p38 signaling pathway is an important branch of mitogen-activated protein kinase（MAPK)-mediated signal transduction pathway. It plays pivotal roles in various physiological and pathological events, such as inflammation, cell stress, apoptosis, cell cycle and growth. Previous research in osteoarthritis, p38 participation was found in the inflammatory factors activate, cartilage cell apoptosis etc. Disc degeneration, also associated with inflammatory response, apoptosis and pathological changes which p38 MAPK signaling pathways role is not clear. Some reports about this area are reviewed in this article.

ObjectiveTo evaluate the feasibility of using injective chitosan scaffold and induced- adipose-derived stromal cells(ADSCs) to construct tissue engineered injectable nucleus pulposus (NP).MethodsADSCs were harvested from rabbits to culture 3 passage and induce 2 weeks to NP-like cells. The injective chitosan hydrogel scaffold was made of chitosan and disodium β-glycerophosphate. Its physical properties and gross condition were observed. The tissue engineered NP was constructed by compounding the scaffold and induced-ADSCs. Then, the viability of ADSCs in the scaffold was observed 2 days after compound culture and the growth condition of ADSCs on the scaffold was observed by scanning electron microscope (SEM) 14 days after compound culture. Expression of aggrecan and Col Ⅱ mRNA in ADSCs were analyzed by RT-PCR 14 days after inductive culture and compound culture.ResultsThe injective chitosan hydrogel was liquid at room temperature and solidified into gel at 37 ℃ (10～15 minutes) due to crosslinking reaction. Acridine orange/propidiumiodide staining showed that the viability rate of induced-ADSCs in chitosan scaffoldl was above 90%. Scanning electron microscope observation demonstrated that the ADSCs were distributed in the reticulate scaffold. RT-PCR results showed that the expression of Col Ⅱ and aggrecan mRNA in induced-ADSCs demonstrated differentiation of ADSCs to a phenotype which showed similarities to NP cells, and the co-culture NP-like cells with scaffold didn`t cause dedifferentiation.ConclusionWith good cellular compatibilities, C/Gp scaffold may be a potential NP cells carrier for tissue engineered NP.