scholarly journals Soluble syndecan-1 and glycosaminoglycans in preeclamptic and normotensive pregnancies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Hassani Lahsinoui ◽  
F. Amraoui ◽  
L. J. A. Spijkers ◽  
G. J. M. Veenboer ◽  
S. L. M. Peters ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heparan Sulphate ◽  
Activated Partial Thromboplastin Time ◽  
Male Mice ◽  
Wild Type ◽  
Dermatan Sulphate ◽  
Keratan Sulphate ◽  
Blood Pressure Elevation ◽  
Wild Type Male ◽  
Deficient Mice

AbstractPreeclampsia, an important cause of maternal and fetal morbidity and mortality, is associated with increased sFLT1 levels and with structural and functional damage to the glycocalyx contributing to endothelial dysfunction. We investigated glycocalyx components in relation to preeclampsia in human samples. While soluble syndecan-1 and heparan sulphate were similar in plasma of preeclamptic and normotensive pregnant women, dermatan sulphate was increased and keratan sulphate decreased in preeclamptic women. Dermatan sulphate was correlated with soluble syndecan-1, and inversely correlated with blood pressure and activated partial thromboplastin time. To determine if syndecan-1 was a prerequisite for the sFlt1 induced increase in blood pressure in mice we studied the effect of sFlt1 on blood pressure and vascular contractile responses in syndecan-1 deficient and wild type male mice. The classical sFlt1 induced rise in blood pressure was absent in syndecan-1 deficient mice indicating that syndecan-1 is a prerequisite for sFlt1 induced increase in blood pressure central to preeclampsia. The results show that an interplay between syndecan-1 and dermatan sulphate contributes to sFlt1 induced blood pressure elevation in pre-eclampsia.

scholarly journals Salt sensitivity of blood pressure in NKCC1-deficient mice

2008 ◽  
Vol 295 (4) ◽  
pp. F1230-F1238 ◽  
Author(s):  
Soo Mi Kim ◽  
Christoph Eisner ◽  
Robert Faulhaber-Walter ◽  
Diane Mizel ◽  
Susan M. Wall ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Wheel Running ◽  
Plasma Renin ◽  
Pressure Change ◽  
Standard Diet ◽  
Wild Type ◽  
Vascular Effects ◽  
Arterial Blood ◽  
Deficient Mice

NKCC1 is a widely expressed isoform of the Na-2Cl-K cotransporter that mediates several direct and indirect vascular effects and regulates expression and release of renin. In this study, we used NKCC1-deficient (NKCC1−/−) and wild-type (WT) mice to assess day/night differences of blood pressure (BP), locomotor activity, and renin release and to study the effects of high (8%) or low (0.03%) dietary NaCl intake on BP, activity, and the renin/aldosterone system. On a standard diet, 24-h mean arterial blood pressure (MAP) and heart rate determined by radiotelemetry, and their day/night differences, were not different in NKCC1−/− and WT mice. Spontaneous and wheel-running activities in the active night phase were lower in NKCC1−/− than WT mice. In NKCC1−/− mice on a high-NaCl diet, MAP increased by 10 mmHg in the night without changes in heart rate. In contrast, there was no salt-dependent blood pressure change in WT mice. MAP reductions by hydralazine (1 mg/kg) or isoproterenol (10 μg/mouse) were significantly greater in NKCC1−/− than WT mice. Plasma renin (PRC; ng ANG I·ml−1·h−1) and aldosterone (aldo; pg/ml) concentrations were higher in NKCC1−/− than WT mice (PRC: 3,745 ± 377 vs. 1,245 ± 364; aldo: 763 ± 136 vs. 327 ± 98). Hyperreninism and hyperaldosteronism were found in NKCC1−/− mice during both day and night. High Na suppressed PRC and aldosterone in both NKCC1−/− and WT mice, whereas a low-Na diet increased PRC and aldosterone in WT but not NKCC1−/− mice. We conclude that 24-h MAP and MAP circadian rhythms do not differ between NKCC1−/− and WT mice on a standard diet, probably reflecting a balance between anti- and prohypertensive factors, but that blood pressure of NKCC1−/− mice is more sensitive to increases and decreases of Na intake.

