PM2.5-Induced Programmed Myocardial Cell Death via mPTP Opening Results in Deteriorated Cardiac Function in HFpEF Mice

• Published in: Cardiovascular toxicology Vol. 22; no. 8; pp. 746 - 762
• Main Authors: Wu, Tingting, Tong, Minghui, Chu, Aiai, Wu, Kaiyue, Niu, Xiaowei, Zhang, Zheng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2022; Springer; Springer Nature B.V
• Subjects: Animal experimentation; Animals; Apoptosis; Biochemistry; Biomedical and Life Sciences; Biomedicine; Cardiac function; Cardiology; Cardiomyocytes; Cell death; Cell Death - drug effects; Congestive heart failure; Cyclosporin A; DNA damage; Experiments; Health aspects; Heart; Heart failure; Heart Failure - metabolism; Immunoprecipitation; Membrane permeability; Membrane potential; Mice; Mitochondrial Membrane Transport Proteins - metabolism; Mitochondrial Permeability Transition Pore; Myocytes, Cardiac - metabolism; Necrosis; Necrosis - metabolism; Oxidative stress; Particulate Matter - toxicity; Pathology; Peptidyl-Prolyl Isomerase F; Pharmacology/Toxicology; Reactive oxygen species; Stroke Volume; Tumor Suppressor Protein p53 - metabolism; Heart failure with preserved ejection fraction; Fine particulate matter; Mitochondrial permeability transition pore; Programmed necrosis; PM2.5; Cardiac function impairment
• DOI: 10.1007/s12012-022-09753-7
• ISSN: 1530-7905; 1559-0259

PM2.5 exposure can induce or exacerbate heart failure and is associated with an increased risk of heart failure hospitalization and mortality; however, the underlying mechanisms remain unclear. This study focuses on the potential mechanisms underlying PM2.5 induction of cardiomyocyte programmed necrosis as well as its promotion of cardiac function impairment in a mouse model of heart failure with preserved ejection fraction (HFpEF). HFpEF mice were exposed to concentrated ambient PM2.5 (CAP) (CAP group) or filtered air (FA) (FA group) for 6 weeks. Changes in myocardial pathology and cardiac function were documented for comparisons between the two groups. In vitro experiments were performed to measure oxidative stress and mitochondrial permeability transition pore (mPTP) dynamics in H9C2 cells following 24 h exposure to PM2.5. Additionally, co-immunoprecipitation was conducted to detect p53 and cyclophilin D (CypD) interactions. The results showed exposure to CAP promoted cardiac function impairment in HFpEF mice. Myocardial pathology analysis and in vitro experiments demonstrated that PM2.5 led to mitochondrial damage in cardiomyocytes and, eventually, their necrosis. Moreover, our experiments also suggested that PM2.5 increases mitochondrial reactive oxygen species (ROS), induces DNA oxidative damage, and decreases the inner mitochondrial membrane potential (ΔΨm). This indicates the presence of mPTP opening. Co-immunoprecipitation results showed a p53/CypD interaction in the myocardial tissue of HFpEF mice in the CAP group. Inhibition of CypD by cyclosporin A was found to reverse PM2.5-induced mPTP opening and H9C2 cell death. In conclusion, PM2.5 induces mPTP opening to stimulate mitochondria-mediated programmed necrosis of cardiomyocytes, and it might exacerbate cardiac function impairment in HFpEF mice.