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.