TRPA1deficiency aggravates dilated cardiomyopathy by promotingS100A8expression to induceM1macrophage polarization in rats

Abstract Transient receptor potential ankyrin 1 (TRPA1) plays an important role in different cardiovascular diseases. However, the role of TRPA1 in dilated cardiomyopathy (DCM) remains unclear. Here, we aimed to investigate the role of TRPA1 in DCM induced by doxorubicin (DOX) and explore its possible mechanisms. GEO data were used to explore the expression of TRPA1 in DCM patients. DOX (2.5 mg/kg/week, 6 weeks, i.p.) was used to induce DCM. Bone marrow‐derived macrophages (BMDMs) and neonatal rat cardiomyocytes (NRCMs) were isolated to explore the role of TRPA1 in macrophage polarization, cardiomyocyte apoptosis, and pyroptosis. In addition, DCM rats were treated with the TRPA1 activator, cinnamaldehyde to explore the possibility of clinical translation. TRPA1 expression was increased in left ventricular (LV) tissue in DCM patients and rats. TRPA1 deficiency aggravated the cardiac dysfunction, cardiac injury, and LV remodeling in DCM rats. In addition, TRPA1 deficiency promoted the M1 macrophage polarization, oxidative stress, cardiac apoptosis, and pyroptosis induced by DOX. RNA‐seq results showed that TRPA1 knockout promoted the expression of S100A8, an inflammatory molecule that belongs to the family of Ca 2+ ‐binding S100 proteins, in DCM rats. Furthermore, S100A8 inhibition attenuated M1 macrophage polarization in BMDMs isolated from TRPA1 deficiency rats. Recombinant S100A8 promoted the apoptosis, pyroptosis, and oxidative stress in primary cardiomyocytes stimulated with DOX. Finally, TRPA1 activation via cinnamaldehyde alleviated the cardiac dysfunction and reduced S100A8 expression in DCM rats. Taken together, these results suggested that TRPA1 deficiency aggravates DCM by promoting S100A8 expression to induce M1 macrophage polarization and cardiac apoptosis.