Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are two major defects in type 2 diabetes: 1) insulin resistance and 2) insulin deficiency due to loss of beta-cell function. Here we demonstrated that treatment with muraglitazar (a dual peroxisome proliferator-activated receptor alpha/gamma activator), when initiated before or after the onset of diabetes in mice, is effective against both defects. In study 1, prediabetic db/db mice were treated for 12 weeks. The control mice developed diabetes, as evidenced by hyperglycemia, hyperinsulinemia, reduced insulin levels in the pancreas, blunted insulin response to glucose, and impaired glucose tolerance. The muraglitazar-treated mice had normal plasma glucose, and insulin levels, equivalent or higher pancreatic insulin content than normal mice, showed a robust insulin response to glucose and exhibited greater glucose tolerance. In study 2, diabetic db/db mice were treated for 4 weeks. The control mice displayed increased glucose levels, severe loss of islets, and their isolated islets secreted reduced amounts of insulin in response to glucose and exendin-4 compared with baseline. In muraglitazar-treated mice, glucose levels were reduced to normal. These mice showed reduced loss of islets, and their isolated islets secreted insulin at levels comparable to baseline. Thus, muraglitazar treatment decreased both insulin resistance and preserved beta-cell function. As a result, muraglitazar treatment, when initiated before the onset of diabetes, prevented development of diabetes and, when initiated after the onset of diabetes, prevented worsening of diabetes in db/db mice.
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PMID:The dual peroxisome proliferator-activated receptor alpha/gamma activator muraglitazar prevents the natural progression of diabetes in db/db mice. 1725 49

Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone and is a new clinically available class of agents for improving of insulin resistance in both animals and humans with type 2 diabetes. These studies aimed to determine whether long-term treatment with a long-acting GLP-1 analog, exendin-4, delayed the progression of diabetes. Male db/db mice and db/m mice at 8 wk of age were treated with exendin-4 for 8 wk, whereas the control db/db mice received only vehicle. Urinary albumin excretion was significantly decreased in db/db mice that were treated with 1 nmol/kg exendin-4 compared with those in db/db mice that were treated with 0.5 nmol/kg exendin-4 and control db/db mice (P < 0.005). Intraperitoneal glucose tolerance test was improved in db/db mice that were treated with 1 nmol/kg exendin-4 compared with other groups (P < 0.05). Despite this, fasting blood glucose, glycated hemoglobin, and creatinine concentrations were not significantly different among db/db mice. Renal histology studies further demonstrated that glomerular hypertrophy, mesangial matrix expansion, TGF-beta1 expression, and type IV collagen accumulation and associated glomerular lipid accumulation were significantly decreased in db/db mice that were treated with 1 nmol/kg exendin-4. Furthermore, there were fewer infiltrating inflammatory cells and apoptotic cells in the glomeruli of db/db mice that were treated with 1 nmol/kg exendin-4 compared with those in the other groups accompanied by an increase in the renal immunoreactivity of peroxisome proliferator-activated receptor alpha and GLP-1 receptor-positive cells and a decrease in 24-h urinary 8-hydroxy-deoxyguanosine levels (P < 0.01, respectively) along with decreases in lipid content. Taken together, exendin-4 treatment seems to ameliorate diabetic nephropathy together with improvement of the metabolic anomalies. These results suggest that exendin-4 could provide a therapeutic role in diabetic nephropathy that results from type 2 diabetes.
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PMID:Long-term treatment of glucagon-like peptide-1 analog exendin-4 ameliorates diabetic nephropathy through improving metabolic anomalies in db/db mice. 1736 Sep 51

