title: Aquaporin and brain diseases.
abstract: BACKGROUND
  The presence of water channel proteins, aquaporins (AQPs), in the brain led to intense research in understanding the underlying roles of each of them under normal conditions and pathological conditions.
  
  
  METHODS
  In this review, we summarize some of the recent knowledge on the 3 main AQPs (AQP1, AQP4 and AQP9), with a special focus on AQP4, the most abundant AQP in the central nervous system.
  
  
  CONCLUSIONS
  AQP4 was most studied in several brain pathological conditions ranging from acute brain injuries (stroke, traumatic brain injury) to the chronic brain disease with autoimmune neurodegenerative diseases. To date, no specific therapeutic agents have been developed to either inhibit or enhance water flux through these channels. However, experimental results strongly underline the importance of this topic for future investigation. Early inhibition of water channels may have positive effects in prevention of edema formation in brain injuries but at later time points during the course of a disease, AQP is critical for clearance of water from the brain into blood vessels.
  
  
  CONCLUSIONS
  Thus, AQPs, and in particular AQP4, have important roles both in the formation and resolution of edema after brain injury. The dual, complex function of these water channel proteins makes them an excellent therapeutic target. This article is part of a Special Issue entitled Aquaporins.
authors: Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA; Department of Physiology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA; Univ Bordeaux, CNRS UMR 5287, 146 rue Leo Saignat33076 Bordeaux cedex. Electronic address: jbadaut@llu.edu.
authors: Jérôme
authors: J
authors: Badaut
authors: Department of Physiology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
authors: Andrew M
authors: AM
authors: Fukuda
authors: Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
authors: Amandine
authors: A
authors: Jullienne
authors: INSERM U1049 Neuroinflammation, Imagerie et Thérapie de la Sclérose en Plaques, F-33076 Bordeaux, France.
authors: Klaus G
authors: KG
authors: Petry
mesh_terms: D020346:Aquaporins / Q000502:physiology*; D001834:Body Water; D001927:Brain Diseases / Q000503:physiopathology*; D006801:Humans
chemical_list: D020346:Aquaporins
keywords: Blood–brain barrier; Edema; Neuroimaging; Neuroinflammation; Neurovascular unit; Water channel