scholarly journals Dysregulation of Blood-Brain Barrier and Exacerbated Inflammatory Response in Cx47-Deficient Mice after Induction of EAE

2021 ◽  
Vol 14 (7) ◽  
pp. 621
Author(s):  
Filippos Stavropoulos ◽  
Elena Georgiou ◽  
Irene Sargiannidou ◽  
Kleopas A. Kleopa
Keyword(s):  
Multiple Sclerosis ◽  
Inflammatory Responses ◽  
Severe Disease ◽  
Disease Onset ◽  
Altered Expression ◽  
Gm Csf ◽  
T Cell Infiltration ◽  
Tight Junction Formation ◽  
Inflammatory Profile ◽  
Blood Spinal Cord Barrier

Induction of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), in connexin 32 (Cx32) or Cx47 knockout (KO) mice with deficiency in oligodendrocyte gap junctions (GJs) results in a more severe disease course. In particular, Cx47 KO EAE mice experience an earlier EAE onset and more pronounced disease severity, accompanied by dysregulated pro-inflammatory responses preceding the disease manifestations. In this study, analysis of relevant pro-inflammatory cytokines in wild type EAE, Cx32 KO EAE, and Cx47 KO EAE mice revealed altered expression of Vcam-1 preceding EAE [7 days post injection (dpi)], of Ccl2 at the onset of EAE (12 dpi), and of Gm-csf at the peak of EAE (24 dpi) in Cx47 KO EAE mice. Moreover, Cx47 KO EAE mice exhibited more severe blood-spinal cord barrier (BSCB) disruption, enhanced astrogliosis with defects in tight junction formation at the glia limitans, and increased T-cell infiltration prior to disease onset. Thus, Cx47 deficiency appears to cause dysregulation of the inflammatory profile and BSCB integrity, promoting early astrocyte responses in Cx47 KO EAE mice that lead to a more severe EAE outcome. Further investigation into the role of oligodendrocytic Cx47 in EAE and multiple sclerosis pathology is warranted.

scholarly journals Mast Cells Are Essential for Early Onset and Severe Disease in a Murine Model of Multiple Sclerosis

2000 ◽  
Vol 191 (5) ◽  
pp. 813-822 ◽  
Author(s):  
Virginia H. Secor ◽  
W. Evan Secor ◽  
Claire-Anne Gutekunst ◽  
Melissa A. Brown
Keyword(s):  
Multiple Sclerosis ◽  
Mast Cell ◽  
Mast Cells ◽  
B Cell ◽  
Disease Incidence ◽  
Severe Disease ◽  
Disease Onset ◽  
Allergic Inflammation ◽  
Indirect Evidence ◽  
Wild Type

In addition to their well characterized role in allergic inflammation, recent data confirm that mast cells play a more extensive role in a variety of immune responses. However, their contribution to autoimmune and neurologic disease processes has not been investigated. Experimental allergic encephalomyelitis (EAE) and its human disease counterpart, multiple sclerosis, are considered to be CD4+ T cell–mediated autoimmune diseases affecting the central nervous system. Several lines of indirect evidence suggest that mast cells could also play a role in the pathogenesis of both the human and murine disease. Using a myelin oligodendrocyte glycoprotein (MOG)-induced model of acute EAE, we show that mast cell–deficient W/Wv mice exhibit significantly reduced disease incidence, delayed disease onset, and decreased mean clinical scores when compared with their wild-type congenic littermates. No differences were observed in MOG-specific T and B cell responses between the two groups, indicating that a global T or B cell defect is not present in W/Wv animals. Reconstitution of the mast cell population in W/Wv mice restores induction of early and severe disease to wild-type levels, suggesting that mast cells are critical for the full manifestation of disease. These data provide a new mechanism for immune destruction in EAE and indicate that mast cells play a broader role in neurologic inflammation.

scholarly journals Endothelial Wnt/β-catenin signaling reduces immune cell infiltration in multiple sclerosis

2017 ◽  
Vol 114 (7) ◽  
pp. E1168-E1177 ◽  
Author(s):  
Justin E. Lengfeld ◽  
Sarah E. Lutz ◽  
Julian R. Smith ◽  
Claudiu Diaconu ◽  
Cameron Scott ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Immune Cell ◽  
Disease Onset ◽  
Cell Junctions ◽  
Cell Infiltration ◽  
Immune Cell Infiltration ◽  
Autoimmune Encephalomyelitis ◽  
T Cell Infiltration ◽  
The Central Nervous System ◽  
Cell Adhesion Molecule 1

