scholarly journals Loss of circadian gene Bmal1 in the collecting duct lowers blood pressure in male, but not female, mice

2020 ◽  
Vol 318 (3) ◽  
pp. F710-F719 ◽  
Author(s):  
Dingguo Zhang ◽  
Chunhua Jin ◽  
Ijeoma E. Obi ◽  
Megan K. Rhoads ◽  
Reham H. Soliman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Collecting Duct ◽  
High Salt ◽  
Dependent Manner ◽  
Type B ◽  
Circadian Gene ◽  
High Salt Diet ◽  
Salt Diet ◽  
Female Mice ◽  
Renal Inner Medulla

Kidney function follows a 24-h rhythm subject to regulation by circadian genes including the transcription factor Bmal1. A high-salt diet induces a phase shift in Bmal1 expression in the renal inner medulla that is dependent on endothelin type B (ETB) receptors. Furthermore, ETB receptor-mediated natriuresis is sex dependent. Therefore, experiments tested the hypothesis that collecting duct Bmal1 regulates blood pressure in a sex-dependent manner. We generated a mouse model that lacks Bmal1 expression in the collecting duct, where ETB receptor abundance is highest. Male, but not female, collecting duct Bmal1 knockout (CDBmal1KO) mice had significantly lower 24-h mean arterial pressure (MAP) than flox controls (105 ± 2 vs. 112 ± 3 mmHg for male mice and 106 ± 1 vs. 108 ± 1 mmHg for female mice, by telemetry). After 6 days on a high-salt (4% NaCl) diet, MAP remained significantly lower in male CDBmal1KO mice than in male flox control mice (107 ± 2 vs. 113 ± 1 mmHg), with no significant differences between genotypes in female mice (108 ± 2 vs. 109 ± 1 mmHg). ETB receptor blockade for another 6 days increased MAP similarly in both male and female CDBmal1KO and flox control mice. However, MAP remained lower in male CDBmal1KO mice than in male flox control mice (124 ± 2 vs. 130 ± 2 mmHg). No significant differences were observed between female CDBmal1KO and flox mice during ETB blockade (130 ± 2 vs. 127 ± 2 mmHg). There were no significant genotype differences in amplitude or phase of MAP in either sex. These data suggest that collecting duct Bmal1 has no role in circadian MAP but plays an important role in overall blood pressure in male, but not female, mice.

Abstract 096: Leptin and High Salt Diet Induce Greater Increases in Blood Pressure in Female than Male Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Jessica L Faulkner ◽  
Eric J Belin de Chantemele
Keyword(s):  
Blood Pressure ◽  
Recovery Period ◽  
Pressure Rise ◽  
High Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Male And Female ◽  
Female Mice ◽  
Males And Females ◽  
Blood Pressure Responses

Recent studies by our group demonstrated that leptin is a direct regulator of aldosterone secretion and increases blood pressure via sex-specific mechanisms involving leptin-mediated activation of the aldosterone-mineralocorticoid receptor signaling pathway in females and sympatho-activation in males. Although it is well accepted that females secrete more leptin and aldosterone than males, it is unknown whether leptin infusion raises blood pressure similarly in male and female mice and whether higher aldosterone levels sensitize females to salt-induced hypertension. We hypothesized that female mice would be more sensitive to leptin than males and also have a potentiated blood pressure rise in response to high salt diet compared to males. Male and female Balb/C mice were implanted with radiotelemeters for continuous measurement of mean arterial pressure (MAP) at 10 weeks of age. MAP was measured for seven days prior to feeding with a high-salt diet (HS, 4%NaCl) for seven days. Following a recovery period, animals were then implanted with osmotic minipumps containing leptin (0.9mg/kg/day) recorded for seven days. Baseline MAP was similar between males and females (101.3±2.9 vs 99.3±3.7 mmHg, n=4 and 5, respectively), however, HS diet resulted in a greater MAP increase in females (15.0±2.6 mmHg) compared to males (3.1±4.5 mmHg, P<0.05). MAP with leptin treatment was increased with leptin in females moreso than in males, however, this did not reach significance (6.8±5.8 vs 1.8±5.9 mmHg, respectively). This potential sex difference in blood pressure responses to leptin was not associated with changes in body weight (0.07±0.44 vs -0.22±0.2 g, respectively) nor changes in blood glucose (-19.67±15.06 vs -15.4±11.4 mg/dl, respectively) in males and females in response to leptin. In summary, female mice are more sensitive to HS diet-induced blood pressure increases than males. Females may be more sensitive to leptin-mediated blood pressure increases than males. Further investigation is needed to determine whether these sex differences in blood pressure responses to HS diet and leptin are mediated by aldosterone or other mechanisms.

