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)

Mitochondria are cellular organelles that have been reported to be altered in diabetes, being closely related to its associated complications. Moreover, mitochondrial biogenesis and function are essential for proper embryo development throughout the placentation period, occurring during organogenesis, when a great rate of congenital malformations have been associated with diabetic pregnancy. Thus, the aim of the current work was to investigate the effect of the diabetic environment on mitochondrial function and biogenesis during the placentation period. For this purpose, we studied the oxidative phosphorylation system (OXPHOS) enzymatic activities as well as the expression of genes involved in the coordinated regulation of both mitochondrial and nuclear genome (PGC-1alpha, NRF-1, NRF-2alpha, mtSSB, and TFAM) and mitochondrial function (COX-IV, COX-I, and beta-ATPase) in rat embryos from control and streptozotocin-induced diabetic mothers. Our results reflected that diabetic pregnancy retarded and altered embryo growth. The embryos from diabetic mothers showing normal morphology presented a reduced content of proteins regulated through the PGC-1alpha mitochondriogenic pathway on gestational day 12. This fact was accompanied by several responses that entailed the activation of OXPHOS activities on the same day and the recovery of the content of the studied proteins to control levels on day 13. As a result, the mitochondria of these embryos would reach a situation close to control on day 13 that could allow them to follow the normal mitochondriogenic schedule throughout a gestational period in which the mitochondrial differentiation process is critical. Nevertheless, malformed embryos from diabetic mothers seemed to show a lower adaptation capability, which could exacerbate their maldevelopment.
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PMID:Responses of mitochondrial biogenesis and function to maternal diabetes in rat embryo during the placentation period. 1760 53

In a previous study, the ciliary neurotrophic factor (CNTF) were demonstrated to lead to weight-loss partly by up-regulating the energy metabolism and the expression of uncoupling protein-1, mitochondrial transcription factor A and nuclear respiratory factor-1 in adipose tissues or muscle. To investigate the up-stream regulators of the expression, recombinant human CNTF (rhCNTF) (0.1, 0.3 and 0.9 mg/kg/day subcutaneously) were administered to KK-Ay mice for 30 days, resulting in reduction of perirenal fat mass, serum free fatty acids and islet triacylglycerol; furthermore, the values of oral glucose tolerance test were found improved. In brown adipose tissues, the gene expressions of peroxisome proliferator-activated receptor alpha (PPARalpha) and peroxisome proliferator-activated receptor coactivator-1 alpha (PGC-1alpha) were found to be up-regulated by rhCNTF. To the best of our knowledge, the changes of gene expression of PPARalpha and PGC-1alpha represent new insights into the mechanisms of anti-diabetes by rhCNTF. In addition, the activity of mitochondrial complexII was found to be increased by rhCNTF. Stimulation of PPARalpha, PGC-1alpha, uncoupling protein-1 and enhanced activity of mitochondrial complex II may be associated with the effects of anti-diabetes. The present study indicates new mechanisms of the activity and mechanisms on anti-diabetes of rhCNTF, which may be a novel anti-diabetes reagent partly acting by enhancing energy metabolism.
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PMID:The novel mechanism of recombinant human ciliary neurotrophic factor on the anti-diabetes activity. 1765 6

The Koletsky (SHROB) strain of rats is spontaneously hypertensive and displays insulin resistance, hyperglucagonemia and hypertriglyceridemia but is normoglycemic under fasting conditions. The aim of this study was to unravel the pattern of expression of genes encoding key regulatory enzymes involved in carbohydrate metabolism in the liver and kidney that may be impacted in this strain. We found that SHROB animals have decreased beta-adrenergic receptor density and, consequently, blunted increases in cAMP levels in response to beta-adrenergic agonists. They also have lower levels of hepatic as well as renal phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) mRNA and protein than their lean littermates. Expression of the genes for glycogen phosphorylase and glycogen synthase was also decreased. Hepatocytes from the SHROB animals exhibited glycogen depletion of only 50% compared to 86% by hepatocytes from lean littermates when challenged with either glucagon or forskolin to stimulate adenylyl cyclase. The expression of C/EBPalpha and C/EBPbeta, two key transcription factors that are essential for the coordinated expression of genes involved in glucose homeostasis, was depressed in livers of the SHROB rats, as were levels of HNF-4alpha, PPARalpha and PGC-1alpha. We conclude that overproduction of glucose is prevented in the SHROB rats by decreased expression of the genes for glycogen phosphorylase and the gluconeogenic enzymes PEPCK and G6Pase, which may prevent progression to diabetes in this model.
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PMID:Metabolic dysregulation in the SHROB rat reflects abnormal expression of transcription factors and enzymes that regulate carbohydrate metabolism. 1768 27

