Catecholamine Surges Cause Cardiomyocyte Necroptosis via a RIPK1–RIPK3-Dependent Pathway in Mice

Abstract

Background: Catecholamine surges and resultant excessive β-adrenergic stimulation occur in a broad spectrum of diseases. Excessive β-adrenergic stimulation causes cardiomyocyte necrosis, but the underlying mechanism remains obscure. Necroptosis, a major form of regulated necrosis mediated by RIPK3-centered pathways, is implicated in heart failure; however, it remains unknown whether excessive β-adrenergic stimulation-induced cardiac injury involves necroptosis. Hence, we conducted the present study to address these critical gaps.Methods and Results: Two consecutive daily injections of isoproterenol (ISO; 85 mg/kg, s.c.) or saline were administered to adult mixed-sex mice. At 24 h after the second ISO injection, cardiac area with Evans blue dye (EBD) uptake and myocardial protein levels of CD45, RIPK1, Ser166-phosphorylated RIPK1, RIPK3, and Ser345-phosphorylated MLKL (p-MLKL) were significantly greater, while Ser321-phosphorylated RIPK1 was significantly lower, in the ISO-treated than in saline-treated wild-type (WT) mice. The ISO-induced increase of EBD uptake was markedly less in RIPK3−/− mice compared with WT mice (p = 0.016). Pretreatment with the RIPK1-selective inhibitor necrostatin-1 diminished ISO-induced increases in RIPK3 and p-MLKL in WT mice and significantly attenuated ISO-induced increases of EBD uptake in WT but not RIPK3−/− mice.Conclusions: A large proportion of cardiomyocyte necrosis induced by excessive β-adrenergic stimulation belongs to necroptosis and is mediated by a RIPK1–RIPK3-dependent pathway, identifying RIPK1 and RIPK3 as potential therapeutic targets for catecholamine surges.

Inflammatory Forms of Cardiomyocyte Cell Death in the Rat Model of Isoprenaline-Induced Takotsubo Syndrome

“…The pathological increase in the concentration of circulating catecholamines and their excessive release from the cardiac sympathetic nerve endings lead to direct damage to the cardiomyocytes [30]. The pathophysiological mechanisms involved in catecholamineinduced myocardial injury include increased oxygen demand of the cardiomyocytes with insufficient supply, oxidative stress, calcium overload, myofibril over-contraction, and upregulation of the expression and release of inflammatory cytokines [31][32][33][34][35][36][37][38][39][40][41][42]. Indeed, histopathological examinations of the myocardium of rats treated with supraphysiological doses of catecholamines showed focal necrosis and degeneration of the cardiomyocytes, disordered myofibrils, advanced cytoplasmic vacuolization, myocardial infiltration with inflammatory cells, and tissue fibrosis [43][44][45].…”

“…Indeed, histopathological examinations of the myocardium of rats treated with supraphysiological doses of catecholamines showed focal necrosis and degeneration of the cardiomyocytes, disordered myofibrils, advanced cytoplasmic vacuolization, myocardial infiltration with inflammatory cells, and tissue fibrosis [43][44][45]. Necrosis is the major pathological feature of catecholamine-induced myocardial injury [42,46]. However, recently, Wu et al (2021) have proven that, in adult mixed-sex mice injected subcutaneously with ISO, a large proportion of cardiomyocyte necrosis induced by ISO is driven by necroptosis and is mediated by the RIPK1-RIPK3-MLKL pathway.…”

“…However, recently, Wu et al (2021) have proven that, in adult mixed-sex mice injected subcutaneously with ISO, a large proportion of cardiomyocyte necrosis induced by ISO is driven by necroptosis and is mediated by the RIPK1-RIPK3-MLKL pathway. Moreover, these authors have proven that targeting RIPK1 or RIPK3 can significantly attenuate ISO-induced necrosis [42]. To the best of our knowledge, the activation of the necroptosis pathway has not yet been investigated in TTS.…”

Cardiomyocyte alpha-1A adrenergic receptors mitigate post-infarct remodeling and mortality by constraining necroptosis

“…The peri-infarct period is characterized by elevated levels of endogenous catecholamines(46) that activate ARs on cardiomyocytes. High concentrations of the -AR agonist isoproterenol (85 mg/kg s.c.) induce cardiomyocyte necrosis with induction of RIP1 and RIP3 in mice (47), suggesting that -AR hyperactivation may promote necroptosis to contribute to the pathobiology of MI. Regulation of necroptosis by 1-ARs has not been studied previously.…”

mTORC1 hyperactivation and resultant suppression of macroautophagy contribute to the induction of cardiomyocyte necroptosis by catecholamine surges

“…Therefore, further investigation into the role of mTORC1 signaling in ISO‐induced myocardial injury and deciphering whether mTORC1‐regulated macroautophagy is potentially involved are warranted. Additionally, our previous study showed that a large proportion of cardiomyocyte necrosis induced by high doses of ISO was necroptosis mediated by the RIPK1–RIPK3–MLKL pathway (Wu et al., 2021 ). The effect of mTORC1 in the induction of cardiomyocyte necroptosis by ISO remains unexamined although some reports suggested a potential association between mTORC1 and RIPK1–‐RIPK3–MLKL necroptotic pathway induced by other etiologies (Abe et al., 2019 ; Liu et al., 2014 ; Ogasawara et al., 2017 ; Xie et al., 2020 ).…”