*4.7. Immunofluorescence*

For in vivo experiments, paraffin-embedded 4-μm sections of obstructed kidneys were deparaffinized with xylene, rehydrated with graded alcohols and boiled in a 10-mM citrate buffer. Thereafter, the sections were blocked with hydrogen peroxide and then reacted with primary antibodies against F4/80 (1:100, Cat#MCA497R, Abd Serotec, Oxford, UK), CD206 (1:100, Cat#60143-1-Ig, Proteintech Group), CLEC7A (1:50, Cat#MBS9414183, MyBiosource, San Diego, CA, USA) or SLAM (1:100, Cat#ab156288, Abcam) at 4 ◦C overnight. Fluorescein isothiocyanate-conjugated goat anti-rat immunoglobulin G (IgG, 1:250, Cat#112-095-003, Jackson ImmunoResearch) and Alexa Fluor 647-conjugated donkey anti-mouse IgG (1:250, Cat# 715-605-151, Jackson ImmunoResearch) were used to visualize the location of F4/80 and CD206, respectively. Alexa Fluor 568-conjugated goat anti-rabbit IgG (1:250, Cat#A11011, Thermo Fisher Scientific) was used to visualize the location of CLEC7A and SLAM. Slides were then mounted with Fluoroshield Mounting Medium with DAPI (ab104139, Abcam).

For in vitro experiments, TGF-β1-stimulated NRK-52E cells were plated in chamber slides (μ-Slide 8-Well, Ibidi, Munich, Germany) for 1, 2 and 4 days in the presence or absence of trichostatin. Afterwards, the chamber slides were fixed with 4% paraformaldehyde for 10 min and blocked with 1% bovine serum albumin for 30 min. Thereafter, slides were incubated with primary antibodies against α-SMA (1:200, ab5694, Abcam) or fibronectin (1:200, 15613-1-AP, Proteintech) at 4 ◦C overnight, reacted with Alexa Fluor 568-conjugated goat anti-rabbit secondary antibody (1:200, Cat#A11011, Thermo Fisher Scientific) and then counterstained with DAPI (ab104139, Abcam).
