Fig. 3: Pericytes dissociated from microvessels with increased α-SMA expression during CCM lesion formation.

a, b P60 cerebrum sections from WT and the moderate CCM model of Pdcd10^BECKO mice were stained for CD31 with NG2, VE-cadherin (VE-cad), or claudin-5 (Cldn5). Representative images of normal EC junction/EC-pericyte association (arrowheads) and disrupted EC junction/EC-pericyte association (arrows) within CCM lesions (asterisks) are shown (a). % of NG2, VE-cadherin, and claudin-5 coverage on CD31 vessels, i.e., % green (NG2, VE-cad, or Cldn5)-conjugated area/total red (CD31) areas was quantified by Image J (b), n = 10. P < 0.0001 (unpaired two-sided Student’s t-test). Data are presented as mean ± SEM. c–f Pericyte phenotype characterization in early CCM lesions. c An early lesion model. Pdcd10^BECKO pups were fed with tamoxifen at P1 to P3 and tissues were harvested at P15. d Brain sections from WT and Pdcd10^BECKO mice were co-stained with CD31, α-SMA, and NG2. Images were captured under SP8 STED microscopy. Representative images for WT normal vessels and CCM lesions in Pdcd10^BECKO mice are shown. n = 6. α-SMA was undetectable in EC or pericyte of WT vessels (arrowhead). α-SMA⁺ cells were co-localized with NG2⁺ pericyte but not with CD31⁺ EC within a lesion (arrows). e, f Retinas from WT and Pdcd10^BECKO pups at P15 were whole-mount stained with CD31, α-SMA, and NG2. Images were captured under confocal microscopy. Representative low power (e) and high-power (f) images for WT and Pdcd10^BECKO mice are shown. n = 6. α-SMA was expressed in artery and weakly in vein, but undetectable in WT microvessels (arrowhead). α-SMA was dramatically increased in CCM lesions of Pdcd10^BECKO retina (asterisks). Scale bar: 25 μm (a); 8 μm (d); 100 μm (e); 5 μm (f). Source data are provided as a Source data file.