Autophagy is involved in degradation of AQP1 in response to an acute decrement in tonicity

Xiangdong Guo; Long Xu; Yonglun Kong; Meng Li; Qingxian Zhai; Baien Liang; Xiaoduo Zhao; Luosha Long; Meiying Huang; Weidong Wang; Chunling Li

doi:10.1016/j.isci.2023.108485

Autophagy is involved in degradation of AQP1 in response to an acute decrement in tonicity

iScience. 2023 Nov 20;26(12):108485. doi: 10.1016/j.isci.2023.108485. eCollection 2023 Dec 15.

Authors

Xiangdong Guo^{1

2}, Long Xu^{1

2}, Yonglun Kong^{2

3}, Meng Li^{1

2}, Qingxian Zhai^{2

3}, Baien Liang^{2

3}, Xiaoduo Zhao^{2

3}, Luosha Long^{1

2}, Meiying Huang^{2

3}, Weidong Wang^{2

3}, Chunling Li^{1

2}

Affiliations

¹ Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
² Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
³ Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.

Abstract

Renal medullary aquaporin-1 (AQP1) plays an important role in the urinary concentration. This study aimed to investigate the regulation of AQP1 by low osmotic stress and a potential role of autophagy. Low osmotic stress induced a dramatically decreased AQP1 protein expression in murine inner medullary collecting duct 3 (mIMCD3) cells, which was associated with a marked activation of autophagy. Inhibition of autophagy by 3-methyladenine (3-MA), chloroquine, or knockdown of autophagy-related protein 5 (ATG5) prevented the decrease in AQP1 protein abundance. Rapamycin-induced autophagy was associated with a decreased AQP1 protein expression and an enhanced interaction between AQP1 and ATG5 in mIMCD3 cells under low osmotic stress. In kidney inner medulla of mice given a 3% NaCl solution, activation of autophagy was associated with decreased AQP1 protein expression, which was prevented by 3-MA. In conclusion, low osmotic stress induced autophagy which contributed to the decreased AQP1 protein expression in the renal medulla.

Keywords: Biological sciences; Cell biology; Molecular biology.