Background: The aim of this study was to investigate whether calcium-sensing receptor (CaSR) was involved in HRF-mediated exacerbation of MI/R injury through NLRP3 inflammasome activation and pyroptosis. Methods: In vivo, a rat MI/R model was established by ligating the left coronary artery, and short-term HRF exposure was induced during reoxygenation. Then, TUNEL, H&E, Masson staining, immunohistochemical (IHC) and serum levels of lactate dehydrogenase (LDH) and creatine kinase isoenzyme (CK), as well as the expression levels of CaSR and pyroptosis-related proteins in heart tissues, were measured. H9c2 cells were cultured to create a hypoxia/reoxygenation (H/R) model and exposed to different concentrations of RF. After pretreatment with the CaSR activator gadolinium chloride (GdCl3) and inhibitor NPS2143 in the H/R model and treatment with HRF, we compared cellular viability, TUNEL, cytosolic [Ca2+]i, the levels of LDH and CK, pyroptosis-related proteins and CaSR in H9c2 cells. We further researched the mechanisms of CaSR-mediated pyroptosis in the H/R+HRF model by CaSR-shRNA, Ac-YVAD-CMK, MCC950 and NAC. Results: We found that HRF significantly increased CaSR expression, rate of cell death, levels of CK and LDH, and exacerbated pyroptosis in MI/R model. In vitro, HRF increased CaSR expression, decreased viability, enhanced cytosolic [Ca2+]i and exacerbated pyroptosis in H/R cells. Pretreated with GdCl3 worsen these changes, and NPS2143, MCC950, Ac-YVAD-CMK, NAC and sh-CaSR can reversed these effects. Conclusion: Exposure to HRF for a short time exacerbates MI/R-induced injury by targeting CaSR to increase cytosolic [Ca2+]i and ROS levels, which mediate the NLRP3 inflammasome and pyroptosis.

中文翻译：

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高剂量瑞芬太尼通过激活钙敏感受体介导的焦亡而加剧心肌缺血再灌注损伤。

背景：本研究的目的是探讨钙敏感受体（CaSR）是否通过 NLRP3 炎性体激活和细胞焦亡参与 HRF 介导的 MI/R 损伤加重。方法：在体内，结扎左冠状动脉建立大鼠MI/R模型，复氧时诱导短期HRF暴露。然后检测心脏组织中TUNEL、H&E、Masson染色、免疫组化（IHC）和乳酸脱氢酶（LDH）和肌酸激酶同工酶（CK）的血清水平，以及CaSR和细胞焦亡相关蛋白的表达水平。培养 H9c2 细胞以创建缺氧/复氧 (H/R) 模型，并暴露于不同浓度的 RF。在 H/R 模型中用 CaSR 激活剂氯化钆 (GdCl3) 和抑制剂 NPS2143 预处理并用 HRF 处理后，我们比较了细胞活力、TUNEL、胞质 [Ca2+]i、LDH 和 CK 水平、细胞焦亡相关蛋白和H9c2 细胞中的 CaSR。我们通过CaSR-shRNA、Ac-YVAD-CMK、MCC950和NAC进一步研究了H/R+HRF模型中CaSR介导的焦亡机制。结果：我们发现 HRF 显着增加 MI/R 模型中的 CaSR 表达、细胞死亡率、CK 和 LDH 水平，并加剧细胞焦亡。在体外，HRF 增加了 H/R 细胞中 CaSR 的表达，降低了活力，增强了胞质 [Ca2+]i 并加剧了细胞焦亡。用 GdCl3 预处理会加剧这些变化，而 NPS2143、MCC950、Ac-YVAD-CMK、NAC 和 sh-CaSR 可以逆转这些影响。结论：短时间接触 HRF 通过靶向 CaSR 增加胞质 [Ca2+]i 和 ROS 水平，从而介导 NLRP3 炎性体和细胞焦亡，从而加剧 MI/R 诱导的损伤。