Significant expression of FURIN and ACE2 on oral epithelial cells may facilitate the efficiency of SARS-CoV-2 entry

  1. Mei Zhong
  2. Bing-peng Lin
  3. Hong-bin Gao
  4. Andrew J Young
  5. Xin-hong Wang
  6. Chang Liu
  7. Kai-bin Wu
  8. Ming-xiao Liu
  9. Jian-ming Chen
  10. Jiang-yong Huang
  11. Learn-han Lee
  12. Cui-ling Qi
  13. Lin-hu Ge
  14. Li-jing Wang

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Abstract

Background

Leading to a sustained epidemic spread with >2,000,000 confirmed human infections, including >100,000 deaths, COVID-19 was caused by SARS-CoV-2 and resulted in acute respiratory distress syndrome (ARDS) and sepsis, which brought more challenges to the patient’s treatment. The S-glycoprotein, which recognized as the key factor for the entry of SARS-CoV-2 into the cell, contains two functional domains: an ACE2 receptor binding domain and a second domain necessary for fusion of the coronavirus and cell membranes. FURIN activity, exposes the binding and fusion domains, is essential for the zoonotic transmission of SARS-CoV-2. Moreover, it has been reported that ACE2 is likely to be the receptor for SARS-CoV-2. In addition, FURIN enzyme and ACE2 receptor were expressed in airway epithelia, cardiac tissue, and enteric canals, which considered as the potential target organ of the virus. However, report about the expression of FURIN and ACE2 in oral tissues was limited.

Methods

In order to investigate the potential infective channel of new coronavirus in oral cavity, we analyze the expression of ACE2 and FURIN that mediate the new coronavirus entry into host cells in oral mucosa using the public single-cell sequence datasets. Furthermore, immunohistochemical staining experiment was performed to confirm the expression of ACE2 and FURIN in the protein level.

Results

The bioinformatics results indicated the differential expression of ACE2 and FURIN on epithelial cells of different oral mucosal tissues and the proportion of FURIN-positive cells was obviously higher than that of ACE2-positive cells. IHC experiments revealed that both the ACE2-positive and FURIN-positive cells in the target tissues were mainly positioned in the epithelial layers, partly expressed in fibroblasts, which further confirm the bioinformatics results.

Conclusions

Based on these findings, we speculated that SARS-CoV-2 could effectively invade oral mucosal cells though two possible routes: binding to the ACE2 receptor and fusion with cell membrane activated by FURIN protease. Our results indicated that oral mucosa tissues are susceptible to SARS-CoV-2, which provides valuable information for virus-prevention strategy in clinical care as well as daily life.

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  1. ScreenIT

    SciScore for 10.1101/2020.04.18.047951: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementConsent: Written informed consent was obtained for each participant, and the study was in accordance with the Declaration of Helsinki and the guidelines approved by the Clinical Ethics Committee of Stomatology Hospital of Guangzhou Medical University.
    IRB: Written informed consent was obtained for each participant, and the study was in accordance with the Declaration of Helsinki and the guidelines approved by the Clinical Ethics Committee of Stomatology Hospital of Guangzhou Medical University.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Subsequently, they were dried and incubated anti-ACE2 (cat. no. ab15348, Abcam, Cambridge, CB, UK) antibody overnight at 4 °C.
    anti-ACE2
    suggested: (Abcam Cat# ab15348, RRID:AB_301861)
    Software and Algorithms
    SentencesResources
    2.1 Public scRNA-seq dataset acquisition: Single-cell RNA-seq dataset(GSE103322) including the gene expression and cell type annotation from human oral squamous cell carcinoma tissue (OSCC) were downloaded from the GEO database (https://www.ncbi.nlm.nih.gov/geo/).
    https://www.ncbi.nlm.nih.gov/geo/
    suggested: (Gene Expression Omnibus (GEO, RRID:SCR_005012)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  2. Version published to 10.1101/2020.04.18.047951v2 on bioRxiv
  3. Version published to 10.1101/2020.04.18.047951v1 on bioRxiv