Abstract
Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been implicated in the clinical pathology of multiple organs and organ systems. Due to the novelty of the disease, there is a need to review emerging literature to understand the profile of SARS-CoV-2 in the placenta. This review sought to evaluate the literature on the mediators, mechanism of entry, pathogenesis, detection, and pathology of SARS-CoV-2 in the placenta. Systematic literature searches found 96 eligible studies. Our review revealed that SARS-CoV-2 canonical mediators, angiotensin-converting enzyme-2 (ACE2), and transmembrane serine protease-2 (TMPRSS2) are variably expressed in various placenta compartments, including the villous cytotrophoblasts, syncytiotrophoblasts (STBs), and extravillous trophoblasts (EVTs) throughout pregnancy. Placental SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs), including basigin (BSG/CD147), dipeptidyl peptidase-4 (DPP4/CD26), cathepsin B/L (CTL B/L), furin, interferon-induced transmembrane protein (IFITM1-3), and lymphocyte antigen 6E (LY6E) may increase or reduce the permissiveness of the placenta to SARS-CoV-2. EVTs express genes that code for proteins that may drive viral pathogenesis in the placenta. Viral RNA, proteins, and particles were detected primarily in the STBs by in situ hybridization, immunohistochemistry, electron microscopy, and polymerase chain reaction. Placental pathology in SARS-CoV-2-infected placentas included maternal and fetal vascular malperfusion and a generally nonspecific inflammatory-immune response. The localization of SARS-CoV-2 receptors, proteases, and genes involved in coding proteins that drive viral pathogenesis in the placenta predisposes the placenta to SARS-CoV-2 infection variably in all pregnancy trimesters, with antecedent placental pathology. There is a need for further studies to explicate the mechanism of entry and pathogenesis of SARS-CoV-2 in the placenta.
Keywords: ACE2; Placental infection; Placental pathology; SARS-CoV-2; Single-cell analysis.
【저자키워드】 SARS-CoV-2, ACE2, placental pathology, single-cell analysis., Placental infection, 【초록키워드】 COVID-19, coronavirus disease, immunohistochemistry, pathology, Coronavirus disease 2019, TMPRSS2, coronavirus, Pathogenesis, Placenta, furin, SARS-COV-2 infection, viral pathogenesis, interferon, Proteins, severe acute respiratory syndrome Coronavirus, virus, Particle, Antigen, DPP4, RNA, Basigin, CD147, Dipeptidyl peptidase-4, Clinical pathology, Protein, lymphocyte, polymerase chain reaction, Pregnancy, electron microscopy, Microscopy, placental, Viral RNA, Proteases, receptor, cathepsin B, angiotensin-converting enzyme-2, Localization, mechanism, CTL, single-cell analysis, In situ hybridization, Angiotensin-converting enzyme, IFITM1, angiotensin, Placental infection, Chain Reaction, organ systems, acute respiratory syndrome, Factor, Particles, Serine, Vascular, pregnancy trimesters, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, profile, enzyme, Cathepsin B/L, coding, transmembrane serine protease, multiple organs, transmembrane, CD26, dipeptidyl peptidase, Express, SARS-CoV-2 receptors, transmembrane protein, LY6E, permissiveness, pathogenesis of SARS-CoV-2, polymerase chain, evaluate, caused, involved, the disease, expressed, reduce, implicated, fetal, canonical, eligible, multiple organ, nonspecific, 【제목키워드】 literature review,