Assessing the Endothelium's Role in COVID-19 Severity Using the HUVEC model

Sanzio Silva Santana^1,2Sètondji Cocou Modeste Alexandre Yahouédéhou¹Corynne Stéphanie Ahouéfa Adanho¹Jéssica Rebouças Silva³Hayna Malta Santos⁴Cynara Gomes Barbosa⁵Thassila Nogueira Pitanga¹Valeria Borges³Vitor Fortuna⁶Isa Menezes Lyra⁷Marilda Souza Goncalves^1,5*

• ¹Laboratório de Investigação em Saúde Global e Doenças Negligenciadas, Instituto Gonçalo Moniz, Salvador, Brazil
• ²Faculdade de Biomedicina, Universidade Católica do Salvador, Salvador, Brazil
• ³Laboratório de Pesquisa Clínica e Translacional, Instituto Gonçalo Moniz, Salvador, Brazil
• ⁴Laboratório de Formulações Farmacêuticas, Instituto de Tecnologia e Saúde – SENAI CIMATEC, Salvador, Brazil
• ⁵Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil
• ⁶Departamento de Bioquímica e Biofísica, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil
• ⁷Departamento de Hematologia, Hospital Universitário Professor Edgard Santos, Salvador, Brazil

We investigated the role of the endothelium in modulating the cytokine storm in severe COVID-19. HUVEC were stimulated with serum from patients with severe COVID-19, convalescent individuals, and healthy volunteers (HV). Stimulation with serum from severe cases induces significant increases in VCAM1, F3, PROCR, IL6, IL12A, NFE2L2, HMOX1, GPX, and GSR expression within 60 minutes. Antioxidant genes SOD1 and CAT were upregulated later, after 120 minutes. HUVEC stimulated with severe COVID-19 sera showed increased levels of sICAM-1, sVCAM-1, P-selectin, sE-selectin, PECAM-1, tissue factor, thrombomodulin, and a broad range of cytokines and growth factors, such as IL-1α, IL-1Ra, IL-5, IL-6, IL-10, IL-12(p40), IL-18, IL-27, TNF-α, TGF-α, FGF-2, G-CSF, M-CSF, FLT-3L, fractalkine, eotaxin, MIG, IP-10, MIP-1β, MDC, GROa and PDGF-AB/BB. In contrast, convalescent sera induced fewer markers, specifically IL-12(p40), IL-18, FGF-2, MIP-1β, MDC, GROa, and PDGF-AB/BB, while HV sera induced significant increases in IL-12(p40), IL-27, TNF-α, VEGF, MDC, eotaxin, and GROa. ROC curve analysis revealed that P-selectin and MIP-1β levels clearly distinguish severe cases from HV. When comparing severe and convalescent groups, we observed increases in IL-27, TGF-α, sVCAM-1, IL-1α, and G-CSF levels. Furthermore, Multivariable logistic regression analysis associated disease severity with decreased IL-10 and increased MIP-1β, sICAM-1, and P-selectin. These findings suggest that HUVEC serves as a promising biological sensor for detecting inflammatory responses in COVID-19 patients and shows the crucial role of the endothelium in sustaining the cytokine storm that contributes to patient severity and mortality.