Dietary Chloride as a Determinant of "Sodium-Dependent" Hypertension

Tw, Kurtz; Morris, R. Curtis

doi:10.1126/science.6648527

Cited by 140 publications

(70 citation statements)

References 33 publications

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“…The relationship between chloride and sensitivity of the renal vasculature to vasoconstrictors may have physiological significance as manipulation of chloride intake can result in changes in plasma chloride concentrations over the range used in this study (Abboud et al, 1979;Kurtz & Morris, 1983;Passmore et al, 1985). In addition, these findings may provide a link between increased chloride reabsorption in the early distal tubule in salt-sensitive hypertension and blood pressure elevation (Kirchner, 1990;Roman & Kaldunski, 1991) and, conversely, between the defect in chloride reabsorption in the loop of Henle and the hypotension in Bartter's syndrome (Gill & Bartter, 1978).…”

Section: Discussionmentioning

confidence: 99%

Chloride anion concentration as a determinant of renal vascular responsiveness to vasoconstrictor agents

Quilley

Lin

McGiff

1993

British J Pharmacology

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Section: Discussionmentioning

confidence: 99%

Chloride anion concentration as a determinant of renal vascular responsiveness to vasoconstrictor agents

Quilley

Lin

McGiff

1993

British J Pharmacology

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“…chloride channel | epithelium | hypertension C hloride is the most abundant extracellular anion and thereby determines extracellular fluid volume (ECFV) and blood pressure (BP) (1,2). The kidney plays a vital role in ECFV and BP control through complex regulatory mechanisms acting upon ion channels and transporters located in the aldosterone-sensitive distal nephron (ASDN) (3,4).…”

mentioning

confidence: 99%

The Cap1–claudin-4 regulatory pathway is important for renal chloride reabsorption and blood pressure regulation

Gong

Yang³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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The paracellular pathway through the tight junction provides an important route for transepithelial chloride reabsorption in the kidney, which regulates extracellular salt content and blood pressure. Defects in paracellular chloride reabsorption may in theory cause deregulation of blood pressure. However, there is no evidence to prove this theory or to demonstrate the in vivo role of the paracellular pathway in renal chloride handling. Here, using a tissue-specific KO approach, we have revealed a chloride transport pathway in the kidney that requires the tight junction molecule claudin-4. The collecting duct-specific claudin-4 KO animals developed hypotension, hypochloremia, and metabolic alkalosis due to profound renal wasting of chloride. The claudin-4-mediated chloride conductance can be regulated endogenously by a proteasechannel-activating protease 1 (cap1). Mechanistically, cap1 regulates claudin-4 intercellular interaction and membrane stability. A putative cap1 cleavage site has been identified in the second extracellular loop of claudin-4, mutation of which abolished its regulation by cap1. The cap1 effects on paracellular chloride permeation can be extended to other proteases such as trypsin, suggesting a general mechanism may also exist for proteases to regulate the tight junction permeabilities. Together, we have discovered a theory that paracellular chloride permeability is physiologically regulated and essential to renal salt homeostasis and blood pressure control.chloride channel | epithelium | hypertension C hloride is the most abundant extracellular anion and thereby determines extracellular fluid volume (ECFV) and blood pressure (BP) (1, 2). The kidney plays a vital role in ECFV and BP control through complex regulatory mechanisms acting upon ion channels and transporters located in the aldosterone-sensitive distal nephron (ASDN) (3, 4). The ASDN comprises the distal convoluted tubule (DCT), the connecting tubule (CNT), and the collecting duct (CD). The primary chloride transport mechanism in the DCT is through the thiazide-sensitive Na + /Cl − cotransporter (NCC) to reabsorb Cl − coupled with equal moles of Na + (5). The chloride transport mechanism in the CNT and CD, on the other hand, has been under debate for many years. Recent advances have identified an electroneutral transport pathway for chloride using the Cl − /bicarbonate exchanger (Slc26a4; pendrin) (6) and the Na + -driven Cl − /bicarbonate exchanger (Slc4a8; NDCBE) (7) in the β-intercalated cells (ICs) of CNT and CD. However, such an electroneutral pathway is not able to couple Cl − reabsorption with epithelial sodium channel (ENaC)-based Na + reabsorption that takes place in the principal cells (PCs) of CNT and CD (8), despite many efforts to connect ENaC and pendrin gene expression through endocrine or paracrine mechanisms (9, 10). We and others have previously demonstrated the presence of a paracellular Cl − pathway or "chloride shunt" in vitro in the CNT and CD cells (11,12). The paracellular Cl − channel is made of a key claud...

