Co-culture of Rat Bone Marrow Mesenchymal Stem Cells Exerts an Anti-apoptotic Effect on Nucleus Pulposus Cells Through the PI3K/Akt Pathway.

Abstract

Introduction: This study aims to investigate the effect of non-contact co-culture of rat bone marrow mesenchymal stem cells (BMSCs) on apoptosis in nucleus pulposus cells (NPCs).

Methods: Rat primary BMSCs and NPCs were isolated and cultured in vitro. To induce apoptosis, NPCs were exposed to varying concentrations of tert-butyl hydroperoxide (TBHP). A non-contact co-culture system was utilized to assess the influence of BMSCs on TBHP-induced apoptosis in NPCs. Apoptosis rates were measured by flow cytometry, and the expression of apoptosis-related proteins was analyzed by Western blot.

Results: Primary cultures successfully yielded both BMSCs and NPCs. TBHP treatment led to a concentration- dependent increase in NPC apoptosis. Based on the CCK-8 assay, 100 μmol/ml was selected as the optimal experimental concentration. Co-culture with BMSCs significantly enhanced the anti-apoptotic capacity of NPCs, reducing the apoptosis rate. This was accompanied by decreased expression of pro-apoptotic proteins caspase-3 and Bax, and increased expression of the antiapoptotic protein Bcl-2. Activation of the PI3K/AKT pathway was also observed, with elevated levels of p-PI3K and p-AKT.

Discussion: In the non-contact co-culture system, BMSCs alleviated TBHP-induced NPC damage via a paracrine effect, providing new theoretical insights for therapeutic development.

Conclusion: BMSCs may reduce TBHP-induced NPC damage through paracrine signaling, a mechanism linked to the activation of the PI3K/AKT pathway.