Antifade mounting medium

5-μm cryostat sections of hearts were fixed in 4% paraformaldehyde for 10 min, and processed for immunofluorescence staining as previously described [65 (link)]. The sections were blocked by 10% bovine serum albumin for 30 min and stained with vimentin (1:50, abcam) or collagen type I (1:50, boster) for 1 hour at 37°C. Afterwards, the sections were washed 3 times in PBS and incubated with Alexa 488 or 549-conjugated goat anti-rabbit secondary antibodies (Rockland) for 1 h at room temperature. Nuclei were stained with DAPI. Slices were mounted with antifade mounting medium (Applygen, China) and analyzed using Olympus microscope (IX51).

Cryostat sections (5 μm) of hearts were fixed in 4% paraformaldehyde for 10 minutes, and processed for immunostaining as previously described.32 The H9c2 cells cultured on six‐well glass chamber slides were fixed in 4% paraformaldehyde, blocked by 10% bovine serum albumin for 30 minutes and stained with antibodies overnight at 4°C. Afterwards, the sections were washed 3 times in PBS and incubated with Alexa 549‐conjugated goat anti‐rabbit antibodies (Rockland) for 1 hour at room temperature. Nuclei were stained with DAPI. Slices were mounted with antifade mounting medium (Applygen, China) and analysed using Olympus microscope (IX51).