Emerging neurotropic features of SARS-CoV-2

Extracellular Vesicles: The Invisible Heroes and Villains of COVID-19 Central Neuropathology

Acknowledging the neurological symptoms of COVID-19 and the long-lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS-CoV-2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro-inflammatory, pro-coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID-19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID-19 due to their innate homing properties, low immunogenicity, and ability to cross the blood-brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID-19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID-19 neuropathology as carriers of SARS-CoV-2 or other pathogenic contents, as predictors of COVID-19 neuropathology by transporting brain-derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID-19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease.

Identification of key genes as potential diagnostic and therapeutic targets for comorbidity of myasthenia gravis and COVID-19

Introduction

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disorder. Coronavirus disease 2019 (COVID-19) has a significant impact on the health and quality of life of MG patients and may even trigger the onset of MG in some cases. With the worldwide development of the COVID-19 vaccination, several new-onset MG cases and exacerbations following the COVID-19 vaccines have been acknowledged. The potential link between myasthenia gravis (MG) and COVID-19 has prompted the need for further investigation into the underlying molecular mechanism.

Methods and results

The differential expression analysis identified six differentially expressed genes (DEGs) shared by myasthenia gravis (MG) and COVID-19, namely SAMD9, PLEK, GZMB, JUNB, NR4A1, and NR1D1. The relationship between the six common genes and immune cells was investigated in the COVID-19 dataset. The predictive value of the shared genes was assessed and a nomogram was constructed using machine learning algorithms. The regulatory miRNAs, transcription factors and small molecular drugs were predicted, and the molecular docking was carried out by AutoDock.

Discussion

We have identified six common DEGs of MG and COVID-19 and explored their immunological effects and regulatory mechanisms. The result may provide new insights for further mechanism research.

Association of SARS-CoV-2 infection with neurological impairments in pediatric population: A systematic review

Neurological manifestations have been widely reported in adults with COVID-19, yet the extent of involvement among the pediatric population is currently poorly characterized. The objective of our systematic review is to evaluate the association of SARS-CoV-2 infection with neurological symptoms and neuroimaging manifestations in the pediatric population. A literature search of Cochrane Library; EBSCO CINAHL; Global Index Medicus; OVID AMED, Embase, Medline, PsychINFO; and Scopus was conducted in accordance with the Peer Review of Electronic Search Strategies form (October 1, 2019 to March 15, 2022). Studies were included if they reported (1) COVID-19-associated neurological symptoms and neuroimaging manifestations in individuals aged <18 years with a confirmed, first SARS-CoV-2 infection and were (2) peer-reviewed. Full-text reviews of 222 retrieved articles were performed, along with subsequent reference searches. A total of 843 no-duplicate records were retrieved. Of the 19 identified studies, there were ten retrospective observational studies, seven case series, one case report, and one prospective cohort study. A total of 6985 individuals were included, where 12.8% (n = 892) of hospitalized patients experienced neurocognitive impairments which includes: 1) neurological symptoms (n = 294 of 892, 33.0%), 2) neurological syndromes and neuroimaging abnormalities (n = 223 of 892, 25.0%), and 3) other phenomena (n = 233 of 892, 26.1%). Based on pediatric-specific cohorts, children experienced more drowsiness (7.3% vs. 1.3%) and muscle weakness (7.3% vs. 6.3%) as opposed to adolescents. Agitation or irritability was observed more in children (7.3%) than infants (1.3%). Our findings revealed a high prevalence of immune-mediated patterns of disease among COVID-19 positive pediatric patients with neurocognitive abnormalities.

The effect of COVID-19 on Multiple Sclerosis relapse: A systematic review and meta-analysis

BACKGROUND

Multiple Sclerosis (MS) is a chronic autoimmune disease, affecting over 2.5 million people worldwide. There has been growing concern about the impact of COVID-19 on the clinical course of MS. However, these findings remain controversial, and there is a lack of high-quality evidence to establish the relationship between COVID-19 and MS.

METHODS

A comprehensive search was done to identify relevant studies reporting relapse rate in patients with MS (pwMS), those comparing the relapse rate of COVID-19 pwMS and MS controls, and studies investigating the effect of COVID-19 on relapse rate of pwMS. The results were presented as proportion of COVID-19 pwMS experiencing relapse and odds ratio determining the impact of COVID-19 on relapse rate.

RESULTS

Fourteen studies were included in the analyses. The proportion of COVID-19 positive pwMS with relapse was 7.71 per 100 cases (95 % confidence interval, CI: 4.41-13.89, I2=96 %). Quantitative evaluation of studies with pwMS without COVID-19 did not demonstrate a statistically significant difference in relapse rate of patients with COVID-19 (OR: 0.75, 95 %CI: 0.44-1.29, I2= 54 %). Subgroup and sensitivity analyses did not alter the lack of significance of association between COVID-19 and MS relapse. Sensitivity analysis excluding the outlying study was largely in favor of no difference between the groups (OR:1.00, 95 %CI: 0.72-1.38, I2=34 %) CONCLUSION: The results of this review does not suggest that COVID-19 influences the relapse rate in pwMS. While the findings alleviate the concerns regarding the co-occurrence of the diseases, further studies are needed to investigate the effects of confounding factors.

Autoimmune myasthenia gravis and COVID-19. A case report-based review

A potential relationship between COVID-19 infection and new onset myasthenia gravis (MG) has been suggested by the coexistence of these two diseases in a number of reports. This study aimed to assess their relationship by reviewing case studies of COVID-19 followed by new onset MG published between 01 December 2019 and 30 June 2023 identified by a search of PubMed/Medline database. In addition, we reviewed evidence in favour and against a potential cause and effect association, and described possible mechanisms that would underpin such a relationship. We identified 14 publications that reported 18 cases. Analysis showed the following features: age 19-83 years; 10 men/8 women; median time interval between COVID-19 and MG (17, 5-56 days); autoimmune comorbidities (4); generalised MG (14); ocular MG (4); thymoma (3); antiacetylcholine receptor antibody (16); antimuscle-specific kinase antibodies (2). All patients improved following treatment. Proof of direct causality between the two conditions can only be established in time by confirming epidemiological increase in the incidence of MG or elucidating pathogenic mechanisms to substantiate a possible cause-effect association, or both.

Association of SARS-CoV-2 Infection with Neurological Symptoms and Neuroimaging Manifestations in the Pediatric Population: A Systematic Review

Background

Neurological manifestations have been widely reported in adults with COVID-19, yet the extent of involvement among the pediatric population is currently poorly characterized. The objective of our systematic review is to evaluate the association of SARS-CoV-2 infection with neurological symptoms and neuroimaging manifestations in the pediatric population.

Methods

A literature search of Cochrane Library; EBSCO CINAHL; Global Index Medicus; OVID AMED, Embase, Medline, PsychINFO; and Scopus was conducted in accordance with the Peer Review of Electronic Search Strategies form (October 1, 2019 to March 15, 2022). Studies were included if they reported (1) COVID-19-associated neurological symptoms and neuroimaging manifestations in individuals aged < 18 years with a confirmed, first SARS-CoV-2 infection and were (2) peer-reviewed. Full-text reviews of 222 retrieved articles were performed, along with subsequent reference searches.

Results

A total of 843 nonduplicate records were retrieved. Of the 19 identified studies, there were ten retrospective observational studies, seven case series, one case report, and one prospective cohort study. A total of 6,985 individuals were included, where 12.8% of hospitalized patients experienced neurocognitive impairments: MIS-C (24.2%), neuroinflammation (10.1%), and encephalopathy (8.1%) were the most common disorders; headaches (16.8%) and seizures (3.8%) were the most common symptoms. Based on pediatric-specific cohorts, children experienced more drowsiness (7.3% vs. 1.3%) and muscle weakness (7.3% vs. 6.3%) as opposed to adolescents. Agitation or irritability was observed more in children (7.3%) than infants (1.3%).

Conclusion

Our findings revealed a high prevalence of immune-mediated patterns of disease among COVID-19 positive pediatric patients with neurocognitive abnormalities.

First-episode mania after COVID-19: A case series in Iran

Background

Increasing reports of manic episodes in patients during acute infection with COVID-19 have been documented since the pandemic began, including individuals without a previous personal or family history of bipolar disorder. As infections and autoimmunity have putative roles in bipolar disorder, we aimed to document the clinical presentations, associated stressors, family aggregation patterns, and brain imaging and electroencephalographic correlates with a series of patients with episodes of mania that emerged shortly after COVID-19 infections.

Methods

We obtained all relevant clinical information from 12 patients whose first manic episode started within a month of COVID-19 infection and were treated at Rasool-e-Akram hospital and Iran psychiatric hospital, two tertiary medical centers in Tehran, Iran, in 2021.

Results

Patients had a mean age of 44. The interval between the onset of symptoms of COVID and mania ranged between 0 and 28 days (mean: 16.25, median: 14 days); it was observed to be shorter in patients with a family history of mood disorders but not in those receiving corticosteroids. Alongside a descriptive overview of our sample, we provide detailed narrative descriptions of two of the cases for illustrative purposes and discuss our observations in the context of other cases reported elsewhere and the state-of-the-art regarding infectious diseases, COVID-19, and bipolar disorder as reported in previous literature.

Conclusion

Our case series documents observational and naturalistic evidence from a dozen of cases of mania in the context of acute COVID-19, which, while limited, calls for analytical research of the phenomenon, and points at a family history of bipolar disorder and the use of corticosteroids as factors for particular focus.

Involvement of NLRP3 Inflammasome in SARS-Cov-2-Induced Multiorgan Dysfunction in Patients with COVID-19: A Review of Molecular Mechanisms

Nucleotide-binding domain and leucine-rich repeat protein- 3 (NLRP3) inflammasome is a critical component of the innate immune system. The inflammasome activation is correlated with the COVID- 19 severity. Furthermore, the underlying conditions are accompanied by hyperactivation of NLRP3 inflammasome and poor outcomes. Herein, we presented the involvement of NLRP3 inflammasome in the pathogenies of SARS-CoV-2-induced multiorgan dysfunction and potential therapeutics. Overexpression of NLRP3 inflammasome components and subsequently increased levels of cytokines following viral infection leads to the cytokine storm and indirectly affects the organ functions. Besides, invading host cells via SARS-CoV-2 further activates the NLRP3 inflammasome and induces pyroptosis in immune cells, resulting in the secretion of higher levels of proinflammatory cytokines into the extracellular matrix. These events continued by induction of fibrosis and organ dysfunction following infection with SARS-CoV-2 in critically ill patients. This condition can be observed in individuals with comorbidities (e.g., diabetes, obesity, etc.) due to a primed state of immunity, which can cause severe disease or death in this population. Therefore, understanding the mechanisms underlying host-SARS-CoV-2 interaction may help to clarify the pathophysiology of SARS-CoV-2- induced multiorgan dysfunction and introduce potential therapeutic strategies.

Effects of COVID-19 on children with autism

The coronavirus disease 2019 (COVID-19) pandemic affects all countries and populations worldwide, significantly impacting people with autism with a high risk of morbidity and mortality due to COVID-19. Approximately 25% of children with autism have an asymptomatic or symptomatic immune deficiency or dysfunction. In addition, they frequently have various comorbid conditions that increase the severity of COVID-19. In addition, severe COVID-19 during pregnancy may increase the risk of autism in the offspring. Furthermore, severe acute respiratory syndrome coronavirus 2 could target human nervous system tissues due to its neurotrophic effects. The COVID-19 pandemic intensely impacts many patients and families in the autism community, especially the complex management of autism-associated disorders during the complete lockdown. During the complete lockdown, children with autism had difficulties coping with the change in their routine, lack of access to special education services, limited physical space available, and problems related to food and sleep. Additionally, children with autism or intellectual disabilities are more liable to be abused by others during the pandemic when the standard community supports are no longer functioning to protect them. Early detection and vaccination of children with autism against COVID-19 are highly indicated. They should be prioritized for testing, vaccination, and proper management of COVID-19 and other infectious diseases. In this review, we discuss the various effects of COVID-19 on children with autism, the difficulties they face, the increased risk of infection during pregnancy, how to alleviate the impact of COVID-19, and how to correct the inequalities in children with autism.

No serological evidence for neuronal damage or reactive gliosis in neuro-COVID-19 patients with long-term persistent headache

Recent studies have indicated that long-term neurological sequelae after COVID-19 are not accompanied by an increase of canonical biomarkers of central nervous system injury in blood, but subgroup stratifications are lacking. This is a particular concern in chronic headache, which can be a leading symptom of Post-COVID diseases associated with neuronal damage such as vasculitis or autoimmune encephalitis. We here compared patients with mild Post-COVID-19 syndrome and persistent headache (persistent Post-COVID-19 headache) lasting longer than 12 weeks after the initial serological diagnosis, to patients with mild and severe COVID-19 and COVID-19-negative controls. Levels of neurofilament light chain and glial fibrillary astrocytic protein, i.e. markers of neuronal damage and reactive astrogliosis, were lower in blood from patients with persistent Post-COVID-19 headache compared to patients with severe COVID-19. Hence, our pilot serological study indicates that long-term Post-COVID-19 headache may not be a sign of underlying neuronal damage or neuroinflammation.

SARS-CoV-2 Permissive glioblastoma cell line for high throughput antiviral screening

Despite the great success of the administered vaccines against SARS-CoV-2, the virus can still spread, as evidenced by the current circulation of the highly contagious Omicron variant. This emphasizes the additional need to develop effective antiviral countermeasures. In the context of early preclinical studies for antiviral assessment, robust cellular infection systems are required to screen drug libraries. In this study, we reported the implementation of a human glioblastoma cell line, stably expressing ACE2, in a SARS-CoV-2 cytopathic effect (CPE) reduction assay. These glioblastoma cells, designated as U87.ACE2⁺, expressed ACE2 and cathepsin B abundantly, but had low cellular levels of TMPRSS2 and cathepsin L. The U87.ACE2⁺ cells fused highly efficiently and quickly with SARS-CoV-2 spike expressing cells. Furthermore, upon infection with SARS-CoV-2 wild-type virus, the U87.ACE2⁺ cells displayed rapidly a clear CPE that resulted in complete cell lysis and destruction of the cell monolayer. By means of several readouts we showed that the U87.ACE2⁺ cells actively replicate SARS-CoV-2. Interestingly, the U87.ACE2⁺ cells could be successfully implemented in an MTS-based colorimetric CPE reduction assay, providing IC₅₀ values for Remdesivir and Nirmatrelvir in the (low) nanomolar range. Lastly, the U87.ACE2⁺ cells were consistently permissive to all tested SARS-CoV-2 variants of concern, including the current Omicron variant. Thus, ACE2 expressing glioblastoma cells are highly permissive to SARS-CoV-2 with productive viral replication and with the induction of a strong CPE that can be utilized in high-throughput screening platforms.