Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin, China; Department of Hyperbaric Oxygen, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, China.
Can J Cardiol. 2020 Jun;36(6):893-905. doi: 10.1016/j.cjca.2019.09.026. Epub 2019 Nov 1.
The infiltration of neutrophils aggravates inflammatory response in acute myocardial infarction (AMI), and the role of calcium-sensing receptor (CaSR) in neutrophil-associated inflammation is largely unknown. The aim of this study was to evaluate the regulatory effects of CaSR on nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome in neutrophils and to explore its role in AMI-related ventricular remodelling.
The expression of CaSR, NLRP3 inflammasome, and interleukin 1β (IL-1β) in peripheral blood and infiltrating neutrophils in patients and rats with AMI was detected by western blotting and immunofluorescence. Cardiomyocyte apoptosis was detected by western blotting and transmission electron microscopy. The degree of fibrosis was evaluated by Masson staining and western blotting.
We found upregulation of CaSR, NLRP3 inflammasome, Caspase-1, and IL-1β in peripheral neutrophils from patients with AMI compared with matched healthy controls, peaking on day 1 and decreasing gradually till 7 days. Peripheral and infiltrating neutrophils from rats with AMI showed the same trend. Calindol enhanced NLRP3 inflammasome activation and IL-1β release in neutrophils from healthy volunteers, which was blocked by inhibitors of the PLC-IP pathway and ER-Ca release. Calhex-231 decreased NLRP3 inflammasome activation and IL-1β release in neutrophils from patients with AMI. The calindol-stimulated neutrophils from healthy rats promoted cardiomyocyte apoptosis and fibrosis of cardiac fibroblasts from healthy rats, which were inhibited by calhex-231.
The results suggest that CaSR activates NLRP3 inflammasome in neutrophils, contributing to ventricular remodelling after AMI. CaSR inhibition may be a potential therapeutic target for heart failure in AMI.
中性粒细胞的浸润会加重急性心肌梗死（AMI）中的炎症反应，而钙敏感受体（CaSR）在中性粒细胞相关炎症中的作用在很大程度上尚不清楚。本研究旨在评估 CaSR 对中性粒细胞中核苷酸结合寡聚结构域样受体含pyrin 结构域蛋白 3（NLRP3）炎性小体的调节作用，并探讨其在 AMI 相关心室重构中的作用。
通过 Western blot 和免疫荧光法检测 AMI 患者和大鼠外周血和浸润中性粒细胞中 CaSR、NLRP3 炎性小体和白细胞介素 1β（IL-1β）的表达。通过 Western blot 和透射电镜检测心肌细胞凋亡。通过 Masson 染色和 Western blot 评估纤维化程度。
与匹配的健康对照相比，AMI 患者外周血中性粒细胞中 CaSR、NLRP3 炎性小体、Caspase-1 和 IL-1β的表达上调，在第 1 天达到峰值，然后逐渐下降至第 7 天。AMI 大鼠的外周血和浸润中性粒细胞也呈现出相同的趋势。Calindol 增强了健康志愿者中性粒细胞中 NLRP3 炎性小体的激活和 IL-1β 的释放，该作用被 PLC-IP 途径抑制剂和 ER-Ca 释放抑制剂阻断。Calhex-231 降低了 AMI 患者中性粒细胞中 NLRP3 炎性小体的激活和 IL-1β 的释放。Calindol 刺激的健康大鼠中性粒细胞促进了健康大鼠心肌成纤维细胞的心肌细胞凋亡和纤维化，而 calhex-231 则抑制了这一过程。
研究结果表明，CaSR 在中性粒细胞中激活 NLRP3 炎性小体，导致 AMI 后心室重构。CaSR 抑制可能成为 AMI 心力衰竭的潜在治疗靶点。