Disruption of the blood–brain barrier (BBB) is a defining and early feature of multiple sclerosis (MS) that directly damages the central nervous system (CNS), promotes immune cell infiltration, and influences clinical outcomes. There is an urgent need for new therapies to protect and restore BBB function, either by strengthening endothelial tight junctions or suppressing endothelial vesicular transcytosis. Although wingless integrated MMTV (Wnt)/β-catenin signaling plays an essential role in BBB formation and maintenance in healthy CNS, its role in BBB repair in neurologic diseases such as MS remains unclear. Using a Wnt/β-catenin reporter mouse and several downstream targets, we demonstrate that the Wnt/β-catenin pathway is up-regulated in CNS endothelial cells in both human MS and the mouse model experimental autoimmune encephalomyelitis (EAE). Increased Wnt/β-catenin activity in CNS blood vessels during EAE progression correlates with up-regulation of neuronal Wnt3 expression, as well as breakdown of endothelial cell junctions. Genetic inhibition of the Wnt/β-catenin pathway in CNS endothelium before disease onset exacerbates the clinical presentation of EAE, CD4+ T-cell infiltration into the CNS, and demyelination by increasing expression of vascular cell adhesion molecule-1 and the transcytosis protein Caveolin-1 and promoting endothelial transcytosis. However, Wnt signaling attenuation does not affect the progressive degradation of tight junction proteins or paracellular BBB leakage. These results suggest that reactivation of Wnt/β-catenin signaling in CNS vessels during EAE/MS partially restores functional BBB integrity and limits immune cell infiltration into the CNS.

scholarly journals ScRNA-Seq study of neutrophils reveals vast heterogeneity and breadth of inflammatory responses in severe COVID-19 patients

2021 ◽  
Author(s):  
Jintao Xu ◽  
Bing He ◽  
Kyle Carver ◽  
Debora Vanheyningen ◽  
Brian Parkin ◽  
...  
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Severe Disease ◽  
Detailed Examination ◽  
Immune Dysregulation ◽  
Ribosomal Genes ◽  
Leukocyte Population ◽  
Inflammatory Profile ◽  
Severity Of The Disease ◽  
First Time

AbstractSevere cases of COVID-19 are characterized by dysregulated immune responses, but specific mechanisms contributing to the most severe outcomes remain unclear. Neutrophils are the most abundant leukocyte population in human hosts and reach markedly high numbers during severe COVID-19. However, a detailed examination of their responses has been largely overlooked in the COVID-19 literature to date. Here, we report for the first time a dedicated study of neutrophil responses using single-cell RNA sequencing (scRNA-Seq) of fresh leukocytes from 11 hospitalized adult patients with mild and severe COVID-19 disease and 5 healthy controls. We observed that neutrophils display a pronounced inflammatory profile, with dramatic disruption of predicted cell-cell interactions as the severity of the disease increases. We also identified unique mature and immature neutrophil subpopulations based on transcriptomic profiling, including an antiviral phenotype, and changes in the proportion of each population linked to the severity of the disease. Finally, pathway analysis revealed increased markers of oxidative phosphorylation and ribosomal genes, along with downregulation of many antiviral and host defense pathway genes during severe disease compared to mild infections. Collectively, our findings indicate that neutrophils are capable of mounting effective antiviral defenses but adopt a form of immune dysregulation characterized by excess cellular stress, thereby contributing to the pathogenesis of severe COVID-19.

An examination of the association between b2 adrenergic receptor polymorphisms and multiple sclerosis

2002 ◽  
Vol 8 (6) ◽  
pp. 475-478 ◽  
Author(s):  
M Niino ◽  
S Kikuchi ◽  
R Miyagishi ◽  
T Fukazawa ◽  
I Yabe ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Adrenergic Receptor ◽  
Gene Polymorphisms ◽  
Clinical Characteristics ◽  
Mononuclear Cells ◽  
Disease Onset ◽  
Japanese Patients ◽  
Peripheral Blood Mononuclear ◽  
Altered Expression ◽  
Control Subjects

