Role of Uncoupling Protein 2 in Pancreatic _ Cell Function

Diabetes Mellitus is a group of metabolic disorders characterized by hyperglycaemic resulting from the defects of insulin secretion, insulin action or both. The present study was conducted in order to know the molecular genetic cause of the T2DM patients belonging to the Jammu region of J&K State. Many genes have been known to be linked with the onset and progression of the T2DM therefore the present data represents the role of one of the genes Uncoupling protein 2 (UCP2) known to be strongly associated with T2DM was selected. A total of 250 confirmed cases & controls samples belonging to four population groups (Hindu, Muslim, Sikh & Christians) of Jammu region were also screened for UCP2 -866G/A promoter polymorphism (rs659366). The allelic odds ratio (OR) as observed for UCP2 -866G/A polymorphism in the four population groups showed significant association with Muslim & Sikh population groups. The study undertaken supports the findings of the previous investigations and thus is an addition to the existing literatute in support of UCP2 and T2DM.

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The role of uncoupling protein 2 in macrophages and its impact on obesity-induced adipose tissue inflammation and insulin resistance

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.014868 ◽

2020 ◽

Vol 295 (51) ◽

pp. 17535-17548

Author(s):

Xanthe A. M. H. van Dierendonck ◽

Tiphaine Sancerni ◽

Marie-Clotilde Alves-Guerra ◽

Rinke Stienstra

Keyword(s):

Insulin Resistance ◽

Adipose Tissue ◽

Macrophage Activation ◽

Uncoupling Protein ◽

Uncoupling Protein 2 ◽

Adipose Tissue Inflammation ◽

Tissue Inflammation ◽

Obesity And Diabetes ◽

Adipose Tissue Macrophages

The development of a chronic, low-grade inflammation originating from adipose tissue in obese subjects is widely recognized to induce insulin resistance, leading to the development of type 2 diabetes. The adipose tissue microenvironment drives specific metabolic reprogramming of adipose tissue macrophages, contributing to the induction of tissue inflammation. Uncoupling protein 2 (UCP2), a mitochondrial anion carrier, is thought to separately modulate inflammatory and metabolic processes in macrophages and is up-regulated in macrophages in the context of obesity and diabetes. Here, we investigate the role of UCP2 in macrophage activation in the context of obesity-induced adipose tissue inflammation and insulin resistance. Using a myeloid-specific knockout of UCP2 (Ucp2ΔLysM), we found that UCP2 deficiency significantly increases glycolysis and oxidative respiration, both unstimulated and after inflammatory conditions. Strikingly, fatty acid loading abolished the metabolic differences between Ucp2ΔLysM macrophages and their floxed controls. Furthermore, Ucp2ΔLysM macrophages show attenuated pro-inflammatory responses toward Toll-like receptor-2 and -4 stimulation. To test the relevance of macrophage-specific Ucp2 deletion in vivo, Ucp2ΔLysM and Ucp2fl/fl mice were rendered obese and insulin resistant through high-fat feeding. Although no differences in adipose tissue inflammation or insulin resistance was found between the two genotypes, adipose tissue macrophages isolated from diet-induced obese Ucp2ΔLysM mice showed decreased TNFα secretion after ex vivo lipopolysaccharide stimulation compared with their Ucp2fl/fl littermates. Together, these results demonstrate that although UCP2 regulates both metabolism and the inflammatory response of macrophages, its activity is not crucial in shaping macrophage activation in the adipose tissue during obesity-induced insulin resistance.

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