Tesaglitazar (GALIDA; AstraZeneca, Wilmington, DE) is a dual peroxisome proliferator-activated receptor alpha/gamma agonist previously in clinical development for the treatment of glucose and lipid abnormalities associated with type 2 diabetes mellitus and insulin resistance. This study compared the efficacy of tesaglitazar with that of pioglitazone as adjunctive therapy to atorvastatin in subjects with abdominal obesity and dyslipidemia. In this open-label, 3-way crossover study, 58 subjects received atorvastatin 10 mg once daily in a 6-week run-in period, followed by tesaglitazar 3 mg, pioglitazone 45 mg, or placebo, as adjunctive therapy to atorvastatin, in a randomized sequence for 6 weeks each. Serum triglycerides and other lipids, apolipoproteins, glucose, and insulin concentrations were compared between treatments. Tesaglitazar adjunctive therapy reduced serum triglycerides significantly more from baseline (-1.07 mmol/L) than pioglitazone (-0.33 mmol/L; P = .007) or placebo (-0.09 mmol/L; P < .0001). Tesaglitazar also resulted in significantly greater improvements in free fatty acids, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio, low-density lipoprotein particle size, apolipoprotein (apo) B, apo C-III, and the apo B/apo A-I ratio compared with pioglitazone or placebo. Tesaglitazar adjunctive therapy also reduced fasting plasma glucose, fasting plasma insulin, and insulin resistance (homeostasis model assessment index) significantly more than pioglitazone or placebo (P < .0001 for all comparisons). Tesaglitazar was generally well tolerated in combination with atorvastatin, but hemoglobin and absolute neutrophil count decreased and serum creatinine increased more with tesaglitazar than with pioglitazone or placebo. These effects, also shown in previous trials, led to the discontinuation of the clinical development of the drug. In conclusion, the addition of tesaglitazar to a background of atorvastatin therapy further improved the dyslipidemia associated with insulin resistance.
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PMID:The dual peroxisome proliferator-activated receptor alpha/gamma agonist tesaglitazar further improves the lipid profile in dyslipidemic subjects treated with atorvastatin. 1769 74

This study assessed the effects of tesaglitazar (0.5 or 1 mg/day), a dual peroxisome proliferator-activated receptor alpha/gamma agonist, when added to maximally tolerated metformin (2-2.5 g/day) in patients with poorly controlled type 2 diabetes. The primary end point of this 24-week, randomised, placebo-controlled study was the absolute change from baseline in glycosylated haemoglobin (HbA1C). Tesaglitazar significantly reduced HbA1C, fasting plasma glucose and insulin levels compared with placebo (p<0.0001 for all) when added to metformin. Triglycerides, high-density lipoprotein cholesterol (HDL-C) and non-HDL-C levels also improved with tesaglitazar treatment (p<0.0001 for all). Adverse events were generally similar across treatments, except for higher frequencies of peripheral oedema and weight gain in the tesaglitazar 1 mg group. Although reversibility was not fully evaluated, dose-dependent changes in mean serum creatinine levels and haematology measures tended to return towards baseline at follow-up. Despite the clinical discontinuation of tesaglitazar, this study has demonstrated the potential benefits of dual PPAR agonism as add-on therapy to metformin, in patients with poorly controlled type 2 diabetes.
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PMID:The effects of tesaglitazar as add-on treatment to metformin in patients with poorly controlled type 2 diabetes. 1790 10

The insulin-sensitizing adipokine, adiponectin, acts through 2 receptors, AdipoR1 and AdipoR2. A decreased expression of these receptors could contribute to insulin resistance and diabetes. We determined if the expression of adiponectin receptors is decreased in an experimental model, the Zucker diabetic rat (ZDF), and if a peroxisome proliferator-activated receptor alpha agonist, fenofibrate, and metformin could increase these expressions. The ZDF and control (L) rats were studied at 7, 14, and 21 weeks. After initial study at 7 weeks, ZDF received no treatment (n = 10), metformin (n = 10), or fenofibrate (n = 10) until final studies at 14 or 21 weeks. The L rats received no treatment. AdipoR1 and R2 expressions were measured in liver, muscle, and white adipose tissue (WAT). As expected, ZDF rats were insulin resistant at 7 weeks, had type 2 diabetes mellitus at 14 weeks, and had diabetes with insulin deficiency at 21 weeks. Compared with L rats, AdipoRs messenger RNA was decreased only in the WAT (P < .05) of 7-week-old ZDF rats, but was unchanged in muscle and increased in liver. Metformin and fenofibrate decreased plasma triacylglycerols (P < .01) as expected. The only effect of fenofibrate on AdipoRs was a moderate increase (P < .01) of both receptors' messenger RNA in liver. Metformin increased AdipoR1 and R2 expression in muscle (P < .01) and AdipoR1 (P < .01) in WAT. These results do not support an important role for decreased AdipoRs expression in the development of insulin resistance and diabetes. Parts of the actions of fenofibrate and of metformin could be mediated by a stimulation of the expression of these receptors in liver and in insulin-sensitive, glucose-utilizing tissues (muscle, WAT), respectively.
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PMID:Adiponectin receptors: expression in Zucker diabetic rats and effects of fenofibrate and metformin. 1855 36

