In this new crown obstruction battle without gunpowder smoke, there is a core scientific question: how exactly does the new coronavirus invade the human body?Thanks to the joint efforts of multi-party research teams, the answer to this question has a more precise answer: 2019-nCoV, like SARS, infects cells through the ACE2 (angiotensin converting enzyme 2) receptor.ACE2 is mainly expressed in human type II alveolar cells (AT2), which means that it is likely to be the target cell of neocoronavirus.This explains why pneumonia occurs in 100% of new crown virus infections.Knowing the target cells, new questions ensued: Which groups of people are relatively more susceptible to infection with the new crown virus, that is, more likely to express ACE2?Only by knowing the answer to this question can we better identify susceptible people (although the current data show that everyone is susceptible).Professor Guoshuai Cai, a professor at the University of South Carolina, analyzed large-scale data sets and found that race, age, and gender were not the differentiating factors for ACE2 gene expression.However, ACE2 gene expression was significantly higher in smokers than in non-smokers, suggesting that smokers may be more susceptible to infection with the new crown virus.The study was published on the preprinted website medRxiv on February 17.ACE2 gene expression was significantly increased in smokers. The authors analyzed two RNA-seq datasets and two DNA microarray datasets from white and Asian lung cancer patients. All datasets included paired tumors and normal samples.Personnel used only normal sample data.Key findings: There were no significant differences in ACE2 gene expression between races (Asian and Caucasian), age (greater than 60 years old and younger than 60 years), or gender (male and female).This is different from the previous study of the team of professor Zuo Wei of the Medical College of Tongji University in Shanghai who found that Asian males expressed more ACE2 cells than other races (2.5% vs 0.47%).However, in three data sets containing a history of smoking, the expression of the ACE2 gene was increased in smokers.After adjusting for other factors (age, gender, ethnicity, and data set), smokers still showed a significant increase in ACE2 (p = 0.01).Moreover, there was no significant difference in the expression level of ACE2 gene in the lung tissue of different ethnic groups.ACE2 expressing cells may differ between smokers and nonsmokers.Previous studies have shown that the bronchial epithelial cells of smokers are rebuilt, the number of rod cells is reduced, and goblet cells are proliferated.The researchers found that ACE2 is mainly expressed in goblet cells in smokers, but not in rod cells in nonsmokers.In summary, this analysis suggests that smokers may be more susceptible to infection with 2019-nCoV, so smoking history should be considered when identifying susceptible populations and standardized treatment options.It should be noted that this study also has certain limitations.For example, the data analyzed in this study came from normal lung tissue in patients with lung adenocarcinoma, which may differ from lung tissue in healthy people.These analyses are based on the average expression of large tissues, which is not conducive to assessing the ACE2 expression level of specific cells (for example, AT2 cells can specifically express high levels of ACE2).Whether ACE2 is the sole receptor for 2019-nCoV is unclear.Of course, in this study, the “correlation relationship” between ACE2 expression level and smoking is not equal to causality. What kind of factors cause the correlation needs to be further studied to verify.Smokers have far lower infection rates than nonsmokers?Stop dreaming!Regarding the relationship between smoking and viral infections, rumors on social media seem to have never stopped.As early as the SARS virus raged, some people fabricated a rumor that “smoking can prevent SARS.” Some even provided a so-called theoretical basis for this: “Smoke oil can cover the surface of lung cells, which is equivalent to a tight protective layer. The virusIf you enter the lungs, you will be blocked by smoke oil and cannot be copied. “However, such rumors are obviously self-defeating.In theory, smoking can cause a lot of damage to lung cells, and the injured cells are obviously more susceptible to virus infection.Moreover, studies in Hong Kong and South Korea have confirmed that the mortality rate of SARS or MERS is significantly higher among smokers or patients with a history of smoking than non-smokers.It is irritating that such rumors “re-emerged” again during the new crown epidemic.On