D220828

Harvested hearts were embedded in paraffin or stored at −80°C before cutting. The embedded tissues were then sectioned and stained with haematoxylin‐eosin, picrosirius red or Massion's trichrome staining according to the manufacturer's protocols. The interstitial fields without any blood vessels and the perivascular fibrosis from the fields containing vasculature were imaged. For immunohistochemistry, we used antibody against IL‐6 (D220828, Sangon) to detect the protein expression in LV tissues according to the manufacturer's protocols. Image capture was operated using EVOS FL Auto Imaging System (Life Technologies, ThermoFisher Scientific).

The paraffin-embedded tissues were sliced and performed with hematoxylin-eosin (HE), Sirius red, or Masson trichrome staining. The interstitial fields and the perivascular fields containing vasculature were imaged. Immunohistochemistry was performed with antibodies of IL-6 (D220828, Sangon, Shanghai, China), TNF-α (bs-2081R, Bioss, Beijing, China), and ANP and MYH7B (ab225844 and ab172967, Abcam, U.S.). The EVOS FL Auto Imaging System (Life Technologies, ThermoFisher Scientific, Waltham, MA, U.S.) was operated to obtain 3-5 random fields of each image.