Endothelial cells and blood vessels are major targets for COVID-19-induced tissue injury and spreading to various organs

Abstract

The coronavirus disease 2019 (COVID-19) infected so far over 250 million people and caused the death of over 5 million worldwide. Aging, diabetes, and cardiovascular diseases, conditions with preexisting impaired endothelial functions predispose to COVID-19. While respiratory epithelium is the main route of virus entry, the endothelial cells (ECs) lining pulmonary blood vessels are also an integral part of lung injury in COVID-19 patients. COVID-19 not only affects the lungs and respiratory system but also gastrointestinal (GI) tract, liver, pancreas, kidneys, heart, brain, and skin. Blood vessels are likely conduits for the virus dissemination to these distant organs. Importantly, ECs are also critical for vascular regeneration during injury/lesions healing and restoration of vascular network. The World Journal of Gastroenterology has published in last two years over 67 outstanding papers on COVID-19 infection with a focus on the GI tract, liver, pancreas, etc., however, the role of the endothelial and vascular components as major targets for COVID-19-induced tissue injury, spreading to various organs, and injury healing have not been sufficiently emphasized. In the present article, we focus on these subjects and on current treatments including the most recent oral drugs molnupiravir and paxlovid that show a dramatic, significant efficacy in controlling severe COVID-19 infection.

Keywords: Endothelial cells; Impaired endothelial function; Blood vessels; SARS-CoV-2; COVID-19; Cytokine storm

Core Tip: The coronavirus disease 2019 (COVID-19) pandemic has enormous health care and economic impact on the entire world - infecting more than 250 million people in 213 countries and territories, causing death of more than 5 million (as of November 1, 2021). We comment here on some outstanding papers on COVID-19 published in World Journal of Gastroenterology and reviewed the important role of endothelium and blood vessels in COVID-19 infection. Endothelial cells and blood vessels are both the targets and a conduit for the spread of severe acute respiratory syndrome coronavirus 2 and play a critical role in COVID-19-induced tissue injury and dissemination to various organs. Pre-existing endothelial impaired function could make endothelial cells more sensitive to COVID-19 or at least COVID-19-induced impairment might be synergistic with pre-existing impairment. That could be one contributing factor explaining why older or diabetic patients have more severe responses to infection, since these conditions are already impacted impaired endothelial function.