Loss of α-CGRP diminishes angiogenic sprouting after ischemic stroke. (A) Schematic illustration showing in vivo α-CGRP KO strategy (created with https://BioRender.com). (B) Immunofluorescence and 3D views of α-CGRP expression in ILC2s from WT mice and Calca-KO mice. Scale bar, 10 µm. (C) Schematic illustration showing in vitro co-culture experiment of ILC2s with bEnd.3 cells (created with https://BioRender.com). (D–F) Mouse-derived cell assay and quantified results of endothelial tube formation. Data are shown as bar plots (SD, median), analyzed by one-way ANOVA with Tukey’s multiple comparisons. ***P = 0.0002; ****P < 0.0001; ns indicates P > 0.05. Scale bar, 100 µm. (G–I) Mouse-derived cell assay and quantified results of endothelial sprouting. Data are shown as bar plots (SD, median), analyzed by one-way ANOVA with Tukey’s multiple comparisons. ***P = 0.0003; ****P < 0.0001; ns indicates P > 0.05. Scale bar, 250 µm. (J) Schematic illustration showing in vivo validation of angiogenic effect in WT or Calca-KO ILC2s at day 5 after MCAO and ILC2 infusion. Calca-KO ILC2s were labeled with CFSE (created with https://BioRender.com). (K and L) Immunofluorescence and quantification (n = 3) of labeled cell number in ischemic area of a mouse brain at day 5 after MCAO and CFSE-labeled Calca-KO ILC2s transfer, analyzed by two-sided, unpaired Student’s t test. Data are from biological replicates and represent two independent experiments. P > 0.05. Scale bars, 100 µm (50 µm for zoomed out). (M and N) Morphometric quantification (n = 5) of angiogenic sprouting and by calculating the number of tip cells and endothelial cells with filopodia per 40× view, analyzed by two-sided, unpaired Student’s t test. Data are from biological replicates and represent two independent experiments. ***P = 0.0007.