Lactate dehydrogenase

Myocardial tissue samples or CFs were harvested, frozen, and homogenized in lysis buffer. The levels of fasting insulin, collagen I and collagen III (Yuanye Biotechnology Co. Ltd., Shanghai, China), lactate dehydrogenase (Beyotime Biotechnology Co. Ltd., Shanghai, China), and ATP (Jiancheng Bioengineering Institute, Nanjing, China) in the homogenates were measured using specific kits. All absorbance values were within the linear range of the standard curve and standardized with the total protein concentration.

OEA, DMSO, PEG300, and Tween-80 were purchased from Sigma Chemical (USA). Tunicamycin (TM) was purchased from MCE (NJ, USA). Dulbecco's modified Eagle's medium (DMEM) and fetal bovine serum (FBS) were purchased from Viva Cell Biosciences (China). RIPA Lysis Buffer, PMSF, Cell Counting Kit-8 (C0037), DAB Horseradish Peroxidase Color Development Kit, lactate dehydrogenase (LDH), Cytotoxicity Assay Kit, and TUNEL Apoptosis Assay Kit (C1086) were purchased from Beyotime (China). PPARα antibody (Cat: 15540-1-AP), Grp78 antibody (Cat: 11587-1-AP), CHOP antibody (Cat: 15204-1-AP), Caspase 12 antibody (Cat: 55238-1-AP), cleaved-Caspase 3 (Cat: 19677-1-AP), Bcl2 (Cat: 12789-1-AP) antibody, Bax antibody (Cat: 50599-2-Ig), β-actin antibody (Cat: 66009-1-Ig), and HRP-conjugated goat anti-mouse/rabbit IgG (SA00001-1/2) were purchased from Proteintech (China). ALT assay kit (C009-2-1) and AST assay kit (C010-2-1) were purchased from Jiancheng Bioengineering Institute (Nanjing, China). Annexin V PE Apoptosis Detection Kit (559763) was purchased from BD Pharmingen (NJ, USA). Lipofectamine™3000 and TRIzol were purchased from Invitrogen. SYBR Green® Premix was purchased from TaKaRa. Chemiluminescent kit was purchased from NCM Biotech (Suzhou, China).

Cell cytotoxicity was evaluated by measuring the release of lactate dehydrogenase (Beyotime, China). After 24 h transfection with Bqu-BepC tagged with Strep and control plasmid (no gene insertion), the cultured supernatant of HEK293T cells was collected and detected using a commercial LDH kit according to the manufacturer’s protocols (Beyotime, China).