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Sample records for calcineurin inhibitor toxicity

  1. Calcineurin inhibitor toxicity in renal allografts: Morphologic clues from protocol biopsies

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    Sharma Alok

    2010-10-01

    Full Text Available Background: Calcineurin inhibitors (cyclosporine and tacrolimus are important constituents of post renal transplant immunosuppression. However, renal toxicity limits their utility. Histological features of calcineurin inhibitor toxicity (CNIT have been the subject of few studies using protocol biopsy samples, and consensus on diagnostic criteria is still evolving. Aims: To analyze the spectrum of histological changes in protocol renal allograft biopsies with evidence of CNIT and identify additional features that are likely to help the pathologist in arriving at a diagnosis. Materials and Methods: One hundred and forty protocol allograft biopsies performed at 1, 6 and 12 months post renal transplant were studied. The defining features of CNIT included: isometric vacuolization of proximal tubular cells, arteriolar hyalinosis with medial/peripheral nodules and striped pattern of tubular atrophy/interstitial fibrosis. Other features such as global glomerulosclerosis, vacuolization of smooth muscle cells of arterioles, tubular microcalcinosis, ischemic shrinkage of glomeruli and hyperplasia of juxtaglomerular apparatus (JGA were also analyzed and graded semiquantitatively. Results: CNIT was seen in 17/140 protocol biopsies (12.1%. In addition to the diagnostic criteria, arteriolar hyalinosis, smooth muscle cell vacuolization of arterioles and hyperplasia of JGA were found to be useful indicators of CNIT. Conclusions: There is a relatively high incidence of CNIT in protocol allograft biopsies. A critical analysis of renal biopsy in adequate number of serial step sections to identify these features is mandatory, as many of these features are subtle and are likely to be missed if not specifically sought.

  2. Utilization of an EMR-biorepository to identify the genetic predictors of calcineurin-inhibitor toxicity in heart transplant recipients.

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    Oetjens, Matthew; Bush, William S; Birdwell, Kelly A; Dilks, Holli H; Bowton, Erica A; Denny, Joshua C; Wilke, Russell A; Roden, Dan M; Crawford, Dana C

    2014-01-01

    Calcineurin-inhibitors CI are immunosuppressive agents prescribed to patients after solid organ transplant to prevent rejection. Although these drugs have been transformative for allograft survival, long-term use is complicated by side effects including nephrotoxicity. Given the narrow therapeutic index of CI, therapeutic drug monitoring is used to prevent acute rejection from underdosing and acute toxicity from overdosing, but drug monitoring does not alleviate long-term side effects. Patients on calcineurin-inhibitors for long periods almost universally experience declines in renal function, and a subpopulation of transplant recipients ultimately develop chronic kidney disease that may progress to end stage renal disease attributable to calcineurin inhibitor toxicity (CNIT). Pharmacogenomics has the potential to identify patients who are at high risk for developing advanced chronic kidney disease caused by CNIT and providing them with existing alternate immunosuppressive therapy. In this study we utilized BioVU, Vanderbilt University Medical Center's DNA biorepository linked to de-identified electronic medical records to identify a cohort of 115 heart transplant recipients prescribed calcineurin-inhibitors to identify genetic risk factors for CNIT We identified 37 cases of nephrotoxicity in our cohort, defining nephrotoxicity as a monthly median estimated glomerular filtration rate (eGFR)pharmacogenomic genotyping platform that assays 184 variants across 34 genes. In Cox regression analysis adjusting for age at transplant, pre-transplant chronic kidney disease, pre-transplant diabetes, and the three most significant principal components (PCAs), we did not identify any markers that met our multiple-testing threshold. As a secondary analysis we also modeled post-transplant eGFR directly with linear mixed models adjusted for age at transplant, cyclosporine use, median BMI, and the three most significant principal components. While no SNPs met our threshold for

  3. Once-daily oral administration of cyclosporine in a lung transplant patient with a history of renal toxicity of calcineurin inhibitors.

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    Matsuda, Yuya; Chen, Fengshi; Miyata, Hitomi; Date, Hiroshi

    2014-07-01

    Cyclosporine is usually administered orally in two divided doses every 12 h in transplant patients. However, some patients have difficulty in achieving therapeutic levels after transplantation. In fact, cyclosporine is reportedly administered once daily in renal and liver transplantation cases, but not in lung transplantation cases. We report a patient with a history of calcineurin inhibitor-induced renal toxicity who successfully underwent living-donor lobar lung transplantation (LDLLT) with the novel immunosuppressive strategy of once-daily administration of cyclosporine. An 18-year old man with progressive respiratory insufficiency after bone marrow transplantation was referred to our hospital for lung transplantation. He had a history of renal toxicity due to calcineurin inhibitors. Based on his history of tacrolimus- and cyclosporine-induced renal toxicity, we decided to initiate basiliximab as induction therapy, followed by once-daily cyclosporine administration to obtain high enough blood cyclosporine concentrations at 2 h post-dose (C2) and lowered trough blood concentrations (C0) for protection of renal function as maintenance therapy. LDLLT was successfully performed, and the postoperative course was uneventful and free of rejection episodes. Cyclosporine dosing was adjusted with intensive therapeutic drug monitoring of blood cyclosporine levels. One year after LDLLT, the patient is alive and well with no problems with daily life activities. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  4. Calcineurin inhibitor minimisation versus continuation of calcineurin inhibitor treatment for liver transplant recipients

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    Penninga, Luit; Wettergren, Andre; Chan, An-Wen;

    2012-01-01

    The therapeutic success of liver transplantation has been largely attributable to the development of effective immunosuppressive treatment regimens. In particular, calcineurin inhibitors were essential in reducing acute rejection and improving early survival. Currently, more than 90% of all liver...

  5. Efficacy of topical calcineurin inhibitors in vitiligo.

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    Wong, Russell; Lin, Andrew N

    2013-04-01

    Topical tacrolimus and pimecrolimus are indicated for the treatment of atopic dermatitis, but they have been studied in many off-label uses. We reviewed the English language literature to define their roles in treatment of vitiligo. Double-blind studies show that tacrolimus 0.1% ointment combined with excimer laser is superior to placebo, especially for UV resistant areas, such as bony prominences of the extremities. When used alone, tacrolimus 0.1% ointment is almost as effective as clobetasol propionate 0.05% ointment. Other studies suggest it can also be effective for facial lesions. Double blind studies show that pimecrolimus 1% cream combined with narrow band UVB is superior to placebo, especially for facial lesions. Additional studies would further clarify the role of topical calcineurin inhibitors in vitiligo. © 2013 The International Society of Dermatology.

  6. Are calcineurin inhibitors-free regimens ready for prime time?

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    Vincenti, Flavio

    2012-11-01

    The goal of research in transplant therapeutics is to achieve safe and effective immunosuppression strategies that allow durable engraftment free of toxicities. The calcineurin inhibitors (CNIs) regimens, because of their inherent toxicities (including nephrotoxicity), have been unable to meet these promises. Over the past decade acute cellular rejection decreased dramatically with a concomitant robust increase in 1-year graft survival; however, long-term graft outcome showed only modest improvement. This is due in part to the toxicities of the immunosuppressive drugs. The quest for a toxicity-free-CNI-free regimen has been both intense and frustrating. A turning point in CNIs-free therapy may have occurred with the recent approval of belatacept, which represents a new paradigm in immunosuppression: biological therapy for chronic immunosuppression devoid of the usual toxicities associated with the CNIs. Belatacept, a fusion receptor protein, blocks costimulation signals necessary for the activation of T cells. Although costimulation blockade has not been shown to induce tolerance, it can provide safe and effective immunosuppression without renal or cardiovascular toxicities. The approval of belatacept in both the United States and Europe for use in renal transplantation will finally push CNI-free regimens into prime time. Novel biologics such as ASKP1240 (a human anti-CD40 monoclonal antibody) and one small molecule, tofacitinib, may advance further the use of CNI-free regimens in organ transplantation.

  7. Conversion of calcineurin inhibitors with mammalian target of rapamycin inhibitors after kidney transplant.

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    Nikoueinejad, Hassan; Soleimani, Alireza; Mirshafiey, Abbas; Amirzargar, Aliakbar; Sarrafnejad, Abdolfattah; Kamkar, Ideh; Einollahi, Behzad

    2013-02-01

    One way to overcome chronic allograft nephropathy induced by calcineurin inhibitors in immunosuppression protocols for organ transplants is to replace such inhibitors with mammalian target of rapamycin inhibitors, which are not clinically nephrotoxic because they have better renal function. If patients tolerate replacement, there could be a clear preference for mammalian target of rapamycin inhibitors as a maintenance immunosuppressant after renal transplant. This replacement could be sufficient if it were used for a certain time after calcineurin inhibitors. This review considers the conversion effects of calcineurin inhibitors with mammalian target of rapamycin inhibitors from the view point of kidney function during different periods after a kidney transplant.

  8. The effects of calcineurin inhibitors on prostanoid synthesis

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Stubbe, Jane; Jespersen, Bente

    2013-01-01

    The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus (Tac) are implicated in post-transplant complications such as cardiovascular morbidity. Prostanoids are fatty acid-derived compounds essential for controlling cardiovascular homeostasis. We tested the hypothesis that CNIs suppress...

  9. Oral voclosporin: novel calcineurin inhibitor for treatment of noninfectious uveitis

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    Roesel M

    2011-09-01

    Full Text Available Martin Roesel1, Christoph Tappeiner2, Arnd Heiligenhaus1,3, Carsten Heinz1,31Department of Ophthalmology, St Franziskus-Hospital, Muenster, Germany; 2Department of Ophthalmology, Inselspital, University of Bern, Switzerland; 3University Duisburg-Essen, GermanyAbstract: Voclosporin, a novel immunomodulatory drug inhibiting the calcineurin enzyme, was developed to prevent organ graft rejection and to treat autoimmune diseases. The chemical structure of voclosporin is similar to that of cyclosporine A, with a difference in one amino acid, leading to superior calcineurin inhibition and less variability in plasma concentration. Compared with placebo, voclosporin may significantly reduce inflammation and prevent recurrences of inflammation in patients with noninfectious uveitis. Future studies have to show if these advantages are accompanied by greater clinical efficacy and fewer side effects compared with the classic calcineurin inhibitors.Keywords: uveitis, immunosuppression, voclosporin

  10. A comparative study on renal biopsy before and after long-term calcineurin inhibitors therapy: an insight for pathogenesis of its toxicity.

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    Singh, Lavleen; Singh, Geetika; Sharma, Alok; Sinha, Aditi; Bagga, Arvind; Dinda, A K

    2015-01-01

    Calcineurin inhibitors (CNIs) are effective immunosuppressive agents for the successful treatment of childhood steroid-resistant nephrotic syndrome (SRNS). Because these patients require long-term treatment, the identification of early markers of CNI-induced nephrotoxicity (CNIN) is imperative. The monitoring of CNI trough levels, serum creatinine, and glomerular filtration rate is not an accurate marker of CNIN. The present study has been undertaken to identify early markers of CNIN in SRNS patients. Twenty-four pediatric SRNS patients were included with paired renal biopsies, before initiation (time zero biopsy) and at least 1 year after CNI therapy (protocol renal biopsy) with standard dosage. Semiquantitative morphologic grading of the histologic features was done for assessing CNIN. Immunohistochemical markers for oxidative stress (nitrotyrosine [NT]), fibrogenic cytokine (transforming growth factor β1 [TGF-β1]), and endothelial injury (endothelial nitric oxide synthase [eNOS]) were evaluated. In addition, ultrastructural study was done to assess mitochondrial injury in endothelial and tubular epithelial cells. The protocol renal biopsies in comparison with time zero biopsies showed significant increase in glomerulosclerosis, juxtaglomerular apparatus hyperplasia, tubular atrophy, interstitial fibrosis, arteriolar hyalinosis, and smooth muscle vacuolization (P biopsies. Mean mitochondrial injury grade among post-CNI cases in endothelial cells and proximal tubular cells was 2.28 and 1.4, whereas in pre-CNI, it was 0.28 and 0.27, respectively. We propose that immunohistochemical overexpression of NT, eNOS, and TGF-β1 is an early marker of CNIN. Endothelial and proximal tubular mitochondrial injury may play an important role in the pathogenesis of CNIN.

  11. Molecular comparison of calcineurin inhibitor-induced fibrogenic responses in protocol renal transplant biopsies

    NARCIS (Netherlands)

    Groningen, Marian C. Roos-van; Scholten, Eduard M.; Lelieveld, Patrick M.; Rowshani, Ajda T.; Baelde, Hans J.; Bajema, Ingeborg M.; Florquin, Sandrine; Bemelman, Frederike J.; de Heer, Emile; de Fijter, Johan W.; Bruijn, Jan A.; Eikmans, Michael

    The calcineurin inhibitor cyclosporine (CsA) induces a fibrogenic response that may lead to scarring of the renal allograft. This study investigated whether tacrolimus, a novel calcineurin inhibitor, exerts fibrogenic effects to a similar extent. Sixty patients were enrolled in a randomized study:

  12. High on Cannabis and Calcineurin Inhibitors: A Word of Warning in an Era of Legalized Marijuana.

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    Hauser, Naomi; Sahai, Tanmay; Richards, Rocco; Roberts, Todd

    2016-01-01

    Tacrolimus, a potent immunosuppressant medication, acts by inhibiting calcineurin, which eventually leads to inhibition of T-cell activation. The drug is commonly used to prevent graft rejection in solid organ transplant and graft-versus-host disease in hematopoietic stem cell transplant patients. Tacrolimus has a narrow therapeutic index with variable oral bioavailability and metabolism via cytochrome P-450 3A enzyme. Toxicity can occur from overdosing or from drug-drug interactions with the simultaneous administration of cytochrome P-450 3A inhibitors and possibly P-glycoprotein inhibitors. Tacrolimus toxicity can be severe and may include multiorgan damage. We present a case of suspected tacrolimus toxicity in a postallogeneic hematopoietic stem cell transplant patient who was concurrently using oral marijuana. This case represents an important and growing clinical scenario with the increasing legalization and use of marijuana throughout the United States.

  13. High on Cannabis and Calcineurin Inhibitors: A Word of Warning in an Era of Legalized Marijuana

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    Naomi Hauser

    2016-01-01

    Full Text Available Tacrolimus, a potent immunosuppressant medication, acts by inhibiting calcineurin, which eventually leads to inhibition of T-cell activation. The drug is commonly used to prevent graft rejection in solid organ transplant and graft-versus-host disease in hematopoietic stem cell transplant patients. Tacrolimus has a narrow therapeutic index with variable oral bioavailability and metabolism via cytochrome P-450 3A enzyme. Toxicity can occur from overdosing or from drug-drug interactions with the simultaneous administration of cytochrome P-450 3A inhibitors and possibly P-glycoprotein inhibitors. Tacrolimus toxicity can be severe and may include multiorgan damage. We present a case of suspected tacrolimus toxicity in a postallogeneic hematopoietic stem cell transplant patient who was concurrently using oral marijuana. This case represents an important and growing clinical scenario with the increasing legalization and use of marijuana throughout the United States.

  14. Calcineurin inhibitors and male fertility after renal transplantation - a review.

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    Georgiou, G K; Dounousi, E; Harissis, H V

    2016-06-01

    Renal transplantation and restoration of renal function are associated with significant favourable changes regarding the reproductive capacity of male patients with previous end-stage renal disease. However, there is evidence that some of the immunosuppressive agents may impair male fertility after all. Calcineurin inhibitors (CNIs), cyclosporine A and tacrolimus (FK506), which constitute the cornerstone of immunosuppression regimen following renal transplantation, have been implicated in causing an overall decline in the fertilisation capacity of male renal transplant recipients (RTRs). In this review, data from human clinical studies are collectively presented in an effort to estimate the potential adverse effects of CNIs on the masculine reproductive organs, the hormonal axis of males, the process of spermatogenesis and generally the male RTRs capacity to fertilise. © 2015 Blackwell Verlag GmbH.

  15. Late concentration-controlled calcineurin inhibitor withdrawal with mycophenolate mofetil in renal transplant recipients

    NARCIS (Netherlands)

    Mourer, Jacqueline Sarah

    2014-01-01

    Calcineurin inhibitor (CNI)-based therapy is associated with nephrotoxicity and cardiovascular adverse effects in renal transplant recipients. Early CNI withdrawal with mycophenolate mofetil (MMF) has not become routine practice, due to concerns about acute rejection. Therapeutic drug monitoring (TD

  16. Incidence of PTLD in pediatric renal transplant recipients receiving basiliximab, calcineurin inhibitor, sirolimus and steroids

    NARCIS (Netherlands)

    McDonald, R. A.; Smith, J. M.; Ho, M.; Lindblad, R.; Ikle, D.; Grimm, P.; Wyatt, R.; Arar, M.; Liereman, D.; Bridges, N.; Harmon, W.

    2008-01-01

    Pediatric renal transplant recipients were enrolled in a multicenter, randomized, double-blind trial of steroid withdrawal. Subjects received basiliximab, calcineurin inhibitor, sirolimus and steroids. Of 274 subjects enrolled, 19 (6.9%) subjects developed posttransplant lymphoproliferative disorder

  17. Calcineurin-inhibitor minimization in liver transplant patients with calcineurin-inhibitor-related renal dysfunction: a meta-analysis.

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    Yuan Kong

    Full Text Available BACKGROUND: Introduction of calcineurin-inhibitor (CNI has made transplantation a miracle in the past century. However, the side effects of long-term use of CNI turn out to be one of the major challenges in the current century. Among these, renal dysfunction attracts more and more attention. Herein, we undertook a meta-analysis to evaluate the efficacy and safety of calcineurin-inhibitor (CNI minimization protocols in liver transplant recipients with CNI-related renal dysfunction. METHODS: We included randomized trials with no year and language restriction. All data were analyzed using random effect model by Review Manager 5.0. The primary endpoints were glomerular filtration rate (GFR, serum creatinine level (sCr and creatinine clearance rate (CrCl, and the secondary endpoints were acute rejection episodes, incidence of infection and patient survival at the end of follow-up. RESULTS: GFR was significantly improved in CNI minimization group than in routine CNI regimen group (Z = 5.45, P<0.00001; I(2 = 0%. Likely, sCr level was significantly lower in the CNI minimization group (Z = 2.84, P = 0.005; I(2 = 39%. However, CrCl was not significantly higher in the CNI minimization group (Z = 1.59, P = 0.11; I(2 = 0%. Both acute rejection episodes and patient survival were comparable between two groups (rejection: Z = 0.01, P = 0.99; I(2 = 0%; survival: Z = 0.28, P = 0.78; I(2 = 0%, respectively. However, current CNI minimization protocols may be related to a higher incidence of infections (Z = 3.06, P = 0.002; I(2 = 0%. CONCLUSION: CNI minimization can preserve or even improve renal function in liver transplant patients with renal impairment, while sharing similar short term acute rejection rate and patient survival with routine CNI regimen.

  18. Regulatory T-Cell Augmentation or Interleukin-17 Inhibition Prevents Calcineurin Inhibitor-Induced Hypertension in Mice.

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    Chiasson, Valorie L; Pakanati, Abhinandan R; Hernandez, Marcos; Young, Kristina J; Bounds, Kelsey R; Mitchell, Brett M

    2017-07-01

    The immunosuppressive calcineurin inhibitors cyclosporine A and tacrolimus alter T-cell subsets and can cause hypertension, vascular dysfunction, and renal toxicity. We and others have reported that cyclosporine A and tacrolimus decrease anti-inflammatory regulatory T cells and increase proinflammatory interleukin-17-producing T cells; therefore, we hypothesized that inhibition of these effects using noncellular therapies would prevent the hypertension, endothelial dysfunction, and renal glomerular injury induced by calcineurin inhibitor therapy. Daily treatment of mice with cyclosporine A or tacrolimus for 1 week significantly decreased CD4(+)/FoxP3(+) regulatory T cells in the spleen and lymph nodes, as well as induced hypertension, vascular injury and dysfunction, and glomerular mesangial expansion in mice. Daily cotreatment with all-trans retinoic acid reported to increase regulatory T cells and decrease interleukin-17-producing T cells, prevented all of the detrimental effects of cyclosporine A and tacrolimus. All-trans retinoic acid also increased regulatory T cells and prevented the hypertension, endothelial dysfunction, and glomerular injury in genetically modified mice that phenocopy calcineurin inhibitor-treated mice (FKBP12-Tie2 knockout). Treatment with an interleukin-17-neutralizing antibody also increased regulatory T-cell levels and prevented the hypertension, endothelial dysfunction, and glomerular injury in cyclosporine A-treated and tacrolimus-treated mice and FKBP12-Tie2 knockout mice, whereas an isotype control had no effect. Augmenting regulatory T cells and inhibiting interleukin-17 signaling using noncellular therapies prevents the cardiovascular and renal toxicity of calcineurin inhibitors in mice. © 2017 American Heart Association, Inc.

  19. Imaging findings in a child with calcineurin inhibitor-induced pain syndrome after bone marrow transplant for beta thalassemia major

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    Ayyala, Rama S.; Arnold, Staci D.; Bhatia, Monica; Dastgir, Jahannaz [Columbia University Medical Center, Morgan Stanley Children' s Hospital, Department of Radiology, New York, NY (United States)

    2016-10-15

    Calcineurin inhibitor-induced pain syndrome is an entity recognized in patients on immunosuppressive therapy after transplantation. Diagnosis is characterized by onset of pain beginning in the setting of an elevated calcineurin-inhibitor trough level. Reducing the medication dose relieves symptoms. Imaging findings can be nonspecific, including bone marrow edema and periosteal reaction. We present the unique case of calcineurin inhibitor-induced pain syndrome in a child and review the imaging findings. (orig.)

  20. Calcineurin Inhibitors in the Treatment of Primary Focal Segmental Glomerulosclerosis

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    Laurin, Louis-Philippe; Nachman, Patrick H.; Foster, Bethany J.

    2017-01-01

    Purpose of review: Primary focal segmental glomerulosclerosis (FSGS) is the most common cause of nephrotic syndrome in adults. Glucocorticoids have been evaluated in the treatment of primary FSGS in numerous retrospective studies. Evidence suggesting a role for including calcineurin inhibitors (CNIs) in early therapy remains limited. The aim of this study was to systematically review the literature examining the efficacy of CNIs in the treatment of primary FSGS both as first-line therapy and as an adjunctive agent in steroid-resistant patients, with respect to remission in proteinuria and renal survival. Sources of information: PubMed and EMBASE were searched from inception to August 2014 for prospective controlled trials, and case-control and cohort studies. Findings: After systematically applying our inclusion criteria, a total of 152 titles and abstracts were identified. Six randomized controlled trials and 2 cohort studies were reviewed. Three randomized controlled trials compared CNIs with placebo or supportive therapy. The pooled relative “risk” of proteinuria remission associated with cyclosporine was 7.0 (95% confidence interval, 2.9-16.8) compared with placebo/supportive therapy. There was very low heterogeneity among these studies with an I-squared of 0%. Three studies compared CNIs with another immunosuppressive agent. All prospective trials were conducted in patients with primary FSGS deemed steroid-resistant. Limitations: The relatively small number of included studies and their heterogeneity with respect to treatment protocols, and possible publication bias, limit conclusions drawn from this systematic review. Implications: The efficacy of CNIs has been evaluated in steroid-resistant primary FSGS patients. There is no evidence supporting their role as first-line therapy. Further studies are needed to determine this role. PMID:28321320

  1. Calcineurin Inhibitors in the Treatment of Primary Focal Segmental Glomerulosclerosis

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    Louis-Philippe Laurin

    2017-02-01

    Full Text Available Purpose of review: Primary focal segmental glomerulosclerosis (FSGS is the most common cause of nephrotic syndrome in adults. Glucocorticoids have been evaluated in the treatment of primary FSGS in numerous retrospective studies. Evidence suggesting a role for including calcineurin inhibitors (CNIs in early therapy remains limited. The aim of this study was to systematically review the literature examining the efficacy of CNIs in the treatment of primary FSGS both as first-line therapy and as an adjunctive agent in steroid-resistant patients, with respect to remission in proteinuria and renal survival. Sources of information: PubMed and EMBASE were searched from inception to August 2014 for prospective controlled trials, and case-control and cohort studies. Findings: After systematically applying our inclusion criteria, a total of 152 titles and abstracts were identified. Six randomized controlled trials and 2 cohort studies were reviewed. Three randomized controlled trials compared CNIs with placebo or supportive therapy. The pooled relative “risk” of proteinuria remission associated with cyclosporine was 7.0 (95% confidence interval, 2.9-16.8 compared with placebo/supportive therapy. There was very low heterogeneity among these studies with an I-squared of 0%. Three studies compared CNIs with another immunosuppressive agent. All prospective trials were conducted in patients with primary FSGS deemed steroid-resistant. Limitations: The relatively small number of included studies and their heterogeneity with respect to treatment protocols, and possible publication bias, limit conclusions drawn from this systematic review. Implications: The efficacy of CNIs has been evaluated in steroid-resistant primary FSGS patients. There is no evidence supporting their role as first-line therapy. Further studies are needed to determine this role.

  2. Systematic Review on Role of Mammalian Target of Rapamycin Inhibitors as an Alternative to Calcineurin Inhibitors in Renal Transplant: Challenges and Window to Excel.

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    Kumar, Jayant; Bridson, Julie M; Sharma, Ajay; Halawa, Ahmed

    2017-06-01

    This review focuses on the current limited evidence of graft function and graft survival in various immunosuppressive regimens involving mammalian target of rapamycin inhibitors with or without calcineurin inhibitors. We evaluated the current literature for describing the role of mammalian target of rapamycin inhibitors as an alternative to calcineurin inhibitors by searching the PubMed, EMBASE, Cochrane, Crossref, and Scopus databases using medical subject heading terms. Our detailed analyses of all relevant literature showed use of mammalian target of rapamycin inhibitor-based de novo regimens, early calcineurin inhibitor withdrawal with subsequent introduction of mammalian target of rapamycin inhibitor-based regimens, and late conversion from a calcineurin inhibitor-based regimen to mammalian target of rapamycin inhibitor-based regimens. Notably, early calcineurin inhibitor withdrawal with subsequent introduction of mammalian target of rapamycin inhibitor-based regimen seemed to be a more practical and realistic approach toward immunosuppressive treatment of renal transplant recipients. However, in view of the high rejection rate observed in these studies, it is advisable not to offer these regimens to patients with moderate to high immunologic risk. The present evidences suggest that treatment with mammalian target of rapamycin inhibitors allows early and substantial calcineurin inhibitor minimization. The mammalian target of rapamycin inhibitors everolimus and sirolimus are preferred due to their complementary mechanisms of action and favorable nephrotoxicity profile, which have opened the way for calcineurin inhibitor reduction/withdrawal in the early posttransplant period.

  3. Calcineurin inhibitor sparing with mycophenolate in kidney transplantation: a systematic review and meta-analysis.

    LENUS (Irish Health Repository)

    Moore, Jason

    2009-02-27

    Limiting the exposure of kidney transplant recipients to calcineurin inhibitors (CNIs) has potential merit, but there is no clear consensus on the utility of current strategies. In an attempt to aid clarification, we conducted a systematic review and meta-analysis of randomized trials that assessed CNI sparing (minimization or elimination) with mycophenolate as sole adjunctive immunosuppression.

  4. The role of calcineurin signaling in microcystin-LR triggered neuronal toxicity

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    Li, Guangyu; Yan, Wei; Dang, Yao; Li, Jing; Liu, Chunsheng; Wang, Jianghua

    2015-06-01

    Microcystin-LR (MCLR) is a commonly acting potent hepatotoxin and has been pointed out of potentially causing neurotoxicity, but the exact mechanisms of action still remain unclear. Using proteomic analysis, forty-five proteins were identified to be significantly altered in hippocampal neurons of rats treated with MCLR. Among them, Ca2+-activated phosphatase calcineurin (CaN) and the nuclear factor of activated T-cells isoform c3 (NFATc3) were up-regulated remarkably. Validation of the changes in CaN and NFATc3 expression by Western blotting demonstrated CaN cleavage and subsequent NFATc3 nuclear translocation were generated, suggesting that exposure to MCLR leads to activation of CaN, which in turn activates NFATc3. Activation of CaN signaling has been reported to result in apoptosis via dephosphorylation of the proapoptotic Bcl-2 family member Bad. In agreement with this, our results revealed that treatment of neurons with the CaN inhibitor FK506 blocked the reduction in Bad dephosphorylation and cytochrome c (cyt c) release triggered by MCLR. Consistent with these biochemical results, we observed a marked decrease in apoptotic and necrotic cell death after MCLR exposure in the presence of FK506, supporting the hypothesis that MCLR appeared to cause neuronal toxicity by activation of CaN and the CaN-mediated mitochondrial apoptotic pathway.

  5. Calcineurin inhibitor tacrolimus does not interfere with the suppression of hepatitis C virus infection by interferon-α

    NARCIS (Netherlands)

    Q. Pan (Qiuwei); H.J. Metselaar (Herold); P.E. de Ruiter (Petra); J. Kwekkeboom (Jaap); H.W. Tilanus (Hugo); H.L.A. Janssen (Harry); L.J.W. van der Laan (Luc)

    2010-01-01

    textabstractImmunosuppression considerably affects hepatitis C virus (HCV) recurrence and the outcome of antiviral treatment after liver transplantation. Recent findings have suggested that the calcineurin inhibitor tacrolimus (Tac), unlike cyclosporine A (CsA), interferes with the antiviral activit

  6. Lifetime Cost-Effectiveness of Calcineurin Inhibitor Withdrawal After De Novo Renal Transplantation

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    Earnshaw, Stephanie R; Graham, Christopher N.; Irish, William D.; Sato, Reiko; Mark A. Schnitzler

    2008-01-01

    After renal transplantation, immunosuppressive regimens associated with high short-term survival rates are not necessarily associated with high long-term survival rates, suggesting that regimens may need to be optimized over time. Calcineurin inhibitor (CNI) withdrawal from a sirolimus-based immunosuppressive regimen may maximize the likelihood of long-term graft and patient survival by minimizing CNI-associated nephrotoxicity. In this study, a lifetime Markov model was created to compare the...

  7. Use of Rituximab in Children with Steroid- and Calcineurin-Inhibitor-Dependent Idiopathic Nephrotic Syndrome

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    Ravani, Pietro; Ponticelli, Alessandro; Siciliano, Chiara; Fornoni, Alessia; Magnasco, Alberto; Sica, Felice; Bodria, Monica; Caridi, Gianluca; Wei, Changli; Belingheri, Mirco; Ghio, Luciana; Merscher-Gomez, Sandra; Edefonti, Alberto; Pasini, Andrea; Montini, Giovanni; Murtas, Corrado; Wang, Xiangyu; Muruve, Daniel; Vaglio, Augusto; Martorana, Davide; Pani, Antonello; Scolari, Francesco; Reiser, Jochen; Ghiggeri, Gian Marco

    2013-01-01

    In children with idiopathic nephrotic syndrome rituximab can maintain short-term remission with withdrawal of prednisone and calcineurin-inhibitors. Long-term effects including number of repeated infusions to maintain remission are unknown. We treated with rituximab 46 consecutive children with idiopathic nephrotic syndrome lasting for at least one year (6.3±4.1 years), who were maintained in remission with oral prednisone and calcineurin inhibitors. They received 1–5 rituximab courses during a median follow-up of three years (range 1–5). Oral agents were tapered after each infusion, and completely withdrawn within 45 days. Rituximab was well tolerated. Six-month probabilities of remission were 48% after the first infusion and 37% after subsequent infusions. One- and two-year-remission probabilities were respectively 20% and 10%. Median time intervals between complete oral-agent withdrawal and relapse were 5.6 and 8.5 months respectively following the first and subsequent courses. Time to reconstitution of CD20 cells correlated with the duration of remission, but was not associated with variation in FcyR, CD20 or SMPDL-3B polymorphisms. Podocyte Src phosphorylation was normal. Rituximab can be safely and repeatedly used as prednisone and calcineurin-inhibitor-sparing therapy in a considerable proportion of children with dependent forms of idiopathic nephrotic syndrome. Further research is needed to identify patients who will benefit most from rituximab therapy. PMID:23739238

  8. The calcineurin inhibitor Sarah (Nebula exacerbates Aβ42 phenotypes in a Drosophila model of Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Soojin Lee

    2016-03-01

    Full Text Available Expression of the Down syndrome critical region 1 (DSCR1 protein, an inhibitor of the Ca2+-dependent phosphatase calcineurin, is elevated in the brains of individuals with Down syndrome (DS or Alzheimer's disease (AD. Although increased levels of DSCR1 were often observed to be deleterious to neuronal health, its beneficial effects against AD neuropathology have also been reported, and the roles of DSCR1 on the pathogenesis of AD remain controversial. Here, we investigated the role of sarah (sra; also known as nebula, a Drosophila DSCR1 ortholog, in amyloid-β42 (Aβ42-induced neurological phenotypes in Drosophila. We detected sra expression in the mushroom bodies of the fly brain, which are a center for learning and memory in flies. Moreover, similar to humans with AD, Aβ42-expressing flies showed increased Sra levels in the brain, demonstrating that the expression pattern of DSCR1 with regard to AD pathogenesis is conserved in Drosophila. Interestingly, overexpression of sra using the UAS-GAL4 system exacerbated the rough-eye phenotype, decreased survival rates and increased neuronal cell death in Aβ42-expressing flies, without modulating Aβ42 expression. Moreover, neuronal overexpression of sra in combination with Aβ42 dramatically reduced both locomotor activity and the adult lifespan of flies, whereas flies with overexpression of sra alone showed normal climbing ability, albeit with a slightly reduced lifespan. Similarly, treatment with chemical inhibitors of calcineurin, such as FK506 and cyclosporin A, or knockdown of calcineurin expression by RNA interference (RNAi, exacerbated the Aβ42-induced rough-eye phenotype. Furthermore, sra-overexpressing flies displayed significantly decreased mitochondrial DNA and ATP levels, as well as increased susceptibility to oxidative stress compared to that of control flies. Taken together, our results demonstrating that sra overexpression augments Aβ42 cytotoxicity in Drosophila suggest that DSCR1

  9. Calcineurin inhibitor cyclosporine A activates renal Na-K-Cl cotransporters via local and systemic mechanisms.

    Science.gov (United States)

    Blankenstein, K I; Borschewski, A; Labes, R; Paliege, A; Boldt, C; McCormick, J A; Ellison, D H; Bader, M; Bachmann, S; Mutig, K

    2017-03-01

    Calcineurin dephosphorylates nuclear factor of activated T cells transcription factors, thereby facilitating T cell-mediated immune responses. Calcineurin inhibitors are instrumental for immunosuppression after organ transplantation but may cause side effects, including hypertension and electrolyte disorders. Kidneys were recently shown to display activation of the furosemide-sensitive Na-K-2Cl cotransporter (NKCC2) of the thick ascending limb and the thiazide-sensitive Na-Cl cotransporter (NCC) of the distal convoluted tubule upon calcineurin inhibition using cyclosporin A (CsA). An involvement of major hormones like angiotensin II or arginine vasopressin (AVP) has been proposed. To resolve this issue, the effects of CsA treatment in normal Wistar rats, AVP-deficient Brattleboro rats, and cultured renal epithelial cells endogenously expressing either NKCC2 or NCC were studied. Acute administration of CsA to Wistar rats rapidly augmented phosphorylation levels of NKCC2, NCC, and their activating kinases suggesting intraepithelial activating effects. Chronic CsA administration caused salt retention and hypertension, along with stimulation of renin and suppression of renal cyclooxygenase 2, pointing to a contribution of endocrine and paracrine mechanisms at long term. In Brattleboro rats, CsA induced activation of NCC, but not NKCC2, and parallel effects were obtained in cultured cells in the absence of AVP. Stimulation of cultured thick ascending limb cells with AVP agonist restored their responsiveness to CsA. Our results suggest that the direct epithelial action of calcineurin inhibition is sufficient for the activation of NCC, whereas its effect on NKCC2 is more complex and requires concomitant stimulation by AVP. Copyright © 2017 the American Physiological Society.

  10. Calcineurin inhibitors acutely improve insulin sensitivity without affecting insulin secretion in healthy human volunteers

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Møller, Niels; Juhl, Claus

    2012-01-01

    of calcineurin inhibitors (CNIs) ciclosporin (CsA) and tacrolimus (Tac) has improved the outcome of organ transplants, but complications such as new onset diabetes mellitus after transplantation (NODAT) cause impairment of survival rates. The relative contribution of each CNI to the pathogenesis and development.......047), whereas first phase and pulsatile insulin secretion were unaffected. Coinciding with the CNI induced improved insulin sensitivity, glucose oxidation rates increased, while insulin clearance rates decreased, only non-significantly. Tac singularly lowered hsCRP concentrations, otherwise no changes were...

  11. Everolimus Initiation With Early Calcineurin Inhibitor Withdrawal in De Novo Heart Transplant Recipients

    DEFF Research Database (Denmark)

    Andreassen, A K; Andersson, B; Gustafsson, F

    2016-01-01

    In a randomized, open-label trial, de novo heart transplant recipients were randomized to everolimus (3-6 ng/mL) with reduced-exposure calcineurin inhibitor (CNI; cyclosporine) to weeks 7-11 after transplant, followed by increased everolimus exposure (target 6-10 ng/mL) with cyclosporine withdrawal...... events occurred in 37.3% and 19.6% of everolimus- and CNI-treated patients, respectively (p = 0.078). These results suggest that early CNI withdrawal after heart transplantation supported by everolimus, mycophenolic acid and steroids with lymphocyte-depleting induction is safe at intermediate follow...

  12. Photocarcinogenicity of selected topically applied dermatological drugs: calcineurin inhibitors, corticosteroids, and vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Catharina Margrethe Lerche

    2010-09-01

    Full Text Available Topical therapies constitute the mainstay of dermatological treatments for skin disorders, such as atopic dermatitis, contact dermatitis, psoriasis, or acne. Since some of these diseases are often chronic, treatment duration may last for years and may even last the patient’s entire lifetime. Obviously, such long-term therapy may raise safety concerns, which also include the potential photocarcinogenic effect. Most patients are exposed to ultraviolet radiation (UVR during leisure, work, vacations, or in tanning beds. Additionally, the patients may receive UVR via UVB phototherapy or psoralens plus UVA radiation (PUVA. The use of immunosuppressant’s, such as corticosteroids and calcineurin inhibitors, has markedly increased. Patients with skin diseases have benefited from both systemic and topical treatment of both new and established drugs. The issue of a black box warning by the US Food and Drug Administration has increased concerns about photocarcinogenesis, which raises the question: “Are these drugs safe?” This review focuses on the mechanism of action and photocarcinogenic potential of commonly used topical treatments, such as corticosteroids, calcineurin inhibitors, and vitamin D analogs.

  13. Two-year outcomes in thoracic transplant recipients after conversion to everolimus with reduced calcineurin inhibitor within a multicenter, open-label, randomized trial

    DEFF Research Database (Denmark)

    Gullestad, Lars; Mortensen, Svend-Aage; Eiskjær, Hans

    2010-01-01

    Use of the mammalian target of rapamycin inhibitor everolimus with an accompanying reduction in calcineurin inhibitor (CNI) exposure has shown promise in preserving renal function in maintenance thoracic transplant patients, but robust, long-term data are required....

  14. Two-year outcomes in thoracic transplant recipients after conversion to everolimus with reduced calcineurin inhibitor within a multicenter, open-label, randomized trial

    DEFF Research Database (Denmark)

    Gullestad, Lars; Mortensen, Svend-Aage; Eiskjær, Hans;

    2010-01-01

    Use of the mammalian target of rapamycin inhibitor everolimus with an accompanying reduction in calcineurin inhibitor (CNI) exposure has shown promise in preserving renal function in maintenance thoracic transplant patients, but robust, long-term data are required.......Use of the mammalian target of rapamycin inhibitor everolimus with an accompanying reduction in calcineurin inhibitor (CNI) exposure has shown promise in preserving renal function in maintenance thoracic transplant patients, but robust, long-term data are required....

  15. The calcineurin inhibitor cyclosporin A exhibits synergism with antifungals against Candida parapsilosis species complex.

    Science.gov (United States)

    Cordeiro, Rossana de Aguiar; Macedo, Ramila de Brito; Teixeira, Carlos Eduardo Cordeiro; Marques, Francisca Jakelyne de Farias; Bandeira, Tereza de Jesus Pinheiro Gomes; Moreira, José Luciano Bezerra; Brilhante, Raimunda Sâmia Nogueira; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa

    2014-07-01

    Candida parapsilosis complex comprises three closely related species, C. parapsilosis sensu stricto, Candida metapsilosis and Candida orthopsilosis. In the last decade, antifungal resistance to azoles and caspofungin among C. parapsilosis sensu lato strains has been considered a matter of concern worldwide. In the present study, we evaluated the synergistic potential of antifungals and the calcineurin inhibitor cyclosporin A (Cys) against planktonic and biofilms of C. parapsilosis complex from clinical sources. Susceptibility assays with amphotericin, fluconazole, voriconazole, caspofungin and Cys were performed by microdilution in accordance with Clinical and Laboratory Standards Institute guidelines. Synergy testing against planktonic cells of C. parapsilosis sensu lato strains was assessed by the chequerboard method. Combinations formed by antifungals with Cys were evaluated against mature biofilms in microtitre plates. No differences in the antifungal susceptibility pattern among species were observed, but C. parapsilosis sensu stricto strains were more susceptible to Cys than C. orthopsilosis and C. metapsilosis. Synergism between antifungals and Cys was observed in C. parapsilosis sensu lato strains. Combinations formed by antifungals and Cys were able to prevent biofilm formation and showed an inhibitory effect against mature biofilms of C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. These results strengthen the potential of calcineurin inhibition as a promising approach to enhance the efficiency of antifungal drugs.

  16. Early conversion from calcineurin inhibitor- to everolimus-based therapy following kidney transplantation : Results of the randomized ELEVATE trial

    NARCIS (Netherlands)

    de Fijter, Johan W; Holdaas, Hallvard; Øyen, Ole; Sanders, Jan Stephan; Sundar, Sankaran; Bemelman, Frederike J; Sommerer, Claudia; Pascual, Julio; Avihingsanon, Yingyos; Pongskul, Cholatip; Oppenheimer, Frederic; Toselli, Lorenzo; Russ, Graeme; Wang, Zailong; Lopez, Patricia; Kochuparampil, Jossy; Cruzado, Josep M; van der Giet, Markus

    In a 24-month, multicenter, open-label, randomized trial, 715 de novo kidney transplant recipients were randomized at 10-14 weeks to convert to everolimus (n=359) or remain on standard calcineurin inhibitor (CNI) therapy (n=356; 231 tacrolimus; 125 cyclosporine), all with mycophenolic acid and

  17. Early conversion from calcineurin inhibitor- to everolimus-based therapy following kidney transplantation : Results of the randomized ELEVATE trial

    NARCIS (Netherlands)

    de Fijter, Johan W; Holdaas, Hallvard; Øyen, Ole; Sanders, Jan Stephan; Sundar, Sankaran; Bemelman, Frederike J; Sommerer, Claudia; Pascual, Julio; Avihingsanon, Yingyos; Pongskul, Cholatip; Oppenheimer, Frederic; Toselli, Lorenzo; Russ, Graeme; Wang, Zailong; Lopez, Patricia; Kochuparampil, Jossy; Cruzado, Josep M; van der Giet, Markus

    2016-01-01

    In a 24-month, multicenter, open-label, randomized trial, 715 de novo kidney transplant recipients were randomized at 10-14 weeks to convert to everolimus (n=359) or remain on standard calcineurin inhibitor (CNI) therapy (n=356; 231 tacrolimus; 125 cyclosporine), all with mycophenolic acid and stero

  18. NaCl cotransporter abundance in urinary vesicles is increased by calcineurin inhibitors and predicts thiazide sensitivity

    NARCIS (Netherlands)

    Tutakhel, O.A.Z.; Moes, A.D.; Valdez Flores, M.A.; Kortenoeven, M.L.A.; Vrie, M. van de; Jelen, S.K.; Fenton, R.A.; Zietse, R.; Hoenderop, J.G.J.; Hoorn, E.J.; Hilbrands, L.B.; Bindels, R.J.M.

    2017-01-01

    Animal studies have shown that the calcineurin inhibitors (CNIs) cyclosporine and tacrolimus can activate the thiazide-sensitive NaCl cotransporter (NCC). A common side effect of CNIs is hypertension. Renal salt transporters such as NCC are excreted in urinary extracellular vesicles (uEVs) after

  19. NaCl cotransporter abundance in urinary vesicles is increased by calcineurin inhibitors and predicts thiazide sensitivity

    NARCIS (Netherlands)

    Tutakhel, O.A.Z. (Omar A. Z.); A.D. Moes (Arthur); Valdez-Flores, M.A. (Marco A.); Kortenoeven, M.L.A. (Marleen L. A.); Vrie, M.V.D. (Mathijs V.D.); Jelen, S. (Sabina); R.A. Fenton (Robert); R. Zietse (Bob); J.G.J. Hoenderop (Joost); E.J. Hoorn (Ewout); L.B. Hilbrands (Luuk); Bindels, R.J.M. (Reneâ J. M.)

    2017-01-01

    textabstractAnimal studies have shown that the calcineurin inhibitors (CNIs) cyclosporine and tacrolimus can activate the thiazide-sensitive NaCl cotransporter (NCC). A common side effect of CNIs is hypertension. Renal salt transporters such as NCC are excreted in urinary extracellular vesicles

  20. Renal impairment after liver transplantation - a pilot trial of calcineurin inhibitor-free vs. calcineurin inhibitor sparing immunosuppression in patients with mildly impaired renal function after liver transplantation

    Directory of Open Access Journals (Sweden)

    Gerhardt T

    2009-05-01

    Full Text Available Abstract Objectives Chronic kidney disease is frequent in patients after orthotopic liver transplantation (OLT and has impact on survival. Patients receiving calcineurin inhibitors (CNI are at increased risk to develop impaired renal function. Early CNI reduction and concomitant use of mycophenolat mofetil (MMF has been shown to improve renal function. Methods The aim of this trial was to compare dose-reduced CNI/MMF versus CNI-free MMF/prednisone-based treatment in stable patients after OLT with respect to glomerular filtration rate (GFR. 21 patients [GFR 44.9 ± 9.9 mL/min/1.73 m2 measured by 99m-Tc-DTPA-clearance, serum creatinine (SCr 1.5 ± 0.42 mg/dL] were randomized either to exchange CNI for 10 mg prednisone (group 1; n = 8 or to receive CNI at 25% of the initial dose (group 2; n = 13 each in combination with 1000 mg MMF b.i.d. Results At month 12 mean SCr (-0.3 ± 0.4 mg/dL, p = 0.031 and GFR improved (8.6 ± 13.1 mL/min/1.73 m2, p = 0.015 in group 2 but remained unchanged in group 1. Main side effects were gastroinstestinal symptoms (14.3% and infections (4.8%. Two biopsy proven, steroid-responsive rejections occurred. In group 1 mean diastolic blood pressure (BP increased by 11 ± 22 mmHg (p = 0.03. Conclusions Reduced dose CNI in combination with MMF but not CNI-free-immunosuppression leads to improvement of GFR in patients with moderately elevated SCr levels after OLT. Addition of steroids resulted in increased diastolic blood pressure presumably counterbalancing the benefits of CNI withdrawal on renal function.

  1. Decreased calcineurin immunoreactivity in the postmortem brain of a patient with schizophrenia who had been prescribed the calcineurin inhibitor, tacrolimus, for leukemia

    Directory of Open Access Journals (Sweden)

    Wada A

    2016-07-01

    Full Text Available Akira Wada,1,2 Yasuto Kunii,1 Jyunya Matsumoto,1 Mizuki Hino,1 Atsuko Nagaoka,1 Shin-ichi Niwa,3 Hirooki Yabe1 1Department of Neuropsychiatry, Fukushima Medical University School of Medicine, Fukushima City, Fukushima, 2Department of Neuropsychiatry, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, 3Department of Psychiatry, Aizu Medical Center, Fukushima Medical University, Aizuwakamatsu City, Fukushima, Japan Background: The calcineurin (CaN inhibitor, tacrolimus, is widely used in patients undergoing allogeneic organ transplantation and in those with certain allergic diseases. Recently, several reports have suggested that CaN is also associated with schizophrenia. However, little data are currently available on the direct effect of tacrolimus on the human brain.Case: A 23-year-old Japanese female experienced severe delusion of persecution, delusional mood, suspiciousness, aggression, and excitement. She visited our hospital and was diagnosed with schizophrenia. When she was 27 years old, she had severe general fatigue, persistent fever, systemic joint pain, gingival bleeding, and breathlessness and was diagnosed with acute myelomonocytic leukemia. Later she underwent bone marrow transplantation (BMT, she was administered methotrexate and cyclosporin A to prevent graft versus host disease (GVHD. Three weeks after BMT, she showed initial symptoms of GVHD and was prescribed tacrolimus instead of cyclosporin A. Seven months after BMT at the age of 31 years, she died of progression of GVHD. Pathological anatomy was examined after her death, including immunohistochemical analysis of her brain using anti-CaN antibodies. For comparison, we used our previous data from both a schizophrenia group and a healthy control group. No significant differences were observed in the percentage of CaN-immunoreactive neurons among the schizophrenia group, healthy control group, and the tacrolimus case (all P>0.5, analysis of covariance. Compared with the

  2. Effect of topical calcineurin inhibitors as monotherapy or combined with phototherapy for vitiligo treatment: a meta-analysis.

    Science.gov (United States)

    Dang, Yu-Ping; Li, Qiang; Shi, Fei; Yuan, Xiao-Ying; Liu, Wei

    2016-01-01

    Vitiligo is a common skin disease for which immunomodulating calcineurin inhibitors have been considered reasonable treatment. We searched the MEDLINE, Embase, and Cochrane central register of controlled trials databases for articles published prior to September 2014. Thirteen studies were included in the meta-analysis. After pooling the trials, we concluded that calcineurin inhibitors showed a better therapeutic effect on vitiligo than placebo, according to lesion report (RR = 2.62, 95%CI, 1.39-4.93, p = 0.003) and patient report (RR = 1.42, 95%, 0.87-2.31, p = 0.157). Subgroup analysis was performed to determine whether the combination with phototherapy was a source of heterogeneity. The trial sequence analysis indicated that the results of combined therapy by lesion report were reliable and conclusive. However, in the patient report trials, the frequency of lesions on the hand and foot was higher, and the effect of combined therapy was still not significant. Calcineurin inhibitors showed a better therapeutic effect than placebo in the treatment of vitiligo with phototherapy. However, the typical UV-resistant sites (i.e., hand and foot) were still difficult to cure even with combined therapy. Because of concerns about photocarcinogenesis, the clinical application of combined therapy should be explored with caution.

  3. Lifetime Cost-Effectiveness of Calcineurin Inhibitor Withdrawal After De Novo Renal Transplantation

    Science.gov (United States)

    Earnshaw, Stephanie R.; Graham, Christopher N.; Irish, William D.; Sato, Reiko; Schnitzler, Mark A.

    2008-01-01

    After renal transplantation, immunosuppressive regimens associated with high short-term survival rates are not necessarily associated with high long-term survival rates, suggesting that regimens may need to be optimized over time. Calcineurin inhibitor (CNI) withdrawal from a sirolimus-based immunosuppressive regimen may maximize the likelihood of long-term graft and patient survival by minimizing CNI-associated nephrotoxicity. In this study, a lifetime Markov model was created to compare the cost-effectiveness of a sirolimus-based CNI withdrawl regimen (sirolimus plus steroids) with other common CNI-containing regimens in adult de novo renal transplantation patients. Long-term graft survival was estimated by renal function and data from published studies and the US transplant registry, including short- and long-term outcomes, utility weights, and health-state costs were incorporated. Drug costs were based on average daily consumption and wholesale acquisition costs. The model suggests that treatment with sirolimus plus steroids is more efficacious and less costly than regimens consisting of a CNI, mycophenolate mofetil, and steroids; therefore, CNI withdrawal not only shows potential for long-term clinical benefits but also is expected to be cost-saving over a patient's life compared with the most commonly prescribed CNI-containing regimens. PMID:18562571

  4. Microproteinuria for detecting calcineurin inhibitor-related nephrotoxicity after liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Bin Liu; Lu-Nan Yan; Lan-Lan Wang; Wan Y Lau; Bo Li; Wen-Tao Wang; Ming-Qing Xu; Jia-Yin Yang; Fu-Gui Li

    2009-01-01

    AIM: To investigate whether microproteinuria could be used as an early and sensitive indicator to detect calcineurin inhibitor (CNI)-related nephrotoxicity after liver transplantation. METHODS: All liver transplant recipients with normal serum creatinine (SCr) and detectable microproteinuria at baseline were included in this study. The renal function was monitored by the blood clearance of 99mTc-diethylenetriaminepentaacetic acid every 6 mo. Microproteinuria, SCr and blood urea nitrogen (BUN) were measured at entry and at subsequent follow-up visits. The patients were divided into different groups according to the mean values of glomerular filtration rate (GFR) at the follow-up time points: Group 1, GFR decreased from baseline by 0%-10%; Group 2, GFR decreased from baseline by 11%-20%; Group 3, GFR decreased from baseline by 21%-40%; Group 4, GFR decreased from baseline by > 40% and/or SCr was increasing. RESULTS: A total of 143 patients were enrolled into this study (23 females and 120 males). The mean follow-up was 32 mo (range 16-36 mo). Downward trends in renal function over time were observed in the study groups. SCr and BUN increased significantly only in Group 4 patients ( P < 0.001). β2-microglobulin (β2m) and α1-microglobulin (α1m) significantly increased with the subtle change of renal function in recipients who were exposed to CNI-based immunosuppression regimens. The reductions in GFR were closely correlated with elevated α1m ( r2 = -0.728, P < 0.001) and β2m ( r2 = -0.787, P < 0.001). CONCLUSION: β2m and α1m could be useful as early and sensitive indicators of CNI-induced nephrotoxicity.

  5. Long term outcomes in children with steroid resistant nephrotic syndrome treated with calcineurin inhibitors

    Directory of Open Access Journals (Sweden)

    Nathan T Beins

    2015-11-01

    Full Text Available Background: Steroid resistant nephrotic syndrome (SRNS is an important cause of chronic kidney disease (CKD in children that often progresses to end-stage renal disease (ESRD. Calcineurin inhibitors (CNIs have been shown to be effective in inducing short-term remission in some patients with SRNS. However, there are little data examining their long-term impact on ESRD progression rates.Methods: We performed a retrospective chart review of all patients treated for SRNS with CNIs at our institution from 1995-2013. Data collected including demographics, initial response to medical therapy, number of relapses, progression to ESRD, and treatment complications.Results: A total of 16 patients met inclusion criteria with a mean follow-up of 6.6 years (range 0.6-17.6 years. Histopathological diagnoses were focal segmental glomerulosclerosis (8, mesangial proliferative glomerulonephritis (4, IgM nephropathy (3, and minimal change disease (1. Three patients (18.8% were unresponsive to CNIs while the remaining 13 (81.2% achieved remission with CNI therapy. Six patients (37.5% progressed to ESRD during the study period, three of whom did so after initially responding to CNI therapy. Renal survival rates were 87%, 71%, and 57% at 2 years, 5 years, and 10 years respectively. Non-Caucasian ethnicity was associated with progression to ESRD. Finally, a higher number of acute kidney injury episodes was associated with a lower final estimated glomerular filtration rate.Discussion: Despite the majority of SRNS patients initially responding to CNI therapy, a significant percentage still progressed to ESRD despite achieving short-term remission. Recurrent episodes of AKI may be associated with progression of CKD in SRNS patients with.

  6. Race, Calcineurin Inhibitor Exposure, and Renal Function After Solid Organ Transplantation.

    Science.gov (United States)

    Yessayan, L; Shafiq, A; Peterson, E; Wells, K; Hu, Y; Williams, L K; Lanfear, D

    2015-12-01

    Calcineurin-inhibitor (CNI)-induced nephrotoxicity frequently complicates transplantation. African-Americans are at a greater risk of renal failure than the general population. We investigated whether race was an effect modifier of the relationship between CNI exposure and kidney function after nonrenal solid organ transplantation. This is a retrospective cohort study of 1609 patients who underwent initial nonrenal solid organ transplantation between January 2000 and June 2012. A central repository administrative database was queried electronically for demographics, comorbidities, and serial levels of tacrolimus, cyclosporine, and serum creatinine. Predictors of interest were total drug exposure of tacrolimus and cyclosporine (area under the concentration-time curve) and self-reported race. The outcome of interest was cumulative change in estimated glomerular filtration rate (GFR). There were 1109 patients treated with tacrolimus (271 African-Americans) and 500 patients treated with cyclosporine (113 African Americans). A decline in GFR over time was seen with total tacrolimus exposure (-1.3 mL/min/1.73 m(2) for every 5 ng/mL·year increase in tacrolimus) and total cyclosporine exposure (-1.1 mL/min/1.73 m(2) for every 50 ng/mL·year increase in cyclosporine). However, total CNI exposure effect on estimated GFR changes did not vary by race (P interaction was 0.9 for tacrolimus and 0.6 for cyclosporine). Total CNI exposure is associated with worsening kidney function among patients with nonrenal solid organ transplantation. However, African-American patients are not more vulnerable to chronic CNI-induced nephrotoxicity when compared to white patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The Coordinated Action of Calcineurin and Cathepsin D Protects Against α-Synuclein Toxicity

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    Andreas Aufschnaiter

    2017-06-01

    Full Text Available The degeneration of dopaminergic neurons during Parkinson’s disease (PD is intimately linked to malfunction of α-synuclein (αSyn, the main component of the proteinaceous intracellular inclusions characteristic for this pathology. The cytotoxicity of αSyn has been attributed to disturbances in several biological processes conserved from yeast to humans, including Ca2+ homeostasis, general lysosomal function and autophagy. However, the precise sequence of events that eventually results in cell death remains unclear. Here, we establish a connection between the major lysosomal protease cathepsin D (CatD and the Ca2+/calmodulin-dependent phosphatase calcineurin. In a yeast model for PD, high levels of human αSyn triggered cytosolic acidification and reduced vacuolar hydrolytic capacity, finally leading to cell death. This could be counteracted by overexpression of yeast CatD (Pep4, which re-installed pH homeostasis and vacuolar proteolytic function, decreased αSyn oligomers and aggregates, and provided cytoprotection. Interestingly, these beneficial effects of Pep4 were independent of autophagy. Instead, they required functional calcineurin signaling, since deletion of calcineurin strongly reduced both the proteolytic activity of endogenous Pep4 and the cytoprotective capacity of overexpressed Pep4. Calcineurin contributed to proper endosomal targeting of Pep4 to the vacuole and the recycling of the Pep4 sorting receptor Pep1 from prevacuolar compartments back to the trans-Golgi network. Altogether, we demonstrate that stimulation of this novel calcineurin-Pep4 axis reduces αSyn cytotoxicity.

  8. Renal function in heart transplant patients after switch to combined mammalian target of rapamycin inhibitor and calcineurin inhibitor therapy

    Directory of Open Access Journals (Sweden)

    Helmschrott M

    2017-06-01

    Full Text Available Matthias Helmschrott,1 Rasmus Rivinius,1 Thomas Bruckner,2 Hugo A Katus,1 Andreas O Doesch1 1Department of Cardiology, Angiology, Pneumology, 2Institute for Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany Background: A calcineurin inhibitor (CNI-based immunosuppression combined with mammalian target of rapamycin inhibitors (mTORs seems to be attractive in patients after heart transplantation (HTX in special clinical situations, for example, in patients with adverse drug effects of prior immunosuppression. Previous studies in patients after HTX detected advantageous effects regarding renal function of a tacrolimus (TAC-based vs cyclosporine-A (CSA-based immunosuppression (in combination with mycophenolate mofetil. However, data regarding renal function after HTX in mTOR/CNI patients remain limited. Aim: Primary end point of the present study was to analyze renal function in HTX patients 1 year after switch to an mTOR/CNI-based immunosuppression. Methods: Data of 80 HTX patients after change to mTOR/CNI-based immunosuppression were retrospectively analyzed. Renal function was assessed by measured serum creatinine and by estimated glomerular filtration rate (eGFR calculated from Modification of Diet in Renal Disease equation. Results: Twenty-nine patients received mTOR/CSA-based treatment and 51 patients received mTOR/TAC-based therapy. At time of switch and at 1-year follow-up, serum creatinine and eGFR did not differ significantly between both study groups (all P=not statistically significant. Analysis of variances with repeated measurements detected a similar change of renal function in both study groups. Conclusion: The present study detected no significant differences between both mTOR/CNI study groups, indicating a steady state of renal function in HTX patients after switch of immunosuppressive regimen. Keywords: heart transplantation, cyclosporine A, tacrolimus, risk factors

  9. Plasma NGAL and glomerular filtration rate in cardiac transplant recipients treated with standard or reduced calcineurin inhibitor levels

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Gude, Einar; Sigurdardottir, Vilborg

    2014-01-01

    GFR) at baseline (R(2) = 0.21; p year (median [25-75 % percentiles]: ΔmGFR 5.5 [-0.5-11.5] vs -1 [-7-4] ml/min/1.73 m(2); p = 0.006). Baseline P-NGAL predicted mGFR after 1 year (R(2) = 0.18; p ...: P-NGAL was measured in 88 cardiac transplantation patients (median 5 years post-transplant) with renal dysfunction randomized to continuation of conventional calcineurin inhibitor-based immunosuppression or switching to an everolimus-based regimen. RESULTS: P-NGAL correlated with measured GFR (m...

  10. Differential effects of calcineurin inhibitors, tacrolimus and cyclosporin a, on interferon-induced antiviral protein in human hepatocyte cells.

    Science.gov (United States)

    Hirano, Kumi; Ichikawa, Tatsuki; Nakao, Kazuhiko; Matsumoto, Azusa; Miyaaki, Hisamitsu; Shibata, Hidetaka; Eguchi, Susumu; Takatsuki, Mitsuhisa; Ikeda, Masanori; Yamasaki, Hironori; Kato, Nobuyuki; Kanematsu, Takashi; Ishii, Nobuko; Eguchi, Katsumi

    2008-03-01

    The premise of our study is that selective inhibition of interferon (IFN) by calcineurin inhibitors contribute to the increased severity of hepatitis C virus (HCV) posttransplantation. Therefore, we examined the influence of calcineurin inhibitors in the human hepatocyte cell line on IFN-alpha-induced phosphorylation of Janus kinase (Jak) and signal transducers and activators of transcription (STAT), nuclear translocation of IFN-stimulated gene factor 3 (ISGF-3), IFN-stimulated regulatory element (ISRE)-contained promoter activity, and the expressions of antiviral proteins. Tacrolimus (Tac), but not cyclosporin A (CyA), had an inhibitory effect on IFN-alpha-induced double-stranded ribonucleic acid (RNA)-dependent protein kinase (PKR) in a dose-dependent manner. STAT-1 also acted in a similar fashion to PKR. IFN-alpha combined with Tac attenuated the ISRE-containing promoter gene activity as compared with IFN-alpha alone. In contrast, its expression in pretreated CyA was slightly attenuated. In pretreated Tac, but not CyA, the levels of IFN-alpha-induced tyrosine phosphorylated STAT-1 and -2 were clearly lower than those induced by IFN-alpha alone. Tac and CyA did not decrease the IFN-alpha-induced JAK-1 phosphorylation. The nuclear translocation rate of tyrosine phosphorylated STAT-1 was inhibited by pretreatment of both Tac and CyA by western blotting and immunohistochemistry. In an HCV replicon system, pretreated Tac diminished the replication inhibitory effect of IFN-alpha. In this study, we show that calcineurin inhibitors, especially Tac, are the negative regulators of IFN signaling in the hepatocyte; the greatest cause of such inhibition is the phosphorylation disturbance of STAT-1, next to inhibition of the nuclear translocation of STAT-1. In conclusion, disturbance of tyrosine phosphorylation of STAT-1 resulted in diminished ISRE-containing promoter activity and a decline in antiviral protein expression. Moreover, the replication of HCV was activated. This

  11. Heat shock protein 90 and calcineurin pathway inhibitors enhance the efficacy of triazoles against Scedosporium prolificans via induction of apoptosis

    Directory of Open Access Journals (Sweden)

    Fazal Shirazi

    2014-06-01

    Full Text Available Scedosporium prolificans is a pathogenic mold resistant to current antifungals, and infection results in high mortality. Simultaneous targeting of both ergosterol biosynthesis and heat shock protein 90 (Hsp90 or the calcineurin pathway in S. prolificans may be an important strategy for enhancing the potency of antifungal agents. We hypothesized that the inactive triazoles posaconazole (PCZ and itraconazole (ICZ acquire fungicidal activity when combined with the calcineurin inhibitor tacrolimus (TCR or Hsp90 inhibitor 17-demethoxy-17-(2-propenylamino geldanamycin (17AAG. PCZ, ICZ, TCR and 17AAG alone were inactive in vitro against S. prolificans spores (MICs > 128 μg/ml. In contrast, MICs for PCZ or ICZ in combination with TCR or 17AAG (0.125-0.50 μg/ml were much lower compared with drug alone. In addition PCZ and ICZ in combination with TCR or 17AAG became fungicidal. Because apoptosis is regulated by the calcineurin pathway in fungi and is under the control of Hsp90, we hypothesized that this synergistic fungicidal effect is mediated via apoptosis. This observed fungicidal activity was mediated by increased apoptosis of S. prolificans germlings, as evidenced by reactive oxygen species accumulation, decreased mitochondrial membrane potential, phosphatidylserine externalization, and DNA fragmentation. Furthermore, induction of caspase-like activity was correlated with TCR or 17AAG + PCZ/ICZ-induced cell death. In conclusion, we report for the first time that PCZ or ICZ in combination with TCR or 17AAG renders S. prolificans exquisitely sensitive to PCZ or ICZ via apoptosis. This finding may stimulate the development of new therapeutic strategies for patients infected with this recalcitrant fungus.

  12. The calcineurin inhibitor cyclosporin A cyclophilin A complex reduces desensitization of GABA(A)-mediated responses in acutely dissociated rat hippocampal neurons

    NARCIS (Netherlands)

    Martina, M; Mozrzymas, JW; Boddeke, HWGM; Cherubini, E

    1996-01-01

    The effects of the selective inhibitor of calcineurin, cyclosporin A-cyclophilin A (CC) complex on the desensitization kinetics of GABA(A) receptors was studied in acutely dissociated hippocampal neurons, using the patch clamp technique in the whole cell configuration. In control conditions, the dec

  13. The phosphatase calcineurin regulates pathological TDP-43 phosphorylation.

    Science.gov (United States)

    Liachko, Nicole F; Saxton, Aleen D; McMillan, Pamela J; Strovas, Timothy J; Currey, Heather N; Taylor, Laura M; Wheeler, Jeanna M; Oblak, Adrian L; Ghetti, Bernardino; Montine, Thomas J; Keene, C Dirk; Raskind, Murray A; Bird, Thomas D; Kraemer, Brian C

    2016-10-01

    Detergent insoluble inclusions of TDP-43 protein are hallmarks of the neuropathology in over 90 % of amyotrophic lateral sclerosis (ALS) cases and approximately half of frontotemporal dementia (FTLD-TDP) cases. In TDP-43 proteinopathy disorders, lesions containing aggregated TDP-43 protein are extensively post-translationally modified, with phosphorylated TDP-43 (pTDP) being the most consistent and robust marker of pathological TDP-43 deposition. Abnormally phosphorylated TDP-43 has been hypothesized to mediate TDP-43 toxicity in many neurodegenerative disease models. To date, several different kinases have been implicated in the genesis of pTDP, but no phosphatases have been shown to reverse pathological TDP-43 phosphorylation. We have identified the phosphatase calcineurin as an enzyme binding to and catalyzing the removal of pathological C-terminal phosphorylation of TDP-43 in vitro. In C. elegans models of TDP-43 proteinopathy, genetic elimination of calcineurin results in accumulation of excess pTDP, exacerbated motor dysfunction, and accelerated neurodegenerative changes. In cultured human cells, treatment with FK506 (tacrolimus), a calcineurin inhibitor, results in accumulation of pTDP species. Lastly, calcineurin co-localizes with pTDP in degenerating areas of the central nervous system in subjects with FTLD-TDP and ALS. Taken together, these findings suggest calcineurin acts on pTDP as a phosphatase in neurons. Furthermore, patient treatment with calcineurin inhibitors may have unappreciated adverse neuropathological consequences.

  14. Introduction of MMF in conjunction with stepwise reduction of calcineurin inhibitor in stable liver transplant patients with renal dysfunction.

    Science.gov (United States)

    Kornberg, Arno; Küpper, Bernadette; Hommann, Merten; Scheele, Johannes

    2005-01-01

    Mycophenolat mofetil (MMF) is a new imunosuppressant without nephrotoxic adverse effects. The aim of this study was to evaluate feasibility and effect of MMF introduction in conjunction with stepwise reduction of calcineurin inhibitors (CNI) in stable liver transplant patients with chronic CNI-induced renal dysfunction (RDF). In the MMF-group (n=27) but not in the controls (n=16), mean serum level of creatinine fell from a baseline of 227.4+/-67.9 micromol/l to 159.2+/-48.2 micromol/l (PMMF. Additionally, systolic and diastolic blood pressure values improved. In 52% of patients, dose reduction (n=11) or withdrawal (n=3) of MMF was necessary due to gastrointestinal or hematologic adverse effects. But also in patients on low dose MMF, there was a significant improvement of renal function without increased immunological risk.

  15. High-dose calcineurin inhibitor-free everolimus as a maintenance regimen for heart transplantation may be a risk factor for Pneumocystis pneumonia.

    Science.gov (United States)

    Hu, Yu-Ning; Lee, Nan-Yao; Roan, Jun-Neng; Hsu, Chi-Hsin; Luo, Chwan-Yau

    2017-08-01

    Everolimus reduces the incidence of cardiac-allograft vasculopathy (CAV) and is less renally toxic than are calcineurin inhibitors (CNIs). We evaluated the safety of CNI-free everolimus for post-heart transplant (HTx) patients. We retrospectively reviewed the records of 36 consecutive patients who had undergone an HTx between January 2006 and December 2013 in National Cheng Kung University Hospital. All patients initially had been treated with the standard tacrolimus regimen. The Study group-12 patients with CAV, renal impairment, or a history of malignancy-were switched from tacrolimus to everolimus. The Control group consisted of 19 patients who remained on the standard regimen. The target everolimus trough concentration was 8-14 ng/mL. The primary outcome was survival, and the secondary outcomes were bacterial, viral, fungal, and other infections; Pneumocystis jirovecii pneumonia (PJP); and rejection (≥2R). During a 53.3±25.6-month follow-up, the survival rate, rejection rate, and number of infections, except for PJP, were not significantly different between the two groups. In the Study group, 6 patients were diagnosed with PJP 33±18.2 months after switching. None of the Control group patients were diagnosed with PJP during follow-up. A high-dose CNI-free everolimus maintenance regimen might yield a higher incidence of post-transplantation PJP. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. The calcineurin inhibitor cyclosporine A improves lipopolysaccharide-induced vascular dysfunction but does not rescue from cardiovascular collapse in endotoxemic mice

    DEFF Research Database (Denmark)

    Stæhr, Mette; Khatam-Lashgari, Apameh; Vanhoutte, Paul M

    2013-01-01

    The calcineurin inhibitor cyclosporine A (CsA) improves survival in endotoxemic mice. It was hypothesized that CsA counteracts the bradycardia and hypotension characteristic of endotoxemia. Vascular reactivity was determined in lipopolysaccharide (LPS; 50 μg/mL)-treated mouse aortic rings suspended...... and suppression of systemic NO formation by cyclosporine A are not sufficient to prevent cardiovascular collapse, which is caused primarily by compromised cardiac function....

  17. Identification of alkylbenzene sulfonate surfactants leaching from an acrylonitrile butadiene rubber as novel inhibitors of calcineurin activity.

    Science.gov (United States)

    Ito, Noboru; Shibuguchi, Nao; Ishikawa, Ryoki; Tanaka, Susumu; Tokita, Yoshiharu; Nakajima-Shimada, Junko; Hosaka, Kohei

    2013-01-01

    Calcineurin (CN) is a Ca(2+)/calmodulin (CaM) dependent serine/threonine protein phosphatase and plays important role in several cellular functions in both higher and lower eukaryotes. Here we report inhibition of CN by linear alkylbenzene sulfonate. The clue to the finding was obtained while identifying the inhibitory material leaching from acrylonitrile butadiene rubber used for packing. Using standard dodecylbenzene sulfonate (C12-LAS), we obtained strong inhibition of CN with a half maximal inhibitory concentration of 9.3 µM, whereas analogs such as p-octylbenzene sulfonate and SDS hardly or only slightly affected CN activity. Three alkaline phosphatases, derived from shrimp, bacteria, and calf-intestine, which exhibit similar enzymatic activities to CN, were not inhibited by C12-LAS at concentrations of up to 100 µM. Furthermore, C12-LAS did not inhibit Ca(2+)/CaM-dependent myosin light chain kinase activity when tested at concentrations of up to 36 µM. The results indicate that C12-LAS is a potent selective inhibitor of CN activity.

  18. Pulmonary Toxicity of Cholinesterase Inhibitors

    Science.gov (United States)

    2006-01-01

    discusses respiratory and pulmonary toxicity through direct venomous and was synthesized at Porton Down, England, inhalation of AChEIs and indirect...effects on all aspects of res- in 1952. piration through systemic toxicity. Due to their high toxicity in mammals and volatile OP nerve agents can be... produc - century with the development of the present-day vesicants tion facility late in the war and moved it back to Russia, and AChEIs (or OP class

  19. Deferred pre-emptive switch from calcineurin inhibitor to sirolimus leads to improvement in GFR and expansion of T regulatory cell population: a randomized, controlled trial.

    Directory of Open Access Journals (Sweden)

    Dinesh Bansal

    Full Text Available BACKGROUND: Measures to prevent chronic calcineurin inhibitor (CNI toxicity have included limiting exposure by switching to sirolimus (SIR. SIR may favorably influence T regulator cell (T(reg population. This randomized controlled trial compares the effect of switching from CNI to SIR on glomerular filtration rate (GFR and T(reg frequency. METHODS: In this prospective open label randomized trial, primary living donor kidney transplant recipients on CNI-based immunosuppression were randomized to continue CNI or switched to sirolimus 2 months after surgery; 29 were randomized to receive CNI and 31 to SIR. All patients received mycophenolate mofetil and steroids. The main outcome parameter was estimated GFR (eGFR at 180 days. T(reg population was estimated by flowcytometry. RESULTS: Baseline characteristics in the two groups were similar. Forty-eight patients completed the trial. At six months, patients in the SIR group had significantly higher eGFR as compared to those in the CNI group (88.94 ± 11.78 vs 80.59 ± 16.51 mL/min, p = 0.038. Patients on SIR had a 12 mL/min gain of eGFR of at the end of six months. Patients in the SIR group showed significant increase in T(reg population at 30 days, which persisted till day 180. There was no difference in the adverse events in terms of number of acute rejection episodes, death, infections, proteinuria, lipid profile, blood pressure control and hematological parameters between the two groups. Four patients taking SIR developed enthesitis. No patient left the study or switched treatment because of adverse event. CONCLUSIONS: A deferred pre-emptive switch over from CNI to SIR safely improves renal function and T(reg population at 6 months in living donor kidney transplant recipients. Registered in Clinical Trials Registry of India (CTRI/2011/091/000034.

  20. Pro: The use of calcineurin inhibitors in the treatment of lupus nephritis.

    Science.gov (United States)

    Mok, Chi Chiu

    2016-10-01

    Renal disease in systemic lupus erythematosus (SLE) carries significant morbidity and mortality. Cyclophosphamide (CYC)- and mycophenolate mofetil (MMF)-based induction regimens are not ideal in terms of efficacy and toxicity. The adverse effects of CYC, such as infection risk, infertility, urotoxicity and oncogenicity, limit its use in lupus nephritis. Although MMF is non-inferior to CYC as induction therapy and has reduced gonadal toxicity and oncogenic potential, meta-analyses of clinical trials do not show a lower rate of infective and gastrointestinal complications. Tacrolimus (TAC) has recently been shown to have equal efficacy to either MMF or CYC for inducing remission of lupus nephritis. A low-dose combination of MMF and TAC appears to be more effective than intravenous CYC pulses in Chinese patients, and has potential to replace the more toxic CYC regimens in high-risk subgroups. TAC may be considered as another non-CYC alternative for induction therapy of lupus nephritis and in those with refractory disease or intolerance to CYC or MMF. TAC has no negative effect on fertility in younger women, and unlike MMF and CYC, it is safe in pregnancy. However, TAC has a narrow therapeutic window and drug level monitoring is required to ensure drug exposure and minimize acute toxicities. Current evidence for the efficacy of TAC in lupus nephritis is limited to 6 months and the incidence of renal flare after discontinuation of therapy or switching to azathioprine appears to be higher than other induction agents. Long-term data and the incidence of chronic nephrotoxicity of TAC as maintenance therapy in lupus nephritis are currently lacking and further prospective trials are needed to address these issues.

