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)

Epidemiological studies suggest that infants of low birth weight show poor neonatal growth and increased susceptibility to adult diseases such as diabetes and lung disease. Uncoupling protein 2 and 3 (UCP2 and UCP3) have been implicated in the development of such diseases; pigs provide an ideal model to examine the influence of birth weight due to the natural variance in piglet weight within a litter. This study examined whether birth weight influences the expression of UCP2 and UCP3 in adipose tissue, skeletal muscle, and lung. Piglets from 11 litters were ranked according to birth weight and three from each litter assigned to small (SFD), normal (NFD), or large for dates (LFD) groups. Blood samples and morphometric measurements were taken over the first 14 days of life, and tissue samples were taken on day 7 or 14. Plasma hormone and metabolite concentrations and the expression of UCP2 and UCP3 mRNA in adipose tissue, skeletal muscle, and lung were measured. UCP2 and UCP3 expression in adipose tissue was lower in the SFD compared with the LFD group on day 7. UCP3 expression in skeletal muscle was higher than that of adipose tissue. Lung UCP2 and skeletal muscle UCP3 mRNA expression were unaffected by size at birth. Regression analysis indicated that UCP3 expression was differentially associated with IGF-1, leptin, and insulin. In conclusion, low birth weight is associated with tissue-specific effects on UCP expression. It remains to be established whether these subsequently contribute to pathological conditions such as diabetes.
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PMID:Influence of size at birth on the endocrine profiles and expression of uncoupling proteins in subcutaneous adipose tissue, lung, and muscle of neonatal pigs. 1574 6

Androgen receptor (AR) null male mice (AR(L-/Y)) revealed late-onset obesity, which was confirmed by computed tomography-based body composition analysis. AR(L-/Y) mice were euphagic compared with the wild-type male (AR(X/Y)) controls, but they were also less dynamic and consumed less oxygen. Transcript profiling indicated that AR(L-/Y) mice had lower transcripts for the thermogenetic uncoupling protein 1, which was subsequently found to be ligand-dependently activated by AR. We also found enhanced secretion of adiponectin, which is insulin sensitizing, from adipose tissue and a relatively lower expression of peroxisome proliferator-activated receptor-gamma in white adipose tissue in comparison to AR(X/Y) mice. Both factors might explain why the overall insulin sensitivity of AR(L-/Y) mice remained intact, despite their apparent obesity. The results revealed that AR plays important roles in male metabolism by affecting the energy balance, and it is negative to both adiposity and insulin sensitivity.
Diabetes 2005 Apr
PMID:Androgen receptor null male mice develop late-onset obesity caused by decreased energy expenditure and lipolytic activity but show normal insulin sensitivity with high adiponectin secretion. 1579 38

Sympathetic stimulation activates glucose utilization in parallel with fatty acid oxidation and thermogenesis in brown adipose tissue (BAT) through the beta-adrenergic receptors. To clarify the roles of the principal thermogenic molecule mitochondrial uncoupling protein 1 (UCP1) in the sympathetically stimulated glucose utilization, we investigated the uptake of 2-deoxyglucose (2-DG) into BAT and some other tissues of UCP1-knockout (KO) mice in vivo. In wild-type (WT) mice, administration of norepinephrine (NE) accelerated the disappearance of plasma 2-DG and increased 2-DG uptake into BAT and heart without any rise of plasma insulin level. In UCP1-KO mice, the stimulatory effect of NE on 2-DG uptake into BAT, but not into heart, disappeared completely. Insulin administration increased 2-DG uptake into BAT and also heart similarly in WT and UCP1-KO mice. NE also increased the activity of AMP-activated protein kinase (AMP kinase) in BAT of WT but not UCP1-KO mice. Our results, together with reports that the activation of AMP kinase increases glucose transport in myocytes, suggest that the sympathetically stimulated glucose utilization in BAT is due to the serial activation of UCP1 and AMP kinase.
Diabetes 2005 May
PMID:Uncoupling protein 1 is necessary for norepinephrine-induced glucose utilization in brown adipose tissue. 1585 24

Since it was first realized that biological energy transduction involves oxygen and ATP, opinions about the amount of ATP made per oxygen consumed have continually evolved. The coupling efficiency is crucial because it constrains mechanistic models of the electron-transport chain and ATP synthase, and underpins the physiology and ecology of how organisms prosper in a thermodynamically hostile environment. Mechanistically, we have a good model of proton pumping by complex III of the electron-transport chain and a reasonable understanding of complex IV and the ATP synthase, but remain ignorant about complex I. Energy transduction is plastic: coupling efficiency can vary. Whether this occurs physiologically by molecular slipping in the proton pumps remains controversial. However, the membrane clearly leaks protons, decreasing the energy funnelled into ATP synthesis. Up to 20% of the basal metabolic rate may be used to drive this basal leak. In addition, UCP1 (uncoupling protein 1) is used in specialized tissues to uncouple oxidative phosphorylation, causing adaptive thermogenesis. Other UCPs can also uncouple, but are tightly regulated; they may function to decrease coupling efficiency and so attenuate mitochondrial radical production. UCPs may also integrate inputs from different fuels in pancreatic beta-cells and modulate insulin secretion. They are exciting potential targets for treatment of obesity, cachexia, aging and diabetes.
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PMID:The efficiency and plasticity of mitochondrial energy transduction. 1624 6

