MLKL(Phospho Ser345) Recombinant Rabbit Monoclonal Antibody [43C07]

Aims ASGR1 is a hepatocyte surface glycoprotein receptor that plays a crucial role in maintaining liver homeostasis. This study investigates its role in acute liver injury (ALI) and whether it is associated with the regulation of PANoptosis-like pathway. Materials and methods An LPS/D-Gal-induced ALI model was established using ASGR1 knockout mice. Liver function, inflammation, oxidative stress, mitochondrial function, and PANoptosis-like markers were assessed. In vitro studies on primary hepatocytes examined the effects of ASGR1 knockout or overexpression on ALI, with the ROS inhibitor NAC and NOXs inhibitor DPI used to explore underlying mechanisms. Key findings In the ALI model, ASGR1 expression was decreased, and ASGR1 −/− mice showed lower survival, more severe liver injury, and higher inflammatory cytokine levels. Electron microscopy revealed pronounced cell death–associated morphological changes in ASGR1 −/− hepatocytes under ALI. Using multiple cell death inhibitors, we confirmed that apoptosis and necroptosis were the predominant death modalities, consistent with increased BAX/BCL-2 ratio, cleaved caspase-8, p-RIPK1, p-RIPK3, and p-MLKL. Proteomic analysis revealed that the differentially expressed proteins were predominantly enriched in pathways related to oxidative stress and mitochondrial function. ASGR1 deficiency in ALI led to elevated ROS levels and a marked reduction in mitochondrial membrane potential, both of which were reversed by NOXs inhibition. Importantly, scavenging ROS and inhibiting NOXs substantially mitigated the activation of the PANoptosis-like pathway induced by ASGR1 deficiency. Significance ASGR1 downregulation aggravates ALI via the NOXs–ROS–PANoptosis-like axis, underscoring the pivotal role of ASGR1 in ALI progression.

Background:Chronic heart failure (CHF) is a serious cardiovascular condition. Vascular peroxidase 1 (VPO1) is associated with various cardiovascular diseases, yet its role in CHF remains unclear. This research aims to explore the involvement of VPO1 in CHF.Methods:CHF was induced in rats using adriamycin, and the expression levels of VPO1 and cylindromatosis (CYLD) were assessed. In parallel, the effects of VPO1 on programmed necrosis in H9c2 cells were evaluated through cell viability assays, lactate dehydrogenase (LDH) level measurements, and analysis of receptor-interacting protein kinase 1/receptor-interacting protein kinase 3/mixed lineage kinase domain-like protein (RIPK1/RIPK3/MLKL) pathway-related proteins. The impact of CYLD on RIPK1 protein stability and ubiquitination was also investigated, along with the interaction between VPO1 and CYLD. Additionally, cardiac structure and function were assessed using echocardiography, Hematoxylin-eosin (HE) staining, Masson staining, and measurements of myocardial injury-related factors, including N-terminal prohormone of brain natriuretic peptide (NT-proBNP), Aspartate aminotransferase (AST), LDH, and creatine kinase-myocardial band (CK-MB).Results:VPO1 expression was upregulated in CHF rats and in H9c2 cells treated with adriamycin. In cellular experiments, VPO1 knockdown improved cell viability, inhibited necrosis and the expression of proteins associated with the RIPK1/RIPK3/MLKL pathway. Mechanistically, VPO1 promoted cardiomyocyte programmed necrosis by interacting with the deubiquitinating enzyme CYLD, which enhanced RIPK1 ubiquitination and degradation, leading to activation of the RIPK1/RIPK3/MLKL signaling pathway. At animal level, overexpression of CYLD counteracted the cardiac failure, cardiac hypertrophy, myocardial injury, myocardial fibrosis, and tissue necrosis caused by VPO1 knockdown.Conclusions:VPO1 exacerbates cardiomyocyte programmed necrosis in CHF rats by upregulating CYLD, which activates the RIPK1/RIPK3/MLKL signaling pathway. Thus, VPO1 may represent a potential therapeutic target for CHF.