The sarcomeric interaction of α-myosin heavy chain (α-MHC) with Titin is vital for cardiac structure and contraction. However, the mechanism regulating this interaction in normal and failing hearts remains unknown. Lactate is a crucial energy substrate of the heart. Here, we identify that α-MHC undergoes lactylation on lysine 1897 to regulate the interaction of α-MHC with Titin. We observed a reduction of α-MHC K1897 lactylation in mice and patients with heart failure. Loss of K1897 lactylation in α-MHC K1897R knock-in mice reduces α-MHC–Titin interaction and leads to impaired cardiac structure and function. Furthermore, we identified that p300 and Sirtuin 1 act as the acyltransferase and delactylase of α-MHC, respectively. Decreasing lactate production by chemical or genetic manipulation reduces α-MHC lactylation, impairs α-MHC–Titin interaction and worsens heart failure. By contrast, upregulation of the lactate concentration by administering sodium lactate or inhibiting the pivotal lactate transporter in cardiomyocytes can promote α-MHC K1897 lactylation and α-MHC–Titin interaction, thereby alleviating heart failure. In conclusion, α-MHC lactylation is dynamically regulated and an important determinant of overall cardiac structure and function. Excessive lactate efflux and consumption by cardiomyocytes may decrease the intracellular lactate level, which is the main cause of reduced α-MHC K1897 lactylation during myocardial injury. Our study reveals that cardiac metabolism directly modulates the sarcomeric structure and function through lactate-dependent modification of α-MHC.

Poly(ADP-ribose) polymerase 1 (PARP1) has a major regulatory role in cardiovascular disease. However, inhibiting PARP1 activity does not significantly improve clinical outcomes of cardiovascular disease, which suggests that the regulatory mechanism of PARP1 in cardiovascular disease is unclear. Here, we focused on deacetylation regulatory mechanisms of PARP1 and crosstalk of PARP1 post-translational modifications. We uncovered the crucial molecular interactions and protein modifications of deacetylase Sirtuin 2 (SIRT2) and PARP1 in vascular damage. The results showed that SIRT2 was involved in this process and oxidative stress damage factor PARP1 was a novel physiological substrate of SIRT2. SIRT2 interacted with PARP1 at the PARP-A-helical domain and deacetylated the K249 residue of PARP1. Furthermore, SIRT2 promoted ubiquitination of the K249 residue of PARP1 via mobilization of the E3 ubiquitin ligase WW domain-containing protein 2 (WWP2), which led to proteasome-mediated degradation of PARP1. Knockout of SIRT2 in mice and cells increased PARP1 acetylation and decreased PARP1 ubiquitination, which in turn aggravated oxidative stress-induced vascular injury and remodeling. Conversely, overexpression of SIRT2 in mice and cells decreased PARP1 acetylation, increased PARP1 ubiquitination, and relieved oxidative stress-induced vascular injury and remodeling. Overall, this study revealed a previously unrecognized mechanistic link between SIRT2 and PARP1 in the regulation of oxidative stress-induced vascular injury.

Tyrosine phosphorylation by protein tyrosine kinases (PTKs) is a type of post-translational modification. Tec kinases, which are a subfamily of non-receptor PTKs, were originally discovered in the hematopoietic system and include five members: Tec, Btk, Itk/Emt/Tsk, Etk/Bmx, and Txk/Rlk. With the progression of modern research, certain members of the Tec family of kinases have been found to be expressed outside the hematopoietic system and are involved in the development and progression of a variety of diseases. The role of Tec family kinases in cardiovascular disease is receiving increasing attention. Tec kinases are involved in the occurrence and progression of ischemic heart disease, atherosclerosis, cardiac dysfunction associated with sepsis, atrial fibrillation, myocardial hypertrophy, coronary atherosclerotic heart disease, and myocardial infarction and post-myocardial. However, no reviews have comprehensively clarified the role of Tec kinases in the cardiovascular system. Therefore, this review summarizes research on the role of Tec kinases in cardiovascular disease, providing new insights into the prevention and treatment of cardiovascular disease.