Expression of aging markers 4- Hydroxynonenal ( 4- HNE), p16 and Id1 in bmMSCs as the cells were exposed to acetyl- L- carnitine ( ALCAR, 0.1 mM) and TGF- β1 (5 ng/ mL) simultaneously. A. 4-HNE expression; B. P16 expression; C. Id1 expression. Bar graphs represent mean ± SD (4 independent experiments/group). *P < 0.05 vs. treatments with 5 ng/mL TGF-β1.