  1. Discontinuation of calcineurin inhibitors treatment allows the development of FOXP3+ regulatory T-cells in patients after kidney transplantation.

    Science.gov (United States)

    van de Wetering, Jacqueline; Koumoutsakos, Periklis; Peeters, Annemiek; van der Mast, Barbara J; de Kuiper, Petronella; IJzermans, Jan N M; Weimar, Willem; Baan, Carla C

    2011-01-01

    This study investigated specific gene expression profiles in patients with donor-specific cytotoxic-hyporesponsiveness, reflected by cytotoxic T-lymphocyte precursor frequency (CTLpf). The effect of calcineurin inhibitor (CNI) withdrawal was studied on markers for cytotoxicity (perforin, granzyme B), apoptosis (Fas,FasL), Th1 and Th2 cytokines (IL-2, IL-10), Th1 and Th2 transcription factors (T-bet, GATA 3), Th17 transcription factor and cytokine (RORγt, IL-17), and for immune regulation/activation (CD25, FOXP3). Peripheral blood samples from renal allograft recipients (n = 18) more than two yr after transplantation with stable renal function were analyzed before and four months after CNI withdrawal. Additionally, systolic and diastolic blood pressure, cholesterol, serum creatinine and proteinuria were evaluated, and no significant differences were measured before and after CNI withdrawal. However, CNIs' discontinuation influenced peripheral gene expression profiles. After CNI withdrawal, the mRNA expression of Granzyme B, Perforin, Fas, FasL, T-bet, GATA3 and CD25 were significantly lower than during CNI treatment. After CNI discontinuation, donor-specific CTLpf decreased, while FOXP3 expression discriminated between detectable and non-detectable donor-specific cytolysis reactivity; FOXP3 transcript values were highest in absence of donor-specific cytotoxicity (p < 0.01). Our study shows CNI withdrawal in stable kidney transplant recipients two yr after transplantation is safe. Moreover, discontinuation of CNIs' treatment allows FOXP3+ regulatory T-cells development, resulting in a significant decrease of anti-donor immune reactivity.

  2. The role of calcineurin/NFAT in SFRP2 induced angiogenesis--a rationale for breast cancer treatment with the calcineurin inhibitor tacrolimus.

    Directory of Open Access Journals (Sweden)

    Sharareh Siamakpour-Reihani

    Full Text Available Tacrolimus (FK506 is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506-FKBP12 complex associates with calcineurin and inhibits its phosphatase activity, resulting in inhibition of nuclear translocation of nuclear factor of activated T-cells (NFAT. There is increasing data supporting a critical role of NFAT in mediating angiogenic responses stimulated by both vascular endothelial growth factor (VEGF and a novel angiogenesis factor, secreted frizzled-related protein 2 (SFRP2. Since both VEGF and SFRP2 are expressed in breast carcinomas, we hypothesized that tacrolimus would inhibit breast carcinoma growth. Using IHC (IHC with antibodies to FKBP12 on breast carcinomas we found that FKBP12 localizes to breast tumor vasculature. Treatment of MMTV-neu transgenic mice with tacrolimus (3 mg/kg i.p. daily (n = 19 resulted in a 73% reduction in the growth rate for tacrolimus treated mice compared to control (n = 15, p = 0.003; which was associated with an 82% reduction in tumor microvascular density (p<0.001 by IHC. Tacrolimus (1 µM inhibited SFRP2 induced endothelial tube formation by 71% (p = 0.005 and inhibited VEGF induced endothelial tube formation by 67% (p = 0.004. To show that NFATc3 is required for SFRP2 stimulated angiogenesis, NFATc3 was silenced with shRNA in endothelial cells. Sham transfected cells responded to SFRP2 stimulation in a tube formation assay with an increase in the number of branch points (p<0.003, however, cells transfected with shRNA to NFATc3 showed no increase in tube formation in response to SFRP2. This demonstrates that NFATc3 is required for SFRP2 induced tube formation, and tacrolimus inhibits angiogenesis in vitro and breast carcinoma growth in vivo. This provides a rationale for examining the therapeutic potential of tacrolimus at inhibiting breast carcinoma growth in humans.

  3. 钙调神经磷酸酶抑制剂治疗白癜风的进展%Calcineurin inhibitors in the treatment of vitiligo

    Institute of Scientific and Technical Information of China (English)

    曹永萍; 许爱娥

    2011-01-01

    Vitiligo is an acquired hypopigmented disease characterized by the destruction of melanocytes.Many scholars consider that the pathogenesis of vitiligo is mainly associated with immune abnormalities.Topical calcineurin inhibitors have favorable efficacy in the treatment of vitiligo,and the efficacy is associated with the treatment regimen,course,application sites,duration and stage of vitiligo,etc.The combination with narrow-band ultraviolet B,308-nm excimer laser or other therapies may have synergistic effect on the efficiency of calcineurin inhibitors.Although calcineurin inhibitors are safe and effective in the treatment of vitiligo,further studies are needed to evaluate their long-term safety and stability.%白癜风是一种以黑素细胞破坏为特征的获得性色素脱失性疾病,目前许多学者认为其发病机制主要与免疫异常有关.局部外用钙调神经磷酸酶抑制剂治疗白癜风有较好的疗效.单用钙调神经磷酸酶抑制剂治疗白癜风的疗效与用药方法、用药部位、疾病的病程、分期有关,也与疗程有关系.联合窄谱中波紫外线、308准分子激光及其他方法可以提高其有效率.钙调神经磷酸酶抑制剂治疗白癜风安全有效,长期使用的安全性和稳定性还需要进一步评估.

  4. Calcineurin inhibitor-free mycophenolate mofetil/sirolimus maintenance in liver transplantation: the randomized spare-the-nephron trial.

    Science.gov (United States)

    Teperman, Lewis; Moonka, Dilip; Sebastian, Anthony; Sher, Linda; Marotta, Paul; Marsh, Christopher; Koneru, Baburao; Goss, John; Preston, Dennis; Roberts, John P

    2013-07-01

    Mycophenolate mofetil (MMF) and sirolimus (SRL) have been used for calcineurin inhibitor (CNI) minimization to reduce nephrotoxicity following liver transplantation. In this prospective, open-label, multicenter study, patients undergoing transplantation from July 2005 to June 2007 who were maintained on MMF/CNI were randomized 4 to 12 weeks after transplantation to receive MMF/SRL (n = 148) or continue MMF/CNI (n = 145) and included in the intent-to-treat population. The primary efficacy endpoints were the mean percentage change in the calculated glomerular filtration rate (GFR) and a composite of biopsy-proven acute rejection (BPAR), graft lost, death, and lost to follow-up 12 months after transplantation. Patients were followed for a median of 519 days after randomization. MMF/SRL was associated with a significantly greater renal function improvement from baseline with a mean percentage change in GFR of 19.7 ± 40.6 (versus 1.2 ± 39.9 for MMF/CNI, P = 0.0012). The composite endpoint demonstrated the noninferiority of MMF/SRL versus MMF/CNI (16.4% versus 15.4%, 90% confidence interval = -7.1% to 9.0%). The incidence of BPAR was significantly greater with MMF/SRL (12.2%) versus MMF/CNI (4.1%, P = 0.02). Graft loss (including death) occurred in 3.4% of the MMF/SRL-treated patients and in 8.3% of the MMF/CNI-treated patients (P = 0.04). Malignancy-related deaths were less frequent with MMF/SRL. Adverse events caused withdrawal for 34.2% of the MMF/SRL-treated patients and for 24.1% of the MMF/CNI-treated patients (P = 0.06). The use of MMF/SRL is an option for liver transplant recipients who can benefit from improved renal function but is associated with an increased risk of rejection (but not graft loss).

  5. Regulator of calcineurin 1 modulates cancer cell migration in vitro

    OpenAIRE

    Espinosa, Allan V.; Shinohara, Motoo; Porchia,Leonardo M; Chung, Yun Jae; McCarty, Samantha; Saji, Motoyasu; Ringel, Matthew D.

    2009-01-01

    Metastasis suppressors and other regulators of cell motility play an important role in tumor invasion and metastases. We previously identified that activation of the G protein coupled receptor 54 (GPR54) by the metastasis suppressor metastin inhibits cell migration in association with overexpression of Regulator of calcineurin 1 (RCAN1), an endogenous regulator of calcineurin. Calcineurin inhibitors also blocked cell migration in vitro and RCAN1 protein levels were reduced in nodal metastases...

  6. Increased adherence eight months after switch from twice daily calcineurin inhibitor based treatment to once daily modified released tacrolimus in heart transplantation

    Directory of Open Access Journals (Sweden)

    Doesch AO

    2013-10-01

    Full Text Available Andreas O Doesch,1 Susanne Mueller,1 Ceylan Akyol,1 Christian Erbel,1 Lutz Frankenstein,1 Arjang Ruhparwar,2 Philipp Ehlermann,1 Thomas J Dengler,3 Hugo A Katus11Department of Cardiology, University of Heidelberg, Heidelberg, Germany; 2Department of Cardiovascular Surgery, University of Heidelberg, Heidelberg, Germany; 3Department of Cardiology, SLK-Kliniken Heilbronn, Bad Friedrichshall, GermanyBackground: Modified-release tacrolimus (TAC is a new, once-daily oral formulation of the established immunosuppressive agent TAC. This study evaluated long-term patient adherence, as well as safety and efficacy, in stable patients after heart transplantation (HTx who switched from a conventional twice daily calcineurin inhibitor-based regimen (TAC or cyclosporine A [CsA] to a once-daily modified-release TAC regimen.Methods: Stable patients were switched from conventional TAC or CsA (twice-daily dosing to modified-release TAC (once-daily dosing according to manufacturer's recommendations using a pre-experimental design. Self-reported adherence was assessed at baseline and 8 months after the switch with the Basel Assessment of Adherence with Immunosuppressive Medication Scale (BAASIS. Additionally, routine laboratory values were analyzed 8 months after switch.Results: Of 76 patients (58 male, 18 female initially included, 72 were available for statistical analysis, as modified-release TAC was discontinued due to diarrhea in one patient and gastrointestinal discomfort in three patients. Overall nonadherence at baseline for any of the four BAASIS items was 75.0% versus 40.3% after 8 months (P<0.0001. After 8 months, adherence was improved in 41 patients (56.9%, unchanged in 27 (37.5%, and reduced in four patients (5.6%. The BAASIS visual analog scale score improved significantly from 87.0% ± 13.5% to 97.5% ± 5.7% (P<0.0001. No significant changes were observed for hematological, renal, or liver function parameters after 8 months (all P=not significant

  7. Kaempferol Promotes Transplant Tolerance by Sustaining CD4+FoxP3+ Regulatory T Cells in the Presence of Calcineurin Inhibitor.

    Science.gov (United States)

    Zeng, Y Q; Liu, X S; Wu, S; Zou, C; Xie, Q; Xu, S M; Jin, X W; Li, W; Zhou, A; Dai, Z

    2015-07-01

    Calcineurin inhibitor cyclosporine is widely used as an immunosuppressant in clinic. However, mounting evidence has shown that cyclosporine hinders tolerance induction by dampening Tregs. Therefore, it is of paramount importance to overcome this pitfall. Kaempferol was reported to inhibit DC function. Here, we found that kaempferol delayed islet allograft rejection. Combination of kaempferol and low-dose, but not high-dose, of cyclosporine induced allograft tolerance in majority of recipient mice. Although kaempferol plus either dose of cyclosporine largely abrogated proliferation of graft-infiltrating T cells and their CTL activity, both proliferation and CTL activity in mice treated with kaempferol plus low-dose, but not high-dose, cyclosporine reemerged rapidly upon treatment withdrawal. Kaempferol increased CD4+FoxP3+ Tregs both in transplanted mice and in vitro, likely by suppressing DC maturation and their IL-6 expression. Reduction in Tregs by low dose of cyclosporine was reversed by kaempferol. Kaempferol-induced Tregs exhibited both allospecific and non-allospecific suppression. Administering IL-6 abrogated allograft tolerance induced by kaempferol and cyclosporine via diminishing CD4+FoxP3+ Tregs. Thus, for the first time, we demonstrated that kaempferol promotes transplant tolerance in the presence of low dose of cyclosporine, which allows for sufficient Treg generation while minimizing side effects, resulting in much-needed synergy between kaempferol and cyclosporine.

  8. High-throughput screening of one-bead-one-compound libraries: identification of cyclic peptidyl inhibitors against calcineurin/NFAT interaction.

    Science.gov (United States)

    Liu, Tao; Qian, Ziqing; Xiao, Qing; Pei, Dehua

    2011-09-12

    One-bead-one-compound (OBOC) libraries provide a powerful tool for drug discovery as well as biomedical research. However, screening a large number of beads/compounds (>1 million) and rank ordering the initial hits (which are covalently attached to a solid support) according to their potencies still post significant technical challenges. In this work, we have integrated some of the latest technical advances from our own as well as other laboratories to develop a general methodology for rapidly screening large OBOC libraries. The methodology has been applied to synthesize and screen a cyclic peptide library that features: (1) spatially segregated beads containing cyclic peptides on the surface layer and linear encoding peptides in their interior; (2) rapid on-bead screening of the library (>1 million) by a multistage procedure (magnetic bead sorting, enzyme-linked assay, and fluorescence based screening); (3) selective release of cyclic peptides from single positive beads for solution-phase determination of their binding affinities; and (4) hit identification by partial Edman degradation/mass spectrometry (PED/MS). Screening of the library against protein phosphatase calcineurin (Cn) identified a series of cyclic peptides that bind to the substrate-docking site for nuclear factor of activated T cells (NFAT) with K(D) values of ∼1 μM. Further improvement of the affinity and specificity of these compounds may lead to a new class of immunosuppressive agents that are more selective and therefore less toxic than cyclosporine A and FK506.

  9. Calcineurin inhibitors recruit protein kinases JAK2 and JNK, TLR signaling and the UPR to activate NF-κB-mediated inflammatory responses in kidney tubular cells

    Energy Technology Data Exchange (ETDEWEB)

    González-Guerrero, Cristian, E-mail: cristian.gonzalez@fjd.es [Renal and Vascular Pathology Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Av. Reyes Católicos 2, 28040 Madrid (Spain); Ocaña-Salceda, Carlos, E-mail: carlos.ocana@fjd.es [Renal and Vascular Pathology Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Av. Reyes Católicos 2, 28040 Madrid (Spain); Berzal, Sergio, E-mail: sberzal@fjd.es [Renal and Vascular Pathology Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Av. Reyes Católicos 2, 28040 Madrid (Spain); Carrasco, Susana, E-mail: scarrasco@fjd.es [Renal and Vascular Pathology Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Av. Reyes Católicos 2, 28040 Madrid (Spain); Fernández-Fernández, Beatriz, E-mail: bfernandez@fjd.es [Nephrology, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), Av. Reyes Católicos 2, 28040 Madrid (Spain); and others

    2013-11-01

    The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are key drugs in current immunosuppressive regimes for solid organ transplantation. However, they are nephrotoxic and promote death and profibrotic responses in tubular cells. Moreover, renal inflammation is observed in CNI nephrotoxicity but the mechanisms are poorly understood. We have now studied molecular pathways leading to inflammation elicited by the CNIs in cultured and kidney tubular cells. Both CsA and tacrolimus elicited a proinflammatory response in tubular cells as evidenced by a transcriptomics approach. Transcriptomics also suggested several potential pathways leading to expression of proinflammatory genes. Validation and functional studies disclosed that in tubular cells, CNIs activated protein kinases such as the JAK2/STAT3 and TAK1/JNK/AP-1 pathways, TLR4/Myd88/IRAK signaling and the Unfolded Protein Response (UPR) to promote NF-κB activation and proinflammatory gene expression. CNIs also activated an Nrf2/HO-1-dependent compensatory response and the Nrf2 activator sulforaphane inhibited JAK2 and JNK activation and inflammation. A murine model of CsA nephrotoxicity corroborated activation of the proinflammatory pathways identified in cell cultures. Human CNIs nephrotoxicity was also associated with NF-κB, STAT3 and IRE1α activation. In conclusion, CNIs recruit several intracellular pathways leading to previously non-described proinflammatory actions in renal tubular cells. Identification of these pathways provides novel clues for therapeutic intervention to limit CNIs nephrotoxicity. - Highlights: • Molecular mechanisms modulating CNI renal inflammation were investigated. • Kinases, immune receptors and ER stress mediate the inflammatory response to CNIs. • Several intracellular pathways activate NF-κB in CNIs-treated tubular cells. • A NF-κB-dependent cytokine profile characterizes CNIs-induced inflammation. • CNI nephrotoxicity was associated to inflammatory

  10. Calcineurin inhibitor-induced and Ras-mediated overexpression of VEGF in renal cancer cells involves mTOR through the regulation of PRAS40.

    Directory of Open Access Journals (Sweden)

    Aninda Basu

    Full Text Available Malignancy is a major problem in patients treated with immunosuppressive agents. We have demonstrated that treatment with calcineurin inhibitors (CNIs can induce the activation of proto-oncogenic Ras, and may promote a rapid progression of human renal cancer through the overexpression of vascular endothelial growth factor (VEGF. Interestingly, we found that CNI-induced VEGF overexpression and cancer cell proliferation was inhibited by rapamycin treatment, indicating potential involvement of the mammalian target of rapamycin (mTOR pathway in this tumorigenic process. Here, we examined the role of mTOR pathway in mediating CNI- and Ras-induced overexpression of VEGF in human renal cancer cells (786-0 and Caki-1. We found that the knockdown of raptor (using siRNA significantly decreased CNI-induced VEGF promoter activity as observed by promoter-luciferase assay, suggesting the role of mTOR complex1 (mTORC1 in CNI-induced VEGF transcription. It is known that mTOR becomes activated following phosphorylation of its negative regulator PRAS40, which is a part of mTORC1. We observed that CNI treatment and activation of H-Ras (through transfection of an active H-Ras plasmid markedly increased the phosphorylation of PRAS40, and the transfection of cells using a dominant-negative plasmid of Ras, significantly decreased PRAS40 phosphorylation. Protein kinase C (PKC-ζ and PKC-δ, which are critical intermediary signaling molecules for CNI-induced tumorigenic pathway, formed complex with PRAS40; and we found that the CNI treatment increased the complex formation between PRAS40 and PKC, particularly (PKC-ζ. Inhibition of PKC activity using pharmacological inhibitor markedly decreased H-Ras-induced phosphorylation of PRAS40. The overexpression of PRAS40 in renal cancer cells significantly down-regulated CNI- and H-Ras-induced VEGF transcriptional activation. Finally, it was observed that CNI treatment increased the expression of phosho-PRAS40 in renal tumor

  11. Nephro and neurotoxicity of calcineurin inhibitors and mechanisms of rejections: A review on tacrolimus and cyclosporin in organ transplantation.

    Science.gov (United States)

    Tolou-Ghamari, Zahra

    2012-04-01

    In the meadow of medical sciences substituting a diseased organ with a healthy one from another individual, dead or alive, to allow a human to stay alive could be consider as the most string event. In this article we review the history of transplantation, mechanisms of rejection, nephro-neurotoxicity of tacrolimus and cyclosporin in organ transplantations. Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched. The first reference to the concept of organ transplantation and replacement for therapeutic purposes appears to be to Hua-To (136 to 208 A.D), who replaced diseased organs with healthy ones in patients under analgesia induced with a mixture of Indian hemp. In 1936, the first human renal transplant performed by Voronoy in Russia. The first liver transplant in humans was performed on March 1, 1963 by Starzl in Denver, USA. Medawar was the first to assert that rejection was an immunological response, with the inflammatory reaction due to lymphocyte infiltration. Consequently, rational immunosuppressive therapies could inhibit deleterious T-cell responses in an antigen specific manner. Searching related to the history of organ transplantation from mythic to modern times suggests that, to prevent graft rejection, minimize nephro and neuro toxicity monitoring of immunosupressive concentrations could provide an invaluable and essential aid in adjusting dosage to ensure adequate immunosuppression.

  12. A Randomized 2x2 Factorial Clinical Trial of Renal Transplantation: Steroid-Free Maintenance Immunosuppression with Calcineurin Inhibitor Withdrawal after Six Months Associates with Improved Renal Function and Reduced Chronic Histopathology.

    Directory of Open Access Journals (Sweden)

    R Brian Stevens

    Full Text Available The two most significant impediments to renal allograft survival are rejection and the direct nephrotoxicity of the immunosuppressant drugs required to prevent it. Calcineurin inhibitors (CNI, a mainstay of most immunosuppression regimens, are particularly nephrotoxic. Until less toxic antirejection agents become available, the only option is to optimize our use of those at hand.To determine whether intensive rabbit anti-thymocyte globulin (rATG induction followed by CNI withdrawal would individually or combined improve graft function and reduce graft chronic histopathology-surrogates for graft and, therefore, patient survival. As previously reported, a single large rATG dose over 24 hours was well-tolerated and associated with better renal function, fewer infections, and improved patient survival. Here we report testing whether complete CNI discontinuation would improve renal function and decrease graft pathology.Between April 20, 2004 and 4-14-2009 we conducted a prospective, randomized, non-blinded renal transplantation trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment = 180. Subsequent maintenance immunosuppression consisted of tacrolimus, a CNI, and sirolimus, a mammalian target of rapamycin inhibitor. We report here the outcome of converting patients after six months either to minimized tacrolimus/sirolimus or mycophenolate mofetil/sirolimus. Primary endpoints were graft function and chronic histopathology from protocol kidney biopsies at 12 and 24 months.CNI withdrawal (on-treatment analysis associated with better graft function (p <0.001 and lower chronic histopathology composite scores in protocol biopsies at 12 (p = 0.003 and 24 (p = 0.013 months, without affecting patient (p = 0.81 or graft (p = 0.93 survival, or rejection rate (p = 0.17.CNI (tacrolimus withdrawal at six months may provide a strategy for decreased nephrotoxicity and improved long-term function

  13. Calcineurin controls drug tolerance, hyphal growth, and virulence in Candida dubliniensis.

    Science.gov (United States)

    Chen, Ying-Lien; Brand, Alexandra; Morrison, Emma L; Silao, Fitz Gerald S; Bigol, Ursela G; Malbas, Fedelino F; Nett, Jeniel E; Andes, David R; Solis, Norma V; Filler, Scott G; Averette, Anna; Heitman, Joseph

    2011-06-01

    Candida dubliniensis is an emerging pathogenic yeast species closely related to Candida albicans and frequently found colonizing or infecting the oral cavities of HIV/AIDS patients. Drug resistance during C. dubliniensis infection is common and constitutes a significant therapeutic challenge. The calcineurin inhibitor FK506 exhibits synergistic fungicidal activity with azoles or echinocandins in the fungal pathogens C. albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In this study, we show that calcineurin is required for cell wall integrity and wild-type tolerance of C. dubliniensis to azoles and echinocandins; hence, these drugs are candidates for combination therapy with calcineurin inhibitors. In contrast to C. albicans, in which the roles of calcineurin and Crz1 in hyphal growth are unclear, here we show that calcineurin and Crz1 play a clearly demonstrable role in hyphal growth in response to nutrient limitation in C. dubliniensis. We further demonstrate that thigmotropism is controlled by Crz1, but not calcineurin, in C. dubliniensis. Similar to C. albicans, C. dubliniensis calcineurin enhances survival in serum. C. dubliniensis calcineurin and crz1/crz1 mutants exhibit attenuated virulence in a murine systemic infection model, likely attributable to defects in cell wall integrity, hyphal growth, and serum survival. Furthermore, we show that C. dubliniensis calcineurin mutants are unable to establish murine ocular infection or form biofilms in a rat denture model. That calcineurin is required for drug tolerance and virulence makes fungus-specific calcineurin inhibitors attractive candidates for combination therapy with azoles or echinocandins against emerging C. dubliniensis infections.

  14. EGFR-inhibitors, radiotherapy and normal tissue toxicity

    DEFF Research Database (Denmark)

    Eriksen, J. G.

    2015-01-01

    will be explained with references to the current knowledge of the biology of skin toxicity. Treatment options for acute side-effects in skin and mucosa after bio-radiotherapy is rarely causal. A few attempts have been done; some of them aiming to rephosphorylate the EGFreceptor in the skin with vitamin K3. The talk......EGFR-inhibitors have been used in several clinical settings during the last decade and side-effects related to normal tissues like the skin, mucosa and kidney has been well described. However, when EGFR-inhibitors are combined with radiotherapy, then different skin and mucosa toxicity profiles can...... will discuss the available data from these studies. Across several tumour sites and for different EGFR-inhibitors, a correlation between skin toxicity and tumour response has also been documented. The reason for this correlation is not obvious but probably related to genetic alterations or certain genetic...

  15. Inhibition of human calcineurin and yeast calcineurin-dependent gene expression by Jasminum humile leaf and root extracts.

    Science.gov (United States)

    Prescott, Thomas A K; Ariño, Joaquín; Kite, Geoffrey C; Simmonds, Monique S J

    2012-03-27

    The leaves of Jasminum humile are used to treat skin disorders in a way which resembles the use of modern topical anti-inflammatory drugs. Ethanolic extracts of the roots and leaves were shown to inhibit calcineurin which is a regulator of inflammatory gene expression. A novel yeast calcineurin reporter gene assay suitable for a 96 well plate format was developed to test for inhibition of calcineurin-dependent gene expression. Calmodulin/calcineurin phosphatase assays were then used to further elucidate the mode of action of the extracts. Jasminum humile root and leaf extract exhibited calcineurin inhibition activity that was shown to be mediated through a direct interaction with calcineurin enzyme. The activity is sufficient to block calcineurin-dependent gene expression in a yeast model. The activity of the plant supports its traditional use in the treatment of inflammatory skin disorders. The specially adapted yeast reporter assay was found to be a highly effective way of detecting calcineurin inhibitors in plant extracts. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Progress in the treatment of young patients with lupus nephritis using calcineurin inhibitors%钙神经蛋白抑制剂治疗儿童狼疮性肾炎的新进展

    Institute of Scientific and Technical Information of China (English)

    魏伟; 夏正坤

    2014-01-01

    激素联合环磷酰胺静脉冲击治疗是儿童狼疮性肾炎的经典治疗方案,但疾病复发仍难控制,且环磷酰胺有骨髓毒性、生殖毒性以及继发肿瘤的风险,使其应用受到限制。治疗相关副作用是免疫抑制剂治疗狼疮性肾炎的主要治疗风险,因此选择安全有效的方案仍是临床医师治疗儿童狼疮性肾炎患者时面临的一大困境。钙神经蛋白抑制剂如环孢素 A 和他克莫司治疗狼疮性肾炎有效,且安全性较好。含他克莫司的多靶点治疗方案是近年来的热点。本文就钙神经蛋白抑制剂治疗儿童狼疮性肾炎的新进展作一综述。%Steroids with intermittent pulses of intravenous cyclophosphamide is standard treatment protocol for pediatric-onset lupus nephritis, but disease flare is still frequent and difficult to control. Cyclophosphamide is associated with myelotoxicity, gonadal toxicity, and an increased risk of secondary malignancy, which limits its clinical usage. Since therapy-related adverse events are a major concern of immunosuppressive agents for the patients with lupus nephritis, how to establish a safe and effective treatment protocol is a dilemma for physicians treating young patients. Calcineurin inhibitor, such as cyclosporine A and tacrolimus, are effective and relatively safe for lupus nephritis. Tacrolimus containning multidrug therapy is becoming a hot spot in recent years.

  17. ESR Study on calcineurin

    Institute of Scientific and Technical Information of China (English)

    魏群; 肖方祥; 卢景芬; 周捷

    1995-01-01

    X-band electron spin resonance spectroscopy was used to investigate the binding of Mn2+tothe apo-forms of calcineurin and its A and B subunits.The results indicated the presence of 2Mn2+binding sites of different affinities(20μmol/L and 60μmol/L)in the calcineurin A subunit and 4Mn2+binding sites in the calcineurin subunit B,2 high affinity and 2 low affinity binding sites withKd’s of 4μmol/L and 90μmol/L,respectively.Interestingly and quite surprisingly,Mn2+binding to theholoenzyme was characterized by only 2 binding sites with Kd’s of 7μmol/L and 33μmol/L.However,inthe presence of calmodulin about 10 Mn2+sites were detected,and the Mn2+calmodulin-calcineurin complexexhibited enzymatic activity.These results,based on direct spectral measurements of the metal ligand,demonstrate that Mn2+binds to both free subunits of calcineurin in a manner distinct from binding to theholoenzyme.Also,the data suggest that conformational changes occur upon heterodimer formation andassociation of the holoenzyme with the regulatory protein calmodulin.

  18. Conversion from calcineurin inhibitors to sirolimus of recipients with chronic kidney graft disease grade iii for a period 2003-2011

    Directory of Open Access Journals (Sweden)

    Ignjatović Ljiljana

    2013-01-01

    Full Text Available Background/Aim. Tremendous breakthrough in solid organ transplantation was made with the introduction of calcineurin inhibitors (CNI. At the same time, they are potentially nephrotoxic drugs with influence on onset and progression of renal graft failure. The aim of this study was to evaluate the outcome of a conversion from CNIbased immunosuppressive protocol to sirolimus (SRL in recipients with graft in chronic kidney disease (CKD grade III and proteinuria below 500 mg/day. Methods. In the period 2003-2011 24 patients (6 famale and 18 male, mean age 41 ± 12.2 years, on triple immunosuppressive therapy: steroids, antiproliferative drug [mycophenolate mofetil (MMF or azathiopirine (AZA] and CNI were switched from CNI to SRL and followe-up for 76 ± 13 months. Nine patients (the group I had early postransplant conversion after 4 ± 3 months and 15 patients (the group II late conversion after 46 ± 29 months. During the regular outpatient controls we followed graft function through the serum creatinine and glomerular filtration rate (GFR, proteinuria, lipidemia and side effects. Results. Thirty days after conversion, in all the patients GFR, proteinuria and lipidemia were insignificantly increased. In the first two post-conversion months all the patients had at least one urinary or respiratory infection, and 10 patients reactivated cytomegalovirus (CMV infection or disease, and they were successfully treated with standard therapy. After 21 ± 11 months 15 patients from both groups discontinued SRL therapy due to reconversion to CNI (10 patients and double immunosuppressive therapy (3 patients, return to hemodialysis (1 patient and death (1 patient. Nine patients were still on SRL therapy. By the end of the follow-up they significantly improved GFR (from 53.2 ± 12.7 to 69 ± 15 mL/min, while the increase in proteinuria (from 265 ± 239 to 530.6 ± 416.7 mg/day and lipidemia (cholesterol from 4.71 ± 0.98 to 5.61 ± 1.6 mmol/L and triglycerides

  19. ELEVATE: an innovative study design to assess the efficacy, safety, and evolution of cardiovascular parameters in de novo kidney transplant recipients after early conversion from a calcineurin inhibitor to everolimus

    Directory of Open Access Journals (Sweden)

    van der Giet M

    2014-03-01

    Full Text Available Markus van der Giet,1 Josep M Cruzado,2 Johan W de Fijter,3 Hallvard Holdaas,4 Zailong Wang,5 Antonio Speziale,6 Guido Junge61Department of Nephrology, Campus Benjamin Franklin, Charite'-Universitätsmedizin, Berlin, Germany; 2Department of Nephrology, University Hospital of Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; 3Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands; 4Section of Nephrology, Department of Transplant Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway; 5Biometrics and Statistical Science, Novartis Pharmaceuticals, East Hanover, NJ, USA; 6Research and Development, Novartis Pharma AG, Basel, SwitzerlandAbstract: Progressive decline in allograft function and cardiovascular mortality after kidney transplantation remain major clinical challenges that can potentially be addressed by the mammalian target of rapamycin (mTOR inhibitors, everolimus and sirolimus. mTOR inhibitors maintain immunosuppressive efficacy after minimization of calcineurin inhibitor (CNI therapy and can achieve significant long-term improvements in renal function. Recently, data have accumulated that suggest mTOR inhibitors may offer cardioprotective effects. In animal models, inhibition of mTOR leads to regression of cardiac hypertrophy, and the limited data consistently point to a remodeling benefit following heart transplantation. Experimentally, mTOR inhibitors restrict atherogenesis, confirmed clinically by intravascular ultrasound data demonstrating lower rates of transplant vasculopathy in heart transplant recipients on everolimus. Lastly, mTOR inhibitors appear to ameliorate arterial stiffness, a known risk factor for post-transplant cardiovascular events, but data remain sparse. The ELEVATE study will examine the renal effect of early conversion from CNI therapy to everolimus after kidney transplantation. Key secondary endpoints include the change in left ventricular mass index, the first time

  20. Calcineurin/NFAT signalling inhibits myeloid haematopoiesis.

    Science.gov (United States)

    Fric, Jan; Lim, Clarice X F; Koh, Esther G L; Hofmann, Benjamin; Chen, Jinmiao; Tay, Hock Soon; Mohammad Isa, Siti Aminah Bte; Mortellaro, Alessandra; Ruedl, Christiane; Ricciardi-Castagnoli, Paola

    2012-04-01

    Nuclear factor of activated T cells (NFAT) comprises a family of transcription factors that regulate T cell development, activation and differentiation. NFAT signalling can also mediate granulocyte and dendritic cell (DC) activation, but it is unknown whether NFAT influences their development from progenitors. Here, we report a novel role for calcineurin/NFAT signalling as a negative regulator of myeloid haematopoiesis. Reconstituting lethally irradiated mice with haematopoietic stem cells expressing an NFAT-inhibitory peptide resulted in enhanced development of the myeloid compartment. Culturing bone marrow cells in media supplemented with Flt3-L in the presence of the calcineurin/NFAT inhibitor Cyclosporin A increased numbers of differentiated DC. Global gene expression analysis of untreated DC and NFAT-inhibited DC revealed differential expression of transcripts that regulate cell cycle and apoptosis. In conclusion, these results provide evidence that calcineurin/NFAT signalling negatively regulates myeloid lineage development. The finding that inhibition of NFAT enhances myeloid development provides a novel insight into understanding how the treatment with drugs targeting calcineurin/NFAT signalling influence the homeostasis of the innate immune system.

  1. Shikonin, a constituent of Lithospermum erythrorhizon exhibits anti-allergic effects by suppressing orphan nuclear receptor Nr4a family gene expression as a new prototype of calcineurin inhibitors in mast cells.

    Science.gov (United States)

    Wang, Xiaoyu; Hayashi, Shusaku; Umezaki, Masahito; Yamamoto, Takeshi; Kageyama-Yahara, Natsuko; Kondo, Takashi; Kadowaki, Makoto

    2014-12-05

    inhibition of calcineurin activity. Therefore, shikonin has therapeutic potential for the treatment of allergic diseases as a new calcineurin inhibitor.

  2. Inhibition of calcineurin phosphatase promotes exocytosis of renin from juxtaglomerular cells

    DEFF Research Database (Denmark)

    Madsen, Kirsten; Friis, Ulla Glenert; Gooch, Jennifer L;

    2010-01-01

    To examine the role of the calcium/calmodulin-dependent phosphatase calcineurin in regulation of renin release, we assayed exocytosis using whole-cell patch clamp of single juxtaglomerular cells in culture. The calcineurin inhibitor, cyclosporine A (CsA), significantly increased juxtaglomerular......A, but not tacrolimus, significantly stimulated renin release from cultured juxtaglomerular cells. Juxtaglomerular cells expressed the calcineurin isoforms A-beta and A-gamma but not A-alpha. Plasma renin concentrations (PRCs) were not different in wild-type, calcineurin A-alpha, or A-beta knockout mice but increased...... cell membrane capacitance, an index of cell surface area and an established measure of exocytosis in single-cell assays. This effect was mimicked by intracellular delivery of a calcineurin inhibitory peptide, the calcium chelator ethylene glycol tetraacetic acid (EGTA), or the calmodulin inhibitor W-13...

  3. Role of calcineurin (CN) in kidney glomerular podocyte: CN inhibitor ameliorated proteinuria by inhibiting the redistribution of CN at the slit diaphragm.

    Science.gov (United States)

    Wakamatsu, Ayako; Fukusumi, Yoshiyasu; Hasegawa, Eriko; Tomita, Masayuki; Watanabe, Toru; Narita, Ichiei; Kawachi, Hiroshi

    2016-03-01

    Although calcineurin (CN) is distributed in many cell types and functions in regulating cell functions, the precise roles ofCNremained in each type of the cells are not well understood yet. ACNinhibitor (CNI) has been used for steroid-resistant nephrotic syndrome. ACNIis assumed to ameliorate proteinuria by preventing the overproduction of T-cell cytokines. However, recent reports suggest thatCNIhas a direct effect on podocyte. It is accepted that a slit diaphragm (SD), a unique cell-cell junction of podocytes, is a critical barrier preventing a leak of plasma protein into urine. Therefore, we hypothesized thatCNIhas an effect on theSD In this study, we analyzed the expression ofCNin physiological and in the nephrotic model caused by the antibody against nephrin, a critical component of theSD We observed thatCNis expressed at theSDin normal rat and human kidney sections and has an interaction with nephrin. The staining ofCNat theSDwas reduced in the nephrotic model, whileCNactivity in glomeruli was increased. We also observed that the treatment with tacrolimus, aCNI, in this nephrotic model suppressed the redistribution ofCN, nephrin, and otherSDcomponents and ameliorated proteinuria. These observations suggested that the redistribution and the activation ofCNmay participate in the development of theSDinjury. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  4. Selection by phage display of a mustard chymotrypsin inhibitor toxic to pea aphid.

    NARCIS (Netherlands)

    Ceci, L.R.; Volpicella, M.; Conti, S.; Gallerani, R.; Beekwilder, M.J.; Jongsma, M.A.

    2003-01-01

    The mustard trypsin inhibitor, MTI-2, is a potent inhibitor of trypsin with no activity towards chymotrypsin. MTI-2 is toxic for lepidopteran insects, but has low activity against aphids. In an attempt to improve the activity of the inhibitor towards aphids, a library of inhibitor variants was const

  5. Calcineurin is required for pseudohyphal growth, virulence, and drug resistance in Candida lusitaniae.

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    Full Text Available Candida lusitaniae is an emerging fungal pathogen that infects immunocompromised patients including HIV/AIDS, cancer, and neonatal pediatric patients. Though less prevalent than other Candida species, C. lusitaniae is unique in its ability to develop resistance to amphotericin B. We investigated the role of the calcium-activated protein phosphatase calcineurin in several virulence attributes of C. lusitaniae including pseudohyphal growth, serum survival, and growth at 37°C. We found that calcineurin and Crz1, a C. albicans Crz1 homolog acting as a downstream target of calcineurin, are required for C. lusitaniae pseudohyphal growth, a process for which the underlying mechanism remains largely unknown in C. lusitaniae but hyphal growth is fundamental to C. albicans virulence. We demonstrate that calcineurin is required for cell wall integrity, ER stress response, optimal growth in serum, virulence in a murine systemic infection model, and antifungal drug tolerance in C. lusitaniae. To further examine the potential of targeting the calcineurin signaling cascade for antifungal drug development, we examined the activity of a calcineurin inhibitor FK506 in combination with caspofungin against echinocandin resistant C. lusitaniae clinical isolates. Broth microdilution and drug disk diffusion assays demonstrate that FK506 has synergistic fungicidal activity with caspofungin against echinocandin resistant isolates. Our findings reveal that pseudohyphal growth is controlled by the calcineurin signaling cascade, and highlight the potential use of calcineurin inhibitors and caspofungin for emerging drug-resistant C. lusitaniae infections.

  6. Calcineurin is required for pseudohyphal growth, virulence, and drug resistance in Candida lusitaniae.

    Science.gov (United States)

    Zhang, Jing; Silao, Fitz Gerald S; Bigol, Ursela G; Bungay, Alice Alma C; Nicolas, Marilou G; Heitman, Joseph; Chen, Ying-Lien

    2012-01-01

    Candida lusitaniae is an emerging fungal pathogen that infects immunocompromised patients including HIV/AIDS, cancer, and neonatal pediatric patients. Though less prevalent than other Candida species, C. lusitaniae is unique in its ability to develop resistance to amphotericin B. We investigated the role of the calcium-activated protein phosphatase calcineurin in several virulence attributes of C. lusitaniae including pseudohyphal growth, serum survival, and growth at 37°C. We found that calcineurin and Crz1, a C. albicans Crz1 homolog acting as a downstream target of calcineurin, are required for C. lusitaniae pseudohyphal growth, a process for which the underlying mechanism remains largely unknown in C. lusitaniae but hyphal growth is fundamental to C. albicans virulence. We demonstrate that calcineurin is required for cell wall integrity, ER stress response, optimal growth in serum, virulence in a murine systemic infection model, and antifungal drug tolerance in C. lusitaniae. To further examine the potential of targeting the calcineurin signaling cascade for antifungal drug development, we examined the activity of a calcineurin inhibitor FK506 in combination with caspofungin against echinocandin resistant C. lusitaniae clinical isolates. Broth microdilution and drug disk diffusion assays demonstrate that FK506 has synergistic fungicidal activity with caspofungin against echinocandin resistant isolates. Our findings reveal that pseudohyphal growth is controlled by the calcineurin signaling cascade, and highlight the potential use of calcineurin inhibitors and caspofungin for emerging drug-resistant C. lusitaniae infections.

  7. Mechanisms of Ca2+-dependent calcineurin activation in mechanical stretch-induced hypertrophy.

    Science.gov (United States)

    Zobel, Carsten; Rana, Obaida R; Saygili, Erol; Bölck, Birgit; Saygili, Esra; Diedrichs, Holger; Reuter, Hannes; Frank, Konrad; Müller-Ehmsen, Jochen; Pfitzer, Gabriele; Schwinger, Robert H G

    2007-01-01

    Pressure overload is the major stimulus for cardiac hypertrophy. Accumulating evidence suggests an important role for calcium-induced activation of calcineurin in mediating hypertrophic signaling. Hypertrophy is an important risk factor for cardiovascular morbidity and mortality. We therefore employed an in vitro mechanical stretch model of cultured neonatal cardiomyocytes to evaluate proposed mechanisms of calcium-induced calcineurin activation in terms of inhibition of calcineurin activity and hypertrophy. The protein/DNA ratio and ANP gene expression were used as markers for stretch-induced hypertrophy. Stretch increased the calcineurin activity, MCIP1 gene expression and DNA binding of NFATc as well as the protein/DNA ratio and ANP mRNA in a significant manner. The specific inhibitor of calcineurin, cyclosporin A, inhibited the stretch-induced increase in calcineurin activity, MCIP1 gene expression and hypertrophy. The L-type Ca2+ channel blocker nifedipine and a blocker of the Na+/H+ exchanger (cariporide) both suppressed stretch-dependent enhanced calcineurin activity and hypertrophy. Also application of a blocker of the Na+/Ca2+ exchanger (KB-R7943) was effective in preventing calcineurin activation and increases in the protein/DNA ratio. Inhibition of capacitative Ca2+ entry with SKF 96365 was also sufficient to abrogate calcineurin activation and hypertrophy. The blocker of stretch-activated ion channels, streptomycin, was without effect on stretch-induced hypertrophy and calcineurin activity. The present work suggests that of the proposed mechanisms for the calcium-induced activation of calcineurin (L-type Ca2+ channels, capacitative Ca2+ entry, Na+/H+ exchanger, Na+/Ca2+ exchanger and stretch-activated channels) all but stretch-activated channels are possible targets for the inhibition of hypertrophy. 2007 S. Karger AG, Basel

  8. Toxicity of Nitrification Inhibitors on Dehydrogenase Activity in Soils

    Directory of Open Access Journals (Sweden)

    Ferisman Tindaon

    2011-01-01

    Full Text Available The objective of this research was to determine the effects of nitrification inhibitors (NIs such as 3,4-dimethylpyrazolephosphate=DMPP, 4-Chlor-methylpyrazole phosphate=ClMPP and dicyandiamide,DCD which might be expected to inhibit microbial activity, on dehydrogenase activity (DRA,in three different soils in laboratory conditions. Dehydrogenase activity were assessed via reduction of 2-p-Iodophenyl-3-p-nitrophenyl-5-phenyltetrazoliumchloride (INT. The toxicity and dose response curve of three NIs were quantified under laboratory conditions using a loamy clay, a sandy loam and a sandy soil. The quantitative determination of DHA was carried out spectrophotometrically. In all experiments, the influence of 5-1000 times the base concentration were examined. To evaluate the rate of inhibition with the increasing NI concentrations, dose reponse curves were presented and no observable effect level =NOEL, as well as effective dose ED10 and ED 50(10% and 50% inhibition were calculated. The NOEL for common microbial activity such as DHA was about 30–70 times higher than base concentration in all investigated soils. ClMPP exhibited the strongest influence on the non target microbial processes in the three soils if it compare to DMPP and DCD. The NOEL,ED10 and ED50 values higher in clay than in loamy or sandy soil. The NIs were generally most effective in sandy soils. The three NIs considered at the present state of knowledge as environmentally safe in use.

  9. Study of gastrointestinal toxicity of selective COX-2 inhibitors in comparison with conventional NSAIDs

    Directory of Open Access Journals (Sweden)

    Hima Bindu K.

    2016-12-01

    Conclusions: In our short-term study, selective COX-2 inhibitors did not show any advantage over non-selective NSAIDs regarding their gastrointestinal toxicity. [Int J Res Med Sci 2016; 4(12.000: 5180-5184

  10. ROLE OF CALCINEURIN IN ANGIOTENSIN II INDUCED CARDIAC MYOCYTE HYPERTROPHY OF RATS

    Institute of Scientific and Technical Information of China (English)

    符民桂; 张继峰; 许松; 庞永政; 刘乃奎; 唐朝枢

    2001-01-01

    Objective. The present study investigated the role of calcineurin in angiotensin II(AngII) induced cardiac myocyte hypertrophy of rats. Method. The primary cardiac myocytes were cultured under the standard conditions. The calcineurin activity in AngII treated cardiomyocytes was tested by using PNPP;protein synethsis rate was assessed by 3H leucine incorporation; atrial natriuretic factor(ANF) Mrna level was determined by Northern blot analysis. Cell viability was estimated by lactate dehydrogenase(LDH) levels in cultured medium and by dyed cell numbers. Result. After stimulation of 10,100 and 1 000nmol/L of AngII, calcineurin activities in the cardiomyocytes were increased by 13% ,57% (P< 0.05) and 228% (P< 0.01) respectively, compared with control group. Cyclosporin A(CsA), a specific inhibitor of calcineurin, markedly inhibited the calcineurin activity and decreased the 3H leucine incorporation in AngII treated cardiomyocytes in a dose dependent manner. It was also found that CsA slightly reduced the Mrna level of ANF gene in AngII stimulated cardiomyocytes. Conclusion. During AngII induced cardiac myocyte hypertrophy, calcineurin signal pathway is activated, and inhibition of the pathway can attenuate AngII induced cardiac myocyte hypertrophy, which suggests that the calcineurin signal pathway may play an important role in AngII induced myocardial hypertrophy of rats.

  11. Bosutinib induced pleural effusions: Case report and review of tyrosine kinase inhibitors induced pulmonary toxicity

    Directory of Open Access Journals (Sweden)

    Natalia I. Moguillansky, MD

    2017-01-01

    Full Text Available Tyrosine kinase inhibitors are known to cause pulmonary complications. We report a case of bosutinib related bilateral pleural effusions in a patient with chronic myeloid leukemia. Characteristics of the pleural fluid are presented. We also discuss other tyrosine kinase inhibitors induced pulmonary toxicities, including pulmonary hypertension and interstitial lung disease.

  12. Dermatologic Toxicities in Epidermal Growth Factor Receptor and Multikinase Inhibitors

    Science.gov (United States)

    Eaby-Sandy, Beth; Grande, Carolyn; Viale, Pamela Hallquist

    2012-01-01

    Targeted therapies have produced significant treatment advances for patients diagnosed with a variety of tumor types. These therapies are associated with unique dermatologic toxicities that may hamper treatment efforts and cause significant discomfort for patients. Prevention and management of these toxicities can allow patients to remain on therapy and hence receive maximum clinical benefit from the drug. PMID:25031940

  13. Tyrosine Kinase Inhibitors and Vascular Toxicity: Impetus for a Classification System?

    Science.gov (United States)

    Herrmann, Joerg

    2016-06-01

    The introduction of molecularly targeted therapies with tyrosine kinase inhibitors has revolutionized cancer therapy and has contributed to a steady decline in cancer-related mortality since the late 1990s. However, not only cardiac but also vascular toxicity has been reported for these agents, some as expected on-target effects (e.g., VEGF receptor inhibitors) and others as unanticipated events (e.g., BCR-Abl inhibitors). A sound understanding of these cardiovascular toxic effects is critical to advance mechanistic insight into vascular disease and clinical care. From a conceptual standpoint, there might be value in defining type I (permanent) and type II (transient) vascular toxicity. This review will focus on the tyrosine kinase inhibitors in current clinical use and their associated vascular side effects.

  14. BRAF inhibitors: experience in thyroid cancer and general review of toxicity.

    Science.gov (United States)

    Cabanillas, M E; Patel, A; Danysh, B P; Dadu, R; Kopetz, S; Falchook, G

    2015-02-01

    The US Food and Drug Administration-approved BRAF inhibitors, vemurafenib and dabrafenib, have demonstrated superior efficacy in patients with BRAF-mutant melanomas but have limited efficacy in BRAF-mutant colorectal cancer. Little is known at this time regarding BRAF inhibitors in thyroid cancer. Initial reports in patients with progressive, radioactive iodine-refractory BRAF-mutant papillary thyroid cancer suggest response rates of approximately 30-40%. In this review, we discuss BRAF inhibitors in the context of thyroid cancer, the toxicities associated with BRAF inhibitors, and the suggested management of those toxicities. The management of vemurafenib and dabrafenib toxicities is applicable across all tumor types and may serve as a practical guide to their use.

  15. Mitochondrial alterations in PINK1 deficient cells are influenced by calcineurin-dependent dephosphorylation of dynamin-related protein 1.

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    Anna Sandebring

    Full Text Available PTEN-induced novel kinase 1 (PINK1 mutations are associated with autosomal recessive parkinsonism. Previous studies have shown that PINK1 influences both mitochondrial function and morphology although it is not clearly established which of these are primary events and which are secondary. Here, we describe a novel mechanism linking mitochondrial dysfunction and alterations in mitochondrial morphology related to PINK1. Cell lines were generated by stably transducing human dopaminergic M17 cells with lentiviral constructs that increased or knocked down PINK1. As in previous studies, PINK1 deficient cells have lower mitochondrial membrane potential and are more sensitive to the toxic effects of mitochondrial complex I inhibitors. We also show that wild-type PINK1, but not recessive mutant or kinase dead versions, protects against rotenone-induced mitochondrial fragmentation whereas PINK1 deficient cells show lower mitochondrial connectivity. Expression of dynamin-related protein 1 (Drp1 exaggerates PINK1 deficiency phenotypes and Drp1 RNAi rescues them. We also show that Drp1 is dephosphorylated in PINK1 deficient cells due to activation of the calcium-dependent phosphatase calcineurin. Accordingly, the calcineurin inhibitor FK506 blocks both Drp1 dephosphorylation and loss of mitochondrial integrity in PINK1 deficient cells but does not fully rescue mitochondrial membrane potential. We propose that alterations in mitochondrial connectivity in this system are secondary to functional effects on mitochondrial membrane potential.

  16. Calcineurin activity in children with Mental handicap.

    Science.gov (United States)

    Bindu, L Hema; Rani, P Usha; Reddy, P P

    2007-09-01

    Calcineurin, a Ca(2+)-Calmodulin dependent protein phosphatase, is important for Ca(2+) mediated signal transduction. The main objective of this study was to examine the potential role of calcineurin in idiopathic mental handicap. Calcineurin levels were estimated in 20 children in the age group of 5-16 years with idiopathic mental handicap attending the Special. Education Centre for the Mentally Handicapped in Hyderabad. The results of the present study showed decreased activity of serum calcineurin in children with idiopathic mental handicap compared to those of normal subjects in the same age group. The observations thus suggest impaired calcineurin activity in children with mental handicap. Calcineurin that is involved in biosynthesis and release of neurotransmitters at the synaptic terminal brain is affected thereby causing brain damage and leading to mental handicap. Impaired calcineurin activity was already indicated in many human diseases such as Down's syndrome, Alzheimers, Brain ischemia, cardiac hypertrophy etc. It is therefore necessary to check the calcineurin levels in children with mental handicap to understand the role of calcineurin in the causation of Mental handicap.

  17. Cutaneous toxicity from epidermal growth factor receptor inhibitors: would a subcutaneous desensitization be helpful? Case report.

    Science.gov (United States)

    D'Alessio, Andrea; Cecchini, Sara; Di Mauro, Daniela; Geroli, Luca; Villa, Simonetta; Quadri, Antonello; Resta, Davide; Fortugno, Carmelo

    2016-11-11

    Cetuximab and panitumumab are monoclonal antibody inhibitors that bind the epidermal growth factor receptor (EGFR) currently used in the treatment of metastatic colorectal cancer. The main adverse event related to EGFR inhibitors (EGFR-Is) is cutaneous toxicity, which can cause dosage reduction and interruption of treatment. State-of-the-art management of skin toxicity associated with EGFR-Is therapy involves the topical administration of corticosteroids and oral antibiotics, but is not completely effective in the management of toxicity. Subcutaneous desensitization with increasing concentrations of monoclonal antibodies can induce a tolerance to drug administration and reduce cutaneous adverse effects. To our knowledge, this is the first case in which a reduction or a disappearance of skin toxicity caused by EGFR-Is through subcutaneous desensitization has been achieved. We present cases of 2 Caucasian patients with adenocarcinoma of the colon treated with EGFR-Is who developed severe cutaneous toxicity. A 73-year-old man presented grade 4 skin toxicity of the face and grade 3 skin toxicity of the trunk during treatment with cetuximab. A 68-year-old woman developed G2 rash on the face after the first administration of cetuximab. These patients underwent subcutaneous desensitization with increasing concentrations of EGFR-Is. After this procedure, patients restarted therapy at the optimal dosage with reduction or disappearance of skin toxicity. These cases suggest that by giving rising doses of antibody it is possible to obtain desensitization able to prevent severe cutaneous adverse events in patients treated with EGFR-Is.

  18. Protection against Acetylcholinesterase Inhibitor Toxicity by Alpha- Adrenergic Agonists

    Science.gov (United States)

    1992-10-28

    in Rats 22 " fable 4 Prevalence of Soman-Evoked Behaviors at the Time of Maximal Expression 23 Table 5 Open-field Motor Activity 2 Days After Soman... Brecht , K.M. and Lenz, D.E. (1987). Effect of carboxylesterase inhibition on carbamate protection against soman toxicity. In: Proceedings of the 1987...Medical Defense Bioscience Review, Aberdeen Proving Ground. pp. 17-24. 33. Maxwell, D.M., Brecht . K.M. and O’neill, B.L1 (1987).The effect of

  19. Assessing and managing toxicities induced by kinase inhibitors.

    Science.gov (United States)

    Castoldi, Raffaella E; Pennella, Giulia; Saturno, Grazia S; Grossi, Pietro; Brughera, Marco; Venturi, Miro

    2007-01-01

    Currently, several protein kinase-modulating compounds have received market approval across a range of diverse therapeutic indications. Furthermore, a large number of chemical and biological protein kinase-modulating compounds are undergoing testing at the preclinical and clinical level. Protein kinases are both major pharmacological targets and diagnostically useful. Progression of kinase modulators toward clinically viable therapies is aided by a reversible mechanism of action, short treatment durations and patient-compliant administration routes. However, the physiological role and essential functional activity of protein kinases in many organs and tissues complicates, to different extents, the development of useful, highly potent protein kinase modulators. In this review, we will highlight common problems in the development of these compounds and lessons learned from the extensive preclinical and clinical characterization of some key protein kinase modulators, some of which have either entered and successfully completed clinical trials or have been abandoned as a consequence of unacceptable toxicity issues. We will ultimately explore how molecular profiling tools combined with histopathological endpoints can be adopted to address and further understand these toxicities in humans and understand their relevance and characterization when identified during early animal experiments.

  20. Downregulation of calcineurin activity in cervical carcinoma

    Directory of Open Access Journals (Sweden)

    Jain Meenakshi

    2005-04-01

    Full Text Available Abstract Background Calcineurin (CaN is an important serine-threonine phosphatase (PP2B, which plays a crucial role in calcium-calmodulin mediated signal transduction events. Calcineurin has been implicated in pathogenesis of various diseases cardiac hypertrophy, diabetic neuropathy and Alzheimer's, however its role in neoplasia remains unclear. Results In view of this we evaluated the calcineurin activity in serum and biopsy samples collected from women diagnosed with invasive squamous cell carcinoma of cervix. A significant reduction was observed in the calcineurin activity in cancer cervix patients compared to the control group. However the calcineurin activity remained unaltered in the cervical scrapes obtained from patients diagnosed with low-grade squamous intra epithelial lesions (LSIL. Interestingly the downregulation of calcineurin activity in squamous cell carcinomas was not accompanied by any significant change in DNA-binding affinity of the transcriptional factor NFAT (Nuclear Factor of Activated T-cells. All the squamous cell carcinoma samples used in the present study were positive for high-risk human papillomavirus (HPV types. Conclusion The present study demonstrates the downregulation of calcineurin activity in squamous cell carcinoma of cervix with high risk HPV infection. We conclude that perturbations in calcineurin-mediated pathway may be involved in development of cervical neoplasia.

  1. Calcineurin-NFAT signaling is involved in phenylephrine-induced vascular smooth muscle cell proliferation

    Institute of Scientific and Technical Information of China (English)

    Xiao PANG; Ning-ling SUN

    2009-01-01

    Aim: Catecholamine-induced vascular smooth muscle cell (VSMC) proliferation is one of the major events in the pathogenesis of atherosclerosis and vascular remodeling. The calcineurin-NFAT pathway plays a role in regulating growth and differentiation in various cell types. We investigated whether the calcineurin-NFAT pathway was involved in the regulation of phenylephrine-induced VSMC proliferation.Methods: Proliferation of VSMC was measured using an MTT assay and cell counts. Localization of NFATcl was detected by immunofluorescence staining. NFATcl-DNA binding was determined by EMSA and luciferase activity analyses.NFATcl and calcineurin levels were assayed by immunoprecipitation.Results: Phenylephrine (PE, an α1-adrenoceptor agonist) increased VSMC proliferation and cell number. Prazosin (an α1-adrenoceptor antagonist), cyclosporin A (CsA, an inhibitor of calcineurin) and chelerythrine (an inhibitor of PKC)decreased PE-induced proliferation and cell number. Additional treatment of VSMC with CsA or chelerythrine further inhibited proliferation and cell number in the chelerythrine-pretreatment group and the CsA-pretreatment group. CsA and chelerythrine alone had no effect on either absorbance or cell number. CsA decreased PE-induced calcineurin levels and activity. NFATc1 was translocated from the cytoplasm to the nucleus upon treatment with PE. This translocation was reversed by CsA. CsA decreased the PE-induced NFATc1 level in the nucleus. PE increased NFAT's DNA binding activity and NFAT-dependent reporter gene expression. CsA blocked these effects.Conclusion: CsA partially suppresses PE-induced VSMC proliferation by inhibiting calcineurin activity and NFATc1 nuclear translocation. The calcineurin-NFATc1 pathway is involved in the hyperplastic growth of VSMC induced by phenylephrine.

  2. Non-toxic melanin production inhibitors from Garcinia livingstonei (Clusiaceae).

    Science.gov (United States)

    Mulholland, Dulcie A; Mwangi, Elizabeth M; Dlova, Ncoza C; Plant, Nick; Crouch, Neil R; Coombes, Phillip H

    2013-09-16

    The stem bark of Garcinia livingstonei is used traditionally as a skin lightening agent. To isolate and identify compounds responsible for the observed skin lightening activity of Garcinia livingstonei and to evaluate their cytotoxicity. Constituents of the stem bark and fruits of Garcinia livingstonei were isolated using chromatographic techniques and structures were determined using 1D and 2D NMR and MS analysis. MeWo cells were used to evaluate the cytotoxicity and impact on melanin levels of extracts and compounds isolated, in vitro. Twelve known compounds, morelloflavone (1), morelloflavone-7″-sulphate (2), guttiferone A (3), sargaol (4), isojacareubin (5), 6-deoxyisojacareubin (6) and in addition to the common triterpenoids, betulin, betulin aldehyde, lupeol, lupenone, euphol and stigmasterol were isolated in this investigation. Morelloflavone, morelloflavone-7″-sulphate and sargaol, were found to be considerably less cytotoxic and more effective as skin lightening agents than hydroquinone. A range of compounds was isolated from the stem bark and fruit of Garcinia livingstonei. Although the bark extract contained the cytotoxic guttiferone A, it was found to be less toxic than hydroquinone, and morelloflavone, the 7″-sulphate derivative and sargaol show potential for development as depigmentation/skin lightening agents. © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Computational selection of inhibitors of Abeta aggregation and neuronal toxicity.

    Science.gov (United States)

    Chen, Deliang; Martin, Zane S; Soto, Claudio; Schein, Catherine H

    2009-07-15

    Alzheimer's disease (AD) is characterized by the cerebral accumulation of misfolded and aggregated amyloid-beta protein (Abeta). Disease symptoms can be alleviated, in vitro and in vivo, by 'beta-sheet breaker' pentapeptides that reduce plaque load. However the peptide nature of these compounds, made them biologically unstable and unable to penetrate membranes with high efficiency. The main goal of this study was to use computational methods to identify small molecule mimetics with better drug-like properties. For this purpose, the docked conformations of the active peptides were used to identify compounds with similar activities. A series of related beta-sheet breaker peptides were docked to solid state NMR structures of a fibrillar form of Abeta. The lowest energy conformations of the active peptides were used to design three dimensional (3D)-pharmacophores, suitable for screening the NCI database with Unity. Small molecular weight compounds with physicochemical features and a conformation similar to the active peptides were selected, ranked by docking and biochemical parameters. Of 16 diverse compounds selected for experimental screening, 2 prevented and reversed Abeta aggregation at 2-3microM concentration, as measured by Thioflavin T (ThT) fluorescence and ELISA assays. They also prevented the toxic effects of aggregated Abeta on neuroblastoma cells. Their low molecular weight and aqueous solubility makes them promising lead compounds for treating AD.

  4. Low affinity Ca2+-binding sites of calcineurin B mediate conformational changes in calcineurin A.

    Science.gov (United States)

    Yang, S A; Klee, C B

    2000-12-26

    Limited proteolysis of calcineurin in the presence of Ca(2+) suggested that its calmodulin-binding domain, readily degraded by proteases, was unfolded while calcineurin B was compactly folded [Hubbard, M. J., and Klee, C. B. (1989) Biochemistry 28, 1868-1874]. Moreover, in the crystal structure of calcineurin, with the four Ca(2+) sites of calcineurin B occupied, the calmodulin-binding domain is not visible in the electron density map [Kissinger, C. R., et al. (1995) Nature 378, 641-644]. Limited proteolysis of calcineurin in the presence of EGTA, shows that, when the low affinity sites of calcineurin B are not occupied, the calmodulin-binding domain is completely protected against proteolytic attack. Slow cleavages are, however, detected in the linker region between the calmodulin-binding and the autoinhibitory domains of calcineurin A. Upon prolonged exposure to the protease, selective cleavages in carboxyl-terminal end of the first helix and the central helix linker of calcineurin B and the calcineurin B-binding helix of calcineurin A are also detected. Thus, Ca(2+) binding to the low-affinity sites of calcineurin B affects the conformation of calcineurin B and induces a conformational change of the regulatory domain of calcineurin A, resulting in the exposure of the calmodulin-binding domain. This conformational change is needed for the partial activation of the enzyme in the absence of calmodulin and its full activation by calmodulin. A synthetic peptide corresponding to the calmodulin-binding domain is shown to interact with a peptide corresponding to the calcineurin B-binding domain, and this interaction is prevented by calcineurin B in the presence but not the absence of Ca(2+). These observations provide a mechanism to explain the dependence on Ca(2+) binding to calcineurin B for calmodulin activation and for the 10-20-fold increase in affinity of calcineurin for Ca(2+) upon removal of the regulatory domain by limited proteolysis [Stemmer, P. M., and Klee

  5. Semiology of skin toxicity associated with epidermal growth factor receptor (EGFR) inhibitors.

    Science.gov (United States)

    Peuvrel, L; Bachmeyer, C; Reguiai, Z; Bachet, J B; André, T; Bensadoun, R J; Bouché, O; Ychou, M; Dréno, B

    2012-05-01

    Advances in the understanding of the mechanisms involved in oncogenesis have led to the development of so-called targeted therapies such as epidermal growth factor receptor (EGFR) inhibitors, which take on an increasingly important role in the management of cancer. These treatments have the advantage not to trigger the adverse effects traditionally encountered with chemotherapy, such as nausea, vomiting or haematological toxicity. However, they do cause new forms of toxicity: the most common one is skin toxicity. It is important to be aware of it because it can be debilitating, adversely impacting patients' quality of life and altering treatment compliance, although it appears to be correlated with treatment response in certain series. Non-specialists can have difficulty in recognising this unusual skin toxicity. The dermatologic side effects most frequently triggered by EGFR inhibitors are discussed in this article. They are divided into three categories depending on their target: inflammation of the pilo-sebaceous follicle, represented by EGFR inhibitor-associated folliculitis, which occurs at an early stage and is frequent; alteration in the skin barrier, primarily responsible for xerosis, fissures and pruritus, which are frequent and delayed; and lesions of the skin appendages (paronychia, pyogenic granuloma, hair changes), which are delayed and less frequent. It is essential for all practitioners concerned to know about these dermatologic side effects in order to ensure better global management of patients, particularly in terms of quality of life.

  6. Hsp90 governs echinocandin resistance in the pathogenic yeast Candida albicans via calcineurin.

    Directory of Open Access Journals (Sweden)

    Sheena D Singh

    2009-07-01

    Full Text Available Candida albicans is the leading fungal pathogen of humans, causing life-threatening disease in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs whose efficacy is compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. We previously established that the molecular chaperone Hsp90, which regulates the form and function of diverse client proteins, potentiates resistance to the azoles in C. albicans and in the model yeast Saccharomyces cerevisiae. Genetic studies in S. cerevisiae revealed that Hsp90's role in azole resistance is to enable crucial cellular responses to the membrane stress exerted by azoles via the client protein calcineurin. Here, we demonstrate that Hsp90 governs cellular circuitry required for resistance to the only new class of antifungals to reach the clinic in decades, the echinocandins, which inhibit biosynthesis of a critical component of the fungal cell wall. Pharmacological or genetic impairment of Hsp90 function reduced tolerance of C. albicans laboratory strains and resistance of clinical isolates to the echinocandins and created a fungicidal combination. Compromising calcineurin function phenocopied compromising Hsp90 function. We established that calcineurin is an Hsp90 client protein in C. albicans: reciprocal co-immunoprecipitation validated physical interaction; Hsp90 inhibition blocked calcineurin activation; and calcineurin levels were depleted upon genetic reduction of Hsp90. The downstream effector of calcineurin, Crz1, played a partial role in mediating calcineurin-dependent stress responses activated by echinocandins. Hsp90's role in echinocandin resistance has therapeutic potential given that genetic compromise of C. albicans HSP90 expression enhanced the efficacy of an echinocandin in a murine model of disseminated candidiasis. Our results identify the first Hsp90 client protein in C. albicans, establish an entirely

  7. Cyclosporin A promotes tumor angiogenesis in a calcineurin-independent manner by increasing mitochondrial reactive oxygen species.

    Science.gov (United States)

    Zhou, Alice Yao; Ryeom, Sandra

    2014-11-01

    The widely used immunosuppressant cyclosporin A, a potent calcineurin inhibitor, significantly increases the incidence of cancer in organ transplant patients. Calcineurin signaling is an important mediator of VEGF signaling in endothelial cells. Negative regulation of calcineurin by its endogenous inhibitor, Down Syndrome Candidate Region-1 (DSCR1), suppresses tumor growth and angiogenesis, in contrast to the effect observed after long-term cyclosporin A treatment. Despite the significance of calcineurin signaling in endothelial cells, the consequences of cyclosporin A on tumor angiogenesis have not been investigated. Using an in vivo model of skin carcinogenesis, prolonged treatment with cyclosporin A promoted tumor growth and angiogenesis. The addition of cyclosporin A to endothelial cells in vitro increased proliferation and migration in a calcineurin-independent manner and is associated with increased mitochondrial reactive oxygen species (ROS). Co-treatment with antioxidants significantly abrogated cyclosporin A-induced endothelial cell activation. Furthermore, mice treated with antioxidants were protected against cyclosporin A-mediated tumor progression. Taken together, these findings suggest that cyclosporin A affects endothelial cells in a calcineurin-independent manner to potentiate tumor growth by promoting tumor angiogenesis through increasing mitochondrial ROS production. This work identifies a previously undescribed mechanism underlying a significantly adverse off-target effect of cyclosporin A and suggests that co-treatment with antioxidants would inhibit the tumor-promoting effects of cyclosporin A. Targeting the proangiogenic effects of cyclosporin A may be useful in the management of transplant-associated cancers. ©2014 American Association for Cancer Research.

  8. Toxicity of cylindrospermopsin to the brine shrimp Artemia salina: comparisons with protein synthesis inhibitors and microcystins.

    Science.gov (United States)

    Metcalf, J S; Lindsay, J; Beattie, K A; Birmingham, S; Saker, M L; Törökné, A K; Codd, G A

    2002-08-01

    The Artemia salina bioassay was successfully applied to the analysis of the hepatotoxic cyanobacterial alkaloid and protein synthesis inhibitor, cylindrospermopsin. A dose-dependent response in mortality was observed for purified cylindrospermopsin and LC(50) values decreased with time from 8.1 to 0.71 microg/ml(-1), between 24 and 72 h, respectively. Cylindrospermopsin was slightly less potent than micro cystin-LR, with similar LC(50) values on a gravimetric basis, but was more toxic to A.salina than the protein synthesis inhibitors, cycloheximide, chloramphenicol and tetracycline. Cylindrospermopsin-containing strains of the cyanobacterium Cylindrospermopsis raciborskii were found to be toxic to A.salina and the LC(50) concentration for these strains over time was greater than the LC(50) for purified cylindrospermopsin, with the exception of C. raciborskii strain CR1.

  9. Calcineurin /NFAT activation-dependence of leptin synthesis and vascular growth in response to mechanical stretch

    Directory of Open Access Journals (Sweden)

    Nadia Soudani

    2016-09-01

    Full Text Available Background and Aims- Hypertension and obesity are important risk factors of cardiovascular disease. They are both associated with high leptin levels and have been shown to promote vascular hypertrophy, through the RhoA/ROCK and ERK1/2 phosphorylation. Calcineurin/NFAT activation also induces vascular hypertrophy by upregulating various genes. This study aimed to decipher whether a crosstalk exists between the RhoA/ROCK pathway, Ca+2/calcineurin/NFAT pathway, and ERK1/2 phosphorylation in the process of mechanical stretch-induced vascular smooth muscle cell (VSMC hypertrophy and leptin synthesis. Methods and Results- Rat portal vein (RPV organ culture was used to investigate the effect of mechanical stretch and exogenous leptin (3.1 nM on VSMC hypertrophy and leptin synthesis. Results showed that stretching the RPV significantly upregulated leptin secretion, mRNA and protein expression, which were inhibited by the calcium channel blocker nifedipine (10 μM, the selective calcineurin inhibitor FK506 (1 nM and the ERK1/2 inhibitor PD98059 (1 μM. The transcription inhibitor actinomycin D (0.1M and the translation inhibitor cycloheximide (1 mM significantly decreased stretch-induced leptin protein expression. Mechanical stretch or leptin caused an increase in wet weight changes and protein synthesis, considered as hypertrophic markers, while they were inhibited by FK506 (0.1 nM; 1 nM. In addition, stretch or exogenous leptin significantly increased calcineurin activity and MCIP1 expression whereas leptin induced NFAT nuclear translocation in VSMCs. Moreover, in response to stretch or exogenous leptin, the Rho inhibitor C3 exoenzyme (30 ng/mL, the ROCK inhibitor Y-27632 (10 μM, and the actin depolymerization agents Latrunculin B (50 nM and cytochalasin D (1 μM reduced calcineurin activation and NFAT nuclear translocation. ERK1/2 phosphorylation was inhibited by FK506 and C3. Conclusions- Mechanical stretch-induced VSMC hypertrophy and leptin

  10. Nitrogen-dependent calcineurin activation in the yeast Hansenula polymorpha.

    Science.gov (United States)

    Rodríguez, Celia; Galindo, Luis R; Siverio, José M

    2013-04-01

    Non-preferred nitrogen sources, unlike preferred ones, raised total cell Ca(2+) content and expression of ENA1, a very well-known calcineurin-regulated gene. This indicates calcineurin activation is regulated by nitrogen source. Nitrogen catabolite repression (NCR) and nitrate induction mechanisms, both regulating nitrate assimilation in Hansenula polymorpha, are controlled by calcineurin. Concerning NCR, lack of calcineurin (cnb1 mutant) decreased nitrate-assimilation gene expression, levels of the transcription factor Gat1 and growth in several nitrogen sources. We found that the role of calcineurin in NCR was mediated by Crz1 via Gat1. Regarding nitrate induction, calcineurin also affects the levels of transcription factors Gat2 and Yna2 involved in this process. We conclude that Ca(2+) and calcineurin play a central role in nitrogen signalling and assimilation. Thus, the nitrogen source modulates Ca(2+) content and calcineurin activation. Calcineurin in turn regulates nitrogen assimilation genes.

  11. Toxicity and Physiological Actions of Carbonic Anhydrase Inhibitors to Aedes aegypti and Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Sheena A. M. Francis

    2016-12-01

    Full Text Available The physiological role of carbonic anhydrases in pH and ion regulation is crucial to insect survival. We examined the toxic and neurophysiological effects of five carbonic anhydrase inhibitors (CAIs against Aedes aegypti. The 24 h larvicidal toxicities followed this rank order of potency: dichlorphenamide > methazolamide > acetazolamide = brinzolamide = dorzolamide. Larvicidal activity increased modestly in longer exposures, and affected larvae showed attenuated responses to probing without overt tremors, hyperexcitation, or convulsions. Acetazolamide and dichlorphenamide were toxic to adults when applied topically, but were of low potency and had an incomplete effect (<50% at 300 ng/mosquito even after injection. Dichlorphenamide was also the most toxic compound when fed to adult mosquitoes, and they displayed loss of posture and occasionally prolonged fluttering of the wings. Co-exposure with 500 ng of the synergist piperonyl butoxide (PBO increased the toxicity of dichlorphenamide ca. two-fold in feeding assays, indicating that low toxicity was not related to oxidative metabolism. Dichlorphenamide showed mild depolarizing and nerve discharge actions on insect neuromuscular and central nervous systems, respectively. These effects were increased in low buffer salines, indicating they were apparently related to loss of pH control in these tissues. Overall, sulfonamides displayed weak insecticidal properties on Aedes aegypti and are weak lead compounds.

  12. A proposed EGFR inhibitor dermatologic adverse event-specific grading scale from the MASCC skin toxicity study group

    NARCIS (Netherlands)

    Lacouture, Mario E.; Maitland, Michael L.; Segaert, Siegfried; Setser, Ann; Baran, Robert; Fox, Lindy P.; Epstein, Joel B.; Barasch, Andrei; Einhorn, Lawrence; Wagner, Lynne; West, Dennis P.; Rapoport, Bernardo L.; Kris, Mark G.; Basch, Ethan; Eaby, Beth; Kurtin, Sandra; Olsen, Elise A.; Chen, Alice; Dancey, Janet E.; Trotti, Andy

    2010-01-01

    Accurate grading of dermatologic adverse events (AE) due to epidermal growth factor receptor (EGFR) inhibitors (EGFRIs) is necessary for drug toxicity determinations, interagent comparisons, and supportive care trials. The most widely used severity grading scale, the National Cancer Institute's Comm

  13. Amide hydrolysis of a novel chemical series of microsomal prostaglandin E synthase-1 inhibitors induces kidney toxicity in the rat

    National Research Council Canada - National Science Library

    Bylund, Johan; Annas, Anita; Hellgren, Dennis; Bjurström, Sivert; Andersson, Håkan; Svanhagen, Alexander

    2013-01-01

    A novel microsomal prostaglandin E synthase 1 (mPGES-1) inhibitor induced kidney injury at exposures representing less than 4 times the anticipated efficacious exposure in man during a 7-day toxicity study in rats...

