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)

High fat diet or insulin deficiency is commonly seen in Type II diabetes, while the mechanism remains unclear. To test our hypothesis that DPP-IV contributes to Type II diabetes, we examined the expression and activity of DPP-IV in rats (n=8 to each group) treated for 12 weeks with 3 separate diets: a) normal control; b) a high fat diet; and c) a high fat diet plus streptozotocin, a chemical for induction of insulin-deficient diabetes. Compared to rats on the normal diet, the rats with a high fat diet significantly increased DPP-IV's expression and activity about 142-152% in the intestine (P<0.05) and 153-240% in kidneys (P<0.05), but there was no change in the liver. Administration of streptozotocin to the rats treated with the high fat diet showed an insufficient insulin secretion and higher blood glucose in response to glucose/insulin tolerance test, and an increase in expression of DPP-IV and activity by 188-242% in the intestine (P<0.01); 191-225% in liver (P<0.01); and 211-321% in the kidneys (P<0.01). Immunohistochemistry studies confirmed the above results, showing increased DPP-IV immunostaining localized primarily in intestinal epithelium, hepatocytes and renal tubular cells. This study, for the first time reports an increase in DPP-IV associated with a high fat diet, as well as in the combination of a high fat diet with an insulin deficiency. Since both high fat diet and insulin deficiency are closely linked with etiology of Type II diabetes, the evidence in this study suggests a role of DPP-IV in development of Type II diabetes.
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PMID:Increase in DPP-IV in the intestine, liver and kidney of the rat treated with high fat diet and streptozotocin. 1758 52

Dipeptidyl peptidase 4 (DPP-4) inhibition prevents the rapid degradation of the incretins, glucagon-like peptide 1 and glucose-dependent insulinotropic peptide. Incretins have beneficial effects on glycaemic control in patients with type 2 diabetes through their effects on both alpha- and beta-cells in the pancreas and possibly through additional non-pancreatic effects. Vildagliptin is a potent and selective oral DPP-4 inhibitor that has been studied both as monotherapy and in combination with other antidiabetic treatments. This agent has been shown to be well tolerated and is efficacious in reducing glycosylated haemoglobin, fasting plasma glucose and postprandial glucose levels in trials lasting up to 52 weeks. Vildagliptin is weight neutral, does not cause oedema and is associated with a very low incidence of hypoglycaemia. Recently reported clinical data have helped to further clarify the mechanisms of action and effects of vildagliptin. These results suggest that vildagliptin, as a member of the novel class of DPP-4 inhibitors, has the potential to significantly change the clinical management of diabetes. Future research will further define its use in various patient populations and its possible disease-modifying effects.
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PMID:Dipeptidyl peptidase 4 inhibition and vildagliptin therapy for type 2 diabetes. 1759 76

Dipeptidyl peptidase IV (DPP-IV) deactivates the incretin hormones GLP-1 and GIP by cleaving the penultimate proline or alanine from the N-terminal (P1-position) of the peptide. Inhibition of this enzyme will prevent the degradation of the incretin hormones and maintain glucose homeostasis; this makes it an attractive target for the development of drugs for diabetes. This paper reports 3D-QSAR analysis of several DPP-IV inhibitors, which were aligned by the receptor-based technique. The conformation of the molecules in the active site was obtained through docking methods. The QSAR models were generated on two training sets composed of 74 and 25 molecules which included phenylalanine, thiazolidine, and fluorinated pyrrolidine analogs. The 3D-QSAR models are robust with statistically significant r(2), q(2), and r(pred)(2) values. The CoMFA and CoMSIA models were used to design some new inhibitors with several fold higher binding affinity.
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PMID:3D-QSAR studies of Dipeptidyl peptidase IV inhibitors using a docking based alignment. 1767 45

In France, prevalence of drug-treated diabetes reached 3.60% in 2005, with 92% of type 2 diabetic patients. In 2007, there are probably nearly 3000 000 diagnosed or undiagnosed diabetic patients. Ageing of the population and increase in obesity are the main causes of this "diabetes epidemic". Type 2 diabetes is a multifactorial disease, defined as resulting from defects in insulin secretion (including abnormalities in pulsatility and kinetics, quantitative and qualitative abnormalities of insulin, beta-cell loss progressing with time) associated with insulin resistance (affecting liver, and skeletal muscle) and increased glucagon secretion. The lack of compensation of insulin resistance by augmented insulin secretion results in rise in blood glucose. To achieve satisfactory glycaemic control in order to prevent diabetes related complications, drug therapy is generally required in addition to life style changes. Currently available oral therapies offer a large panel of complementary drugs, but they have several contraindications and side effects. In spite of major advances in the management of type 2 diabetes, and the strictness of new guidelines, some goals remain unachieved and the new family of insulin-secretors (DPP-IV inhibitors, GLP-1 analogues) should enrich therapeutic approaches.
Diabetes Metab 2007 Sep
PMID:Type 2 diabetes mellitus: epidemiology, pathophysiology, unmet needs and therapeutical perspectives. 1770 79

