miRNA-seq analysis of high glucose induced osteoblasts provides insight into the mechanism underlying diabetic osteoporosis

Abstract Diabetic osteoporosis (DOP) is a chronic complication resulting from diabetes mellitus. The objective of this study is to investigate the underlying pathological mechanisms responsible for bone loss in DOP. Specifically, we aimed to screen the miRNA biomarkers of DOP and investigated whether miRNAs regulate the osteoblasts and thus contribute to DOP. To achieve this, an animal model of DOP was induced through the administration of streptozotocin and subsequent treatment with a high fat diet. Bone microarchitecture and histopathology analysis were carried out. Rat calvarial osteoblasts (ROBs) were induced by high glucose (HG). MiRNA-sequencing was employed to compare the miRNA profiles of HG-induced ROBs and control ROBs. The proliferation and mineralization abilities of ROBs were assessed using MTT assay, alkaline phosphatase, and alizarin red staining. The expression levels of osteoglycin (OGN), Runx2, and ALP were determined through qRT-PCR and Western blot analysis. The miRNA-sequencing results revealed a significant upregulation of miRNA-702-5p. The luciferase reporter gene was utilized in order to investigate the correlation between miR-702-5p and OGN. In vitro experiments demonstrated impaired proliferation and mineralization abilities induced by high glucose. The expressions of OGN, Runx2, and ALP were found to be inhibited. Interference of miR-702-5p resulted in the downregulation of OGN, Runx2, and ALP, which were subsequently upregulated through OGN overexpression. Furthermore, the downregulation of OGN and Runx2 in the femurs of DOP rat models has been confirmed. Consequently, it is reasonable to propose that the miRNA-702-5p/OGN/Runx2 signaling axis could potentially function as a mechanism underlying DOP. This newly discovered mechanism holds promise as a diagnostic biomarker and therapeutic target not only for DOP but also for other forms of osteoporosis.