence on two factors: thrombomodulin (TM and intercellular adhesion molecule-1 (ICAM-1 in endothelial cells and monocytes. Recombinant human macrophage migration inhibitory factor (rMIF was used to treat monocytic THP-1 cells and endothelial HMEC-1 cells or primary HUVEC cells. The subsequent expression of TM and ICAM-1 was assessed by immunofluorescent staining and flow cytometry analysis. Additionally, the co-incubation of THP-1 cells with various cell signaling pathway inhibitors was used to determine the pathways through which MIF mediated its effect. The data provided evidence that severe DV infections induce MIF expression, which in turn stimulates monocytes or endothelial cells to express TM and ICAM-1 via the Erk, JNK MAPK and the PI3K signaling pathways, supporting the idea that MIF may play an important role as a regulator of coagulation.

  19. PI3K/AKT signaling inhibits NOTCH1 lysosome-mediated degradation.

    Science.gov (United States)

    Platonova, Natalia; Manzo, Teresa; Mirandola, Leonardo; Colombo, Michela; Calzavara, Elisabetta; Vigolo, Emilia; Cermisoni, Greta Chiara; De Simone, Daria; Garavelli, Silvia; Cecchinato, Valentina; Lazzari, Elisa; Neri, Antonino; Chiaramonte, Raffaella

    2015-06-06

    The pathways of NOTCH and PI3K/AKT are dysregulated in about 60% and 48% of T-cell acute lymphoblastic leukemia (T-ALL) patients, respectively. In this context, they interact and cooperate in controlling tumor cell biology. Here, we propose a novel mechanism by which the PI3K/AKT pathway regulates NOTCH1 in T-ALL, starting from the evidence that the inhibition of PI3K/AKT signaling induced by treatment with LY294002 or transient transfection with a dominant negative AKT mutant downregulates NOTCH1 protein levels and activity, without affecting NOTCH1 transcription. We showed that the withdrawal of PI3K/AKT signaling was associated to NOTCH1 phosphorylation in tyrosine residues and monoubiquitination of NOTCH1 detected by Ubiquitin capture assay. Co-immunoprecipitation assay and colocalization analysis further showed that the E3 ubiquitin ligase c-Cbl interacts and monoubiquitinates NOTCH1, activating its lysosomal degradation. These results suggest that the degradation of NOTCH1 could represent a mechanism of control by which NOTCH1 receptors are actively removed from the cell surface. This mechanism is finely regulated by the PI3K/AKT pathway in physiological conditions. In pathological conditions characterized by PI3K/AKT hyperactivation, such as T-ALL, the excessive AKT signaling could lead to NOTCH1 signaling dysregulation. Therefore, a therapeutic strategy directed to PI3K/AKT in T-ALL could contemporaneously inhibit the dysregulated NOTCH1 signaling. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  20. AKT-independent PI3-K signaling in cancer – emerging role for SGK3

    International Nuclear Information System (INIS)

    Bruhn, Maressa A; Pearson, Richard B; Hannan, Ross D; Sheppard, Karen E

    2013-01-01

    The phosphoinositide 3-kinase (PI3-K) signaling pathway plays an important role in a wide variety of fundamental cellular processes, largely mediated via protein kinase B/v-akt murine thymoma viral oncogene homolog (PKB/AKT) signaling. Given the crucial role of PI3-K/AKT signaling in regulating processes such as cell growth, proliferation, and survival, it is not surprising that components of this pathway are frequently dysregulated in cancer, making the AKT kinase family members important therapeutic targets. The large number of clinical trials currently evaluating PI3-K pathway inhibitors as a therapeutic strategy further emphasizes this. The serum- and glucocorticoid-inducible protein kinase (SGK) family is made up of three isoforms, SGK1, 2, and 3, that are PI3-K-dependent, serine/threonine kinases, with similar substrate specificity to AKT. Consequently, the SGK family also regulates similar cell processes to the AKT kinases, including cell proliferation and survival. Importantly, there is emerging evidence demonstrating that SGK3 plays a critical role in AKT-independent oncogenic signaling. This review will focus on the role of SGK3 as a key effector of AKT-independent PI3-K oncogenic signaling

  1. The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma

    International Nuclear Information System (INIS)

    Matsuoka, Tasuku; Yashiro, Masakazu

    2014-01-01

    The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma

  2. The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Tasuku [Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Yashiro, Masakazu, E-mail: m9312510@med.osaka-cu.ac.jp [Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Oncology Institute of Geriatrics and Medical Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan)

    2014-07-07

    The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma.

  3. Notoginsenoside Ft1 Promotes Fibroblast Proliferation via PI3K/Akt/mTOR Signaling Pathway and Benefits Wound Healing in Genetically Diabetic Mice.

    Science.gov (United States)

    Zhang, Eryun; Gao, Bo; Yang, Li; Wu, Xiaojun; Wang, Zhengtao

    2016-02-01

    Wound healing requires the essential participation of fibroblasts, which is impaired in diabetic foot ulcers (DFU). Notoginsenoside Ft1 (Ft1), a saponin from Panax notoginseng, can enhance platelet aggregation by activating signaling network mediated through P2Y12 and induce proliferation, migration, and tube formation in cultured human umbilical vein endothelial cells. However, whether it can accelerate fibroblast proliferation and benefit wound healing, especially DFU, has not been elucidated. In the present study on human dermal fibroblast HDF-a, Ft1 increased cell proliferation and collagen production via PI3K/Akt/mTOR signaling pathway. On the excisional wound splinting model established on db/db diabetic mouse, topical application of Ft1 significantly shortened the wound closure time by 5.1 days in contrast with phosphate-buffered saline (PBS) treatment (15.8 versus 20.9 days). Meanwhile, Ft1 increased the rate of re-epithelialization and the amount of granulation tissue at day 7 and day 14. The molecule also enhanced mRNA expressions of COL1A1, COL3A1, transforming growth factor (TGF)-β1 and TGF-β3 and fibronectin, the genes that contributed to collagen expression, fibroblast proliferation, and consequent scar formation. Moreover, Ft1 facilitated the neovascularization accompanied with elevated vascular endothelial growth factor, platelet-derived growth factor, and fibroblast growth factor at either mRNA or protein levels and alleviated the inflammation of infiltrated monocytes indicated by reduced tumor necrosis factor-α and interleukin-6 mRNA expressions in the diabetic wounds. Altogether, these results indicated that Ft1 might accelerate diabetic wound healing by orchestrating multiple processes, including promoting fibroblast proliferation, enhancing angiogenesis, and attenuating inflammatory response, which provided a great potential application of it in clinics for patients with DFU. Copyright © 2016 by The American Society for Pharmacology and

  4. Netrin-1 induces the migration of Schwann cells via p38 MAPK and PI3K-Akt signaling pathway mediated by the UNC5B receptor

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    Lv, Jianwei [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Zhang, Yang; Li, Fengbo; Li, Yanjun; Zhao, Zhihu [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China)

    2015-08-14

    Schwann cells (SCs) play an essentially supportive role in the regeneration of injured peripheral nerve system (PNS). As Netrin-1 is crucial for the normal development of nervous system (NS) and can direct the process of damaged PNS regeneration, our study was designed to determine the role of Netrin-1 in RSC96 Schwann cells (an immortalized rat Schwann cell line) proliferation and migration. Our studies demonstrated that Netrin-1 had no effect on RSC96 cells proliferation, while significantly promoted RSC96 cells migration. The Netrin-1-induced RSC96 cells migration was significantly attenuated by inhibition of p38 and PI3K through pretreatment with SB203580 and LY294002 respectively, but not inhibition of MEK1/2 and JNK by U0126-EtOH and SP600125 individually. Treatment with Netrin-1 enhanced the phosphorylation of p38 and Akt. QRT-PCR indicated that Netrin-1 and only its receptors Unc5a, Unc5b and Neogenin were expressed in RSC96 cells, among which Unc5b expressed the most. And UNC5B protein was significantly increased after stimulated by Netrin-1. In conclusion, we show here that Netrin-1-enhanced SCs migration is mediated by activating p38 MAPK and PI3K-Akt signal cascades via receptor UNC5B, which suggests that Netrin-1 could serve as a new therapeutic strategy and has potential application value for PNS regeneration. - Highlights: • Netrin-1 attracts RSC96 Schwann cells migration in a dose dependent manner. • Netrin-1 induced Schwann cells migration is p38 and PI3K-Akt signaling dependent. • UNC5B may be dominant receptor mediating Netrin-1′ effect on RSC96 cells motility. • Netrin-1 may promote peripheral nerve repair by enhancing Schwann cells motility.

  5. Hydrogen protects against hyperoxia-induced apoptosis in type II alveolar epithelial cells via activation of PI3K/Akt/Foxo3a signaling pathway.

    Science.gov (United States)

    Wu, Dan; Liang, Mulin; Dang, Hongxing; Fang, Fang; Xu, Feng; Liu, Chengjun

    2018-01-08

    Oxidative stress is regarded as a key regulator in the pathogenesis of prolonged hyperoxia-induced lung injury, which causes injury to alveolar epithelial cells and eventually leads to development of bronchopulmonary dysplasia (BPD). Many studies have shown that hydrogen has a protective effect in a variety of cells. However, the mechanisms by which hydrogen rescues cells from damage due to oxidative stress in BPD remains to be fully elucidated. This study sought to evaluate the effects of hydrogen on hyperoxia-induced lung injury and to investigate the underlying mechanism. Primary type II alveolar epithelial cells (AECIIs) were divided into four groups: control (21% oxygen), hyperoxia (95% oxygen), hyperoxia + hydrogen, and hyperoxia + hydrogen + LY294002 (a PI3K/Akt inhibitor). Proliferation and apoptosis of AECIIs were assessed using MTS assay and flow cytometry (FCM), respectively. Gene and protein expression were detected by quantitative polymerase chain reaction (q-PCR) and western blot analysis. Stimulation with hyperoxia decreased the expression of P-Akt, P- FoxO3a, cyclinD1 and Bcl-2. Hyperoxic conditions increased levels of Bim, Bax, and Foxo3a, which induced proliferation restriction and apoptosis of AECIIs. These effects of hyperoxia were reversed with hydrogen pretreatment. Furthermore, the protective effects of hydrogen were abrogated by PI3K/Akt inhibitor LY294002. The results indicate that hydrogen protects AECIIs from hyperoxia-induced apoptosis by inhibiting apoptosis factors and promoting the expression of anti-apoptosis factors. These effects were associated with activation of the PI3K/Akt/FoxO3a pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. S100A11 promotes human pancreatic cancer PANC-1 cell proliferation and is involved in the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Xiao, Mingbing; Li, Tao; Ji, Yifei; Jiang, Feng; Ni, Wenkai; Zhu, Jing; Bao, Baijun; Lu, Cuihua; Ni, Runzhou

    2018-01-01

    S100A11, a member of S100 calcium-binding protein family, is associated with the numerous processes of tumorigenesis and metastasis. In the present study, the role of S100A11, and its possible underlying mechanisms in cell proliferation, apoptosis and cell cycle distribution in human pancreatic cancer were explored. Immunohistochemical analyses of S100A11 and phosphorylated (p)-AKT serine/threonine kinase (AKT) were performed in 30 resected specimens from patients with pancreatic cancer. PANC-1 cells were transfected with pcDNA3.1-S100A11 or treated with 50 µmol/l LY294002 for 48 h. Cell proliferation was determined using a cell counting kit-8 assay, whereas apoptosis and cell cycle distribution were determined by flow cytometry analysis. The mRNA and protein levels of S100A11, and AKT were determined using semi quantitative reverse transcription-polymerase chain reaction and western blot analyses, respectively. Pearson correlation analysis revealed that the expression levels of S100A11 and p-AKT were positively correlated (r, 0.802; PPANC-1 cell proliferation and reduced the percentage of early apoptotic cells. Flow cytometric analysis indicated that the proportion of PANC-1 cells in the S phase was significantly elevated and cell percentage in the G0/G1 phase declined in response to S100A11 overexpression (all PPANC-1 cell proliferation, promoted apoptosis and caused G1/S phase arrest in PANC-1 cells (all PPANC-1 cells through the upregulation of the PI3K/AKT signaling pathway. Thus, S100A11 may be considered as a novel drug target for targeted therapy of pancreatic cancer.

  7. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Huey-Chun Huang

    2016-01-01

    Full Text Available The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS. The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1–10 mg/mL and its major fatty acids such as linoleic acid and oleic acid (6.25–50 μM effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA, phosphatidylinositol-3-kinase (PI3K/Akt, and mitogen-activated protein kinases (MAPK signaling pathways, which may be due to linoleic acid and oleic acid.

  8. Kaempferol Inhibits Angiogenesis by Suppressing HIF-1α and VEGFR2 Activation via ERK/p38 MAPK and PI3K/Akt/mTOR Signaling Pathways in Endothelial Cells.

    Science.gov (United States)

    Kim, Gi Dae

    2017-12-01

    Kaempferol has been shown to inhibit vascular formation in endothelial cells. However, the underlying mechanisms are not fully understood. In the present study, we evaluated whether kaempferol exerts antiangiogenic effects by targeting extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathways in endothelial cells. Endothelial cells were treated with various concentrations of kaempferol for 24 h. Cell viability was determined by the 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay; vascular formation was analyzed by tube formation, wound healing, and mouse aortic ring assays. Activation of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor receptor 2 (VEGFR2), ERK/p38 MAPK, and PI3K/Akt/mTOR was analyzed by Western blotting. Kaempferol significantly inhibited cell migration and tube formation in endothelial cells, and suppressed microvessel sprouting in the mouse aortic ring assay. Moreover, kaempferol suppressed the activation of HIF-1α, VEGFR2, and other markers of ERK/p38 MAPK and PI3K/Akt/mTOR signaling pathways in endothelial cells. These results suggest that kaempferol inhibits angiogenesis by suppressing HIF-1α and VEGFR2 activation via ERK/p38 MAPK and PI3K/Akt/mTOR signaling in endothelial cells.

  9. ANTITUMOR AND APOPTOTIC EFFECTS OF CUCURBITACIN A IN A-549 LUNG CARCINOMA CELLS IS MEDIATED VIA G2/M CELL CYCLE ARREST AND M-TOR/PI3K/AKT SIGNALLING PATHWAY.

    Science.gov (United States)

    Wang, Wen-Dong; Liu, Yan; Su, Yuan; Xiong, Xian-Zhi; Shang, Dan; Xu, Juan-Juan; Liu, Hong-Ju

    2017-01-01

    The main aim of this study was to demonstrate the antitumor potential of cucurbitacin A on A-549 NSCLC (non-small cell lung cancer cells). The effects of Cucurbitacin A on apoptotic induction, cell physic, cell cycle failure and m-TOR/PI3K/Akt signalling pathway were also investigated in the present study. MTT assay and clonogenic assay were carried out to study effects of this compound on cell cytotoxicity and colony forming tendency in A-549 cells. Moreover, phase and fluorescence microscopic techniques were used to examine the effects on cell morphology and induction of apoptosis. The effects on cell cycle phase distribution were investigated by flow cytometry and effects on m-TOR/PI3K/Akt signalling proteins were assessed by western blot analysis. Results showed that cucurbitacin A induced dose-dependent cytotoxic effects along with suppressing the colony forming tendency in these cells. Cucurbitacin A also induced morphological changes in these cells featuring chromatin condensation, cell shrinkage and apoptotic body formation. G2/M phase cell cycle collapse was also induced by Cucurbitacin A along with inhibition of expression levels of m-TOR/PI3K/Akt proteins. In conclusion, cucurbitacin A inhibits cancer growth in A-549 NSCLC cells by inducing apoptosis, targeting m-TOR/PI3K/Akt signalling pathway and G2/M cell cycle.

  10. G protein-coupled receptors (GPCRs) That Signal via Protein Kinase A (PKA) Cross-talk at Insulin Receptor Substrate 1 (IRS1) to Activate the phosphatidylinositol 3-kinase (PI3K)/AKT Pathway.

    Science.gov (United States)

    Law, Nathan C; White, Morris F; Hunzicker-Dunn, Mary E

    2016-12-30

    G protein-coupled receptors (GPCRs) activate PI3K/v-AKT thymoma viral oncoprotein (AKT) to regulate many cellular functions that promote cell survival, proliferation, and growth. However, the mechanism by which GPCRs activate PI3K/AKT remains poorly understood. We used ovarian preantral granulosa cells (GCs) to elucidate the mechanism by which the GPCR agonist FSH via PKA activates the PI3K/AKT cascade. Insulin-like growth factor 1 (IGF1) is secreted in an autocrine/paracrine manner by GCs and activates the IGF1 receptor (IGF1R) but, in the absence of FSH, fails to stimulate YXXM phosphorylation of IRS1 (insulin receptor substrate 1) required for PI3K/AKT activation. We show that PKA directly phosphorylates the protein phosphatase 1 (PP1) regulatory subunit myosin phosphatase targeting subunit 1 (MYPT1) to activate PP1 associated with the IGF1R-IRS1 complex. Activated PP1 is sufficient to dephosphorylate at least four IRS1 Ser residues, Ser 318 , Ser 346 , Ser 612 , and Ser 789 , and promotes IRS1 YXXM phosphorylation by the IGF1R to activate the PI3K/AKT cascade. Additional experiments indicate that this mechanism also occurs in breast cancer, thyroid, and preovulatory granulosa cells, suggesting that the PKA-dependent dephosphorylation of IRS1 Ser/Thr residues is a conserved mechanism by which GPCRs signal to activate the PI3K/AKT pathway downstream of the IGF1R. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Antidiabetic Effects of a Chinese Herbal Medicinal Compound Sangguayin Preparation via PI3K/Akt Signaling Pathway in db/db Mice

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    Qichang Xing

    2018-01-01

    Full Text Available Sangguayin (SGY, comprising four types of Chinese herbs, can be used as both food and medicine and has been clinically used to treat type 2 diabetes mellitus (T2DM for a long time. Our previous study demonstrated the antidiabetic effect of SGY in experimental T2DM rats fed with a high-fat diet and treated with a low dose of streptozotocin. However, its mechanism of action is questionable. In this study, we refined the traditional SGY decoction and investigated its antidiabetic activity in db/db mice. We evaluated the possible molecular mechanism using skeletal muscle tissues. The results show that the treatment with SGY preparation resulted in a decrease in the blood glucose, glycated serum protein, and blood lipid levels and an improvement in the glucose tolerance as well as insulin resistance. In addition, SGY preparation remarkably upregulated the expression of insulin receptor, insulin receptor substrate-1, phosphoinositide 3 kinase (PI3K, protein kinase B (Akt, and glucose transporter type 4 (GLUT4. Thus, SGY preparation is an effective agent for the treatment of T2DM, and its molecular mechanism may be related to the regulation of PI3K/Akt signaling in the skeletal muscle.

  12. Resveratrol increases nucleus pulposus matrix synthesis through activating the PI3K/Akt signaling pathway under mechanical compression in a disc organ culture.

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    Han, Xiaorui; Leng, Xiaoming; Zhao, Man; Wu, Mei; Chen, Amei; Hong, Guoju; Sun, Ping

    2017-12-22

    Disc nucleus pulposus (NP) matrix homeostasis is important for normal disc function. Mechanical overloading seriously decreases matrix synthesis and increases matrix degradation. The present study aims to investigate the effects of resveratrol on disc NP matrix homeostasis under a relatively high-magnitude mechanical compression and the potential mechanism underlying this process. Porcine discs were perfusion-cultured and subjected to a relatively high-magnitude mechanical compression (1.3 MPa at a frequency of 1.0 Hz for 2 h once per day) for 7 days in a mechanically active bioreactor. The non-compressed discs were used as controls. Resveratrol was added along with culture medium to observe the effects of resveratrol on NP matrix synthesis under mechanical load respectively. NP matrix synthesis was evaluated by histology, biochemical content (glycosaminoglycan (GAG) and hydroxyproline (HYP)), and expression of matrix macromolecules (aggrecan and collagen II). Results showed that this high-magnitude mechanical compression significantly decreased NP matrix content, indicated by the decreased staining intensity of Alcian Blue and biochemical content (GAG and HYP), and the down-regulated expression of NP matrix macromolecules (aggrecan and collagen II). Further analysis indicated that resveratrol partly stimulated NP matrix synthesis and increased activity of the PI3K/Akt pathway in a dose-dependent manner under mechanical compression. Together, resveratrol is beneficial for disc NP matrix synthesis under mechanical overloading, and the activation of the PI3K/Akt pathway may participate in this regulatory process. Resveratrol may be promising to regenerate mechanical overloading-induced disc degeneration. © 2017 The Author(s).

  13. Ghrelin promotes human non-small cell lung cancer A549 cell proliferation through PI3K/Akt/mTOR/P70S6K and ERK signaling pathways.

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    Zhu, Jianhua; Yao, Jianfeng; Huang, Rongfu; Wang, Yueqin; Jia, Min; Huang, Yan

    2018-04-06

    Ghrelin is a gastric acyl-peptide that plays an important role in cell proliferation. In the present study, we explored the role of ghrelin in A549 cell proliferation and the possible molecular mechanisms. We found that ghrelin promotes A549 cell proliferation, knockdown of the growth hormone secretagogue receptor (GHSR) attenuated A549 cell proliferation caused by ghrelin. Ghrelin induced the rapid phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt, ERK, mammalian target of rapamycin (mTOR) and P70S6K. PI3K inhibitor (LY 294002), ERK inhibitor (PD98059) and mTOR inhibitor (Rapamycin) inhibited ghrelin-induced A549 cell proliferation. Moreover, GHSR siRNA inhibited phosphorylation of PI3K, Akt, ERK, mTOR and P70S6K induced by ghrelin. Akt and mTOR/P70S6K phosphorylation was inhibited by LY 294002 but not by PD98059. These results indicate that ghrelin promotes A549 cell proliferation via GHSR-dependent PI3K/Akt/mTOR/P70S6K and ERK signaling pathways. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Effect of microRNA-135a on Cell Proliferation, Migration, Invasion, Apoptosis and Tumor Angiogenesis Through the IGF-1/PI3K/Akt Signaling Pathway in Non-Small Cell Lung Cancer.

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    Zhou, Yufei; Li, Shaoxia; Li, Jiangtao; Wang, Dongfeng; Li, Quanxing

    2017-01-01

    This study explored the ability of microRNA-135a (miR-135a) to influence cell proliferation, migration, invasion, apoptosis and tumor angiogenesis through the IGF-1/PI3K/Akt signaling pathway in non-small cell lung cancer (NSCLC). NSCLC tissues and adjacent normal tissues were collected from 138 NSCLC patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-135a and IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 mRNA; western blotting was used to determine the expression levels of IGF-1, PI3K and Akt protein; and enzyme-linked immunosorbent assay (ELISA) was used to analyze the expression levels of VEGF, bFGF and IL-8 protein. Human NSCLC cell lines (A549, H460, and H1299) and the human bronchial epithelial cell line (HBE) were selected. A549 cells were assigned to blank, negative control (NC), miR-135a mimics, miR-135a inhibitors, IGF-1 siRNA and miR-135a inhibitors + IGF-1 siRNA groups. The following were performed: an MTT assay to assess cell proliferation, a scratch test to detect cell migration, a Transwell assay to measure cell invasion, and a flow cytometry to analyze cell apoptosis. The expression level of miR-135a was lower while those of IGF-1, PI3K and Akt mRNA were higher in NSCLC tissues than in the adjacent normal tissues. Dual-luciferase reporter assay indicated IGF-1 as a target of miR-135a. The in vitro results showed that compared with the blank group, cell proliferation, migration and invasion were suppressed, mRNA and protein levels of IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 were reduced, and cell apoptosis was enhanced in the miR-135a mimics and IGF-1 siRNA groups. Compared with the IGF-1 siRNA group, cells in the miR-135a inhibitors + IGF-1 siRNA group demonstrated increased cell proliferation, migration and invasion, elevated mRNA and protein levels of IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 and reduced cell apoptosis. These findings indicated that miR-135a promotes cell apoptosis and inhibits

  15. PI3K/Akt/mTOR Intracellular Pathway and Breast Cancer: Factors, Mechanism and Regulation.

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    Sharma, Var Ruchi; Gupta, Girish Kumar; Sharma, A K; Batra, Navneet; Sharma, Daljit K; Joshi, Amit; Sharma, Anil K

    2017-01-01

    The most recurrent and considered second most frequent cause of cancer-related deaths worldwide in women is the breast cancer. The key to diagnosis is early prediction and a curable stage but still treatment remains a great clinical challenge. Origin of the Problem: A number of studies have been carried out for the treatment of breast cancer which includes the targeted therapies and increased survival rates in women. Essential PI3K/mTOR signaling pathway activation has been observed in most breast cancers. The cell growth and tumor development in such cases involve phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) complex intracellular pathway. Through preclinical and clinical trials, it has been observed that there are a number of other inhibitors of PI3K/Akt/mTOR pathway, which either alone or in combination with cytotoxic agents can be used for endocrine therapies. Structure and regulation/deregulation of mTOR provides a greater insight into the action mechanism. Also, through this review, one could easily scan first and second generation inhibitors for PI3K/Akt/mTOR pathway besides targeted therapies for breast cancer and the precise role of mTOR. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. AKT-independent PI3-K signaling in cancer – emerging role for SGK3

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    Bruhn MA

    2013-08-01

    Full Text Available Maressa A Bruhn,1,6 Richard B Pearson,1–4 Ross D Hannan,1–5 Karen E Sheppard1–3 1Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia; 2Sir Peter MacCallum Department of Oncology, 3Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia; 4Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; 5School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia; 6School of Biological Sciences, Flinders University, Bedford Park, South Australia, Australia Abstract: The phosphoinositide 3-kinase (PI3-K signaling pathway plays an important role in a wide variety of fundamental cellular processes, largely mediated via protein kinase B/v-akt murine thymoma viral oncogene homolog (PKB/AKT signaling. Given the crucial role of PI3-K/AKT signaling in regulating processes such as cell growth, proliferation, and survival, it is not surprising that components of this pathway are frequently dysregulated in cancer, making the AKT kinase family members important therapeutic targets. The large number of clinical trials currently evaluating PI3-K pathway inhibitors as a therapeutic strategy further emphasizes this. The serum- and glucocorticoid-inducible protein kinase (SGK family is made up of three isoforms, SGK1, 2, and 3, that are PI3-K-dependent, serine/threonine kinases, with similar substrate specificity to AKT. Consequently, the SGK family also regulates similar cell processes to the AKT kinases, including cell proliferation and survival. Importantly, there is emerging evidence demonstrating that SGK3 plays a critical role in AKT-independent oncogenic signaling. This review will focus on the role of SGK3 as a key effector of AKT-independent PI3-K oncogenic signaling. Keywords: SGK3, AKT, PI3-kinase, mTOR, cancer

  17. Hallway gossip between Ras and PI3K pathways.

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    Emanuel, Peter D

    2014-05-01

    In this issue of Blood, Goodwin et al investigate the pathogenesis of juvenile myelomonocytic leukemia (JMML), demonstrating that mutant Shp2 induces granulocyte macrophage-colony-stimulating factor (GM-CSF) hypersensitivity and that the p110δ subunit of phosphatidylinositol 3-kinase (PI3K) further promotes this dysregulation

  18. Resveratrol Inhibits the Invasion of Glioblastoma-Initiating Cells via Down-Regulation of the PI3K/Akt/NF-κB Signaling Pathway

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    Yuming Jiao

    2015-06-01

    Full Text Available Invasion and metastasis of glioblastoma-initiating cells (GICs are thought to be responsible for the progression and recurrence of glioblastoma multiforme (GBM. A safe drug that can be applied during the rest period of temozolomide (TMZ maintenance cycles would greatly improve the prognosis of GBM patients by inhibiting GIC invasion. Resveratrol (RES is a natural compound that exhibits anti-invasion properties in multiple tumor cell lines. The current study aimed to evaluate whether RES can inhibit GIC invasion in vitro and in vivo. GICs were identified using CD133 and Nestin immunofluorescence staining and tumorigenesis in non-obese diabetic severe combined immunodeficient (NOD/SCID mice. Invasive behaviors, including the adhesion, invasion and migration of GICs, were determined by tumor invasive assays in vitro and in vivo. The activity of matrix metalloproteinases (MMPs was measured by the gelatin zymography assay. Western blotting analysis and immunofluorescence staining were used to determine the expression of signaling effectors in GICs. We demonstrated that RES suppressed the adhesion, invasion and migration of GICs in vitro and in vivo. Moreover, we proved that RES inhibited the invasion of GICs via the inhibition of PI3K/Akt/NF-κB signal transduction and the subsequent suppression of MMP-2 expression.

  19. Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma.

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    Yang, Yang; Hui, Lv; Yuqin, Che; Jie, Li; Shuai, Hou; Tiezhu, Zhou; Wei, Wang

    2014-08-01

    Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 10 4 cells/well. In the experimental group, 1 μl/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; Psaw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction.

  20. PI3K: A Crucial Piece in the RAS Signaling Puzzle.

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    Krygowska, Agata Adelajda; Castellano, Esther

    2018-06-01

    RAS proteins are key signaling switches essential for control of proliferation, differentiation, and survival of eukaryotic cells. RAS proteins are mutated in 30% of human cancers. In addition, mutations in upstream or downstream signaling components also contribute to oncogenic activation of the pathway. RAS proteins exert their functions through activation of several signaling pathways and dissecting the contributions of these effectors in normal cells and in cancer is an ongoing challenge. In this review, we summarize our current knowledge about how RAS regulates type I phosphatidylinositol 3-kinase (PI3K), one of the main RAS effectors. RAS signaling through PI3K is necessary for normal lymphatic vasculature development and for RAS-induced transformation in vitro and in vivo, especially in lung cancer, where it is essential for tumor initiation and necessary for tumor maintenance. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  1. Hydrogen-Rich Saline Attenuates Brain Injury Induced by Cardiopulmonary Bypass and Inhibits Microvascular Endothelial Cell Apoptosis Via the PI3K/Akt/GSK3β Signaling Pathway in Rats

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    Keyan Chen

    2017-10-01

    Full Text Available Background/Aims: Cardiopulmonary bypass (CPB is prone to inducing brain injury during open heart surgery. A hydrogen-rich solution (HRS can prevent oxidation and apoptosis, and inhibit inflammation. This study investigated effects of HRS on brain injury induced by CPB and regulatory mechanisms of the PI3K/Akt/GSK3β signaling pathway. Methods: A rat CPB model and an in vitro cell hypoxia model were established. After HRS treatment, Rat behavior was measured using neurological deficit score; Evans blue (EB was used to assess permeability of the blood-brain barrier (BBB; HE staining was used to observe pathological changes; Inflammatory factors and brain injury markers were detected by ELISA; the PI3K/Akt/GSK3β pathway-related proteins and apoptosis were assessed by western blot, immunohistochemistry and qRT –PCR analyses of brain tissue and neurons. Results: After CPB, brain tissue anatomy was disordered, and cell structure was abnormal. Brain tissue EB content increased. There was an increase in the number of apoptotic cells, an increase in expression of Bax and caspase-3, a decrease in expression of Bcl2, and increases in levels of Akt, GSK3β, P-Akt, and P-GSK3β in brain tissue. HRS treatment attenuated the inflammatory reaction ,brain tissue EB content was significantly reduced and significantly decreased expression levels of Bax, caspase-3, Akt, GSK3β, P-Akt, and P-GSK3β in the brain. After adding the PI3K signaling pathway inhibitor, LY294002, to rat cerebral microvascular endothelial cells (CMECs, HRS could reduce activated Akt expression and downstream regulatory gene phosphorylation of GSK3β expression, and inhibit CMEC apoptosis. Conclusion: The PI3K/Akt/GSK3β signaling pathway plays an important role in the mechanism of CPB-induced brain injury. HRS can reduce CPB-induced brain injury and inhibit CMEC apoptosis through the PI3K/Akt/GSK3β signaling pathway.

  2. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's Sarcoma-associated herpesvirus by herpes simplex virus type 1

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    Lv Zhigang

    2011-10-01

    Full Text Available Abstract Background Kaposi's sarcoma-associated herpesvirus (KSHV is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS, primary effusion lymphoma (PEL and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1 was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1/signal transducer and activator of transcription 3 (STAT3 or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K/protein kinase B (PKB, also called AKT pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN and glycogen synthase kinase-3β (GSK-3β. PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK mitogen-activated protein kinase (MAPK pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.

  3. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

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    Su, Tzu-Rong; Lin, Jen-Jie; Tsai, Chi-Chu; Huang, Tsu-Kei; Yang, Zih-Yan; Wu, Ming-O; Zheng, Yu-Qing; Su, Ching-Chyuan; Wu, Yu-Jen

    2013-01-01

    Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP1), and dopachrome tautomerase (Dct). In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK). Using inhibitors against PI3K/Akt (LY294002) or MEK/ERK-specific (PD98059), the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763) restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions. PMID:24129178

  4. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

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    Yu-Jen Wu

    2013-10-01

    Full Text Available Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP1, and dopachrome tautomerase (Dct. In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK/extracellular signal-regulated kinase (ERK. Using inhibitors against PI3K/Akt (LY294002 or MEK/ERK-specific (PD98059, the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763 restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

  5. Tanshinone IIA protects PC12 cells from β-amyloid(25-35)-induced apoptosis via PI3K/Akt signaling pathway.

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    Dong, Huimin; Mao, Shanping; Mao, Shanpin; Wei, Jiajun; Liu, Baohui; Zhang, Zhaohui; Zhang, Qian; Yan, Mingmin

    2012-06-01

    For the aging populations of any nation, Dementia is becoming a primary problem and Alzheimer’s dementia (AD) is the most common type. However, until now, there is no effective treatment for AD. Tanshinone IIA (Tan IIA) has been reported for neuroprotective potential to against amyloid β peptides (Aβ)-induced cytotoxicity in the rat pheochromocytoma cell line PC-12, which is widely used as AD research model, but the mechanism still remains unclear. To investigate the effect of Tan IIA and the possible molecular mechanism in the apoptosis of PC12 cells, we induced apoptosis in PC12 cells with β-amyloid(25-35), and treated cells with Tan IIA. After 24 h treatment, we found that Tan IIA increased the cell viability and reduced the number of apoptotic cells induced by Aβ(25-35). However, neuroprotection of Tan IIA was abolished by PI3K inhibitor LY294002. Meanwhile, Treatment with lithium chloride, a phosphorylation inhibitor of GSK3β, which is a downstream target of PI3K/Akt, can block Aβ(25-35)-induced cell apoptosis in a Tan IIA-like manner. Our findings suggest that Tan IIA is an effective neuroprotective agent and a viable candidate in AD therapy and PI3K/Akt activation and GSK3β phosphorylation are involved in the neuroprotection of Tan IIA.

  6. PI3K-GLUT4 Signal Pathway Associated with Effects of EX-B3 Electroacupuncture on Hyperglycemia and Insulin Resistance of T2DM Rats

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    Bing-Yan Cao

    2016-01-01

    Full Text Available Objectives. To explore electroacupuncture’s (EA’s effects on fasting blood glucose (FBG and insulin resistance of type 2 diabetic mellitus (T2DM model rats and give a possible explanation for the effects. Method. It takes high fat diet and intraperitoneal injection of streptozotocin (STZ, 30 mg/kg for model preparation. Model rats were randomly divided into T2DM Model group, EA weiwanxiashu (EX-B3 group, and sham EA group (n=12/group. EA (2 Hz continuous wave, 2 mA, 20 min/day, 6 days/week, 4 weeks was applied as intervention. FBG, area under curve (AUC of oral glucose tolerance test (OGTT, insulin resistance index (HOMA-IR, pancreatic B cell function index (HOMA-B, skeletal muscle phosphorylated phosphatidylinositol-3-kinase (PI3K, glucose transporter 4 (GLUT4, and membrane GLUT4 protein expression were measured. Results. EA weiwanxiashu (EX-B3 can greatly upregulate model rat’s significantly reduced skeletal muscle PI3K (Y607 and membrane GLUT4 protein expression (P<0.01, effectively reducing model rats’ FBG and AUC of OGTT (P<0.01. The effects are far superior to sham EA group. Conclusion. EA weiwanxiashu (EX-B3 can upregulate skeletal muscle phosphorylated PI3K protein expression, to stimulate membrane translocation of GLUT4 and thereby increase skeletal muscle glucose intake to treat T2DM.

  7. Transmembrane collagen XVII modulates integrin dependent keratinocyte migration via PI3K/Rac1 signaling.

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    Stefanie Löffek

    Full Text Available The hemidesmosomal transmembrane component collagen XVII (ColXVII plays an important role in the anchorage of the epidermis to the underlying basement membrane. However, this adhesion protein seems to be also involved in the regulation of keratinocyte migration, since its expression in these cells is strongly elevated during reepithelialization of acute wounds and in the invasive front of squamous cell carcinoma, while its absence in ColXVII-deficient keratinocytes leads to altered cell motility. Using a genetic model of murine Col17a1⁻/⁻ keratinocytes we elucidated ColXVII mediated signaling pathways in cell adhesion and migration. Col17a1⁻/⁻ keratinocytes exhibited increased spreading on laminin 332 and accelerated, but less directed cell motility. These effects were accompanied by increased expression of the integrin subunits β4 and β1. The migratory phenotype, as evidenced by formation of multiple unstable lamellipodia, was associated with enhanced phosphoinositide 3-kinase (PI3K activity. Dissection of the signaling pathway uncovered enhanced phosphorylation of the β4 integrin subunit and the focal adhesion kinase (FAK as activators of PI3K. This resulted in elevated Rac1 activity as a downstream consequence. These results provide mechanistic evidence that ColXVII coordinates keratinocyte adhesion and directed motility by interfering integrin dependent PI3K activation and by stabilizing lamellipodia at the leading edge of reepithelializing wounds and in invasive squamous cell carcinoma.

  8. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons.

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    Wei Jiang

    Full Text Available Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer's disease (AD. Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons. We found that Okadaic acid (OA induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH, superoxide dismutase (SOD, mitochondria membrane potential (MMP and Glutathione peroxidase (GSH-Px. It up-regulated malondialdehyde (MDA production and intracellular reactive oxygen species (ROS. In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β and mitogen activated protein kinase (MAPK were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD.

  9. Reciprocal feedback regulation of PI3K and androgen receptor signaling in PTEN-deficient prostate cancer.

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    Carver, Brett S; Chapinski, Caren; Wongvipat, John; Hieronymus, Haley; Chen, Yu; Chandarlapaty, Sarat; Arora, Vivek K; Le, Carl; Koutcher, Jason; Scher, Howard; Scardino, Peter T; Rosen, Neal; Sawyers, Charles L

    2011-05-17

    Prostate cancer is characterized by its dependence on androgen receptor (AR) and frequent activation of PI3K signaling. We find that AR transcriptional output is decreased in human and murine tumors with PTEN deletion and that PI3K pathway inhibition activates AR signaling by relieving feedback inhibition of HER kinases. Similarly, AR inhibition activates AKT signaling by reducing levels of the AKT phosphatase PHLPP. Thus, these two oncogenic pathways cross-regulate each other by reciprocal feedback. Inhibition of one activates the other, thereby maintaining tumor cell survival. However, combined pharmacologic inhibition of PI3K and AR signaling caused near-complete prostate cancer regressions in a Pten-deficient murine prostate cancer model and in human prostate cancer xenografts, indicating that both pathways coordinately support survival. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

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    Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun [Department of Surgery, The Children' s Hospital of Xuzhou, Xuzhou, Jiangsu Province 221006 (China); Wang, Rong, E-mail: wangrong2008163@163.com [Department of Ultrasonography, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province 221006 (China)

    2015-08-21

    Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2.

  11. PI3K-GSK3 signalling regulates mammalian axon regeneration by inducing the expression of Smad1

    Science.gov (United States)

    Saijilafu; Hur, Eun-Mi; Liu, Chang-Mei; Jiao, Zhongxian; Xu, Wen-Lin; Zhou, Feng-Quan

    2013-10-01

    In contrast to neurons in the central nervous system, mature neurons in the mammalian peripheral nervous system (PNS) can regenerate axons after injury, in part, by enhancing intrinsic growth competence. However, the signalling pathways that enhance the growth potential and induce spontaneous axon regeneration remain poorly understood. Here we reveal that phosphatidylinositol 3-kinase (PI3K) signalling is activated in response to peripheral axotomy and that PI3K pathway is required for sensory axon regeneration. Moreover, we show that glycogen synthase kinase 3 (GSK3), rather than mammalian target of rapamycin, mediates PI3K-dependent augmentation of the growth potential in the PNS. Furthermore, we show that PI3K-GSK3 signal is conveyed by the induction of a transcription factor Smad1 and that acute depletion of Smad1 in adult mice prevents axon regeneration in vivo. Together, these results suggest PI3K-GSK3-Smad1 signalling as a central module for promoting sensory axon regeneration in the mammalian nervous system.

  12. Pathway-based identification of biomarkers for targeted therapeutics: personalized oncology with PI3K pathway inhibitors.

    Science.gov (United States)

    Andersen, Jannik N; Sathyanarayanan, Sriram; Di Bacco, Alessandra; Chi, An; Zhang, Theresa; Chen, Albert H; Dolinski, Brian; Kraus, Manfred; Roberts, Brian; Arthur, William; Klinghoffer, Rich A; Gargano, Diana; Li, Lixia; Feldman, Igor; Lynch, Bethany; Rush, John; Hendrickson, Ronald C; Blume-Jensen, Peter; Paweletz, Cloud P

    2010-08-04

    Although we have made great progress in understanding the complex genetic alterations that underlie human cancer, it has proven difficult to identify which molecularly targeted therapeutics will benefit which patients. Drug-specific modulation of oncogenic signaling pathways in specific patient subpopulations can predict responsiveness to targeted therapy. Here, we report a pathway-based phosphoprofiling approach to identify and quantify clinically relevant, drug-specific biomarkers for phosphatidylinositol 3-kinase (PI3K) pathway inhibitors that target AKT, phosphoinositide-dependent kinase 1 (PDK1), and PI3K-mammalian target of rapamycin (mTOR). We quantified 375 nonredundant PI3K pathway-relevant phosphopeptides, all containing AKT, PDK1, or mitogen-activated protein kinase substrate recognition motifs. Of these phosphopeptides, 71 were drug-regulated, 11 of them by all three inhibitors. Drug-modulated phosphoproteins were enriched for involvement in cytoskeletal reorganization (filamin, stathmin, dynamin, PAK4, and PTPN14), vesicle transport (LARP1, VPS13D, and SLC20A1), and protein translation (S6RP and PRAS40). We then generated phosphospecific antibodies against selected, drug-regulated phosphorylation sites that would be suitable as biomarker tools for PI3K pathway inhibitors. As proof of concept, we show clinical translation feasibility for an antibody against phospho-PRAS40(Thr246). Evaluation of binding of this antibody in human cancer cell lines, a PTEN (phosphatase and tensin homolog deleted from chromosome 10)-deficient mouse prostate tumor model, and triple-negative breast tumor tissues showed that phospho-PRAS40(Thr246) positively correlates with PI3K pathway activation and predicts AKT inhibitor sensitivity. In contrast to phosphorylation of AKT(Thr308), the phospho-PRAS40(Thr246) epitope is highly stable in tissue samples and thus is ideal for immunohistochemistry. In summary, our study illustrates a rational approach for discovery of drug

  13. Francisella subverts innate immune signaling: Focus on PI3K/Akt

    Directory of Open Access Journals (Sweden)

    Thomas John Cremer

    2011-02-01

    Full Text Available Intracellular bacterial pathogens exploit host cells as a part of their lifecycle, and they do so by manipulating host cell signaling events. Many such bacteria are known to produce effector proteins that promote cell invasion, alter membrane trafficking and disrupt signaling cascades. This review highlights recent advances in our understanding of signaling pathways involved in host cell responses to Francisella tularensis, a facultative Gram-negative intracellular pathogen that causes tularemia. We highlight several key pathways that are targeted by Francisella, with a focus on the PI3K/Akt pathway. Lastly, we discuss the emerging role of microRNAs, specifically miR-155, as a key regulator of host signaling and defense.

  14. Anti-proliferative effect of RCE-4 from Reineckia carnea on human cervical cancer HeLa cells by inhibiting the PI3K/Akt/mTOR signaling pathway and NF-κB activation.

    Science.gov (United States)

    Bai, Caihong; Yang, Xiaojiao; Zou, Kun; He, Haibo; Wang, Junzhi; Qin, Huilin; Yu, Xiaoqin; Liu, Chengxiong; Zheng, Juyan; Cheng, Fan; Chen, Jianfeng

    2016-06-01

    Cervical cancer is the second leading cause of cancer deaths in women worldwide. In recent years, the studies find that inflammation is a critical component of tumor progression, and the ideal therapeutic methods should be aimed at the inflammation reaction triggers. (1β,3β,5β,25S)-spirostan-1,3-diol1-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranoside] (RCE-4) was the main active composition of Reineckia carnea (Andr.) Kunth. It significantly induced apoptosis in cervical cancer Caski cells through the mitochondrial pathway in our previous studies; however, its underlying mechanism remains poorly understood. This study aimed to further evaluate the effect of RCE-4 on human cervical cancer HeLa cells. Based on this observation, we investigated the anti-cervical cancer effect of RCE-4 by modulating phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway, nuclear factor-kappa B (NF-κB) activation, and inflammation-related key factors in HeLa cells. The results indicated that the HeLa cell was the most sensitive with an IC50 of 7.01 μM; RCE-4 significantly promoted the release of cellular lactate dehydrogenase (LDH); increased DNA fragmentation and apoptosis; reduced PI3K, Akt, mTOR, and NF-κBp65 phosphorylation levels; increased the Bax and cleaved poly (ADP-ribose) polymerase (PARP) protein levels; suppressed Bcl-2 protein expression; elevated the Bax/Bcl-2 expression ratio; and decreased the interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) mRNA expressions in HeLa cells in a concentration-dependent manner. These findings suggest that RCE-4 exerted beneficially anti-cervical cancer effect on HeLa cells, mainly inhibiting PI3K/Akt/mTOR signaling pathway phosphorylation and NF-κB activation, promoting HeLa cell apoptosis. Graphical abstract Anti-tumor effect of RCE-4 on HeLa cells.