  14. Hepatocellular Toxicity Associated with Tyrosine Kinase Inhibitors: Mitochondrial Damage and Inhibition of Glycolysis

    Directory of Open Access Journals (Sweden)

    Franziska Paech

    2017-06-01

    Full Text Available Tyrosine kinase inhibitors (TKIs are anticancer drugs with a lesser toxicity than classical chemotherapeutic agents but still with a narrow therapeutic window. While hepatotoxicity is known for most TKIs, underlying mechanisms remain mostly unclear. We therefore aimed at investigating mechanisms of hepatotoxicity for imatinib, sunitinib, lapatinib and erlotinib in vitro. We treated HepG2 cells, HepaRG cells and mouse liver mitochondria with TKIs (concentrations 1–100 μM for different periods of time and assessed toxicity. In HepG2 cells maintained with glucose (favoring glycolysis, all TKIs showed a time- and concentration-dependent cytotoxicity and, except erlotinib, a drop in intracellular ATP. In the presence of galactose (favoring mitochondrial metabolism, imatinib, sunitinib and erlotinib showed a similar toxicity profile as for glucose whereas lapatinib was less toxic. For imatinib, lapatinib and sunitinib, cytotoxicity increased in HepaRG cells induced with rifampicin, suggesting formation of toxic metabolites. In contrast, erlotinib was more toxic in HepaRG cells under basal than CYP-induced conditions. Imatinib, sunitinib and lapatinib reduced the mitochondrial membrane potential in HepG2 cells and in mouse liver mitochondria. In HepG2 cells, these compounds increased reactive oxygen species production, impaired glycolysis, and induced apoptosis. In addition, imatinib and sunitinib impaired oxygen consumption and activities of complex I and III (only imatinib, and reduced the cellular GSH pool. In conclusion, imatinib and sunitinib are mitochondrial toxicants after acute and long-term exposure and inhibit glycolysis. Lapatinib affected mitochondria only weakly and inhibited glycolysis, whereas the cytotoxicity of erlotinib could not be explained by a mitochondrial mechanism.

  15. Anaerobic digestion of aircraft deicing fluid wastes: interactions and toxicity of corrosion inhibitors and surfactants.

    Science.gov (United States)

    Gruden, Cyndee L; Hernandez, Mark

    2002-01-01

    Corrosion inhibitors and surfactants are present in aircraft deicing fluids (ADFs) at significant concentrations (> 1% w/w). The purpose of this research was to study the interactions of a common nonionic surfactant with the commercially significant corrosion inhibitors used in modern ADF (4- and 5-methylbenzotriazole [MeBT]), and to determine the effects of their mixture on the conventional anaerobic digestion process. In mesophilic anaerobic microcosms codigesting wastewater solids, propylene glycol, and MeBT, increasing surfactant levels resulted in enhanced MeBT sorption on digester solids. As judged by anaerobic toxicity assays, responses from digesters containing surfactant concentrations below their critical micelle concentration (CMC) suggested that low nonionic surfactant concentrations could facilitate a reduction in the apparent toxicity of MeBT. In microcosms exposed to surfactant concentrations above their CMC, no increase in MeBT solubility was observed, and the anaerobic toxicity response corresponded to control systems not containing surfactant. Direct microscopic measurements of digesting biomass using fluorescent phylogenetic probes (fluorescent in situ hybridization) revealed that members of the domain Bacteria were more sensitive to MeBT in the presence of surfactant than were members of the domain Archaea.

  16. Effect of Natural β-Glucosidase Inhibitors in Reducing Toxicity of Amygdalin in Persicae Semen.

    Science.gov (United States)

    Liu, Chao; Li, Xia; Yang, Honggai; Mao, Xinhui; Wang, Juan; Gao, Wenyuan

    2017-05-01

    Amygdalin can be decomposed into hydrocyanic acid, which is the primary source of Persicae Semen toxicity, by gut flora. Here, the inhibitory activity of β-glucosidase for test herb extracts was first determined and compared. In turn, optimization of the ratio of substrate and inhibitor in vitro and LD50 values of extracts, serum and liver contents of amygdalin in vivo was measured. Lycii Cortex was found to be the best inhibitory activity for β-glucosidase. The ratio of amygdalin-to-Lycii Cortex extract of 7.19:8.18 (mmol L(-1) /mg mL(-1) ) can be relatively suitable for inhibiting β-glucosidase activity in test in vitro reaction system. After mixed with Lycii Cortex extract, the toxicity of Persicae Semen ethanol extract in mice is significantly reduced and more amygdalin can be absorbed into the bloodstream. The study provides useful information for reducing toxicity of Persicae Semen and suggests how to better use these natural β-glucosidase inhibitors in the utilization of glycosides and aglycones. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Inhibition of Drp1-dependent mitochondrial fragmentation and apoptosis by a polypeptide antagonist of calcineurin

    Science.gov (United States)

    Cereghetti, GM; Costa, V; Scorrano, L

    2010-01-01

    During apoptosis, mitochondria lose their membrane potential and undergo fragmentation around the time of release of cytochrome c. Apoptotic fission is at least in part sustained by the translocation of dynamin-related protein 1 (Drp1), normally located in the cytosol, to mitochondria. This process depends on dephosphorylation of Drp1 by the phosphatase calcineurin. Here, we report the identification of a novel inhibitor of this process. A polypeptide (PPD1) from the immunophilin FKBP52 inhibits calcineurin activation triggered by mitochondrial dysfunction. PPD1 blocks Drp1 translocation to mitochondria and fragmentation of the organelle. PPD1 delays apoptosis by intrinsic stimuli by preventing fragmentation and release of cytochrome c. Cells expressing PPD1 display enhanced clonogenic ability after exposure to staurosporine. A genetic analysis revealed that the activity of PPD1 is independent of the BH3-only protein BAD, another target of calcineurin during apoptosis, and is not additive to inhibition of Drp1. Thus, PPD1 is a novel inhibitor of apoptosis that elucidates the function of calcineurin-dependent mitochondrial fragmentation in the amplification of cell death. PMID:20489733

  18. Cysteine as a non toxic corrosion inhibitor for copper alloys in conservation

    DEFF Research Database (Denmark)

    Gravgaard, Mari; van Lanschot, Jettie

    2012-01-01

    The aim of this work is to examine cysteine as an alternative to benzotriazole (BTA) for the conservation of archaeological objects with bronze disease. Investigation of the two inhibitors involved the use of electrochemical techniques, measurements of weight change in high humidity and comparative...... studies of colour changes in the corrosion products. The results obtained in this article demonstrate that cysteine could be a non-toxic alternative to BTA. Cysteine performed as well as BTA on pre-corroded coupons with bronze disease in high humidity and showed acceptable results during testing...

  19. Dermatologic Toxicities from Monoclonal Antibodies and Tyrosine Kinase Inhibitors against EGFR: Pathophysiology and Management

    Directory of Open Access Journals (Sweden)

    Shaad E. Abdullah

    2012-01-01

    Full Text Available Epidermal growth factor receptor (EGFR inhibition has now been well established as an effective treatment for various cancers. The EGFR belongs to the ErbB family of tyrosine kinase receptors which regulate tumor cell differentiation, survival and proliferation. Activation of EGFR drives tumorigenesis in lung, head and neck, colorectal and pancreatic cancers. Irrespective of the type of cancer being treated and the mechanism by which tumor EGFR drives tumorigenesis, the major side effect of EGFR inhibition is a papulopustular (also described as maculopapular or acneiform rash which occurs in about two thirds of treated patients. Interestingly, this rash has been commonly correlated with better clinical outcomes (objective tumor response and patient survival. The pathophysiology of dermatological toxicity from EGFR inhibitors is an important area of clinical research, and the proper management of the rash is essential to increase the therapeutic index from this class of drugs. In this paper, we review the dermatologic toxicities associated with EGFR inhibitors with an emphasis on its pathophysiology and clinical management.

  20. Dermatologic Toxicities from Monoclonal Antibodies and Tyrosine Kinase Inhibitors against EGFR: Pathophysiology and Management

    Science.gov (United States)

    Abdullah, Shaad E.; Haigentz, Missak; Piperdi, Bilal

    2012-01-01

    Epidermal growth factor receptor (EGFR) inhibition has now been well established as an effective treatment for various cancers. The EGFR belongs to the ErbB family of tyrosine kinase receptors which regulate tumor cell differentiation, survival and proliferation. Activation of EGFR drives tumorigenesis in lung, head and neck, colorectal and pancreatic cancers. Irrespective of the type of cancer being treated and the mechanism by which tumor EGFR drives tumorigenesis, the major side effect of EGFR inhibition is a papulopustular (also described as maculopapular or acneiform) rash which occurs in about two thirds of treated patients. Interestingly, this rash has been commonly correlated with better clinical outcomes (objective tumor response and patient survival). The pathophysiology of dermatological toxicity from EGFR inhibitors is an important area of clinical research, and the proper management of the rash is essential to increase the therapeutic index from this class of drugs. In this paper, we review the dermatologic toxicities associated with EGFR inhibitors with an emphasis on its pathophysiology and clinical management. PMID:22997576

  1. Effects of metal ions on recombinant calcineurin A subunit

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Effects of metal ions on activities and solution conformations of calcineurin A subunit have been examined.The ability of several metal ions to activate calcineurin A has been tested with Ni2+>Mn2+>Mg2+/Ca2+.The corresponding CD spectra and intrinsic fluorescent emission spectra show that calcineurin A exists in different metal ion-dependent conformation states.Effects of the different concentritions of Ni2+ on activities and solution conformations of calcineurin A have been tested too.Results indicate that effects of these metal ions to activate calcineurin are due to their conformational changes.

  2. Simulating complex calcium-calcineurin signaling network

    NARCIS (Netherlands)

    Cui, J.; Kaandorp, J.A.

    2008-01-01

    Understanding of processes in which calcium signaling is involved is of fundamental importance in systems biology and has many applications in medicine. In this paper we have studied the particular case of the complex calcium-calcineurin-MCIP-NFAT signaling network in cardiac myocytes, the understan

  3. Effects of calcineurin on LTP of rats in vivo

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Calcineurin (CN) is thought to play a role in the synaptic plastivity and long-term potentiation (LTP) in the hippocampus. Based on two LTP models in vivo, a specific inhibitor cyclosporin A (CsA) of CN was observed, which affected LTP in the hippocampal dentate gyrus of the rats. The results indicated that CsA blocked LTP induced by high frequency stimulation (HFS) partly, but it had no effect on the decrease of the onset and peak latency of population spikes (PS) except that it reduced the increase of the amplitude after HFS. On the other hand, CsA blocked LTP induced by ginsenosides (GSS) completely. It suppressed the GSS-enhanced amplitude of PS reversibly and blocked the decrease of the peak latency of PS induced by the GSS. These results suggest that the postsynaptic CN plays a role in the induction of LTP in the hippocampus of the rats.

  4. The role of calcineurin in the lung fibroblasts proliferation and collagen synthesis induced by basic fibroblast growth factor

    Institute of Scientific and Technical Information of China (English)

    陈亚红; 赵鸣武; 符民桂; 姚婉贞; 唐朝枢

    2003-01-01

    Objective To investigate the role of calcineurin (CaN) in the lung fibroblast proliferation and collagen synthesis induced by basic fibroblast growth factor (bFGF).Methods We used Western blot and immunohistochemical methods for investigating the content and distribution of calcineurin in the lung tissue. Calcineurin activity in different tissues was measured using 32P-labelled substrate. In the primary culture of lung fibroblasts, 3H-thymidine (3H-TdR) and 3H-proline incorporation methods were used to study the effect of cyclosporin A(CsA), an inhibitor of calcineurin, on the lung fibroblast DNA and collagen synthesis stimulated by bFGF. Results We found that calcineurin was expressed in lung tissue and has phosphatase activity (7.1±2.0 pmol Pi/mg pr/min). CsA(10-8-10-6mol/L) inhibited lung fibroblast,3H-TdR incorporation induced by bFGF in a dose-dependent manner, with the inhibitory rates by20%, 46% and 66%(P<0.01). CsA(10-7-10-6mol/L) inhibited 3H-proline incorporation in lung fibroblasts stimulated by bFGF, with the inhibitory rates by 21% and 37%(P<0.01). In a culture medium, CsA (10-8-10-6mol/L) inhibited 3H-proline secretion induced by bFGF in a dose-dependent manner, with the inhibitory rates by 19%,29%(P<0.05) and 56% (P<0.01). CsA (10-7mol/L) could inhibit calcineurin activity by 44% in lung fibroblasts(P<0.01). Conclusions Calcineurin is expressed in lung tissue and has phosphatase activity. It is involved in the bFGF stimulated lung fibroblast DNA and collagen synthesis.

  5. Effects of breast cancer resistance protein inhibitors and pharmaceutical excipients on decreasing gastrointestinal toxicity of camptothecin analogs

    Institute of Scientific and Technical Information of China (English)

    Xin-xin ZHANG; Wei-san PAN; Li GAN; Chun-liu ZHU; Yong GAN

    2008-01-01

    Aim: To investigate the effect of breast cancer resistance protein (BCRP) inhibitors and pharmaceutical excipients on reducing the biliary excretion of camptothecins (CPT), ameliorating delayed-type diarrhea and intestinal mucosa damage induced by CPT. Methods: The cumulative biliary excretion of irinotecan (CPT-11) and hydroxycamptothecin (HCPT) with or without BCRP inhibitors and excipients was investigated in rats. The gastrointestinal toxicity, assessed as the diarrheal score, body weight change and microscopic pathological damage was also determined in rats. Results: Breast cancer resistance protein (BCRP) exhibited important effects on the biliary excretion of CPT. Coadministration of BCRP inhibitors such as GF120918 and cyclosporin A reduced the biliary excretion of CPT-11 and HCPT. Pharmaceutical excipients such as Pluronic F68 and PEG 2000 stearate also showed inhibitory effects on BCRP and similarly reduced CPT biliary excretion. The observed gastrointestinal toxicity was ameliorated by coadministration of BCRP inhibitors and excipients compared with injection of CPT-11 and HCPT alone. Conclusion:The use of excipients as inhibitors of BCRP is safe and relatively non-toxic, and may lead to important pharmacotherapeutic benefits by decreasing the gastrointestinal toxicity of CPT.

  6. The Emerging Roles of the Calcineurin-Nuclear Factor of Activated T-Lymphocytes Pathway in Nervous System Functions and Diseases

    Directory of Open Access Journals (Sweden)

    Maulilio John Kipanyula

    2016-01-01

    Full Text Available The ongoing epidemics of metabolic diseases and increase in the older population have increased the incidences of neurodegenerative diseases. Evidence from murine and cell line models has implicated calcineurin-nuclear factor of activated T-lymphocytes (NFAT signaling pathway, a Ca2+/calmodulin-dependent major proinflammatory pathway, in the pathogenesis of these diseases. Neurotoxins such as amyloid-β, tau protein, and α-synuclein trigger abnormal calcineurin/NFAT signaling activities. Additionally increased activities of endogenous regulators of calcineurin like plasma membrane Ca2+-ATPase (PMCA and regulator of calcineurin 1 (RCAN1 also cause neuronal and glial loss and related functional alterations, in neurodegenerative diseases, psychotic disorders, epilepsy, and traumatic brain and spinal cord injuries. Treatment with calcineurin/NFAT inhibitors induces some degree of neuroprotection and decreased reactive gliosis in the central and peripheral nervous system. In this paper, we summarize and discuss the current understanding of the roles of calcineurin/NFAT signaling in physiology and pathologies of the adult and developing nervous system, with an emphasis on recent reports and cutting-edge findings. Calcineurin/NFAT signaling is known for its critical roles in the developing and adult nervous system. Its role in physiological and pathological processes is still controversial. However, available data suggest that its beneficial and detrimental effects are context-dependent. In view of recent reports calcineurin/NFAT signaling is likely to serve as a potential therapeutic target for neurodegenerative diseases and conditions. This review further highlights the need to characterize better all factors determining the outcome of calcineurin/NFAT signaling in diseases and the downstream targets mediating the beneficial and detrimental effects.

  7. Intermittent targeting as a tool to minimize toxicity of tyrosine kinase inhibitor therapy.

    Science.gov (United States)

    Martinelli, Giovanni; Soverini, Simona; Iacobucci, Ilaria; Baccarani, Michele

    2009-02-01

    Tyrosine kinase inhibitor therapy has revolutionized the outcome of chronic myeloid leukemia (CML), and has transformed a fatal disease into a chronic condition for most patients. At present, the therapeutic armamentarium against CML includes imatinib for newly diagnosed patients, and dasatinib and nilotinib, which have both received marketing approval, for imatinib-resistant and imatinib-intolerant disease. Research efforts are now focused on how to optimize therapeutic strategies in an attempt to improve clinical results further, counteract the development of drug resistance and reduce adverse effects. A randomized, international, phase III study of dasatinib dose and schedule optimization in imatinib-resistant and imatinib-intolerant patients with CML has demonstrated that intermittent target inhibition can preserve therapeutic efficacy and reduce toxicity. This finding has important implications, not only for patients with CML, but also for the development of targeted therapies for human malignancies in general.

  8. Bio-testing integral toxicity of corrosion inhibitors, biocides and oil hydrocarbons in oil-and gas-processing industry

    Energy Technology Data Exchange (ETDEWEB)

    Chugunov, V.A.; Kholodenko, V.P.; Irkhina, I.A.; Fomchenkov, V.M.; Novikov, I.A. [State Research Center for Applied Microbiology, Obolensk, Moscow (Russian Federation)

    2004-07-01

    In recent years bioassays have been widely used for assessing levels of contamination of the environment. This is due to the fact that test-organisms provide a general response to toxicants present in samples. Based on microorganisms as test objects, it is possible to develop cheap, sensitive and rapid assays to identify environmental xenobiotics and toxicants. The objective of the research was to develop different microbiological assays for assessing integral toxicity of water environments polluted with corrosion inhibitors, biocides and hydrocarbons in oil- and gas-processing industry. Bio-luminescent, electro-orientational, osmo-optic and microorganism reducing activity assays were used for express evaluation of integral toxicity. They are found to determine promptly integral toxicity of water environments containing various pollutants (oil, oil products, corrosion inhibitors, biocides). Results conclude that the assays may be used for analyzing integral toxicity of water polluted with hydrocarbons, as well as for monitoring of water changes as a result of biodegradation of pollutants by microorganisms and their associations. Using a kit of different assays, it is also possible to evaluate ecological safety of biocides, corrosion inhibitors, and their compositions. Bioassays used as a kit are more effective than each assay individually, allowing one to get complete characterization of a reaction of bacterial test organisms to different environments. (authors)

  9. Determination of FVIIa-sTF Inhibitors in Toxic Microcystis Cyanobacteria by LC-MS Technique.

    Science.gov (United States)

    Anas, Andrea Roxanne J; Nakajima, Anna; Naruse, Chiaki; Tone, Mineka; Asukabe, Hirohiko; Harada, Ken-ichi

    2015-12-30

    The blood coagulation cascade involves the human coagulation factors thrombin and an activated factor VII (fVIIa). Thrombin and fVIIa are vitamin-K-dependent clotting factors associated with bleeding, bleeding complications and disorders. Thrombin and fVIIa cause excessive bleeding when treated with vitamin-K antagonists. In this research, we explored different strains of toxic Microcystis aeruginosa and cyanobacteria blooms for the probable fVIIa-soluble Tissue Factor (fVIIa-sTF) inhibitors. The algal cells were subjected to acidification, and reverse phase (ODS) chromatography-solid phase extraction eluted by water to 100% MeOH with 20%-MeOH increments except for M. aeruginosa NIES-89, from the National Institute for Environmental Studies (NIES), which was eluted with 5%-MeOH increments as an isolation procedure to separate aeruginosins 89A and B from co-eluting microcystins. The 40%-80% MeOH fractions of the cyanobacterial extract are active against fVIIa-sTF. The fVIIa-sTF active fractions from cultured cyanobacteria and cyanobacteria blooms were subjected to liquid chromatography-mass spectrometry (LC-MS). The 60% MeOH fraction of M. aeruginosa K139 exhibited an m/z 603 [M + H]⁺ attributed to aeruginosin K139, and the 40% MeOH fraction of M. aeruginosa NIES-89 displayed ions with m/z 617 [M - SO3 + H]⁺ and m/z [M + H]⁺ 717, which attributed to aeruginosin 89. Aeruginosins 102A/B and 298A/B were also observed from other toxic strains of M. aeruginosa with positive fVIIa-sTF inhibitory activity. The active fractions contained cyanobacterial peptides of the aeruginosin class as fVIIa-sTF inhibitors detected by LC-MS.

  10. The neuropeptide catestatin promotes vascular smooth muscle cell proliferation through the Ca{sup 2+}-calcineurin-NFAT signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiaoxia [Department of Cardiology, People' s Hospital, Peking University, No. 11 South Avenue, Xi Zhi Men Xicheng District, Beijing 100044 (China); Zhou, Chunyan, E-mail: chunyanzhou@bjmu.edu.cn [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Haidian District, Beijing 100191 (China); Sun, Ningling, E-mail: nlsun@263.net [Department of Cardiology, People' s Hospital, Peking University, No. 11 South Avenue, Xi Zhi Men Xicheng District, Beijing 100044 (China)

    2011-04-22

    Highlights: {yields} Catestatin stimulates proliferation of vascular smooth muscle cells in a dose-dependent manner. {yields} Catestatin provokes sustained increase in intracellular Ca{sup 2+}. {yields} Catestatin produces increased activation of calcineurin and promotes NFATc1 translocation into the nucleus. -- Abstract: The Chromogranin A-derived neuropeptide catestatin is an endogenous nicotinic cholinergic antagonist that acts as a pleiotropic hormone. Since catestatin shares several functions with other members derived from the chromogranin/secretogranin protein family and other neuropeptides which exert proliferative effects on vascular smooth muscle cells (VSMCs), we therefore hypothesized that catestatin would regulate VSMC proliferation. The present study demonstrates that catestatin caused a dose-dependent induction of proliferation in rat aortic smooth muscle cells and furthermore evoked a sustained increase in intracellular calcium. This subsequently leaded to enhanced activation of the Ca{sup 2+}/calmodulin-dependent phosphatase, calcineurin and resulted in an activation of the Ca{sup 2+}-dependent transcription factor, nuclear factor of activated T cells (NFAT), initiating transcription of proliferative genes. In addition, cyclosporin A (CsA), a potent inhibitor of calcineurin, abrogated catestatin-mediated effect on VSMCs, indicating that the calcineurin-NFAT signaling is strongly required for catestatin-induced growth of VSMCs. The present study establishes catestatin as a novel proliferative cytokine on vascular smooth muscle cells and this effect is mediated by the Ca{sup 2+}-calcineurin-NFAT signaling pathway.

  11. Mitochondrial toxicities of nucleoside analogue reverse transcriptase inhibitors in AIDS cases

    Directory of Open Access Journals (Sweden)

    Yogesh S Marfatia

    2014-01-01

    Full Text Available The development of antiretroviral therapy (ART has been one of the most dramatic progressions in the history of medicine. Concomitant with this momentous therapeutic advance, the mitochondrial toxicities of ART were recognized as an important clinical entity. Aim: The aim was to study the mitochondrial toxicities in terms of peripheral neuropathy (PN, lipodystrophy (LD, hepatic steatosis, lactic academia (LA, and pancreatitis developing in AIDS cases on nucleoside analog reverse transcriptase inhibitors (NRTIs based ART regimens. Materials and Methods: An observational study, which included 90 AIDS cases, receiving first line ART regimens containing two NRTIs (zidovudine [AZT]/stavudine [d4T] with lamivudine [3TC] and one nonNRTIs (nevirapine/efavirenz was conducted at Skin-VD outpatient department of a tertiary care hospital attached to a Medical College. Thorough history was taken, and clinical examination was done. Cases were subjected to measurements of abdominal girth and mid-arm circumference, liver function tests, blood sugar, lipid profile, serum lactate, and amylase levels. Results: Of 90 cases on ART, 66% were males and 34% were females. Mitochondrial toxicities developed in 26 (30% cases out of 90, which included 3 (7% out of 42 cases on AZT + 3TC and 23 (48% out of 48 cases on d4T + 3TC. Most common toxicity was PN seen in 20 (22% cases; male cases developed PN at a lower CD4 count than female cases. LD was observed in total of 13 (14.5% cases; deposition of fat in the abdomen in seven cases and at the nape of the neck (buffalo hump in one case while loss of fat from extremities was seen in seven cases and loss of buccal fat in seven cases. Women presented more with fat accumulation (breast and abdomen, while men with loss of fat (limbs and buttocks. Both PN and LD were more common in d4T based regimen. LA was reported in one case on d4T. Hepatic steatosis was seen in three cases and pancreatitis in one case receiving AZT. Conclusion

  12. Developmental toxicity of the HMG-CoA reductase inhibitor (PPD10558) in rats and rabbits.

    Science.gov (United States)

    Faqi, Ali S; Prohaska, David; Lopez, Rocio; McIntyre, Gail

    2012-02-01

    PPD10558 is an orally active, lipid-lowering 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) being developed as a treatment for hypercholesterolemia in patients who have not been able to tolerate statins because of statin-associated myalgia. We have studied the potential developmental toxicity effects of PPD10558 in pregnant rats and rabbits given daily oral doses during the period of organogenesis. Rats were dosed with 0, 20, 80, or 320 mg/kg/day from Gestation Day (GD) 6 to 17 and rabbits received dose levels of 0, 12.5, 25, or 50 mg/kg/day from GD 6 to 18. Additional groups in both studies served as toxicokinetic animals and received the PPD10558 in the same manner as the main study groups at the same dose levels. Blood samples were collected from toxicokinetic animals at designated time points on GD 6 and 17 in rats and GD 6 and 18 in rabbits. Fetal exposure in rats was assessed on GD 20. Maternal and developmental parameters were evaluated in rats and rabbits on GD 20 and GD 29, respectively. No maternal and developmental toxicity was observed at any of the dose levels used in the rat study. Evidence of fetal exposure was determined in fetal plasma with mean fetal concentrations of PPD10558 and the metabolite (PPD11901) found to be between 1 and 6% of the mean maternal concentrations. In rabbits, marked maternal toxicity including mortality (eight deaths; 1 dose at 25 and 7 at 50 mg/kg/day), abortions (2 at 25 mg/kg/day and 6 at 50 mg/kg/day) and reduction in gestation body weight, gestation body weight changes and decreased food consumption were observed. In addition, fetal body weights of the combined sexes were significantly reduced at 50 mg/kg/day in comparison with the controls. Mean peak exposure (Cmax) and total exposure (AUC(0-24)) of PPD11901 in both rats and rabbits were higher than that of PPD10558 on GD 6 and GD 17 at each of the three dose levels.. Based on the results of these studies, the no observed adverse effect

  13. Screening for Small Molecule Inhibitors of Statin-Induced APP C-terminal Toxic Fragment Production.

    Science.gov (United States)

    Poksay, Karen S; Sheffler, Douglas J; Spilman, Patricia; Campagna, Jesus; Jagodzinska, Barbara; Descamps, Olivier; Gorostiza, Olivia; Matalis, Alex; Mullenix, Michael; Bredesen, Dale E; Cosford, Nicholas D P; John, Varghese

    2017-01-01

    Alzheimer's disease (AD) is characterized by neuronal and synaptic loss. One process that could contribute to this loss is the intracellular caspase cleavage of the amyloid precursor protein (APP) resulting in release of the toxic C-terminal 31-amino acid peptide APP-C31 along with the production of APPΔC31, full-length APP minus the C-terminal 31 amino acids. We previously found that a mutation in APP that prevents this caspase cleavage ameliorated synaptic loss and cognitive impairment in a murine AD model. Thus, inhibition of this cleavage is a reasonable target for new therapeutic development. In order to identify small molecules that inhibit the generation of APP-C31, we first used an APPΔC31 cleavage site-specific antibody to develop an AlphaLISA to screen several chemical compound libraries for the level of N-terminal fragment production. This antibody was also used to develop an ELISA for validation studies. In both high throughput screening (HTS) and validation testing, the ability of compounds to inhibit simvastatin- (HTS) or cerivastatin- (validation studies) induced caspase cleavage at the APP-D720 cleavage site was determined in Chinese hamster ovary (CHO) cells stably transfected with wildtype (wt) human APP (CHO-7W). Several compounds, as well as control pan-caspase inhibitor Q-VD-OPh, inhibited APPΔC31 production (measured fragment) and rescued cell death in a dose-dependent manner. The effective compounds fell into several classes including SERCA inhibitors, inhibitors of Wnt signaling, and calcium channel antagonists. Further studies are underway to evaluate the efficacy of lead compounds - identified here using cells and tissues expressing wt human APP - in mouse models of AD expressing mutated human APP, as well as to identify additional compounds and determine the mechanisms by which they exert their effects.

  14. Screening for Small Molecule Inhibitors of Statin-Induced APP C-terminal Toxic Fragment Production

    Science.gov (United States)

    Poksay, Karen S.; Sheffler, Douglas J.; Spilman, Patricia; Campagna, Jesus; Jagodzinska, Barbara; Descamps, Olivier; Gorostiza, Olivia; Matalis, Alex; Mullenix, Michael; Bredesen, Dale E.; Cosford, Nicholas D. P.; John, Varghese

    2017-01-01

    Alzheimer’s disease (AD) is characterized by neuronal and synaptic loss. One process that could contribute to this loss is the intracellular caspase cleavage of the amyloid precursor protein (APP) resulting in release of the toxic C-terminal 31-amino acid peptide APP-C31 along with the production of APPΔC31, full-length APP minus the C-terminal 31 amino acids. We previously found that a mutation in APP that prevents this caspase cleavage ameliorated synaptic loss and cognitive impairment in a murine AD model. Thus, inhibition of this cleavage is a reasonable target for new therapeutic development. In order to identify small molecules that inhibit the generation of APP-C31, we first used an APPΔC31 cleavage site-specific antibody to develop an AlphaLISA to screen several chemical compound libraries for the level of N-terminal fragment production. This antibody was also used to develop an ELISA for validation studies. In both high throughput screening (HTS) and validation testing, the ability of compounds to inhibit simvastatin- (HTS) or cerivastatin- (validation studies) induced caspase cleavage at the APP-D720 cleavage site was determined in Chinese hamster ovary (CHO) cells stably transfected with wildtype (wt) human APP (CHO-7W). Several compounds, as well as control pan-caspase inhibitor Q-VD-OPh, inhibited APPΔC31 production (measured fragment) and rescued cell death in a dose-dependent manner. The effective compounds fell into several classes including SERCA inhibitors, inhibitors of Wnt signaling, and calcium channel antagonists. Further studies are underway to evaluate the efficacy of lead compounds – identified here using cells and tissues expressing wt human APP – in mouse models of AD expressing mutated human APP, as well as to identify additional compounds and determine the mechanisms by which they exert their effects.

  15. Blockade of the Interaction of Calcineurin with FOXO in Astrocytes Protects Against Amyloid-β-Induced Neuronal Death.

    Science.gov (United States)

    Fernandez, Ana M; Hervas, Ruben; Dominguez-Fraile, Manuel; Garrido, Victoria Navarro; Gomez-Gutierrez, Patricia; Vega, Miguel; Vitorica, Javier; Perez, Juan J; Torres Aleman, Ignacio

    2016-04-12

    Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer's disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD-associated pathological inflammation, suggesting a potential new druggable target for this devastating disease. We have now developed decoy molecules to interfere with calcineurin/FOXO3 interactions, and tested them in astrocytes and neuronal co-cultures exposed to amyloid-β (Aβ) toxicity. We observed that interference of calcineurin/FOXO3 interactions exerts a protective action against Aβ-induced neuronal death and favors the production of a set of growth factors that we hypothesize form part of a cytoprotective pathway to resolve inflammation. Furthermore, interference of the Aβ-induced interaction of calcineurin with FOXO3 by decoy compounds significantly decreased amyloid-β protein precursor (AβPP) synthesis, reduced the AβPP amyloidogenic pathway, resulting in lower Aβ levels, and blocked the expression of pro-inflammatory cytokines TNFα and IL-6 in astrocytes. Collectively, these data indicate that interrupting pro-inflammatory calcineurin/FOXO3 interactions in astrocytes triggered by Aβ accumulation in brain may constitute an effective new therapeutic approach in AD. Future studies with intranasal delivery, or brain barrier permeable decoy compounds, are warranted.

  16. USING A DOE AND EIS TO EVALUATE THE SYNERGISTIC EFFECTS OF LOW TOXICITY INHIBITORS FOR MILD STEEL

    Directory of Open Access Journals (Sweden)

    G. V. Bueno

    2015-03-01

    Full Text Available Abstract Inhibitors are widely used to prevent corrosion in cooling-water systems, and their protective performance can be enhanced by combination. The aim of this paper is to identify possible synergistic effects between four low toxicity substances used as corrosion inhibitors for mild steel in industrial cooling-water systems. Electrochemical measurements were obtained following a design of experiments (DOE where the independent variables were the inhibitors concentrations and the response variable the charge transfer resistance estimated from impedance diagrams. Potentiodynamic polarization curves show that all of them act as anodic corrosion inhibitors. Among the tested formulations, only the interaction between sodium molybdate and sodium tungstate showed statistically significant effects, indicating that they can perform better when used together. The results of this work show the importance of using a statistical tool when designing inhibitor mixtures.

  17. Toxic agents causing cerebellar ataxias.

    Science.gov (United States)

    Manto, Mario

    2012-01-01

    The cerebellum is particularly vulnerable to intoxication and poisoning, especially so the cerebellar cortex and Purkinje neurons. In humans, the most common cause of a toxic lesion to the cerebellar circuitry is alcohol related, but the cerebellum is also a main target of drug exposure (such as anticonvulsants, antineoplastics, lithium salts, calcineurin inhibitors), drug abuse and addiction (such as cocaine, heroin, phencyclidine), and environmental toxins (such as mercury, lead, manganese, toluene/benzene derivatives). Although data for the prevalence and incidence of cerebellar lesions related to intoxication and poisoning are still unknown in many cases, clinicians should keep in mind the list of agents that may cause cerebellar deficits, since toxin-induced cerebellar ataxias are not rare in daily practice. Moreover, the patient's status may require immediate therapies when the intoxication is life-threatening. 2012 Elsevier B.V. All rights reserved.

  18. Inhibition of calcineurin by FK506 stimulates germinal vesicle breakdown of mouse oocytes in hypoxanthine-supplemented medium

    Science.gov (United States)

    Wang, Li; Zhen, Yan-Hong; Liu, Xiao-Ming; Cao, Jing; Wang, Yan-Ling

    2017-01-01

    Calcineurin (CN) is a serine/threonine phosphatase which plays important roles in meiosis maturation in invertebrate oocytes; however, the role of CN in mouse oocytes is relatively unexplored. In this study, we examined the expression, localization and functional roles of CN in mouse oocytes and granulosa cells. The RT-PCR results showed that the β isoform of calcineurin A subunit (Cn A) expressed significantly higher than α and γ isoforms, and the expression of Cn Aβ mRNA obviously decreased in oocytes in which germinal vesicle breakdown (GVBD) occurred, while only B1 of calcineurin B subunit (Cn B) was detected in oocytes and stably expressed during oocytes maturation. The following fluorescence experiment showed that Cn A was mainly located in the nucleus of germinal vesicle (GV) stage oocytes and gruanlosa cells, and subsequently dispersed into the entire cytoplasm after GVBD. The decline of Cn A in oocytes suggested that it may play an important role in GVBD. To further clarify the role of calcineurin during meiotic maturation, FK506 (a calcineurin inhibitor) was used in the culture medium contained hypoxanthine (HX) which could keep mouse oocytes staying at GV stage. As expected, FK506 could induce a significant elevation of GVBD rate and increase the MPF level of denuded oocytes (DOs). Furthermore, FK506 could also play an induction role of GVBD of oocytes in COCs and follicles, and the process could be counteracted by MAPK kinase inhibitor (U0126). Above all, the results implied that calcineurin might play a crucial role in development of mouse oocytes and MPF and MAPK pathways are involved in this process. PMID:28243539

  19. Calcineurin Targets Involved in Stress Survival and Fungal Virulence.

    Directory of Open Access Journals (Sweden)

    Hee-Soo Park

    2016-09-01

    Full Text Available Calcineurin governs stress survival, sexual differentiation, and virulence of the human fungal pathogen Cryptococcus neoformans. Calcineurin is activated by increased Ca2+ levels caused by stress, and transduces signals by dephosphorylating protein substrates. Herein, we identified and characterized calcineurin substrates in C. neoformans by employing phosphoproteomic TiO2 enrichment and quantitative mass spectrometry. The identified targets include the transactivator Crz1 as well as novel substrates whose functions are linked to P-bodies/stress granules (PBs/SGs and mRNA translation and decay, such as Pbp1 and Puf4. We show that Crz1 is a bona fide calcineurin substrate, and Crz1 localization and transcriptional activity are controlled by calcineurin. We previously demonstrated that thermal and other stresses trigger calcineurin localization to PBs/SGs. Several calcineurin targets localized to PBs/SGs, including Puf4 and Pbp1, contribute to stress resistance and virulence individually or in conjunction with Crz1. Moreover, Pbp1 is also required for sexual development. Genetic epistasis analysis revealed that Crz1 and the novel targets Lhp1, Puf4, and Pbp1 function in a branched calcineurin pathway that orchestrates stress survival and virulence. These findings support a model whereby calcineurin controls stress and virulence, at the transcriptional level via Crz1, and post-transcriptionally by localizing to PBs/SGs and acting on targets involved in mRNA metabolism. The calcineurin targets identified in this study share little overlap with known calcineurin substrates, with the exception of Crz1. In particular, the mRNA binding proteins and PBs/SGs residents comprise a cohort of novel calcineurin targets that have not been previously linked to calcineurin in mammals or in Saccharomyces cerevisiae. This study suggests either extensive evolutionary rewiring of the calcineurin pathway, or alternatively that these novel calcineurin targets have yet

  20. Chemoproteomic profiling reveals that cathepsin D off-target activity drives ocular toxicity of β-secretase inhibitors

    Science.gov (United States)

    Zuhl, Andrea M.; Nolan, Charles E.; Brodney, Michael A.; Niessen, Sherry; Atchison, Kevin; Houle, Christopher; Karanian, David A.; Ambroise, Claude; Brulet, Jeffrey W.; Beck, Elizabeth M.; Doran, Shawn D.; O'Neill, Brian T.; am Ende, Christopher W.; Chang, Cheng; Geoghegan, Kieran F.; West, Graham M.; Judkins, Joshua C.; Hou, Xinjun; Riddell, David R.; Johnson, Douglas S.

    2016-01-01

    Inhibition of β-secretase BACE1 is considered one of the most promising approaches for treating Alzheimer's disease. Several structurally distinct BACE1 inhibitors have been withdrawn from development after inducing ocular toxicity in animal models, but the target mediating this toxicity has not been identified. Here we use a clickable photoaffinity probe to identify cathepsin D (CatD) as a principal off-target of BACE1 inhibitors in human cells. We find that several BACE1 inhibitors blocked CatD activity in cells with much greater potency than that displayed in cell-free assays with purified protein. Through a series of exploratory toxicology studies, we show that quantifying CatD target engagement in cells with the probe is predictive of ocular toxicity in vivo. Taken together, our findings designate off-target inhibition of CatD as a principal driver of ocular toxicity for BACE1 inhibitors and more generally underscore the power of chemical proteomics for discerning mechanisms of drug action. PMID:27727204

  1. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Bhupesh, E-mail: drbhupeshresearch@gmail.com; Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential

  2. Effects of Colloidal Oatmeal Lotion on Symptoms of Dermatologic Toxicities Induced by Epidermal Growth Factor Receptor Inhibitors.

    Science.gov (United States)

    Ke, Ya-Ting; Kuo, Chia-Chi

    2017-01-01

    The common adverse effects associated with targeted therapy for cancer, such as epidermal growth factor receptor inhibitors (EGFRIs), are dermatologic toxicities that cause the patient physical discomfort and affect treatment. Colloidal oatmeal lotion (COL) has been proven to help prevent dermatitis and xerosis. Evidence of its effect on EGFRI-induced dermatologic toxicities, however, is limited. The purpose of this study was to explore the effect of COL on EGFRI-induced dermatologic toxicities. This study used a 1-group pretest-posttest design with a convenience sample of 30 patients with cancer who developed EGFRI-induced dermatologic toxicities from a medical center in southern Taiwan. All participants applied topical COL 3 to 5 times a day for 4 consecutive weeks and received a pretest and 4 posttests. A generalized estimating equation was used to assess the impact of demographics, disease characteristics, and weeks of COL use on dermatologic toxicity severity, body surface area affected, and level of pruritus. Significant differences were found between the pretest and all posttests after using COL with regard to the severity, body surface area affected, and level of pruritus in participants who developed EGFRI-induced dermatologic toxicities (P dermatologic toxicities. Based on the study results, COL could improve the symptoms of dermatologic toxicities in those receiving EGFRIs with no adverse effects. Therefore, the authors suggest the use of COL in clinical settings.

  3. Compensatory renal hypertrophy following uninephrectomy is calcineurin-independent.

    Science.gov (United States)

    Williams, Clintoria R; Wynne, Brandi M; Walker, Makeeva; Hoover, Robert S; Gooch, Jennifer L

    2014-12-01

    Calcineurin is a calcium-dependent phosphatase that is involved in many cellular processes including hypertrophy. Inhibition or genetic loss of calcineurin blocks pathological cardiac hypertrophy and diabetic renal hypertrophy. However, calcineurin does not appear to be involved in physiological cardiac hypertrophy induced by exercise. The role of calcineurin in a compensatory, non-pathological model of renal hypertrophy has not been tested. Therefore, in this study, we examined activation of calcineurin and the effect of calcineurin inhibition or knockout on compensatory hypertrophy following uninephrectomy (UNX). UNX induces ~15% increase in the size of the remaining kidney; the data show no change in the generation of reactive oxygen species (ROS), Nox4 or transforming growth factor-β expression confirming the model as one of compensatory hypertrophy. Next, analyses of the remaining kidney reveal that total calcineurin activity is increased, and, to a lesser extent, transcriptional activity of the calcineurin substrate nuclear factor of activated T cell is up-regulated following UNX. However, inhibition of calcineurin with cyclosporine failed to prevent compensatory renal hypertrophy. Likewise, hypertrophy was comparable to WT in mice lacking either isoform of the catalytic subunit of calcineurin (CnAα-/- or CnAβ-/-). In conclusion, similar to its role in the heart, calcineurin is required for pathological but not compensatory renal hypertrophy. This separation of signalling pathways could therefore help further define key factors necessary for pathological hypertrophy including diabetic nephropathy. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  4. Intermedilysin induces EGR-1 expression through calcineurin/NFAT pathway in human cholangiocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Susilowati, Heni [Department of Oral Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Okamura, Hirohiko [Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Hirota, Katsuhiko, E-mail: hirota@dent.tokushima-u.ac.jp [Department of Oral Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Shono, Masayuki [Support Center for Advanced Medical Sciences, The University of Tokushima, Tokushima 770-8504 (Japan); Yoshida, Kaya [Department of Fundamental Oral Health Science, School of Oral Health and Welfare, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Murakami, Keiji [Department of Oral Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Tabata, Atsushi; Nagamune, Hideaki [Department of Biological Science and Technology, Life System, Institute of Technology and Science, The University of Tokushima Graduate School, Tokushima 770-8506 (Japan); Haneji, Tatsuji [Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan); Miyake, Yoichiro [Department of Oral Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504 (Japan)

    2011-01-07

    Research highlights: {yields} ILY leads to the accumulation of [Ca{sup 2+}]i in the nucleus in HuCCT1 cells. {yields} ILY induced activation of NFAT1 through a calcineurin-dependent pathway. {yields} Calcineuri/NFAT pathway is involved in EGR-1 expression in response to ILY treatment. -- Abstract: Intermedilysin (ILY) is a cholesterol-dependent cytolysin produced by Streptococcus intermedius, which is associated with human brain and liver abscesses. Although intrahepatic bile duct cells play a valuable role in the pathogenesis of liver abscess, the molecular mechanism of ILY-treated intrahepatic bile duct cells remains unknown. In this study, we report that ILY induced a nuclear accumulation of intracellular calcium ([Ca{sup 2+}]i) in human cholangiocellular cells HuCCT1. We also demonstrate that 10 ng/ml ILY induced NFAT1 dephosphorylation and its nuclear translocation in HuCCT1 cells. In contrast to the result that ILY induced NF-{kappa}B translocation in human hepatic HepG2 cells, ILY did not affect NF-{kappa}B localization in HuCCT1 cells. Dephosphorylation and nuclear translocation of NFAT1 caused by ILY were prevented by [Ca{sup 2+}]i calcium chelator, BAPTA/AM, and calcineurin inhibitors, cyclosporine A and tacrolimus. ILY induced early growth response-1 (EGR-1) expression and it was inhibited by the pre-treatment with cyclosporine A, indicating that the calcineurin/NFAT pathway was involved in EGR-1 expression in response to ILY. ILY-induced calcineurin/NFAT1 activation and sequential EGR-1 expression might be related to the pathogenesis of S. intermedius in human bile duct cells.

  5. Isoflurane induced cognitive impairment in aged rats through hippocampal calcineurin/NFAT signaling

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Cheng; Li, Zhengqian; Qian, Min; Zhou, Yang; Wang, Jun; Guo, Xiangyang, E-mail: puthmzk@163.com

    2015-05-15

    Calcineurin (CaN) over-activation constrains synaptic plasticity and memory formation. Upon CaN activation, NFAT imports into the nucleus and guides its downstream genes, which also affect neuronal and synaptic function. Aberrant CaN/NFAT signaling involves in neurotoxicity and cognitive impairment in neurological disorders such as Alzheimer's disease, but its role in postoperative cognitive dysfunction (POCD) remains uninvestigated. Inhaled anesthetic isoflurane facilitates the development of POCD, and the present study investigated the role of CaN/NFAT signaling in isoflurane induced cognitive impairment of aged rats, and the therapeutic effects of CaN inhibitor cyclosporine A (CsA). The results indicated that hippocampal CaN activity increased and peaked at 6 h after isoflurane exposure, and NFAT, especially NFATc4, imported into the nucleus following CaN activation. Furthermore, phamacological inhibition of CaN by CsA markedly attenuated isoflurane induced aberrant CaN/NFATc4 signaling in the hippocampus, and rescued relevant spatial learning and memory impairment of aged rats. Overall, the study suggests hippocampal CaN/NFAT signaling as the upstream mechanism of isoflurane induced cognitive impairment, and provides potential therapeutic target and possible treatment methods for POCD. - Highlights: • Isoflurane induces hippocampal calcineurin activation. • Isoflurane induces hippocampal NFAT, especially NFATc4, nuclear import. • Cyclosporine A attenuates isoflurane induced aberrant calcineurin/NFAT signaling. • Cyclosporine A rescues isoflurane induced cognitive impairment. • Calcineurin/NFAT signaling is the upstream mechanism of isoflurane induced synaptic dysfunction and cognitive impairment.

  6. Calcineurin inhibition with FK506 ameliorates dendritic spine density deficits in plaque-bearing Alzheimer model mice.

    Science.gov (United States)

    Rozkalne, Anete; Hyman, Bradley T; Spires-Jones, Tara L

    2011-03-01

    Synapse loss is the strongest correlate of cognitive decline in Alzheimer's disease, and synapses are an attractive therapeutic target due to their plastic nature that allows for potential recovery with intervention. We have previously demonstrated in transgenic mice that form senile plaques that dendrites surrounding plaques become dystrophic and lose postsynaptic dendritic spines. Furthermore, we found strong evidence that plaque-associated dendritic changes are mediated by calcineurin, a calcium-dependent phosphatase involved in cell signaling, using in vitro models and genetically encoded inhibitors in mouse models. In this study, we pharmacologically inhibited calcineurin with FK506 treatment to test the hypothesis that calcineurin inhibition will allow recovery of plaque-associated synapse loss. We found that in plaque bearing transgenic mice, short term (1 week) FK506 treatment results in an amelioration of dendritic spine loss. We also observe an effect on spine morphology in wild-type mice with FK506 treatment. These data show that systemic FK506 administration, and hence calcineurin inhibition, may be neuroprotective for amyloid beta induced synaptic alterations.

  7. Calcineurin Antagonizes AMPK to Regulate Lipolysis in Caenorhabditis elegans.

    Science.gov (United States)

    Wang, Yanli; Xie, Cangsang; Diao, Zhiqing; Liang, Bin

    2017-06-26

    Calcineurin is a calcium- and calmodulin-dependent serine/threonine protein phosphatase, and the target of immunosuppressive agent tacrolimus (TAC). The dysfunction of calcineurin, or clinical applications of tacrolimus, have been reported to be associated with dyslipidemia. The underlying mechanisms of calcineurin and tacrolimus in lipid metabolism are largely unknown. Here, we showed that mutations of tax-6 and cnb-1, which respectively encode the catalytic subunit and the regulatory subunit of calcineurin, together with tacrolimus treatment, consistently led to decreased fat accumulation and delayed growth in the nematode Caenorhabditis elegans. In contrast, disruption of the AMP-activated protein kinase (AMPK) encoded by aak-1 and aak-2 reversed the above effects in worms. Moreover, calcineurin deficiency and tacrolimus treatment consistently activated the transcriptional expression of the lipolytic gene atgl-1, encoding triglyceride lipase. Furthermore, RNAi knockdown of atgl-1 recovered the decreased fat accumulation in both calcineurin deficient and tacrolimus treated worms. Collectively, our results reveal that immunosuppressive agent tacrolimus and their target calcineurin may antagonize AMPK to regulate ATGL and lipolysis, thereby providing potential therapy for the application of immunosuppressive agents.

  8. Calcineurin Antagonizes AMPK to Regulate Lipolysis in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Yanli Wang

    2017-06-01

    Full Text Available Calcineurin is a calcium- and calmodulin-dependent serine/threonine protein phosphatase, and the target of immunosuppressive agent tacrolimus (TAC. The dysfunction of calcineurin, or clinical applications of tacrolimus, have been reported to be associated with dyslipidemia. The underlying mechanisms of calcineurin and tacrolimus in lipid metabolism are largely unknown. Here, we showed that mutations of tax-6 and cnb-1, which respectively encode the catalytic subunit and the regulatory subunit of calcineurin, together with tacrolimus treatment, consistently led to decreased fat accumulation and delayed growth in the nematode Caenorhabditis elegans. In contrast, disruption of the AMP-activated protein kinase (AMPK encoded by aak-1 and aak-2 reversed the above effects in worms. Moreover, calcineurin deficiency and tacrolimus treatment consistently activated the transcriptional expression of the lipolytic gene atgl-1, encoding triglyceride lipase. Furthermore, RNAi knockdown of atgl-1 recovered the decreased fat accumulation in both calcineurin deficient and tacrolimus treated worms. Collectively, our results reveal that immunosuppressive agent tacrolimus and their target calcineurin may antagonize AMPK to regulate ATGL and lipolysis, thereby providing potential therapy for the application of immunosuppressive agents.

  9. Effects of arsenite and UVA-1 radiation on calcineurin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Musson, Ruben E.A., E-mail: rm@ream.nl [Department of Clinical Chemistry, Leiden University Medical Center (Netherlands); Department of Toxicogenetics, Leiden University Medical Center (Netherlands); Mullenders, Leon H.F. [Department of Toxicogenetics, Leiden University Medical Center (Netherlands); Smit, Nico P.M. [Department of Clinical Chemistry, Leiden University Medical Center (Netherlands)

    2012-07-01

    Calcineurin is a Ca{sup 2+}-dependent serine/threonine phosphatase and the target of the immunosuppressive drugs cyclosporin and tacrolimus, which are used in transplant recipients to prevent rejection. Unfortunately, the therapeutic use of this drugs is complicated by a high incidence of skin malignancy, which has set off a number of studies into the role of calcineurin signaling in skin, particularly with respect to cell cycle control and DNA repair. Both UVA1 radiation and arsenic species are known to promote skin cancer development via production of reactive oxygen species. In light of the well-documented sensitivity of calcineurin to oxidative stress, we examined and compared the effects of UVA1 and arsenite on calcineurin signaling. In this paper, we show that physiologically relevant doses of UVA1 radiation and low micromolar concentrations of arsenite strongly inhibit calcineurin phosphatase activity in Jurkat and skin cells and decrease NFAT nuclear translocation in Jurkat cells. The effects on calcineurin signaling could be partly prevented by inhibition of NADPH oxidase in Jurkat cells or increased dismutation of superoxide in Jurkat and skin cells. In addition, both UVA1 and arsenite decreased NF-{kappa}B activity, although at lower concentrations, arsenite enhanced NF-{kappa}B activity. These data indicate that UVA1 and arsenite affect a signal transduction route of growingly acknowledged importance in skin and that calcineurin may serve as a potential link between ROS exposure and impaired tumor suppression.

  10. Effects of a phospholipase A/sub 2/ inhibitor on uptake and toxicity of liposomes containing plant phosphatidylinositol

    Energy Technology Data Exchange (ETDEWEB)

    Jett, M.; Alving, C.R.

    1986-05-01

    Plant phosphatidylinositol (PI) has been shown by us to have a direct cytotoxic effect on cultured tumor cells but not on normal cells. Synthetic PI containing /sup 14/C-linoleic acid in the sn-2 position, also showed the same pattern of selective cytotoxicity. When the metabolic fate of synthetic PI was examined with tumor cells, the radioactivity which no longer occurred as PI, was found as either products of phospholipase A/sub 2/ (93%, free fatty acids and phosphatidylcholine) or phospholipase C (7%, diglycerides). Uptake of liposomal PI was directly correlated with cytotoxicity. They tested a variety of inhibitors to see the effect on uptake and/or cytotoxicity of plant PI. General metabolic inhibitors such as metrizamide or sodium azide did not alter cellular uptake of the plant PI liposomes. Inhibitors of lipoxygenase formation, such as indomethacin, also did not alter the uptake or cytotoxicity induced by plant PI. Quinacrine, an inhibitor of phospholipase A/sub 2/, decreased the uptake of the PI containing liposomes to 50% of that seen in the presence or absence of any other inhibitor. Although quinacrine is itself toxic to cells, at low concentrations of quinacrine, plant PI did not show the same degree of cytotoxicity as in the absence of quinacrine. These data are compatible with the hypothesis that plant PI exerts cytotoxicity by serving as a substrate for phospholipase A/sub 2/.

  11. New, highly potent and non-toxic, chromone inhibitors of the human breast cancer resistance protein ABCG2.

    Science.gov (United States)

    Pires, Amanda do Rocio Andrade; Lecerf-Schmidt, Florine; Guragossian, Nathalie; Pazinato, Jaqueline; Gozzi, Gustavo Jabor; Winter, Evelyn; Valdameri, Glaucio; Veale, Alexander; Boumendjel, Ahcène; Di Pietro, Attilio; Pérès, Basile

    2016-10-21

    Breast cancer resistance protein (BCRP/ABCG2) is one of the major transporters involved in the efflux of anticancer compounds, contributing to multidrug resistance (MDR). Inhibition of ABCG2-mediated transport is then considered a promising strategy for overcoming MDR in tumors. We recently identified a chromone derivative, namely MBL-II-141 as a selective ABCG2 inhibitor, with relevant in vivo activity. Here, we report the pharmacomodulation of MBL-II-141, with the aim of identifying key pharmacophoric elements to design more potent selective and non-toxic inhibitors. Through rational structural modifications of MBL-II-141, using simple and affordable chemistry, we obtained highly active and easily-made inhibitors of ABCG2. Among the investigated compounds, derivative 4a, was found to be 3-fold more potent than MBL-II-141. It was similarly efficient as the reference inhibitor Ko143 but with the advantage of a lower intrinsic cytotoxicity, and therefore constitutes the best ABCG2 inhibitor ever reported displaying a very high therapeutic ratio. Copyright © 2016. Published by Elsevier Masson SAS.

  12. The toxicity of angiotensin converting enzyme inhibitors to larvae of the disease vectors Aedes aegypti and Anopheles gambiae.

    Science.gov (United States)

    Abu Hasan, Zatul-'Iffah; Williams, Helen; Ismail, Nur M; Othman, Hidayatulfathi; Cozier, Gyles E; Acharya, K Ravi; Isaac, R Elwyn

    2017-03-27

    The control of mosquitoes is threatened by the appearance of insecticide resistance and therefore new control chemicals are urgently required. Here we show that inhibitors of mosquito peptidyl dipeptidase, a peptidase related to mammalian angiotensin-converting enzyme (ACE), are insecticidal to larvae of the mosquitoes, Aedes aegypti and Anopheles gambiae. ACE inhibitors (captopril, fosinopril and fosinoprilat) and two peptides (trypsin-modulating oostatic factor/TMOF and a bradykinin-potentiating peptide, BPP-12b) were all inhibitors of the larval ACE activity of both mosquitoes. Two inhibitors, captopril and fosinopril (a pro-drug ester of fosinoprilat), were tested for larvicidal activity. Within 24 h captopril had killed >90% of the early instars of both species with 3(rd) instars showing greater resistance. Mortality was also high within 24 h of exposure of 1(st), 2(nd) and 3(rd) instars of An. gambiae to fosinopril. Fosinopril was also toxic to Ae. aegypti larvae, although the 1(st) instars appeared to be less susceptible to this pro-drug even after 72 h exposure. Homology models of the larval An. gambiae ACE proteins (AnoACE2 and AnoACE3) reveal structural differences compared to human ACE, suggesting that structure-based drug design offers a fruitful approach to the development of selective inhibitors of mosquito ACE enzymes as novel larvicides.

  13. Calcineurin inhibition in splenocytes induced by pavlovian conditioning.

    Science.gov (United States)

    Pacheco-López, Gustavo; Riether, Carsten; Doenlen, Raphael; Engler, Harald; Niemi, Maj-Britt; Engler, Andrea; Kavelaars, Annemieke; Heijnen, Cobi J; Schedlowski, Manfred

    2009-04-01

    Pavlovian conditioning is one of the major neurobiological mechanisms of placebo effects, potentially influencing the course of specific diseases and the response to a pharmacological therapy, such as immunosuppression. In our study with behaviorally conditioned rats, a relevant taste (0.2% saccharin) preceded the application of the immunosuppressive drug cyclosporin A (CsA), a specific calcineurin (CaN) inhibitor. Our results demonstrate that through pavlovian conditioning the particular pharmacological properties of CsA can be transferred to a neutral taste, i.e., CaN activity was inhibited in splenocytes from conditioned rats after reexposure to the gustatory stimulus. Concomitant immune consequences were observed on ex vivo mitogenic challenge (anti-CD3). Particularly, Th1-cytokine, but not Th2-cytokine, production and cell proliferation were impeded. Appropriate pharmacological and behavioral controls certify that all these changes in T-lymphocyte reactivity are attributable to mere taste reexposure. Furthermore, the underlying sympathetic-lymphocyte interaction was revealed modeling the conditioned response in vitro. CaN activity in CD4(+) T lymphocytes is reduced by beta-adrenergic stimulation (terbutaline), with these effects antagonized by the beta-adrenoreceptor antagonist nadolol. In summary, CaN was identified as the intracellular target for inducing conditioned immunosuppression by CsA, contributing to our understanding of the intracellular mechanisms behind "learned placebo effects."

  14. Application of calcineurin inhibitor monotherapy in renal transplantation after alemtuzumab induction:a Meta-analysis%阿仑单抗诱导后钙神经蛋白抑制剂单药治疗方案在肾移植中的应用:一项系统评价研究

    Institute of Scientific and Technical Information of China (English)

    谢礼波; 王应强; 王显丁; 林涛; 卢一平

    2016-01-01

    Objective To evaluate the clinical efficacy and safety of immunosuppression of calcineurin inhibitor monotherapy (AiCNIm)after alemtuzumab induction following renal transplantation.Methods Randomized control clinical trials related to application of AiCNIm (AiCNIm group ) and conventional triple regimes (Triple group ) for immunosupression after renal transplantation,published from 1 980 to December 31 201 4,were searched online from PubMed,Embase,Web of Science,Cochrance library and China National Knowledge Infrastructure (CNKI) databases.Meta-analysis was performed by Rev Man 5.2 software.Results Five randomized control studies consisting of 421 renal transplant recipients were included.The results of follow up for 6-1 2 months revealed that compared with the Triple group, the incidence of rejection response confirmed by acute rejection or aspiration biopsy in the AiCNIm group was significantly lower [relative risk (RR) =0.59,95% confidence interval (CI):0.40-0.89 ].However,there was no significant difference in the risk of renal allograft dysfunction (RR =0.85,95%CI:0.38-1 .87),death of recipient (RR =0.89,95%CI:0.30-2.67),infection (RR =1 .03,95%CI:0.91 -1 .1 7)and new-onset diabetes after transplantation (RR =0.62, 95%CI:0.29-1 .30)between two groups (all in P >0.05).Conclusions According to the existing evidence,application of calcineurin inhibitor monotherapy after renal transplantation exerts short-term immunosuppressive effect and high safety after alemtuzumab induction.%目的:探讨阿仑单抗诱导后钙神经蛋白抑制剂单药治疗(AiCNIm)方案应用于肾移植术后免疫抑制的有效性和安全性。方法应用计算机检索 Pubmed、Embase、Web of science、Cochrance library 及中国知网(CNKI)等数据库,查找1980年至2014年12月31日发表的有关 AiCNIm 方案(AiCNIm 组)和常规三联方案(Triple 组)进行肾移植术后免疫抑制的随机对照临床研究。采用 Rev Man 5.2软件进行 Meta

  15. Reduced systemic toxicity and preserved vestibular toxicity following co-treatment with nitriles and CYP2E1 inhibitors: a mouse model for hair cell loss.

    Science.gov (United States)

    Saldaña-Ruíz, Sandra; Boadas-Vaello, Pere; Sedó-Cabezón, Lara; Llorens, Jordi

    2013-10-01

    Several nitriles, including allylnitrile and cis-crotononitrile, have been shown to be ototoxic and cause hair cell degeneration in the auditory and vestibular sensory epithelia of mice. However, these nitriles can also be lethal due in large part to the microsomal metabolic release of cyanide, which is mostly dependent on the activity of the 2E1 isoform of the cytochrome P450 (CYP2E1). In this study, we co-administered mice with a nitrile and, to reduce their lethal effects, a selective CYP2E1 inhibitor: diallylsulfide (DAS) or trans-1,2-dichloroethylene (TDCE). Both in female 129S1/SvImJ (129S1) mice co-treated with DAS and cis-crotononitrile and in male RjOrl:Swiss/CD-1 (Swiss) mice co-treated with TDCE and allylnitrile, the nitrile caused a dose-dependent loss of vestibular function, as assessed by a specific behavioral test battery, and of hair cells, as assessed by hair bundle counts using scanning electron microscopy. In the experiments, the CYP2E1 inhibitors provided significant protection against the lethal effects of the nitriles and did not diminish the vestibular toxicity as assessed by behavioral effects in comparison to animals receiving no inhibitor. Additional experiments using a single dose of allylnitrile demonstrated that TDCE does not cause hair cell loss on its own and does not modify the vestibular toxicity of the nitrile in either male or female 129S1 mice. In all the experiments, high vestibular dysfunction scores in the behavioral test battery predicted extensive to complete loss of hair cells in the utricles. This provides a means of selecting animals for subsequent studies of vestibular hair cell regeneration or replacement.

  16. [Pharmacovigilance of calcineurin inhibitor in peidatric kidney and liver transplantation].

    Science.gov (United States)

    Riva, N; Cáceres Guido, P; Rousseau, M; Dip, M; Monteverde, M; Imventarza, O; Mato, G; Schaiquevich, P

    2013-01-01

    Objetivo: Desarrollar un programa de farmacovigilancia de pacientes pediátricos trasplantados hepáticos y renales centrado en inmunosupresores calcineurínicos del Hospital de Pediatría JP Garrahan de Argentina. Métodos: Se evaluaron las reacciones adversas a medicamentos (RAM) de los pacientes pediátricos trasplantados renales y hepáticos de nuestro hospital tratados con inhibidores de calcineurina (ciclosporina y tacrolimus) por revisión retrospectiva de historias clínicas de pacientes trasplantados en 2010-2011, y análisis prospectivo por farmacovigilancia activa de trasplantados fuera de dicho período, cuyas complicaciones se hayan presentado en los ateneos semanales del Servicio de Trasplante desde marzo de 2011. Las RAM se notificaron a la autoridad sanitaria nacional. Resultados: Se analizaron un total de 59 pacientes, 28 trasplantados renales y 31 hepáticos. Se notificaron, en ambos trasplantes, 60 RAM a ciclosporina destacándose (número de casos) hipertensión arterial (19) y nefrotoxicidad (6). Asimismo, se registraron 46 RAM a tacrolimus, incluyendo hipomagnesemia (25), hipertensión (7) y nefrotoxicidad (5). El 95% y 96% de los eventos adversos a ciclosporina y a tacrolimus, respectivamente, han sido agrupados como probables o definitivos. El 70% y 98% de los eventos adversos a ciclosporina y a tacrolimus respectivamente, han sido de severidad moderada o grave. Conclusiones: Este es el primer proyecto en América Latina que propone y desarrolla el estudio cuali-cuantitativo intensivo de RAM a inhibidores de calcineurina en trasplante pediátrico renal y hepático. Es necesario estimular la notificación espontánea así como continuar el seguimiento de RAM a mediano y largo plazo para mejorar la calidad de vida del paciente trasplantado.

  17. Corticosteroid and calcineurin inhibitor sparing regimens in kidney transplantation.

    Science.gov (United States)

    Cortazar, Frank; Diaz-Wong, Roque; Roth, David; Isakova, Tamara

    2013-11-01

    Chronic kidney disease is a major public health problem that is associated with increased risks of kidney disease progression, cardiovascular disease and death. Kidney transplantation remains the renal replacement therapy of choice for patients with end-stage kidney disease. Despite impressive strides in short-term allograft survival, there has been little improvement in long-term kidney graft survival, and rates of death with a functioning allograft remain high. Long-term safety profiles of existing immunosuppressive regimens point to a need for continued search for alternative agents. This overview discusses emerging evidence on a few promising therapeutic approaches, juxtaposes conflicting findings and highlights remaining knowledge gaps.

  18. Regulation of ITAM adaptor molecules and their receptors by inhibition of calcineurin-NFAT signalling during late stage osteoclast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Zawawi, M.S.F. [Universiti Sains Malaysia (USM) (Malaysia); Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Dharmapatni, A.A.S.S.K.; Cantley, M.D. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); McHugh, K.P. [University of Florida, College of Dentistry, Fl (United States); Haynes, D.R. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Crotti, T.N., E-mail: tania.crotti@adelaide.edu.au [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer Calcineurin/NFAT inhibitors FK506 and VIVIT treated human PBMC derived osteoclasts in vitro. Black-Right-Pointing-Pointer Differential regulation of ITAM receptors and adaptor molecules by calcineurin/NFAT inhibitors. Black-Right-Pointing-Pointer FK506 and VIVIT suppress ITAM factors during late phase osteoclast differentiation. -- Abstract: Osteoclasts are specialised bone resorptive cells responsible for both physiological and pathological bone loss. Osteoclast differentiation and activity is dependent upon receptor activator NF-kappa-B ligand (RANKL) interacting with its receptor RANK to induce the transcription factor, nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1). The immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway has been identified as a co-stimulatory pathway in osteoclasts. Osteoclast-associated receptor (OSCAR) and triggering receptor expressed in myeloid cells (TREM2) are essential receptors that pair with adaptor molecules Fc receptor common gamma chain (FcR{gamma}) and DNAX-activating protein 12 kDa (DAP12) respectively to induce calcium signalling. Treatment with calcineurin-NFAT inhibitors, Tacrolimus (FK506) and the 11R-VIVIT (VIVIT) peptide, reduces NFATc1 expression consistent with a reduction in osteoclast differentiation and activity. This study aimed to investigate the effects of inhibiting calcineurin-NFAT signalling on the expression of ITAM factors and late stage osteoclast genes including cathepsin K (CathK), Beta 3 integrin ({beta}3) and Annexin VIII (AnnVIII). Human peripheral blood mononuclear cells (PBMCs) were differentiated with RANKL and macrophage-colony stimulating factor (M-CSF) over 10 days in the presence or absence of FK506 or VIVIT. Osteoclast formation (as assessed by tartrate resistant acid phosphatase (TRAP)) and activity (assessed by dentine pit resorption) were significantly reduced with treatment. Quantitative real

  19. E2/ER β inhibit ISO-induced cardiac cellular hypertrophy by suppressing Ca2+-calcineurin signaling.

    Science.gov (United States)

    Tsai, Cheng-Yen; Kuo, Wei-Wen; Shibu, Marthandam Asokan; Lin, Yueh-Min; Liu, Chien-Nam; Chen, Yi-Hui; Day, Cecilia-Hsuan; Shen, Chia-Yao; Viswanadha, Vijaya Padma; Huang, Chih-Yang

    2017-01-01

    Cardiovascular incidences are markedly higher in men than in pre-menstrual women. However, this advantage in women declines with aging and therefore can be correlated with the sex hormone 17β-Estradiol (E2) which is reported to protect heart cells by acting though estrogen receptors (ERs). In this study we have determined the effect of E2/ERβ against ISO induced cellular hypertrophy in H9c2 cardiomyoblast cells. The results confirm that ISO induced cardiac-hypertrophy by elevating the levels of hypertrophy associated proteins, ANP and BNP and further by upregulating p-CaMKII, calcineurin, p-GATA4 and NFATc3 which was correlated with a significant enlargement of the H9c2 cardiomyoblast. However, overexpression of ERβ and/or administration of E2 inhibited ISO-induced hypertrophy in H9c2 cells. In addition, E2/ERβ also inhibited ISO-induced NFATc3 translocation, and reduced the protein level of downstream marker, BNP. Furthermore, by testing with the calcineurin inhibitor (CsA), it was confirmed that calcineurin acted as a key mediator for the anti-hypertrophic effect of E2/ERβ. In cells treated with calcium blocker (BATPA), the inhibitory effect of E2/ERβ on ISO-induced Ca2+ influx and hypertrophic effects were totally blocked suggesting that E2/ERβ inhibited calcineurin activity to activate I-1 protein and suppress PP1, then induce PLB protein phosphorylation and activation, resulting in Ca2+ reuptake into sarcoplasmic reticulum through SR Ca2+ cycling modification. In conclusion, E2/ERβ suppresses the Ca2+ influx and calcineurin activity induced by ISO to enhance the PLB protein activity and SR Ca2+ cycling.

  20. [Role of calcineurin in down-regulation of left ventricular transmural voltage- dependent K(+) currents in mice with heart failure].

    Science.gov (United States)

    Shi, Chen-Xia; Dong, Fang; Chang, Yan-Chao; Wang, Xiao-Feng; Xu, Yan-Fang

    2015-08-25

    The aim of the present study was to investigate the role of calcineurin in the down-regulation of left ventricular transmural voltage-dependent K(+) currents in heart failure. Transverse aorta was banded by using microsurgical techniques to create mouse heart failure model. Sham-operated (Sham) or aorta banded (Band) mice were randomized to receive calcineurin inhibitor cyclosporine A (CsA) or vehicle. The densities and kinetic properties of voltage-dependent K(+) currents, as well as action potential (AP), of left ventricular subendocardial (Endo) and subepicardial (Epi) myocytes were determined by using whole-cell patch-clamp technique. The results showed that calcineurin activity was significant higher in Endo myocytes than that in Epi ones in all the groups. Compared with Sham group, Band mice showed significantly increased calcineurin activity both in Endo and Epi myocytes. CsA significantly reduced calcineurin activity in Band mice. CsA treatment in Band mice partially reversed the down-regulation of Ito density, completely reversed the down-regulation of IK,slow density both in Endo and Epi myocytes, and Iss density in Endo myocytes. In addition, CsA treatment in Band mice partially antagonized the prolongation of action potential duration (APD), and APD at 50% (APD50) and 90% repolarization (APD90) were significantly reduced. Because of non-parallel shortening of APD in Endo and Epi myocytes, the ratio of Endo/Epi APD90 was reduced from 4.8:1 in Band mice to 2.6:1 in CsA-treated mice, which was close to that in Sham mice. The results suggest that non-parallel activation of calcineurin in Endo and Epi myocytes contributes to the down-regulation of transmural voltage-dependent K(+) currents and the amplification of transmural dispersion of repolarization (TDR) in left ventricular failure hearts. Inhibition of calcineurin may be a potential new therapeutic strategy to prevent and cure arrhythmias and sudden death in heart failure.

  1. Acute toxicity of second generation HIV protease-inhibitors in combination with radiotherapy: a retrospective case series

    Directory of Open Access Journals (Sweden)

    Tran Phuoc T

    2011-03-01

    Full Text Available Abstract Background There is little data on the safety of combining radiation therapy and human immunodeficiency virus (HIV protease inhibitors to treat cancers in HIV-positive patients. We describe acute toxicities observed in a series of HIV-positive patients receiving modern radiation treatments, and compare patients receiving HIV protease inhibitors (PI with patients not receiving HIV PIs. Methods By reviewing the clinical records beginning January 1, 2009 from the radiation oncology department, we identified 29 HIV-positive patients who received radiation therapy to 34 body sites. Baseline information, treatment regimen, and toxicities were documented by review of medical records: patient age, histology and source of the primary tumor, HIV medication regimen, pre-radiation CD4 count, systemic chemotherapy, radiation therapy dose and fractionation, irradiated body region, toxicities, and duration of follow-up. Patients were grouped according to whether they received concurrent HIV PIs and compared using Pearson's chi-square test. Results At baseline, the patients in the two groups were similar with the exception of HIV medication regimens, CD4 count and presence of AIDS-defining malignancy. Patients taking concurrent PIs were more likely to be taking other HIV medications (p = 0.001 and have CD4 count >500 (p = 0.006. Patients taking PIs were borderline less likely to have an AIDS-defining malignancy (p = 0.06. After radiation treatment, 100 acute toxicities were observed and were equally common in both groups (64 [median 3 per patient, IQR 1-7] with PIs; 36 [median 3 per patient, IQR 2-3] without PIs. The observed toxicities were also equally severe in the two groups (Grades I, II, III respectively: 30, 30, 4 with PIs; 23, 13, 0 without PIs: p = 0.38. There were two cases that were stopped early, one in each group; these were not attributable to toxicity. Conclusions In this study of recent radiotherapy in HIV-positive patients taking

  2. Stimulatory and inhibitory effects of inorganic lead on calcineurin.

    Science.gov (United States)

    Kern, M; Audesirk, G

    2000-09-07

    Calcineurin is a phosphatase with activity dependent on both Ca(2+)/calmodulin binding to the catalytic A subunit and Ca(2+) binding to the regulatory B subunit. We have previously shown that Pb(2+) activates calmodulin with a threshold of about 100 pM free Pb(2+), and that Pb(2+) and Ca(2+) are roughly additive in calmodulin activation (Kern et al., NeuroToxicology 21, 353-364 (2000)). In the present study, we evaluated the effects of Pb(2+), with and without Ca(2+) and calmodulin, on calcineurin activity. In calmodulin-containing, Ca(2+)-free solutions, Pb(2+) activated calcineurin with a threshold of about 100 pM free Pb(2+). Maximum calcineurin activity (comparable to that induced by 10 microM Ca(2+)) was reached at about 200 pM free Pb(2+). Higher Pb(2+) concentrations reduced activity, although some activity remained even at 2000 pM free Pb(2+). Combined with subsaturating Ca(2+) concentrations, as little as 20 pM free Pb(2+) enhanced calcineurin activity, but free Pb(2+) concentrations greater than 200 pM still reduced activity below maximum. Extremely high Ca(2+) concentrations (10 microM) completely reversed the inhibition of activity by 2000 pM free Pb(2+). In the absence of calmodulin, Ca(2+) slightly stimulated calcineurin activity. Pb(2+) did not substitute for Ca(2+) in calmodulin-free activation; in fact, high concentrations of Pb(2+) inhibited Ca(2+)-mediated activation. We tentatively conclude that low concentrations of free Pb(2+) activate calcineurin by activating calmodulin. Higher concentrations reduce calcineurin activity, perhaps by binding to the B subunit.

