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)

ErbB3 is an epidermal growth factor receptor-related type I tyrosine kinase receptor capable, in conjunction with ErbB2 or epidermal growth factor receptor, of transmitting proliferative and differentiative signals in a variety of cell types. We previously showed that ErbB3 messenger RNA and protein increase in cultured hepatocytes during the first 12 h in culture, as does the binding of heregulin beta1, a ligand for ErbB3. Insulin inhibits the increase in heregulin beta1 binding, as well as the increase in ErbB3 messenger RNA and protein. Two models of insulin deficiency in vivo (diabetes and fasting) demonstrated elevated levels of hepatic ErbB3 protein, strengthening the relevance of our observations in vitro. Using chemical activators or antagonists, we sought to identify the signaling pathways that link insulin to ErbB3 expression. The PI-3 kinase inhibitors, wortmannin and LY294002, completely blocked the inhibition of ErbB3 protein expression by insulin, suggesting a role for PI-3 kinase in the regulation of this growth factor receptor. Rapamycin, an inhibitor of p70 S6 kinase, an enzyme downstream of PI-3 kinase, failed to block the effect of insulin on ErbB3 expression. These results suggest a complex regulatory paradign for ErbB3 that includes PI-3 kinase and may be linked, via insulin, to the metabolic status of the animal.
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PMID:Hepatic expression of ErbB3 is repressed by insulin in a pathway sensitive to PI-3 kinase inhibitors. 938 1

Insulin resistance in 3-day streptozotocin (STZ)-treated rats was manifested by the lack of antiproteolytic action of insulin as well as by a reduction of its stimulatory effect on protein synthesis (-60% compared with the control group) in epitrochlearis muscle incubated in vitro. In the present study, we have investigated the diabetes-associated alterations in the insulin signalling cascade, especially the phosphatidylinositol-3 kinase (PI-3 kinase)/p70 S6 kinase (p70(S6K)) pathway, in rat skeletal muscle. LY 294002, a specific inhibitor of PI-3 kinase, markedly decreased the basal rate of protein synthesis and completely prevented insulin-mediated stimulation of this process both in control and diabetic rats. Thus, PI-3 kinase is required for insulin-stimulated muscle protein synthesis in diabetic rats as in the controls. Rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), had no effect on the basal rate of protein synthesis in either of the experimental groups. In control rats, the stimulatory action of insulin on muscle protein synthesis was diminished by 36% in the presence of rapamycin, whereas in diabetic muscles this reduction amounted to 68%. The rapamycin-sensitive pathway makes a relatively greater contribution to the stimulatory effect of insulin on muscle protein synthesis in diabetic rats compared with the controls, due presumably to the preferential decrease in the rapamycin-insensitive component of protein synthesis. Neither basal nor insulin-stimulated p70(S6K) activity, a signalling element lying downstream of mTOR, were modified by STZ-diabetes.
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PMID:Involvement of the rapamycin-sensitive pathway in the insulin regulation of muscle protein synthesis in streptozotocin-diabetic rats. 985 85

DE NOVO DIABETES AND CARDIOVASCULAR RISK: Certain kidney transplant recipients who develop de novo diabetes have an unfavorable cardiovascular risk profile, comparable to patients with type 2 diabetes mellitus, with advanced age, dyslipidemia, obesity and high blood pressure. MYOCARDIAL INFARCTION IN THE PERIOPERATIVE PERIOD: Among kidney transplant recipients, those whose risk factors include male gender diabetes, age over 50 years and prior revascularization procedure for coronary artery disease have a higher risk for myocardial infarction in the perioperative period. The usefulness of anticoagulant or beta-blockers as preventive treatment for these high-risk patients remains to be determined. HYPERLIPIDEMIA: A retrospective analysis of 530 kidney transplant recipients demonstrated that a very significant proportion of those with dyslipidemia are not receiving appropriate care although their lipid profile is indicative of a high or very high cardiovascular risk. MASSIVE PROTEINURIA: An angiotensin II inhibitor, losartan, has been found to be effective against massive proteinuria (> 3.5 g/l) occurring after kidney transplantation. CALCINEURIN-INHIBITOR-INDUCED HEMOLYTIC UREMIA SYNDROME: Five to ten percent of patients given calcineurin inhibitors develop a hemolytic uremia syndrome. Sirolimus appears to be a very interesting alternative for immunoprophylaxys against acute rejection.
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PMID:[Complications in kidney transplantation]. 1157 77

