Cells isolation and culture

Primary human aortic smooth muscle cells (HASMCs) were harvested from healthy ascending aortas of donors during heart transplantation surgeries as previously described (Chen et al. 2020). This study was approved by the Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Review Board. The aortic wall was transferred to the laboratory in prechilled DME/F12 medium (SH30023.01, HyClone) as soon as the tissue was isolated from the donors. After carefully peeling off the intima and adventitia of the aorta, the media was torn into 3–5 layers with micro tweezers in cold DME/F12 medium. Then, the peeled and thin media of the aorta was transferred into a culture flask and cut into 1 mm tissue blocks, which were spread evenly on the bottom of the flask with scissors. The flask was subsequently placed in the incubator and stood upright for 30–40 min. After making sure the tissue blocks attached to the wall of the flask, 7 mL DME/F12 medium containing 10% fetal bovine serum (SH30084.03, Hyclone) and 1% penicillin-streptomycin (15140-122, Thermo Fisher Scientific) was add into the culture flask. After 1 week, some spindle-shaped smooth muscle cells could be observed around the tissue pieces. When the HASMCs grew to a suitable density, they were digested with trypsin and transferred to ordinary culture dishes for experiments and passaged every 2–3 days.