Expression and function of CLC and cystic fibrosis transmembrane conductance regulator chloride channels in renal epithelial tubule cells: pathophysiological implications.
Cl(-) channels play important roles in the regulation of a variety of functions, including electrical excitability, cell volume regulation, transepithelial transport and acidification of cellular organelles. They are expressed in plasma membranes or reside in intracellular organelles. A large number of Cl(-) channels with different functions have been identified. Some of them are highly expressed in the kidney. They include members of the CLC Cl(-) channel family: ClC-K1 (or ClC-Ka), ClC-K2 (or ClC-Kb) and ClC-5. The identification of mutations responsible for human inherited diseases (Bartter syndrome for ClC-Kb and Dent's disease for ClC-5) and studies on knockout mice models have evidenced the physiological importance of these CLC Cl(-) channels, permitting better understanding on their functions in renal tubule epithelial cells. The cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel, also expressed in renal tubule epithelial cells, is involved in the transepithelial transport of Cl(-) in the distal nephron. This short review focuses on intrarenal distribution, subcellular localization and function of the ClK(-1), ClC-K2 and ClC-5 Cl(-) channels in renal tubule epithelial cells, and the role of the CFTR Cl(-) channel in chloride fluxes elicited by vasopressin in the distal nephron.
Vandewalle
Alain
A
INSERM, U773, Centre de Recherche Biomedicale Bichat-Beaujon, UFR de Medecine Xavier Bichat, Paris, France. vandewal@bichat.inserm.fr
D000818:Animals; D018118:Chloride Channels / Q000032:analysis / Q000502:physiology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000032:analysis / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007684:Kidney Tubules / Q000378:metabolism*
C097503:CLC-5 chloride channel; D018118:Chloride Channels; D019005:Cystic Fibrosis Transmembrane Conductance Regulator