The Increased Apoptosis of Mesenchymal Stem Cells Mediated Osteopenia Due to Prenatal Nicotine Exposure in Female Offspring Rats via IGF1 Pathway

Nicotine exposure is a common adverse environment during pregnancy and causes developmental toxicity of long bones in offspring. However, the effect of prenatal nicotine exposure (PNE) on bone mass accumulation in female offspring and its mechanism remained to be further investigated. In this study, we constructed a PNE rat model and collected the long bone and the bone marrow mesenchymal stem cells (BMSCs) from female offspring rats for the detection of bone mass, cell apoptosis, and the expressions of osteogenesis- and apoptosis-related genes. The results revealed that PNE induced low bone mass in female offspring rats and was associated with the suppression of osteogenic function. Moreover, the apoptosis of BMSCs derived from the PNE female offspring rats was raised, and the expression ratio of apoptosis marker genes BAX/BCL-2 was significantly increased. Further, PNE inhibited the expression and function of insulin-like growth factor l (IGF1) signaling pathway in BMSCs. However, the exogenous IGF1 treatment partially ameliorated the increased apoptosis of BMSCs derived from the PNE female offspring rats. In conclusion, PNE induced low bone mass in female offspring rats, which was attributed to the increased apoptosis of BMSCs due to functional inhibition of IGF1 signaling pathway.