Neurofascin-155 as a putative antigen in combined central and peripheral demyelination.
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ABSTRACT:
SUBMITTER: Cortese A
PROVIDER: S-EPMC4897982 | biostudies-literature |
REPOSITORIES: biostudies-literature
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| S-EPMC9116708 | biostudies-literature
Project description:Axon pathfinding and synapse formation are essential processes for nervous system development and function. The assembly of myelinated fibres and nodes of Ranvier is mediated by a number of cell adhesion molecules of the immunoglobulin superfamily including neurofascin, encoded by the NFASC gene, and its alternative isoforms Nfasc186 and Nfasc140 (located in the axonal membrane at the node of Ranvier) and Nfasc155 (a glial component of the paranodal axoglial junction). We identified 10 individuals from six unrelated families, exhibiting a neurodevelopmental disorder characterized with a spectrum of central (intellectual disability, developmental delay, motor impairment, speech difficulties) and peripheral (early onset demyelinating neuropathy) neurological involvement, who were found by exome or genome sequencing to carry one frameshift and four different homozygous non-synonymous variants in NFASC. Expression studies using immunostaining-based techniques identified absent expression of the Nfasc155 isoform as a consequence of the frameshift variant and a significant reduction of expression was also observed in association with two non-synonymous variants affecting the fibronectin type III domain. Cell aggregation studies revealed a severely impaired Nfasc155-CNTN1/CASPR1 complex interaction as a result of the identified variants. Immunofluorescence staining of myelinated fibres from two affected individuals showed a severe loss of myelinated fibres and abnormalities in the paranodal junction morphology. Our results establish that recessive variants affecting the Nfasc155 isoform can affect the formation of paranodal axoglial junctions at the nodes of Ranvier. The genetic disease caused by biallelic NFASC variants includes neurodevelopmental impairment and a spectrum of central and peripheral demyelination as part of its core clinical phenotype. Our findings support possible overlapping molecular mechanisms of paranodal damage at peripheral nerves in both the immune-mediated and the genetic disease, but the observation of prominent central neurological involvement in NFASC biallelic variant carriers highlights the importance of this gene in human brain development and function.
| S-EPMC6763744 | biostudies-literature
Project description:Combined central and peripheral demyelination (CCPD) is not encountered frequently in the clinical practice, and it requires a high level of suspicion for diagnosis. We describe a case of a young man who was diagnosed with radiologically isolated syndrome (RIS) after presenting initially with symptoms suggestive of central nervous system (CNS) insult in the form of double vision, slurred speech, left-sided numbness, and unsteadiness. However, on the next day of admission, his neurological examination was remarkable for ataxia, areflexia, and ophthalmoplegia, the typical triad of Miller Fisher syndrome (MFS). After confirming both diagnoses, the final diagnosis of CCPD was made. The challenges one may face to diagnose and treat CCPD urge sharing of similar cases to open the door for further extensive and thorough investigations and to encourage further studies and analysis of available data to come up with consolidated management guidelines for rare disorders.
| S-EPMC8639527 | biostudies-literature
Project description:Background During the era of the Coronavirus disease 2019 (COVID-19) pandemic, various neurological syndromes were reported during or after the infection. Fortunately, efforts were made to successfully develop various vaccines with high efficacy and safety. Despite the promising results of those vaccines, they are too novel to be fully understood. Here we are shedding light on a neurological case presentation that may be attributed to one of the COVID-19 vaccines. Case presentation A 23-year-old male patient with no prior comorbidities presented with quadriparesis and numbness that were clinically and electrophysiologically consistent with Guillain-Barré Syndrome (GBS). The condition started 10 days after the first dose of the AstraZeneca vaccine. Moreover, MRI of the brain and spinal cord has shown evidence of non-specific central demyelination. Despite the radiological finding, the patient is not fulfilling the diagnosis of a known demyelination disorder and the lesions regressed on follow-up. Since no better explanation or trigger could be found, a post-vaccination immune-mediated reaction was considered. Conclusion We still cannot assume the certainty of the causality association between the vaccine and the neurological presentation. Meanwhile, we suggest vigilance for cases of GBS or myelitis following vaccination for Covid-19 and that post-vaccination surveillance programs ensure a statistically significant tool to prove or dispsrove the causality.