  3. The cathepsin B inhibitor, z-FA-CMK is toxic and readily induced cell death in human T lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Liow, K.Y.; Chow, S.C., E-mail: chow.sek.chuen@monash.edu

    2013-11-01

    The cathepsin B inhibitor, benzyloxycarbonyl-phenylalanine-alanine-chloromethylketone (z-FA-CMK) was found to be toxic and readily induced cell death in the human T cell line, Jurkat, whereas two other analogs benzyloxycarbonyl-phenylalanine-alanine-fluoromethylketone (z-FA-FMK) and benzyloxycarbonyl-phenylalanine-alanine-diazomethylketone (z-FA-DMK) were not toxic. The toxicity of z-FA-CMK requires not only the CMK group, but also the presence of alanine in the P1 position and the benzyloxycarbonyl group at the N-terminal. Dose–response studies showed that lower concentrations of z-FA-CMK induced apoptosis in Jurkat T cells whereas higher concentrations induced necrosis. In z-FA-CMK-induced apoptosis, both initiator caspases (-8 and -9) and effector caspases (-3, -6 and -7) were processed to their respective subunits in Jurkat T cells. However, only the pro-form of the initiator caspases were reduced in z-FA-CMK-induced necrosis and no respective subunits were apparent. The caspase inihibitor benzyloxycarbonyl-valine-alanine-aspartic acid-(O-methyl)-fluoromehylketone (z-VAD-FMK) inhibits apoptosis and caspase processing in Jurkat T cells treated with low concentration of z-FA-CMK but has no effect on z-FA-CMK-induced necrosis and the loss of initiator caspases. This suggests that the loss of initiator caspases in Jurkat T cells during z-FA-CMK-induced necrosis is not a caspase-dependent process. Taken together, we have demonstrated that z-FA-CMK is toxic to Jurkat T cells and induces apoptosis at low concentrations, while at higher concentrations the cells die of necrosis. - Highlights: • z-FA-CMK is toxic and induce cell death in the human T cells. • z-FA-CMK toxicity requires the CMK group, alanine and the benzyloxycarbonyl group. • z-FA-CMK induced apoptosis at low concentration and necrosis at high concentration.

  4. The neuronal nitric oxide synthase inhibitor NANT blocks acetaminophen toxicity and protein nitration in freshly isolated hepatocytes.

    Science.gov (United States)

    Banerjee, Sudip; Melnyk, Stepan B; Krager, Kimberly J; Aykin-Burns, Nukhet; Letzig, Lynda G; James, Laura P; Hinson, Jack A

    2015-12-01

    3-Nitrotyrosine (3NT) in liver proteins of mice treated with hepatotoxic doses of acetaminophen (APAP) has been postulated to be causative in toxicity. Nitration is by a reactive nitrogen species formed from nitric oxide (NO). The source of the NO is unclear. iNOS knockout mice were previously found to be equally susceptible to APAP toxicity as wildtype mice and iNOS inhibitors did not decrease toxicity in mice or in hepatocytes. In this work we examined the potential role of nNOS in APAP toxicity in hepatocytes using the specific nNOS inhibitor NANT (10 µM)(N-[(4S)-4-amino-5-[(2-aminoethyl)amino]pentyl]-N'-nitroguanidinetris (trifluoroacetate)). Primary hepatocytes (1 million/ml) from male B6C3F1 mice were incubated with APAP (1mM). Cells were removed and assayed spectrofluorometrically for reactive nitrogen and oxygen species using diaminofluorescein (DAF) and Mitosox red, respectively. Cytotoxicity was determined by LDH release into media. Glutathione (GSH, GSSG), 3NT, GSNO, acetaminophen-cysteine adducts, NAD, and NADH were measured by HPLC. APAP significantly increased cytotoxicity at 1.5-3.0 h. The increase was blocked by NANT. NANT did not alter APAP mediated GSH depletion or acetaminophen-cysteine adducts in proteins which indicated that NANT did not inhibit metabolism. APAP significantly increased spectroflurometric evidence of reactive nitrogen and oxygen formation at 0.5 and 1.0 h, respectively, and increased 3NT and GSNO at 1.5-3.0 h. These increases were blocked by NANT. APAP dramatically increased NADH from 0.5-3.0 h and this increase was blocked by NANT. Also, APAP decreased the Oxygen Consumption Rate (OCR), decreased ATP production, and caused a loss of mitochondrial membrane potential, which were all blocked by NANT.

  5. BCR Signaling Inhibitors: an Overview of Toxicities Associated with Ibrutinib and Idelalisib in Patients with Chronic Lymphocytic Leukemia.

    Science.gov (United States)

    Falchi, Lorenzo; Baron, Jessica M; Orlikowski, Carrie Anne; Ferrajoli, Alessandra

    2016-01-01

    The B-cell receptor (BCR) signaling inhibitors ibrutinib and idelalisib are revolutionizing the treatment of chronic lymphocytic leukemia (CLL) and other B-cell malignancies. These oral agents, both alone and in combination with other drugs, have shown remarkable clinical activity in relapsed or refractory CLL across all risk groups, and have been approved by the Food and Drug Administration for this indication. Preliminary data suggest that an even greater benefit can be expected in treatment-naïve CLL patients. Both ibrutinib and idelalisib are well tolerated by most patients, including older, frailer individuals. Toxicities are usually mild and self-resolving. Clinicians must, however, be aware of a number of peculiar adverse events, the effects of which can be severe enough to limit the clinical use of these agents. In this review, we survey the salient aspects of the pharmacology and clinical experience with the use of BCR signaling inhibitors for the treatment of patients with CLL. We next focus on both the most common and the most clinically significant toxicities associated with these drugs.

  6. In vivo toxicity, metabolism and pharmacokinetic properties of FAK inhibitor 14 or Y15 (1, 2, 4, 5-benzenetetramine tetrahydrochloride).

    Science.gov (United States)

    Golubovskaya, Vita; Curtin, Leslie; Groman, Adrienne; Sexton, Sandra; Cance, William G

    2015-07-01

    Y15 or inhibitor 14 (1,2,4,5-benzenetetramine tetrahydrochloride) is a potent and specific inhibitor of focal adhesion kinase that inhibits its autophosphorylation activity, decreases the viability of cancer cells, and blocks tumor growth. In this preclinical study, we analyzed the pharmacokinetics of Y15 in mice plasma, its metabolic stability in mouse and human liver microsomes and toxicity in mice. The pharmacokinetics study in mice demonstrated that, following intraperitoneal administration at 30 mg/kg dose, Y15 was very rapidly absorbed in mice, reaching maximum plasma concentration in 4.8 min. Y15 rapidly metabolized in mouse and human liver microsomes with half-life t1/2 of 6.9 and 11.6 min, respectively. The maximal tolerated dose of single-dose administration of Y15 by oral administration was 200 mg/kg, and the multiple maximum tolerated dose of Y15 was 100 mg/kg by PO during 7 day study. Y15 did not cause any mortality or statistically significant differences in the body weight at 30 mg/kg by IP during 28-day study, and at 100 mg/kg by PO during the 7-day study. There were no clinical chemical, hematological, or histopathological changes in different mice organs at 30 mg/kg by IP during 28 days and at 100 mg/kg dose by PO during 7 days. Thus, this is the first preclinical toxicity, pharmacokinetics, and metabolic stability study of Y15 inhibitor. Further development of Y15 will provide a basis for new therapeutic and future clinical studies.

  7. Evidence for the Role of Calcineurin in Morphogenesis and Calcium Homeostasis during Mycelium-to-Yeast Dimorphism of Paracoccidioides brasiliensis▿

    Science.gov (United States)

    Campos, Claudia B. L.; Di Benedette, Joao Paulo T.; Morais, Flavia V.; Ovalle, Rafael; Nobrega, Marina P.

    2008-01-01

    Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25°C to 37°C and is critical for pathogenicity. Intracellular Ca2+ levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca2+ with extracellular (EGTA) or intracellular (BAPTA) calcium chelators inhibited temperature-induced dimorphism, whereas the addition of extracellular Ca2+ accelerated dimorphism. The calcineurin inhibitor cyclosporine A (CsA), but not tacrolimus (FK506), effectively decreased cell growth, halted the M-Y transition that is associated with virulence, and caused aberrant growth morphologies for all forms of P. brasiliensis. The difference between CsA and FK506 was ascribed by the higher levels of cyclophilins contrasted to FKBPs, the intracellular drug targets required for calcineurin suppression. Chronic exposure to CsA abolished intracellular Ca2+ homeostasis and decreased mRNA transcription of the CCH1 gene for the plasma membrane Ca2+ channel in yeast-form cells. CsA had no detectable effect on multidrug resistance efflux pumps, while the effect of FK506 on rhodamine excretion was not correlated with the transition to yeast form. In this study, we present evidence that Ca2+/calmodulin-dependent phosphatase calcineurin controls hyphal and yeast morphology, M-Y dimorphism, growth, and Ca2+ homeostasis in P. brasiliensis and that CsA is an effective chemical block for thermodimorphism in this organism. The effects of calcineurin inhibitors on P. brasiliensis reinforce the therapeutic potential of these drugs in a combinatory approach with antifungal drugs to treat endemic paracoccidioidomycosis. PMID:18776037

  8. High-efficiency liposomal encapsulation of a tyrosine kinase inhibitor leads to improved in vivo toxicity and tumor response profile.

    Science.gov (United States)

    Mukthavaram, Rajesh; Jiang, Pengfei; Saklecha, Rohit; Simberg, Dmitri; Bharati, Ila Sri; Nomura, Natsuko; Chao, Ying; Pastorino, Sandra; Pingle, Sandeep C; Fogal, Valentina; Wrasidlo, Wolf; Makale, Milan; Kesari, Santosh

    2013-01-01

    Staurosporine (STS) is a potent pan-kinase inhibitor with marked activity against several chemotherapy-resistant tumor types in vitro. The translational progress of this compound has been hindered by poor pharmacokinetics and toxicity. We sought to determine whether liposomal encapsulation of STS would enhance antitumor efficacy and reduce toxicity, thereby supporting the feasibility of further preclinical development. We developed a novel reverse pH gradient liposomal loading method for STS, with an optimal buffer type and drug-to-lipid ratio. Our approach produced 70% loading efficiency with good retention, and we provide, for the first time, an assessment of the in vivo antitumor activity of STS. A low intravenous dose (0.8 mg/kg) inhibited U87 tumors in a murine flank model. Biodistribution showed preferential tumor accumulation, and body weight data, a sensitive index of STS toxicity, was unaffected by liposomal STS, but did decline with the free compound. In vitro experiments revealed that liposomal STS blocked Akt phosphorylation, induced poly(ADP-ribose) polymerase cleavage, and produced cell death via apoptosis. This study provides a basis to explore further the feasibility of liposomally encapsulated STS, and potentially related compounds for the management of resistant solid tumors.

  9. Clinical practice guidelines for the prevention and treatment of EGFR inhibitor-associated dermatologic toxicities

    NARCIS (Netherlands)

    M.E. Lacouture; M.J. Anadkat; R.J. Bensadoun; J. Bryce; A. Chan; J.B. Epstein; B. Eaby-Sandy; B.A. Murphy; A. Barasch; C. Beder; C.B. Boers-Doets; T. Doherty; J.E. Raber-Durlacher; D. Forstner; S. Langer; J. Lees; D. Mellor

    2011-01-01

    Background Epidermal growth factor receptor inhibitors (EGFRI) produce various dermatologic side effects in the majority of patients, and guidelines are crucial for the prevention and treatment of these untoward events. The purpose of this panel was to develop evidence-based recommendations for EGFR

  10. Clinical practice guidelines for the prevention and treatment of EGFR inhibitor-associated dermatologic toxicities

    NARCIS (Netherlands)

    Lacouture, M.E.; Anadkat, M.J.; Bensadoun, R.J.; Bryce, J.; Chan, A.; Epstein, J.B.; Eaby-Sandy, B.; Murphy, B.A.; Barasch, A.; Beder, C.; Boers-Doets, C.B.; Doherty, T.; Raber-Durlacher, J.E.; Forstner, D.; Langer, S.; Lees, J.; Mellor, D.

    2011-01-01

    Background Epidermal growth factor receptor inhibitors (EGFRI) produce various dermatologic side effects in the majority of patients, and guidelines are crucial for the prevention and treatment of these untoward events. The purpose of this panel was to develop evidence-based recommendations for

  11. Toxicity to cotton boll weevil Anthonomus grandis of a trypsin inhibitor from chickpea seeds.

    Science.gov (United States)

    de P G Gomes, Angélica; Dias, Simoni C; Bloch, Carlos; Melo, Francislete R; Furtado, José R; Monnerat, Rose G; Grossi-de-Sá, Maria F; Franco, Octávio L

    2005-02-01

    Cotton (Gossypium hirsutum L.) is an important agricultural commodity, which is attacked by several pests such as the cotton boll weevil Anthonomus grandis. Adult A. grandis feed on fruits and leaf petioles, reducing drastically the crop production. The predominance of boll weevil digestive serine proteinases has motivated inhibitor screenings in order to discover new ones with the capability to reduce the digestion process. The present study describes a novel proteinase inhibitor from chickpea seeds (Cicer arietinum L.) and its effects against A. grandis. This inhibitor, named CaTI, was purified by using affinity Red-Sepharose Cl-6B chromatography, followed by reversed-phase HPLC (Vydac C18-TP). SDS-PAGE and MALDI-TOF analyses, showed a unique monomeric protein with a mass of 12,877 Da. Purified CaTI showed significant inhibitory activity against larval cotton boll weevil serine proteinases (78%) and against bovine pancreatic trypsin (73%), when analyzed by fluorimetric assays. Although the molecular mass of CaTI corresponded to alpha-amylase/trypsin bifunctional inhibitors masses, no inhibitory activity against insect and mammalian alpha-amylases was observed. In order to observe CaTI in vivo effects, an inhibitor rich fraction was added to an artificial diet at different concentrations. At 1.5% (w/w), CaTI caused severe development delay, several deformities and a mortality rate of approximately 45%. These results suggested that CaTI could be useful in the production of transgenic cotton plants with enhanced resistance toward cotton boll weevil.

  12. [Current management of toxic megacolon].

    Science.gov (United States)

    Leifeld, L; Kruis, W

    2012-03-01

    Toxic megacolon is a rare and life-threatening complication of severe colitis, defined as a dilatation of the colon > 6 cm in the absence of distal obstruction in combination with signs of systemic toxicity (major criteria: fever, tachycardia, leukocytosis, anaemia). Various triggers are known and the most common causes are underlying ulcerative colitis and Clostridium difficile. Diagnosis can easily be made by clinical examination, routine laboratory parameters and a plain X-ray of the abdomen. Much more difficult is to decide between non-surgical treatment including intensive care treatment or surgery (mostly subtotal colectomy with terminal ileostomy). Non-surgical therapy includes balancing of electrolytes and fluid volumes, broad-spectrum antibiotics including metronidazole, positioning of patients and probably careful intermittent decompression. In case of ulcerative colitis immunosuppression should be started with corticosteroids and potentially with calcineurin inhibitors. In pseudomembranous colitis vancomycin should be given orally and metronidazole should be given intravenously. As far as possible the patient should be treated in a centre with experience in the field.

  13. Screening for angiogenic inhibitors in zebrafish to evaluate a predictive model for developmental vascular toxicity

    Science.gov (United States)

    Chemically-induced vascular toxicity during embryonic development may cause a wide range of adverse effects. To identify putative vascular disrupting chemicals (pVDCs), a predictive signature was constructed from U.S. EPA ToxCast high-throughput screening (HTS) assays that map to...

  14. Cytosolic CARP promotes angiotensin II- or pressure overload-induced cardiomyocyte hypertrophy through calcineurin accumulation.

    Directory of Open Access Journals (Sweden)

    Ci Chen

    Full Text Available The gene ankyrin repeat domain 1 (Ankrd1 is an enigmatic gene and may exert pleiotropic function dependent on its expression level, subcellular localization and even types of pathological stress, but it remains unclear how these factors influence the fate of cardiomyocytes. Here we attempted to investigate the role of CARP on cardiomyocyte hypertrophy. In neonatal rat ventricular cardiomyocytes (NRVCs, angiotensin II (Ang II increased the expression of both calpain 1 and CARP, and also induced cytosolic translocation of CARP, which was abrogated by a calpain inhibitor. In the presence of Ang-II in NRVCs, infection with a recombinant adenovirus containing rat Ankrd1 cDNA (Ad-Ankrd1 enhanced myocyte hypertrophy, the upregulation of atrial natriuretic peptide and β-myosin heavy chain genes and calcineurin proteins as well as nuclear translocation of nuclear factor of activated T cells. Cyclosporin A attenuated Ad-Ankrd1-enhanced cardiomyocyte hypertrophy. Intra-myocardial injection of Ad-Ankrd1 in mice with transverse aortic constriction (TAC markedly increased the cytosolic CARP level, the heart weight/body weight ratio, while short hairpin RNA targeting Ankrd1 inhibited TAC-induced hypertrophy. The expression of calcineurin was also significantly increased in Ad-Ankrd1-infected TAC mice. Olmesartan (an Ang II receptor antagonist prevented the upregulation of CARP in both Ang II-stimulated NRVCs and hearts with pressure overload. These findings indicate that overexpression of Ankrd1 exacerbates pathological cardiac remodeling through the enhancement of cytosolic translocation of CARP and upregulation of calcineurin.

  15. Germline genetic predictors of aromatase inhibitor concentrations, estrogen suppression and drug efficacy and toxicity in breast cancer patients.

    Science.gov (United States)

    Hertz, Daniel L; Henry, N Lynn; Rae, James M

    2017-04-01

    The third-generation aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, are highly effective for the treatment of estrogen receptor-positive breast cancer in postmenopausal women. AIs inhibit the aromatase (CYP19A1)-mediated production of estrogens. Most patients taking AIs achieve undetectable blood estrogen concentrations resulting in drug efficacy with tolerable side effects. However, some patients have suboptimal outcomes, which may be due, in part, to inherited germline genetic variants. This review summarizes published germline genetic associations with AI treatment outcomes including systemic AI concentrations, estrogenic response to AIs, AI treatment efficacy and AI treatment toxicities. Significant associations are highlighted with commentary about prioritization for future validation to identify pharmacogenetic predictors of AI treatment outcomes that can be used to inform personalized treatment decisions in patients with estrogen receptor-positive breast cancer.

  16. Macrophage Wnt-Calcineurin-Flt1 signaling regulates mouse wound angiogenesis and repair.

    Science.gov (United States)

    Stefater, James A; Rao, Sujata; Bezold, Katie; Aplin, Alfred C; Nicosia, Roberto F; Pollard, Jeffrey W; Ferrara, Napoleone; Lang, Richard A

    2013-03-28

    The treatment of festering wounds is one of the most important aspects of medical care. Macrophages are important components of wound repair, both in fending off infection and in coordinating tissue repair. Here we show that macrophages use a Wnt-Calcineurin-Flt1 signaling pathway to suppress wound vasculature and delay repair. Conditional mutants deficient in both Wntless/GPR177, the secretory transporter of Wnt ligands, and CNB1, the essential component of the nuclear factor of activated T cells dephosporylation complex, displayed enhanced angiogenesis and accelerated repair. Furthermore, in myeloid-like cells, we show that noncanonical Wnt activates Flt1, a naturally occurring inhibitor of vascular endothelial growth factor-A-mediated angiogenesis, but only when calcineurin function is intact. Then, as expected, conditional deletion of Flt1 in macrophages resulted in enhanced wound angiogenesis and repair. These results are consistent with the published link between enhanced angiogenesis and enhanced repair, and establish novel therapeutic approaches for treatment of wounds.

  17. Bruton's Tyrosine Kinase Small Molecule Inhibitors Induce a Distinct Pancreatic Toxicity in Rats.

    Science.gov (United States)

    Erickson, Rebecca I; Schutt, Leah K; Tarrant, Jacqueline M; McDowell, Michelle; Liu, Lichuan; Johnson, Adam R; Lewin-Koh, Sock-Cheng; Hedehus, Maj; Ross, Jed; Carano, Richard A D; Staflin, Karin; Zhong, Fiona; Crawford, James J; Zhong, Shelly; Reif, Karin; Katewa, Arna; Wong, Harvey; Young, Wendy B; Dambach, Donna M; Misner, Dinah L

    2017-01-01

    Bruton's tyrosine kinase (BTK) is a member of the Tec family of cytoplasmic tyrosine kinases involved in B-cell and myeloid cell signaling. Small molecule inhibitors of BTK are being investigated for treatment of several hematologic cancers and autoimmune diseases. GDC-0853 ((S)-2-(3'-(hydroxymethyl)-1-methyl-5-((5-(2-methyl-4-(oxetan-3-yl)piperazin-1-yl)pyridin-2-yl)amino)-6-oxo-1,6-dihydro-[3,4'-bipyridin]-2'-yl)-7,7-dimethyl-3,4,7,8-tetrahydro-2H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1(6H)-one) is a selective and reversible oral small-molecule BTK inhibitor in development for the treatment of rheumatoid arthritis and systemic lupus erythematosus. In Sprague-Dawley (SD) rats, administration of GDC-0853 and other structurally diverse BTK inhibitors for 7 days or longer caused pancreatic lesions consisting of multifocal islet-centered hemorrhage, inflammation, fibrosis, and pigment-laden macrophages with adjacent lobular exocrine acinar cell atrophy, degeneration, and inflammation. Similar findings were not observed in mice or dogs at much higher exposures. Hemorrhage in the peri-islet vasculature emerged between four and seven daily doses of GDC-0853 and was histologically similar to spontaneously occurring changes in aging SD rats. This suggests that GDC-0853 could exacerbate a background finding in younger animals. Glucose homeostasis was dysregulated following a glucose challenge; however, this occurred only after 28 days of administration and was not directly associated with onset or severity of pancreatic lesions. There were no changes in other common serum biomarkers assessing endocrine and exocrine pancreatic function. Additionally, these lesions were not readily detectable via Doppler ultrasound, computed tomography, or magnetic resonance imaging. Our results indicate that pancreatic lesions in rats are likely a class effect of BTK inhibitors, which may exacerbate an islet-centered pathology that is unlikely to be relevant to humans. Copyright © 2016 by

  18. Mixture and single-substance toxicity of selective serotonin reuptake inhibitors toward algae and crustaceans

    DEFF Research Database (Denmark)

    Christensen, Anne Munch; Faaborg-Andersen, S.; Ingerslev, Flemming

    2007-01-01

    with an identical mechanism of action in mammals (inhibit reuptake of serotonin), and they have been found in different aqeous as well as biological samples collected in the environment. In the present study, we tested the toxicities of five SSRIs (citalopram, fluoxetine, fluoxamine, paroxetine, and sertraline......) as single substances and of citalopram, fluoxetine. and sertraline in binary mixtures in two standardized bioassays. Test organisms were the freshwater algae Pseudo-kirchneriella subcapitata and the freshwater crustacean Daphnia magna. In algae, test median effect concentrations (EC50s) ranged from 0...

  19. Long term adverse effects related to nucleoside reverse transcriptase inhibitors: clinical impact of mitochondrial toxicity.

    Science.gov (United States)

    Maagaard, Anne; Kvale, Dag

    2009-01-01

    Antiretroviral treatment (ART) has provided excellent clinical efficacy in HIV infection, and individuals treated for HIV might therefore expect normal duration of life. However, this enthusiasm might be moderated by some devastating long-term adverse effects that are frequently observed in HIV-infected individuals, phenomena that may be even more pronounced as the HIV-infected populations become older and therefore perhaps more susceptible to some of these adverse effects. We here review the clinical impact of mitochondrial toxicity giving rise to many of the adverse effects caused by ART.

  20. BCR SIGNALING INHIBITORS: AN OVERVIEW OF TOXICITIES ASSOCIATED WITH IBRUTINIB AND IDELALISIB IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA

    Directory of Open Access Journals (Sweden)

    Lorenzo Falchi

    2016-02-01

    Full Text Available The B-cell receptor signaling inhibitors ibrutinib and idelalisib are revolutionizing the treatment landscape of chronic lymphocytic leukemia (CLL and other B-cell malignancies. These oral agents, both alone and in combination with other drugs, have shown remarkable clinical activity in relapsed or refractory CLL across all risk groups, and have been approved by the Food and Drug Administration for this indication. Preliminary data suggest that an even greater benefit can be expected in treatment-naïve CLL patients. Both ibrutinib and idelalisib are well tolerated by most patients, including older, frailer individuals. Toxicities are usually mild and self-resolving. Clinicians must, however, be aware of a number of peculiar adverse events, the effects of which can be severe enough to limit the clinical use of these agents. In this review, we survey the salient aspects of the pharmacology of these agents, as well as clinical experience regarding their use for the treatment of patients with CLL. Our foci will be both the most common and the most clinically significant toxicities associated with these drugs.

  1. High-efficiency liposomal encapsulation of a tyrosine kinase inhibitor leads to improved in vivo toxicity and tumor response profile

    Directory of Open Access Journals (Sweden)

    Mukthavaram R

    2013-10-01

    Full Text Available Rajesh Mukthavaram,1 Pengfei Jiang,1 Rohit Saklecha,1 Dmitri Simberg,3,4 Ila Sri Bharati,1 Natsuko Nomura,1 Ying Chao,1 Sandra Pastorino,1 Sandeep C Pingle,1 Valentina Fogal,1 Wolf Wrasidlo,1,2 Milan Makale,1,2 Santosh Kesari1,21Translational Neuro-Oncology Laboratories, 2Department of Neurosciences, 3Solid Tumor Therapeutics Program, Moores Cancer Center, UC San Diego, La Jolla, CA, 4Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Denver, CO, USAAbstract: Staurosporine (STS is a potent pan-kinase inhibitor with marked activity against several chemotherapy-resistant tumor types in vitro. The translational progress of this compound has been hindered by poor pharmacokinetics and toxicity. We sought to determine whether liposomal encapsulation of STS would enhance antitumor efficacy and reduce toxicity, thereby supporting the feasibility of further preclinical development. We developed a novel reverse pH gradient liposomal loading method for STS, with an optimal buffer type and drug-to-lipid ratio. Our approach produced 70% loading efficiency with good retention, and we provide, for the first time, an assessment of the in vivo antitumor activity of STS. A low intravenous dose (0.8 mg/kg inhibited U87 tumors in a murine flank model. Biodistribution showed preferential tumor accumulation, and body weight data, a sensitive index of STS toxicity, was unaffected by liposomal STS, but did decline with the free compound. In vitro experiments revealed that liposomal STS blocked Akt phosphorylation, induced poly(ADP-ribose polymerase cleavage, and produced cell death via apoptosis. This study provides a basis to explore further the feasibility of liposomally encapsulated STS, and potentially related compounds for the management of resistant solid tumors.Keywords: liposomes, staurosporine, glioblastoma, biodistribution, efficacy

  2. Expression of a constitutively active calcineurin encoded by an intron-retaining mRNA in follicular keratinocytes.

    Directory of Open Access Journals (Sweden)

    Atsushi Fujimura

    Full Text Available Hair growth is a highly regulated cyclical process. Immunosuppressive immunophilin ligands such as cyclosporin A (CsA and FK506 are known as potent hair growth modulatory agents in rodents and humans that induce active hair growth and inhibit hair follicle regression. The immunosuppressive effectiveness of these drugs has been generally attributed to inhibition of T cell activation through well-characterized pathways. Specifically, CsA and FK506 bind to intracellular proteins, principally cyclophilin A and FKBP12, respectively, and thereby inhibit the phosphatase calcineurin (Cn. The calcineurin (Cn/NFAT pathway has an important, but poorly understood, role in the regulation of hair follicle development. Here we show that a novel-splicing variant of calcineurin Aß CnAß-FK, which is encoded by an intron-retaining mRNA and is deficient in the autoinhibitory domain, is predominantly expressed in mature follicular keratinocytes but not in the proliferating keratinocytes of rodents. CnAß-FK was weakly sensitive to Ca(2+ and dephosphorylated NFATc2 under low Ca(2+ levels in keratinocytes. Inhibition of Cn/NFAT induced hair growth in nude mice. Cyclin G2 was identified as a novel target of the Cn/NFATc2 pathway and its expression in follicular keratinocytes was reduced by inhibition of Cn/NFAT. Overexpression of cyclin G2 arrested the cell cycle in follicular keratinocytes in vitro and the Cn inhibitor, cyclosporin A, inhibited nuclear localization of NFATc2, resulting in decreased cyclin G2 expression in follicular keratinocytes of rats in vivo. We therefore suggest that the calcineurin/NFAT pathway has a unique regulatory role in hair follicle development.

  3. 肝移植术后钙调磷酸酶抑制剂相关性肾损伤所致高钾血症的诊断与治疗%The diagnosis and treatment of hy perk alemia caused by calcineurin inhibitor associated nephrotoxicity after liver transplantation

    Institute of Scientific and Technical Information of China (English)

    田敏; 刘学民; 刘鹏; 吕毅; 王博; 于良; 刘昌; 张晓刚

    2016-01-01

    目的研究肝移植受者术后高钾血症的发生情况,探讨钙调磷酸酶抑制剂( CNI)与高钾血症的关系及其诊治方案。方法回顾性分析西安交通大学第一附属医院肝胆外科2010年1月至2015年12月行肝移植术后发生高血钾症的6例患者资料,了解患者性别、年龄、术前诊断等一般情况和首次发生高血钾症时血钾浓度、血钠浓度、肾功能、血气分析、CNI血药浓度等相关情况。结果本中心肝移植受者术后高钾血症的发生率为2.4%(6/254)。6例患者中男性5例,女性1例,年龄45~64岁,供肝均来源于公民逝世后器官捐献;肝移植术后均采用CNI+吗替麦考酚酯+泼尼松三联免疫抑制方案,其中4例采用他克莫司,2例采用环孢素。6例患者肝移植术后首次发生高血钾症的时间为术后70~729 d,血钾浓度为5.72~6.70 mmol/L。血清尿素氮、血清肌酐均升高,5例血气分析提示代谢性酸中毒, CNI血药浓度和血钠浓度在正常范围。治疗给予静脉滴注碳酸氢钠、葡萄糖加胰岛素(按4∶1比例)及口服呋塞米、聚苯乙烯磺酸钙,同时尽量减少CNI剂量。其中2例患者将环孢素转换为他克莫司,并增加吗替麦考酚酯剂量。6例患者均长期规律随访,其中1例因多器官功能衰竭死亡,其余5例截至2015年12月仍存活;有2例患者仍反复发作高钾血症,住院次数>3次。结论肝移植术后采用CNI为基础的免疫抑制方案,需要关注CNI 相关性肾小管损伤导致的高钾血症,建议减少CNI剂量或将其更换为西罗莫司。%Objective To study the incidence of hyperkalemia in the postoperative liver transplantation patients and explore the relationship between calcineurin inhibitor ( CNI ) immunosuppressant and hyperkalemia as well as its treatment .Methods A retrospective study was performed on 6 patients with hyperkalemia after liver

  4. A single-center retrospective study on calcineurin inhibitors withdraw and conversion to sirolimus for drug adverse reactions%肝移植后因药物不良反应暂停及转换钙调磷酸酶抑制剂的单中心经验

    Institute of Scientific and Technical Information of China (English)

    滕飞; 王桂华; 张晓君; 郭闻渊; 李瑞东; 傅志仁

    2011-01-01

    Objective To report the results of a single-center, retrospective study on the effect of calcineurin inhibitors (CNI) withdraw for controlling infections and conversion to sirolimus (SRL)for ameliorating renal dysfunction. Methods A total of 947 liver transplant cases from 2002 to 2010were divided into two eras (Jan. 2002 to Dec. 2007 and Jan. 2008 to Dec. 2010). There were 234cases of infections after liver transplantation (LT) in the first era and 101 cases in the second era. And of 329 cases of CNI-related renal dysfunction after LT in two eras, 40 cases (converting group) had converted CNI to SRL, while 289 cases (reducing group) adopted protocol of CNI reducing and mycophenolate mofetil (MMF) raising. Results CNI-based IS took up 95.8 %, 95. 3 %, 97. 5 % of the IS protocols with recipient survival time longer than 1, 3, and 5 years. The primary cause for CNI withdraw was infection (88. 2 %, 15/17) in the second era, and renal dysfunction for conversion to SRL in the two eras (83. 3 %, 40/48). In the second era, 14. 9% (15/101) of the cases of infections after LT experienced CNI withdraw. Of the 15 patients, 11 had effectively controlled the infection (77. 3 %) while rejection rate was 6. 7 % (1/15). The cumulative survival rate of the second era was significantly higher than the first era (P<0. 05). The glomerular filtration rate (GFR) of converting group at 6th week and 6th month was statistically elevated as compared with that before conversion,respectively (1.28 ± 0. 31, 1.36 ± 0. 32 mL/s vs. 0. 82 ± 0. 24 mL/s, P<0. 05). Six months after CNI adjustments, survival rate of converting group and reducing group was 85. 0% and 83. 7 %,respectively (P>0. 05). Conclusion Reducing or even short-term withdraw of CNI may allow the better control of infections after LT, and the conversion from CNI to SRL can ameliorate the CNIrelated nephrotoxicity. These individually tailored IS protocols will benefit the long term survival for LT.%目的 研究肝移植术

  5. Calcineurin signaling in the heart: The importance of time and place.

    Science.gov (United States)

    Parra, Valentina; Rothermel, Beverly A

    2017-02-01

    The calcium-activated protein phosphatase, calcineurin, lies at the intersection of protein phosphorylation and calcium signaling cascades, where it provides an essential nodal point for coordination between these two fundamental modes of intracellular communication. In excitatory cells, such as neurons and cardiomyocytes, that experience rapid and frequent changes in cytoplasmic calcium, calcineurin protein levels are exceptionally high, suggesting that these cells require high levels of calcineurin activity. Yet, it is widely recognized that excessive activation of calcineurin in the heart contributes to pathological hypertrophic remodeling and the progression to failure. How does a calcium activated enzyme function in the calcium-rich environment of the continuously contracting heart without pathological consequences? This review will discuss the wide range of calcineurin substrates relevant to cardiovascular health and the mechanisms calcineurin uses to find and act on appropriate substrates in the appropriate location while potentially avoiding others. Fundamental differences in calcineurin signaling in neonatal verses adult cardiomyocytes will be addressed as well as the importance of maintaining heterogeneity in calcineurin activity across the myocardium. Finally, we will discuss how circadian oscillations in calcineurin activity may facilitate integration with other essential but conflicting processes, allowing a healthy heart to reap the benefits of calcineurin signaling while avoiding the detrimental consequences of sustained calcineurin activity that can culminate in heart failure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Calcineurin-dependent galactomannan release in Aspergillus fumigatus

    NARCIS (Netherlands)

    Mennink-Kersten, M.A.S.H.; Ruegebrink, D.; Verweij, P.E.; Steinbach, W.J.

    2011-01-01

    The galactomannan assay to diagnose invasive aspergillosis is recommended and clinically utilized, yet the mechanism of galactomannan release from Aspergillus fumigatus is unknown. We used an A. fumigatus strain lacking calcineurin A (cnaA), already shown to be critically important for pathogenicity

  7. Discovery of Potential, Non-Toxic Influenza Virus Inhibitor by Computational Techniques.

    Science.gov (United States)

    Karthick, V; Toropova, Alla P; Toropov, Andrey A; Ramanathan, K

    2014-08-01

    Influenza infection continues to be a major problem in many parts of the world. Rimantadine is a first-line drug used to treat the influenza infection by targeting M2 proton channel. However, S31N mutation in M2 proton channel diminishes the efficiency of rimantadine and creates resistance. To address this issue, the present study was aimed to screen the effective lead candidate against drug resistance strain of influenza from DrugBank database. Initially, the lead molecules were filtered using Lipinski rule of five and the drug likeliness property. Subsequently, the data reduction was carried out by employing molecular docking study. Finally, molecular dynamics simulations techniques were performed to validate the lead compound. Most importantly, the -p LD50 of the screened lead molecule was calculated using CORAL software to estimate the Rat oral toxicity. Accordingly, memantine may possibly become a promising lead compound of rimantadine-resistant influenza virus strain. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Azanitrile Cathepsin K Inhibitors: Effects on Cell Toxicity, Osteoblast-Induced Mineralization and Osteoclast-Mediated Bone Resorption.

    Directory of Open Access Journals (Sweden)

    Zhong-Yuan Ren

    Full Text Available The cysteine protease cathepsin K (CatK, abundantly expressed in osteoclasts, is responsible for the degradation of bone matrix proteins, including collagen type 1. Thus, CatK is an attractive target for new anti-resorptive osteoporosis therapies, but the wider effects of CatK inhibitors on bone cells also need to be evaluated to assess their effects on bone. Therefore, we selected, among a series of synthetized isothiosemicarbazides, two molecules which are highly selective CatK inhibitors (CKIs to test their effects on osteoblasts and osteoclasts.Cell viability upon treatment of CKIs were was assayed on human osteoblast-like Saos-2, mouse monocyte cell line RAW 264.7 and mature mouse osteoclasts differentiated from bone marrow. Osteoblast-induced mineralization in Saos-2 cells and in mouse primary osteoblasts from calvaria, with or without CKIs,; were was monitored by Alizarin Red staining and alkaline phosphatase activity, while osteoclast-induced bone resorption was performed on bovine slices.Treatments with two CKIs, CKI-8 and CKI-13 in human osteoblast-like Saos-2, murine RAW 264.7 macrophages stimulated with RANKL and mouse osteoclasts differentiated from bone marrow stimulated with RANKL and MCSF were found not to be toxic at doses of up to 100 nM. As probed by Alizarin Red staining, CKI-8 did not inhibit osteoblast-induced mineralization in mouse primary osteoblasts as well as in osteoblast-like Saos-2 cells. However, CKI-13 led to a reduction in mineralization of around 40% at 10-100 nM concentrations in osteoblast-like Saos-2 cells while it did not in primary cells. After a 48-hour incubation, both CKI-8 and CKI-13 decreased bone resorption on bovine bone slices. CKI-13 was more efficient than the commercial inhibitor E-64 in inhibiting bone resorption induced by osteoclasts on bovine bone slices. Both CKI-8 and CKI-13 created smaller bone resorption pits on bovine bone slices, suggesting that the mobility of osteoclasts was slowed

  9. Expression of serine/threonine protein-kinases and related factors in normal monkey and human retinas: the mechanistic understanding of a CDK2 inhibitor induced retinal toxicity.

    Science.gov (United States)

    Saturno, Grazia; Pesenti, Manuela; Cavazzoli, Cristiano; Rossi, Anna; Giusti, Anna M; Gierke, Berthold; Pawlak, Michael; Venturi, Miro

    2007-12-01

    Protein-kinase inhibitors are among the most advanced compounds in development using the new drug discovery paradigm of developing small-molecule drugs against specific molecular targets in cancer. After treatment with a cyclin dependent kinase CDK2 inhibitor in monkey, histopathological analysis of the eye showed specific cellular damage in the photoreceptor layer. Since this CDK2 inhibitor showed activity also on other CDKs, in order to investigate the mechanism of toxicity of this compound, we isolated cones and rods from the retina of normal monkey and humans by Laser Capture Microdissection. Using Real-Time PCR we first measured the expression of cyclin dependent protein-kinases (CDK)1, 2, 4, 5, Glycogen synthase kinase 3beta (GSK3beta) and microtubule associated protein TAU. We additionally verified the presence of these proteins in monkey eye sections by immuno-histochemistry and immunofluorescence analysis and afterwards quantified GSK3beta, phospho-GSK3beta and TAU by Reverse Phase Protein Microarrays. With this work we demonstrate how complementary gene expression and protein-based technologies constitute a powerful tool for the understanding of the molecular mechanism of a CDK2 inhibitor induced toxicity. Moreover, this investigative approach is helpful to better understand and characterize the mechanism of species-specific toxicities and further support a rational, molecular mechanism-based safety assessment in humans.

  10. 西罗莫司在肾移植术后早期计划性切换的前瞻性对照研究%Early conversion from calcineurin inhibitor to sirolimusto after renal transplantation:a prospective,open-label and non-randomized control study

    Institute of Scientific and Technical Information of China (English)

    黄洪锋; 谢文卿; 吴建永; 徐莹; 余献平; 任萍萍; 陈江华

    2014-01-01

    Objective To explore the efficacy and safety of designed early conversion from calcineurin inhibitor (CNI) to sirolimus (SRL) as major immunosuppressive therapy in renal transplant recipients with stable renal function.Methods A prospective,open-label and non-randomized control study was performed for 112 renal transplant recipients (3-6 months post-operation) with stable renal function between June 2008 and June 2011.The patients in SRL group (n =57) switched to sirolimus while those in CNI group (n =55) continued CNI.The dosing of mycophenolate mofetil and steroids had no change.They were followed up for at least 24 months to evaluate the acute rejection,patient and graft survival,renal function,estimated glomerular filtration rate (eGFR),blood lipids,blood glucose,liver function and urinary protein at 1,6,12 and 24 months after inclusion.Adverse events were also recorded.Results The serum creatinine of SRL group decreased significantly after conversion ((89.2 ± 24.7),(87.6 ± 23.8),(86.1 ±20.4),(86.7 ± 19.7) vs(117.0 ± 16.3) μ.mol/L,all P < 0.05).CNI group showed no improvement of renal function.SRL group had a significantly higher eGFR than CNI group (P < 0.05).Among 3 cases of acute rejection,there were 2 in SRL group and 1 in CNI group (P > 0.05).Blood lipids in SRL group increased significantly at 1 month after conversion (P < 0.05) and reverted back to average level after intervention (P > 0.05).SRL group had a drop of hemoglobin level within the normal range.Two patients in SRL group developed hypokalemia and another 2 patients had oral ulcer.They all improved after treatment.During follow-ups,1 case of mild proteinuria was found in SIR group.Three patients were diagnosed with diabetes (1 in SRL group vs 2 in CNI group).Conclusions Early conversion from CNI to SRL as major immunosuppressive therapy in renal transplant recipients with stable renal function further improves renal function.There is no higher rate of acute rejection during

  11. Bosutinib safety and management of toxicity in leukemia patients with resistance or intolerance to imatinib and other tyrosine kinase inhibitors

    Science.gov (United States)

    Cortes, Jorge E.; Kim, Dong-Wook; Khoury, H. Jean; Brümmendorf, Tim H.; Porkka, Kimmo; Martinelli, Giovanni; Durrant, Simon; Leip, Eric; Kelly, Virginia; Turnbull, Kathleen; Besson, Nadine; Gambacorti-Passerini, Carlo

    2014-01-01

    Bosutinib is an oral, dual SRC/ABL tyrosine kinase inhibitor (TKI) with clinical activity in Philadelphia chromosome–positive (Ph+) leukemia. We assessed the safety and tolerability of bosutinib 500 mg per day in a phase 1/2 study in chronic-phase (CP) chronic myeloid leukemia (CML) or advanced Ph+ leukemia following resistance/intolerance to imatinib and possibly other TKIs. Patient cohorts included second-line CP CML (n = 286), third-/fourth-line CP CML (n = 118), and advanced leukemia (n = 166). Median bosutinib duration was 11.1 (range, 0.03-83.4) months. Treatment-emergent adverse events (TEAEs) in each cohort were primarily gastrointestinal (diarrhea [86%/83%/74%], nausea [46%/48%/48%], and vomiting [37%/38%/43%]). Diarrhea presented early, with few (8%) patients experiencing grade 3/4 events; dose reduction due to diarrhea occurred in 6% of affected patients. Grade 3/4 myelosuppression TEAEs were reported in 41% of patients; among affected patients, 46% were managed with bosutinib interruption and 32% with dose reduction. Alanine aminotransferase elevation TEAEs occurred in 17% of patients (grade 3/4, 7%); among patients managed with dose interruption, bosutinib rechallenge was successful in 74%. Bosutinib demonstrated acceptable safety with manageable toxicities in Ph+ leukemia. This trial (NCT00261846) was registered at www.ClinicalTrials.gov (this manuscript is based on a different data snapshot from that in ClinicalTrials.gov). PMID:24345751

  12. A conserved docking surface on calcineurin mediates interaction with substrates and immunosuppressants

    Science.gov (United States)

    Rodríguez, Antonio; Roy, Jagoree; Martínez-Martínez, Sara; López-Maderuelo, Ma Dolores; Niño-Moreno, Perla; Ortí, Leticia; Pantoja, David; Pineda-Lucena, Antonio; Cyert, Martha S.; Redondo, Juan Miguel

    2009-01-01

    SUMMARY The phosphatase calcineurin, target of the immunosuppressants cyclosporin A and FK506, dephosphorylates NFAT transcription factors to promote immune activation and development of the vascular and nervous systems. NFAT interacts with calcineurin through distinct binding motifs: the PxIXIT and LxVP sites. While many calcineurin substrates contain PxIxIT motifs, the generality of LxVP-mediated interactions is unclear. We define critical residues in the LxVP motif, and demonstrate its binding to a hydrophobic pocket at the interface of the two calcineurin subunits. Mutations in this region disrupt binding of mammalian calcineurin to NFATc1, and interaction of yeast calcineurin with substrates including Rcn1, which contains an LxVP motif. These mutations also interfere with calcineurin-immunosuppressant binding, and an LxVP-based peptide competes with immunosuppressant-immunophilin complexes for binding to calcineurin. These studies suggest that LxVP-type sites are a common feature of calcineurin substrates and that immunosuppressant-immunophilin complexes inhibit calcineurin by interfering with this mode of substrate recognition. PMID:19285944

  13. The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukaemia cells.

    Science.gov (United States)

    Cellai, C; Balliu, M; Laurenzana, A; Guandalini, L; Matucci, R; Miniati, D; Torre, E; Nebbioso, A; Carafa, V; Altucci, L; Romanelli, M N; Paoletti, F

    2012-08-01

    Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn(++)--chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, which were first comparatively tested in promyelocytic NB4 cells. (S)-2 and partially 4--but not (R)-2--caused G0/G1 cell-cycle arrest by up-regulating cyclin G2 and p21 expression and down-regulating cyclin D2 expression, and also apoptosis as assessed by cell morphology and cytofluorimetric assay, histone H2AX phosphorylation and PARP cleavage. Notably, these events were partly prevented by an anti-oxidant. Moreover, novel HDACi prompted p53 and α-tubulin acetylation and, consistently, inhibited HDAC1 and 6 activity. The rank order of potency was (S)-2 > 4 > (R)-2, reflecting that of other biological assays and addressing (S)-2 as the most effective compound capable of triggering apoptosis in various acute myeloid leukaemia (AML) cell lines and blasts from patients with different AML subtypes. Importantly, (S)-2 was safe in mice (up to 150 mg/kg/week) as determined by liver, spleen, kidney and bone marrow histopathology; and displayed negligible affinity for peripheral/central BDZ-receptors. Overall, the BDZ-hydroxamate (S)-2 showed to be a low-toxic HDACi with powerful anti-proliferative and pro-apototic activities towards different cultured and primary AML cells, and therefore of clinical interest to support conventional anti-leukaemic therapy.

  14. Toxic effects of nucleoside reverse transcriptase inhibitors on the liver. Value of electron microscopy analysis for the diagnosis of mitochondrial cytopathy.

    Science.gov (United States)

    Duong Van Huyen, Jean-Paul; Landau, Alain; Piketty, Christophe; Bélair, Marie-France; Batisse, Dominique; Gonzalez-Canali, Gustavo; Weiss, Laurence; Jian, Raymond; Kazatchkine, Michel D; Bruneval, Patrick

    2003-04-01

    Nucleoside reverse transcriptase inhibitors (NRTIs) induce mitochondrial toxic effects resulting in multiple organ disorders. Liver involvement has been associated mainly with severe lactic acidosis and massive steatosis. However, patients with HIV infection who are receiving antiretroviral treatment frequently have mildly abnormal liver test results that, to date, have not been linked unambiguously to the toxic effects of NRTIs. Thirteen patients with HIV infection treated with NRTI-based regimens had low-grade abnormal liver test results associated with digestive and nonspecific general symptoms. Histologic examination of liver samples showed diffuse steatosis in only 6 cases and mild steatosis in the remaining cases, associated with megamitochondria, mild lobular inflammation and necrosis, Mallory bodies, and perisinusoidal fibrosis. In all cases, ultrastructural study disclosed mitochondrial abnormalities. Our work demonstrates that NRTI-induced toxic effects in the liver may occur as indolent nonspecific disease with variable histologic features and emphasizes the diagnostic value of electron microscopy, particularly when diffuse steatosis is absent.

  15. PKC signaling regulates drug resistance of the fungal pathogen Candida albicans via circuitry comprised of Mkc1, calcineurin, and Hsp90.

    Directory of Open Access Journals (Sweden)

    Shantelle L LaFayette

    Full Text Available Fungal pathogens exploit diverse mechanisms to survive exposure to antifungal drugs. This poses concern given the limited number of clinically useful antifungals and the growing population of immunocompromised individuals vulnerable to life-threatening fungal infection. To identify molecules that abrogate resistance to the most widely deployed class of antifungals, the azoles, we conducted a screen of 1,280 pharmacologically active compounds. Three out of seven hits that abolished azole resistance of a resistant mutant of the model yeast Saccharomyces cerevisiae and a clinical isolate of the leading human fungal pathogen Candida albicans were inhibitors of protein kinase C (PKC, which regulates cell wall integrity during growth, morphogenesis, and response to cell wall stress. Pharmacological or genetic impairment of Pkc1 conferred hypersensitivity to multiple drugs that target synthesis of the key cell membrane sterol ergosterol, including azoles, allylamines, and morpholines. Pkc1 enabled survival of cell membrane stress at least in part via the mitogen activated protein kinase (MAPK cascade in both species, though through distinct downstream effectors. Strikingly, inhibition of Pkc1 phenocopied inhibition of the molecular chaperone Hsp90 or its client protein calcineurin. PKC signaling was required for calcineurin activation in response to drug exposure in S. cerevisiae. In contrast, Pkc1 and calcineurin independently regulate drug resistance via a common target in C. albicans. We identified an additional level of regulatory control in the C. albicans circuitry linking PKC signaling, Hsp90, and calcineurin as genetic reduction of Hsp90 led to depletion of the terminal MAPK, Mkc1. Deletion of C. albicans PKC1 rendered fungistatic ergosterol biosynthesis inhibitors fungicidal and attenuated virulence in a murine model of systemic candidiasis. This work establishes a new role for PKC signaling in drug resistance, novel circuitry through which

  16. A comparison of potency differences among thyroid peroxidase (TPO) inhibitors to induce developmental toxicity and other thyroid gland-linked toxicities in humans and rats.

    Science.gov (United States)

    Motonaga, Kozo; Ota, Mika; Odawara, Kyoko; Saito, Shoji; Welsch, Frank

    2016-10-01

    The potencies of resorcinol, 6-propylthiouracil (PTU) and methimazole (MMI) for inducing developmental toxicity and neurotoxicity were compared in pregnant rats, regarded as valid model for human thyroid toxicity. Profound differences on maternal thyroid hormone levels (THs), maternal toxicity as well as developmental and neurotoxicity sequelae occurred. Resorcinol affected none of those end points. PTU and MMI caused significant effects. Therapy with either PTU or MMI during the first trimester of human pregnancy can cause reductions of maternal THs, accompanied by disruptions of prenatal development. Clinical MMI studies show sporadic evidence of teratogenic effects, with equivocal relation to thyroid peroxidase (TPO) inhibition. In recent decades no MMI associated prenatal toxicity has been reported, an outcome possibly related to carefully managed therapy. Orally administered resorcinol was rapidly absorbed, metabolized and excreted and was undetectable in the thyroid. In contrast, PTU or MMI accumulated. Resorcinol's potency to inhibit TPO was profoundly lower than that of PTU or MMI. Quantum chemical calculations may explain low resorcinol reactivity with TPO. Thus, distinctions in the target organ and the TPO inhibitory potency between these chemicals are likely contributing to different reductions of maternal THs levels and affecting the potency to cause developmental toxicity and neurotoxicity. Copyright © 2016. Published by Elsevier Inc.

  17. Efficacy and Toxicity of Mammalian Target Rapamycin Inhibitors in Patients with Metastatic Renal Cell Carcinoma with Renal Insufficiency: The Korean Cancer Study Group GU 14-08

    Science.gov (United States)

    Kim, Ki Hyang; Kim, Joo Hoon; Lee, Ji Young; Kim, Hyo Song; Heo, Su Jin; Kim, Ji Hyung; Kim, Ho Young; Rha, Sun Young

    2016-01-01

    Purpose We evaluated the efficacy and toxicity of mammalian target rapamycin inhibitors in Korean patients with metastatic renal cell carcinoma (mRCC) with chronic renal insufficiency not requiring dialysis. Materials and Methods Korean patients with mRCC and chronic renal insufficiency not requiring dialysis treated with everolimus or temsirolimus between January 2008 and December 2014 were included. Patient characteristics, clinical outcomes, and toxicities were evaluated. Overall survival (OS) and progression-free survival (PFS) durations were evaluated according to the degree of renal impairment. Results Eighteen patients were considered eligible for the study (median age, 59 years). The median glomerular filtration rate was 51.5 mL/min/1.73 m2. The best response was partial response in six patients and stable disease in 11 patients. The median PFS and OS durations were 8 months (95% confidence interval [CI], 0 to 20.4) and 32 months (95% CI, 27.5 to 36.5), respectively. The most common non-hematologic and grade 3/4 adverse events included stomatitis, fatigue, flu-like symptoms, and anorexia as well as elevated creatinine level. Conclusion Mammalian target rapamycin inhibitors were efficacious and did not increase toxicity in Korean patients with mRCC and chronic renal insufficiency not requiring dialysis. PMID:26875195

  18. Promising Diabetes Therapy Based on the Molecular Mechanism for Glucose Toxicity: Usefulness of SGLT2 Inhibitors as well as Incretin-Related Drugs.

    Science.gov (United States)

    Kaneto, Hideaki; Obata, Atsushi; Shimoda, Masashi; Kimura, Tomohiko; Hirukawa, Hidenori; Okauchi, Seizo; Matsuoka, Taka-Aki; Kaku, Kohei

    2016-01-01

    Pancreatic β-cell dysfunction and insulin resistance are the main characteristics of type 2 diabetes. Chronic exposure of β-cells to hyperglycemia leads to the deterioration of β-cell function. Such phenomena are well known as pancreatic β-cell glucose toxicity. MafA, a strong transactivator of insulin gene, is particularly important for the maintenance of mature β-cell function, but its expression level is significantly reduced under diabetic conditions which is likely associated with β-cell failure. Reduction of incretin receptor expression level in β-cells in diabetes is also likely associated with β-cell failure. On the other hand, incretin-related drugs and sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising diabetes therapy based on the mechanism for pancreatic β-cell glucose toxicity. Indeed, it was shown that incretin-related drugs exerted protective effects on β-cells through the augmentation of IRS-2 expression especially in the presence of pioglitazone. It was also shown that incretin-related drug and/or pioglitazone exerted more protective effects on β-cells at the early stage of diabetes compared to the advanced stage. SGLT2 inhibitors, new hypoglycemic agents, also exert beneficial effects for the protection of pancreatic β-cells as well as for the reduction of insulin resistance in various insulin target tissues. Taken together, it is important to select appropriate therapy based on the molecular mechanism for glucose toxicity.

  19. The multiple faces of calcineurin signaling in Caenorhabditis elegans: Development, behaviour and aging

    Indian Academy of Sciences (India)

    Jin Il Lee; Sutapa Mukherjee; Kyoung–Hye Yoon; Meenakshi Dwivedi; Jaya Bandyopadhyay

    2013-06-01

    Calcineurin, a well-conserved protein phosphatase 2B (PP2B), is a Ca2+-calmodulin–dependent serine/threonine protein phosphatase that is known to be involved in a myriad of cellular processes and signal transduction pathways. The biological role of calcineurin has been extensively studied in diverse groups of organisms. Homologues of mammalian and Drosophila calcineurin subunits exist in the nematode, Caenorhabditis elegans. The C. elegans counterpart of the catalytic subunit, calcineurin A, cna-1/tax-6, and the regulatory subunit, calcineurin B, cnb-1, are known to express ubiquitously in multiple tissues including neurons. The characterization of C. elegans calcineurin mutants facilitates identification of its physiological functions and signaling pathways. Genetic interactions between cna-1/tax-6 and cnb-1 mutants with a number of mutants involved in several signaling pathways have exemplified the pivotal role of calcineurin in regulating nematode development, behaviour and lifespan (aging). The present review has been aimed to provide a succinct summary of the multiple functions of calcineurin in C. elegans relating to its development, fertility, proliferation, behaviour and lifespan. Analyses of cna-1/tax-6 and cnb-1 interacting proteins and regulators of the phosphatase in this fascinating worm model have an immense scope to identify potential drug targets in various parasitic nematodes, which cause many diseases inflicting huge economic loss; and also for many human diseases, particularly neurodegenerative and myocardial diseases.

  20. Arctigenin inhibits osteoclast differentiation and function by suppressing both calcineurin-dependent and osteoblastic cell-dependent NFATc1 pathways.

    Science.gov (United States)

    Yamashita, Teruhito; Uehara, Shunsuke; Udagawa, Nobuyuki; Li, Feng; Kadota, Shigetoshi; Esumi, Hiroyasu; Kobayashi, Yasuhiro; Takahashi, Naoyuki

    2014-01-01

    Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM) cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA), a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the pit

  1. Arctigenin Inhibits Osteoclast Differentiation and Function by Suppressing Both Calcineurin-Dependent and Osteoblastic Cell-Dependent NFATc1 Pathways

    Science.gov (United States)

    Yamashita, Teruhito; Uehara, Shunsuke; Udagawa, Nobuyuki; Li, Feng; Kadota, Shigetoshi; Esumi, Hiroyasu; Kobayashi, Yasuhiro; Takahashi, Naoyuki

    2014-01-01

    Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM) cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA), a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the pit

  2. Arctigenin inhibits osteoclast differentiation and function by suppressing both calcineurin-dependent and osteoblastic cell-dependent NFATc1 pathways.

    Directory of Open Access Journals (Sweden)

    Teruhito Yamashita

    Full Text Available Arctigenin, a lignan-derived compound, is a constituent of the seeds of Arctium lappa. Arctigenin was previously shown to inhibit osteoclastogenesis; however, this inhibitory mechanism has yet to be elucidated. Here, we showed that arctigenin inhibited the action of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1, a key transcription factor for osteoclastogenesis. NFATc1 in osteoclast precursors was activated through two distinct pathways: the calcineurin-dependent and osteoblastic cell-dependent pathways. Among the several lignan-derived compounds examined, arctigenin most strongly inhibited receptor activator of nuclear factor κB ligand (RANKL-induced osteoclast-like cell formation in mouse bone marrow macrophage (BMM cultures, in which the calcineurin-dependent NFATc1 pathway was activated. Arctigenin suppressed neither the activation of nuclear factor κB and mitogen-activated protein kinases nor the up-regulation of c-Fos expression in BMMs treated with RANKL. However, arctigenin suppressed RANKL-induced NFATc1 expression. Interestingly, the treatment of osteoclast-like cells with arctigenin converted NFATc1 into a lower molecular weight species, which was translocated into the nucleus even in the absence of RANKL. Nevertheless, arctigenin as well as cyclosporin A (CsA, a calcineurin inhibitor, suppressed the NFAT-luciferase reporter activity induced by ionomycin and phorbol 12-myristate 13-acetate in BMMs. Chromatin immunoprecipitation analysis confirmed that arctigenin inhibited the recruitment of NFATc1 to the promoter region of the NFATc1 target gene. Arctigenin, but not CsA suppressed osteoclast-like cell formation in co-cultures of osteoblastic cells and bone marrow cells, in which the osteoblastic cell-dependent NFATc1 pathway was activated. The forced expression of constitutively active NFATc1 rescued osteoclastogenesis in BMM cultures treated with CsA, but not that treated with arctigenin. Arctigenin also suppressed the

  3. Calcineurin is universally involved in vesicle endocytosis at neuronal and nonneuronal secretory cells.

    Science.gov (United States)

    Wu, Xin-Sheng; Zhang, Zhen; Zhao, Wei-Dong; Wang, Dongsheng; Luo, Fujun; Wu, Ling-Gang

    2014-05-22

    Calcium influx triggers and accelerates endocytosis in nerve terminals and nonneuronal secretory cells. Whether calcium/calmodulin-activated calcineurin, which dephosphorylates endocytic proteins, mediates this process is highly controversial for different cell types, developmental stages, and endocytic forms. Using three preparations that previously produced discrepant results (i.e., large calyx-type synapses, conventional cerebellar synapses, and neuroendocrine chromaffin cells containing large dense-core vesicles), we found that calcineurin gene knockout consistently slowed down endocytosis, regardless of cell type, developmental stage, or endocytic form (rapid or slow). In contrast, calcineurin and calmodulin blockers slowed down endocytosis at a relatively small calcium influx, but did not inhibit endocytosis at a large calcium influx, resulting in false-negative results. These results suggest that calcineurin is universally involved in endocytosis. They may also help explain the discrepancies among previous pharmacological studies. We therefore suggest that calcineurin should be included as a key player in mediating calcium-triggered and -accelerated vesicle endocytosis.

  4. Synthesis of benzofuran derivatives as selective inhibitors of tissue-nonspecific alkaline phosphatase: effects on cell toxicity and osteoblast-induced mineralization.

    Science.gov (United States)

    Marquès, Stéphanie; Buchet, René; Popowycz, Florence; Lemaire, Marc; Mebarek, Saïda

    2016-03-01

    Tissue-nonspecific alkaline phosphatase (TNAP) by hydrolyzing pyrophosphate, an inhibitor of apatite formation, promotes extracellular matrix calcification during bone formation and growth, as well as during ectopic calcification under pathological conditions. TNAP is a target for the treatment of soft tissue pathological ossification. We synthesized a series of benzofuran derivatives. Among these, SMA14, displayed TNAP activity better than levamisole. SMA14 was found to be not toxic at doses of up to 40μM in osteoblast-like Saos-2 cells and primary osteoblasts. As probed by Alizarin Red staining, this compound inhibited mineral formation in murine primary osteoblast and in osteoblast-like Saos-2 cells.

  5. Crystals of phospholipase A2 inhibitor. The non-toxic component of vipoxin from the venom of Bulgarian viper (Vipera ammodytes).

    Science.gov (United States)

    Devedjiev, Y; Atanasov, B; Mancheva, I; Aleksiev, B

    1993-02-20

    Phospholipase A2 inhibitor, the non-toxic, acidic component of vipoxin from the venom of Bulgarian viper (Vipera ammodytes), has been crystallized. The tetragonal crystals obtained, exhibit the symmetry of space group P4(1)22 (or 4(3)22) with unit cell dimensions a = b = 59.9 A; c = 141.1 A; alpha = beta = gamma = 90 degrees. For two molecules per asymmetric unit, this would give Vm = 2.3 A3/Da, indicating normal packing. The crystals diffract to 2.5 A and a native data set to 3.2 A resolution has been collected.

  6. Crystallization and preliminary X-ray diffraction studies of a toxic phospholipase A2 from the venom of Vipera ammodytes meridionalis complexed to a synthetic inhibitor.

    Science.gov (United States)

    Georgieva, Dessislava Nikolova; Rypniewski, Wojciech; Perbandt, Markus; Jain, Mahendra; Genov, Nicolay; Betzel, Christian

    2003-08-21

    A toxic phospholipase A(2) (PLA(2)) is isolated from the neurotoxic complex Vipoxin, the major lethal component of the venom of Vipera ammodytes meridionalis. The enzyme is complexed to the synthetic inhibitor elaidoylamide and crystallized. The crystals belong to the space group P2(1)2(1)2(1), with unit cell dimensions a=46.57 A, b=82.68 A, c=119.47 A and beta=90 degrees. Initial diffraction data to 3.3 A resolution are collected.

  7. Prediction of mixture toxicity from the hormesis of a single chemical: A case study of combinations of antibiotics and quorum-sensing inhibitors with gram-negative bacteria.

    Science.gov (United States)

    Wang, Ting; Wang, Dali; Lin, Zhifen; An, Qingqing; Yin, Chunsheng; Huang, Qinghui

    2016-05-01

    The 50% effect level of a single chemical in the real environment is almost impossible to determine at the low exposure concentration, and the prediction of the concentration of a mixture at the 50% effect level from the concentration of a single chemical at the low effect level is even more difficult. The current literature does not address this problem. Thus, to determine solutions for this question, single/mixture chronic toxicities of sulfonamides (SAs) and quorum-sensing inhibitors (QSIs) were determined using Gram-negative bacteria (Vibrio fischeri and E. coli.) and Gram-positive bacteria (B. subtilis) as the target organisms. The results showed that the joint effects of SAs and QSIs were primarily antagonistic responses. In addition, the toxicity mechanisms of mixtures of SAs and QSIs were investigated further, and the results revealed that the chronic joint effects were primarily an antagonistic response due to the QSI competing against acyl-homoserine lactones (AHL) for luxR in V. fischeri and SdiA in E. coli generated by the SAs, leading to negative effects exerted by the QSI-luxR or QSI-SdiA complexes on luxI in V. fischeri or FtsZ in E. coli. This phenomenon eventually weakened the stimulatory effect caused by the SAs. Based on the mixture toxicity mechanism, the relationship between the mixture toxicity and the simulation effect was formulated.

  8. Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2016-03-01

    Full Text Available Polyglutamine (polyQ diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1, a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration.

  9. Elucidating the Mechanism of Gain of Toxic Function From Mutant C1 Inhibitor Proteins in Hereditary Angioedema

    Science.gov (United States)

    2015-10-01

    in Hereditary Angioedema PRINCIPAL INVESTIGATOR: Dr. Bruce Zuraw, M.D. CONTRACTING: ORGANIZATION Veterans Medical Research Foundation San...C1 Inhibitor 5a. CONTRACT NUMBER Proteins in Hereditary Angioedema 5b. GRANT NUMBER W81XWH-14-1-0506 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr...unique structural characteristics of C1INH make it more susceptible to GOTF than other serpins. 2. KEYWORDS: Hereditary angioedema , C1 inhibitor, serpin

  10. Systemic and Nonrenal Adverse Effects Occurring in Renal Transplant Patients Treated with mTOR Inhibitors

    Directory of Open Access Journals (Sweden)

    Gianluigi Zaza

    2013-01-01

    Full Text Available The mammalian target of rapamycin inhibitors (mTOR-I, sirolimus and everolimus, are immunosuppressive drugs largely used in renal transplantation. The main mechanism of action of these drugs is the inhibition of the mammalian target of rapamycin (mTOR, a regulatory protein kinase involved in lymphocyte proliferation. Additionally, the inhibition of the crosstalk among mTORC1, mTORC2, and PI3K confers the antineoplastic activities of these drugs. Because of their specific pharmacological characteristics and their relative lack of nephrotoxicity, these inhibitors are valid option to calcineurine inhibitors (CNIs for maintenance immunosuppression in renal transplant recipients with chronic allograft nephropathy. However, as other immunosuppressive drugs, mTOR-I may induce the development of several adverse effects that need to be early recognized and treated to avoid severe illness in renal transplant patients. In particular, mTOR-I may induce systemic nonnephrological side effects including pulmonary toxicity, hematological disorders, dysmetabolism, lymphedema, stomatitis, cutaneous adverse effects, and fertility/gonadic toxicity. Although most of the adverse effects are dose related, it is extremely important for clinicians to early recognize them in order to reduce dosage or discontinue mTOR-I treatment avoiding the onset and development of severe clinical complications.

  11. Synchronous BRAFV600E and MEK inhibition leads to superior control of murine melanoma by limiting MEK inhibitor induced skin toxicity

    Directory of Open Access Journals (Sweden)

    Gadiot J

    2013-11-01

    Full Text Available Jules Gadiot,1,* Anna I Hooijkaas,1,* Marcel A Deken,1 Christian U Blank1,21Department of Immunology, 2Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands* These authors contributed equally to this workAbstract: The BRAF inhibitor (BRAFi treatment has led to impressive responses in BRAFV600E mutation-positive melanomas, but responses are not durable in many patients. As most of the BRAFi escape mechanisms involve ERK reactivation, combinations with MEK inhibitors (MEKi are currently tested to improve BRAFi-mediated response durations. Additionally, such a combination is expected to reduce MEKi-induced skin toxicities, as these drugs are thought to have antagonistic effects on ERK activation in keratinocytes. However, preclinical in vivo data exploring the combination of BRAFi and MEKi to achieve improved tumor control in the absence of skin toxicities are limited. Using a murine Tyr::CreERT2;PtenLoxP/LoxP;BrafCA/+ melanoma model, we have determined the effect of BRAFi and MEKi treatment and their combination on melanoma control and occurrence of adverse events. We found that the MEKi dosed beyond the maximum tolerable dose (MTD led to stronger control of tumor growth than did the BRAFi, but mice had to be removed from treatment because of skin toxicity. The combination of BRAFi and MEKi reduced MEKi-associated skin toxicity. This allowed high and long-term dosing of the MEKi, resulting in long-term tumor control. In contrast to previous hypotheses, the addition of a BRAFi did not restore the MEKi-mediated downregulation of pErk1/2 in skin cells. Our data describe, for the first time, the alleviation of MEKi-mediated dose-limiting toxicity by addition of a BRAFi in a mouse melanoma model. Additional clinical Phase I studies should be implemented to explore MEKi dosing beyond the single drug MTD in combination with BRAFi.Keywords: melanoma, BRAF, MEK, skin toxicity, vemurafenib, trametinib

  12. Cyclosporin A enhances neural precursor cell survival in mice through a calcineurin-independent pathway.

    Science.gov (United States)

    Sachewsky, Nadia; Hunt, Jessica; Cooke, Michael J; Azimi, Ashkan; Zarin, Taraneh; Miu, Carween; Shoichet, Molly S; Morshead, Cindi M

    2014-08-01

    Cyclosporin A (CsA) has direct effects on neural stem and progenitor cells (together termed neural precursor cells; NPCs) in the adult central nervous system. Administration of CsA in vitro or in vivo promotes the survival of NPCs and expands the pools of NPCs in mice. Moreover, CsA administration is effective in promoting NPC activation, tissue repair and functional recovery in a mouse model of cortical stroke. The mechanism(s) by which CsA mediates this cell survival effect remains unknown. Herein, we examined both calcineurin-dependent and calcineurin-independent pathways through which CsA might mediate NPC survival. To examine calcineurin-dependent pathways, we utilized FK506 (Tacrolimus), an immunosuppressive molecule that inhibits calcineurin, as well as drugs that inhibit cyclophilin A-mediated activation of calcineurin. To evaluate the calcineurin-independent pathway, we utilized NIM811, a non-immunosuppressive CsA analog that functions independently of calcineurin by blocking mitochondrial permeability transition pore formation. We found that only NIM811 can entirely account for the pro-survival effects of CsA on NPCs. Indeed, blocking signaling pathways downstream of calcineurin activation using nNOS mice did not inhibit CsA-mediated cell survival, which supports the proposal that the effects are calcinuerin-independent. In vivo studies revealed that NIM811 administration mimics the pro-survival effects of CsA on NPCs and promotes functional recovery in a model of cortical stroke, identical to the effects seen with CsA administration. We conclude that CsA mediates its effect on NPC survival through calcineurin-independent inhibition of mitochondrial permeability transition pore formation and suggest that this pathway has potential therapeutic benefits for developing NPC-mediated cell replacement strategies. © 2014. Published by The Company of Biologists Ltd.

  13. MMF and calcineurin taper in recurrent hepatitis C after liver transplantation: impact on histological course.

    Science.gov (United States)

    Bahra, Marcus; Neumann, U I F P; Jacob, Dietmar; Puhl, Gero; Klupp, Jochen; Langrehr, Jan M; Berg, Thomas; Neuhaus, Peter

    2005-02-01

    Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is almost universal. The optimal immunosuppression for these patients is still under discussion. We designed a retrospective case-control study to evaluate the effect of mycophenolate mofetil (MMF) treatment in patients with recurrent hepatitis C. Forty patients with histologically proven hepatitis C recurrence after OLT were treated with MMF and calcineurin inhibitor (CNI) taper for 24 months and matched with 40 non-MMF-treated positive liver transplant recipients. Liver biopsies were obtained prior to MMF treatment and after a mean follow-up of 24 months. Histological changes were evaluated utilizing the Metavir score. Comparison of fibrosis/inflammation showed no impairment of histological findings during MMF treatment. In contrast, histological findings of the 40 non-MMF patients showed a significant increase of severity for inflammation/fibrosis. Viral load was similar in both groups. The course of alanin amino transferase (ALT) levels measured during MMF treatment showed a significant decrease. MMF in combination with CNI taper showed a positive effect on fibrosis progression, graft inflammation and ALT levels and may improve the clinical course of HCV after OLT, however, the antiviral properties of MMF are still unconfirmed.

  14. Cdk1, PKCδ and calcineurin-mediated Drp1 pathway contributes to mitochondrial fission-induced cardiomyocyte death

    Energy Technology Data Exchange (ETDEWEB)

    Zaja, Ivan [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bai, Xiaowen, E-mail: xibai@mcw.edu [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Liu, Yanan; Kikuchi, Chika; Dosenovic, Svjetlana; Yan, Yasheng; Canfield, Scott G. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bosnjak, Zeljko J. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States)

    2014-10-31

    Highlights: • Drp1-mediated increased mitochondrial fission but not fusion is involved the cardiomyocyte death during anoxia-reoxygenation injury. • Reactive oxygen species are upstream initiators of mitochondrial fission. • Increased mitochondrial fission is resulted from Cdk1-, PKCδ-, and calcineurin-mediated Drp1 pathways. - Abstract: Myocardial ischemia–reperfusion (I/R) injury is one of the leading causes of death and disability worldwide. Mitochondrial fission has been shown to be involved in cardiomyocyte death. However, molecular machinery involved in mitochondrial fission during I/R injury has not yet been completely understood. In this study we aimed to investigate molecular mechanisms of controlling activation of dynamin-related protein 1 (Drp1, a key protein in mitochondrial fission) during anoxia-reoxygenation (A/R) injury of HL1 cardiomyocytes. A/R injury induced cardiomyocyte death accompanied by the increases of mitochondrial fission, reactive oxygen species (ROS) production and activated Drp1 (pSer616 Drp1), and decrease of inactivated Drp1 (pSer637 Drp1) while mitochondrial fusion protein levels were not significantly changed. Blocking Drp1 activity with mitochondrial division inhibitor mdivi1 attenuated cell death, mitochondrial fission, and Drp1 activation after A/R. Trolox, a ROS scavenger, decreased pSer616 Drp1 level and mitochondrial fission after A/R. Immunoprecipitation assay further indicates that cyclin dependent kinase 1 (Cdk1) and protein kinase C isoform delta (PKCδ) bind Drp1, thus increasing mitochondrial fission. Inhibiting Cdk1 and PKCδ attenuated the increases in pSer616 Drp1, mitochondrial fission, and cardiomyocyte death. FK506, a calcineurin inhibitor, blocked the decrease in expression of inactivated pSer637 Drp1 and mitochondrial fission. Our findings reveal the following novel molecular mechanisms controlling mitochondrial fission during A/R injury of cardiomyocytes: (1) ROS are upstream initiators of

  15. JANEX-1, a JAK3 inhibitor, protects pancreatic islets from cytokine toxicity through downregulation of NF-{kappa}B activation and the JAK/STAT pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Na; Kim, Eun-Kyung; Song, Mi-Young [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Choi, Ha-Na; Moon, Woo Sung [Department of Pathology, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Sung-Joo [Department of Herbology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Jin-Woo [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kwon, Kang-Beom, E-mail: desson@wonkwang.ac.kr [Department of Physiology, School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Park, Byung-Hyun, E-mail: bhpark@chonbuk.ac.kr [Department of Biochemistry, Medical School and Diabetes Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2009-07-15

    JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic {beta}-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1{beta} and interferon (IFN)-{gamma}-induced {beta}-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor {kappa}B (NF-{kappa}B) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3{sup -/-} mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects {beta}-cells from cytokine toxicity through suppression of the NF-{kappa}B and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional {beta}-cell mass.

  16. Correlations between calcineurin phosphatase inhibition and cyclosporine metabolites concentrations in kidney transplant recipients: implications for immunoassays

    DEFF Research Database (Denmark)

    Karamperis, N; Koefoed-Nielsen, PB; Brahe, P

    2006-01-01

    transplant patients were included in the study. Blood samples were drawn before, 1, 2, 3, 4, 6, 8, and 12 hr after oral intake of cyclosporine. Parent drug and metabolites were determined by liquid chromatography/tandem mass spectrometry (LC/MSMS). Additionally, cyclosporine concentration was determined...... by the enzyme multiplied immunoassay technique (EMIT) and by the polyclonal fluorescence polarization immunoassay (pFPIA). Calcineurin phosphatase activity was measured by its ability to dephosphorylate a previously phosphorylated 19-amino acid peptide. We found that calcineurin phosphatase inhibition...... by inhibiting the enzyme calcineurin phosphatase. Determination of the enzyme's activity is one of the most promising pharmacodynamic markers. It is unknown how calcineurin phosphatase inhibition correlates with various cyclosporine monitoring assays and what is the potential impact of metabolites...

