Exploring eNOS-Caveolin-1 interaction in placentas of SARS-Cov-2 positive pregnancies

Area of Science:

• Reproductive biology
• Virology
• Immunology

Background:

• The placenta is crucial for maternal-fetal exchange and immune function.
• While the placenta blocks many pathogens, viruses like CMV and Zika can transmit vertically.
• Mechanisms of SARS-CoV-2 vertical transmission are not fully understood.

Purpose of the Study:

• To examine caveolin-1 (Cav-1) and endothelial nitric oxide synthase (eNOS) expression in placentas from SARS-CoV-2-positive pregnancies.
• To investigate the role of Cav-1 and eNOS in limiting SARS-CoV-2 vertical transmission.

Main Methods:

• Placental tissues from COVID-19-positive and healthy pregnancies were analyzed.
• Histological, immunohistochemical, and immunofluorescence techniques assessed tissue morphology and Cav-1/eNOS expression.

Main Results:

• Healthy placentas showed intact villi and strong endothelial Cav-1 and eNOS expression.
• COVID-19 placentas exhibited villous damage, altered erythrocytes, and reduced endothelial Cav-1 and eNOS.
• Cav-1 was notably absent in syncytiotrophoblasts across all samples.

Conclusions:

• Decreased endothelial Cav-1 and eNOS, along with absent syncytiotrophoblast Cav-1, may confer placental resistance to SARS-CoV-2.
• These findings suggest that placental molecular characteristics, particularly Cav-1/eNOS pathways, play a protective role against vertical transmission.