Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The growth and function of organs such as pancreatic islets adapt to meet physiological challenges and maintain metabolic balance, but the mechanisms controlling these facultative responses are unclear. Diabetes in patients treated with calcineurin inhibitors such as cyclosporin A indicates that calcineurin/nuclear factor of activated T-cells (NFAT) signalling might control adaptive islet responses, but the roles of this pathway in beta-cells in vivo are not understood. Here we show that mice with a beta-cell-specific deletion of the calcineurin phosphatase regulatory subunit, calcineurin b1 (Cnb1), develop age-dependent diabetes characterized by decreased beta-cell proliferation and mass, reduced pancreatic insulin content and hypoinsulinaemia. Moreover, beta-cells lacking Cnb1 have a reduced expression of established regulators of beta-cell proliferation. Conditional expression of active NFATc1 in Cnb1-deficient beta-cells rescues these defects and prevents diabetes. In normal adult beta-cells, conditional NFAT activation promotes the expression of cell-cycle regulators and increases beta-cell proliferation and mass, resulting in hyperinsulinaemia. Conditional NFAT activation also induces the expression of genes critical for beta-cell endocrine function, including all six genes mutated in hereditary forms of monogenic type 2 diabetes. Thus, calcineurin/NFAT signalling regulates multiple factors that control growth and hallmark beta-cell functions, revealing unique models for the pathogenesis and therapy of diabetes.
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PMID:Calcineurin/NFAT signalling regulates pancreatic beta-cell growth and function. 1698 14

Stimulation of local renin-angiotensin system and increased levels of oxidants characterize the diabetic heart. Downregulation of ANG II type 1 receptors (AT(1)) and enhancement in PKC activity in the heart point out the role of AT(1) blockers in diabetes. The purpose of this study was to evaluate a potential role of an AT(1) blocker, candesartan, on abnormal Ca(2+) release mechanisms and its relationship with PKC in the cardiomyocytes from streptozotocin-induced diabetic rats. Cardiomyocytes were isolated enzymatically and then incubated with either candesartan or a nonspecific PKC inhibitor bisindolylmaleimide I (BIM) for 6-8 h at 37 degrees C. Both candesartan and BIM applied on diabetic cardiomyocytes significantly restored the altered kinetic parameters of Ca(2+) transients, as well as depressed Ca(2+) loading of sarcoplasmic reticulum, basal Ca(2+) level, and spatiotemporal properties of the Ca(2+) sparks. In addition, candesartan and BIM significantly antagonized the hyperphosphorylation of cardiac ryanodine receptor (RyR2) and restored the depleted protein levels of both RyR2 and FK506 binding protein 12.6 (FKBP12.6). Furthermore, candesartan and BIM also reduced the increased PKC levels and oxidized protein thiol level in membrane fraction of diabetic rat cardiomyocytes. Taken together, these data demonstrate that AT(1) receptor blockade protects cardiomyocytes from development of cellular alterations typically associated with Ca(2+) release mechanisms in diabetes mellitus. Prevention of these alterations by candesartan may present a useful pharmacological strategy for the treatment of diabetic cardiomyopathy.
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PMID:Restoration of diabetes-induced abnormal local Ca2+ release in cardiomyocytes by angiotensin II receptor blockade. 1701 47

Using biochemical/pharmacological approaches, we previously showed that type 2 ryanodine receptors (RyR2) become dysfunctional in hearts of streptozotocin-induced type 1 diabetic rats. However, the functional consequence of this observation remains incompletely understood. Here we use laser confocal microscopy to investigate whether RyR2 dysfunction during diabetes alters evoked and spontaneous Ca(2+) release from the sarcoplasmic reticulum (SR). After 7-8 weeks of diabetes, steady-state levels of RyR2 remain unchanged in hearts of male Sprague-Dawley rats, but the number of functional receptors decreased by >37%. Interestingly, residual functional RyR2 from diabetic rat hearts exhibited increased sensitivity to Ca(2+) activation (EC(50activation) decreased from 80 microM to 40 microM, peak Ca(2+) activation decreased from 425 microM to 160 microM). When field stimulated, intracellular Ca(2+) release in diabetic ventricular myocytes was dyssynchronous (non-uniform) and this was independent of L-type Ca(2+) currents. Time to peak Ca(2+) increased 3.7-fold. Diabetic myocytes also exhibited diastolic Ca(2+) release and 2-fold higher frequency of spontaneous Ca(2+) sparks, albeit at a lower amplitude. The amplitude of caffeine-releasable Ca(2+) was also lower in diabetic myocytes. RyR2 from diabetic rat hearts exhibited increased phosphorylation at Ser2809 and contained reduced levels of FKBP12.6 (calstablin2). Collectively, these data suggest that RyR2 becomes leaky during diabetes and this defect may be responsible to the reduced SR Ca(2+) load. Diastolic Ca(2+) release could also serve as a substrate for delayed after-depolarizations, contributing to the increased incidence of arrhythmias and sudden cardiac death in type 1 diabetes.
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PMID:Dyssynchronous (non-uniform) Ca2+ release in myocytes from streptozotocin-induced diabetic rats. 1702 51