February 9, Zhong Nanshan’s team published a paper entitled “Clinical Features of a New Type of Coronavirus Infection in China” on medRxiv.Surprisingly, after that, a piece of “Smokers’ infection rate with the new crown virus was much lower than that of non-smokers?”Zhong Nanshan’s first paper was published.The author of this article analyzed the data of the paper and concluded that the prevalence of infection was significantly lower in smokers than in nonsmokers!In addition, the author has arrogantly rendered various “benefits” brought by tobacco, such as treating skin diseases, migraines, mosquito bites, and even mass production of antimalarial drugs instead of Artemisia annua.It is understood that this article mainly intercepted a set of data from Academician Zhong Nanshan’s thesis: “According to clinical data, 927 of 1099 cases had no history of smoking, accounting for 85.4%; 21 cases had a history of smoking, accounting for 1.9%; Smoking and suffering from 137 cases, accounting for 12.6%. According to this, the author of the article came to the conclusion that “from a comparative analysis of data, it is clear that the infection rate of smokers is much lower than non-smokers!”In fact, Zhong Nanshan’s team’s paper did not mention any relationship between smoking and infection with new coronary pneumonia.Zhang Jianshu, president of the Beijing Tobacco Control Association, also said that Zhong Nanshan’s team’s thesis only classified smokers, non-smokers, and patients with a history of smoking.”Using a small sample of 137 smokers to analyze the relationship between smoking and infection with new coronary pneumonia, there is no statistical significance at all. Moreover, the article” Yao Shuo Yao said classroom “ignores the death of patients with lung disease in critically illThe fact that the rate is high. “Zhang Jianshu said,” This is a repeat of the old tricks of the tobacco industry. During the SARS period, rumors spread that SARS-infected people smoked less. This fallacy has been rejected. “During the epidemic, the publicTo write Zhong Nanshan’s trust and fear of virus infection, writing such an article to sell tobacco is purely rumorous and deceptive.As of now, the article has been deleted.The potential harms of smoking are not limited to these. In addition to being potentially susceptible to viruses, the harms of smoking are almost ubiquitous: 1. Tobacco smoke contains 69 known carcinogens. These carcinogens cause mutations in key genes in the body and grow normally.Imbalanced control mechanisms eventually lead to the development of cancerous cells and malignant tumors.Smoking is the number one cause of lung cancer.Compared with non-smokers, smokers have an average 4-10 times higher risk of developing lung cancer, and heavy smokers can reach 10-25 times.Smoking can also cause hundreds of cancers besides lung cancer, such as oral cancer, esophageal cancer, colorectal cancer, breast cancer, and so on.2. Smoking affects respiratory immune function and lung function, increasing the risk of chronic lung disease.3. Smoking can damage the function of vascular endothelium, which can lead to the occurrence of atherosclerosis, narrow the arterial vascular cavity, block the arterial blood flow, and cause a variety of cardiovascular and cerebrovascular diseases.4. Smoking can also cause type 2 diabetes and can increase the risk of major and microvascular complications in people with diabetes.5. Tobacco smoke contains a variety of harmful substances that can affect human reproductive and developmental functions.6. Not only is smoking unhealthy for smokers themselves, exposure to second-hand smoke also increases the risk of developing a variety of smoking-related diseases.Moreover, there is no so-called safe level of second-hand smoke exposure, and even short-term exposure to second-hand smoke can cause harm to human health.According to the 2012 China Health Report on the Harm of Smoking, China is the world’s largest tobacco producer and consumer. China has more than 300 million smokers, and about 740 million non-smokers are harmed by second-hand smoke..
Every year, the number of deaths caused by smoking-related diseases in China exceeds one million. If the epidemic situation of smoking is not controlled, the number of deaths will exceed 3 million per year by 2050, which will become an unbearable burden on people’s lives, health, and social and economic development.”Smoking is the first evil of disease.”For yourself and your family, please quit smoking decisively!The above content is only authorized for exclusive use by 39Health.com, please do not reprint without the authorization of the copyright party.