High glucose prevents osteogenic differentiation of mesenchymal stem cells via lncRNA AK028326/CXCL13 pathway.

Abstract

High glucose (HG) often induces unfavorable effects on proliferation and differentiation of mesenchymal stem cells (MSCs). This study aimed to explore potential molecular pathways underlying HG functional mechanism during osteogenic differentiation of MSCs, involving lncRNA AK028326 and CXCL13. Murine bone marrow-derived MSCs were cultured in osteogenic-inducing medium supplemented with high glucose level at 25mM or 5.5mM as normal control. Expression levels of lncRNA AK028326 and CXCL13 were measured by using real-time PCR. The mineralized nodule formation and alkaline phosphatase (ALP) activity were detected after 21 and 7days of incubation respectively. Western blot were also performed to determine the expression of CXCL13 and osteogenic gene markers. Plasmid pcDNAs and small interference RNAs were transfected as indicated for functional analysis of AK028326 and CXCL13. HG suppressed the expression of AK028326 and CXCL13 in MSCs in a time-dependent manner, and also the mineralization, ALP activity, and osteogenic gene expression, which could be reversed by overexpression of AK028326 or CXCL13. CXCL13 expression was positively regulated by AK028326 at both mRNA and protein levels. Moreover, CXCL13 mediated the positive regulation of AK028326 on osteogenic gene expression in MSCs and MC3T3-E1 cells, mineralization and ALP activity in MSCs and also HG-induced inhibitory effects during MSCs differentiation into osteoblast. HG could inhibit osteogenic differentiation of MSCs via inhibited expression of CXCL13 mediated by lncRNA AK028326, thereby providing new insights into the molecular mechanism of many osteogenesis-related diseases especially for patients with hyperglycemia.