  15. Estrogen receptor and PI3K/Akt signaling pathway involvement in S-(-equol-induced activation of Nrf2/ARE in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Ting Zhang

    Full Text Available S-(-equol, a natural product of the isoflavone daidzein, has been reported to offer cytoprotective effects with respect to the cardiovascular system, but how this occurs is unclear. Interestingly, S-(-equol is produced by the human gut, suggesting a role in physiological processes. We report that treatment of human umbilical vein endothelial cells and EA.hy926 cells with S-(-equol induces ARE-luciferase reporter gene activity that is dose and time dependent. S-(-equol (10-250 nM increases nuclear factor-erythroid 2-related factor 2 (Nrf2 as well as gene products of Nrf2 target genes heme oxygenase-1 (HO-1 and NAD(PH (nicotinamide-adenine-dinucleotide-phosphate quinone oxidoreductase 1 (NQO1. Endothelial cells transfected with an HA-Nrf2 expression plasmid had elevated HA-Nrf2, HO-1, and NQO1 in response to S-(-equol exposure. S-(-equol treatment affected Nrf2 mRNA only slightly but significantly increased HO-1 and NQO1 mRNA. The pretreatment of cells with specific ER inhibitors or PI3K/Akt (ICI182,780 and LY294002 increased Nrf2, HO-1, and NQO1 protein, impaired nuclear translocation of HA-Nrf2, and decreased ARE-luciferase activity. Identical experiments were conducted with daidzein, which had effects similar to S-(-equol. In addition, DPN treatment (an ERβ agonist induced the ARE-luciferase reporter gene, promoting Nrf2 nuclear translocation. Cell pretreatment with an ERβ antagonist (PHTPP impaired S-(-equol-induced Nrf2 activation. Pre-incubation of cells followed by co-treatment with S-(-equol significantly improved cell survival in response to H2O2 or tBHP and reduced apoptotic and TUNEL-positively-stained cells. Notably, the ability of S-(-equol to protect against H2O2-induced cell apoptosis was attenuated in cells transfected with an siRNA against Nrf2. Thus, beneficial effects of S-(-equol with respect to cytoprotective antioxidant gene activation may represent a novel strategy to prevent and treat cardiovascular diseases.

  16. Effect of Jianpi Jiedu Recipe on angiogenesis and the PTEN/PI3K/AKT signaling pathway in the course of Helicobacter pylori-induced gastric cancer in C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Ning-Ning Liu

    2018-01-01

    Full Text Available Objective: To reveal the effect of Jianpi Jiedu recipe (JPJDR on angiogenesis and the PTEN (Phosphatase and tensin homolog deleted on chromosome ten/PI3K/AKT signaling pathway in the course of H. pylori infection-induced carcinogenesis of gastric mucosa in C57BL/6 mice. Methods: Two-hundred C57BL/6 mice were randomly divided into five groups (control group, model group, JPJDR low-dose group, JPJDR medium-dose group, and JPJDR high-dose group, 40 in each group. A mouse model of gastric cancer, induced by H. pylori standard strain infection, was established. The mice of JPJDR low-dose, middle-dose, and high-dose groups were intragastrically administered 250, 500, and 1000 mg/kg JPJDR per day, respectively. After 72 weeks, the H. pylori infection in gastric mucosa of the mice was analyzed by rapid urease test; the pathological changes in the gastric mucosa of mice were assessed by histopathological examination, and micro-vessel density (MVD, vascular endothelial growth factor (VEGF, and PTEN/PI3K/AKT levels were determined. Results: The incidence of gastric cancer in each group (control group, model group, JPJDR low-dose, medium-dose, high-dose group was 0%, 26.3%, 13.2%, 10%, and 7.5% respectively. The incidence of gastric cancer in the Chinese medicine group was significantly lower than that of the model group (P = 0.020, P = 0.023, P = 0.007. The expression of MVD and VEGF in the model group was significantly higher than that in the control group (P = 0.002, P < 0.001, while the expression of MVD and VEGF decreased in the Chinese medicine group. The expression of p-PTEN and p-AKT in the model group was significantly higher than that in the control group (All P < 0.001, while Chinese medicine could reduce the expression of p-PTEN and p-AKT to varying extents. Conclusion: Long-term infection of C57BL/6 mice with H. pylori induces gastric carcinogenesis, by increasing gastric mucosal MVD, promoting the expression of VEGF, inhibiting the activity of

  17. 4-Acetylantroquinonol B suppresses autophagic flux and improves cisplatin sensitivity in highly aggressive epithelial cancer through the PI3K/Akt/mTOR/p70S6K signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Mingche [Graduate Institute of Biomedical Materials and Tissue Engineering, College of biomedical engineering, Taipei Medical University, Taipei, Taiwan (China); Department of Urology, Taipei Medical University Hospital, Taipei, Taiwan (China); Department of Urology, School of Medicine, college of Medicine, Taipei Medical University, Taipei, Taiwan (China); Bamodu, Oluwaseun Adebayo [Department of Hematology and Oncology, Cancer Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan (China); Department of Medical Research & Education, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan (China); Huang, Wen-Chien [Institute of Traditional Medicine, School of Medicine, National Yang Ming University, Taipei, Taiwan (China); Department of Surgery, Division of Thoracic Surgery, MacKay Memorial Hospital, Taipei, Taiwan (China); Zucha, Muhammad Ary [Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan (China); Lin, Yen-Kuang [Biostatistics and Research Consultation Center, Taipei Medical University, Taipei 11031, Taiwan (China); Wu, Alexander T.H. [The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan (China); Huang, Chun-Chih [Center for General Education, National Taitung University, Taitung, Taiwan (China); Lee, Wei-Hwa [Department of Pathology, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan (China); Yuan, Chiou-Chung [Obstetrics and Gynecology Department, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan (China); Hsiao, M. [Genomics Research Center, Academia Sinica, Taipei, Taiwan (China); Deng, Li [Beijing Bioprocess Key Laboratory, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing (China); Amoy-BUCT Industrial Bio-technovation Institute, Amoy (China); and others

    2017-06-15

    Targeting residual self-renewing, chemoresistant cancerous cells may represent the key to overcoming therapy resistance. The entry of these quiescent cells into an activated state is associated with high metabolic demand and autophagic flux. Therefore, modulating the autophagy pathway in aggressive carcinomas may be beneficial as a therapeutic modality. In this study, we evaluated the anti-tumor activities of 4-acetylantroquinonol B (4-AAQB) in chemoresistant ovarian cancer cells, particularly its ability to modulate autophagy through autophagy-related genes (Atg). Atg-5 was overexpressed in invasive ovarian cancer cell lines and tissue (OR: 5.133; P = 0.027) and depleting Atg-5 in ES-2 cell lines significantly induced apoptosis. 4-AAQB effectively suppressed viability of various subtypes of ovarian cancer. Cells with higher cisplatin-resistance were more responsive to 4-AAQB. For the first time, we demonstrate that 4-AAQB significantly suppress Atg-5 and Atg-7 expression with decreased autophagic flux in ovarian cancer cells via inhibition of the PI3K/Akt/mTOR/p70S6K signaling pathway. Similar to Atg-5 silencing, 4-AAQB-induced autophagy inhibition significantly enhanced cell death in vitro. These results are comparable to those of hydroxychloroquine (HCQ). In addition, 4-AAQB/cisplatin synergistically induced apoptosis in ovarian cancer cells. In vivo, 4-AAQB/cisplatin also significantly induced apoptosis and autophagy in an ES-2 mouse xenografts model. This is the first report demonstrating the efficacy of 4-AAQB alone or in combination with cisplatin on the suppression of ovarian cancer via Atg-5-dependent autophagy. We believe these findings will be beneficial in the development of a novel anti-ovarian cancer therapeutic strategy. - Highlights: • Atg-5 is overexpressed in ovarian cancer and silencing Atg-5 induces apoptosis. • 4-AAQB suppresses autophagy and PI3K/Akt/mTOR pathway. • 4-AAQB + cisplatin synergistically suppresses ovarian cancer via

  18. 4-Acetylantroquinonol B suppresses autophagic flux and improves cisplatin sensitivity in highly aggressive epithelial cancer through the PI3K/Akt/mTOR/p70S6K signaling pathway

    International Nuclear Information System (INIS)

    Liu, Mingche; Bamodu, Oluwaseun Adebayo; Huang, Wen-Chien; Zucha, Muhammad Ary; Lin, Yen-Kuang; Wu, Alexander T.H.; Huang, Chun-Chih; Lee, Wei-Hwa; Yuan, Chiou-Chung; Hsiao, M.; Deng, Li

    2017-01-01

    Targeting residual self-renewing, chemoresistant cancerous cells may represent the key to overcoming therapy resistance. The entry of these quiescent cells into an activated state is associated with high metabolic demand and autophagic flux. Therefore, modulating the autophagy pathway in aggressive carcinomas may be beneficial as a therapeutic modality. In this study, we evaluated the anti-tumor activities of 4-acetylantroquinonol B (4-AAQB) in chemoresistant ovarian cancer cells, particularly its ability to modulate autophagy through autophagy-related genes (Atg). Atg-5 was overexpressed in invasive ovarian cancer cell lines and tissue (OR: 5.133; P = 0.027) and depleting Atg-5 in ES-2 cell lines significantly induced apoptosis. 4-AAQB effectively suppressed viability of various subtypes of ovarian cancer. Cells with higher cisplatin-resistance were more responsive to 4-AAQB. For the first time, we demonstrate that 4-AAQB significantly suppress Atg-5 and Atg-7 expression with decreased autophagic flux in ovarian cancer cells via inhibition of the PI3K/Akt/mTOR/p70S6K signaling pathway. Similar to Atg-5 silencing, 4-AAQB-induced autophagy inhibition significantly enhanced cell death in vitro. These results are comparable to those of hydroxychloroquine (HCQ). In addition, 4-AAQB/cisplatin synergistically induced apoptosis in ovarian cancer cells. In vivo, 4-AAQB/cisplatin also significantly induced apoptosis and autophagy in an ES-2 mouse xenografts model. This is the first report demonstrating the efficacy of 4-AAQB alone or in combination with cisplatin on the suppression of ovarian cancer via Atg-5-dependent autophagy. We believe these findings will be beneficial in the development of a novel anti-ovarian cancer therapeutic strategy. - Highlights: • Atg-5 is overexpressed in ovarian cancer and silencing Atg-5 induces apoptosis. • 4-AAQB suppresses autophagy and PI3K/Akt/mTOR pathway. • 4-AAQB + cisplatin synergistically suppresses ovarian cancer via

  19. IGF-1 promotes angiogenesis in endothelial cells/adipose-derived stem cells co-culture system with activation of PI3K/Akt signal pathway.

    Science.gov (United States)

    Lin, Shiyu; Zhang, Qi; Shao, Xiaoru; Zhang, Tao; Xue, Changyue; Shi, Sirong; Zhao, Dan; Lin, Yunfeng

    2017-12-01

    The aim of this study was to investigate the role of insulin-like growth factor-1 (IGF-1) and crosstalk between endothelial cells (ECs) and adipose-derived stem cells (ASCs) in the process of angiogenesis. A three-dimensional collagen gel used to culture mouse ASCs and mouse ECs in vitro was established. The effects of angiogenesis after exposure to IGF-1 were observed by confocal laser scanning microscopy. Western blotting and qPCR were performed to elucidate the underlying mechanisms. IGF-1 treatment promoted the formation of vessel-like structures and the recruitment of ASCs in the three-dimensional collagen gel. The angiogenic genes and proteins in ECs were up-regulated by IGF-1 and in co-culture. Similar changes in the genes and in the proteins were detected in ASCs after exposure to IGF-1 and co-culture. p-Akt expression levels were high in ECs and ASCs after exposure to IGF-1 and co-culture. IGF-1 and co-culture between cells facilitate the process of angiogenesis via the PI3-kinase/Akt signalling pathway. In ECs, IGF-1 stimulates the expression of angiogenesis-related growth factors with the activation of the PI3-kinase/Akt signalling pathway. Co-cultured ECs exposed to excess VEGF-A and other angiogenesis-related growth factors para-secreted from ASCs exhibit high expression of angiogenesis-related genes and proteins. In ASCs, IGF-1 induces the recruitment and function of ASCs by up-regulating the expression of PDGFB, MMPs and α-SMA. Crosstalk with ECs further facilitates changes in ASCs. © 2017 John Wiley & Sons Ltd.

  20. 3-Bromopyruvate induces apoptosis in breast cancer cells by downregulating Mcl-1 through the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Liu, Zhe; Zhang, Yuan-Yuan; Zhang, Qian-Wen; Zhao, Su-Rong; Wu, Cheng-Zhu; Cheng, Xiu; Jiang, Chen-Chen; Jiang, Zhi-Wen; Liu, Hao

    2014-04-01

    The hexokinase inhibitor 3-bromopyruvate (3-BrPA) can inhibit glycolysis in tumor cells to reduce ATP production, resulting in apoptosis. However, as 3-BrPA is an alkylating agent, its cytotoxic action may be induced by other molecular mechanisms. The results presented here reveal that 3-BrPA-induced apoptosis is caspase independent. Further, 3-BrPA induces the generation of reactive oxygen species in MDA-MB-231 cells, leading to mitochondria-mediated apoptosis. These results suggest that caspase-independent apoptosis may be induced by the generation of reactive oxygen species. In this study, we also demonstrated that 3-BrPA induces apoptosis through the downregulation of myeloid cell leukemia-1 (Mcl-1) in MDA-MB-231 breast cancer cells. The results of Mcl-1 knockdown indicate that Mcl-1 plays an important role in 3-BrPA-induced apoptosis. Further, the upregulation of Mcl-1 expression in 3-BrPA-treated MDA-MB-231 cells significantly increases cell viability. In addition, 3-BrPA treatment resulted in the downregulation of p-Akt, suggesting that 3-BrPA may downregulate Mcl-1 through the phosphoinositide-3-kinase/Akt pathway. These findings indicate that 3-BrPA induces apoptosis in breast cancer cells by downregulating Mcl-1 through the phosphoinositide-3-kinase/Akt signaling pathway.

  1. Pi3kcb links Hippo-YAP and PI3K-AKT signaling pathways to promote cardiomyocyte proliferation and survival.

    Science.gov (United States)

    Lin, Zhiqiang; Zhou, Pingzhu; von Gise, Alexander; Gu, Fei; Ma, Qing; Chen, Jinghai; Guo, Haidong; van Gorp, Pim R R; Wang, Da-Zhi; Pu, William T

    2015-01-02

    Yes-associated protein (YAP), the nuclear effector of Hippo signaling, regulates cellular growth and survival in multiple organs, including the heart, by interacting with TEA (transcriptional enhancer activator)-domain sequence-specific DNA-binding proteins. Recent studies showed that YAP stimulates cardiomyocyte proliferation and survival. However, the direct transcriptional targets through which YAP exerts its effects are poorly defined. To identify direct YAP targets that mediate its mitogenic and antiapoptotic effects in the heart. We identified direct YAP targets by combining differential gene expression analysis in YAP gain- and loss-of-function with genome-wide identification of YAP-bound loci using chromatin immunoprecipitation and high throughput sequencing. This screen identified Pik3cb, encoding p110β, a catalytic subunit of phosphoinositol-3-kinase, as a candidate YAP effector that promotes cardiomyocyte proliferation and survival. YAP and TEA-domain occupied a conserved enhancer within the first intron of Pik3cb, and this enhancer drove YAP-dependent reporter gene expression. Yap gain- and loss-of-function studies indicated that YAP is necessary and sufficient to activate the phosphoinositol-3-kinase-Akt pathway. Like Yap, Pik3cb gain-of-function stimulated cardiomyocyte proliferation, and Pik3cb knockdown dampened YAP mitogenic activity. Reciprocally, impaired heart function in Yap loss-of-function was significantly rescued by adeno-associated virus-mediated Pik3cb expression. Pik3cb is a crucial direct target of YAP, through which the YAP activates phosphoinositol-3-kinase-AKT pathway and regulates cardiomyocyte proliferation and survival. © 2014 American Heart Association, Inc.

  2. Parathyroid hormone contributes to the down-regulation of cytochrome P450 3A through the cAMP/PI3K/PKC/PKA/NF-κB signaling pathway in secondary hyperparathyroidism.

    Science.gov (United States)

    Watanabe, Hiroshi; Sugimoto, Ryusei; Ikegami, Komei; Enoki, Yuki; Imafuku, Tadashi; Fujimura, Rui; Bi, Jing; Nishida, Kento; Sakaguchi, Yoshiaki; Murata, Michiya; Maeda, Hitoshi; Hirata, Kenshiro; Jingami, Sachiko; Ishima, Yu; Tanaka, Motoko; Matsushita, Kazutaka; Komaba, Hirotaka; Fukagawa, Masafumi; Otagiri, Masaki; Maruyama, Toru

    2017-12-01

    Chronic kidney disease (CKD), which affects, not only renal clearance, but also non-renal clearance, is accompanied by a decline in renal function. Although it has been suggested that humoral factors, such as uremic toxins that accumulate in the body under CKD conditions, could be involved in the changes associated with non-renal drug clearance, the overall process is not completely understood. In this study, we report on the role of parathyroid hormone (PTH), a middle molecule uremic toxin, on the expression of drug metabolizing or transporting proteins using rats with secondary hyperparathyroidism (SHPT) as models. In SHPT rats, hepatic and intestinal CYP3A expression was suppressed, but the changes were recovered by the administration of the calcimimetic cinacalcet, a PTH suppressor. Under the same experimental conditions, a pharmacokinetic study using orally administered midazolam, a substrate for CYP3A, showed that the AUC was increased by 5 times in SHPT rats, but that was partially recovered by a cinacalcet treatment. This was directly tested in rat primary hepatocytes and intestinal Caco-2 cells where the expression of the CYP3A protein was down-regulated by PTH (1-34). In Caco-2 cells, PTH (1-34) down-regulated the expression of CYP3A mRNA, but an inactive PTH derivative (13-34) had no effect. 8-Bromo-cyclic adenosine monophosphate, a membrane-permeable cAMP analog, reduced mRNA expression of CYP3A whereas the inhibitors of PI3K, NF-κB, PKC and PKA reversed the PTH-induced CYP3A down-regulation. These results suggest that PTH down-regulates CYP3A through multiple signaling pathways, including the PI3K/PKC/PKA/NF-κB pathway after the elevation of intracellular cAMP, and the effect of PTH can be prevented by cinacalcet treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. MACC1 facilitates chemoresistance and cancer stem cell‑like properties of colon cancer cells through the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Wang, Jiankai; Wang, Wenjuan; Cai, Hongyi; Du, Binbin; Zhang, Lijuan; Ma, Wen; Hu, Yongguo; Feng, Shifang; Miao, Guoying

    2017-12-01

    With regards to colon cancer, resistance to 5‑fluorouracil (5‑FU)‑based chemotherapy and cancer stem cells (CSCs) are considered important factors underlying therapy failure. Metastasis‑associated colon cancer 1 (MACC1) has been associated with poor prognosis and the promotion of metastasis within several types of cancer. However, the biological behavior of MACC1 in chemoresistance and CSC‑like properties remains unclear. In the present study, various methods including gene knockdown, gene overexpression, western blotting, quantitative polymerase chain reaction and MTT assay, have been adopted. According to the results of the present study, MACC1 was depleted in two colon cancer cell lines resistant to 5‑FU; subsequently, CSC‑like properties and 5‑FU sensitivity were investigated. Within 5‑FU‑resistant cells, cell death was facilitated by MACC1 knockdown. Furthermore, sphere formation and the expression levels of pluripotent markers, including cluster of differentiation (CD) 44, CD133 and Nanog were reduced due to MACC1 depletion. Additionally, it was indicated that the phosphoinositide 3‑kinase/protein kinase B signaling pathway may be associated with 5‑FU resistance and CSC‑like properties via MACC1.

  4. MACC1 facilitates chemoresistance and cancer stem cell-like properties of colon cancer cells through the PI3K/AKT signaling pathway

    Science.gov (United States)

    Wang, Jiankai; Wang, Wenjuan; Cai, Hongyi; Du, Binbin; Zhang, Lijuan; Ma, Wen; Hu, Yongguo; Feng, Shifang; Miao, Guoying

    2017-01-01

    With regards to colon cancer, resistance to 5-fluorouracil (5-FU)-based chemotherapy and cancer stem cells (CSCs) are considered important factors underlying therapy failure. Metastasis-associated colon cancer 1 (MACC1) has been associated with poor prognosis and the promotion of metastasis within several types of cancer. However, the biological behavior of MACC1 in chemoresistance and CSC-like properties remains unclear. In the present study, various methods including gene knockdown, gene overexpression, western blotting, quantitative polymerase chain reaction and MTT assay, have been adopted. According to the results of the present study, MACC1 was depleted in two colon cancer cell lines resistant to 5-FU; subsequently, CSC-like properties and 5-FU sensitivity were investigated. Within 5-FU-resistant cells, cell death was facilitated by MACC1 knockdown. Furthermore, sphere formation and the expression levels of pluripotent markers, including cluster of differentiation (CD) 44, CD133 and Nanog were reduced due to MACC1 depletion. Additionally, it was indicated that the phosphoinositide 3-kinase/protein kinase B signaling pathway may be associated with 5-FU resistance and CSC-like properties via MACC1. PMID:28990068

  5. Effects of endoplasmic reticulum stress on the autophagy, apoptosis, and chemotherapy resistance of human breast cancer cells by regulating the PI3K/AKT/mTOR signaling pathway.

    Science.gov (United States)

    Zhong, Jia-Teng; Yu, Jian; Wang, Hai-Jun; Shi, Yu; Zhao, Tie-Suo; He, Bao-Xia; Qiao, Bin; Feng, Zhi-Wei

    2017-05-01

    Nowadays, although chemotherapy is an established therapy for breast cancer, the molecular mechanisms of chemotherapy resistance in breast cancer remain poorly understood. This study aims to explore the effects of endoplasmic reticulum stress on autophagy, apoptosis, and chemotherapy resistance in human breast cancer cells by regulating PI3K/AKT/mTOR signaling pathway. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the cell viability of six human breast cancer cell lines (MCF-7, ZR-75-30, T47D, MDA-MB-435s, MDA-MB-453, and MDA-MB-231) treated with tunicamycin (5 µM), after which MCF-7 cells were selected for further experiment. Then, MCF-7 cells were divided into the control (without any treatment), tunicamycin (8 µ), BEZ235 (5 µ), and tunicamycin + BEZ235 groups. Cell viability of each group was testified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blotting was applied to determine the expressions of endoplasmic reticulum stress and PI3K/AKT/mTOR pathway-related proteins and autophagy- and apoptosis-related proteins. Monodansylcadaverine and Annexin V-fluorescein isothiocyanate/propidium iodide staining were used for determination of cell autophagy and apoptosis. Furthermore, MCF-7 cells were divided into the control (without any treatment), tunicamycin (5 µM), cisplatin (16 µM), cisplatin (16 µM) + BEZ235 (5 µM), tunicamycin (5 µM) + cisplatin (16 µM), and tunicamycin (5 µM) + cisplatin (16 µM) + BEZ235 groups. Cell viability and apoptosis were also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Annexin V-fluorescein isothiocyanate/propidium iodide staining. In MCF-7 cells treated with tunicamycin, cell viability decreased significantly, but PEAK, eIF2, and CHOP were upregulated markedly and p-PI3K, p-AKT, and p-MTOR were downregulated in dose- and time-dependent manners. In the tunicamycin

  6. Protective effects of a green tea polyphenol, epigallocatechin-3-gallate, against sevoflurane-induced neuronal apoptosis involve regulation of CREB/BDNF/TrkB and PI3K/Akt/mTOR signalling pathways in neonatal mice.

    Science.gov (United States)

    Ding, Mei-Li; Ma, Hui; Man, Yi-Gang; Lv, Hong-Yan

    2017-12-01

    Epigallocatechin-3-gallate (EGCG), a polyphenol in green tea, is an effective antioxidant and possesses neuroprotective effects. Brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are crucial for neurogenesis and synaptic plasticity. In this study, we aimed to assess the protective effects of EGCG against sevoflurane-induced neurotoxicity in neonatal mice. Distinct groups of C57BL/6 mice were given EGCG (25, 50, or 75 mg/kg body weight) from postnatal day 3 (P3) to P21 and were subjected to sevoflurane (3%; 6 h) exposure on P7. EGCG significantly inhibited sevoflurane-induced neuroapoptosis as determined by Fluoro-Jade B staining and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Increased levels of cleaved caspase-3, downregulated Bad and Bax, and significantly enhanced Bcl-2, Bcl-xL, xIAP, c-IAP-1, and survivin expression were observed. EGCG induced activation of the PI3K/Akt pathway as evidenced by increased Akt, phospho-Akt, GSK-3β, phospho-GSK-3β, and mTORc1 levels. Sevoflurane-mediated downregulation of cAMP/CREB and BDNF/TrkB signalling was inhibited by EGCG. Reverse transcription PCR analysis revealed enhanced BDNF and TrkB mRNA levels upon EGCG administration. Improved performance of mice in Morris water maze tests suggested enhanced learning and memory. The study indicates that EGCG was able to effectively inhibit sevoflurane-induced neurodegeneration and improve learning and memory retention of mice via activation of CREB/BDNF/TrkB-PI3K/Akt signalling.

  7. EGCG protects against homocysteine-induced human umbilical vein endothelial cells apoptosis by modulating mitochondrial-dependent apoptotic signaling and PI3K/Akt/eNOS signaling pathways.

    Science.gov (United States)

    Liu, Shumin; Sun, Zhengwu; Chu, Peng; Li, Hailong; Ahsan, Anil; Zhou, Ziru; Zhang, Zonghui; Sun, Bin; Wu, Jingjun; Xi, Yalin; Han, Guozhu; Lin, Yuan; Peng, Jinyong; Tang, Zeyao

    2017-05-01

    Homocysteine (Hcy) induced vascular endothelial injury leads to the progression of endothelial dysfunction in atherosclerosis. Epigallocatechin gallate (EGCG), a natural dietary antioxidant, has been applied to protect against atherosclerosis. However, the underlying protective mechanism of EGCG has not been clarified. The present study investigated the mechanism of EGCG protected against Hcy-induced human umbilical vein endothelial cells (HUVECs) apoptosis. Methyl thiazolyl tetrazolium assay (MTT), transmission electron microscope, fluorescent staining, flow cytometry, western blot were used in this study. The study has demonstrated that EGCG suppressed Hcy-induced endothelial cell morphological changes and reactive oxygen species (ROS) generation. Moreover, EGCG dose-dependently prevented Hcy-induced HUVECs cytotoxicity and apoptotic biochemical changes such as reducing mitochondrial membrane potential (MMP), decreasing Bcl-2/Bax protein ratio and activating caspase-9 and 3. In addition, EGCG enhanced the protein ratio of p-Akt/Akt, endothelial nitric oxide synthase (eNOS) activation and nitric oxide (NO) formation in injured cells. In conclusion, the present study shows that EGCG prevents Hcy-induced HUVECs apoptosis via modulating mitochondrial apoptotic and PI3K/Akt/eNOS signaling pathways. Furthermore, the results indicate that EGCG is likely to represent a potential therapeutic strategy for atherosclerosis associated with Hyperhomocysteinemia (HHcy).

  8. PTEN differentially regulates expressions of ICAM-1 and VCAM-1 through PI3K/Akt/GSK-3β/GATA-6 signaling pathways in TNF-α-activated human endothelial cells.

    Science.gov (United States)

    Tsoyi, Konstantin; Jang, Hwa Jin; Nizamutdinova, Irina Tsoy; Park, Kyungok; Kim, Young Min; Kim, Hye Jung; Seo, Han Geuk; Lee, Jae Heun; Chang, Ki Churl

    2010-11-01

    Phosphotase and tensin homolog deleted on chromosome 10 (PTEN) is a potent negative regulator of PI3K/Akt pathway. Here, we tried to elucidate the role of PTEN in the regulation of endothelial adhesion molecules, vascular cell adhesion molecule (VCAM)-1 and intracellular adhesion molecule (ICAM)-1, induced by TNF-α in human endothelial cells (ECs). Transfection with PTEN overexpressing vector resulted in the significant decrease in phosphorylation of Akt in TNF-α-treated ECs. PTEN strongly inhibited VCAM-1 but not ICAM-1, however this inhibitory effect was reversed by co-transfection with constitutively active-Akt (CA-Akt-HA) in TNF-α-stimulated ECs. Additionally, silencing of PTEN with specific siRNA showed significant increase of phosphor-Akt compared with TNF-α alone treated ECs. siPTEN significantly upregulated VCAM-1 but was indifferent to ICAM-1 in TNF-α-treated cells. Further, chromatin immunoprecipitation (ChIP) assay showed that PTEN targets GATA-6 but not IRF-1 binding to VCAM-1 promoter. In addition, GATA-6 is associated with glycogen synthesis kinase-3beta (GSK-3β) which is in turn regulated by PTEN-dependent Akt activity. Finally, PTEN significantly prevented monocyte adhesion to TNF-α-induced ECs probably through VCAM-1 regulation. It is concluded that PTEN selectively inhibits expression of VCAM-1 but not ICAM-1 through modulation of PI3K/Akt/GSK-3β/GATA-6 signaling cascade in TNF-α-treated ECs. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  9. High Glucose Promotes Tumor Invasion and Increases Metastasis-Associated Protein Expression in Human Lung Epithelial Cells by Upregulating Heme Oxygenase-1 via Reactive Oxygen Species or the TGF-β1/PI3K/Akt Signaling Pathway

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    Xiaowen Kang

    2015-02-01

    Full Text Available Background: Growing evidence indicates that heme oxygenase-1 (HO-1 is up-regulated in malignancies and subsequently alters tumor aggressiveness and various cancer-related factors, such as high glucose (HG levels. HO-1 expression can be induced when glucose concentrations are above 25 mM; however, the role of HO-1 in lung cancer patients with diabetes remains unknown. Therefore, in this study we investigated the promotion of tumor cell invasion and the expression of metastasis-associated proteins by inducing the up-regulation of HO-1 expression by HG treatment in A549 human lung epithelial cells. Methods: The expression of HO-1and metastasis-associated protein expression was explored by western blot analysis. HO-1 enzymatic activity, reactive oxygen species (ROS production and TGF-β1 production were examined by ELISA. Invasiveness was analyzed using a Transwell chamber. Results: HG treatment of A549 cells induced an increase in HO-1 expression, which was mediated by the HG-induced generation of reactive oxygen species (ROS and transforming growth factor-β1 (TGF-β1 in a concentration- and time-dependent manner. Following the increase in HO-1 expression, the enzymatic activity of HO-1 also increased in HG-treated cells. Pretreatment with N-acetyl-L-cysteine (NAC or with phosphatidylinositol 3-kinase (PI3K/Akt inhibitors attenuated the HG-induced increase in HO-1 expression. HG treatment of A549 cells enhanced the invasion potential of these cells, as shown with a Transwell assay, and increased metastasis-associated protein expression. However, HO-1 siRNA transfection significantly decreased these capabilities. Conclusion: this study is the first to demonstrate that HG treatment of A549 human lung epithelial cells promotes tumor cell invasion and increases metastasis-associated protein expression by up-regulating HO-1 expression via ROS or the TGF-β1/PI3K/Akt signaling pathway.

  10. Chronic intermittent fasting improves the survival following large myocardial ischemia by activation of BDNF/VEGF/PI3K signaling pathway.

    Science.gov (United States)

    Katare, Rajesh G; Kakinuma, Yoshihiko; Arikawa, Mikihiko; Yamasaki, Fumiyasu; Sato, Takayuki

    2009-03-01

    Chronic heart failure (CHF) is the major cause of death in the developed countries. Calorie restriction is known to improve the recovery in these patients; however, the exact mechanism behind this protective effect is unknown. Here we demonstrate the activation of cell survival PI3kinase/Akt and VEGF pathway as the mechanism behind the protection induced by intermittent fasting in a rat model of established chronic myocardial ischemia (MI). Chronic MI was induced in rats by occlusion of the left coronary artery. Two weeks later, the rats were randomly assigned to a normal feeding group (MI-NF) and an alternate-day feeding group (MI-IF). After 6 weeks of observation, we evaluated the effect of intermittent fasting on cellular and ventricular remodeling and long-term survival after CHF. Compared with the normally fed group, intermittent fasting markedly improved the survival of rats with CHF (88.5% versus 23% survival, Pfasted hearts. Immunohistochemical studies confirmed increased capillary density (Pfasting also upregulated the expression of other anti-apoptotic factors such as Akt and Bcl-2 and reduced the TUNEL positive apoptotic nuclei in the border zone. Chronic intermittent fasting markedly improves the long-term survival after CHF by activation through its pro-angiogenic, anti-apoptotic and anti-remodeling effects.

  11. N-carbamylglutamate enhances pregnancy outcome in rats through activation of the PI3K/PKB/mTOR signaling pathway.

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    Xiangfang Zeng

    Full Text Available Administration of N-carbamylglutamate (NCG, an analogue of endogenous N-acetyl-glutamate (an activator of arginine synthesis has been shown to enhance neonatal growth by increasing circulating arginine levels. However, the effect of NCG on pregnancy remains unknown. This study examined the effects of NCG on pregnancy outcome and evaluated potential mechanisms involved. Reproductive performance, embryo implantation, and concentration of amino acids in serum and uterine flushing, were determined in rats fed control or NCG supplemented diets. Ishikawa cells and JAR cells were used to examine the mechanism by which NCG affects embryo implantation. Dietary NCG supplementation increased serum levels of arginine, onithine, and proline, as well as uterine levels of arginine, glutamine, glutamate, and proline. Additionally, it stimulated LIF expression, and enhanced the activation of signal transduction and activator of transcription 3 (Stat3, protein kinase B (PKB, and 70-kDa ribosomal protein S6 kinase (S6K1 during the periimplantation period, resulting in an increase in litter size but not birth weight. In uterine Ishikawa cells, LIF expression was also enhanced by treatment with arginine and its metabolites. In trophoblast JAR cells, treatment with arginine and its metabolites enhanced Stat3, PKB, and S6K1 activation and facilitated cellular adhesion activity. These effects were abolished by pretreatment with inhibitors of phosphatidylinositol 3-kinase (wortmannin and mammalian target of rapamycin (rapamycin. The results demonstrate that NCG supplementation enhances pregnancy outcome and have important implications for the pregnancy outcome of mammalian species.

  12. Jiang Tang Xiao Ke Granule Play an Anti-diabetic Role in Diabetic Mice Pancreatic Tissue by Regulating the mRNAs and MicroRNAs Associated with PI3K-Akt Signaling Pathway

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    Fang-Fang Mo

    2017-11-01

    Full Text Available Purpose: To investigate the effect of JTXK granule on the expression pattern of miRNA in pancreatic tissue of KKAy diabetic mice, and to explore the molecular mechanism and pathways of JTXK granule in anti-diabetic effect.Methods: We used high fat diet (HFD to induce the KKAy diabetic mice and screened the differentially expressed miRNAs (DEMs between JTXK-treated group (n = 6 and the diabetic group (n = 6 using MicroRNA (miRNA Microarray. C57BL/6J mice were given a normal diet as the control group (n = 6. Subsequently, miRNA target gene prediction, GO and Pathway analysis were used to explore the function of DEMs. Finally, the mechanism of anti-diabetic effects of JTXK granule was tested by in vitro INS-1 pancreatic β-cell experiment.Results: The blood glucose and body weight of JTXK-treated group was significantly lower compared with the model group. Moreover, a total of 45 miRNAs with significant differences were detected in the model group and the JTXK-treated group (P ≤ 0.05, Fold Change > 2. Further, miRNA-mRNA analysis showed that the differential expression of mmu-miR-192-5p, mmu-miR-291a-3p, mmu-miR-320-3p, mmu-miR-139-5p and mmu-miR-378a-3p are closely related to pancreatic histological changes. In addition, pathway analysis showed that the DEMs were closely related to PI3K-Akt Signaling Pathway. Furthermore, the levels of serine/threonine-protein kinase (Akt, phosphorylated Akt (p-Akt and phosphorylated forkhead transcription factor O1 (p-Foxo1 in INS-1-FOXO1 overexpressing model cells were lower than those in normal group, while JTXK granules could increase the expression of Akt, p-Akt and p-Foxo1.Conclusions: The results showed that JTXK granule could play an anti-diabetic role by regulating the mRNA and miRNAs associated with PI3K-Akt pathway in diabetic mice pancreatic tissue.

  13. Alisertib induces cell cycle arrest and autophagy and suppresses epithelial-to-mesenchymal transition involving PI3K/Akt/mTOR and sirtuin 1-mediated signaling pathways in human pancreatic cancer cells

    Science.gov (United States)

    Wang, Feng; Li, Hai; Yan, Xiao-Gang; Zhou, Zhi-Wei; Yi, Zhi-Gang; He, Zhi-Xu; Pan, Shu-Ting; Yang, Yin-Xue; Wang, Zuo-Zheng; Zhang, Xueji; Yang, Tianxing; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Pancreatic cancer is the most aggressive cancer worldwide with poor response to current therapeutics. Alisertib (ALS), a potent and selective Aurora kinase A inhibitor, exhibits potent anticancer effects in preclinical and clinical studies; however, the effect and underlying mechanism of ALS in the pancreatic cancer treatment remain elusive. This study aimed to examine the effects of ALS on cell growth, autophagy, and epithelial-to-mesenchymal transition (EMT) and to delineate the possible molecular mechanisms in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that ALS exerted potent cell growth inhibitory, pro-autophagic, and EMT-suppressing effects in PANC-1 and BxPC-3 cells. ALS remarkably arrested PANC-1 and BxPC-3 cells in G2/M phase via regulating the expression of cyclin-dependent kinases 1 and 2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. ALS concentration-dependently induced autophagy in PANC-1 and BxPC-3 cells, which may be attributed to the inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), p38 mitogen-activated protein kinase (p38 MAPK), and extracellular signal-regulated kinases 1 and 2 (Erk1/2) but activation of 5′-AMP-dependent kinase signaling pathways. ALS significantly inhibited EMT in PANC-1 and BxPC-3 cells with an increase in the expression of E-cadherin and a decrease in N-cadherin. In addition, ALS suppressed the expression of sirtuin 1 (Sirt1) and pre-B cell colony-enhancing factor/visfatin in both cell lines with a rise in the level of acetylated p53. These findings show that ALS induces cell cycle arrest and promotes autophagic cell death but inhibits EMT in pancreatic cancer cells with the involvement of PI3K/Akt/mTOR, p38 MAPK, Erk1/2, and Sirt1-mediated signaling pathways. Taken together, ALS may represent a promising anticancer drug for pancreatic cancer treatment. More studies are warranted to investigate other molecular targets and

  14. Regulation of the PI3K pathway through a p85α monomer–homodimer equilibrium

    KAUST Repository

    Cheung, Lydia W T; Walkiewicz, Katarzyna Wiktoria; Besong, Tabot M.D.; Guo, Huifang; Hawke, David H.; Arold, Stefan T.; Mills, Gordon B.

    2015-01-01

    The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity. p110α-free p85α homodimerizes via two intermolecular interactions (SH3:proline-rich region and BH:BH) to selectively bind unphosphorylated activated PTEN. As a consequence, homodimeric but not monomeric p85α suppresses the PI3K pathway by protecting PTEN from E3 ligase WWP2-mediated proteasomal degradation. Further, the p85α homodimer enhances the lipid phosphatase activity and membrane association of PTEN. Strikingly, we identified cancer patient-derived oncogenic p85α mutations that target the homodimerization or PTEN interaction surface. Collectively, our data suggest the equilibrium of p85α monomerdimers regulates the PI3K pathway and disrupting this equilibrium could lead to disease development. © Cheung et al.

  15. Regulation of the PI3K pathway through a p85α monomer–homodimer equilibrium

    KAUST Repository

    Cheung, Lydia W T

    2015-07-29

    The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity. p110α-free p85α homodimerizes via two intermolecular interactions (SH3:proline-rich region and BH:BH) to selectively bind unphosphorylated activated PTEN. As a consequence, homodimeric but not monomeric p85α suppresses the PI3K pathway by protecting PTEN from E3 ligase WWP2-mediated proteasomal degradation. Further, the p85α homodimer enhances the lipid phosphatase activity and membrane association of PTEN. Strikingly, we identified cancer patient-derived oncogenic p85α mutations that target the homodimerization or PTEN interaction surface. Collectively, our data suggest the equilibrium of p85α monomerdimers regulates the PI3K pathway and disrupting this equilibrium could lead to disease development. © Cheung et al.

  16. Activation of the PI3K/AKT pathway in Merkel cell carcinoma.

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    Christian Hafner

    Full Text Available Merkel cell carcinoma (MCC is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV. Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4% MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients.

  17. Role of androgen receptor on cyclic mechanical stretch-regulated proliferation of C2C12 myoblasts and its upstream signals: IGF-1-mediated PI3K/Akt and MAPKs pathways.

    Science.gov (United States)

    Ma, Yiming; Fu, Shaoting; Lu, Lin; Wang, Xiaohui

    2017-07-15

    To detect the effects of androgen receptor (AR) on cyclic mechanical stretch-modulated proliferation of C2C12 myoblasts and its pathways: roles of IGF-1, PI3K and MAPK. C2C12 were randomly divided into five groups: un-stretched control, six or 8 h of fifteen percent stretch, and six or 8 h of twenty percent stretch. Cyclic mechanical stretch of C2C12 were completed using a computer-controlled FlexCell Strain Unit. Cell proliferation and IGF-1 concentration in medium were detected by CCK8 and ELISA, respectively. Expressions of AR and IGF-1R, and expressions and activities of PI3K, p38 and ERK1/2 in stretched C2C12 cells were determined by Western blot. ①The proliferation of C2C12 cells, IGF-1 concentration in medium, expressions of AR and IGF-1R, and activities of PI3K, p38 and ERK1/2 were increased by 6 h of fifteen percent stretch, while decreased by twenty percent stretch for six or 8 h ②The fifteen percent stretch-increased proliferation of C2C12 cells was reversed by AR inhibitor, Flutamide. ③The increases of AR expression, activities of PI3K, p38 and ERK1/2 resulted from fifteen percent stretch were attenuated by IGF-1 neutralizing antibody, while twenty percent stretch-induced decreases of the above indicators were enhanced by recombinant IGF-1. ④Specific inhibitors of p38, ERK1/2 and PI3K all decreased the expression of AR in fifteen percent and twenty percent of stretched C2C12 cells. Cyclic mechanical stretch modulated the proliferation of C2C12 cells, which may be attributed to the alterations of AR via IGF-1-PI3K/Akt and IGF-1-MAPK (p38, ERK1/2) pathways in C2C12 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. IGF-II-mediated downregulation of peroxisome proliferator-activated receptor-γ coactivator-1α in myoblast cells involves PI3K/Akt/FoxO1 signaling pathway.

    Science.gov (United States)

    Mu, Xiaoyu; Qi, Weihong; Liu, Yunzhang; Zhou, Jianfeng; Li, Yun; Rong, Xiaozhi; Lu, Ling

    2017-08-01

    Insulin-like growth factor II (IGF-II) can stimulate myogenesis and is critically involved in skeletal muscle differentiation. The presence of negative regulators of this process, however, is not well explored. Here, we showed that in myoblast cells, IGF-II negatively regulated peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mRNA expression, while constitutive expression of PGC-1α induced myoblast differentiation. These results suggest that the negative regulation of PGC-1α by IGF-II may act as a negative feedback mechanism in IGF-II-induced myogenic differentiation. Reporter assays demonstrated that IGF-II suppresses the basal PGC-1α promoter activity. Blocking the IGF-II signaling pathway increased the endogenous PGC-1α levels. In addition, pharmacological inhibition of PI3 kinase activity prevented the downregulation of PGC-1α but the activation of mTOR was not required for this process. Importantly, further analysis showed that forkhead transcription factor FoxO1 contributes to mediating the effects of IGF-II on PGC-1 promoter activity. These findings indicate that IGF-II reduces PGC-1α expression in skeletal muscle cells through a mechanism involving PI3K-Akt-FoxO1 but not p38 MAPK or Erk1/2 MAPK pathways.

  19. A Novel Bromophenol Derivative BOS-102 Induces Cell Cycle Arrest and Apoptosis in Human A549 Lung Cancer Cells via ROS-Mediated PI3K/Akt and the MAPK Signaling Pathway

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    Chuan-Long Guo

    2018-01-01

    Full Text Available Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4′-bipiperidin]-1′-ylpropoxy-3-bromo-5-methoxybenzylidene-N-(4-bromophenyl-2-oxoindoline-5-sulfonamide (BOS-102 was synthesized, which showed excellent anticancer activities on human lung cancer cell lines. A study of the mechanisms indicated that BOS-102 could significantly block cell proliferation in human A549 lung cancer cells and effectively induce G0/G1 cell cycle arrest via targeting cyclin D1 and cyclin-dependent kinase 4 (CDK4. BOS-102 could also induce apoptosis, including activating caspase-3 and poly (ADP-ribose polymerase (PARP, increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS generation, decreasing mitochondrial membrane potential (MMP, ΔΨm, and leading cytochrome c release from mitochondria. Further research revealed that BOS-102 deactivated the PI3K/Akt pathway and activated the mitogen-activated protein kinase (MAPK signaling pathway resulting in apoptosis and cell cycle arrest, which indicated that BOS-102 has the potential to develop into an anticancer drug.

  20. Ganoderma tsugae Induces S Phase Arrest and Apoptosis in Doxorubicin-Resistant Lung Adenocarcinoma H23/0.3 Cells via Modulation of the PI3K/Akt Signaling Pathway

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    Yang-Hao Yu

    2012-01-01

    Full Text Available Ganoderma tsugae (GT is a traditional Chinese medicine that exhibits significant antitumor activities against many types of cancer. This study investigated the molecular mechanism by which GT suppresses the growth of doxorubicin-resistant lung adenocarcinoma H23/0.3 cells. Our results reveal that GT inhibits the viability of H23/0.3 cells in vitro and in vivo and sensitizes the growth suppression effect of doxorubicin on H23/0.3 cells. The data also show that GT induces S phase arrest by interfering with the protein expression of cyclin A, cyclin E, CDK2, and CDC25A. Furthermore, GT induces cellular apoptosis via induction of a mitochondria/caspase pathway. In addition, we also demonstrate that the suppression of cell proliferation by GT is through down-regulation of the PI3K/Akt signaling pathway. In conclusion, this study suggests that GT may be a useful adjuvant therapeutic agent in the treatment of lung cancer.

  1. IGF-1 and PDGF-bb Suppress IL-1β-Induced Cartilage Degradation through Down-Regulation of NF-κB Signaling: Involvement of Src/PI-3K/AKT Pathway

    Science.gov (United States)

    Mobasheri, Ali; Buhrmann, Constanze; Aldinger, Constance; Rad, Jafar Soleimani; Shakibaei, Mehdi

    2011-01-01

    Objective Interleukin-1β (IL-1β) is a pro-inflammatory cytokine that plays a key role in the pathogenesis of osteoarthritis (OA). Growth factors (GFs) capable of antagonizing the catabolic actions of cytokines may have therapeutic potential in the treatment of OA. Herein, we investigated the potential synergistic effects of insulin-like growth factor (IGF-1) and platelet-derived growth factor (PDGF-bb) on different mechanisms participating in IL-1β-induced activation of nuclear transcription factor-κB (NF-κB) and apoptosis in chondrocytes. Methods Primary chondrocytes were treated with IL-1β to induce dedifferentiation and co-treated with either IGF-1 or/and PDGF-bb and evaluated by immunoblotting and electron microscopy. Results Pretreatment of chondrocytes with IGF-1 or/and PDGF-bb suppressed IL-1β-induced NF-κB activation via inhibition of IκB-α kinase. Inhibition of IκB-α kinase by GFs led to the suppression of IκB-α phosphorylation and degradation, p65 nuclear translocation and NF-κB-regulated gene products involved in inflammation and cartilage degradation (COX-2, MMPs) and apoptosis (caspase-3). GFs or BMS-345541 (specific inhibitor of the IKK) reversed the IL-1β-induced down-regulation of collagen type II, cartilage specific proteoglycans, β1-integrin, Shc, activated MAPKinase, Sox-9 and up-regulation of active caspase-3. Furthermore, the inhibitory effects of IGF-1 or/and PDGF-bb on IL-1β-induced NF-κB activation were sensitive to inhibitors of Src (PP1), PI-3K (wortmannin) and Akt (SH-5), suggesting that the pathway consisting of non-receptor tyrosine kinase (Src), phosphatidylinositol 3-kinase and protein kinase B must be involved in IL-1β signaling. Conclusion The results presented suggest that IGF-1 and PDGF-bb are potent inhibitors of IL-1β-mediated activation of NF-κB and apoptosis in chondrocytes, may be mediated in part through suppression of Src/PI-3K/AKT pathway, which may contribute to their anti-inflammatory effects. PMID

  2. 17β-Estradiol up-regulates Nrf2 via PI3K/AKT and estrogen receptor signaling pathways to suppress light-induced degeneration in rat retina.

