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)

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors, and when activated by their ligands, they induce perixosome proliferation. Three receptors have been identified: PPAR gamma, PPAR delta, and PPAR alpha, all with different tissue expression. PPAR gamma is predominantly expressed in adipose tissue and regulates the formation of fat cells and their function. The effect of PPAR gamma activation is to enhance the action of insulin in insulin-sensitive tissue by increasing peripheral glucose disposal and decreasing hepatic glucose production. The thiazolidinediones (TZDs) are a class of medications used for treatment and possibly the prevention of type 2 diabetes, which are potent agonists for the PPAR gamma receptor. Because the thiazolidinediones target insulin resistance, these agents may improve many of the risk factors associated with obesity and insulin resistance including dyslipidemia, hypertension, impaired fibrinolysis, and atherosclerosis. The impact of the thiazolidinediones on cardiovascular mortality is currently unclear but it appears that the thiazolidinediones exert numerous non-glycemic effects that may improve cardiovascular outcomes. Several non-TZD PPAR gamma agonists and combined PPAR gamma/alpha effect on cardiovascular disease are also being evaluated. These drugs have anti-inflammatory and vascular properties and are currently the subject of numerous studies targeting the primary and secondary prevention of macrovascular disease in patients with diabetes and insulin resistance and might be developed as anti-atherogenic agents on the basis of their actions.
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PMID:Effects of PPAR gamma agonists on cardiovascular function in obese, non-diabetic patients. 1677 91

Agonists of peroxisome proliferator-activated receptor gamma (PPAR gamma) are of interest as a treatment for diabetes, which prompted the identification of a new class of non-TZD PPAR gamma agonist. Moreover, compound 14c has displayed the most active agonistic activity with an EC50 value of 50 nM, in addition to exhibiting a new binding mode in the X-ray cocrystal structure.
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PMID:Indenone derivatives: a novel template for peroxisome proliferator-activated receptor gamma (PPARgamma) agonists. 1685 85

Agonists of peroxisome proliferator-activated receptor gamma (PPARgamma) are a new class of oral drugs designed to treat insulin-resistant diabetes (i.e., type 2 diabetes). However, troglitazone, the first compound in the class approved by the US Food and Drug Administration (FDA) in 1997 was found to be hepatotoxic and was withdrawn from the market after reports of severe liver failure. The mechanism of PPAR gamma agonist-induced hepatotoxicity remains unknown. In this study, we examined the hepatotoxic effects of five PPAR gamma agonists (ciglitazone, pioglitazone, rosiglitazone, troglitazone, and JTT-501) on rat primary hepatocytes and human HepG2 cells. We also compared the gene expression profiles of rat primary hepatocytes after exposure to PPAR gamma agonists by using the Rat Genome Survey Microarray system from Applied Biosystems in order to understand the mechanisms of hepatotoxicities induced by PPARgamma agonists. Consistent with the hepatotoxicity data, our results demonstrate that the gene expression profiles affected by troglitazone and ciglitazone can be clearly distinguished from those by pioglitazone and rosiglitazone. Genes that are differentially expressed between the more toxic troglitazone/ciglitazone group and the less toxic rosiglitazone/pioglitazone group are involved in necrotic, apoptotic, and cell proliferative pathways. The five compounds were also clustered based on a set of molecular descriptors. The clustering based on chemical structural information is in good agreement with the clustering of compounds based on cytotoxicity or gene expression data, indicating a strong relationship between chemical structure and biological endpoints. Our work suggests that microarray analysis together with toxicological observations can be used to rank drugs for hepatotoxicity and to evaluate the safety of new compounds.
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PMID:Differences in hepatotoxicity and gene expression profiles by anti-diabetic PPAR gamma agonists on rat primary hepatocytes and human HepG2 cells. 1703 37