The immunosuppressive benefits of cyclosporine and tacrolimus in short-term and medium-term renal allograft survival are well documented. It is becoming increasingly clear that the basis of this immunosuppression, the inhibition of calcineurin, may be linked with nephrotoxicity, hypertension, hyperlipidemia, and new-onset diabetes mellitus, side effects that may lead to CRAD, death due to CVD, and late renal allograft loss. This clinical picture presents a clear need for new strategies that produce adequate immunosuppression to prevent acute rejection while simultaneously reducing the side effects associated with CNI-related therapies. Sirolimus combined with cyclosporine and tacrolimus has demonstrated an ability to reduce incidences of early acute rejection and, used as base therapy, has provided protection against acute rejection equivalent to that of cyclosporine, without the consequent nephrotoxicity associated with CNIs. In preliminary results from an ongoing clinical trial, sirolimus has been used to eliminate cyclosporine during maintenance immunosuppression, with subsequent improvements in measures of blood pressure and renal function. In addition, the antiproliferative properties of sirolimus and its ability to prevent graft vascular disease in animal studies make sirolimus a promising agent to decrease incidences of CRAD and improve long-term renal allograft survival. These findings point to a clear need to further explore both the efficacy of sirolimus immunotherapy and its long-term effects.
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PMID:Exploring treatment options in renal transplantation: the problems of chronic allograft dysfunction and drug-related nephrotoxicity. 1158 88

Sirolimus is an immunosuppressant that inhibits interleukin (IL)-2 signaling of T-cell proliferation but not IL-2-induced T-cell apoptosis. Therefore, we hypothesized that administration of IL-2, together with sirolimus, might shift T-cell proliferation to apoptosis and prevent autoimmune destruction of islet beta-cells. We found that sirolimus and IL-2 therapy of female NOD mice, beginning at age 10 weeks, was synergistic in preventing diabetes development, and disease prevention continued for 13 weeks after stopping sirolimus and IL-2 therapy. Similarly, sirolimus and IL-2 were synergistic in protecting syngeneic islet grafts from recurrent autoimmune destruction after transplantation in diabetic NOD mice, and diabetes did not recur after stopping sirolimus and IL-2 combination therapy. Immunocytochemical examination of islet grafts revealed significantly decreased numbers of leukocytes together with increased apoptosis of these cells in mice treated with sirolimus and IL-2, whereas beta-cells were more numerous, and significantly fewer were apoptotic. In addition, Th1-type cells (gamma-interferon-positive and IL-2(+)) were decreased the most, and Th2-type cells (IL-4(+) and IL-10(+)) and Th3-type cells (transforming growth factor-beta1(+)) were increased the most in islet grafts of sirolimus and IL-2-treated mice. We conclude that 1) combination therapy with sirolimus and IL-2 is synergistic in protecting islet beta-cells from autoimmune destruction; 2) diabetes prevention continues after withdrawal of therapy; and 3) the mechanism of protection involves a shift from Th1- to Th2- and Th3-type cytokine-producing cells, possibly due to deletion of autoreactive Th1 cells.
Diabetes 2002 Mar
PMID:Combination therapy with sirolimus and interleukin-2 prevents spontaneous and recurrent autoimmune diabetes in NOD mice. 1187 61

