Department of Critical Care Medicine, the First Affiliated Hospital of Harbin Medical University, 23 Youzheng Road, Harbin, 150001, China.
Department of Critical Care Medicine, the Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin, 150086, China.
Inflammation. 2018 Jun;41(3):1073-1083. doi: 10.1007/s10753-018-0759-x.
Sepsis-induced myocardial injury is a well-known cause of mortality. The cholinergic anti-inflammatory pathway (CHAIP) is a physiological mechanism by which the central nervous system regulates immune response through the vagus nerve and acetylcholine; the α7-nicotinic acetylcholine receptor (α7nAChR) is the main component of CHAIP; GTS-21, a synthetic α7nAChR selective agonist, has repeatedly shown its powerful anti-inflammatory effect. However, little is known about its effect on LPS-induced myocardial injury. We investigated the protective effects of GTS-21 on lipopolysaccharide (LPS)-induced cardiomyopathy via the cholinergic anti-inflammatory pathway in a mouse sepsis model. We constructed the model of myocardial injury in sepsis mice by C57BL/6 using LPS and determined the time of LPS treatment by hematoxylin-eosin (HE) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). C57BL/6 mice were randomized into five groups: blank control group, model group, α-bungarotoxin + LPS group, GTS-21 + LPS group, and α-bungarotoxin + GTS-21 + LPS group. The pathological results of myocardial tissue were detected by the HE method; the apoptosis rate was detected by the TUNEL method; the relative expressions of NF-κB p65, Caspase-3, Caspase-8, Bcl-2, Bax, p53, and a7nAChR were detected by real-time quantitative PCR (RT-PCR); and the protein expressions of IL-6, IL-1 β, TNF-α, and pSTAT3 were detected by western blot. The results showed that LPS-induced myocardial pathological and apoptosis changes were significant compared with the blank group, which was reversed by GTS-21; however, pretreatment with α-bungarotoxin obviously blocked the protective effect of GTS-21. NF-κB p65, Caspase-3, Caspase-8, Bax, p53, IL-6, IL-1β, TNF-α, and pSTAT3 were significantly increased in the model group, while a7nAChR and Bcl-2 were significantly decreased; GTS-21 treatment reversed that result, while pretreatment with α-bungarotoxin strengthened the result in the model. And pretreatment with α-bungarotoxin blocked the protective effect of GTS-21. GTS-21 can alleviate the LPS-induced damage in the heart via a7nAChR, and pretreatment with α-bungarotoxin obviously blocked the protective effect of GTS-21 on sepsis in mice.
脓毒症诱导的心肌损伤是死亡的一个众所周知的原因。胆碱能抗炎途径（CHAI P）是一种生理机制，通过迷走神经和乙酰胆碱，中枢神经系统调节免疫反应；α7-烟碱型乙酰胆碱受体（α7nAChR）是 CHAI P 的主要组成部分；GTS-21 是一种合成的α7nAChR 选择性激动剂，已反复显示出其强大的抗炎作用。然而，关于其对脂多糖（LPS）诱导的心肌损伤的作用知之甚少。我们通过 LPS 在脓毒症小鼠中的 C57BL/6 构建了心肌损伤模型，研究了 GTS-21 通过胆碱能抗炎途径对 LPS 诱导的心肌病的保护作用。我们通过苏木精-伊红（HE）和末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）确定 LPS 处理时间，构建了脓毒症小鼠心肌损伤模型。C57BL/6 小鼠随机分为五组：空白对照组、模型组、α-银环蛇毒素+LPS 组、GTS-21+LPS 组和α-银环蛇毒素+GTS-21+LPS 组。通过 HE 法检测心肌组织的病理变化；通过 TUNEL 法检测细胞凋亡率；通过实时定量 PCR（RT-PCR）检测 NF-κB p65、Caspase-3、Caspase-8、Bcl-2、Bax、p53 和 a7nAChR 的相对表达；通过 Western blot 检测 IL-6、IL-1β、TNF-α和 pSTAT3 的蛋白表达。结果表明，与空白组相比，LPS 诱导的心肌病理和凋亡变化明显，GTS-21 可逆转；然而，α-银环蛇毒素预处理明显阻断了 GTS-21 的保护作用。NF-κB p65、Caspase-3、Caspase-8、Bax、p53、IL-6、IL-1β、TNF-α和 pSTAT3 在模型组中明显增加，而 a7nAChR 和 Bcl-2 明显减少；GTS-21 治疗逆转了这一结果，而α-银环蛇毒素预处理则强化了模型组的结果。并且，α-银环蛇毒素预处理阻断了 GTS-21 的保护作用。GTS-21 可通过 a7nAChR 减轻 LPS 诱导的心脏损伤，而α-银环蛇毒素预处理明显阻断了 GTS-21 对脓毒症小鼠的保护作用。