Neutral endopeptidase (NEP) is the major enzyme involved in the metabolic inactivation of a number of bioactive peptides including the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, as well as the incretin hormone glucagon-like peptide 1 (GLP-1), which is a potent stimulator of insulin secretion. The activity of GLP-1 is also rapidly abolished by the serine protease dipeptidyl peptidase IV (DPP-IV), which led to an elevated interest in inhibitors of this enzyme for the treatment of type II diabetes. A dual NEP/DPP-IV inhibitor concept is proposed, offering an alternative strategy for the treatment of type 2 diabetes. Here, the synthesis and crystal structures of the soluble extracellular domain of human NEP (residues 52-749) complexed with the NEP, competitive and potent dual NEP/DPP-IV inhibitor MCB3937 are described.
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PMID:Structural studies of a bifunctional inhibitor of neprilysin and DPP-IV. 1770 66

Dipeptidyl peptidase 4 (DPP-4) inhibitors are a new pharmacological class of drugs for treating Type 2 diabetes. They improve the capacity of the organism to control glycemia by increasing the levels of active incretins. Their mechanism of action is thus radically different from those of other anti-diabetic drugs currently available. DDP-4 inhibitors use a physiological mechanism to control hyperglycemia, by stimulating the secretion of insulin from beta-cells, decreasing the secretion of glucagon from pancreatic alpha-cells, and at the same time reducing the production of glucose by the liver. DDP-4 inhibitors have shown significant efficacy in maintaining reduced levels of glycosylated hemoglobin for up to 1 year. In vitro and animal studies have shown that they can inhibit apoptosis of beta-cells and favor their regeneration and differentiation. The oral DPP-4 inhibitors vildagliptin, sitagliptin, and saxagliptin are efficacious both alone and in association with other oral anti-diabetic agents and may be administered in a single daily dose. Lastly, they have substantial advantages with respect to other anti-diabetic drugs, since they involve a low risk of hypoglycemia and do not affect body weight.
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PMID:Dipeptidyl peptidase 4 (DPP-4) inhibitors and their role in Type 2 diabetes management. 1784 46

Incretins are gut peptides that potentiate nutrient-stimulated insulin secretion following meal ingestion. Activities of the dominant incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, include glucose-dependent stimulation of insulin secretion and, in preclinical models, improvement in islet beta-cell mass. GLP-1 additionally reduces glucagon secretion, inhibits gastric emptying and promotes satiety. Patients with type 2 diabetes mellitus (T2DM) exhibit reduced total and intact GLP-1 levels, and exogenous administration of the hormone via continuous infusion results in glucose profiles similar to those in non-diabetic subjects. Incretins are rapidly degraded by dipeptidyl peptidase-4 (DPP-4). Thus, strategies to enhance incretin activity have included development of GLP-1 receptor agonists resistant to the action of DPP-4 (e.g. exenatide and liraglutide) and DPP-4 inhibitors that act to increase concentrations of endogenous intact incretins (e.g. sitagliptin and vildagliptin). Clinical trials of these incretin-based therapies have shown them to be effective in improving glycaemic control in patients with T2DM.
Diabetes Obes Metab 2007 Sep
PMID:Incretin-based treatment of type 2 diabetes: glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors. 1787 44

Vildagliptin is a potent selective inhibitor of dipeptidyl peptidase-4 (DPP-4) that improves glycaemic control by increasing islet alpha-cell and beta-cell responsiveness to glucose. In patients with type 2 diabetes mellitus (T2DM), vildagliptin improves beta-cell function, measured as insulin secretory rate relative to glucose level, and reduces glucagon secretion and endogenous glucose production in the postprandial period, resulting in reduced glucose levels. In clinical trials in T2DM, vildagliptin 100 mg/day monotherapy is effective in reducing haemoglobin A1c (HbA1c) across the spectrum of hyperglycaemia and has maintained efficacy over long-term treatment with neutral effects on body weight and lipids. Vildagliptin is associated with a low risk of hypoglycaemia, and has an adverse event profile comparable to placebo, including a reduced rate of gastrointestinal adverse effects compared with metformin and a reduced rate of oedema compared with rosiglitazone. As add-on combination therapy, vildagliptin produces significant further reductions in HbA1c in patients receiving metformin, pioglitazone, glimepiride and insulin, and has been found to reduce frequency of hypoglycaemia as an add-on to insulin. Preliminary findings indicate that the improved islet cell function underlying the efficacy of vildagliptin in T2DM is also observed in patients with impaired glucose tolerance, with vildagliptin treatment resulting in reduced glycaemic excursions. The overall profile of vildagliptin and the preliminary evidence of beneficial effects in the prediabetic state suggest that DPP-4 inhibition could be an effective strategy to prevent or delay progression from the prediabetic state to overt T2DM.
Diabetes Obes Metab 2007 Sep
PMID:The DPP-4 inhibitor vildagliptin: robust glycaemic control in type 2 diabetes and beyond. 1787 45