scholarly journals Sex dependent compensatory mechanisms to preserve blood pressure homeostasis in PGI2 receptor deficient mice

2020 ◽  
Author(s):  
Soon Yew Tang ◽  
Seán T. Anderson ◽  
Hu Meng ◽  
Dimitra Sarantopoulou ◽  
Emanuela Ricciotti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Oxidant Stress ◽  
High Salt ◽  
Prostaglandin E ◽  
High Salt Diet ◽  
Salt Loading ◽  
Salt Diet ◽  
Female Mice ◽  
The Impact ◽  
Deficient Mice

AbstractInhibitors of microsomal prostaglandin E synthase-1 (mPges-1) are in the early phase of clinical development. Deletion of mPges-1 confers analgesia, restrains atherogenesis and fails to accelerate thrombogenesis, while suppressing prostaglandin (PG) E2, but increasing biosynthesis of prostacyclin (PGI2). In hyperlipidemic mice, this last effect represents the dominant mechanism by which mPges-1 deletion restrains thrombogenesis, while suppression of PGE2 accounts for its anti-atherogenic effect. However, the impact of mPges-1 depletion on blood pressure (BP) in this setting remains unknown.To address how differential effects on PGE2 and PGI2 might modulate salt-evoked BP responses in the absence of mPges-1, we generated mice lacking the I prostanoid (Ipr) receptor or mPges-1 on a hyperlipidemic background caused by deletion of the low density lipoprotein receptor (Ldlr KOs). Here, mPges-1 depletion significantly increased the BP response to salt loading in male Ldlr KO mice, whereas, despite the direct vasodilator properties of PGI2, Ipr deletion suppressed it. Furthermore, combined deletion of the Ipr abrogated the exaggerated BP response in male mPges-1 KO mice. Suppression of PGE2 biosynthesis was enough to explain the exaggerated BP response to salt loading by either mPges-1/Ldlr depletion or by an MPGES-1 inhibitor in mice expressing human mPGES-1. However, the lack of a hypertensive response to salt in Ipr-deficient mice was attributable to reactive activation of the atrial natriuretic peptide pathway. Interestingly, these unexpected BP phenotypes were not observed in female mice fed a high salt diet. This is attributable to the protective effect of estrogen in Ldlr KO mice and in Ipr /Ldlr DKOs. Thus, estrogen compensates for a deficiency in PGI2 to maintain BP homeostasis in response to high salt in hyperlipidemic female mice. In males, by contrast, augmented formation of ANP plays a similar compensatory role, restraining hypertension and oxidant stress in the setting of Ipr depletion. Hyperlipidemic males on a high salt diet might be at risk of a hypertensive response to mPGES-1 inhibitors.

scholarly journals Knockout of the circadian clock protein PER1 results in sex-dependent alterations of ET-1 production in mice in response to a high-salt diet plus mineralocorticoid treatment

2020 ◽  
Vol 98 (9) ◽  
pp. 579-586 ◽  
Author(s):  
Lauren G. Douma ◽  
G. Ryan Crislip ◽  
Kit-Yan Cheng ◽  
Dominique Barral ◽  
Sarah Masten ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Collecting Duct ◽  
High Salt ◽  
Negative Regulator ◽  
Specific Response ◽  
Cortical Collecting Duct ◽  
High Salt Diet ◽  
Salt Diet ◽  
Female Mice ◽  
Endothelin B

