The Pharmacological Inhibition of CaMKII Regulates Sodium Chloride Cotransporter Activity in mDCT15 Cells

• Type of Material: Article
• Authors: Mohammed F Gholam, University of Florida; Benjamin Ko, University of Chicago; Zinah M Ghazi, Emory University; Robert Hoover Jr., Emory University; Abdel Alli, Emory University
• Language: English
• Date: 2021-12-01
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2021 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/biology10121335
• Title of Journal or Parent Work: BIOLOGY-BASEL
• Volume: 10
• Issue: 12
• Grant/Funding Information: This work was supported by grants from the National Institutes of Health K01DK099617 (A.A.A.), R01 DK-085097 (to R.S.H.), Department of Veteran Affairs VA Merit Award I01BX002322-01 (R.S.H.) and the University of Florida College of Medicine.
• Keywords: LATRUNCULINS; CYTOCHALASIN; NA+-CL-COTRANSPORTER; CaMKII; DISRUPT MICROFILAMENT ORGANIZATION; CYTOSKELETON; PHOSPHORYLATION; ENAC ACTIVITY; Biology; Life Sciences & Biomedicine - Other Topics; MARCKS; Life Sciences & Biomedicine; Science & Technology; EXPRESSION; filamin A; NCC; FILAMIN-A
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

The thiazide-sensitive sodium chloride cotransporter (NCC) in the distal convoluted tubule is responsible for reabsorbing up to one-tenth of the total filtered load of sodium in the kidney. The actin cytoskeleton is thought to regulate various transport proteins in the kidney but the regulation of the NCC by the actin cytoskeleton is largely unknown. Here, we identify a direct interaction between the NCC and the cytoskeletal protein filamin A in mouse distal convoluted tubule (mDCT15) cells and in the native kidney. We show that the disruption of the actin cytoskeleton by two different mechanisms downregulates NCC activity. As filamin A is a substrate of the Ca2+/calmodulin-dependent protein kinase II (CaMKII), we investigate the physiological significance of CaMKII inhibition on NCC luminal membrane protein expression and NCC activity in mDCT15 cells. The pharmacological inhibition of CaMKII with the compound KN93 increases the active form of the NCC (phospho-NCC) at the luminal membrane and also increases NCC activity in mDCT15 cells. These data suggest that the interaction between the NCC and filamin A is dependent on CaMKII activity, which may serve as a feedback mechanism to maintain basal levels of NCC activity in the distal nephron.