Adiponectin and adiponectin receptors (AdipoRs) have been found to play significant roles in the etiology of obesity-related chronic disease. Their discovery has been a long and complicated path, with many challenges. Developing methods to unravel the molecular secrets has been an informative process in itself. However, with both functional and genetic studies confirming adiponectin as a therapeutic target adipokine, many roles and interactions with certain other biomolecules have been clearly defined. We have found that decreased high molecular weight (HMW) adiponectin plays a crucial and causal role in obesity-linked insulin resistance and metabolic syndrome; that AdipoR1 and AdipoR2 serve as the major AdipoRs in vivo; and that AdipoR1 activates the AMP kinase (AMPK) pathway and AdipoR2, the peroxisome proliferator-activated receptor alpha (PPARalpha) pathway in the liver, to increase insulin sensitivity and decrease inflammation. Further conclusions are that decreased adiponectin action and increased monocyte chemoattractant protein-1 (MCP-1) form a vicious adipokine network causing obesity-linked insulin resistance and metabolic syndrome; PPARgamma upregulates HMW adiponectin and PPARalpha upregulates AdipoRs; that dietary osmotin can serve as a naturally occurring adiponectin receptor agonist; and finally, that under starvation conditions, MMW adiponectin activates AMPK in hypothalamus, and promotes food intake, and at the same time HMW adiponectin activates AMPK in peripheral tissues, such as skeletal muscle, and stimulates fatty-acids combustion. Importantly, under pathophysiological conditions, such as obesity and diabetes, only HMW adiponectin was decreased; therefore, strategies to increase only HMW adiponectin may be a logical approach to provide a novel treatment modality for obesity-linked diseases, such as insulin resistance and type 2 diabetes. It is hoped that these data will be helpful in developing treatments to counteract the destructive, expensive and painful effects of obesity.
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PMID:Physiological and pathophysiological roles of adiponectin and adiponectin receptors in the integrated regulation of metabolic and cardiovascular diseases. 1913 82

Adiponectin stimulates cholesterol efflux in macrophages and low adiponectin may in part contribute to disturbed reverse cholesterol transport in type 2 diabetes. Monocytes express high levels of annexin A6 that could inhibit cholesterol efflux and it was investigated whether the atheroprotective effects of adiponectin are accompanied by changes in annexin A6 levels. Adiponectin reduces annexin A6 protein whereas mRNA levels are not affected. Adiponectin-mediated activation of peroxisome proliferator-activated receptor alpha (PPARalpha) and AMP-activated protein kinase (AMPK) does not account for reduced annexin A6 expression. Further, fatty acids and lipopolysaccharide that are elevated in obesity do not influence annexin A6 protein levels. Annexin A6 in monocytes from overweight probands or type 2 diabetic patients is significantly elevated compared to monocytes of normal-weight controls. Monocytic annexin A6 positively correlates with body mass index and negatively with systemic adiponectin of the blood donors. Therefore, the current study demonstrates that adiponectin reduces annexin A6 in monocytes and thereby may enhance cholesterol efflux. In agreement with these in vitro finding an increase of monocytic annexin A6 in type 2 diabetes monocytes was observed.
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PMID:Annexin A6 is highly abundant in monocytes of obese and type 2 diabetic individuals and is downregulated by adiponectin in vitro. 1932 30

