Aquaporins

Water is a critical component of all living cells.  Interestingly, tissue membranes show a great degree of water permeability.  Choroid plexus, mammalian red cells, renal proximal tubules, and descending thin limb of Henle are extraordinary permeable to water.  Water crosses hydrophobic plasma membranes either by simple diffusion or through a facilitative transport mechanism mediated by a special protein known as “aquaporin”.   Almost all members of the aquaporin family have, at least in part, a homology to MIP (Major Intrinsic Protein), and contain six trans membrane domains.

Taking into account the involvement of membrane-associated proteins in diagnostic and therapeutic studies, aquaporins may be of considerable importance in biomedical research.  Our research team hopes to open a window of cure and early diagnosis of hydrocephalus.   We are also studying aquaporin (Aqp1, Aqp4, and Aqp9) expression in the H-Tx rat and their possible alterations in the hydrocephalic condition.  Considering the importance of membrane proteins, this recent study complements our main project to study the role of ciliary proteins in hydrocephalus.  In postmitotic cells, such as choroid plexus, the mother centriole of the centrosomes migrates to the apical membrane of cells and nucleates the assembly of cilia. Meanwhile, the research team at UCF is highly focused on discovering the molecular mechanism of hydrocephalus.

A) Schematic of CSF production and steady-state ICP regulation. CSF fluid is produced by transchoroidal (arrow) and extrachoroidal routes (dot arrow). Left upper schema indicates molecular channels of water and ions in choroid plexus epithelium. Water can enter the ventricle in transcellular and paracellular routes via choroid plexus. B) Systemic and cerebral effects of AQP1 deletion act synergistically to decrease ICP.