  17. Evaluation of Protease Inhibitors and an Antioxidant for Treatment of Sulfur Mustard-Induced Toxic Lung Injury

    Science.gov (United States)

    2009-01-01

    airways are becoming bstructed with loose cellular debris, damaged cells and exudate. hese physical obstructions may contribute to the changes in PF...days post-exposure. In addition to measures described in this eport, we intend to evaluate the effect of therapies on SM-induced ungfibrosis (in addition...inhibitor pre- vents cigarette smoke-induced emphysema in the mouse. COPD 2 (3), 303– 310. utnam, J.B., Royston, D. (Eds.), 2003. Evaluating the Role

  18. Estradiol upregulates calcineurin expression via overexpression of estrogen receptor alpha gene in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Hui-Li Lin

    2011-04-01

    Full Text Available Systemic lupus erythematosus (SLE is an autoimmune disease primarily affecting women (9:1 compared with men. To investigate the influence of female sex hormone estrogen on the development of female-biased lupus, we compared the expression of estrogen receptor alpha (ERα gene and protein levels as well as expression of T-cell activation gene calcineurin in response to estrogen in peripheral blood lymphocytes (PBLs from SLE patients and normal controls. PBLs were isolated from 20 female SLE patients and 6 normal female controls. The amount of ERα protein in PBL was measured by flow cytometry. The expression of ERα and calcineurin messenger RNA was measured by semi-quantitative reverse transcription-polymerase chain reaction. Calcineurin phosphatase activity was measured by calcineurin assay kit. The expression of ERα messenger RNA and ERα protein was significantly increased (p=0.001 and p=0.023, respectively in PBL from SLE patients compared with that from normal controls. In addition, the basal calcineurin in PBL from SLE patients was significantly higher (p=0.000 than that from normal controls, and estrogen-induced expression of calcineurin was increased (p=0.007 in PBL from SLE patients compared with that from normal controls, a 3.15-fold increase. This increase was inhibited by the ERα antagonism ICI 182,780. The effects of ER antagonism were also found in calcineurin activity. These data suggest that overexpression of ERα gene and enhanced activation of calcineurin in response to estrogen in PBL may contribute to the pathogenesis of female dominant in SLE.

  19. The Ca2+/calcineurin-dependent signaling pathway in the gray mold Botrytis cinerea: the role of calcipressin in modulating calcineurin activity.

    Directory of Open Access Journals (Sweden)

    Karin Harren

    Full Text Available In the gray mold fungus Botrytis cinerea the Gα subunit Bcg1 of a heterotrimeric G protein is an upstream activator of the Ca(2+/calmodulin-dependent phosphatase calcineurin. In this study we focused on the functional characterization of the catalytic subunit of calcineurin (BcCnA and its putative regulator calcipressin (BcRcn1. We deleted the genes encoding both proteins to examine their role concerning growth, differentiation and virulence. The ΔbccnA mutant shows a severe growth defect, does not produce conidia and is avirulent, while the loss of BcRcn1 caused retardation of hyphal growth and delayed infection of host plants, but had no impact on conidiation and sclerotia formation. Expression of several calcineurin-dependent genes and bccnA itself is positively affected by BcRcn1. Complementation of the Δbcrcn1 mutant with a GFP-BcRcn1 fusion construct revealed that BcRcn1 is localized in the cytoplasm and accumulates around the nuclei. Furthermore, we showed that BcCnA physically interacts with BcRcn1 and the regulatory subunit of calcineurin, BcCnB. We investigated the impact of several protein domains characteristic for modulation and activation of BcCnA via BcRcn1, such as the phosphorylation sites and the calcineurin-docking site, by physical interaction studies between BcCnA and wild-type and mutated copies of BcRcn1. Based on the observed phenotypes we conclude that BcRcn1 acts as a positive modulator of BcCnA and the Ca(2+/calcineurin-mediated signal transduction in B. cinerea, and that both proteins regulate fungal development and virulence.

  20. PKA regulates calcineurin function through the phosphorylation of RCAN1: Identification of a novel phosphorylation site

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Sook; Lee, Eun Hye [Department of Molecular Bioscience, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Lee, Kooyeon [Department of Bio-Health Technology, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Jo, Su-Hyun, E-mail: suhyunjo@kangwon.ac.kr [Department of Physiology, BK21 Plus Graduate Program, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Seo, Su Ryeon, E-mail: suryeonseo@kangwon.ac.kr [Department of Molecular Bioscience, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2015-04-17

    Calcineurin is a calcium/calmodulin-dependent phosphatase that has been implicated in T cell activation through the induction of nuclear factors of activated T cells (NFAT). We have previously suggested that endogenous regulator of calcineurin (RCAN1, also known as DSCR1) is targeted by protein kinase A (PKA) for the control of calcineurin activity. In the present study, we characterized the PKA-mediated phosphorylation site in RCAN1 by mass spectrometric analysis and revealed that PKA directly phosphorylated RCAN1 at the Ser 93. PKA-induced phosphorylation and the increase in the half-life of the RCAN1 protein were prevented by the substitution of Ser 93 with Ala (S93A). Furthermore, the PKA-mediated phosphorylation of RCAN1 at Ser 93 potentiated the inhibition of calcineurin-dependent pro-inflammatory cytokine gene expression by RCAN1. Our results suggest the presence of a novel phosphorylation site in RCAN1 and that its phosphorylation influences calcineurin-dependent inflammatory target gene expression. - Highlights: • We identify novel phosphorylation sites in RCAN1 by LC-MS/MS analysis. • PKA-dependent phosphorylation of RCAN1 at Ser 93 inhibits calcineurin-mediated intracellular signaling. • We show the immunosuppressive function of RCAN1 phosphorylation at Ser 93 in suppressing cytokine expression.

  1. Micro-RNA Feedback Loops Modulating the Calcineurin/NFAT Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Shichina Kannambath

    2016-05-01

    Full Text Available Nuclear factor of activated T cells (NFAT is a family of transcription factors important for innate and adaptive immune responses. NFAT activation is tightly regulated through the calcineurin/NFAT signaling pathway. There is increasing evidence on non-coding RNAs such as miRNAs playing a crucial role in regulating transcription factors and signaling pathways. However, not much is known about microRNAs (miRNAs targeting the calcineurin/NFAT signaling pathway involved in immune response in human. In this study, a comprehensive pathway level analysis has been carried out to identify miRNAs regulating the calcineurin/NFAT signaling pathway. Firstly, by incorporating experimental data and computational predictions, 191 unique miRNAs were identified to be targeting the calcineurin/NFAT signaling pathway in humans. Secondly, combining miRNA expression data from activated T cells and computational predictions, 32 miRNAs were observed to be induced by NFAT transcription factors. Finally, 11 miRNAs were identified to be involved in a feedback loop to modulate the calcineurin/NFAT signaling pathway activity. This data demonstrate the potential role of miRNAs as regulators of the calcineurin/NFAT signaling pathway. The present study thus emphasizes the importance of pathway level analysis to identify miRNAs and understands their role in modulating signaling pathways and transcription factor activity.

  2. MCPIP1 contributes to the toxicity of proteasome inhibitor MG-132 in HeLa cells by the inhibition of NF-κB.

    Science.gov (United States)

    Skalniak, Lukasz; Dziendziel, Monika; Jura, Jolanta

    2014-10-01

    Recently, we have shown that the treatment of cells with proteasome inhibitor MG-132 results in the induction of expression of monocyte chemotactic protein-1 induced protein 1 (MCPIP1). MCPIP1 is a ribonuclease, responsible for the degradation of transcripts encoding certain pro-inflammatory cytokines. The protein is also known as an inhibitor of NF-κB transcription factor. Thanks to its molecular properties, MCPIP1 is considered as a regulator of inflammation, differentiation, and survival. Using siRNA technology, we show here that MCPIP1 expression contributes to the toxic properties of MG-132 in HeLa cells. The inhibition of proteasome by MG-132 and epoxomicin markedly increased MCPIP1 expression. While MG-132 induces HeLa cell death, down-regulation of MCPIP1 expression by siRNA partially protects HeLa cells from MG-132 toxicity and restores Nuclear factor-κB (NF-κB) activity, inhibited by MG-132 treatment. Inversely, overexpression of MCPIP1 decreased constitutive activity of NF-κB and limited the survival of HeLa cells, as we have shown in the previous study. Interestingly, although MG-132 decreased the expression of IκBα and increased p65 phosphorylation, the inhibition of constitutive NF-κB activity was observed in MG-132-treated cells. Since the elevated constitutive activity of NF-κB is one of the mechanisms providing increased survival of cancer cells, including HeLa cells, we propose that death-promoting properties of MCPIP1 in MG-132-treated HeLa cells may, at least partially, derive from the negative effect on the constitutive NF-κB activity.

  3. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C., E-mail: cdirusso2@unl.edu

    2015-09-25

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

  4. Monoamine oxidase inhibitors l-deprenyl and clorgyline protect nonmalignant human cells from ionising radiation and chemotherapy toxicity.

    LENUS (Irish Health Repository)

    Seymour, C B

    2003-11-17

    l-Deprenyl (R-(-)-deprenyl, selegiline) is an inhibitor of monoamine oxidase-B (MAO-B) that is known to protect nerve cells from a variety of chemical and physical insults. As apoptosis is a common mechanism of radiation-induced cell death, the effect of l-deprenyl on the survival of cultured cells and tissue explants was studied following exposure to gamma radiation. The results obtained were compared with the effects of the less-selective MAO-B inhibitor pargyline and the MAO-A inhibitor clorgyline. l-Deprenyl at a concentration of 10(-9) M protected the nontumorigenic cell line (HaCaT) and normal human urothelial explants from the effects of cobalt-60 gamma radiation, but did not protect tumorigenic human cell lines HaCaT-ras, HPV-transfected human keratinocytes (HPV-G cells), or PC3. Human bladder carcinoma explants were not protected. Clorgyline showed a smaller protective effect of normal cells, whereas pargyline had no effect. Radiation-induced delayed effects (genomic instability measured as delayed cell death) were prevented in normal cells by l-deprenyl but, interestingly, deprenyl appeared to increase the amount of delayed death in the tumorigenic cell lines. Studies using l-deprenyl prior to the exposure of nonmalignant cells to cisplatin showed that cell death due to this agent was also reduced. Treatment of cultures of nontumorigenic cells with l-deprenyl or clorgyline significantly increased the levels of the protein Bcl-2 following irradiation, but there was no such effect on the already-elevated levels of this protein in the tumour samples. Since the Bcl-2 has been shown to be an inhibitor of apoptosis or programmed cell death, this would imply that the protective effects of l-deprenyl and clorgyline involve activation of antiapoptotic pathways within the normal cell. This hypothesis is supported by data showing reduced levels of apoptosis in HaCAT cells and in normal bladder explant cultures following treatment with l-deprenyl.

  5. The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukaemia cells

    OpenAIRE

    2012-01-01

    Abstract Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn++-chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, wh...

  6. Fatty Acid Transport Protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    Science.gov (United States)

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-01-01

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC50 8–11μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC50 58μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of 13C-oleate demonstrating its potential as a therapeutic agent. PMID:26284975

  7. Mitochondrial toxicity of selective COX-2 inhibitors via inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria

    DEFF Research Database (Denmark)

    Syed, Muzeeb; Skonberg, Christian; Hansen, Steen Honoré

    2016-01-01

    Cyclooxygenase-2 (COX-2) inhibitors (coxibs) are non-steroidal anti-inflammatory drugs (NSAIDs) designed to selectively inhibit COX-2. However, drugs of this therapeutic class are associated with drug induced liver injury (DILI) and mitochondrial injury is likely to play a role. The effects...... of selective COX-2 inhibitors on inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria were investigated. The order of potency of inhibition of ATP synthesis was: lumiracoxib (IC50: 6.48 ± 2.74 μM)>celecoxib (IC50: 14.92 ± 6.40 μM)>valdecoxib (IC50: 161.4 ± 28.6 μM)>rofecoxib (IC50...... correlation (with r(2)=0.921) was observed between the potency of inhibition of ATP synthesis and the log P values. The in vitro metabolism of coxibs in rat liver mitochondria yielded for each drug substance a major single metabolite and identified a hydroxy metabolite with each of the coxibs...

  8. Catalytic synthesis of α-amino chromone phosphonates and their antimicrobial, toxicity and potential HIV-1 RT inhibitors based on silico screening.

    Science.gov (United States)

    Jaiyeola, Abosede Oluwabukola; Anand, K; Kasumbwe, K; Ramesh, M; Gengan, R M

    2017-01-01

    The α-amino phosphonates exhibit a wide range of biological properties which create demand for simple and efficient synthetic routes of new molecules. In this study synthesis of a new series of derivatives of α-amino chromone phosphonates (ACPs) was reported using RhBT catalyst. The RhBT was first prepared by simply mixing boron nitride in a solution of rhodium acetate, under inert atmosphere for a week followed by filtration (yield: 92%). The catalyst can be re-used for up to four times and showed minimal loss of activity. The ACPs was prepared in a one pot reaction containing chromone based aldehydes, aniline derivatives and diethyl phosphite. The structures of these compounds were characterized by IR, (1)H NMR, (13)C NMR, (31)P NMR and high resolution mass spectral analysis. The synthesized ACPs were evaluated for their antimicrobial activities against three bacteria B. cereus, M. luteus, E. coli and one fungus C. albicans. The ACPs displayed selective toxicity toward the brine shrimp (Artemia salina). Compounds 8j and 8m was found to be less toxic to the brine shrimp and may have more valuable biological application. Furthermore, molecular docking studies were conducted to predict the possible therapeutic potential of ACPs. The compounds (8i, 8j, 8k and 8m) were predicted as highly active HIV-1 reverse transcriptase inhibitors. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Characterization of forced degradation products and in silico toxicity prediction of Sofosbuvir: A novel HCV NS5B polymerase inhibitor.

    Science.gov (United States)

    Swain, Debasish; Samanthula, Gananadhamu; Bhagat, Shweta; Bharatam, P V; Akula, Venkatakrishna; Sinha, Barij N

    2016-02-20

    Sofosbuvir is a direct acting antiviral medication used to treat Hepatitis C viral infection. The present study focuses on the degradation behavior of the drug under various stress conditions (hydrolysis, oxidative, thermal and photolytic) as per International Conference on Harmonization (ICH Q1A (R2)) guidelines. A high performance liquid chromatographic system (HPLC) was used to develop a selective, precise and accurate method for separating all the degradation products. The separation was achieved on a Sunfire™ C18 (150mm×4.6mm×5μm) stationary phase with a mobile phase of 10mM ammonium acetate (pH 5.0) buffer and acetonitrile in gradient elution mode. A quadrupole-time of flight mass analyzer equipped with an electrospray ionization technique was used to propose the structural information based on the MS/MS and accurate mass measurements. Seven degradation products were identified and characterised by LC-ESI-QTOF-MS/MS. In silico toxicity of the drug and its degradation products was determined using TOPKAT and DEREK toxicity prediction softwares. The proposed method was validated as per the ICH Q2 guidelines.

  10. VEGFR tyrosine kinase inhibitor II (VRI) induced vascular insufficiency in zebrafish as a model for studying vascular toxicity and vascular preservation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shang; Dang, Yuan Ye; Oi Lam Che, Ginny [State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macao (China); Kwan, Yiu Wa [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Chan, Shun Wan [State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong (China); Leung, George Pak Heng [Pharmacology and Pharmacy, Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Lee, Simon Ming Yuen, E-mail: simonlee@umac.mo [State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macao (China); Hoi, Maggie Pui Man, E-mail: maghoi@umac.mo [State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macao (China)

    2014-11-01

    In ischemic disorders such as chronic wounds and myocardial ischemia, there is inadequate tissue perfusion due to vascular insufficiency. Besides, it has been observed that prolonged use of anti-angiogenic agents in cancer therapy produces cardiovascular toxicity caused by impaired vessel integrity and regeneration. In the present study, we used VEGFR tyrosine kinase inhibitor II (VRI) to chemically induce vascular insufficiency in zebrafish in vivo and human umbilical vein endothelial cells (HUVEC) in vitro to further study the mechanisms of vascular morphogenesis in these pathological conditions. We also explored the possibility of treating vascular insufficiency by enhancing vascular regeneration and repair with pharmacological intervention. We observed that pretreatment of VRI induced blood vessel loss in developing zebrafish by inhibiting angiogenesis and increasing endothelial cell apoptosis, accompanied by down-regulation of kdr, kdrl and flt-1 genes expression. The VRI-induced blood vessel loss in zebrafish could be restored by post-treatment of calycosin, a cardiovascular protective isoflavone. Similarly, VRI induced cytotoxicity and apoptosis in HUVEC which could be rescued by calycosin post-treatment. Further investigation of the underlying mechanisms showed that the PI3K/AKT/Bad cell survival pathway was a main contributor of the vascular regenerative effect of calycosin. These findings indicated that the cardiovascular toxicity in anti-angiogenic therapy was mainly caused by insufficient endothelial cell survival, suggesting its essential role in vascular integrity, repair and regeneration. In addition, we showed that VRI-induced blood vessel loss in zebrafish represented a simple and effective in vivo model for studying vascular insufficiency and evaluating cancer drug vascular toxicities. - Highlights: • In vivo VRI model • Rescue effects of calycosin • Calycosin EC survival pathways.

  11. In vivo toxicity and pharmacokinetic features of the janus kinase 3 inhibitor WHI-P131 [4-(4'hydroxyphenyl)-amino-6,7- dimethoxyquinazoline.

    Science.gov (United States)

    Uckun, F M; Ek, O; Liu, X P; Chen, C L

    1999-10-01

    4-(4'Hydroxyphenyl)-amino-6,7-dimethoxyquinazoline (WHI-P131) is a potent and selective inhibitor of the Janus kinase 3, which triggers apoptosis in human acute lymphoblastic leukemia (ALL) cells. In this preclinical study, we evaluated the pharmacokinetics and toxicity of WHI-P131 in rats, mice, and cynomolgus monkeys. Following i.v. administration, the terminal elimination half-life of WHI-P131 was 73.2 min in rats, 103.4 min in mice, and 45.0 min in monkeys. The i.v. administered WHI-P131 showed a very wide tissue distribution in mice. Following i.p. administration, WHI-P131 was rapidly absorbed in both rats and mice, and the time to reach the maximum plasma concentration (tmax) was 24.8 min in rats and 10.0 min in mice. Subsequently, WHI-P131 was eliminated with a terminal elimination half-life of 51.8 min in rats and 123.6 min in mice. The estimated i.p. bioavailability was 95% for rats, as well as for mice. WHI-P131 was quickly absorbed after oral administration in mice with a tmax of 5.8 min, but its oral bioavailability was relatively low (29.6%). The elimination half-life of WHI-P131 after oral administration was 297.6 min. WHI-P131 was not acutely toxic to mice at single i.p. bolus doses ranging from 0.5-250 mg/kg. Two cynomolgus monkeys treated with 20 mg/kg WHI-P131 and one cynomolgus monkey treated with 100 mg/kg WHI-P131 experienced no side effects. Plasma samples from WHI-P131-treated monkeys exhibited potent antileukemic activity against human ALL cells in vitro. To our knowledge, this is the first preclinical toxicity and pharmacokinetic study of a Janus kinase 3 inhibitor. Further development of WHI-P131 may provide the basis for new and effective treatment programs for relapsed ALL in clinical settings.

  12. The RCAN carboxyl end mediates calcineurin docking-dependent inhibition via a site that dictates binding to substrates and regulators

    Science.gov (United States)

    Martínez-Martínez, Sara; Genescà, Lali; Rodríguez, Antonio; Raya, Alicia; Salichs, Eulàlia; Were, Felipe; López-Maderuelo, María Dolores; Redondo, Juan Miguel; de la Luna, Susana

    2009-01-01

    Specificity of signaling kinases and phosphatases toward their targets is usually mediated by docking interactions with substrates and regulatory proteins. Here, we characterize the motifs involved in the physical and functional interaction of the phosphatase calcineurin with a group of modulators, the RCAN protein family. Mutation of key residues within the hydrophobic docking-cleft of the calcineurin catalytic domain impairs binding to all human RCAN proteins and to the calcineurin interacting proteins Cabin1 and AKAP79. A valine-rich region within the RCAN carboxyl region is essential for binding to the docking site in calcineurin. Although a peptide containing this sequence compromises NFAT signaling in living cells, it does not inhibit calcineurin catalytic activity directly. Instead, calcineurin catalytic activity is inhibited by a motif at the extreme C-terminal region of RCAN, which acts in cis with the docking motif. Our results therefore indicate that the inhibitory action of RCAN on calcineurin-NFAT signaling results not only from the inhibition of phosphatase activity but also from competition between NFAT and RCAN for binding to the same docking site in calcineurin. Thus, competition by substrates and modulators for a common docking site appears to be an essential mechanism in the regulation of Ca2+-calcineurin signaling. PMID:19332797

  13. Calcineurin signaling and membrane lipid homeostasis regulates iron mediated multidrug resistance mechanisms in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Saif Hameed

    Full Text Available We previously demonstrated that iron deprivation enhances drug susceptibility of Candida albicans by increasing membrane fluidity which correlated with the lower expression of ERG11 transcript and ergosterol levels. The iron restriction dependent membrane perturbations led to an increase in passive diffusion and drug susceptibility. The mechanisms underlying iron homeostasis and multidrug resistance (MDR, however, are not yet resolved. To evaluate the potential mechanisms, we used whole genome transcriptome and electrospray ionization tandem mass spectrometry (ESI-MS/MS based lipidome analyses of iron deprived Candida cells to examine the new cellular circuitry of the MDR of this pathogen. Our transcriptome data revealed a link between calcineurin signaling and iron homeostasis. Among the several categories of iron deprivation responsive genes, the down regulation of calcineurin signaling genes including HSP90, CMP1 and CRZ1 was noteworthy. Interestingly, iron deprived Candida cells as well as iron acquisition defective mutants phenocopied molecular chaperone HSP90 and calcineurin mutants and thus were sensitive to alkaline pH, salinity and membrane perturbations. In contrast, sensitivity to above stresses did not change in iron deprived DSY2146 strain with a hyperactive allele of calcineurin. Although, iron deprivation phenocopied compromised HSP90 and calcineurin, it was independent of protein kinase C signaling cascade. Notably, the phenotypes associated with iron deprivation in genetically impaired calcineurin and HSP90 could be reversed with iron supplementation. The observed down regulation of ergosterol (ERG1, ERG2, ERG11 and ERG25 and sphingolipid biosynthesis (AUR1 and SCS7 genes followed by lipidome analysis confirmed that iron deprivation not only disrupted ergosterol biosynthesis, but it also affected sphingolipid homeostasis in Candida cells. These lipid compositional changes suggested extensive remodeling of the membranes in iron

  14. Distribution of calcineurin Aβ isoenzyme mRNA's in rat brain : Comparison with the distribution of calcineurin Aα isoenzyme mRNA's

    NARCIS (Netherlands)

    Buttini, M.; Luyten, M.; Limonta, S.; Boddeke, H.

    1994-01-01

    Using in situ hybridization histochemistry with specific antisense oligonucleotides, we have studied the distribution of the β subtypes of the catalytic subunit (A) of calcineurin in rat brain. The predominant isoform, Aβ2, was found to be highly expressed in the hippocampus, the medial habenula, th

  15. Calcineurin phosphatase activity and immunosuppression. A review on the role of calcineurin phosphatase activity and the immunosuppressive effect of cyclosporin A and tacrolimus

    DEFF Research Database (Denmark)

    Jørgensen, Kaj Anker; Koefoed-Nielsen, P.B.; Karamperis, N.

    2003-01-01

    The mode of immunosuppressive action of tacrolimus (FK506) and cyclosporin A has been elucidated. Both drugs bind to proteins in the cytoplasm to form complexes, which in turn inhibit the phosphatase activity of calcineurin, an important limiting step in the activation of T cells. The association...

  16. Effect of different immunosuppressive drugs on calcineurin and its mutants

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Several mutants in Loop7 region and near Loop7 region of calcineurin A (CN A) subunit have been constructed and purified using site-directed mutagenesis.Their phosphatase activity and the corresponding solution conformation were examined.Their phosphatase activities between wild-type CN and mutants were compared to identify the interaction of different immunosuppressive drugs with CN.The results showed that the phosphatase activities of the mutants at Loop7 were much higher than the one of wild-type CN.Furthermore,circular dichroism spectra of the mutants revealed that their solution conformations gave rise in changes in native structure of the protein.Cyclophilin-CyclosporinA (CyP-CsA) significantly inhibited the phosphatase activity of wild-type CN,and had no effects on the phosphatase activity of mutants in Loop7 region,which indicates that the site-directed mutagenesis at Loop7 region made a significant change in the interaction between CyP-CsA and CN.Examination of the activities of these mutants resulted in the presence of immunosuppressive component from traditional Chinese drugs.The component of Chinese drug,ZIP1,could directly inhibit both CN and CN mutants without drug binding protein.These results suggest that the Loop7 region is an important structural area involved in the inhibition by CyP-CsA.It is valuable to further study the inhibition by ZIP1.

  17. Effect of different immunosuppressive drugs on calcineurin and its mutants

    Institute of Scientific and Technical Information of China (English)

    阎力君; 于翠娟; 张丽芳; 魏群

    2000-01-01

    Several mutants in Loop7 region and near Loop7 region of calcineurin A (CN A) subunit have been constructed and purified using site-directed mutagenesis. Their phosphatase activity and the corresponding solution conformation were examined. Their phosphatase activities between wild-type CN and mutants were compared to identify the interaction of different immuno-suppressive drugs with CN. The results showed that the phosphatase activities of the mutants at Loop7 were much higher than the one of wild-type CN. Furthermore, circular dichroism spectra of the mutants revealed that their solution conformations gave rise in changes in native structure of the protein. Cyclophilin-CyclosporinA (CyP-CsA) significantly inhibited the phosphatase activity of wild-type CN, and had no effects on the phosphatase activity of mutants in Loop7 region, which indicates that the site-directed mutagenesis at Loop7 region made a significant change in the interaction between CyP-CsA and CN. Examination of the activities of these

  18. AMYLOID BETA OLIGOMERS IMPAIR FEAR CONDITIONED MEMORY IN A CALCINEURIN-DEPENDENT FASHION IN MICE

    Science.gov (United States)

    Dineley, Kelly T.; Kayed, Rakez; Neugebauer, Volker; Fu, Yu; Zhang, Wenru; Reese, Lindsay C.; Taglialatela, Giulio

    2010-01-01

    Soluble oligomeric aggregates of the amyloid beta (Aβ) peptide are believed to be the most neurotoxic Aβ species affecting the brain in Alzheimer Disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underlined by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that Aβ oligomers are recruited at the synapse, oppose expression of long term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of Aβ-mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in the pathological processes of AD. CaN is especially abundant in the CNS where it is involved in synaptic activity, LTP and memory function. Here, we describe how oligomeric Aβ treatment causes memory deficits and depresses LTP expression in a CaN-dependent fashion. Mice given a single intracerebroventricular injection of Aβ oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by Aβ oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disrupting effect induced by acute oligomeric Aβ treatment in mice. PMID:20544830

  19. Amyloid-beta oligomers impair fear conditioned memory in a calcineurin-dependent fashion in mice.

    Science.gov (United States)

    Dineley, Kelly T; Kayed, Rakez; Neugebauer, Volker; Fu, Yu; Zhang, Wenru; Reese, Lindsay C; Taglialatela, Giulio

    2010-10-01

    Soluble oligomeric aggregates of the amyloid-beta (A beta) peptide are believed to be the most neurotoxic A beta species affecting the brain in Alzheimer disease (AD), a terminal neurodegenerative disorder involving severe cognitive decline underscored by initial synaptic dysfunction and later extensive neuronal death in the CNS. Recent evidence indicates that A beta oligomers are recruited at the synapse, oppose expression of long-term potentiation (LTP), perturb intracellular calcium balance, disrupt dendritic spines, and induce memory deficits. However, the molecular mechanisms behind these outcomes are only partially understood; achieving such insight is necessary for the comprehension of A beta-mediated neuronal dysfunction. We have investigated the role of the phosphatase calcineurin (CaN) in these pathological processes of AD. CaN is especially abundant in the CNS, where it is involved in synaptic activity, LTP, and memory function. Here, we describe how oligomeric A beta treatment causes memory deficits and depresses LTP expression in a CaN-dependent fashion. Mice given a single intracerebroventricular injection of A beta oligomers exhibited increased CaN activity and decreased pCREB, a transcription factor involved in proper synaptic function, accompanied by decreased memory in a fear conditioning task. These effects were reversed by treatment with the CaN inhibitor FK506. We further found that expression of hippocampal LTP in acutely cultured rodent brain slices was opposed by A beta oligomers and that this effect was also reversed by FK506. Collectively, these results indicate that CaN activation may play a central role in mediating synaptic and memory disruption induced by acute oligomeric A beta treatment in mice. (c) 2010 Wiley-Liss, Inc.

  20. Lamivudine plus a boosted-protease inhibitor as simplification strategy in HIV-infected patients with toxicity to nucleoside analogues

    Directory of Open Access Journals (Sweden)

    J Casado

    2012-11-01

    Full Text Available Purpose of the study: Dual therapy with lamivudine plus a PI boosted with ritonavir (PI/r could be an alternative to standard triple therapy or PI/r monotherapy as a simplification strategy in patients with toxicity to nucleoside analogues (NA. Methods: Retrospective cohort study of 44 HIV-infected patients on suppressive HAART, with no chronic HBV, who simplified to this dual therapy since 2008. Virological and immunological outcome, lipids and renal changes were evaluated. Summary of results: Mean age was 50 years (38-70, 66% were male, and the median time of HIV infection was 18.6 years. The median nadir CD4+ count was 150 cells/ml (2–407. At inclusion, patients were receiving therapy with lamivudine plus atazanavir/r in 5 cases, lopinavir/r in 12, and darunavir/r in 27, and they had an HIV RNA level<50 copies/ml for a median time of 794 days (129–2344, 90% >6 months. The NA discontinued was tenofovir (27, didanosine (12, AZT (3, and d4T (2. The reasons for changing were toxicity in 76% of cases, especially renal impairment. They had received a mean of 8 regimens before (2–20, and 55% were in CDC-stage C. In 11 cases, history of resistance was available (to NA in 7 cases, including the 210W mutation in four. The mutations 184V was not observed, but four patients (9% had a previous failure to therapy including 3tC. Mutations in the protease gene were observed in 8 patients (2 to 7 mutations, the most frequent 77I and 93L, without resistance to the current PI/r. During 62.8 patient-years of follow-up (median, 802 days, only 2 patients failed (4.5%, due to incomplete adherence, at 27 and 141 days. Of note, these two patients had no previous failed with 3tC or PI. Overall, CD4+ count increased for 55 cells/ml. No new adverse events were observed, but total cholesterol (from 180 to 246 mg/dl, p=0.007 and triglycerides (from 166 to 195, p=0.01 increased during the first 24 weeks with improvement at 48 weeks. On the other hand, estimated

  1. Inhibition of Calcineurin A by FK506 Suppresses Seizures and Reduces the Expression of GluN2B in Membrane Fraction.

    Science.gov (United States)

    Wen, Yuetao; Fu, Pengfei; Wu, Kunlun; Si, Kaichuang; Xie, Yanfeng; Dan, Wei; Zhan, Yan; Shi, Quanhong

    2017-08-01

    FK506, a calcineurin inhibitor, shows neuroprotective effects and has been associated with neurodegenerative diseases. Calcineurin A (CaNA), a catalytic subunit of calcineurin, mediates the dephosphorylation of various proteins. N-methyl-D-aspartate receptor (GluN) is closely related to epileptogenesis, and various phosphorylation sites of GluN2B, a regulatory subunit of the GluN complex, have different functions. Thus, we hypothesized that one of the potential anti-epileptic mechanisms of FK506 is mediated by its ability to promote the phosphorylation of GluN2B and reduce the expression of GluN2B in membrane fraction by down-regulating CaNA. CaNA expression was increased in the cortex of patients with temporal lobe epilepsy and pentylenetetrazol (PTZ)-induced epileptic models. CaNA was shown to be expressed in neurons using immunofluorescence staining. According to our behavioral observations, epileptic rats exhibited less severe seizures and were less sensitive to PTZ after a systemic injection of FK506. The levels of phosphorylated GluN2B were decreased in epileptic rats but increased after the FK506 treatment. Moreover, there was no difference in the total GluN2B levels before and after FK506 treatment. However, the expression of GluN2B in membrane fraction was suppressed after FK506 treatment. Based on these results, FK506 may reduce the severity and frequency of seizures by reducing the expression of GluN2B in membrane fraction.

  2. Reduced Cardiac Calcineurin Expression Mimics Long-Term Hypoxia-Induced Heart Defects in Drosophila.

    Science.gov (United States)

    Zarndt, Rachel; Walls, Stanley M; Ocorr, Karen; Bodmer, Rolf

    2017-10-01

    Hypoxia is often associated with cardiopulmonary diseases, which represent some of the leading causes of mortality worldwide. Long-term hypoxia exposures, whether from disease or environmental condition, can cause cardiomyopathy and lead to heart failure. Indeed, hypoxia-induced heart failure is a hallmark feature of chronic mountain sickness in maladapted populations living at high altitude. In a previously established Drosophila heart model for long-term hypoxia exposure, we found that hypoxia caused heart dysfunction. Calcineurin is known to be critical in cardiac hypertrophy under normoxia, but its role in the heart under hypoxia is poorly understood. In the present study, we explore the function of calcineurin, a gene candidate we found downregulated in the Drosophila heart after lifetime and multigenerational hypoxia exposure. We examined the roles of 2 homologs of Calcineurin A, CanA14F, and Pp2B in the Drosophila cardiac response to long-term hypoxia. We found that knockdown of these calcineurin catalytic subunits caused cardiac restriction under normoxia that are further aggravated under hypoxia. Conversely, cardiac overexpression of Pp2B under hypoxia was lethal, suggesting that a hypertrophic signal in the presence of insufficient oxygen supply is deleterious. Our results suggest a key role for calcineurin in cardiac remodeling during long-term hypoxia with implications for diseases of chronic hypoxia, and it likely contributes to mechanisms underlying these disease states. © 2017 American Heart Association, Inc.

  3. Cyclosporin A, but not everolimus, inhibits DNA repair mediated by calcineurin: implications for tumorigenesis under immunosuppression.

    Science.gov (United States)

    Thoms, Kai-Martin; Kuschal, Christiane; Oetjen, Elke; Mori, Toshio; Kobayashi, Nobuhiko; Laspe, Petra; Boeckmann, Lars; Schön, Michael P; Emmert, Steffen

    2011-03-01

    Unlike other immunosuppressive drugs including everolimus, cyclosporin A causes a dramatic increase of UV-induced skin cancer, a feature that is reminiscent of xeroderma pigmentosum (XP), where defective nucleotide excision repair (NER) of UV-induced DNA damage results in cutaneous carcinogenesis. The molecular basis of the clinically important differential activities of cyclosporin A and everolimus is still unclear. We measured post-UV cell survival of cyclosporin A- and everolimus-treated human fibroblasts and lymphoblasts using a cell proliferation assay (MTT). The cellular NER capacity was assessed by host cell reactivation. Using an ELISA and specific antibodies, cyclobutane pyrimidine and pyrimidine-6,4-pyrimidone photoproduct removal from the cellular genome was measured. The effect of calcineurin on NER was investigated using a calcineurin A expression vector and specific RNAi. Cyclosporin A led to a dose dependent decrease in post-UV cell survival, inhibited NER and blocked photoproduct removal. In contrast, none of these effects where seen in everolimus-treated cells. Overexpression of calcineurin A resulted in increased NER and complemented the Cyclosporin A-induced reduction of NER. Downregulation of calcineurin using RNAi inhibited NER comparable to cyclosporin A-treatment. We conclude that cyclosporin A, but not everolimus, leads to an increased skin cancer risk via a calcineurin signalling-dependent impairment of NER. © 2010 John Wiley & Sons A/S.

  4. Increased Bowel Toxicity in Patients Treated With a Vascular Endothelial Growth Factor Inhibitor (VEGFI) After Stereotactic Body Radiation Therapy (SBRT)

    Energy Technology Data Exchange (ETDEWEB)

    Barney, Brandon M., E-mail: barney.brandon@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Markovic, Svetomir N. [Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota (United States); Laack, Nadia N.; Miller, Robert C.; Sarkaria, Jann N. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Macdonald, O. Kenneth [Therapeutic Radiologists Incorporated, Kansas City, Kansas (United States); Bauer, Heather J.; Olivier, Kenneth R. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2013-09-01

    Purpose: Gastrointestinal injury occurs rarely with agents that affect the vascular endothelial growth factor receptor and with abdominal stereotactic body radiation therapy (SBRT). We explored the incidence of serious bowel injury (SBI) in patients treated with SBRT with or without vascular endothelial growth factor inhibitor (VEGFI) therapy. Methods and Materials: Seventy-six patients with 84 primary or metastatic intra-abdominal lesions underwent SBRT (median dose, 50 Gy in 5 fractions). Of the patients, 20 (26%) received VEGFI within 2 years after SBRT (bevacizumab, n=14; sorafenib, n=4; pazopanib, n=1; sunitinib, n=1). The incidence of SBI (Common Terminology Criteria for Adverse Events, version 4.0, grade 3-5 ulceration or perforation) after SBRT was obtained, and the relationship between SBI and VEGFI was examined. Results: In the combined population, 7 patients (9%) had SBI at a median of 4.6 months (range, 3-17 months) from SBRT. All 7 had received VEGFI before SBI and within 13 months of completing SBRT, and 5 received VEGFI within 3 months of SBRT. The 6-month estimate of SBI in the 26 patients receiving VEGFI within 3 months of SBRT was 38%. No SBIs were noted in the 63 patients not receiving VEGFI. The log–rank test showed a significant correlation between SBI and VEGFI within 3 months of SBRT (P=.0006) but not between SBI and radiation therapy bowel dose (P=.20). Conclusions: The combination of SBRT and VEGFI results in a higher risk of SBI than would be expected with either treatment independently. Local therapies other than SBRT may be considered if a patient is likely to receive a VEGFI in the near future.

  5. Effects of chlorogenic acid,an active compound activating calcineurin,purified from Flos Lonicerae on macrophage

    Institute of Scientific and Technical Information of China (English)

    He-zhen WU; Jing LUO; Yan-xia YIN; Qun WEI

    2004-01-01

    AIM: To investigate the activation of chlorogenic acid (CHA) purified from Flos Lonicerae to calcineurin and its effects on macrophage functions in vivo and in vitro. METHODS: According to the screening results that Flos Lonicerae could activate calcineurin, the active component which could activate calcineurin was purified from Flos Lonicerae by column chromatography on silica gel and identified as CHA. The activation of CHA on calcineurin had been validated with both p-NPP and 32p-labeled RII peptide as the substrates. The clearance of charcoal particles in normal mice and the cytotoxicity of U937 to MCF-7 were used together to determine the effects of CHA on macrophage functions. RESULTS: CHA could activate calcineurin, and the concentration of CHA on maximal activating calcineurin was 282.5μmol/L. CHA administration (10 mg/kg,ig×7 d) significantly enhanced the macrophage functions in normal mice. CHA (70.6, 141.2, and 282.5μmol/L) obviously increased the cytotoxicity of U937 to MCF-7. CONCLUSION: CHA could activate calcineurin and enhance the macrophage functions in vivo and in vitro, and its functions in vivo may be realized via the signal pathways of calcineurin.

  6. Correlations between calcineurin phosphatase inhibition and cyclosporine metabolites concentrations in kidney transplant recipients: implications for immunoassays

    DEFF Research Database (Denmark)

    Karamperis, N; Koefoed-Nielsen, PB; Brahe, P

    2006-01-01

    Cyclosporine exhibits a wide spectrum of metabolites that vary considerably in the extent to which they interfere with the various parent drug monitoring immunoassays. There is no consensus regarding the clinical significance of metabolites. Cyclosporine exerts its immunosuppressive action...... by inhibiting the enzyme calcineurin phosphatase. Determination of the enzyme's activity is one of the most promising pharmacodynamic markers. It is unknown how calcineurin phosphatase inhibition correlates with various cyclosporine monitoring assays and what is the potential impact of metabolites...... in this perspective? The aim of the present study was to determine the concentration of cyclosporine (by means of three different assay methods) and the four most significant metabolites (AM1, AM4N, AM9, and AM1C) in relation to calcineurin phosphatase inhibition. Twelve randomly selected cyclosporine-treated renal...

  7. Subacute toxicity evaluation of KR-33493, FAF1 inhibitor for a new anti-parkinson's disease agent, after oral administration in rats and dogs.

    Science.gov (United States)

    Jeong, Jong-Woo; Yu, Changsun; Lee, Jong-Hwa; Moon, Kyoung-Sik; Kim, Eunhee; Yoo, Sung-Eun; Koo, Tae-Sung

    2016-11-01

    KR33493, a newly developed FAS-associated factor 1 (FAF1) inhibitor for Parkinson's disease, is being evaluated in a Phase I clinical trial. In the present study, the subchronic toxicity of KR33493 in Sprague-Dawley (SD) rats and beagle dogs was investigated at various oral doses for 28 and 14 days, respectively. During the study, food consumption, body weights, organ weights, gross findings, and mortality were examined; and ophthalmoscopy, electrocardiography, hematology, serum biochemistry, urinalysis, histopathology, and toxicokinetics were performed. In rats, weight gain decreased in both sexes at 500 mg/kg/day, with no significant differences. In dogs, some significant differences compared with the control were found during the trial; however, at the end of recovery periods, these were no longer observed and there was no dose correlation. Some histopathological findings were observed, but these were considered as incidental changes. Since no other significant changes were observed, doses above 500 and 1000 mg/kg KR33493 in rat and dogs, respectively, caused no observed adverse effects. Therefore, based on these results, the Phase 1 clinical trial for KR33493 was approved by the Korean Food & Drug Administration.

  8. Improved renal function after early conversion from a calcineurin inhibitor to everolimus

    DEFF Research Database (Denmark)

    Mjörnstedt, L; Sørensen, S S; von Zur Mühlen, B;

    2012-01-01

    .2) mL/min with everolimus versus a decrease of 0.4 (12.0) mL/min in controls (p biopsy-proven acute rejection (BPAR) was 27.5% (n = 28) with everolimus and 11.0% (n = 11) in controls (p = 0.004). All...

  9. Everolimus initiation and early calcineurin inhibitor withdrawal in heart transplant recipients

    DEFF Research Database (Denmark)

    Andreassen, A K; Andersson, B; Gustafsson, F

    2014-01-01

    In a randomized, open-label trial, everolimus was compared to cyclosporine in 115 de novo heart transplant recipients. Patients were assigned within 5 days posttransplant to low-exposure everolimus (3–6 ng/mL) with reduced-exposure cyclosporine (n = 56), or standard-exposure cyclosporine (n = 59...... infection was less common with everolimus (5.4% vs. 30.5%, p heart transplantation. Since postoperative safety...

  10. Improvement in renal function after everolimus introduction and calcineurin inhibitor reduction in maintenance thoracic transplant recipients

    DEFF Research Database (Denmark)

    Arora, Satish; Gude, Einar; Sigurdardottir, Vilborg

    2012-01-01

    The NOCTET (NOrdic Certican Trial in HEart and lung Transplantation) trial demonstrated that everolimus improves renal function in maintenance thoracic transplant (TTx) recipients. Nevertheless, introduction of everolimus is not recommended for patients with advanced renal failure. We evaluated...... NOCTET data to assess everolimus introduction amongst TTx recipients with advanced renal failure....

  11. Renal function three years after early conversion from a calcineurin inhibitor to everolimus

    DEFF Research Database (Denmark)

    Mjörnstedt, Lars; Schwartz Sørensen, Søren; von Zur Mühlen, Bengt

    2015-01-01

    In a 36-month, open-label, multicenter trial, 202 kidney transplant recipients were randomized at week 7 post-transplant to convert to everolimus or remain on cyclosporine: 182 were analyzed to month 36 (92 everolimus, 90 controls). Mean (SD) change in measured GFR (mGFR) from randomization to mo......, but discontinuation was more frequent with everolimus (33.7% vs. 10.0%). Conversion from cyclosporine to everolimus at 7 weeks post-transplant was associated with a significant benefit in renal function at 3 years when everolimus was continued.......In a 36-month, open-label, multicenter trial, 202 kidney transplant recipients were randomized at week 7 post-transplant to convert to everolimus or remain on cyclosporine: 182 were analyzed to month 36 (92 everolimus, 90 controls). Mean (SD) change in measured GFR (mGFR) from randomization...

  12. Calcineurin Inhibition Blocks Within-, but Not Between-Session Fear Extinction in Mice

    Science.gov (United States)

    Almeida-Corrêa, Suellen; Moulin, Thiago C.; Carneiro, Clarissa F. D.; Gonçalves, Marina M. C.; Junqueira, Lara S.; Amaral, Olavo B.

    2015-01-01

    Memory extinction involves the formation of a new associative memory that inhibits a previously conditioned association. Nonetheless, it could also depend on weakening of the original memory trace if extinction is assumed to have multiple components. The phosphatase calcineurin (CaN) has been described as being involved in extinction but not in…

  13. Lifespan extension induced by AMPK and calcineurin is mediated by CRTC-1 and CREB.

    Science.gov (United States)

    Mair, William; Morantte, Ianessa; Rodrigues, Ana P C; Manning, Gerard; Montminy, Marc; Shaw, Reuben J; Dillin, Andrew

    2011-02-17

    Activating AMPK or inactivating calcineurin slows ageing in Caenorhabditis elegans and both have been implicated as therapeutic targets for age-related pathology in mammals. However, the direct targets that mediate their effects on longevity remain unclear. In mammals, CREB-regulated transcriptional coactivators (CRTCs) are a family of cofactors involved in diverse physiological processes including energy homeostasis, cancer and endoplasmic reticulum stress. Here we show that both AMPK and calcineurin modulate longevity exclusively through post-translational modification of CRTC-1, the sole C. elegans CRTC. We demonstrate that CRTC-1 is a direct AMPK target, and interacts with the CREB homologue-1 (CRH-1) transcription factor in vivo. The pro-longevity effects of activating AMPK or deactivating calcineurin decrease CRTC-1 and CRH-1 activity and induce transcriptional responses similar to those of CRH-1 null worms. Downregulation of crtc-1 increases lifespan in a crh-1-dependent manner and directly reducing crh-1 expression increases longevity, substantiating a role for CRTCs and CREB in ageing. Together, these findings indicate a novel role for CRTCs and CREB in determining lifespan downstream of AMPK and calcineurin, and illustrate the molecular mechanisms by which an evolutionarily conserved pathway responds to low energy to increase longevity.

  14. Differential distribution of calcineurin Aα isoenzyme mRNA's in rat brain

    NARCIS (Netherlands)

    Buttini, M.; Limonta, S.; Luyten, M.; Boddeke, H.

    1993-01-01

    Specific antisense oligonucleotide probes for the α isoforms of the catalytic subunit (A-subunit) of calcineurin were prepared and the distribution of Aα1 and Aα2 mRNA's has been studied in rat brain using in situ hybridization histochemistry. Clear regional differences have been observed for the Aα

  15. Differential involvement of hippocampal calcineurin during learning and reversal learning in a Y-maze task

    NARCIS (Netherlands)

    Havekes, Robbert; Nijholt, Ingrid M.; Luiten, Paul G. M.; Van der Zee, Eddy A.

    2006-01-01

    The regulation and function of the calcium-dependent phosphatase calcineurin (CaN, protein phosphatase 2B) in learning and memory remain unclear, although recent work indicates that CaN may play a differential role in training and reversal training. To gain more insight into the involvement of CaN

  16. Insulin Increases Expression of TRPC6 Channels in Podocytes by a Calcineurin-Dependent Pathway

    DEFF Research Database (Denmark)

    Xia, Shengqiang; Liu, Ying; Li, Xinming

    2016-01-01

    BACKGROUND/AIMS: Insulin signaling to podocytes is relevant for the function of the glomerulus. Now, we tested the hypothesis that insulin increases the surface expression of canonical transient receptor potential canonical type 6 (TRPC6) channels in podocytes by a calcineurin-dependent pathway. ...

  17. Regulator of Calcineurin (RCAN-1) Regulates Thermotaxis Behavior in Caenorhabditis elegans.

    Science.gov (United States)

    Li, Weixun; Bell, Harold W; Ahnn, Joohong; Lee, Sun-Kyung

    2015-11-01

    Regulator of calcineurin (RCAN) is a calcineurin-interacting protein that inhibits calcineurin phosphatase when overexpressed, often upregulated under neuropathological conditions with impaired learning and memory processes, such as Down syndrome or Alzheimer's disease. Thermotactic behavior in the nematode Caenorhabditis elegans is a form of memory in which calcineurin signaling plays a pivotal role in the thermosensation of AFD neurons. In this study, we found that rcan-1 deletion mutants exhibited cryophilic behavior dependent on tax-6, which was rescued by expressing rcan-1 in AFD neurons. Interaction between RCAN-1 and TAX-6 requires the conserved PxIxIT motif of RCAN-1, without which thermotactic behavior could not be fully rescued. In addition, the loss of crh-1/CREB suppressed the thermotaxis phenotypes of rcan-1 and tax-6 mutants, indicating that crh-1 is crucial in thermotaxis memory in these mutants. Taken together, our results suggest that rcan-1 is an inhibitory regulator of tax-6 and that it acts in the formation of thermosensory behavioral memory in C. elegans.

  18. Calcineurin Inhibition Blocks Within-, but Not Between-Session Fear Extinction in Mice

    Science.gov (United States)

    Almeida-Corrêa, Suellen; Moulin, Thiago C.; Carneiro, Clarissa F. D.; Gonçalves, Marina M. C.; Junqueira, Lara S.; Amaral, Olavo B.

    2015-01-01

    Memory extinction involves the formation of a new associative memory that inhibits a previously conditioned association. Nonetheless, it could also depend on weakening of the original memory trace if extinction is assumed to have multiple components. The phosphatase calcineurin (CaN) has been described as being involved in extinction but not in…

  19. Recruitment of calcineurin to the TCR positively regulates T cell activation.

    Science.gov (United States)

    Dutta, Debjani; Barr, Valarie A; Akpan, Itoro; Mittelstadt, Paul R; Singha, Laishram I; Samelson, Lawrence E; Ashwell, Jonathan D

    2017-02-01

    Calcineurin is a phosphatase whose primary targets in T cells are NFAT transcription factors, and inhibition of calcineurin activity by treatment with cyclosporin A (CsA) or FK506 is a cornerstone of immunosuppressive therapies. Here we found that calcineurin was recruited to the T cell antigen receptor (TCR) signaling complex, where it reversed inhibitory phosphorylation of the tyrosine kinase Lck on Ser59 (Lck(S59)). Loss of calcineurin activity impaired phosphorylation of Tyr493 of the tyrosine kinase ZAP-70 (ZAP-70(Y493)), as well as some downstream pathways in a manner consistent with signaling in cells expressing Lck(S59A) (Lck that cannot be phosphorylated) or Lck(S59E) (a phosphomimetic mutant). Notably, CsA inhibited integrin-LFA-1-dependent and NFAT-independent adhesion of T cells to the intercellular adhesion molecule ICAM-1, with little effect on cells expressing mutant Lck. These results provide new understanding of how widely used immunosuppressive drugs interfere with essential processes in the immune response.

  20. Differential involvement of hippocampal calcineurin during learning and reversal learning in a Y-maze task

    NARCIS (Netherlands)

    Havekes, Robbert; Nijholt, Ingrid M.; Luiten, Paul G. M.; Van der Zee, Eddy A.

    2006-01-01

    The regulation and function of the calcium-dependent phosphatase calcineurin (CaN, protein phosphatase 2B) in learning and memory remain unclear, although recent work indicates that CaN may play a differential role in training and reversal training. To gain more insight into the involvement of CaN i

  1. The calcineurin activity profiles of cyclosporin and tacrolimus are different in stable renal transplant patients

    DEFF Research Database (Denmark)

    Koefoed-Nielsen, PB; Karamperis, N; Hojskov, C

    2006-01-01

    Cyclosporin and tacrolimus remain the cornerstone immunosuppressive drugs in organ transplantation. Dosing and monitoring these drugs is based on pharmacokinetic protocols, but measuring a pharmacodynamic parameter, calcineurin phosphatase (CaN) activity, could be a valuable supplement in determi......Cyclosporin and tacrolimus remain the cornerstone immunosuppressive drugs in organ transplantation. Dosing and monitoring these drugs is based on pharmacokinetic protocols, but measuring a pharmacodynamic parameter, calcineurin phosphatase (CaN) activity, could be a valuable supplement...... in determining optimal doses. Forty stable renal transplant patients were investigated three times in a 6-month period. Blood samples were drawn at 0, 1, 2, 3 and 4 h after oral intake of tacrolimus (FK) or cyclosporin at days 1 and 180. At day 90, one blood sample at trough level (FK) or C2 level (cyclosporin A...... at days 1 and 180 were the same for both drugs. Furthermore, we found that patients treated with tacrolimus or cyclosporin displayed different calcineurin activity profiles. We found that cyclosporin displayed greater calcineurin inhibition than tacrolimus. We have demonstrated that the two drugs exert...

  2. Transthyretin Protects against A-Beta Peptide Toxicity by Proteolytic Cleavage of the Peptide: A Mechanism Sensitive to the Kunitz Protease Inhibitor

    Science.gov (United States)

    Costa, Rita; Ferreira-da-Silva, Frederico; Saraiva, Maria J.; Cardoso, Isabel

    2008-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the deposition of amyloid β-peptide (A-Beta) in the brain. Transthyretin (TTR) is a tetrameric protein of about 55 kDa mainly produced in the liver and choroid plexus of the brain. The known physiological functions of TTR are the transport of thyroid hormone T4 and retinol, through binding to the retinol binding protein. TTR has also been established as a cryptic protease able to cleave ApoA-I in vitro. It has been described that TTR is involved in preventing A-Beta fibrilization, both by inhibiting and disrupting A-Beta fibrils, with consequent abrogation of toxicity. We further characterized the nature of the TTR/A-Beta interaction and found that TTR, both recombinant or isolated from human sera, was able to proteolytically process A-Beta, cleaving the peptide after aminoacid residues 1, 2, 3, 10, 13, 14,16, 19 and 27, as determined by mass spectrometry, and reversed phase chromatography followed by N-terminal sequencing. A-Beta peptides (1–14) and (15–42) showed lower amyloidogenic potential than the full length counterpart, as assessed by thioflavin binding assay and ultrastructural analysis by transmission electron microscopy. A-Beta cleavage by TTR was inhibited in the presence of an αAPP peptide containing the Kunitz Protease Inhibitor (KPI) domain but not in the presence of the secreted αAPP derived from the APP isoform 695 without the KPI domain. TTR was also able to degrade aggregated forms of A-Beta peptide. Our results confirmed TTR as a protective molecule in AD, and prompted A-Beta proteolysis by TTR as a protective mechanism in this disease. TTR may prove to be a useful therapeutic agent for preventing or retarding the cerebral amyloid plaque formation implicated in AD pathology. PMID:18682830

  3. Transthyretin protects against A-beta peptide toxicity by proteolytic cleavage of the peptide: a mechanism sensitive to the Kunitz protease inhibitor.

    Directory of Open Access Journals (Sweden)

    Rita Costa

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disorder characterized by the deposition of amyloid beta-peptide (A-Beta in the brain. Transthyretin (TTR is a tetrameric protein of about 55 kDa mainly produced in the liver and choroid plexus of the brain. The known physiological functions of TTR are the transport of thyroid hormone T(4 and retinol, through binding to the retinol binding protein. TTR has also been established as a cryptic protease able to cleave ApoA-I in vitro. It has been described that TTR is involved in preventing A-Beta fibrilization, both by inhibiting and disrupting A-Beta fibrils, with consequent abrogation of toxicity. We further characterized the nature of the TTR/A-Beta interaction and found that TTR, both recombinant or isolated from human sera, was able to proteolytically process A-Beta, cleaving the peptide after aminoacid residues 1, 2, 3, 10, 13, 14,16, 19 and 27, as determined by mass spectrometry, and reversed phase chromatography followed by N-terminal sequencing. A-Beta peptides (1-14 and (15-42 showed lower amyloidogenic potential than the full length counterpart, as assessed by thioflavin binding assay and ultrastructural analysis by transmission electron microscopy. A-Beta cleavage by TTR was inhibited in the presence of an alphaAPP peptide containing the Kunitz Protease Inhibitor (KPI domain but not in the presence of the secreted alphaAPP derived from the APP isoform 695 without the KPI domain. TTR was also able to degrade aggregated forms of A-Beta peptide. Our results confirmed TTR as a protective molecule in AD, and prompted A-Beta proteolysis by TTR as a protective mechanism in this disease. TTR may prove to be a useful therapeutic agent for preventing or retarding the cerebral amyloid plaque formation implicated in AD pathology.

  4. Dephosphorylation of Bcl-10 by calcineurin is essential for canonical NF-κB activation in Th cells.

    Science.gov (United States)

    Frischbutter, Stefan; Gabriel, Christian; Bendfeldt, Hanna; Radbruch, Andreas; Baumgrass, Ria

    2011-08-01

    Antigen-specific stimulation of T helper (Th) cells initiates signaling cascades that ultimately result in the activation of the transcription factors NF-κB, NFAT, and AP-1 which regulate, together with other factors, many T-cell functions such as cytokine production, proliferation, and differentiation. Ordered assembly and different phosphorylation events, along with subcellular translocation of the CARMA1/Bcl-10/MALT1 complex, determine NF-κB activation after T-cell receptor (TCR) triggering. We now provide evidence that inhibition of the Ser/Thr phosphatase calcineurin (CaN) prevents dephosphorylation of Bcl-10. CaN, in constant interaction with the Bcl-10/MALT1 complex, is able to dephosphorylate Bcl-10. The CaN inhibitor cyclosporine A (CsA) converts a transient phosphorylation of Bcl-10 Ser138 during the immediate early phase of T-cell activation into a persistent state. Thus, subsequent processes such as IKKβ phosphorylation, IκBα degradation, p65 nuclear translocation, and DNA binding are diminished. Consistently, CsA treatment does not affect the phosphorylation pattern of the upstream kinase PKCθ. Together, our findings demonstrate that CaN functions as a critical signaling molecule during Th cell activation, regulating Bcl-10 phosphorylation and thereby NF-κB activation.

  5. Search for Ah(dioxin) receptor target genes which mediate dioxin toxicity: induction of p27{sup Kip1} cell cycle inhibitor and N-myristoyltransferase 2

    Energy Technology Data Exchange (ETDEWEB)

    Kolluri, S.K.

    1999-01-01

    Dioxins, in particular TCDD, are potent mammalian toxins acting predominantly in the thymus and skin, in body weight regulation and in liver carcinogenesis. The Ah receptor (AhR) a ligand activated transcription factor belonging to the bHLH-PAS protein family mediates the toxicity of dioxins. Despite the extensive research conducted during the past 20 years, the mechanism by which AhR mediates the toxicity of dioxins is not understood. Known AhR regulated genes mostly code for xenobiotica metabolizing enzymes but the AhR target gene(s) which mediate toxicity are not known. In this study 5L rat hepatoma cells were employed as a model system for dioxin toxicity in which TCDD severely delays cell cycle progression in the G1 phase by an AhR dependent mechanism. An AhR deficient variant subclone of 5L cells, the BP8 cells, are resistant to TCDD. These AhR-deficient cells were used for a mutational analysis of AhR overexpression to test the required properties of AhR to delay cell cycle progression. Both, the receptor`s capacity for sequence specific DNA recognition and the presence of the transcriptional activation domain are necessary to induce the cell cycle delay. This suggests that AhR mediates the TCDD effects on cell cycle by bona fide induction of yet to be identified target genes. Such AhR target genes were searched following two approaches, e.g. based on the biochemical analysis of the cell cycle machinery and by a systematic search for AhR induced genes. Evidence from biochemical analysis of the cell cycle machinery suggested that TCDD might induce cell cycle inhibitor(s). One of the inhibitory proteins, p27{sup Kip1}, is induced by TCDD in 5L cells. Induction of p27{sup Kip1} occurs through the direct induction of Kip1 mRNA by AhR. AhR-dependent activation of Kip1-transcription is a novel mechanism of Kip1 induction which is distinct from the accumulation of Kip1 protein caused by posttranscriptional regulation in all the cases reported so far. Kip1 is the

  6. Localized calcineurin confers Ca2+-dependent inactivation on neuronal L-type Ca2+ channels.

    Science.gov (United States)

    Oliveria, Seth F; Dittmer, Philip J; Youn, Dong-ho; Dell'Acqua, Mark L; Sather, William A

    2012-10-31

    Excitation-driven entry of Ca(2+) through L-type voltage-gated Ca(2+) channels controls gene expression in neurons and a variety of fundamental activities in other kinds of excitable cells. The probability of opening of Ca(V)1.2 L-type channels is subject to pronounced enhancement by cAMP-dependent protein kinase (PKA), which is scaffolded to Ca(V)1.2 channels by A-kinase anchoring proteins (AKAPs). Ca(V)1.2 channels also undergo negative autoregulation via Ca(2+)-dependent inactivation (CDI), which strongly limits Ca(2+) entry. An abundance of evidence indicates that CDI relies upon binding of Ca(2+)/calmodulin (CaM) to an isoleucine-glutamine motif in the carboxy tail of Ca(V)1.2 L-type channels, a molecular mechanism seemingly unrelated to phosphorylation-mediated channel enhancement. But our work reveals, in cultured hippocampal neurons and a heterologous expression system, that the Ca(2+)/CaM-activated phosphatase calcineurin (CaN) is scaffolded to Ca(V)1.2 channels by the neuronal anchoring protein AKAP79/150, and that overexpression of an AKAP79/150 mutant incapable of binding CaN (ΔPIX; CaN-binding PXIXIT motif deleted) impedes CDI. Interventions that suppress CaN activity-mutation in its catalytic site, antagonism with cyclosporine A or FK506, or intracellular perfusion with a peptide mimicking the sequence of the phosphatase's autoinhibitory domain-interfere with normal CDI. In cultured hippocampal neurons from a ΔPIX knock-in mouse, CDI is absent. Results of experiments with the adenylyl cyclase stimulator forskolin and with the PKA inhibitor PKI suggest that Ca(2+)/CaM-activated CaN promotes CDI by reversing channel enhancement effectuated by kinases such as PKA. Hence, our investigation of AKAP79/150-anchored CaN reconciles the CaM-based model of CDI with an earlier, seemingly contradictory model based on dephosphorylation signaling.

  7. Activation of calcineurin in human failing heart ventricle by endothelin-1, angiotensin II and urotensin II.

    Science.gov (United States)

    Li, Joan; Wang, Jianchun; Russell, Fraser D; Molenaar, Peter

    2005-06-01

    1 The calcineurin (CaN) enzyme-transcriptional pathway is critically involved in hypertrophy of heart muscle in some animal models. Currently there is no information concerning the regulation of CaN activation by endogenous agonists in human heart. 2 Human right ventricular trabeculae from explanted human (14 male/2 female) failing hearts were set up in a tissue bath and electrically paced at 1 Hz and incubated with or without 100 nM endothelin-1 (ET-1), 10 M, angiotensin-II (Ang II) or 20 nM human urotensin-II (hUII) for 30 min. Tissues from four patients were incubated with 200 nM tacrolimus (FK506) for 30 min and then incubated in the presence or absence of ET-1 for a further 30 min. 3 ET-1 increased contractile force in all 13 patients (P0.1). FK506 had no effect on contractile force (P=0.12). 4 ET-1, Ang II and hUII increased calcineurin activity by 32, 71 and 15%, respectively, while FK506 reduced activity by 34%. ET-1 in the presence of FK506 did not restore calcineurin activity (P=0.1). 5 There was no relationship between basal CaN activity and expression levels in the right ventricle. Increased levels of free phosphate were detected in ventricular homogenates that were incubated with PKC(epsilon) compared to samples incubated without PKC(epsilon). 6 Endogenous cardiostimulants which activate G(alpha)q-coupled receptors increase the activity of calcineurin in human heart following acute (30 min) exposure. PKC may contribute to this effect by increasing levels of phosphorylated calcineurin substrate.

  8. Arabidopsis CALCINEURIN B-LIKE10 Functions Independently of the SOS Pathway during Reproductive Development in Saline Conditions.

    Science.gov (United States)

    Monihan, Shea M; Magness, Courtney A; Yadegari, Ramin; Smith, Steven E; Schumaker, Karen S

    2016-05-01

    The accumulation of sodium in soil (saline conditions) negatively affects plant growth and development. The Salt Overly Sensitive (SOS) pathway in Arabidopsis (Arabidopsis thaliana) functions to remove sodium from the cytosol during vegetative development preventing its accumulation to toxic levels. In this pathway, the SOS3 and CALCINEURIN B-LIKE10 (CBL10) calcium sensors interact with the SOS2 protein kinase to activate sodium/proton exchange at the plasma membrane (SOS1) or vacuolar membrane. To determine if the same pathway functions during reproductive development in response to salt, fertility was analyzed in wild type and the SOS pathway mutants grown in saline conditions. In response to salt, CBL10 functions early in reproductive development before fertilization, while SOS1 functions mostly after fertilization when seed development begins. Neither SOS2 nor SOS3 function in reproductive development in response to salt. Loss of CBL10 function resulted in reduced anther dehiscence, shortened stamen filaments, and aborted pollen development. In addition, cbl10 mutant pistils could not sustain the growth of wild-type pollen tubes. These results suggest that CBL10 is critical for reproductive development in the presence of salt and that it functions in different pathways during vegetative and reproductive development.

  9. Multi-parameter optimization of aza-follow-ups to BI 207524, a thumb pocket 1 HCV NS5B polymerase inhibitor. Part 2: Impact of lipophilicity on promiscuity and in vivo toxicity.

    Science.gov (United States)

    Beaulieu, Pierre L; Bolger, Gordon; Deon, Dan; Duplessis, Martin; Fazal, Gulrez; Gagnon, Alexandre; Garneau, Michel; LaPlante, Steven; Stammers, Timothy; Kukolj, George; Duan, Jianmin

    2015-03-01

    We describe our efforts to identify analogs of thumb pocket 1 HCV NS5B inhibitor 1 (aza-analog of BI 207524) with improved plasma to liver partitioning and a predicted human half-life consistent with achieving a strong antiviral effect at a reasonable dose in HCV-infected patients. Compounds 3 and 7 were identified that met these criteria but exhibited off-target promiscuity in an in vitro pharmacology screen and in vivo toxicity in rats. High lipophilicity in this class was found to correlate with increased probability for promiscuous behavior and toxicity. The synthesis of an 8×11 matrix of analogs allowed the identification of C3, an inhibitor that displayed comparable potency to 1, improved partitioning to the liver and reduced lipophilicity. Although C3 displayed reduced propensity for in vitro off-target inhibition and the toxicity profile in rats was improved, the predicted human half-life of this compound was short, resulting in unacceptable dosing requirements to maintain a strong antiviral effect in patients.

  10. A Novel Inhibitor Of Topoisomerase I is Selectively Toxic For A Subset of Non-Small Cell Lung Cancer Cell Lines | Office of Cancer Genomics

    Science.gov (United States)

    SW044248, identified through a screen for chemicals that are selectively toxic for NSCLC cell lines, was found to rapidly inhibit macromolecular synthesis in sensitive, but not in insensitive cells. SW044248 killed approximately 15% of a panel of 74 NSCLC cell lines and was non-toxic to immortalized human bronchial cell lines.

  11. The calcineurin activity profiles of cyclosporin and tacrolimus are different in stable renal transplant patients

    DEFF Research Database (Denmark)

    Koefoed-Nielsen, PB; Karamperis, N; Hojskov, C

    2006-01-01

    in determining optimal doses. Forty stable renal transplant patients were investigated three times in a 6-month period. Blood samples were drawn at 0, 1, 2, 3 and 4 h after oral intake of tacrolimus (FK) or cyclosporin at days 1 and 180. At day 90, one blood sample at trough level (FK) or C2 level (cyclosporin A......Cyclosporin and tacrolimus remain the cornerstone immunosuppressive drugs in organ transplantation. Dosing and monitoring these drugs is based on pharmacokinetic protocols, but measuring a pharmacodynamic parameter, calcineurin phosphatase (CaN) activity, could be a valuable supplement...... significantly different effects on calcineurin activity in renal transplant patients with stable, well-functioning grafts and that tacrolimus-treated patients can maintain good, stable graft function with minimal CaN inhibition....

  12. Calcineurin is involved in cardioprotection induced by ischemic postconditioning through attenuating endoplasmic reticulum stress

    Institute of Scientific and Technical Information of China (English)

    CHEN Yi-hong; WU Xu-dong; YAO Shu-tong; SUN Seng; LIU Xiu-hua

    2011-01-01

    Background Ischemic postconditioning (I-postC) is a newly discovered and more amenable cardioprotective strategy capable of protecting the myocardium from ischemia/reperfusion (I/R) injury.Endoplasmic reticulum (ER) is a principal site for secretary protein synthesis and calcium storage.Myocardial I/R causes ER stress and emerging studies suggest that the cardioprotection has been linked to the modulation of ER stress.The aim of the present study was to determine whether cardioprotection of I-postC involves reduction in ER stress through calcineurin pathway.Methods In the in vivo model of rat myocardial I/R,myocardial infarct size was measured by triphenyltetrazolium chloride (TTC) staining and apoptosis was detected using terminal eoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay.Expression of calreticulin,C/EBP homologous protein (CHOP),caspase-12,and activation of caspase-12 in myocardium were detected by Western blotting.The activity and expression of calcineurin in myocardium were also detected.Results I-postC protected the I/R heart against apoptosis,myocardial infarction,and leakage of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB).I-postC suppressed I/R-induced ER stress,as shown by a decrease in the expression of calreticulin and CHOP,and caspase-12 activation.I-postC downregulated calcineurin activation in myocardium subjected to I/R.Conclusion I-postC protects myocardium from I/R injury by suppressing ER stress and calcineurin pathways are not associated with the I-postC-induced suppression of ER stress-related apoptosis.

  13. Acute calcineurin inhibition with tacrolimus increases phosphorylated UT-A1.

    Science.gov (United States)

    Ilori, Titilayo O; Wang, Yanhua; Blount, Mitsi A; Martin, Christopher F; Sands, Jeff M; Klein, Janet D

    2012-04-15

    UT-A1, the urea transporter present in the apical membrane of the inner medullary collecting duct, is crucial to the kidney's ability to concentrate urine. Phosphorylation of UT-A1 on serines 486 and 499 is important for plasma membrane trafficking. The effect of calcineurin on dephosphorylation of UT-A1 was investigated. Inner medullary collecting ducts from Sprague-Dawley rats were metabolically labeled and treated with tacrolimus to inhibit calcineurin or calyculin to inhibit protein phosphatases 1 and 2A. UT-A1 was immunoprecipitated, electrophoresed, blotted, and total UT-A1 phosphorylation was assessed by autoradiography. Total UT-A1 was determined by Western blotting. A phospho-specific antibody to pser486-UT-A1 was used to determine whether serine 486 can be hyperphosphorylated by inhibiting phosphatases. Inhibition of calcineurin showed an increase in phosphorylation per unit protein at serine 486. In contrast, inhibition of phosphatases 1 and 2A resulted in an increase in UT-A1 phosphorylation but no increase in pser486-UT-A1. In vitro perfusion of inner medullary collecting ducts showed tacrolimus-stimulated urea permeability consistent with stimulated urea transport. The location of phosphorylated UT-A1 in rats treated acutely and chronically with tacrolimus was determined using immunohistochemistry. Inner medullary collecting ducts of the acutely treated rats showed increased apical membrane association of phosphorylated UT-A1 while chronic treatment reduced membrane association of phosphorylated UT-A1. We conclude that UT-A1 may be dephosphorylated by multiple phosphatases and that the PKA-phosphorylated serine 486 is dephosphorylated by calcineurin. This is the first documentation of the role of phosphatases and the specific site of phosphorylation of UT-A1, in response to tacrolimus.

  14. Design and evaluation of a novel series of 2,3-oxidosqualene cyclase inhibitors with low systemic exposure, relationship between pharmacokinetic properties and ocular toxicity.

    Science.gov (United States)

    Fouchet, Marie-Hélène; Donche, Frédéric; Martin, Christelle; Bouillot, Anne; Junot, Christophe; Boullay, Anne-Bénédicte; Potvain, Florent; Magny, Sylvie Demaria; Coste, Hervé; Walker, Max; Issandou, Marc; Dodic, Nérina

    2008-06-01

    We describe the discovery of novel potent inhibitors of 2,3-oxidosqualene:lanosterol cyclase inhibitors (OSCi) from a focused pharmacophore-based screen. Optimization of the most tractable hits gave a series of compounds showing inhibition of cholesterol biosynthesis at 2mg/kg in the rat with distinct pharmacokinetic profiles. Two compounds were selected for toxicological study in the rat for 21 days in order to test the hypothesis that low systemic exposure could be used as a strategy to avoid the ocular side effects previously described with OSCi. We demonstrate that for this series of inhibitors, a reduction of systemic exposure is not sufficient to circumvent cataract liabilities.

  15. Calcineurin activation influences muscle phenotype in a muscle-specific fashion

    Directory of Open Access Journals (Sweden)

    Lees Simon J

    2004-07-01

    Full Text Available Abstract Background The calcium activated protein phosphatase 2B, also known as calcineurin, has been implicated as a cell signaling molecule involved with transduction of physiological signals (free cytosolic Ca2+ into molecular signals that influence the expression of phenotype-specific genes in skeletal muscle. In the present study we address the role of calcineurin in mediating adaptations in myosin heavy chain (MHC isoform expression and muscle mass using 3-month old wild-type (WT and transgenic mice displaying high-level expression of a constitutively active form of calcineurin (MCK-CN* mice. Results Slow muscles, e.g., soleus, were significantly larger (by ~24%, whereas fast muscles, e.g., medial gastrocnemius (MG and tibialis anterior were significantly smaller (by ~26 and ~16%, respectively in MCK-CN* mice compared to WT. The masses of mixed phenotype muscles, such as the plantaris and the extensor digitorum longus, were not significantly changed from WT. The soleus, plantaris, MG and diaphragm displayed shifts toward slower MHC isoforms, e.g., soleus from WT mice contained ~52% MHC-I, ~39% MHC-IIa, and ~9% MHC-IIx, whereas MCK-CN* mice had ~67% MHC-I, ~26% MHC-IIa, and ~7% MHC-IIx. The specific isoforms that were either up or down-regulated were muscle-specific. For instance, the proportion of MHC-IIa was decreased in the soleus and diaphragm, but increased in the plantaris and MG of MCK-CN* mice. Also, the proportion of MHC-IIx was unchanged in the soleus, decreased in the diaphragm and increased in the plantaris and MG of MCK-CN* relative to WT mice. Fast to slow shifts in fiber type proportions were evident for the plantaris, but not the soleus. Fast, but not slow, plantaris fibers of MCK-CN* mice had higher oxidative and lower glycolytic properties than WT. Conclusion These data suggest that calcineurin activation can influence muscle phenotype and that the specific influence of calcineurin activation on the phenotypic and mass

  16. Calcineurin inhibition at the clinical phase of prion disease reduces neurodegeneration, improves behavioral alterations and increases animal survival.

    Directory of Open Access Journals (Sweden)

    Abhisek Mukherjee

    Full Text Available Prion diseases are fatal neurodegenerative disorders characterized by a long pre-symptomatic phase followed by rapid and progressive clinical phase. Although rare in humans, the unconventional infectious nature of the disease raises the potential for an epidemic. Unfortunately, no treatment is currently available. The hallmark event in prion diseases is the accumulation of a misfolded and infectious form of the prion protein (PrP(Sc. Previous reports have shown that PrP(Sc induces endoplasmic reticulum stress and changes in calcium homeostasis in the brain of affected individuals. In this study we show that the calcium-dependent phosphatase Calcineurin (CaN is hyperactivated both in vitro and in vivo as a result of PrP(Sc formation. CaN activation mediates prion-induced neurodegeneration, suggesting that inhibition of this phosphatase could be a target for therapy. To test this hypothesis, prion infected wild type mice were treated intra-peritoneally with the CaN inhibitor FK506 at the clinical phase of the disease. Treated animals exhibited reduced severity of the clinical abnormalities and increased survival time compared to vehicle treated controls. Treatment also led to a significant increase in the brain levels of the CaN downstream targets pCREB and pBAD, which paralleled the decrease of CaN activity. Importantly, we observed a lower degree of neurodegeneration in animals treated with the drug as revealed by a higher number of neurons and a lower quantity of degenerating nerve cells. These changes were not dependent on PrP(Sc formation, since the protein accumulated in the brain to the same levels as in the untreated mice. Our findings contribute to an understanding of the mechanism of neurodegeneration in prion diseases and more importantly may provide a novel strategy for therapy that is beneficial at the clinical phase of the disease.

