Analysis of 2019-nCoV receptor ACE2 expression in different tissues and its significance study.

BACKGROUND: On March 11, 2020, the World Health Organization (WHO) officially announced that the coronavirus disease 2019 (COVID-19) had reached global pandemic status. Current studies have found that angiotensin-converting enzyme 2 (ACE2) is a cell surface receptor of the novel coronavirus that plays a vital role in the pathogenesis of COVID-19. It is of immense importance for the prevention of virus transmission and treatment to clarify the distribution and expression of ACE2 in various tissues and organs of the body. METHODS: RNAseq transcriptome data and sex data were obtained from the genotype-tissue expression (GTEx) and the Cancer Genome Atlas (TCGA) databases. We separately analyzed the distribution of ACE2 expression in different tissues in the GTEx and TCGA database, and explored the correlation between sex and ACE2 expression levels. Next, the expression levels of ACE2 in different tissues and organs and its correlation with sex were analyzed once again after combing all samples from the two databases. RESULTS: ACE2 expression data were collected from the GTEx database for 6738 normal tissues. Six hundred eighteen tumor tissue data were collected from the TCGA database. The results of the analysis are consistent from different databases. The results indicated that the expression of ACE2 was the highest in the small intestines, higher in tissues such as salivary glands in the testicular, kidney, heart, thyroid and adipose tissues, while the expression of ACE2 was lower in tissues such as the spleen, brain, muscle, pituitary, and skin. There were no significant differences in the expression of ACE2 in the different organs when it came to the individual's sex. CONCLUSIONS: Our study deeply explored the distribution and expression of ACE2 in various tissues of the human body. The tissues and organs with high ACE2 expression were consistent with the current clinical and basic research results of the novel coronavirus. Our study is conducive to the discovery of potential target organs for viral infection, to provide a reference for the development of clinical progress of patients with novel coronavirus infection.

Four-tier response system and spatial propagation of COVID-19 in China by a network model.

In order to investigate the effectiveness of lockdown and social distancing restrictions, which have been widely carried out as policy choice to curb the ongoing COVID-19 pandemic around the world, we formulate and discuss a staged and weighted network system based on a classical SEAIR epidemiological model. Five stages have been taken into consideration according to four-tier response to Public Health Crisis, which comes from the National Contingency Plan in China. Staggered basic reproduction number has been derived and we evaluate the effectiveness of lockdown and social distancing policies under different scenarios among 19 cities/regions in mainland China. Further, we estimate the infection risk associated with the sequential release based on population mobility between cities and the intensity of some non-pharmaceutical interventions. Our results reveal that Level I public health emergency response is necessary for high-risk cities, which can flatten the COVID-19 curve effectively and quickly. Moreover, properly designed staggered-release policies are extremely significant for the prevention and control of COVID-19, furthermore, beneficial to economic activities and social stability and development.

Clinical features and imaging findings in six coronavirus disease 2019 patients

Objective To summarize the clinical features and imaging findings of six coronavirus disease 2019 (COVID-19) patients, so as to provide evidences for early diagnosis and clinical intervention. Methods Six COVID-19 patients with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were enrolled from the Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine from Jan. 1 to Feb. 22, 2020. The epidemiological history, clinical manifestations, imaging data and laboratory indicators were retrospectively analyzed. Results All six patients had a clear travel or residence history in Wuhan. Four patients had fever, three had cough, two had upper respiratory tract symptoms such as runny nose and sore throat, and two had systemic symptoms such as headache and muscle ache. Chest computed tomography (CT) showed that all the six patients had abnormal manifestations in bilateral lungs, and the lower lung lesions were more common than the upper lung lesions. The main manifestations were multiple ground-glass opacities, consolidation shadows, crazy paving sign and different degrees of fibrosis in lateral field of bilateral lungs. Chest CT examination later after onset showed lung consolidation and severe fibrosis. Conclusion The imaging of COVID-19 has special characteristics. Combined with the epidemiological history, clinical manifestations and the detection of SARS-CoV-2 nucleic acid, COVID-19 can be effectively diagnosed in the early stage.