RNA sequencing identified specific circulating miRNA biomarkers for early detection of diabetes retinopathy

Abstract

Diabetic retinopathy (DR) is the leading cause of blindness in patients with diabetes. However, biomarkers for early detection of DR are still lacking. MicroRNAs (miRNAs) regulate multiple biological functions and are often deregulated in DR. We aimed to investigate whether circulating miRNAs can be used as biomarkers of early-stage DR. We used RNA-seq and qRT-PCR to identify differential serum miRNAs in patients with type 2 diabetes mellitus with DR (T2DM-DR), T2DM without DR (T2DM-no-DR), and healthy controls. We validated differential circulating miRNAs in two phases using qRT-PCR assays. RNA-seq analysis identified 7 differential circulating miRNAs between T2DM-DR and T2DM-no-DR and 47 differential miRNAs between T2DM-DR and healthy subjects. Two-stage analysis verified that a profile of five serum miRNAs (hsa-let-7a-5p, hsa-miR-novel-chr5_15976, hsa-miR-28-3p, has-miR-151a-5p, has-miR-148a-3p) was significantly associated with T2DM-DR. Receiver-operator-characteristic analyses showed that a panel of three miRNAs (hsa-let-7a-5p, hsa-miR-novel-chr5_15976, and hsa-miR-28-3p) presented 0.92 sensitivity and 0.94 specificity for distinguishing T2DM-DR from T2DM-no-DR, and 0.93 sensitivity and 0.86 specificity for differentiating early-stage T2DM-DR (NPDR) from late-stage DR (PDR). Lentivirus-mediated overexpression of hsa-let-7a-5p in human retinal microvascular endothelial cells (HRMECs) significantly promoted proliferation rates of HRMECs. In conclusion, the three-miRNA signature from serum may serve as a noninvasive diagnostic biomarker for DR. Furthermore, we showed that DR-associated miRNAs may be involved in the pathogenesis of DR, at least in part, through modifying proliferation of HRMECs.

Diabetic Retinopathy–An Underdiagnosed and Undertreated Inflammatory, Neuro-Vascular Complication of Diabetes

“…Such techniques should provide improved evaluation of retinal injury to both the neuronal unit as well as the microvasculature and allow for improved, earlier treatments, both local as well as systemic. Currently there are no systemic factors established for retinopathy risk screening outside of hyperglycemia (HgbA1c), glycemic variability, hypertension, and obstructive sleep apnea, although early reviews suggest some serum autoimmune inflammatory constituents (85) and circulating miRNA markers are associated with early stages of diabetic retinopathy (86), and certainly need to be further investigated for screening and to define chronologic progression.…”

Plasma levels of miR‐29b and miR‐200b in type 2 diabetic retinopathy

“…51 During the course of this study, other investigators attempted to identify dysregulated circulating miRNAs in DR in humans. [17][18][19][20][21][22][23] These studies were carried out in patients with type 1 diabetes, 17,18 type 2 diabetes [19][20][21][22] or diabetes type not reported, 23 using serum, 18,20,22,23 plasma 19,21 or endothelial progenitor cells cultured from isolated peripheral blood mononuclear cells. 17 They reported that angiogenic miRNAs are associated with incident DR, 18 as compared to subjects with idiopathic macular holes.…”

“…Given their high stability and omnipresence in body fluids, several studies have identified the potential of circulating miRNAs as biomarkers of diagnosis, prognosis and management of type 2 diabetes and its vascular complications . Despite this, the profile of circulating miRNAs in DR has been evaluated only recently …”

“…8,[12][13][14] Despite this, the profile of circulating miRNAs in DR has been evaluated only recently. [15][16][17][18][19][20][21][22][23][24][25] MiR-29b and miR-200b were one of the first miRNAs found to be dysregulated in high glucose-exposed retinal cells and diabetic murines, thereby suggesting their involvement in the development of DR. MiR-29b exerts anti-apoptotic and antifibrotic effects on retinal cells 12,26 and contributes to endothelial function by increasing nitric oxide, 27 while miR-200b protects against vascular permeability and angiogenesis. Down-regulation of miR-29b results in increased matrix deposition and retinal fibrosis, whereas down-regulation of miR-200b results in increased inflammation.…”

miR-874 ameliorates retinopathy in diabetic rats by NF-κB signaling pathway

“…The activity of NF-κB signaling pathway significantly increases in diabetes rats, and the up-regulation of NF-κB p65 expression augments the generation of reactive oxygen species and further leads to the occurrence of microaneurysms, retinal neovascularization and vitreous hemorrhage, boosting the progression of retinopathy in diabetes rats [9][10][11]. Encoded by endogenous gene, microRNA (miRNA) is a non-coding single-stranded RNA molecule (containing about 21-23 nucleotides) and has the features of high conservation, time sequence and tissue specificity [12,13]. miRNAs can interact with the 3'UTR region of the mRNA for a specific target gene by sequence-specific mode to regulate the protein expression of target gene.…”