Coronavirus disease 2019 (COVID-19) is a worldwide pandemic. It has a high transmission rate among humans, and is a threat to global public health. However, there are no effective prophylactics or therapeutics available. It is necessary to identify vulnerable and susceptible groups for adequate protection and care against this disease. Recent studies have reported that COVID-19 has angiotensin-converting enzyme 2 (ACE2) as a functional receptor, which may lead to the development of severe cerebrovascular diseases (CVD), including strokes, in patients with risk factors for CVD such as diabetes and smoking. Thus, the World Health Organization (WHO) advised caution against COVID-19 for smokers and patients with underlying clinical symptoms, including cardiovascular diseases. Here, we observed ACE2 expression in the brain of rat middle cerebral artery occlusion (MCAO) model and evaluated the effects of cigarette smoke extract (CSE) and diabetes on ACE2 expression in vessels. We showed that the levels of ACE2 expression was increased in the cortex penumbra after ischemic injuries. CSE treatment significantly elevated ACE2 expression in human brain vessels. We found that ACE2 expression was upregulated in primary cultured human blood vessels with diabetes compared to healthy controls. This study demonstrates that ACE2 expression is increased in ischemic brains and vessels exposed to diabetes or smoking, makes them vulnerable to COVID-19 infection.

冠状病毒病2019（COVID-19）是世界性大流行。它在人类之间的传播率很高，并且对全球公共健康构成威胁。但是，没有有效的预防或治疗方法。有必要确定脆弱和易感人群，以对这种疾病进行充分的保护和护理。最近的研究报道，COVID-19具有血管紧张素转换酶2（ACE2）作为功能受体，在患有CVD和糖尿病等具有CVD危险因素的患者中，可能导致严重的脑血管疾病（CVD）的发展，包括中风抽烟。因此，世界卫生组织（WHO）建议吸烟者和有潜在临床症状（包括心血管疾病）的患者注意COVID-19。这里，我们观察了大鼠大脑中动脉闭塞（MCAO）模型在大脑中的ACE2表达，并评估了香烟烟雾提取物（CSE）和糖尿病对血管中ACE2表达的影响。我们表明缺血损伤后皮质半影中ACE2表达水平增加。CSE治疗显着提高了人脑血管中ACE2的表达。我们发现，与健康对照组相比，糖尿病原代培养人血管中的ACE2表达上调。这项研究表明，在患有糖尿病或吸烟的缺血性脑和血管中，ACE2的表达增加，使它们易受COVID-19感染。我们表明缺血损伤后皮质半影中ACE2表达水平增加。CSE治疗显着提高了人脑血管中ACE2的表达。我们发现，与健康对照组相比，糖尿病原代培养人血管中的ACE2表达上调。这项研究表明，在患有糖尿病或吸烟的缺血性脑和血管中，ACE2的表达增加，使它们易受COVID-19感染。我们表明缺血损伤后皮质半影中ACE2表达水平增加。CSE治疗可显着提高人脑血管中ACE2的表达。我们发现，与健康对照组相比，糖尿病原代培养人血管中的ACE2表达上调。这项研究表明，在患有糖尿病或吸烟的缺血性脑和血管中，ACE2的表达增加，使它们易受COVID-19感染。