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)

Increased production of reactive oxygen species (ROS) has been suggested as a cause of diabetic complications. Uncoupling proteins (UCPs) have been ascribed a role in reducing the formation of ROS, and genetic variation in genes encoding for UCPs could thus be putative candidate genes for diabetic nephropathy. To test this hypothesis we searched for association between the A-->G (-3862) variant in UCP1, the insertion/deletion (I/D) polymorphism in exon 8 in UCP2, and the C-->T (-55) polymorphism in UCP3 and diabetic nephropathy in 218 diabetic patients with normal urinary albumin excretion rate (AER), 216 with micro- or macroalbuminuria, and in 106 control subjects without a family history of diabetes. We did not find any association between the different polymorphisms and diabetic nephropathy, nor did we observe any difference in AER among carriers of different UCP1-3 genotypes. We could, however, confirm the reported association between BMI and the UCP3 -55 C-->T polymorphism; patients carrying the T allele had higher BMI than patients homozygous for the C allele (26.4+/-4.2 vs. 25.3+/-4.3 kg/m(2); P=.01). We conclude that studied polymorphisms in the UCP1-3 genes do not play a major role in the development of micro- or macroalbuminuria in Scandinavian diabetic patients.
J Diabetes Complications
PMID:Putative role of polymorphisms in UCP1-3 genes for diabetic nephropathy. 1512 Jul 4

Wnt is a family of secreted signaling proteins that regulate diverse developmental processes. Activation of canonical Wnt signaling by Wnt10b inhibits differentiation of preadipocytes in vitro. To determine whether Wnt signaling blocks adipogenesis in vivo, we created transgenic mice in which Wnt10b is expressed from the FABP4 promoter. Expression of Wnt10b in adipose impairs development of this tissue throughout the body, with a decline of approximately 50% in total body fat and a reduction of approximately 60% in weight of epididymal and perirenal depots. FABP4-Wnt10b mice resist accumulation of adipose tissue when fed a high fat diet. Furthermore, transgenic mice are more glucose-tolerant and insulin-sensitive than wild type mice. Expression of Wnt10b from the FABP4 promoter also blocks development of brown adipose tissue. Interscapular tissue of FABP4-Wnt10b mice has the visual appearance of white adipose tissue but expresses neither brown (e.g. uncoupling protein 1) nor white adipocyte markers. Transgenic mice are unable to maintain a core body temperature when placed in a cold environment, providing further evidence that Wnt10b inhibits development of brown adipose tissue. Although food intake is not altered in FABP4-Wnt10b mice, oxygen consumption is decreased. Thus, FABP4-Wnt10b mice on a chow diet gain more weight than controls, largely because of an increase in weight of skin. In summary, inhibition by Wnt10b of white and brown adipose tissue development results in lean mice without lipodystrophic diabetes.
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PMID:Wnt10b inhibits development of white and brown adipose tissues. 1519 75

Histamine H(1) receptors (H(1)-Rs) are found in peripheral tissues and in regions of the hypothalamus that are concerned with regulating body composition. In the present study, we investigated the detailed mechanisms of histamine H(1)-Rs in the development of obesity. Histamine H(1)-R knockout (H1KO) mice gradually developed mature-onset obesity, which was accompanied by hyperphagia and decreased expression of uncoupling protein-1 (UCP-1) mRNA. Both younger nonobese (12-week-old) and older obese (48-week-old) H1KO mice exhibited impairment of the responsiveness to the leptin. In addition, disruption of the diurnal rhythm of feeding occurred before the onset of obesity in H1KO mice. Correction of these abnormal feeding rhythms by means of scheduled feeding caused a reduction in obesity and associated metabolic disorders in H1KO mice. Furthermore, central administration of a histamine H(1)-R agonist affected feeding behavior, body weight, and c-fos-like immunoreactivity in the hypothalamus. Taken together, these findings suggest that histamine H(1)-Rs are crucial for the regulation of feeding rhythm and in mediating the effects of leptin. Early disruption of H(1)-R-mediated functions in H1KO mice may lead to hyperphagia and decreased expression of UCP-1 mRNA, which may contribute to the development of obesity in these animals. In addition, centrally acting histamine H(1)-R may be a novel therapeutic target for the treatment of obesity and related metabolic disorders.
Diabetes 2004 Sep
PMID:Involvement of hypothalamic histamine H1 receptor in the regulation of feeding rhythm and obesity. 1533 34