Compounds that simultaneously activate the three peroxisome proliferator-activated receptor (PPAR) subtypes alpha, gamma, and delta hold potential to address the adverse metabolic and cardiovascular conditions associated with diabetes and the metabolic syndrome. We recently identified the indanylacetic acid moiety as a well-tunable PPAR agonist head group. Here we report the synthesis and structure-activity relationship (SAR) studies of novel aryl tail group derivatives that led to a new class of potent PPAR pan agonists. While most of the tail group modifications imparted potent PPAR delta agonist activity, improvement of PPAR alpha and gamma activity required the introduction of new heterocyclic substituents that were not known in the PPAR literature. Systematic optimization led to the discovery of 4-thiazolyl-phenyl derivatives with potent PPAR alpha/gamma/delta pan agonistic activity. The lead candidate from this series was found to exhibit excellent ADME properties and superior therapeutic potential compared to known PPAR gamma activating agents by favorably modulating lipid levels in hApoA1 mice and hyperlipidemic hamsters, while normalizing glucose levels in diabetic rodent models.
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PMID:Indanylacetic acid derivatives carrying 4-thiazolyl-phenoxy tail groups, a new class of potent PPAR alpha/gamma/delta pan agonists: synthesis, structure-activity relationship, and in vivo efficacy. 1727 10

Altered vascular responses to various vasopressors in animal models of insulin resistance (IR) and diabetes have been well documented. However, the precise mechanisms about vascular responses in IR with or without frank hyperglycemia (prediabetic state) are not available. Moreover, recently the role of peroxisome proliferators activated receptor-gamma (PPAR gamma) has been linked to influence the vascular responses in hypertensive and diabetic state. Hence, the present study was conceived to determine the role of hyperglycemia on angiotensin II (Ang II) mediated vascular responses in the high fat diet (HFD) induced insulin resistance either with mild or frank hyperglycemia [induced by injection of low dose streptozotocin (STZ) to HFD fed rats (HFD+STZ)]. In addition, insulin-sensitizing agent such as rosiglitazone and pioglitazone were also studied on biochemical and vascular responses. Ang II-induced contractions were studied isometrically in thoracic aortic rings isolated from 4 weeks of normal pellet diet (NPD) fed control, HFD and HFD+STZ fed insulin resistant rats. Specific binding of Ang II receptors were carried out using radioligand ([(3)H]-Ang II) binding studies. After 4 weeks of HFD feeding, rats exhibited characteristics features of insulin resistance such as mild hyperglycemia, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia and hypertension; whereas HFD+STZ treated rats showed all above parameters along with frank hyperglycemia. Maximal contractile response (E(max)) to Ang II is increased in HFD fed rats as compared to control rats. Moreover, E(max) values are further elevated in HFD+STZ group where the frank hyperglycemia was induced by low dose of streptozotocin. Rosiglitazone (5 mg kg(-1), p.o.) and pioglitazone (10 mg kg(-1), p.o.) treatment significantly lowered the plasma glucose, triglycerides, insulin and cholesterol levels in insulin resistance rats. In addition, it also restored the elevated systolic, mean arterial, diastolic blood pressure and attenuated the enhanced contractile responses to Ang II in thoracic aortic rings obtained from both HFD and HFD+STZ treated rats. Specific binding of [(3)H]-Ang II is upregulated in HFD-fed and HFD+STZ treated rats. Treatment with pioglitazone and rosiglitazone significantly decreased the AT(1)R specific binding in HFD fed rats. Our results indicate the role of hyperglycemia in the elevation of Ang II induced vascular responses in thoracic aorta isolated from insulin resistant rats and PPAR gamma agonists can attenuate these responses.
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PMID:PPAR gamma agonists partially restores hyperglycemia induced aggravation of vascular dysfunction to angiotensin II in thoracic aorta isolated from rats with insulin resistance. 1736 46

