Skip to main content
. 2022 Sep 20;9:908639. doi: 10.3389/fmed.2022.908639

Figure 3.

Figure 3

Endothelial p16INK4A mediates hypoxia-induced TWIST1 expression in the mouse lung. (A) Gene network demonstrating interactions between Twist1, Pdgfb, and differentially expressed genes listed in the top 50 BP GO Term categories relating to senescence/SASP in ECs isolated from mouse lungs treated with hypoxia for 3 weeks compared to those from normoxia-treated mouse lung ECs. Red: Transcription/gene expression, Gold: Protein/RNA processing, Green: Cell cycle. Blue: Inflammatory/immune response. Pink: Cell signaling/signal transduction, Gray: Miscellaneous. (B) IF images of representative pulmonary arterioles in the lungs of tamoxifen-induced p16fl/fl or p16iΔEC mice treated with normoxia or hypoxia for 3 weeks stained for TWIST1, ERG, and DAPI. Scale bar: 25 μm. Graph showing integrated fluorescent density of TWIST1 in tamoxifen-induced p16fl/fl or p16iΔEC mouse lungs treated with normoxia or hypoxia for 3 weeks (n = 7, mean ± SEM, *p < 0.05). (C) Graph showing the mRNA levels of Twist1 in tamoxifen-induced p16fl/fl or p16iΔEC mouse lungs treated with normoxia or hypoxia for 3 weeks (n = 5–9, mean ± SEM, *p < 0.05). (D) Graph showing the mRNA levels of p16INK4A in PAECs treated with p16INK4A siRNA or scrambled control siRNA (left, n = 4–5, mean ± SEM, *p < 0.05). Graph showing the mRNA levels of TWIST1 in IPAH PAECs treated with p16INK4A siRNA or scrambled control siRNA (right, n = 4, mean ± SEM, *p < 0.05).