In multiple sclerosis (MS), β-adrenergic receptor densities on peripheral blood mononuclear cells are enhanced, while the astrocytes present in plaques lack β2 adrenergic receptor (β2AR) expression. This differentially altered expression suggests that β2ARs may influence the pathogenesis of MS. In the present study, we investigated the association of polymorphisms of the β2AR gene with the occurrence of MS. Our results showed no significant differences in the distribution of the polymorphisms between MS patients overall and control subjects. Furthermore, no association was observed between the presence of β2AR gene polymorphisms and clinical characteristics, such as age at disease onset and disease severity. While a trend towards an increase of the Gly allele frequency in codon 16 was observed in the secondary-progressive MS, this result was not significantly different from that observed in relapsing-remitting MS patients or control subjects. Together, our findings suggest that the presence of β2AR gene polymorphisms may be inconclusive in the susceptibility to MS or in the clinical characteristics of Japanese patients with MS and, therefore, need further studies.

scholarly journals Cognitive Issues in Pediatric Multiple Sclerosis

2021 ◽  
Vol 11 (4) ◽  
pp. 442
Author(s):  
Emilio Portaccio ◽  
Ermelinda De Meo ◽  
Angelo Bellinvia ◽  
Maria Pia Amato
Keyword(s):  
Multiple Sclerosis ◽  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Pediatric Patients ◽  
Leisure Activities ◽  
Disease Onset ◽  
Cognitive Profiles ◽  
Brain Growth ◽  
Network Activation ◽  
Definition Of

Multiple sclerosis (MS) is one of the leading causes of disability in young adults. The onset of MS during developmental age makes pediatric patients particularly susceptible to cognitive impairment, resulting from both disease-related damage and failure of age-expected brain growth. Despite different test batteries and definitions, cognitive impairment has been consistently reported in approximately one-third of pediatric patients with MS. However, the lack of a uniform definition of cognitive impairment and the adoption of different test batteries have led to divergent results in terms of cognitive domains more frequently affected across the cohorts explored. This heterogeneity has hampered large international collaborative studies. Moreover, research aimed at the identification of risk factors (e.g., demographic, clinical, and radiological features) or protective factors (e.g., cognitive reserve, leisure activities) for cognitive decline is still scanty. Mood disorders, such as depression and anxiety, can be detected in these patients alongside cognitive decline or in isolation, and can negatively affect quality of life scores as well as academic performances. By using MRI, cognitive impairment was attributed to damage to specific brain compartments as well as to abnormal network activation patterns. However, multimodal MRI studies are still needed in order to assess the contribution of each MRI metric to cognitive impairment. Importantly, longitudinal studies have recently demonstrated failure of age-expected brain growth and of white matter (WM) and gray matter (GM) maturation plays a relevant role in determining cognitive dysfunction, in addition to MS-related direct damage. Whether these growth retardations might result in specific cognitive profiles according to the age at disease onset has not been studied, yet. A better characterization of cognitive profiles in pediatric MS patients, as well as the definition of neuroanatomical substrates of cognitive impairment and their longitudinal evolution are needed to develop efficient therapeutic strategies against cognitive impairment in this patient population.

scholarly journals Pattern of inflammatory immune response determines the clinical course and outcome of COVID-19: unbiased clustering analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eunyoung Emily Lee ◽  
Kyoung-Ho Song ◽  
Woochang Hwang ◽  
Sin Young Ham ◽  
Hyeonju Jeong ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Clustering Analysis ◽  
Validation Cohort ◽  
Inflammatory Responses ◽  
Clinical Course ◽  
Severe Disease ◽  
Outcome Data ◽  
Inflammatory Immune Response ◽  
Cluster 2

AbstractThe objective of the study was to identify distinct patterns in inflammatory immune responses of COVID-19 patients and to investigate their association with clinical course and outcome. Data from hospitalized COVID-19 patients were retrieved from electronic medical record. Supervised k-means clustering of serial C-reactive protein levels (CRP), absolute neutrophil counts (ANC), and absolute lymphocyte counts (ALC) was used to assign immune responses to one of three groups. Then, relationships between patterns of inflammatory responses and clinical course and outcome of COVID-19 were assessed in a discovery and validation cohort. Unbiased clustering analysis grouped 105 patients of a discovery cohort into three distinct clusters. Cluster 1 (hyper-inflammatory immune response) was characterized by high CRP levels, high ANC, and low ALC, whereas Cluster 3 (hypo-inflammatory immune response) was associated with low CRP levels and normal ANC and ALC. Cluster 2 showed an intermediate pattern. All patients in Cluster 1 required oxygen support whilst 61% patients in Cluster 2 and no patient in Cluster 3 required supplementary oxygen. Two (13.3%) patients in Cluster 1 died, whereas no patient in Clusters 2 and 3 died. The results were confirmed in an independent validation cohort of 116 patients. We identified three different patterns of inflammatory immune response to COVID-19. Hyper-inflammatory immune responses with elevated CRP, neutrophilia, and lymphopenia are associated with a severe disease and a worse outcome. Therefore, targeting the hyper-inflammatory response might improve the clinical outcome of COVID-19.