The pharmacological treatment of obesity should be considered when cannot be achieved a 10% weight loss with diet therapy and physical activity. The drugs effective in obesity treatment may act by different mechanisms such as reduction in food intake, inhibition of fat absorption, increase of thermogenesis and stimulation of adipocyte apoptosis. At present, we only have two marketed drugs for obesity treatment. Sibutramine is an inhibitor of norepinephrine, dopamine and serotonina reuptake which inhibits food intake and increases thermogenesis. Sibutramine administration for a year can induce a weight loss of 4-7%. Its main side effects are hypertension, headache, insomnia and constipation. Orlistat is an inhibitor of pancreatic lipase which is able to block the absorption of 30% of ingested fat. Its administration induces weight loss and reduction of ulterior weight regain. Also, this drug improves hypertension dyslipdaemia and helps to prevent diabetes in 52% of cases when administered over four years. The increase in frequency of stools and interference with vitamin absorption are its main side effects. Glucagon-like peptide 1, which increases insulin sensitivity and satiety, adiponectin and PPAR-gamma agonists which reduce insulin resistance and modulates adipocyte generation are the basis for future therapeutic approaches of obesity. Phosphatase inhibitors induce PPAR-gamma phosphorylation and UCP-1 expression leading to an increase in thermogenesis and reduction in appetite.
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PMID:[Pharmacological treatment of obesity]. 1538 15

Ciliary neurotrophic factor (CNTF) potently reduces appetite and body weight in rodents and humans. We studied the short- and long-term effects of CNTF(Ax15), a second-generation CNTF analog, in diet-induced obese C57BL/6J mice and brown adipose tissue (BAT)-deficient obese UCP1-DTA (uncoupling protein 1-diphtheria toxin A) mice. CNTF(Ax15) administration (0.1, 0.3, or 1.0 microg . g(-1) . day(-1) s.c.) for 3 or 7 days reduced food intake and body weight (mainly body fat mass). The effect of CNTF(Ax15) on food intake and body weight was more pronounced in CNTF(Ax15)-treated diet-induced obese C57BL/6J mice compared with pair-fed controls and was associated with suppressed expression of hypothalamic neuropeptide Y and agouti gene-related protein. Moreover, CNTF(Ax15) increased uncoupling protein 1 mRNA expression in BAT and energy expenditure in diet-induced obese C57BL/6J mice. Longitudinal observations revealed a sustained reduction in body weight for several days post-CNTF(Ax15) treatment of CNTF(Ax15)-treated but not pair-fed mice, followed by a gradual regain in body weight over 28 days. Finally, CNTF(Ax15) administration improved the metabolic profile in both diet-induced obese C57BL/6J and UCP1-DTA mice and resulted in a significantly improved glycemic response to oral glucose tolerance tests in CNTF(Ax15)-treated UCP1-DTA compared with pair-fed mice of similar body weight. These data suggest that CNTF(Ax15) may act through a pathway downstream of the putative point responsible for leptin resistance in diet-induced obese C57BL/6J and UCP1-DTA mice to alter food intake, body weight, body composition, and metabolism. CNTF(Ax15) has delayed and persistent effects in diet-induced obese C57BL/6J mice, which account for a reduction in body weight over and above what would be expected based on decreased foot intake alone.
Diabetes 2004 Nov
PMID:Ciliary neurotrophic factorAx15 alters energy homeostasis, decreases body weight, and improves metabolic control in diet-induced obese and UCP1-DTA mice. 1550 58

