Hydrochlorothiazide Treatment Increases the Abundance of the NaCl Cotransporter in Urinary Extracellular Vesicles of Essential Hypertensive Patients

Am J Physiol Renal Physiol. 2017 Jun 1;312(6):F1063-F1072. doi: 10.1152/ajprenal.00644.2016. Epub 2017 Mar 8.

Abstract

The thiazide-sensitive NaCl cotransporter (NCC), located apically in distal convoluted tubule epithelia, regulates the fine-tuning of renal sodium excretion. Three isoforms of NCC are generated through alternative splicing of the transcript, of which the third isoform has been the most extensively investigated in pathophysiological conditions. The aim of this study was to investigate the effect of different anti-hypertensive treatments on the abundance and phosphorylation of all three NCC isoforms in urinary extracellular vesicles (uEVs) of essential hypertensive patients. In uEVs isolated from patients (n = 23) before and after hydrochlorothiazide or valsartan treatment, the abundance and phosphorylation of the NCC isoforms was determined. Additionally, clinical biochemistry and blood pressure of the patients was assessed. Our results show that NCC detected in human uEVs has a glycosylated and oligomeric structure, comparable to NCC present in human kidney membrane fractions. Despite the inhibitory action of hydrochlorothiazide on NCC activity, immunoblot analysis of uEVs showed significantly increased abundance of NCC isoforms 1 and 2 (NCC1/2), total NCC (NCC1-3), and the phosphorylated form of total NCC (pNCC1-3-T55/T60) in essential hypertensive patients treated with hydrochlorothiazide but not with valsartan. This study highlights that NCC1/2, NCC1-3, and pNCC1-3-T55/T60 are upregulated by hydrochlorothiazide, and the increase in NCC abundance in uEVs of essential hypertensive patients correlates with the blood pressure response to hydrochlorothiazide.

Keywords: NaCl cotransporter; hypertension; kidney; thiazide diuretics; urinary extracellular vesicles.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Angiotensin II Type 1 Receptor Blockers / therapeutic use*
  • Antihypertensive Agents / therapeutic use*
  • Biomarkers / urine
  • Blood Pressure / drug effects
  • Cross-Over Studies
  • Extracellular Vesicles / drug effects*
  • Extracellular Vesicles / metabolism
  • Female
  • Glycosylation
  • Humans
  • Hydrochlorothiazide / therapeutic use*
  • Hypertension / drug therapy*
  • Hypertension / physiopathology
  • Hypertension / urine
  • Kidney / drug effects*
  • Kidney / metabolism
  • Kidney / physiopathology
  • Male
  • Middle Aged
  • Netherlands
  • Phosphorylation
  • Prospective Studies
  • Protein Isoforms
  • Sodium Chloride Symporter Inhibitors / therapeutic use*
  • Solute Carrier Family 12, Member 3 / drug effects
  • Solute Carrier Family 12, Member 3 / urine
  • Treatment Outcome
  • Up-Regulation
  • Valsartan / therapeutic use*
  • Young Adult

Substances

  • Angiotensin II Type 1 Receptor Blockers
  • Antihypertensive Agents
  • Biomarkers
  • Protein Isoforms
  • SLC12A3 protein, human
  • Sodium Chloride Symporter Inhibitors
  • Solute Carrier Family 12, Member 3
  • Hydrochlorothiazide
  • Valsartan