Lithospermic acid alleviates myocardial ischemia/reperfusion injury by inhibiting mitophagy via the Piezo1-PPP3/calcineurin-TFEB pathway

Abstract

Introduction: Myocardial ischemia/reperfusion injury poses a human health threat, and lithospermic acid (LA) has shown potential as a therapeutic agent.

Objectives: To investigate the preventive effects of LA and elucidate its modulation of Piezo-Type Mechanosensitive Ion Channel Component 1 .

Methods: Cardiac function was evaluated using cardiac ultrasound, Evans blue/TTC staining, and hematoxylin-eosin staining. To evaluate the effects of LA on cardiomyocyte inflammation, necroptosis, and mitophagy, we performed immunofluorescence, Western blotting, flow cytometry, and RT-qPCR. Additionally, RNA sequencing, cellular thermal shift assay, small molecule agonists/inhibitors, and cardiomyocyte-specific Piezo1 knockout mice were employed to further elucidate the molecular mechanisms and confirm that LA targeted Piezo1 to alleviate myocardial I/R injury.

Results: LA treatment markedly ameliorated myocardial I/R injury. This improvement correlated with reduced inflammation, decreased accumulation of reactive oxygen species, attenuated cardiomyocyte necroptosis, and inhibited mitophagy. Mechanistically, LA reduced calcium influx and inhibited mitophagy in cardiomyocytes, which contributed to the observed alleviation of inflammation, lower ROS levels, and decreased cell necrosis. Further studies revealed that LA targeted Piezo1, suppressing calcium influx, decreasing calcineurin activity, and modulating nuclear translocation of transcription factor EB to inhibit mitophagy. Notably, the beneficial effects of LA on myocardial I/R injury were partially abolished in Piezo1 cardiomyocyte-specific knockout mice, underscoring the crucial role of Piezo1 in mediating the therapeutic effects of LA.

Conclusion: These findings highlight LA is a prospective therapeutic agent to improve cardiac function after myocardial I/R injury, offering a new direction for regulating Piezo1.