    Science.gov (United States)

    Zhu, C; Wang, S; Wang, B; Du, F; Hu, C; Li, H; Feng, Y; Zhu, R; Mo, M; Cao, Y; Li, A; Yu, X

    2015-09-24

    Human age-related retinal diseases, such as age-related macular degeneration (AMD), are intimately associated with decreased tissue oxygenation and hypoxia. Different antioxidants have been investigated to reverse AMD. In the present study, we describe the antioxidant 17β-estradiol (βE2) and investigate its protective effects on retinal neurons. Fourteen days after ovariectomy, adult Sprague-Dawley rats were exposed to 8000-lux light for 12h to induce retinal degeneration. Reactive oxygen species (ROS) levels were assessed by confocal fluorescence microscopy using 2,7-dichlorofluorescein diacetate. Nuclear factor erythroid 2-related factor 2 (Nrf2) and antioxidant enzyme mRNA expression were detected by real-time PCR. Western blotting was used to evaluate NRF2 activation. NRF2 translocation was determined by immunohistochemistry, with morphological changes monitored by hematoxylin and eosin staining. Following light exposure, βE2 significantly reduced ROS production. βE2 also up-regulated NRF2 mRNA and protein levels, with maximal expression at 4 and 12h post-exposure, respectively. Interestingly, following βE2 administration, NRF2 was translocated from the cytoplasm to the nucleus, primarily in the outer nuclear layer. βE2 also up-regulated NRF2, which triggered phase-2 antioxidant enzyme expression (superoxide dismutases 1 and 2, catalase, glutaredoxins 1 and 2, and thioredoxins 1 and 2), reduced ROS production, and ameliorated retinal damage. However, the beneficial effects of βE2 were markedly suppressed by pretreatment with LY294002 or ICI182780, specific inhibitors of the phosphatidylinositol 3-kinase-Akt (PI3K/AKT), and estrogen receptor (ER) signaling pathways, respectively. Taken together, these observations suggest that βE2 exerts antioxidative effects following light-induced retinal degeneration potentially via NRF2 activation. This protective mechanism may depend on two pathways: a rapid, non-genomic-type PI3K/AKT response, and a genomic-type ER

  3. Insulin-like growth factor-1 (IGF-1) promotes primordial follicle growth and reduces DNA fragmentation through the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signalling pathway.

    Science.gov (United States)

    Bezerra, Maria É S; Barberino, Ricássio S; Menezes, Vanúzia G; Gouveia, Bruna B; Macedo, Taís J S; Santos, Jamile M S; Monte, Alane P O; Barros, Vanessa R P; Matos, Maria H T

    2018-05-30

    We investigated the effects of insulin-like growth factor 1 (IGF-1) on the morphology and follicular activation of ovine preantral follicles cultured in situ and whether the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway is involved in IGF-1 action in the sheep ovary. Ovine ovarian fragments were fixed for histological and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) analyses (fresh control) or cultured in supplemented alpha-minimum essential medium (α-MEM+; control) or α-MEM+ with IGF-1 (1, 10, 50, 100 or 200ngmL-1) for 7 days. Follicles were classified as normal or atretic, primordial or growing and the oocyte and follicle diameters were measured. DNA fragmentation was evaluated by TUNEL assay. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was performed on the fresh control, α-MEM+ and 100ngmL-1 IGF-1 samples. Inhibition of PI3K activity was performed through pretreatment with the PI3K inhibitor LY294002 and phosphorylated AKT (pAKT) expression was analysed after culture in the absence or presence of LY294002. IGF-1 at 100ngmL-1 increased (PIGF-1. LY294002 significantly inhibited follicular activation stimulated by α-MEM+ and 100ngmL-1 IGF-1 and reduced pAKT expression in follicles. Overall, IGF-1 at 100ngmL-1 promoted primordial follicle activation, cell proliferation and reduced DNA fragmentation after in situ culture through the PI3K/AKT pathway.

  4. Flaccidoxide-13-Acetate Extracted from the Soft Coral Cladiella kashmani Reduces Human Bladder Cancer Cell Migration and Invasion through Reducing Activation of the FAK/PI3K/AKT/mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Choo-Aun Neoh

    2017-12-01

    Full Text Available Metastasis of cancer is the cause of the majority of cancer deaths. Active compound flaccidoxide-13-acetate, isolated from the soft coral Cladiella kashmani, has been found to exhibit anti-tumor activity. In this study, Boyden chamber analysis, Western blotting and gelatin zymography assays indicated that flaccidoxide-13-acetate exerted inhibitory effects on the migration and invasion of RT4 and T24 human bladder cancer cells. The results demonstrated that flaccidoxide-13-acetate, in a concentration-dependent manner, reduced the levels of matrix metalloproteinase-2 (MMP-2, MMP-9, urokinase-type plasminogen activator receptor (uPAR, focal adhesion kinase (FAK, phosphatidylinositide-3 kinases (PI3K, p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR, p-mTOR, Ras homolog gene family, member A (Rho A, Ras, mitogen-activated protein kinase kinase 7 (MKK7 and mitogen-activated protein kinase kinase kinase 3 (MEKK3, and increased the expressions of tissue inhibitor of metalloproteinase-1 (TIMP-1 and TIMP-2 in RT4 and T24 cells. This study revealed that flaccidoxide-13-acetate suppressed cell migration and invasion by reducing the expressions of MMP-2 and MMP-9, regulated by the FAK/PI3K/AKT/mTOR pathway. In conclusion, our study was the first to demonstrate that flaccidoxide-13-acetate could be a potent medical agent for use in controlling the migration and invasion of bladder cancer.

  5. The Effects of IGF-1 on TNF-α-Treated DRG Neurons by Modulating ATF3 and GAP-43 Expression via PI3K/Akt/S6K Signaling Pathway.

    Science.gov (United States)

    Zhang, Lei; Yue, Yaping; Ouyang, Meishuo; Liu, Huaxiang; Li, Zhenzhong

    2017-05-01

    imply that IGF-1 counteracts the toxic effect of higher concentration of TNF-α, while potentiates the growth-promoting effect of lower concentration of TNF-α, with the node for TNF-α and IGF-1 interaction being the PI3K/Akt/S6K signaling pathway. This study is helpful for interpretation of the association of IGF-1 with TNF-α and the neurobiological effects elicited by interaction of IGF-1 and TNF-α in neurological disorders.

  6. PI3K pathway activation results in low efficacy of both trastuzumab and lapatinib

    International Nuclear Information System (INIS)

    Wang, Leiping; Hu, Xichun; Zhang, Qunling; Zhang, Jian; Sun, Si; Guo, Haiyi; Jia, Zhen; Wang, Biyun; Shao, Zhimin; Wang, Zhonghua

    2011-01-01

    Human epidermal growth factor receptor 2 (HER2) is the most crucial ErbB receptor tyrosine kinase (RTK) family member in HER2-positive (refered to HER2-overexpressing) breast cancer which are dependent on or 'addictive' to the Phosphatidylinositol-3-kinase (PI3K) pathway. HER2-related target drugs trastuzumab and lapatinib have been the foundation of treatment of HER2--positive breast cancer. This study was designed to explore the relationship between PI3K pathway activation and the sensitivity to lapatinib in HER2--positive metastatic breast cancer patients pretreated with anthracyclins, taxanes and trastuzumab. Sixty-seven HER2-positive metastatic breast cancer patients were recruited into a global lapatinib Expanded Access Program and 57 patients have primary tumor specimens available for determination of PI3K pathway status. PTEN status was determined by immunohistochemical staining and PIK3CA mutations were detected via PCR sequencing. All patients were treated with lapatinib 1250 mg/day continuously and capecitabine 1000 mg/m 2 twice daily on a 2-week-on and 1-week-off schedule until disease progression, death, withdrawal of informed consent, or intolerable toxicity. PIK3CA mutations and PTEN loss were detected in 12.3% (7/57) and 31.6% (18/57) of the patients, respectively. Twenty-two patients with PI3K pathway activation (defined as PIK3CA mutation and/or PTEN expression loss) had a lower clinical benefit rate (36.4% versus 68.6%, P = 0.017) and a lower overall response rate (9.1% versus 31.4%, P = 0.05), when compared with the 35 patients with no activation. A retrospective analysis of first trastuzumab-containing regimen treatment data showed that PI3K pathway activation correlated with a shorter median progression-free survival (4.5 versus 9.0 months, P = 0.013). PIK3CA mutations occur more frequently in elder patients for HER2-positive breast cancer. PIK3CA mutations and PTEN loss are not mutually exclusive. PI3K pathway activation resulting

  7. Isoviolanthin Extracted from Dendrobium officinale Reverses TGF-β1-Mediated Epithelial–Mesenchymal Transition in Hepatocellular Carcinoma Cells via Deactivating the TGF-β/Smad and PI3K/Akt/mTOR Signaling Pathways

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    Shangping Xing

    2018-05-01

    Full Text Available Dendrobium officinale is a precious medicinal herb and health food, and its pharmacological actions have been studied and proved. However, the mechanisms by which its active flavonoid glycosides affect epithelial–mesenchymal transition (EMT in hepatocellular carcinoma (HCC cells, such as HepG2 and Bel-7402 cells, have not been previously investigated. Therefore, we investigated whether isoviolanthin extracted from the leaves of Dendrobium officinale inhibits transforming growth factor (TGF-β1-induced EMT in HCC cells. In this study, the physicochemical properties and structure of isoviolanthin were identified by HPLC, UV, ESIMS, and NMR and were compared with literature data. HCC cells were pretreated with 10 ng/mL TGF-β1 to induce EMT and then treated with isoviolanthin. Herein, we found that isoviolanthin exhibited no cytotoxic effects on normal liver LO2 cells but notably reduced the migratory and invasive capacities of TGF-β1-treated HCC cells. Additionally, isoviolanthin treatment decreased matrix metalloproteinase (MMP-2 and -9 levels, and remarkably altered the expression of EMT markers via regulating the TGF-β/Smad and PI3K/Akt/mTOR signaling pathways; Western blot analysis confirmed that the effects of the inhibitors SB431542 and LY294002 were consistent with those of isoviolanthin. These findings demonstrate the potential of isoviolanthin as a therapeutic agent for the treatment of advanced-stage metastatic HCC.

  8. Chimaphilin inhibits human osteosarcoma cell invasion and metastasis through suppressing the TGF-β1-induced epithelial-to-mesenchymal transition markers via PI-3K/Akt, ERK1/2, and Smad signaling pathways.

    Science.gov (United States)

    Dong, Feng; Liu, Tingting; Jin, Hao; Wang, Wenbo

    2018-01-01

    Epithelial-to-mesenchymal transition is a cellular process associated with cancer invasion and metastasis. However, the antimetastatic effects of chimaphilin remain elusive. In this study, we attempted to investigate the potential use of chimaphilin as an inhibitor of TGF-β1-induced epithelial-to-mesenchymal transition in U2OS cells. We found that TGF-β1 induced epithelial-to-mesenchymal transition to promote U2OS cell invasion and metastasis. Western blotting demonstrated that chimaphilin inhibited U2OS cell invasion and migration, increased the expression of the epithelial phenotype marker E-cadherin, repressed the expression of the mesenchymal phenotype marker vimentin, as well as decreased the level of epithelial-to-mesenchymal-inducing transcription factors Snail1 and Slug during the initiation of TGF-β1-induced epithelial-to-mesenchymal transition. In this study, we revealed that chimaphilin up-regulated the E-cadherin expression level and inhibited the production of vimentin, Snail1, and Slug in TGF-β1-induced U2OS cells by blocking PI-3K/Akt and ERK 1/2 signaling pathway. Additionally, the TGF-β1-mediated phosphorylated levels of Smad2/3 were inhibited by chimaphilin pretreatment. Above all, we conclude that chimaphilin represents an effective inhibitor of the metastatic potential of U2OS cells through suppression of TGF-β1-induced epithelial-to-mesenchymal transition.

  9. Lycium barbarum polysaccharide protects against oxygen glucose deprivation/reoxygenation-induced apoptosis and autophagic cell death via the PI3K/Akt/mTOR signaling pathway in primary cultured hippocampal neurons.

    Science.gov (United States)

    Yu, Yang; Wu, Xiuquan; Pu, Jingnan; Luo, Peng; Ma, Wenke; Wang, Jiu; Wei, Jialiang; Wang, Yuanxin; Fei, Zhou

    2018-01-01

    Lycium barbarum polysaccharide (LBP) is the main active ingredient of Lycium barbarum, which exhibits several beneficial effects, including neuroprotection, anti-aging and anti-oxidation. However, the mechanism by which LBP protects against cerebral ischemia/reperfusion-induced injury remains obscure. In this study, we found that LBP pretreatment greatly attenuated oxygen glucose deprivation/reperfusion (OGD/R) injury in primary cultured hippocampal neurons. LBP also suppressed OGD/R-induced lactate dehydrogenase (LDH) leakage, and ameliorated oxidative stress. In addition, LBP significantly reduced OGD/R-induced apoptosis and autophagic cell death. LBP caused the down-regulation of cleaved Caspase-3/Caspase-3, LC3II/LC3I and Beclin 1, as well as up-regulation of Bcl-2/Bax and p62. Furthermore, mechanistic studies indicated that LBP pretreatment increased p-Akt and p-mTOR levels after OGD/R. In summary, our results indicated that LBP protects against OGD/R-induced neuronal injury in primary hippocampal neurons by activating the PI3K/Akt/mTOR signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Synergistic effects of targeted PI3K signaling inhibition and chemotherapy in liposarcoma.

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    Shang Guo

    Full Text Available While liposarcoma is the second most common soft tissue malignant tumor, the molecular pathogenesis in this malignancy is poorly understood. Our goal was therefore to expand the understanding of molecular mechanisms that drive liposarcoma and identify therapeutically-susceptible genetic alterations. We studied a cohort of high-grade liposarcomas and benign lipomas across multiple disease sites, as well as two liposarcoma cell lines, using multiplexed mutational analysis. Nucleic acids extracted from diagnostic patient tissue were simultaneously interrogated for 150 common mutations across 15 essential cancer genes using a clinically-validated platform for cancer genotyping. Western blot analysis was implemented to detect activation of downstream pathways. Liposarcoma cell lines were used to determine the effects of PI3K targeted drug treatment with or without chemotherapy. We identified mutations in the PIK3CA gene in 4 of 18 human liposarcoma patients (22%. No PIK3CA mutations were identified in benign lipomas. Western blot analysis confirmed downstream activation of AKT in both PIK3CA mutant and non-mutant liposarcoma samples. PI-103, a dual PI3K/mTOR inhibitor, effectively inhibited the activation of the PI3K/AKT in liposarcoma cell lines and induced apoptosis. Importantly, combination with PI-103 treatment strongly synergized the growth-inhibitory effects of the chemotherapy drugs doxorubicin and cisplatin in liposarcoma cells. Taken together, these findings suggest that activation of the PI3K/AKT pathway is an important cancer mechanism in liposarcoma. Targeting the PI3K/AKT/pathway with small molecule inhibitors in combination with chemotherapy could be exploited as a novel strategy in the treatment of liposarcoma.

  11. iTRAQ proteomics analysis reveals that PI3K is highly associated with bupivacaine-induced neurotoxicity pathways.

    Science.gov (United States)

    Zhao, Wei; Liu, Zhongjie; Yu, Xujiao; Lai, Luying; Li, Haobo; Liu, Zipeng; Li, Le; Jiang, Shan; Xia, Zhengyuan; Xu, Shi-yuan

    2016-02-01

    Bupivacaine, a commonly used local anesthetic, has potential neurotoxicity through diverse signaling pathways. However, the key mechanism of bupivacaine-induced neurotoxicity remains unclear. Cultured human SH-SY5Y neuroblastoma cells were treated (bupivacaine) or untreated (control) with bupivacaine for 24 h. Compared to the control group, bupivacaine significantly increased cyto-inhibition, cellular reactive oxygen species, DNA damage, mitochondrial injury, apoptosis (increased TUNEL-positive cells, cleaved caspase 3, and Bcl-2/Bax), and activated autophagy (enhanced LC3II/LC3I ratio). To explore changes in protein expression and intercommunication among the pathways involved in bupivacaine-induced neurotoxicity, an 8-plex iTRAQ proteomic technique and bioinformatics analysis were performed. Compared to the control group, 241 differentially expressed proteins were identified, of which, 145 were up-regulated and 96 were down-regulated. Bioinformatics analysis of the cross-talk between the significant proteins with altered expression in bupivacaine-induced neurotoxicity indicated that phosphatidyl-3-kinase (PI3K) was the most frequently targeted protein in each of the interactions. We further confirmed these results by determining the downstream targets of the identified signaling pathways (PI3K, Akt, FoxO1, Erk, and JNK). In conclusion, our study demonstrated that PI3K may play a central role in contacting and regulating the signaling pathways that contribute to bupivacaine-induced neurotoxicity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Mitochondrial stress and activation of PI3K and Akt survival pathway in bladder ischemia

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    Yang JH

    2017-06-01

    behavior and cystometric changes in bladder ischemia were associated with significant decrease in DNA binding activity of Nrf2, significant increase in cellular levels of stress protein Hsp70 and mitochondrial stress protein GRP75, and significant decrease in mitochondrial oxygen consumption and upregulation of PI3K and Akt expression. Conclusion: Chronic bladder ischemia may be a mediating variable in the development of detrusor overactivity in the non-obstructive bladder. The mechanism may involve ischemia-induced cellular stress, Nrf2 functional deficit, depression of mitochondrial respiration, and upregulation of PI3K/Akt cell survival signaling pathway. Keywords: atherosclerosis, blood flow, redox, cellular stress, detrusor overactivity, survival signaling 

  13. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

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    Wei-Ru Huang

    Full Text Available Avian reovirus (ARV protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128 of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  14. Regulation of the PI3K pathway through a p85a monomer-homodimer equilibrium

    KAUST Repository

    Aljedani, Safia Salim Eid

    2017-01-08

    The phosphatidylinositol-3-kinase a (PI3Ka) is heterodimeric enzyme that is composed of p85a regulatory subunit and a p110a catalytic subunit. PI3Ka plays a key role in cell survival, growth and differentation. Owing to its role as a key regulator, the PI3Ka pathway is the most frequently mutated pathway in human cancers, and is targeted by many viruses to insure their survival and successful reproduction. Previous studies have shown that the equilibrium of p85 monomers and dimers regulates the PI3K pathway, suggesting that interrupting this equilibrium could lead to disease development. Moreover, studies suggest that the p85a monomers and dimers have opposing effects on PI3Ka signaling as only the p85a dimers bind to the PTEN phosphatase, whereas p85a monomers bind to the catalytic p110 subunit. However, the mechanism for dimerisation is controversial, and it is unknown why PTEN or p110a bind only dimer or monomer. Therefore, we combine molecular biology, biophsical, computational and structural methods to investigate the suprosingly complex p85 dimerisation mechanism and its control by ligands. Results may inspire novel theraputic approaches.

  15. Upregulation of MAPK/Erk and PI3K/Akt pathways in ulcerative colitis-associated colon cancer.

    Science.gov (United States)

    Setia, Shruti; Nehru, Bimla; Sanyal, Sankar Nath

    2014-10-01

    An extracellular signal like a cytokine or chemokine, secreted in the inflammatory microenvironment can activate the mitogen activated protein kinase (MAPK) pathway by binding to a cytokine receptor tyrosine kinase, which further activates tyrosine kinases such as Janus Kinase-3 (Jak-3). This signal is transferred from Jak-3 to the DNA in the nucleus of the cell by a chain of kinases, ultimately activating extracellular receptor kinase (Erk/MAPK). The latter phosphorylates c-myc, an oncogene, which alters the levels and activities of many transcription factors leading to cell survival, proliferation and invasion. The oncogenic PI3K pathway plays a similar role by activating c-myc, leading to cell survival and proliferation. The present study explores the role of ulcerative colitis in colon cancer by investigating the activities of tyrosine kinase activated MAPK pathway and various components of the PI3K pathway including PI3K, PTEN, PDK1, GSK3β, Akt, mTOR, Wnt and β-catenin. This was done by western blot and fluorescent immunohistochemical analysis of the above-mentioned proteins. Also, the morphological and histological investigation of the colonic samples from various animal groups revealed significant alterations as compared to the control in both inflammatory as well as carcinogenic conditions. These effects were reduced to a large extent by the co-administration of celecoxib, a second-generation non-steroidal anti-inflammatory drug (NSAID). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  16. VEGFA upregulates FLJ10540 and modulates migration and invasion of lung cancer via PI3K/AKT pathway.

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    Chang-Han Chen

    Full Text Available BACKGROUND: Lung adenocarcinoma is the leading cause of cancer-related deaths among both men and women in the world. Despite recent advances in diagnosis and treatment, the mortality rates with an overall 5-year survival of only 15%. This high mortality is probably attributable to early metastasis. Although several well-known markers correlated with poor/metastasis prognosis in lung adenocarcinoma patients by immunohistochemistry was reported, the molecular mechanisms of lung adenocarcinoma development are still not clear. To explore novel molecular markers and their signaling pathways will be crucial for aiding in treatment of lung adenocarcinoma patients. METHODOLOGY/PRINCIPAL FINDINGS: To identify novel lung adenocarcinoma-associated /metastasis genes and to clarify the underlying molecular mechanisms of these targets in lung cancer progression, we created a bioinformatics scheme consisting of integrating three gene expression profile datasets, including pairwise lung adenocarcinoma, secondary metastatic tumors vs. benign tumors, and a series of invasive cell lines. Among the novel targets identified, FLJ10540 was overexpressed in lung cancer tissues and is associated with cell migration and invasion. Furthermore, we employed two co-expression strategies to identify in which pathway FLJ10540 was involved. Lung adenocarcinoma array profiles and tissue microarray IHC staining data showed that FLJ10540 and VEGF-A, as well as FLJ10540 and phospho-AKT exhibit positive correlations, respectively. Stimulation of lung cancer cells with VEGF-A results in an increase in FLJ10540 protein expression and enhances complex formation with PI3K. Treatment with VEGFR2 and PI3K inhibitors affects cell migration and invasion by activating the PI3K/AKT pathway. Moreover, knockdown of FLJ10540 destabilizes formation of the P110-alpha/P85-alpha-(PI3K complex, further supporting the participation of FLJ10540 in the VEGF-A/PI3K/AKT pathway. CONCLUSIONS

  17. Alteration of cellular behavior and response to PI3K pathway inhibition by culture in 3D collagen gels.

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    Brian Fallica

    Full Text Available Most investigations into cancer cell drug response are performed with cells cultured on flat (2D tissue culture plastic. Emerging research has shown that the presence of a three-dimensional (3D extracellular matrix (ECM is critical for normal cell behavior including migration, adhesion, signaling, proliferation and apoptosis. In this study we investigate differences between cancer cell signaling in 2D culture and a 3D ECM, employing real-time, live cell tracking to directly observe U2OS human osteosarcoma and MCF7 human breast cancer cells embedded in type 1 collagen gels. The activation of the important PI3K signaling pathway under these different growth conditions is studied, and the response to inhibition of both PI3K and mTOR with PI103 investigated. Cells grown in 3D gels show reduced proliferation and migration as well as reduced PI3K pathway activation when compared to cells grown in 2D. Our results quantitatively demonstrate that a collagen ECM can protect U2OS cells from PI103. Overall, our data suggests that 3D gels may provide a better medium for investigation of anti-cancer drugs than 2D monolayers, therefore allowing better understanding of cellular response and behavior in native like environments.

  18. Synergistic effects of concurrent blockade of PI3K and MEK pathways in pancreatic cancer preclinical models.

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    Hua Zhong

    Full Text Available Patients with pancreatic cancer have dismal prognoses, and novel therapies are urgently needed. Mutations of the KRAS oncogene occur frequently in pancreatic cancer and represent an attractive target. Direct targeting of the predominant KRAS pathways have been challenging and research into therapeutic strategies have been now refocused on pathways downstream of KRAS, phosphoinositide 3-kinase (PI3K and mitogen-activated protein kinase (MAPK [MEK]. We hypothesized that concurrent inhibition of the PI3K and MEK pathways would result in synergistic antitumor activity, as it would circumvent the compensatory feedback loop between the two pathways. We investigated the combined effect of the PI3K inhibitor, GDC0941, and the MEK inhibitor, AZD6244, on cell viability, apoptosis and cell signaling in a panel of pancreatic cancer cell lines. An in vivo analysis was conducted on pancreatic cancer xenografts. While BxPC-3 (KRAS wild type and MIA PaCa-2 (KRAS mutated cell lines were sensitive to GDC0941 and AZD6244 as single agents, synergistic inhibition of tumor cell growth and induction of apoptosis were observed in both cell lines when the two drugs were combined. Interestingly, phosphorylation of the cap-dependent translational components, 4E-binding protein (p-4E-BP1 and S6 was found to be closely associated with sensitivity to GDC0941 and AZD6244. In BxPC-3 cell xenografts, survival differences were observed between the control and the AZD6244, GDC0941, and combination groups. Our study provides the rationale for concurrent targeting of the PI3K and MEK pathways, regardless of KRAS status, and suggests that phosphorylation of 4E-BP1and S6 can serve as a predictive biomarker for response to treatment.

  19. α-Methyl artoflavanocoumarin from Juniperus chinensis exerts anti-diabetic effects by inhibiting PTP1B and activating the PI3K/Akt signaling pathway in insulin-resistant HepG2 cells.

    Science.gov (United States)

    Jung, Hee Jin; Seong, Su Hui; Ali, Md Yousof; Min, Byung-Sun; Jung, Hyun Ah; Choi, Jae Sue

    2017-12-01

    Diabetes mellitus is one of the greatest global health issues and much research effort continues to be directed toward identifying novel therapeutic agents. Insulin resistance is a challenging integrally related topic and molecules capable of overcoming it are of considerable therapeutic interest in the context of type 2 diabetes mellitus (T2DM). Protein tyrosine phosphatase 1B (PTP1B) negatively regulates insulin signaling transduction and is regarded a novel therapeutic target in T2DM. Here, we investigated the inhibitory effect of α-methyl artoflavanocoumarin (MAFC), a natural flavanocoumarin isolated from Juniperus chinensis, on PTP1B in insulin-resistant HepG2 cells. MAFC was found to potently inhibit PTP1B with an IC 50 of 25.27 ± 0.14 µM, and a kinetics study revealed MAFC is a mixed type PTP1B inhibitor with a K i value of 13.84 µM. Molecular docking simulations demonstrated MAFC can bind to catalytic and allosteric sites of PTP1B. Furthermore, MAFC significantly increased glucose uptake and decreased the expression of PTP1B in insulin-resistant HepG2 cells, down-regulated the phosphorylation of insulin receptor substrate (IRS)-1 (Ser307), and dose-dependently enhanced the protein levels of IRS-1, phosphorylated phosphoinositide 3-kinase (PI3K), Akt, and ERK1. These results suggest that MAFC from J. chinensis has therapeutic potential in T2DM by inhibiting PTP1B and activating insulin signaling pathways.

  20. H2O2 treatment or serum deprivation induces autophagy and apoptosis in naked mole-rat skin fibroblasts by inhibiting the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Zhao, Shanmin; Li, Li; Wang, Shiyong; Yu, Chenlin; Xiao, Bang; Lin, Lifang; Cong, Wei; Cheng, Jishuai; Yang, Wenjing; Sun, Wei; Cui, Shufang

    2016-12-20

    Naked mole-rats (NMR; Heterocephalus glaber) display extreme longevity and resistance to cancer. Here, we examined whether autophagy contributes to the longevity of NMRs by assessing the effects of the PI3K/Akt pathway inhibitor LY294002 and the autophagy inhibitor chloroquine (CQ) on autophagy and apoptosis in NMR skin fibroblasts. Serum starvation, H2O2 treatment, and LY294002 treatment all increased the LC3-II/LC3-I ratio and numbers of double-membraned autophagosomes and autophagic vacuoles, and decreased levels of p70S6K, p-AktSer473, and p-AktThr308. By contrast, CQ treatment decreased p70S6K, AktSer473, and AktThr308 levels. The Bax/Bcl-2 ratio increased after 12 h of exposure to LY294002 or CQ. These data show that inhibiting the Akt pathway promotes autophagy and apoptosis in NMR skin fibroblasts. Furthermore, LY294002 or CQ treatment decreased caspase-3, p53, and HIF1-α levels, suggesting that serum starvation or H2O2 treatment increase autophagy and apoptosis in NMR skin fibroblasts by inhibiting the PI3K/Akt pathway. CQ-induced inhibition of late autophagy stages also prevented Akt activation and induced apoptosis. Finally, the HIF-1α and p53 pathways were involved in serum starvation- or H2O2-induced autophagy in NMR skin fibroblasts.

  1. Alisertib induces cell cycle arrest and autophagy and suppresses epithelial-to-mesenchymal transition involving PI3K/Akt/mTOR and sirtuin 1-mediated signaling pathways in human pancreatic cancer cells

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    Wang F

    2015-01-01

    PC-3 cells in G2/M phase via regulating the expression of cyclin-dependent kinases 1 and 2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. ALS concentration-dependently induced autophagy in PANC-1 and BxPC-3 cells, which may be attributed to the inhibition of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR, p38 mitogen-activated protein kinase (p38 MAPK, and extracellular signal-regulated kinases 1 and 2 (Erk1/2 but activation of 5'-AMP-dependent kinase signaling pathways. ALS significantly inhibited EMT in PANC-1 and BxPC-3 cells with an increase in the expression of E-cadherin and a decrease in N-cadherin. In addition, ALS suppressed the expression of sirtuin 1 (Sirt1 and pre-B cell colony-enhancing factor/visfatin in both cell lines with a rise in the level of acetylated p53. These findings show that ALS induces cell cycle arrest and promotes autophagic cell death but inhibits EMT in pancreatic cancer cells with the involvement of PI3K/Akt/mTOR, p38 MAPK, Erk1/2, and Sirt1-mediated signaling pathways. Taken together, ALS may represent a promising anticancer drug for pancreatic cancer treatment. More studies are warranted to investigate other molecular targets and mechanisms and verify the efficacy and safety of ALS in the treatment of pancreatic cancer.Keywords: alisertib, pancreatic cancer, cell cycle, autophagy, EMT, Sirt1

  2. Hydrogels preserve native phenotypes of valvular fibroblasts through an elasticity-regulated PI3K/AKT pathway.

    Science.gov (United States)

    Wang, Huan; Tibbitt, Mark W; Langer, Stephen J; Leinwand, Leslie A; Anseth, Kristi S

    2013-11-26

    Matrix elasticity regulates proliferation, apoptosis, and differentiation of many cell types across various tissues. In particular, stiffened matrix in fibrotic lesions has been shown to promote pathogenic myofibroblast activation. To better understand the underlying pathways by which fibroblasts mechano-sense matrix elasticity, we cultured primary valvular interstitial cells (VICs) isolated from porcine aortic valves on poly(ethylene glycol)-based hydrogels with physiologically relevant and tunable elasticities. We show that soft hydrogels preserve the quiescent fibroblast phenotype of VICs much better than stiff plastic plates. We demonstrate that the PI3K/AKT pathway is significantly up-regulated when VICs are cultured on stiff gels or tissue culture polystyrene compared with freshly isolated VICs. In contrast, myofibroblasts de-activate and pAKT/AKT decreases as early as 2 h after reducing the substrate modulus. When PI3K or AKT is inhibited on stiff substrates, myofibroblast activation is blocked. When constitutively active PI3K is overexpressed, the myofibroblast phenotype is promoted even on soft substrates. These data suggest that valvular fibroblasts are sensing the changes in matrix elasticity through the PI3K/AKT pathway. This mechanism may be used by other mechano-sensitive cells in response to substrate modulus, and this pathway may be a worthwhile target for treating matrix stiffness-associated diseases. Furthermore, hydrogels can be designed to recapitulate important mechanical cues in native tissues to preserve aspects of the native phenotype of primary cells for understanding basic cellular responses to biophysical and biochemical signals, and for tissue-engineering applications.

  3. Regulation of the PI3K pathway through a p85α monomer–homodimer equilibrium | Office of Cancer Genomics

    Science.gov (United States)

    The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity.

  4. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    International Nuclear Information System (INIS)

    Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

    2014-01-01

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways

  5. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Kook, Sung-Ho [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Lim, Shin-Saeng [School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Kwon, Jungkee [College of Veterinary Medicine, Chonbuk National University, Jeonju (Korea, Republic of); Hwang, Jae-Won; Bae, Cheol-Hyeon [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Seo, Young-Kwon [Research Institute of Biotechnology, Dongguk University, Seoul (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  6. A postsynaptic PI3K-cII dependent signaling controller for presynaptic homeostatic plasticity

    Science.gov (United States)

    Hauswirth, Anna G; Ford, Kevin J; Wang, Tingting; Fetter, Richard D; Tong, Amy

    2018-01-01

    Presynaptic homeostatic plasticity stabilizes information transfer at synaptic connections in organisms ranging from insect to human. By analogy with principles of engineering and control theory, the molecular implementation of PHP is thought to require postsynaptic signaling modules that encode homeostatic sensors, a set point, and a controller that regulates transsynaptic negative feedback. The molecular basis for these postsynaptic, homeostatic signaling elements remains unknown. Here, an electrophysiology-based screen of the Drosophila kinome and phosphatome defines a postsynaptic signaling platform that includes a required function for PI3K-cII, PI3K-cIII and the small GTPase Rab11 during the rapid and sustained expression of PHP. We present evidence that PI3K-cII localizes to Golgi-derived, clathrin-positive vesicles and is necessary to generate an endosomal pool of PI(3)P that recruits Rab11 to recycling endosomal membranes. A morphologically distinct subdivision of this platform concentrates postsynaptically where we propose it functions as a homeostatic controller for retrograde, trans-synaptic signaling. PMID:29303480

  7. Photoactivation of GLUT4 translocation promotes glucose uptake via PI3-K/Akt2 signaling in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2014-05-01

    Full Text Available Insulin resistance is a hallmark of the metabolic syndrome and type 2 diabetes. Dysfunction of PI-3K/Akt signaling was involved in insulin resistance. Glucose transporter 4 (GLUT4 is a key factor for glucose uptake in muscle and adipose tissues, which is closely regulated by PI-3K/Akt signaling in response to insulin treatment. Low-power laser irradiation (LPLI has been shown to regulate various physiological processes and induce the synthesis or release of multiple molecules such as growth factors, which (especially red and near infrared light is mainly through the activation of mitochondrial respiratory chain and the initiation of intracellular signaling pathways. Nevertheless, it is unclear whether LPLI could promote glucose uptake through activation of PI-3K/Akt/GLUT4 signaling in 3T3L-1 adipocytes. In this study, we investigated how LPLI promoted glucose uptake through activation of PI-3K/Akt/GLUT4 signaling pathway. Here, we showed that GLUT4 was localized to the Golgi apparatus and translocated from cytoplasm to cytomembrane upon LPLI treatment in 3T3L-1 adipocytes, which enhanced glucose uptake. Moreover, we found that glucose uptake was mediated by the PI3-K/Akt2 signaling, but not Akt1 upon LPLI treatment with Akt isoforms gene silence and PI3-K/Akt inhibitors. Collectively, our results indicate that PI3-K/Akt2/GLUT4 signaling act as the key regulators for improvement of glucose uptake under LPLI treatment in 3T3L-1 adipocytes. More importantly, our findings suggest that activation of PI3-K/Akt2/GLUT4 signaling by LPLI may provide guidance in practical applications for promotion of glucose uptake in insulin-resistant adipose tissue.

  8. Estrogen receptor β exhibited anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kB/BCL-2 and PI3K/Akt signal pathway

    Directory of Open Access Journals (Sweden)

    Minfei Yang

    2017-11-01

    Full Text Available This study aimed to investigate the effects of Estrogen receptor β (ERβ on osteosarcoma cells, and explore the regulatory mechanisms involved in this process. Osteosarcoma U2-OS cells consisted four groups, and treated by E2, E2 + LY294002 (ERβ agonists, E2 + ERβ siRNA, E2 + ERβ siRNA + LY294002, respectively. Cell counting kit 8 (CCK-8 assay was performed to detect the cell viability of U2-OS cells in each group. The effects of ERβ on the migration and invasion ability of U2-OS cells were examined by wound healing assay and transwell cell culture chamber, respectively. The expression of Inhibitor of apoptosis protein (IAP and integrin α5 in U2-OS cells of each group was detected by quantitative RT-PCR, and the expression of phosphorylated p65 (p-p65, p-AKT and Bcl-2 was detected by western blotting. The cell viability, migration and invasion ability of U2-OS cells were significantly increased by ERβ siRNA, but inhibited by ERβ agonists LY294002 (p < 0.05. ERβ siRNA significantly downregulated Integrin α5 and unregulated IAP in U2-OS cells (p < 0.05. The expression of p-p65, p-AKT and Bcl-2 was significantly reduced by LY294002, but increased by ERβ siRNA (p < 0.05. In conclusion, ERβ exhibited obvious anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kBBCL-2 and PI3K/Akt signal pathway. Keywords: Estrogen receptor β, Osteosarcoma, Anti-tumor, Regulatory mechanism

  9. Control of fibroblast fibronectin expression and alternative splicing via the PI3K/Akt/mTOR pathway

    International Nuclear Information System (INIS)

    White, Eric S.; Sagana, Rommel L.; Booth, Adam J.; Yan, Mei; Cornett, Ashley M.; Bloomheart, Christopher A.; Tsui, Jessica L.; Wilke, Carol A.; Moore, Bethany B.; Ritzenthaler, Jeffrey D.; Roman, Jesse; Muro, Andres F.

    2010-01-01

    Fibronectin (FN), a ubiquitous glycoprotein that plays critical roles in physiologic and pathologic conditions, undergoes alternative splicing which distinguishes plasma FN (pFN) from cellular FN (cFN). Although both pFN and cFN can be incorporated into the extracellular matrix, a distinguishing feature of cFN is the inclusion of an alternatively spliced exon termed EDA (for extra type III domain A). The molecular steps involved in EDA splicing are well-characterized, but pathways influencing EDA splicing are less clear. We have previously found an obligate role for inhibition of the tumor suppressor phosphatase and tensin homologue on chromosome 10 (PTEN), the primary regulator of the PI3K/Akt pathway, in fibroblast activation. Here we show TGF-β, a potent inducer of both EDA splicing and fibroblast activation, inhibits PTEN expression and activity in mesenchymal cells, corresponding with enhanced PI3K/Akt signaling. In pten -/- fibroblasts, which resemble activated fibroblasts, inhibition of Akt attenuated FN production and decreased EDA alternative splicing. Moreover, inhibition of mammalian target of rapamycin (mTOR) in pten -/- cells also blocked FN production and EDA splicing. This effect was due to inhibition of Akt-mediated phosphorylation of the primary EDA splicing regulatory protein SF2/ASF. Importantly, FN silencing in pten -/- cells resulted in attenuated proliferation and migration. Thus, our results demonstrate that the PI3K/Akt/mTOR axis is instrumental in FN transcription and alternative splicing, which regulates cell behavior.

  10. Branched-Chain Amino Acid Negatively Regulates KLF15 Expression via PI3K-AKT Pathway.

    Science.gov (United States)

    Liu, Yunxia; Dong, Weibing; Shao, Jing; Wang, Yibin; Zhou, Meiyi; Sun, Haipeng

    2017-01-01

    Recent studies have linked branched-chain amino acid (BCAA) with numerous metabolic diseases. However, the molecular basis of BCAA's roles in metabolic regulation remains to be established. KLF15 (Krüppel-like factor 15) is a transcription factor and master regulator of glycemic, lipid, and amino acids metabolism. In the present study, we found high concentrations of BCAA suppressed KLF15 expression while BCAA starvation induced KLF15 expression, suggesting KLF15 expression is negatively controlled by BCAA.Interestingly, BCAA starvation induced PI3K-AKT signaling. KLF15 induction by BCAA starvation was blocked by PI3K and AKT inhibitors, indicating the activation of PI3K-AKT signaling pathway mediated the KLF15 induction. BCAA regulated KLF15 expression at transcriptional level but not post-transcriptional level. However, BCAA starvation failed to increase the KLF15-promoter-driven luciferase expression, suggesting KLF15 promoter activity was not directly controlled by BCAA. Finally, fasting reduced BCAA abundance in mice and KLF15 expression was dramatically induced in muscle and white adipose tissue, but not in liver. Together, these data demonstrated BCAA negatively regulated KLF15 expression, suggesting a novel molecular mechanism underlying BCAA's multiple functions in metabolic regulation.

  11. Branched-Chain Amino Acid Negatively Regulates KLF15 Expression via PI3K-AKT Pathway

    Directory of Open Access Journals (Sweden)

    Yunxia Liu

    2017-10-01

    Full Text Available Recent studies have linked branched-chain amino acid (BCAA with numerous metabolic diseases. However, the molecular basis of BCAA's roles in metabolic regulation remains to be established. KLF15 (Krüppel-like factor 15 is a transcription factor and master regulator of glycemic, lipid, and amino acids metabolism. In the present study, we found high concentrations of BCAA suppressed KLF15 expression while BCAA starvation induced KLF15 expression, suggesting KLF15 expression is negatively controlled by BCAA.Interestingly, BCAA starvation induced PI3K-AKT signaling. KLF15 induction by BCAA starvation was blocked by PI3K and AKT inhibitors, indicating the activation of PI3K-AKT signaling pathway mediated the KLF15 induction. BCAA regulated KLF15 expression at transcriptional level but not post-transcriptional level. However, BCAA starvation failed to increase the KLF15-promoter-driven luciferase expression, suggesting KLF15 promoter activity was not directly controlled by BCAA. Finally, fasting reduced BCAA abundance in mice and KLF15 expression was dramatically induced in muscle and white adipose tissue, but not in liver. Together, these data demonstrated BCAA negatively regulated KLF15 expression, suggesting a novel molecular mechanism underlying BCAA's multiple functions in metabolic regulation.

  12. Cancer Therapy Targeting the HER2-PI3K Pathway: Potential Impact on the Heart

    Directory of Open Access Journals (Sweden)

    Giannoula Lakka Klement

    2012-06-01

    Full Text Available The HER2-PI3K pathway is the one of the most mutated pathways in cancer. Several drugs targeting the major kinases of this pathway have been approved by the Food and Drug Administration and many are being tested in clinical trials for the treatment of various cancers. However, the HER2-PI3K pathway is also pivotal for maintaining the physiological function of the heart, especially in the presence of cardiac stress. Clinical studies have shown that in patients treated with doxorubicin concurrently with Trastuzumab, a monoclonal antibody that blocks the HER2 receptor, the New York Heart Association class III/IV heart failure was significantly increased compared to those who were treated with doxorubicin alone (16 vs. 3%. Studies in transgenic mice have also shown that other key kinases of this pathway, such as PI3Kα, PDK1, Akt and mTOR, are important for protecting the heart from ischemia-reperfusion and aortic stenosis induced cardiac dysfunction. Studies, however, have also shown that inhibition of PI3Kγ improve cardiac function of a failing heart. In addition, results from transgenic mouse models are not always consistent with the outcome of the pharmacological inhibition of this pathway. Here, we will review these findings and discuss how we can address the cardiac side-effects caused by inhibition of this important pathway in both cancer and cardiac biology.

  13. Dapper1 attenuates hepatic gluconeogenesis and lipogenesis by activating PI3K/Akt signaling.

    Science.gov (United States)

    Kuang, Jian-Ren; Zhang, Zhi-Hui; Leng, Wei-Ling; Lei, Xiao-Tian; Liang, Zi-Wen

    2017-05-15

    Studies have shown that hepatic insulin resistance, a disorder of glucose and lipid metabolism, plays a vital role in type 2 diabetes (T2D). To clarify the function of Dapper1 in glucose and lipid metabolism in the liver, we investigated the relationships between Dapper1 and adenosine triphosphate (ATP)- and Ca 2+ -mediated activation of PI3K/Akt. We observed a reduction in hepatic Dapper1 in db/db (mice that are homozygous for a spontaneous diabetes mutation) and HFD-induced diabetic mice with T2D. Hepatic overexpression of Dapper1 improved hyperglycemia, insulin resistance, and fatty liver. It also increased Akt (pAkt) signaling and repressed both gluconeogenesis and lipogenesis. Conversely, Ad-shDapper1-induced knockdown of hepatic Dapper1 promoted gluconeogenesis and lipogenesis. Furthermore, Dapper1 activated PI3K p110α/Akt in an insulin-independent manner by inducing ATP production and secretion in vitro. Blockade of P2 ATP receptors, the downstream phospholipase C (PLC), or the inositol triphosphate receptor (IP3R all reduced the Dapper1-induced increase in cytosolic free calcium and Dapper1-mediated PI3K/Akt activation, as did removal of calcium in the medium. In conclusion, Dapper1 attenuates hepatic gluconeogenesis and lipogenesis in T2D. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Regulation of dendritic cell function by insulin/IGF-1/PI3K/Akt signaling through klotho expression.

    Science.gov (United States)

    Xuan, Nguyen Thi; Hoang, Nguyen Huy; Nhung, Vu Phuong; Duong, Nguyen Thuy; Ha, Nguyen Hai; Hai, Nong Van

    2017-06-01

    Insulin or insulin-like growth factor 1 (IGF-1) promotes the activation of phosphoinositide 3 kinase (PI3K)/Akt signaling in immune cells including dendritic cells (DCs), the most potent professional antigen-presenting cells for naive T cells. Klotho, an anti-aging protein, participates in the regulation of the PI3K/Akt signaling, thus the Ca 2+ -dependent migration is reduced in klotho-deficient DCs. The present study explored the effects of insulin/IGF-1 on DC function through klotho expression. To this end, the mouse bone marrow cells were isolated and cultured with GM-CSF to attain bone marrow-derived DCs (BMDCs). Cells were treated with insulin or IGF-1 and followed by stimulating with lipopolysaccharides (LPS). Tumor necrosis factor (TNF)-α formation was examined by enzyme-linked immunosorbent assay (ELISA). Phagocytosis was analyzed by FITC-dextran uptake assay. The expression of klotho was determined by quantitative PCR, immunoprecipitation and western blotting. As a result, treatment of the cells with insulin/IGF-1 resulted in reducing the klotho expression as well as LPS-stimulated TNF-α release and increasing the FITC-dextran uptake but unaltering reactive oxygen species (ROS) production in BMDCs. The effects were abolished by using pharmacological inhibition of PI3K/Akt with LY294002 and paralleled by transfecting DCs with klotho siRNA. In conclusion, the regulation of klotho sensitive DC function by IGF-1 or insulin is mediated through PI3K/Akt signaling pathway in BMDCs.

