Fig. 1: Endovascular injury-induced macrophage accumulation and inflammation in PVAT followed by upregulation of BAT markers.

a Gene expressions of immune cell markers in PVAT 24 h after vascular injury (sham, n = 4 for Cd8, 6 for others; injury, n = 9, two-tailed t tests with Holm-Sidak’s correction for multiple comparisons). b Haematoxylin and eosin (H&E), Elastica van Gieson (EVG) and immunohistochemical staining for F4/80 in the early (day 3) and late (day 14) phases after injury. Blue dashed lines indicate the external elastic lamina. Scale bars represent 100 μm (thick bars) and 50 μm (thin bars). Images are representative of three independent experiments. c Time course of F4/80⁺ cell accumulation in arteries (vessel) and outer tissues mainly composed of PVAT (n = 3, 4, 7, 7, 6 (from left to right) at each group, respectively, one-way analysis of variance (ANOVA) and Tukey–Kramer post-hoc test). d Gene expressions of inflammatory cytokine markers in PVAT 48 h after vascular injury (sham, n = 12, 14, 12, 12, 12, 8, 8, respectively; injury, n = 10, 12, 7, 7, 8, 8, 8, respectively, two-tailed t tests with Holm-Sidak’s correction for multiple comparisons. e Gene expressions of BAT (Ucp1 and Elovl3) and WAT [Rstn (Resistin) and Cfd (Adipsin)] markers in PVAT at 24 and 48 h after injury (sham, n = 6, 8, 8, 8, respectively; injury 24 h, n = 6, 6, 8, 8, respectively; injury 48 h, n = 11, 7, 6, 6, respectively, one-way ANOVA followed by Tukey–Kramer post-hoc test). f In situ hybridization showing Ucp1 mRNA expression 14 days after vascular injury in wild type mice. Scale bars represent 50 μm (thick bars) and 20 μm (thin bars). Images are representative of three independent experiments. g H&E and immunohistochemical staining for UCP1 in injured (3 and 14 days after injury) or sham-operated FAs and outer tissue. Scale bars represent 100 μm (thick bars) and 50 μm (thin bars). Images are representative of three independent experiments. h Time course of UCP1⁺ cells accumulation in PVAT (n = 3, 4, 7, 7, 6 at each group, respectively, one-way ANOVA followed by Tukey–Kramer post-hoc test). i Histograms of adipocyte area of sham-operated or injured PVAT (14 days after injury). Three images of each biological replicate were analyzed and combined to create the histogram. The size distribution between each group was compared using Kolmogorov-Smirnov test. Each bin was normalized to a percent of the total count for that individual tissue. Adipocytes of the bin size in the range of 20-500 μm² were included for the analysis. j Representative images of western blots for UCP1 in arteries (vessel) and outer tissues mainly composed of PVAT harvested 48 h after injury. Intra-scapular BAT was used as a positive control. GAPDH was used for internal control (n = 4 for each group, representative images are shown). k Immunohistochemical staining for F4/80 and UCP1 in outer tissue surrounding FAs 14 days after injury was performed in mice treated with either clodronate or vehicle. Scale bars represent 50 μm. Images are representative of three independent experiments. l F4/80⁺ and UCP1⁺ area in PVAT (vehicle, n = 9; clodronate, n = 4, unpaired two-tailed Student’s t test). Data represent mean ± SEM. Source data are provided as a Source Data file.