Fig. 4

Cell–cell interaction between venous BECs and Tcm. a The activation status of biological processes related to leukocyte migration was assessed by calculating their NES using GSEA. Shown are the biological processes associated with leukocyte migration that were predicted to be activated in arterial capillary, capillary, and vein clusters. b Dot plot showing the upregulated genes in the term lymphocyte migration across different vascular segments. Dot size means the power of gene pairs by summing up the log₂(fold change) values of participating genes. Dot color means the aggerated confidence for gene pairs. c Dot plot depicting the interaction between T cells and BECs from different vascular segments. Node size represents the count of interaction pairs and node color represents the power of interaction pairs. d Dot plot showing the gene pairs between venous BECs and central memory T cells. Gene pairs with p-value < 0.05 in permutation test are fetched. Dot color represents the power of gene pairs by multiplying the expression levels of participating genes. e Expression profiles of Itgb1 and Itgb2 in both young and aged CD8⁺ T cells are shown using the UMAP visualization approach. f Violin plots showing expression of Itgb1 and Itgb2 in young and aged CD8⁺ T cells. g–h Representative confocal microscopic images and quantification of VCAM1 (g), ICAM1 h colocalization with CD31 in four young (6–8 weeks old) and four aged (18 months old) male mice. Nuclei are labeled with DAPI. Scale bars: 50 μm. **P = 0.0096 (g), ***P = 0.0008(h), two-tailed Student’s t test. Data are shown as mean ± s.e.m.