  17. Src Family Kinase Inhibitors Antagonize the Toxicity of Multiple Serotypes of Botulinum Neurotoxin in Human Embryonic Stem Cell-Derived Motor Neurons

    Science.gov (United States)

    Burnett, James C.; Nuss, Jonathan E.; Wanner, Laura M.; Peyser, Brian D.; Du, Hao T.; Gomba, Glenn Y.; Kota, Krishna P.; Panchal, Rekha G.; Gussio, Rick; Kane, Christopher D.; Tessarollo, Lino

    2015-01-01

    Botulinum neurotoxins (BoNTs), the causative agents of botulism, are potent inhibitors of neurotransmitter release from motor neurons. There are currently no drugs to treat BoNT intoxication after the onset of the disease symptoms. In this study, we explored how modulation of key host pathways affects the process of BoNT intoxication in human motor neurons, focusing on Src family kinase (SFK) signaling. Motor neurons derived from human embryonic stem (hES) cells were treated with a panel of SFK inhibitors and intoxicated with BoNT serotypes A, B, or E (which are responsible for >95 % of human botulism cases). Subsequently, it was found that bosutinib, dasatinib, KX2-391, PP1, PP2, Src inhibitor-1, and SU6656 significantly antagonized all three of the serotypes. Furthermore, the data indicated that the treatment of hES-derived motor neurons with multiple SFK inhibitors increased the antagonistic effect synergistically. Mechanistically, the small molecules appear to inhibit BoNTs by targeting host pathways necessary for intoxication and not by directly inhibiting the toxins’ proteolytic activity. Importantly, the identified inhibitors are all well-studied with some in clinical trials while others are FDA-approved drugs. Overall, this study emphasizes the importance of targeting host neuronal pathways, rather than the toxin’s enzymatic components, to antagonize multiple BoNT serotypes in motor neurons. PMID:25782580

  18. Long-term habituation of the gill-withdrawal reflex in Aplysia requires gene transcription, calcineurin and L-type voltage-gated calcium channels

    Directory of Open Access Journals (Sweden)

    Joseph eEsdin

    2010-11-01

    Full Text Available Although habituation is possibly the simplest form of learning, we still do not fully understand the neurobiological basis of habituation in any organism. To advance the goal of a comprehensive understanding of habituation, we have studied long-term habituation (LTH of the gill-withdrawal reflex (GWR in the marine snail Aplysia californica. Previously, we showed that habituation of the GWR in a reduced preparation lasts for up to 12 hr, and depends on protein synthesis, as well as activation of protein phosphatases 1 and 2A and postsynaptic glutamate receptors. Here, we have used the reduced preparation to further analyze the mechanisms of LTH in Aplysia. We found that LTH of the GWR depends on RNA synthesis because it was blocked by both the irreversible transcriptional inhibitor actinomycin-D and the reversible transcriptional inhibitor, 5,6-dichlorobenzimidazole riboside (DRB. In addition, LTH requires activation of protein phosphatase 2B (calcineurin, because it was disrupted by ascomycin. Finally, LTH was blocked by nitrendipine, which indicates that activation of L-type voltage-gated Ca2+ channels is required for this form of learning. Together with our previous results, the present results indicate that exclusively presynaptic mechanisms, although possibly sufficient for short-term habituation, are insufficient for LTH. Rather, LTH must involve postsynaptic, as well as presynaptic, mechanisms.

  19. Phenolic indeno[1,2-b]indoles as ABCG2-selective potent and non-toxic inhibitors stimulating basal ATPase activity.

    Science.gov (United States)

    Gozzi, Gustavo Jabor; Bouaziz, Zouhair; Winter, Evelyn; Daflon-Yunes, Nathalia; Honorat, Mylène; Guragossian, Nathalie; Marminon, Christelle; Valdameri, Glaucio; Bollacke, Andre; Guillon, Jean; Pinaud, Noël; Marchivie, Mathieu; Cadena, Silvia M; Jose, Joachim; Le Borgne, Marc; Di Pietro, Attilio

    2015-01-01

    Ketonic indeno[1,2-b]indole-9,10-dione derivatives, initially designed as human casein kinase II (CK2) inhibitors, were recently shown to be converted into efficient inhibitors of drug efflux by the breast cancer resistance protein ABCG2 upon suited substitutions including a N (5)-phenethyl on C-ring and hydrophobic groups on D-ring. A series of ten phenolic and seven p-quinonic derivatives were synthesized and screened for inhibition of both CK2 and ABCG2 activities. The best phenolic inhibitors were about threefold more potent against ABCG2 than the corresponding ketonic derivatives, and showed low cytotoxicity. They were selective for ABCG2 over both P-glycoprotein and MRP1 (multidrug resistance protein 1), whereas the ketonic derivatives also interacted with MRP1, and they additionally displayed a lower interaction with CK2. Quite interestingly, they strongly stimulated ABCG2 ATPase activity, in contrast to ketonic derivatives, suggesting distinct binding sites. In contrast, the p-quinonic indenoindoles were cytotoxic and poor ABCG2 inhibitors, whereas a partial inhibition recovery could be reached upon hydrophobic substitutions on D-ring, similarly to the ketonic derivatives.

  20. Switch to 1.5 grams MMF monotherapy for CNI-related toxicity in liver transplantation is safe and improves renal function, dyslipidemia, and hypertension.

    Science.gov (United States)

    Orlando, Giuseppe; Baiocchi, Leonardo; Cardillo, Andrea; Iaria, Giuseppe; De Liguori Carino, Nicola; De Liguori, Nicola; De Luca, Linda; Ielpo, Benedetto; Tariciotti, Laura; Angelico, Mario; Tisone, Giuseppe

    2007-01-01

    Although mycophenolate mofetil (MMF) monotherapy has been successfully used in liver transplant recipients suffering from calcineurin-inhibitor (CNI)-related chronic toxicity, still no consensus has been reached on its safety, efficacy and tolerability. We attempted the complete weaning off CNI in 42 individuals presenting chronic renal dysfunction and/or dyslipidemia and/or arterial hypertension and simultaneously introduced 1.5 gm/day MMF. CNI could be completely withdrawn in 41 cases. A total of 32 (75%) patients are currently on MMF. Mean follow-up from the introduction of MMF is 31.5 months and mean length of follow-up from the beginning of MMF monotherapy is 27.3 months. Renal function improved in 31/36 (89%) cases. Blood levels of cholesterol and triglycerides decreased in 13 of 17 (76%) and 15 of 17 (89%) patients, respectively. Arterial hypertension improved in 4 of 5 (80%) cases. A total of 8 patients showed a single episode of fluctuation of liver function tests during tapering off CNI. This feature was interpreted as an acute rejection (AR), based on the resolution of the clinical setting after escalation of MMF daily dose to 2 gm. A further patient developed a biopsy-proven AR insensitive to MMF adjustment, requiring reinstitution of the CNI dose. No deaths or major toxicity requiring MMF discontinuation occurred. In conclusion, low dose MMF monotherapy is safe, effective, and well tolerated.

  1. Naturally Occurring Genetic Variants of Human Acetylcholinesterase and Butyrylcholinesterase and Their Potential Impact on the Risk of Toxicity from Cholinesterase Inhibitors

    Science.gov (United States)

    2016-01-01

    Acetylcholinesterase (AChE) is the physiologically important target for organophosphorus toxicants (OP) including nerve agents and pesticides. Butyrylcholinesterase (BChE) in blood serves as a bioscavenger that protects AChE in nerve synapses from inhibition by OP. Mass spectrometry methods can detect exposure to OP by measuring adducts on the active site serine of plasma BChE. Genetic variants of human AChE and BChE do exist, but loss of function mutations have been identified only in the BCHE gene. The most common AChE variant, His353Asn (H322N), also known as the Yt blood group antigen, has normal AChE activity. The most common BChE variant, Ala567Thr (A539T) or the K-variant in honor of Werner Kalow, has 33% reduced plasma BChE activity. The genetic variant most frequently associated with prolonged response to muscle relaxants, Asp98Gly (D70G) or atypical BChE, has reduced activity and reduced enzyme concentration. Early studies in young, healthy males, performed at a time when it was legal to test nerve agents in humans, showed that individuals responded differently to the same low dose of sarin with toxic symptoms ranging in severity from minimal to moderate. Additionally, animal studies indicated that BChE protects from toxicants that have a higher reactivity with AChE than with BChE (e.g., nerve agents) but not from toxicants that have a higher reactivity with BChE than with AChE (e.g., OP pesticides). As a corollary, we hypothesize that individuals with genetic variants of BChE may be at increased risk of toxicity from nerve agents but not from OP pesticides. PMID:27551784

  2. Tonic 5nM DA stabilizes neuronal output by enabling bidirectional activity-dependent regulation of the hyperpolarization activated current via PKA and calcineurin.

    Directory of Open Access Journals (Sweden)

    Wulf-Dieter C Krenz

    Full Text Available Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA at type 1 DA receptors (D1Rs are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h. In the presence but not absence of 5nM DA, I h maximal conductance (G max was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP, which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation. Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP's first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output.

  3. Tonic 5nM DA stabilizes neuronal output by enabling bidirectional activity-dependent regulation of the hyperpolarization activated current via PKA and calcineurin.

    Science.gov (United States)

    Krenz, Wulf-Dieter C; Rodgers, Edmund W; Baro, Deborah J

    2015-01-01

    Volume transmission results in phasic and tonic modulatory signals. The actions of tonic dopamine (DA) at type 1 DA receptors (D1Rs) are largely undefined. Here we show that tonic 5nM DA acts at D1Rs to stabilize neuronal output over minutes by enabling activity-dependent regulation of the hyperpolarization activated current (I h). In the presence but not absence of 5nM DA, I h maximal conductance (G max) was adjusted according to changes in slow wave activity in order to maintain spike timing. Our study on the lateral pyloric neuron (LP), which undergoes rhythmic oscillations in membrane potential with depolarized plateaus, demonstrated that incremental, bi-directional changes in plateau duration produced corresponding alterations in LP I hG max when preparations were superfused with saline containing 5nM DA. However, when preparations were superfused with saline alone there was no linear correlation between LP I hGmax and duty cycle. Thus, tonic nM DA modulated the capacity for activity to modulate LP I h G max; this exemplifies metamodulation (modulation of modulation). Pretreatment with the Ca2+-chelator, BAPTA, or the specific PKA inhibitor, PKI, prevented all changes in LP I h in 5nM DA. Calcineurin inhibitors blocked activity-dependent changes enabled by DA and revealed a PKA-mediated, activity-independent enhancement of LP I hG max. These data suggested that tonic 5nM DA produced two simultaneous, PKA-dependent effects: a direct increase in LP I h G max and a priming event that permitted calcineurin regulation of LP I h. The latter produced graded reductions in LP I hG max with increasing duty cycles. We also demonstrated that this metamodulation preserved the timing of LP's first spike when network output was perturbed with bath-applied 4AP. In sum, 5nM DA permits slow wave activity to provide feedback that maintains spike timing, suggesting that one function of low-level, tonic modulation is to stabilize specific features of a dynamic output.

  4. Novel agents and associated toxicities of inhibitors of the pi3k/Akt/mtor pathway for the treatment of breast cancer

    OpenAIRE

    Chia, S.; Gandhi, S.; Joy, A.A.; Edwards, S.; Gorr, M.; Hopkins, S; Kondejewski, J.; Ayoub, J.P.; Califaretti, N.; Rayson, D.; Dent, S.F.

    2015-01-01

    The pi3k/Akt/mtor (phosphatidylinositol 3 kinase/ Akt/mammalian target of rapamycin) signalling pathway is an established driver of oncogenic activity in human malignancies. Therapeutic targeting of this pathway holds significant promise as a treatment strategy. Everolimus, an mtor inhibitor, is the first of this class of agents approved for the treatment of hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer. Everolimus has been associated with...

  5. Blockades of mitogen-activated protein kinase and calcineurin both change fibre-type markers in skeletal muscle culture

    DEFF Research Database (Denmark)

    Higginson, James; Wackerhage, Henning; Woods, Niall

    2002-01-01

    A and mitogen-activated protein kinase kinase (MEK1/2) blockade with U0126 upon myosin heavy chain (MHC) isoform mRNA levels and activities of metabolic enzymes after 1 day, 3 days and 7 days of treatment in primary cultures of spontaneously twitching rat skeletal muscle. U0126 treatment significantly decreased......Activation of either the calcineurin or the extracellular signal-regulated kinase (ERK1/2) pathway increases the percentage of slow fibres in vivo suggesting that both pathways can regulate fibre phenotypes in skeletal muscle. We investigated the effect of calcineurin blockade with cyclosporin...

  6. Identification of the glycosidase inhibitors swainsonine and calystegine B2 in Weir vine (Ipomoea sp. Q6 [aff. calobra]) and correlation with toxicity.

    Science.gov (United States)

    Molyneux, R J; McKenzie, R A; O'Sullivan, B M; Elbein, A D

    1995-06-01

    The polyhydroxy alkaloid glycosidase inhibitors swainsonine [1] and calystegine B2 [6] have been identified as constituents of the seeds of the Australian plant Ipomoea sp. Q6 [aff. calobra] (Weir vine) by gas chromatography-mass spectrometry and by their biological activity as inhibitors of specific glycosidases. This plant, which is known only from a small area of southern Queensland, has been reported to produce a neurological disorder when consumed by livestock. The extract of the seeds showed inhibition of alpha-mannosidase, beta-glucosidase, and alpha-galactosidase, consistent with the presence of 1 and alkaloids of the calystegine class. Histological examination of brain tissue from field cases of sheep and cattle poisoned by Weir vine showed lesions similar to those observed in animals poisoned by the swainsonine-containing poison peas (Swainsona spp.) of Australia and locoweeds (Astragalus and Oxytropis spp.) of North America. These results indicate that Weir vine poisoning is an additional manifestation of the induced lysosomal storage disease, mannosidosis, possibly exacerbated by inhibition of the enzymes beta-glucosidase and alpha-galactosidase by calystegine B2. This is the first reported example of a single plant species capable of producing structurally distinct glycosidase inhibitors, namely, alkaloids of the indolizidine and nortropane classes.

  7. Blood and marrow transplant clinical trials network toxicity committee consensus summary: thrombotic microangiopathy after hematopoietic stem cell transplantation.

    Science.gov (United States)

    Ho, Vincent T; Cutler, Corey; Carter, Shelly; Martin, Paul; Adams, Roberta; Horowitz, Mary; Ferrara, James; Soiffer, Robert; Giralt, Sergio

    2005-08-01

    The syndrome of microangiopathic hemolysis associated with renal failure, neurologic impairment, or both is a recognized complication of hematopoietic stem cell transplantation. This entity is often called hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP), yet it is clear that the pathophysiology of transplant-associated HUS/TTP is different from that of classic HUS or TTP. Furthermore, the incidence of this syndrome varies from 0.5% to 76% in different transplant series, primarily because of the lack of a uniform definition. The toxicity committee of the Blood and Marrow Transplant Clinical Trials Network has reviewed the current literature on transplant-related HUS/TTP and recommends that it be henceforth renamed posttransplantation thrombotic microangiopathy (TMA). An operational definition for TMA based on the presence of microangiopathic hemolysis and renal and/or neurologic dysfunction is proposed. The primary intervention after diagnosis of TMA should be withdrawal of calcineurin inhibitors. Plasma exchange, although frequently used in this condition, has not been proven to be effective. In the absence of definitive trials, plasma exchange cannot be considered a standard of care for TMA. It is hoped that these positions will improve the identification and reporting of this devastating complication after hematopoietic stem cell transplantation and facilitate future clinical studies for its prevention and treatment.

  8. Quercetin targets the interaction of calcineurin with LxVP-type motifs in immunosuppression.

    Science.gov (United States)

    Zhao, Yane; Zhang, Jin; Shi, Xiaoyu; Li, Jing; Wang, Rui; Song, Ruiwen; Wei, Qun; Cai, Huaibin; Luo, Jing

    2016-08-01

    Calcineurin (CN) is a unique calcium/calmodulin (CaM)-activated serine/threonine phosphatase. To perform its diverse biological functions, CN communicates with many substrates and other proteins. In the physiological activation of T cells, CN acts through transcriptional factors belonging to the NFAT family and other transcriptional effectors. The classic immunosuppressive drug cyclosporin A (CsA) can bind to cyclophilin (CyP) and compete with CN for the NFAT LxVP motif. CsA has debilitating side effects, including nephrotoxicity, hypertension and tremor. It is desirable to develop alternative immunosuppressive agents. To this end, we first tested the interactions between CN and the LxVP-type substrates, including endogenous regulators of calcineurin (RCAN1) and NFAT. Interestingly, we found that quercetin, the primary dietary flavonol, can inhibit the activity of CN and significantly disrupt the associations between CN and its LxVP-type substrates. We then validated the inhibitory effects of quercetin on the CN-NFAT interactions in cell-based assays. Further, quercetin also shows dose-dependent suppression of cytokine gene expression in mouse spleen cells. These data raise the possibility that the interactions of CN with its LxVP-type substrates are potential targets for immunosuppressive agents.

  9. Calcineurin and its regulator sra/DSCR1 are essential for sleep in Drosophila.

    Science.gov (United States)

    Nakai, Yasuhiro; Horiuchi, Junjiro; Tsuda, Manabu; Takeo, Satomi; Akahori, Shin; Matsuo, Takashi; Kume, Kazuhiko; Aigaki, Toshiro

    2011-09-07

    Sleep is a fundamental biological process for all animals. However, the molecular mechanisms that regulate sleep are still poorly understood. Here we report that sleep-like behavior in Drosophila is severely impaired by mutations in sarah (sra), a member of the Regulator of Calcineurin (RCAN) family of genes. Sleep reduction in sra mutants is highly correlated with decreases in Sra protein levels. Pan-neural expression of sra rescues this behavioral phenotype, indicating that neuronal sra function is required for normal sleep. Since Sra regulates calcineurin (CN), we generated and examined the behavior of knock-out mutants for all Drosophila CN genes: CanA-14F, Pp2B-14D, and CanA1 (catalytic subunits), and CanB and CanB2 (regulatory subunits). While all mutants show at least minor changes in sleep, CanA-14F(KO) and CanB(KO) have striking reductions, suggesting that these are the major CN subunits regulating sleep. In addition, neuronal expression of constitutively active forms of CN catalytic subunits also significantly reduces sleep, demonstrating that both increases and decreases in CN activity inhibit sleep. sra sleep defects are suppressed by CN mutations, indicating that sra and CN affect sleep through a common mechanism. Our results demonstrate that CN and its regulation by Sra are required for normal sleep in Drosophila and identify a critical role of Ca(2+)/calmodulin-dependent signaling in sleep regulation.

  10. Effects of L-NAME, a non-specific nitric oxide synthase inhibitor, on AlCl3-induced toxicity in the rat forebrain cortex.

    Science.gov (United States)

    Stevanović, Ivana D; Jovanović, Marina D; Jelenković, Ankica; Colić, Miodrag; Stojanović, Ivana; Ninković, Milica

    2009-03-01

    The present experiments were done to determine the effectiveness of a non-specific nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME), on oxidative stress parameters induced by aluminium chloride (AlCl(3)) intrahippocampal injections in Wistar rats. Animals were sacrificed 3 h and 30 d after treatments, heads were immediately frozen in liquid nitrogen and forebrain cortices were removed. Crude mitochondrial fraction preparations of forebrain cortices were used for the biochemical analyses: nitrite levels, superoxide production, malondialdehyde concentrations, superoxide dismutase (SOD) activities and reduced glutathione contents. AlCl(3) injection resulted in increased nitrite concentrations, superoxide anion production, malondialdehyde concentrations and reduced glutathione contents in the forebrain cortex, suggesting that AlCl(3) exposure promoted oxidative stress in this brain structure. The biochemical changes observed in neuronal tissues showed that aluminium acted as a pro-oxidant. However, the nonspecific nitric oxide synthase (NOS) inhibitor, L-NAME, exerted anti-oxidant actions in AlCl(3)-treated animals. These results revealed that NO-mediated neurotoxicity due to intrahippocampal AlCl3 injection spread temporally and spatially to the forebrain cortex, and suggested a potentially neuroprotective effect for L-NAME.

  11. Cardiac CaM Kinase II Genes δ and γ Contribute to Adverse Remodeling but Redundantly Inhibit Calcineurin-Induced Myocardial Hypertrophy

    Science.gov (United States)

    Kreusser, Michael M.; Lehmann, Lorenz H.; Keranov, Stanislav; Hoting, Marc-Oscar; Oehl, Ulrike; Kohlhaas, Michael; Reil, Jan-Christian; Neumann, Kay; Schneider, Michael D.; Hill, Joseph A.; Dobrev, Dobromir; Maack, Christoph; Maier, Lars S.; Gröne, Hermann-Josef; Katus, Hugo A.; Olson, Eric N.; Backs, Johannes

    2014-01-01

    Background Ca2+-dependent signaling through CaM Kinase II (CaMKII) and calcineurin was suggested to contribute to adverse cardiac remodeling. However, the relative importance of CaMKII versus calcineurin for adverse cardiac remodeling remained unclear. Methods and Results We generated double-knockout mice (DKO) lacking the 2 cardiac CaMKII genes δ and γ specifically in cardiomyocytes. We show that both CaMKII isoforms contribute redundantly to phosphorylation not only of phospholamban, ryanodine receptor 2, and histone deacetylase 4, but also calcineurin. Under baseline conditions, DKO mice are viable and display neither abnormal Ca2+ handling nor functional and structural changes. On pathological pressure overload and β-adrenergic stimulation, DKO mice are protected against cardiac dysfunction and interstitial fibrosis. But surprisingly and paradoxically, DKO mice develop cardiac hypertrophy driven by excessive activation of endogenous calcineurin, which is associated with a lack of phosphorylation at the auto-inhibitory calcineurin A site Ser411. Likewise, calcineurin inhibition prevents cardiac hypertrophy in DKO. On exercise performance, DKO mice show an exaggeration of cardiac hypertrophy with increased expression of the calcineurin target gene RCAN1-4 but no signs of adverse cardiac remodeling. Conclusions We established a mouse model in which CaMKII’s activity is specifically and completely abolished. By the use of this model we show that CaMKII induces maladaptive cardiac remodeling while it inhibits calcineurin-dependent hypertrophy. These data suggest inhibition of CaMKII but not calcineurin as a promising approach to attenuate the progression of heart failure. PMID:25124496

  12. Suppression of Coronavirus Replication by Cyclophilin Inhibitors

    Directory of Open Access Journals (Sweden)

    Takashi Sasaki

    2013-05-01

    Full Text Available Coronaviruses infect a variety of mammalian and avian species and cause serious diseases in humans, cats, mice, and birds in the form of severe acute respiratory syndrome (SARS, feline infectious peritonitis (FIP, mouse hepatitis, and avian infectious bronchitis, respectively. No effective vaccine or treatment has been developed for SARS-coronavirus or FIP virus, both of which cause lethal diseases. It has been reported that a cyclophilin inhibitor, cyclosporin A (CsA, could inhibit the replication of coronaviruses. CsA is a well-known immunosuppressive drug that binds to cellular cyclophilins to inhibit calcineurin, a calcium-calmodulin-activated serine/threonine-specific phosphatase. The inhibition of calcineurin blocks the translocation of nuclear factor of activated T cells from the cytosol into the nucleus, thus preventing the transcription of genes encoding cytokines such as interleukin-2. Cyclophilins are peptidyl-prolyl isomerases with physiological functions that have been described for many years to include chaperone and foldase activities. Also, many viruses require cyclophilins for replication; these include human immunodeficiency virus, vesicular stomatitis virus, and hepatitis C virus. However, the molecular mechanisms leading to the suppression of viral replication differ for different viruses. This review describes the suppressive effects of CsA on coronavirus replication.

  13. Calcium-Mediated Induction of Paradoxical Growth following Caspofungin Treatment Is Associated with Calcineurin Activation and Phosphorylation in Aspergillus fumigatus.

    Science.gov (United States)

    Juvvadi, Praveen R; Muñoz, Alberto; Lamoth, Frédéric; Soderblom, Erik J; Moseley, M Arthur; Read, Nick D; Steinbach, William J

    2015-08-01

    The echinocandin antifungal drug caspofungin at high concentrations reverses the growth inhibition of Aspergillus fumigatus, a phenomenon known as the "paradoxical effect," which is not consistently observed with other echinocandins (micafungin and anidulafungin). Previous studies of A. fumigatus revealed the loss of the paradoxical effect following pharmacological or genetic inhibition of calcineurin, yet the underlying mechanism is poorly understood. Here, we utilized a codon-optimized bioluminescent Ca(2+) reporter aequorin expression system in A. fumigatus and showed that caspofungin elicits a transient increase in cytosolic free Ca(2+) ([Ca(2+)]c) in the fungus that acts as the initial trigger of the paradoxical effect by activating calmodulin-calcineurin signaling. While the increase in [Ca(2+)]c was also observed upon treatment with micafungin, another echinocandin without the paradoxical effect, a higher [Ca(2+)]c increase was noted with the paradoxical-growth concentration of caspofungin. Treatments with a Ca(2+)-selective chelator, BAPTA [1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid], or the L-type Ca(2+) channel blocker verapamil abolished caspofungin-mediated paradoxical growth in both the wild-type and the echinocandin-resistant (EMFR-S678P) strains. Concomitant with increased [Ca(2+)]c levels at higher concentrations of caspofungin, calmodulin and calcineurin gene expression was enhanced. Phosphoproteomic analysis revealed that calcineurin is activated through phosphorylation at its serine-proline-rich region (SPRR), a domain previously shown to be essential for regulation of hyphal growth, only at a paradoxical-growth concentration of caspofungin. Our results indicate that as opposed to micafungin, the increased [Ca(2+)]c at high concentrations of caspofungin activates calmodulin-calcineurin signaling at both a transcriptional and a posttranslational level and ultimately leads to paradoxical fungal growth.

  14. Effects of the aldehyde dehydrogenase inhibitor disulfiram on the plasma pharmacokinetics, metabolism, and toxicity of benzaldehyde dimethane sulfonate (NSC281612, DMS612, BEN) in mice

    Science.gov (United States)

    Parise, Robert A.; Beumer, Jan H.; Clausen, Dana M.; Rigatti, Lora H.; Ziegler, Judy A.; Gasparetto, Maura; Smith, Clayton A; Eiseman, Julie L.

    2013-01-01

    Purpose Benzaldehyde dimethane sulfonate (DMS612, NSC281612, BEN) is an alkylator with activity against renal cell carcinoma, currently in phase I trials. In blood, BEN is rapidly metabolized into its highly reactive carboxylic acid (BA), presumably the predominant alkylating species. We hypothesized that BEN is metabolized to BA by aldehyde dehydrogenase (ALDH) and aimed to increase BEN exposure in blood and tissues by inhibiting ALDH with disulfiram thereby shifting BA production from blood to tissues. Methods Female CD2F1 mice were dosed with 20 mg/kg BEN iv alone or 24 h after 300 mg/kg disulfiram ip. BEN, BA and metabolites were quantitated in plasma and urine, and toxicities were assessed. Results BEN had a plasma t½ <5 min and produced at least 12 products. The metabolite half-lives were <136 min. Disulfiram increased BEN plasma exposure 368-fold, (AUC0-inf from 0.11 to 40.5 mg/L•min), while plasma levels of BA remained similar. Urinary BEN excretion increased (1.0% to 1.5% of dose) while BA excretion was unchanged. Hematocrit, white blood cells counts and %lymphocytes decreased after BEN administration. Co-administration of disulfiram appeared to enhance these effects. Profound liver pathology was observed in mice treated with disulfiram and BEN. Conclusions BEN plasma concentrations increased after administration of disulfiram, suggesting that ALDH mediates the rapid metabolism of BEN in vivo, which may explain the increased toxicity seen with BEN after administration of disulfiram. Our results suggest that the co-administration of BEN with drugs that inhibit ALDH or to patients that are ALDH deficient may cause liver damage. PMID:24061865

  15. Toxicity profile of epidermal growth factor receptor tyrosine kinase inhibitors in patients with epidermal growth factor receptor gene mutation-positive lung cancer

    Science.gov (United States)

    Takeda, Masayuki; Nakagawa, Kazuhiko

    2017-01-01

    Recent progress in the research on the molecular biology of lung cancer revealed that the clinical response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is associated with the presence of activating EGFR mutations. Three EGFR-TKIs, namely afatinib, erlotinib and gefitinib, are currently available for the treatment of patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC). Due to the dearth of published phase III trials prospectively evaluating the effects of one EGFR-TKI in comparison with another in such patients, the decision-making regarding which agent to recommend to any given patient lies with the treating physician. Given the potential long-term exposure of such patients to EGFR-TKIs, the toxicological properties of these drugs in such patients may differ from those observed in unselected patients. The aim of the present study was to provide an overview of the key adverse events (rash, diarrhea, hepatotoxicity and interstitial lung disease) reported for EGFR-TKIs in clinical trials including patients with advanced NSCLC. PMID:28123721

  16. Conditional calcineurin knockout mice exhibit multiple abnormal behaviors related to schizophrenia.

    Science.gov (United States)

    Miyakawa, Tsuyoshi; Leiter, Lorene M; Gerber, David J; Gainetdinov, Raul R; Sotnikova, Tatyana D; Zeng, Hongkui; Caron, Marc G; Tonegawa, Susumu

    2003-07-22

    Calcineurin (CN), a calcium- and calmodulin-dependent protein phosphatase, plays a significant role in the central nervous system. Previously, we reported that forebrain-specific CN knockout mice (CN mutant mice) have impaired working memory. To further analyze the behavioral effects of CN deficiency, we subjected CN mutant mice to a comprehensive behavioral test battery. Mutant mice showed increased locomotor activity, decreased social interaction, and impairments in prepulse inhibition and latent inhibition. In addition, CN mutant mice displayed an increased response to the locomotor stimulating effects of MK-801. Collectively, the abnormalities of CN mutant mice are strikingly similar to those described for schizophrenia. We propose that alterations affecting CN signaling could comprise a contributing factor in schizophrenia pathogenesis.

  17. Regulator of Calcineurin 1 Gene Isoform 4, Down-regulated in Hepatocellular Carcinoma, Prevents Proliferation, Migration, and Invasive Activity of Cancer Cells and Metastasis of Orthotopic Tumors by Inhibiting Nuclear Translocation of NFAT1.

    Science.gov (United States)

    Jin, Haojie; Wang, Cun; Jin, Guangzhi; Ruan, Haoyu; Gu, Dishui; Wei, Lin; Wang, Hui; Wang, Ning; Arunachalam, Einthavy; Zhang, Yurong; Deng, Xuan; Yang, Chen; Xiong, Yi; Feng, Hugang; Yao, Ming; Fang, Jingyuan; Gu, Jianren; Cong, Wenming; Qin, Wenxin

    2017-09-01

    xenograft tumors, with fewer metastases and blood vessels, than control HCC cells. In HCC cells, RCAN1.4 inhibited expression of insulin-like growth factor 1 and vascular endothelial growth factor A by reducing calcineurin activity and blocking nuclear translocation of nuclear factor of activated T cells (NFAT1). HCC cells incubated with the calcineurin inhibitor cyclosporin A had decreased nuclear level of NFAT1. HCC cells had hypermethylation of a CpG island in the 5' regulatory region of RCAN1.4, which reduced its expression. RCAN1.4 is down-regulated in HCC tissues, compared with non-tumor liver tissues. RCAN1.4 prevents cell proliferation, migration, and invasion in vitro; overexpressed RCAN1.4 in HCC cells prevents growth, angiogenesis, and metastases of xenograft tumors by inhibiting calcineurin activity and nuclear translocation of NFAT1. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  18. Fas ligand based immunotherapy: A potent and effective neoadjuvant with checkpoint inhibitor properties, or a systemically toxic promoter of tumor growth?

    Science.gov (United States)

    Modiano, Jaime F; Bellgrau, Donald

    2016-02-01

    Fas ligand (FasL, CD95L) is a 40-kDa type II transmembrane protein that binds to Fas (CD95) receptors and promotes programmed cell death. Fas receptors are expressed at higher levels in many tumors than in normal cells; however, systemic administration of FasL or agonistic anti-Fas antibodies to mice with tumors caused lethal hepatitis. Somewhat paradoxically, elimination of Fas or FasL from tumors also leads to death induced by CD95 receptor/ligand elimination (DICE). At face value, this suggests that Fas signaling not only kills normal cells, but that it also is essential for tumor cell survival. Targeting this pathway may not only fail to kill tumors, but instead may even enhance their growth, leading some to report the demise of Fas ligand in cancer immunotherapy. But, to paraphrase Mark Twain, is this death an exaggeration? Here, we provide a careful examination of the literature exploring the merits of FasL as a novel form of cancer immunotherapy. With local administration using delivery vectors that achieve high levels of expression in the tumor environment, our results indicate that the potential for systemic toxicity is eliminated in higher mammals, and that a systemic anti-tumor response ensues, which delays or prevents progression and simultaneously attacks distant metastases.

  19. Evaluation of the Toxicity of 5-Aryl-2-Aminoimidazole-Based Biofilm Inhibitors against Eukaryotic Cell Lines, Bone Cells and the Nematode Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Hans Steenackers

    2014-10-01

    Full Text Available Previously, we have synthesized several series of compounds based on the 5-aryl-2-aminoimidazole scaffold, which showed a preventive activity against microbial biofilms. We here studied the cytotoxicity of the most active compounds of each series. First, the cytostatic activity was investigated against a number of tumor cell lines (L1210, CEM and HeLa. A subset of monosubstituted 5-aryl-2-aminoimidazoles showed a moderate safety window, with therapeutic indices (TIs ranging between 3 and 20. Whereas introduction of a (cyclo-alkyl chain at the N1-position strongly reduced the TI, introduction of a (cyclo-alkyl chain or a triazole moiety at the 2N-position increased the TI up to 370. Since a promising application of preventive anti-biofilm agents is their use in anti-biofilm coatings for orthopedic implants, their effects on cell viability and functional behavior of human osteoblasts and bone marrow derived mesenchymal stem cells were tested. The 2N-substituted 5-aryl-2-aminoimidazoles consistently showed the lowest toxicity and allowed survival of the bone cells for up to 4 weeks. Moreover they did not negatively affect the osteogenic differentiation potential of the bone cells. Finally, we examined the effect of the compounds on the survival of Caenorhabditis elegans, which confirmed the higher safety window of 2N-substituted 5-aryl-2-aminoimidazoles.

  20. Nutritional intervention restores muscle but not kidney phenotypes in adult calcineurin Aα null mice.

    Directory of Open Access Journals (Sweden)

    Kirsten Madsen

    Full Text Available Mice lacking the α isoform of the catalytic subunit of calcineurin (CnAα were first reported in 1996 and have been an important model to understand the role of calcineurin in the brain, immune system, bones, muscle, and kidney. Research using the mice has been limited, however, by failure to thrive and early lethality of most null pups. Work in our laboratory led to the rescue of CnAα-/- mice by supplemental feeding to compensate for a defect in salivary enzyme secretion. The data revealed that, without intervention, knockout mice suffer from severe caloric restriction. Since nutritional deprivation is known to significantly alter development, it is imperative that previous conclusions based on CnAα-/- mice are revisited to determine which aspects of the phenotype were attributable to caloric restriction versus a direct role for CnAα. In this study, we find that defects in renal development and function persist in adult CnAα-/- mice including a significant decrease in glomerular filtration rate and an increase in blood urea nitrogen levels. These data indicate that impaired renal development we previously reported was not due to caloric restriction but rather a specific role for CnAα in renal development and function. In contrast, we find that rather than being hypoglycemic, rescued mice are mildly hyperglycemic and insulin resistant. Examination of muscle fiber types shows that previously reported reductions in type I muscle fibers are no longer evident in rescued null mice. Rather, loss of CnAα likely alters insulin response due to a reduction in insulin receptor substrate-2 (IRS2 expression and signaling in muscle. This study illustrates the importance of re-examining the phenotypes of CnAα-/- mice and the advances that are now possible with the use of adult, rescued knockout animals.

  1. Calcineurin phosphatase as a negative regulator of fear memory in hippocampus: control on nuclear factor-κB signaling in consolidation and reconsolidation.

    Science.gov (United States)

    de la Fuente, Verónica; Federman, Noel; Fustiñana, María Sol; Zalcman, Gisela; Romano, Arturo

    2014-12-01

    Protein phosphatases are important regulators of neural plasticity and memory. Some studies support that the Ca(2+) /calmodulin-dependent phosphatase calcineurin (CaN) is, on the one hand, a negative regulator of memory formation and, on the other hand, a positive regulator of memory extinction and reversal learning. However, the signaling mechanisms by which CaN exerts its action in such processes are not well understood. Previous findings support that CaN negatively regulate the nuclear factor kappaB (NF-κB) signaling pathway during extinction. Here, we have studied the role of CaN in contextual fear memory consolidation and reconsolidation in the hippocampus. We investigated the CaN control on the NF-κB signaling pathway, a key mechanism that regulates gene expression in memory processes. We found that post-training intrahippocampal administration of the CaN inhibitor FK506 enhanced memory retention one day but not two weeks after training. Accordingly, the inhibition of CaN by FK506 increased NF-κB activity in dorsal hippocampus. The administration of the NF-κB signaling pathway inhibitor sulfasalazine (SSZ) impeded the enhancing effect of FK506. In line with our findings in consolidation, FK506 administration before memory reactivation enhanced memory reconsolidation when tested one day after re-exposure to the training context. Strikingly, memory was also enhanced two weeks after training, suggesting that reinforcement during reconsolidation is more persistent than during consolidation. The coadministration of SSZ and FK506 blocked the enhancement effect in reconsolidation, suggesting that this facilitation is also dependent on the NF-κB signaling pathway. In summary, our results support a novel mechanism by which memory formation and reprocessing can be controlled by CaN regulation on NF-κB activity. © 2014 Wiley Periodicals, Inc.

  2. The anti-tumor histone deacetylase inhibitor SAHA and the natural flavonoid curcumin exhibit synergistic neuroprotection against amyloid-beta toxicity.

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    Jia Meng

    Full Text Available With the trend of an increasing aged population worldwide, Alzheimer's disease (AD, an age-related neurodegenerative disorder, as one of the major causes of dementia in elderly people is of growing concern. Despite the many hard efforts attempted during the past several decades in trying to elucidate the pathological mechanisms underlying AD and putting forward potential therapeutic strategies, there is still a lack of effective treatments for AD. The efficacy of many potential therapeutic drugs for AD is of main concern in clinical practice. For example, large bodies of evidence show that the anti-tumor histone deacetylase (HDAC inhibitor, suberoylanilidehydroxamic acid (SAHA, may be of benefit for the treatment of AD; however, its extensive inhibition of HDACs makes it a poor therapeutic. Moreover, the natural flavonoid, curcumin, may also have a potential therapeutic benefit against AD; however, it is plagued by low bioavailability. Therefore, the integrative effects of SAHA and curcumin were investigated as a protection against amyloid-beta neurotoxicity in vitro. We hypothesized that at low doses their synergistic effect would improve therapeutic selectivity, based on experiments that showed that at low concentrations SAHA and curcumin could provide comprehensive protection against Aβ25-35-induced neuronal damage in PC12 cells, strongly implying potent synergism. Furthermore, network analysis suggested that the possible mechanism underlying their synergistic action might be derived from restoration of the damaged functional link between Akt and the CBP/p300 pathway, which plays a crucial role in the pathological development of AD. Thus, our findings provided a feasible avenue for the application of a synergistic drug combination, SAHA and curcumin, in the treatment of AD.

  3. The proteasome inhibitor bortezomib induces testicular toxicity by upregulation of oxidative stress, AMP-activated protein kinase (AMPK) activation and deregulation of germ cell development in adult murine testis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [Department of Human Anatomy, Histology and Embryology, Fourth Military Medical University, Xi' an 710032 (China); Fu, Jianfang [Department of Endocrinology, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); Zhang, Shun [Reproductive Medicine Center, Department of Gynecology and Obstetrics, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China); Zhao, Jie [Department of Human Anatomy, Histology and Embryology, Fourth Military Medical University, Xi' an 710032 (China); Xie, Nianlin, E-mail: xienianlin@126.com [Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi' an 710038 (China); Cai, Guoqing, E-mail: firstchair@fmmu.edu.cn [Department of Gynaecology and Obstetrics, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China)

    2015-06-01

    Understanding how chemotherapeutic agents mediate testicular toxicity is crucial in light of compelling evidence that male infertility, one of the severe late side effects of intensive cancer treatment, occurs more often than they are expected to. Previous study demonstrated that bortezomib (BTZ), a 26S proteasome inhibitor used to treat refractory multiple myeloma (MM), exerts deleterious impacts on spermatogenesis in pubertal mice via unknown mechanisms. Here, we showed that intermittent treatment with BTZ resulted in fertility impairment in adult mice, evidenced by testicular atrophy, desquamation of immature germ cells and reduced caudal sperm storage. These deleterious effects may originate from the elevated apoptosis in distinct germ cells during the acute phase and the subsequent disruption of Sertoli–germ cell anchoring junctions (AJs) during the late recovery. Mechanistically, balance between AMP-activated protein kinase (AMPK) activation and Akt/ERK pathway appeared to be indispensable for AJ integrity during the late testicular recovery. Of particular interest, the upregulated testicular apoptosis and the following disturbance of Sertoli–germ cell interaction may both stem from the excessive oxidative stress elicited by BTZ exposure. We also provided the in vitro evidence that AMPK-dependent mechanisms counteract follicle-stimulating hormone (FSH) proliferative effects in BTZ-exposed Sertoli cells. Collectively, BTZ appeared to efficiently prevent germ cells from normal development via multiple mechanisms in adult mice. Employment of antioxidants and/or AMPK inhibitor may represent an attractive strategy of fertility preservation in male MM patients exposed to conventional BTZ therapy and warrants further investigation. - Highlights: • Intermittent treatment with BTZ caused fertility impairment in adult mice. • BTZ treatment elicited apoptosis during early phase of testicular recovery. • Up-regulation of oxidative stress by BTZ treatment

  4. First-in-Human study of CH5132799, an Oral Class I PI3K Inhibitor, Studying Toxicity, Pharmacokinetics and Pharmacodynamics, in Patients with Metastatic Cancer

    Science.gov (United States)

    Blagden, Sarah; Olmin, Aurelius; Josephs, Debra; Stavraka, Chara; Zivi, Andrea; Pinato, David J.; Anthoney, Alan; Decordova, Shaun; Swales, Karen; Riisnaes, Ruth; Pope, Lorna; Noguchi, Kohei; Shiokawa, Rie; Inatani, Michiyasu; Prince, Jenny; Jones, Keith; Twelves, Chris; Spicer, James; Banerji, Udai

    2014-01-01

    Purpose This Phase I dose-escalation study investigated the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), safety, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary clinical activity of CH5132799. Patients and Methods Patients with metastatic solid tumors were eligible for the study. CH5132799 was administered orally once daily (QD) or twice daily (BID) in 28-day cycles. Results Thirty-eight patients with solid tumors received CH5132799 at 2-96 mg QD or 48-72 mg BID. The MTD was 48 mg on the BID schedule but was not reached on the QD schedule. DLTs were grade 3 elevated liver function tests (LFT), grade 3 fatigue, grade 3 encephalopathy, grade 3 diarrhea and grade 3 diarrhea with grade 3 stomatitis; all DLTs were reversible. Most drug-related adverse events were grade 1/2. Diarrhea (34%) and nausea (32%) were the most common events. Mean Cmax and AUC0-24 in steady state at MTD were 175 ng/ml and 1,550 ng·hr/ml respectively, consistent with efficacious exposure based on preclinical modelling. Reduction in SUVmax with [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) was observed in five of seven patients at MTD. A patient with PIK3CA-mutated clear cell carcinoma of the ovary achieved a partial response by GCIG CA125 criteria and further, a heavily pre-treated patient with triple negative breast cancer had marked improvement in her cutaneous skin lesions lasting 6 cycles. Conclusion CH5132799 is well tolerated at the MTD dose 48 mg BID. At this dose the drug had a favorable PK and PD profile and preliminary evidence of clinical activity. PMID:25231405

  5. Toxic proteins in plants.

    Science.gov (United States)

    Dang, Liuyi; Van Damme, Els J M

    2015-09-01

    Plants have evolved to synthesize a variety of noxious compounds to cope with unfavorable circumstances, among which a large group of toxic proteins that play a critical role in plant defense against predators and microbes. Up to now, a wide range of harmful proteins have been discovered in different plants, including lectins, ribosome-inactivating proteins, protease inhibitors, ureases, arcelins, antimicrobial peptides and pore-forming toxins. To fulfill their role in plant defense, these proteins exhibit various degrees of toxicity towards animals, insects, bacteria or fungi. Numerous studies have been carried out to investigate the toxic effects and mode of action of these plant proteins in order to explore their possible applications. Indeed, because of their biological activities, toxic plant proteins are also considered as potentially useful tools in crop protection and in biomedical applications, such as cancer treatment. Genes encoding toxic plant proteins have been introduced into crop genomes using genetic engineering technology in order to increase the plant's resistance against pathogens and diseases. Despite the availability of ample information on toxic plant proteins, very few publications have attempted to summarize the research progress made during the last decades. This review focuses on the diversity of toxic plant proteins in view of their toxicity as well as their mode of action. Furthermore, an outlook towards the biological role(s) of these proteins and their potential applications is discussed.

  6. The role of mTOR inhibitors in the prevention of organ rejection in adult liver transplant patients: a focus on everolimus

    Directory of Open Access Journals (Sweden)

    Casanovas T

    2014-06-01

    Full Text Available Teresa Casanovas Liver Transplant Unit, Bellvitge University Hospital, Barcelona, Spain Abstract: Liver transplantation remains the therapy of choice for patients with end-stage liver disease and in selected cases of hepatocellular carcinoma. While short-term allograft survival has improved significantly in recent years, there has been little improvement in long-term survival after liver transplantation. A growing body of evidence on factors influencing the long-term outcomes and the safety profiles of existing immunosuppressive agents after liver transplant points to a need to continue searching for alternative strategies. The calcineurin inhibitors (CNIs (cyclosporine and tacrolimus currently represent the backbone of most immunosuppressor regimens. They have had a revolutionary effect on the overall success of transplantation, as is reflected in greatly reduced rates of acute rejection. However, the CNIs have significant toxicities that produce renal dysfunction, cardiovascular disease, and other unwanted effects, such as malignancies. The recognition of these risk factors has sparked interest in regimens that limit exposure to CNIs. Nowadays, the use of immunosuppressive drugs with different mechanisms of action, which allow for a reduction or avoidance of CNIs, is common. Everolimus, which belongs to the mammalian target-of-rapamycin inhibitor family and is best known for its use in kidney and heart transplantation, has recently been approved for liver transplantation. This overview discusses the emerging evidence on the role of everolimus in the prevention of rejection after liver transplantation, in de novo transplants, conversion regimens, or as a rescue therapy. In addition, some of the most relevant and current clinical problems related to everolimus in this field are discussed. Keywords: everolimus, mTOR inhibitors, tacrolimus, liver transplant, cyclosporine, renal impairment

  7. Combining ChIP-chip and expression profiling to model the MoCRZ1 mediated circuit for Ca/calcineurin signaling in the rice blast fungus.

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    Soonok Kim

    2010-05-01

    Full Text Available Significant progress has been made in defining the central signaling networks in many organisms, but collectively we know little about the downstream targets of these networks and the genes they regulate. To reconstruct the regulatory circuit of calcineurin signal transduction via MoCRZ1, a Magnaporthe oryzae C2H2 transcription factor activated by calcineurin dephosphorylation, we used a combined approach of chromatin immunoprecipitation - chip (ChIP-chip, coupled with microarray expression studies. One hundred forty genes were identified as being both a direct target of MoCRZ1 and having expression concurrently differentially regulated in a calcium/calcineurin/MoCRZ1 dependent manner. Highly represented were genes involved in calcium signaling, small molecule transport, ion homeostasis, cell wall synthesis/maintenance, and fungal virulence. Of particular note, genes involved in vesicle mediated secretion necessary for establishing host associations, were also found. MoCRZ1 itself was a target, suggesting a previously unreported autoregulation control point. The data also implicated a previously unreported feedback regulation mechanism of calcineurin activity. We propose that calcium/calcineurin regulated signal transduction circuits controlling development and pathogenicity manifest through multiple layers of regulation. We present results from the ChIP-chip and expression analysis along with a refined model of calcium/calcineurin signaling in this important plant pathogen.

  8. AKAP150 participates in calcineurin/NFAT activation during the down-regulation of voltage-gated K(+) currents in ventricular myocytes following myocardial infarction.

    Science.gov (United States)

    Nieves-Cintrón, Madeline; Hirenallur-Shanthappa, Dinesh; Nygren, Patrick J; Hinke, Simon A; Dell'Acqua, Mark L; Langeberg, Lorene K; Navedo, Manuel; Santana, Luis F; Scott, John D

    2016-07-01

    The Ca(2+)-responsive phosphatase calcineurin/protein phosphatase 2B dephosphorylates the transcription factor NFATc3. In the myocardium activation of NFATc3 down-regulates the expression of voltage-gated K(+) (Kv) channels after myocardial infarction (MI). This prolongs action potential duration and increases the probability of arrhythmias. Although recent studies infer that calcineurin is activated by local and transient Ca(2+) signals the molecular mechanism that underlies the process is unclear in ventricular myocytes. Here we test the hypothesis that sequestering of calcineurin to the sarcolemma of ventricular myocytes by the anchoring protein AKAP150 is required for acute activation of NFATc3 and the concomitant down-regulation of Kv channels following MI. Biochemical and cell based measurements resolve that approximately 0.2% of the total calcineurin activity in cardiomyocytes is associated with AKAP150. Electrophysiological analyses establish that formation of this AKAP150-calcineurin signaling dyad is essential for the activation of the phosphatase and the subsequent down-regulation of Kv channel currents following MI. Thus AKAP150-mediated targeting of calcineurin to sarcolemmal micro-domains in ventricular myocytes contributes to the local and acute gene remodeling events that lead to the down-regulation of Kv currents.

  9. Effect of everolimus initiation and early calcineurin inhibitor withdrawal on myocardial FOXP3+ regulatory T cells in heart transplantation

    DEFF Research Database (Denmark)

    Mirza, Kiran; Gustafsson, Finn; Gullestad, Lars

    2016-01-01

    hypothesized treatment with everolimus reduced the risk of CAV by modulating myocardial FoxP3 levels. METHODS: 15 patients from the Schedule trial comparing everolimus, MMF, steroid and early CNI (Everolimus, n=8) withdrawal to conventional CNI based immunosuppression (Controls, n=7) after de novo HTx were...

  10. Central nervous system disposition and metabolism of Fosdevirine (GSK2248761), a non-nucleoside reverse transcriptase inhibitor: an LC-MS and Matrix-assisted laser desorption/ionization imaging MS investigation into central nervous system toxicity.

    Science.gov (United States)

    Castellino, Stephen; Groseclose, M Reid; Sigafoos, James; Wagner, David; de Serres, Mark; Polli, Joseph W; Romach, Elizabeth; Myer, James; Hamilton, Brad

    2013-02-18

    The CNS disposition and metabolism of Fosdevirine (FDV), an HIV non-nucleoside reverse transcriptase inhibitor, was investigated in four patients who unexpectedly experienced seizures after at least 4 weeks of treatment in a Phase IIb, HIV-1 treatment experienced study. In addition, the CNS disposition and metabolism of FDV was examined in samples from rabbit, minipig, and monkey studies. LC-MS was used to characterize and estimate the concentrations of FDV and its metabolites in cerebral spinal fluid (seizure patients, rabbit, and monkey) and brain homogenate (rabbit, minipig, and monkey). The application of matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) provided the spatial distribution of FDV and its metabolites in brain tissue (rabbit, minipig, and monkey). A cysteine conjugate metabolite resulting from an initial glutathione (GSH) Michael addition to the trans-phenyl acrylonitrile moiety of FDV was the predominant drug-related component in the samples from seizure patients, rabbits, and minipigs. This metabolite persisted in the CNS for an extended period of time after the last dose in both seizure patients and minipigs. Furthermore, the localization of this metabolite was found to be highly associated with the white matter in rabbit and minipig brain sections by MALDI IMS. In contrast, the predominant component in monkey CNS was FDV, which was shown to be highly associated with the gray matter. On the basis of these data, several hypothesizes are considered, which might provide insights into species differences in CNS toxicity/seizures observed after FDV dosing.

  11. Olmesartan attenuates cardiac hypertrophy and improves cardiac diastolic function in spontaneously hypertensive rats through inhibition of calcineurin pathway.

    Science.gov (United States)

    Fu, Mingqiang; Zhou, Jingmin; Xu, Jianfeng; Zhu, Hongmin; Liao, Jianquan; Cui, Xiaotong; Sun, Aijun; Fu, Michael; Zou, Yunzeng; Hu, Kai; Ge, Junbo

    2014-03-01

    To test whether olmesartan ameliorates cardiac diastolic dysfunction in spontaneously hypertensive rats (SHRs) through calcineurin pathway. Twenty-four male SHRs of 6 months were divided into saline- (n = 12) and olmesartan-treated (n = 12) groups. Age-matched WKY (n = 12) rats served as controls. Saline (10 mL·kg·d) or the same volume of olmesartan liquor (2.5 mg·kg·d) was administered by gavage for 3 months. Heart rate, systolic blood pressure, cardiac structure, and function and histological studies were determined. Expression of calcineurin and downstream NFAT3 were also detected. Compared with age-matched Wistar Kyoto rats, SHRs of 6 months exhibited evident cardiac hypertrophy and diastolic dysfunction as demonstrated by elevated systolic blood pressure and E/E', decreased E/A and E'/A', while F, left ventricular ejection fraction and fractional shortening remained unimpaired. Treatment with olmesartan significantly decreased systolic blood pressure and ventricular hypertrophy, attenuated fibrosis, and improved diastolic function (all P olmesartan group compared with the other 2 groups (both P olmesartan on cardiac structure and diastolic dysfunction, and it may be mediated through calcineurin pathway. This indicates a new therapeutic target for diastolic dysfunction.

  12. Construction of Rat Calcineurin A α cDNA Recombinant Adenovirus Vector and Its Identification

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Rat calcineurin (CaN) A α isoform (Ppp3ca) cDNA recombinant adenovirus vector was constructed in order to explore the effect of CaN on the myocardium apoptosis induced by ischemiareperfusion injury. Total RNA was isolated from the heart of the adult Wistar rat, and Ppp3ca CDS segment of approximate 1.59 kb size was amplified by reverse transcriptional PCR method. Ppp3ca cDNA segment was cloned into pMD18-T Simple vector for sequencing, and the right clone was named T-Ppp3ca. Ppp3ca cDNA segment obtained from T-Ppp3ca was ligated with pShuttle2-IRES-EGFP to construct a recombinant plasmid pShuttle2-Ppp3ca-IRES-EGFP. Ppp3ca-IRES-EG-FP expression cassette containing CMV, Ppp3ca-IRES-EGFP and SV40 polyA DNA fragment (3.97 kb) obtained from pShuttle2-Ppp3ca-IRES-EGFP was connected with pAdeno-X backbone sequence to construct a recombinant plasmid pAdeno-Ppp3ca. After being identified by PCR and enzyme digestion, recombinant plasmid pAdeno-Ppp3ca was packaged in HEK293 cells. Supernatant of adenovirus from HEK293 cells was collected after a visible cytopathic effect (CPE) appeared.The DNA of the recombinant adenovirus was extracted with the standard method. The presence of the recombinant adenovirus was verified by PCR. The results showed that sequencing results veri fied that the PCR product of Ppp3ca gene was identical to GenBank. Agarose electrophoresis showed the bands of recombined plasmid pAdeno-Ppp3ca and the recombinant adenovirus identified by enzyme digestion and PCR were in the right range corresponding with expectation. It was concluded that the recombinant adenovirus carrying rat calcineurin A α (Ppp3ca) cDNA as well as a report gene-enhancer green fluorescent protein gene was successfully constructed in this experiment.

  13. Regulation of intracellular Ca2+ and calcineurin by NO/PKG in proliferation of vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Shi-jun LI; Ning-ling SUN

    2005-01-01

    Aim: To determine whether Ca2+/calcineurin mediated the inhibitory effects of nitric oxide/cGMP-dependent protein kinase (NO/PKG) on the proliferation of vascular smooth muscle cells (VSMC). Methods: Proliferation and viability of primary VSMC from rat aorta were measured using [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) assay and acridine orange and ethidium bromide staining, respectively. Cytosolic Ca2+ was determined by Fluo-3/AM.Calcineurin protein and its activity were assayed using immunoblotting and free inorganic phosphate analysis, respectively. Results: (±)-S-nitroso-N-acetylpenicillamine (SNAP) and Sp-8-(4-chlorophenylthio)-guanosine-3',5'-cyclic monophosphorothioate (Sp-8-pCPT-cGMPS) decreased phenylephrine (PE)-induced proliferation of VSMC by 27.3% and 36.6%, respectively, but Rp-8-[(4-chlorophenyl)thio]-guanosine-3',5'-cyclic monophosphorothioate (Rp-8-pCPT-cGMPS) increased PE-induced proliferation of VSMC. SNAP, Sp-8-pCPT-cGMPS,and Rp-8-pCPT-cGMPS did not affect the viability of VSMC. Calcineurin protein was decreased by 63.1% and its activity was decreased by 59.7% in smooth muscle cells (SMC) pretreated with verapamil (Ver) and then stimulated by PE. In SMC pretreated with Ver, the absorbance of cells stimulated by PE decreased by 22.0% and was further inhibited by the additional treatment of SNAP and Sp-8-pCPT-cGMPS. In SMC pretreated with cyclosporin A (CsA), the absorbance of cells stimulated by PE decreased by 36.7%, but could not be further altered by the additional treatment of SNAP, Sp-8-pCPT-cGMPS, and Rp-8-pCPT-cGMPS. In addition, Ver inhibited PE-induced intracellular Ca2+ variations, which could be further inhibited by SNAP and Sp-8-pCPT-cGMPS, but not by Rp-8-pCPT-cGMPS.Moreover, the increase in calcineurin activity induced by PE was inhibited by SNAP and Sp-8-pCPT-cGMPS, but was promoted by Rp-8-pCPT-cGMPS.Conclusion: NO/PKG regulates calcineurin activity via the modulation of intracellular Ca2

  14. Functional characterization of calcineurin homologs PsCNA1/PsCNB1 in Puccinia striiformis f. sp. tritici using a host-induced RNAi system.

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    Hong Zhang

    Full Text Available Calcineurin plays a key role in morphogenesis, pathogenesis and drug resistance in most fungi. However, the function of calcineurin genes in Puccinia striiformis f. sp. tritici (Pst is unclear. We identified and characterized the calcineurin genes PsCNA1 and PsCNB1 in Pst. Phylogenetic analyses indicate that PsCNA1 and PsCNB1 form a calcium/calmodulin regulated protein phosphatase belonging to the calcineurin heterodimers composed of subunits A and B. Quantitative RT-PCR analyses revealed that both PsCNA1 and PsCNB1 expression reached their maximum in the stage of haustorium formation, which is one day after inoculation. Using barely stripe mosaic virus (BSMV as a transient expression vector in wheat, the expression of PsCNA1 and PsCNB1 in Pst was suppressed, leading to slower extension of fungal hyphae and reduced production of urediospores. The immune-suppressive drugs cyclosporin A and FK506 markedly reduced the germination rates of urediospores, and when germination did occur, more than two germtubes were produced. These results suggest that the calcineurin signaling pathway participates in stripe rust morphogenetic differentiation, especially the formation of haustoria during the early stage of infection and during the production of urediospores. Therefore PsCNA1 and PsCNB1 can be considered important pathogenicity genes involved in the wheat-Pst interaction.

  15. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors...... to human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  16. Molecular cloning of Schistosoma mansoni calcineurin subunits and immunolocalization to the excretory system.

    Science.gov (United States)

    Mecozzi, B; Rossi, A; Lazzaretti, P; Kady, M; Kaiser, S; Valle, C; Cioli, D; Klinkert, M Q

    2000-10-01

    In order to explain the schistosomicidal effect of cyclosporin A, the hypothesis was advanced that the drug, complexed with cyclophilin, inhibits the phosphatase activity of parasite calcineurin (CN), with mechanisms similar to those operating in its immunosuppressive action. As a preparatory step to the testing of this hypothesis, we report the molecular cloning of both CN subunits in Schistosoma mansoni. The catalytic (A) subunit has a predicted sequence of 607 amino acids and shows substantial similarity to other cloned CNs, except for the carboxy-terminal end that is highly divergent. The regulatory (B) subunit consists of 169 amino acids that are 86% identical to those of the human counterpart and, from its anomalous electrophoretic mobility, it appears to be myristoylated. The results of Southern blotting experiments are compatible with the existence of multiple genes for CNA and a single gene for CNB. Western blots showed that both subunits are present at all stages of the parasite life cycle and can be detected both in the soluble and in the membrane fraction. Immunofluorescence confocal microscopy revealed a striking concentration of the anti-CNA reactivity in 6-8 discrete spots in the schistosomula and in distinct spots along the body of the adult parasite, corresponding to the expected localization of flame cells. Both patterns were confirmed by a perfect co-localization of the anti-CNA signal with that of a previously characterized anti-flame cell monoclonal antibody. The preferential confinement of schistosome CN to the protonephridial system suggests that the enzyme in the parasite may fulfil similar functions to those performed in mammalian kidneys.

  17. Biochemical and molecular characterization of the calcineurin in Echinococcus granulosus larval stages.

    Science.gov (United States)

    Nicolao, María Celeste; Cumino, Andrea C

    2015-06-01

    Calcineurin (CaN) is a Ca(2+)-calmodulin activated serine-threonine protein phosphatase that couples the local or global calcium signals, thus controlling important cellular functions in physiological and developmental processes. The aim of this study was to characterize CaN in Echinococcus granulosus (Eg-CaN), a human cestode parasite of clinical importance, both functionally and molecularly. We found that the catalytic subunit isoforms have predicted sequences of 613 and 557 amino acids and are substantially similar to those of the human counterpart, except for the C-terminal end. We also found that the regulatory subunit consists of 169 amino acids which are 87% identical to the human ortholog. We cloned a cDNA encoding for one of the two catalytic subunit isoforms of CaN (Eg-can-A1) as well as the only copy of the Eg-can-B gene, both constitutively transcribed in all Echinococcus larval stages and responsible for generating a functionally active heterodimer. Eg-CaN native enzyme has phosphatase activity, which is enhanced by Ca(2+)/Ni(2+) and reduced by cyclosporine A and Ca(2+) chelators. Participation of Eg-CaN in exocytosis was demonstrated using the FM4-64 probe and Eg-CaN-A was immunolocalized in the cytoplasm of tegumental cells, suckers and excretory bladder of protoscoleces. We also showed that the Eg-can-B transcripts were down-regulated in response to low Ca(2+) intracellular level, in agreement with decreased enzyme activity. Confocal microscopy revealed a striking pattern of Eg-CaN-A in discrete fluorescent spots in the protoscolex posterior bladder and vesicularized protoscoleces beginning the vesicular differentiation. In contrast, Eg-CaN-A was undetectable during the pre-microcyst closing stage while a high DDX-like RNA helicase expression was evidenced. Finally, we identified and analyzed the expression of CaN-related endogenous regulators.

  18. Immunosuppression in the elderly renal allograft recipient

    DEFF Research Database (Denmark)

    Montero, Nuria; Pérez-Sáez, María José; Pascual, Julio

    2016-01-01

    avoidance using mycophenolate mofetil (MMF). Observational cohort studies looked at different antibody induction strategies, calcineurin-inhibitors based maintenance immunosuppression, calcineurin-inhibitor-free sirolimus-based therapy and use of MMF versus azathioprine. Treatment with interleukin-2...... receptor antibody induction, calcineurin-inhibitor minimization with MMF and steroid minimization is advisable in the low immunologic risk elderly recipient, considering the increased risk of toxicities, infection and malignancies. In the high immunologic risk elderly recipient, taking into account...... the morbid consequences of acute rejection in the elderly, observational studies support antibody induction with depletive antibodies, calcineurin-inhibitor, MMF and steroids; calcineurin-inhibitor-minimization is not recommended. CONCLUSIONS: There is very limited evidence for the benefits and harms...

  19. Milk fermentation products of L. helveticus R389 activate calcineurin as a signal to promote gut mucosal immunity

    Directory of Open Access Journals (Sweden)

    Perdigón Gabriela

    2007-09-01

    Full Text Available Background Fermented milks containing probiotic bacteria are a way of delivering bioactive constituents to targets in the gastrointestinal tract. We reported previously that the fermentation of milk at constant pH 6 by L. helveticus R389 increased its content of peptide fractions, and the oral administration of the non-bacterial fraction (FMSpH6 to mice increased total secretory IgA in the intestinal lumen and enhanced the number of IgA and various cytokines producing cells as well as the secretion of IL-6 by small intestine epithelial cells. We also demonstrated that this FMSpH6 was effective for the prevention of Salmonella typhimurium infection in mice. In this work, we studied in mice the impact of the oral administration of the supernatant of milk fermented by L. helveticus R389 on the gut physiology by measuring parameters such as calcium channels and E-cadherin expression, the activation of the biological signal calcineurin and mast and goblet cells, as a way to determine some mechanisms involved in the immunomodulating effects of the milk fermentation products, observed in previous studies. We analyzed the impact of the supernatant of milk fermented by L. helveticus R389 at pH6-controlled on the expression of calcineurin and on the reinforcement of the ephitelial barrier, measuring parameters such as calcium channels and E-cadherin expression and in the reinforcement of the non-specific immunity determining mast cells and goblet cells associated to the gut. Results We observed an enhanced expression of TRPV6 channels in the duodenum, indicating an improved capacity for dietary Ca2+ uptake. We demonstrated an enhanced expression of calcineurin in the small intestine, able to upregulate immune parameters such as IL-2 and TNF production, with an increase in the number of these cytokines secreting cells. We determined an increase in the number of mucosal mast cells and goblet cells, which would mean an improved state of mucosal surveillance

  20. Conformation-specific inhibitors of Raf kinases.

    Science.gov (United States)

    Wang, Xiaolun; Schleicher, Kristin

    2013-01-01

    Since the discovery linking B-Raf mutations to human tumors in 2002, significant advances in the development of Raf inhibitors have been made, leading to the recent approval of two Raf inhibitor drugs. This chapter includes a brief introduction to B-Raf as a validated target and focuses on the three different binding modes observed with Raf small-molecule inhibitors. These various binding modes lock the Raf kinase in different conformations that impact the toxicity profiles of the inhibitors. Possible solutions to mitigate the side effects caused by inhibitor-induced dimerization are also discussed.

  1. Renal toxicity of the anticancer drug fostriecin

    NARCIS (Netherlands)

    de Vries, EGE; Meijer, S; Mulder, NH; de Jong, Paul; de Jong, Robert

    Purpose: Fostriecin is an inhibitor of topoisomerase II catalytic activity. In a phase I trial we observed renal toxicity, documented as a rise in serum creatinine, which was reversible and non-dose-limiting. The purpose of this study was a detailed analysis of this toxicity. Methods: A total of 20

  2. Transcriptomic Analysis Reveals Genes Mediating Salt Tolerance through Calcineurin/CchA-Independent Signaling in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Sha Wang

    2017-01-01

    Full Text Available Adaptation to changes in the environment is crucial for the viability of all organisms. Although the importance of calcineurin in the stress response has been highlighted in filamentous fungi, little is known about the involvement of ion-responsive genes and pathways in conferring salt tolerance without calcium signaling. In this study, high-throughput RNA-seq was used to investigate salt stress-induced genes in the parent, ΔcnaB, and ΔcnaBΔcchA strains of Aspergillus nidulans, which differ greatly in salt adaption. In total, 2,884 differentially expressed genes including 1,382 up- and 1,502 downregulated genes were identified. Secondary transporters, which were upregulated to a greater extent in ΔcnaBΔcchA than in the parent or ΔcnaB strains, are likely to play important roles in response to salt stress. Furthermore, 36 genes were exclusively upregulated in the ΔcnaBΔcchA under salt stress. Functional analysis of differentially expressed genes revealed that genes involved in transport, heat shock protein binding, and cell division processes were exclusively activated in ΔcnaBΔcchA. Overall, our findings reveal that secondary transporters and stress-responsive genes may play crucial roles in salt tolerance to bypass the requirement for the CchA-calcineurin pathway, contributing to a deeper understanding of the mechanisms that influence fungal salt stress adaption in Aspergillus.

  3. The 1p36 Tumor Suppressor KIF 1Bβ Is Required for Calcineurin Activation, Controlling Mitochondrial Fission and Apoptosis.

    Science.gov (United States)

    Li, Shuijie; Fell, Stuart M; Surova, Olga; Smedler, Erik; Wallis, Karin; Chen, Zhi Xiong; Hellman, Ulf; Johnsen, John Inge; Martinsson, Tommy; Kenchappa, Rajappa S; Uhlén, Per; Kogner, Per; Schlisio, Susanne

    2016-01-25

    KIF1Bβ is a candidate 1p36 tumor suppressor that regulates apoptosis in the developing sympathetic nervous system. We found that KIF1Bβ activates the Ca(2+)-dependent phosphatase calcineurin (CN) by stabilizing the CN-calmodulin complex, relieving enzymatic autoinhibition and enabling CN substrate recognition. CN is the key mediator of cellular responses to Ca(2+) signals and its deregulation is implicated in cancer, cardiac, neurodegenerative, and immune disease. We show that KIF1Bβ affects mitochondrial dynamics through CN-dependent dephosphorylation of Dynamin-related protein 1 (DRP1), causing mitochondrial fission and apoptosis. Furthermore, KIF1Bβ actuates recognition of all known CN substrates, implying a general mechanism for KIF1Bβ in Ca(2+) signaling and how Ca(2+)-dependent signaling is executed by CN. Pathogenic KIF1Bβ mutations previously identified in neuroblastomas and pheochromocytomas all fail to activate CN or stimulate DRP1 dephosphorylation. Importantly, KIF1Bβ and DRP1 are silenced in 1p36 hemizygous-deleted neuroblastomas, indicating that deregulation of calcineurin and mitochondrial dynamics contributes to high-risk and poor-prognosis neuroblastoma.

  4. Phentolamine inhibits exocytosis of glucagon by Gi2 protein-dependent activation of calcineurin in rat pancreatic alpha -cells.

    Science.gov (United States)

    Høy, M; Bokvist, K; Xiao-Gang, W; Hansen, J; Juhl, K; Berggren, P O; Buschard, K; Gromada, J

    2001-01-12

    Capacitance measurements were used to investigate the molecular mechanisms by which imidazoline compounds inhibit glucagon release in rat pancreatic alpha-cells. The imidazoline compound phentolamine reversibly decreased depolarization-evoked exocytosis >80% without affecting the whole-cell Ca(2+) current. During intracellular application through the recording pipette, phentolamine produced a concentration-dependent decrease in the rate of exocytosis (IC(50) = 9.7 microm). Another imidazoline compound, RX871024, exhibited similar effects on exocytosis (IC(50) = 13 microm). These actions were dependent on activation of pertussis toxin-sensitive G(i2) proteins but were not associated with stimulation of ATP-sensitive K(+) channels or adenylate cyclase activity. The inhibitory effect of phentolamine on exocytosis resulted from activation of the protein phosphatase calcineurin and was abolished by cyclosporin A and deltamethrin. Exocytosis was not affected by intracellular application of specific alpha(2), I(1), and I(2) ligands. Phentolamine reduced glucagon release (IC(50) = 1.2 microm) from intact islets by 40%, an effect abolished by pertussis toxin, cyclosporin A, and deltamethrin. These data suggest that imidazoline compounds inhibit glucagon secretion via G(i2)-dependent activation of calcineurin in the pancreatic alpha-cell. The imidazoline binding site is likely to be localized intracellularly and probably closely associated with the secretory granules.

  5. Tungsten toxicity.

    Science.gov (United States)

    Witten, Mark L; Sheppard, Paul R; Witten, Brandon L

    2012-04-05

    There is emerging evidence that tungsten has toxic health effects. We summarize the recent tungsten toxicity research in this short review. Tungsten is widely used in many commercial and military applications because it has the second highest melting temperature of any element. Consequently, it is important to elucidate the potential health effects of tungsten.

  6. There is communication between all four Ca(2+)-bindings sites of calcineurin B.

    Science.gov (United States)

    Gallagher, S C; Gao, Z H; Li, S; Dyer, R B; Trewhella, J; Klee, C B

    2001-10-09

    We have used site-directed mutagenesis, flow dialysis, and Fourier transform infrared (FTIR) spectroscopy to study Ca(2+)-binding to the regulatory component of calcineurin. Single Glu-Gln(E --> Q) mutations were used to inactivate each of the four Ca(2+)-binding sites of CnB in turn, generating mutants Q1, Q2, Q3, and Q4, with the number indicating which Ca(2+) site is inactivated. The binding data derived from flow dialysis reveal two pairs of sites in the wild-type protein, one pair with very high affinity and the other with lower affinity Ca(2+)-binding sites. Also, only three sites are titratable in the wild-type protein because one site cannot be decalcified. Mutation of site 2 leaves the protein with only two titratable sites, while mutation of sites 1, 3, or 4 leave three titratable sites that are mostly filled with 3 Ca(2+) equiv added. The binding data further show that each of the single-site mutations Q2, Q3, and Q4 affects the affinities of at least one of the remaining sites. Mutation in either of sites 3 or 4 results in a protein with no high-affinity sites, indicating communication between the two high-affinity sites, most likely sites 3 and 4. Mutation in site 2 decreases the affinity of all three remaining sites, though still leaving two relatively high-affinity sites. The FTIR data support the conclusions from the binding data with respect to the number of titratable sites as well as the impact of each mutation on the affinities of the remaining sites. We conclude therefore that there is communication between all four Ca(2+)-binding sites. In addition, the Ca(2+) induced changes in the FTIR spectra for the wild-type and Q4 mutant are most similar, suggesting that the same three Ca(2+)-binding sites are being titrated, i.e., site 4 is the very high-affinity site under the conditions of the FTIR experiments.

  7. Benzoylurea Chitin Synthesis Inhibitors.

    Science.gov (United States)

    Sun, Ranfeng; Liu, Chunjuan; Zhang, Hao; Wang, Qingmin

    2015-08-12

    Benzoylurea chitin synthesis inhibitors are widely used in integrated pest management (IPM) and insecticide resistance management (IRM) programs due to their low toxicity to mammals and predatory insects. In the past decades, a large number of benzoylurea derivatives have been synthesized, and 15 benzoylurea chitin synthesis inhibitors have been commercialized. This review focuses on the history of commercial benzolyphenylureas (BPUs), synthetic methods, structure-activity relationships (SAR), action mechanism research, environmental behaviors, and ecotoxicology. Furthermore, their disadvantages of high risk to aquatic invertebrates and crustaceans are pointed out. Finally, we propose that the para-substituents at anilide of benzoylphenylureas should be the functional groups, and bipartite model BPU analogues are discussed in an attempt to provide new insight for future development of BPUs.

  8. Tungsten Toxicity in Plants

    Science.gov (United States)

    Adamakis, Ioannis-Dimosthenis S.; Panteris, Emmanuel; Eleftheriou, Eleftherios P.