Corticosteroid avoidance is feasible and may be desirable in liver transplantation. Approximately 50% of liver transplant recipients who use calcineurin inhibitors and azathioprine do not need corticosteroids. The availability of newer agents, such as mycophenolate mofetil and antibody therapy, has increased the percentage of patients who do not need to use corticosteroids to about 75%. The feasibility of corticosteroid-free immunosuppression has been established by controlled trials demonstrating non-inferiority with respect to patterns of rejection as well as patient and graft survival. However, the evidence available to date does not unequivocally establish the benefits of corticosteroid-free immunosuppression, although some advantage has been established relating to post-transplant diabetes mellitus, cytomegalovirus infection and growth patterns in children. The effect of corticosteroid-free immunosuppression in hepatitis C liver transplant recipients is yet to be resolved.
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PMID:Corticosteroid-free strategies in liver transplantation. 1704 Jan 15

New immunosuppressive regimens have decreased acute rejection rates after kidney transplant. However, the use of these new agents has modified the profile of surgical complications. We compared the incidence of surgical complications in relation with the use of three types of drugs: calcineurin inhibitors, antiproliferative agents, and mammalian target of rapamycin (mTOR) inhibitors. This retrospective study included 359 cadaveric recipients who received an allograft between 1997 and 2004. The mean age was 54 years. The prevalence of diabetes was 8.5% and that of obesity (body mass index > 30 kg/m(2)) was 15.4%. The mean follow-up time was 44 +/- 5.6 months. The regimen most frequently used was tacrolimus (TACRO), mycophenolate mofetil (MMF), and prednisone (PRED) (n = 172), followed by TACRO-PRED (n = 49), cyclosporine (CSA) and MMF and PRED (n = 41), and CSA-azathioprine (AZA) and PRED (n = 24). A surgical complication was considered to be any type of event during the first year, although minimal, directly related to surgery. The rate of surgical complications was 34.8% (122/350). Collections and bleeding were higher in CSA than in TACRO regimens, 12% versus 3.8% (P < .05) and 11.5% versus 3% (P = .002), respectively. The incidence of lymphoceles was higher in regimens with than without mTOR inhibitors: 16% versus 3.7% (P = .012). The incidence of surgical complications was not influenced by the use of MMF or diabetes. In conclusion, the use of mTOR inhibitor-based immunosuppressive regimens leads to a higher incidence of lymphoceles, while the use of MMF does not increase the incidence of surgical complications.
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PMID:Post-kidney transplant surgical complications under new immunosuppressive regimens. 1709 62

Enormous advancements in visceral transplantation have led to significant improvements in the quality of life of patients. However, despite these developments, the average graft half-life after transplantation has remained almost unchanged and chronic rejection is still considered a major problem. In this regard, more concerns have shifted to factors influencing long-term graft survival, patient survival, and quality of life. To achieve this goal, detrimental effects of immunosuppressive (IS) agents, which have deleterious influence on the quality of life and/or patient survival, should be reduced. In the course of recent years, the transplant community has worked on reducing these side effects by developing new ISs, employing new combination regimens, or finding and adjusting optimal dosages and blood level concentrations. Among the IS agents, the antifungal, antitumoral and IS activity of mammalian target of rapamycin (mTOR) inhibitors without nephrotoxicity, have received special attention regarding this new class of IS. Sirolimus (SRL), as the first member of mTOR inhibitors, has been utilized in many clinical trials with respect to its benefit-risk assessment. In our review, the clinical evolution of SRL, as well as the evidence-based clinical benefits of SRL in kidney and liver transplantation (KTx, LTx), are summarized. Various studies of SRL in KTx and LTx have shown that combination therapy with SRL will enrich the variety of IS modalities. It also can be regarded as a safe base therapy to which other necessary drugs can be added. In addition to the enhanced acute rejection prophylaxis, and in contrast to the calcineurin inhibitors (CNI) and steroids, this drug solely does not have common side effects such as nephrotoxicity, neurotoxicity, diabetes mellitus and hypertension. Moreover, this agent might diminish vasculopathic processes that mediate chronic allograft nephropathy (CAN). Therefore, by reducing the likelihood of CAN it can decrease the rate of long-term organ failure. One possibly desirable characteristic of SRL is its antiproliferative effect, which could provoke antitumoral or antiatherogenic activity following transplantation. Despite all promising impacts of SRL in organ transplantation, there are some concerns regarding the adverse effects of this drug, for instance dyslipidemia, pneumonitis and wound healing problems. However, the majority of these side effects can be reduced or ceased by careful dose adjustments and correct timing of use. In conclusion, after a decade of both in vivo and in vitro studies on SRL, it can be advocated that SRL is a promising, potent and effective IS agent as it reduces the rate of acute rejection episodes in de novo transplants. It could improve the quality of life, graft and patient survival rate, and achieve excellent outcomes with few adverse effects when wisely used in combination with other immunosuppressants.
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PMID:The role and value of sirolimus administration in kidney and liver transplantation. 1710 Jun 99

