Genetic systems for a new approach to risk of progression of diabetic retinopathy

Objective: To evaluate the risk of progression of diabetic retinopathy (DR) using new strategies to obtain genetic information in type 2 diabetes (T2D) based on interfering ribonucleic acid (RNA).

Material and methods: A prospective multicentre case-control study of 132 participants was distributed into: T2D with (+DR) or without (-DR) (T2DG; n=77), and a control group (CG; n=55). After an eye examination and personal interview, tears were collected for molecular analysis (expression of microRNAs [miRNAs] (miRCURY ™ ARN Isolation Kit, Qiagen)]. Libraries, 137 vs. 140bp (GeneMapper, Applied Biosystems), were obtained in 18 samples (T2DG+DR=6; T2DG-DR=6; CG=6) by performing next-generation sequencing (NGS). SPSS 15.0 statistical program was used to perform data analysis.

Results: The mean age was 67±12 years in the T2DG vs. 55±21 years in the CG. Distribution men/women: 25/30 in T2DG vs. 51/28 in CG. A family history of DM, diet compliance, smoking, drinking and exercise, showed significant differences between groups (P<.001). A 20-25 microlitre sample of tears contained a mean of 9.42±3.30 ng/mL of purified ARN, with significant differences between T2DG/CG (P=.002) and T2DG+RD/CG (P=.004). Tear expression of miARNs in T2DG directly correlated with age/obesity/T2D duration (P<.05), and indirectly with visual acuity (P<.05). A total of 14 miRNAs related to the presence, pathogenic mechanisms and risk factors for the progression of diabetic retinopathy, were identified.

Conclusions: We propose to use tears as a source of genetic information for DM. Specific miRNAs involved in DR development and/or progression can be used as molecular biomarkers, and based on these, for developing future biotherapies.