The prevalence of Type 2 diabetes is increasing at an alarming rate in most parts of the world. Effective therapeutic drugs are urgently needed, not only to control the disease but also to prevent or delay its progression. Therapies that target the underlying pathogenesis could, in theory, hold such potential. Recent evidence strongly suggests that impaired mitochondrial function is part of the underlying pathogenesis of insulin resistance and Type 2 diabetes. Peroxisome proliferator-activated receptor gamma co-activator-1 alpha (PGC-1alpha) is a transcription co-activator that plays a key role in regulating mitochondrial biogenesis and energy metabolism in multiple tissues. Thus, improvement and restoration of mitochondrial function and oxidative capacity through activation of PGC-1alpha could provide new treatments for metabolic diseases. A diverse array of proteins has been shown to regulate PGC-1alpha transcription and/or activity, some of which represent promising targets for pharmaceutical intervention.
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PMID:Targeting PGC-1 alpha to control energy homeostasis. 1790 62

Peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) is a highly regulated transcriptional coactivator that coordinates energy metabolism in mammals. Misregulation of PGC-1alpha has been implicated in the pathogenesis of several human diseases, including diabetes, obesity, and neurological disorders. We identified SCF(Cdc4) as an E3 ubiquitin ligase that regulates PGC-1alpha through ubiquitin-mediated proteolysis. PGC-1alpha contains two Cdc4 phosphodegrons that bind Cdc4 when phosphorylated by Glycogen Synthase Kinase 3beta (GSK3beta) and p38 MAPK, leading to SCF(Cdc4)-dependent ubiquitylation and proteasomal degradation of PGC-1alpha. Furthermore, SCF(Cdc4) negatively regulates PGC-1alpha-dependent transcription. We demonstrate that RNAi-mediated reduction of Cdc4 in primary neurons results in an increase of endogenous PGC-1alpha protein, while ectopic expression of Cdc4 leads to a reduction of endogenous PGC-1alpha protein. Finally, under conditions of oxidative stress in neurons, Cdc4 levels are decreased, leading to an increase in PGC-1alpha protein and PGC-1alpha-dependent transcription. These results suggest that attenuation of SCF(Cdc4)-dependent proteasomal degradation of PGC-1alpha has a role in mediating the PGC-1alpha-dependent transcriptional response to oxidative stress.
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PMID:SCFCdc4 acts antagonistically to the PGC-1alpha transcriptional coactivator by targeting it for ubiquitin-mediated proteolysis. 1819 41

Diabetes and obesity are characterised by an impairment in mitochondrial function resulting in a decrease in glucose and fatty acid oxidation, respiration and an increase in intramuscular triglycerides (IMTG's) and insulin resistance. Peroxisome proliferator-activated receptor (PPAR)-gamma coactivator 1alpha (PGC-1alpha) is a nuclear transcriptional coactivator which regulates several important metabolic processes including, mitochondrial biogenesis, adaptive thermogenesis, respiration, insulin secretion and gluconeogenesis. In addition, PGC-1alpha has been shown to increase the percentage of oxidative type I muscle fibres, with the latter responsible for the majority of insulin stimulated glucose uptake. PGC-1alpha also co-activates PPAR's alpha, beta/delta and gamma which are important transcription factors of genes regulating lipid and glucose metabolism. Exercise causes mitochondrial biogenesis, improves skeletal muscle fatty acid oxidation capacity and insulin sensitivity, therefore making it an important intervention for the treatment of insulin resistance. The expression of PGC-1alpha mRNA is reduced in diabetic subjects, however, it is rapidly induced in response to interventions which signal alterations in metabolic requirements, such as exercise. Because of the important role of PGC-1alpha in the control of energy metabolism and insulin sensitivity, it is seen as a candidate factor in the etiology of type 2 diabetes and a drug target for its therapeutic treatment.
Curr Diabetes Rev 2005 May
PMID:PGC-1alpha and exercise: important partners in combating insulin resistance. 1822 May 93

The transcriptional coactivator PGC-1alpha is a potent regulator of several metabolic pathways, including, in particular, the activation of oxidative phosphorylation and mitochondrial biogenesis. Recent evidence suggests that increasing PGC-1alpha activity may have beneficial effects in various conditions, including muscular dystrophy, diabetes, and neurodegenerative diseases. We describe here a high-throughput screen to identify small molecules that induce PGC-1alpha expression in skeletal muscle cells. A number of drug classes are identified, including glucocorticoids, microtubule inhibitors, and protein synthesis inhibitors. These drugs induce PGC-1alpha mRNA, and the expression of a number of genes known to be regulated by PGC-1alpha. No induction of these target genes is seen in PGC-1alpha -/- cells, demonstrating that the drugs act through PGC-1alpha. These data demonstrate the feasibility of high-throughput screening for inducers of PGC-1alpha. Moreover, the data identify microtubule inhibitors and protein synthesis inhibitors as modulators of PGC-1alpha and oxidative phosphorylation.
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PMID:Gene expression-based screening identifies microtubule inhibitors as inducers of PGC-1alpha and oxidative phosphorylation. 1834 29

