The mechanosensitive Piezo1 channel exacerbates myocardial ischaemia/reperfusion injury by activating caspase-8-mediated PANoptosis.

PANoptosis is a newly discovered type of cell death characterized by pyroptosis, apoptosis and/or necroptosis and has been implicated in the inflammatory response. Piezo1 is a mechanosensitive ion channel that plays important roles in physiological development and various diseases. However, whether cardiomyocytes undergo PANoptosis during myocardial ischaemia/reperfusion (I/R) injury and the role of Piezo1 in this process remain largely unexplored. In this study, our results revealed that the expression levels of the main components of the PANoptosome, including caspase-8, caspase-3, NLRP3, caspase-1, GSDMD, RIPK1, RIPK3 and MLKL, were significantly upregulated in I/R heart tissues over time, indicating the occurrence of PANoptosis in I/R hearts. Accordingly, Piezo1 expression was significantly upregulated in I/R-injured hearts and hypoxia/reoxygenation (H/R)-treated cardiomyocytes. In contrast, pharmacological inhibition of Piezo1 by the inhibitor GsMTx4 in mice markedly attenuated the I/R-mediated decline in cardiac contractile function and increases in infarct size, apoptosis, oxidative stress and inflammation accompanied by the inhibition of PANoptosis-related mediators in I/R hearts. Consistently, the effects of Piezo1 on calcium influx and PANoptosis were further verified by GsMTx4 and Piezo1 activator Yoda1 in H/R-treated cardiomyocytes in vitro. Moreover, caspase-8 rather than calcium influx was required for H/R-induced PANoptosis in vitro. Mechanistically, Piezo1 interacts with caspase-8, a key initial activator of the PANoptosome complex, which subsequently activates cardiomyocyte PANoptosis, leading to cardiac dysfunction. In summary, these data suggest that Piezo1 is a new cardiac mechanosensor that promotes cardiac I/R injury possibly through the caspase-8-mediated activation of cardiomyocyte PANoptosis and highlight that Piezo1 may represent a new target for treating ischaemic heart disease.

N-arachidonoylphenolamine alleviates ischaemia/reperfusion-induced cardiomyocyte necroptosis by restoring proteasomal activity.

Necroptosis and apoptosis contribute to the pathogenesis of myocardial ischaemia/reperfusion (I/R) injury and subsequent heart failure. N-arachidonoylphenolamine (AM404) is a paracetamol lipid metabolite that has pleiotropic activity to modulate the endocannabinoid system. However, the protective role of AM404 in modulating I/R-mediated myocardial damage and the underlying mechanism remain largely unknown. A murine I/R model was generated by occlusion of the left anterior descending artery. AM404 (20 mg/kg) was injected intraperitoneally into mice at 2 and 24 h before the I/R operation. Our data revealed that AM404 administration to mice greatly ameliorated I/R-triggered impairment of myocardial performance and reduced infarct area, myocyte apoptosis, oxidative stress and inflammatory response accompanied by the reduction of receptor interacting protein kinase (RIPK)1/3- mixed lineage kinase domain-like (MLKL)-mediated necroptosis and upregulation of the immunosubunits (ß2i and ß5i). In contrast, administration of epoxomicin (a proteasome inhibitor) dramatically abolished AM404-dependent protection against myocardial I/R damage. Mechanistically, AM404 treatment increases ß5i expression, which interacts with Pellino-1 (Peli1), an E3 ligase, to form a complex with RIPK1/3, thereby promoting their degradation, which leads to inhibition of cardiomyocyte necroptosis in the I/R heart. In conclusion, these findings demonstrate that AM404 could prevent cardiac I/R damage and may be a promising drug for the treatment of ischaemic heart disease.

Molecular mechanism of rhubarb in treatment of acute pancreatitis based on network pharmacology and molecular docking / 中国药理学通报

Aim To analyze the molecular mechanism of rhubarb in the treatment of aeute pancreatitis ( AP) by network pharmacology and molecular docking.Methods TCMSP,TCMID and Swiss target predic¬tion databases were used to screen the active compo¬nents and targets of rhubarb,and genecards and OMIM databases were used to screen the targets of AP.Then the active ingredient drug target network of rhubarb and theactive ingredient disease target network of rhubarb for AP were constructed by using Cytoscape software.PPI network was constructed in string database, and go and KEGG enrichment analysis was performed in metascape database and R language.Finally,molecular docking was used to verify the possibility of binding the core active components to the core target.Results A total of 192 active components and 1 882 AP targets were obtained.The first three active components of rhubarb in the treatment of AP were beta sitosterol, aloe emodin and eupatin.The core target of rhubarb in the treatment of AP was hsp90aal.Go enrichment analysis focused on reaction to toxic substances, while KEGG enrichment analysis was significantly enriched in p53 signaling pathway closely related to AP.Molecular docking showed good binding and stable conformation.Conclusions Rhubarb can affect the expression of AP related genes and proteins through p53 signaling pathway, thereby inhibiting cell apoptosis and allevia¬ting the inflammatory injury of AP.

The biological information and experimental verification of studying on Qingjie HuaGong decoction inhibiting inflammatory response of SAP model rats induced by cerulein based on TLR4/NF-kB/MYD88 pathway / 中国药理学通报

Aim To study the protective effect of Qingjie HuaGong decoction ( QJHGD) for severe acute pancreatitis ( SAP ) model rats induced by cerulein based on TLR4/NF-kB/MYD88 pathway.Methods The effective component groups and potential targets of QJHGD were collected by network pharmacology method , and we constructed the component-target network.The GO and KEGG of important targets were enriched and analyzed by metascape database, and we selected the targeted pathways related with SAP inflammation mechanism.The rat model of severe acute pancreatitis was established by cerulein combined with lipopolysac- charide, followed by QJHGD gavage.Pancreatic tissues were observed by hematoxylin and eosin staining.We verified the therapeutic effect of QJHGD on SAP rats and the regulatory effect on TLR4/NF-kB/MyD88 target pathway, by Enzyme linked immunosorbent and immunohistochemistry methods.Results A total of 105 active components and 148 key targets for SAP were screened; KEGG was enriched 320 different channels including toll like receptor and NF-kB classical pathways.Animal experiments showed that QJHGD harl protective changes in pancreatic pathological tissues, which was observed by HE staining; QJHGD reduced amylase, lipase, 1L-6 and TNF-a in SAP rat serum, inhibiting the positive expression of key proteins on TLR4/N F- kB/MyD88 inflammatory transduction j j pathways.Conclusion The mechanisms of QJHGD protecting pancreatic injury of SAP rat may be related to reducing the expression of key proteins on TLR4/ NF-kB/MvD88 pathway.