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“…ion channel | chloride shunt | blood pressure | siRNA | protein interaction C hloride is the predominant extracellular ionic constituent and thereby determines extracellular fluid volume (ECFV) and blood pressure (1)(2)(3). Although only responsible for the reabsorption of 2-3% filtered chloride, the aldosterone-sensitive distal nephron (ASDN) plays a vital regulatory role in renal handling of salt, ECFV control, and managing blood pressure (4).…”

mentioning

confidence: 99%

“…This electrogenic transport step creates a favorable electrical driving force for luminal reabsorption of chloride and secretion of potassium and proton. Chloride is transported by two major mechanisms (1). Chloride is actively reabsorbed by an electroneutral Cl − /HCO − exchanger (Slc26a4: pendrin) localized to the apical membrane of the β-type intercalated cell (7).…”

mentioning

confidence: 99%

Claudin-4 forms paracellular chloride channel in the kidney and requires claudin-8 for tight junction localization

Hou

Renigunta²,

Yang³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

210

233

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Tight junctions (TJs) play a key role in mediating paracellular ion reabsorption in the kidney. The paracellular pathway in the collecting duct of the kidney is a predominant route for transepithelial chloride reabsorption that determines the extracellular NaCl content and the blood pressure. However, the molecular mechanisms underlying the paracellular chloride reabsorption in the collecting duct are not understood. Here we showed that in mouse kidney collecting duct cells, claudin-4 functioned as a Cl -channel. A positively charged lysine residue at position 65 of claudin-4 was critical for its anion selectivity. Claudin-4 was observed to interact with claudin-8 using several criteria. In the collecting duct cells, the assembly of claudin-4 into TJ strands required its interaction with claudin-8. Depletion of claudin-8 resulted in the loss of paracellular chloride conductance, through a mechanism involving its recruitment of claudin-4 during TJ assembly. Together, our data show that claudin-4 interacts with claudin-8 and that their association is required for the anion-selective paracellular pathway in the collecting duct, suggesting a mechanism for coupling chloride reabsorption with sodium reabsorption in the collecting duct.C hloride is the predominant extracellular ionic constituent and thereby determines extracellular fluid volume (ECFV) and blood pressure (1-3). Although only responsible for the reabsorption of 2-3% filtered chloride, the aldosterone-sensitive distal nephron (ASDN) plays a vital regulatory role in renal handling of salt, ECFV control, and managing blood pressure (4). The ASDN comprises the distal convoluted tubule (DCT), the connecting tubule (CNT), and the collecting duct. The collecting duct is characterized by a heterogeneous epithelium-the principal cells and intercalated cells (5). Sodium reabsorption in the collecting duct is an active process driven by the basolateral Na + /K + -ATPase; acts through the apical epithelial sodium channel (ENaC) in the principal cell (6); and is responsible for generating the lumen-negative transepithelial potential. This electrogenic transport step creates a favorable electrical driving force for luminal reabsorption of chloride and secretion of potassium and proton. Chloride is transported by two major mechanisms (1). Chloride is actively reabsorbed by an electroneutral Cl − /HCO − exchanger (Slc26a4: pendrin) localized to the apical membrane of the β-type intercalated cell (7). Choride exits this cell via a basolateral Cl − channel (2) and diffuses passively down electrochemical gradients via the paracellular channel in the tight junction (TJ).The TJ is the most apical member of the junctional complex found in vertebrate epithelia responsible for the barrier to movement of ions and molecules between apical and basal compartments, the paracellular pathway (8). TJs are composed of three transmembrane proteins: occludin, claudins, and junctional adhesion molecule (JAM). The claudins (CLDNs) are a 28-member family of tetraspan proteins that range in m...

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Dietary Chloride as a Determinant of "Sodium-Dependent" Hypertension

Cited by 140 publications

References 33 publications

Chloride anion concentration as a determinant of renal vascular responsiveness to vasoconstrictor agents

Chloride anion concentration as a determinant of renal vascular responsiveness to vasoconstrictor agents

The Cap1–claudin-4 regulatory pathway is important for renal chloride reabsorption and blood pressure regulation

Claudin-4 forms paracellular chloride channel in the kidney and requires claudin-8 for tight junction localization

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