  15. Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

    Science.gov (United States)

    Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

    2015-08-01

    Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

  16. Knockdown of long noncoding antisense RNA brain-derived neurotrophic factor attenuates hypoxia/reoxygenation-induced nerve cell apoptosis through the BDNF-TrkB-PI3K/Akt signaling pathway.

    Science.gov (United States)

    Zhong, Jian-Bin; Li, Xie; Zhong, Si-Ming; Liu, Jiu-Di; Chen, Chi-Bang; Wu, Xiao-Yan

    2017-09-27

    Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal cell apoptosis. The antisense RNA of brain-derived neurotrophic factor (BDNF-AS) is a natural antisense transcript that is transcribed opposite the gene that encodes BDNF. The aim of this study was to determine whether knockdown of BDNF-AS can suppress hypoxia/reoxygenation (H/R)-induced neuronal cell apoptosis and whether this is mediated by the BDNF-TrkB-PI3K/Akt pathway. We detected the expression of BDNF and BDNF-AS in brain tissue from 20 patients with cerebral infarction and five patients with other diseases (but no cerebral ischemia). We found that BDNF expression was significantly downregulated in patients with cerebral infarction, whereas the expression of BDNF-AS was significantly upregulated. In both human cortical neurons (HCN2) and human astrocytes, H/R significantly induced the expression of BDNF-AS, but significantly decreased BDNF expression. H/R also significantly induced apoptosis and reduced the mitochondrial membrane potential in these cells. Following downregulation of BDNF-AS by siRNA in human cortical neurons and human astrocyte cells, BDNF expression was significantly upregulated and the H/R-induced upregulation of BDNF-AS was significantly attenuated. BDNF-AS siRNA inhibited H/R-induced cell apoptosis and ameliorated the H/R-induced suppression of mitochondrial membrane potential. H/R inhibited the expression of BDNF, p-AKT/AKT, and TrKB, and this inhibition was recovered by BDNF-AS siRNA. In summary, this study indicates that BDNF-AS siRNA induces activation of the BDNF-TrkB-PI3K/Akt pathway following H/R-induced neurotoxicity. These findings will be useful toward the application of BDNF-AS siRNA for the treatment of neurodegenerative diseases.

  17. Quercetin suppresses HeLa cells by blocking PI3K/Akt pathway.

    Science.gov (United States)

    Xiang, Tao; Fang, Yong; Wang, Shi-Xuan

    2014-10-01

    To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin-V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were observed under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related proteins in the HeLa cells were assessed by Western blotting. The results showed that quercetin significantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate expression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix cancer.

  18. Activation of PI3K/Akt signaling by n-terminal SH2 domain mutants of the p85α regulatory subunit of PI3K is enhanced by deletion of its c-terminal SH2 domain.

    Science.gov (United States)

    Hofmann, Bianca T; Jücker, Manfred

    2012-10-01

    The phosphoinositide 3-kinase (PI3K) is frequently activated in human cancer cells due to gain of function mutations in the catalytic (p110) and the regulatory (p85) subunits. The regulatory subunit consists of an SH3 domain and two SH2 domains. An oncogenic form of p85α named p65 lacking the c-terminal SH2 domain (cSH2) has been cloned from an irradiation-induced murine thymic lymphoma and transgenic mice expressing p65 in T lymphocytes develop a lymphoproliferative disorder. We have recently detected a c-terminal truncated form of p85α named p76α in a human lymphoma cell line lacking most of the cSH2 domain due to a frame shift mutation. Here, we report that the deletion of the cSH2 domain enhances the activating effects of the n-terminal SH2 domain (nSH2) mutants K379E and R340E on the PI3K/Akt pathway and micro tumor formation in a focus assay. Further analysis revealed that this transforming effect is mediated by activation of the catalytic PI3K isoform p110α and downstream signaling through mTOR. Our data further support a mechanistic model in which mutations of the cSH2 domain of p85α can abrogate its negative regulatory function on PI3K activity via the nSH2 domain of p85α. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Allosteric modulation of Ras and the PI3K/AKT/mTOR pathway: emerging therapeutic opportunities

    Science.gov (United States)

    Hubbard, Paul A.; Moody, Colleen L.; Murali, Ramachandran

    2014-01-01

    GTPases and kinases are two predominant signaling modules that regulate cell fate. Dysregulation of Ras, a GTPase, and the three eponymous kinases that form key nodes of the associated phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K)/AKT/mTOR pathway have been implicated in many cancers, including pancreatic cancer, a disease noted for its current lack of effective therapeutics. The K-Ras isoform of Ras is mutated in over 90% of pancreatic ductal adenocarcinomas (PDAC) and there is growing evidence linking aberrant PI3K/AKT/mTOR pathway activity to PDAC. Although these observations suggest that targeting one of these nodes might lead to more effective treatment options for patients with pancreatic and other cancers, the complex regulatory mechanisms and the number of sequence-conserved isoforms of these proteins have been viewed as significant barriers in drug development. Emerging insights into the allosteric regulatory mechanisms of these proteins suggest novel opportunities for development of selective allosteric inhibitors with fragment-based drug discovery (FBDD) helping make significant inroads. The fact that allosteric inhibitors of Ras and AKT are currently in pre-clinical development lends support to this approach. In this article, we will focus on the recent advances and merits of developing allosteric drugs targeting these two inter-related signaling pathways. PMID:25566081

  20. PI3K/Akt1 signalling specifies foregut precursors by generating regionalized extra-cellular matrix

    DEFF Research Database (Denmark)

    Villegas, S Nahuel; Rothová, Michaela; Barrios-Llerena, Martin E

    2013-01-01

    -to-mesenchymal transition (EMT). Akt1 transduced this activity via modifications to the extracellular matrix (ECM) and appropriate ECM could itself induce anterior endodermal identity in the absence of PI3K signalling. PI3K/Akt1-modified ECM contained low levels of Fibronectin (Fn1) and we found that Fn1 dose was key...... to specifying anterior endodermal identity in vivo and in vitro. Thus, localized PI3K activity affects ECM composition and ECM in turn patterns the endoderm. DOI: http://dx.doi.org/10.7554/eLife.00806.001....

  1. Ibervillea sonorae (Cucurbitaceae) induces the glucose uptake in human adipocytes by activating a PI3K-independent pathway.

    Science.gov (United States)

    Zapata-Bustos, Rocio; Alonso-Castro, Angel Josabad; Gómez-Sánchez, Maricela; Salazar-Olivo, Luis A

    2014-03-28

    Ibervillea sonorae (S. Watson) Greene (Cucurbitaceae), a plant used for the empirical treatment of type 2 diabetes in México, exerts antidiabetic effects on animal models but its mechanism of action remains unknown. The aim of this study is to investigate the antidiabetic mechanism of an Ibervillea sonorae aqueous extract (ISE). Non-toxic ISE concentrations were assayed on the glucose uptake by insulin-sensitive and insulin-resistant murine and human cultured adipocytes, both in the absence or the presence of insulin signaling pathway inhibitors, and on murine and human adipogenesis. Chemical composition of ISE was examined by spectrophotometric and HPLC techniques. ISE stimulated the 2-NBDGlucose uptake by mature adipocytes in a concentration-dependent manner. ISE 50 µg/ml induced the 2-NBDG uptake in insulin-sensitive 3T3-F442A, 3T3-L1 and human adipocytes by 100%, 63% and 33%, compared to insulin control. Inhibitors for the insulin receptor, PI3K, AKT and GLUT4 blocked the 2-NBDG uptake in murine cells, but human adipocytes were insensitive to the PI3K inhibitor Wortmannin. ISE 50 µg/ml also stimulated the 2-NBDG uptake in insulin-resistant adipocytes by 117% (3T3-F442A), 83% (3T3-L1) and 48% (human). ISE induced 3T3-F442A adipogenesis but lacked proadipogenic effects on 3T3-L1 and human preadipocytes. Chemical analyses showed the presence of phenolics in ISE, mainly an appreciable concentration of gallic acid. Ibervillea sonorae exerts its antidiabetic properties by means of hydrosoluble compounds stimulating the glucose uptake in human preadipocytes by a PI3K-independent pathway and without proadipogenic effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Active PI3K pathway causes an invasive phenotype which can be reversed or promoted by blocking the pathway at divergent nodes.

    Directory of Open Access Journals (Sweden)

    Jeffrey J Wallin

    Full Text Available The PTEN/PI3K pathway is commonly mutated in cancer and therefore represents an attractive target for therapeutic intervention. To investigate the primary phenotypes mediated by increased pathway signaling in a clean, patient-relevant context, an activating PIK3CA mutation (H1047R was knocked-in to an endogenous allele of the MCF10A non-tumorigenic human breast epithelial cell line. Introduction of an endogenously mutated PIK3CA allele resulted in a marked epithelial-mesenchymal transition (EMT and invasive phenotype, compared to isogenic wild-type cells. The invasive phenotype was linked to enhanced PIP(3 production via a S6K-IRS positive feedback mechanism. Moreover, potent and selective inhibitors of PI3K were highly effective in reversing this phenotype, which is optimally revealed in 3-dimensional cell culture. In contrast, inhibition of Akt or mTOR exacerbated the invasive phenotype. Our results suggest that invasion is a core phenotype mediated by increased PTEN/PI3K pathway activity and that therapeutic agents targeting different nodes of the PI3K pathway may have dramatic differences in their ability to reverse or promote cancer metastasis.

  3. Expression of the RAE-1 Family of Stimulatory NK-Cell Ligands Requires Activation of the PI3K Pathway during Viral Infection and Transformation

    Science.gov (United States)

    Tokuyama, Maria; Lorin, Clarisse; Delebecque, Frederic; Jung, Heiyoun; Raulet, David H.; Coscoy, Laurent

    2011-01-01

    Natural killer (NK) cells are lymphocytes that play a major role in the elimination of virally-infected cells and tumor cells. NK cells recognize and target abnormal cells through activation of stimulatory receptors such as NKG2D. NKG2D ligands are self-proteins, which are absent or expressed at low levels on healthy cells but are induced upon cellular stress, transformation, or viral infection. The exact molecular mechanisms driving expression of these ligands remain poorly understood. Here we show that murine cytomegalovirus (MCMV) infection activates the phosphatidylinositol-3-kinase (PI3K) pathway and that this activation is required for the induction of the RAE-1 family of mouse NKG2D ligands. Among the multiple PI3K catalytic subunits, inhibition of the p110α catalytic subunit blocks this induction. Similarly, inhibition of p110α PI3K reduces cell surface expression of RAE-1 on transformed cells. Many viruses manipulate the PI3K pathway, and tumors frequently mutate the p110α oncogene. Thus, our findings suggest that dysregulation of the PI3K pathway is an important signal to induce expression of RAE-1, and this may represent a commonality among various types of cellular stresses that result in the induction of NKG2D ligands. PMID:21966273

  4. Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Zhang, Z.Z.; Wu, Y.; Ke, J.J.; He, X.H.; Wang, Y.L. [Department of Anesthesiology, Zhongnan Hospital, Wuhan University, Wuhan (China)

    2013-09-24

    Quercetin (Que), a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R) injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group): sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05). Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05). Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

  5. Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-09-01

    Full Text Available Quercetin (Que, a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group: sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05. Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05. Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

  6. Bi-phasic regulation of glycogen content in astrocytes via Cav-1/PTEN/PI3K/AKT/GSK-3β pathway by fluoxetine.

    Science.gov (United States)

    Bai, Qiufang; Song, Dan; Gu, Li; Verkhratsky, Alexei; Peng, Liang

    2017-04-01

    Here, we present the data indicating that chronic treatment with fluoxetine regulates Cav-1/PTEN/PI3K/AKT/GSK-3β signalling pathway and glycogen content in primary cultures of astrocytes with bi-phasic concentration dependence. At lower concentrations, fluoxetine downregulates gene expression of Cav-1, decreases membrane content of PTEN, increases activity of PI3K/AKT, and elevates GSK-3β phosphorylation thus suppressing its activity. At higher concentrations, fluoxetine acts in an inverse fashion. As expected, fluoxetine at lower concentrations increased while at higher concentrations decreased glycogen content in astrocytes. Our findings indicate that bi-phasic regulation of glycogen content via Cav-1/PTEN/PI3K/AKT/GSK-3β pathway by fluoxetine may be responsible for both therapeutic and side effects of the drug.

  7. PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of posttraumatic epilepsy

    Science.gov (United States)

    Berdichevsky, Yevgeny; Dryer, Alexandra M.; Saponjian, Yero; Mahoney, Mark M.; Pimentel, Corrin A.; Lucini, Corrina A.; Usenovic, Marija; Staley, Kevin J.

    2013-01-01

    mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an antiepileptogenic, or merely anti-convulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with LDH release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well-correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are: (1), the organotypic hippocampal culture model of posttraumatic epilepsy comprises a rapid assay of antiepileptogenic and neuroprotective activities and, in this model (2), mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy. PMID:23699517

  8. TET1-GPER-PI3K/AKT pathway is involved in insulin-driven endometrial cancer cell proliferation

    International Nuclear Information System (INIS)

    Xie, Bing-ying; Lv, Qiao-ying; Ning, Cheng-cheng; Yang, Bing-yi; Shan, Wei-wei; Cheng, Ya-li; Gu, Chao; Luo, Xue-zhen; Zhang, Zhen-bo; Chen, Xiao-jun; Xi, Xiao-wei; Feng, You-ji

    2017-01-01

    Large amount of clinical evidence has demonstrated that insulin resistance is closely related to oncogenesis of endometrial cancer (EC). Despite recent studies showed the up-regulatory role of insulin in G protein-coupled estrogen receptor (GPER/GPR30) expression, GPER expression was not decreased compared to control when insulin receptor was blocked even in insulin treatment. The purpose of this study was to explore the possible mechanism by which insulin up-regulates GPER that drives EC cell proliferation. For this purpose, we first investigated the GPER expression in tissues of endometrial lesions, further explored the effect of GPER on EC cell proliferation in insulin resistance context. Then we analyzed the role of Ten-Eleven Translocation 1 (TET1) in insulin-induced GEPR expression and EC cell proliferation. The results showed that GPER was highly expressed in endometrial atypical hyperplasia and EC tissues. Mechanistically, insulin up-regulated TET1 expression and the latter played an important role in up-regulating GPER expression and activating PI3K/AKT signaling pathway. TET1 mediated GPER up-regulation was another mechanism that insulin promotes EC cell proliferation. - Highlights: • GPER acts as an oncogene to drive EC cell growth in insulin resistance context. • TET1 is associated with insulin-induced GPER expression. • Insulin resistance contributed to EC through TET1-GPER-PI3K/AKT pathway.

  9. HSPC159 promotes proliferation and metastasis via inducing EMT and activating PI3K/Akt pathway in breast cancer.

    Science.gov (United States)

    Zheng, Jie; Zhang, Mengxue; Zhang, Liying; Ding, Xiaodi; Li, Wentong; Lu, Shijun

    2018-05-08

    HSPC159 is a novel human galectin-related protein and has been shown to involved in the carcinogenesis. Little is known about HSPC159 expression and function in breast cancer. Here we showed that HSPC159 was aberrantly expressed in both breast cancer cell lines and tumor tissues and that its expression was associated with poor prognosis of breast cancer patients. Using gain- and loss-of-function methods we found that HSPC159 enhanced breast cancer cells proliferation and metastasis in vitro and in vivo. Mechanistically, HSPC159 was found to induce epithelial-mesenchymal transition (EMT) and F-actin polymerization process of breast cancer cells. Moreover, HSPC159 promoted proliferation, migration and invasion through activating PI3K/Akt signaling pathway in breast cancer. In conclusion, our findings demonstrated that HSPC159 contributed to breast cancer progression via PI3K/Akt pathway and might serve as a potential therapeutic target for the treatment of breast cancer. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Inactivation of the Class II PI3K-C2β Potentiates Insulin Signaling and Sensitivity

    Directory of Open Access Journals (Sweden)

    Samira Alliouachene

    2015-12-01

    Full Text Available In contrast to the class I phosphoinositide 3-kinases (PI3Ks, the organismal roles of the kinase activity of the class II PI3Ks are less clear. Here, we report that class II PI3K-C2β kinase-dead mice are viable and healthy but display an unanticipated enhanced insulin sensitivity and glucose tolerance, as well as protection against high-fat-diet-induced liver steatosis. Despite having a broad tissue distribution, systemic PI3K-C2β inhibition selectively enhances insulin signaling only in metabolic tissues. In a primary hepatocyte model, basal PI3P lipid levels are reduced by 60% upon PI3K-C2β inhibition. This results in an expansion of the very early APPL1-positive endosomal compartment and altered insulin receptor trafficking, correlating with an amplification of insulin-induced, class I PI3K-dependent Akt signaling, without impacting MAPK activity. These data reveal PI3K-C2β as a critical regulator of endosomal trafficking, specifically in insulin signaling, and identify PI3K-C2β as a potential drug target for insulin sensitization.

  11. Toll-like receptor 4 promotes angiogenesis in pancreatic cancer via PI3K/AKT signaling

    International Nuclear Information System (INIS)

    Sun, Yunliang; Wu, Congshan; Ma, Jianxia; Yang, Yu; Man, Xiaohua; Wu, Hongyu; Li, Shude

    2016-01-01

    Deregulation of Toll-like receptor 4 (TLR4) is closely associated with the progression of various types of cancers, but its role in pancreatic carcinogenesis is unclear. This study aimed to investigate the role of TLR4 in the angiogenesis of pancreatic cancer and the underlying molecular mechanisms. The culture supernatant (conditioned medium) of PANC-1 cells after appropriate treatment was used for the treatment of HUVECs. The proliferation, migration and tube formation of HUVECs were assessed by MTT, Transwell and Matrigel, respectively. In pancreatic cancer tissues, TLR4, VEGF and CD31 were upregulated as determined by immunohistochemistry and the expression of TLR4 and VEGF was positively correlated with microvessel density as detected by CD31 staining. Activation of TLR4 signaling by LPS in PANC-1 cells resulted in increased VEGF and phosphorylation of AKT, which were abolished by TLR4 silencing with siRNA and PI3K/AKT signaling inhibitor LY294002. The conditioned medium from PANC-1 cells treated with LY294002 or transfected with TRL4 siRNA reduced the proliferation, migration and tube formation of HUVECs. In contrast, the conditioned medium from PANC-1 cells treated with LPS stimulated the proliferation, migration and tube formation of HUVECs, which was however significantly inhibited by pretreatment of PANC-1 cells with LY294002 or transfection with TRL4 siRNA. Our findings suggest TLR4 may promote angiogenesis in pancreatic cancer by activating the PI3K/AKT signaling pathway to induce VEGF expression.

  12. Toll-like receptor 4 promotes angiogenesis in pancreatic cancer via PI3K/AKT signaling

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yunliang; Wu, Congshan [Department of Gastroenterology, Lianyungang Ganyu People’s Hospital, Ganyu, Jiangsu (China); Ma, Jianxia, E-mail: yz_mjx@163.com [Department of Gastroenterology, Huadong Hospital, Fudan University, Shanghai (China); Yang, Yu [Department of Gastroenterology, Huadong Hospital, Fudan University, Shanghai (China); Man, Xiaohua; Wu, Hongyu; Li, Shude [Department of Gastroenterology, Changhai Hospital, The Second Military Medical University, Shanghai (China)

    2016-10-01

    Deregulation of Toll-like receptor 4 (TLR4) is closely associated with the progression of various types of cancers, but its role in pancreatic carcinogenesis is unclear. This study aimed to investigate the role of TLR4 in the angiogenesis of pancreatic cancer and the underlying molecular mechanisms. The culture supernatant (conditioned medium) of PANC-1 cells after appropriate treatment was used for the treatment of HUVECs. The proliferation, migration and tube formation of HUVECs were assessed by MTT, Transwell and Matrigel, respectively. In pancreatic cancer tissues, TLR4, VEGF and CD31 were upregulated as determined by immunohistochemistry and the expression of TLR4 and VEGF was positively correlated with microvessel density as detected by CD31 staining. Activation of TLR4 signaling by LPS in PANC-1 cells resulted in increased VEGF and phosphorylation of AKT, which were abolished by TLR4 silencing with siRNA and PI3K/AKT signaling inhibitor LY294002. The conditioned medium from PANC-1 cells treated with LY294002 or transfected with TRL4 siRNA reduced the proliferation, migration and tube formation of HUVECs. In contrast, the conditioned medium from PANC-1 cells treated with LPS stimulated the proliferation, migration and tube formation of HUVECs, which was however significantly inhibited by pretreatment of PANC-1 cells with LY294002 or transfection with TRL4 siRNA. Our findings suggest TLR4 may promote angiogenesis in pancreatic cancer by activating the PI3K/AKT signaling pathway to induce VEGF expression.

  13. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    International Nuclear Information System (INIS)

    Li, Guofeng; Xu, Jingren; Li, Zengchun

    2012-01-01

    Highlights: ► RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. ► RAGE overexpression decreases Wnt/β-catenin signaling. ► RAGE overexpression decreases ERK and PI3K signaling. ► Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. ► Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  14. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guofeng [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Xu, Jingren [Department of Traditional Chinese Orthopaedics, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Li, Zengchun, E-mail: lizc.2007@yahoo.com.cn [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer RAGE overexpression decreases Wnt/{beta}-catenin signaling. Black-Right-Pointing-Pointer RAGE overexpression decreases ERK and PI3K signaling. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  15. Aurora kinase A revives dormant laryngeal squamous cell carcinoma cells via FAK/PI3K/Akt pathway activation

    Science.gov (United States)

    Yang, Li-yun; He, Chang-yu; Chen, Xue-hua; Su, Li-ping; Liu, Bing-ya; Zhang, Hao

    2016-01-01

    Revival of dormant tumor cells may be an important tumor metastasis mechanism. We hypothesized that aurora kinase A (AURKA), a cell cycle control kinase, promotes the transition of laryngeal squamous cell carcinoma (LSCC) cells from G0 phase to active division. We therefore investigated whether AURKA could revive dormant tumor cells to promote metastasis. Western blotting revealed that AURKA expression was persistently low in dormant laryngeal cancer Hep2 (D-Hep2) cells and high in non-dormant (T-Hep2) cells. Decreasing AURKA expression in T-Hep2 cells induced dormancy and reduced FAK/PI3K/Akt pathway activity. Increasing AURKA expression in D-Hep2 cells increased FAK/PI3K/Akt pathway activity and enhanced cellular proliferation, migration, invasion and metastasis. In addition, FAK/PI3K/Akt pathway inhibition caused dormancy-like behavior and reduced cellular mobility, migration and invasion. We conclude that AURKA may revive dormant tumor cells via FAK/PI3K/Akt pathway activation, thereby promoting migration and invasion in laryngeal cancer. AURKA/FAK/PI3K/Akt inhibitors may thus represent potential targets for clinical LSCC treatment. PMID:27356739

  16. Icariin Prevents Amyloid Beta-Induced Apoptosis via the PI3K/Akt Pathway in PC-12 Cells

    Directory of Open Access Journals (Sweden)

    Dongdong Zhang

    2015-01-01

    Full Text Available Icariin is a prenylated flavonol glycoside derived from the Chinese herb Epimedium sagittatum that exerts a variety of pharmacological activities and shows promise in the treatment and prevention of Alzheimer’s disease. In this study, we investigated the neuroprotective effects of icariin against amyloid beta protein fragment 25–35 (Aβ25–35 induced neurotoxicity in cultured rat pheochromocytoma PC12 cells and explored potential underlying mechanisms. Our results showed that icariin dose-dependently increased cell viability and decreased Aβ25–35-induced apoptosis, as assessed by MTT assay and Annexin V/propidium iodide staining, respectively. Results of western blot analysis revealed that the selective phosphatidylinositol 3-kinase (PI3K inhibitor LY294002 suppressed icariin-induced Akt phosphorylation, suggesting that the protective effects of icariin are associated with activation of the PI3K/Akt signaling pathway. LY294002 also blocked the icariin-induced downregulation of proapoptotic factors Bax and caspase-3 and upregulation of antiapoptotic factor Bcl-2 in Aβ25–35-treated PC12 cells. These findings provide further evidence for the clinical efficacy of icariin in the treatment of Alzheimer’s disease.

  17. Induction of Autophagy and Apoptosis via PI3K/AKT/TOR Pathways by Azadirachtin A in Spodoptera litura Cells.

    Science.gov (United States)

    Shao, Xuehua; Lai, Duo; Zhang, Ling; Xu, Hanhong

    2016-10-18

    Azadirachtin is one of the most effective botanical insecticides and has been widely used in pest control. Toxicological reports show that azadirachtin can induce apoptosis in various insect cell lines. However, studies of azadirachtin-induced autophagy in cultured insect cells are lacking. This study reports that azadirachtin A significantly inhibits cell proliferation by inducing autophagic and apoptotic cell death in Spodoptera litura cultured cell line (SL-1 cell). Characteristic autophagolysosome and Atg8-PE (phosphatidylethanolamine) accumulation were observed by electron microscopy and western blotting, indicating that azadirachtin triggered autophagy in SL-1 cell. Furthermore, azadirachtin inhibited survival signaling by blocking the activation of PI3K, AKT and the down-stream target of rapamycin. Similar to the positive control of starvation, azadirachtin induced the activation of insulin receptor (InR) via a cellular feedback mechanism. In addition, the autophagy-related 5 (Atg5), a molecular switch of autophagy and apoptosis, was truncated (tAtg5) to trigger cytochrome c release into the cytoplasm under azadirachtin stress, which indicated that azadirachtin induced apoptosis through autophagy. Our findings suggest that azadirachtin primarily induced autophagy in SL-1 cell by dysregulating InR- and PI3K/AKT/TOR pathways, then stimulated apoptosis by activating tAtg5.

  18. CD147-CD98hc complex contributes to poor prognosis of non-small cell lung cancer patients through promoting cell proliferation via the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Fei, Fei; Li, Xiaofei; Xu, Li; Li, Deyang; Zhang, Zhipei; Guo, Xu; Yang, Hushan; Chen, Zhinan; Xing, Jinliang

    2014-12-01

    It has been reported that CD147 and CD98 heavy chain (CD98hc) form a complex on the cell plasma membrane of several cancers; however, whether this complex exists in non-small cell lung cancer (NSCLC) cells and affects the prognosis of patients remains to be elucidated. The expression of CD147 and CD98hc was assessed in tissue samples from 241 NSCLC patients and NSCLC cell lines. The correlation between CD147 and CD98hc expression and their association with the prognosis of NSCLC patients were analyzed. We also evaluated the impact of CD147 and CD98hc on the growth of NSCLC cells as well as Akt phosphorylation. Both CD147 and CD98hc were significantly upregulated in NSCLC cells, and their expression levels were significantly correlated (p CD147 and CD98hc could form a complex on NSCLC cells. Compared with NSCLC patients with CD147-/CD98hc-, those with CD147+/CD98hc+ exhibited a significantly poor overall survival (OS) with a hazard ratio (HR) of 1.92 (p = 0.010), and a significantly increased risk of recurrence with a HR of 1.97 (p = 0.004). Also, we demonstrated that the proliferation of lung cancer cell lines was significantly affected by knockdown and force-expression of the CD147-CD98hc complex. Western blot analysis indicated that the phosphorylation of Akt in NSCLC cells was significantly affected by knockdown and overexpression of either or both CD147 and CD98hc. Our findings indicate that the CD147-CD98hc complex significantly contributes to poor prognosis of NSCLC patients through promoting cell proliferation via the PI3K/Akt pathway.

  19. Imp2 regulates GBM progression by activating IGF2/PI3K/Akt pathway.

    Science.gov (United States)

    Mu, Qingchun; Wang, Lijun; Yu, Fengbo; Gao, Haijun; Lei, Ting; Li, Peiwen; Liu, Pengfei; Zheng, Xu; Hu, Xitong; Chen, Yong; Jiang, Zhenfeng; Sayari, Arash J; Shen, Jia; Huang, Haiyan

    2015-01-01

    Glioblastomas multiforme (GBM) are the most frequently occurring malignant brain cancers. Treatment for GBM consists of surgical resection and subsequent adjuvant radiation therapy and chemotherapy. Despite this, GBM patient survival is limited to 12-15 months, and researchers are continually trying to develop improved therapy options. Insulin-like growth factor 2 mRNA-binding protein 2 (Imp2) is known to be upregulated in many cancers and is known to regulate the signaling activity of insulin-like growth factor 2 (IGF2). However, relatively little is known about its role in malignant development of GBM. In this study, we first found Imp2 is upregulated in GBM tissues by using clinical samples and public database search. Studies with loss and gain of Imp2 expression in in vitro GBM cell culture system demonstrated the role of Imp2 in promoting GBM cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT). Additionally, our results show that Imp2 regulates the activity of IGF2, which further activates PI3K/Akt signaling, thereby to promote GBM malignancy. Inhibition of Imp2 was also found to sensitize GBM to temozolomide treatment. These observations add to the current knowledge of GBM biology, and may prove useful in development of more effective GBM therapy.

  20. Cytoglobin inhibits migration through PI3K/AKT/mTOR pathway in fibroblast cells.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Apdik, Hüseyin; Tuysuz, Emre Can; Gulluoglu, Sukru; Bayrak, Omer Faruk; Şahin, Fikrettin

    2018-01-01

    Cell proliferation and migration are crucial in many physiological processes including development, cancer, tissue repair, and wound healing. Cell migration is regulated by several signaling molecules. Identification of genes related to cell migration is required to understand molecular mechanism of non-healing chronic wounds which is a major concern in clinics. In the current study, the role of cytoglobin (CYGB) gene in fıbroblast cell migration and proliferation was described. L929 mouse fibroblast cells were transduced with lentiviral particles for CYGB and GFP, and analyzed for cell proliferation and migration ability. Fibroblast cells overexpressing CYGB displayed decreased cell proliferation, colony formation capacity, and cell migration. Phosphorylation levels of mTOR and two downstream effectors S6 and 4E-BP1 which take part in PI3K/AKT/mTOR signaling declined in CYGB-overexpressing cells. Microarray analysis indicated that CYGB overexpression leads to downregulation of cell proliferation, migration, and tumor growth associated genes in L929 cell line. This study demonstrated the role of CYGB in fibroblast cell motility and proliferation. CYGB could be a promising candidate for further studies as a potential target for diseases related to cell migration such as cancer and chronic wound treatment.

  1. A PKC-MARCKS-PI3K regulatory module links Ca2+ and PIP3 signals at the leading edge of polarized macrophages.

    Science.gov (United States)

    Ziemba, Brian P; Falke, Joseph J

    2018-01-01

    The leukocyte chemosensory pathway detects attractant gradients and directs cell migration to sites of inflammation, infection, tissue damage, and carcinogenesis. Previous studies have revealed that local Ca2+ and PIP3 signals at the leading edge of polarized leukocytes play central roles in positive feedback loop essential to cell polarization and chemotaxis. These prior studies showed that stimulation of the leading edge Ca2+ signal can strongly activate PI3K, thereby triggering a larger PIP3 signal, but did not elucidate the mechanistic link between Ca2+ and PIP3 signaling. A hypothesis explaining this link emerged, postulating that Ca2+-activated PKC displaces the MARCKS protein from plasma membrane PIP2, thereby releasing sequestered PIP2 to serve as the target and substrate lipid of PI3K in PIP3 production. In vitro single molecule studies of the reconstituted pathway on lipid bilayers demonstrated the feasibility of this PKC-MARCKS-PI3K regulatory module linking Ca2+ and PIP3 signals in the reconstituted system. The present study tests the model predictions in live macrophages by quantifying the effects of: (a) two pathway activators-PDGF and ATP that stimulate chemoreceptors and Ca2+ influx, respectively; and (b) three pathway inhibitors-wortmannin, EGTA, and Go6976 that inhibit PI3K, Ca2+ influx, and PKC, respectively; on (c) four leading edge activity sensors-AKT-PH-mRFP, CKAR, MARCKSp-mRFP, and leading edge area that report on PIP3 density, PKC activity, MARCKS membrane binding, and leading edge expansion/contraction, respectively. The results provide additional evidence that PKC and PI3K are both essential elements of the leading edge positive feedback loop, and strongly support the existence of a PKC-MARCKS-PI3K regulatory module linking the leading edge Ca2+ and PIP3 signals. As predicted, activators stimulate leading edge PKC activity, displacement of MARCKS from the leading edge membrane and increased leading edge PIP3 levels, while inhibitors

  2. A PKC-MARCKS-PI3K regulatory module links Ca2+ and PIP3 signals at the leading edge of polarized macrophages.

    Directory of Open Access Journals (Sweden)

    Brian P Ziemba

    Full Text Available The leukocyte chemosensory pathway detects attractant gradients and directs cell migration to sites of inflammation, infection, tissue damage, and carcinogenesis. Previous studies have revealed that local Ca2+ and PIP3 signals at the leading edge of polarized leukocytes play central roles in positive feedback loop essential to cell polarization and chemotaxis. These prior studies showed that stimulation of the leading edge Ca2+ signal can strongly activate PI3K, thereby triggering a larger PIP3 signal, but did not elucidate the mechanistic link between Ca2+ and PIP3 signaling. A hypothesis explaining this link emerged, postulating that Ca2+-activated PKC displaces the MARCKS protein from plasma membrane PIP2, thereby releasing sequestered PIP2 to serve as the target and substrate lipid of PI3K in PIP3 production. In vitro single molecule studies of the reconstituted pathway on lipid bilayers demonstrated the feasibility of this PKC-MARCKS-PI3K regulatory module linking Ca2+ and PIP3 signals in the reconstituted system. The present study tests the model predictions in live macrophages by quantifying the effects of: (a two pathway activators-PDGF and ATP that stimulate chemoreceptors and Ca2+ influx, respectively; and (b three pathway inhibitors-wortmannin, EGTA, and Go6976 that inhibit PI3K, Ca2+ influx, and PKC, respectively; on (c four leading edge activity sensors-AKT-PH-mRFP, CKAR, MARCKSp-mRFP, and leading edge area that report on PIP3 density, PKC activity, MARCKS membrane binding, and leading edge expansion/contraction, respectively. The results provide additional evidence that PKC and PI3K are both essential elements of the leading edge positive feedback loop, and strongly support the existence of a PKC-MARCKS-PI3K regulatory module linking the leading edge Ca2+ and PIP3 signals. As predicted, activators stimulate leading edge PKC activity, displacement of MARCKS from the leading edge membrane and increased leading edge PIP3 levels, while

  3. Activation of the PI3K/Akt pathway mediates bone morphogenetic protein 2-induced invasion of pancreatic cancer cells Panc-1.

    Science.gov (United States)

    Chen, Xiong; Liao, Jie; Lu, YeBin; Duan, XiaoHui; Sun, WeiJia

    2011-06-01

    Bone morphogenetic proteins (BMPs) signaling has an emerging role in pancreatic cancer. However, because of the multiple effects of different BMPs, no final conclusions have been made as to the role of BMPs in pancreatic cancer. In our studies, we have focused on bone morphogenetic protein 2(BMP-2) because it induces an epithelial to mesenchymal transition (EMT) and accelerates invasion in the human pancreatic cancer cell line Panc-1. It has been reported that the phosphatidylinositol 3-kinase (PI3K)/Akt pathway mediates invasion of gastric and colon cancer cells, which is unrevealed in pancreatic cancer cells. The objective of our study was to investigate whether BMP-2 mediated invasion might pass through the PI3K/Akt pathway. Our results show that expression of phosphorylation of Akt was increased by treatment with BMP-2, but not Noggin, a BMP-2 antagonist. Then pretreatment of Panc-1 cells with LY294002, an inhibitor of the PI3K/AKT pathway, significantly inhibited BMP-2-induced EMT and invasiveness. The data suggest that BMP-2 accelerates invasion of panc-1 cells via the PI3K/AKT pathway in panc-1 cells, which gives clues to searching new therapy targets in advanced pancreatic cancer.

  4. PKI-587 and sorafenib targeting PI3K/AKT/mTOR and Ras/Raf/MAPK pathways synergistically inhibit HCC cell proliferation.

    Science.gov (United States)

    Gedaly, Roberto; Angulo, Paul; Hundley, Jonathan; Daily, Michael F; Chen, Changguo; Evers, B Mark

    2012-08-01

    Deregulated Ras/Raf/MAPK and PI3K/AKT/mTOR signaling pathways are found in hepatocellular carcinoma (HCC). This study aimed to test the inhibitory effects of PKI-587 and sorafenib as single agents or in combination on HCC (Huh7 cell line) proliferation. (3)H-thymidine incorporation and MTT assay were used to assess Huh7 cell proliferation. Phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways was detected by Western blot. We found that PKI-587 is a more potent PI3K/mTOR inhibitor than PI-103. Combination of PKI-587 and sorafenib was a more effective inhibitor of Huh7 proliferation than the combination of PI-103 and sorafenib. Combination of PKI-587 and sorafenib synergistically inhibited epidermal growth factor (EGF)-stimulated Huh7 proliferation compared with monodrug therapy. EGF increased phosphorylation of Ras/Raf downstream signaling proteins MEK and ERK; EGF-stimulated activation was inhibited by sorafenib. However, sorafenib, as a single agent, increased AKT (Ser473) phosphorylation. EGF-stimulated AKT (ser473) activation was inhibited by PKI-587. PKI-587 is a potent inhibitor of AKT (Ser473), mTOR (Ser2448), and S6K (Thr389) phosphorylation; in contrast, rapamycin stimulated mTOR complex 2 substrate AKT(Ser473) phosphorylation although it inhibited mTOR complex 1 substrate S6K phosphorylation. PKI-587, as a single agent, stimulated MEK and ERK phosphorylation. However, when PKI-587 and sorafenib were used in combination, they inhibited all the tested kinases in the Ras/Raf /MAPK and PI3K/AKT/mTOR pathways. The combination of PKI-587 and sorafenib has the advantage over monodrug therapy on inhibition of HCC cell proliferation by blocking both PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. A novel imidazopyridine derivative, HS-106, induces apoptosis of breast cancer cells and represses angiogenesis by targeting the PI3K/mTOR pathway.

    Science.gov (United States)

    Li, Guang-Yong; Jung, Kyung Hee; Lee, Hyunseung; Son, Mi Kwon; Seo, JuHyeon; Hong, Sang-Won; Jeong, Yujeong; Hong, Sungwoo; Hong, Soon-Sun

    2013-02-01

    Abnormal activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is an essential step for the formation and growth of tumors in humans. HS-106 is an imidazopyridine derivative that inhibits the kinase activity of PI3K by binding to the ATP-binding cleft. We found that this compound suppressed breast cancer cell proliferation and induced apoptosis by specifically inhibiting the activity of target proteins in the PI3K/Akt/mTOR signaling pathway. Cell cycle analysis revealed that treatment with HS-106 resulted in cell cycle arrest at the G(2)/M phase due to up-regulation of p-cdc25 and down-regulation of cyclin B1. Also, HS-106 induced apoptosis by increasing the levels of cleaved caspase-3 and cleaved PARP. In addition, chromatin condensation and apoptotic bodies were detected in HS-106-treated breast cancer cells. Furthermore, HS-106 decreased the expression of hypoxia-inducible factor 1α (HIF-1α), and inhibited tube formation and migration of human umbilical vein endothelial cells (HUVECs) in vitro and blood vessel formation in an in vivo Matrigel plug assay. These results show that HS-106 may be an effective novel therapeutic candidate in clinical trials as a potential treatment for human breast cancers or other advanced malignancies with aberrant PI3K/Akt/mTOR signaling. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

  6. Fucoxanthin prevents H2O2-induced neuronal apoptosis via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway.

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    Yu, Jie; Lin, Jia-Jia; Yu, Rui; He, Shan; Wang, Qin-Wen; Cui, Wei; Zhang, Jin-Rong

    2017-01-01

    Background : As a natural carotenoid abundant in chloroplasts of edible brown algae, fucoxanthin possesses various health benefits, including anti-oxidative activity in particular. Objective : In the present study, we studied whether fucoxanthin protected against hydrogen peroxide (H 2 O 2 )-induced neuronal apoptosis. Design : The neuroprotective effects of fucoxanthin on H 2 O 2 -induced toxicity were studied in both SH-SY5Y cells and primary cerebellar granule neurons. Results : Fucoxanthin significantly protected against H 2 O 2 -induced neuronal apoptosis and intracellular reactive oxygen species. H 2 O 2 treatment led to the reduced activity of phosphoinositide 3-kinase (PI3-K)/Akt cascade and the increased activity of extracellular signal-regulated kinase (ERK) pathway in SH-SY5Y cells. Moreover, fucoxanthin significantly restored the altered activities of PI3-K/Akt and ERK pathways induced by H 2 O 2 . Both specific inhibitors of glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase (MEK) significantly protected against H 2 O 2 -induced neuronal death. Furthermore, the neuroprotective effects of fucoxanthin against H 2 O 2 -induced neuronal death were abolished by specific PI3-K inhibitors. Conclusions : Our data strongly revealed that fucoxanthin protected against H 2 O 2 -induced neurotoxicity via concurrently activating the PI3-K/Akt cascade and inhibiting the ERK pathway, providing support for the use of fucoxanthin to treat neurodegenerative disorders induced by oxidative stress.

  7. Activation of the PI3K/AKT pathway by microRNA-22 results in CLL B-cell proliferation.

    Science.gov (United States)

    Palacios, F; Abreu, C; Prieto, D; Morande, P; Ruiz, S; Fernández-Calero, T; Naya, H; Libisch, G; Robello, C; Landoni, A I; Gabus, R; Dighiero, G; Oppezzo, P

    2015-01-01

    Chronic lymphocytic leukemia (CLL) is characterized by accumulation of clonal B cells arrested in G0/G1 stages that coexist, in different proportions, with proliferative B cells. Understanding the crosstalk between the proliferative subsets and their milieu could provide clues on CLL biology. We previously identified one of these subpopulations in the peripheral blood from unmutated patients that appears to be a hallmark of a progressive disease. Aiming to characterize the molecular mechanism underlying this proliferative behavior, we performed gene expression analysis comparing the global mRNA and microRNA expression of this leukemic subpopulation, and compared it with their quiescent counterparts. Our results suggest that proliferation of this fraction depend on microRNA-22 overexpression that induces phosphatase and tensin homolog downregulation and phosphoinositide 3-kinase (PI3K)/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B cells switches on PI3K/AKT, leading to downregulation of p27(-Kip1) and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40 ligand/interleukin-4 and, more importantly, that this regulatory loop is also present in lymph nodes from progressive unmutated patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide additional rationale for the usage of PI3K inhibitors.

  8. Upstream and Downstream Co-inhibition of Mitogen-Activated Protein Kinase and PI3K/Akt/mTOR Pathways in Pancreatic Ductal Adenocarcinoma

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    Matthew H. Wong

    2016-07-01

    Full Text Available BACKGROUND: Extensive cross talk exists between PI3K/Akt/mTOR and mitogen-activated protein kinase (MAPK pathways, and both are upregulated in pancreatic ductal adenocarcinoma (PDAC. Our previous study suggested that epidermal growth factor receptor inhibitor erlotinib which acts upstream of these pathways acts synergistically with PI3K inhibitors in PDAC. Horizontal combined blockade upstream and downstream of these two pathways is therefore explored. METHODS: Erlotinib paired with PI3K inhibitor (BYL719 was tested against erlotinib plus dual PI3K/mTOR inhibitor BEZ-235, and MEK inhibitor (PD98059 plus BEZ235, on five primary PDAC cell lines and on two pairs of parent and erlotinib-resistant (ER cell lines. A range of in vitro assays including cell proliferation, Western blotting, migration, clonogenic, cell cycle, and apopotic assays was used to test for the efficacy of combined blockade. RESULTS: Dual downstream blockade of the MAPK and PAM pathways was more effective in attenuating downstream molecular signals. Synergy was demonstrated for erlotinib and BEZ235 and for PD-98059 and BEZ-235. This resulted in a trend of increased growth cell cycle arrest, apoptosis, cell proliferation, and colony and migration suppression. This combination showed more efficacy in cell lines with acquired resistance to erlotinib. CONCLUSIONS: The additional mTOR blockade provided by BEZ235 in combined blockade resulted in increased anticancer effect. The hypersensitivity of ER cell lines to additional mTOR blockade suggested PAM pathway oncogenic dependence via mTOR. Dual downstream combined blockade of MAPK and PAM pathways with MEK and PI3K/mTOR inhibitor appeared most effective and represents an attractive therapeutic strategy against pancreatic cancer and its associated drug resistance.

  9. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  10. Valsartan regulates the interaction of angiotensin II type 1 receptor and endothelial nitric oxide synthase via Src/PI3K/Akt signalling.

    Science.gov (United States)

    Su, Kuo-Hui; Tsai, Jin-Yi; Kou, Yu Ru; Chiang, An-Na; Hsiao, Sheng-Huang; Wu, Yuh-Lin; Hou, Hsin-Han; Pan, Ching-Chian; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2009-06-01

    Valsartan, a selective angiotensin II type 1 receptor (AT1R) blocker, has beneficial effects in the cardiovascular system in part by its increase of nitric oxide (NO) bioavailability, yet the mechanisms are unclear. We investigated the molecular mechanisms underlying this effect in endothelial cells (ECs). NO production was examined by Griess reagent assay, DAF-2 DA fluorescence staining and cGMP ELISA kits. Protein interaction was determined by western blotting and immunoprecipitation. Treating bovine or human aortic ECs with valsartan increased NO production, as evidenced by elevated level of stable NO metabolites and intracellular cGMP. Valsartan increased the phosphorylation but not the protein level of endothelial NO synthase (eNOS). Inhibition of phosphoinositide-3 kinase (PI3K)/Akt and Src pathways by specific inhibitors suppressed valsartan-induced NO release. In addition, valsartan increased the tyrosine residue phosphorylation of AT1R, which was attenuated by inhibition of Src but not PI3K activities. Valsartan also suppressed the interaction of eNOS and AT1R, which was blocked by Src or PI3K inhibition. Valsartan-induced NO production in ECs is mediated through Src/PI3K/Akt-dependent phosphorylation of eNOS. Valsartan-induced AT1R phosphorylation depends on Src but not PI3K, whereas valsartan-induced suppression of AT1R-eNOS interaction depends on Src/PI3K/Akt signalling. These results indicate a novel vasoprotective mechanism of valsartan in upregulating NO production in ECs.

