Abstract P131: Jak2 Expression In Cd11c+ Myeloid Cells Plays A Role In Salt-sensitive Hypertension Through An Enac-dependent Mechanism.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Luul A Aden ◽  
Ashley Pitzer ◽  
Samantha Grimes ◽  
Evan C Ray ◽  
Thomas R Kleyman ◽  
...  

Hypertension is a major risk factor for development of cardiovascular disease. Excess dietary salt contributes to inflammation and the genesis of hypertension. We recently found that gamma and alpha subunits of the epithelial sodium channel (ENaCαγ) on dendritic cells mediate NADPH oxidase-dependent formation of immunogenic isolevuglandin (IsoLG)-protein adducts leading to inflammation and salt-sensitive hypertension. We hypothesized that Jak2 expression, specifically in CD11c + myeloid cells, regulates expression of ENaCγ and promotes salt-sensitive hypertension. Our results indicate that deletion of Jak2 in CD11c + myeloid cells reduced the salt-induced expression of ENaCγ in CD11c+ cells. Moreover, mice lacking Jak2 in CD11c+ cells developed a blunted hypertensive response (123.8±4.7) during the high salt feeding phase of the N-Nitro-L-arginine methyl ester hydrochloride (L- NAME)/high salt model of salt-sensitive hypertension compared to their wildtype littermate controls (140.5±6.5). These mice also exhibited less infiltration of monocyte/macrophages in their kidneys and less volume retention (69.55±5.8) in response to high salt-feeding when compared to the wildtype litter mate controls (57.89±9.5). These results indicate that Jak2 expression in CD11c + myeloid cells plays a role in salt- sensitive hypertension through an ENaC-dependent mechanism.

1991 ◽  
Vol 261 (6) ◽  
pp. H1895-H1902 ◽  
Author(s):  
L. A. Cowen ◽  
M. R. Harold ◽  
C. M. Chen ◽  
R. E. Abbott ◽  
D. Schachter

The Dahl salt-sensitive rat (DS) is a model of genetically determined arterial hypertension exacerbated by dietary salt. We report two additional abnormalities of DS rats, which are both genetically determined and enhanced by salt: 1) immunoglobulin disorders and 2) renal dysfunctions. These abnormalities precede and are not the result of the arterial hypertension. In young, prehypertensive DS rats the plasma and tissue concentrations of immunoglobulin (Ig) G, but not of IgM or IgA, are decreased compared with those of the salt-resistant strain (DR). A high-salt diet (8.0% NaCl) decreases the plasma and tissue IgG levels of DS but not of DR rats. Reduction of IgG in the DS strain results from both decreased synthesis and increased urinary excretion. Renal dysfunction in young, prehypertensive DS animals is manifested by increased excretion of high molecular weight proteins, including albumin, IgG, IgA, and IgM. The high-salt diet increases the urinary excretion of these proteins within 1-2 days, and the effect is much greater in DS compared with DR rats. The urinary excretion of IgG is selectively increased relative to immunoglobulin light chains, IgA and IgM in DS compared with DR animals. The present studies provide new markers characteristic of the DS phenotype and pose the issue of possible genetic or functional interrelationships among the salt-sensitive hypertension, immunoglobulin disorders, and renal dysfunctions.


Author(s):  
Dominique M Bovee ◽  
Estrellita Uijl ◽  
David Severs ◽  
Eloisa Rubio-Beltrán ◽  
Richard van Veghel ◽  
...  

Chronic kidney disease (CKD) contributes to hypertension, but the mechanisms are incompletely understood. To address this, we applied the 5/6th nephrectomy rat model to characterize hypertension and the response to dietary salt and renin-angiotensin inhibition. 5/6th nephrectomy caused low-renin, salt-sensitive hypertension with hyperkalemia and unsuppressed aldosterone. Compared to sham, 5/6Nx rats had lower NHE3, NKCC2, NCC, a-ENaC and Kir4.1, but higher SKG1, prostasin, g-ENaC, and Kir5.1. These differences correlated with plasma renin, aldosterone, and/or potassium. On a normal salt diet, adrenalectomy (0 ± 9 mmHg) and spironolactone (-11 ± 10 mmHg) prevented a progressive rise in blood pressure (10 ± 8 mmHg), and this was enhanced in combination with losartan (-41 ± 12 mmHg and -43 ± 9 mmHg). A high salt diet caused skin sodium and water accumulation and aggravated hypertension that could only be attenuated by spironolactone (-16 ± 7 mmHg) and in which the additive effect of losartan was lost. Spironolactone also increased natriuresis, reduced skin water accumulation and restored vasorelaxation. In summary, in the 5/6th nephrectomy rat CKD model, salt-sensitive hypertension develops with a selective increase in g-ENaC and despite appropriate transporter adaptations to low renin and hyperkalemia. With a normal salt diet, hypertension in 5/6th nephrectomy depends on angiotensin II and aldosterone, while a high salt diet causes more severe hypertension mediated through the mineralocorticoid receptor.