    2012-01-01

    Tungsten (W) is a rare heavy metal, widely used in a range of industrial, military and household applications due to its unique physical properties. These activities inevitably have accounted for local W accumulation at high concentrations, raising concerns about its effects for living organisms. In plants, W has primarily been used as an inhibitor of the molybdoenzymes, since it antagonizes molybdenum (Mo) for the Mo-cofactor (MoCo) of these enzymes. However, recent advances indicate that, beyond Mo-enzyme inhibition, W has toxic attributes similar with those of other heavy metals. These include hindering of seedling growth, reduction of root and shoot biomass, ultrastructural malformations of cell components, aberration of cell cycle, disruption of the cytoskeleton and deregulation of gene expression related with programmed cell death (PCD). In this article, the recent available information on W toxicity in plants and plant cells is reviewed, and the knowledge gaps and the most pertinent research directions are outlined. PMID:27137642

  9. Aspergillus parasiticus CrzA, Which Encodes a Calcineurin Response Zinc-Finger Protein, is Required for Aflatoxin Production Under Calcium Stress

    Science.gov (United States)

    Calcium has been reported to be required for aflatoxin production. Calcium, like cAMP, is a second messenger. Cacineurin, a calmodulin-dependent serine/threonine protein phosphatase, is an important component of the calcium signaling pathway. The control of calcineurin-dependent gene expression is v...

  10. Calcineurin/nuclear factor of activated T cells-coupled vanilliod transient receptor potential channel 4 ca2+ sparklets stimulate airway smooth muscle cell proliferation.

    Science.gov (United States)

    Zhao, Limin; Sullivan, Michelle N; Chase, Marlee; Gonzales, Albert L; Earley, Scott

    2014-06-01

    Proliferation of airway smooth muscle cells (ASMCs) contributes to the remodeling and irreversible obstruction of airways during severe asthma, but the mechanisms underlying this disease process are poorly understood. Here we tested the hypothesis that Ca(2+) influx through the vanilliod transient receptor potential channel (TRPV) 4 stimulates ASMC proliferation. We found that synthetic and endogenous TRPV4 agonists increase proliferation of primary ASMCs. Furthermore, we demonstrate that Ca(2+) influx through individual TRPV4 channels produces Ca(2+) microdomains in ASMCs, called "TRPV4 Ca(2+) sparklets." We also show that TRPV4 channels colocalize with the Ca(2+)/calmodulin-dependent protein phosphatase calcineurin in ASMCs. Activated calcineurin dephosphorylates nuclear factor of activated T cells (NFAT) transcription factors cytosolic (c) to allow nuclear translocation and activation of synthetic transcriptional pathways. We show that ASMC proliferation in response to TRPV4 activity is associated with calcineurin-dependent nuclear translocation of the NFATc3 isoform tagged with green florescent protein. Our findings suggest that Ca(2+) microdomains created by TRPV4 Ca(2+) sparklets activate calcineurin to stimulate nuclear translocation of NFAT and ASMC proliferation. These findings further suggest that inhibition of TRPV4 could diminish asthma-induced airway remodeling.

  11. COX-2 Inhibitors and Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2014-01-01

    Full Text Available The evidence that cyclooxygenase-2 (COX-2 is upregulated and plays an important role in carcinogenesis of gastric cancer has triggered the topic of COX-2 inhibitors as chemopreventive agents for gastric cancer. Studies find that COX-2 inhibitors are associated not only with chemoprophylactic effects, but also with chemotherapeutic potentials in gastric cancer. Both COX-dependent and COX-independent pathways have a role in the anticancer efficiency of COX-2 inhibitors. However, enthusiasm is thwarted by the potential toxicity, that is, gastrointestinal toxicity of nonselective COX-2 inhibitors and cardiovascular risk of selective COX-2 inhibitors. Therefore, more studies are needed to develop new targeted antitumor agents (such as prostaglandin E receptor antagonist and to define fundamental questions such as optimal treatment regimens, integration of cotherapy, and careful selection of candidates.

  12. Toxicants inhibiting anaerobic digestion: a review.

    Science.gov (United States)

    Chen, Jian Lin; Ortiz, Raphael; Steele, Terry W J; Stuckey, David C

    2014-12-01

    Anaerobic digestion is increasingly being used to treat wastes from many sources because of its manifold advantages over aerobic treatment, e.g. low sludge production and low energy requirements. However, anaerobic digestion is sensitive to toxicants, and a wide range of compounds can inhibit the process and cause upset or failure. Substantial research has been carried out over the years to identify specific inhibitors/toxicants, and their mechanism of toxicity in anaerobic digestion. In this review we present a detailed and critical summary of research on the inhibition of anaerobic processes by specific organic toxicants (e.g., chlorophenols, halogenated aliphatics and long chain fatty acids), inorganic toxicants (e.g., ammonia, sulfide and heavy metals) and in particular, nanomaterials, focusing on the mechanism of their inhibition/toxicity. A better understanding of the fundamental mechanisms behind inhibition/toxicity will enhance the wider application of anaerobic digestion.

  13. Naphthalene toxicity and antioxidant nutrients.

    Science.gov (United States)

    Stohs, Sidney J; Ohia, Sunny; Bagchi, Debasis

    2002-10-30

    Naphthalene is a bicyclic aromatic compound that has wide industrial and commercial applications. It is used as the starting material for the synthesis of other compounds, as a moth repellent, soil fumigant and lavatory deodorant. Most exposure occurs through low dose chronic inhalation, dermal contact or ingestion through the food chain. The lungs and eyes appear to be most susceptible to toxicity, although biochemical markers of toxicity can be demonstrated in other tissues, such as the kidney, brain and liver. In addition to lens opacification (cataracts) and histological changes associated with pneumotoxicity, other biomarkers of toxic effects include glutathione depletion, lipid peroxidation, DNA fragmentation and the production of the active oxygen species as superoxide anion and hydroxyl radical. In addition, the urinary excretion of lipid metabolites occurs. A role for the tumor suppressor gene p53 has been demonstrated. Toxic manifestations of naphthalene are associated with its oxidative metabolism to various products including quinones. The ability to protect against the toxic effects of naphthalene by using various antioxidants and free radical scavengers has been demonstrated. Studies have been conducted with vitamin E, vitamin E succinate, melatonin, curcumin, various L-cysteine prodrugs, several aldose reductase inhibitors and spin-trapping agents. The ability to prevent the toxic manifestations of naphthalene is dependent on the pharmacokinetic properties of the agents, which have been studied. The appropriate selection of chemoprotectants can be useful in preventing naphthalene toxicity.

  14. Human Toxicity

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Fantke, Peter

    2015-01-01

    . The first section of this chapter outlines the complete cause-effect pathway, from emissions of toxic substances to intake by the population up to damages in terms of human health effects. Section 2 outlines the framework for assessing human toxicity in LCIA. Section 3 discusses the contributing substances......This chapter reviews the human toxicological impacts of chemicals and how to assess these impacts in life cycle impact assessment (LCIA), in order to identify key processes and pollutants. The complete cause-effect pathway – from emissions of toxic substances up to damages on human health...... – demonstrates the importance to account for both outdoor and indoor exposure, including consumer products. Analysing the variations in intake fraction (the fraction of the emitted or applied chemical that is taken in by the consumer and the general population), effect factor and characterisation factor across...

  15. Toxic myopathies.

    Science.gov (United States)

    Pasnoor, Mamatha; Barohn, Richard J; Dimachkie, Mazen M

    2014-08-01

    Muscle tissue is highly sensitive to many substances. Early recognition of toxic myopathies is important, because they potentially are reversible on removal of the offending drug or toxin, with greater likelihood of complete resolution the sooner this is achieved. Clinical features range from mild muscle pain and cramps to severe weakness with rhabdomyolysis, renal failure, and even death. The pathogenic bases can be multifactorial. This article reviews some of the common toxic myopathies and their clinical presentation, histopathologic features, and possible underlying cellular mechanisms.

  16. [Application of process engineering to remove lignocellulose fermentation inhibitors].

    Science.gov (United States)

    Wang, Lan; Xia, Menglei; Chen, Hongzhang

    2014-05-01

    Fermentation inhibitors are toxic to cells, which is one of the bottlenecks for lignocellulose bio-refinery process. How to remove those inhibitors serves a key role in the bioconversion of lignocellulose. This article reviews the sources and the types of the inhibitors, especially the updated removal strategies including physical methods, chemical methods, biological methods and inhibitor-tolerant strain construction strategies. Based on these, we introduce a new bio-refinery model named "fractional conversion", which reduces the production of inhibitors at pretreatment stage, and a novel in situ detoxification method named "fermentation promoter exploitation technology". This review could provide new research ideas on the removal of fermentation inhibitors.

  17. Toxic synovitis

    Science.gov (United States)

    ... Names Synovitis - toxic; Transient synovitis References Horowitz R. Pediatric orthopedic emergencies. In: Adams JG, ed. Emergency Medicine: Clinical ... JW III, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap ... Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David ...

  18. Human Toxicity

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Fantke, Peter

    2015-01-01

    This chapter reviews the human toxicological impacts of chemicals and how to assess these impacts in life cycle impact assessment (LCIA), in order to identify key processes and pollutants. The complete cause-effect pathway – from emissions of toxic substances up to damages on human health...... on characterisation factors means that results should by default be reported and interpreted in log scales when comparing scenarios or substance contribution! We conclude by outlining future trends in human toxicity modelling for LCIA, with promising developments for (a) better estimates of degradation halflives, (b......) the inclusion of ionization of chemicals in human exposure including bioaccumulation, (c) metal speciation, (d) spatialised models to differentiate the variability associated with spatialisation from the uncertainty, and (e) the assessment of chemical exposure via consumer products and occupational settings...

  19. Calcium-activated-calcineurin reduces the In vitro and In vivo sensitivity of fluconazole to Candida albicans via Rta2p.

    Directory of Open Access Journals (Sweden)

    Yu Jia

    Full Text Available Due to the emergence of drug-resistance, first-line therapy with fluconazole (FLC increasingly resulted in clinical failure for the treatment of candidemia. Our previous studies found that in vitro RTA2 was involved in the calcineurin-mediated resistance to FLC in C. albicans. In this study, we found that calcium-activated-calcineurin significantly reduced the in vitro sensitivity of C. albicans to FLC by blocking the impairment of FLC to the plasma membrane via Rta2p. Furthermore, we found that RTA2 itself was not involved in C. albicans virulence, but the disruption of RTA2 dramatically increased the therapeutic efficacy of FLC in a murine model of systemic candidiasis. Conversely, both re-introduction of one RTA2 allele and ectopic expression of RTA2 significantly reduced FLC efficacy in a mammalian host. Finally, we found that calcium-activated-calcineurin, through its target Rta2p, dramatically reduced the efficacy of FLC against candidemia. Given the critical roles of Rta2p in controlling the efficacy of FLC, Rta2p can be a potential drug target for antifungal therapies.

  20. Thermal Stress and Toxicity

    Science.gov (United States)

    Elevating ambient temperature above thermoneutrality exacerbates toxicity of most air pollutants, insecticides, and other toxic chemicals. On the other hand, safety and toxicity testing of toxicants and drugs is usually performed in mice and rats maintained at subthermoneutral te...

  1. PARP inhibitors.

    Science.gov (United States)

    Anwar, Maheen; Aslam, Hafiz Muhammad; Anwar, Shahzad

    2015-01-01

    Poly (ADP-ribose) polymerases, abbreviated as PARPs, are a group of familiar proteins that play a central role in DNA repair employing the base excision repair (BER) pathway. There about 17 proteins in this family out of which the primary nuclear PARPs are PARP-1, PARP-2, PARP-3, and tankyrases 1 and 2 (PARP-5a and -5b) .The PARP family members are known to engage in a wide range of cellular activities, for example, DNA repair, transcription, cellular signaling, cell cycle regulation and mitosis amongst others. The chief functional units of PARP-1 are an amino terminal DNA binding domain (DBD), a central auto modification domain (AMD), and a carboxyl-terminal catalytic domain (CD). PARP inhibitors are currently undergoing clinical trials as targeted treatment modalities of breast, uterine, colorectal and ovarian cancer. This review summarizes current insights into the mechanism of action of PARP inhibitors, its recent clinical trials, and potential next steps in the evaluation of this promising class of anti-cancer drugs.

  2. Calpain-Calcineurin-Nuclear Factor Signaling and the Development of Atrial Fibrillation in Patients with Valvular Heart Disease and Diabetes

    Directory of Open Access Journals (Sweden)

    Yong Zhao

    2016-01-01

    Full Text Available Calpain, calcineurin (CaN, and nuclear factor of activated T cell (NFAT play a key role in the development of atrial fibrillation. Patients with valvular heart disease (VHD are prone to develop atrial fibrillation (AF. Thus, our current study was aimed at investigating whether activation of calpain-CaN-NFAT pathway is associated with the incidence of AF in the patients with VHD and diabetes. The expressions of calpain 2 and alpha- and beta-isoforms of CaN catalytic subunit (CnA as well as NFAT-c3 and NFAT-c4 were quantified by quantitative reverse transcription-polymerase chain reaction in atrial tissues from 77 hospitalized patients with VHD and diabetes. The relevant protein content was measured by Western blot and calpain 2 in human atrium was localized by immunohistochemistry. We found that the expressions of calpain 2, CnA alpha and CnA beta, and NFAT-c3 but not NFAT-c4 were significantly elevated in the samples from patients with AF compared to those with sinus rhythm (SR. Elevated protein levels of calpain 2 and CnA were observed in patients with AF, and so was the enhanced localization of calpain 2. We thereby concluded that CaN together with its upstream molecule, calpain 2, and its downstream effector, NFAT-c3, might contribute to the development of AF in patients with VHD and diabetes.

  3. GmHs1-1, encoding a calcineurin-like protein, controls hard-seededness in soybean.

    Science.gov (United States)

    Sun, Lianjun; Miao, Zhenyan; Cai, Chunmei; Zhang, Dajian; Zhao, Meixia; Wu, Yanyan; Zhang, Xueling; Swarm, Stephen A; Zhou, Liwen; Zhang, Zhanyuan J; Nelson, Randall L; Ma, Jianxin

    2015-08-01

    Loss of seed-coat impermeability was essential in the domestication of many leguminous crops to promote the production of their highly nutritious seeds. Here we show that seed-coat impermeability in wild soybean is controlled by a single gene, GmHs1-1, which encodes a calcineurin-like metallophosphoesterase transmembrane protein. GmHs1-1 is primarily expressed in the Malpighian layer of the seed coat and is associated with calcium content. The transition from impermeability to permeability in domesticated soybean was caused by artificial selection of a point mutation in GmHs1-1. Interestingly, a number of soybean landraces evaded selection for permeability because of an alternative selection for seed-coat cracking that also enables seed imbibition. Despite the single origin of the mutant allele Gmhs1-1, the distribution pattern of allelic variants in the context of soybean population structure and the detected signature of genomic introgression between wild and cultivated soybeans suggest that Gmhs1-1 may have experienced reselection for seed-coat permeability.

  4. A calcineurin inhibitory protein overexpressed in Down's syndrome interacts with the product of a ubiquitously expressed transcript

    Directory of Open Access Journals (Sweden)

    H.C.S. Silveira

    2004-06-01

    Full Text Available The Down's syndrome candidate region 1 (DSCR1 protein, encoded by a gene located in the human chromosome 21, interacts with calcineurin and is overexpressed in Down's syndrome patients. As an approach to clarifying a putative function for this protein, in the present study we used the yeast two-hybrid system to identify DSCR1 partners. The two-hybrid system is a method that allows the identification of protein-protein interactions through reconstitution of the activity of the yeast GAL 4 transcriptional activator. The gene DSCR1 fused to the GAL 4 binding domain (BD was used to screen a human fetal brain cDNA library cloned in fusion with the GAL 4 activation domain (AD. Three positive clones were found and sequence analysis revealed that all the plasmids coded for the ubiquitously expressed transcript (UXT. UXT, which is encoded in human Xp11, is a 157-amino acid protein present in both cytosol and nucleus of the cells. This positive interaction of DSCR1 and UXT was confirmed in vivo by mating the yeast strain AH109 (MATaexpressing AD-UXT with the strain Y187 (MATalpha expressing BD-DSCR1, and in vitro by co-immunoprecipitation experiments. These results may help elucidate a new function for DSCR1 and its participation in Down's syndrome pathogenesis.

  5. A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation

    Directory of Open Access Journals (Sweden)

    Eilis Hannon

    2015-07-01

    Full Text Available Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm, although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506 to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type CaV1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

  6. Atomic and dynamic insights into the beneficial effect of the 1,4-naphthoquinon-2-yl-L-tryptophan inhibitor on Alzheimer's Aβ1-42 dimer in terms of aggregation and toxicity.

    Science.gov (United States)

    Zhang, Tong; Xu, Weixin; Mu, Yuguang; Derreumaux, Philippe

    2014-02-19

    Aggregation of the amyloid β protein (Aβ) peptide with 40 or 42 residues is one key feature in Alzheimer's disease (AD). The 1,4-naphthoquinon-2-yl-L-tryptophan (NQTrp) molecule was reported to alter Aβ self-assembly and reduce toxicity. Though nuclear magnetic resonance experiments and various simulations provided atomic information about the interaction of NQTrp with Aβ peptides spanning the regions of residues 12-28 and 17-42, none of these studies were conducted on the full-length Aβ1-42 peptide. To this end, we performed extensive atomistic replica exchange molecular dynamics simulations of Aβ1-42 dimer with two NQTrp molecules in explicit solvent, by using a force field known to fold diverse proteins correctly. The interactions between NQTrp and Aβ1-42, which change the Aβ interface by reducing most of the intermolecular contacts, are found to be very dynamic and multiple, leading to many transient binding sites. The most favorable binding residues are Arg5, Asp7, Tyr10, His13, Lys16, Lys18, Phe19/Phe20, and Leu34/Met35, providing therefore a completely different picture from in vitro and in silico experiments with NQTrp with shorter Aβ fragments. Importantly, the 10 hot residues that we identified explain the beneficial effect of NQTrp in reducing both the level of Aβ1-42 aggregation and toxicity. Our results also indicate that there is room to design more efficient drugs targeting Aβ1-42 dimer against AD.

  7. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  8. Reducing Toxicity of Radiation Treatment of Advanced Prostate Cancer

    Science.gov (United States)

    2015-10-01

    408- mitigated mice showed lineage-balanced, long-term, multilineage potential as determined by serial bone marrow transplantation , indicative of...kappaB inhibitors alleviate and the proteasome inhibitor PS-341 exacerbates radiation toxicity in zebrafish embryos . Molecular Cancer Therapeutics 8

  9. Mitochondrial DNA depletion sensitizes cancer cells to PARP inhibitors by translational and post-translational repression of BRCA2.

    Science.gov (United States)

    Arbini, A A; Guerra, F; Greco, M; Marra, E; Gandee, L; Xiao, G; Lotan, Y; Gasparre, G; Hsieh, J-T; Moro, L

    2013-12-16

    Previous studies have shown that pharmacologic inhibition of poly (ADP-ribose) polymerase (PARP), a nuclear protein that is crucial in signaling single-strand DNA breaks, is synthetically lethal to cancer cells from patients with genetic deficiency in the DNA repair proteins BRCA1 and BRCA2. Herein, we demonstrate that depletion of the mitochondrial genome (mtDNA) in breast, prostate and thyroid transformed cells resulted in elevated steady-state cytosolic calcium concentration and activation of calcineurin/PI3-kinase/AKT signaling leading to upregulation of miR-1245 and the ubiquitin ligase Skp2, two potent negative regulators of the tumor suppressor protein BRCA2, thus resulting in BRCA2 protein depletion, severe reduction in homologous recombination (HR) and increased sensitivity to the PARP inhibitor rucaparib. Treatment of mtDNA-depleted cells with the PI3-kinase inhibitor LY294002, the calmodulin antagonist W-7, the calcineurin inhibitor FK506, the calcium chelator BAPTA-AM, or suppression of AKT activity by AKT small-interfering RNA (siRNA) enhanced BRCA2 protein levels as well as HR. Decreasing the intracellular calcium levels using BAPTA, or direct reconstitution of BRCA2 protein levels either by recombinant expression or by small molecule inhibition of both Skp2 and miR-1245 restored sensitivity to rucaparib to wild-type levels. Furthermore, by studying prostate tissue specimens from prostate carcinoma patients we found a direct correlation between the presence of mtDNA large deletions and loss of BRCA2 protein in vivo, suggesting that mtDNA status may serve as a marker to predict therapeutic efficacy to PARP inhibitors. In summary, our results uncover a novel mechanism by which mtDNA depletion restrains HR, and highlight the role of mtDNA in regulating sensitivity to PARP inhibitors in transformed cells.

  10. Atomic and Dynamic Insights into the Beneficial Effect of the 1,4-Naphthoquinon-2-yl-l-tryptophan Inhibitor on Alzheimer’s Aβ1–42 Dimer in Terms of Aggregation and Toxicity

    Science.gov (United States)

    2013-01-01

    Aggregation of the amyloid β protein (Aβ) peptide with 40 or 42 residues is one key feature in Alzheimer’s disease (AD). The 1,4-naphthoquinon-2-yl-l-tryptophan (NQTrp) molecule was reported to alter Aβ self-assembly and reduce toxicity. Though nuclear magnetic resonance experiments and various simulations provided atomic information about the interaction of NQTrp with Aβ peptides spanning the regions of residues 12–28 and 17–42, none of these studies were conducted on the full-length Aβ1–42 peptide. To this end, we performed extensive atomistic replica exchange molecular dynamics simulations of Aβ1–42 dimer with two NQTrp molecules in explicit solvent, by using a force field known to fold diverse proteins correctly. The interactions between NQTrp and Aβ1–42, which change the Aβ interface by reducing most of the intermolecular contacts, are found to be very dynamic and multiple, leading to many transient binding sites. The most favorable binding residues are Arg5, Asp7, Tyr10, His13, Lys16, Lys18, Phe19/Phe20, and Leu34/Met35, providing therefore a completely different picture from in vitro and in silico experiments with NQTrp with shorter Aβ fragments. Importantly, the 10 hot residues that we identified explain the beneficial effect of NQTrp in reducing both the level of Aβ1–42 aggregation and toxicity. Our results also indicate that there is room to design more efficient drugs targeting Aβ1–42 dimer against AD. PMID:24246047

  11. Renal Toxicities of Targeted Therapies.

    Science.gov (United States)

    Abbas, Anum; Mirza, Mohsin M; Ganti, Apar Kishor; Tendulkar, Ketki

    2015-12-01

    With the incorporation of targeted therapies in routine cancer therapy, it is imperative that the array of toxicities associated with these agents be well-recognized and managed, especially since these toxicities are distinct from those seen with conventional cytotoxic agents. This review will focus on these renal toxicities from commonly used targeted agents. This review discusses the mechanisms of these side effects and management strategies. Anti-vascular endothelial growth factor (VEGF) agents including the monoclonal antibody bevacizumab, aflibercept (VEGF trap), and anti-VEGF receptor (VEGFR) tyrosine kinase inhibitors (TKIs) all cause hypertension, whereas some of them result in proteinuria. Monoclonal antibodies against the human epidermal growth factor receptor (HER) family of receptors, such as cetuximab and panitumumab, cause electrolyte imbalances including hypomagnesemia and hypokalemia due to the direct nephrotoxic effect of the drug on renal tubules. Cetuximab may also result in renal tubular acidosis. The TKIs, imatinib and dasatinib, can result in acute or chronic renal failure. Rituximab, an anti-CD20 monoclonal antibody, can cause acute renal failure following initiation of therapy because of the onset of acute tumor lysis syndrome. Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, can result in proteinuria. Discerning the renal adverse effects resulting from these agents is essential for safe treatment strategies, particularly in those with pre-existing renal disease.

  12. Engineering Performance of a New Siloxane-Based Corrosion Inhibitor

    OpenAIRE

    Holmes, Niall; O'Brien, R.; Basheer, P. A.M.

    2013-01-01

    This paper presents an evaluation of a new non-toxic corrosion inhibitor on selected engineering properties of concrete mixes with different cementitious materials following a corrosion and durability study on concrete samples. Corrosion inhibitors consist of powders or solutions which are added to concrete when mixed to prevent or delay corrosion of steel by their reaction with ferrous ions to form a stable and passive ferric oxide film on the steel surface. The new inhibitor functions sligh...

  13. The Role of mTOR Inhibitors in Liver Transplantation: Reviewing the Evidence

    Directory of Open Access Journals (Sweden)

    Goran B. Klintmalm

    2014-01-01

    Full Text Available Despite the success of liver transplantation, long-term complications remain, including de novo malignancies, metabolic syndrome, and the recurrence of hepatitis C virus (HCV and hepatocellular carcinoma (HCC. The current mainstay of treatment, calcineurin inhibitors (CNIs, can also worsen posttransplant renal dysfunction, neurotoxicity, and diabetes. Clearly there is a need for better immunosuppressive agents that maintain similar rates of efficacy and renal function whilst minimizing adverse effects. The mammalian target of rapamycin (mTOR inhibitors with a mechanism of action that is different from other immunosuppressive agents has the potential to address some of these issues. In this review we surveyed the literature for reports of the use of mTOR inhibitors in adult liver transplantation with respect to renal function, efficacy, safety, neurological symptoms, de novo tumors, and the recurrence of HCC and HCV. The results of our review indicate that mTOR inhibitors are associated with efficacy comparable to CNIs while having benefits on renal function in liver transplantation. We also consider newer dosing schedules that may limit side effects. Finally, we discuss evidence that mTOR inhibitors may have benefits in the oncology setting and in relation to HCV-related allograft fibrosis, metabolic syndrome, and neurotoxicity.

  14. TWO TOPICAL CALCINEURIN INHIBITORS FOR THE TREATMENT OF ATOPIC DERMATITIS IN PEDIATRIC PATIENTS: A META-ANALYSIS OF RANDOMIZED CLINICAL TRIALS (VARIANT OF THE ARTICLE IN RUSSIAN

    Directory of Open Access Journals (Sweden)

    S.L. Chen

    2011-01-01

    Full Text Available Two new topical immunomodulators, pimecrolimus cream and tacrolimus ointment for atopic dermatitis (AD in pediatric patients, have provided alternatives to topical corticosteroids without the associated adverse events. Objective: To evaluate the efficacy and safety of tacrolimus ointment and pimecrolimus cream for the treatment of AD in pediatric patients. MEDLINE, Embase, the CNKI and Cochrane Library databases were searched up to December 2008. Additional data sources were manual searches of abstract proceedings and personal contact with investigators and pharmaceutical companies. Two investigators assessed the quality of trials with unified tables independently. Disagreements on validity assessment were resolved through discussion or consultation with the third author. Quality analysis of methodology was evaluated according to the Jadad scale, including randomization, blinding and patients’ discontinuation. Twenty trials involving 6288 infants and children with AD met the inclusion criteria. More patients using tacrolimus had a good response than those in control groups including vehicle, 1% hydrocortisone acetate and 1% pimecrolimus, the corresponding OR were (4.56; 95%CI: 2.80 to 7.44, (3.92; 95% CI: 2.96 to 5.20 and (1.58; 95% CI: 1.18 to 2.12. The effect difference between 0.03% tacrolimus and 0.1% tacrolimus ointments was not statistically significant (OR = 0.90; 95% CI: 0.55 to 1.48. The incidence of adverse events of tacrolimus ointment or pimecrolimus cream was similar to the vehicle. The major adverse events were burning and pruritus. Both tacrolimus ointment and pimecrolimus cream are safe and effective in the treatment of AD in pediatric patients. Tacrolimus ointments were superior to pimecrolimus cream.Key words: atopic dermatitis, children, meta-analysis, pimecrolimus, tacrolimus.

  15. The CECARI Study: Everolimus (Certican®) Initiation and Calcineurin Inhibitor Withdrawal in Maintenance Heart Transplant Recipients with Renal Insufficiency: A Multicenter, Randomized Trial

    Science.gov (United States)

    Derthoo, David; Van Caenegem, Olivier; De Pauw, Michel; Nellessen, Eric; Duerinckx, Nathalie; Droogne, Walter; Vörös, Gábor; Meyns, Bart; Belmans, Ann; Janssens, Stefan; Vanhaecke, Johan

    2017-01-01

    In this 3-year, open-label, multicenter study, 57 maintenance heart transplant recipients (>1 year after transplant) with renal insufficiency (eGFR 30–60 mL/min/1.73 m2) were randomized to start everolimus with CNI withdrawal (N = 29) or continue their current CNI-based immunosuppression (N = 28). The primary endpoint, change in measured glomerular filtration rate (mGFR) from baseline to year 3, did not differ significantly between both groups (+7.0 mL/min in the everolimus group versus +1.9 mL/min in the CNI group, p = 0.18). In the on-treatment analysis, the difference did reach statistical significance (+9.4 mL/min in the everolimus group versus +1.9 mL/min in the CNI group, p = 0.047). The composite safety endpoint of all-cause mortality, major adverse cardiovascular events, or treated acute rejection was not different between groups. Nonfatal adverse events occurred in 96.6% of patients in the everolimus group and 57.1% in the CNI group (p < 0.001). Ten patients (34.5%) in the everolimus group discontinued the study drug during follow-up due to adverse events. The poor adherence to the everolimus therapy might have masked a potential benefit of CNI withdrawal on renal function.

  16. Cross talk among PMCA, calcineurin and NFAT transcription factors in control of calmodulin gene expression in differentiating PC12 cells.

    Science.gov (United States)

    Boczek, Tomasz; Lisek, Malwina; Ferenc, Bozena; Zylinska, Ludmila

    2017-04-01

    Brain aging is characterized by progressive loss of plasma membrane calcium pump (PMCA) and its activator - calmodulin (CaM), but the mechanism of this phenomenon remains unresolved. CaM encoded by three genes Calm1, Calm2, Calm3, works to translate Ca(2+) signal into changes in frequently opposite cellular activities. This unique function allows CaM to affect gene expression via stimulation of calcineurin (CaN) and its downstream target - nuclear factor of activated T-cells (NFAT) and to terminate Ca(2+) signal by stimulation of its extrusion. PMCA, which exists in four isoforms PMCA1-4, may in turn shape the pattern of Ca(2+) transients and control CaN activity by its direct binding. Therefore, the interplay between PMCA, CaM and CaN/NFAT is highly plausible. To verify that, we used differentiated PC12 cells with reduced expression of PMCA2 or PMCA3 to mimic the potential changes in aged brain. Manipulation in PMCAs level decreased CaM protein in PMCA2 or PMCA3-reduced lines that was accompanied by down-regulation of Calm1 and Calm2 in both lines, but Calm3 only in PMCA2-reduced cells. Further studies showed substantially higher NFATc2 nuclear accumulation and increased NFAT transcriptional activity. Blocking of CaN/NFAT signalling resulted in almost full CaM recovery, mainly due to up-regulation of Calm2 and Calm3 genes. Moreover, higher occupancy of Calm2 and Calm3 promoters by NFATc2 and increased expression of these genes in response to NFATc2 silencing were demonstrated in PMCA2 and PMCA3-reduced lines. Our results indicate that decrease in CaM level in response to PMCAs downregulation can be driven by CaN/NFAT pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Calcineurin B homologous protein 3 negatively regulates cardiomyocyte hypertrophy via inhibition of glycogen synthase kinase 3 phosphorylation.

    Science.gov (United States)

    Kobayashi, Soushi; Nakamura, Tomoe Y; Wakabayashi, Shigeo

    2015-07-01

    Cardiac hypertrophy is a leading cause of serious heart diseases. Although many signaling molecules are involved in hypertrophy, the functions of some proteins in this process are still unknown. Calcineurin B homologous protein 3 (CHP3)/tescalcin is an EF-hand Ca(2+)-binding protein that is abundantly expressed in the heart; however, the function of CHP3 is unclear. Here, we aimed to identify the cardiac functions of CHP3. CHP3 was expressed in hearts at a wide range of developmental stages and was specifically detected in neonatal rat ventricular myocytes (NRVMs) but not in cardiac fibroblasts in culture. Moreover, knockdown of CHP3 expression using adenoviral-based RNA interference in NRVMs resulted in enlargement of cardiomyocyte size, concomitant with increased expression of a pathological hypertrophy marker ANP. This same treatment elevated glycogen synthase kinase (GSK3α/β) phosphorylation, which is known to inhibit GSK3 function. In contrast, CHP3 overexpression blocked the insulin-induced phosphorylation of GSK3α/β without affecting the phosphorylation of Akt, which is an upstream kinase of GSK3α/β, in HEK293 cells, and it inhibited both IGF-1-induced phosphorylation of GSK3β and cardiomyocyte hypertrophy in NRVMs. Co-immunoprecipitation experiments revealed that GSK3β interacted with CHP3. However, a Ca(2+)-binding-defective mutation of CHP3 (CHP3-D123A) also interacted with GSK3β and had the same inhibitory effect on GSK3α/β phosphorylation, suggesting that the action of CHP3 was independent of Ca(2+). These findings suggest that CHP3 functions as a novel negative regulator of cardiomyocyte hypertrophy via inhibition of GSK3α/β phosphorylation and subsequent enzymatic activation of GSK3α/β. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The yeast transcription factor Crz1 is activated by light in a Ca2+/calcineurin-dependent and PKA-independent manner.

    Directory of Open Access Journals (Sweden)

    Kristofer Bodvard

    Full Text Available Light in the visible range can be stressful to non-photosynthetic organisms. The yeast Saccharomyces cerevisiae has earlier been reported to respond to blue light via activation of the stress-regulated transcription factor Msn2p. Environmental changes also induce activation of calcineurin, a Ca(2+/calmodulin dependent phosphatase, which in turn controls gene transcription by dephosphorylating the transcription factor Crz1p. We investigated the connection between cellular stress caused by blue light and Ca(2+ signalling in yeast by monitoring the nuclear localization dynamics of Crz1p, Msn2p and Msn4p. The three proteins exhibit distinctly different stress responses in relation to light exposure. Msn2p, and to a lesser degree Msn4p, oscillate rapidly between the nucleus and the cytoplasm in an apparently stochastic fashion. Crz1p, in contrast, displays a rapid and permanent nuclear localization induced by illumination, which triggers Crz1p-dependent transcription of its target gene CMK2. Moreover, increased extracellular Ca(2+ levels stimulates the light-induced responses of all three transcription factors, e.g. Crz1p localizes much quicker to the nucleus and a larger fraction of cells exhibits permanent Msn2p nuclear localization at higher Ca(2+ concentration. Studies in mutants lacking Ca(2+ transporters indicate that influx of extracellular Ca(2+ is crucial for the initial stages of light-induced Crz1p nuclear localization, while mobilization of intracellular Ca(2+ stores appears necessary for a sustained response. Importantly, we found that Crz1p nuclear localization is dependent on calcineurin and the carrier protein Nmd5p, while not being affected by increased protein kinase A activity (PKA, which strongly inhibits light-induced nuclear localization of Msn2/4p. We conclude that the two central signalling pathways, cAMP-PKA-Msn2/4 and Ca(2+-calcineurin-Crz1, are both activated by blue light illumination.

  19. Interplay between calcineurin and the Slt2 MAP-kinase in mediating cell wall integrity, conidiation and virulence in the insect fungal pathogen Beauveria bassiana.

    Science.gov (United States)

    Huang, Shuaishuai; He, Zhangjiang; Zhang, Shiwei; Keyhani, Nemat O; Song, Yulin; Yang, Zhi; Jiang, Yahui; Zhang, Wenli; Pei, Yan; Zhang, Yongjun

    2015-10-01

    The entomopathogenic fungus, Beauveria bassiana, is of environmental and economic importance as an insect pathogen, currently used for the biological control of a number of pests. Cell wall integrity and conidiation are critical parameters for the ability of the fungus to infect insects and for production of the infectious propagules. The contribution of calcineurin and the Slt2 MAP kinase to cell wall integrity and development in B. bassiana was investigated. Gene knockouts of either the calcineurin CNA1 subunit or the Slt2 MAP kinase resulted in decreased tolerance to calcofluor white and high temperature. In contrast, the Δcna1 strain was more tolerant to Congo red but more sensitive to osmotic stress (NaCl, sorbitol) than the wild type, whereas the Δslt2 strain had the opposite phenotype. Changes in cell wall structure and composition were seen in the Δslt2 and Δcna1 strains during growth under cell wall stress as compared to the wild type. Both Δslt2 and Δcna1 strains showed significant alterations in growth, conidiation, and viability. Elevation of intracellular ROS levels, and decreased conidial hydrophobicity and adhesion to hydrophobic surfaces, were also seen for both mutants, as well as decreased virulence. Under cell wall stress conditions, inactivation of Slt2 significantly repressed CN-mediated phosphatase activity suggesting some level of cross talk between the two pathways. Comparative transcriptome profiling of the Δslt2 and Δcna1 strains revealed alterations in the expression of distinct gene sets, with overlap in transcripts involved in cell wall integrity, stress response, conidiation and virulence. These data illustrate convergent and divergent phenotypes and targets of the calcineurin and Slt2 pathways in B. bassiana.

  20. Toxic Amblyopia (Nutritional Amblyopia)

    Science.gov (United States)

    ... Finds Additional Content Medical News Toxic Amblyopia (Nutritional Amblyopia) By James Garrity, MD, Whitney and Betty MacMillan ... Neuropathies) Ischemic Optic Neuropathy Optic Neuritis Papilledema Toxic Amblyopia Toxic amblyopia is damage to the optic nerve ...

  1. L-F001, a Multifunction ROCK Inhibitor Prevents 6-OHDA Induced Cell Death Through Activating Akt/GSK-3beta and Nrf2/HO-1 Signaling Pathway in PC12 Cells and Attenuates MPTP-Induced Dopamine Neuron Toxicity in Mice.

    Science.gov (United States)

    Luo, Liting; Chen, Jingkao; Su, Dan; Chen, Meihui; Luo, Bingling; Pi, Rongbiao; Wang, Lan; Shen, Wei; Wang, Rikang

    2017-02-01

    Amounting evidences demonstrated that Rho/Rho-associated kinase (ROCK) might be a novel target for the therapy of Parkinson's disease (PD). Recently, we synthesized L-F001 and revealed it was a potent ROCK inhibitor with multifunctional effects. Here we investigated the effects of L-F001 in PD models. We found that L-F001 potently attenuated 6-OHDA-induced cytotoxicity in PC12 cells and significantly decreased intracellular reactive oxygen species (ROS), prevented the 6-OHDA-induced decline of mitochondrial membrane potential and intracellular GSH levels. In addition, L-F001 increased Akt and GSK-3beta phosphorylation and induced the nuclear Nrf2 and HO-1 expression in a time- and concentration-dependent manner. Moreover, L-F001 restored the levels of p-Akt and p-GSK-3beta (Ser9) as well as HO-1 expression reduced by 6-OHDA. Those effects were blocked by the specific PI3K inhibitor, LY294002, indicating the involvement of Akt/GSK-3beta pathway in the neuroprotective effect of L-F001. In addition, L-F001 significantly attenuated the tyrosinehydroxylase immunoreactive cell loss in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP)-induced mice PD model. Together, our findings suggest that L-F001 prevents 6-OHDA-induced cell death through activating Akt/GSK-3beta and Nrf2/HO-1 signaling pathway and attenuates MPTP-induced dopaminergic neuron toxicity in mice. L-F001 might be a promising drug candidate for PD.

  2. Distributed Structure Searchable Toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Distributed Structure Searchable Toxicity (DSSTox) online resource provides high quality chemical structures and annotations in association with toxicity data....

  3. Acute Demyelinating Polyneuropathy after Lung Transplantation: Guillain-Barré Syndrome or Tacrolimus Toxicity?

    Directory of Open Access Journals (Sweden)

    Nirmal S. Sharma

    2014-01-01

    Full Text Available Guillain-Barré syndrome (GBS has been described after solid organ and bone marrow transplantation mostly due to viral infections and possibly calcineurin inhibitors. Incidence after bone marrow transplant is 0.3–0.7%, though incidence in other transplants is not well known. We present the first description of tacrolimus associated GBS in lung transplant recipients in the English language literature. The pathophysiology of tacrolimus-induced polyneuropathy is not known, but some have hypothesized that tacrolimus induces an inflammatory phenomenon by differential effects on T cell subsets. Diagnosis of association may be challenging and requires high index of suspicion. The optimal treatment of GBS-associated with tacrolimus after lung transplantation is unknown, although drug discontinuation may result in improvement in some patients, while some reports suggest that the use of IVIG and/or plasmapheresis may be helpful and safe in organ transplant recipients with severe symptoms.

  4. E2/ER β Enhances Calcineurin Protein Degradation and PI3K/Akt/MDM2 Signal Transduction to Inhibit ISO-Induced Myocardial Cell Apoptosis

    Directory of Open Access Journals (Sweden)

    Kuan-Ho Lin

    2017-04-01

    Full Text Available Secretion of multifunctional estrogen and its receptor has been widely considered as the reason for markedly higher frequency of heart disease in men than in women. 17β-Estradiol (E2, for instance, has been reported to prevent development of cardiac apoptosis via activation of estrogen receptors (ERs. In addition, protein phosphatase such as protein phosphatase 1 (PP1 and calcineurin (PP2B are also involved in cardiac hypertrophy and cell apoptosis signaling. However, the mechanism by which E2/ERβ suppresses apoptosis is not fully understood, and the role of protein phosphatase in E2/ERβ action also needs further investigation. In this study, we observed that E2/ERβ inhibited isoproterenol (ISO-induced myocardial cell apoptosis, cytochrome c release and downstream apoptotic markers. Moreover, we found that E2/ERβ blocks ISO-induced apoptosis in H9c2 cells through the enhancement of calcineurin protein degradation through PI3K/Akt/MDM2 signaling pathway. Our results suggest that supplementation with estrogen and/or overexpression of estrogen receptor β gene may prove to be effective means to treat stress-induced myocardial damage.

  5. Aromatase inhibitors and bone loss.

    Science.gov (United States)

    Perez, Edith A; Weilbaecher, Katherine

    2006-08-01

    The aromatase inhibitors (AIs) anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin) are significantly more effective than the selective estrogen-receptor modulator (SERM) tamoxifen in preventing recurrence in estrogen receptor-positive early breast cancer. Aromatase inhibitors are likely to replace SERMs as first-line adjuvant therapy for many patients. However, AIs are associated with significantly more osteoporotic fractures and greater bone mineral loss. As antiresorptive agents, oral and intravenous bisphosphonates such as alendronate (Fosamax), risedronate (Actonel), ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) have efficacy in preventing postmenopausal osteoporosis, cancer treatment-related bone loss, or skeletal complications of metastatic disease. Clinical practice guidelines recommend baseline and annual follow-up bone density monitoring for all patients initiating AI therapy. Bisphosphonate therapy should be prescribed for patients with osteoporosis (T score vitamin D intake, weight-bearing exercise, and smoking cessation should be addressed. Adverse events associated with bisphosphonates include gastrointestinal toxicity, renal toxicity, and osteonecrosis of the jaw. These safety concerns should be balanced with the potential of bisphosphonates to minimize or prevent the debilitating effects of AI-associated bone loss in patients with early, hormone receptor-positive breast cancer.

  6. Chemical origins of isoform selectivity in histone deacetylase inhibitors.

    Science.gov (United States)

    Butler, Kyle V; Kozikowski, Alan P

    2008-01-01

    Histones undergo extensive posttranslational modifications that affect gene expression. Acetylation is a key histone modification that is primarily regulated by two enzymes, one of which is histone deacetylase (HDAC). The activity of HDAC causes transcriptional silencing of DNA. Eleven distinct zinc-dependent histone deacetylase isoforms have been identified in humans. Each isoform has a unique structure and function, and regulates a unique set of genes. HDAC is responsible for the regulation of many genes involved in cancer cell proliferation, and it has been implicated in the pathogenesis of many neurological conditions. HDAC inhibitors are known to be very effective anti-cancer agents, and research has shown them to be potential treatments for many other conditions. Histone deacetylase inhibitors modify the expression of many genes, and it is possible that inhibition of one isoform could cause epigenetic changes that are beneficial to treatment of a disease, while inhibition of another isoform could cause contradictory changes. Selective HDAC inhibitors will be better able to avoid these types of situations than non-specific inhibitors, and may also be less toxic than pan-HDAC inhibitors. Many potent pan-HDAC inhibitors have already been developed, leaving the development of selective inhibitors at the forefront of HDAC drug development. Certain structural moieties may be added to HDAC inhibitors to give isoform selectivity, and these will be discussed in this review. This review will focus on the applications of selective HDAC inhibitors, inhibitors reported to show selectivity, and the relationship between inhibitor structure and selectivity.

  7. A new "brew" of MALT1 inhibitors.

    Science.gov (United States)

    Young, Ryan M; Staudt, Louis M

    2012-12-11

    The activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL) is an aggressive lymphoma that is addicted to NF-κB signaling through the CARD11-BCL10-MALT1 complex. In this issue of Cancer Cell, Nagel and colleagues and Fontan and colleagues describe MALT1 inhibitors suitable for clinical use that are selectively toxic to this malignancy.

  8. Proton pump inhibitors

    Science.gov (United States)

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  9. Proteomic analysis of rat cerebral cortex following subchronic acrolein toxicity.

    Science.gov (United States)

    Rashedinia, Marzieh; Lari, Parisa; Abnous, Khalil; Hosseinzadeh, Hossein

    2013-10-01

    Acrolein, a member of reactive α,β-unsaturated aldehydes, is a major environmental pollutant. Acrolein is also produced endogenously as a toxic by-product of lipid peroxidation. Because of high reactivity, acrolein may mediate oxidative damages to cells and tissues. It has been shown to be involved in a wide variety of pathological states including pulmonary, atherosclerosis and neurodegenerative diseases. In this study we employed proteomics approach to investigate the effects of subchronic oral exposures to 3mg/kg of acrolein on protein expression profile in the brain of rats. Moreover effects of acrolein on malondialdehyde (MDA) levels and reduced glutathione (GSH) content were investigated. Our results revealed that treatment with acrolein changed levels of several proteins in diverse physiological process including energy metabolism, cell communication and transport, response to stimulus and metabolic process. Interestingly, several differentially over-expressed proteins, including β-synuclein, enolase and calcineurin, are known to be associated with human neurodegenerative diseases. Changes in the levels of some proteins were confirmed by Western blot. Moreover, acrolein increases the level of MDA, as a lipid peroxidation biomarker and decreased GSH concentrations, as a non-enzyme antioxidant in the brain of acrolein treated rats. These findings suggested that acrolein induces the oxidative stress and lipid peroxidation in the brain, and so that may contribute to the pathophysiology of neurological disorders.

  10. Transcriptional Profiling of Hypoxic Neural Stem Cells Identifies Calcineurin-NFATc4 Signaling as a Major Regulator of Neural Stem Cell Biology.

    Science.gov (United States)

    Moreno, Marta; Fernández, Virginia; Monllau, Josep M; Borrell, Víctor; Lerin, Carles; de la Iglesia, Núria

    2015-08-11

    Neural stem cells (NSCs) reside in a hypoxic microenvironment within the brain. However, the crucial transcription factors (TFs) that regulate NSC biology under physiologic hypoxia are poorly understood. Here we have performed gene set enrichment analysis (GSEA) of microarray datasets from hypoxic versus normoxic NSCs with the aim of identifying pathways and TFs that are activated under oxygen concentrations mimicking normal brain tissue microenvironment. Integration of TF target (TFT) and pathway enrichment analysis identified the calcium-regulated TF NFATc4 as a major candidate to regulate hypoxic NSC functions. Nfatc4 expression was coordinately upregulated by top hypoxia-activated TFs, while NFATc4 target genes were enriched in hypoxic NSCs. Loss-of-function analyses further revealed that the calcineurin-NFATc4 signaling axis acts as a major regulator of NSC self-renewal and proliferation in vitro and in vivo by promoting the expression of TFs, including Id2, that contribute to the maintenance of the NSC state.

  11. Expression profile of IGF-I-calcineurin-NFATc3-dependent pathway genes in skeletal muscle during early development between duck breeds differing in growth rates.

    Science.gov (United States)

    Shu, Jingting; Li, Huifang; Shan, Yanju; Xu, Wenjuan; Chen, Wenfeng; Song, Chi; Song, Weitao

    2015-06-01

    The insulin-like growth factor I (IGF-I)-calcineurin (CaN)-NFATc signaling pathways have been implicated in the regulation of myocyte hypertrophy and fiber-type specificity. In the present study, the expression of the CnAα, NFATc3, and IGF-I genes was quantified by RT-PCR for the first time in the breast muscle (BM) and leg muscle (LM) on days 13, 17, 21, 25, and 27 of embryonic development, as well as at 7 days posthatching (PH), in Gaoyou and Jinding ducks, which differ in their muscle growth rates. Consistent expression patterns of CnAα, NFATc3, and IGF-I were found in the same anatomical location at different development stages in both duck breeds, showing significant differences in an age-specific fashion. However, the three genes were differentially expressed in the two different anatomical locations (BM and LM). CnAα, NFATc3, and IGF-I messenger RNA (mRNA) could be detected as early as embryonic day 13 (ED13), and the highest level appeared at this stage in both BM and LM. Significant positive relationships were observed in the expression of the studied genes in the BM and LM of both duck breeds. Also, the expression of these three genes showed a positive relationship with the percentage of type IIb fibers and a negative relationship with the percentage of type I fibers and type IIa fibers. Our data indicate differential expression and coordinated developmental regulation of the selected genes involved in the IGF-I-calcineurin-NFATc3 pathway in duck skeletal muscle during embryonic and early PH growth and development; these data also indicate that this signaling pathway might play a role in the regulation of myofiber type transition.

  12. The mTOR inhibitor sirolimus suppresses renal, hepatic, and cardiac tissue cellular respiration.

    Science.gov (United States)

    Albawardi, Alia; Almarzooqi, Saeeda; Saraswathiamma, Dhanya; Abdul-Kader, Hidaya Mohammed; Souid, Abdul-Kader; Alfazari, Ali S

    2015-01-01

    The purpose of this in vitro study was to develop a useful biomarker (e.g., cellular respiration, or mitochondrial O2 consumption) for measuring activities of mTOR inhibitors. It measured the effects of commonly used immunosuppressants (sirolimus-rapamycin, tacrolimus, and cyclosporine) on cellular respiration in target tissues (kidney, liver, and heart) from C57BL/6 mice. The mammalian target of rapamycin (mTOR), a serine/ threonine kinase that supports nutrient-dependent cell growth and survival, is known to control energy conversion processes within the mitochondria. Consistently, inhibitors of mTOR (e.g., rapamycin, also known as sirolimus or Rapamune®) have been shown to impair mitochondrial function. Inhibitors of the calcium-dependent serine/threonine phosphatase calcineurin (e.g., tacrolimus and cyclosporine), on the other hand, strictly prevent lymphokine production leading to a reduced T-cell function. Sirolimus (10 μM) inhibited renal (22%, P=0.002), hepatic (39%, Pcellular respiration. Tacrolimus and cyclosporine had no or minimum effects on cellular respiration in these tissues. Thus, these results clearly demonstrate that impaired cellular respiration (bioenergetics) is a sensitive biomarker of the immunosuppressants that target mTOR.

  13. Toxic effects of Ricinus communis non proteic trypsin inhibitor for ...

    African Journals Online (AJOL)

    Marcelo Haro

    2015-10-21

    Oct 21, 2015 ... insect pest of maize in Brazil, attacking the plant at different .... This unit represents the amount of light absorbed by. 1 nMole .... Figure 2. Growth curve of S. frugiperda larvae fed on artificial diet containing extract from the.

  14. Low Toxicity Corrosion Inhibitors for Smart Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Kennedy Space Center (KSC) is located near one of the most corrosive natural environments in the world. Corrosion of KSC ground assets is exacerbated by the...

  15. Low Toxicity Corrosion Inhibitors for Smart Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Kennedy Space Center maintains approximately $2 billion worth of ground support facilities to support its launch vehicle program. Maintenance of the ground...

  16. 钙调蛋白磷酸酶Calcineurin对构巢曲霉产孢功能的影响%On the Role of Calcineurin in the Regulation of Asexual Sporulation in Aspergillus nidulans

    Institute of Scientific and Technical Information of China (English)

    王莎; 徐伯赢; 韩江余; 李小余

    2016-01-01

    Asexual sporulation is a common reproductive mode for a diverse group of medical fungi. Aspergillus nidulans,a premier model fungus for filamentous fungi,is used in this study.On the base of successfully constructed theΔcnaA andΔcnaB strains,we investigate the biological function of Calci-neurin in the regulation of asexual sporulation from the following three aspects:① Comparison of conidiation phenotypes between calcineurin deletion mutants and wild type strain;② Comparison of quantification conidia between calcineurin deletion mutants and wild type strain;③ Characterization of conidiophores defects in calcineurin mutants indicated by the scanning electron micrographs (SEM).Our results suggest that Calcineurin,especially its regulatory subunit B (cnaB),is critical for conidial devel-opment,with the decreased number of conidiospores and abnormal phialides in calcineurin mutants. Nevertheless,our findings in the present study will provide the theoretical basis for us to control patho-genic microorganism and be of great help in finding novel drug therapies for fungal infections.%无性产孢是医学上多种丝状真菌最为普遍的繁殖方式。以模式生物构巢曲霉为研究对象,通过观察钙调蛋白磷酸酶Calcineurin敲除菌株的菌落表型、产孢量的统计,以及扫描电镜分析产孢结构及其分生孢子的表面结构特征,探讨Calcineurin在构巢曲霉产孢过程中的功能。结果表明,Calcineurin尤其是其调节亚基 CnaB严重影响构巢曲霉的产孢,引起产孢结构和分生孢子的异常。此结果将有助于筛选出新的真菌特异性药靶,为真菌感染防治提供新策略。

  17. Janus kinase inhibitors: jackpot or potluck?

    Directory of Open Access Journals (Sweden)

    Pavithran Keechilat

    2012-06-01

    Full Text Available The reports of a unique mutation in the Janus kinase-2 gene (JAK2 in polycythemia vera by several independent groups in 2005 quickly spurred the development of the Janus kinase inhibitors. In one of the great victories of translational research in recent times, the first smallmolecule Janus kinase inhibitor ruxolitinib entered a phase I trial in 2007. With the approval of ruxolitinib by the US Federal Drug Administration in November 2011 for high-risk and intermediate-2 risk myelofibrosis, a change in paradigm has occurred in the management of a subset of myeloproliferative neoplasms (MPN: primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Whereas the current evidence for ruxolitinib only covers high-risk and intermediate-2 risk myelofibrosis, inhibitors with greater potency are likely to offer better disease control and survival advantage in patients belonging to these categories, and possibly to the low-risk and intermediate-1 risk categories of MPN as well. But use of the Janus kinase inhibitors also probably has certain disadvantages, such as toxicity, resistance, withdrawal phenomenon, non-reversal of histology, and an implausible goal of disease clone eradication, some of which could offset the gains. In spite of this, Janus kinase inhibitors are here to stay, and for use in more than just myeloproliferative neoplasms.

  18. Impacts of lignocellulose-derived inhibitors on L-lactic acid fermentation by Rhizopus oryzae.

    Science.gov (United States)

    Zhang, Li; Li, Xin; Yong, Qiang; Yang, Shang-Tian; Ouyang, Jia; Yu, Shiyuan

    2016-03-01

    Inhibitors generated in the pretreatment and hydrolysis of corn stover and corn cob were identified. In general, they inhibited cell growth, lactate dehydrogenase, and lactic acid production but with less or no adverse effect on alcohol dehydrogenase and ethanol production in batch fermentation by Rhizopus oryzae. Furfural and 5-hydroxymethyl furfural (HMF) were highly toxic at 0.5-1 g L(-1), while formic and acetic acids at less than 4 g L(-1) and levulinic acid at 10 g L(-1) were not toxic. Among the phenolic compounds at 1 g L(-1), trans-cinnamic acid and syringaldehyde had the highest toxicity while syringic, ferulic and p-coumaric acids were not toxic. Although these inhibitors were present at concentrations much lower than their separately identified toxic levels, lactic acid fermentation with the hydrolysates showed much inferior performance compared to the control without inhibitor, suggesting synergistic or compounded effects of the lignocellulose-degraded compounds on inhibiting lactic acid fermentation.

  19. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  20. The therapeutic potential of aromatase inhibitors.

    Science.gov (United States)

    Miller, W R; Jackson, J

    2003-03-01

    The third generation aromatase inhibitors are both remarkably potent and specific endocrine agents inhibiting aromatase activity and reducing circulating oestrogen levels in postmenopausal women to levels never previously seen. Their therapeutic potential is consequently much greater than the earlier prototype drugs. Their excellent side-effect profile also allows for potential wider indications in the treatment of oestrogen-related diseases, including breast cancer. It still remains to determine whether their potent endocrine effects translate into increased therapeutic benefit. In advanced breast cancer, aromatase inhibitors have been shown to have improved efficacy and toxicity profiles when compared with progestins, aminoglutethimide and tamoxifen. Aromatase inhibitors have also been used in the neoadjuvant setting, where they have been shown to achieve higher response rates than tamoxifen and to be more successful at downstaging tumours. Early results comparing an aromatase inhibitor with tamoxifen in the adjuvant setting in early breast cancer show anastrozole to be superior to tamoxifen in terms of both disease-free survival and a lower incidence of new contralateral tumours. There was also a more favourable side-effect profile, which has implications for potential future prophylactic treatment. Additionally, since aromatase inhibitors have different mechanisms of action, unlike antioestrogens, they may be particularly useful as chemopreventive agents if oestrogens are themselves genotoxic. Aromatase inhibitors have been used to date almost exclusively in postmenopausal women. The potential of combining them with luteinising hormone-releasing hormone analogues allows the possibility of treating premenopausal women with either oestrogen receptor-positive breast cancer or benign conditions such as cyclical breast pain, fibroadenomata, recurrent cystic disease or endometriosis. There is also the potential for their use in men with conditions such as

  1. Synthesis and Evaluation of Heterocyclic Catechol Mimics as Inhibitors of Catechol-O-methyltransferase (COMT)

    Science.gov (United States)

    2015-01-01

    3-Hydroxy-4-pyridinones and 5-hydroxy-4-pyrimidinones were identified as inhibitors of catechol-O-methyltransferase (COMT) in a high-throughput screen. These heterocyclic catechol mimics exhibit potent inhibition of the enzyme and an improved toxicity profile versus the marketed nitrocatechol inhibitors tolcapone and entacapone. Optimization of the series was aided by X-ray cocrystal structures of the novel inhibitors in complex with COMT and cofactors SAM and Mg2+. The crystal structures suggest a mechanism of inhibition for these heterocyclic inhibitors distinct from previously disclosed COMT inhibitors. PMID:25815153

  2. Streptococcal toxic shock syndrome

    OpenAIRE

    Gvozdenović Ljiljana; Pasternak Janko; Milovanović Stanislav; Ivanov Dejan; Milić Saša

    2010-01-01

    Introduction. Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella pre...

  3. CHEMICAL TOXICITY OF URANIUM

    Directory of Open Access Journals (Sweden)

    Sermin Cam

    2007-06-01

    Full Text Available Uranium, occurs naturally in the earth’s crust, is an alpha emitter radioactive element from the actinide group. For this reason, U-235 and U-238, are uranium isotopes with long half lives, have got radiological toxicity. But, for natural-isotopic-composition uranium (NatU, there is greater risk from chemical toxicity than radiological toxicity. When uranium is get into the body with anyway, also its chemical toxicity must be thought. [TAF Prev Med Bull 2007; 6(3.000: 215-220

  4. A New “Brew” of MALT1 Inhibitors

    OpenAIRE

    Young, Ryan M.; Staudt, Louis M.

    2012-01-01

    The activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL) is an aggressive lymphoma that is addicted to NF-κB signaling through the CARD11-BCL10-MALT1 complex. In this issue of Cancer Cell, two reports describe MALT1 inhibitors suitable for clinical use that are selectively toxic to this malignancy.

  5. Synthesis of a new class of HIV-1 inhibitors.

    Science.gov (United States)

    Farese-Di Giorgio, A; Pairot, S; Patino, N; Condom, R; Di Giorgio, C; Aumelas, A; Aubertin, A M; Guedj, R

    1999-02-01

    A new family of molecules potentially inhibitors of the HIV-1 Tat-TAR complex was prepared. These compounds are constituted by dinucleotide analogs (PNA dimer) bound, through a linker, to an arginine residue. In this series, several molecules inhibit viral development in cell culture with a micromolar IC50 and without cellular toxicity until 200 microM concentration.

  6. miR-155 functions downstream of angiotensin II receptor subtype 1 and calcineurin to regulate cardiac hypertrophy.

    Science.gov (United States)

    Yang, Yong; Zhou, Yong; Cao, Zheng; Tong, Xin Zhu; Xie, Hua Qiang; Luo, Tao; Hua, Xian Ping; Wang, Han Qin

    2016-09-01

    Cardiac hypertrophy is characterized by maladaptive tissue remodeling that may lead to heart failure or sudden death. MicroRNAs (miRs) are negative regulators of angiotensin II and the angiotensin II receptor subtype 1 (AGTR1), which are two components involved in cardiac hypertrophy. In the present study, the interaction between angiotensin II receptor subtype 1 (AGTR1) signaling and miR-155 was investigated. Rat H9C2 (2-1) cardiomyocytes were transfected with miR-155 analogues or inhibitors, then stimulated with angiotensin II to induce cardiac hypertrophy. miR-155 expression was revealed to be altered following transfection with chemically-modified miR-155 analogues and inhibitors in rat cardiomyocytes. In cell cardiac hypertrophy models, the cell surface area, AGTR1, atrial natriuretic peptide and myosin heavy chain-β mRNA expression levels were revealed to be lower in cells stimulated with miR-155 analogue-transfected cells treated with angiotensin II compared with cells stimulated with angiotensin alone (PAGTR1 and suppressing the calcium signaling pathways activated by AGTR1.

  7. Pyridostigmine Synergistic Toxicity Study.

    Science.gov (United States)

    1995-05-31

    AND DEET IN THE LABORATORY RAT 1. Executive Sum m ary .............................................................................................. 2 2...TOXICOLOGICAL STUDY 75-48-2665 ACUTE ORAL TOXICITY STUDY OF PYRIDOSTIGMINE BROMIDE. PERMETHRIN. AND DEET IN THE LABORATORY RAT 1. REFERENCES: See Appendix A... LABORATORY RAT 1. PURPOSE: The purpose of this study was to determine potential toxic interactions when pyridostigmine bromide. permethrin. and DEET are given

  8. Place of mTOR inhibitors in management of BKV infection after kidney transplantation.

    Science.gov (United States)

    Jouve, Thomas; Rostaing, Lionel; Malvezzi, Paolo

    2016-01-01

    BK virus (BKV) viremia and BKV-associated nephropathy (BKVAN) have become a serious nuisance to kidney transplant (KT) patients since the mid-nineties, when the incidence of this disease has increased significantly. Directory of open access journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science have been searched. Many hypothesis have been made as to why this phenomenon has developed; it is of general opinion that a more potent immunosuppression is at the core of the problem. The use of the association of tacrolimus (TAC) with mycophenolic acid (MPA) has gained momentum in the same years as the increase in BKV viremia incidence making it seem to be the most likely culprit. m-TOR inhibitors (m-TORIs) have been shown to have antiviral properties in vitro and this fact has encouraged different transplant teams to use these agents when confronted with BKV infection (viremia or nephropathy). However, the results are mitigated. There had been conflicting results for example when converting from TAC-to sirolimus-based immunosuppression in the setting of established BKVAN. In order to prevent BKV infection we have to minimize to some extent immunosuppression, but it is not always possible, e.g. in high immunological risk patients. Conversely, we could use m-TORIs associated with low-dose calcineurin inhibitors (CNIs). This could be actually the key to a safe immunosuppression regimen both from the immunological stand point and from the viral one.

  9. Identification of fermentation inhibitors in wood hydrolyzates and removal of inhibitors by ion exchange and liquid-liquid extraction

    Science.gov (United States)

    Luo, Caidian

    1998-12-01

    Common methods employed in the ethanol production from biomass consist of chemical or enzymatic degradation of biomass into sugars and then fermentation of sugars into ethanol or other chemicals. However, some degradation products severely inhibit the fermentation processes and substantially reduce the efficiency of ethanol production. How to remove inhibitors from the reaction product mixture and increase the production efficiency are critical in the commercialization of any processes of energy from biomass. The present study has investigated anion exchange and liquid-liquid extraction as potential methods for inhibitor removal. An analytical method has been developed to identify the fermentation inhibitors in a hydrolyzate. The majority of inhibitors present in hybrid poplar hydrolyzate have positively been identified. Ion exchange with weak basic Dowex-MWA-1 resin has been proved to be an effective mean to remove fermentation inhibitors from hybrid poplar hydrolyzate and significantly increase the fermentation productivity. Extraction with n-butanol might be a preferred way to remove inhibitors from wood hydrolyzates and improve the fermentability of sugars in the hydrolyzates. n-Butanol also removes some glucose, mannose and xylose from the hydrolyzate. Inhibitor identification reveals that lignin and sugar degradation compounds including both aromatic and aliphatic aldehydes and carboxylic acids formed in hydrolysis, plus fatty acids and other components from wood extractives are major fermentation inhibitors in Sacchromyces cerevisiae fermentation. There are 35 components identified as fermentation inhibitors. Among them, 4-hydroxy benzoic acid, 3,4-dihydroxy benzoic acid, syringic acid, syringaldehyde, and ferulic acid are among the most abundant aromatic inhibitors in hybrid poplar hydrolyzate. The conversion of aldehyde groups into carboxylic acid groups in the nitric acid catalyzed hydrolysis reduces the toxicity of the hydrolyzate. A wide spectrum of

  10. Mechanisms of Phosphine Toxicity

    Directory of Open Access Journals (Sweden)

    Nisa S. Nath

    2011-01-01

    Full Text Available Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3, the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N and arsenic (As, which also produce toxic hydrides, namely, NH3 and AsH3. The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity.

  11. Mechanisms of phosphine toxicity.

    Science.gov (United States)

    Nath, Nisa S; Bhattacharya, Ishita; Tuck, Andrew G; Schlipalius, David I; Ebert, Paul R

    2011-01-01

    Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH(3)), the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N) and arsenic (As), which also produce toxic hydrides, namely, NH(3) and AsH(3). The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity.

  12. Mechanisms of Phosphine Toxicity

    Science.gov (United States)

    Nath, Nisa S.; Bhattacharya, Ishita; Tuck, Andrew G.; Schlipalius, David I.; Ebert, Paul R.

    2011-01-01

    Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3), the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N) and arsenic (As), which also produce toxic hydrides, namely, NH3 and AsH3. The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity. PMID:21776261

  13. Inhibitors of the Cellular Trafficking of Ricin

    Directory of Open Access Journals (Sweden)

    Daniel Gillet

    2012-01-01

    Full Text Available Throughout the last decade, efforts to identify and develop effective inhibitors of the ricin toxin have focused on targeting its N-glycosidase activity. Alternatively, molecules disrupting intracellular trafficking have been shown to block ricin toxicity. Several research teams have recently developed high-throughput phenotypic screens for small molecules acting on the intracellular targets required for entry of ricin into cells. These screens have identified inhibitory compounds that can protect cells, and sometimes even animals against ricin. We review these newly discovered cellular inhibitors of ricin intoxication, discuss the advantages and drawbacks of chemical-genetics approaches, and address the issues to be resolved so that the therapeutic development of these small-molecule compounds can progress.

  14. Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes

    Directory of Open Access Journals (Sweden)

    Čolović Mirjana B.

    2013-01-01

    Full Text Available Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE. Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP, have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes, simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of

  15. Corrosion inhibitors for intermediate cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Falk, I.; Suhr, L.

    1985-04-01

    The selected inhibitors were tested for heat and radiation stability and corrosion protection on the bench scale. Based on the results from these tests two of the products were selected, Bycoguard 81 and Bycoguard MP4S for continuing corrosion tests in an autoclave loop at 90 degrees C and 120 degrees C. Oxygen saturated deionized water with an addition of 1 ppm chloride was recirculated in the loop. Samples of copper and carbon steel were exposed to the water in the autoclave for periods up to 10 weeks. The purpose of this project was to find a substitute for hydrazine and chromates. Besides good corrosion protection qualities the toxic and environmental effect of the inhibitors should be minimal. The investigation has shown that the copper inhibitor BTA (benzotriazole) loses its corrosion protection qualities at a water temperature of 120 degrees C. The protection effects at 90 degrees C were satisfactory for both of the materials. The corrosion rates measured were 0.01 mm/y or less for the copper and carbon steel samples. The environment in the autoclave during the testing was more corrosive than is to be found in intermediate cooling systems. Due to the low corrosion rates measured the two inhibitors are to be recommended as alternatives to hydrazine and chromates.

  16. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; de Oliveira Alvares, Lucas

    2016-01-01

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca2+ channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca2+ influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time. PMID:26947131

  17. The Calcineurin B-Like Calcium Sensors CBL1 and CBL9 Together with Their Interacting Protein Kinase CIPK26 Regulate the Arabidopsis NADPH Oxidase RBOHF

    Institute of Scientific and Technical Information of China (English)

    Maria Magdalena Drerup; Kathrin Schlücking; Kenji Hashimoto; Prabha Manishankar; Leonie Steinhorst; Kazuyuki Kuchitsu; J(o)rg Kudla

    2013-01-01

    Stimulus-specific accumulation of second messengers like reactive oxygen species (ROS) and Ca2+ are central to many signaling and regulation processes in plants.However,mechanisms that govern the reciprocal interrelation of Ca2+ and ROS signaling are only beginning to emerge.NADPH oxidases of the respiratory burst oxidase homolog (RBOH) family are critical components contributing to the generation of ROS while Calcineurin B-like (CBL) Ca2+ sensor proteins together with their interacting kinases (CIPKs) have been shown to function in many Ca2+-signaling processes.In this study,we identify direct functional interactions between both signaling systems.We report that the CBL-interacting protein kinase ClPK26 specifically interacts with the N-terminal domain of RBOHF in yeast two-hybrid analyses and with the full-length RBOHF protein in plant cells.In addition,CIPK26 phosphorylates RBOHF in vitro and co-expression of either CBL1 or CBL9 with CIPK26 strongly enhances ROS production by RBOHF in HEK293T cells.Together,these findings identify a direct interconnection between CBL-ClPK-mediated Ca2+ signaling and ROS signaling in plants and provide evidence for a synergistic activation of the NADPH oxidase RBOHF by direct Ca2+-binding to its EF-hands and Ca2+-induced phosphorylation by CBL1/9-ClPK26 complexes.

  18. Transcriptional Profiling of Hypoxic Neural Stem Cells Identifies Calcineurin-NFATc4 Signaling as a Major Regulator of Neural Stem Cell Biology

    Science.gov (United States)

    Moreno, Marta; Fernández, Virginia; Monllau, Josep M.; Borrell, Víctor; Lerin, Carles; de la Iglesia, Núria

    2015-01-01

    Summary Neural stem cells (NSCs) reside in a hypoxic microenvironment within the brain. However, the crucial transcription factors (TFs) that regulate NSC biology under physiologic hypoxia are poorly understood. Here we have performed gene set enrichment analysis (GSEA) of microarray datasets from hypoxic versus normoxic NSCs with the aim of identifying pathways and TFs that are activated under oxygen concentrations mimicking normal brain tissue microenvironment. Integration of TF target (TFT) and pathway enrichment analysis identified the calcium-regulated TF NFATc4 as a major candidate to regulate hypoxic NSC functions. Nfatc4 expression was coordinately upregulated by top hypoxia-activated TFs, while NFATc4 target genes were enriched in hypoxic NSCs. Loss-of-function analyses further revealed that the calcineurin-NFATc4 signaling axis acts as a major regulator of NSC self-renewal and proliferation in vitro and in vivo by promoting the expression of TFs, including Id2, that contribute to the maintenance of the NSC state. PMID:26235896

  19. Transcriptional Profiling of Hypoxic Neural Stem Cells Identifies Calcineurin-NFATc4 Signaling as a Major Regulator of Neural Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Marta Moreno

    2015-08-01

    Full Text Available Neural stem cells (NSCs reside in a hypoxic microenvironment within the brain. However, the crucial transcription factors (TFs that regulate NSC biology under physiologic hypoxia are poorly understood. Here we have performed gene set enrichment analysis (GSEA of microarray datasets from hypoxic versus normoxic NSCs with the aim of identifying pathways and TFs that are activated under oxygen concentrations mimicking normal brain tissue microenvironment. Integration of TF target (TFT and pathway enrichment analysis identified the calcium-regulated TF NFATc4 as a major candidate to regulate hypoxic NSC functions. Nfatc4 expression was coordinately upregulated by top hypoxia-activated TFs, while NFATc4 target genes were enriched in hypoxic NSCs. Loss-of-function analyses further revealed that the calcineurin-NFATc4 signaling axis acts as a major regulator of NSC self-renewal and proliferation in vitro and in vivo by promoting the expression of TFs, including Id2, that contribute to the maintenance of the NSC state.

  20. Regulation of the Na+/K+-ATPase Ena1 Expression by Calcineurin/Crz1 under High pH Stress: A Quantitative Study

    Science.gov (United States)

    Petrezsélyová, Silvia; López-Malo, María; Canadell, David; Roque, Alicia; Serra-Cardona, Albert; Marqués, M. Carmen; Vilaprinyó, Ester; Alves, Rui; Yenush, Lynne

    2016-01-01

    Regulated expression of the Ena1 Na+-ATPase is a crucial event for adaptation to high salt and/or alkaline pH stress in the budding yeast Saccharomyces cerevisiae. ENA1 expression is under the control of diverse signaling pathways, including that mediated by the calcium-regulatable protein phosphatase calcineurin and its downstream transcription factor Crz1. We present here a quantitative study of the expression of Ena1 in response to alkalinization of the environment and we analyze the contribution of Crz1 to this response. Experimental data and mathematical models substantiate the existence of two stress-responsive Crz1-binding sites in the ENA1 promoter and estimate that the contribution of Crz1 to the early response of the ENA1 promoter is about 60%. The models suggest the existence of a second input with similar kinetics, which would be likely mediated by high pH-induced activation of the Snf1 kinase. PMID:27362362

  1. Calcineurin B-like interacting protein kinase OsCIPK23 functions in pollination and drought stress responses in rice(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Droughtis very harmful to grain yield due to its adverse effect on reproduction,especially on pollination proeess in rice.However,the molecular basis of such an effect still remains largely unknown.Here,wereport the role of amember of CBL(Calcineurin B-Like)Interacting Protein Kinase(CIPK)family,OsCIPK23,in pollination and stress responses in dee.Molecular analyses revealed that it is mainly expressed in pistil and anther but up-regulated by pollination,as well as by treatments of various abiotic stresses and phytohormones.RNA interference-mediated suppression of OsCIPK23 expression significantly reduced seed set and conferred a hypersensitive response to drought stress,indicating its possible roles in pollination and drought stress.In consistent,overexpression of OsCIPK23 induced the expression of seVeral drought tolerance related genes.Taken together,these results indicate that OsCIPK23 is a multistress induced gene and likely mediatesa signaling pathway commonly shared by both pollination and drought stress responses in rice.

  2. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin.

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; Alvares, Lucas de Oliveira

    2016-03-07

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca(2+) channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca(2+) influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time.

  3. Calcineurin-B-Like Protein CBL9 Interacts with Target Kinase CIPK3 in the Regulation of ABA Response in Seed Germination

    Institute of Scientific and Technical Information of China (English)

    Girdhar K.Pandey; John J.Grant; Yong Hwa Cheong; Beom-Gi Kim; Le Gong Li; Sheng Luan

    2008-01-01

    Calcium plays a vital role as a second messenger in many signaling pathways in plants.The calcineurin B-like proteins (CBLs) represent a family of plant calcium-binding proteins that function in calcium signaling by interacting with their interacting protein kinases (CIPKs).In our previous study,we have reported a role for one of the CBLs (CBL9) and one of the CIPKs (CIPK3) in ABA signaling.Here,we have shown that CBL9 and CIPK3 physically and functionally interact with each other in regulating the ABA responses.The CBL9 and CIPK3 proteins interacted with each other in the yeast twohybrid system and when expressed in plant cells.The double mutant cbl9cipk3 showed the similar hypersensitive response to ABA as observed in single mutants (cbl9 or cipk3).The constitutively active form of CIPK3 genetically complemented the cbl9 mutant,indicating that CIPK3 function downstream of CBL9.Based on these findings,we conclude that CBL9 and CIPK3 act together in the same pathway for regulating ABA responses.

  4. Toxic Shock Syndrome (For Teens)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Toxic Shock Syndrome KidsHealth > For Teens > Toxic Shock Syndrome Print ... it, then take some precautions. What Is Toxic Shock Syndrome? If you're a girl who's had ...