Cardiovascular disorders are the major cause of mortality in patients of diabetes mellitus. Peroxisome proliferator activated receptors (PPARs) are ligand-activated transcription factors of nuclear hormone receptor superfamily comprising of three subtypes such as PPARalpha, PPARgamma and PPARdelta/beta. Activation of PPARalpha reduces triglycerides and involves in regulation of energy homeostasis. Activation of PPARgamma causes insulin sensitization and enhances glucose metabolism, whereas activation of PPARdelta enhances fatty acid metabolism. Current therapeutic strategies available for the treatment of diabetes do not inhibit the associated secondary cardiovascular complications. Hence, the development of multimodal drugs which can reduce hyperglycemia and concomitantly inhibit the progression of secondary cardiovascular complications may offer valuable therapeutic option. Several basic and clinical studies have exemplified the beneficial effects of PPARalpha and PPARgamma ligands in preventing the cardiovascular risks. The PPARalpha/gamma dual agonists are developed to increase insulin sensitivity and simultaneously prevent diabetic cardiovascular complications. Such compounds are under clinical trials and proposed for treatment of Type II diabetes with secondary cardiovascular complications. However, PPARalpha/gamma dual agonists such as muraglitazar, tesaglitazar and ragaglitazar have been noted to produce several cardiovascular risks and carcinogenicity, which raised number of questions about the clinical applications of dual agonists in diabetes and its associated complications. The ongoing basic studies have elucidated the cardio protective role of PPARdelta. Therefore, further studies are on the track to develop PPARalpha/delta and PPAR gamma/delta dual agonists and PPARalpha/gamma/delta pan agonists for the treatment of diabetic cardiovascular complications. The present review critically analyzes the protective and detrimental effect of PPAR agonists in diabetic cardiovascular complications. Moreover, the newly developed PPARalpha/delta and PPAR gamma/delta dual agonists and PPARalpha/gamma/delta pan agonists have also been discussed which may open a new vista in the management of diabetic cardiovascular complications in near future.
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PMID:PPAR dual agonists: are they opening Pandora's Box? 1742 74

Genes play an important role in the development of diabetes mellitus. Type 2 diabetes is a polygenic disorder with multiple genes located on different chromosomes contributing to its susceptibility. Analysis of the genetic factors is further complicated by the fact that numerous environmental factors interact with genes to produce the disorder. Only a minority of cases of type 2 diabetes are caused by single gene defects and one example is maturity onset diabetes of the young (MODY). Till date knowledge of the genetics of type 2 diabetes is limited. Consistent with the complex web of physiologic defects in type 2 diabetes, the genetics of the disorder involves a large number of susceptibility genes, each with a relatively small effect. In this article, the studies on genetics of diabetes in Asian Indians are reviewed. As Asian Indians have an increased susceptibility to diabetes and have increased insulin resistance, they are a unique population for carrying out genetic studies. There appears to be certain genes which predispose Indians to diabetes while other genes (for example Pro 12 Ala polymorphism of PPAR gamma gene) which afford protection against diabetes and insulin resistance to Caucasians, do not appear to protect Indians. Further studies are needed to unravel the genetics of diabetes in South Asians .
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PMID:Genetic predisposition to type 2 diabetes among Asian Indians. 1749 55

Insulin resistance is a common finding in diabetes mellitus, and may serve as a measure of efficacy of therapies for diabetes mellitus: exercise, exogenous insulin, sulfonylureas, and PPAR gamma agonists, and as a possible marker for risk for developing type II diabetes mellitus. The purpose of our study was to compare one measure of insulin resistance, the QUICKI method, which is a calculation of the inverse of the sum of the log of fasting serum glucose plus the log of fasting insulin level, with the observational measure of fasting serum insulin levels. We studied 79 African-American and Caribbean Black patients in an inner-city hospital-based internal medicine practice, 37 of them with type 2 diabetes mellitus and 42 controls. We found that most controls fell within manufacturers proposed reference range for fasting insulin levels. However, about 5% were appreciably above the range, suggesting insulin resistance, despite euglycemia. Among our diabetics there were two subpopulations: those with elevated fasting insulin levels and those with normal or deficient insulin levels. Only about 30% had elevated fasting insulin levels; however, by the QUICKI method, 54% showed insulin resistance. These findings suggest that QUICKI might be more sensitive measure of insulin resistance, while elevated fasting insulin levels may be more specific.
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PMID:Fasting insulin levels as a measure of insulin resistance in American blacks. 1768 9