1993 ◽  
Vol 264 (2) ◽  
pp. H505-H511 ◽  
Author(s):  
M. Weinstock ◽  
M. Borosh

The aim of this study was to determine the effect of an increase in dietary salt on blood pressure (BP), Na+ balance, and plasma renin activity (PRA) in normotensive rabbits bred for differences in cardiac baroreflex sensitivity (BRS). Food and fluid intake, BP, heart rate, body weight, PRA, hematocrit, and creatinine clearance were monitored weekly and Na+ balance daily for 3 wk each on normal NaCl (8 meq/day) and high salt (32 meq/day) in 27 rabbits of the second and third generation of animals bred for high BRS (group I, 6.1 +/- 0.3 beats.min-1.mmHg-1, n = 9) or low BRS (group II, 3.61 +/- 0.1 beats.min-1.mmHg-1, n = 18). BRS was assessed in each animal on normal salt and at the end of the high-salt period. Both systolic and diastolic BP rose by > 10 mmHg in 50% of group II and by < 5 mmHg in the remainder and in all group I. The rise in BP was associated with Na+ and fluid retention and weight gain during the first 2 wk, which returned to presalt levels by the 3rd wk, although BP continued to rise. The lack of effect on BP in the remaining nine group II was associated with a marked sensitization of their BRS by the high salt to 6 +/- 0.4 beats.min-1.mmHg-1. BRS remained unchanged in the other rabbits. A highly significant correlation (P < 0.001) was found between the increment of BP and BRS after 3 wk of raised salt intake.(ABSTRACT TRUNCATED AT 250 WORDS)


2019 ◽  
Vol 20 (14) ◽  
pp. 3495 ◽  
Author(s):  
Yanling Yan ◽  
Jiayan Wang ◽  
Muhammad A. Chaudhry ◽  
Ying Nie ◽  
Shuyan Sun ◽  
...  

We have demonstrated that Na/K-ATPase acts as a receptor for reactive oxygen species (ROS), regulating renal Na+ handling and blood pressure. TALLYHO/JngJ (TH) mice are believed to mimic the state of obesity in humans with a polygenic background of type 2 diabetes. This present work is to investigate the role of Na/K-ATPase signaling in TH mice, focusing on susceptibility to hypertension due to chronic excess salt ingestion. Age-matched male TH and the control C57BL/6J (B6) mice were fed either normal diet or high salt diet (HS: 2, 4, and 8% NaCl) to construct the renal function curve. Na/K-ATPase signaling including c-Src and ERK1/2 phosphorylation, as well as protein carbonylation (a commonly used marker for enhanced ROS production), were assessed in the kidney cortex tissues by Western blot. Urinary and plasma Na+ levels were measured by flame photometry. When compared to B6 mice, TH mice developed salt-sensitive hypertension and responded to a high salt diet with a significant rise in systolic blood pressure indicative of a blunted pressure-natriuresis relationship. These findings were evidenced by a decrease in total and fractional Na+ excretion and a right-shifted renal function curve with a reduced slope. This salt-sensitive hypertension correlated with changes in the Na/K-ATPase signaling. Specifically, Na/K-ATPase signaling was not able to be stimulated by HS due to the activated baseline protein carbonylation, phosphorylation of c-Src and ERK1/2. These findings support the emerging view that Na/K-ATPase signaling contributes to metabolic disease and suggest that malfunction of the Na/K-ATPase signaling may promote the development of salt-sensitive hypertension in obesity. The increased basal level of renal Na/K-ATPase-dependent redox signaling may be responsible for the development of salt-sensitive hypertension in polygenic obese TH mice.


