High glucose induces endothelial-to-chondrocyte transition in human aortic endothelial cells / 中华肾脏病杂志

ABSTRACT

Objective To explore whether high glucose (HG)-induced endothelial-to-mesenchymal transition (EndMT) could be transitioned into mesenchymal stem cells (MSCs) and further differentiated into chondrocytes.Methods Human aortic endothelial cells (HAECs) were divided into three groupsnormal glucose (NG,5.5 mmol/L glucose) group,HG (30 mmol/L glucose) group,and mannitol (5.5 mmol/L glucose + 24.5 mmol/L mannitol) group,and were cultured for 48 h.Immunofluorescence staining was performed to detect the co-expression of CD31 (endothelial markers),and fibroblast-specific protein 1 (FSP1,fibroblast markers).The expression of CD31 and FSP1 mRNA and protein was detected by real-time PCR and Western blotting.When endothelial-derived MSCs were grown in MSC medium for one week,the expression of the MSCs markers CD44,CD10 and the chondrocyte marker SOX9 was detected by Western blotting and RT-PCR.Chondrocyte expression was detected by alcian blue staining.Calcium deposit was analyzed by alizarin red staining.Pathological changes were investigated using electron microscopy.Results The expression of FSP1 mRNA and protein was significantly increased,but the expression of CD31 mRNA and protein was decreased (P ＜0.01),and the cells undergoing EndMT also significantly expressed CD10,CD44 and SOX9 in the HG group compared with those in normal glucose group (P ＜ 0.01).The incubation of HAECs exposed to HG resulted in a fibroblast-like phenotype,wherein increased microfilamentation and a roughened endoplasmic reticulum structure were observed in the cytoplasm.Double staining of the HAECs indicated a co-localization of CD31 and FSP1.After one week culture for chondrocyte medium,the expression of MSCs marker STRO-1 was significantly increased by immunofluorescence staining.Additionally,aleian blue staining in the HG group was positive compared to the NG group.Consistent with the elevation of SOX9 expression,calcium deposit also enhanced in the HG group.Conclusion HG can induce endothelial cells transdifferentiation into chondrocyte-like cells via the EndMT.