  11. Signaling via class IA Phosphoinositide 3-kinases (PI3K in human, breast-derived cell lines.

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    Veronique Juvin

    Full Text Available We have addressed the differential roles of class I Phosphoinositide 3-kinases (PI3K in human breast-derived MCF10a (and iso-genetic derivatives and MDA-MB 231 and 468 cells. Class I PI3Ks are heterodimers of p110 catalytic (α, β, δ and γ and p50-101 regulatory subunits and make the signaling lipid, phosphatidylinositol (3,4,5-trisphosphate (PtdIns(3,4,5P3 that can activate effectors, eg protein kinase B (PKB, and responses, eg migration. The PtdIns(3,4,5P3-3-phosphatase and tumour-suppressor, PTEN inhibits this pathway. p110α, but not other p110s, has a number of onco-mutant variants that are commonly found in cancers. mRNA-seq data shows that MCF10a cells express p110β>>α>δ with undetectable p110γ. Despite this, EGF-stimulated phosphorylation of PKB depended upon p110α-, but not β- or δ- activity. EGF-stimulated chemokinesis, but not chemotaxis, was also dependent upon p110α, but not β- or δ- activity. In the presence of single, endogenous alleles of onco-mutant p110α (H1047R or E545K, basal, but not EGF-stimulated, phosphorylation of PKB was increased and the effect of EGF was fully reversed by p110α inhibitors. Cells expressing either onco-mutant displayed higher basal motility and EGF-stimulated chemokinesis.This latter effect was, however, only partially-sensitive to PI3K inhibitors. In PTEN(-/- cells, basal and EGF-stimulated phosphorylation of PKB was substantially increased, but the p110-dependency was variable between cell types. In MDA-MB 468s phosphorylation of PKB was significantly dependent on p110β, but not α- or δ- activity; in PTEN(-/- MCF10a it remained, like the parental cells, p110α-dependent. Surprisingly, loss of PTEN suppressed basal motility and EGF-stimulated chemokinesis. These results indicate that; p110α is required for EGF signaling to PKB and chemokinesis, but not chemotaxis; onco-mutant alleles of p110α augment signaling in the absence of EGF and may increase motility, in part, via acutely

  12. Effects of Different Ratio of n-6/n-3 Polyunsaturated Fatty Acids on the PI3K/Akt Pathway in Rats with Reflux Esophagitis.

    Science.gov (United States)

    Zhuang, Jia-Yuan; Chen, Zhi-Yao; Zhang, Tao; Tang, Du-Peng; Jiang, Xiao-Yin; Zhuang, Ze-Hao

    2017-01-30

    BACKGROUND We designed this study to investigate the influence of different ratios of n-6/n-3 polyunsaturated fatty acid in the diet of reflux esophagitis (RE) rats' and the effect on the PI3K/Akt pathway. MATERIAL AND METHODS RE rats were randomly divided into a sham group and modeling groups of different concentrations of n-6/n-3 polyunsaturated fatty acid (PUFA): 12:1 group, 10:1 group, 5:1 group, and 1:1 group. RT-PCR and Western-blot were used to detect the expression of PI3K, Akt, p-Akt, NF-κBp50, and NF-κBp65 proteins in esophageal tissue. RESULTS In the n-6/n-3 PUFAs groups the expression of PI3K, Akt, p-Akt, nf-κbp50, and NF-κBp65 mRNA decreased with the decrease in n-6/n-3 ratios in the diet. The lowest expression of each indicator occurred in the 1:1 n-6/n-3 group compared with other n-6/n-3 groups, the difference was statistically significant (p<0.05). CONCLUSIONS The inhibition of n-3 PUFAs in the development of esophageal inflammation in rats with RE was attributed to the function of PI3K/Akt-NF-κB signaling pathway.

  13. Si Shen Wan Regulates Phospholipase Cγ-1 and PI3K/Akt Signal in Colonic Mucosa from Rats with Colitis

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    Duan-yong Liu

    2015-01-01

    Full Text Available The present study explored the feasible pathway of Si Shen Wan (SSW in inhibiting apoptosis of intestinal epithelial cells (IECs by observing activation of phospholipase Cγ-1 (PLC-γ1 and PI3K/Akt signal in colonic mucosa from rats with colitis. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS in the Sprague-Dawley rats. After SSW was administrated for 7 days after TNBS infusion, western blot showed an increment in levels of PI3K, p-Akt, and IL-23 and a decrement in levels of PLC-γ1 and HSP70 in colonic mucosal injury induced by TNBS. Meanwhile, assessments by ELISA revealed an increment in concentrations of IL-2, IL-6, and IL-17 and a reduction in level of TGF-β after TNBS challenge. Impressively, treatment with SSW for 7 days significantly attenuated the expressions of PI3K and p-Akt and the secretion of IL-2, IL-6, IL-17, and IL-23 and promoted the activation of PLC-γ1, HSP70, and TGF-β. Our previous studies had demonstrated that SSW restored colonic mucosal ulcers by inhibiting apoptosis of IECs. The present study demonstrated that the effect of SSW on inhibiting apoptosis of IECs was realized probably by activation of PLC-γ1 and suppression of PI3K/Akt signal pathway.

  14. Somatic stem cell differentiation is regulated by PI3K/Tor signaling in response to local cues.

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    Amoyel, Marc; Hillion, Kenzo-Hugo; Margolis, Shally R; Bach, Erika A

    2016-11-01

    Stem cells reside in niches that provide signals to maintain self-renewal, and differentiation is viewed as a passive process that depends on loss of access to these signals. Here, we demonstrate that the differentiation of somatic cyst stem cells (CySCs) in the Drosophila testis is actively promoted by PI3K/Tor signaling, as CySCs lacking PI3K/Tor activity cannot differentiate properly. We find that an insulin peptide produced by somatic cells immediately outside of the stem cell niche acts locally to promote somatic differentiation through Insulin-like receptor (InR) activation. These results indicate that there is a local 'differentiation' niche that upregulates PI3K/Tor signaling in the early daughters of CySCs. Finally, we demonstrate that CySCs secrete the Dilp-binding protein ImpL2, the Drosophila homolog of IGFBP7, into the stem cell niche, which blocks InR activation in CySCs. Thus, we show that somatic cell differentiation is controlled by PI3K/Tor signaling downstream of InR and that the local production of positive and negative InR signals regulates the differentiation niche. These results support a model in which leaving the stem cell niche and initiating differentiation are actively induced by signaling. © 2016. Published by The Company of Biologists Ltd.

  15. Preclinical rationale for PI3K/Akt/mTOR pathway inhibitors as therapy for epidermal growth factor receptor inhibitor-resistant non-small-cell lung cancer.

    Science.gov (United States)

    Gadgeel, Shirish M; Wozniak, Antoinette

    2013-07-01

    Mutations in the epidermal growth factor receptor gene (EGFR) are frequently observed in non-small-cell lung cancer (NSCLC), occurring in about 40% to 60% of never-smokers and in about 17% of patients with adenocarcinomas. EGFR tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib, have transformed therapy for patients with EGFR-mutant NSCLC and have proved superior to chemotherapy as first-line treatment for this patient group. Despite these benefits, there are currently 2 key challenges associated with EGFR inhibitor therapy for patients with NSCLC. First, only 85% to 90% of patients with the EGFR mutation derive clinical benefit from EGFR TKIs, with the remainder demonstrating innate resistance to therapy. Second, acquired resistance to EGFR TKIs inevitably occurs in patients who initially respond to therapy, with a median duration of response of about 10 months. Mutant EGFR activates various subcellular signaling cascades, including the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, which demonstrates maintained activity in a variety of TKI-resistant cancers. Given the fundamental role of the PI3K/Akt/mTOR pathway in tumor oncogenesis, proliferation, and survival, PI3K pathway inhibitors have emerged as a possible solution to the problem of EGFR TKI resistance. However resistance to EGFR TKIs is associated with considerable heterogeneity and complexity. Preclinical experiments investigating these phenomena suggest that in some patients, PI3K inhibitors will have to be paired with other targeted agents if they are to be effective. This review discusses the preclinical data supporting PI3K/Akt/mTOR pathway inhibitor combinations in EGFR TKI-resistant NSCLC from the perspective of the various agents currently being investigated in clinical trials. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Cosmosiin Increases ADAM10 Expression via Mechanisms Involving 5’UTR and PI3K Signaling

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    Zhuo Min

    2018-06-01

    Full Text Available The α-secretase “a disintegrin and metalloproteinase domain-containing protein” (ADAM10 is involved in the processing of amyloid precursor protein (APP. Upregulation of ADAM10 precludes the generation of neurotoxic β-amyloid protein (Aβ and represents a plausible therapeutic strategy for Alzheimer’s disease (AD. In this study, we explored compounds that can potentially promote the expression of ADAM10. Therefore, we performed high-throughput small-molecule screening in SH-SY5Y (human neuroblastoma cells that stably express a luciferase reporter gene driven by the ADAM10 promoter, including a portion of its 5’-untranslated region (5’UTR. This has led to the discovery of cosmosiin (apigenin 7-O-β-glucoside. Here, we report that in human cell lines (SH-SY5Y and HEK293, cosmosiin proportionally increased the levels of the immature and mature forms of the ADAM10 protein without altering its mRNA level. This effect was attenuated by translation inhibitors or by deleting the 5’UTR of ADAM10, suggesting that a translational mechanism was responsible for the increased levels of ADAM10. Luciferase deletion assays revealed that the first 144 nucleotides of the 5’UTR were necessary for mediating the cosmosiin-induced enhancement of ADAM10 expression in SH-SY5Y cells. Cosmosiin failed to increase the levels of the ADAM10 protein in murine cells, which lack native expression of the ADAM10 transcript containing the identified 5’UTR element. The potential signaling pathway may involve phosphatidylinositide 3-kinase (PI3K because pharmacological inhibition of PI3K attenuated the effect of cosmosiin on the expression of the ADAM10 protein. Finally, cosmosiin attenuated Aβ generation because the levels of Aβ40/42 in HEK-APP cells were significantly reduced after cosmosiin treatment. Collectively, we found that the first 144 nucleotides of the ADAM10 5’UTR, and PI3K signaling, are involved in cosmosiin-induced enhancement of the expression

  17. Morphine Suppresses T helper Lymphocyte Differentiation to Th1 Type Through PI3K/AKT Pathway.

    Science.gov (United States)

    Mao, Mao; Qian, Yanning; Sun, Jie

    2016-04-01

    To investigate the effect of morphine on T helper lymphocyte differentiation and PI3K/AKT pathway mechanism, CD4+ lymphocytes were treated by phorbol-myristate-acetate (25 ng/ml) (PMA) plus ionomycin (1 μg/ml) in the presence of various concentrations of morphine (25, 50, 100, 200 ng/ml) for 4 h. Th1 and Th2 subsets, supernatant cytokines, and PI3K, AKT, and protein kinase C-theta (PKC-θ) levels were detected. The Th1 cell percentage, Th1-derived cytokines, and ratio of Th1/Th2 decreased in the presence of morphine in a concentration-dependent manner. However, Th2 cell percentage kept stable after morphine treatment. The phosphorylation of PI3K and AKT decreased, but the phosphorylation of PKC-θ did not change in the presence of morphine. The decreased percentage of Th1 cells and ratio of Th1/Th2 was recovered by naloxone concentration-dependently. Morphine can inhibit the differentiation of Th1 lymphocytes and decrease the ratio of Th1/Th2 via the pathway of PI3K/AKT. The effect can be inhibited by naloxone.

  18. FOXO3a is a major target of inactivation by PI3K/AKT signaling in aggressive neuroblastoma

    NARCIS (Netherlands)

    Santo, Evan E.; Stroeken, Peter; Sluis, Peter V.; Koster, Jan; Versteeg, Rogier; Westerhout, Ellen M.

    2013-01-01

    Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have

  19. Distinctive and selective route of PI3K/PKCα-PKCδ/RhoA-Rac1 signaling in osteoclastic cell migration.

    Science.gov (United States)

    Kim, Jin-Man; Kim, Mi Yeong; Lee, Kyunghee; Jeong, Daewon

    2016-12-05

    Cell migration during specialized stages of osteoclast precursors, mononuclear preosteoclasts, and multinucleated mature osteoclasts remain uncertain. M-CSF- and osteopontin-induced osteoclastic cell migration was inhibited by function-blocking monoclonal antibodies specific to the integrin αv and β3 subunits, suggesting that integrin αvβ3 mediates migratory signaling induced by M-CSF and osteopontin. M-CSF and osteopontin stimulation was shown to regulate two branched signaling processes, PI3K/PKCα/RhoA axis and PI3K/PKCδ/Rac1 axis. Interestingly, inactivation of RhoA or Rac1 blocked preosteoclast and mature osteoclast migration but not osteoclast precursor migration in a transwell-based cell migration assay. Moreover, the inhibitory effect on preosteoclast and mature osteoclast migration induced by Rac1 inactivation was more effective than that by RhoA inactivation. Collectively, our findings suggest that osteoclast precursor migration depends on PI3K/PKCα-PKCδ signaling mediated via integrin αvβ3 bypassing RhoA and Rac1, whereas preosteoclast and mature osteoclast migration relies on PI3K/PKCα-PKCδ/RhoA-Rac1 axis signaling mediated via integrin αvβ3 with increased dependency on PKCδ/Rac1 signaling route as differentiation progresses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Celecoxib Down-Regulates the Hypoxia-Induced Expression of HIF-1α and VEGF Through the PI3K/AKT Pathway in Retinal Pigment Epithelial Cells

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    Yi-zhou Sun

    2017-12-01

    Full Text Available Background/Aims: The goal of this study was to detect the expression of hypoxia-inducible factor 1α (HIF-1α and vascular endothelial growth factor (VEGF in human retinal pigmented epithelial (RPE cells treated with celecoxib, a selective cyclooxygenase-2 (COX-2 inhibitor, under hypoxic and normoxic conditions and to explore the signaling mechanism involved in regulating the hypoxia-induced expression of HIF-1α and VEGF in RPE cells. Methods: D407 cells were cultured in normoxic or hypoxic conditions, with or without celecoxib or a PI3K inhibitor (LY294002. The anti-proliferative effect of celecoxib was assessed using the MTT assay. RT-PCR, Western blotting and ELISA were performed to detect the levels of PI3K, phosphorylated AKT (p-AKT, HIF-1α, VEGF and COX-2. Results: Celecoxib inhibited the proliferation of RPE cells in a dose-dependent manner. Celecoxib suppressed the expression of VEGF at both the mRNA and protein levels and decreased HIF-1α protein expression. HIF-1α activation was regulated by the PI3K/AKT pathway. The celecoxib-induced down-regulation of HIF-1α and VEGF required the suppression of the hypoxia-induced PI3K/AKT pathway. However, the down-regulation of COX-2 did not occur in cells treated with celecoxib. Conclusions: The antiangiogenic effects of celecoxib in RPE cells under hypoxic conditions resulted from the inhibition of HIF-1α and VEGF expression, which may be partly mediated by a COX-2-independent, PI3K/AKT-dependent pathway.

  1. Ethanol Extracts of Fruiting Bodies of Antrodia cinnamomea Suppress CL1-5 Human Lung Adenocarcinoma Cells Migration by Inhibiting Matrix Metalloproteinase-2/9 through ERK, JNK, p38, and PI3K/Akt Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Ying-Yi Chen

    2012-01-01

    Full Text Available Cancer metastasis is a primary cause of cancer death. Antrodia cinnamomea (A. cinnamomea, a medicinal mushroom in Taiwan, has shown antioxidant and anticancer activities. In this study, we first observed that ethanol extract of fruiting bodies of A. cinnamomea (EEAC exerted a concentration-dependent inhibitory effect on migration and motility of the highly metastatic CL1-5 cells in the absence of cytotoxicity. The results of a gelatin zymography assay showed that A. cinnamomea suppressed the activities of matrix metalloproteinase-(MMP- 2 and MMP-9 in a concentration-dependent manner. Western blot results demonstrated that treatment with A. cinnamomea decreased the expression of MMP-9 and MMP-2; while the expression of the endogenous inhibitors of these proteins, that is, tissue inhibitors of MMP (TIMP-1 and TIMP-2 increased. Further investigation revealed that A. cinnamomea suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. A. cinnamomea also suppressed the expressions of PI3K and phosphorylation of Akt. Furthermore, treatment of CL1-5 cells with inhibitors specific for PI3K (LY 294002, ERK1/2 (PD98059, JNK (SP600125, and p38 MAPK (SB203580 decreased the expression of MMP-2 and MMP-9. This is the first paper confirming the antimigration activity of this potentially beneficial mushroom against human lung adenocarcinoma CL1-5 cancer cells.

  2. Computer-Aided Targeting of the PI3K/Akt/mTOR Pathway: Toxicity Reduction and Therapeutic Opportunities

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    Tan Li

    2014-10-01

    Full Text Available The PI3K/Akt/mTOR pathway plays an essential role in a wide range of biological functions, including metabolism, macromolecular synthesis, cell growth, proliferation and survival. Its versatility, however, makes it a conspicuous target of many pathogens; and the consequential deregulations of this pathway often lead to complications, such as tumorigenesis, type 2 diabetes and cardiovascular diseases. Molecular targeted therapy, aimed at modulating the deregulated pathway, holds great promise for controlling these diseases, though side effects may be inevitable, given the ubiquity of the pathway in cell functions. Here, we review a variety of factors found to modulate the PI3K/Akt/mTOR pathway, including gene mutations, certain metabolites, inflammatory factors, chemical toxicants, drugs found to rectify the pathway, as well as viruses that hijack the pathway for their own synthetic purposes. Furthermore, this evidence of PI3K/Akt/mTOR pathway alteration and related pathogenesis has inspired the exploration of computer-aided targeting of this pathway to optimize therapeutic strategies. Herein, we discuss several possible options, using computer-aided targeting, to reduce the toxicity of molecularly-targeted therapy, including mathematical modeling, to reveal system-level control mechanisms and to confer a low-dosage combination therapy, the potential of PP2A as a therapeutic target, the formulation of parameters to identify patients who would most benefit from specific targeted therapies and molecular dynamics simulations and docking studies to discover drugs that are isoform specific or mutation selective so as to avoid undesired broad inhibitions. We hope this review will stimulate novel ideas for pharmaceutical discovery and deepen our understanding of curability and toxicity by targeting the PI3K/Akt/mTOR pathway.

  3. Analysis of genes involved in the PI3K/Akt pathway in radiation- and MNU-induced rat mammary carcinomas.

    Science.gov (United States)

    Showler, Kaye; Nishimura, Mayumi; Daino, Kazuhiro; Imaoka, Tatsuhiko; Nishimura, Yukiko; Morioka, Takamitsu; Blyth, Benjamin J; Kokubo, Toshiaki; Takabatake, Masaru; Fukuda, Maki; Moriyama, Hitomi; Kakinuma, Shizuko; Fukushi, Masahiro; Shimada, Yoshiya

    2017-03-01

    The PI3K/AKT pathway is one of the most important signaling networks in human breast cancer, and since it was potentially implicated in our preliminary investigations of radiation-induced rat mammary carcinomas, our aim here was to verify its role. We included mammary carcinomas induced by the chemical carcinogen 1-methyl-1-nitrosourea to determine whether any changes were radiation-specific. Most carcinomas from both groups showed activation of the PI3K/AKT pathway, but phosphorylation of AKT1 was often heterogeneous and only present in a minority of carcinoma cells. The negative pathway regulator Inpp4b was significantly downregulated in both groups, compared with in normal mammary tissue, and radiation-induced carcinomas also showed a significant decrease in Pten expression, while the chemically induced carcinomas showed a decrease in Pik3r1 and Pdk1. Significant upregulation of the positive regulators Erbb2 and Pik3ca was observed only in chemically induced carcinomas. However, no genes showed clear correlations with AKT phosphorylation levels, except in individual carcinomas. Only rare carcinomas showed mutations in PI3K/AKT pathway genes, yet these carcinomas did not exhibit stronger AKT phosphorylation. Thus, while AKT phosphorylation is a common feature of rat mammary carcinomas induced by radiation or a canonical chemical carcinogen, the mutation of key genes in the pathways or permanent changes to gene expression of particular signaling proteins do not explain the pathway activation in the advanced cancers. Although AKT signaling likely facilitates cancer development and growth in rat mammary carcinomas, it is unlikely that permanent disruption of the PI3K/AKT pathway genes is a major causal event in radiation carcinogenesis. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  4. Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

    Science.gov (United States)

    Ma, Dandan; Kou, Xiaoxing; Jin, Jing; Xu, Taotao; Wu, Mengjie; Deng, Liquan; Fu, Lusi; Liu, Yi; Wu, Gang; Lu, Haiping

    2016-01-01

    Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK)-ERK (extracellular signal–regulated kinase)/PI3K (phosphatidylinositol-3-kinase) signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs) of different magnitudes (0, 50, 100, 150, 200, and 250 kPa) for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway. PMID:27827993

  5. Saposin C promotes survival and prevents apoptosis via PI3K/Akt-dependent pathway in prostate cancer cells

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    Lee Tae-Jin

    2004-11-01

    Full Text Available Abstract Background In addition to androgens, growth factors are also implicated in the development and neoplastic growth of the prostate gland. Prosaposin is a potent neurotrophic molecule. Homozygous inactivation of prosaposin in mice has led to the development of a number of abnormalities in the male reproductive system, including atrophy of the prostate gland and inactivation of mitogen-activated protein kinase (MAPK and Akt in prostate epithelial cells. We have recently reported that prosaposin is expressed at a higher level by androgen-independent (AI prostate cancer cells as compared to androgen-sensitive prostate cancer cells or normal prostate epithelial and stromal cells. In addition, we have demonstrated that a synthetic peptide (prosaptide TX14A, derived from the trophic sequence of the saposin C domain of prosaposin, stimulated cell proliferation, migration and invasion and activated the MAPK signaling pathway in prostate cancer cells. The biological significances of saposin C and prosaposin in prostate cancer are not known. Results Here, we report that saposin C, in a cell type-specific and dose-dependent manner, acts as a survival factor, activates the Akt-signaling pathway, down-modulates caspase-3, -7, and -9 expression and/or activity, and decreases the cleaved nuclear substrate of caspase-3 in prostate cancer cells under serum-starvation stress. In addition, prosaptide TX14A, saposin C, or prosaposin decreased the growth-inhibitory effect, caspase-3/7 activity, and apoptotic cell death induced by etoposide. We also discovered that saposin C activates the p42/44 MAP kinase pathway in a pertussis toxin-sensitive and phosphatidylinositol 3-kinase (PI3K /Akt-dependent manner in prostate cancer cells. Our data also show that the anti-apoptotic activity of saposin C is at least partially mediated via PI3K/Akt signaling pathway. Conclusion We postulate that as a mitogenic, survival, and anti-apoptotic factor for prostate cancer cells

  6. Cyclic mechanical strain maintains Nanog expression through PI3K/Akt signaling in mouse embryonic stem cells

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    Horiuchi, Rie [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Akimoto, Takayuki, E-mail: akimoto@m.u-tokyo.ac.jp [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Institute for Biomedical Engineering, Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513 Waseda-tsurumaki, Shinjuku, Tokyo 162-0041 (Japan); Hong, Zhang [Institute for Biomedical Engineering, Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513 Waseda-tsurumaki, Shinjuku, Tokyo 162-0041 (Japan); Ushida, Takashi [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-15

    Mechanical strain has been reported to affect the proliferation/differentiation of many cell types; however, the effects of mechanotransduction on self-renewal as well as pluripotency of embryonic stem (ES) cells remains unknown. To investigate the effects of mechanical strain on mouse ES cell fate, we examined the expression of Nanog, which is an essential regulator of self-renewal and pluripotency as well as Nanog-associated intracellular signaling during uniaxial cyclic mechanical strain. The mouse ES cell line, CCE was plated onto elastic membranes, and we applied 10% strain at 0.17 Hz. The expression of Nanog was reduced during ES cell differentiation in response to the withdrawal of leukemia inhibitory factor (LIF); however, two days of cyclic mechanical strain attenuated this reduction of Nanog expression. On the other hand, the cyclic mechanical strain promoted PI3K-Akt signaling, which is reported as an upstream of Nanog transcription. The cyclic mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor wortmannin. Furthermore, cytochalasin D, an inhibitor of actin polymerization, also inhibited the mechanical strain-induced increase in phospho-Akt. These findings imply that mechanical force plays a role in regulating Nanog expression in ES cells through the actin cytoskeleton-PI3K-Akt signaling. -- Highlights: Black-Right-Pointing-Pointer The expression of Nanog, which is an essential regulator of 'stemness' was reduced during embryonic stem (ES) cell differentiation. Black-Right-Pointing-Pointer Cyclic mechanical strain attenuated the reduction of Nanog expression. Black-Right-Pointing-Pointer Cyclic mechanical strain promoted PI3K-Akt signaling and mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor and an inhibitor of actin polymerization.

  7. Cyclic mechanical strain maintains Nanog expression through PI3K/Akt signaling in mouse embryonic stem cells

    International Nuclear Information System (INIS)

    Horiuchi, Rie; Akimoto, Takayuki; Hong, Zhang; Ushida, Takashi

    2012-01-01

    Mechanical strain has been reported to affect the proliferation/differentiation of many cell types; however, the effects of mechanotransduction on self-renewal as well as pluripotency of embryonic stem (ES) cells remains unknown. To investigate the effects of mechanical strain on mouse ES cell fate, we examined the expression of Nanog, which is an essential regulator of self-renewal and pluripotency as well as Nanog-associated intracellular signaling during uniaxial cyclic mechanical strain. The mouse ES cell line, CCE was plated onto elastic membranes, and we applied 10% strain at 0.17 Hz. The expression of Nanog was reduced during ES cell differentiation in response to the withdrawal of leukemia inhibitory factor (LIF); however, two days of cyclic mechanical strain attenuated this reduction of Nanog expression. On the other hand, the cyclic mechanical strain promoted PI3K-Akt signaling, which is reported as an upstream of Nanog transcription. The cyclic mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor wortmannin. Furthermore, cytochalasin D, an inhibitor of actin polymerization, also inhibited the mechanical strain-induced increase in phospho-Akt. These findings imply that mechanical force plays a role in regulating Nanog expression in ES cells through the actin cytoskeleton-PI3K-Akt signaling. -- Highlights: ► The expression of Nanog, which is an essential regulator of “stemness” was reduced during embryonic stem (ES) cell differentiation. ► Cyclic mechanical strain attenuated the reduction of Nanog expression. ► Cyclic mechanical strain promoted PI3K-Akt signaling and mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor and an inhibitor of actin polymerization.

  8. Inhibitors of pan PI3K signaling synergize with BRAF or MEK inhibitors to prevent BRAF-mutant melanoma cell growth

    Directory of Open Access Journals (Sweden)

    Melanie eSweetlove

    2015-06-01

    Full Text Available BRAF and MEK inhibitors have improved outcomes for patients with BRAF-mutant melanoma, but their efficacy is limited by both intrinsic and acquired resistance. Activation of the PI3K pathway can mediate resistance to these agents, providing a strong rationale for combination therapy in melanoma. Here, a panel of 9 low passage human metastatic melanoma cell lines with BRAF mutations were tested in cell proliferation and protein expression assays for sensitivity to inhibitors of MEK (selumetinib and BRAF (vemurafenib as single agents and in combination with inhibitors of pan-PI3K (ZSTK474, pan-PI3K/mTOR (BEZ235, individual PI3K isoforms (p110α, A66; p110β, TGX-221; p110γ, AS-252424; p110δ, idelalisib, or mTORC1/2 (KU-0063794. Selumetinib and vemurafenib potently inhibited cell proliferation in all cell lines, especially in those that expressed low levels of pAKT. ZSTK474 and BEZ235 also inhibited cell proliferation in all cell lines and enhanced the antitumor activity of selumetinib and vemurafenib in the majority of lines by either interacting synergistically or additively to increase potency or by inducing cytotoxicity by significantly increasing the magnitude of cell growth inhibition. Furthermore, ZSTK474 or BEZ235 combined with selumetinib to produce robust inhibition of pERK, pAKT and pS6 expression and synergistic inhibition of NZM20 tumor growth. The inhibitors of individual PI3K isoforms or mTORC1/2 were less effective at inhibiting cell proliferation either as single agents or in combination with selumetinib or vemurafenib, although KU-0063794 synergistically interacted with vemurafenib and increased the magnitude of cell growth inhibition with selumetinib or vemurafenib in certain cell lines. Overall, these results suggest that the sensitivity of BRAF-mutant melanoma cells to BRAF or MEK inhibitors is at least partly mediated by activation of the PI3K pathway and can be enhanced by combined inhibition of the BRAF/MEK and PI3K

  9. Gelidium elegans Extract Ameliorates Type 2 Diabetes via Regulation of MAPK and PI3K/Akt Signaling.

    Science.gov (United States)

    Choi, Jia; Kim, Kui-Jin; Koh, Eun-Jeong; Lee, Boo-Yong

    2018-01-06

    Gelidium elegans , a red alga native to the Asia Pacific region, contains biologically active polyphenols. We conducted a molecular biological study of the anti-diabetic effect of Gelidium elegans extract (GEE) in C57BL/KsJ-db/db mice. Mice that had been administered GEE had significantly lower body mass, water consumption, and fasting blood glucose than db/db controls. Moreover, hemoglobin A1c (HbA1c), an indicator of the glycemic status of people with diabetes, was significantly lower in mice that had been administered GEE. We also found that 200 mg/kg/day GEE upregulates the insulin signaling pathway by activating insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K), and increasing the expression of glucose transporter type 4 (GLUT4). In parallel, mitogen-activated protein kinase (MAPK) activity was lower in GEE-treated groups. In summary, these findings indicate that GEE regulates glucose metabolism by activating the insulin signaling pathway and downregulating the MAPK signaling pathway.

  10. Gelidium elegans Extract Ameliorates Type 2 Diabetes via Regulation of MAPK and PI3K/Akt Signaling

    Directory of Open Access Journals (Sweden)

    Jia Choi

    2018-01-01

    Full Text Available Gelidium elegans, a red alga native to the Asia Pacific region, contains biologically active polyphenols. We conducted a molecular biological study of the anti-diabetic effect of Gelidium elegans extract (GEE in C57BL/KsJ-db/db mice. Mice that had been administered GEE had significantly lower body mass, water consumption, and fasting blood glucose than db/db controls. Moreover, hemoglobin A1c (HbA1c, an indicator of the glycemic status of people with diabetes, was significantly lower in mice that had been administered GEE. We also found that 200 mg/kg/day GEE upregulates the insulin signaling pathway by activating insulin receptor substrate-1 (IRS-1 and phosphoinositide 3-kinase (PI3K, and increasing the expression of glucose transporter type 4 (GLUT4. In parallel, mitogen-activated protein kinase (MAPK activity was lower in GEE-treated groups. In summary, these findings indicate that GEE regulates glucose metabolism by activating the insulin signaling pathway and downregulating the MAPK signaling pathway.

  11. Estrogen increases Nrf2 activity through activation of the PI3K pathway in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Juanjuan, E-mail: jwu32@emory.edu [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Williams, Devin [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Walter, Grant A. [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Thompson, Winston E. [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Sidell, Neil [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States)

    2014-11-01

    The actions of the transcription factor Nuclear factor erythroid 2-related factor (Nrf2) in breast cancer have been shown to include both pro-oncogenic and anti-oncogenic activities which is influenced, at least in part, by the hormonal environment. However, direct regulation of Nrf2 by steroid hormones (estrogen and progesterone) has received only scant attention. Nrf2 is known to be regulated by its cytosolic binding protein, Kelch-like ECH-associated protein 1 (Keap1), and by a Keap1-independent mechanism involving a series of phosphorylation steps mediated by phosphatidylinositol 3-kinase (PI3K) and glycogen synthase kinase 3 beta (GSK3β). Here, we report that estrogen (E2) increases Nrf2 activity in MCF7 breast cancer cells through activation of the PI3K/GSK3β pathway. Utilizing antioxidant response element (ARE)-containing luciferase reporter constructs as read-outs for Nrf2 activity, our data indicated that E2 increased ARE activity >14-fold and enhanced the action of the Nrf2 activators, tertiary butylhydroquinone (tBHQ) and sulforaphane (Sul) 4 to 9 fold compared with cells treated with tBHQ or Sul as single agents. This activity was shown to be an estrogen receptor-mediated phenomenon and was antagonized by progesterone. In addition to its action on the reporter constructs, mRNA and protein levels of heme oxygenase 1, an endogenous target gene of Nrf2, was markedly upregulated by E2 both alone and in combination with tBHQ. Importantly, E2-induced Nrf2 activation was completely suppressed by the PI3K inhibitors LY294002 and Wortmannin while the GSK3β inhibitor CT99021 upregulated Nrf2 activity. Confirmation that E2 was, at least partly, acting through the PI3K/GSK3β pathway was indicated by our finding that E2 increased the phosphorylation status of both GSK3β and Akt, a well-characterized downstream target of PI3K. Together, these results demonstrate a novel mechanism by which E2 can regulate Nrf2 activity in estrogen receptor-positive breast cancer

  12. PDGF stimulation of Mueller cell proliferation: Contributions of c-JNK and the PI3K/Akt pathway

    International Nuclear Information System (INIS)

    Moon, Sang Woong; Chung, Eun Jee; Jung, Sun-Ah; Lee, Joon H.

    2009-01-01

    Platelet-derived growth factor (PDGF) has a critical role in proliferative vitreoretinopathy (PVR) as a chemoattractant and mitogen for retinal pigment epithelial cells and retinal glial cells. Here, we investigated the potential effects of PDGF on the proliferation of Mueller cells and the intracellular signaling pathway mediating these changes. PDGF induced Mueller cell proliferation and increased phosphorylation of the PDGF receptor (PDGFR), as shown by an MTT assay and immunoprecipitation analyses. Both effects were blocked by JNJ, a PDGFR-selective tyrosine kinase inhibitor. PDGF also stimulated phosphorylation of c-JNK and Akt. PDGF-induced Mueller cell proliferation was significantly reduced by pre-treatment with SP600125 and LY294002, inhibitors of c-JNK and Akt phosphorylation, respectively. Our findings collectively indicate that PDGF-stimulated Mueller cell proliferation occurs via activation of the c-JNK and PI3K/Akt signaling pathways. These data provide useful information in establishing the role of Mueller cells in the development of proliferative vitreoretinopathy.

  13. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons

    Science.gov (United States)

    Shi, Xuemei; Zhou, Fuguo; Li, Xiaojie; Chang, Benny; Li, Depei; Wang, Yi; Tong, Qingchun; Xu, Yong; Fukuda, Makoto; Zhao, Jean J.; Li, Defa; Burrin, Douglas G.; Chan, Lawrence; Guan, Xinfu

    2013-01-01

    Glucagon-like peptides (GLP-1/2) are co-produced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We show that mice lacking GLP-2 receptor (GLP-2R) in POMC neurons display glucose intolerance and hepatic insulin resistance. GLP-2R activation in POMC neurons is required for GLP-2 to enhance insulin-mediated suppression of hepatic glucose production (HGP) and gluconeogenesis. GLP-2 directly modulates excitability of POMC neurons in GLP-2R- and PI3K-dependent manners. GLP-2 initiates GLP-2R-p85α interaction and facilitates PI3K-Akt-dependent FoxO1 nuclear exclusion in POMC neurons. Central GLP-2 suppresses basal HGP and enhances insulin sensitivity, which are abolished in POMC-p110α KO mice. Thus, CNS GLP-2 plays a key physiological role in the control of hepatic glucose production through activating PI3K-dependent modulation of membrane excitability and nuclear transcription of POMC neurons in the brain. PMID:23823479

  14. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons.

    Science.gov (United States)

    Shi, Xuemei; Zhou, Fuguo; Li, Xiaojie; Chang, Benny; Li, Depei; Wang, Yi; Tong, Qingchun; Xu, Yong; Fukuda, Makoto; Zhao, Jean J; Li, Defa; Burrin, Douglas G; Chan, Lawrence; Guan, Xinfu

    2013-07-02

    Glucagon-like peptides (GLP-1/GLP-2) are coproduced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We show that mice lacking GLP-2 receptor (GLP-2R) in POMC neurons display glucose intolerance and hepatic insulin resistance. GLP-2R activation in POMC neurons is required for GLP-2 to enhance insulin-mediated suppression of hepatic glucose production (HGP) and gluconeogenesis. GLP-2 directly modulates excitability of POMC neurons in GLP-2R- and PI3K-dependent manners. GLP-2 initiates GLP-2R-p85α interaction and facilitates PI3K-Akt-dependent FoxO1 nuclear exclusion in POMC neurons. Central GLP-2 suppresses basal HGP and enhances insulin sensitivity, which are abolished in POMC-p110α KO mice. Thus, CNS GLP-2 plays a key physiological role in the control of HGP through activating PI3K-dependent modulation of membrane excitability and nuclear transcription of POMC neurons in the brain. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Placental growth factor enhances angiogenesis in human intestinal microvascular endothelial cells via PI3K/Akt pathway: Potential implications of inflammation bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yi, E-mail: mondayzy@126.com; Tu, Chuantao, E-mail: tu.chuantao@zs-hospital.sh.cn; Zhao, Yuan, E-mail: zhao.yuan@zs-hospital.sh.cn; Liu, Hongchun, E-mail: liuhch@aliyun.com; Zhang, Shuncai, E-mail: zhang.shuncai@zs-hospital.sh.cn

    2016-02-19

    Background: Angiogenesis plays a major role in the pathogenesis of inflammatory bowel disease (IBD). Placental growth factor (PlGF) is a specific regulator of pathological angiogenesis and is upregulated in the sera of IBD patients. Therefore, the role of PlGF in IBD angiogenesis was investigated here using HIMECs. Methods: The expression of PlGF and its receptors in human intestinal microvascular endothelial cells (HIMECs) and inflamed mucosa of IBD patients were examined using quantitative PCR and western blot analysis and the role of PlGF in IBD HIMECs was further explored using small interfering RNA (siRNA). The induction of pro-inflammatory cytokine by PlGF in HIMECs was confirmed by ELISA. The capacity of PlGF to induce angiogenesis in HIMECs was tested through proliferation, cell-migration, matrigel tubule-formation assays and its underlying signaling pathway were explored by western blot analysis of ERK1/2 and PI3K/Akt phosphorylation. Results: mRNA and protein expression of PlGF and its receptor NRP-1 were significantly increased in IBD HIMECs. Inflamed mucosa of IBD patients also displayed higher expression of PIGF. The production of IL-6 and TNF-α in culture supernatant of HIMECs treated with exogenous recombinant human PlGF-1 (rhPlGF-1) were increased. Furthermore, rhPlGF-1 significantly induced HIMECs migration and tube formation in a dose-dependent manner and knockdown of endogenous PlGF in IBD HIMECs using siRNA substantially reduced these angiogenesis activities. PlGF induced PI3K/Akt phosphorylation in HIMECs and pretreatment of PlGF-stimulated HIMECs with PI3K inhibitor (LY294002) significantly inhibited the PlGF-induced cell migration and tube formation. Conclusion: Our results demonstrated the pro-inflammatory and angiogenic effects of PlGF on HIMECs in IBD through activation of PI3K/Akt signaling pathway. PlGF/PI3K/Akt signaling may serve as a potential therapeutic target for IBD. - Highlights: • Expression of PlGF and its receptor NRP-1

  16. Triiodothyronine increases mRNA and protein leptin levels in short time in 3T3-L1 adipocytes by PI3K pathway activation.

    Directory of Open Access Journals (Sweden)

    Miriane de Oliveira

    Full Text Available The present study aimed to examine the effects of thyroid hormone (TH, more precisely triiodothyronine (T3, on the modulation of leptin mRNA expression and the involvement of the phosphatidyl inositol 3 kinase (PI3K signaling pathway in adipocytes, 3T3-L1, cell culture. We examined the involvement of this pathway in mediating TH effects by treating 3T3-L1 adipocytes with physiological (P=10nM or supraphysiological (SI=100 nM T3 dose during one hour (short time, in the absence or the presence of PI3K inhibitor (LY294002. The absence of any treatment was considered the control group (C. RT-qPCR was used for mRNA expression analyzes. For data analyzes ANOVA complemented with Tukey's test was used at 5% significance. T3 increased leptin mRNA expression in P (2.26 ± 0.36, p 0.001. These results demonstrate that the activation of the PI3K signaling pathway has a role in TH-mediated direct and indirect leptin gene expression in 3T3-L1 adipocytes.

  17. PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

    Science.gov (United States)

    Gasparri, Maria Luisa; Bardhi, Erlisa; Ruscito, Ilary; Papadia, Andrea; Farooqi, Ammad Ahmad; Marchetti, Claudia; Bogani, Giorgio; Ceccacci, Irene; Mueller, Michael D; Benedetti Panici, Pierluigi

    2017-10-01

    The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

  18. Frequent alterations of the PI3K/AKT/mTOR pathways in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Ekstrand, Anna Isinger; Jönsson, Mats; Lindblom, Annika

    2010-01-01

    The phosphatidylinositol 3-kinases-AKT-mammalian target of rapamycin pathway (PI3K/AKT/mTOR) is central in colorectal tumors. Data on its role in hereditary cancers are, however, scarce and we therefore characterized mutations in PIK3CA and KRAS, and expression of PIK3CA, phosphorylated AKT......, and PTEN in colorectal cancers linked to hereditary nonpolyposis colorectal cancer (HNPCC). Sequencing was used to identify mutations in PIK3CA, a real-time PCR-based method to identify KRAS mutations, and immunohistochemical staining was used to evaluate the expression of PIK3CA, phosphorylated AKT...... and PTEN in 58 HNPCC-associated colorectal cancers. Derangements of at least one of the PI3K/AKT/mTOR components analyzed were found in 51/58 (88%) tumors. Mutations in PIK3CA and KRAS were identified in 14 and 31% of the tumors respectively. Overexpression of PIK3CA and phosphorylated AKT occurred in 59...

  19. A natural diarylheptanoid promotes neuronal differentiation via activating ERK and PI3K-Akt dependent pathways.

    Science.gov (United States)

    Tang, G; Dong, X; Huang, X; Huang, X-J; Liu, H; Wang, Y; Ye, W-C; Shi, L

    2015-09-10

    Neuronal differentiation is a critical developmental process that determines accurate synaptic connection and circuit wiring. A wide variety of naturally occurring compounds have been shown as promising drug leads for the generation and differentiation of neurons. Here we report that a diarylheptanoid from the plant Alpinia officinarum, 7-(4-hydroxyphenyl)-1-phenyl-4E-hepten-3-one (Cpd 1), exhibited potent activities in neuronal differentiation and neurite outgrowth. Cpd 1 induced differentiation of neuroblastoma Neuro-2a cells into a neuron-like morphology, and accelerated the establishment of axon-dendrite polarization of cultured hippocampal neurons. Moreover, Cpd 1 promoted neurite extension in both Neuro-2a cells and neurons. We showed that the effects of Cpd 1 on neuronal differentiation and neurite growth were specifically dependent on the activation of extracellular signal-regulated kinases (ERKs) and phosphoinositide 3-kinase (PI3K)-Akt signaling pathways. Importantly, intraperitoneal administration of Cpd 1 promoted the differentiation of new-born progenitor cells into mature neurons in the adult hippocampal dentate gyrus. Collectively, this study identifies a naturally occurring diarylheptanoid with beneficial effects on neuronal differentiation and neurite outgrowth in vitro and in vivo. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Andrographolide reduces proliferation and migration of lens epithelial cells by modulating PI3K/Akt pathway.

    Science.gov (United States)

    Kayastha, Forum; Madhu, Hardik; Vasavada, Abhay; Johar, Kaid

    2014-11-01

    Lens epithelial cell proliferation, migration, and transdifferentiation are involved in the development of subcapsular cataracts and postoperative capsular opacification (PCO). PI3K/Akt pathway is involved in the proliferation and migration of lens epithelial cells. Andrographolide is the main bioactive component of Andrographis paniculata and is known to possess anti-proliferative and anti-migratory activities. The purpose of this study is to evaluate the effect of andrographolide on proliferation and migration induced by growth factors (TGF-β and bFGF) in the lens epithelial cell line, FHL 124. We have also evaluated the role of the PI3K/Akt pathway and its alteration by andrographolide during proliferation and migration of lens epithelial cells. The results showed that andrographolide significantly inhibited proliferation in a dose and time dependent manner. The growth factors, TGF-β and bFGF, induced migration of lens epithelial cells, which was lowered by andrographolide. The growth factors also up regulated phosphorylated Akt (Ser473) and Akt (Thr308), which was abolished by simultaneous treatment of andrographolide. Similar changes were also observed with the PI3K inhibitor, LY290042. Our findings suggest that andrographolide reduces proliferation, migration, and phosphorylated Akt levels in lens epithelial cells. Hence andrographolide can be utilized for the prevention of PCO. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Frequent alterations of the PI3K/AKT/mTOR pathways in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Ekstrand, Anna Isinger; Jönsson, Mats; Lindblom, Annika

    2010-01-01

    The phosphatidylinositol 3-kinases-AKT-mammalian target of rapamycin pathway (PI3K/AKT/mTOR) is central in colorectal tumors. Data on its role in hereditary cancers are, however, scarce and we therefore characterized mutations in PIK3CA and KRAS, and expression of PIK3CA, phosphorylated AKT...... and PTEN in 58 HNPCC-associated colorectal cancers. Derangements of at least one of the PI3K/AKT/mTOR components analyzed were found in 51/58 (88%) tumors. Mutations in PIK3CA and KRAS were identified in 14 and 31% of the tumors respectively. Overexpression of PIK3CA and phosphorylated AKT occurred in 59...... and 75% and were strongly associated (P = 0.005). Reduced/lost PTEN expression was found in 63% of the tumors. Though HNPCC-associated colorectal cancers show simple genetic profiles with few chromosomal alterations, we demonstrate frequent and repeated targeting of the PI3K/AKT/mTOR pathway, which...