Abstract P199: Mas Receptor Deficiency Regulates Obesity-Hypertension and Cardiac Function in Female and Male Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Robin C Shoemaker ◽  
Yu Wang ◽  
Sean Thatcher ◽  
Lisa Cassis
Keyword(s):  
Blood Pressure ◽  
Sexual Dimorphism ◽  
Cardiac Function ◽  
Male Mice ◽  
Reduced Ejection Fraction ◽  
Obesity Hypertension ◽  
Obese Male ◽  
Deficient Mice ◽  
Cmr Imaging

Angiotensin-1-7 (Ang-(1-7)) counteracts angiotensin II through effects at Mas receptors (MasR). We demonstrated that sexual dimorphism of obesity-hypertension was associated with dysregulated production of Ang-(1-7). However, the role of MasR in sexual dimorphism of obesity-hypertension has not been examined. MasR deficient mice have also been reported to exhibit deficits in cardiac function. In this study, we hypothesized that deficiency of the MasR would differentially regulate obesity-hypertension in male versus ( vs ) female mice. In addition, we quantified effects of MasR deficiency on cardiac function in obese male mice. Male and female MasR +/+ and -/- mice were fed a low fat (LF, 10%kcal) or high fat (HF, 60% kcal) diet for 16 weeks, and blood pressure was quantified by radiotelemetry. As demonstrated previously, male MasR +/+ mice (24 hr diastolic blood pressure, DBP: LF, 90 ± 3; HF, 96 ± 2 mmHg; P<0.05), but not females (LF, 85 ± 1; HF, 85 ± 2 mmHg), developed hypertension in response to HF feeding. MasR deficiency converted female HF-fed mice to an obesity-hypertension phenotype (DBP: 92 ± 1 mmHg; P<0.05). Surprisingly, male HF-fed MasR -/- mice exhibited reduced DBP compared to HF-fed MasR +/+ males (90 ± 1 vs 96 ± 2 mmHg; P<0.05). To define mechanisms for reductions in DBP of HF-fed male MasR -/- mice, we performed cardiac magnetic resonance (CMR) imaging in both genotypes at 1 month of HF feeding. MasR -/- mice had significantly reduced ejection fraction (EF) compared to MasR +/+ mice at baseline (51.4 ± 2.5 vs 59.3 ± 2.1%; P<0.05) and after one month of HF-feeding (49.8 ± 2.4 vs 52.6 ± 1.9%; P<0.05). Further, CMR imaging demonstrated a thickening of the ventricle wall in MasR -/- mice with 1 month of HF-feeding. MasR +/+ , but not MasR -/- mice, exhibited diet-induced reductions in EF (by 16%; P<0.05) at 1 month of HF feeding, which were reversed by infusion of Ang-(1-7). These results demonstrate that MasR contributes to sexual dimorphism of obesity-hypertension. Ang-(1-7) protects females from obesity-hypertension through the MasR. In contrast, reductions in DBP in obese male mice with MasR deficiency may arise from deficits in cardiac function. These results suggest that MasR agonists may be effective therapies for obesity-associated cardiovascular conditions.

A γGT-AT1A receptor transgene protects renal cortical structure in AT1 receptor-deficient mice

2004 ◽  
Vol 18 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Thu H. Le ◽  
Michael I. Oliverio ◽  
Hyung-Suk Kim ◽  
Harmony Salzler ◽  
Rajesh C. Dash ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Transgenic Mice ◽  
Proximal Tubule ◽  
Physiological Role ◽  
Renal Proximal Tubule ◽  
Hypoxanthine Phosphoribosyl Transferase ◽  
Wild Type ◽  
Specific Expression ◽  
Low Levels ◽  
Deficient Mice