Resistin is an adipocyte-secreted hormone proposed to link obesity with insulin resistance and diabetes, but no previous study has performed a joint quantitative evaluation of white adipose tissue (WAT) resistin mRNA expression and serum levels in relation to insulinemia and glycemia in mice. We have thus comparatively assessed WAT resistin mRNA expression and serum resistin levels in lean C57BL/6J mice and various mouse models of obesity, including diet-induced obese (DIO) C57BL/6J mice, high fat-fed TNF-alpha-/- mice, and brown adipose tissue (BAT)-deficient uncoupling protein-diphtheria toxin A chain (UCP1-DTA) mice. We also studied whether treatment with the weight-reducing and insulin-sensitizing compounds, MTII, an alpha-melanocyte-stimulating hormone analog, or CNTF(Ax15), a ciliary neurotrophic factor analog, alters resistin mRNA expression and/or circulating levels in lean and DIO C57BL/6J mice. We find that resistin mRNA expression is similar in DIO and lean C57BL/6J mice, as well as in TNF-alpha-/- and wild-type (WT) mice. Circulating resistin levels, however, are higher in DIO C57BL/6J, high fat-fed TNF-alpha-/-, and UCP1-DTA mice compared with lean controls. Moreover, although resistin mRNA expression is upregulated by MTII treatment for 24 h and downregulated by CNTF(Ax15) treatment for 3 or 7 days, circulating resistin levels are not altered by MTII or CNTF(Ax15) treatment. In addition, serum resistin levels, but not resistin mRNA expression levels, are correlated with body weight, and neither resistin mRNA expression nor serum resistin levels are correlated with serum insulin or glucose levels. We conclude that transcriptional regulation of resistin in WAT does not correlate with circulating resistin levels and that circulating resistin is unlikely to play a major endocrine role in insulin resistance or glycemia in mice.
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PMID:Circulating resistin in lean, obese, and insulin-resistant mouse models: lack of association with insulinemia and glycemia. 1552 96

We have generated MIN6 beta-cells that stably overexpress cytosolic phospholipase A(2) (cPLA(2)) and show a ninefold increase in cPLA(2) activity. Overexpression of cPLA(2) did not affect the capacity of MIN6 cells to show elevations in intracellular Ca(2+) concentration ([Ca(2+)](i)) in response to tolbutamide and KCl, and these depolarizing stimuli produced insulin secretion profiles in cPLA(2)-overexpressing cells similar to those they produced in passage-matched nontransfected MIN6 cells. However, cPLA(2)-overexpressing MIN6 cells did not respond to elevations in extracellular glucose with increases in ATP, [Ca(2+)](i), or insulin secretion. Nontransfected MIN6 cells showed a rapid and sustained increase in NAD(P)H autofluorescence in response to 25 mmol/l glucose, and this was reduced by approximately 95% in MIN6 cells overexpressing cPLA(2). This effect was mimicked in nontransfected MIN6 cells by p-(trifluoromethoxy) phenylylhydrazone, a mitochondrial uncoupler. Quantitative RT-PCR indicated that mRNA for uncoupling protein-2 (UCP-2) was increased in the cPLA(2)-overexpressing MIN6 cells, and this could be prevented by exposure to 100 mumol/l methyl arachidonyl fluorophosphate, a cPLA(2) inhibitor. Glucose caused a decrease in rhodamine 123 fluorescence in control cells, but not in those overexpressing cPLA(2), consistent with the transfected cells being unable to maintain mitochondrial proton gradients as a consequence of UCP-2 upregulation. Our data indicate that overexpression of cPLA(2) results in severe impairment of the calcium and secretory responses of beta-cells to glucose through upregulation of UCP-2 and uncoupling of mitochondrial metabolism from ATP generation.
Diabetes 2005 Jan
PMID:Uncoupling of nutrient metabolism from insulin secretion by overexpression of cytosolic phospholipase A(2). 1561 18

