Figure 5.

Regulation and activation of p21 in lung resident mesenchymal stem cells (MSC) by cyclic mechanical stretch (CMS) and hyperoxia (HOX). A: correlation of log2 fold-changes vs. control of CMS and CMS_Hox80 treated cells. Each dot represents an individual gene. The color gradient indicates the spatial density of the dots. The diagonal line is the identity line. Most genes are regulated in the same direction under both treatments (Pearson's r = 0.46, P < 0.001), with a generally stronger regulation by CMS_Hox80. The highlighted point indicates CDKN1A (p21). B: representative western blot analysis of p21 activation after 24 h exposure to CMS and HOX 80%. CMS and HOX induced the accumulation of p21 whereas more pronounced for HOX and CMS+HOX, n = 9 MSC cultures. The order of samples was rearranged for the clearness of presentation without any further manipulation (indicated by separated boxes). The bar graphs show the densitometry results expressed as the ratio of adjusted total band volume normalized to GAPDH and control. Data are expressed as means ± SD, *P < 0.05, ***P < 0.001, by paired t test.