To understand the physiological role of angiotensin type 1 (AT1) receptors in the proximal tubule of the kidney, we generated a transgenic mouse line in which the major murine AT1 receptor isoform, AT1A, was expressed under the control of the P1 portion of the γ-glutamyl transpeptidase (γGT) promoter. In transgenic mice, this promoter has been shown to confer cell-specific expression in epithelial cells of the renal proximal tubule. To avoid random integration of multiple copies of the transgene, we used gene targeting to produce mice with a single-copy transgene insertion at the hypoxanthine phosphoribosyl transferase ( Hprt) locus on the X chromosome. The physiological effects of the γGT-AT1A transgene were examined on a wild-type background and in mice with targeted disruption of one or both of the murine AT1 receptor genes ( Agtr1a and Agtr1b). On all three backgrounds, γGT-AT1A transgenic mice were healthy and viable. On the wild-type background, the presence of the transgene did not affect development, blood pressure, or kidney structure. Despite relatively low levels of expression in the proximal tubule, the transgene blunted the increase in renin expression typically seen in AT1-deficient mice and partially rescued the kidney phenotype associated with Agtr1a−/− Agtr1b−/− mice, significantly reducing cortical cyst formation by more than threefold. However, these low levels of cell-specific expression of AT1 receptors in the renal proximal tubule did not increase the low blood pressures or abolish sodium sensitivity, which are characteristic of AT1 receptor-deficient mice. Although our studies do not clearly identify a role for AT1 receptors in the proximal tubules of the kidney in blood pressure homeostasis, they support a major role for these receptors in modulating renin expression and in maintaining structural integrity of the renal cortex.

scholarly journals Genetic deletion of AT1a receptors attenuates intracellular accumulation of ANG II in the kidney of AT1a receptor-deficient mice

2007 ◽  
Vol 293 (2) ◽  
pp. F586-F593 ◽  
Author(s):  
Xiao C. Li ◽  
L. Gabriel Navar ◽  
Yuan Shao ◽  
Jia L. Zhuo
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Rat Kidney ◽  
Systolic Pressure ◽  
Weight Ratio ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Ang Ii ◽  
Wild Type ◽  
Deficient Mice

We and others have previously shown that high levels of ANG II are accumulated in the rat kidney via a type 1 (AT1) receptor-mediated mechanism, but it is not known which AT1 receptor is involved in this process in rodents. We tested the hypothesis that AT1a receptor-deficient mice (Agtr1a−/−) are unable to accumulate ANG II intracellularly in the kidney because of the absence of AT1a receptor-mediated endocytosis. Adult male wild-type (Agtr1a+/+), heterozygous (Agtr1a+/−), and Agtr1a−/− were treated with vehicle, ANG II (40 ng/min ip via osmotic minipump), or ANG II plus the AT1 antagonist losartan (10 mg·kg−1·day−1 po) for 2 wk. In wild-type mice, ANG II induced hypertension (168 ± 4 vs. 113 ± 3 mmHg, P < 0.001), increased kidney-to-body weight ratio ( P < 0.01), caused pressure natriuresis ( P < 0.05), and elevated plasma and whole kidney ANG II levels ( P < 0.001). Concurrent administration of ANG II with losartan attenuated these responses to ANG II. In contrast, Agtr1a−/− mice had lower basal systolic pressures ( P < 0.001), smaller kidneys with much fewer AT1b receptors ( P < 0.001), higher basal 24-h urinary sodium excretion ( P < 0.01), as well as basal plasma and whole kidney ANG II levels ( P < 0.01). However, intracellular ANG II levels in the kidney were lower in Agtr1a−/− mice. In Agtr1a−/− mice, ANG II slightly increased systolic pressure ( P < 0.05) but had no effect on the kidney weight, urinary sodium excretion, and whole kidney ANG II levels. Losartan restored systolic pressure to basal levels and decreased whole kidney ANG II levels by ∼20% ( P < 0.05). These results demonstrate a predominant role of AT1a receptors in blood pressure regulation and in the renal responses to long-term ANG II administration, that AT1b receptors may play a limited role in blood pressure control and mediating intrarenal ANG II accumulation in the absence of AT1a receptors.