| S-EPMC8724022 | biostudies-literature
Project description:A one-year-old male Maltese terrier presented with mild ataxia and disorientation for 4 months. Over time, clinical signs progressed from paraparesis to non-ambulatory tetraparesis, voice change and dysphagia. Histological examination revealed concurrent leukoencephalomyelitis and polyneuritis. Infectious etiologies, including dengue, Japanese encephalitis, Zika, canine distemper, pseudorabies, rabies, toxoplasmosis, neosporosis, leishmaniasis, and encephalitozoonosis, were ruled out by PCR and/or immunohistochemical (IHC) staining. IHC tested on neurological tissues highlighted a heterogeneous population of infiltrating T and B lymphocytes admixed macrophages. Therefore, this case was diagnosed with current leukoencephalomyelitis and polyneuritis, resembling combined central and peripheral demyelination (CCPD), an autoimmune inflammatory demyelinating disease affecting both the CNS and PNS in humans.
| S-EPMC6785618 | biostudies-literature
Project description:ObjectiveWe report the clinical and serologic features of Japanese patients with chronic inflammatory demyelinating polyneuropathy (CIDP) displaying anti-neurofascin-155 (NF155) immunoglobulin G4 (IgG4) antibodies.MethodsIn sera from 533 patients with CIDP, anti-NF155 IgG4 antibodies were detected by ELISA. Binding of IgG antibodies to central and peripheral nerves was tested.ResultsAnti-NF155 IgG4 antibodies were identified in 38 patients (7%) with CIDP, but not in disease controls or normal participants. These patients were younger at onset as compared to 100 anti-NF155-negative patients with CIDP. Twenty-eight patients (74%) presented with sensory ataxia, 16 (42%) showed tremor, 5 (13%) presented with cerebellar ataxia associated with nystagmus, 3 (8%) had demyelinating lesions in the CNS, and 20 of 25 (80%) had poor response to IV immunoglobulin. The clinical features of the antibody-positive patients were statistically more frequent as compared to negative patients with CIDP (n = 100). Anti-NF155 IgG antibodies targeted similarly central and peripheral paranodes.ConclusionAnti-NF155 IgG4 antibodies were associated with a subgroup of patients with CIDP showing a younger age at onset, ataxia, tremor, CNS demyelination, and a poor response to IV immunoglobulin. The autoantibodies may serve as a biomarker to improve patients' diagnosis and guide treatments.
| S-EPMC4793783 | biostudies-literature
Project description:ObjectiveTo investigate anti-neurofascin 155 (NF155) antibody-positive chronic inflammatory demyelinating polyneuropathy (CIDP).MethodsSera from 50 consecutive CIDP patients diagnosed in our clinic, 32 patients with multiple sclerosis, 40 patients with other neuropathies including 26 with Guillain-Barré syndrome (GBS)/Fisher syndrome, and 30 healthy controls were measured for anti-NF antibodies by flow cytometry using HEK293 cell lines stably expressing human NF155 or NF186. Four additional CIDP patients with anti-NF155 antibodies referred from other clinics were enrolled for clinical characterization.ResultsThe positivity rate for anti-NF155 antibodies in CIDP patients was 18% (9/50), who all showed a predominance of IgG4 subclass. No other subjects were positive, except one GBS patient harboring IgG1 anti-NF155 antibodies. No anti-NF155 antibody carriers had anti-NF186 antibodies. Anti-NF155 antibody-positive CIDP patients had a significantly younger onset age, higher frequency of drop foot, gait disturbance, tremor and distal acquired demyelinating symmetric phenotype, greater cervical root diameter on magnetic resonance imaging neurography, higher cerebrospinal fluid protein levels, and longer distal and F-wave latencies than anti-NF155 antibody-negative patients. Marked symmetric hypertrophy of cervical and lumbosacral roots/plexuses was present in all anti-NF155 antibody-positive CIDP patients examined by neurography. Biopsied sural nerves from two patients with anti-NF155 antibodies demonstrated subperineurial edema and occasional paranodal demyelination, but no vasculitis, inflammatory cell infiltrates, or onion bulbs. Among anti-NF155 antibody-positive patients, treatment responders more frequently had daily oral corticosteroids and/or immunosuppressants in addition to intravenous immunoglobulins than nonresponders did.InterpretationAnti-NF155 antibodies occur in a subset of CIDP patients with distal-dominant involvement and symmetric nerve hypertrophy.