New-onset diabetes after transplantation (NODAT) contributes to the risk for cardiovascular disease and infection, reducing graft and patient survival. For improvement of the outcome of kidney transplant recipients, it is of great interest to know precisely the risk factors that contribute to NODAT development. Nonmodifiable risk factors for development of NODAT are age, race, genetic background, family history of diabetes, and previous glucose intolerance. Modifiable risk factors are obesity and overweight, hepatitis C virus and cytomegalovirus infections, and immunosuppressive drugs. Both steroids and calcineurin inhibitors influence the appearance of NODAT, whereas the role of sirolimus in glucose metabolism currently is controversial.
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PMID:New-onset diabetes after kidney transplantation: risk factors. 1713 Feb 77

Post-transplant diabetes mellitus (PTDM) has emerged as a major adverse effect of immunosuppressive drugs (ISD). As recipients of organ transplants survive longer, the complications of diabetes mellitus have assumed greater importance. The predominant factor for causing PTDM by corticosteroids seems to be the aggravation of insulin resistance, however several studies have displayed deleterious effects on insulin secretion and beta-cells. Calcineurin inhibitors induce PTDM by a number of mechanisms, including decreased insulin secretion and a direct toxic effect on the pancreatic beta-cells. Recent in vitro studies stress on the increased apoptosis of beta-cells when exposed to these drugs. Studies involving other immunosuppressive agents (mycophenolate mofetil [MMF], sirolimus) are scarcer and lead to conflicting results, while daclizumab seems to have a neutral effect. Clinical studies have consistently shown a greater potential of tacrolimus to induce PTDM compared with cyclosporine. Reducing PTDM incidence is a feasible goal while using corticosteroid-sparing regimens and/or lower tacrolimus trough levels. In patients developing PTDM, conversion from tacrolimus to cyclosporine could improve or reverse glucose tolerance abnormalities. In the absence of well-designed studies in this specific indication, treatment of PTDM is based on the same principles as type 2 diabetes mellitus. Thiazolidinediones do not display any pharmacological interaction with calcineurin inhibitors, but their safety and efficacy in PTDM need to be confirmed in large-scale randomized trials. Use of sulfonylureas has to be cautious regarding the suspected interaction of some of them with calcineurin inhibitors. If needed, insulin regimens have to be adapted in patients who display the particular glycaemic profile of corticosteroid-induced diabetes. Incretin-based therapies, due to their specific action on beta-cell apoptosis and proliferation, raise promises that have to be confirmed in clinical studies. Until methods for inducing specific graft tolerance become available, immunosuppressive regimens should be tailored to the individual patient on the basis of predictive criteria for the development of PTDM.
Diabetes Metab 2006 Dec
PMID:Immunosuppressive drug-induced diabetes. 1713 Aug 15

