Downregulation of plasma microRNA-29c-3p expression may be a new risk factor for diabetic retinopathy

Minerva Endocrinol (Torino). 2023 Mar;48(1):42-50. doi: 10.23736/S2724-6507.20.03278-2. Epub 2020 Nov 19.

Abstract

Background: Circulation miRNAs have emerged as new biomarkers for identifying and monitoring the microvascular complications of diabetes. The aim of this study is to evaluate the levels of five candidate miRNAs (miR-29c-3p, miR-18a, miR-31, miR-181 and miR-20a) in patients with diabetic retinopathy (DR) and their relationship with disease severity.

Methods: The study included 31 diabetes patients without DR (NDR group), 68 patients with DR (DR group) and 30 healthy controls (HC group). Twenty-five of patients with DR were proliferative DR (PDR group) and 43 were non-proliferative DR (NPDR group) patients. Metabolic parameters and serum vascular endothelial growth factor (VEGF) levels of all participants were measured. Circulating miRNAs levels were determined by quantitative real-time PCR. Fundus examinations of all patients were performed by a single ophthalmologist.

Results: VEGF levels were significantly higher in the NDR, and DR groups compared to HC group (P=0.011 and P=0.014, respectively). Plasma miR-29c-3p was downregulated in diabetic patients with retinopathy and without retinopathy. This downregulation was more prominent in diabetic patients without retinopathy compared to those with retinopathy (P=0.016). There was no significant difference in plasma levels of miR-18a, miR-20a, miR-18a and miR-31 between diabetic subjects with and without retinopathy (P>0.05). There was no correlation between DR severity and the levels of miRNAs (P>0.05). In multivariate logistic regression analysis, it was found that changes in plasma miR-29c-3p expression of diabetic patients increased DR risk independent of other risk factors.

Conclusions: Plasma miR-29c-3p expression is downregulated in diabetic patients with and without retinopathy, and changes in this miRNA are an independent risk factor for the development of DR.

MeSH terms

  • Diabetes Mellitus*
  • Diabetic Retinopathy* / genetics
  • Down-Regulation
  • Humans
  • MicroRNAs* / genetics
  • Risk Factors
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Vascular Endothelial Growth Factor A
  • MicroRNAs