Hyperinsulinemia has been shown to be associated with diabetic angiopathy. Migration and proliferation of vascular smooth muscle cells (VSMC) are the processes required for the development of atherosclerosis. In this study, we attempted to determine whether insulin affects mitogenic signaling induced by platelet-derived growth factor (PDGF) in a rat VSMC cell line (A10 cells). PDGF stimulated DNA synthesis which was totally dependent on Ras, because transfection of dominant negative Ras resulted in complete loss of PDGF-stimulated DNA synthesis. Initiation of DNA synthesis was preceded by activation of Raf-1, MEK and MAP kinases (Erk 1 and Erk2). Treatment of the cells with PD98059, an inhibitor of MAPK kinase (MEK) attenuated but did not abolish PDGF-stimulated DNA synthesis, suggesting that MAPK is required but not essential for DNA synthesis. PDGF also stimulated phosphorylation of protein kinase B (Akt/PKB) and p70 S6Kinase (p70S6K) in a wortmannin-sensitive manner. Rapamycin, an inhibitor of p70S6K, markedly suppressed DNA synthesis. Low concentrations of insulin (1-10 nmol/l) alone showed little mitogenic activity and no significant effect on MAPK activity. However, the presence of insulin enhanced both DNA synthesis and MAPK activation by PDGF. The enhancing effect of insulin was not seen in cells treated with PD98059. Insulin was without effect on PDGF-stimulated activations of protein kinase B (Akt/PKB) and p70S6K. We conclude that insulin, at pathophysiologically relevant concentrations, potentiates the PDGF-stimulated DNA synthesis, at least in part, by potentiating activation of the MAPK cascade. These results are consistent with the notion that hyperinsulinemia is a risk factor for the development of atherosclerosis.
Int J Exp Diabetes Res
PMID:Potentiation of mitogenic activity of platelet-derived growth factor by physiological concentrations of insulin via the MAP kinase cascade in rat A10 vascular smooth muscle cells. 1199 Nov 99

Mammalian target of rapamycin (mTOR) is a serine and threonine protein kinase that regulates numerous cellular functions, in particular, the initiation of protein translation. mTOR-mediated phosphorylation of both the translational repressor eukaryotic initiation factor 4E binding protein-1 and p70 S6 kinase are early events that control the translation initiation process. Rapamycin, an inhibitor of mTOR, is a potent immunosuppressant due, in part, to its ability to interfere with T-cell activation at the level of translation, and it has gained a prominent role in preventing the development and progression of rejection in pancreatic islet transplant recipients. The characterization of the insulin signaling cascade that modulates mTOR in insulin-sensitive tissues has been a major focus of investigation. Recently, the ability of nutrients, in particular the branched-chain amino acid leucine, to activate mTOR independent of insulin by a process designated as nutrient signaling has been identified. The beta-cell expresses components of the insulin signaling cascade and utilizes the metabolism of nutrients to affect insulin secretion. These combined transduction processes make the beta-cell an unique cell to study metabolic and autocrine regulation of mTOR signaling. Our studies have described the ability of insulin and IGFs in concert with the nutrients leucine, glutamine, and glucose to modulate protein translation through mTOR in beta-cells. These findings suggest that mitochondria-derived factors, ATP in particular, may be responsible for nutrient signaling. The significance of these findings is that the optimization of mitochondrial function is not only important for insulin secretion but may significantly impact the growth and proliferation of beta-cells through these mTOR signaling pathways.
Diabetes 2002 Oct
PMID:Metabolic and autocrine regulation of the mammalian target of rapamycin by pancreatic beta-cells. 1235 22

