Figure 4

Isotype Cell Treatment with Nicotine, Nicotinic Receptor Agonist, and Antagonist. (a,b) Calvarial derived pre-osteoblasts (MCT3T-E1) cells increase in proliferation with nicotine treatment alone or in combination with nicotinic receptor agonist or antagonists as compared to control. Further, treatment with nicotinic receptor agonist (Varenicline) and antagonist (BTX) combined with nicotine decreases apoptotic activity in these cells compared to control whereas, nicotine in isolation increases apoptotic activity compared to combined treatments. n = 3. (c,d) Murine Bone Marrow Stromal Cells showed no proliferative response to treatments, however treatment with BTX with nicotine decreased apoptotic activity as compared to all other treatments. Further, treatment with nicotinic receptor agonist Varenicline with nicotine also reduced apoptotic activity compared to control and nicotine alone treatments. n = 3 (e,f) ATDC chondrocyte cells reduce proliferation with BTX plus nicotine treatment as compared to control and nicotine with Bupropion. These cells showed no effect on apoptotic activity with treatment. n = 3 Data presented as mean ± standard error of the mean. *p < 0.05, **p < 0.01, ***p < 0.001.