scholarly journals THU0351 MUSCLE INVOLVEMENT IN PATIENTS WITH SYSTEMIC SCLEROSIS AND ANTI-PM/SCL+ ANTIBODIES IS ASSOCIATED WITH CARDIAC AND PULMONARY INVOLVEMENT. ANALYSIS OF THE MULTICENTRE EUSTAR COHORT.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 407.1-407
Author(s):  
M. G. Lazzaroni ◽  
S. Zingarelli ◽  
P. Airò ◽  
Y. Allanore ◽  
O. Distler
Keyword(s):  
Systemic Sclerosis ◽  
Cardiac Involvement ◽  
Severe Disease ◽  
Disease Onset ◽  
Pulmonary Involvement ◽  
Left Ventricular ◽  
Research Support ◽  
Muscle Involvement ◽  
Group A ◽  
Tendon Friction Rubs

Background:Anti-PM/Scl antibodies positivity has been associated with frequent skeletal muscle involvement in patients with Systemic Sclerosis (SSc) in different studies, including the EUSTAR cohort (1). Moreover, although myositis has been previously associated with heart involvement in SSc patients (2), this issue has never been explored among anti-PM/Scl+ patients.Objectives:To evaluate the cardiac involvement in anti-PM/Scl patients with SSc in the large multicentre EUSTAR database, with focus on the subgroup of patients with muscle involvement.Methods:Patients from the EUSTAR database were included when the item anti-PM/Scl was fulfilled in at least one visit.Results:Anti-PM/Scl status was available in 7,353 SSc patients from EUSTAR database: 295 were anti-PM/Scl+. After exclusion of 151 patients with multiple autoantibody positivity, 144 anti-PM/Scl + patients were compared with 7,058 anti-PM/Scl- patients. Among them, 3,120 (44.2%) were positive for ACA, 2,361 (33.5%) for anti-Topo I and 274 (3.88%) for anti-RNAP3.Regarding the specific cardiac outcomes, in the anti-PM/Scl+ as compared to the anti-PM/Scl- group, a decreased rate of elevated sPAP at ECHO was recorded (12.8% vs 25.0%, p:0.001), while no differences were observed in the frequency of conduction blocks (26.2% vs 23.7%, p:0.526), abnormal diastolic function (33.9% vs 36.4%, p:0.582), pericardial effusion (10.2% vs 10.9%, p:1.000) and LVEF ≤50% (4.76% vs 6.11%, p:0.818). In multivariate analysis, adjusted for age at disease onset, sex, and disease duration, the negative association of anti-PM/Scl with elevated sPAP was not confirmed (p:0.061).When comparing anti-PM/Scl+ patients with (n=47) and without (n=87) CK elevation, the former group had a higher frequency of conduction blocks (43.2% vs 17.5%, p:0.005; OR 95% CI 3.47, 1.51-7.97) and left ventricular dysfunction, both diastolic (45.6% vs 27.2%, p:0.050; OR 95% CI 2.25, 1.05-4.81) and systolic (LVEF ≤50% 13.3% vs 0%, p:0.018; OR 95% CI 16.8, 0.87-324). Moreover, anti-PM/Scl+ patients with CK elevation had significantly increased rate of lung fibrosis on HRCT (p:0.045), intestinal symptoms (p:0.017), joint contractures (p:0.045) and tendon friction rubs (p:0.034).Conclusion:In the largest series of anti-PM/Scl positive SSc patients so far reported, muscle involvement in anti-PM/Scl+ patients (defined as increased serum CK) seems to represent a marker of a more severe disease phenotype, including a higher frequency of cardio-pulmonary involvement.References:[1]Lazzaroni MG, et al. Ann Rheum Dis 2018. 77 (2), 421-2.[2]Follansbee WP, et al. Am Heart J 1993. 125: 194-203.Acknowledgments:Authors would like to thank the patients’ association GILS (Gruppo Italiano Lotta Sclerodermia) for the grant that supported the project.Disclosure of Interests:Maria Grazia Lazzaroni: None declared, Stefania Zingarelli: None declared, Paolo Airò: None declared, Yannick Allanore Grant/research support from: BMS, Inventiva, Roche, Sanofi, Consultant of: Actelion, Bayer AG, BMS, BI, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche

Sign in / Sign up

Export Citation Format

Share Document