scholarly journals Retinol-Binding Protein 4 Activates STRA6 Provoking Pancreatic β Cell Dysfunction in Type 2 Diabetes

Diabetes ◽  
2020 ◽  
pp. db191241
Author(s):  
Rong Huang ◽  
Xinxiu Bai ◽  
Xueyan Li ◽  
Xiaohui Wang ◽  
Lina Zhao
2020 ◽  
Author(s):  
Ada Admin ◽  
Rong Huang ◽  
Xinxiu Bai ◽  
Xueyan Li ◽  
Xiaohui Wang ◽  
...  

Pancreatic β cell dysfunction plays a decisive role in progression of type 2 diabetes. Retinol binding protein 4 (RBP4) is a prominent adipokine in type 2 diabetes while its effect on β cell function remains elusive and the underlying mechanisms are unknown. Here, we found that elevated circulating RBP4 levels were inversely correlated with pancreatic β cell function in db/db mice across different glycemic stages. RBP4 directly suppressed glucose stimulated insulin secretion (GSIS) in primary isolated islets and INS-1E cells in a dose- and time-dependent manner. RBP4-transgenic overexpressing mice (RBP4-Tg) showed a dynamic decrease of GSIS which appeared as early as 8-week-old preceding the impairment of insulin sensitivity and glucose tolerance. Islets isolated from RBP4-Tg mice showed a significant decrease of GSIS. Mechanistically, we demonstrated that the stimulated by retinoic acid 6(STRA6), RBP4’s only known specific membrane receptor, is expressed in β cells and mediates the inhibitory effect of RBP4 on insulin synthesis via JAK2/STAT1/ISL-1 pathway. Moreover, decreasing circulating RBP4 level could effectively restore β cell dysfunction and ameliorate hyperglycemia in db/db mice. These observations revealed a role of RBP4 in pancreatic β cell dysfunction which provided new insight into the diabetogenic effect of RBP4.


2020 ◽  
Author(s):  
Ada Admin ◽  
Rong Huang ◽  
Xinxiu Bai ◽  
Xueyan Li ◽  
Xiaohui Wang ◽  
...  

Pancreatic β cell dysfunction plays a decisive role in progression of type 2 diabetes. Retinol binding protein 4 (RBP4) is a prominent adipokine in type 2 diabetes while its effect on β cell function remains elusive and the underlying mechanisms are unknown. Here, we found that elevated circulating RBP4 levels were inversely correlated with pancreatic β cell function in db/db mice across different glycemic stages. RBP4 directly suppressed glucose stimulated insulin secretion (GSIS) in primary isolated islets and INS-1E cells in a dose- and time-dependent manner. RBP4-transgenic overexpressing mice (RBP4-Tg) showed a dynamic decrease of GSIS which appeared as early as 8-week-old preceding the impairment of insulin sensitivity and glucose tolerance. Islets isolated from RBP4-Tg mice showed a significant decrease of GSIS. Mechanistically, we demonstrated that the stimulated by retinoic acid 6(STRA6), RBP4’s only known specific membrane receptor, is expressed in β cells and mediates the inhibitory effect of RBP4 on insulin synthesis via JAK2/STAT1/ISL-1 pathway. Moreover, decreasing circulating RBP4 level could effectively restore β cell dysfunction and ameliorate hyperglycemia in db/db mice. These observations revealed a role of RBP4 in pancreatic β cell dysfunction which provided new insight into the diabetogenic effect of RBP4.


2013 ◽  
Vol 16 (2) ◽  
pp. 388-397 ◽  
Author(s):  
Vivian C. Luft ◽  
Mark Pereira ◽  
James S. Pankow ◽  
Christie Ballantyne ◽  
David Couper ◽  
...  

Background: Retinol binding protein 4 (RBP4) has been described as a link between impaired glucose uptake in adipocytes and systemic insulin sensitivity. Objective: To determine whether RBP4 fasting levels predict the development of type 2 diabetes. Methods: Using a case-cohort design, we followed 543 middle-aged individuals who developed diabetes and 537 who did not over ~9 years within the population-based Atherosclerosis Risk in Communities Study. Weighted Cox proportional hazards analyses permitted statistical inference of the RBP4 – incident diabetes associations to the entire cohort. Results: Women in the highest tertile of RBP4 presented greater risk of developing diabetes (HR = 1.74; 95%CI 1.03 – 2.94) in analyses adjusted for age, ethnicity, study center, parental history of diabetes, hypertension, glomerular filtration rate, body mass index, waist-hip ratio, nonesterified fatty acids, adiponectin, leptin, triglycerides and HDL-C. When additionally adjusted for fasting insulin, this association’s significance became borderline (HR = 1.68; 95%CI 1.00 – 2.82). No association between RBP4 levels and incident diabetes was found in men. Conclusion: These findings suggest that RBP4 levels may be directly involved in the pathogenesis of type 2 diabetes in women.


iScience ◽  
2020 ◽  
Vol 23 (10) ◽  
pp. 101566
Author(s):  
Saifur R. Khan ◽  
Yousef Manialawy ◽  
Andreea Obersterescu ◽  
Brian J. Cox ◽  
Erica P. Gunderson ◽  
...  

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