  2. Nontranscriptional activation of PI3K/Akt signaling mediates hypotensive effect following activation of estrogen receptor β in the rostral ventrolateral medulla of rats

    Directory of Open Access Journals (Sweden)

    Wu Kay LH

    2012-08-01

    Full Text Available Abstract Background Estrogen acts on the rostral ventrolateral medulla (RVLM, where sympathetic premotor neurons are located, to elicit vasodepressor effects via an estrogen receptor (ERβ-dependent mechanism. We investigated in the present study nontranscriptional mechanism on cardiovascular effects following activation of ERβ in the RVLM, and delineated the involvement of phosphatidylinositol 3-kinase (PI3K/serine/threonine kinase (Akt signaling pathway in the effects. Methods In male Sprague–Dawley rats maintained under propofol anesthesia, changes in arterial pressure, heart rate and sympathetic neurogenic vasomotor tone were examined after microinjection bilaterally into RVLM of 17β-estradiol (E2β or a selective ERα or ERβ agonist. Involvement of ER subtypes and PI3K/Akt signaling pathway in the induced cardiovascular effects were studied using pharmacological tools of antagonists or inhibitors, gene manipulation with antisense oligonucleotide (ASON or adenovirus-mediated gene transfection. Results Similar to E2β (1 pmol, microinjection of ERβ agonist, diarylpropionitrile (DPN, 1, 2 or 5 pmol, into bilateral RVLM evoked dose-dependent hypotension and reduction in sympathetic neurogenic vasomotor tone. These vasodepressive effects of DPN (2 pmol were inhibited by ERβ antagonist, R,R-tetrahydrochrysene (50 pmol, ASON against ERβ mRNA (250 pmol, PI3K inhibitor LY294002 (5 pmol, or Akt inhibitor (250 pmol, but not by ERα inhibitor, methyl-piperidino-pyrazole (1 nmol, or transcription inhibitor, actinomycin D (5 or 10 nmol. Gene transfer by microinjection into bilateral RVLM of adenovirus encoding phosphatase and tensin homologues deleted on chromosome 10 (5 × 108 pfu reversed the vasodepressive effects of DPN. Conclusions Our results indicate that vasodepressive effects following activation of ERβ in RVLM are mediated by nongenomic activation of PI3K/Akt signaling pathway. This study provides new insight in the

  3. The role of sodium hydrosulfide in attenuating the aging process via PI3K/AKT and CaMKKβ/AMPK pathways

    Directory of Open Access Journals (Sweden)

    Xubo Chen

    2017-08-01

    Full Text Available Age-related dysfunction of the central auditory system, known as central presbycusis, is characterized by defects in speech perception and sound localization. It is important to determine the pathogenesis of central presbycusis in order to explore a feasible and effective intervention method. Recent work has provided fascinating insight into the beneficial function of H2S on oxidative stress and stress-related disease. In this study, we investigated the pathogenesis of central presbycusis and tried to explore the mechanism of H2S action on different aspects of aging by utilizing a mimetic aging rat and senescent cellular model. Our results indicate that NaHS decreased oxidative stress and apoptosis levels in an aging model via CaMKKβ and PI3K/AKT signaling pathways. Moreover, we found that NaHS restored the decreased activity of antioxidants such as GSH, SOD and CAT in the aging model in vivo and in vitro by regulating CaMKKβ and PI3K/AKT. Mitochondria function was preserved by NaHS, as indicated by the following: DNA POLG and OGG-1, the base excision repair enzymes in mitochondrial, were upregulated; OXPHOS activity was downregulated; mitochondrial membrane potential was restored; ATP production was increased; and mtDNA damage, indicated by the common deletion (CD, declined. These effects were also achieved by activating CaMKKβ/AMPK and PI3K/AKT signaling pathways. Lastly, protein homeostasis, indicated by HSP90 alpha, was strengthened by NaHS via CaMKKβ and PI3K/AKT. Our findings demonstrate that the ability to resist oxidative stress and mitochondria function are both decreased as aging developed; however, NaHS, a novel free radical scavenger and mitochondrial protective agent, precludes the process of oxidative damage by activating CaMKKβ and PI3K/AKT. This study might provide a therapeutic target for aging and age-related disease. Keywords: Aging, Hydrogen sulfide, ROS, Mitochondria, PI3K/AKT, CaMKKβ/AMPK

  4. Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weijie, E-mail: 459586768@qq.com; Liu, Yuxi, E-mail: 924013616@qq.com; Wang, Youhua, E-mail: wyouhua1516@163.com

    2016-05-13

    Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwann cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.

  5. Downregulation of PI3-K/Akt/PTEN pathway and activation of mitochondrial intrinsic apoptosis by Diclofenac and Curcumin in colon cancer.

    Science.gov (United States)

    Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

    2015-04-01

    Phosphatidylinositol 3-kinase (PI3-K)/PTEN/Akt signaling is over activated in various tumors including colon cancer. Activation of this pathway regulates multiple biological processes such as apoptosis, metabolism, cell proliferation, and cell growth that underlie the biology of a cancer cell. In the present study, the chemopreventive effects have been observed of Diclofenac, a preferential COX-2 inhibitory non-steroidal anti-inflammatory drugs, and Curcumin, a natural anti-inflammatory agent, in the early stage of colorectal carcinogenesis induced by 1,2-dimethylhydrazine dihydrochloride in rats. The tumor-promoting role of PI3-K/Akt/PTEN signal transduction pathway and its association with anti-apoptotic family of proteins are also observed. Both Diclofenac and Curcumin downregulated the PI3-K and Akt expression while promoting the apoptotic mechanism. Diclofenac and Curcumin administration significantly increased the expression of pro-apoptotic Bcl-2 family members (Bad and Bax) while decreasing the anti-apoptotic Bcl-2 protein. An up-regulation of cysteine protease family apoptosis executioner, such as caspase-3 and -9, is seen. Diclofenac and Curcumin inhibited the Bcl-2 protein by directly interacting at the active site by multiple hydrogen bonding, as also evident by negative glide score of Bcl-2. These drugs stimulated apoptosis by increasing reactive oxygen species (ROS) generation and simultaneously decreasing the mitochondrial membrane potential (ΔΨ M). Diclofenac and Curcumin showed anti-neoplastic effects by downregulating PI3-K/Akt/PTEN pathway, inducing apoptosis, increasing ROS generation, and decreasing ΔΨ M. The anti-neoplastic and apoptotic effects were found enhanced when both Diclofenac and Curcumin were administered together, rather than individually.

  6. Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

    International Nuclear Information System (INIS)

    Wu, Weijie; Liu, Yuxi; Wang, Youhua

    2016-01-01

    Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwann cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.

  7. Metastatic function of BMP-2 in gastric cancer cells: The role of PI3K/AKT, MAPK, the NF-{kappa}B pathway, and MMP-9 expression

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Myoung Hee [Graduate School of Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Oh, Sang Cheul [Division of Oncology/Hematology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Hyun Joo [Department of Pathology, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kang, Han Na; Kim, Jung Lim [Graduate School of Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kim, Jun Suk [Division of Oncology/Hematology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Yoo, Young A., E-mail: ydanbi@korea.ac.kr [Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of)

    2011-07-15

    Bone morphogenetic proteins (BMPs) have been implicated in tumorigenesis and metastatic progression in various types of cancer cells, but the role and cellular mechanism in the invasive phenotype of gastric cancer cells is not known. Herein, we determined the roles of phosphoinositide 3-kinase (PI3K)/AKT, extracellular signal-regulated protein kinase (ERK), nuclear factor (NF)-{kappa}B, and matrix metalloproteinase (MMP) expression in BMP-2-mediated metastatic function in gastric cancer. We found that stimulation of BMP-2 in gastric cancer cells enhanced the phosphorylation of AKT and ERK. Accompanying activation of AKT and ERK kinase, BMP-2 also enhanced phosphorylation/degradation of I{kappa}B{alpha} and the nuclear translocation/activation of NF-{kappa}B. Interestingly, blockade of PI3K/AKT and ERK signaling using LY294002 and PD98059, respectively, significantly inhibited BMP-2-induced motility and invasiveness in association with the activation of NF-{kappa}B. Furthermore, BMP-2-induced MMP-9 expression and enzymatic activity was also significantly blocked by treatment with PI3K/AKT, ERK, or NF-{kappa}B inhibitors. Immunohistochemistry staining of 178 gastric tumor biopsies indicated that expression of BMP-2 and MMP-9 had a significant positive correlation with lymph node metastasis and a poor prognosis. These results indicate that the BMP-2 signaling pathway enhances tumor metastasis in gastric cancer by sequential activation of the PI3K/AKT or MAPK pathway followed by the induction of NF-{kappa}B and MMP-9 activity, indicating that BMP-2 has the potential to be a therapeutic molecular target to decrease metastasis.

  8. VEGF attenuated increase of outward delayed-rectifier potassium currents in hippocampal neurons induced by focal ischemia via PI3-K pathway.

    Science.gov (United States)

    Wu, K W; Yang, P; Li, S S; Liu, C W; Sun, F Y

    2015-07-09

    We recently indicated that the vascular endothelial growth factor (VEGF) protects neurons against hypoxic death via enhancement of tyrosine phosphorylation of Kv1.2, an isoform of the delayed-rectifier potassium channels through activation of the phosphatidylinositol 3-kinase (PI3-K) signaling pathway. The present study investigated whether VEGF could attenuate ischemia-induced increase of the potassium currents in the hippocampal pyramidal neurons of rats after ischemic injury. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) to induce brain ischemia. The whole-cell patch-clamp technique was used to record the potassium currents of hippocampal neurons in brain slices from the ischemically injured brains of the rats 24h after MCAO. We detected that transient MCAO caused a significant increase of voltage-gated potassium currents (Kv) and outward delayed-rectifier potassium currents (IK), but not outward transient potassium currents (IA), in the ipsilateral hippocampus compared with the sham. Moreover, we found that VEGF could acutely, reversibly and voltage-dependently inhibit the ischemia-induced IK increase. This inhibitory effect of VEGF could be completely abolished by wortmannin, an inhibitor of PI3-K. Our data indicate that VEGF attenuates the ischemia-induced increase of IK via activation of the PI3-K signaling pathway. Published by Elsevier Ltd.

  9. Effects of Ursodeoxycholic Acid and Insulin on Palmitate-Induced ROS Production and Down-Regulation of PI3K/Akt Signaling Activity.

    Science.gov (United States)

    Yokoyama, Kunihiro; Tatsumi, Yasuaki; Hayashi, Kazuhiko; Goto, Hidemi; Ishikawa, Tetsuya; Wakusawa, Shinya

    2017-01-01

    In obese and diabetic patients, plasma free fatty acid (FFA) levels are often elevated and may play a causal role in insulin resistance and reactive oxygen species (ROS) production. We have previously shown that ursodeoxycholic acid (UDCA) has antioxidative activity through the phosphatidylinositol 3-kinase (PI3K)/Akt signaling-mediated glutathione production. In this study, we investigated the effects of UDCA on insulin response by analyzing intracellular ROS and the activation of the PI3K/Akt signaling pathway in HepG2 cells treated with palmitate. The level of ROS was quantified using 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA), and the activation of the PI3K/Akt signaling pathway was determined by Western blotting assay using appropriate antibodies. The intracellular ROS levels were increased by palmitate but were reduced by treatment with UDCA and insulin. Furthermore, insulin significantly stimulated the phosphorylation of Akt. When the cells were pre-treated with palmitate, insulin-induced Akt-phosphorylation was markedly inhibited. However, when the cells were treated with palmitate and UDCA, the effects of insulin were partially restored. UDCA may have protective effects against palmitate-induced decreases in responsiveness to insulin.

  10. Initiation factor eIF2B not p70 S6 kinase is involved in the activation of the PI-3K signalling pathway induced by the v=src oncogene

    Czech Academy of Sciences Publication Activity Database

    Vojtěchová, Martina; Šloncová, Eva; Kučerová, Dana; Jiřička, Jaroslav; Sovová, Vlasta; Tuháčková, Zdena

    2003-01-01

    Roč. 543, 1-3 (2003), s. 81-86 ISSN 0014-5793 R&D Projects: GA ČR GV312/96/K205; GA ČR GA301/00/0269; GA MZd NC5428 Institutional research plan: CEZ:AV0Z5052915 Keywords : phosphoinositide 3-kinase signalling pathway * mRNA translation * 70 kDa ribosomal protein S6 kinase Subject RIV: CE - Biochemistry Impact factor: 3.609, year: 2003

  11. Thimerosal-induced apoptosis in mouse C2C12 myoblast cells occurs through suppression of the PI3K/Akt/survivin pathway.

    Directory of Open Access Journals (Sweden)

    Wen-Xue Li

    Full Text Available BACKGROUND: Thimerosal, a mercury-containing preservative, is one of the most widely used preservatives and found in a variety of biological products. Concerns over its possible toxicity have reemerged recently due to its use in vaccines. Thimerosal has also been reported to be markedly cytotoxic to neural tissue. However, little is known regarding thimerosal-induced toxicity in muscle tissue. Therefore, we investigated the cytotoxic effect of thimerosal and its possible mechanisms on mouse C2C12 myoblast cells. METHODOLOGY/PRINCIPAL FINDINGS: The study showed that C2C12 myoblast cells underwent inhibition of proliferation and apoptosis after exposure to thimerosal (125-500 nM for 24, 48 and 72 h. Thimerosal caused S phase arrest and induced apoptosis as assessed by flow cytometric analysis, Hoechst staining and immunoblotting. The data revealed that thimerosal could trigger the leakage of cytochrome c from mitochondria, followed by cleavage of caspase-9 and caspase-3, and that an inhibitor of caspase could suppress thimerosal-induced apoptosis. Thimerosal inhibited the phosphorylation of Akt(ser473 and survivin expression. Wortmannin, a PI3K inhibitor, inhibited Akt activity and decreased survivin expression, resulting in increased thimerosal-induced apoptosis in C2C12 cells, while the activation of PI3K/Akt pathway by mIGF-I (50 ng/ml increased the expression of survivin and attenuated apoptosis. Furthermore, the inhibition of survivin expression by siRNA enhanced thimerosal-induced cell apoptosis, while overexpression of survivin prevented thimerosal-induced apoptosis. Taken together, the data show that the PI3K/Akt/survivin pathway plays an important role in the thimerosal-induced apoptosis in C2C12 cells. CONCLUSIONS/SIGNIFICANCE: Our results suggest that in C2C12 myoblast cells, thimerosal induces S phase arrest and finally causes apoptosis via inhibition of PI3K/Akt/survivin signaling followed by activation of the mitochondrial apoptotic

  12. IGF-1 protects SH-SY5Y cells against MPP+-induced apoptosis via PI3K/PDK-1/Akt pathway.

    Science.gov (United States)

    Kim, Chanyang; Park, Seungjoon

    2018-03-01

    Insulin-like growth factor (IGF)-1 is a well-known anti-apoptotic pro-survival factor and phosphatidylinositol-3-kinase (PI3K)/Akt pathway is linked to cell survival induced by IGF-1. It is also reported that Akt signaling is modulated by 3-phosphoinositide-dependent kinase-1 (PDK1). In the current study, we investigated whether the anti-apoptotic effect of IGF-1 in SH-SY5Y cells exposed to 1-methyl-4-phenylpyridinium (MPP + ) is associated with the activity of PI3K/PDK1/Akt pathway. Treatment of cells with IGF-1 inhibited MPP + -induced apoptotic cell death. IGF-1-induced activation of Akt and the protective effect of IGF-1 on MPP + -induced apoptosis were abolished by chemical inhibition of PDK1 (GSK2334470) or PI3K (LY294002). The phosphorylated levels of Akt and PDK1 were significantly suppressed after MPP + exposure, while IGF-1 treatment completely restored MPP+-induced reductions in phosphorylation. IGF-1 protected cells from MPP + insult by suppressing intracellular reactive oxygen species (ROS) production and malondialdehyde levels and increasing superoxide dismutase activity. Mitochondrial ROS levels were also increased during MPP + exposure, which were attenuated by IGF-1 treatment. In addition, IGF-1-treated cells showed increased activities of succinate dehydrogenase and citrate synthase, stabilization of mitochondrial transmembrane potential, increased ratio of Bcl-2 to Bax, prevention of cytochrome c release and inhibition of caspase-3 activation with PARP cleavage. Furthermore, the protective effects of IGF-1 on oxidative stress and mitochondrial dysfunction were attenuated when cells were preincubated with GSK2334470 or LY294002. Our data suggest that IGF-1 protects SH-SY5Y cells against MPP + -associated oxidative stress by preserving mitochondrial integrity and inhibiting mitochondrial apoptotic cascades via the activation of PI3K/PDK1/Akt pathway. © 2018 The authors.

  13. Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

    International Nuclear Information System (INIS)

    He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang; Zhang, Shu-Jie; Irwin, Michael G.; Wong, Tak-Ming; Zhang, Ye

    2015-01-01

    Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

  14. Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

    Energy Technology Data Exchange (ETDEWEB)

    He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Zhang, Shu-Jie [Department of Ultrasound, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Irwin, Michael G.; Wong, Tak-Ming [Department of Anesthesiology, University of Hong Kong (Hong Kong); Zhang, Ye, E-mail: zhangye_hassan@aliyun.com [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China)

    2015-11-01

    Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

  15. PI3K/Akt/GSK3β induced CREB activation ameliorates arsenic mediated alterations in NMDA receptors and associated signaling in rat hippocampus: Neuroprotective role of curcumin.

    Science.gov (United States)

    Srivastava, Pranay; Dhuriya, Yogesh K; Kumar, Vivek; Srivastava, Akriti; Gupta, Richa; Shukla, Rajendra K; Yadav, Rajesh S; Dwivedi, Hari N; Pant, Aditya B; Khanna, Vinay K

    2018-04-30

    Protective efficacy of curcumin in arsenic induced NMDA receptor dysfunctions and PI3K/Akt/ GSK3β signalling in hippocampus has been investigated in vivo and in vitro. Exposure to sodium arsenite (in vivo - 20 mg/kg, body weight p.o. for 28 days; in vitro - 10 μM for 24 h) and curcumin (in vivo - 100 mg/kg body weight p.o. for 28 days; in vitro - 20 μM for 24 h) was carried out alone or simultaneously. Treatment with curcumin ameliorated sodium arsenite induced alterations in the levels of NMDA receptors, its receptor subunits and synaptic proteins - pCaMKIIα, PSD-95 and SynGAP both in vivo and in vitro. Decreased levels of BDNF, pAkt, pERK1/2, pGSK3β and pCREB on sodium arsenite exposure were also protected by curcumin. Curcumin was found to decrease sodium arsenite induced changes in hippocampus by modulating PI3K/Akt/GSK3β neuronal survival pathway, known to regulate various cellular events. Treatment of hippocampal cultures with pharmacological inhibitors for ERK1/2, GSK3β and Akt individually inhibited levels of CREB and proteins associated with PI3K/Akt/GSK3β pathway. Simultaneous treatment with curcumin was found to improve sodium arsenite induced learning and memory deficits in rats assessed by water maze and Y-maze. The results provide evidence that curcumin exercises its neuroprotective effect involving PI3K/Akt pathway which may affect NMDA receptors and downstream signalling through TrKβ and BDNF in arsenic induced cognitive deficits in hippocampus. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Differential Effects of Phosphatidylinositol 4-Kinase (PI4K and 3-Kinase (PI3K Inhibitors on Stomatal Responses to Environmental Signals

    Directory of Open Access Journals (Sweden)

    Koh Iba

    2017-05-01

    Full Text Available Specific cellular components including products of phosphatidylinositol (PI metabolism play an important role as signaling molecules in stomatal responses to environmental signals. In this study, pharmacological inhibitors of a set of cellular components, including PI4-kinase (PI4K and PI3K, were used to investigate stomatal closure in response to CO2, darkness, and abscisic acid (ABA. Treatment with PAO, a specific inhibitor of PI4K, specifically inhibited the stomatal response to CO2 compared with that to darkness and ABA. In contrast, treatment with LY294002, a PI3K-specific inhibitor, specifically inhibited the stomatal response to darkness compared with that to CO2 and ABA. The specific inhibitory effects of PAO and LY294002 were also observed as changes in the spatial density of dot-like structures labeled by green fluorescent protein-tagged PATROL1, a protein that controls stomatal aperture possibly via regulation of H+-ATPase amount in guard cell plasma membranes. Our results suggest an important role for PI4K and PI3K in the CO2 and darkness signal transduction pathways, respectively, that mediate PATROL1 dynamics.

  17. Dual PI3K/mTOR inhibitor BEZ235 as a promising therapeutic strategy against paclitaxel-resistant gastric cancer via targeting PI3K/Akt/mTOR pathway.

    Science.gov (United States)

    Chen, Dongshao; Lin, Xiaoting; Zhang, Cheng; Liu, Zhentao; Chen, Zuhua; Li, Zhongwu; Wang, Jingyuan; Li, Beifang; Hu, Yanting; Dong, Bin; Shen, Lin; Ji, Jiafu; Gao, Jing; Zhang, Xiaotian

    2018-01-26

    Paclitaxel (PTX) is widely used in the front-line chemotherapy for gastric cancer (GC), but resistance limits its use. Due to the lack of proper models, mechanisms underlying PTX resistance in GC were not well studied. Using established PTX-resistant GC cell sublines HGC-27R, we for the first time integrated biological traits and molecular mechanisms of PTX resistance in GC. Data revealed that PTX-resistant GC cells were characterized by microtubular disorders, an EMT phenotype, reduced responses to antimitotic drugs, and resistance to apoptosis (marked by upregulated β-tubulin III, vimentin, attenuated changes in G 2 /M molecules or pro-apoptotic factors in response to antimitotic drugs or apoptotic inducers, respectively). Activation of the phosphoinositide 3-kinase, the serine/threonine kinase Akt and mammalian target of rapamycin (PI3K/Akt/mTOR) and mitogen-activated protein kinase (MAPK) pathways were also observed, which might be the reason for above phenotypic alternations. In vitro data suggested that targeting these pathways were sufficient to elicit antitumor responses in PTX-resistant GC, in which the dual PI3K/mTOR inhibitor BEZ235 displayed higher therapeutic efficiency than the mTOR inhibitor everolimus or the MEK inhibitor AZD6244. Antitumor effects of BEZ235 were also confirmed in mice bearing HGC-27R tumors. Thus, these data suggest that PI3K/Akt/mTOR and MAPK pathway inhibition, especially PI3K/mTOR dual blockade, might be a promising therapeutic strategy against PTX-resistant GC.

  18. The naturally processed CD95L elicits a c-yes/calcium/PI3K-driven cell migration pathway.

    Directory of Open Access Journals (Sweden)

    Sébastien Tauzin

    2011-06-01

    Full Text Available Patients affected by chronic inflammatory disorders display high amounts of soluble CD95L. This homotrimeric ligand arises from the cleavage by metalloproteases of its membrane-bound counterpart, a strong apoptotic inducer. In contrast, the naturally processed CD95L is viewed as an apoptotic antagonist competing with its membrane counterpart for binding to CD95. Recent reports pinpointed that activation of CD95 may attract myeloid and tumoral cells, which display resistance to the CD95-mediated apoptotic signal. However, all these studies were performed using chimeric CD95Ls (oligomerized forms, which behave as the membrane-bound ligand and not as the naturally processed CD95L. Herein, we examine the biological effects of the metalloprotease-cleaved CD95L on CD95-sensitive activated T-lymphocytes. We demonstrate that cleaved CD95L (cl-CD95L, found increased in sera of systemic lupus erythematosus (SLE patients as compared to that of healthy individuals, promotes the formation of migrating pseudopods at the leading edge of which the death receptor CD95 is capped (confocal microscopy. Using different migration assays (wound healing/Boyden Chamber/endothelial transmigration, we uncover that cl-CD95L promotes cell migration through a c-yes/Ca²⁺/PI3K-driven signaling pathway, which relies on the formation of a CD95-containing complex designated the MISC for Motility-Inducing Signaling Complex. These findings revisit the role of the metalloprotease-cleaved CD95L and emphasize that the increase in cl-CD95L observed in patients affected by chronic inflammatory disorders may fuel the local or systemic tissue damage by promoting tissue-filtration of immune cells.

  19. Bauhinia championii flavone inhibits apoptosis and autophagy via the PI3K/Akt pathway in myocardial ischemia/reperfusion injury in rats.

    Science.gov (United States)

    Jian, Jie; Xuan, Feifei; Qin, Feizhang; Huang, Renbin

    2015-01-01

    This study aimed to determine the effects of Bauhinia championii flavone (BCF) on myocardial ischemia/reperfusion injury (MI/RI) in rats and to explore potential mechanisms. The MI/RI model in rats was established by ligating the left anterior descending coronary artery for 30 minutes, then reperfusing for 3 hours. BCF at 20 mg/kg was given 20 minutes prior to ischemia via sublingual intravenous injection, with 24 μg/kg phosphoinositide 3-kinase inhibitor (PI3K; wortmannin) as a control. The creatine kinase-MB and nitric oxide content were assessed by colorimetry. The levels of mitochondrial permeability transition pores and tumor necrosis factor alpha were determined by an enzyme-linked immunosorbent assay. Cardiomyocyte apoptosis was detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Additionally, the expression of PI3K, endothelial nitric oxide synthase, caspase-3, and Beclin1 was analyzed by fluorescence quantitative polymerase chain reaction and Western blotting, respectively. Akt and microtubule-associated protein 1 light chain 3-II protein levels were also evaluated. Pretreatment with BCF significantly decreased the levels of creatine kinase-MB, tumor necrosis factor alpha, and mitochondrial permeability transition pores, but increased the nitric oxide content. Furthermore, BCF inhibited apoptosis, downregulated caspase-3, Beclin1, and microtubule-associated protein 1 light chain 3-II, upregulated PI3K, and increased the protein levels of phosphorylated Akt and endothelial nitric oxide synthase. However, all of the previously mentioned effects of BCF were blocked when BCF was coadministered with wortmannin. In conclusion, these observations indicated that BCF has cardioprotective effects against MI/RI by reducing cell apoptosis and excessive autophagy, which might be related to the activation of the PI3K/Akt signaling pathway.

  20. The role of sodium hydrosulfide in attenuating the aging process via PI3K/AKT and CaMKKβ/AMPK pathways.

    Science.gov (United States)

    Chen, Xubo; Zhao, Xueyan; Cai, Hua; Sun, Haiying; Hu, Yujuan; Huang, Xiang; Kong, Wen; Kong, Weijia

    2017-08-01

    Age-related dysfunction of the central auditory system, known as central presbycusis, is characterized by defects in speech perception and sound localization. It is important to determine the pathogenesis of central presbycusis in order to explore a feasible and effective intervention method. Recent work has provided fascinating insight into the beneficial function of H 2 S on oxidative stress and stress-related disease. In this study, we investigated the pathogenesis of central presbycusis and tried to explore the mechanism of H 2 S action on different aspects of aging by utilizing a mimetic aging rat and senescent cellular model. Our results indicate that NaHS decreased oxidative stress and apoptosis levels in an aging model via CaMKKβ and PI3K/AKT signaling pathways. Moreover, we found that NaHS restored the decreased activity of antioxidants such as GSH, SOD and CAT in the aging model in vivo and in vitro by regulating CaMKKβ and PI3K/AKT. Mitochondria function was preserved by NaHS, as indicated by the following: DNA POLG and OGG-1, the base excision repair enzymes in mitochondrial, were upregulated; OXPHOS activity was downregulated; mitochondrial membrane potential was restored; ATP production was increased; and mtDNA damage, indicated by the common deletion (CD), declined. These effects were also achieved by activating CaMKKβ/AMPK and PI3K/AKT signaling pathways. Lastly, protein homeostasis, indicated by HSP90 alpha, was strengthened by NaHS via CaMKKβ and PI3K/AKT. Our findings demonstrate that the ability to resist oxidative stress and mitochondria function are both decreased as aging developed; however, NaHS, a novel free radical scavenger and mitochondrial protective agent, precludes the process of oxidative damage by activating CaMKKβ and PI3K/AKT. This study might provide a therapeutic target for aging and age-related disease. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Gallic acid attenuates high-fat diet fed-streptozotocin-induced insulin resistance via partial agonism of PPARγ in experimental type 2 diabetic rats and enhances glucose uptake through translocation and activation of GLUT4 in PI3K/p-Akt signaling pathway.

    Science.gov (United States)

    Gandhi, Gopalsamy Rajiv; Jothi, Gnanasekaran; Antony, Poovathumkal James; Balakrishna, Kedike; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu; Stalin, Antony; Al-Dhabi, Naif Abdullah

    2014-12-15

    In this study, the therapeutic efficacy of gallic acid from Cyamopsis tetragonoloba (L.) Taub. (Fabaceae) beans was examined against high-fat diet fed-streptozotocin-induced experimental type 2 diabetic rats. Molecular-dockings were done to determine the putative binding modes of gallic acid into the active sites of key insulin-signaling markers. Gallic acid (20 mg/kg) given to high-fat diet fed-streptozotocin-induced rats lowered body weight gain, fasting blood glucose and plasma insulin in diabetic rats. It further restored the alterations of biochemical parameters to near normal levels in diabetic treated rats along with cytoprotective action on pancreatic β-cell. Histology of liver and adipose tissues supported the biochemical findings. Gallic acid significantly enhanced the level of peroxisome proliferator-activated receptor γ (PPARγ) expression in the adipose tissue of treated rat compared to untreated diabetic rat; it also slightly activated PPARγ expressions in the liver and skeletal muscle. Consequently, it improved insulin-dependent glucose transport in adipose tissue through translocation and activation of glucose transporter protein 4 (GLUT4) in phosphatidylinositol 3-kinase (PI3K)/phosphorylated protein kinase B (p-Akt) dependent pathway. Gallic acid docked with PPARγ; it exhibited promising interactions with the GLUT4, glucose transporter protein 1 (GLUT1), PI3K and p-Akt. These findings provided evidence to show that gallic acid could improve adipose tissue insulin sensitivity, modulate adipogenesis, increase adipose glucose uptake and protect β-cells from impairment. Hence it can be used in the management of obesity-associated type 2 diabetes mellitus. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Wada, Eiji, E-mail: gacchu1@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Zammit, Peter S., E-mail: peter.zammit@kcl.ac.uk [Randall Division of Cell and Molecular Biophysics, King' s College London, London SE1 1UL (United Kingdom); Shiozuka, Masataka, E-mail: cmuscle@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Matsuda, Ryoichi, E-mail: cmatsuda@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan)

    2015-05-01

    Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc on differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.

  3. Niacin activates the PI3K/Akt cascade via PKC- and EGFR-transactivation-dependent pathways through hydroxyl-carboxylic acid receptor 2.

    Directory of Open Access Journals (Sweden)

    Huawang Sun

    Full Text Available Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation.

  4. Isoegomaketone induces apoptosis in SK-MEL-2 human melanoma cells through mitochondrial apoptotic pathway via activating the PI3K/Akt pathway.

    Science.gov (United States)

    Kwon, Soon-Jae; Lee, Ju-Hye; Moon, Kwang-Deog; Jeong, Il-Yun; Yee, Sung-Tae; Lee, Mi-Kyung; Seo, Kwon-Il

    2014-11-01

    Isoegomaketone (IK) is a major biologically active component of Perilla frutescens. In this study, we investigated the contribution of reactive oxygen species (ROS) to IK-induced apoptosis in human melanoma SK-MEL-2 cells. We found that IK inhibited the proliferation of SK-MEL-2 human melanoma cells in a dose-dependent manner. IK also induced sub-G1 DNA accumulation, formation of apoptotic bodies, nuclear condensation, and a DNA ladder in SK-MEL-2 cells. IK also induced activation of caspase-3 and -9, whereas caspase‑8 was unaffected. Further, N-acetyl-L-cysteine (NAC, ROS scavenger) treatment to SK-MEL-2 cells significantly reduced IK-induced cell death. Pretreatment of NAC to SK-MEL-2 cells followed by 100 µM IK reduced the protein levels of Bax and cytochrome c as well as PARP cleavage, whereas the protein level of Bcl-2 increased. Moreover, IK inhibited the phosphorylation of AKT/mTOR protein and cell proliferation induced by LY294002, a PI3K inhibitor. In conclusion, IK-induced ROS generation regulates cell growth inhibition and it induces apoptosis through caspase‑dependent and -independent pathways via modulation of PI3K/AKT signaling in SK-MEL-2 cells.

  5. Netrin-1 Ameliorates Blood-Brain Barrier Impairment Secondary to Ischemic Stroke via the Activation of PI3K Pathway

    Directory of Open Access Journals (Sweden)

    Jian Yu

    2017-12-01

    Full Text Available Secondary impairment of blood-brain barrier (BBB occurs in the remote thalamus after ischemic stroke. Netrin-1, an axonal guidance molecule, presents bifunctional effects on blood vessels through receptor-dependent pathways. This study investigates whether netrin-1 protects BBB against secondary injury. Netrin-1 (600 ng/d for 7 days was intracerebroventricularly infused 24 h after middle cerebral artery occlusion (MCAO in hypertensive rats. Neurological function was assessed 8 and 14 days after MCAO, and the permeability of BBB in the ipsilateral thalamus was detected. The viability of brain microvascular endothelial cells was determined after being disposed with netrin-1 (50 ng/mL before oxygen-glucose deprivation (OGD. The role of netrin-1 was further explored by examining its receptors and their function. We found that netrin-1 infusion improved neurological function, attenuated secondary impairment of BBB by up-regulating the levels of tight junction proteins and diminishing extravasation of albumin, with autophagy activation 14 days after MCAO. Netrin-1 also enhanced cell survival and autophagy activity in OGD-treated cells, inhibited by UNC5H2 siRNA transfection. Furthermore, the beneficial effects of netrin-1 were suppressed by PI3K inhibitors 3-Methyladenine and LY294002. Our results showed that netrin-1 ameliorated BBB impairment secondary to ischemic stroke by promoting tight junction function and endothelial survival. PI3K-mediated autophagy activation depending on UNC5H2 receptor could be an underlying mechanism.

  6. Src homology domain 2-containing protein-tyrosine phosphatase-1 (SHP-1) binds and dephosphorylates G(alpha)-interacting, vesicle-associated protein (GIV)/Girdin and attenuates the GIV-phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway.

    Science.gov (United States)

    Mittal, Yash; Pavlova, Yelena; Garcia-Marcos, Mikel; Ghosh, Pradipta

    2011-09-16

    GIV (Gα-interacting vesicle-associated protein, also known as Girdin) is a bona fide enhancer of PI3K-Akt signals during a diverse set of biological processes, e.g. wound healing, macrophage chemotaxis, tumor angiogenesis, and cancer invasion/metastasis. We recently demonstrated that tyrosine phosphorylation of GIV by receptor and non-receptor-tyrosine kinases is a key step that is required for GIV to directly bind and enhance PI3K activity. Here we report the discovery that Src homology 2-containing phosphatase-1 (SHP-1) is the major protein-tyrosine phosphatase that targets two critical phosphotyrosines within GIV and antagonizes phospho-GIV-dependent PI3K enhancement in mammalian cells. Using phosphorylation-dephosphorylation assays, we demonstrate that SHP-1 is the major and specific protein-tyrosine phosphatase that catalyzes the dephosphorylation of tyrosine-phosphorylated GIV in vitro and inhibits ligand-dependent tyrosine phosphorylation of GIV downstream of both growth factor receptors and GPCRs in cells. In vitro binding and co-immunoprecipitation assays demonstrate that SHP-1 and GIV interact directly and constitutively and that this interaction occurs between the SH2 domain of SHP-1 and the C terminus of GIV. Overexpression of SHP-1 inhibits tyrosine phosphorylation of GIV and formation of phospho-GIV-PI3K complexes, and specifically suppresses GIV-dependent activation of Akt. Consistently, depletion of SHP-1 enhances peak tyrosine phosphorylation of GIV, which coincides with an increase in peak Akt activity. We conclude that SHP-1 antagonizes the action of receptor and non-receptor-tyrosine kinases on GIV and down-regulates the phospho-GIV-PI3K-Akt axis of signaling.

  7. Neurotrophin Promotes Neurite Outgrowth by Inhibiting Rif GTPase Activation Downstream of MAPKs and PI3K Signaling.

    Science.gov (United States)

    Tian, Xiaoxia; Yan, Huijuan; Li, Jiayi; Wu, Shuang; Wang, Junyu; Fan, Lifei

    2017-01-13

    Members of the well-known semaphorin family of proteins can induce both repulsive and attractive signaling in neural network formation and their cytoskeletal effects are mediated in part by small guanosine 5'-triphosphatase (GTPases). The aim of this study was to investigate the cellular role of Rif GTPase in the neurotrophin-induced neurite outgrowth. By using PC12 cells which are known to cease dividing and begin to show neurite outgrowth responding to nerve growth factor (NGF), we found that semaphorin 6A was as effective as nerve growth factor at stimulating neurite outgrowth in PC12 cells, and that its neurotrophic effect was transmitted through signaling by mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase (PI3K). We further found that neurotrophin-induced neurite formation in PC12 cells could be partially mediated by inhibition of Rif GTPase activity downstream of MAPKs and PI3K signaling. In conclusion, we newly identified Rif as a regulator of the cytoskeletal rearrangement mediated by semaphorins.

  8. A preclinical orthotopic model for glioblastoma recapitulates key features of human tumors and demonstrates sensitivity to a combination of MEK and PI3K pathway inhibitors.

    Science.gov (United States)

    El Meskini, Rajaa; Iacovelli, Anthony J; Kulaga, Alan; Gumprecht, Michelle; Martin, Philip L; Baran, Maureen; Householder, Deborah B; Van Dyke, Terry; Weaver Ohler, Zoë

    2015-01-01

    Current therapies for glioblastoma multiforme (GBM), the highest grade malignant brain tumor, are mostly ineffective, and better preclinical model systems are needed to increase the successful translation of drug discovery efforts into the clinic. Previous work describes a genetically engineered mouse (GEM) model that contains perturbations in the most frequently dysregulated networks in GBM (driven by RB, KRAS and/or PI3K signaling and PTEN) that induce development of Grade IV astrocytoma with properties of the human disease. Here, we developed and characterized an orthotopic mouse model derived from the GEM that retains the features of the GEM model in an immunocompetent background; however, this model is also tractable and efficient for preclinical evaluation of candidate therapeutic regimens. Orthotopic brain tumors are highly proliferative, invasive and vascular, and express histology markers characteristic of human GBM. Primary tumor cells were examined for sensitivity to chemotherapeutics and targeted drugs. PI3K and MAPK pathway inhibitors, when used as single agents, inhibited cell proliferation but did not result in significant apoptosis. However, in combination, these inhibitors resulted in a substantial increase in cell death. Moreover, these findings translated into the in vivo orthotopic model: PI3K or MAPK inhibitor treatment regimens resulted in incomplete pathway suppression and feedback loops, whereas dual treatment delayed tumor growth through increased apoptosis and decreased tumor cell proliferation. Analysis of downstream pathway components revealed a cooperative effect on target downregulation. These concordant results, together with the morphologic similarities to the human GBM disease characteristics of the model, validate it as a new platform for the evaluation of GBM treatment. © 2015. Published by The Company of Biologists Ltd.

  9. A preclinical orthotopic model for glioblastoma recapitulates key features of human tumors and demonstrates sensitivity to a combination of MEK and PI3K pathway inhibitors

    Directory of Open Access Journals (Sweden)

    Rajaa El Meskini

    2015-01-01

    Full Text Available Current therapies for glioblastoma multiforme (GBM, the highest grade malignant brain tumor, are mostly ineffective, and better preclinical model systems are needed to increase the successful translation of drug discovery efforts into the clinic. Previous work describes a genetically engineered mouse (GEM model that contains perturbations in the most frequently dysregulated networks in GBM (driven by RB, KRAS and/or PI3K signaling and PTEN that induce development of Grade IV astrocytoma with properties of the human disease. Here, we developed and characterized an orthotopic mouse model derived from the GEM that retains the features of the GEM model in an immunocompetent background; however, this model is also tractable and efficient for preclinical evaluation of candidate therapeutic regimens. Orthotopic brain tumors are highly proliferative, invasive and vascular, and express histology markers characteristic of human GBM. Primary tumor cells were examined for sensitivity to chemotherapeutics and targeted drugs. PI3K and MAPK pathway inhibitors, when used as single agents, inhibited cell proliferation but did not result in significant apoptosis. However, in combination, these inhibitors resulted in a substantial increase in cell death. Moreover, these findings translated into the in vivo orthotopic model: PI3K or MAPK inhibitor treatment regimens resulted in incomplete pathway suppression and feedback loops, whereas dual treatment delayed tumor growth through increased apoptosis and decreased tumor cell proliferation. Analysis of downstream pathway components revealed a cooperative effect on target downregulation. These concordant results, together with the morphologic similarities to the human GBM disease characteristics of the model, validate it as a new platform for the evaluation of GBM treatment.

  10. Agmatine Reduces Lipopolysaccharide-Mediated Oxidant Response via Activating PI3K/Akt Pathway and Up-Regulating Nrf2 and HO-1 Expression in Macrophages.

    Directory of Open Access Journals (Sweden)

    Jianshen Chai

    Full Text Available Macrophages are key responders of inflammation and are closely related with oxidative stress. Activated macrophages can enhance oxygen depletion, which causes an overproduction of reactive oxygen species (ROS and leads to further excessive inflammatory response and tissue damage. Agmatine, an endogenous metabolite of L-arginine, has recently been shown to have neuroprotective effects based on its antioxidant properties. However, the antioxidant effects of agmatine in peripheral tissues and cells, especially macrophages, remain unclear. In this study we explored the role of agmatine in mediating antioxidant effects in RAW 264.7 cells and studied its antioxidant mechanism. Our data demonstrate that agmatine is an activator of Nrf2 signaling that markedly enhances Nrf2 nuclear translocation, increases nuclear Nrf2 protein level, up-regulates the expression of the Nrf2 downstream effector HO-1, and attenuates ROS generation induced by Lipopolysaccharide (LPS. We further demonstrated that the agmatine-induced activation of Nrf2 is likely through the PI3K/Akt pathway. LY294002, a specific PI3K/Akt inhibitor, abolished agmatine-induced HO-1 up-regulation and ROS suppression significantly. Inhibiting HO-1 pathway significantly attenuated the antioxidant effect of agmatine which the products of HO-1 enzymatic activity contributed to. Furthermore, the common membrane receptors of agmatine were evaluated, revealing that α2-adrenoceptor, I1-imidazoline receptor or I2-imidazoline receptor are not required by the antioxidant properties of agmatine. Taken together, our findings revealed that agmatine has antioxidant activity against LPS-induced ROS accumulation in RAW 264.7 cells involving HO-1 expression induced by Nrf2 via PI3K/Akt pathway activation.

  11. PI3KC2{alpha}, a class II PI3K, is required for dynamin-independent internalization pathways

    DEFF Research Database (Denmark)

    Krag, Claudia; Malmberg, Emily Kim; Salcini, Anna Elisabetta

    2010-01-01

    as fluid-phase endocytosis. Our data suggest a general role for PI3KC2a in regulating physiologically relevant dynamin-independent internalization pathways by recruiting early endosome antigen 1 (EEA1) to vesicular compartments, a step required for the intracellular trafficking of vesicles generated...... screen using a cell line expressing a diphtheria toxin receptor (DTR, officially known as HBEGF) anchored to GPI (DTR-GPI), which internalizes diphtheria toxin (DT, officially known as DTX) in a dynamin-independent manner, identified PI3KC2a, a class II phosphoinositide 3-kinase (PI3K), as a specific...... regulator of dynamin-independent DT internalization. We found that the internalization of several proteins that enter the cell through dynamin-independent pathways led to a relocalization of PI3KC2a to cargo-positive vesicles. Furthermore, downregulation of PI3KC2a impaired internalization of CD59 as well...

  12. The neuroprotective action of pyrroloquinoline quinone against glutamate-induced apoptosis in hippocampal neurons is mediated through the activation of PI3K/Akt pathway

    International Nuclear Information System (INIS)

    Zhang Qi; Shen Mi; Ding Mei; Shen Dingding; Ding Fei

    2011-01-01

    Pyrroloquinoline quinone (PQQ), a cofactor in several enzyme-catalyzed redox reactions, possesses a potential capability of scavenging reactive oxygen species (ROS) and inhibiting cell apoptosis. In this study, we investigated the effects of PQQ on glutamate-induced cell death in primary cultured hippocampal neurons and the possible underlying mechanisms. We found that glutamate-induced apoptosis in cultured hippocampal neurons was significantly attenuated by the ensuing PQQ treatment, which also inhibited the glutamate-induced increase in Ca2+ influx, caspase-3 activity, and ROS production, and reversed the glutamate-induced decrease in Bcl-2/Bax ratio. The examination of signaling pathways revealed that PQQ treatment activated the phosphorylation of Akt and suppressed the glutamate-induced phosphorylation of c-Jun N-terminal protein kinase (JNK). And inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt cascade by LY294002 and wortmannin significantly blocked the protective effects of PQQ, and alleviated the increase in Bcl-2/Bax ratio. Taken together, our results indicated that PQQ could protect primary cultured hippocampal neurons against glutamate-induced cell damage by scavenging ROS, reducing Ca2+ influx, and caspase-3 activity, and suggested that PQQ-activated PI3K/Akt signaling might be responsible for its neuroprotective action through modulation of glutamate-induced imbalance between Bcl-2 and Bax. - Research Highlights: →PQQ attenuated glutamate-induced cell apoptosis of cultured hippocampal neurons. →PQQ inhibited glutamate-induced Ca 2+ influx and caspase-3 activity. →PQQ reduced glutamate-induced increase in ROS production. →PQQ affected phosphorylation of Akt and JNK signalings after glutamate injury. →PI3K/Akt was required for neuroprotection of PQQ by modulating Bcl-2/Bax ratio.

  13. PI3K/AKT signaling modulates transcriptional expression of EWS/FLI1 through specificity protein 1.

    Science.gov (United States)

    Giorgi, Chiara; Boro, Aleksandar; Rechfeld, Florian; Lopez-Garcia, Laura A; Gierisch, Maria E; Schäfer, Beat W; Niggli, Felix K

    2015-10-06

    Ewing sarcoma (ES) is the second most frequent bone cancer in childhood and is characterized by the presence of the balanced translocation t(11;22)(q24;q12) in more than 85% of cases, generating a dysregulated transcription factor EWS/FLI1. This fusion protein is an essential oncogenic component of ES development which is necessary for tumor cell maintenance and represents an attractive therapeutic target. To search for modulators of EWS/FLI1 activity we screened a library of 153 targeted compounds and identified inhibitors of the PI3K pathway to directly modulate EWS/FLI1 transcription. Surprisingly, treatment of four different ES cell lines with BEZ235 resulted in down regulation of EWS/FLI1 mRNA and protein by ~50% with subsequent modulation of target gene expression. Analysis of the EWS/FLI1 promoter region (-2239/+67) using various deletion constructs identified two 14 bp minimal elements as being important for EWS/FLI1 transcription. We identified SP1 as modulator of EWS/FLI1 gene expression and demonstrated direct binding to one of these regions in the EWS/FLI1 promoter by EMSA and ChIP experiments. These results provide the first insights on the transcriptional regulation of EWS/FLI1, an area that has not been investigated so far, and offer an additional molecular explanation for the known sensitivity of ES cell lines to PI3K inhibition.

  14. A gene expression signature of RAS pathway dependence predicts response to PI3K and RAS pathway inhibitors and expands the population of RAS pathway activated tumors.

    Science.gov (United States)

    Loboda, Andrey; Nebozhyn, Michael; Klinghoffer, Rich; Frazier, Jason; Chastain, Michael; Arthur, William; Roberts, Brian; Zhang, Theresa; Chenard, Melissa; Haines, Brian; Andersen, Jannik; Nagashima, Kumiko; Paweletz, Cloud; Lynch, Bethany; Feldman, Igor; Dai, Hongyue; Huang, Pearl; Watters, James

    2010-06-30

    Hyperactivation of the Ras signaling pathway is a driver of many cancers, and RAS pathway activation can predict response to targeted therapies. Therefore, optimal methods for measuring Ras pathway activation are critical. The main focus of our work was to develop a gene expression signature that is predictive of RAS pathway dependence. We used the coherent expression of RAS pathway-related genes across multiple datasets to derive a RAS pathway gene expression signature and generate RAS pathway activation scores in pre-clinical cancer models and human tumors. We then related this signature to KRAS mutation status and drug response data in pre-clinical and clinical datasets. The RAS signature score is predictive of KRAS mutation status in lung tumors and cell lines with high (> 90%) sensitivity but relatively low (50%) specificity due to samples that have apparent RAS pathway activation in the absence of a KRAS mutation. In lung and breast cancer cell line panels, the RAS pathway signature score correlates with pMEK and pERK expression, and predicts resistance to AKT inhibition and sensitivity to MEK inhibition within both KRAS mutant and KRAS wild-type groups. The RAS pathway signature is upregulated in breast cancer cell lines that have acquired resistance to AKT inhibition, and is downregulated by inhibition of MEK. In lung cancer cell lines knockdown of KRAS using siRNA demonstrates that the RAS pathway signature is a better measure of dependence on RAS compared to KRAS mutation status. In human tumors, the RAS pathway signature is elevated in ER negative breast tumors and lung adenocarcinomas, and predicts resistance to cetuximab in metastatic colorectal cancer. These data demonstrate that the RAS pathway signature is superior to KRAS mutation status for the prediction of dependence on RAS signaling, can predict response to PI3K and RAS pathway inhibitors, and is likely to have the most clinical utility in lung and breast tumors.

