病毒学报

新型冠状病毒感染（Coronavirus disease 2019, COVID-19）急性感染导致心血管系统损伤的病理生理学机制尚不明确，揭示严重急性呼吸综合征冠状病毒2(Severe acute respiratory syndrome coronary virus 2, SARS-CoV-2)病毒蛋白在人体心血管组织中的分布特征将有助于认识和理解心脏损伤的病理机制。本研究纳入COVID-19急性感染期死亡患者8例，其中6例男性，2例女性，平均年龄81.4岁（66～98）。通过病理尸检获取心脏组织，分别采用HE染色观察心血管组织病理变化，免疫组织化学染色观察SARS-CoV-2刺突蛋白（Spike S1、S2亚基）和核衣蛋白（Nucleocapsid,N蛋白）在心脏组织中的分布。在所有8例标本的心脏组织中发现，在心外膜脂肪细胞、心外膜浸润细胞、心血管内皮细胞以及心肌细胞中可见S1、S2和N蛋白的表达，在血管周围脂肪细胞中可见S2亚基和N蛋白的表达。但是，在心外膜、血管外膜等组织中广泛分布着S1亚基。本研究发现COVID-19急性感染期心血管组织细胞中存在S1、S2、N等蛋白的表达，在心外膜和血管外膜中存在S1蛋白的表达，这种外膜中广泛分布的S1导致心血管系统损伤的致病机制尚不清楚，值得进一步研究。

The pathophysiological mechanisms underlying the cardiovascular system injury caused by acute COVID-19 infection remain unclear. Investigating the distribution of SARS-CoV-2 viral proteins in human cardiovascular tissues could aid in recognizing and understanding the pathogenesis of cardiac injury. This study collected eight cases of patients who died during the acute phase of COVID-19 infection, including six males and two females with an average age of 81.4 years old(range 66～98). Cardiac tissues were obtained through autopsy, and histopathological changes in cardiovascular tissues were observed after hematoxylin-eosin(HE) staining. The distribution of SARS-CoV-2 spike protein subunits(S1, S2) and nucleocapsid protein(N protein) in cardiac tissues was examined after immunohistochemical staining. Expression of S1, S2, and N proteins was detected in all eight cardiac specimens within epicardial adipocytes, epicardial infiltrating cells, cardiovascular endothelial cells and cardiomyocytes. N protein and S2 protein expression were observed in perivascular adipocytes. However, S1 subunit was widely distributed in the epicardium and vascular adventitia.This study found that S1, S2, and N proteins are expressed in cells of the cardiovascular tissues during the acute phase of COVID-19 infection, with S1 protein expression in the epicardium and vascular adventitia. The pathogenic mechanism of this widespread S1 distribution leading to cardiovascular system injury is not well understood and warrants further investigation.