Fig. 2: Endothelial loss of Sparcl1 attenuates influenza-induced pneumonia.

A Time course of changes in body weight and B capillary oxygen saturation in WT and EC^Sparcl1-KO mice after influenza infection, n = 7 mice per group, independent biological replicates. A p = 0.04; B p = 0.04. C Kaplan–Meier survival curves after influenza infection, log-rank test. D–H The levels of pro-inflammatory cytokines IL-6 (D), TNF (E), IFN-γ(F), IL-4(G), and IL-10 (H) in bronchoalveolar lavage fluid (BALF) were measured by ELISA in WT and EC^Sparcl1-KO mice at day 0 (uninjured) and/or D12 days after influenza infection, each dot represents one mouse, n = 4–7 mice per group, independent biological replicates. D p = 0.03; E p = 0.04. I and J Total protein (I) and cells (J) were quantified in BALF on day 12 post influenza infection, n = 6 mice per group, I p = 0.018, J p = 0.07. K CCL-2 concentration in BALF from WT (wild-type) and EC^Sparcl1-KO mice at day 12 after infection. n = 6 mice per group, independent biological replicates, p = 0.02. L. Quantification of the proportion of total macrophages (CD64⁺F4/80⁺), alveolar macrophages (CD45⁺Ly6G^-CD64⁺F4/80⁺SiglecF⁺) and interstitial and recruited macrophages (CD45⁺Ly6G^-CD64⁺F4/80⁺SiglecF^-) in CD45⁺ live cells at day 12 after influenza infection in WT (n = 7 mice) and EC^Sparcl1-KO (n = 6 mice) mice, independent biological replicates. Gated as shown in Supplementary Fig. 11A. Total macrophages: WT vs. EC^Sparcl1-KO: p = 0.033. M Left: tile scan images of H&E stain at 25 days post-infection, demarcated boxes indicate different injury zones. Right: clustered injury zone maps produced from left H&E images, scale bars, 1 mm. N Quantification of injured area in different injury zones in M, n = 5 mice per group, independent biological replicates. Total injured zone: WT vs. EC^Sparcl1-KO: p = 0.033. Data in A, B, D to (L) and (N) are presented as means ± SEM, calculated using unpaired two-tailed t-test. Data in (C) were calculated using log-rank test. *P < 0.05, ns not significant, P > 0.05. Source data are provided as a Source Data file.