Differential Profile of Plasma Circular RNAs in Type 1 Diabetes Mellitus

Abstract

Background: No currently available biomarkers or treatment regimens fully meet therapeutic needs of type 1 diabetes mellitus (T1DM). Circular RNA (circRNA) is a recently identified class of stable noncoding RNA that have been documented as potential biomarkers for various diseases. Our objective was to identify and analyze plasma circRNAs altered in T1DM. Methods: We used microarray to screen differentially expressed plasma circRNAs in patients with new onset T1DM (n=3) and age-/gender-matched healthy controls (n=3). Then, we selected six candidates with highest fold-change and validated them by quantitative real-time polymerase chain reaction in independent human cohort samples (n=12). Bioinformatic tools were adopted to predict putative microRNAs (miRNAs) sponged by these validated circRNAs and their downstream messenger RNAs (mRNAs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to gain further insights into T1DM pathogenesis. Results: We identified 68 differentially expressed circRNAs, with 61 and seven being up-and downregulated respectively. Four of the six selected candidates were successfully validated. Curations of their predicted interacting miRNAs revealed critical roles in inflammation and pathogenesis of autoimmune disorders. Functional relations were visualized by a circRNA-miRNA-mRNA network. GO and KEGG analyses identified multiple inflammation-related processes that could be potentially associated with T1DM pathogenesis, including cytokine-cytokine receptor interaction, inflammatory mediator regulation of transient receptor potential channels and leukocyte activation involved in immune response. Conclusion: Our study report, for the first time, a profile of differentially expressed plasma circRNAs in new onset T1DM. Further in silico annotations and bioinformatics analyses supported future application of circRNAs as novel biomarkers of T1DM.

Circular RNAs in diabetes mellitus and its complications

“…Another study detected 8,214 circRNAs in human plasma by microarray analysis of the samples of three subjects with new-onset T1DM and identified 61 upregulated and 7 downregulated circRNAs. Notably, the results of gene analysis revealed that these differentially expressed circRNAs participate in inflammation and the pathogenesis of T1DM ( 9 ), supporting the future applications of circRNAs as novel biomarkers of T1DM. Additionally, hsa_circ_0072697 is significantly downregulated in patients with T1DM ( 40 ).…”

“…CircRNAs can serve as the sponges for specific miRNAs to further regulate the expression levels of the target genes. Advancement of RNA sequencing technology and bioinformatics-based prediction resulted in identification of an increasing number of circRNAs and their biological functions (6,(8)(9)(10).…”

Type 1 Diabetes Mellitus-Related circRNAs Regulate CD4+ T Cell Functions

“…circRNAs are widely distributed in different tissues, blood, and urine as well as saliva where their extractions are easy to conduct [ 22 ]. Because of their tissue and cell specificity, high-throughput sequencing of circRNAs using specific tissues and especially certain cells is the basis of accurate research, and circRNAs in body fluids are potential diagnostic markers [ 30 , 31 ]. For instance, the biomarker potential of circRNAs can be increased if they were found in exosomes, as has been evidenced in solid tumors.…”

Understanding Competitive Endogenous RNA Network Mechanism in Type 1 Diabetes Mellitus Using Computational and Bioinformatics Approaches

“… 20 Among them, the long non-coding RNA (lncRNA) is a kind of linear non-coding RNA with a length of more than 200 nucleotides, 21 and circular RNA (circRNA) is a kind of endogenous non-coding RNA with a closed-loop structure. 22 Previous studies have shown the vital roles of various lncRNAs and circRNAs in T1DM. lncRNA Lnc13 is up-regulated in β-cells and contributes to the pathogenesis of T1DM by increasing pancreatic β-cell inflammation.…”

“…Li et al and Luo et al identified the circRNA-miRNA-mRNA network in T1DM via bioinformatic analysis. 22 , 33 Shi et al reported the lncRNA-miRNA-mRNA regulatory networks in T1DM. 34 Thus, further studies aimed at clarifying ceRNA-based molecular mechanisms in T1DM are needed to provide potential opportunities for better understanding the pathogenesis and treatment of T1DM.…”