Fig. 4

Expression of aging-associated indicators in control, COPD, COPD+EPCs and COPD+P5091 groups of liver tissue. A Representative images of SA-gal staining (blue). Scale indicates 50 μm; B–D qRT-PCR assay was used to analysis the relative mRNA expression of cyclin D1, p300 and TERT; E Western blot was served to analysis the protein expression of cyclin D1, p300 and TERT. β-actin was used as internal control. p values were calculated by one-way ANOVA in multiple groups and two-sided t-test between two groups. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; ns means p > 0.05