Post-transplantation diabetes (PTD) is a serious complication in organ transplantation: not only does it increase the risk of graft dysfunction; it also increases cardiovascular morbidity and mortality. PTD incidence is correlated with age, non-Caucasian ethnic background, a family history of diabetes, excess weight, hepatitis C infection and steroid boluses for potential rejection. Different mechanisms might explain post-transplantation glucose metabolism disorders: ischemia-reperfusion disorders, whether renal, hepatic or cardiac, are responsible for insulin-resistance, which is increased by post-transplantation steroids; the detrimental effect of non-steroid immunosuppressive drugs on insulin-secretion could also be involved, especially with calcineurin inhibitors. In vivo and in vitro studies have shown that tacrolimus has inhibitory effects on insulin-secretion, while these effects are less obvious for cyclosporin, and were mainly demonstrated in vitro. Mycophenolate has no overt effect on insulin-secretion. Sirolimus and everolimus, two mTOR inhibitors, have shown controversial results in this realm. The effects of sirolimus (most often studied mTOR inhibitor) appear to depend on serum levels, cell type (ss cell or cell line), species (human or animal) and also environmental nutrients. At therapeutic concentrations, a stimulatory effect on insulin secretion was observed on human beta cells. This might explain the success of islet cell transplantation with the Edmonton protocol. Finally, steroids are mainly detrimental because they accentuate insulin resistance whereas anticalcineurins, in particular tacrolimus, lower insulin synthesis.
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PMID:Effects of non-steroid immunosuppressive drugs on insulin secretion in transplantation. 1731 44