scholarly journals Cardiac hypertrophy and decreased high-density lipoprotein cholesterol in Lrig3-deficient mice

2016 ◽  
Vol 310 (11) ◽  
pp. R1045-R1052 ◽  
Author(s):  
Martin Hellström ◽  
Madelene Ericsson ◽  
Bengt Johansson ◽  
Mahmood Faraz ◽  
Fredrick Anderson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
High Density Lipoprotein ◽  
Heart Function ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Wild Type ◽  
Lipid Levels ◽  
Deficient Mice

Genetic factors confer risk for cardiovascular disease. Recently, large genome-wide population studies have shown associations between genomic loci close to LRIG3 and heart failure and plasma high-density lipoprotein (HDL) cholesterol level. Here, we ablated Lrig3 in mice and investigated the importance of Lrig3 for heart function and plasma lipid levels. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze Lrig3 expression in the hearts of wild-type and Lrig3-deficient mice. In addition, molecular, physiological, and functional parameters such as organ weights, heart rate, blood pressure, heart structure and function, gene expression in the heart, and plasma insulin, glucose, and lipid levels were evaluated. The Lrig3-deficient mice were smaller than the wild-type mice but otherwise appeared grossly normal. Lrig3 was expressed at detectable but relatively low levels in adult mouse hearts. At 9 mo of age, ad libitum-fed Lrig3-deficient mice had lower insulin levels than wild-type mice. At 12 mo of age, Lrig3-deficient mice exhibited increased blood pressure, and the Lrig3-deficient female mice displayed signs of cardiac hypertrophy as assessed by echocardiography, heart-to-body weight ratio, and expression of the cardiac hypertrophy marker gene Nppa. Additionally, Lrig3-deficient mice had reduced plasma HDL cholesterol and free glycerol. These findings in mice complement the human epidemiological results and suggest that Lrig3 may influence heart function and plasma lipid levels in mice and humans.

Tissue kallikrein, blood pressure regulation, and hypertension: insight from genetic kallikrein deficiency

2013 ◽  
Vol 394 (3) ◽  
pp. 329-333 ◽  
Author(s):  
Louis Potier ◽  
Ludovic Waeckel ◽  
Christine Richer ◽  
Ronan Roussel ◽  
Nadine Bouby ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Regulation ◽  
Genetic Models ◽  
Tissue Kallikrein ◽  
Sodium Retention ◽  
Pressure Regulation ◽  
Blood Pressure Elevation ◽  
Genetic Deficiency ◽  
Kallikrein Activity ◽  
Deficient Mice

Abstract Tissue kallikrein has been suggested to be involved in blood pressure regulation and in protection against hypertension. However, this hypothesis remains debated. Recently, murine genetic models of kallikrein deficiency have been engineered and partial genetic deficiency in kallikrein activity has been characterized in humans. Studies in kallikrein-deficient mice indicate that kallikrein indeed influences blood pressure in the setting of mineralocorticoid excess and salt retention but not in normotensive animals and in high renin hypertension. These observations suggest that kallikrein can have antihypertensive function in physiological situations where sodium retention can trigger blood pressure elevation.

scholarly journals Studies of Salt and Stress Sensitivity on Arterial Pressure in Renin-b Deficient Mice

2021 ◽  
Author(s):  
Pablo Nakagawa ◽  
Javier Gomez ◽  
Ko-Ting Lu ◽  
Justin L. Grobe ◽  
Curt D. Sigmund
Keyword(s):  
Blood Pressure ◽  
Restraint Stress ◽  
Sodium Intake ◽  
High Salt ◽  
Ventrolateral Medulla ◽  
High Salt Diet ◽  
Blood Pressure Elevation ◽  
Salt Diet ◽  
The Brain ◽  
Deficient Mice

