Ion permeability profiles of renal paracellular channel‐forming claudins

• DOI: 10.1111/apha.14264
• Publication Date: 2025-01-17T13:37:19Z
• Authors: Ioanna Pouyiourou; Anja Fromm; Jörg Piontek; Rita Rosenthal; Mikio Furuse; Dorothee Günzel
• Keywords: Paracellular transport; Claudin

Members of the claudin protein family are major constituents tight junction strands and determine permeability properties paracellular pathway. In kidney, each nephron segment expresses a distinct subset claudins that form either barriers against solute transport or charge- size-selective channels. It was aim present study to compare permeation these renal ion channel-forming claudins. MDCK II cells, in which five had been knocked out (claudin quintupleKO), were stably transfected with individual mouse Cldn2, -4, -8, -10a, -10b, -15, dog Cldn16 -19, combination Cldn4 Cldn8, Cldn19. Permeation investigated Ussing chamber interactions by FRET assays. Claudin-4 -19 formed permeation. However, at low pH values absence HCO3 -, claudin-4 conveyed weak chloride nitrate permeability. Claudin-8 needed for assembly into TJ abolished this anion preference. Claudin-2, -16+19 highly permeable channels distinctive profiles different monovalent divalent anions cations, but ions opposite charge tracer fluorescein. Paracellular permeabilities along strictly determined expression patterns. specific certain thus lower transepithelial resistance, yet other solutes.