The mitochondrial uncoupling proteins (UCP-2 and UCP-3), which have been suggested to be involved in the development of obesity by controlling the energy expenditure (EE), were studied in 22 healthy first-degree relatives (FDRs) of patients with type 2 diabetes and 13 body mass index (BMI)- and age-matched healthy control subjects. Abdominal subcutaneous adipose tissue biopsies were obtained before and after 150-min hyperinsulinaemic clamp (average serum insulin 250 pM). Basal adipose tissue UCP-2 mRNA levels in the FDR group were significantly lower than that in the control group. After the hyperinsulinaemic clamp, adipose tissue UCP-2 mRNA levels were increased by 32% in the control group (p < 0.05) and 32% in the FDR group (p < 0.05). The basal adipose tissue UCP-3 mRNA level was similar in the two groups and increased in both the groups during hyperinsulinaemia (p < 0.001). Dual energy X-ray absorptiometry showed that despite similar BMI the FDR group had significantly higher fat mass (FM) per cent compared to that of the control group (p < 0.01). The UCP-2 mRNA expression was inversely correlated with the amount of adipose tissue (r = -0.53, p < 0.001), and multiple regression analysis revealed that only the amount of FM was independently correlated with basal UCP-2 mRNA levels, whereas age, gender nor family history of type 2 diabetes contributed independently to the variation in UCP-2 mRNA levels. No differences in EE were observed between the two groups, and no association between EE and UCP mRNA expression was found. In conclusion, we have demonstrated that adipose tissue UCP-2 and UCP-3 mRNA levels are significantly increased during a 150-min hyperinsulinaemic clamp. The UCP-2 mRNA levels were expressed at a significantly lower level FDR to type 2 diabetes compared to control subjects. However, in multiple regression analysis controlling for amount of adipose tissue, the difference between the two groups disappeared. Thus, only the amount of adipose tissue contributed independently to the variation in UCP-2 mRNA expression.
Diabetes Obes Metab 2005 Jan
PMID:Increased adiposity and reduced adipose tissue mRNA expression of uncoupling protein-2 in first-degree relatives of type 2 diabetic patients: evidence for insulin stimulation of UCP-2 and UCP-3 gene expression in adipose tissue. 1564 81

For examining whether dissipating excess energy in the liver is a possible therapeutic approach to high-fat diet-induced metabolic disorders, uncoupling protein-1 (UCP1) was expressed in murine liver using adenoviral vectors in mice with high-fat diet-induced diabetes and obesity, and in standard diet-fed lean mice. Once diabetes with obesity developed, hepatic UCP1 expression increased energy expenditure, decreased body weight, and reduced fat in the liver and adipose tissues, resulting in markedly improved insulin resistance and, thus, diabetes and dyslipidemia. Decreased expressions of enzymes for lipid synthesis and glucose production and activation of AMP-activated kinase in the liver seem to contribute to these improvements. Hepatic UCP1 expression also reversed high-fat diet-induced hyperphagia and hypothalamic leptin resistance, as well as insulin resistance in muscle. In contrast, intriguingly, in standard diet-fed lean mice, hepatic UCP1 expression did not significantly affect energy expenditure or hepatic ATP contents. Furthermore, no alterations in blood glucose levels, body weight, or adiposity were observed. These findings suggest that ectopic UCP1 in the liver dissipates surplus energy without affecting required energy and exerts minimal metabolic effects in lean mice. Thus, enhanced UCP expression in the liver is a new potential therapeutic target for the metabolic syndrome.
Diabetes 2005 Feb
PMID:Dissipating excess energy stored in the liver is a potential treatment strategy for diabetes associated with obesity. 1567 88

Uncoupling protein(UCP)1 is an integral membrane protein that is located in the mitochondrial inner membrane of brown adipocytes. Its physiological role is to mediate a regulated, thermogenic proton leak. UCP2 and UCP3 are recently identified UCP1 homologues. They also mediate regulated proton leak, and might function to control the production of superoxide and other downstream reactive oxygen species. However, their role in normal physiology remains unknown. Recent studies have shown that UCP2 has an important part in the pathogenesis of type-2 diabetes. The obscure roles of the UCP homologues in normal physiology, together with their emerging role in pathophysiology, provide exciting potential for further investigation.
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PMID:The mitochondrial uncoupling-protein homologues. 1573 89


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