Previously, we showed that global knockout (KO) of the circadian clock transcription factor PER1 in male, but not female, mice fed a high-salt diet plus mineralocorticoid treatment (HS/DOCP) resulted in nondipping hypertension and decreased night/day ratio of sodium (Na) excretion. Additionally, we have shown that the endothelin-1 (ET-1) gene is targeted by both PER1 and aldosterone. We hypothesized that ET-1 would exhibit a sex-specific response to HS/DOCP treatment in PER1 KO. Here we show that male, but not female, global PER1 KO mice exhibit a decreased night/day ratio of urinary ET-1. Gene expression analysis revealed significant genotype differences in ET-1 and endothelin A receptor (ETA) expression in male, but not female, mice in response to HS/DOCP. Additionally, both wild-type and global PER1 KO male mice significantly increase endothelin B receptor (ETB) expression in response to HS/DOCP, but female mice do not. Finally, siRNA-mediated knockdown of PER1 in mouse cortical collecting duct cells (mpkCCDc14) resulted in increased ET-1 mRNA expression and peptide secretion in response to aldosterone treatment. These data suggest that PER1 is a negative regulator of ET-1 expression in response to HS/DOCP, revealing a novel mechanism for the regulation of renal Na handling in response to HS/DOCP treatment.

Abstract 160: Characterization of a Comt Knock-out Rat for Blood Pressure and Associated Phenotypes.

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Marc Casati ◽  
Mathew Hoffman ◽  
Rebecca Schilling ◽  
Michael Flister ◽  
Aron M Geurts ◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Salt ◽  
Male Rats ◽  
Zinc Finger Nucleases ◽  
Dependent Manner ◽  
Electrolyte Excretion ◽  
High Salt Diet ◽  
Salt Diet ◽  
Low Salt ◽  
Salt Sensitive Hypertension

The catecholamine system plays an important role in the control of blood pressure and sodium excretion. One of the inactivation pathways of catecholamines is the enzymatic metabolism by catechol-O-methyltransferase (Comt). There are conflicting data regarding the role of Comt on the development of salt-sensitive hypertension, so the goal of our study was to evaluate the importance of Comt in the context of a susceptible background in vivo. Comt was mutated in the Dahl SS rat by zinc finger nucleases (ZFNs) injections targeting the sequence CTGTTCCAGGTCACCATCctcaatGGGGCATCCCAGGATCTT into SS/JrHsdMcwi (Dahl S) rat embryos. The resulting mutation was a 14-bp frameshift deletion in exon 4. Conscious blood pressure was measured by telemetry on male and female Comt knockout and wild type (WT) rats on low salt diet (0.4% NaCl) and during three weeks of high salt diet (8%NaCl). Disruption of Comt caused the protein not to express in the kidneys of the Dahl S rat. There were no differences in mean arterial pressure (MAP) between the Comt -/- and the Comt +/+ male rats at any time point during the day-night cycle at low or high salt diet. Body and organ weights, and protein and electrolyte excretion was also unchanged by the Comt mutation. On the other hand, female Comt -/- rats evidenced a higher MAP, which was only significantly higher at night during low salt diet (112±2 mmHg in Comt +/+ vs 125±2 mmHg in the Comt -/-, n>6) and both during day and night after 21 days of high-salt diet (∼ 30 mmHg difference between Comt +/+ and Comt -/- strains at both day and night). Systolic blood pressure differences were mostly responsible for the observed blood pressure diferences in females KO of the Comt gene, despite blood pressure effect, was not followed by a parallel difference in urine flow, electrolyte excretion or renal damage (protein and albumin excretion). In conclusion, we are the first ones to show that disruption of Comt enhances salt-sensitive hypertension in a gender-dependent manner.

scholarly journals Female mice retain more sodium than male mice but maintain lower blood pressure during 30 days on a high salt diet (1135.1)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Al Rouch ◽  
Lucia Kudo ◽  
Liming Fan ◽  
Heba Hammami ◽  
Maria Nadeem ◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Salt ◽  
Lower Blood Pressure ◽  
Male Mice ◽  
High Salt Diet ◽  
Salt Diet ◽  
Female Mice ◽  
Lower Blood

scholarly journals Metabolic Syndrome and Salt-Sensitive Hypertension in Polygenic Obese TALLYHO/JngJ Mice: Role of Na/K-ATPase Signaling

2019 ◽  
Vol 20 (14) ◽  
pp. 3495 ◽  
Author(s):  
Yanling Yan ◽  
Jiayan Wang ◽  
Muhammad A. Chaudhry ◽  
Ying Nie ◽  
Shuyan Sun ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Significant Rise ◽  
Protein Carbonylation ◽  
High Salt ◽  
Kidney Cortex ◽  
High Salt Diet ◽  
Salt Diet ◽  
Salt Sensitive Hypertension

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.