Dipeptidyl peptidase (DPP-IV) rapidly metabolizes hormones such as glucagon-like peptide-1(7-36)amide. This study evaluated circulating DPP-IV activity in type 2 diabetic patients in relation to GLP-1 degradation and metabolic control. Blood samples were collected from type 2 diabetic patients in three main categories: good glycaemic control (HbA(1c) <7%, upper limit of non-diabetic range), moderate glycaemic control (HbA(1c) 7-9%) and poor glycaemic control (HbA(1c) >9%). Age- and sex-matched non-diabetic subjects were used as controls. Circulating DPP-IV activity of healthy control subjects was 22.5+/-0.7 nmol/ml/min (n=70). In the combined groups of type 2 diabetic subjects, circulating DPP-IV activity was significantly decreased at 18.1+/-0.7 nmol/ml/min (p<0.001, n=54). DPP-IV activity was negatively correlated with both glucose (p<0.01) and HbA(1c) (p<0.01) in this population. Furthermore, DPP-IV activity was reduced 1.2-fold (p<0.01, n=25), 1.3-fold (p<0.001, n=19) and 1.3-fold (p<0.05, n=10) in good, moderate and poorly controlled diabetic groups, 18.7+/-1.0, 17.4+/-1.4 and 18.0+/-1.5 nmol/ml/min, respectively. Degradation of GLP-1 by in vitro incubation with pooled plasma samples from healthy and type 2 diabetic subjects revealed decreased degradation to the inactive metabolite, GLP-1(9-36), in the diabetic group. These data indicate decreased DPP-IV activity and GLP-1 degradation in type 2 diabetes. DPP-IV enzyme activity appears to be depressed in response to poor glycaemic control.
Diabetes Res Clin Pract 2008 Jan
PMID:Decreased dipeptidyl peptidase-IV activity and glucagon-like peptide-1(7-36)amide degradation in type 2 diabetic subjects. 1790 81

Type 2 diabetes is an endocrine/metabolic disease characterized by hyperglycemia. It is now well established that insulin resistance and pancreatic beta-cell dysfunction/failure are the two major components of the physiopathology of the disease. Current available therapies do not successfully enable patients with type 2 diabetes to reach glycemic goals. Even with intensive treatment type 2 diabetic patients may face spikes in blood glucose after meals, weight gain, and a loss of effectiveness of their treatments over time. The novel agents recently developed by the Pharmaceutical Industry may either provide an alternative therapeutic strategy or offer useful adjuncts to existing therapies. Glucagon-like peptide 1 (GLP-1), produced in the small intestine and amylin, produced by beta cells in the pancreas, also have glucose lowering effects. Amylin is an hormone secreted after a meal, having a complementary action to insulin. GLP-1, also released in a post-prandial manner, promotes insulin production and secretion, reduces glucagon secretion, delays gastric emptying and induces a feeling of fullness. The most promising effect of GLP-1 is its ability to increase beta-cell mass by stimulating neogenesis and reducing apoptosis in rodents. However the fact that GLP-1 is rapidly degraded by dipeptidylpeptidase IV (DPPIV) in vivo reduces its usefulness. Thus, in order to improve therapeutic efficacy, two approaches have been investigated: the development of GLP-1 analogs resistant to degradation or the development of DPP-IV inhibitors. Synthetic analogs of amylin (pramlintide), GLP-1 (exenatide) and inhibitors of the degradation of GLP-1 (sitagliptin, DPP-IV inhibitor) are now available for clinical use. Promising biological targets being investigated include those leading to insulin sensitization (11beta-HSD-1 inhibitors and antagonists of glucocorticoids receptor), reducing hepatic glucose output (antagonist of glucagon receptor, inhibitors of glycogen phosphorylase and fructose-1,6-biphosphatase) and finally increasing urinary elimination of excess glucose (SGLT inhibitors). A particular role is played by glucokinase activators (GKA) which can both increase insulin secretion and improve hepatic glucose metabolism. In this review, we present a summary of the data available on newly approved treatments (amylin and GLP-1 analogs as well as DPP-IV inhibitors) and give an overview of the targets currently being studied for the treatment of type 2 diabetes with an emphasis on the small molecule drug design.
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PMID:Newly approved and promising antidiabetic agents. 1798 55


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