Overexpression of the AR promotes androgen-accelerated premature senescence in DPCs.

<p>(A) Non-balding DPCs of frontal scalp were transfected with pcDNA3-hAR, or pcDNA3 empty vector and cultured in the presence of DHT or ethanol (vehicle control) for 3 days. Premature senescence of DPCs was evaluated on day 5. Scale bar = 100 µm. DHT increased SA-β-Gal activity (B), cell size (C), and the number of SAHF-containing DPCs. (D) Overexpression of AR enhanced the statistical significance of DHT effects. Values are means ± SDs from three independent experiments (*<i>P</i><0.01, **<i>P</i><0.001). (E)A representative immunoblot of cell lysates of DPCs after treatment with DHT or vehicle for 84 hours and (F) Quantitative densitometry of the p16/GAPDH protein expression was performed by using ImageJ software. Values are means ± SDs from 6 independent experiments Asterisk indicates <i>P</i><0.05. (G) DHT increased p16<i>^INK4a</i> protein expression in DPCs isolated from transitional zone of balding scalp but unaltered in DPCs isolated from beard. The numbers indicate p16<i>^INK4a</i>/GAPDH and AR/GAPDH ratios. GAPDH (glyceraldehyde 3-phosphate dehydrogenase) was used as an internal standard.