Screening and Validating Insulin Signaling Pathway-Related Circulating circRNAs in Type 2 Diabetes

Abstract

Background: The underlying molecular mechanism of type 2 diabetes (T2D) and insulin resistance is that abnormalities occur in the complex insulin signaling pathway. Circular RNAs (circRNAs) are involved in the development of diseases by regulating gene expression and become promising novel biomarkers for diseases. This study systematically screened and validated the insulin signaling pathway-related circulating circRNAs, which are associated with T2D. Methods: circRNA expression profiles were screened by microarray between five T2D patients and five healthy controls. Insulin signaling pathway-related circRNAs were then selected from those differently expressed circRNAs whose potential target miRNAs are involved in regulating key genes in the pathway. The expression of candidate circRNAs were validated in a second sample with 30 T2D cases and 30 controls by real-time quantitative polymerase chain reaction (RT-qPCR). Eventually, the association between circRNAs and T2D and their clinical significance were further confirmed in a large independent sample, including 103 T2D cases, 93 controls and 80 individuals with impaired fasting glucose (IFG) as prediabetes cases. Results: Four circRNAs including hsa_circ_0063425, hsa_circ_0056891, hsa_circ_0078166 and hsa_circ_0071336 were validated by RT-qPCR. Low expressed circ_0063425, hsa_circ_0056891 and hsa_circ_0071336 were independent predictor of T2D, IFG and insulin resistance. The three-circRNA panel had a high accuracy for diagnosing T2D and IFG in the training set and testing set, especially when body mass index (BMI) was integrated. Bioinformatics Gene Ontology and pathway analysis confirmed that these circRNAs involve in the regulation of insulin signaling pathway. Conclusion: circ_0063425, hsa_circ_0056891 and hsa_circ_0071336 are valuable circulating biomarkers for T2D, and may involve in regulating insulin signaling pathway. Funding Statement: This study was supported by the National Natural Science Foundation (81773511, 81573214), the Beijing Municipal Natural Science Foundation (7162020). Declaration of Interests: The authors state: None. Ethics Approval Statement: This study was approved by the university ethical committee and written informed consent was obtained from each participant before the investigation.