Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China.
Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China; Department of Critical Care Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China.
J Inorg Biochem. 2022 Nov;236:111972. doi: 10.1016/j.jinorgbio.2022.111972. Epub 2022 Aug 18.
Excessive organophosphate flame retardant (OPFR) use in consumer products has been reported to increase human disease susceptibility. However, the adverse effects of tris(2-chloroethyl) phosphate (TCEP) (a chlorinated alkyl OPFR) on the heart remain unknown. In this study, we tested whether cardiac fibrosis occurred in animal models of TCEP (10 mg/kg b.w./day) administered continuously by gavage for 30 days and evaluated the specific role of sarco/endoplasmic reticulum Ca ATPase (SERCA). First, we confirmed that TCEP could trigger cardiac fibrosis by histopathological observation and cardiac fibrosis markers. We further verified that cardiac fibrosis occurred in animal models of TCEP exposure accompanied by SERCA2a, SERCA2b and SERCA2c downregulation. Notably, inductively coupled plasma-mass spectrometry (ICP-MS) analysis revealed that the cardiac concentrations of Ca increased by 45.3% after TCEP exposure. Using 4-Isopropoxy-N-(2-methylquinolin-8-yl)benzamide (CDN1163, a small molecule SERCA activator), we observed that Ca overload and subsequent cardiac fibrosis caused by TCEP were both alleviated. Simultaneously, the protein levels of endoplasmic reticulum (ER) markers (protein kinase R-like endoplasmic reticulum kinase (PERK), inositol requiring protein 1α (IRE1α), eukaryotic initiation factor 2 α (eIF2α)) were upregulated by TCEP, which could be abrogated by CDN1163 pretreatment. Furthermore, we observed that CDN1163 supplementation prevented overactive autophagy induced by TCEP in the heart. Mechanistically, TCEP could lead to Ca overload by inhibiting the expression of SERCA, thereby triggering ER stress and overactive autophagy, eventually resulting in cardiac fibrosis. Together, our results suggest that the Ca overload/ER stress/autophagy axis can act as a driver of cardiotoxicity induced by TCEP.
过量的有机磷阻燃剂（OPFR）在消费品中的使用已被报道会增加人类患病的易感性。然而，三（2-氯乙基）磷酸酯（TCEP）（一种氯化烷基 OPFR）对心脏的不良影响尚不清楚。在这项研究中，我们通过连续灌胃 30 天的方式测试了 TCEP（10mg/kg bw/天）动物模型是否会发生心脏纤维化，并评估了肌浆/内质网 Ca ATP 酶（SERCA）的特定作用。首先，我们通过组织病理学观察和心脏纤维化标志物证实 TCEP 可引发心脏纤维化。我们进一步验证了 TCEP 暴露的动物模型中存在 SERCA2a、SERCA2b 和 SERCA2c 下调导致的心脏纤维化。值得注意的是，电感耦合等离子体质谱（ICP-MS）分析显示 TCEP 暴露后心脏内 Ca 浓度增加了 45.3%。使用 4-异丙氧基-N-（2-甲基喹啉-8-基）苯甲酰胺（CDN1163，一种小分子 SERCA 激活剂），我们观察到 TCEP 引起的 Ca 超载和随后的心脏纤维化均得到缓解。同时，TCEP 上调了内质网（ER）标志物（蛋白激酶 R 样内质网激酶（PERK）、肌醇需求蛋白 1α（IRE1α）、真核起始因子 2α（eIF2α））的蛋白水平，而 CDN1163 预处理可阻断这种上调。此外，我们观察到 CDN1163 补充可防止 TCEP 引起的心脏过度自噬。机制上，TCEP 通过抑制 SERCA 的表达导致 Ca 超载，从而引发 ER 应激和过度自噬，最终导致心脏纤维化。综上所述，我们的研究结果表明，Ca 超载/ER 应激/自噬轴可作为 TCEP 引起心脏毒性的驱动因素。
