Aquaporin-4 (AQP4) is a water-selective transporter expressed in astrocytes throughout the central nervous system, as well as in kidney, lung, stomach and skeletal muscle. The two AQP4 isoforms produced by alternative spicing, M1 and M23 AQP4, form heterotetramers that assemble in cell plasma membranes in supramolecular structures called orthogonal arrays of particles (OAPs). Phenotype analysis of AQP4-null mice indicates the involvement of AQP4 in brain and spinal cord water balance, astrocyte migration, neural signal transduction and neuroinflammation.
Pathogenic autoantibodies target aquaporin-4 (AQP4) water channels in individuals with neuromyelitis optica (NMO). Recently, allelic mutations were reported at residue 19 of AQP4 in three cases of NMO, and it was suggested that polymorphisms may influence disease by altering AQP4 supramolecular assembly into orthogonal arrays of particles (OAPs)
The autoantibody to aquaporin-4 (AQP4) is a marker and a pathogenetic factor in Neuromyelitis Optica (NMO) (Devic’s syndrome). Our aim was to identify B-cell antigenic linear epitopes of the AQP4 protein and investigate similarities with other molecules. To this end, we screened sera from 21 patients positive for anti-AQP4 antibodies (study group), from 23 SLE and 23 pSS patients without neurologic involvement (disease controls) and from 28 healthy individuals (normal controls)
BACKGROUND: Antibodies to the water channel protein aquaporin-4 (AQP4), which is expressed in astrocytic endfeet at the blood brain barrier, have been identified in the serum of Neuromyelitis optica (NMO) patients and are believed to induce damage to astrocytes. However, AQP4 specific T helper cell responses that are required for the generation of anti-AQP4 antibodies and most likely also for the formation of intraparenchymal CNS lesions have not been characterized. METHODOLOGY/PRINCIPAL FINDINGS: Using overlapping 15-meric peptides of AQP4, we identified the immunogenic T cell epitopes of AQP4 that are restricted to murine major histocompatibility complex (MHC) I-A(b).
Neuromyelitis optica spectrum disorders (NMOSD) are associated with anti-aquaporin-4 autoantibodies (AQP4-IgG). Limited data is available on longitudinal cerebrospinal fluid (CSF) AQP4-IgG and their relation to disease activity and inflammatory parameters. AQP4-IgG titers were measured in matched longitudinal serum and CSF samples of 12 patients with NMOSD by an immunofluorescence assay and correlated with clinical parameters
Aquaporin 4(AQP4) is a water channel protein strongly expressed in the central nervous system in perimicrovessel astrocyte foot processes, the glia limitans, and ependyma. Expression of AQP4 is highest at the blood-brain barrier and blood-spinal cord barrier, supporting its critical function in material transport across these structures. Recently, presence of the anti-aquaporin-4 antibody in sera has been used as an important diagnostic tool for neuromyelitis optica, suggesting a potential role in central nervous system inflammation.
Neuromyelitis optica is an autoimmune demyelinating disease characterized by the presence of anti aquaporin-4 (AQP4) antibodies in the patient sera.
BACKGROUND: Antibodies targeting membrane proteins play an important role in various autoimmune diseases of the nervous system.
Background: Macular star results from deposits of hard exsudate in Henle’s fiber layer radiating out in a starlike pattern in patients with infectious optic neuritis or neuroretinitis.
Background: Neuromyelitis optica (NMO) is characterized by severe optic neuritis and transverse myelitis. A disease-specific autoantibody against aquaporin (AQP) 4, mainly expressed in astrocytic foot processes, was found in the sera from patients with NMO.
Introduction: The association between susceptibility to MS and class II alleles of the major histocompatibility complex (MHC) is well established in MS patients but not in NMOR. The ethnicity has an important role in MS HLA DQ and DR profile. Brazilian population has ethnic particularities with a high mixed African and Caucasian Mediterranean population
Background: Neuromyelitis optica (NMO) is a human inflammatory/demyelinating disease of the central nervous system characterized by optic neuritis and longitudinally extensive transverse myelitis.