2002 ◽  
Vol 283 (5) ◽  
pp. F1132-F1141 ◽  
Author(s):  
Violeta Alvarez ◽  
Yasmir Quiroz ◽  
Mayerly Nava ◽  
Héctor Pons ◽  
Bernardo Rodríguez-Iturbe

Recent evidence suggests that salt-sensitive hypertension develops as a consequence of renal infiltration with immunocompetent cells. We investigated whether proteinuria, which is known to induce interstitial nephritis, causes salt-sensitive hypertension. Female Lewis rats received 2 g of BSA intraperitoneally daily for 2 wk. After protein overload (PO), 6 wk of a high-salt diet induced hypertension [systolic blood pressure (SBP) = 156 ± 11.8 mmHg], whereas rats that remained on a normal-salt diet and control rats (without PO) on a high-salt diet were normotensive. Administration of mycophenolate mofetil (20 mg · kg−1 · day−1) during PO resulted in prevention of proteinuria-related interstitial nephritis, reduction of renal angiotensin II-positive cells and oxidative stress (superoxide-positive cells and renal malondialdehyde content), and resistance to the hypertensive effect of the high-salt diet (SBP = 129 ± 12.2 mmHg). The present studies support the participation of renal inflammatory infiltrate in the pathogenesis of salt-sensitive hypertension and provide a direct link between two risk factors of progressive renal damage: proteinuria and hypertension.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Bernardo Lopez ◽  
Galina Petrova ◽  
Justine M Abais-Battad ◽  
Hayley Lund ◽  
Daniel Fehrenbach ◽  
...  

Epidemiological data indicates that acute kidney injury (AKI) is an independent risk factor for the development of hypertension and chronic kidney disease in patients. Previous studies demonstrated that rats develop sodium-dependent hypertension and kidney damage following experimental AKI induced by a renal ischemia-reperfusion (IR) insult; furthermore, these high salt deleterious effects could be blunted by administration of immunosuppressive agents. The present study was performed on Dahl SS (SS) rats and SS rats with a null mutation in the CD247 gene (SS-CD247) leading to depletion of T-lymphocytes in order to specifically examine the role of T cells in this response (n=5-6 rats/group). As assessed by serum creatinine (SCr) levels, no difference was observed in the initial response to IR injury between SS and SS-CD247: SCr increased from 0.44±0.03 to 2.16±0.32 mg/dl in SS rats 24 hours after an initial 30 minute period of renal ischemia and returned to control levels after 8 days of recovery. Moreover, no differences were noted in mean arterial pressure (MAP) or albumin excretion rate (UAlb) between SS and SS-CD247 after 43 days of recovery from IR injury while the rats were maintained on a low salt (0.4% NaCl) diet. When the rats were fed a 4.0% NaCl diet for two weeks, MAP and UAlb significantly increased in the sham SS to 178±9 mmHg and 189±25 mg/day, respectively; values significantly greater than observed in the sham SS-CD247 rats (148±2 mmHg and 87±17 mg/day). As expected, the SS rats recovered from IR injury demonstrated an exaggerated increase in MAP (peaking at 183±2 mmHg) and UAlb (275±54 mg/day) in response to high salt. There was no difference in the number of total CD3+ lymphocytes in the kidneys of IR and sham SS after high salt, though the ratio of CD4+/CD8+ T cells was increased in the IR group. Compared to sham CD247, an exaggerated elevation of MAP (157±9 mmHg) and UAlb (210±32 mg/day) was also observed in the SS-CD247 rats recovered from IR injury, demonstrating enhanced responsiveness following IR injury in animals lacking T cells. These data indicate that T lymphocytes amplify salt-sensitive hypertension and renal damage, but other mechanisms also mediate the salt-sensitive hypertension and renal damage that occurs in animals recovered from IR injury.


2021 ◽  
Author(s):  
Sharan Swarup ◽  
J. Wade Harper

Lysosomes are a major degradative organelle within eukaryotic cells. Previous work has developed a method wherein the TMEM192 protein is tagged on its C-terminus with an epitope tag in order to immunopurify (IP) lysosomes from cell extracts.1 This process is referred to as Lyso-IP. Such lysosomes can be used for proteomic analysis or for metabolomic analysis. The Lyso-IP is adapted from a previous reported method (Wyant et al., 2018). Here we also describe processing steps using proteomics after lysosome purification in the context of lysosomal damaging agents. Agents such as L-Leucyl-L-Leucine methyl ester (hydrochloride) (LLoMe) and Gly-Phe-β-naphthylamide (GPN) induce lysosomal damage, leading to the degradation of damaged lysosomes by lysophagy. This adaptation of Lyso-IP provides a route to identify proteins that are recruited to damaged lysosomes using quantitative proteomics.


