Modulating Lysine Crotonylation in Cardiomyocytes Improves Myocardial Outcomes

Abstract

Background: Ischemic heart disease is a major global public health challenge, and its functional outcomes remain poor. Lysine crotonylation (Kcr) was recently identified as a post-translational histone modification that robustly indicates active promoters. However, the role of Kcr in myocardial injury is unknown. In this study, we aimed to clarify the pathophysiological significance of Kcr in cardiac injury and explore the underlying mechanism. Methods: We investigated the dynamic change of both the Kcr sites and protein level in left ventricular tissues at 2 time points following sham or cardiac ischemia-reperfusion injury, followed by liquid chromatography-coupled tandem mass tag mass spectrometry. After validation of the enriched protein Kcr by immunoprecipitation and Western blot, the function and mechanism of specific Kcr sites were further investigated in vitro and in vivo by gain- or loss-of-function mutations targeting Kcr sites of selected proteins. Results: We found that cardiac ischemia-reperfusion injury triggers preferential Kcr of proteins required for cardiomyocyte contractility, including mitochondrial and cytoskeleton proteins, which occurs largely independently of protein-level changes in the same proteins. Those exhibiting Kcr changes were associated not only with disruption of cardiomyocyte mitochondrial, sarcomere architecture, and gap junction but also with cardiomyocyte autophagy and apoptosis. Modulating site-specific Kcr of selected mitochondrial protein IDH3a (isocitrate dehydrogenase 3 [NAD+] alpha) at K199 and cytoskeletal protein TPM1 (tropomyosin alpha-1 chain) at K28/29 or enhancing general Kcr via sodium crotonate provision not only protects cardiomyocyte from apoptosis by inhibiting BNIP3 (Bcl-2 adenovirus E18 19-kDa–interacting protein 3)-mediated mitophagy or cytoskeleton structure rearrangement but also preserves postinjury myocardial function by inhibiting fibrosis and apoptosis. Conclusions: Our results indicate that Kcr modulation is a key response of cardiomyocytes to ischemia-reperfusion injury and may represent a novel therapeutic target in the context of ischemic heart disease.

TNC Accelerates Hypoxia-Induced Cardiac Injury in a METTL3-Dependent Manner

“…Our teams have also shown that, through modulating the maturation of miR-210 that targets AIFM3 mRNAs, it regulates cardiomyocyte health and the progression of cardiac dysfunction, implicating the differential regulations of miRNA biogenesis in cardiomyocytes under hypoxia [ 29 ]. Epigenetic regulations, not only including miRNAs, DNA methylation, and histone modification, have also been implicated in the myocardial protection process [ 41 , 42 ]. Recently, m 6 A methylation of RNA has also come into prominence as a new important mechanism regulating various biological processes [ 43 , 44 ].…”

Acylations in cardiovascular biology and diseases, what's beyond acetylation

“…Modulating site-specific Kcr of selected mitochondrial protein isocitrate dehydrogenase 3 [NAD+] alpha (IDH3a) at K199 and cytoskeletal protein tropomyosin alpha-1 chain (TPM1) at K28/29 protects cardiomyocytes from apoptosis induced by isoprenaline and cardiac function after I/R injury. 33 It is important to consider that the conclusion largely depends on the mutation of substrate proteins. Whether the mutated lysine sites of IDH3a or TPM1 can be acetylated remains elusive, which is important for excluding the contribution of IDH3a and TPM1 acetylation to the phenotypes observed in this study.…”

Protein acylation: mechanisms, biological functions and therapeutic targets

“… 200 , 201 Histone and nonhistone Kcro have been demonstrated to participate in tumor and ischemic heart disease (IHD) via regulating metabolic enzymatic activity or protein stability. 202 , 203 …”

“…A proteomic analysis revealed that cardiac ischemia-reperfusion injury causes Kcro of proteins associated with cardiomyocyte contractility, resulting in the disruption of cardiomyocyte mitochondrial, sarcomere architecture, and gap junction, as well as the induction of cardiomyocyte apoptosis. 203 The pathological role of Kcro modification on cytoskeletal protein tropomyosin alpha-1 chain (TPM1) and metabolic enzyme IDH3a were further investigated. In detail, Kcro mimicking mutants of IDH3a (K199Q) and TPM1 (K28/29Q) not only protect cardiomyocyte from apoptosis by inhibiting Bcl-2 adenovirus E18 19-kDa-interacting protein 3 (BNIP3)-mediated mitophagy or cytoskeleton structure rearrangement but also preserves post-injury myocardial function by inhibiting fibrosis and apoptosis.…”

“…200,201 Histone and nonhistone Kcro have been demonstrated to participate in tumor and ischemic heart disease (IHD) via regulating metabolic enzymatic activity or protein stability. 202,203 Protein crotonylation in tumor. In recent years, lysine crotonylation was demonstrated to play opposite roles in diverse cancer types by regulating metabolic enzymes or oncogenic proteins.…”