Effects of spike protein and toxin-like peptides found in COVID-19 patients on human 3D neuronal/glial model undergoing differentiation: Possible implications for SARS-CoV-2 impact on brain development

• Published in: Reproductive toxicology (Elmsford, N.Y.) N.Y.), 2022-08, Vol.111, p.34-48
• Main Authors: Pistollato, Francesca, Petrillo, Mauro, Clerbaux, Laure-Alix, Leoni, Gabriele, Ponti, Jessica, Bogni, Alessia, Brogna, Carlo, Cristoni, Simone, Sanges, Remo, Mendoza-de Gyves, Emilio, Fabbri, Marco, Querci, Maddalena, Soares, Helena, Munoz, Amalia, Whelan, Maurice, Van de Eede, Guy
• Format: Article
• Language: English
• Subjects: 3D neurospheres; Angiotensin-Converting Enzyme 2; AOP; Brain - metabolism; brain development; Child; CIAO Project; COVID-19; Electrical activity; Humans; Neuroglia; Neurons - metabolism; Peptides; RNA-Seq; SARS-CoV-2; Spike Glycoprotein, Coronavirus - metabolism; Spike protein; Toxin-like peptides
• ISSN: 0890-6238; 1873-1708
• DOI: 10.1016/j.reprotox.2022.04.011

The possible neurodevelopmental consequences of SARS-CoV-2 infection are presently unknown. In utero exposure to SARS-CoV-2 has been hypothesized to affect the developing brain, possibly disrupting neurodevelopment of children. Spike protein interactors, such as ACE2, have been found expressed in the fetal brain, and could play a role in potential SARS-CoV-2 fetal brain pathogenesis. Apart from the possible direct involvement of SARS-CoV-2 or its specific viral components in the occurrence of neurological and neurodevelopmental manifestations, we recently reported the presence of toxin-like peptides in plasma, urine and fecal samples specifically from COVID-19 patients. In this study, we investigated the possible neurotoxic effects elicited upon 72-hour exposure to human relevant levels of recombinant spike protein, toxin-like peptides found in COVID-19 patients, as well as a combination of both in 3D human iPSC-derived neural stem cells differentiated for either 2 weeks (short-term) or 8 weeks (long-term, 2 weeks in suspension + 6 weeks on MEA) towards neurons/glia. Whole transcriptome and qPCR analysis revealed that spike protein and toxin-like peptides at non-cytotoxic concentrations differentially perturb the expression of SPHK1, ELN, GASK1B, HEY1, UTS2, ACE2 and some neuronal-, glia- and NSC-related genes critical during brain development. Additionally, exposure to spike protein caused a decrease of spontaneous electrical activity after two days in long-term differentiated cultures. The perturbations of these neurodevelopmental endpoints are discussed in the context of recent knowledge about the key events described in Adverse Outcome Pathways relevant to COVID-19, gathered in the context of the CIAO project (https://www.ciao-covid.net/). •SARS-CoV-2 Spike protein decreased electrical activity in 3D neurospheres.•Spike and Peptides dysregulated SPHK1, ELN, GASK1B, HEY1, UTS2 and ACE2 gene expression.•Spike and Peptides perturbed the expression of neuronal-, glia- and NSC-related genes.•Peptides can exacerbate DNT effects induced by Spike protein in vitro.•DNT effects induced by Spike and Peptides are partially in line with COVID-19 AOPs.