An unique isoform of hormone-sensitive lipase (HSL) is expressed in beta-cells. Recent findings suggest that HSL could be involved in the regulation of glucose stimulated insulin secretion (GSIS), however, these findings are controversial. To test the hypothesis that HSL is involved in control of normal GSIS via changes in its expression and/or activity in response to stimuli, we examined the effects of free fatty acid (FFA) loading and glucagon like peptide-1 (GLP-1) stimulation on the regulation of HSL expression and activity. With prolonged FFA loading, there was increased expression of beta-cell HSL and increased HSL hydrolytic activity in clonal beta-cells. Short-term treatment with GLP-1 increased HSL activity without changing the expression of the beta-cell isoform of HSL. Basal insulin secretion was increased, whereas GLP-1 potentiation of GSIS was decreased in islets isolated from HSL-/- mice, as compared to islets from wild type mice. Furthermore, using PancChip 2.2 cDNA microarrays (NIDDK consortium), the gene expression profile in the islets of HSL-/- mice was compared with wild type mice. Results showed changes in several metabolic pathways due to changes in lipid homeostasis caused by inactivation of HSL. Quantitative PCR for selected genes also revealed changes in genes that are related to insulin secretion, such as UCP-2. Therefore, these results suggest that the beta-cell isoform of HSL is involved in maintaining lipid homeostasis in islets and contributes to the proper control of GSIS.
Diabetes Res Clin Pract 2007 Jan
PMID:Regulation of hormone-sensitive lipase in islets. 1676 72

American ginseng root displays the ability to achieve glucose homeostasis both experimentally and clinically but the unknown mechanism used by ginseng to achieve its therapeutic effects on diabetes limits its application. Disruption in the insulin secretion of pancreatic beta cells is considered the major cause of diabetes. A mitochondrial protein, uncoupling protein-2 (UCP-2) has been found to play a critical role in insulin synthesis and beta cell survival. Our preliminary studies found that the extracts of American ginseng inhibit UCP-2 expression which may contribute to the ability of ginseng protecting beta cell death and improving insulin synthesis. Therefore, we hypothesized that ginseng extracts suppress UCP-2 in the mitochondria of pancreatic beta cells, promoting insulin synthesis and anti-apoptosis (a programmed cell-death mechanism). To test the hypothesis, the serum-deprived quiescent beta cells were cultured with or without interleukin-1beta (IL-1beta), (200 pg ml(-1), a cytokine to induce beta cell apoptosis) and water extracts of American ginseng (25 mug per 5 mul administered to wells of 0.5 ml culture) for 24 h. We evaluated effects of ginseng on UCP-2 expression, insulin production, anti-/pro-apoptotic factors Bcl-2/caspase-9 expression and cellular ATP levels. We found that ginseng suppresses UCP-2, down-regulates caspase-9 while increasing ATP and insulin production/secretion and up-regulates Bcl-2, reducing apoptosis. These findings suggest that stimulation of insulin production and prevention of beta cell loss by American ginseng extracts can occur via the inhibition of mitochondrial UCP-2, resulting in increase in the ATP level and the anti-apoptotic factor Bcl-2, while down-regulation of pro-apoptotic factor caspase-9 occurs, lowering the occurrence of apoptosis, which support the hypothesis.
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PMID:American ginseng stimulates insulin production and prevents apoptosis through regulation of uncoupling protein-2 in cultured beta cells. 1695 21

