(A) Schematic of the experimental workflow. (B) Flow cytometric analysis of the percentage and number of CD31⁺Ki67⁺ cells and the total number of CD31⁺ cells in control and neutrophil-depleted lungs. n = 4 (neutrophil depletion); n = 6 (isotype control). (C) Schematic of the experimental workflow. (D) Volcano plot showing DEGs between control and neutrophil-depleted lungs. Transcripts significantly upregulated in either PMN-depleted or control lungs are colored in blue and red, respectively (log₂ fold change ± 0.5 and adjusted P < 0.05). (E) GO enrichment analysis was performed on the DEGs. Blue indicates enrichment in lungs from neutrophil-depleted mice, while red indicates enrichment in lungs from control mice. (F) Intracellular VEGFA levels in neutrophils from the indicated tissues. n = 3–4 mice. (G) Percentage and absolute count of proliferating ECs in lungs from 3-week-old mice. n = 4 WT mice; n = 5 Piezo1-cKO mice. (H) Absolute count of total ECs in lung from 3-week-old mice. n = 4 WT mice; n = 5 Piezo1-cKO mice. (I) RVSP in normoxia (Nx) and hypoxia (Hx) for 3 weeks. n = 9 (Nx), n = 11 (Hx, WT); n = 12 (Hx, Piezo1-cKO). (J) Representative images and quantification of α-SMA–stained arterioles. Scale bars: 10 μm. n = 3. (K) Flow cytometric analysis of proliferating ECs in lung after 3 weeks of hypoxia. n = 4. Data in B and F–K are shown as the mean ± SEM. Statistical significance was determined by 1-way ANOVA with Tukey’s multiple-comparison test (I) and unpaired, 2-tailed Student’s t test (B, F, G, H, J, and K).