Aquaporin-4's overall function is to provide fast water transportation as well as maintain homeostatic balance within the central nervous system. This channel can transport water up to speeds of 3E9 molecules per second. It is the primary water channel protein that reconciles the homeostasis of water in the CNS.
Where is aquaporin-4 expressed?
astrocytes
What is aquaporin-4 receptor antibody?
Antibodies to aquaporin-4 (called NMO-IgG or AQP4-Ab) constitute a sensitive and highly specific serum marker of neuromyelitis optica (NMO) that can facilitate the differential diagnosis of NMO and classic multiple sclerosis.Antibodies to aquaporin-4 (called NMO-IgG or AQP4-Ab) constitute a sensitive and highly specific serum marker of neuromyelitis opticaneuromyelitis opticaPrevalence of NMOSD The prevalence range of NMOSD is ~0.5–4/100,000, and may be up to 10/100,000 in certain racial groups.https://www.ncbi.nlm.nih.gov › pmc › articles › PMC7332882Epidemiology of Neuromyelitis Optica Spectrum Disorder and Its - NCBI (NMO) that can facilitate the differential diagnosis of NMO and classic multiple sclerosis.
What is the physiological role of aquaporins in the eye?
The aquaporins (AQPs) are integral membrane proteins whose main function is to transport water across cell membranes in response to osmotic gradients. At the ocular surface, AQP1 is expressed in corneal endothelium, AQP3 and AQP5 in corneal epithelium, and AQP3 in conjunctival epithelium.The aquaporins (AQPs) are integral membrane proteins whose main function is to transport water across cell membranes in response to osmotic gradients. At the ocular surface, AQP1 is expressed in corneal endothelium, AQP3 and AQP5 in corneal epitheliumcorneal epitheliumThe human corneal epithelium has five to seven cell layers and an accepted central thickness of approximately 50 to 52 μm.https://www.ncbi.nlm.nih.gov › pmc › articles › PMC2592549Epithelial Thickness in the Normal Cornea: Three-dimensional Display , and AQP3 in conjunctival epithelium.
Where is aquaporin 4 found?
Aquaporin-4 is the most common aquaporin in the brain, spinal cord, and optic nerve. It is highly expressed in the human body primarily at the end-feet of astrocytes.
What causes AQP4?
AQP4 knockout mice have in creased seizure duration,44 impaired glial scarring,45 and attenuated experimental autoimmune encephalo myelitis. Impaired AQP4 water permeability in astrocytes is probably the cause of these phenotypes.
What is NMO IgG?
Neuromyelitis optica-specific immunoglobulin (NMO-IgG) recognizes the water-channel protein AQP4. Presence of AQP4 antibody is important in the differential diagnosis of NMOSD from other TM diseases. ~75% of patients with NMO express antibodies to the AQP4 receptor.Neuromyelitis optica-specific immunoglobulin (NMO-IgG) recognizes the water-channel protein AQP4AQP4Through x-ray crystallography, it was found that “each AQP4 monomer consists of six helical, membrane-spanning domains and two short helical segments surrounding a narrow aqueous pore.” At the narrowest point the aqueous pore measures 2.8 angstroms, just large enough for the single-file passage of water molecules.https://en.wikipedia.org › wiki › Aquaporin_4Aquaporin 4 - Wikipedia. Presence of AQP4 antibody is important in the differential diagnosis of NMOSD from other TM diseases. ~75% of patients with NMO express antibodies to the AQP4 receptor.
What is aquaporin-4 antibody test?
Aquaporin-4 receptor (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibody testing is used for diagnosis and evaluation of neuromyelitis optica (NMO), acute myelitis, spinal cord lesions, autoimmune encephalitis, or NMOSD.
What is the difference between NMO and MOG?
MOG-EM differs from NMOSD in further clinical characteristics e.g., in gender ratio and age at onset. In (relapsing) NMOSD, up to 90% of the patients are female, whereas the proportion of male patients in MOG-EM ranges from 43 to 63% (22, 26, 29–31, 73).23 Oct 2018