SARS-CoV-2 Infected Pediatric Cerebral Cortical Neurons: Transcriptomic Analysis and Potential Role of Toll-like Receptors in Pathogenesis

• Published in: International journal of molecular sciences 2021-07, Vol.22 (15), p.8059
• Main Authors: Gugliandolo, Agnese, Chiricosta, Luigi, Calcaterra, Valeria, Biasin, Mara, Cappelletti, Gioia, Carelli, Stephana, Zuccotti, Gianvincenzo, Avanzini, Maria Antonietta, Bramanti, Placido, Pelizzo, Gloria, Mazzon, Emanuela
• Format: Article
• Language: English
• Subjects: ACE2; Angiotensin-converting enzyme 2; Asymptomatic; Bacterial infections; Brain; Caspase-8; Cerebral Cortex - metabolism; Chemokines; Child; children; Coronaviruses; COVID-19; COVID-19 - genetics; COVID-19 - immunology; COVID-19 - metabolism; Cytokines; Cytokines - metabolism; Deregulation; Disease transmission; Gene expression; Gene Expression Profiling; Gene Expression Regulation; Genes; human neuronal cells; Humans; Infections; Interferon regulatory factor 3; Multisystem inflammatory syndrome in children; Nervous system; Neurons; Neurons - immunology; Neurons - virology; Next-generation sequencing; NF-κB protein; Pattern recognition; Pediatrics; Proteins; SARS-CoV-2; SARS-CoV-2 - immunology; SARS-CoV-2 - metabolism; SARS-CoV-2 - pathogenicity; Scavenger receptors; Severe acute respiratory syndrome coronavirus 2; Signal Transduction - genetics; TLR1 protein; TLR4 protein; Toll-like receptors; Toll-Like Receptors - genetics; Toll-Like Receptors - metabolism; transcriptomic analysis; Transcriptomics; Virus Replication; Viruses
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22158059

Different mechanisms were proposed as responsible for COVID-19 neurological symptoms but a clear one has not been established yet. In this work we aimed to study SARS-CoV-2 capacity to infect pediatric human cortical neuronal HCN-2 cells, studying the changes in the transcriptomic profile by next generation sequencing. SARS-CoV-2 was able to replicate in HCN-2 cells, that did not express , confirmed also with Western blot, and . Looking for pattern recognition receptor expression, we found the deregulation of scavenger receptors, such as SR-B1, and the downregulation of genes encoding for Nod-like receptors. On the other hand, , and encoding for Toll-like receptors (TLRs) were upregulated. We also found the upregulation of genes encoding for ERK, JNK, NF-κB and Caspase 8 in our transcriptomic analysis. Regarding the expression of known receptors for viral RNA, only RIG-1 showed an increased expression; downstream RIG-1, the genes encoding for TRAF3, IKKε and IRF3 were downregulated. We also found the upregulation of genes encoding for chemokines and accordingly we found an increase in cytokine/chemokine levels in the medium. According to our results, it is possible to speculate that additionally to ACE2 and TMPRSS2, also other receptors may interact with SARS-CoV-2 proteins and mediate its entry or pathogenesis in pediatric cortical neurons infected with SARS-CoV-2. In particular, TLRs signaling could be crucial for the neurological involvement related to SARS-CoV-2 infection.