scholarly journals Role of Perivascular Adipose Tissue on Vascular Reactive Oxygen Species in Type 2 Diabetes: A Give-and-Take Relationship: Figure 1

Diabetes ◽  
2015 ◽  
Vol 64 (6) ◽  
pp. 1904-1906 ◽  
Author(s):  
Jaume Padilla ◽  
Victoria J. Vieira-Potter ◽  
Guanghong Jia ◽  
James R. Sowers
2021 ◽  
Author(s):  
Yingying Li ◽  
Hai Wang ◽  
Yuan Liao ◽  
Quanmei Yan ◽  
Zhen Ouyang ◽  
...  

Abstract Obesity is one of the most important risk factors for type 2 diabetes (T2DM). The CREBRF missense allele of rs373863828 (p.Arg457Gln) is associated with increased body mass index (BMI), yet reduced risk of T2DM in people with Pacific ancestry. To investigate the functional consequences of the CREBRF variant, we introduced the corresponding human mutation p.Arg457Gln into porcine genome by using a CRISPR/Cas9-mediated homologous recombination (HR)-dependent approach. The CREBRF p.Arg457Gln pig models displayed dramatically increased fat deposition, yet improved sensitivity to insulin. Transcriptome and metabolome analyses of subcutaneous white adipose tissues showed that the CREBRF p.Arg457Gln mutation promoted preadipocyte differentiation, which indicated that obesity was caused by increased number (hyperplasia) rather than size (hypertrophy) of adipocytes. In addition, the oxidative capacity decreased in the adipose tissue of pigs with CREBRF p.Arg457Gln variant. The pre-oxidative metabolite content (4-HNE and MDA) significantly decreased, while activity of antioxidant enzymes (GPX, SOD, and CAT) increased, thereby repressing oxidative metabolism of adipose tissue and reducing level of reactive oxygen species (ROS). The low reactive oxygen species could prevent insulin resistance and reduce risk of obesity-induced type 2 diabetes. This study provides further mechanistic insights into favourable adiposity resulting from CREBRF p.Arg457Gln.


2017 ◽  
Vol 102 (2) ◽  
pp. 139-153 ◽  
Author(s):  
Robert M. Restaino ◽  
Shekhar H. Deo ◽  
Alan R. Parrish ◽  
Paul J. Fadel ◽  
Jaume Padilla

2007 ◽  
Vol 293 (5) ◽  
pp. E1311-E1319 ◽  
Author(s):  
Edward R. Duncan ◽  
Simon J. Walker ◽  
Vivienne A. Ezzat ◽  
Stephen B. Wheatcroft ◽  
Jian-Mei Li ◽  
...  

Insulin resistance is well established as an independent risk factor for the development of type 2 diabetes and cardiovascular atherosclerosis. Most studies have examined atherogenesis in models of severe insulin resistance or diabetes. However, by the time of diagnosis, individuals with type 2 diabetes already demonstrate a significant atheroma burden. Furthermore, recent studies suggest that, even in adolescence, insulin resistance is a progressive disorder that increases cardiovascular risk. In the present report, we studied early mechanisms of reduction in the bioavailability of the antiatheroscerotic molecule nitric oxide (NO) in very mild insulin resistance. Mice with haploinsufficiency for the insulin receptor (IRKO) are a model of mild insulin resistance with preserved glycemic control. We previously demonstrated that 2-mo-old (Young) IRKO mice have preserved vasorelaxation responses to ACh. This remained the case at 4 mo of age. However, by 6 mo, despite no significant deterioration in glucose homeostasis (Adult), IRKO mice had marked blunting of ACh-mediated vasorelaxation [IRKO maximum contraction response (Emax) 66 ± 5% vs. wild type 87 ± 4%, P < 0.01]. Despite the endothelial dysfunction demonstrated, aortic endothelial nitric oxide synthase (eNOS) mRNA levels were similar in Adult IRKO and wild-type mice, and, interestingly, aortic eNOS protein levels were increased, suggesting a compensatory upregulation in the IRKO. We then examined the potential role of reactive oxygen species in mediating early endothelial dysfunction. The superoxide dismutase mimetic Mn(III)tetrakis(1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP) restored ACh relaxation responses in the Adult IRKO (Emax to ACh with MnTMPyP 85 ± 5%). Dihydroethidium fluorescence of aortas and isolated coronary microvascular endothelial cells confirmed a substantial increase in endothelium-derived reactive oxygen species in IRKO mice. These data demonstrate that mild insulin resistance is a potent substrate for accelerated endothelial dysfunction and support a role for endothelial cell superoxide production as a mechanism underlying the early reduction in NO bioavailability.


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