title: Primary cilia regulate the osmotic stress response of renal epithelial cells through TRPM3.
abstract: Primary cilia sense environmental conditions, including osmolality, but whether cilia participate in the osmotic response in renal epithelial cells is not known. The transient receptor potential (TRP) channels TRPV4 and TRPM3 are osmoresponsive. TRPV4 localizes to cilia in certain cell types, while renal subcellular localization of TRPM3 is not known. We hypothesized that primary cilia are required for maximal activation of the osmotic response of renal epithelial cells and that ciliary TRPM3 and TRPV4 mediate that response. Ciliated [murine epithelial cells from the renal inner medullary collecting duct (mIMCD-3) and 176-5] and nonciliated (176-5Δ) renal cells expressedTrpv4andTrpm3Ciliary expression of TRPM3 was observed in mIMCD-3 and 176-5 cells and in wild-type mouse kidney tissue. TRPV4 was identified in cilia and apical membrane of mIMCD-3 cells by electrophysiology and in the cell body by immunofluorescence. Hyperosmolal stress at 500 mOsm/kg (via NaCl addition) induced the osmotic response genes betaine/GABA transporter (Bgt1) and aldose reductase (Akr1b3) in all ciliated cell lines. This induction was attenuated in nonciliated cells. A TRPV4 agonist abrogatedBgt1andAkr1b3induction in ciliated and nonciliated cells. A TRPM3 agonist attenuatedBgt1andAkr1b3induction in ciliated cells only. TRPM3 knockout attenuatedAkr1b3induction. Viability under osmotic stress was greater in ciliated than nonciliated cells.Akr1b3induction was also less in nonciliated than ciliated cells when mannitol was used to induce hyperosmolal stress. These findings suggest that primary cilia are required for the maximal osmotic response in renal epithelial cells and that TRPM3 is involved in this mechanism. TRPV4 appears to modulate the osmotic response independent of cilia.
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Siroky
authors.affiliation: Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and.
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Kleene
authors.affiliation: Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and.
authors.forename: Steven J
authors.identifier: 0000-0001-7663-3590
authors.initials: SJ
authors.lastname: Kleene
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Varnell
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Raven G
authors.initials: RG
authors.lastname: Comer
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Jialiu
authors.initials: J
authors.lastname: Liu
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Nolan W
authors.initials: NW
authors.lastname: Pachciarz
authors.affiliation: St. Jude Children's Research Hospital and Le Bonheur Children's Hospital, University of Tennessee Health Science Center, Memphis, Tennessee.
authors.forename: John J
authors.initials: JJ
authors.lastname: Bissler
authors.affiliation: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; bradley.dixon@cchmc.org.
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Dixon
mesh_terms: D000818:Animals; D064113:CRISPR-Cas Systems; D002460:Cell Line; D002923:Cilia / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D000072669:Gene Editing; D006911:Hydroxyprostaglandin Dehydrogenases / Q000235:genetics / Q000378:metabolism; D007685:Kidney Tubules, Collecting / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D064587:Osmoregulation / Q000187:drug effects; D009997:Osmotic Pressure / Q000187:drug effects; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D015398:Signal Transduction; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D050485:GABA Plasma Membrane Transport Proteins; D012462:Saline Solution, Hypertonic; C490439:Slc6a12 protein, mouse; D050053:TRPM Cation Channels; C533868:TRPM3 protein, mouse; D050916:TRPV Cation Channels; C486576:Trpv4 protein, mouse; D006911:Hydroxyprostaglandin Dehydrogenases; C031051:prostaglandin-F synthase
keywords: TRPM3; TRPV4; osmoregulation; primary cilium