Aquaporin-5 Protein Is Selectively Reduced in Rat Parotid Glands Under Conditions of Fasting or a Liquid Diet

Overview

Journal Acta Histochem Cytochem

Specialty Biochemistry

Date 2024 Mar 11

PMID 38463206

Authors

Yoshie Fujita

Akie Taniguchi

Hanako Yamamoto

Hideru Obinata

Hiroshi Kogo

Akiko Iizuka-Kogo

Maiko Ikezawa

Yukiko Tajika

Satoshi Yokoo

Toshiyuki Matsuzaki

Affiliations

Soon will be listed here.

Abstract

Aquaporin-5 (AQP5) water channel, transmembrane protein 16A (TMEM16A) Ca-activated Cl channel, and Na-K-2Cl cotransporter (NKCC1) are membrane proteins on salivary gland acinar cells that function in watery saliva secretion. We examined their expression changes in rat parotid glands under reduced mastication. Rats were either fed regular chow as a control group, fasted for 48 hr or fed a liquid diet for 48 hr or 1 week to reduce mastication. The parotid glands were then resected to analyze the protein and mRNA levels by immunofluorescence, immunoblotting, and reverse-transcription quantitative PCR (RT-qPCR). AQP5 protein was significantly decreased in both liquid diet groups and the fasting group but its mRNA levels showed no apparent changes compared with the control group. The protein and mRNA levels of TMEM16A and NKCC1 showed no significant changes between any of the groups other than an increase in NKCC1 mRNA in the 1-week liquid diet group. These results suggest that reduced mastication may increase the AQP5 protein degradation, but not that of other membrane proteins necessary for saliva secretion.

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