Placental expression of ACE2 and TMPRSS2 in maternal SARS-CoV-2 infection: are placental defenses mediated by fetal sex?

  1. Lydia L Shook
  2. Evan A Bordt
  3. Marie-Charlotte Meinsohn
  4. David Pepin
  5. Rose M De Guzman
  6. Sara Brigida
  7. Laura J Yockey
  8. Kaitlyn E James
  9. Mackenzie W Sullivan
  10. Lisa M Bebell
  11. Drucilla J Roberts
  12. Anjali J Kaimal
  13. Jonathan Z Li
  14. Danny Schust
  15. Kathryn J Gray
  16. Andrea G Edlow

Reviewed by

Read the full article See related articles

Discuss this preprint

Start a discussion What are Sciety discussions?

Listed in

Log in to save this article

Abstract

Background

Sex differences in vulnerability to and severity of SARS-CoV-2 infection have been described in non-pregnant populations. ACE2 and TMPRSS2, host molecules required for viral entry, are regulated by sex steroids and expressed in the placenta. We sought to investigate whether placental ACE2 and TMPRSS2 expression vary by fetal sex and in the presence of maternal SARS-CoV-2 infection.

Methods

Placental ACE2 and TMPRSS2 were quantified in 68 pregnant individuals (38 SARS-CoV-2 positive, 30 SARS-CoV-2 negative) delivering at Mass General Brigham from April to June 2020. Maternal SARS-CoV-2 status was determined by nasopharyngeal RT-PCR. Placental SARS-CoV-2 viral load was quantified. RTqPCR was performed to quantify expression of ACE2 and TMPRSS2 relative to the reference gene YWHAZ . Western blots were performed on placental homogenates to quantify protein levels. The impact of fetal sex and SARS-CoV-2 exposure on ACE2 and TMPRSS2 expression was analyzed by 2-way ANOVA.

Results

SARS-CoV-2 virus was undetectable in all placentas. Maternal SARS-CoV-2 infection impacted TMPRSS2 placental gene and protein expression in a sexually dimorphic fashion (2-way ANOVA interaction p-value: 0.002). We observed no impact of fetal sex or maternal SARS-CoV-2 status on placental ACE2 gene or protein expression. Placental TMPRSS2 expression was significantly correlated with ACE2 expression in males (Spearman’s ρ=0.54, p=0.02) but not females (ρ=0.23, p=0.34) exposed to maternal SARS-CoV-2.

Conclusions

Sex differences in placental TMPRSS2 but not ACE2 were observed in the setting of maternal SARS-CoV-2 infection. These findings may have implications for offspring vulnerability to placental infection and vertical transmission.These findings may have implications for offspring vulnerability to placental infection and vertical transmission.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2021.04.01.438089: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: This study was approved by the Mass General Brigham Institutional Review Board (#2020P003538).
    Consent: All participants provided written informed consent.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableStudy design and participant enrollment: These experiments include 68 pregnant women (38 SARS-CoV-2 positive, 30 SARS-CoV-2 negative) enrolled in a cohort study at Massachusetts General Hospital and Brigham and Women’s Hospital from April to June 2020, coincident with universal screening for SARS-CoV-2 infection by nasopharyngeal RT-PCR on the Labor and Delivery unit.

    Table 2: Resources

    Antibodies
    SentencesResources
    ACE2 and TMPRSS2 primary antibodies were then incubated in Intercept T20 (TBS) Antibody Diluent (Li-Cor Biosciences) overnight at 4°C.
    ACE2
    suggested: None
    TMPRSS2
    suggested: None
    Software and Algorithms
    SentencesResources
    Demographic and clinical outcomes data were abstracted from the electronic medical record using REDCap electronic data capture tools [40].
    REDCap
    suggested: (REDCap, RRID:SCR_003445)
    Statistical analyses were performed using GraphPad Prism 9.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)

    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.
    • No funding statement was detected.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.04.01.438089 on bioRxiv