Endothelin B receptors impair baroreflex function and increase blood pressure variability during high salt diet

2021 ◽  
pp. 102796
Author(s):  
Bryan K. Becker ◽  
Jermaine G. Johnston ◽  
Carolyn Young ◽  
Alfredo A. Torres Rodriguez ◽  
Chunhua Jin ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Variability ◽  
High Salt ◽  
Increase Blood Pressure ◽  
High Salt Diet ◽  
Salt Diet ◽  
Baroreflex Function ◽  
Endothelin B

Abstract 16835: Targeted Disruption of Paraoxonase 3 in a Dahl Salt-Sensitive Rat Model of Chronic Kidney Disease Increases Renal Cortical Pro-Inflammatory Eicosanoids

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Chrysan J Mohammed ◽  
Fatimah K Khalaf ◽  
Prabhatchandra Dube ◽  
Tyler J Reid ◽  
Jacob A Connolly ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Injury ◽  
Renal Cortex ◽  
High Salt ◽  
High Density Lipoproteins ◽  
Wild Type ◽  
Targeted Disruption ◽  
High Salt Diet ◽  
Salt Diet ◽  
Mediators Of Inflammation

Background: Paraoxonase 3 (Pon3), is one of the three isoforms of the paraoxonase gene family. While Pon1 and Pon2 are widely studied, there is a paucity of knowledge regarding Pon3. Pon3 is synthesized in the liver and can circulate bound to high-density lipoproteins. There is significant expression in the kidney also. Pon3 has the ability to metabolize eicosanoids, which can act as signaling molecules and have known roles in the pathophysiology of some renal diseases. Decreased Pon activity is associated with elevated levels of eicosanoid metabolites and adverse clinical outcomes. We tested the hypothesis that targeted disruption of Pon3 results in elevated levels of pro-inflammatory eicosanoids and progression of renal injury. Methods/ Results: Ten week old male Dahl salt-sensitive (SS rats) and Pon3 mutant rats (SS Pon3 KO) were maintained on 8% high salt diet for eight weeks, to initiate salt-sensitive hypertensive renal disease. Previously we observed that SS Pon3 KO rats on eight weeks high salt diet demonstrated significantly increased phenotypic renal injury and mortality. In the current study, we noted that SS Pon3 KO had significantly decreased (p<0.05) glomerular filtration rate compared to SS wild type. Blood pressure (radiotelemetry) as well as plasma angiotensin and aldosterone (LC-MS/MS) were not different between the two groups after high salt diet. We used targeted lipidomic profiling to determine eicosanoid content in renal cortex from SS Pon3 KO and SS wild type rats at the end of eight weeks of high salt diet. We found that hydroxyl fatty acids 5-HEPE and 5-HETE (5-lipoxygenase dependent arachidonic acid metabolites) were significantly (p<0.05) elevated in the renal cortex of SS Pon3 KO compared to SS wild type rats. In addition to being mediators of inflammation, these metabolites are associated with renal cell injury and death. Furthermore, prostaglandin 6-keto-PGF 1α , which has known links to renal inflammation, was significantly (p<0.05) increased in renal cortex of SS- Pon3 KO compared to SS wild type rats. Conclusion: These findings suggest that targeted deletion of Pon3 increases pro-inflammatory eicosanoids (5-HETE and 5-HEPE) and prostaglandins (6-keto-PGF 1α ), as well as increases renal damage independent of blood pressure.

Abstract 376: The Expression of (pro)renin Receptor is Upregulated in the Kidney by High Salt Diet and No Inhibition

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Rong Rong ◽  
Osamu Ito ◽  
Nobuyoshi Mori ◽  
Yuma Tamura ◽  
Akihiro Sakuyama ◽  
...  
Keyword(s):  
Collecting Duct ◽  
High Salt ◽  
Kidney Cortex ◽  
Control Group ◽  
Thick Ascending Limb ◽  
High Salt Diet ◽  
Salt Diet ◽  
Protein Levels ◽  
Nephron Segments ◽  
Sd Rats

