Decreased miR-150 in obesity-associated type 2 diabetic mice increases intraocular inflammation and exacerbates retinal dysfunction

• Published in: BMJ open diabetes research & care 2020-09, Vol.8 (1), p.e001446
• Main Authors: Yu, Fei, Chapman, Samantha, Pham, Dylan Luc, Ko, Michael Lee, Zhou, Beiyan, Ko, Gladys Y-P
• Format: Article
• Language: English
• Subjects: Angiogenesis; Animals; Calories; Carbohydrates; Diabetes; Diabetes Mellitus, Experimental - complications; Diabetes Mellitus, Experimental - genetics; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - genetics; Diabetic retinopathy; Diet; Hyperglycemia; Inflammation; Inflammation - genetics; Laboratories; Mice; Mice, Obese; MicroRNAs; MicroRNAs - genetics; Obesity; Obesity - complications; Obesity - genetics; Pathogenesis; Pathophysiology/Complications; Retina; Vascular endothelial growth factor
• ISSN: 2052-4897; 2052-4897
• DOI: 10.1136/bmjdrc-2020-001446

IntroductionDiabetic retinopathy (DR) is the leading cause of blindness among the working population in the USA. Current therapies, including anti-vascular endothelial growth factor treatments, cannot completely reverse the visual defects induced by DR. MicroRNA-150 (miR-150) is a regulator that suppresses inflammation and pathological angiogenesis. In patients with diabetes, miR-150 is downregulated. As chronic inflammation is a major contributor to the pathogenesis of DR, whether diabetes-associated decrease of miR-150 is merely associated with the disease progression or decreased miR-150 causes retinal inflammation and pathological angiogenesis is still unknown.Research design and methodsWe used high-fat diet (HFD)-induced type 2 diabetes (T2D) in wild type (WT) and miR-150 knockout (miR-150-/-) mice for this study and compared retinal function and microvasculature morphology.ResultsWe found that WT mice fed with an HFD for only 1 month had a significant decrease of miR-150 in the blood and retina, and retinal light sensitivity also decreased. The miR-150-/- mice on the HFD developed diabetes similar to that of the WT. At 7–8 months old, miR-150-/- mice under normal diet had increased degeneration of retinal capillaries compared with WT mice, indicating that miR-150 is important in maintaining the structural integrity of retinal microvasculature. Deletion of miR-150 worsened HFD-induced retinal dysfunction as early as 1 month after the diet regimen, and it exacerbated HFD-induced T2DR by further increasing retinal inflammation and microvascular degeneration.ConclusionThese data suggest that decreased miR-150 caused by obesity or diabetic insults is not merely correlated to the disease progression, but it contributes to the retinal dysfunction and inflammation, as well as the development of DR.