Effect of the cAMP Pathway on the Length of the Primary Cilium of LLC-PK1 Renal Epithelial Cells

CANTERO MR; PEREZ PL; CANTIELLO HF; SCARINCI MN

Mar del Plata

Congreso; Reunión Conjunta SAIC SAI SAFIS 2018; 2018

SAIC, SAI, SAFIS, SAV

The primary cilium is a sensory organelle whose dysfunction leads to the onset of cystic renal disease. The primary cilium may contribute to the regulation of Ca2+ transport in renal epithelial cells. Little is known, however, as to how renal epithelial cells control primary cilium length and in particular how Polycystin-2 (PC2) function in the PC may contribute to this regulation. In this study, we explored the effect of the cAMP pathway on ciliary length in LLC-PK1 renal epithelial cells. The length of the primary cilium was obtained by labeling with a specific antibody against -acetylated tubulin and tracing the immunochemical signal with the ImageJ software. Under Control conditions (1,2 mM Ca2+) the ciliary length was 4,72 ± 0,05 µm (n = 510). Exposure of cells to 8-Br-cAMP (1 mM) in the presence of normal Ca2+ increased primary cilium length by 16.31 ± 1,46% (n = 157, p < 0.001). Similar results were obtained after exposure of cells to arginine-vasopressin (AVP, 10 µM). In high calcium (6,2 mM), however, where ciliary length is 13,5 ± 1,47% shorter than Control, exposure of cells to 8-Br-cAMP induced an increase in the length of the primary cilium of 13,77 ± 2,23% (n = 136, p < 0.001). The data indicate that maneuvers that lead to activation of the cAMP pathway feedback Ca2+ signals and control ciliary length in LLC-PK1 cells. Dysregulation of this mechanism may be essential in the onset of autosomal dominant polycystic kidney disease.