The effects of cigarette smoking and nicotine on the therapeutic potential of mesenchymal stem cells.

Due to their immunoregulatory properties and capacity for multi-lineage differentiation, mesenchymal stem cells (MSCs) have been used as new therapeutic agents in regenerative medicine. Numerous lifestyle habits and behavioral risk factors may modulate metabolic and cell growth signaling pathways in MSCs, affecting their phenotype and function. Accordingly, identification of these factors and minimization of their influence on viability and function of transplanted MSCs may greatly contribute to their better therapeutic efficacy. A large number of experimental and clinical studies have demonstrated the detrimental effects of cigarette smoke and nicotine on proliferation, homing, chondrogenic and osteogenic differentiation of MSCs. Cigarette smoke down-regulates expression of chemokine receptors and modulates activity of anti-oxidative enzymes in MSCs, while nicotine impairs synthesis of transcriptional factors that regulate the cell cycle, metabolism, migration, chondrogenesis and osteogenesis. In this review article, we summarize current knowledge about molecular mechanisms that are responsible for cigarette smoke and nicotine-dependent modulation of MSCs' therapeutic potential.