Deciphering the role of circulating lncRNAs: RNCR2, NEAT2, CDKN2B-AS1, and PVT1 and the possible prediction of anti-VEGF treatment outcomes in diabetic retinopathy patients

Purpose: Putative roles of long non-coding RNAs (lncRNAs) as indicators for diabetic retinopathy (DR) and associated complications are beginning to emerge. We aimed to evaluate a panel of circulating hyperglycemia-related lncRNAs: RNCR2, NEAT2, CDKN2B-AS1, and PVT1 in type 2 diabetes patients with/without DR and to correlate their levels with the clinical characteristics and response to aflibercept intravitreal injection in terms of visual acuity (VA) improvement, central macular thickness (CMT) decline, and macular edema resolution after 4 weeks of the initial injection. Methods: Pre-treatment plasma relative expression levels of the specified lncRNAs were quantified in 130 consecutive patients with diabetes (75 and 55 with/without DR, respectively) and 108 controls using quantitative real-time PCR. Results: One month after aflibercept injection, significant reductions in CMT and VA were observed in DR cohorts. The four lncRNAs were over-expressed in DM compared with those in controls. However, downregulated baseline plasma levels of RNCR2 and NEAT2 were observed in glycemic-controlled DR patients. None of the lncRNAs showed a correlation with the severity of retinopathy or drug response. Conclusion: Though circulating levels of the analyzed lncRNAs did not show an association with DR progression or aflibercept therapy response, the expression pattern demonstrated good diagnostic performance in differentiating DM from controls and DR.