The (pro)renin receptor ((P)RR)-bound (pro)renin not only causes the generation of angiotensin II via the increased enzymatic activity, it also activates the receptor’s own intracellular signaling pathways up-regulating the expression of the profibrotic proteins. To clarify the regulation of (P)RR expression, the present study examined the effects of high salt diet and nitric oxide synthase (NOS) inhibition on the (P)RR expression in the kidney. The nephron segments were isolated from male Sprague-Dawley (SD) rats by microdissection and bulk isolation technique, and the (P)RR mRNA and protein expressions were examined by using reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. In adiition, 5 week-old, male SD rats were randomly divided into 3 groups: a control group, a high salt diet (HS) group and a Nω-Nitro-L-arginine (L-NAME) group, and each group was treated with vehicle, high salt diet (8%, NaCl), or L-NAME (600mg/ml in drinking water), respectively. After 4 weeks, the (P)RR expression in the kidney was compared among these groups. The (P)RR mRNA was expressed in the glomerulus (Glm), the proximal convoluted and straight tubule, the cortical and medullary thick ascending limb (TAL) and collecting duct. The (P)RR protein as well as mRNA was expressed widely in the nephron segments; the preglomerular arteriole, the Glm, the proximal tubules (PT), the medullary TAL (mTAL) and inner medullary collecting duct (IMCD). Compared with the control group, the (P)RR protein levels significantly increased in the kidney cortex of both HS group and L-NAME group by 96% (p<0.01) and 506% (p<0.01) and in the inner medulla of L-NAME group by 148% (p<0.05), but did not significantly change in the outer medulla of HS group or L-NAME group. HS increased the (P)RR protein levels in the Glm and PT by 48% (p<0.05) and 39% (p<0.01), but did not affect them in other nephron segments. These results indicated that (P)RR is expressed widely in the nephron segments and that HS and NOS inhibition upregulate the (P)RR expression in the kidney, suggesting roles of (P)RR in hypertensive kidney disorder.

Abstract 370: Upregulation of Renal D5 Dopamine Receptor Ameliorates Hypertension in D3 Deficient Mice

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Xiaoyan Wang ◽  
Crisanto S Escano ◽  
Laureano Asico ◽  
John E Jones ◽  
Alan Barte ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Nadph Oxidase ◽  
Protein Expression ◽  
Dopamine Receptors ◽  
Dopamine Receptor ◽  
High Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Deficient Mice

D 3 dopamine receptor (D 3 R) deficient mice have renin-dependent hypertension but the hypertension is mild and is not associated with oxidative stress. In order to determine if any compensatory mechanism in the kidney is involved in the regulation of blood pressure with disruption of D 3 R, we measured the renal protein expression of dopamine receptors in D 3 R homozygous (D 3 -/-) and heterozygous (D 3 +/-) knockout mice and their wild type (D 3 +/+) littermates. D 5 dopamine receptor (D 5 R) (169±23%, reported as % of D 3 +/+, n=5/group) expression was increased but D 4 dopamine receptors protein expression (59±8%) was decreased, while no significant changes were found with D 1 and D 2 dopamine receptors. Immunocytochemistry showed a stronger renal staining of D 5 R but without a change in renal tubule cell distribution in D 3 -/- relative to D 3 +/+ mice. D 5 R abundance was also increased in D 3 +/- (205±30%, n=5/group) relative to D 3 +/+ mice, while D 1 R abundance was similar between D 3 +/- and D 3 +/+ mice. The increase in D 5 R expression was abolished while blood pressure was increased further in D 3 -/- mice fed a high salt diet. Treatment of the D 1 -like (including D 1 and D 5 receptors) antagonist, SCH23390 , increased the blood pressure to a greater extent in anesthetized D 3 -/- mice than in D 3 +/+ mice (n=4/group), suggesting that the upregulation of D 5 R may modulate the hypertension in mice caused by the disruption of D 3 R. Since dopamine inhibits the NADPH oxidase-induced production of reactive oxygen species (ROS) via the D 5 R, we also measured the protein expression of NOXs in the kidney and isoprostane in the urine. No NADPH oxidase subunit was increased in D 3 -/- and D 3 +/- mice relative to D 3 +/+ mice fed a normal or salt high salt diet, and urinary isoprostane excretion was also similar in D 3 -/- and D 3 +/+ mice. Our findings suggest that the upregulation of D 5 R may minimize the hypertension and prevent oxidative stress in D 3 -/- mice.

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