Activation of the calcium sensing receptor increases claudin-14 expression via a PLC -p38-Sp1 pathway.

ABSTRACT: Activation of the basolateral calcium sensing receptor (CaSR) in the renal tubular thick ascending limb (TAL) increases claudin-14 expression, which reduces paracellular calcium (Ca²⁺ ) permeability, thus increasing urinary Ca²⁺ excretion. However, the upstream signaling pathway contributing to altered CLDN14 gene expression is unknown. To delineate this pathway, we identified and then cloned the CaSR responsive region including the promoter of mouse Cldn14 into a luciferase reporter vector. This 1500 bp sequence upstream of the 5' UTR of Cldn14 variant 1, conferred increased reporter activity in the presence of high extracellular Ca²⁺ (5 mM) relative to a lower (0.5 mM) concentration. Assessment of Cldn14 reporter activity in response to increased extracel

SUBMITTER: Lee JJ 

PROVIDER: S-EPMC9297942 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature