Nrf2/Nlrp3 signaling in aging BMSCs: Traf6 intervention as a novel approach to osteoporosis treatment

Abstract

Senile osteoporosis progression is closely related to the decreased osteogenic differentiation capacity of senescent bone marrow stromal stem cells (BMSCs). This study demonstrated that the Traf6-mediated Nrf2/Nlrp3 signaling axis significantly influences inflammatory senescence progression in BMSCs, and targeting Traf6 can effectively alleviate bone loss caused by inflammatory senescence. High-throughput sequencing revealed that primary BMSCs from 18Ms mice were differentially enriched in anti-inflammatory, antioxidant, and immune-related biological processes compared to those from young mice, with significant differences in the protein expression of Traf6, Nrf2, and Nlrp3-related pathways, indicating potential crosstalk. In vitro experiments using western blotting and immunofluorescence confirmed high levels of intracellular inflammation, oxidative stress, and elevated expression of Traf6, Nrf2, and Nlrp3 inflammatory vesicles in senescent BMSCs. We used lentiviral transfection to knockdown Traf6 and intervention with Nrf2 agonists and inhibitors, and we verified the regulation of the expression of Nrf2/Nlrp3 inflammatory vesicles by Traf6 and its effect on inflammatory senescence progression in BMSCs. We performed in vivo experiments involving targeted Traf6 knockdown in bone tissue, morphological analysis of the femur by micro-computed tomography and immunohistochemistry, measurement of serum MDA and bone metabolism-related indices using ELISA, and calcein labeling to observe the calcium salt deposition rate. These experiments confirmed that the Traf6-mediated Nrf2/Nlrp3 signaling axis significantly influences the inflammatory senescence of BMSCs. Targeting Traf6 effectively alleviates bone loss caused by inflammatory senescence, presenting a potential method for preventing and controlling senile osteoporosis.