| S-EPMC4603379 | biostudies-literature
Project description:Stability of the myelin-axon unit is achieved, at least in part, by specialized paranodal junctions comprised of the neuronal heterocomplex of contactin and contactin-associated protein and the myelin protein neurofascin 155. In multiple sclerosis, normal distribution of these proteins is altered, resulting in the loss of the insulating myelin and consequently causing axonal dysfunction. Previously, this laboratory reported that mice lacking the myelin-enriched lipid sulphatide are characterized by a progressive deterioration of the paranodal structure. Here, it is shown that this deterioration is preceded by significant loss of neurofascin 155 clustering at the myelin paranode. Interestingly, prolonged electrophoretic separation revealed the existence of two neurofascin 155 bands, neurofascin 155 high and neurofascin 155 low, which are readily observed following N-linked deglycosylation. Neurofascin 155 high is observed at 7 days of age and reaches peak expression at one month of age, while neurofascin 155 low is first observed at 14 days of age and constantly increases until 5 months of age. Studies using conditional neurofascin knockout mice indicated that neurofascin 155 high and neurofascin 155 low are products of the neurofascin gene and are exclusively expressed by oligodendrocytes within the central nervous system. Neurofascin 155 high is a myelin paranodal protein while the distribution of neurofascin 155 low remains to be determined. While neurofascin 155 high levels are significantly reduced in the sulphatide null mice at 15 days, 30 days and 4 months of age, neurofascin 155 low levels remain unaltered. Although maintained at normal levels, neurofascin 155 low is incapable of preserving paranodal structure, thus indicating that neurofascin 155 high is required for paranodal stability. Additionally, comparisons between neurofascin 155 high and neurofascin 155 low in human samples revealed a significant alteration, specifically in multiple sclerosis plaques.
| S-EPMC2822635 | biostudies-literature
Project description:OBJECTIVE:To characterize the CSF cytokine profile in chronic inflammatory demyelinating polyneuropathy (CIDP) patients with IgG4 anti-neurofascin 155 (NF155) antibodies (NF155+ CIDP) or those lacking anti-NF155 antibodies (NF155- CIDP). METHODS:Twenty-eight CSF cytokines/chemokines/growth factors were measured by multiplexed fluorescent immunoassay in 35 patients with NF155+ CIDP, 36 with NF155- CIDP, and 28 with non-inflammatory neurological disease (NIND). RESULTS:CSF CXCL8/IL-8, IL-13, TNF-α, CCL11/eotaxin, CCL2/MCP-1, and IFN-γ were significantly higher, while IL-1β, IL-1ra, and G-CSF were lower, in NF155+ CIDP than in NIND. Compared with NF155- CIDP, CXCL8/IL-8 and IL-13 were significantly higher, and IL-1β, IL-1ra, and IL-6 were lower, in NF155+ CIDP. CXCL8/IL-8, IL-13, CCL11/eotaxin, CXCL10/IP-10, CCL3/MIP-1α, CCL4/MIP-1β, and TNF-α levels were positively correlated with markedly elevated CSF protein, while IL-13, CCL11/eotaxin, and IL-17 levels were positively correlated with increased CSF cell counts. IL-13, CXCL8/IL-8, CCL4/MIP-1β, CCL3/MIP-1α, and CCL5/RANTES were decreased by combined immunotherapies in nine NF155+ CIDP patients examined longitudinally. By contrast, NF155- CIDP had significantly increased IFN-γ compared with NIND, and exhibited positive correlations of IFN-γ, CXCL10/IP-10, and CXCL8/IL-8 with CSF protein. Canonical discriminant analysis of cytokines/chemokines revealed that NF155+ and NF155- CIDP were separable, and that IL-4, IL-10, and IL-13 were the three most significant discriminators. INTERPRETATION:Intrathecal upregulation of type 2 helper T (Th2) cell cytokines is characteristic of IgG4 NF155+ CIDP, while type 1 helper T cell cytokines are increased in CIDP regardless of the presence or absence of anti-NF155 antibodies, suggesting that overproduction of Th2 cell cytokines is unique to NF155+ CIDP.
| S-EPMC6856599 | biostudies-literature
Project description:Cell-surface expressed contactin 1 and neurofascin 155 control wiring of the nervous system and interact across cells to form and maintain paranodal myelin-axon junctions. The molecular mechanism of contactin 1 - neurofascin 155 adhesion complex formation is unresolved. Crystallographic structures of complexed and individual contactin 1 and neurofascin 155 binding regions presented here, provide a rich picture of how competing and complementary interfaces, post-translational glycosylation, splice differences and structural plasticity enable formation of diverse adhesion sites. Structural, biophysical, and cell-clustering analysis reveal how conserved Ig1-2 interfaces form competing heterophilic contactin 1 - neurofascin 155 and homophilic neurofascin 155 complexes whereas contactin 1 forms low-affinity clusters through interfaces on Ig3-6. The structures explain how the heterophilic Ig1-Ig4 horseshoe's in the contactin 1 - neurofascin 155 complex define the 7.4 nm paranodal spacing and how the remaining six domains enable bridging of distinct intercellular distances.
| S-EPMC9633819 | biostudies-literature