Isotechnika is developing the immunosuppressive drug ISA 247, a calcineurin inhibitor that is undergoing clinical development for the treatment of psoriasis (phase III) and prevention of organ rejection after transplantation (phase II). Preclinical development for uveitis is also underway. Other autoimmune disease indications that could be explored include arthritis, type I diabetes and Crohn's disease. ISA 247 was being co-developed as R 1524 by Isotechnika and Roche. However, Roche is no longer involved in the development of this compound. Based on analysis of previously collected data, the trans-ISA 247 isomer was found to be more bioavailable and it is expected that this isomer can be administered at a lower dose compared with the previous formulation that consisted of an equivalent mixture of the two geometric isomers (cis and trans). Preclinical observations indicate that ISA 247 has the potential to be more potent and less toxic than other marketed immunosuppressants in its class used for the prevention of transplant rejection. Experiments to date suggest that ISA 247 is about three times as potent as ciclosporin, while genotoxicity studies in animals have shown that the compound has a significantly reduced tendency to cause renal toxicity. The combination of reduced toxicity and improved potency would give ISA 247 a therapeutic benefit over existing calcineurin-based treatments. Isotechnika and Roche entered into a co-development and commercialisation agreement in April 2002, with Roche gaining the exclusive worldwide marketing rights for ISA 247; Isotechnika received milestone payments of $US4 million and $CAN21.9 million in September 2002 and May 2003, respectively. The agreement was restructured in April 2004, under which Isotechnika will now solely manage and fund the clinical development of trans-ISA 247. Upon successful completion of these trials, Isotechnika will conduct at its own expense a phase IIb study in renal transplantation and phase III studies in psoriasis. Roche will have the right to opt-in to the development and commercialisation of trans-ISA 247 for transplant indications up to the end of the phase IIb renal transplantation trial. Isotechnika retains all rights to develop and commercialise the product outside of transplant indications. Under an agreement signed with Cellgate Inc. on 25 April 2006, Isotechnika has the option to obtain an exclusive licence to develop and commercialise conjugates consisting of Cellgate's patented transporter technology, for the topical delivery of ISA 247 in patients with mild-to-moderate psoriasis. Cellgate will perform studies to evaluate the feasibility of using their technology to topically deliver ISA 247. In return, Isotechnika will pay Cellgate Inc. a total of $US500 000, with $US100 000 paid upfront, and the remainder at predetermined time points. Upon successful completion of the studies, Isotechnika has the option to further develop and commercialise conjugates for topical delivery of ISA 247. Isotechnika and Atrium Medical Corporation announced an exclusive worldwide licensing agreement for ISA 247 alone and in combination with TAFA 93 with respect to drug-eluting devices, in September 2005. Atrium's implantable products include those for the local, non-systemic treatment of vascular and cardiovascular disorders, soft tissue repair and other disorders. In May 2006, Isotechnika licensed ISA 247 to Lux Biosciences for ophthalmic indications. Under terms of the agreement, Lux Biosciences obtains the exclusive worldwide marketing rights to ISA 247 for treatment and prophylaxis of all ophthalmic indications. The company will be responsible for development, registration and marketing of the drug for ophthalmic indications and will make upfront and milestone payments to Isotechnika in addition to royalties on any sales. Isotechnika formalised a manufacturing agreement with Swiss-based Lonza Ltd in June 2004. Under the terms of the agreement, Lonza will manufacture sufficient quantities of trans-ISA 247 in a GMP environment for use in the company's upcoming clinical trials. Isotechnika completed the phase III SPIRIT trial of ISA 247 for psoriasis in Canada. The randomised, double-blind trial compared the efficacy of three doses of ISA 247 (0.2 mg/kg [low dose], 0.3 mg/kg [mid dose] and 0.4 mg/kg [high dose] twice daily) with placebo, with equal numbers of patients assigned to each of the four groups. Subsequent to the first 12 weeks, those patients who received placebo moved into the mid-dose group for the remaining 12 weeks of the study. Patients already receiving ISA 247 remained in their respective dosing groups for the final 12 weeks of the trial. Patients completing the 24-week SPIRIT trial were given the opportunity to continue therapy for an addditonal 36 weeks or to discontinue therapy. Those patients who chose to enrol in the extension trial were moved from the 0.2 mg/kg bid (low-dose) or 0.4 mg/kg bid (high-dose) groups into the the 0.3 bid mg/kg bid (mid dose) group. Patients who commenced the SPIRIT trial in the mid-dose group remained on the same dosage regimen for the duration of the extension trial. The goal of the extension trial is to demonstrate continued therapeutic benefit to psoriasis patients while gathering long-term safety data. So far, data has been received on 193 patients receiving treatment for a total of 48 weeks. A phase IIa trial investigating the safety and efficacy of ISA 247 in renal transplantation was completed in the US and Canada in January 2003. The trial compared ISA 247 with ciclosporin (Neoral in approximately 130 stable renal transplant patients who underwent transplantation at least 6 months prior to enrolment; patient recruitment was completed in October 2002. Half of the patients were treated with ciclosporin and the other half received ISA 247 over a 90-day period. An extension trial was then initiated in which another 200 patients were treated with ISA 247 for up to 6 months from the time of transplantation. Results from the trial were reported. All endpoints were achieved in a multiple ascending dose study of trans-ISA 247 in November 2004. The study, initiated in June 2004, was conducted by SFBC Anapharm in Montreal, Canada and involved 43 healthy volunteers. Final dosing recommendations are to be determined in phase III trials in patients with psoriasis. Interim results reported in September 2004, of a double-blind, parallel-group, placebo and moxifloxacin controlled, randomised single-dose QTc trial in healthy volunteers, showed no evidence of QTc prolongation when trans-ISA 247 was administered at therapeutic doses. A single ascending dose (SAD) trial for trans-ISA 247 was completed in July 2004. The SAD trial was conducted among healthy volunteers to assess the appropriate dosage of trans-ISA 247 for further clinical evaluations. The trial commenced in March 2004 with approximately 46 subjects enrolled under the supervision of MDS Pharma Services in Phoenix, Arizona, USA. Isotechnika received US FDA approval for the SAD trial in February 2004. A European patent (No. EP 0 991 660) entitled 'Deuterated and Undeuterated Cyclosporine Analgoues and Their Use as Immunomodulating Agents' was issued to Isotechnika for ISA 247, in October 2006. A US patent entitled 'Novel Cyclosporin Analogue Formulations' was issued to Isotechnika (No. 7 060 672) for ISA 247 in June 2006. The patent claims have been filed in 36 countries, and in the US it is the first patent to be issued in this patent family. Isotechnika was issued a US patent (No. 6 998 385, entitled 'Cyclosporine Analogue Mixtures and their use as Immunomodulating Agents') in February 2006 covering mixtures of cis- and trans- isomers of ISA 257. This patent is the first US patent to be issued in this family of patents. These patent claims have been filed in 36 countries. Three patents relating to this claim were previously issued in the following countries; Morocco (No. 26337 issued 1 October 2004); Pakistan (No. 138338 issued 30 September 2004) and South Africa (No. 2004/2270 issued 25 May 2005). A US patent (No 6 686 454) was issued in February 2004 entitled 'Antibodies to Specific Regions of Cyclosporine Related Compounds'. This patent covers a novel, simple and cost-effective assay used in the use and management of ISA 247. It also received another US patent entitled 'Deuterated Cyclosporine Analogs and their Use as Immunomodulating Agents'. Isotechnika has received patents for chemical composition of ISA 247 in New Zealand (November 2001; New Zealand Patent No. 502362), Canada (December 2001; Canadian Patent No. 2 298 572), South Korea (June 2006; South Korean Patent No. 585348) and Australia (November 2002; Australian Patent No. 750245). In addition, Isotechnika announced in August 2003 that it had been granted US patent No. 6 605 593, entitled 'Deuterated Ciclosporine Analogs and their use as Immunomodulating Agents'. An additional US patent covering ISA 247 was granted in September 2003.
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PMID:ISA 247: trans-ISA 247, trans-R 1524, ISA(TX)247, ISAtx 247, ISATx247, LX 211, LX211, R 1524, R-1524. 1732 8


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