Fig. 1.

PARP activity is increased in calcifying arteries and VSMCs. a Representative western blot analysis of PARP1 expression and PARP activity (Poly(ADP-ribosyl)ation) in radial arteries. Chronic renal failure (CRF): patients with CRF and uremia who underwent arterial venous fistular surgery (n = 5); Control (n = 5): patients who underwent amputation surgery due to arm trauma, without diagnosed complications of diabetes and chronic kidney disease. b PARP activity in radial arteries of control (n = 9) and CRF patients (n = 17) were assayed using the universal colorimetric PARP assay kit. c The calcium content and PARP activity were positively correlated in CRF arteries. R² = 0.4463, P < 0.05. Statistical significance of correlations was determined by Pearson’s correlation coefficient analysis. d Wistar rats were fed an adenine diet or a chow diet for 6 weeks (n = 10–12 per group). Arteries were isolated and performed by hematoxylin/eosin (H&E) and von Kossa staining. The PAR level was determined by immunofluorescence staining. Scale bars: black, 200 μm; white, 100 μm. e Rat aortic rings were treated with high Pi (osteogenic medium containing 10 mM β-glycerophosphate) for indicated days (0, 3, 7, and 10 days), and PARP activity was then detected by immunofluorescence staining. (n = 5 per group). Scale bar, 100 μm. f–h Rat VSMCs were treated with high Pi (10 mM β-glycerophosphate) for indicated days (0, 3, 7, and 14 days). The calcium content (f), ALP activity (g), and PARP activity (h) in calcified VSMCs were assayed. (n = 5 per group). Statistical significance was assessed using one-way ANOVA for multiple comparison and two-tailed t-tests for two groups and is presented as follows: *P < 0.05 and **P < 0.01. All values are means ± S.D.