  15. A gene expression signature of RAS pathway dependence predicts response to PI3K and RAS pathway inhibitors and expands the population of RAS pathway activated tumors

    Directory of Open Access Journals (Sweden)

    Paweletz Cloud

    2010-06-01

    Full Text Available Abstract Background Hyperactivation of the Ras signaling pathway is a driver of many cancers, and RAS pathway activation can predict response to targeted therapies. Therefore, optimal methods for measuring Ras pathway activation are critical. The main focus of our work was to develop a gene expression signature that is predictive of RAS pathway dependence. Methods We used the coherent expression of RAS pathway-related genes across multiple datasets to derive a RAS pathway gene expression signature and generate RAS pathway activation scores in pre-clinical cancer models and human tumors. We then related this signature to KRAS mutation status and drug response data in pre-clinical and clinical datasets. Results The RAS signature score is predictive of KRAS mutation status in lung tumors and cell lines with high (> 90% sensitivity but relatively low (50% specificity due to samples that have apparent RAS pathway activation in the absence of a KRAS mutation. In lung and breast cancer cell line panels, the RAS pathway signature score correlates with pMEK and pERK expression, and predicts resistance to AKT inhibition and sensitivity to MEK inhibition within both KRAS mutant and KRAS wild-type groups. The RAS pathway signature is upregulated in breast cancer cell lines that have acquired resistance to AKT inhibition, and is downregulated by inhibition of MEK. In lung cancer cell lines knockdown of KRAS using siRNA demonstrates that the RAS pathway signature is a better measure of dependence on RAS compared to KRAS mutation status. In human tumors, the RAS pathway signature is elevated in ER negative breast tumors and lung adenocarcinomas, and predicts resistance to cetuximab in metastatic colorectal cancer. Conclusions These data demonstrate that the RAS pathway signature is superior to KRAS mutation status for the prediction of dependence on RAS signaling, can predict response to PI3K and RAS pathway inhibitors, and is likely to have the most clinical

  16. Mechanism of modulation through PI3K-AKT pathway about Nepeta cataria L.'s extract in non-small cell lung cancer.

    Science.gov (United States)

    Fan, Jiaxin; Bao, Yongrui; Meng, Xiansheng; Wang, Shuai; Li, Tianjiao; Chang, Xin; Yang, Guanlin; Bo, Tao

    2017-05-09

    Non-small cell lung cancer (NSCLC) is regarded as one of the major intractable diseases, which was cured mainly by chemotherapeutics in the clinical treatment at present. But it is still a vital mission for the current medical and researchers that hunting a natural medicine which have little side effects and high-efficiency against the NSCLC on account of the shortcomings on current drugs. Nepeta cataria L. plays an important role in anti-cancer treatment according to the reports which was recorded in the Chinese Pharmacopoeia of version 2015 and belongs to one of the Traditional Chinese medicine (TCM). Microfluidic chip technology is widely used in scientific research field due to its high-throughput, high sensitivity and low cost with the continuous progress of science and technology. In this study, we investigate the effect of total flavonoid extracted from Nepeta cataria L. (TFS) through human lung cancer cell line A549 based on the microfluidic device and Flow Cytometry. So we detected the mRNA expression of MicroRNA-126 (miR-126), VEGF, PI3K, PTEN and proteins expression respectively to explore the partial PI3K-AKT pathway molecular mechanisms through Quantitative Real-time PCR (qRT-PCR) and Western Blot. The results showed that TFS can disturb the expression of miR-126 and regulate the PI3K-AKT signaling pathway to meet the effect of anti-cancer. Taking all these results into consideration we can draw a conclusion that TFS may be used as a novel therapeutic agent for NSCLC in the near future.

  17. Plumbagin induces cell cycle arrest and autophagy and suppresses epithelial to mesenchymal transition involving PI3K/Akt/mTOR-mediated pathway in human pancreatic cancer cells

    Science.gov (United States)

    Wang, Feng; Wang, Qi; Zhou, Zhi-Wei; Yu, Song-Ning; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Yin-Xue; Yang, Tianxing; Sun, Tao; Li, Min; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Plumbagin (PLB), an active naphthoquinone compound, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of PLB for the treatment of pancreatic cancer is unclear. This study aimed to examine the pancreatic cancer cell killing effect of PLB and investigate the underlying mechanism in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that PLB exhibited potent inducing effects on cell cycle arrest in PANC-1 and BxPC-3 cells via the modulation of cell cycle regulators including CDK1/CDC2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. PLB treatment concentration- and time-dependently increased the percentage of autophagic cells and significantly increased the expression level of phosphatase and tensin homolog, beclin 1, and the ratio of LC3-II over LC3-I in both PANC-1 and BxPC-3 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin and p38 mitogen-activated protein kinase (p38 MAPK) pathways and activation of 5′-AMP-dependent kinase as indicated by their altered phosphorylation, contributing to the proautophagic activities of PLB in both cell lines. Furthermore, SB202190, a selective inhibitor of p38 MAPK, and wortmannin, a potent, irreversible, and selective PI3K inhibitor, remarkably enhanced PLB-induced autophagy in PANC-1 and BxPC-3 cells, indicating the roles of PI3K and p38 MAPK mediated signaling pathways in PLB-induced autophagic cell death in both cell lines. In addition, PLB significantly inhibited epithelial to mesenchymal transition phenotype in both cell lines with an increase in the expression level of E-cadherin and a decrease in N-cadherin. Moreover, PLB treatment significantly suppressed the expression of Sirt1 in both cell lines. These findings show that PLB promotes cell cycle arrest and autophagy but inhibits epithelial to mesenchymal transition phenotype in pancreatic cancer cells with the involvement of

  18. Pro-apoptotic and pro-autophagic effects of the Aurora kinase A inhibitor alisertib (MLN8237 on human osteosarcoma U-2 OS and MG-63 cells through the activation of mitochondria-mediated pathway and inhibition of p38 MAPK/PI3K/Akt/mTOR signaling pathway

    Directory of Open Access Journals (Sweden)

    Niu NK

    2015-03-01

    mesenchymal transition (EMT and the underlying mechanisms in two human OS cell lines U-2 OS and MG-63. The results showed that ALS had potent growth inhibitory, pro-apoptotic, pro-autophagic, and EMT inhibitory effects on U-2 OS and MG-63 cells. ALS remarkably induced G2/M arrest and down-regulated the expression levels of cyclin-dependent kinases 1 and 2 and cyclin B1 in both U-2 OS and MG-63 cells. ALS markedly induced mitochondria-mediated apoptosis with a significant increase in the expression of key pro-apoptotic proteins and a decrease in main anti-apoptotic proteins. Furthermore, ALS promoted autophagic cell death via the inhibition of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR and p38 mitogen-activated protein kinase (p38 MAPK signaling pathways, and activation of 5'-AMP-dependent kinase (AMPK signaling pathway. Inducers or inhibitors of apoptosis or autophagy simultaneously altered ALS-induced apoptotic and autophagic death in both U-2 OS and MG-63 cells, suggesting a crosstalk between these two primary modes of programmed cell death. Moreover, ALS suppressed EMT-like phenotypes with a marked increase in the expression of E-cadherin but a decrease in N-cadherin in U-2 OS and MG-63 cells. ALS treatment also induced reactive oxygen species (ROS generation but inhibited the expression levels of sirtuin 1 and nuclear factor-erythroid-2-related factor 2 (Nrf2 in both cell lines. Taken together, these findings show that ALS promotes apoptosis and autophagy but inhibits EMT via PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways with involvement of ROS- and sirtuin 1-associated pathways in U-2 OS and MG-63 cells. ALS is a promising anticancer agent in OS treatment and further studies are needed to confirm its efficacy and safety in OS chemotherapy. Keywords: ALS, autophagy, apoptosis, osteosarcoma, PI3K/Akt/mTOR pathway, EMT

  19. IGF-1 Promotes Brn-4 Expression and Neuronal Differentiation of Neural Stem Cells via the PI3K/Akt Pathway

    Science.gov (United States)

    Zhang, Xinhua; Zhang, Lei; Cheng, Xiang; Guo, Yuxiu; Sun, Xiaohui; Chen, Geng; Li, Haoming; Li, Pengcheng; Lu, Xiaohui; Tian, Meiling; Qin, Jianbing; Zhou, Hui; Jin, Guohua

    2014-01-01

    Our previous studies indicated that transcription factor Brn-4 is upregulated in the surgically denervated hippocampus in vivo, promoting neuronal differentiation of hippocampal neural stem cells (NSCs) in vitro. The molecules mediating Brn-4 upregulation in the denervated hippocampus remain unknown. In this study we examined the levels of insulin-like growth factor-1 (IGF-1) in hippocampus following denervation. Surgical denervation led to a significant increase in IGF-1 expression in vivo. We also report that IGF-1 treatment on NSCs in vitro led to a marked acceleration of Brn-4 expression and cell differentiation down neuronal pathways. The promotion effects were blocked by PI3K-specific inhibitor (LY294002), but not MAPK inhibitor (PD98059); levels of phospho-Akt were increased by IGF-1 treatment. In addition, inhibition of IGF-1 receptor (AG1024) and mTOR (rapamycin) both attenuated the increased expression of Brn-4 induced by IGF-1. Together, the results demonstrated that upregulation of IGF-1 induced by hippocampal denervation injury leads to activation of the PI3K/Akt signaling pathway, which in turn gives rise to upregulation of the Brn-4 and subsequent stem cell differentiation down neuronal pathways. PMID:25474202

  20. IGF-1 promotes Brn-4 expression and neuronal differentiation of neural stem cells via the PI3K/Akt pathway.

    Directory of Open Access Journals (Sweden)

    Xinhua Zhang

    Full Text Available Our previous studies indicated that transcription factor Brn-4 is upregulated in the surgically denervated hippocampus in vivo, promoting neuronal differentiation of hippocampal neural stem cells (NSCs in vitro. The molecules mediating Brn-4 upregulation in the denervated hippocampus remain unknown. In this study we examined the levels of insulin-like growth factor-1 (IGF-1 in hippocampus following denervation. Surgical denervation led to a significant increase in IGF-1 expression in vivo. We also report that IGF-1 treatment on NSCs in vitro led to a marked acceleration of Brn-4 expression and cell differentiation down neuronal pathways. The promotion effects were blocked by PI3K-specific inhibitor (LY294002, but not MAPK inhibitor (PD98059; levels of phospho-Akt were increased by IGF-1 treatment. In addition, inhibition of IGF-1 receptor (AG1024 and mTOR (rapamycin both attenuated the increased expression of Brn-4 induced by IGF-1. Together, the results demonstrated that upregulation of IGF-1 induced by hippocampal denervation injury leads to activation of the PI3K/Akt signaling pathway, which in turn gives rise to upregulation of the Brn-4 and subsequent stem cell differentiation down neuronal pathways.

  1. Neuroprotective Effects of Salidroside in the MPTP Mouse Model of Parkinson’s Disease: Involvement of the PI3K/Akt/GSK3β Pathway

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2016-01-01

    Full Text Available The degenerative loss through apoptosis of dopaminergic neurons in the substantia nigra pars compacta plays a primary role in the progression of Parkinson’s disease (PD. Our in vitro experiments suggested that salidroside (Sal could protect against 1-methyl-4-phenylpyridine-induced cell apoptosis in part by regulating the PI3K/Akt/GSK3β pathway. The current study aims to increase our understanding of the protective mechanisms of Sal in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine- (MPTP- induced PD mouse model. We found that pretreatment with Sal could protect against MPTP-induced increase of the time of turning downwards and climbing down to the floor. Sal also prevented MPTP-induced decrease of locomotion frequency and the increase of the immobile time. Sal provided a protection of in MPTP-induced loss of tyrosine hydroxylase-positive neurons in SNpc and the level of DA, DOPAC, and HVA in the striatum. Furthermore, Sal could increase the phosphorylation level of Akt and GSK3β, upregulate the ratio of Bcl-2/Bax, and inhibit the activation of caspase-3, caspase-6, and caspase-9. These results show that Sal prevents the loss of dopaminergic neurons and the PI3K/Akt/GSK3β pathway signaling pathway may have mediated the protection of Sal against MPTP, suggesting that Sal may be a potential candidate in neuroprotective treatment for PD.

  2. Metformin and pioglitazone combination therapy ameliorate polycystic ovary syndrome through AMPK/PI3K/JNK pathway

    Science.gov (United States)

    Wu, Yuanyuan; Li, Pengfen; Zhang, Dan; Sun, Yingpu

    2018-01-01

    Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder, which results in health problems such as menstrual disorders, hyperandrogenism and persistent anovulation. Hyperandrogenism and insulin resistance are the basic characteristics of PCOS. To investigate the combined effect of metformin and pioglitazone on POCS and the potential mechanisms, a rat model of PCOS was established by intramuscular injection of estradiol valerate (EV). The effect of metformin and pioglitazone monotherapy or combination therapy in control rats and PCOS rats was evaluated, involving the testosterone level, follicular development and insulin resistance. The potential mechanism for the therapeutic effect of metformin and pioglitazone on POCS was explored through using three inhibitors of the 5′adenosine monophosphate-activated protein kinase (AMPK)/phosphoinositide-3 kinase (PI3K)/c-Jun N-terminal kinase (JNK) pathway (Compound C, Wortmannin and SP600125). The results showed that EV-induced PCOS rats demonstrated hyperandrogenemia, hyperinsulinemia and follicular dysplasia. Metformin or pioglitazone monotherapy significantly suppressed the high level of testosterone, reduced the raised percentage of cystic follicles and primary follicles, promoted the number of early antral follicles, and markedly decreased the high concentration of fasting insulin and homeostatic model assessment for insulin resistance index in PCOS rats. In addition, metformin and pioglitazone combination therapy demonstrated greater efficacy than its individual components. Furthermore, individual or joint treatment with metformin and pioglitazone affected the phosphorylation level of JNK in PCOS rats. Compound C and Wortmannin eliminated the effect of metformin and pioglitazone combination therapy on improving the follicular growth in PCOS rats, whereas SP600125 treatment enhanced this combination therapy effect. These data suggested that metformin and pioglitazone combination therapy

  3. Aldose reductase inhibition prevents allergic airway remodeling through PI3K/AKT/GSK3β pathway in mice.

    Directory of Open Access Journals (Sweden)

    Umesh C S Yadav

    Full Text Available Long-term and unresolved airway inflammation and airway remodeling, characteristic features of chronic asthma, if not treated could lead to permanent structural changes in the airways. Aldose reductase (AR, an aldo-sugar and lipid aldehyde metabolizing enzyme, mediates allergen-induced airway inflammation in mice, but its role in the airway remodeling is not known. In the present study, we have examined the role of AR on airway remodeling using ovalbumin (OVA-induced chronic asthma mouse model and cultured human primary airway epithelial cells (SAECs and mouse lung fibroblasts (mLFs.Airway remodeling in chronic asthma model was established in mice sensitized and challenged twice a week with OVA for 6 weeks. AR inhibitor, fidarestat, was administered orally in drinking water after first challenge. Inflammatory cells infiltration in the lungs and goblet cell metaplasia, airway thickening, collagen deposition and airway hyper-responsiveness (AHR in response to increasing doses of methacholine were assessed. The TGFβ1-induced epithelial-mesenchymal transition (EMT in SAECs and changes in mLFs were examined to investigate AR-mediated molecular mechanism(s of airway remodeling.In the OVA-exposed mice for 6 wks inflammatory cells infiltration, levels of inflammatory cytokines and chemokines, goblet cell metaplasia, collagen deposition and AHR were significantly decreased by treatment with AR inhibitor, fidarestat. Further, inhibition of AR prevented TGFβ1-induced altered expression of E-cadherin, Vimentin, Occludin, and MMP-2 in SAECs, and alpha-smooth muscle actin and fibronectin in mLFs. Further, in SAECs, AR inhibition prevented TGFβ1- induced activation of PI3K/AKT/GSK3β pathway but not the phosphorylation of Smad2/3.Our results demonstrate that allergen-induced airway remodeling is mediated by AR and its inhibition blocks the progression of remodeling via inhibiting TGFβ1-induced Smad-independent and PI3K/AKT/GSK3β-dependent pathway.

  4. Hsp27 promotes ABCA1 expression and cholesterol efflux through the PI3K/PKCζ/Sp1 pathway in THP-1 macrophages.

    Science.gov (United States)

    Kuang, Hai-Jun; Zhao, Guo-Jun; Chen, Wu-Jun; Zhang, Min; Zeng, Gao-Feng; Zheng, Xi-Long; Tang, Chao-Ke

    2017-09-05

    Heat shock protein 27 (Hsp27) is a putative biomarker and therapeutic target in atherosclerosis. This study was to explore the potential mechanisms underlying Hsp27 effects on ATP-binding cassette transporter A1 (ABCA1) expression and cellular cholesterol efflux. THP-1 macrophage-derived foam cells were infected with adenovirus to express wild-type Hsp27, hyper-phosphorylated Hsp27 mimic (3D Hsp27), antisense Hsp27 or hypo-phosphorylated Hsp27 mimic (3A Hsp27). Wild-type and 3D Hsp27 were found to up-regulate ABCA1 mRNA and protein expression and increase cholesterol efflux from cells. Expression of antisense or 3A Hsp27 suppressed the expression of ABCA1 and cholesterol efflux. Furthermore, over-expression of wild-type and 3D Hsp27 significantly increased the levels of phosphorylated specificity protein 1 (Sp1), protein kinase C ζ (PKCζ) and phosphatidylinositol 3-kinase (PI3K). In addition, the up-regulation of ABCA1 expression and cholesterol efflux induced by 3D Hsp27 was suppressed by inhibition of Sp1, PKCζ and PI3K with specific kinase inhibitors. Taken together, our results revealed that Hsp27 may up-regulate the expression of ABCA1 and promotes cholesterol efflux through activation of the PI3K/PKCζ/Sp1 signal pathway in THP-1 macrophage-derived foam cells. Our findings may partly explain the mechanisms underlying the anti-atherogenic effect of Hsp27. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Quantitative analysis of phosphoinositide 3-kinase (PI3K) signaling using live-cell total internal reflection fluorescence (TIRF) microscopy.

    Science.gov (United States)

    Johnson, Heath E; Haugh, Jason M

    2013-12-02

    This unit focuses on the use of total internal reflection fluorescence (TIRF) microscopy and image analysis methods to study the dynamics of signal transduction mediated by class I phosphoinositide 3-kinases (PI3Ks) in mammalian cells. The first four protocols cover live-cell imaging experiments, image acquisition parameters, and basic image processing and segmentation. These methods are generally applicable to live-cell TIRF experiments. The remaining protocols outline more advanced image analysis methods, which were developed in our laboratory for the purpose of characterizing the spatiotemporal dynamics of PI3K signaling. These methods may be extended to analyze other cellular processes monitored using fluorescent biosensors. Copyright © 2013 John Wiley & Sons, Inc.

  6. PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of post-traumatic epilepsy.

    Science.gov (United States)

    Berdichevsky, Yevgeny; Dryer, Alexandra M; Saponjian, Yero; Mahoney, Mark M; Pimentel, Corrin A; Lucini, Corrina A; Usenovic, Marija; Staley, Kevin J

    2013-05-22

    mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an anti-epileptogenic, or merely anticonvulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long-term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with lactate dehydrogenase (LDH) release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are as follows: (1) the organotypic hippocampal culture model of post-traumatic epilepsy comprises a rapid assay of anti-epileptogenic and neuroprotective activities and, in this model (2) mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy.

  7. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model.

    Science.gov (United States)

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p Arctigenin (p Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH.

  8. Impact of somatic PI3K pathway and ERBB family mutations on pathological complete response (pCR) in HER2-positive breast cancer patients who received neoadjuvant HER2-targeted therapies.

    LENUS (Irish Health Repository)

    Toomey, Sinead

    2017-07-27

    The Cancer Genome Atlas analysis revealed that somatic EGFR, receptor tyrosine-protein kinase erbB-2 (ERBB2), Erb-B2 receptor tyrosine kinase 3 (ERBB3) and Erb-B2 receptor tyrosine kinase 4 (ERBB4) gene mutations (ERBB family mutations) occur alone or co-occur with somatic mutations in the gene encoding the phosphatidylinositol 3-kinase (PI3K) catalytic subunit (PIK3CA) in 19% of human epidermal growth factor receptor 2 (HER2)-positive breast cancers. Because ERBB family mutations can activate the PI3K\\/AKT pathway and likely have similar canonical signalling effects to PI3K pathway mutations, we investigated their combined impact on response to neoadjuvant HER2-targeted therapies.

  9. Silica nanoparticles induce multinucleation through activation of PI3K/Akt/GSK-3β pathway and downregulation of chromosomal passenger proteins in L-02 cells

    Science.gov (United States)

    Geng, Weijia; Li, Yang; Yu, Yongbo; Yu, Yang; Duan, Junchao; Jiang, Lizhen; Li, Qiuling; Sun, Zhiwei

    2016-04-01

    Silica nanoparticles (SNPs) are applicable in various fields due to their unique physicochemical characteristics. However, concerns over their potential adverse effects have been raised. In our previous studies, we reported that SNPs could induce abnormal high incidence of multinucleation. The aim of this study is to further investigate the mechanisms of multinucleation induced by SNPs (68 nm) in human normal liver L-02 cells (L-02 cells). In order to determine the cytotoxicity of SNPs, MTT assay was performed, and the cell viability was decreased in a dose-dependent manner. The intracellular reactive oxygen species (ROS) detected by flow cytometry and multinucleation observed by Giemsa stain showed that ROS generation and rate of multinucleated cells increased after SNPs exposure. N-acetyl-cysteine (NAC), a glutathione precursor against SNP-induced toxicity, was used as a ROS inhibitor to elucidate the relationship between ROS and multinucleation. The presence of NAC resulted in inhibition of both ROS generation and rate of multinucleation. Moreover, Western blot analysis showed that the protein levels of Cdc20, Aurora B, and Survivin were down-regulated, and the PI3K/Akt/GSK-3β pathway was activated by SNPs. In conclusion, our findings strongly suggested that multinucleation induced by SNPs was related to PI3K/Akt/GSK-3β signal pathway activation and downregulation of G2/M phase-related protein and chromosomal passenger proteins.

  10. Absence of both Sos-1 and Sos-2 in peripheral CD4+ T cells leads to PI3K pathway activation and defects in migration

    Science.gov (United States)

    Guittard, Geoffrey; Kortum, Robert L; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L; Samelson, Lawrence E

    2015-01-01

    Sos-1 and Sos-2 are ubiquitously expressed Ras-Guanine Exchange Factors involved in Erk-MAP kinase pathway activation. Using mice lacking genes encoding Sos-1 and Sos-2, we evaluated the role of these proteins in peripheral T-cell signaling and function. Our results confirmed that TCR-mediated Erk activation in peripheral CD4+ T cells does not depend on Sos-1 and Sos-2, although IL-2-mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos-1/2dKO CD4+ T cells upon TCR and IL-2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL-2 stimulation in Sos-1/2dKO CD4+ T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos-1/2dKO T cells and a subsequent impairment in T-cell migration. PMID:25973715

  11. Absence of both Sos-1 and Sos-2 in peripheral CD4(+) T cells leads to PI3K pathway activation and defects in migration.

    Science.gov (United States)

    Guittard, Geoffrey; Kortum, Robert L; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L; Samelson, Lawrence E

    2015-08-01

    Sos-1 and Sos-2 are ubiquitously expressed Ras-guanine exchange factors involved in Erk-MAP kinase pathway activation. Using mice lacking genes encoding Sos-1 and Sos-2, we evaluated the role of these proteins in peripheral T-cell signaling and function. Our results confirmed that TCR-mediated Erk activation in peripheral CD4(+) T cells does not depend on Sos-1 and Sos-2, although IL-2-mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos-1/2dKO CD4(+) T cells upon TCR and IL-2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL-2 stimulation in Sos-1/2dKO CD4(+) T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos-1/2dKO T cells and a subsequent impairment in T-cell migration. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  12. Icariin Prevents H2O2-Induced Apoptosis via the PI3K/Akt Pathway in Rat Nucleus Pulposus Intervertebral Disc Cells.

    Science.gov (United States)

    Deng, Xiangyu; Chen, Sheng; Zheng, Dong; Shao, Zengwu; Liang, Hang; Hu, Hongzhi

    2017-01-01

    Icariin is a prenylated flavonol glycoside derived from the Chinese herb Epimedium sagittatum. This study investigated the mechanism by which icariin prevents H 2 O 2 -induced apoptosis in rat nucleus pulposus (NP) cells. NP cells were isolated from the rat intervertebral disc and they were divided into five groups after 3 passages: (A) blank control; (B) 200  μ M H 2 O 2 ; (C) 200  μ M H 2 O 2 + 20  μ M icariin; (D) 20  μ M icariin + 200  μ M H 2 O 2 + 25  μ M LY294002; (E) 200  μ M H 2 O 2 + 25  μ M LY294002. LY294002 is a selective inhibitor of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. NP cell viability, apoptosis rate, intracellular reactive oxygen species levels, and the expression of AKT, p-AKT, p53, Bcl-2, Bax, caspase-3 were estimated. The results show that, compared with the control group, H 2 O 2 significantly increased NP cell apoptosis and the level of intracellular ROS. Icariin pretreatment significantly decreased H 2 O 2 -induced apoptosis and intracellular ROS and upregulated p-Akt and BCL-2 and downregulated caspase-3 and Bax. LY294002 abolished the protective effects of icariin. Our results show that icariin can attenuate H2O2-induced apoptosis in rat nucleus pulposus cells and PI3K/AKT pathway is at least partly included in this protection effect.

  13. Silica nanoparticles induce multinucleation through activation of PI3K/Akt/GSK-3β pathway and downregulation of chromosomal passenger proteins in L-02 cells

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Weijia; Li, Yang; Yu, Yongbo; Yu, Yang; Duan, Junchao; Jiang, Lizhen; Li, Qiuling; Sun, Zhiwei, E-mail: zwsun@ccmu.edu.cn, E-mail: zwsun@hotmail.com [Capital Medical University, School of Public Health (China)

    2016-04-15

    Silica nanoparticles (SNPs) are applicable in various fields due to their unique physicochemical characteristics. However, concerns over their potential adverse effects have been raised. In our previous studies, we reported that SNPs could induce abnormal high incidence of multinucleation. The aim of this study is to further investigate the mechanisms of multinucleation induced by SNPs (68 nm) in human normal liver L-02 cells (L-02 cells). In order to determine the cytotoxicity of SNPs, MTT assay was performed, and the cell viability was decreased in a dose-dependent manner. The intracellular reactive oxygen species (ROS) detected by flow cytometry and multinucleation observed by Giemsa stain showed that ROS generation and rate of multinucleated cells increased after SNPs exposure. N-acetyl-cysteine (NAC), a glutathione precursor against SNP-induced toxicity, was used as a ROS inhibitor to elucidate the relationship between ROS and multinucleation. The presence of NAC resulted in inhibition of both ROS generation and rate of multinucleation. Moreover, Western blot analysis showed that the protein levels of Cdc20, Aurora B, and Survivin were down-regulated, and the PI3K/Akt/GSK-3β pathway was activated by SNPs. In conclusion, our findings strongly suggested that multinucleation induced by SNPs was related to PI3K/Akt/GSK-3β signal pathway activation and downregulation of G2/M phase-related protein and chromosomal passenger proteins.

  14. CCL19/CCR7 contributes to the pathogenesis of endometriosis via PI3K/Akt pathway by regulating the proliferation and invasion of ESCs.

    Science.gov (United States)

    Diao, Ruiying; Wei, Weixia; Zhao, Jinghui; Tian, Fuying; Cai, Xueyong; Duan, Yong-Gang

    2017-11-01

    The level of CCL19 increased in the peritoneal fluid of women with endometriosis, but the precise mechanism of CCL19/CCR7 in the pathogenesis of endometriosis remains unknown. ELISA and immunohistochemistry were performed to analyze CCL19/CCR7 expressions in peritoneal fluid and endometrium from women with endometriosis (n = 38) and controls (n = 32). Cell proliferation and transwell invasion assays were applied to detect proliferation and invasion of human endometrial stromal cells (ESCs). Expressions of Bcl2, MMP2, MMP9, and p-AKT/AKT were analyzed by Western blot. Peritoneal fluid concentration of CCL19 in patients with endometriosis was higher than that in controls. Those patients with moderate/severe endometriosis had significantly higher peritoneal fluid concentrations of CCL19 compared to those with minimal/mild endometriosis. Higher CCL19 and CCR7 were found in the endometrium with endometriosis compared to control. CCL19 significantly enhanced ESC proliferation and invasion through CCR7 via activating PI3K/Akt signal pathways. CCL19/CCR7 interaction significantly enhanced phosphorylation of Akt, Bcl2, MMP2, and MMP9 in ESCs. These data indicate CCL19/CCR7 contributes to proliferation and invasion of ESCs, which are conducive to the pathogenesis of endometriosis through activating PI3K/Akt pathway. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Thrombopoietin/MPL participates in initiating and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling.

    Science.gov (United States)

    Pulikkan, John Anto; Madera, Dmitri; Xue, Liting; Bradley, Paul; Landrette, Sean Francis; Kuo, Ya-Huei; Abbas, Saman; Zhu, Lihua Julie; Valk, Peter; Castilla, Lucio Hernán

    2012-07-26

    Oncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by thrombopoietin (THPO), is mutated in myeloproliferative disorders but rarely in AML. Here we show that wild-type MPL expression is increased in a fraction of human AML samples expressing RUNX1-ETO, a fusion protein created by chromosome translocation t(8;21), and that up-regulation of Mpl expression in mice induces AML when coexpressed with RUNX1-ETO. The leukemic cells are sensitive to THPO, activating survival and proliferative responses. Mpl expression is not regulated by RUNX1-ETO in mouse hematopoietic progenitors or leukemic cells. Moreover, we find that activation of PI3K/AKT but not ERK/MEK pathway is a critical mediator of the MPL-directed antiapoptotic function in leukemic cells. Hence, this study provides evidence that up-regulation of wild-type MPL levels promotes leukemia development and maintenance through activation of the PI3K/AKT axis, and suggests that inhibitors of this axis could be effective for treatment of MPL-positive AML.

  16. Selenomethionine promoted hippocampal neurogenesis via the PI3K-Akt-GSK3β-Wnt pathway in a mouse model of Alzheimer's disease

    International Nuclear Information System (INIS)

    Zheng, Rui; Zhang, Zhong-Hao; Chen, Chen; Chen, Yao; Jia, Shi-Zheng; Liu, Qiong; Ni, Jia-Zuan; Song, Guo-Li

    2017-01-01

    The maintenance of neural system integrity and function is the ultimate goal for the treatment of neurodegenerative disease such as Alzheimer's disease (AD). Neurogenesis plays an integral role in the maintenance of neural and cognitive functions, and its dysfunction is regarded as a major cause of cognitive impairment in AD. Moreover, the induction of neurogenesis by targeting endogenous neural stem cells (NSCs) is considered as one of the most promising treatment strategies. Our previous studies demonstrated that selenomethionine (Se-Met) was able to reduce β-amyloid peptide (Aβ) deposition, decrease Tau protein hyperphosphorylation and markedly improve cognitive functions in triple transgenic (3xTg) AD mice. In this study, we reported that the therapeutic effect of Se-Met on AD could also be due to neurogenesis modulation. By using the cultured hippocampal NSCs from 3xTg AD mice, we discovered that Se-Met (1–10 μM) with low concentration could promote NSC proliferation, while the one with a high concentration (50,100 μM) inhibiting proliferation. In subsequent studies, we also found that Se-Met activated the signaling pathway of PI3K/Akt, and thereby inhibited the GSK3β activity, which would further activated the β-catenin/Cyclin-D signaling pathway and promote NSC proliferation. Besides, after the induction of Se-Met, the number of neurons differentiated from NSCs significantly increased, and the number of astrocytes decreased. After a 90-day treatment with Se-Met (6 μg/mL), the number of hippocampal neurons in 4-month-old AD mice increased significantly, while the one of astrocyte saw a sharp drop. Thus, Se-Met treatment promoted NSCs differentiation into neurons, and subsequently repaired damaged neural systems in AD mice. Being consistent with our in vitro studies, Se-Met acts through the PI3K-Akt- GSK3β-Wnt signaling pathway in vivo. This study provides an unparalleled evidence that selenium (Se) compounds are, to some extent, effective

  17. Epidermal growth factor induces HCCR expression via PI3K/Akt/mTOR signaling in PANC-1 pancreatic cancer cells

    International Nuclear Information System (INIS)

    Xu, Zekuan; Zhang, Guoxin; Zhang, Yi; Jiang, Jiakai; Yang, Yang; Shi, Ruihua; Hao, Bo; Zhang, Zhihong; Huang, Zuhu; Kim, Jin W

    2010-01-01

    Human cervical cancer oncoprotein 1 (HCCR-1), reported as a negative regulator of p53, is over-expressed in a variety of human cancers. However, it is yet unknown whether HCCR-1 plays any role in pancreatic cancer development. The aim of this study was to investigate the effect of epidermal growth factor on the expression of HCCR in pancreatic cancer cells, and to explore if PI3K/Akt/mTOR signaling pathway mediated this expression. A polyclonal antibody against HCCR protein was raised by immunizing Balb/c mice with the purified recombinant protein pMBPc-HCCR. Tissue samples were constructed on a tissue chip, and the expression of HCCR was investigated by immunohistochemistry assay and Western blotting. Pancreatic cell line, PANC-1 cells were stably transfected with plasmids containing sense-HCCR-1 fragment and HCCR siRNA fragment. MTT and transwell assay were used to investigate the proliferation and invasion of stable tansfectants. The specific inhibitor of PI3K and mTOR was used to see if PI3K/mTOR signal transduction was involved in the induction of HCCR gene expression. A Luciferase assay was used to see if Akt can enhance the HCCR promoter activity. HCCR was up-regulated in pancreatic tumor tissues (mean Allred score 4.51 ± 1.549 vs. 2.87 ± 2.193, P < 0.01), especially with high expression in poorly differentiated pancreatic cancer. The growth of cells decreased in HCCR-1 siRNA transfected cells compared with vector transfectants. The number of invasion cells was significantly lower in HCCR-1 siRNA transfected cells (24.4 ± 9.9) than that in vector transfectants (49.1 ± 15.4). Treatment of PANC-1 cells with epidermal growth factor increased HCCR protein level in a dose- and time-dependent manner. However, application of LY294002 and rapamycin caused a dramatic reduction of epidermal growth factor-induced HCCR expression. Over-expression of exogenous constitutively active Akt increased the HCCR promoter activity; in contrast, dominant negative Akt decreased

  18. The Role of Insulin/IGF-1/PI3K/Akt/GSK3β Signaling in Parkinson's Disease Dementia

    Directory of Open Access Journals (Sweden)

    Liying Yang

    2018-02-01

    Full Text Available Dementia, a condition that frequently afflicts patients in advanced stages of Parkinson's disease (PD, results in decreased quality of life and survival time. Nevertheless, the pathological mechanisms underlying Parkinson's disease dementia (PDD are not completely understood. The symptoms characteristic of PDD may be the result of functional and structural deficiencies. The present study implicates the accumulation of Lewy bodies in the cortex and limbic system as a potent trigger in the development of PDD. In addition, significant Alzheimer-type pathologies, including amyloid-β (Aβ plaques and NFTs, are observed in almost half of PDD patients. Interestingly, links between PDD pathogenesis and the mechanisms underlying the development of insulin resistance have begun to emerge. Furthermore, previous studies have demonstrated that insulin treatment reduces amyloid plaques in Alzheimer's disease (AD, and normalizes the production and functionality of dopamine and ameliorates motor impairments in 6-OHDA-induced rat PD models. GSK3β, a downstream substrate of PI3K/Akt signaling following induction by insulin and IGF-1, exerts an influence on AD and PD physiopathology. The genetic overexpression of GSK3β in cortex and hippocampus results in signs of neurodegeneration and spatial learning deficits in in vivo models (Lucas et al., 2001, whereas its inhibition results in improvements in cognitive impairment in these rodents, including AD and PD. Accordingly, insulin- or IGF-1-activated PI3K/Akt/GSK3β signaling may be involved in PDD pathogenesis, at least in the pathology of PD-type + AD-type.

  19. Up-regulation of PI3K/Akt signaling by 17β-estradiol through activation of estrogen receptor-α, but not estrogen receptor-β, and stimulates cell growth in breast cancer cells

    International Nuclear Information System (INIS)

    Lee, Young-Rae; Park, Jinny; Yu, Hong-Nu; Kim, Jong-Suk; Youn, Hyun Jo; Jung, Sung Hoo

    2005-01-01

    Estrogen stimulates cell proliferation in breast cancer. The biological effects of estrogen are mediated through two intracellular receptors, estrogen receptor-α (ERα) and estrogen receptor-β (ERβ). However, the role of ERs in the proliferative action of estrogen is not well established. Recently, it has been known that ER activates phosphatidylinositol-3-OH kinase (PI3K) through binding with the p85 regulatory subunit of PI3K. Therefore, possible mechanisms may include ER-mediated phosphoinositide metabolism with subsequent formation of phosphatidylinositol-3,4,5-trisphosphate (PIP 3 ), which is generated from phosphatidylinositol 4,5-bisphosphate via PI3K activation. The present study demonstrates that 17β-estradiol (E2) up-regulates PI3K in an ERα-dependent manner, but not ERβ, and stimulates cell growth in breast cancer cells. In order to study this phenomenon, we have treated ERα-positive MCF-7 cells and ERα-negative MDA-MB-231 cells with 10 nM E2. Treatment of MCF-7 cells with E2 resulted in a marked increase in PI3K (p85) expression, which paralleled an increase in phospho-Akt (Ser-473) and PIP 3 level. These observations also correlated with an increased activity to E2-induced cell proliferation. However, these effects of E2 on breast cancer cells were not observed in the MDA-MB-231 cell line, indicating that the E2-mediated up-regulation of PI3K/Akt pathway is ERα-dependent. These results suggest that estrogen activates PI3K/Akt signaling through ERα-dependent mechanism in MCF-7 cells

  20. Neuroprotective effect of nicorandil through inhibition of apoptosis by the PI3K/Akt1 pathway in a mouse model of deep hypothermic low flow.

    Science.gov (United States)

    Yu, Di; Fan, Changfeng; Zhang, Weiyan; Wen, Zhongyuan; Hu, Liang; Yang, Lei; Feng, Yu; Yin, Ke-Jie; Mo, Xuming

    2015-10-15

    Nicorandil exerts a protective effect on ischemia-reperfusion (I/R) injury in the brain and kidney through anti-apoptotic mechanisms. However, the mechanism by which nicorandil protects against I/R injury induced by deep hypothermic low flow (DHLF) remains unclear. We used a cerebral I/R model induced by DHLF to determine the neuroprotective effects and possible mechanisms of nicorandil. Hematoxylin-eosin (HE) staining and in situ terminal deoxynucleotidyl transferase UTP nick end labeling (TUNEL) assay were used to detect changes in cell morphology and the number of apoptotic cells in hippocampus, respectively. The apoptotic regulators including Bcl-2, Bax, Akt, and p-Akt (the active, phosphorylated form of Akt) were examined by Western blot (WB). Histopathological findings showed that nicorandil significantly alleviated morphological damage in hippocampal and reduced the number of TUNEL-positive nuclei induced by DHLF. Nicorandil also increased the expression of Bcl-2 and decreased the expression of Bax, while increasing p-Akt level. Consistent with these results, nicorandil-mediated neuroprotection was reduced in the Akt1+/- mutant mice and inhibited by LY294002, a PI3K inhibitor. These findings showed that nicorandil provides a neuroprotective role in DHLF-induced I/R injury by inhibiting apoptosis via activation of the PI3K/Akt1 signaling pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Chi-Ming [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China); Department of Ophthalmology, Cardinal Tien Hospital, Taipei Hsien, Taiwan, ROC (China); Fang, Jia-You [Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan, ROC (China); Lin, Hsin-Huang [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China); Yang, Chi-Yea [Department of Biotechnology, Vanung University, Taoyuan, Taiwan, ROC (China); Hung, Chi-Feng, E-mail: 054317@mail.fju.edu.tw [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China)

    2009-10-09

    Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

  2. Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

    International Nuclear Information System (INIS)

    Chan, Chi-Ming; Fang, Jia-You; Lin, Hsin-Huang; Yang, Chi-Yea; Hung, Chi-Feng

    2009-01-01

    Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

  3. Involvement of the MAPK and PI3K pathways in chitinase 3-like 1-regulated hyperoxia-induced airway epithelial cell death

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Na; Lee, Kyung Eun; Hong, Jung Yeon; Heo, Won Il; Kim, Kyung Won; Kim, Kyu Earn [Department of Pediatrics and Institute of Allergy, Severance Medical Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul (Korea, Republic of); Sohn, Myung Hyun, E-mail: mhsohn@yuhs.ac [Department of Pediatrics and Institute of Allergy, Severance Medical Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Hyperoxia induces apoptosis and chitinase 3-like 1 expression in human airway epithelial cells. Black-Right-Pointing-Pointer Presence of chitinase 3-like 1 affects airway epithelial cell death after hyperoxic exposure. Black-Right-Pointing-Pointer Silencing chitinase 3-like 1 manipulate the phosphorylation of ERK, p38 and Akt. -- Abstract: Background: Exposure to 100% oxygen causes hyperoxic acute lung injury characterized by cell death and injury of alveolar epithelial cells. Recently, the role of chitinase 3-like 1 (CHI3L1), a member of the glycosyl hydrolase 18 family that lacks chitinase activity, in oxidative stress was demonstrated in murine models. High levels of serum CHI3L1 have been associated with various diseases of the lung, such as asthma, chronic obstructive pulmonary disease, and cancer. However, the role of CHI3L1 in human airway epithelial cells undergoing oxidative stress remains unknown. In addition, the signaling pathways associated with CHI3L1 in this process are poorly understood. Purpose: In this study, we demonstrate the role of CHI3L1, along with the MAPK and PI3K signaling pathways, in hyperoxia-exposed airway epithelial cells. Method: The human airway epithelial cell line, BEAS-2B, was exposed to >95% oxygen (hyperoxia) for up to 72 h. Hyperoxia-induced cell death was determined by assessing cell viability, Annexin-V FITC staining, caspase-3 and -7 expression, and electron microscopy. CHI3L1 knockdown and overexpression studies were conducted in BEAS-2B cells to examine the role of CHI3L1 in hyperoxia-induced apoptosis. Activation of the MAPK and PI3K pathways was also investigated to determine the role of these signaling cascades in this process. Results: Hyperoxia exposure increased CHI3L1 expression and apoptosis in a time-dependent manner. CHI3L1 knockdown protected cells from hyperoxia-induced apoptosis. In contrast, CHI3L1 overexpression promoted cell death after hyperoxia exposure. Finally

  4. TRPC6 channel-mediated neurite outgrowth in PC12 cells and hippocampal neurons involves activation of RAS/MEK/ERK, PI3K, and CAMKIV signaling.

    Science.gov (United States)

    Heiser, Jeanine H; Schuwald, Anita M; Sillani, Giacomo; Ye, Lian; Müller, Walter E; Leuner, Kristina

    2013-11-01

    The non-selective cationic transient receptor canonical 6 (TRPC6) channels are involved in synaptic plasticity changes ranging from dendritic growth, spine morphology changes and increase in excitatory synapses. We previously showed that the TRPC6 activator hyperforin, the active antidepressant component of St. John's wort, induces neuritic outgrowth and spine morphology changes in PC12 cells and hippocampal CA1 neurons. However, the signaling cascade that transmits the hyperforin-induced transient rise in intracellular calcium into neuritic outgrowth is not yet fully understood. Several signaling pathways are involved in calcium transient-mediated changes in synaptic plasticity, ranging from calmodulin-mediated Ras-induced signaling cascades comprising the mitogen-activated protein kinase, PI3K signal transduction pathways as well as Ca(2+) /calmodulin-dependent protein kinase II (CAMKII) and CAMKIV. We show that several mechanisms are involved in TRPC6-mediated synaptic plasticity changes in PC12 cells and primary hippocampal neurons. Influx of calcium via TRPC6 channels activates different pathways including Ras/mitogen-activated protein kinase/extracellular signal-regulated kinases, phosphatidylinositide 3-kinase/protein kinase B, and CAMKIV in both cell types, leading to cAMP-response element binding protein phosphorylation. These findings are interesting not only in terms of the downstream targets of TRPC6 channels but also because of their potential to facilitate further understanding of St. John's wort extract-mediated antidepressant activity. Alterations in synaptic plasticity are considered to play an important role in the pathogenesis of depression. Beside several other proteins, TRPC6 channels regulate synaptic plasticity. This study demonstrates that different pathways including Ras/MEK/ERK, PI3K/Akt, and CAMKIV are involved in the improvement of synaptic plasticity by the TRPC6 activator hyperforin, the antidepressant active constituent of St. John

  5. Profiling the HER3/PI3K Pathway in Breast Tumors Using Proximity-Directed Assays Identifies Correlations between Protein Complexes and Phosphoproteins

    Science.gov (United States)

    Mukherjee, Ali; Badal, Youssouf; Nguyen, Xuan-Thao; Miller, Johanna; Chenna, Ahmed; Tahir, Hasan; Newton, Alicia; Parry, Gordon; Williams, Stephen

    2011-01-01

    Background The identification of patients for targeted antineoplastic therapies requires accurate measurement of therapeutic targets and associated signaling complexes. HER3 signaling through heterodimerization is an important growth-promoting mechanism in several tumor types and may be a principal resistance mechanism by which EGFR and HER2 expressing tumors elude targeted therapies. Current methods that can study these interactions are inadequate for formalin-fixed, paraffin-embedded (FFPE) tumor samples. Methodology and Principal Findings Herein, we describe a panel of proximity-directed assays capable of measuring protein-interactions and phosphorylation in FFPE samples in the HER3/PI3K/Akt pathway and examine the capability of these assays to inform on the functional state of the pathway. We used FFPE breast cancer cell line and tumor models for this study. In breast cancer cell lines we observe both ligand-dependent and independent activation of the pathway and strong correlations between measured activation of key analytes. When selected cell lines are treated with HER2 inhibitors, we not only observe the expected molecular effects based on mechanism of action knowledge, but also novel effects of HER2 inhibition on key targets in the HER receptor pathway. Significantly, in a xenograft model of delayed tumor fixation, HER3 phosphorylation is unstable, while alternate measures of pathway activation, such as formation of the HER3PI3K complex is preserved. Measurements in breast tumor samples showed correlations between HER3 phosphorylation and receptor interactions, obviating the need to use phosphorylation as a surrogate for HER3 activation. Significance This assay system is capable of quantitatively measuring therapeutically relevant responses and enables molecular profiling of receptor networks in both preclinical and tumor models. PMID:21297994

  6. The Molecular Interaction of CAR and JAML Recruits the Central Cell Signal Transducer PI3K

    Energy Technology Data Exchange (ETDEWEB)

    Verdino, Petra; Witherden, Deborah A.; Havran, Wendy L.; Wilson, Ian A. (Scripps)

    2010-11-15

    Coxsackie and adenovirus receptor (CAR) is the primary cellular receptor for group B coxsackieviruses and most adenovirus serotypes and plays a crucial role in adenoviral gene therapy. Recent discovery of the interaction between junctional adhesion molecule-like protein (JAML) and CAR uncovered important functional roles in immunity, inflammation, and tissue homeostasis. Crystal structures of JAML ectodomain (2.2 angstroms) and its complex with CAR (2.8 angstroms) reveal an unusual immunoglobulin-domain assembly for JAML and a charged interface that confers high specificity. Biochemical and mutagenesis studies illustrate how CAR-mediated clustering of JAML recruits phosphoinositide 3-kinase (P13K) to a JAML intracellular sequence motif as delineated for the {alpha}{beta} T cell costimulatory receptor CD28. Thus, CAR and JAML are cell signaling receptors of the immune system with implications for asthma, cancer, and chronic nonhealing wounds.