There has been intense interest in defining the functions of UCP2 and UCP3 during the nine years since the cloning of these UCP1 homologues. Current data suggest that both UCP2 and UCP3 proteins share some features with UCP1, such as the ability to reduce mitochondrial membrane potential, but they also have distinctly different physiological roles. Human genetic studies consistently demonstrate the effect of UCP2 alleles on type-2 diabetes. Less clear is whether UCP2 alleles influence body weight or body mass index (BMI) with many studies showing a positive effect while others do not. There is strong evidence that both UCP2 and UCP3 protect against mitochondrial oxidative damage by reducing the production of reactive oxygen species. The evidence that UCP2 protein is a negative regulator of insulin secretion by pancreatic beta-cells is also strong: increased UCP2 decreases glucose stimulated insulin secretion ultimately leading to beta-cell dysfunction. UCP2 is also neuroprotective, reducing oxidative stress in neurons. UCP3 may also transport fatty acids out of mitochondria thereby protecting the mitochondria from fatty acid anions or peroxides. Current data suggest that UCP2 plays a role in the metabolic syndrome through down-regulation of insulin secretion and development of type-2 diabetes. However, UCP2 may protect against atherosclerosis through reduction of oxidative stress and both UCP2 and UCP3 may protect against obesity. Thus, these UCP1 homologues may both contribute to and protect from the markers of the metabolic syndrome.
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PMID:Uncoupling proteins, dietary fat and the metabolic syndrome. 1696 50

In this review, the impacts of mitochondrial reactive oxygen species (ROS) on diabetes and its complications are described. In endothelial cells, high-glucose treatment increases mitochondrial ROS and normalization of the ROS production by inhibitors of mitochondrial metabolism, or by overexpression of UCP-1 or MnSOD, prevents glucose-induced activation of PKC, formation of AGE, and accumulation of sorbitol, all of which are believed to be the main molecular mechanisms of diabetic complications. Glomerular hyperfiltration, one of the characteristics of early diabetic nephropathy, may be caused by mitochondrial ROS through activation of COX-2 gene transcription, followed by PGE2 overproduction. In pancreatic beta cells, hyperglycemia also increases mitochondrial ROS, which suppresses the first phase of glucose-induced insulin secretion, at least in part, through the suppression of GAPDH activity. In liver cells, similar to that in hyperglycemia, TNF-alpha increases mitochondrial ROS, which in turn activates apoptosis signal-regulating kinase 1 (ASK1) and c-jun NH2-terminal kinases (JNK), increases serine phosphorylation of IRS-1, and decreases insulin-stimulated tyrosine phosphorylation of IRS-1, leading to insulin resistance. These results suggest the importance of mitochondrial ROS in the pathogenesis of diabetes mellitus and its complications through modification of various cellular events in many tissues, including vessels, kidney, pancreatic beta cells, and liver.
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PMID:Impact of mitochondrial ROS production in the pathogenesis of diabetes mellitus and its complications. 1718 77

Uncoupling proteins (UCPs) are mitochondrial membrane transporters involved in the control of energy conversion in mitochondria. Experimental and genetic evidence relate dysfunctions of UCPs with metabolic syndrome and obesity. The PPAR subtypes mediate to a large extent the transcriptional regulation of the UCP genes, with a distinct relevance depending on the UCP gene and the tissue in which it is expressed. UCP1 gene is under the dual control of PPARgamma and PPARalpha in relation to brown adipocyte differentiation and lipid oxidation, respectively. UCP3 gene is regulated by PPARalpha and PPARdelta in the muscle, heart, and adipose tissues. UCP2 gene is also under the control of PPARs even in tissues in which it is the predominantly expressed UCP (eg, the pancreas and liver). This review summarizes the current understanding of the role of PPARs in UCPs gene expression in normal conditions and also in the context of type-2 diabetes or obesity.
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PMID:PPARs in the Control of Uncoupling Proteins Gene Expression. 1738 66

Central (visceral) obesity is more closely associated with insulin resistance, type 2 diabetes, and cardiovascular disease than peripheral (subcutaneous) obesity, however the underlying differences in morphology and pathophysiology between subcutaneous and visceral adipose are largely unknown. To evaluate the effects of diabetes and rosiglitazone (RSG) treatment, the expression of mitochondrial Hsp60, UCP-1 and F4/80 in inguinal subcutaneous (SC) fat, composed of white and brown adipose tissues, and epididymal (EP) fat, mainly white adipose tissue, were evaluated. In diabetic db/db mice, there was significant increased number of aggregated macrophage foci compared to db/+ mice, especially in EP fat. On the other hand, the expression of mitochondrial Hsp60 protein was suppressed in both SC and EP fat of db/db mice compared to db/+ mice, and the expression level of mitochondrial Hsp60 in db/+ mice was lower in EP fat compared with SC. In db/db mice, RSG suppressed the number of aggregated macrophage foci in EP fat, but not in SC fat. RSG ameliorated the mitochondrial Hsp60 expression and induced the expression of UCP-1 in both SC and EP fat. Taken together, these data suggest that differences exist in mitochondrial and macrophage content, and in the response to RSG between visceral and subcutaneous adipose tissue, and adipose type and distribution may be important for obesity-linked insulin resistance.
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PMID:Comparison of mitochondrial and macrophage content between subcutaneous and visceral fat in db/db mice. 1743 81


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