Cardiovascular disease is the leading cause of morbidity and mortality world-wide. The burden of disease is also increasing as a result of the global epidemics of diabetes and obesity. Peroxisome proliferator-activated receptor alpha (PPARalpha), a member of this nuclear receptor family, has emerged as an important player in this scenario, with evidence supporting a central co-ordinated role in the regulation of fatty acid oxidation, lipid and lipoprotein metabolism and inflammatory and vascular responses, all of which would be predicted to reduce atherosclerotic risk. Additionally, the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study has indicated the possibility of preventive effects in diabetes-related microvascular complications, although the mechanisms of these effects warrant further study. The multimodal pharmacological profile of PPARalpha has prompted development of selective PPAR modulators (SPPARMs) to maximise therapeutic potential. It is anticipated that PPARalpha will continue to have important clinical application in addressing the major challenge of cardiometabolic risk associated with type 2 diabetes, obesity and metabolic syndrome.
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PMID:Peroxisome proliferator-activated receptor-alpha (PPARalpha): at the crossroads of obesity, diabetes and cardiovascular disease. 1938 11

Peroxisome proliferator-activated receptor alpha (PPARalpha) regulates transcription of genes involved both in lipid and glucose metabolism as well as in inflammation. Fibrates are PPARalpha ligands used to normalize lipid and glucose parameters and exert antiinflammatory effects. In fact, fibrates have already been demonstrated to benefit metabolic syndrome, type 2 diabetes and cardiovascular diseases. This article reviews the mechanism of action and the functional roles of fibrates, emphasizing the factors modulating their capacity to activate PPARalpha and affecting their effectiveness. These factors may possibly explain the findings obtained in animal studies and clinical trials with fibrates which showed either untoward effects and/or inefficient hypolipidemic action of PPARalpha activation. We also discuss briefly the natural and synthetic agonists of PPARalphawhich are currently being developed and supposedly display greater effectiveness and fewer adverse effects than fibrates.
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PMID:Factors modulating fibrates response: therapeutic implications and alternative strategies. 1959 20

Obesity and type 2 diabetes are related metabolic disorders of high prevalence. The constitutive androstane receptor (CAR) was initially characterized as a xenobiotic receptor regulating the responses of mammals to xenotoxicants. In this study, we have uncovered an unexpected role of CAR in preventing obesity and alleviating type 2 diabetes. Using a high fat diet (HFD)-induced obesity model, we showed that treatment of wild type mice with the CAR agonist 1,4-bis[2-(3,5 dichloropyridyloxy)] benzene (TCPOBOP) efficiently prevented obesity from happening or reversed preinduced obesity. Treatment with TCPOBOP improved insulin sensitivity in both the HFD-induced type 2 diabetic model and the ob/ob mice. In contrast, CAR null mice maintained on a chow diet showed spontaneous insulin insensitivity, which cannot be relieved by TOPOBOP treatment. The hepatic steatosis in HFD-treated mice and ob/ob mice was markedly reduced by the TCPOBOP treatment. The metabolic benefits of CAR activation may have resulted from the combined effect of inhibition of lipogenesis, very low density lipoprotein secretion and export of triglycerides, and gluconeogenesis as well as increases in brown adipose tissue energy expenditure and peripheral fat mobilization. Moreover, the skeletal muscle of CAR-activated mice showed a decreased incomplete oxidation, despite having a lower expression level of peroxisome proliferator-activated receptor alpha and its target genes involved in fatty acid oxidation. In summary, our results have revealed an important metabolic function of CAR and may establish this "xenobiotic receptor" as a novel therapeutic target for the prevention and treatment of obesity and type 2 diabetes.
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PMID:The constitutive androstane receptor is an anti-obesity nuclear receptor that improves insulin sensitivity. 1961 49


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