Peroxisome proliferators-activated receptor gamma (PPAR gamma) is a nuclear hormone receptor that serves as a master regulator for adipocytes-specific genes contributing to adipocytes differentiation, insulin sensitivity and lipid metabolism. The substitution of proline to alanine at codon 12 of the PPAR gamma 2 gene (Pro12Ala polymorphism) is most widely studied, and the associations with diabetes, obesity, and other clinical parameters have been reported and discussed in several ethnic groups. Among native Qatar ethnicity, however, there is no report about this polymorphism. The aim of this study was to estimate the allele frequency of the Pro12Ala polymorphism of PPAR gamma 2 gene among Qatari population and investigate the association between this polymorphism and obesity or type 2 diabetes. This is a matched case-control study. It was carried out among diabetic patients and healthy subjects at the Primary Healthcare Clinics, and the survey was conducted from February 2003 to March 2006 in Qatari male and female nationals aged 35 to 60 years. The study was based on matched age, sex, and ethnicity of 400 cases (with diabetes) and 450 controls (without diabetes). Face-to-face interviews were based on a questionnaire that included variables such as age, sex, sociodemographic status, body mass index (BMI), and obesity. Their health status was assessed by medical conditions, family history, and blood pressure measurements. The allele frequency of Pro12Ala polymorphism in PPAR gamma 2 gene among Qataris is lower than that in many Caucasian ethnic groups. No association is seen between the Pro12Ala and type 2 Diabetes (0.055 vs 0.059, OR = 1.1311, P = 0.669). Nearly half of the diabetic type 2 patients (48.5%) were obese (BMI > 30) compared to nondiabetic subjects (29.8%) (P < 0.001). In this study, no association is seen between the Pro12Ala polymorphism in PPAR gamma 2 gene and the type 2 diabetes in Qatar.
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PMID:Lack of association between the Pro12Ala polymorphism of the PPAR-gamma 2 gene and type 2 diabetes mellitus in the Qatari consanguineous population. 1780 73

A major reason for the increased incidence of type 2 diabetes mellitus (T2DM) across the world is the so-called obesity epidemic, which occurs both in developed and developing countries. However, a large proportion of patients with T2DM in European and, in particular, Asian countries are non-obese. The non-obese T2DM phenotype is characterized by disproportionally reduced insulin secretion and less insulin resistance, as compared with obese patients with T2DM. Importantly, non-obese patients with T2DM have a similar increased risk of cardiovascular disease as obese T2DM patients. The risk of T2DM in non-obese patients is influenced by genetics as well as factors operating in utero indicated by low birth weight. Furthermore, this phenotype is slightly more prevalent among patients with latent autoimmune diabetes in adults, characterized by positive anti-GAD antibodies. The recently identified TCF7L2 gene polymorphism resulting in low insulin secretion influences the risk of T2DM in both obese and non-obese subjects, but is relatively more prevalent among non-obese patients with T2DM. Furthermore, the Pro12Ala polymorphism of the PPAR gamma gene influencing insulin action increases the risk of T2DM in non-obese subjects. Despite a "normal" body mass index, non-obese patients with T2DM are generally characterized by a higher degree of both abdominal and total fat masses (adiposity). Prevention of T2DM with lifestyle intervention is at least as effective in non-obese as in obese prediabetic subjects, and recent data suggest that metformin treatment targeting insulin resistance and non-glycemic cardiovascular disease risk factors is as beneficial in non-obese as in obese patients with T2DM. Nevertheless, non-obese patients with T2DM may progress to insulin treatment more rapidly as compared with obese patients with T2DM.
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PMID:Non-obese patients with type 2 diabetes and prediabetic subjects: distinct phenotypes requiring special diabetes treatment and (or) prevention? 1805 16


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