Lipid metabolism is a continuum from emulsification and uptake of lipids in the intestine to cellular uptake and transport to compartments such as mitochondria. Whether fats are shuttled into lipid droplets in adipose tissue or oxidized in mitochondria and peroxisomes depends on metabolic substrate availability, energy balance and endocrine signaling of the organism. Several members of the nuclear hormone receptor superfamily are lipid-sensing factors that affect all aspects of lipid metabolism. The physiologic actions of glandular hormones (e.g. thyroid, mineralocorticoid and glucocorticoid), vitamins (e.g. vitamins A and D) and reproductive hormones (e.g. progesterone, estrogen and testosterone) and their cognate receptors are well established. The peroxisome-proliferator activated receptors (PPARs) and liver X receptors (LXRs), acting in concert with PPARgamma Coactivator 1alpha (PGC-1alpha), have been shown to regulate insulin sensitivity and lipid handling. These receptors are the focus of intense pharmacologic studies to expand the armamentarium of small molecule ligands to treat diabetes and the metabolic syndrome (hypertension, insulin resistance, hyperglycemia, dyslipidemia and obesity). Recently, additional partners of PGC-1alpha have moved to the forefront of metabolic research, the estrogen-related receptors (ERRs). Although no endogenous ligands for these receptors have been identified, phenotypic analyses of knockout mouse models demonstrate an important role for these molecules in substrate sensing and handling as well as mitochondrial function.
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PMID:Nuclear receptors, mitochondria and lipid metabolism. 1840 8

Cholesterol 7alpha-hydroxylase (CYP7A1) catalyzes the rate-limiting step in the classic pathway of hepatic bile acid biosynthesis from cholesterol. During fasting and in type I diabetes, elevated levels of peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1alpha) induce expression of the Cyp7A1 gene and overexpression of PGC-1alpha in hepatoma cells stimulates bile acid synthesis. Using Ad-PGC-1alpha-RNA interference to induce acute disruption of PGC-1alpha in mice, here we show that PGC-1alpha is necessary for fasting-mediated induction of CYP7A1. Co-immunoprecipitation and promoter activation studies reveal that the induction of CYP7A1 is mediated by direct interaction between PGC-1alpha and the AF2 domain of liver receptor homolog-1 (LRH-1). In contrast, the very similar PGC-1beta could not substitute for PGC-1alpha. We also show that transactivation of PGC-1alpha and LRH-1 is repressed by the small heterodimer partner (SHP). Treatment of mice with GW4064, a synthetic agonist for farnesoid X receptor, induced SHP expression and decreased both the recruitment of PGC-1alpha to the Cyp7A1 promoter and the fasting-induced expression of CYP7A1 mRNA. These data suggest that PGC-1alpha is an important co-activator for LRH-1 and that SHP targets the interaction between LRH-1 and PGC-1alpha to inhibit CYP7A1 expression. Overall, these studies provide further evidence for the important role of PGC-1alpha in bile acid homeostasis and suggest that pharmacological targeting of farnesoid X receptor in vivo can be used to reverse the increase in CYP7A1 associated with adverse metabolic conditions.
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PMID:Peroxisome proliferator-activated receptor-gamma coactivator-1alpha activation of CYP7A1 during food restriction and diabetes is still inhibited by small heterodimer partner. 1838 39

Single nucleotide polymorphisms (SNPs) in three diabetes-related genes (SIRT1, PPARD, PGC-1alpha) were investigated with a case-control approach. To examine the genetic association of those genes with Alzheimer's disease (AD) risk, we used the TaqMan technique to genotype five SNP sites for SIRT1, six for PPARD and eight for the PGC-1alpha gene, in 326 Finnish AD cases and 463 controls and conducted a single allele and genotypic distribution comparison as well as estimated haplotype frequencies between cases and controls. No significant differences in AD risk were found in single SNP and haplotype analyses for any of the three genes between 326 cases and 463 controls. However, in a subgroup of women older than 65 years, the frequencies of three SNPs in the SIRT1 gene were significantly different between AD and controls. We conclude that there is no real association with SNPs available in the present study between SIRT1, PPARD or PGC-1alpha genes and AD risk in the Finnish population.
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PMID:Genetic study between SIRT1, PPARD, PGC-1alpha genes and Alzheimer's disease. 1843 97


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