Cell culture and transfection

H9c2 cells (ATCC, CRL‐1446™) were cultured in DMEM (Thermofisher, Waltham, MA, USA) supplemented with 10% FBS and 100 μg/ml of each of penicillin and streptomycin (Thermofisher) at 37°C with 5% CO₂. The CD38 knockdown H9c2 stable cell line was prepared as we described previously 16. In different experiments, different cell numbers were used. The cells used for RNA and total protein detection were seeded at 5 × 10⁵ cells/3.5 cm dish for 48 hrs Ang‐II treatment, while only 1 × 10⁵ cells/3.5 cm dish were seeded for Crystal violet staining. In the experiments that need only 20‐min. Ang‐II treatment, 1 × 10⁶ cells/3.5 cm dish were used.