Fig. 6

Coculturing tumor necrosis factor (TNF)-α-treated nucleus pulposus mesenchymal stem cells (NPMSCs) with notochordal cell (NC)-rich nucleus pulposus (NP) explants enhances the expression of NP cell markers. Representative image of immunofluorescence staining (a) and quantification analysis of carbonic anhydrase 12 (CA12) protein expression in the three groups after 7 days of culture (b). Western blot analysis (c) and densitometric quantification (d) of CA12 proteins with different treatments. The gene expression levels of CA12, FOXF1, PAX1, and HIF-1α in NPMSCs were compared among different groups after 7 days of culture (e–h). All data are expressed as mean ± SD values (n = 4). *P < 0.05