title: A primary culture system of mouse thick ascending limb cells with preserved function and uromodulin processing.
abstract: The epithelial cells lining the thick ascending limb (TAL) of the loop of Henle perform essential transport processes and secrete uromodulin, the most abundant protein in normal urine. The lack of differentiated cell culture systems has hampered studies of TAL functions. Here, we report a method to generate differentiated primary cultures of TAL cells, developed from microdissected tubules obtained in mouse kidneys. The TAL tubules cultured on permeable filters formed polarized confluent monolayers in ∼12 days. The TAL cells remain differentiated and express functional markers such as uromodulin, NKCC2, and ROMK at the apical membrane. Electrophysiological measurements on primary TAL monolayers showed a lumen-positive transepithelial potential (+9.4 ± 0.8 mV/cm(2)) and transepithelial resistance similar to that recorded in vivo. The transepithelial potential is abolished by apical bumetanide and in primary cultures obtained from ROMK knockout mice. The processing, maturation and apical secretion of uromodulin by primary TAL cells is identical to that observed in vivo. The primary TAL cells respond appropriately to hypoxia, hypertonicity, and stimulation by desmopressin, and they can be transfected. The establishment of this primary culture system will allow the investigation of TAL cells obtained from genetically modified mouse models, providing a critical tool for understanding the role of that segment in health and disease.
authors.affiliation: Institute of Physiology, ZIHP, University of Zurich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
authors.forename: Bob
authors.initials: B
authors.lastname: Glaudemans
authors.forename: Sara
authors.initials: S
authors.lastname: Terryn
authors.forename: Nadine
authors.initials: N
authors.lastname: Gölz
authors.forename: Martina
authors.initials: M
authors.lastname: Brunati
authors.forename: Angela
authors.initials: A
authors.lastname: Cattaneo
authors.forename: Angela
authors.initials: A
authors.lastname: Bachi
authors.forename: Lama
authors.initials: L
authors.lastname: Al-Qusairi
authors.forename: Urs
authors.initials: U
authors.lastname: Ziegler
authors.forename: Olivier
authors.initials: O
authors.lastname: Staub
authors.forename: Luca
authors.initials: L
authors.lastname: Rampoldi
authors.forename: Olivier
authors.initials: O
authors.lastname: Devuyst
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D008138:Loop of Henle / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D024661:Potassium Channels, Inwardly Rectifying / Q000096:biosynthesis; D064466:Solute Carrier Family 12, Member 1 / Q000096:biosynthesis; D058949:Uromodulin / Q000096:biosynthesis*
chemical_list: C510693:Kcnj1 protein, mouse; D024661:Potassium Channels, Inwardly Rectifying; C578715:Slc12a1 protein, mouse; D064466:Solute Carrier Family 12, Member 1; D058949:Uromodulin