Sirolimus is a new immunosuppressive agent increasingly being used in liver transplant recipients. There is concern that sirolimus may be associated with wound complications and hepatic artery thrombosis (HAT). We have used sirolimus as primary immunosuppression in 170 liver transplant recipients and therefore reviewed our experience with wound complications and HAT in our cohort of patients. Records of all 170 patients administered sirolimus as primary immunosuppression and 180 historic controls were reviewed. Numbers of wound and hepatic artery complications were recorded, as well as the prevalence of obesity, reoperation, diabetes, and OKT3 use, all of which are risk factors for wound complications. The prevalence of wound complications was 12.4% in sirolimus-treated patients compared with 13.9% in historic controls (P = not significant [NS]). The prevalence of hepatic artery complications was 5.3% in sirolimus-treated patients compared with 8.3% in historic controls (P = NS). The prevalence of obesity and OKT3 administration was significantly lower in sirolimus-treated patients. Multivariate analysis failed to show an association between sirolimus therapy and hepatic artery or wound complications. The prevalence of wound and hepatic artery complications is not different in liver transplant recipients administered sirolimus as part of a primary immunosuppressive regimen compared with historic controls.
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PMID:Sirolimus as primary immunosuppression in liver transplantation is not associated with hepatic artery or wound complications. 1274 Jul 88

Rapamycin-coated stents are associated with low restenosis rates, but the ability of oral rapamycin to prevent restenosis is unknown. From December 2001 through February 2002, thirty-four patients with 49 lesions were treated with oral rapamycin for 1 month following percutaneous coronary intervention (PCI) with bare stents. Patients received a loading dose of 6 mg rapamycin followed by a daily dose of 2 mg. Rapamycin blood levels were measured in all patients during the third week of treatment. Cholesterol and triglycerides were evaluated before and 1 month after treatment. A 6-month follow-up angiogram was performed in all patients. Angiographic binary restenosis (> 50%), target lesion revascularization (TLR), late loss, treatment compliance and major adverse cardiac events were analyzed independent of rapamycin levels. Baseline characteristics included a history of diabetes in 35% of patients and the presence of in-stent restenosis in 24.5% of lesions (12/49). The rapamycin was well tolerated and only 1 patient discontinued the therapy due to mild side effects. Angiographic restenosis and TLR at 6 months was present in 26.5% of lesions (13/49). Restenosis in de novo lesions was 18.9% (7/37) compared to 50% of in-stent restenotic lesions (6/12; p = 0.08). Restenosis in de novo lesions in patients with rapamycin levels > 8 ng/ml was 0% (0/12), whereas it was 24% (6/25) when the rapamycin levels were < 8 ng/ml (p = 0.07). Late loss was significantly lower when rapamycin levels were > 8 ng/ml (0.3 mm versus 0.9 mm, respectively; p = 0.04). Thus, in this observational study, oral rapamycin administered for 1 month after PCI with bare stenting was safe and well tolerated. Higher therapeutic rapamycin blood levels were associated with a lower late loss and a trend toward a lower restenosis rate in de novo lesions.
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PMID:Pilot study of oral rapamycin to prevent restenosis in patients undergoing coronary stent therapy: Argentina Single-Center Study (ORAR Trial). 1451 92

Rapamycin (sirolimus) is a macrolide fungicide with immunosuppressant properties that is used in human islet transplantation. Little is known about the effects of rapamycin on MIN-6 cells and islets. Rapamycin had a dose-dependent, time-dependent, and glucose-independent deleterious effect on MIN-6 cell viability. At day 1, using the MTT method, 0.01 nmol/l rapamycin reduced cell viability to 83 +/- 6% of control (P < 0.05). Using the calcein AM method, at day 2, 10 nmol/l rapamycin caused a reduction in cell viability to 73 +/- 5% of control (P < 0.001). Furthermore, 10 and 100 nmol/l rapamycin caused apoptosis in MIN-6 cells as assessed by the transferase-mediated dUTP nick-end labeling assay. Compared with control, there was a 3.1 +/- 0.6-fold increase (P < 0.01) in apoptosis in MIN-6 cells treated with 10 nmol/l rapamycin. A supra-therapeutic rapamycin concentration of 100 nmol/l significantly impaired glucose- and carbachol-stimulated insulin secretion in rat islets and had a deleterious effect on the viability of rat and human islets, causing apoptosis of both alpha- and beta-cells.
Diabetes 2003 Nov
PMID:Rapamycin has a deleterious effect on MIN-6 cells and rat and human islets. 1457 91


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