  5. Aromatase inhibitors in gynecologic cancers.

    Science.gov (United States)

    Krasner, Carolyn

    2007-01-01

    The female genital tract is hormonally responsive, and consequently some tumors, which arise within in it, may be treated at least in part, with hormonal manipulation. The range of responses in clinical trials and case reports will be reviewed. Many of these diseases are too rare for clinical trial testing, and in some cases evidence is anecdotal at best. Recurrences of ovarian cancer have been treated with tamoxifen and megesterol acetate with variable response rates from 0 to 56%. The favorable toxicity profile of aromatase inhibitors led to trials of these agents for the treatment of relapsed epithelial ovarian cancer. These agents have proved tolerable with minor response rates but a significant disease stabilization rate, which may be prolonged in a minority of cases. It is unclear if these responses may be predicted by estrogen receptor expression or aromatase expression. Anastrazole has also been tried in combination with an EGFR receptor-inhibitor, again showing minor responses but possibly an increase in TTT in some patients. Granulosa cell tumors of the ovary are rare, hormonally sensitive tumors, with reported responses to a variety of hormonal manipulations, including aromatase inhibition. In addition, combined endocrine blockade, including aromatase inhibition, has been tried with reports of success. Endometrial cancers, particularly type I lesions, are often treated with hormonal manipulation, most commonly with progestins, but also with antiestrogens such as tamoxifen. A trial of aromatase inhibition in the treatment of recurrent endometrial cancer showed minimal responses. Endometrial stromal sarcoma, an uncommon uterine malignancy, has shown response to hormonal treatments, with multiple case reports of efficacy of aromatase inhibition. Despite the rarity of some of these tumor types, rare tumor study groups, such as within the Gynecologic Oncology Group, should make an effort to prospectively define the utility of these treatments.

  6. Highlights of the Latest Advances in Research on CDK Inhibitors

    Directory of Open Access Journals (Sweden)

    Jonas Cicenas

    2014-10-01

    Full Text Available Uncontrolled proliferation is the hallmark of cancer and other proliferative disorders and abnormal cell cycle regulation is, therefore, common in these diseases. Cyclin-dependent kinases (CDKs play a crucial role in the control of the cell cycle and proliferation. These kinases are frequently deregulated in various cancers, viral infections, neurodegenerative diseases, ischemia and some proliferative disorders. This led to a rigorous pursuit for small-molecule CDK inhibitors for therapeutic uses. Early efforts to block CDKs with nonselective CDK inhibitors led to little specificity and efficacy but apparent toxicity, but the recent advance of selective CDK inhibitors allowed the first successful efforts to target these kinases for the therapies of several diseases. Major ongoing efforts are to develop CDK inhibitors as monotherapies and rational combinations with chemotherapy and other targeted drugs.

  7. Proteomic analysis of rat cerebral cortex following subchronic acrolein toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Rashedinia, Marzieh; Lari, Parisa [Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Abnous, Khalil, E-mail: Abnouskh@mums.ac.r [Pharmaceutical Research Center, Department of Medicinal Chemistry, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Hosseinzadeh, Hossein, E-mail: Hosseinzadehh@mums.ac.ir [Pharmaceutical Research Center, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of)

    2013-10-01

    Acrolein, a member of reactive α,β-unsaturated aldehydes, is a major environmental pollutant. Acrolein is also produced endogenously as a toxic by-product of lipid peroxidation. Because of high reactivity, acrolein may mediate oxidative damages to cells and tissues. It has been shown to be involved in a wide variety of pathological states including pulmonary, atherosclerosis and neurodegenerative diseases. In this study we employed proteomics approach to investigate the effects of subchronic oral exposures to 3 mg/kg of acrolein on protein expression profile in the brain of rats. Moreover effects of acrolein on malondialdehyde (MDA) levels and reduced glutathione (GSH) content were investigated. Our results revealed that treatment with acrolein changed levels of several proteins in diverse physiological process including energy metabolism, cell communication and transport, response to stimulus and metabolic process. Interestingly, several differentially over-expressed proteins, including β-synuclein, enolase and calcineurin, are known to be associated with human neurodegenerative diseases. Changes in the levels of some proteins were confirmed by Western blot. Moreover, acrolein increases the level of MDA, as a lipid peroxidation biomarker and decreased GSH concentrations, as a non-enzyme antioxidant in the brain of acrolein treated rats. These findings suggested that acrolein induces the oxidative stress and lipid peroxidation in the brain, and so that may contribute to the pathophysiology of neurological disorders. - Highlights: • Acrolein intoxication increased lipid peroxidation and deplete GSH in rat brain. • Effect of acrolein on protein levels of cerebral cortex was analyzed by 2DE-PAGE. • Levels of a number of proteins with different biological functions were increased.

  8. Toxics Release Inventory (TRI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) is a dataset compiled by the U.S. Environmental Protection Agency (EPA). It contains information on the release and waste...

  9. Toxicity Reference Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxicity Reference Database (ToxRefDB) contains approximately 30 years and $2 billion worth of animal studies. ToxRefDB allows scientists and the interested...

  10. Aspects of aluminum toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  11. Natural toxicants in foods.

    Science.gov (United States)

    Coon, J M

    1975-09-01

    Food constitutes the most complex part of our chemical environment. Naturally occurring substances in food, such as goitrogens and estrogens, are toxicants. However, there is a difference of degree between toxicity and hazard, and the hazard to man in normal good health from naturally occurring toxicants in food is usually slight, because of (a) the small concentrations and (b) antagonistic interactions between toxicants which provide "safety in numbers." Hazard from foods may indeed exist under some circumstances, such as the presence of abnormal contaminants, ingestion of abnormal amounts, or abnormal susceptibility existing in some disease states. However, the major hazards of the dinner table can ordinarily be ascribed to careless food handling, unbalanced or fad diets, or overeating.

  12. Toxicity of lunar dust

    CERN Document Server

    Linnarsson, Dag; Fubini, Bice; Gerde, Per; Karlsson, Lars L; Loftus, David J; Prisk, G Kim; Staufer, Urs; Tranfield, Erin M; van Westrenen, Wim

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of substantial research efforts, lunar dust properties, and therefore lunar dust toxicity may differ substantially. In this contribution, past and ongoing work on dust toxicity is reviewed, and major knowledge gaps that prevent an accurate assessment of lunar dust toxicity are identified. Finally, a range of studies using ground-based, low-gravity, and in situ measurements is recommended to address the identified knowledge gaps. Because none of the curated lunar samples exist in a pristine state that preserves the surface reactive chemical aspects thought to be present on the lunar surface, studies using this material carry with them considerable uncertainty in terms of fidelity. As a consequence, in situ data on lunar dust...

  13. Mechanisms of Phosphine Toxicity

    OpenAIRE

    Nisa S. Nath; Ishita Bhattacharya; Andrew G. Tuck; Schlipalius, David I.; Paul R. Ebert

    2011-01-01

    Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3), the chemistry of phosphorus is central to its toxicity...

  14. Nonpeptidic Tetrafluorophenoxymethyl Ketone Cruzain Inhibitors as Promising New Leads for Chagas Disease Chemotherapy†

    Science.gov (United States)

    Brak, Katrien; Kerr, Iain D.; Barrett, Kimberly T.; Fuchi, Nobuhiro; Debnath, Moumita; Engel, Juan C.; McKerrow, James H.; Doyle, Patricia S.; Brinen, Linda S.; Ellman, Jonathan A.

    2010-01-01

    A century after discovering that the Trypanosoma cruzi parasite is the etiological agent of Chagas disease, treatment is still plagued by limited efficacy, toxicity, and the emergence of drug resistance. The development of inhibitors of the major T. cruzi cysteine protease, cruzain, has been demonstrated to be a promising drug discovery avenue for this neglected disease. Here we establish that a nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitor substantially ameliorates symptoms of acute Chagas disease in a mouse model with no apparent toxicity. A high-resolution crystal structure confirmed the mode of inhibition and revealed key binding interactions of this novel inhibitor class. Subsequent structure-guided optimization then resulted in inhibitor analogs with improvements in potency despite minimal or no additions in molecular weight. Evaluation of the analogs in cell culture showed enhanced activity. These results suggest that nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors have the potential to fulfill the urgent need for improved Chagas disease chemotherapy. PMID:20088534

  15. Streptococcal toxic shock syndrome

    Directory of Open Access Journals (Sweden)

    Gvozdenović Ljiljana

    2010-01-01

    Full Text Available Introduction. Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella presented roughly 2-4 weeks later with a clinical syndrome highly suggestive of toxic shock syndrome. Characteristics, complications and therapy. It is characterized by a sudden onset of fever, chills, vomiting, diarrhea, muscle aches and rash. It can rapidly progress to severe and intractable hypotension and multisystem dysfunction. Almost every organ system can be involved. Complications of streptococcal toxic shock syndrome may include kidney failure, liver failure and even death. Crystalloids and inotropic agents are used to treat the hypovolemic shock aggressively, with close monitoring of the patient’s mean arterial pressure and central venous pressure. An immediate and aggressive management of hypovolemic shock is essential in streptococcal toxic shock syndrome. Targeted antibiotics are indicated; penicillin or a betalactam antibiotic is used for treating group A streptococci, and clindamycin has emerged as a key portion of the standard treatment.

  16. Toxicity of 13 different antibiotics towards freshwater green algae Pseudokirchneriella subcapitata and their modes of action.

    Science.gov (United States)

    Fu, Ling; Huang, Tao; Wang, Shuo; Wang, Xiaohong; Su, Limin; Li, Chao; Zhao, Yuanhui

    2017-02-01

    Although modes of action (MOAs) play a key role in the understanding of the toxic mechanism of chemicals, the MOAs have not been investigated for antibiotics to green algae. This paper is to discriminate excess toxicity from baseline level and investigate the MOAs of 13 different antibiotics to algae by using the determined toxicity values. Comparison of the toxicities shows that the inhibitors of protein synthesis to bacteria, such as azithromycin, doxycycline, florfenicol and oxytetracycline, exhibit significantly toxic effects to algae. On the other hand, the cell wall synthesis inhibitors, such as cefotaxime and amoxicillin, show relatively low toxic effects to the algae. The concentrations determined by HPLC indicate that quinocetone and amoxicillin can be easily photodegraded or hydrolyzed during the toxic tests. The toxic effects of quinocetone and amoxicillin to the algae are attributed to not only their parent compounds, but also their metabolites. Investigation on the mode of action shows that, except rifampicin, all the tested antibiotics exhibit excess toxicity to Pseudokirchneriella subcapitata (P. subcapitata). These antibiotics can be identified as reactive modes of action to the algae. They act as electrophilic mechanism of action to P. subcapitata. These results are valuable for the understanding of the toxic mechanism to algae.

  17. A zebrafish model for uremic toxicity: role of the complement pathway.

    Science.gov (United States)

    Berman, Nathaniel; Lectura, Melisa; Thurman, Joshua M; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

    2013-01-01

    Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p 50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement.

  18. Endocrine dysfunction following immune checkpoint inhibitor therapy.

    Science.gov (United States)

    Konda, Bhavana; Nabhan, Fadi; Shah, Manisha H

    2017-10-01

    Immune checkpoint inhibitors (ICI) represent an important milestone in the modern era of antineoplastic therapy and have ushered optimism amongst oncologists and patients alike. These agents, however, are associated with significant potential toxicities, the importance of which cannot be overstated. The clinical presentation, diagnosis, and management strategies of immune-related endocrinopathies associated with ICI use are described in this case-based review. An increasing number of ICI have shown promise in the management of various malignancies in the recent years. These include cytotoxic T lymphocyte antigen-4 inhibitors, programmed cell death 1 (PD-1) antibodies, and PD-ligand 1 (PD-L1) antibodies. Several endocrinopathies, including hypophysitis, thyroid dysfunction, hyperglycemia, and primary adrenal insufficiency, have been associated with the use of these agents. Toxicities may range from mild transient laboratory abnormalities to potentially life-threatening ones, warranting immediate therapeutic intervention. Combination ICI therapies may be associated with a greater risk of endocrine dysfunction when compared with monotherapy. The clinical presentation and laboratory assessment of these patients often pose a diagnostic challenge as they may be confused by the symptoms related to their underlying malignancy or potential associated acute illnesses. ICI use is associated with serious endocrinopathies that may have a nonspecific initial presentation. A constant eye for these symptoms and a systematic approach to diagnosis are essential for prompt initiation of therapy and prevention of significant complications.

  19. Calcineurin-NFAT signaling regulates atrogin-1 and MuRF1 via microRNA-23a (miR-23a during muscle atrophy

    Directory of Open Access Journals (Sweden)

    Matthew B. Hudson

    2012-06-01

    Full Text Available Muscle atrophy is prevalent in chronic kidney disease (CKD patients. MicroRNAs play a critical role in biological processes including muscle atrophy. MicroRNA-23a (miR-23a negatively regulates the expression of two atrophy-related ubiquitin ligases, atrogin-1 and MuRF1; it is reduced in muscle during atrophy. Although miR-23a expression was recently shown to be positively regulated by NFATc3, the underlying mechanism of miR-23a suppression during atrophy remains unknown. We previously reported that the activity of calcineurin (Cn, the calcium-activated phosphatase that regulates NFATc proteins, is decreased when insulin signaling is decreased. Since CKD causes muscle atrophy, and glucocorticoids are required for the response, we investigated how dexamethasone (DEX affects Cn activity, NFATc3 signaling, and miR-23a expression. C2C12 or L6 myotubes were treated with 100 uM DEX to induce atrophy. Within 1 h, Cn activity was reduced and less NFATc3 was located in the nucleus. Further, miR-23a was also decreased within 30 minutes. After 48 h, expression of the NFATC3 target gene, MCIP1.4, and miR-23a were decreased. Expression of atrogin-1 and MuRF1 were also increased 48 h after DEX. Collectively, these findings indicate the Cn-NFAT signaling pathway may play an important role in the regulation of atrogin-1 and MuRF1 by suppressing miR23a during CKD and glucocorticoid-related muscle atrophy. Support: NIH DK007656; AHA GRNT7660020

  20. Differentiation of expression proifles of two calcineurin subunit genes in chicken skeletal muscles during early postnatal growth depending on anatomical location of muscles and breed

    Institute of Scientific and Technical Information of China (English)

    SHAN Yan-ju; XU Wen-juan; SHU Jing-ting; ZHANG Ming; SONG Wei-tao; TAO Zhi-yun; ZHU Chun-hong; LI Hui-fang

    2016-01-01

    Calcineurin (Cn or CaN) is implicated in the control of skeletal muscle ifber phenotype and hypertrophy. However, little information is available concerning the expression of Cn in chickens. In the present study, the expression of two Cn subunit genes (CnAα andCnB1) was quantiifed by qPCR in the lateral gastrocnemius (LG, mainly composing of red fast-twitch myoifbers), the soleus (mainly composing of red slow-twitch myoifbers) and the extensor digitorum longus (EDL, mainly composing of white fast-twitch myoifbers) from Qingyuan partridge chickens (QY, slow-growing chicken breed) and Recessive White chickens (RW, fast-growing chicken breed) on different days (1, 8, 22, 36, 50 and 64 days post-hatching). Although CnAα andCnB1 gene expressions were variable with different trends in different skeletal muscles in the two chicken breeds during postnatal growth, it is highly muscle phenotype and breed speciifc. In general, the levels ofCnAαandCnB1gene expressions of the soleus were lower than those of EDL and LG in both chicken breeds at the same stages. Compared be-tween the two chicken breeds, the levels ofCnAα gene expression of the three skeletal muscles in QY chickens were higher than those in RW chickens on days 1 and 22. However, on day 64, the levels of bothCnAα andCnB1 gene expressions of the three skeletal muscles were lower in QY chickens than those in RW chickens. Correlation analysis of the levels of CnAα andCnB1 gene expressions of the same skeletal muscle showed that there were positive correlations for al three skeletal muscle tissues in two chicken breeds. These results provide some valuable clues to understand the role of Cn in the development of chicken skeletal muscles, with a function that may be related to meat quality.

  1. Investigating the Ustilago maydis/Zea mays pathosystem: transcriptional responses and novel functional aspects of a fungal calcineurin regulatory B subunit.

    Science.gov (United States)

    Donaldson, Michael E; Meng, Shaowu; Gagarinova, Alla; Babu, Mohan; Lambie, Scott C; Swiadek, Alexander A; Saville, Barry J

    2013-01-01

    The sustainable control of basidiomycete biotrophic plant pathogenesis requires an understanding of host responses to infection, as well as the identification and functional analysis of fungal genes involved in disease development. The creation and analysis of a suppressive subtractive hybridization (SSH) cDNA library from Ustilago maydis-infected Zea mays seedlings enabled the identification of fungal and plant genes expressed during disease development, and uncovered new insights into the interactions of this model system. Candidate U. maydis pathogenesis genes were identified by using the current SSH cDNA library analysis, and by knowledge generated from previous cDNA microarray and comparative genomic analyses. These identifications were supported by the independent determination of transcript level changes in different cell-types and during pathogenic development. The basidiomycete specific um01632, the highly in planta expressed um03046 (zig1), and the calcineurin regulatory B subunit (um10226, cnb1), were chosen for deletion experiments. um01632 and zig1 mutants showed no difference in morphology and did not have a statistically significant impact on pathogenesis. cnb1 mutants had a distinct cell division phenotype and reduced virulence in seedling assays. Infections with reciprocal wild-type×Δcnb1 haploid strain crosses revealed that the wild-type allele was unable to fully compensate for the lack of a second cnb1 allele. This haploinsufficiency was undetected in other fungal cnb1 mutational analyses. The reported data improves U. maydis genome annotation and expands on the current understanding of pathogenesis genes in this model basidiomycete.

  2. Investigation of genes encoding calcineurin B-like protein family in legumes and their expression analyses in chickpea (Cicer arietinum L..

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Meena

    Full Text Available Calcium ion (Ca2+ is a ubiquitous second messenger that transmits various internal and external signals including stresses and, therefore, is important for plants' response process. Calcineurin B-like proteins (CBLs are one of the plant calcium sensors, which sense and convey the changes in cytosolic Ca2+-concentration for response process. A search in four leguminous plant (soybean, Medicago truncatula, common bean and chickpea genomes identified 9 to 15 genes in each species that encode CBL proteins. Sequence analyses of CBL peptides and coding sequences (CDS suggested that there are nine original CBL genes in these legumes and some of them were multiplied during whole genome or local gene duplication. Coding sequences of chickpea CBL genes (CaCBL were cloned from their cDNAs and sequenced, and their annotations in the genome assemblies were corrected accordingly. Analyses of protein sequences and gene structures of CBL family in plant kingdom indicated its diverse origin but showed a remarkable conservation in overall protein structure with appearance of complex gene structure in the course of evolution. Expression of CaCBL genes in different tissues and in response to different stress and hormone treatment were studied. Most of the CaCBL genes exhibited high expression in flowers. Expression profile of CaCBL genes in response to different abiotic stresses and hormones related to development and stresses (ABA, auxin, cytokinin, SA and JA at different time intervals suggests their diverse roles in development and plant defence in addition to abiotic stress tolerance. These data not only contribute to a better understanding of the complex regulation of chickpea CBL gene family, but also provide valuable information for further research in chickpea functional genomics.

  3. Calcineurin B-like Protein CBL10 Directly Interacts with TOC34 (Translocon of the Outer Membrane of the Chloroplasts) and Decreases Its GTPase Activity in Arabidopsis

    Science.gov (United States)

    Cho, Joo Hyuk; Lee, Jeong Hwan; Park, Yoon Kook; Choi, Mi Na; Kim, Kyung-Nam

    2016-01-01

    As calcium sensor relays in plants, calcineurin B-like (CBL) proteins provide an important contribution to decoding Ca2+ signatures elicited by a variety of abiotic stresses. Currently, it is well known that CBLs perceive and transmit the Ca2+ signals mainly to a group of serine/threonine protein kinases called CBL-interacting protein kinases (CIPKs). In this study, we report that the CBL10 member of this family has a novel interaction partner besides the CIPK proteins. Yeast two-hybrid screening with CBL10 as bait identified an Arabidopsis cDNA clone encoding a TOC34 protein, which is a member of the TOC (Translocon of the Outer membrane of the Chloroplasts) complex and possesses the GTPase activity. Further analyses showed that in addition to CBL10, CBL7 also interacts with TOC34 at much lower strength in the yeast two-hybrid system. However, the rest of the CBL family members failed to interact with TOC34. Bimolecular fluorescence complementation (BiFC) analysis verified that the CBL10-TOC34 interaction occurs at the outer membrane of chloroplasts in vivo. In addition, we also demonstrated that CBL10 physically associates with TOC34 in vitro, resulting in a significant decrease in the GTPase activity of the TOC34 protein. Taken together, our findings clearly indicate that a member of the CBL family, CBL10, can modulate not only the CIPK members but also TOC34, allowing the CBL family to relay the Ca2+ signals in more diverse ways than currently known. PMID:28018422

  4. Investigation of genes encoding calcineurin B-like protein family in legumes and their expression analyses in chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Meena, Mukesh Kumar; Ghawana, Sanjay; Sardar, Atish; Dwivedi, Vikas; Khandal, Hitaishi; Roy, Riti; Chattopadhyay, Debasis

    2015-01-01

    Calcium ion (Ca2+) is a ubiquitous second messenger that transmits various internal and external signals including stresses and, therefore, is important for plants' response process. Calcineurin B-like proteins (CBLs) are one of the plant calcium sensors, which sense and convey the changes in cytosolic Ca2+-concentration for response process. A search in four leguminous plant (soybean, Medicago truncatula, common bean and chickpea) genomes identified 9 to 15 genes in each species that encode CBL proteins. Sequence analyses of CBL peptides and coding sequences (CDS) suggested that there are nine original CBL genes in these legumes and some of them were multiplied during whole genome or local gene duplication. Coding sequences of chickpea CBL genes (CaCBL) were cloned from their cDNAs and sequenced, and their annotations in the genome assemblies were corrected accordingly. Analyses of protein sequences and gene structures of CBL family in plant kingdom indicated its diverse origin but showed a remarkable conservation in overall protein structure with appearance of complex gene structure in the course of evolution. Expression of CaCBL genes in different tissues and in response to different stress and hormone treatment were studied. Most of the CaCBL genes exhibited high expression in flowers. Expression profile of CaCBL genes in response to different abiotic stresses and hormones related to development and stresses (ABA, auxin, cytokinin, SA and JA) at different time intervals suggests their diverse roles in development and plant defence in addition to abiotic stress tolerance. These data not only contribute to a better understanding of the complex regulation of chickpea CBL gene family, but also provide valuable information for further research in chickpea functional genomics.

  5. Exploring BSEP Inhibition-Mediated Toxicity with a Mechanistic Model of Drug-Induced Liver Injury

    Directory of Open Access Journals (Sweden)

    Jeffrey L Woodhead

    2014-11-01

    Full Text Available Inhibition of the bile salt export pump (BSEP has been linked to incidence of drug-induced liver injury (DILI, presumably by the accumulation of toxic bile acids in the liver. We have previously constructed and validated a model of bile acid disposition within DILIsym®, a mechanistic model of DILI. In this paper, we use DILIsym® to simulate the DILI response of the hepatotoxic BSEP inhibitors bosentan and CP-724,714 and the non-hepatotoxic BSEP inhibitor telmisartan in humans in order to explore whether we can predict that hepatotoxic BSEP inhibitors can cause bile acid accumulation to reach toxic levels. We also simulate bosentan in rats in order to illuminate potential reasons behind the lack of toxicity in rats compared to the toxicity observed in humans. DILIsym® predicts that bosentan, but not telmisartan, will cause mild hepatocellular ATP decline and serum ALT elevation in a simulated population of humans. The difference in hepatotoxic potential between bosentan and telmisartan is consistent with clinical observations. However, DILIsym® underpredicts the incidence of bosentan toxicity. DILIsym® also predicts that bosentan will not cause toxicity in a simulated population of rats, and that the difference between the response to bosentan in rats and in humans is primarily due to the less toxic bile acid pool in rats. Our simulations also suggest a potential synergistic role for bile acid accumulation and mitochondrial electron transport chain inhibition in producing the observed toxicity in CP-724,714, and suggest that CP-724,714 metabolites may also play a role in the observed toxicity. Our work also compares the impact of competitive and noncompetitive BSEP inhibition for CP-724,714 and demonstrates that noncompetitive inhibition leads to much greater bile acid accumulation and potential toxicity. Our research demonstrates the potential for mechanistic modeling to contribute to the understanding of how bile acid transport inhibitors

  6. Reactive nitrogen species in acetaminophen-induced mitochondrial damage and toxicity in mouse hepatocytes.

    Science.gov (United States)

    Burke, Angela S; MacMillan-Crow, Lee Ann; Hinson, Jack A

    2010-07-19

    Acetaminophen (APAP) toxicity in primary mouse hepatocytes occurs in two phases. The initial phase (0-2 h) occurs with metabolism to N-acetyl-p-benzoquinoneimine which depletes glutathione, and covalently binds to proteins, but little toxicity is observed. Subsequent washing of hepatocytes to remove APAP and reincubating in media alone (2-5 h) results in toxicity. We previously reported that the reincubation phase occurs with mitochondrial permeability transition (MPT) and increased oxidative stress (dichlorodihydrofluorescein fluorescence) (DCFH(2)). Since DCFH(2) may be oxidized by multiple oxidative mechanisms, we investigated the role of reactive nitrogen species (RNS) leading to 3-nitrotyrosine in proteins by ELISA and by immunoblots. Incubation of APAP with hepatocytes for 2 h did not result in toxicity or protein nitration; however, washing hepatocytes and reincubating in media alone (2-5 h) resulted in protein nitration which correlated with toxicity. Inclusion of the MPT inhibitor, cyclosporine A, in the reincubation media eliminated toxicity and protein nitration. The general nitric oxide synthase (NOS) inhibitor L-NMMA and the neuronal NOS (NOS1) inhibitor, 7-nitroindazole, added in the reincubation media decreased toxicity and protein nitration; however, neither the inducible NOS (NOS2) inhibitors L-NIL (N6-(1-iminoethyl)-L-lysine) nor SAIT (S-(2-aminoethyl)isothiourea) decreased protein nitration or toxicity. The RNS scavengers, N-acetylcysteine, and high concentrations of APAP, added in the reincubation phase decreased toxicity and protein nitration. 7-Nitroindazole and cyclosporine A inhibited the APAP-induced loss of mitochondrial membrane potential when added in the reincubation phase. The data indicate a role for RNS in APAP induced toxicity.

  7. KMUP-1 Attenuates Endothelin-1-Induced Cardiomyocyte Hypertrophy through Activation of Heme Oxygenase-1 and Suppression of the Akt/GSK-3β, Calcineurin/NFATc4 and RhoA/ROCK Pathways.

    Science.gov (United States)

    Liou, Shu-Fen; Hsu, Jong-Hau; Chen, You-Ting; Chen, Ing-Jun; Yeh, Jwu-Lai

    2015-06-05

    The signaling cascades of the mitogen activated protein kinase (MAPK) family, calcineurin/NFATc4, and PI3K/Akt/GSK3, are believed to participate in endothelin-1 (ET-1)-induced cardiac hypertrophy. The aim of this study was to investigate whether KMUP-1, a synthetic xanthine-based derivative, prevents cardiomyocyte hypertrophy induced by ET-1 and to elucidate the underlying mechanisms. We found that in H9c2 cardiomyocytes, stimulation with ET-1 (100 nM) for 4 days induced cell hypertrophy and enhanced expressions of hypertrophic markers, including atrial natriuretic peptide and brain natriuretic peptide, which were all inhibited by KMUP-1 in a dose-dependent manner. In addition, KMUP-1 prevented ET-1-induced intracellular reactive oxygen species generation determined by the DCFH-DA assay in cardiomyocytes. KMUP-1 also attenuated phosphorylation of ERK1/2 and Akt/GSK-3β, and activation of calcineurin/NFATc4 and RhoA/ROCK pathways induced by ET-1. Furthermore, we found that the expression of heme oxygenase-1 (HO-1), a stress-response enzyme implicated in cardio-protection, was up-regulated by KMUP-1. Finally, KMUP-1 attenuated ET-1-stimulated activator protein-1 DNA binding activity. In conclusion, KMUP-1 attenuates cardiomyocyte hypertrophy induced by ET-1 through inhibiting ERK1/2, calcineurin/NFATc4 and RhoA/ROCK pathways, with associated cardioprotective effects via HO-1 activation. Therefore, KMUP-1 may have a role in pharmacological therapy of cardiac hypertrophy.

  8. KMUP-1 Attenuates Endothelin-1-Induced Cardiomyocyte Hypertrophy through Activation of Heme Oxygenase-1 and Suppression of the Akt/GSK-3β, Calcineurin/NFATc4 and RhoA/ROCK Pathways

    Directory of Open Access Journals (Sweden)

    Shu-Fen Liou

    2015-06-01

    Full Text Available The signaling cascades of the mitogen activated protein kinase (MAPK family, calcineurin/NFATc4, and PI3K/Akt/GSK3, are believed to participate in endothelin-1 (ET-1-induced cardiac hypertrophy. The aim of this study was to investigate whether KMUP-1, a synthetic xanthine-based derivative, prevents cardiomyocyte hypertrophy induced by ET-1 and to elucidate the underlying mechanisms. We found that in H9c2 cardiomyocytes, stimulation with ET-1 (100 nM for 4 days induced cell hypertrophy and enhanced expressions of hypertrophic markers, including atrial natriuretic peptide and brain natriuretic peptide, which were all inhibited by KMUP-1 in a dose-dependent manner. In addition, KMUP-1 prevented ET-1-induced intracellular reactive oxygen species generation determined by the DCFH-DA assay in cardiomyocytes. KMUP-1 also attenuated phosphorylation of ERK1/2 and Akt/GSK-3β, and activation of calcineurin/NFATc4 and RhoA/ROCK pathways induced by ET-1. Furthermore, we found that the expression of heme oxygenase-1 (HO-1, a stress-response enzyme implicated in cardio-protection, was up-regulated by KMUP-1. Finally, KMUP-1 attenuated ET-1-stimulated activator protein-1 DNA binding activity. In conclusion, KMUP-1 attenuates cardiomyocyte hypertrophy induced by ET-1 through inhibiting ERK1/2, calcineurin/NFATc4 and RhoA/ROCK pathways, with associated cardioprotective effects via HO-1 activation. Therefore, KMUP-1 may have a role in pharmacological therapy of cardiac hypertrophy.

  9. Toxic Shock Syndrome (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Toxic Shock Syndrome KidsHealth > For Parents > Toxic Shock Syndrome Print ... en español Síndrome de shock tóxico About Toxic Shock Syndrome Toxic shock syndrome (TSS) is a serious ...

  10. Cellular growth kinetics distinguish a cyclophilin inhibitor from an HSP90 inhibitor as a selective inhibitor of hepatitis C virus.

    Directory of Open Access Journals (Sweden)

    Rudolf K F Beran

    Full Text Available During antiviral drug discovery, it is critical to distinguish molecules that selectively interrupt viral replication from those that reduce virus replication by adversely affecting host cell viability. In this report we investigate the selectivity of inhibitors of the host chaperone proteins cyclophilin A (CypA and heat-shock protein 90 (HSP90 which have each been reported to inhibit replication of hepatitis C virus (HCV. By comparing the toxicity of the HSP90 inhibitor, 17-(Allylamino-17-demethoxygeldanamycin (17-AAG to two known cytostatic compounds, colchicine and gemcitabine, we provide evidence that 17-AAG exerts its antiviral effects indirectly through slowing cell growth. In contrast, a cyclophilin inhibitor, cyclosporin A (CsA, exhibited selective antiviral activity without slowing cell proliferation. Furthermore, we observed that 17-AAG had little antiviral effect in a non-dividing cell-culture model of HCV replication, while CsA reduced HCV titer by more than two orders of magnitude in the same model. The assays we describe here are useful for discriminating selective antivirals from compounds that indirectly affect virus replication by reducing host cell viability or slowing cell growth.

  11. Effect of trifluoperazine on toxicity, HIF-1α induction and hepatocyte regeneration in acetaminophen toxicity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Shubhra, E-mail: SCHAUDHURI@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); McCullough, Sandra S., E-mail: mcculloughsandras@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Hennings, Leah, E-mail: lhennings@uams.edu [Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Brown, Aliza T., E-mail: brownalizat@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Li, Shun-Hwa [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Simpson, Pippa M., E-mail: psimpson@mcw.edu [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Hinson, Jack A., E-mail: hinsonjacka@uams.edu [Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); James, Laura P., E-mail: jameslaurap@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States)

    2012-10-15

    Oxidative stress and mitochondrial permeability transition (MPT) are important mechanisms in acetaminophen (APAP) toxicity. The MPT inhibitor trifluoperazine (TFP) reduced MPT, oxidative stress, and toxicity in freshly isolated hepatocytes treated with APAP. Since hypoxia inducible factor-one alpha (HIF-1α) is induced very early in APAP toxicity, a role for oxidative stress in the induction has been postulated. In the present study, the effect of TFP on toxicity and HIF-1α induction in B6C3F1 male mice treated with APAP was examined. Mice received TFP (10 mg/kg, oral gavage) prior to APAP (200 mg/kg IP) and at 7 and 36 h after APAP. Measures of metabolism (hepatic glutathione and APAP protein adducts) were comparable in the two groups of mice. Toxicity was decreased in the APAP/TFP mice at 2, 4, and 8 h, compared to the APAP mice. At 24 and 48 h, there were no significant differences in toxicity between the two groups. TFP lowered HIF-1α induction but also reduced the expression of proliferating cell nuclear antigen, a marker of hepatocyte regeneration. TFP can also inhibit phospholipase A{sub 2}, and cytosolic and secretory PLA{sub 2} activity levels were reduced in the APAP/TFP mice compared to the APAP mice. TFP also lowered prostaglandin E{sub 2} expression, a known mechanism of cytoprotection. In summary, the MPT inhibitor TFP delayed the onset of toxicity and lowered HIF-1α induction in APAP treated mice. TFP also reduced PGE{sub 2} expression and hepatocyte regeneration, likely through a mechanism involving PLA{sub 2}. -- Highlights: ► Trifluoperazine reduced acetaminophen toxicity and lowered HIF-1α induction. ► Trifluoperazine had no effect on the metabolism of acetaminophen. ► Trifluoperazine reduced hepatocyte regeneration. ► Trifluoperazine reduced phospholipase A{sub 2} activity and prostaglandin E{sub 2} levels.

  12. Cholinesterase inhibitors from botanicals

    Directory of Open Access Journals (Sweden)

    Faiyaz Ahmed

    2013-01-01

    Full Text Available Alzheimer′s disease (AD is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh, appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE and butyrylcholinesterase (BChE. Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com are also presented and the scope for future research is discussed.

  13. Green chemistry applied to corrosion and scale inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Darling, D.; Rakshpal, R. [Environmental Protection Agency, Washington, DC (United States)

    1998-12-31

    Numerous breakthroughs in environmental protection and pollution prevention have been realized in recent years by both industry and academia through the application of green chemistry principles. Green chemistry, or pollution prevention at the molecular level, is chemistry designed to reduce or eliminate the use or generation of hazardous materials associated with the manufacture and application of chemicals. The application of the green chemistry principles to the areas of corrosion and scale inhibitors has resulted in the reduction/elimination of many of the more toxic inhibitors and the development of newer, more environmentally friendly ones.

  14. Inhibitors of histone deacetylase

    DEFF Research Database (Denmark)

    2015-01-01

    of the invention are useful for treating, alleviating, and/or preventing various conditions, including for example, a metabolic disorder such as type 1 or type 2 diabetes, dyslipidemias, lipodystrophies, liver disease associated with metabolic syndrome, polycystic ovarian syndrome, or obesity; inflammatory disease...... of making and using them. In one aspect, the invention relates to selective HDAC3 inhibitors useful for protecting beta-cells and improving insulin resistence. The selective HDAC3 inhibitors are also useful for promoting cognitive function and enhancing learning and memory formation. Compounds...

  15. Green Inhibitors for Corrosion Protection of Metals and Alloys: An Overview

    Directory of Open Access Journals (Sweden)

    B. E. Amitha Rani

    2012-01-01

    Full Text Available Corrosion control of metals is of technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options of protecting metals and alloys against corrosion. The environmental toxicity of organic corrosion inhibitors has prompted the search for green corrosion inhibitors as they are biodegradable, do not contain heavy metals or other toxic compounds. As in addition to being environmentally friendly and ecologically acceptable, plant products are inexpensive, readily available and renewable. Investigations of corrosion inhibiting abilities of tannins, alkaloids, organic,amino acids, and organic dyes of plant origin are of interest. In recent years, sol-gel coatings doped with inhibitors show real promise. Although substantial research has been devoted to corrosion inhibition by plant extracts, reports on the detailed mechanisms of the adsorption process and identification of the active ingredient are still scarce. Development of computational modeling backed by wet experimental results would help to fill this void and help understand the mechanism of inhibitor action, their adsorption patterns, the inhibitor-metal surface interface and aid the development of designer inhibitors with an understanding of the time required for the release of self-healing inhibitors. The present paper consciously restricts itself mainly to plant materials as green corrosion inhibitors.

  16. Toxicity of adipic acid.

    Science.gov (United States)

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests.

  17. Use of proteasome inhibitors in anticancer therapy

    Directory of Open Access Journals (Sweden)

    Sara M. Schmitt

    2011-10-01

    Full Text Available The importance of the ubiquitin-proteasome pathway to cellular function has brought it to the forefront in the search for new anticancer therapies. The ubiquitin-proteasome pathway has proven promising in targeting various human cancers. The approval of the proteasome inhibitor bortezomib for clinical treatment of relapsed/refractory multiple myeloma and mantle cell lymphoma has validated the ubiquitin-proteasome as a rational target. Bortezomib has shown positive results in clinical use but some toxicity and side effects, as well as resistance, have been observed, indicating that further development of novel, less toxic drugs is necessary. Because less toxic drugs are necessary and drug development can be expensive and time-consuming, using existing drugs that can target the ubiquitin-proteasome pathway in new applications, such as cancer therapy, may be effective in expediting the regulatory process and bringing new drugs to the clinic. Toward this goal, previously approved drugs, such as disulfiram, as well as natural compounds found in common foods, such as green tea polyphenol (--EGCG and the flavonoid apigenin, have been investigated for their possible proteasome inhibitory and cell death inducing abilities. These compounds proved quite promising in preclinical studies and have now moved into clinical trials, with preliminary results that are encouraging. In addition to targeting the catalytic activity of the proteasome pathway, upstream regulators, such as the 19S regulatory cap, as well as E1, E2, and E3, are now being investigated as potential drug targets. This review outlines the development of novel proteasome inhibitors from preclinical to clinical studies, highlighting their abilities to inhibit the tumor proteasome and induce apoptosis in several human cancers.

  18. Knipholone, a selective inhibitor of leukotriene metabolism.

    Science.gov (United States)

    Wube, A A; Bucar, F; Asres, K; Gibbons, S; Adams, M; Streit, B; Bodensieck, A; Bauer, R

    2006-06-01

    Inhibition of leukotriene formation is one of the approaches to the treatment of asthma and other inflammatory diseases. We have investigated knipholone, isolated from the roots of Kniphofia foliosa, Hochst (Asphodelaceae), for inhibition of leukotriene biosynthesis in an ex vivo bioassay using activated human neutrophile granulocytes. Moreover, activities on 12-lipoxygenase from human platelets and cycloxygenase (COX)-1 and -2 from sheep cotyledons and seminal vesicles, respectively, have been evaluated. Knipholone was found to be a selective inhibitor of leukotriene metabolism in a human blood assay with an IC(50) value of 4.2microM. However, at a concentration of 10microg/ml, the compound showed weak inhibition of 12(S)-HETE production in human platelets and at a concentration of 50microM it produced no inhibition of COX-1 and -2. In our attempt to explain the mechanism of inhibition, we examined the antioxidant activity of knipholone using various in vitro assay systems including free radical scavenging, non-enzymatic lipid peroxidation, and metal chelation. Knipholone was found to be a weak dose-independent free radical scavenger and lipid peroxidation inhibitor, but not a metal chelator. Therefore, the leukotriene biosynthesis inhibitory effect of knipholone was evident by its ability either to inhibit the 5-lipoxygenase activating protein (FLAP) or as a competitive (non-redox) inhibitor of the enzyme. Cytotoxicity results also provided evidence that knipholone exhibits less toxicity for a mammalian host cell.

  19. Toxic and Metabolic Myelopathies.

    Science.gov (United States)

    Ramalho, Joana; Nunes, Renato Hoffmann; da Rocha, Antonio José; Castillo, Mauricio

    2016-10-01

    Myelopathy describes any neurologic deficit related to the spinal cord. It is most commonly caused by its compression by neoplasms, degenerative disc disease, trauma, or infection. Less common causes of myelopathy include spinal cord tumors, infection, inflammatory, neurodegenerative, vascular, toxic, and metabolic disorders. Conditions affecting the spinal cord must be recognized as early as possible to prevent progression that may lead to permanent disability. Biopsy is rarely performed, thus the diagnosis and management rely on patient׳s history, physical examination, laboratory results, and imaging findings. Here we review the clinical presentations, pathophysiological mechanisms, and magnetic resonance imaging findings of myelopathies related to metabolic or toxic etiologies.

  20. Psychostimulant toxicity in children

    Directory of Open Access Journals (Sweden)

    Ozalp Ekinci

    2013-04-01

    Full Text Available Methylphenidate is used for the treatment of attention deficit hyperactivity disorder in children above the age of 6 with a high safety and tolerability. When used above the recommended dosage, methylphenidate has been reported to cause toxicity symptoms including neuro-psychiatric and cardiac adverse reactions. In this overview paper, the available literature on psyhcostimulant toxicity in children and the clinical symptoms and follow-up of a 4-year-old child who accidentally used high dose of methylphenidate will be discussed. [Archives Medical Review Journal 2013; 22(2.000: 184-193

  1. The toxicity of refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1996-07-01

    This paper presents toxicity data and exposure limits for refrigerants. The data address both acute (short-term, single exposure) and chronic (long-term, repeated exposure) effects, with emphasis on the former. The refrigerants covered include those in common use for the last decade, those used as components in alternatives, and selected candidates for future replacements. The paper also reviews the toxicity indicators used in both safety standards and building, mechanical, and fire codes. It then outlines current classification methods for refrigerant safety and relates them to standard and code usage.

  2. The Toxicity of Amyloid ß Oligomers

    Directory of Open Access Journals (Sweden)

    Lock Yue Chew

    2012-06-01

    Full Text Available Abstract: In this review, we elucidate the mechanisms of Aβ oligomer toxicity which may contribute to Alzheimer’s disease (AD. In particular, we discuss on the interaction of Aβ oligomers with the membrane through the process of adsorption and insertion. Such interaction gives rises to phase transitions  in the sub-structures of the Aβ peptide from α-helical to β-sheet  structure. By means of a coarse-grained model, we exhibit the tendency of β-sheet structures to aggregate, thus providing further insights to the process of membrane induced aggregation. We show that the aggregated oligomer causes membrane invagination, which is a precursor to the formation of pore structures and ion channels. Other pathological progressions to AD due to Aβ oligomers  are also covered,  such as their interaction with the membrane receptors, and their direct versus indirect effects on oxidative  stress and intraneuronal accumulation.  We further illustrate that the molecule curcumin is a potential Aβ toxicity inhibitor as a β-sheet breaker by having  a high propensity to interact with certain Aβ residues without  binding to them. The comprehensive understanding gained from these current  researches on the various toxicity mechanisms show promises in the provision of better therapeutics and treatment strategies in the near future.

  3. Inhibitors of histone demethylases

    DEFF Research Database (Denmark)

    Lohse, Brian; Kristensen, Jesper L; Kristensen, Line H;

    2011-01-01

    Methylated lysines are important epigenetic marks. The enzymes involved in demethylation have recently been discovered and found to be involved in cancer development and progression. Despite the relative recent discovery of these enzymes a number of inhibitors have already appeared. Most of the i...

  4. Inhibitors of histone deacetylase

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to compounds of formula (I) or a pharmaceutically acceptable salt, hydrate, solvate, or prodrug thereof, wherein X1, X2, X3, X4, X5, W1, W2, W3, and W4 are as described. The present invention relates generally to inhibitors of histone deacetylase and to methods...

  5. ACE inhibitors and proteinuria

    NARCIS (Netherlands)

    Gansevoort, RT; deZeeuw, D; deJong, PE

    1996-01-01

    This review discusses the clinical consequences of urinary protein loss and the effects of inhibitors of the angiotensin converting enzyme (ACE) on this clinical finding. Proteinuria appears to be an important risk factor for renal function deterioration and for cardiovascular mortality. ACE inhibit

  6. Transglutaminase inhibitor from milk

    NARCIS (Netherlands)

    Jong, G.A.H. de; Wijngaards, G.; Koppelman, S.J.

    2003-01-01

    Cross-linking experiments of skimmed bovine milk with bacterial transglutaminase isolated from Streptoverticillium mobaraense showed only some degree of formation of high-molecular-weight casein polymers. Studies on the nature of this phenomenon revealed that bovine milk contains an inhibitor of tra

  7. Thrombin inhibitor design.

    Science.gov (United States)

    Sanderson, P E; Naylor-Olsen, A M

    1998-08-01

    Recently, iv formulated direct thrombin inhibitors have been shown to be safe and efficacious alternatives to heparin. These results have fueled the hopes for an orally active compound. Such a compound could be a significant advance over warfarin if it had predictable pharmacokinetics and a duration of action sufficient for once or twice a day dosing. In order to develop an orally active compound which meets these criteria, the deficiencies of the prototype inhibitor efegatran have had to be addressed. First, using a combination of structure based design and empirical structure optimization, more selective compounds have been identified by modifying the P1 group or by incorporating different peptidomimetic P2/P3 scaffolds. Secondly, this optimization has resulted in the development of potent and selective non-covalent inhibitors, thus bypassing the liabilities of the serine trap. Thirdly, oral bioavailability has been achieved while maintaining selectivity and efficacy through the incorporation of progressively less basic P1 groups. The duration of action of these compounds remains to be optimized. Other advances in thrombin inhibitor design have included the development of uncharged P1 groups and the discovery of two non-peptide templates.

  8. PRO 140--a novel CCR5 co-receptor inhibitor.

    Science.gov (United States)

    Khatib, Nadia; Das, Satyajit

    2010-01-01

    Despite an increase in the variety of anti-retroviral agents in the market, there remains a need for novel agents to treat HIV 1 infected individuals, in order to overcome existing problems with adherence, toxicities, drug interactions and viral resistance. In this article, we will describe Pro 140, one of the recently developed class of anti-retroviral agent, the CCR5 co-receptor inhibitor. We will also describe several preclinical and clinical studies that have evaluated the efficacy, tolerability and toxicity profiles of Pro-140. We will also look at how its mechanism of action and mode of delivery may change the way patients take highly active anti-retroviral therapy. There are some promising patents discussed in this short review for the use of PRO 140 as CCR5 co-receptor Inhibitor.

  9. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  10. Respiratory Toxicity Biomarkers

    Science.gov (United States)

    The advancement in high throughput genomic, proteomic and metabolomic techniques have accelerated pace of lung biomarker discovery. A recent growth in the discovery of new lung toxicity/disease biomarkers have led to significant advances in our understanding of pathological proce...

  11. Local anaesthetic toxicity

    African Journals Online (AJOL)

    The aim of this review is to follow the history of the search for less toxic local anaesthetic drugs, to highlight ..... Lignocaine is an anti-arrhythmic drug as it causes a fast blockade, ... ion trafficking.32 In terms of their physiological effect, the heart.

  12. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  13. Rational Design of Proteasome Inhibitors as Antimalarial Drugs.

    Science.gov (United States)

    Le Chapelain, Camille; Groll, Michael

    2016-05-23

    One life, two strategies: Crucial structural differences between the human and the Plasmodium falciparum proteasomes were recently identified. A combination of cryo-EM and functional characterization enabled the design of a selective antimalarial proteasome inhibitor that shows low toxicity in the host. When used with artemisinin, this ligand offers a new approach for the efficient treatment of malaria at all stages of the parasite lifecycle.

  14. Delivery of the Porcupine Inhibitor WNT974 in Mice

    Science.gov (United States)

    Zhang, Li-shu; Lum, Lawrence

    2016-01-01

    We describe here a technique for delivering the porcupine inhibitor WNT974 (formerly LGK974) in mice. The protocol entails once-a-day oral delivery of WNT974 for up to 3 months at a concentration sufficient to achieve systemic Wnt pathway inhibition with limited toxicity as measured by weight change. This route of delivery enables extended durations of Wnt signaling inhibition in a mammalian model organism. PMID:27590157

  15. A Decade of Experience Using mTor Inhibitors in Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Jeffrey Campsen

    2011-01-01

    Full Text Available Some studies suggest that Sirolimus (SRL is associated with an increased risk of death in liver transplant recipients compared to treatment with calcineurin inhibitors (CNIs. We compared patients who received SRL or CNI in the first year after liver transplant. Our database included 688 patients who received a liver transplant. The patients were divided into groups. (1 CNI + MPS (mycophenolate sodium at time of discharge. (2 CNI + MPS at time of discharge; SRL was added within the first 6 months and continued through the first year. (3 CNI + MPS at time of discharge; SRL was added within the first 6 months and discontinued before the first year. (4 SRL as primary immunosuppression. (5 SRL as primary immunosuppression and discontinued before the first year. We used mortality and graft loss as the primary measures of outcome. We also quantified renal function using the change in glomerular filtration rate (GFR, the presence of biopsy proven acute cellular reject (ACR, and steroid-resistant rejection (SRR. There were no significant differences in mortality or graft loss. There was no difference in patient or graft survival. Patients that received SRL as primary immunosuppression had 50% less rejection compared to controls.

  16. Comparing toxic air pollutant programs

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, S.C. [ECKENFELDER Inc., Greenville, SC (United States)

    1997-05-01

    This article compares state and federal toxic air pollutant programs. The Clean Air Act Ammendments created a program for the control of Hazardous Air Pollutants based on the establishment of control technology standards. State toxic programs can be classified into two categories: control technology-based and ambient concentration-based. Many states have opened to implement the MACT standards while enforcing their own state air toxics programs. Specific topics discussed include the following: the Federal air toxics program; existing state regulations; New Jersey Air Toxic Program; New York Toxics program.

  17. Inhibitors of the AAA+ Chaperone p97

    Directory of Open Access Journals (Sweden)

    Eli Chapman

    2015-02-01

    Full Text Available It is remarkable that a pathway as ubiquitous as protein quality control can be targeted to treat cancer. Bortezomib, an inhibitor of the proteasome, was first approved by the US Food and Drug Administration (FDA more than 10 years ago to treat refractory myeloma and later extended to lymphoma. Its use has increased the survival rate of myeloma patients by as much as three years. This success was followed with the recent accelerated approval of the natural product derived proteasome inhibitor carfilzomib (Kyprolis®, which is used to treat patients with bortezomib-resistant multiple myeloma. The success of these two drugs has validated protein quality control as a viable target to fight select cancers, but begs the question why are proteasome inhibitors limited to lymphoma and myeloma? More recently, these limitations have encouraged the search for additional targets within the protein quality control system that might offer heightened cancer cell specificity, enhanced clinical utility, a lower rate of resistance, reduced toxicity, and mitigated side effects. One promising target is p97, an ATPase associated with various cellular activities (AAA+ chaperone. p97 figures prominently in protein quality control as well as serving a variety of other cellular functions associated with cancer. More than a decade ago, it was determined that up-regulation of p97 in many forms of cancer correlates with a poor clinical outcome. Since these initial discoveries, a mechanistic explanation for this observation has been partially illuminated, but details are lacking. Understandably, given this clinical correlation, myriad roles within the cell, and its importance in protein quality control, p97 has emerged as a potential therapeutic target. This review provides an overview of efforts towards the discovery of small molecule inhibitors of p97, offering a synopsis of efforts that parallel the excellent reviews that currently exist on p97 structure, function, and

  18. Inhibitors of the AAA+ chaperone p97.

    Science.gov (United States)

    Chapman, Eli; Maksim, Nick; de la Cruz, Fabian; La Clair, James J

    2015-02-12

    It is remarkable that a pathway as ubiquitous as protein quality control can be targeted to treat cancer. Bortezomib, an inhibitor of the proteasome, was first approved by the US Food and Drug Administration (FDA) more than 10 years ago to treat refractory myeloma and later extended to lymphoma. Its use has increased the survival rate of myeloma patients by as much as three years. This success was followed with the recent accelerated approval of the natural product derived proteasome inhibitor carfilzomib (Kyprolis®), which is used to treat patients with bortezomib-resistant multiple myeloma. The success of these two drugs has validated protein quality control as a viable target to fight select cancers, but begs the question why are proteasome inhibitors limited to lymphoma and myeloma? More recently, these limitations have encouraged the search for additional targets within the protein quality control system that might offer heightened cancer cell specificity, enhanced clinical utility, a lower rate of resistance, reduced toxicity, and mitigated side effects. One promising target is p97, an ATPase associated with various cellular activities (AAA+) chaperone. p97 figures prominently in protein quality control as well as serving a variety of other cellular functions associated with cancer. More than a decade ago, it was determined that up-regulation of p97 in many forms of cancer correlates with a poor clinical outcome. Since these initial discoveries, a mechanistic explanation for this observation has been partially illuminated, but details are lacking. Understandably, given this clinical correlation, myriad roles within the cell, and its importance in protein quality control, p97 has emerged as a potential therapeutic target. This review provides an overview of efforts towards the discovery of small molecule inhibitors of p97, offering a synopsis of efforts that parallel the excellent reviews that currently exist on p97 structure, function, and physiology.

  19. Corrosion protection with eco-friendly inhibitors

    Science.gov (United States)

    Shahid, Muhammad

    2011-12-01

    Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal, the existing conditions in the environment and the type of aggressive ions present in the medium. For example, CO3-2 and NO-3 produce an insoluble deposit on the surface of iron, resulting in the isolation of metal and consequent decrease of corrosion. On the other hand, halide ions are adsorbed selectively on the metal surface and prevent formation of the oxide phase on the metal surface, resulting in continuous corrosion. Iron, aluminum and their alloys are widely used, both domestically and industrially. Linear alkylbenzene and linear alkylbenzene sulfonate are commonly used as detergents. They have also been found together in waste water. It is claimed that these chemicals act as inhibitors for stainless steel and aluminum. Release of toxic gases as a result of corrosion in pipelines may lead in certain cases to air pollution and possible health hazards. Therefore, there are two ways to look at the relationship between corrosion and pollution: (i) corrosion of metals and alloys due to environmental pollution and (ii) environmental pollution as a result of corrosion protection. This paper encompasses the two scenarios and possible remedies for various cases, using 'green' inhibitors obtained either from plant extracts or from pharmaceutical compounds. In the present study, the effect of piperacillin sodium as a corrosion inhibitor for mild steel was investigated using a weight-loss method as well as a three-electrode dc electrochemical technique. It was found that the corrosion rate decreased as the concentration of the inhibitor increased up to 9×10-4 M 93% efficiency was exhibited at this concentration.

  20. Effect of trifluoperazine on toxicity, HIF-1α induction and hepatocyte regeneration in acetaminophen toxicity in mice.

    Science.gov (United States)

    Chaudhuri, Shubhra; McCullough, Sandra S; Hennings, Leah; Brown, Aliza T; Li, Shun-Hwa; Simpson, Pippa M; Hinson, Jack A; James, Laura P

    2012-10-15

    Oxidative stress and mitochondrial permeability transition (MPT) are important mechanisms in acetaminophen (APAP) toxicity. The MPT inhibitor trifluoperazine (TFP) reduced MPT, oxidative stress, and toxicity in freshly isolated hepatocytes treated with APAP. Since hypoxia inducible factor-one alpha (HIF-1α) is induced very early in APAP toxicity, a role for oxidative stress in the induction has been postulated. In the present study, the effect of TFP on toxicity and HIF-1α induction in B6C3F1 male mice treated with APAP was examined. Mice received TFP (10mg/kg, oral gavage) prior to APAP (200mg/kg IP) and at 7 and 36h after APAP. Measures of metabolism (hepatic glutathione and APAP protein adducts) were comparable in the two groups of mice. Toxicity was decreased in the APAP/TFP mice at 2, 4, and 8h, compared to the APAP mice. At 24 and 48h, there were no significant differences in toxicity between the two groups. TFP lowered HIF-1α induction but also reduced the expression of proliferating cell nuclear antigen, a marker of hepatocyte regeneration. TFP can also inhibit phospholipase A(2), and cytosolic and secretory PLA(2) activity levels were reduced in the APAP/TFP mice compared to the APAP mice. TFP also lowered prostaglandin E(2) expression, a known mechanism of cytoprotection. In summary, the MPT inhibitor TFP delayed the onset of toxicity and lowered HIF-1α induction in APAP treated mice. TFP also reduced PGE(2) expression and hepatocyte regeneration, likely through a mechanism involving PLA(2).

  1. Cutaneous wound healing through paradoxical MAPK activation by BRAF inhibitors

    Science.gov (United States)

    Escuin-Ordinas, Helena; Li, Shuoran; Xie, Michael W.; Sun, Lu; Hugo, Willy; Huang, Rong Rong; Jiao, Jing; de-Faria, Felipe Meira; Realegeno, Susan; Krystofinski, Paige; Azhdam, Ariel; Komenan, Sara Marie D.; Atefi, Mohammad; Comin-Anduix, Begoña; Pellegrini, Matteo; Cochran, Alistair J.; Modlin, Robert L.; Herschman, Harvey R.; Lo, Roger S.; McBride, William H.; Segura, Tatiana; Ribas, Antoni

    2016-01-01

    BRAF inhibitors are highly effective therapies for the treatment of BRAFV600-mutated melanoma, with the main toxicity being a variety of hyperproliferative skin conditions due to paradoxical activation of the mitogen-activated protein kinase (MAPK) pathway in BRAF wild-type cells. Most of these hyperproliferative skin changes improve when a MEK inhibitor is co-administered, as it blocks paradoxical MAPK activation. Here we show how the BRAF inhibitor vemurafenib accelerates skin wound healing by inducing the proliferation and migration of human keratinocytes through extracellular signal-regulated kinase (ERK) phosphorylation and cell cycle progression. Topical treatment with vemurafenib in two wound-healing mice models accelerates cutaneous wound healing through paradoxical MAPK activation; addition of a mitogen-activated protein kinase kinase (MEK) inhibitor reverses the benefit of vemurafenib-accelerated wound healing. The same dosing regimen of topical BRAF inhibitor does not increase the incidence of cutaneous squamous cell carcinomas in mice. Therefore, topical BRAF inhibitors may have clinical applications in accelerating the healing of skin wounds. PMID:27476449

  2. Green Plant Extract as a passivationpromoting Inhibitor for Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Abdulrahman A. S.

    2011-08-01

    Full Text Available The present corrosion inhibitors in market for the protection of steel reinforcement in concrete exposed to chloride attack are toxic to the environment and compromises sustainability drives. There is the needs to develop inhibitor that are eco-friendly and sustainable. In this work the ability of hydrophobic green plant extracts inhibitor (Bambusa arundinacea to repassivates the chloride induced corrosion of steel was studied. Its efficacy and effectiveness was also compared with calcium nitrite inhibitor. Concrete mix was designed to 30MPa with 0.45 W/C ratios and 1.5% weight of cement content of chloride was added to initiate corrosion.Inhibitors additions were 2%. Electrochemical impedance spectroscopy, linear polarization resistance and Field emission spectroscopy (FESEM were used to monitor corrosion behavior of steel at 180 days exposure period. Corrosion rate of the inhibitors studied showed that Bambusa Arundinacea is superior as compared to calcium nitrite as results of its high concrete resistivity, chloride binding property and polarization resistance. Bambusa Arundinacea may be considered a better substitute for nitrite based corrosion inhibiting admixtures for durable concrete structures due its versatility.

  3. BACE1 inhibitor drugs in clinical trials for Alzheimer's disease.

    Science.gov (United States)

    Vassar, Robert

    2014-01-01

    β-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the β-secretase enzyme required for the production of the neurotoxic β-amyloid (Aβ) peptide that is widely considered to have a crucial early role in the etiology of Alzheimer's disease (AD). As a result, BACE1 has emerged as a prime drug target for reducing the levels of Aβ in the AD brain, and the development of BACE1 inhibitors as therapeutic agents is being vigorously pursued. It has proven difficult for the pharmaceutical industry to design BACE1 inhibitor drugs that pass the blood-brain barrier, however this challenge has recently been met and BACE1 inhibitors are now in human clinical trials to test for safety and efficacy in AD patients and individuals with pre-symptomatic AD. Initial results suggest that some of these BACE1 inhibitor drugs are well tolerated, although others have dropped out because of toxicity and it is still too early to know whether any will be effective for the prevention or treatment of AD. Additionally, based on newly identified BACE1 substrates and phenotypes of mice that lack BACE1, concerns have emerged about potential mechanism-based side effects of BACE1 inhibitor drugs with chronic administration. It is hoped that a therapeutic window can be achieved that balances safety and efficacy. This review summarizes the current state of progress in the development of BACE1 inhibitor drugs and the evaluation of their therapeutic potential for AD.

  4. [+]-Huperzine A protects against soman toxicity in guinea pigs.

    Science.gov (United States)

    Wang, Ying; Wei, Yanling; Oguntayo, Samuel; Jensen, Neil; Doctor, Bhupendra P; Nambiar, Madhusoodana P

    2011-12-01

    The chemical warfare nerve agent (CWNA) soman irreversibly inhibits acetylcholinesterase (AChE) causing seizure, neuropathology and neurobehavioral deficits. Pyridostigmine bromide (PB), the currently approved pretreatment for soman, is a reversible AChE inhibitor that does not cross the blood-brain barrier (BBB) to protect against central nervous system damage. [-]-Huperzine A, a natural reversible AChE inhibitor, rapidly passes through the BBB and has numerous neuroprotective properties that are beneficial for protection against soman. However, [-]-Huperzine A is toxic at higher doses due to potent AChE inhibition which limits the utilization of its neuroprotective properties. [+]-Huperzine A, a synthetic stereoisomer of [-]-Huperzine A and a weak inhibitor of AChE, is non-toxic. In this study, we evaluated the efficacy of [+]-Huperzine A for protection against soman toxicity in guinea pigs. Pretreatments with [+]-Huperzine A, i.m., significantly increased the survival rate in a dose-dependent manner against 1.2× LD(50) soman exposures. Behavioral signs of soman toxicity were significantly reduced in 20 and 40 mg/kg [+]-Huperzine A treated animals at 4 and 24 h compared to vehicle and PB controls. Electroencephalogram (EEG) power spectral analysis showed that [+]-Huperzine A significantly reduces soman-induced seizure compared to PB. [+]-Huperzine A (40 mg/kg) preserved higher blood and brain AChE activity compared to PB in soman exposed animals. These data suggest that [+]-Huperzine A protects against soman toxicity stronger than PB and warrant further development as a potent medical countermeasure against CWNA poisoning.

  5. Backbone and side-chain resonance assignments of (Ca(2+))4-calmodulin bound to beta calcineurin A CaMBD peptide.

    Science.gov (United States)

    Fowler, C Andrew; Núñez Hernandez, Maria F; O'Donnell, Susan E; Yu, Liping; Shea, Madeline A

    2017-08-16

    Calcineurin (CaN) is a heterodimeric and highly conserved serine/threonine phosphatase (PP2B) that plays a critical role in coupling calcium signals to physiological processes including embryonic cardiac development, NF-AT-regulated gene expression in immune responses, and apoptosis. The catalytic subunit (CaNA) has three isoforms (α, β, and γ,) in humans and seven isoforms in Paramecium. In all eukaryotes, the EF-hand protein calmodulin (CaM) regulates CaN activity in a calcium-dependent manner. The N- and C-domains of CaM (CaMN and CaMC) recognize a CaM-binding domain (CaMBD) within an intrinsically disordered region of CaNA that precedes the auto-inhibitory domain (AID) of CaNA. Here we present nearly complete (1)H, (13)C, and (15)N resonance assignments of (Ca(2+))4-CaM bound to a peptide containing the CaMBD sequence in the beta isoform of CaNA (βCaNA-CaMBDp). Its secondary structure elements predicted from the assigned chemical shifts were in good agreement with those observed in the high-resolution structures of (Ca(2+))4-CaM bound to CaMBDs of multiple enzymes. Based on the reported literature, the CaMBD of the α isoform of CaNA can bind to CaM in two opposing orientations which may influence the regulatory function of CaM. Because a high resolution structure of (Ca(2+))4-CaM bound to βCaNA-CaMBDp has not been reported, our studies serve as a starting point for determining the solution structure of this complex. This will demonstrate the preferred orientation of (Ca(2+))4-CaM on the CaMBD as well as the orientations of CaMN and CaMC relative to each other and to the AID of βCaNA.

  6. The role of Ca{sup 2+}/calmodulin-dependent protein kinase II and calcineurin in TNF-α-induced myocardial hypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gui-Jun [Department of Infectious Diseases, First Affiliated Hospital, China Medical University, Shenyang Liaoning Province (China); Liaoning Medical College, Jinzhou (China); Wang, Hong-Xin; Yao, Yu-Sheng; Guo, Lian-Yi [Liaoning Medical College, Jinzhou (China); Liu, Pei [Department of Infectious Diseases, First Affiliated Hospital, China Medical University, Shenyang Liaoning Province (China)

    2012-07-27

    We investigated whether Ca{sup 2+}/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) are involved in myocardial hypertrophy induced by tumor necrosis factor α (TNF-α). The cardiomyocytes of neonatal Wistar rats (1-2 days old) were cultured and stimulated by TNF-α (100 µg/L), and Ca{sup 2+} signal transduction was blocked by several antagonists, including BAPTA (4 µM), KN-93 (0.2 µM) and cyclosporin A (CsA, 0.2 µM). Protein content, protein synthesis, cardiomyocyte volumes, [Ca{sup 2+}]{sub i} transients, CaMKIIδ{sub B} and CaN were evaluated by the Lowry method, [{sup 3}H]-leucine incorporation, a computerized image analysis system, a Till imaging system, and Western blot analysis, respectively. TNF-α induced a significant increase in protein content in a dose-dependent manner from 10 µg/L (53.56 µg protein/well) to 100 µg/L (72.18 µg protein/well), and in a time-dependent manner from 12 h (37.42 µg protein/well) to 72 h (42.81 µg protein/well). TNF-α (100 µg/L) significantly increased the amplitude of spontaneous [Ca{sup 2+}]{sub i} transients, the total protein content, cell size, and [{sup 3}H]-leucine incorporation in cultured cardiomyocytes, which was abolished by 4 µM BAPTA, an intracellular Ca{sup 2+} chelator. The increases in protein content, cell size and [{sup 3}H]-leucine incorporation were abolished by 0.2 µM KN-93 or 0.2 µM CsA. TNF-α increased the expression of CaMKIIδ{sub B} by 35.21% and that of CaN by 22.22% compared to control. These effects were abolished by 4 µM BAPTA, which itself had no effect. These results suggest that TNF-α induces increases in [Ca{sup 2+}]{sub i}, CaMKIIδ{sub B} and CaN and promotes cardiac hypertrophy. Therefore, we hypothesize that the Ca{sup 2+}/CaMKII- and CaN-dependent signaling pathways are involved in myocardial hypertrophy induced by TNF-α.

  7. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  8. Alleviating Cancer Drug Toxicity by Inhibiting a Bacterial Enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Bret D.; Wang, Hongwei; Lane, Kimberly T.; Scott, John E.; Orans, Jillian; Koo, Ja Seol; Venkatesh, Madhukumar; Jobin, Christian; Yeh, Li-An; Mani, Sridhar; Redinbo, Matthew R. (Einstein); (UNC); (North Carolina Central University)

    2011-08-12

    The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial {beta}-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial {beta}-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial {beta}-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy.

  9. Sequencing of aromatase inhibitors

    OpenAIRE

    2005-01-01

    Since the development of the third-generation aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, these agents have been the subject of intensive research to determine their optimal use in advanced breast cancer. Not only have they replaced progestins in second-line therapy and challenged the role of tamoxifen in first-line, but there is also evidence for a lack of cross-resistance between the steroidal and nonsteroidal AIs, meaning that they may be used in sequence to obtain p...

  10. Allegheny County Toxics Release Inventory

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Toxics Release Inventory (TRI) data provides information about toxic substances released into the environment or managed through recycling, energy recovery, and...

  11. Predictive Modeling of Developmental Toxicity

    Science.gov (United States)

    The use of alternative methods in conjunction with traditional in vivo developmental toxicity testing has the potential to (1) reduce cost and increase throughput of testing the chemical universe, (2) prioritize chemicals for further targeted toxicity testing and risk assessment,...

  12. Toxicity of benzotriazole and benzotriazole derivatives to three aquatic species.

    Science.gov (United States)

    Pillard, D A; Cornell, J S; Dufresne, D L; Hernandez, M T

    2001-02-01

    Benzotriazole and its derivatives comprise an important class of corrosion inhibitors, typically used as trace additives in industrial chemical mixtures such as coolants, deicers, surface coatings, cutting fluids, and hydraulic fluids. Recent studies have shown that benzotriazole derivatives are a major component of aircraft deicing fluids (ADFs) responsible for toxicity to bacteria (Microtox). Our current research compared the toxicity of benzotriazole (BT), two methylbenzotriazole (MeBT) isomers, and butylbenzotriazole (BBT). Acute toxicity assays were used to model the response of three common test organisms: Microtox bacteria (Vibrio fischeri), fathead minnow (Pimephales promelas) and water flea (Ceriodaphnia dubia). The response of all the three organisms varied over two orders of magnitude among all compounds. Vibrio fischeri was more sensitive than either C. dubia or P. promelas to all the test materials, while C. dubia was less sensitive than P. promelas. The response of test organisms to unmethylated benzotriazole and 4-methylbenzotriazole was similar, whereas 5-methylbenzotriazole was more toxic than either of these two compounds. BBT was the most toxic benzotriazole derivative tested, inducing acute toxicity at a concentration of < or = 3.3 mg/l to all organisms.

  13. Antidotes for poisoning by alcohols that form toxic metabolites.

    Science.gov (United States)

    McMartin, Kenneth; Jacobsen, Dag; Hovda, Knut Erik

    2016-03-01

    The alcohols, methanol, ethylene glycol and diethylene glycol, have many features in common, the most important of which is the fact that the compounds themselves are relatively non-toxic but are metabolized, initially by alcohol dehydrogenase, to various toxic intermediates. These compounds are readily available worldwide in commercial products as well as in homemade alcoholic beverages, both of which lead to most of the poisoning cases, from either unintentional or intentional ingestion. Although relatively infrequent in overall occurrence, poisonings by metabolically-toxic alcohols do unfortunately occur in outbreaks and can result in severe morbidity and mortality. These poisonings have traditionally been treated with ethanol since it competes for the active site of alcohol dehydrogenase and decreases the formation of toxic metabolites. Although ethanol can be effective in these poisonings, there are substantial practical problems with its use and so fomepizole, a potent competitive inhibitor of alcohol dehydrogenase, was developed for a hopefully better treatment for metabolically-toxic alcohol poisonings. Fomepizole has few side effects and is easy to use in practice and it may obviate the need for haemodialysis in some, but not all, patients. Hence, fomepizole has largely replaced ethanol as the toxic alcohol antidote in many countries. Nevertheless, ethanol remains an important alternative because access to fomepizole can be limited, the cost may appear excessive, or the physician may prefer ethanol due to experience.

  14. Update on Aromatase Inhibitors

    Directory of Open Access Journals (Sweden)

    Seifert-Klauss V

    2015-01-01

    Full Text Available Aromatase inhibitors (AI block the last phase of estrogen production in many types of tissues which express the enzym aromatase, among them muscle, liver, adrenal, brain and fat. The enzyme catalyzes the last step of the biosynthesis of the estrogens, i. e. the aromatisation of testosterone to estradiol and of androstendion to estrone. Aromatase is localized in the membrane of the endoplasmatic reticulum and is also produced in the placenta and the gonads. Mutations in the gene CYP19A1, which codes for aromatase, can lead either to lack or excess of aromatase. Gene polymorphisms also influence the amount of bioavailable estrogen and bone density.br Indications: AI are approved for the treatment of postmenopausal women with hormone receptor positive breast cancer, both in the adjuvant setting as well as after recurrence and in progressive disease. In premenopausal and in perimenopausal women AI cause an increased sensitivity of the ovaries to follicle stimulating hormone (FSH and can thereby lead to a boosted estrogen answer – this effect is particularly pronounced in early perimenopausal women – so that these situations demand a combination with GnRH-analogue if AI treatment is to be initiated. Alternatively, tamoxifene may be used in premenopausal patients, with or without GnRH analogues. Treatment of premenopausal patients with hormone receptor positive breast cancer with aromatase inhibiting therapy alone constitutes an absolute contraindication. Aromatase inhibitors do not lead to estrogen receptor downregulation or block the receptor such as tamoxifene. An exceptional application is the application in reproductive medicine in women who do not have hormone receptor positive breast cancer: because of the higher sensitivity induced by AI-co-therapy, FSH-doses and -costs for assisted reproduction are reduced, and ovarian hyperstimulation syndrome (OHSS may be avoided. For premenopausal diseases which are said to be positively affected by

  15. Ethylene oxide potential toxicity.

    Science.gov (United States)

    da Cunha Mendes, Gisela Cristina; da Silva Brandão, Teresa Ribeiro; Miranda Silva, Cristina Luisa

    2008-05-01

    The future of ethylene oxide (EO) sterilization has been questioned, owing to its associated toxicity. EO has been around for more than 60 years, mainly due to its recognized characteristics of reliability and effectiveness, coupled with the process flexibility, as well as its compatibility with most mechanical devices. Despite the well-known EO toxicity, the undesirable effects of medical devices' EO residues on the patient's health have not yet been well established. There are limitations related to the current risk-assessment studies. To overcome these drawbacks, demands on greater safety are increasing, which lead to improvements in sterilizers and aeration equipment, as well as the design of the processes. The paper under evaluation highlights risks related to EO sterilization of materials used during processing of stem cells for transplantation, but is an example of a study where the dose of the residues in the devices is not considered.

  16. Anticancer therapy-induced vascular toxicity: VEGF inhibition and beyond.

    Science.gov (United States)

    Di Lisi, Daniela; Madonna, Rosalinda; Zito, Concetta; Bronte, Enrico; Badalamenti, Giuseppe; Parrella, Paolo; Monte, Ines; Tocchetti, Carlo Gabriele; Russo, Antonio; Novo, Giuseppina

    2017-01-15

    Cardiotoxicity induced by chemotherapeutic agents and radiotherapy is a growing problem. In recent years, an increasing number of new drugs with targeted action have been designed. These molecules, such as monoclonal antibodies and tyrosine kinase inhibitors, can cause different type of toxicities compared to traditional chemotherapy. However, they can also cause cardiac complications such as heart failure, arterial hypertension, QT interval prolongation and arrhythmias. Currently, a field of intense research is the vascular toxicity induced by new biologic drugs, particularly those which inhibit vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) and other tyrosine kinases. In this review, we aim at focusing on the problem of vascular toxicity induced by new targeted therapies, chemotherapy and radiotherapy, and describe the main mechanisms and emphasizing the importance of early diagnosis of vascular damage, in order to prevent clinical complications.

  17. In Vitro Pulmonary Toxicity of Metal Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Cupi, Denisa; Dreher, Kevin

    for comprehensive toxicological assessments. BEAS2B human bronchial epithelial cells were employed to assess the in vitro pulmonary toxicity of 4 TiO2 and 4 CeO2 particles varying is size (6 - 1288nm) and crystalline structure. Exposures were conducted over several concentrations for each endpoint examined. No BEAS...... particles induced similar increases in HO-1 mRNA levels at 6hr and 24hr post-exposure, respectively. The pattern of HO-1 gene induction was inconsistent with a role of oxidative stress in metal oxide induced BEAS2B cytokine gene expression. Pretreatment of BEAS2B cells with IKK inhibitor III BMS-345541......nm. Results demonstrate the ability to employ in vitro methods to assess NM induced pulmonary toxicity. Many of the responses were found not to be totally dependent on NM size/surface area suggesting composition and surface properties play a role in mediating NM toxicity. This abstract does...

  18. Improved antitumor activity of immunotherapy with BRAF and MEK inhibitors in BRAFV600E melanoma

    OpenAIRE

    Hu-Lieskovan, Siwen; Mok, Stephen; Moreno, Blanca Homet; Tsoi, Jennifer; Faja, Lidia Robert; Goedert, Lucas; Pinheiro, Elaine M.; Koya, Richard C; Graeber, Thomas; Comin-Anduix, Begoña; Ribas, Antoni

    2015-01-01

    Combining immunotherapy and BRAF targeted therapy may result in improved antitumor activity with the high response rates of targeted therapy and the durability of responses with immunotherapy. However, the first clinical trial testing the combination of the BRAF