  7. Regulation of ENaC-mediated alveolar fluid clearance by insulin via PI3K/Akt pathway in LPS-induced acute lung injury.

    Science.gov (United States)

    Deng, Wang; Li, Chang-Yi; Tong, Jin; Zhang, Wei; Wang, Dao-Xin

    2012-03-30

    Stimulation of epithelial sodium channel (ENaC) increases Na(+) transport, a driving force of alveolar fluid clearance (AFC) to keep alveolar spaces free of edema fluid that is beneficial for acute lung injury (ALI). It is well recognized that regulation of ENaC by insulin via PI3K pathway, but the mechanism of this signaling pathway to regulate AFC and ENaC in ALI remains unclear. The aim of this study was to investigate the effect of insulin on AFC in ALI and clarify the pathway in which insulin regulates the expression of ENaC in vitro and in vivo. A model of ALI (LPS at a dose of 5.0 mg/kg) with non-hyperglycemia was established in Sprague-Dawley rats receiving continuous exogenous insulin by micro-osmotic pumps and wortmannin. The lungs were isolated for measurement of bronchoalveolar lavage fluid(BALF), total lung water content(TLW), and AFC after ALI for 8 hours. Alveolar epithelial type II cells were pre-incubated with LY294002, Akt inhibitor and SGK1 inhibitor 30 minutes before insulin treatment for 2 hours. The expressions of α-,β-, and γ-ENaC were detected by immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. In vivo, insulin decreased TLW, enchanced AFC, increased the expressions of α-,β-, and γ-ENaC and the level of phosphorylated Akt, attenuated lung injury and improved the survival rate in LPS-induced ALI, the effects of which were blocked by wortmannin. Amiloride, a sodium channel inhibitor, significantly reduced insulin-induced increase in AFC. In vitro, insulin increased the expressions of α-,β-, and γ-ENaC as well as the level of phosphorylated Akt but LY294002 and Akt inhibitor significantly prevented insulin-induced increase in the expression of ENaC and the level of phosphorylated Akt respectively. Immunoprecipitation studies showed that levels of Nedd4-2 binding to ENaC were decreased by insulin via PI3K/Akt pathway. Our study demonstrated that insulin alleviated pulmonary edema and

  8. Regulation of ENaC-mediated alveolar fluid clearance by insulin via PI3K/Akt pathway in LPS-induced acute lung injury

    Directory of Open Access Journals (Sweden)

    Deng Wang

    2012-03-01

    Full Text Available Abstract Background Stimulation of epithelial sodium channel (ENaC increases Na+ transport, a driving force of alveolar fluid clearance (AFC to keep alveolar spaces free of edema fluid that is beneficial for acute lung injury (ALI. It is well recognized that regulation of ENaC by insulin via PI3K pathway, but the mechanism of this signaling pathway to regulate AFC and ENaC in ALI remains unclear. The aim of this study was to investigate the effect of insulin on AFC in ALI and clarify the pathway in which insulin regulates the expression of ENaC in vitro and in vivo. Methods A model of ALI (LPS at a dose of 5.0 mg/kg with non-hyperglycemia was established in Sprague-Dawley rats receiving continuous exogenous insulin by micro-osmotic pumps and wortmannin. The lungs were isolated for measurement of bronchoalveolar lavage fluid(BALF, total lung water content(TLW, and AFC after ALI for 8 hours. Alveolar epithelial type II cells were pre-incubated with LY294002, Akt inhibitor and SGK1 inhibitor 30 minutes before insulin treatment for 2 hours. The expressions of α-,β-, and γ-ENaC were detected by immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR and western blotting. Results In vivo, insulin decreased TLW, enchanced AFC, increased the expressions of α-,β-, and γ-ENaC and the level of phosphorylated Akt, attenuated lung injury and improved the survival rate in LPS-induced ALI, the effects of which were blocked by wortmannin. Amiloride, a sodium channel inhibitor, significantly reduced insulin-induced increase in AFC. In vitro, insulin increased the expressions of α-,β-, and γ-ENaC as well as the level of phosphorylated Akt but LY294002 and Akt inhibitor significantly prevented insulin-induced increase in the expression of ENaC and the level of phosphorylated Akt respectively. Immunoprecipitation studies showed that levels of Nedd4-2 binding to ENaC were decreased by insulin via PI3K/Akt pathway. Conclusions Our study

  9. Progranulin modulates cholangiocarcinoma cell proliferation, apoptosis, and motility via the PI3K/pAkt pathway

    Directory of Open Access Journals (Sweden)

    Daya M

    2018-01-01

    conclusion, our findings imply that PGRN modulates cell proliferation by dysregulating the G1 phase, inhibiting apoptosis, and that it plays a role in the EMT affecting CCA cell motility, possibly via the PI3K/pAkt pathway. Keywords: progranulin, cholangiocarcinoma, proliferation, migration, invasion, EMT

  10. Anticancer effects of kaempferol in A375 human malignant melanoma cells are mediated via induction of apoptosis, cell cycle arrest, inhibition of cell migration and downregulation of m-TOR/PI3K/AKT pathway.

    Science.gov (United States)

    Yang, Jia; Xiao, Peng; Sun, Jiaming; Guo, Liang

    2018-01-01

    Melanoma is an aggressive form of human cancer with limited treatment options currently available. The present study was aimed to evaluate the anticancer activity of kaempferol (KAM) against the human malignant melanoma A375 cell line along with evaluation of its effects on apoptosis, cell cycle, cell migration and m-TOR/PI3K/AKT pathway. Effects on cell viability were assessed by MTT assay while clonogenic assay measured the effects of KAM on colony formation. Annexin V assay evaluated the apoptotic effects of KAM in these cells using flow cytometry. Effects on cell cycle were determined by using flow cytometry with propidium iodide (PI) as probe. The effects of KAM on m-TOR/ PI3K/AKT signalling pathway were evaluated by western blot assay. MTT assay indicated that KAM exhibits a significant anticancer activity against A375 cells with an IC50 of 20 μM. These antiproliferative effects of KAM were also supported by the colony formation assay wherein KAM reduced the colony formation in a dose-dependent manner. The anticancer effect of KAM was found to be due to the initiation of apoptosis in human malignant melanoma A375 cells. Additionally, KAM also exhibited the capacity to trigger G2/M cell cycle arrest and to inhibit the cell migratory potential of A375 cells. KAM caused significant downregulation of m-TOR, phosphorylated (p) m-TOR, PI3K, p-PI3K and Akt protein levels in A375 malignantmelanoma cells. KAM exerts potent anticancer effects via induction of apoptosis, G2/M cell cycle arrest, cell migration inhibition and downregulation of m-TOR, pm-TOR, PI3K, p-PI3K and Akt protein levels.

  11. Camel Milk Ameliorates 5-Fluorouracil-Induced Renal Injury in Rats: Targeting MAPKs, NF-κB and PI3K/Akt/eNOS Pathways

    Directory of Open Access Journals (Sweden)

    Hany H. Arab

    2018-04-01

    Full Text Available Background/Aims: The clinical utility of 5-fluorouracil (5-FU is limited by its nephrotoxicity. Camel milk (CM has previously displayed beneficial effects in toxicant-induced nephropathies. The current study aimed to investigate the potential of CM to attenuate 5-FU-induced nephrotoxicity in rats. Methods: Renal tissues were studied in terms of oxidative stress, inflammation and apoptosis. The levels of renal injury markers, inflammatory cytokines along with NOX-1, Nrf-2 and HO-1 were assessed by ELISA. The expression of MMP-2, MMP-9, NF-κBp65, p53, Bax and PCNA were detected by Immunohistochemistry. To gain an insight into the molecular signaling mechanisms, we determined the effect of CM on MAPKs, NF-κB and PI3K/Akt/eNOS pathways by Western blotting. Results: CM lowered 5-FU-triggered increase of creatinine, BUN, Kim-1 and NGAL renal injury biomarkers and attenuated the histopathological aberrations. It suppressed oxidative stress and augmented renal antioxidant armory (GSH, SOD, GPx, TAC with restoration of NOX-1, Nrf-2 and HO-1 levels. CM also suppressed renal inflammation as indicated by inhibition of MPO, TNF-α, IL-1β, IL-18 and MCP-1 proinflammatory mediators and downregulation of MMP-2 and MMP-9 expression with boosting of IL-10. Regarding MAPKs signaling, CM suppressed the phosphorylation of p38 MAPK, JNK1/2 and ERK1/2 and inhibited NF-κB activation. For apoptosis, CM downregulated p53, Bax, CytC and caspase-3 proapoptotic signals with enhancement of Bcl-2 and PCNA. It also enhanced PI3K p110α, phospho-Akt and phospho-eNOS levels with augmentation of renal NO, favoring cell survival. Equally important, CM preconditioning enhanced 5-FU cytotoxicity in MCF-7, HepG-2, HCT-116 and PC-3 cells, thus, justifying their concomitant use. Conclusion: The current findings pinpoint, for the first time, the marked renoprotective effects of CM that were mediated via ROS scavenging, suppression of MAPKs and NF-κB along with activation of PI3K

  12. p110α and p110β isoforms of PI3K signaling: are they two sides of the same coin?

    Science.gov (United States)

    Singh, Paramjeet; Dar, Mohd Saleem; Dar, Mohd Jamal

    2016-09-01

    Class-1 phosphatidylinositol-3-kinases (PI3Ks) are activated by a variety of extracellular stimuli and have been implicated in a wide range of cellular processes. p110α and p110β are the two most studied isoforms of the class-1A PI3K signaling pathway. Although these two isoforms are ubiquitously expressed and play multiple redundant roles, they also have distinct functions within the cell. More recently, p110α and p110β isoforms have been shown to translocate into the nucleus and play a role in DNA replication and repair, and in cell cycle progression. In the following Review article, we discuss the overlapping and unique roles of p110α and p110β isoforms with a particular focus on their structure, expression analysis, subcellular localization, and signaling contributions in various cell types and model organisms. © 2016 Federation of European Biochemical Societies.

  13. Effects of exosomes derived from MDA-MB-231 on proliferation of endothelial cells and the role of MAPK/ERK and PI3K/Akt pathways

    Directory of Open Access Journals (Sweden)

    Shuang LONG

    2012-11-01

    Full Text Available Objective  To investigate the effects of exosomes derived from breast cancer cell line MDA-MB-231 on proliferation of human umbilical cord vein endothelial cells (HUVECs, and evaluate the role of MAPK/ERK and PI3K/Akt signal transduction pathway during the process. Methods  Exosomes were derived and purified from MDA-MB-231 by cryogenic ultracentrifugation and density gradient centrifugation. MTT assay was carried out for measurement of cell proliferation in HUVECs with exosome of 50, 100, 200 and 400μg/ml. The states of cell cycle of HUVECs co-cultured with 200μg/ml exosomes were detected by flow cytometry. The effects of 200μg/ml exosomes on the expression of ERK, Akt and phosphorylated ERK, Akt in HUVECs were detected with Western blotting. Results  Exosomes derived from MDA-MB-231 significantly promoted HUVECs proliferation in a classical time-and dose-dependent manner. Flow cytometry revealed that, co-cultured with 200μg/ml exosomes for 24h, S-phase cells in HUVECs increased, while G1/S phase cells in HUVECs decreased. Western blotting showed that, cocultured with 200μg/ml exosomes for 24h, 48h and 72h, the expressions of phosphorylated ERK and Akt were up-regulated in a time-dependent manner. Conclusion  Exosomes derived from breast cancer cell line MDA-MB-231 may promote HUVECs proliferation, the changes in cell cycle and the continuous activation of the MAPK/ERK and PI3K/Akt signal transduction pathways may be the underlying mechanism.

  14. Catestatin exerts direct protective effects on rat cardiomyocytes undergoing ischemia/reperfusion by stimulating PI3K-Akt-GSK3β pathway and preserving mitochondrial membrane potential.

    Directory of Open Access Journals (Sweden)

    Eleonora Bassino

    Full Text Available Catestatin (Cst is a 21-amino acid peptide deriving from Chromogranin A. Cst exerts an overall protective effect against an excessive sympathetic stimulation of cardiovascular system, being able to antagonize catecholamine secretion and to reduce their positive inotropic effect, by stimulating the release of nitric oxide (NO from endothelial cells. Moreover, Cst reduces ischemia/reperfusion (I/R injury, improving post-ischemic cardiac function and cardiomyocyte survival. To define the cardioprotective signaling pathways activated by Cst (5 nM we used isolated adult rat cardiomyocytes undergoing simulated I/R. We evaluated cell viability rate with propidium iodide labeling and mitochondrial membrane potential (MMP with the fluorescent probe JC-1. The involvement of Akt, GSK3β, eNOS and phospholamban (PLN cascade was studied by immunofluorescence. The role of PI3K-Akt/NO/cGMP pathway was also investigated by using the pharmacological blockers wortmannin (Wm, L-NMMA and ODQ. Our experiments revealed that Cst increased cell viability rate by 65% and reduced cell contracture in I/R cardiomyocytes. Wm, L-NMMA and ODQ limited the protective effect of Cst. The protective outcome of Cst was related to its ability to maintain MMP and to increase AktSer473, GSK3βSer9, PLNThr17 and eNOSSer1179 phosphorylation, while treatment with Wm abolished these effects. Thus, the present results show that Cst is able to exert a direct action on cardiomyocytes and give new insights into the molecular mechanisms involved in its protective effect, highlighting the PI3K/NO/cGMP pathway as the trigger and the MMP preservation as the end point of its action.

  15. Dual Inhibition of PI3K/AKT and MEK/ERK Pathways Induces Synergistic Antitumor Effects in Diffuse Intrinsic Pontine Glioma Cells

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    Y. Linda Wu

    2017-04-01

    Full Text Available Diffuse intrinsic pontine glioma (DIPG is a devastating disease with an extremely poor prognosis. Recent studies have shown that platelet-derived growth factor receptor (PDGFR and its downstream effector pathway, PI3K/AKT/mTOR, are frequently amplified in DIPG, and potential therapies targeting this pathway have emerged. However, the addition of targeted single agents has not been found to improve clinical outcomes in DIPG, and targeting this pathway alone has produced insufficient clinical responses in multiple malignancies investigated, including lung, endometrial, and bladder cancers. Acquired resistance also seems inevitable. Activation of the Ras/Raf/MEK/ERK pathway, which shares many nodes of cross talk with the PI3K/AKT pathway, has been implicated in the development of resistance. In the present study, perifosine, a PI3K/AKT pathway inhibitor, and trametinib, a MEK inhibitor, were combined, and their therapeutic efficacy on DIPG cells was assessed. Growth delay assays were performed with each drug individually or in combination. Here, we show that dual inhibition of PI3K/AKT and MEK/ERK pathways synergistically reduced cell viability. We also reveal that trametinib induced AKT phosphorylation in DIPG cells that could not be effectively attenuated by the addition of perifosine, likely due to the activation of other compensatory mechanisms. The synergistic reduction in cell viability was through the pronounced induction of apoptosis, with some effect from cell cycle arrest. We conclude that the concurrent inhibition of the PI3K/AKT and MEK/ERK pathways may be a potential therapeutic strategy for DIPG.

  16. Ginsenoside Rb1 protects against 6-hydroxydopamine-induced oxidative stress by increasing heme oxygenase-1 expression through an estrogen receptor-related PI3K/Akt/Nrf2-dependent pathway in human dopaminergic cells

    International Nuclear Information System (INIS)

    Hwang, Yong Pil; Jeong, Hye Gwang

    2010-01-01

    Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a popular traditional herbal medicine. Ginsenoside Rb1 (Rb1), an active component commonly found in ginseng root, is a phytoestrogen that exerts estrogen-like activity. In this study, we demonstrate that the phytoestrogen Rb1 inhibits 6-hydroxydopamine (6-OHDA)-induced oxidative injury via an ER-dependent Gβ1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of SH-SY5Y cells with Rb1 significantly reduced 6-OHDA-induced caspase-3 activation and subsequent cell death. Rb1 also up-regulated HO-1 expression, which conferred cytoprotection against 6-OHDA-induced oxidative injury. Moreover, Rb1 induced both Nrf2 nuclear translocation, which is upstream of HO-1 expression and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Also, Rb1-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that Rb1 augments the cellular antioxidant defenses through ER-dependent HO-1 induction via the Gβ1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress. Thus our study indicates that Rb1 has a partial cytoprotective role in dopaminergic cell culture systems.

  17. δ-Opioid receptor-stimulated Akt signaling in neuroblastoma x glioma (NG108-15) hybrid cells involves receptor tyrosine kinase-mediated PI3K activation

    International Nuclear Information System (INIS)

    Heiss, Anika; Ammer, Hermann; Eisinger, Daniela A.

    2009-01-01

    δ-Opioid receptor (DOR) agonists possess cytoprotective properties, an effect associated with activation of the 'pro-survival' kinase Akt. Here we delineate the signal transduction pathway by which opioids induce Akt activation in neuroblastoma x glioma (NG108-15) hybrid cells. Exposure of the cells to both [D-Pen 2,5 ]enkephalin and etorphine resulted in a time- and dose-dependent increase in Akt activity, as measured by means of an activation-specific antibody recognizing phosphoserine-473. DOR-mediated Akt signaling is blocked by the opioid antagonist naloxone and involves inhibitory G i/o proteins, because pre-treatment with pertussis toxin, but not over-expression of the G q/11 scavengers EBP50 and GRK2-K220R, prevented this effect. Further studies with Wortmannin and LY294002 revealed that phophoinositol-3-kinase (PI3K) plays a central role in opioid-induced Akt activation. Opioids stimulate Akt activity through transactivation of receptor tyrosine kinases (RTK), because pre-treatment of the cells with inhibitors for neurotrophin receptor tyrosine kinases (AG879) and the insulin-like growth factor receptor IGF-1 (AG1024), but not over-expression of the Gβγ scavenger phosducin, abolished this effect. Activated Akt translocates to the nuclear membrane, where it promotes GSK3 phosphorylation and prevents caspase-3 cleavage, two key events mediating inhibition of cell apoptosis and enhancement of cell survival. Taken together, these results demonstrate that in NG108-15 hybrid cells DOR agonists possess cytoprotective properties mediated by activation of the RTK/PI3K/Akt signaling pathway.

  18. {delta}-Opioid receptor-stimulated Akt signaling in neuroblastoma x glioma (NG108-15) hybrid cells involves receptor tyrosine kinase-mediated PI3K activation

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, Anika; Ammer, Hermann [Institute of Pharmacology, Toxicology and Pharmacy Ludwig-Maximilians-University of Munich Koeniginstrasse 16 80539 Muenchen Federal Republic of Germany (Germany); Eisinger, Daniela A., E-mail: eisinger@pharmtox.vetmed.uni-muenchen.de [Institute of Pharmacology, Toxicology and Pharmacy Ludwig-Maximilians-University of Munich Koeniginstrasse 16 80539 Muenchen Federal Republic of Germany (Germany)

    2009-07-15

    {delta}-Opioid receptor (DOR) agonists possess cytoprotective properties, an effect associated with activation of the 'pro-survival' kinase Akt. Here we delineate the signal transduction pathway by which opioids induce Akt activation in neuroblastoma x glioma (NG108-15) hybrid cells. Exposure of the cells to both [D-Pen{sup 2,5}]enkephalin and etorphine resulted in a time- and dose-dependent increase in Akt activity, as measured by means of an activation-specific antibody recognizing phosphoserine-473. DOR-mediated Akt signaling is blocked by the opioid antagonist naloxone and involves inhibitory G{sub i/o} proteins, because pre-treatment with pertussis toxin, but not over-expression of the G{sub q/11} scavengers EBP50 and GRK2-K220R, prevented this effect. Further studies with Wortmannin and LY294002 revealed that phophoinositol-3-kinase (PI3K) plays a central role in opioid-induced Akt activation. Opioids stimulate Akt activity through transactivation of receptor tyrosine kinases (RTK), because pre-treatment of the cells with inhibitors for neurotrophin receptor tyrosine kinases (AG879) and the insulin-like growth factor receptor IGF-1 (AG1024), but not over-expression of the G{beta}{gamma} scavenger phosducin, abolished this effect. Activated Akt translocates to the nuclear membrane, where it promotes GSK3 phosphorylation and prevents caspase-3 cleavage, two key events mediating inhibition of cell apoptosis and enhancement of cell survival. Taken together, these results demonstrate that in NG108-15 hybrid cells DOR agonists possess cytoprotective properties mediated by activation of the RTK/PI3K/Akt signaling pathway.

  19. Edaravone protects rats and human pulmonary alveolar epithelial cells against hyperoxia injury: heme oxygenase-1 and PI3K/Akt pathway may be involved.

    Science.gov (United States)

    Cao, Huifang; Feng, Ying; Ning, Yunye; Zhang, Zinan; Li, Weihao; Li, Qiang

    2015-01-01

    Hyperoxic acute lung injury (HALI) is a clinical syndrome as a result of prolonged supplement of high concentrations of oxygen. As yet, no specific treatment is available for HALI. The present study aims to investigate the effects of edaravone on hyperoxia-induced oxidative injury and the underlying mechanism. We treated rats and human pulmonary alveolar epithelial cells with hyperoxia and different concentration of edaravone, then examined the effects of edaravone on cell viability, cell injury and two oxidative products. The roles of heme oxygenase-1 (HO-1) and PI3K/Akt pathway were explored using Western blot and corresponding inhibitors. The results showed that edaravone reduced lung biochemical alterations induced by hyperoxia and mortality of rats, dose-dependently alleviated cell mortality, cell injury, and peroxidation of cellular lipid and DNA oxidative damage. It upregulated cellular HO-1 expression and activity, which was reversed by PI3K/Akt pathway inhibition. The administration of zinc protoporphyrin-IX, a HO-1 inhibitor, and LY249002, a PI3K/Akt pathway inhibitor, abolished the protective effects of edaravone in cells. This study indicates that edaravone protects rats and human pulmonary alveolar epithelial cells against hyperoxia-induced injury and the antioxidant effect may be related to upregulation of HO-1, which is regulated by PI3K/Akt pathway.

  20. Kaempferol increases apoptosis in human cervical cancer HeLa cells via PI3K/AKT and telomerase pathways.

    Science.gov (United States)

    Kashafi, Elham; Moradzadeh, Maliheh; Mohamadkhani, Ashraf; Erfanian, Saiedeh

    2017-05-01

    Cervical cancer is one of the most frequent cancers in women worldwide. Defects in the apoptotic pathways are responsible for both the disease pathogenesis and its therapy resistance. It is thus a good candidate for treatment by pro-apoptotic agents. Kaempferol as a flavonoid has antioxidant and anti-tumor properties. Kaempferol has been shown to induce apoptosis and cell death in cancer cells. However, due to the problems in the treatment of cervical cancer, this study is designed to investigate the molecular mechanism by which kaempferol suppresses the growth of cervical cancer HeLa cell as compared with HFF cells (normal cells). Cells treated with kaempferol (12-100μM) and 5-FU (1-10μM), as the positive control, up to 72h. Cell viability was determined by MTT assay and real time PCR was used to investigate apoptosis and telomerase genes expression. The results showed that kaempferol decreased cell viability as concentration- and time-dependently. IC 50 values were 10.48μM for HeLa and 707.00μM for HFF cells, as compared with 1.40μM and 16.38μM for 5-FU after 72h treatment, respectively. Also, kaempferol induced cellular apoptosis and aging through down-regulating the PI3K/AKT and hTERT pathways. This study suggests that kaempferol may be a useful adjuvant therapeutic agent in the treatment of cervical cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Disrupted PI3K p110δ Signaling Dysregulates Maternal Immune Cells and Increases Fetal Mortality In Mice

    Directory of Open Access Journals (Sweden)

    Jens Kieckbusch

    2015-12-01

    Full Text Available Maternal immune cells are an integral part of reproduction, but how they might cause pregnancy complications remains elusive. Macrophages and their dual function in inflammation and tissue repair are thought to play key yet undefined roles. Altered perinatal growth underpins adult morbidity, and natural killer (NK cells may sustain fetal growth by establishing the placental blood supply. Using a mouse model of genetic inactivation of PI3K p110δ, a key intracellular signaling molecule in leukocytes, we show that p110δ regulates macrophage dynamics and NK-cell-mediated arterial remodeling. The uterus of dams with inactive p110δ had decreased IFN-γ and MHC class IIlow macrophages but enhanced IL-6. Poor vascular remodeling and a pro-inflammatory uterine milieu resulted in fetal death or growth retardation. Our results provide one mechanism that explains how imbalanced adaptations of maternal innate immune cells to gestation affect offspring well-being with consequence perinatally and possibly into adulthood.

  2. Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

    International Nuclear Information System (INIS)

    Roffe, Suzy; Hagai, Yosey; Pines, Mark; Halevy, Orna

    2010-01-01

    Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of the phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.

  3. Halofuginone inhibits Smad3 phosphorylation via the PI3K/Akt and MAPK/ERK pathways in muscle cells: Effect on myotube fusion

    Energy Technology Data Exchange (ETDEWEB)

    Roffe, Suzy [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Hagai, Yosey [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Institute of Animal Sciences, Volcani Center, Bet Dagan 50250 (Israel); Pines, Mark [Institute of Animal Sciences, Volcani Center, Bet Dagan 50250 (Israel); Halevy, Orna, E-mail: halevyo@agri.huji.ac.il [Department of Animal Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel)

    2010-04-01

    Halofuginone, a novel inhibitor of Smad3 phosphorylation, has been shown to inhibit muscle fibrosis and to improve cardiac and skeletal muscle functions in the mdx mouse model of Duchenne muscular dystrophy. Here, we demonstrate that halofuginone promotes the phosphorylation of Akt and mitogen-activated protein kinase (MAPK) family members in a C2 muscle cell line and in primary myoblasts derived from wild-type and mdx mice diaphragms. Halofuginone enhanced the association of phosphorylated Akt and MAPK/extracellular signal-regulated protein kinase (ERK) with the non-phosphorylated form of Smad3, accompanied by a reduction in Smad3 phosphorylation levels. This reduction was reversed by inhibitors of the phosphoinositide 3'-kinase/Akt (PI3K/Akt) and MAPK/ERK pathways, suggesting their specific role in mediating halofuginone's inhibitory effect on Smad3 phosphorylation. Halofuginone enhanced Akt, MAPK/ERK and p38 MAPK phosphorylation and inhibited Smad3 phosphorylation in myotubes, all of which are crucial for myotube fusion. In addition, halofuginone increased the association Akt and MAPK/ERK with Smad3. As a consequence, halofuginone promoted myotube fusion, as reflected by an increased percentage of C2 and mdx myotubes containing high numbers of nuclei, and this was reversed by specific inhibitors of the PI3K and MAPK/ERK pathways. Together, the data suggest a role, either direct or via inhibition of Smad3 phosphorylation, for Akt or MAPK/ERK in halofuginone-enhanced myotube fusion, a feature which is crucial to improving muscle function in muscular dystrophies.

  4. Tetramethylpyrazine analogue CXC195 protects against cerebral ischemia/reperfusion-induced apoptosis through PI3K/Akt/GSK3β pathway in rats.

    Science.gov (United States)

    Chen, Lin; Wei, Xinbing; Hou, Yunfeng; Liu, Xiaoqian; Li, Senpeng; Sun, Baozhu; Liu, Xinyong; Liu, Huiqing

    2014-01-01

    CXC195 showed strongest protective effects among the ligustrazine derivatives in cells and prevented apoptosis induced by H2O2 injury. We recently demonstrated that CXC195 protected against cerebral ischemia/reperfusion (I/R) injury by its antioxidant activity. However, whether the anti-apoptotic action of CXC195 is involved in cerebral I/R injury is unknown. Here, we investigated the role of CXC195 in apoptotic processes induced by cerebral I/R and the possible signaling pathways. Male Wistar rats were submitted to transient middle cerebral artery occlusion for 2h, followed by 24h reperfusion. CXC195 was injected intraperitoneally at 2h and 12h after the onset of ischemia. The number of apoptotic cells was measured by TUNEL assay, apoptosis-related protein cleaved caspase-3, Bcl-2, Bax and the phosphorylation levels of Akt and GSK3β in ischemic penumbra were assayed by western blot. The results showed that administration of CXC195 at the doses of 3mg/kg and 10mg/kg significantly inhibited the apoptosis by decreasing the number of apoptotic cells, decreasing the level of cleaved caspase-3 and Bax, and increasing the level of Bcl-2 in rats subjected to I/R injury. Simultaneously, CXC195 treatment markedly increased the phosphorylation of Akt and GSK3β. Blockade of PI3K activity by wortmannin, dramatically abolished its anti-apoptotic effect and lowered both Akt and GSK3β phosphorylation levels. Our study firstly demonstrated that CXC195 protected against cerebral I/R injury by reducing apoptosis in vivo and PI3K/Akt/GSK3β pathway involved in the anti-apoptotic effect. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  5. Oxyfadichalcone C inhibits melanoma A375 cell proliferation and metastasis via suppressing PI3K/Akt and MAPK/ERK pathways.

    Science.gov (United States)

    Peng, Xiaolin; Wang, Zhengming; Liu, Yang; Peng, Xin; Liu, Yao; Zhu, Shan; Zhang, Zhe; Qiu, Yuling; Jin, Meihua; Wang, Ran; Zhang, Qingying; Kong, Dexin

    2018-08-01

    Melanoma remains to be one of the most incurable cancers. Discovery of novel antitumor agent for melanoma therapy is expected. We recently isolated Oxyfadichalcone C from Oxytropis falcate and investigated the anti-proliferative and anti-metastatic activity on human melanoma A375 cells in vitro. Cell viability was determined using MTT assay and soft agar cloning formation assay. The effect of Oxyfadichalcone C on cell cycle distribution and apoptosis were analyzed by flow cytometry. Cell metastasis was determined by wound healing assay, Transwell assay and Gelatin zymography assay. The effect of Oxyfadichalcone C on signal proteins of PI3K/Akt and MAPK/ERK pathways was examined by western blot analysis. Synergism assay was employed to determine whether combination of Oxyfadichalcone C with Vemurafenib would enhance the anti-proliferative effect. Oxyfadichalcone C potently inhibited proliferation, induced G1 phase arrest and weak apoptosis in A375 cells. Anti-migration and anti-invasion activities were also indicated. Such effects were associated with upregulation of p27, reduction of cyclin D1, p-pRb, p-Integrin β1, as well as the proteolytic activity of metalloproteinase (MMP)-2/9. Meanwhile, key molecules of PI3K/Akt and MAPK/ERK pathways were downregulated, which might be involved in the inhibition against proliferation and metastasis of A375 cells by Oxyfadichalcone C. In addition, combination of Oxyfadichalcone C with Vemurafenib at a ratio of IC50 Oxyfadichalcone C : 5 × IC 50 Vemurafenib exhibited synergistic anti-proliferative effect on A375 cells. Our findings suggest that Oxyfadichalcone C has the potential to be developed as a promising drug candidate for the treatment of melanoma. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. CNTN-1 Enhances Chemoresistance in Human Lung Adenocarcinoma Through Induction of Epithelial-Mesenchymal Transition by Targeting the PI3K/Akt Pathway

    Directory of Open Access Journals (Sweden)

    Ruijie Zhang

    2017-09-01

    Full Text Available Background/Aims: Chemoresistance has been a major obstacle to the effective treatment of lung cancer. Previously, we found that contactin-1 (CNTN-1 is related to cisplatin resistance in lung adenocarcinoma. Here, we aimed to investigate the underlying mechanism behind the role of CNTN-1 in cisplatin resistance in lung adenocarcinoma. Methods: EMT-associated phenotypes, including alterations in cellular morphology and marker (E-cadherin, N-cadherin and Vimentin expression, were compared between A549 cells and A549/DDP cells (a cisplatin-resistant cell line of lung adenocarcinoma with abnormal CNTN-1 expression by using real-time time PCR and Western blotting. Other methods, including CNTN-1 overexpression in A549 cells and CNTN-1 knockdown in A549/DDP cells, were also used to investigate the role of CNTN-1 in mediating the EMT phenotype and thr resulting cisplatin resistance and malignant progression of cancer cells in vitro and in vivo. Results: A549/DDP cells exhibited an EMT phenotype and aggravated malignant behaviors. CNTN-1 knockdown in A549/DDP cells partly reversed the EMT phenotype, increased drug sensitivity, and attenuated the malignant progression whereas CNTN-1 overexpression in A549 cells resulted in the opposite trend. Furthermore, the PI3K/Akt pathway was involved in the effects of CNTN-1 on EMT progression in A549/DDP cells, verified by the xenograft mouse model. Conclusion: CNTN-1 promotes cisplatin resistance in human cisplatin-resistant lung adenocarcinoma through inducing the EMT process by activating the PI3K/Akt signaling pathway. CNTN-1 may be a potential therapeutic target to reverse chemoresistance in cisplatin-resistant lung adenocarcinoma.

  7. Effects of SIRT1 gene knock-out via activation of SREBP2 protein-mediated PI3K/AKT signaling on osteoarthritis in mice.

    Science.gov (United States)

    Yu, Fei; Zeng, Hui; Lei, Ming; Xiao, De-Ming; Li, Wei; Yuan, Hao; Lin, Jian-Jing

    2016-10-01

    This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls. The knee joint specimens were then divided into four groups: SIRT1 +/+ control group (group A, n=6); SIRT1 +/+ osteoarthritis group (group B, n=6); SIRT1 -/- control group (group C, n=6); SIRT1 -/- osteoarthritis group (group D, n=6). HE staining, Masson staining, Safranin O-Fast Green staining and Van Gieson staining were used to observe the morphological changes in the articular cartilage of the knee. Immunohistochemical staining was employed to detect the expression of SIRT1, SREBP2, VEGF, AKT, HMGCR and type II collagen proteins. SA-β-gal staining was utilized to evaluate chondrocyte aging. The results showed clear knee joint cartilage destruction and degeneration in the SIRT1 -/- osteoarthritis group. The tidal line was twisted and displaced anteriorly. Type II collagen was destroyed and distributed unevenly. Compared with the SIRT1 +/+ osteoarthritis group and SIRT1 -/- control group, SIRT1 protein expression was not obviously changed in the SIRT1 -/- osteoarthritis group (P>0.05), while the expression levels of the SREBP2, VEGF and HMGCR proteins were significantly increased (Pknock-out may aggravate cartilage degeneration in osteoarthritis by activating the SREBP2 protein-mediated PI3K/AKT signalling pathway, suggesting that SIRT1 gene may play a protective role against osteoarthritis.

  8. PI3K/Akt Pathway Contributes to Neurovascular Unit Protection of Xiao-Xu-Ming Decoction against Focal Cerebral Ischemia and Reperfusion Injury in Rats

    Directory of Open Access Journals (Sweden)

    Rui Lan

    2013-01-01

    Full Text Available In the present study, we used a focal cerebral ischemia and reperfusion rat model to investigate the protective effects of Xiao-Xu-Ming decoction (XXMD on neurovascular unit and to examine the role of PI3K (phosphatidylinositol 3-kinase/Akt pathway in this protection. The cerebral ischemia was induced by 90 min of middle cerebral artery occlusion. Cerebral infarct area was measured by tetrazolium staining, and neurological function was observed at 24 h after reperfusion. DNA fragmentation assay, combined with immunofluorescence, was performed to evaluate apoptosis of neuron, astrocyte, and vascular endothelial cell which constitute neurovascular unit. The expression levels of proteins involved in PI3K/Akt pathway were detected by Western blot. The results showed that XXMD improved neurological function, decreased cerebral infarct area and neuronal damage, and attenuated cellular apoptosis in neurovascular unit, while these effects were abolished by inhibition of PI3K/Akt with LY294002. We also found that XXMD upregulated p-PDKl, p-Akt, and p-GSK3β expression levels, which were partly reversed by LY294002. In addition, the increases of p-PTEN and p-c-Raf expression levels on which LY294002 had no effect were also observed in response to XXMD treatment. The data indicated the protective effects of XXMD on neurovascular unit partly through the activation of PI3K/Akt pathway.

  9. A phosphoinositide 3-kinase (PI3K)-serum- and glucocorticoid-inducible kinase 1 (SGK1) pathway promotes Kv7.1 channel surface expression by inhibiting Nedd4-2 protein

    DEFF Research Database (Denmark)

    Andersen, Martin Nybo; Krzystanek, Katarzyna; Petersen, Frederic

    2013-01-01

    Epithelial cell polarization involves several kinase signaling cascades that eventually divide the surface membrane into an apical and a basolateral part. One kinase, which is activated during the polarization process, is phosphoinositide 3-kinase (PI3K). In MDCK cells, the basolateral potassium...... channel Kv7.1 requires PI3K activity for surface-expression during the polarization process. Here, we demonstrate that Kv7.1 surface expression requires tonic PI3K activity as PI3K inhibition triggers endocytosis of these channels in polarized MDCK. Pharmacological inhibition of SGK1 gave similar results...... as PI3K inhibition, whereas overexpression of constitutively active SGK1 overruled it, suggesting that SGK1 is the primary downstream target of PI3K in this process. Furthermore, knockdown of the ubiquitin ligase Nedd4-2 overruled PI3K inhibition, whereas a Nedd4-2 interaction-deficient Kv7.1 mutant...

  10. Salvinorin A preserves cerebral pial artery autoregulation after forebrain ischemia via the PI3K/AKT/cGMP pathway

    Directory of Open Access Journals (Sweden)

    H.P. Dong

    2018-03-01

    Full Text Available This study aimed to investigate the protective effect of salvinorin A on the cerebral pial artery after forebrain ischemia and explore related mechanisms. Thirty Sprague-Dawley rats received forebrain ischemia for 10 min. The dilation responses of the cerebral pial artery to hypercapnia and hypotension were assessed in rats before and 1 h after ischemia. The ischemia reperfusion (IR control group received DMSO (1 µL/kg immediately after ischemia. Two different doses of salvinorin A (10 and 20 µg/kg were administered following the onset of reperfusion. The 5th, 6th, and 7th groups received salvinorin A (20 µg/kg and LY294002 (10 µM, L-NAME (10 μM, or norbinaltorphimine (norBIN, 1 μM after ischemia. The levels of cGMP in the cerebrospinal fluid (CSF were also measured. The phosphorylation of AKT (p-AKT was measured in the cerebral cortex by western blot at 24 h post-ischemia. Cell necrosis and apoptosis were examined by hematoxylin-eosin staining (HE and TUNEL staining, respectively. The motor function of the rats was evaluated at 1, 2, and 5 days post-ischemia. The dilation responses of the cerebral pial artery were significantly impaired after ischemia and were preserved by salvinorin A treatment. In addition, salvinorin A significantly increased the levels of cGMP and p-AKT, suppressed cell necrosis and apoptosis of the cerebral cortex and improved the motor function of the rats. These effects were abolished by LY294002, L-NAME, and norBIN. Salvinorin A preserved cerebral pial artery autoregulation in response to hypercapnia and hypotension via the PI3K/AKT/cGMP pathway.

  11. Electroacupuncture Ameliorates Acute Renal Injury in Lipopolysaccharide-Stimulated Rabbits via Induction of HO-1 through the PI3K/Akt/Nrf2 Pathways.

    Science.gov (United States)

    Yu, Jian-Bo; Shi, Jia; Zhang, Yuan; Gong, Li-Rong; Dong, Shu-An; Cao, Xin-Shun; Wu, Li-Li; Wu, Li-Na

    2015-01-01

    Electroacupuncture at select acupoints have been verified to protect against organ dysfunctions during endotoxic shock. And, heme oxygenase (HO)-1 as a phase II enzyme and antioxidant contributed to the protection of kidney in septic shock rats. The phosphatidylinositol 3-kinase (PI3K)-Akt pathway mediated the activation of NF-E2 related factor-2 (Nrf2), which was involved in HO-1 induction. To understand the efficacy of electroacupuncture stimulation in ameliorating acute kidney injury (AKI) through the PI3K/Akt/Nrf2 pathway and subsequent HO-1 upregulation, a dose of LPS 5mg/kg was administered intravenously to replicate the rabbit model of AKI induced by endotoxic shock. Electroacupuncture pretreatment was handled bilaterally at Zusanli and Neiguan acupoints for five consecutive days while sham electroacupuncture at non-acupoints as control. Results displayed that electroacupuncture stimulation significantly alleviated the morphologic renal damage, attenuated renal tubular apoptosis, suppressed the elevated biochemical indicators of AKI caused by LPS, enhanced the expressions of phospho-Akt, HO-1protein, Nrf2 total and nucleoprotein, and highlighted the proportions of Nrf2 nucleoprotein as a parallel. Furthermore, partial protective effects of elecroacupuncture were counteracted by preconditioning with wortmannin (the selective PI3K inhibitor), indicating a direct involvement of PI3K/Akt pathway. Inconsistently, wortmannin pretreatment made little difference to the expressions of HO-1, Nrf2 nucleoprotein and total protein, which indicated that PI3K/Akt may be not the only pathway responsible for electroacupuncture-afforded protection against LPS-induced AKI. These findings provide new insights into the potential future clinical applications of electroacupuncture for AKI induced by endotoxic shock instead of traditional remedies.

  12. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ping, E-mail: lping@sdu.edu.cn [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Kong, Feng; Wang, Jue [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Lu, Qinghua [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China); Xu, Haijia [Department of Cardiology, Wendeng Central Hospital of Weihai City, Shandong, Weihai 264400 (China); Qi, Tonggang [Central Laboratory, The Second Hospital of Shandong University, Shandong, Jinan 250033 (China); Meng, Juan [Department of Cardiology, The Second Hospital of Shandong University, No. 247, Beiyuan Road, Shandong, Jinan 250033 (China)

    2015-02-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  13. Involvement of IGF-1 and MEOX2 in PI3K/Akt1/2 and ERK1/2 pathways mediated proliferation and differentiation of perivascular adipocytes

    International Nuclear Information System (INIS)

    Liu, Ping; Kong, Feng; Wang, Jue; Lu, Qinghua; Xu, Haijia; Qi, Tonggang; Meng, Juan

    2015-01-01

    Perivascular adipocyte (PVAC) proliferation and differentiation were closely involved in cardiovascular disease. We aimed to investigate whether phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways enhance PVAC functions activated by insulin-like growth factor 1(IGF-1) and suppressed by mesenchyme homeobox 2 (MEOX2). In this study, PVACs from primary culture were cultured and induced to differentiate. Cell viability assays demonstrated that IGF-1 promoted PVAC proliferation and differentiation. However MEOX2 counteracted these IGF-1-mediated actions. Flow Cytometry revealed that IGF-1 increased S phase cells and decreased apoptosis; however, MEOX2 decreased S phase cells, increased G0–G1 phase cells, and promoted apoptosis. During PVAC proliferation and differentiation, IGF-1 activated PI3K/Akt1/2 and ERK1/2 signaling pathways, upregulated the expression of these signaling proteins and FAS, and increased PVAC lipid content. In contrast, MEOX2 constrained the phosphorylation of ERK1/2 and Akt1/2 protein, down-regulated these signaling molecules and FAS, and decreased PVAC lipid content. Instead, MEOX2 knockdown enhanced the ERK1/2 and Akt1/2 phosphorylation, augmented the expression of these signaling molecules and FAS, and increased PVAC lipid content. Our findings suggested that PI3K/Akt1/2 and ERK1/2 activation mediated by IGF-1 is essential for PVAC proliferation and differentiation, and MEOX2 is a promising therapeutic gene to intervene in the signaling pathways and inhibit PVAC functions. - Highlights: • IGF-1 activated PI3K/Akt2 and ERK1/2 pathways to mediate PVAC proliferation and differentiation. • The expression of ERK1, ERK 2, PI3K, Akt1 and Akt2 showed different change trends between PVAC proliferation and differentiation. • MEOX2 effectively expressed in PVAC, increased early and late cellular apoptosis, and inhibited its proliferation. • MEOX2 depressed PVAC differentiation and FAS expression

  14. Andrographolide inhibits growth of human T-cell acute lymphoblastic leukemia Jurkat cells by downregulation of PI3K/AKT and upregulation of p38 MAPK pathways

    Directory of Open Access Journals (Sweden)

    Yang T

    2016-04-01

    Full Text Available Tingfang Yang,1 Shuluan Yao,2 Xianfeng Zhang,3 Yan Guo2 1Department of Pediatrics, Jining No 1 People’s Hospital, Shandong Province, People’s Republic of China; 2Department of Respiratory Medicine, Jining Medical University Affiliated Hospital, Shandong Province, People’s Republic of China; 3Department of Psychiatry, Jining Psychiatric Hospital, Shandong Province, People’s Republic of China Abstract: T-cell acute lymphoblastic leukemia (T-ALL as a prevalent hematologic malignancy is one of the most common malignant tumors worldwide in children. Andrographolide (Andro, the major active component from Andrographis paniculata, has been shown to possess antitumor activities in several types of cancer cells. However, whether Andro would inhibit T-ALL cell growth remains unclear. In this study, we investigated the cytotoxic effect of Andro on human T-ALL Jurkat cells and explored the mechanisms of cell death. Cell apoptosis was assayed by flow cytometry, and the signaling transduction for Andro was analyzed by Western blotting. The results indicated 10 µg/mL Andro could significantly induce Jurkat cells’ apoptosis, depending on the inhibition of PI3K/AKT pathway. Moreover, Andro-induced apoptosis is enhanced by AKT-selective inhibitor LY294002. ERK- or JNK-selective inhibitors PD98059 and SP600125 had no effect on Andro-induced apoptosis. In addition, p38 inhibitor SB203580 could reverse Andro-induced apoptosis in Jurkat cells. We also found that the protein expression of p-p53 and p-p38 were increased after Andro treatments. The result of an in vivo study also demonstrated Andro’s dose-dependent inhibition in subcutaneous Jurkat xenografts. In conclusion, our findings explained a novel mechanism of drug action by Andro in Jurkat cells and suggested that Andro might be developed into a new candidate therapy for T-ALL patients in the coming days. Keywords: andrographolide, PI3K, AKT, Burkitt lymphoma, Jurkat cell

  15. Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

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    Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Luo, Wenjuan, E-mail: wenjuanluoxa@163.com [School of Pharmacy, Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China); Liu, Min, E-mail: minliusx@163.com [Department of Infectious Diseases, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061 (China)

    2016-07-01

    With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI