Shared genetics and causal associations between COVID-19 and multiple sclerosis.

Neuroinflammation caused by COVID-19 negatively impacts brain metabolism and function, while pre-existing brain pathology may contribute to individuals' vulnerability to the adverse consequences of COVID-19. We used summary statistics from genome-wide association studies (GWAS) to perform Mendelian randomization (MR) analyses, thus assessing potential associations between multiple sclerosis (MS) and two COVID-19 outcomes (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection and COVID-19 hospitalization). Genome-wide risk genes were compared between the GWAS datasets on hospitalized COVID-19 and MS. Literature-based analysis was conducted to construct molecular pathways connecting MS and COVID-19. We found that genetic liability to MS confers a causal effect on hospitalized COVID-19 (odd ratio [OR]: 1.09, 95% confidence interval: 1.03-1.16) but not on SARS-CoV-2 infection (1.03, 1.00-1.05). Genetic liability to hospitalized COVID-19 confers a causal effect on MS (1.15, 1.02-1.30). Hospitalized COVID-19 and MS share five risk genes within two loci, including TNFAIP8, HSD17B4, CDC37, PDE4A, and KEAP1. Pathway analysis identified a panel of immunity-related genes that may mediate the links between MS and COVID-19. Our study suggests that MS was associated with a 9% increased risk for COVID-19 hospitalization, while hospitalized COVID-19 was associated with a 15% increased risk for MS. Immunity-related pathways may underlie the link between MS on COVID-19.

Differential transcriptomic changes in the central nervous system and urinary bladders of mice infected with a coronavirus.

Multiple sclerosis (MS) often leads to the development of neurogenic lower urinary tract symptoms (LUTS). We previously characterized neurogenic bladder dysfunction in a mouse model of MS induced by a coronavirus, mouse hepatitis virus (MHV). The aim of the study was to identify genes and pathways linking neuroinflammation in the central nervous system with urinary bladder (UB) dysfunction to enhance our understanding of the mechanisms underlying LUTS in demyelinating diseases. Adult C57BL/6 male mice (N = 12) received either an intracranial injection of MHV (coronavirus-induced encephalomyelitis, CIE group), or sterile saline (control group). Spinal cord (SC) and urinary bladders (UB) were collected from CIE mice at 1 wk and 4 wks, followed by RNA isolation and NanoString nCounter Neuroinflammation assay. Transcriptome analysis of SC identified a significantly changed expression of >150 genes in CIE mice known to regulate astrocyte, microglia and oligodendrocyte functions, neuroinflammation and immune responses. Two genes were significantly upregulated (Ttr and Ms4a4a), and two were downregulated (Asb2 and Myct1) only in the UB of CIE mice. Siglec1 and Zbp1 were the only genes significantly upregulated in both tissues, suggesting a common transcriptomic link between neuroinflammation in the CNS and neurogenic changes in the UB of CIE mice.

The Role of Cytotoxic T-Lymphocyte Antigen 4 in the Pathogenesis of Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune neurodegenerative disorder of the central nervous system that presents heterogeneous clinical manifestations and course. It has been shown that different immune checkpoints, including Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), can be involved in the pathogenesis of MS. CTLA-4 is a critical regulator of T-cell homeostasis and self-tolerance and represents a key inhibitor of autoimmunity. In this scopingreview, we resume the current preclinical and clinical studies investigating the role of CTLA-4 in MS with different approaches. While some of these studies assessed the expression levels of CTLA-4 on T cells by comparing MS patients with healthy controls, others focused on the evaluation of the effects of common MS therapies on CTLA-4 modulation or on the study of the CTLA-4 blockade or deficiency in experimental autoimmune encephalomyelitis models. Moreover, other studies in this field aimed to discover if the CTLA-4 gene might be involved in the predisposition to MS, whereas others evaluated the effects of treatment with CTLA4-Ig in MS. Although these results are of great interest, they are often conflicting. Therefore, further studies are needed to reveal the exact mechanisms underlying the action of a crucial immune checkpoint such as CTLA-4 in MS to identify novel immunotherapeutic strategies for MS patients.

Bioinformatics approach reveals the critical role of the NOD-like receptor signaling pathway in COVID-19-associated multiple sclerosis syndrome.

Multiple sclerosis (MS) is a kind of central nervous system (CNS) autoimmune disease, which mainly damages nerves, the brain, and the spinal cord. Recently, several clinical cases reported the relativity between Coronavirus Disease 2019 (COVID-19) and the development of MS, but the mechanism of how COVID-19 affects the occurrence of MS was still not clear. It is bioinformatics technology that we use to explore the potential association at the gene level. The genetic information related to the two diseases was collected from the DisGNET platform for functional protein network analysis and used STRING to identify the complete gene set. The protein-protein interaction (PPI) network was analyzed by STRING. Finally, in the GEO database, we selected peripheral blood mononuclear cell (PBMC) RNA sequencing data (GSE164805, GSE21942) from COVID-19 patients and MS patients to verify the potential cross mechanism between the two diseases. The similar gene set of immune or inflammation existed between the patients with COVID-19 and ones with MS, including L2RA, IFNG, IL1B, NLRP3, and TNF. Interaction network analysis among proteins revealed that IL1B, P2RX7, IFNB1, IFNB1, TNF, and CASP1 enhanced the network connectivity between the combined gene set of COVID-19 and MS associated with NOD-like receptor (NLR) signaling. The involvement of NLR signaling in both diseases was further confirmed by comparing peripheral blood monocyte samples from COVID-19 and MS patients. Activation of NLR signaling was found in both COVID-19 and MS. The PBMC samples analyses also indicated the involvement of the NLR signaling pathway. Taken together, our data analyses revealed that the NLR signaling pathway might play a critical role in the COVID-19-related MS.

Molecular Research in Multiple Sclerosis.

The Special Issue, "Molecular Research in Multiple Sclerosis", provides a better comprehension of the disease and establishes possible new biomarkers to ensure better care of MS patients in the future [...].

13th Post-ECTRIMS Meeting: review of the new developments presented at the 2020 ECTRIMS Congress (I). / XIII Reunión Post-ECTRIMS: revisión de las novedades presentadas en el Congreso ECTRIMS 2020 (I).

INTRODUCTION: For more than a decade, following the ECTRIMS Congress, the Post-ECTRIMS Meeting has been held in Spain, where neurologists with expertise in multiple sclerosis (MS) from all over the country meet to review the most relevant latest developments presented at the ECTRIMS congress (on this occasion held together with ACTRIMS). AIM: This article, published in two parts, summarises the presentations that took place at the Post-ECTRIMS Meeting, held online on 16 and 17 October 2020. DEVELOPMENT: This first part includes the latest results regarding the impact of the environment and lifestyle on risk of MS and its clinical course, and the role of epigenetics and genetic factors on these processes. Findings from preclinical and clinical research on the lymphocyte subtypes identified and the involvement of lymphoid follicles and meningeal involvement in the disease are discussed. Changes in brain structure are addressed at the microscopic and macroscopic levels, including results from high-resolution imaging techniques. The latest advances on biomarkers for the diagnosis and prognosis of MS, and on the involvement of the microbiome in these patients are also reported. Finally, results from patient registries on the impact of COVID-19 in MS patients are outlined. CONCLUSIONS: There have been new data on MS risk factors, the impact of MS at the cellular and structural level, the role of the microbiome in the disease, biomarkers, and the relationship between COVID-19 and MS.

TITLE: XIII Reunión Post-ECTRIMS: revisión de las novedades presentadas en el Congreso ECTRIMS 2020 (I).Introducción. Desde hace más de una década, tras el congreso ECTRIMS, se celebra en España la reunión Post-ECTRIMS, donde neurólogos expertos en esclerosis múltiple (EM) de toda España se reúnen para revisar las principales novedades presentadas en el ECTRIMS (en esta ocasión, celebrado junto con el ACTRIMS). Objetivo. En el presente artículo, publicado en dos partes, se resumen las ponencias que tuvieron lugar en la reunión Post-ECTRIMS, celebrada los días 16 y 17 de octubre de 2020 de forma virtual. Desarrollo. En esta primera parte se incluyen los últimos resultados acerca del impacto del ambiente y el estilo de vida sobre el riesgo de EM y su curso clínico, y el papel de la epigenética y los factores genéticos sobre estos procesos. Se discuten los hallazgos en investigación preclínica y clínica sobre los subtipos de linfocitos identificados, y la implicación de los folículos linfoides y la afectación meníngea en la enfermedad. Los cambios en la estructura cerebral se abordan a nivel microscópico y macroscópico, incluyendo resultados de técnicas de imagen de alta resolución. También se presentan los últimos avances sobre biomarcadores para el diagnóstico y el pronóstico de la EM, y sobre la afectación del microbioma en estos pacientes. Por último, se esbozan los resultados de registros de pacientes sobre el impacto de la COVID-19 en los pacientes con EM. Conclusiones. Ha habido nuevos datos sobre factores de riesgo de la EM, impacto de la EM a nivel celular y estructural, papel del microbioma en la enfermedad, biomarcadores y la relación entre COVID-19 y EM.

ACE2, TMPRSS2, and Furin variants and SARS-CoV-2 infection in Madrid, Spain.

It has been suggested that some individuals may present genetic susceptibility to SARS-CoV-2 infection, with particular research interest in variants of the ACE2 and TMPRSS2 genes, involved in viral penetration into cells, in different populations and geographic regions, although insufficient information is currently available. This study addresses the apparently reasonable hypothesis that variants of these genes may modulate viral infectivity, making some individuals more vulnerable than others. Through whole-exome sequencing, the frequency of exonic variants of the ACE2, TMPRSS2, and Furin genes was analyzed in relation to presence or absence of SARS-CoV-2 infection in a familial multiple sclerosis cohort including 120 individuals from Madrid. The ACE2 gene showed a low level of polymorphism, and none variant was significantly associated with SARS-CoV-2 infection. These variants have previously been detected in Italy. While TMPRSS2 is highly polymorphic, the variants found do not coincide with those described in other studies, with the exception of rs75603675, which may be associated with SARS-CoV-2 infection. The synonymous variants rs61735792 and rs61735794 showed a significant association with infection. Despite the limited number of patients with SARS-CoV-2 infection, some variants, especially in TMPRSS2, may be associated with COVID-19.