Unlike other mammalian AQPs, multiple tetramers of AQP4 associate in the plasma membrane to form peculiar structures called Orthogonal Arrays of Particles (OAPs), that are observable by freeze-fracture electron microscopy (FFEM). However, FFEM cannot give information about the composition of OAPs of different sizes, and due to its technical complexity is not easily applicable as a routine technique. Recently, we employed the 2D gel electrophoresis BN-SDS/PAGE that for the first time enabled the biochemical isolation of AQP4-OAPs from several tissues.
Aquaporin-4 (AQP4) exists as two major isoforms that differ in the length of the N terminus, the shorter AQP4-M23 and the longer AQP4-M1. Both isoforms form tetramers, which can further aggregate in the plasma membrane to form typical orthogonal arrays of particles (OAPs) whose dimension depends on the ratio of the M1 and M23. In this study, we tested the hypothesis that the M23 isoform can be produced directly by the M1 mRNA
Immune cells cross the inflamed blood–brain barrier. But it’s unclear how brain inflammation begins before immune-cell entry. Studies of a model of multiple sclerosis start to solve this ‘chicken and egg’ conundrum
Background: NMO-IgG autoantibody is now considered a useful serum biomarker of neuromyelitis optica (NMO). A series of clinical and pathological observations suggest that NMO-IgG may play a central role in NMO physiopathology. Objective: The aim of this in vitro-based study was to characterize molecular and functional consequences of interaction between NMO-IgG and primary cultures of astrocytes.
Background: Neuromyelitis optica (NMO) is characterized by severe optic neuritis and longitudinally extended transverse myelitis. A serum autoantibody against aquaporin-4 (AQP4), a water channel densely expressed on astrocytes, has been detected exclusively in NMO and the high-risk syndrome. Pathologically, an extensive loss of AQP4 with perivascular depositions of activated complements (C9neo) as well as immunoglobulins is seen in NMO lesions, and infiltration of neutrophils is not uncommon in those lesions.
BACKGROUND: Neuromyelitis optica (NMO) is a serious idiopathic inflammatory demyelinating disorder characterized by acute transverse myelitis and optic neuritis. A significant proportion of NMO patients are seropositive for NMO-IgG, an autoantibody targeting aquaporin-4 (AQP4) water channel. Paraneoplastic NMO associated various tumors were recently reported.