Figure 1

Histological and immunohistological assessment of tissue sections from control and fibrotic kidneys. The left (A, C, E and A’, C’, E’) and right panel (B, D, F and B’, D’, F’) show representative sections from two paraffin-embedded biopsies of a non-fibrotic kidney and fibrotic kidney, respectively. (A,B) Whereas Masson’s trichrome stain led to a very mild and only focal positivity in the control kidneys, a more intense staining, was observed in the fibrotic kidney. (C) Immunohistochemistry of the non-fibrotic control kidneys using anti-COL VI antibody (αCol6) revealed some staining in the interstitium and surrounding larger blood vessels. (D) The fibrotic kidneys showed noticeable, αCol6 staining in the fibrotic areas, indicating a prominent upregulation of COL VI in fibrosis. (E) Immunohistochemistry of the non-fibrotic kidneys using the anti-Endotrophin antibody (PRO-C6), did not reveal any staining. (F) The fibrotic kidney section showed a clear Endotrophin signal within the fibrotic foci, particularly those with high COL VI content (1D’ and F’). The subfigures labelled with a mark (e.g. A’) are magnifications of the areas outlined with a square. In the fibrotic kidney, the square outlines the same area in subfigures (B, D and F). The scale bars are 250 µm.