Fig. 5: Identification of a subset of proximal tubular cells that express VCAM1.

a Umap plot displaying VCAM1 gene expression in the snRNA-seq dataset (left), and representative immunohistochemical images of VCAM1 (red) or LTL (Lotus tetragonolobus lectin, green) in the adult kidney (n = 3 patients). Arrowheads indicate the VCAM1+ proximal tubular cells. VCAM1 was expressed in PEC and a subpopulation of LTL+ proximal tubular cells. Scale bar indicates 100 µm (upper right) or 20 µm (lower right). b Immunofluorescence staining for VCAM1 (green), UMOD (red) and LTL (white) in the adult human kidney sections (left, representative image) and quantitation of VCAM1-positive cells on the LTL-positive cells or UMOD-positive cells (right). The quantification was performed in five 200x images randomly taken from each patient (n = 3 patients). Arrowheads indicate VCAM1-positive cells in the LTL-positive PT. Scale bar indicates 100 µm. Box-and-whisker plots depict the median, quartiles and range. ***P < 0.001 (P = 5.47 × 10⁻¹¹, two-sided Student’s t test). c Representative immunohistochemical images of SLC34A1 or AQP1 (blue) and VCAM1 (brown) in the adult human kidneys. An arrowhead marks VCAM1 expression in the DTL and an arrow marks DTL without VCAM1 expression. Scattered brown dots are seen with multiple different antibodies and considered non-specific staining. Scale bar indicates 50 µm. n = 3 samples were independently analyzed and similar results were obtained. d Representative immunostaining images of CD24 or CD133 (red) and VCAM1 (green) in the adult human kidney. Arrowheads indicate VCAM1 co-expression with CD24 or CD133 in PT and arrows mark VCAM1 expression without CD24 or CD133. Scale bar indicates 20 µm. n = 3 samples were independently analyzed and similar results were obtained.