scholarly journals Autoimmune gait disturbance accompanying adaptor protein-3B2-IgG

Neurology ◽  
2019 ◽  
Vol 93 (10) ◽  
pp. e954-e963 ◽  
Author(s):  
Josephe A. Honorat ◽  
A. Sebastian Lopez-Chiriboga ◽  
Thomas J. Kryzer ◽  
Lars Komorowski ◽  
Madeleine Scharf ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Western Blot ◽  
Adaptor Protein ◽  
Sensory Neuropathy ◽  
Clinical Information ◽  
Sympathetic Ganglia ◽  
Immunofluorescence Assay ◽  
Mass Spectrometry Analysis ◽  
Antigen Specificity ◽  
Spectrometry Analysis

ObjectiveTo describe phenotypes, treatment response, and outcomes of autoimmunity targeting a synaptic vesicle coat protein, the neuronal (B2) form of adaptor protein–3 (AP3).MethodsArchived serum and CSF specimens (from 616,025 screened) harboring unclassified synaptic antibodies mimicking amphiphysin–immunoglobulin G (IgG) on tissue-based indirect immunofluorescence assay (IFA) were re-evaluated for novel IgG staining patterns. Autoantigens were identified by western blot and mass spectrometry. Recombinant western blot and cell-binding assay (CBA) were used to confirm antigen specificity. Clinical data were obtained retrospectively.ResultsSerum (10) and CSF (6) specimens of 10 patients produced identical IFA staining patterns throughout mouse nervous system tissues, most prominently in cerebellum (Purkinje neuronal perikarya, granular layer synapses, and dentate regions), spinal cord gray matter, dorsal root ganglia, and sympathetic ganglia. The antigen revealed by mass spectrometry analysis and confirmed by recombinant assays (western blot and CBA) was AP3B2 in all. Of 10 seropositive patients, 6 were women; median symptom onset age was 42 years (range 24–58). Clinical information was available for 9 patients, all with subacute onset and rapidly progressive gait ataxia. Neurologic manifestations were myeloneuropathy (3), peripheral sensory neuropathy (2), cerebellar ataxia (2), and spinocerebellar ataxia (2). Five patients received immunotherapy; none improved, but they did not worsen over the follow-up period (median 36 months; range 3–94). Two patients (both with cancer) died. One of 50 control sera was positive by western blot only (but not by IFA or CBA).ConclusionAP3B2 (previously named β-neuronal adaptin-like protein) autoimmunity appears rare, is accompanied by ataxia (sensory or cerebellar), and is potentially treatable.

scholarly journals Autoimmune septin-5 cerebellar ataxia

2018 ◽  
Vol 5 (5) ◽  
pp. e474 ◽  
Author(s):  
Josephe A. Honorat ◽  
A. Sebastian Lopez-Chiriboga ◽  
Thomas J. Kryzer ◽  
James P. Fryer ◽  
Michelle Devine ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Recombinant Protein ◽  
Western Blot ◽  
Cerebellar Ataxia ◽  
Molecular Layer ◽  
Immunofluorescence Assay ◽  
Mass Spectrometry Analysis ◽  
Antigen Specificity ◽  
Spectrometry Analysis ◽  
Protein Assays

ObjectiveTo report a form of autoimmune cerebellar ataxia in which antibodies target septin-5, a guanosine triphosphate (GTP)-binding neural protein involved in neurotransmitter exocytosis.MethodsArchived sera and CSF specimens with unclassified synaptic antibodies were re-evaluated by tissue-based indirect immunofluorescence assay. Autoantigens were identified by Western blot and mass spectrometry. Recombinant protein assays (Western blot, cell based, and protein screening array) confirmed antigen specificity.ResultsSerum and CSF from 6 patients produced identical synaptic immunoglobulin G (IgG) staining patterns of synaptic regions (neuropil) of the mouse cerebrum and cerebellum. The molecular layer of the cerebellum and the thalamus demonstrated stronger immunoreactivity than the midbrain, hippocampus, cortex, and basal ganglia. The antigen revealed by mass spectrometry analysis of immunoprecipitated cerebellar proteins and confirmed by recombinant protein assays was septin-5. All 4 patients with records available had subacute onset of cerebellar ataxia with prominent eye movement symptoms (oscillopsia or vertigo). None had cancer detected. Improvements occurred after immunotherapies (2) or spontaneously (1). One patient died.ConclusionSeptin-5 IgG represents a biomarker for a potentially fatal but treatable autoimmune ataxia.

scholarly journals Identification of cytoplasmic sialidase NEU2-associated proteins by LC-MS/MS

2018 ◽  
Vol 44 (4) ◽  
pp. 462-472
Author(s):  
Secil Akyildiz Demir ◽  
Volkan Seyrantepe
Keyword(s):  
Mass Spectrometry ◽  
Western Blot ◽  
Blot Analysis ◽  
Actin Filaments ◽  
Western Blot Analysis ◽  
Mammalian Cells ◽  
Protein S ◽  
Mass Spectrometry Analysis ◽  
Interacting Protein ◽  
Spectrometry Analysis

Abstract Background Cytoplasmic sialidase (NEU2) plays an active role in removing sialic acids from oligosaccharides, glycopeptides, and gangliosides in mammalian cells. NEU2 is involved in various cellular events, including cancer metabolism, neuronal and myoblast differentiation, proliferation, and hypertrophy. However, NEU2-interacting protein(s) within the cell have not been identified yet. Objective The aim of this study is to investigate NEU2 interacting proteins using two-step affinity purification (TAP) strategy combined with mass spectrometry analysis. Methods In this study, NEU2 gene was cloned into the pCTAP expression vector and transiently transfected to COS-7 cells by using PEI. The most efficient expression time of NEU2- tag protein was determined by real-time PCR and Western blot analysis. NEU2-interacting protein(s) were investigated by using TAP strategy combined with two different mass spectrometry experiment; LC-MS/MS and MALDI TOF/TOF. Results Here, mass spectrometry analysis showed four proteins; α-actin, β-actin, calmodulin and histone H1.2 proteins are associated with NEU2. The interactions between NEU2 and actin filaments were verified by Western blot analysis and immunofluorescence analysis. Conclusions Our study suggests that association of NEU2 with actin filaments and other protein(s) could be important for understanding the biological role of NEU2 in mammalian cells.

scholarly journals Effect of Ocular Hypertension on D-β-Aspartic Acid-Containing Proteins in the Retinas of Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Kanamoto ◽  
Takashi Tachibana ◽  
Yasushi Kitaoka ◽  
Toshio Hisatomi ◽  
Yasuhiro Ikeda ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ocular Hypertension ◽  
Aspartic Acid ◽  
Atp Synthase ◽  
Wistar Rats ◽  
Protein Band ◽  
Mass Spectrometry Analysis ◽  
Liquid Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Sds Page

Purpose. To investigate the effect of ocular hypertension-induced isomerization of aspartic acid in retinal proteins. Methods. Adult Wistar rats with ocular hypertension were used as an experimental model. D-β-aspartic acid-containing proteins were isolated by SDS-PAGE and western blot with an anti-D-β-aspartic acid antibody and identified by liquid chromatography-mass spectrometry analysis. The concentration of ATP was measured by ELISA. Results. D-β-aspartic acid was expressed in a protein band at around 44.5 kDa at much higher quantities in the retinas of rats with ocular hypertension than in those of normotensive rats. The 44.5 kDa protein band was mainly composed of α-enolase, S-arrestin, and ATP synthase subunits α and β, in both the ocular hypertensive and normotensive retinas. Moreover, increasing intraocular pressure was correlated with increasing ATP concentrations in the retinas of rats. Conclusion. Ocular hypertension affected the expression of proteins containing D-β-aspartic acid, including ATP synthase subunits, and up-regulation of ATP in the retinas of rats.

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