1999 ◽  
Vol 277 (3) ◽  
pp. R624-R630 ◽  
Author(s):  
Luis G. Melo ◽  
Anthony T. Veress ◽  
Chee K. Chong ◽  
Uwe Ackermann ◽  
Harald Sonnenberg

Mice harboring a functional deletion of the pro-atrial natriuretic peptide (ANP) gene (−/−) develop salt-sensitive hypertension relative to their wild-type (+/+) counterparts after prolonged (>1 wk) maintenance on high-salt (HS, 8% NaCl) diet. We reported recently that the sensitization of arterial blood pressure (ABP) to dietary salt in the −/− mice is associated with failure to downregulate plasma renin activity. To further characterize the role and mechanism of ANG II in the sensitization of ABP to salt in the ANP “knockout” mice, we measured ABP, heart rate (HR), and plasma catecholamine and aldosterone concentrations in −/− and +/+ mice maintained on HS for 4 wk and treated with daily injections of AT1 receptor antagonist DuP-753 (losartan) or distilled water (control). Daily food and water intake and fluid and electrolyte excretion were also measured during the first and last weeks of the dietary regimen. Cumulative urinary excretion of fluid and electrolytes did not differ significantly between genotypes and was not altered by chronic treatment with losartan. Basal ABP and HR were significantly elevated in control −/− mice compared with control +/+ mice. Losartan did not affect ABP or HR in +/+ mice, but reduced ABP and HR in the −/− mice to the levels in the +/+ mice. Total plasma catecholamine was elevated by approximately ten-fold in control −/− mice compared with control +/+ mice. Losartan reduced plasma catecholamine concentration significantly in −/− mice and abrogated the difference in plasma catecholamine between −/− and +/+ mice on HS diet. Plasma aldosterone did not differ significantly between genotypes and was not altered by losartan. We conclude that salt sensitivity of ABP in ANP knockout mice is mediated, at least in part, by a synergistic interaction between ANG II and sympathetic nerve activity.


Xenobiotica ◽  
1987 ◽  
Vol 17 (12) ◽  
pp. 1405-1414 ◽  
Author(s):  
F.-J. Leinweber ◽  
A. J. Szuna ◽  
A. C. Loh ◽  
T. H. Williams ◽  
G. J. Sasso ◽  
...  

2002 ◽  
Vol 283 (1) ◽  
pp. H353-H363 ◽  
Author(s):  
Francis A. Sylvester ◽  
David W. Stepp ◽  
Jefferson C. Frisbee ◽  
Julian H. Lombard

Rats were fed a low-salt (LS; 0.4% NaCl) or high-salt (HS; 4.0% NaCl) diet for 3 days, and the responses of isolated cerebral arteries to acetylcholine (ACh), the nitric oxide (NO)-dependent dilator bradykinin, and the NO donor 6-(2-hydroxy-1-methyl-2-nitrosohydrazino)- N-methyl-1-hex-anamine (NOC-9) were determined. ACh-induced vasodilation and NO release, assessed with the fluorescent NO indicator 4,5-diaminofluorescein (DAF-2) diacetate, were eliminated with the HS diet. Inhibition of cyclooxygenase, cytochrome P-450 epoxygenase, and acetylcholinesterase did not alter ACh responses. Bradykinin and NOC-9 caused a similar dilation in cerebral arteries of all groups. Arteries from animals on LS or HS diets exhibited similar levels of basal superoxide (O[Formula: see text]) production, assessed by dihydroethidine fluorescence, and ACh responses were unaffected by O[Formula: see text] scavengers. Muscarinic type 3 receptor expression was unaffected by dietary salt intake. These results indicate that 1) a HS diet attenuates ACh reactivity in cerebral arteries by inhibiting NO release, 2) this attenuation is not due to production of a cyclooxygenase-derived vasoconstrictor or elevated O[Formula: see text] levels, and 3) alteration(s) in ACh signaling are located upstream from NO synthase.


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