Neuropsychiatric sequelae in an experimental model of post-COVID syndrome in mice
Authors: Pimenta Jordane Clarisse , Beltrami Vinícius Amorim , Oliveira Bruna Da Silva , Queiroz-Junior Celso Martins , Barsalini Jéssica , Teixeira Danielle Cunha , de Souza-Costa Luiz Pedro , Lima Anna Luiza Diniz , Machado Caroline Amaral , Parreira Bárbara Zuccolotto Schneider Guimar , Santos Felipe Rocha da Silva , Costa Pedro Augusto Carvalho , Lacerda Larisse De Souza Barbosa , Gonçalves Matheus Rodrigues , Chaves Ian de Meira , Couto Manoela Gonzaga Gontijo Do , Costa Victor Rodrigues de Melo , Nóbrega Natália Ribeiro Cabacinha , Silva Bárbara Luísa , Fonseca Talita , Resende Filipe , Wnuk Natália Teixeira , Umezu Hanna L. , Campolina-Silva Gabriel , Andrade Ana Cláudia dos Santos Pereira , Santana de Aguiar Renato , Costa Guilherme Mattos Jardim , Guimarães Pedro Pires Goulart , da Silva Glauber Santos Ferreira , Vieira Luciene Bruno , Pinho Vanessa , Teixeira Antônio Lúcio , Teixeira Mauro Martins , De Miranda Aline Silva , Costa Vivian Vasconcelos 
Published: January 2024

The global impact of the COVID-19 pandemic has been unprecedented, and presently, the world is facing a new challenge known as Post-COVID syndrome (PCS). Current estimates suggest that more than 65 million people are grappling with PCS, encompassing several manifestations, including pulmonary, musculoskeletal, metabolic, and neuropsychiatric sequelae (cognitive and behavioral). The mechanisms underlying PCS remain unclear. The present study aimed to: (i) comprehensively characterize the acute effects of pulmonary inoculation of the betacoronavirus MHV-A59 in immunocompetent mice at clinical, cellular, and molecular levels; (ii) examine potential acute and long-term pulmonary, musculoskeletal, and neuropsychiatric sequelae induced by the betacoronavirus MHV-A59; and to (iii) assess sex-specific differences. Male and female C57Bl/6 mice were initially inoculated with varying viral titers (3×10³ to 3×105PFU/30 μL) of the betacoronavirus MHV-A59 via the intranasal route to define the highest inoculum capable of inducing disease without causing mortality. Further experiments were conducted with the 3×104PFU inoculum. Mice exhibited an altered neutrophil/lymphocyte ratio in the blood in the 2ndand 5thday post-infection (dpi). Marked lung lesions were characterized by hyperplasia of the alveolar walls, infiltration of polymorphonuclear leukocytes (PMN) and mononuclear leukocytes, hemorrhage, increased concentrations of CCL2, CCL3, CCL5, and CXCL1 chemokines, as well as high viral titers until the 5thdpi. While these lung inflammatory signs resolved, other manifestations were observed up to the 60 dpi, including mild brain lesions with gliosis and hyperemic blood vessels, neuromuscular dysfunctions, anhedonic-like behavior, deficits in spatial working memory, and short-term aversive memory. These musculoskeletal and neuropsychiatric complications were exclusive to female mice and were prevented after ovariectomy. In summary, our study describes for the first time a novel sex-dependent model of PCS focused on neuropsychiatric and musculoskeletal disorders. This model provides a unique platform for future investigations regarding the effects of acute therapeutic interventions on the long-term sequelae unleashed by betacoronavirus infection.