Fig. 7

MKL1, TNC and FLNA correlation analysis using GTEx data and immunohistochemical colocalization of caveolin-1/CAV1 and TNC in healthy and diseased human kidneys. Human kidney expression data were retrieved from the GTExPortal and MKL1 expression levels were correlated with caveolin-1/CAV1 (a), caveolin-2/CAV2 (b) and TNC (c) using the Spearman test. Spearman Rho values and P-values are given in each panel. TNC (d) and FLNA (e) expression levels also correlated with caveolin-1/CAV1. Panels F through H show human kidney tissue co-stained for TNC (brown) and caveolin-1/CAV1 (red). In (f) and (g), staining of normal kidney tissue is shown. Caveolin-1/CAV1 expression is limited to PECs (black arrowhead), smooth muscle cells of the arterial media (black arrow) and endothelial cells (white arrow). PECs also co-express TNC as shown by the presence of both brown and red staining in panel G which shows Bowman’s capsule at high magnification with a distinct, but thin, linear basal TNC band. In h, kidney tissue demonstrating signs of tubular atrophy due to nephrosclerosis is shown. Here, a diffuse reticular and interstitial TNC deposition is seen (brown). Adjacent tubules show signs of atrophy in the form of epithelial simplification and loss of tubular width. Caveolin-1/CAV1 is expressed in the injured tubules. Caveolin-1/CAV1 positive (red) proximal tubular cells (PT) resting on a TNC-positive matrix (brown) are shown at higher magnification in the inset of panel (h). All specimens were counterstained with hematoxylin. Scale bars in f and h = 100 μm. Scale bar of inset in h = 50 μm. Scale bar in g = 75 μm