AbstractExcessive sodium intake is known to increase the risk for hypertension, heart disease, and stroke. Individuals who are more susceptible to the effects of high salt are at higher risk for cardiovascular diseases even independent of their blood pressure status. Local activation of the renin-angiotensin system (RAS) in the brain, among other mechanisms, has been hypothesized to play a key role in contributing to salt balance. We have previously shown that deletion of the alternative renin isoform termed renin-b disinhibits the classical renin-a encoding preprorenin in the brain resulting in elevated brain RAS activity. Thus, we hypothesized that renin-b deficiency results in higher susceptibility to salt-induced elevation in blood pressure. Telemetry implanted Ren-bNull and wildtype littermate mice were first offered a low salt diet for a week and subsequently a high salt diet for another week. A high salt diet induced a mild blood pressure elevation in both Ren-bNull and wildtype mice, but mice lacking renin-b did not exhibit an exaggerated pressor response. When renin-b deficient mice were exposed to a high salt diet for a longer duration (4 weeks), was a trend for increased myocardial enlargement in Ren-bNull mice when compared with control mice. Multiple studies have also demonstrated the association of chronic and acute environmental stress with hypertension. Activation of the RAS in the rostral ventrolateral medulla and the hypothalamus is required for stress-induced hypertension. Thus, we next questioned whether the lack of renin-b would result in exacerbated response to an acute restraint-stress. Wildtype and Ren-bNull mice equally exhibited elevated blood pressure in response to restraint-stress, which was similar in mice fed either a low or high salt diet. These studies highlight a complex mechanism that masks/unmasks roles for renin-b in cardiovascular physiology.

Heparin Fragments Induce Cervical Inflammation by Recruiting Immune Cells through Toll-like Receptor 4 in nonpregnant mice

2021 ◽  
Author(s):  
Anna Åkerud ◽  
Jakob Axelsson ◽  
Manisha Yadav ◽  
Jonas Erjefält ◽  
Gunvor Ekman-Ordeberg ◽  
...  
Keyword(s):  
Heparan Sulphate ◽  
Late Pregnancy ◽  
Primary Response ◽  
Cervical Ripening ◽  
Mucosal Inflammation ◽  
Toll Like Receptor ◽  
Wild Type ◽  
Toll Like Receptor 4 ◽  
Local Inflammatory Response ◽  
Deficient Mice

Abstract Inflammation is a hallmark in the human cervix remodelling. A possible candidate inducing the inflammatory driven ripening of the cervix is the matrix component heparan sulphate, which has been shown to be elevated in late pregnancy in the cervix and uterus. Heparin and a glycol-split low molecular weight heparin (gsHep) with low anticoagulant potency has been shown to enhance myometrial contraction and interleukin (IL)-8 production by cervical fibroblasts. The aim of this study was to investigate the mechanism by which heparin promotes cervical inflammation. Wild-type, Toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 n (MyD88) and Interferon regulatory factor 3 (IRF3)-deficient mice were treated by deposition of gsHep into the vaginas of nonpregnant mice. To identify which cells that responded to the heparin fragments, a rhodamine fluorescent construct of gsHep was used, which initially did bind to the epithelial cells and were at later time points located in the sub-mucosa. The heparin fragments induced a strong local inflammatory response in wild-type mice shown by a rapid infiltration of neutrophils and to a lesser extent macrophages into the epithelium and the underlying extracellular matrix (ECM) of the cervix. Further, a marked migration into the cervical and vaginal lumen was seen by both neutrophils and macrophages. The induced mucosal inflammation was strongly reduced in TLR4- and IRF3-deficient mice. In conclusion, our findings suggest that a TLR4/IRF3-mediated innate immune response in the cervical mucosa is induced by gsHep. This low anticoagulant heparin version, a novel TLR4 agonist, could contribute to human cervical ripening during the initiation of labour.

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