Fig. 6

ATP-activated Sca-1⁺ cell proliferation is mediated predominantly by the p38-MAPK signalling pathway. A, Western blotting results showing enhanced p-P38 protein expression after 30-µM ATP stimulation for 5, 10, 15, 30 and 60 min. B, Statistical histogram of p-P38 protein expression levels after ATP stimulation for the indicated times. C, Western blot showing that P38 phosphorylation stimulated by ATP (30 µM, 5 min) is blocked by P38 inhibitor SB203580 (10 µM). D, Statistical histogram of p-P38 expression levels following cotreatment with ATP and 10-µM SB203580. E, SB203580 also blocks the promotion of Sca-1⁺ stem cell proliferation by ATP. Summary data were obtained from 4 independent experiments and data were first tested by Shapiro–Wilk test for normality and Ordinary one-way ANOVA (Dunnett’s multiple comparisons test) was performed for B and (Tukey’s multiple comparisons test) for D, while summary data were obtained from 8 independent experiments and the Nonparametric test (Kruskal–Wallis test) test was performed for E. A P < 0.05 is considered a statistically significant test, and statistically significant P-values between the two groups are shown on the graph