Abstract P155: B Cells Are Not Necessary for the Developmentof Ang II-induced Hypertension and End-Organ Damage

Previously we have shown that Group IV cytosolic phospholipase A 2 α (cPLA 2 α) is critical for the development of angiotensin (Ang) II-induced hypertension, cardiovascular dysfunction and fibrosis. This study was conducted to determine the role of cPLA 2 α in renal dysfunction and end organ damage associated with Ang II-induced hypertension. Eight weeks old male wild type (cPLA 2 α +/+ ) and cPLA 2 α knockout (cPLA 2 α -/- ) mice were infused with Ang II (700 ng/kg/min) or its vehicle for 2 weeks and systolic blood pressure (SBP) was measured weekly by the tail cuff method. Ang II increased SBP (mmHg) in cPLA 2 α +/+ mice to a greater degree than in cPLA 2 α -/- mice (125 ± 2 to 186 ± 7 vs. 125 ± 2 to 132 ± 2 respectively, P< 0.05). Ang II caused renal fibrosis as indicated by accumulation of α-smooth muscle actin, transforming growth factor-β-positive cells and collagen deposition in the kidneys of cPLA 2 α +/+ but not cPLA 2 α -/- mice. Ang II infusion increased reactive oxygen species production in the kidney measured by 2-hydroxyethidium fluorescence (AU), in cPLA 2 α +/+ mice (16.14 ± 0.61 vehicle vs. 24.08 ± 0.61 Ang II P < 0.05) but not in cPLA 2 α -/- mice (16.93 ± 0.58 vehicle vs. 17.19 ± 0.93 Ang II). Mice were placed in metabolic cages to monitor their water intake and urine output. After 13 days of Ang II infusion, 24 hr water intake was increased (4.33 ± 0.14 ml to 8.17 ± 0.27 ml P < 0.05) in cPLA 2 α +/+ mice but not in cPLA 2 α -/- mice (4.87 ± 0.22 ml to 4.8 ± 0.27 ml). Twenty-four hr urine output (μl) was increased to a greater extent in cPLA 2 α +/+ mice (423.33 ± 67.26 to 2030.94 ± 191.58 P < 0.05) vs. cPLA 2 α -/- mice (374.37 ± 66.89 to 787.37 ± 126.50). Urine osmolality (mOsm/kg) was decreased (3778.33 ± 240.21 to 1620 ± 129.23 P < 0.05) in cPLA 2 α +/+ but not in cPLA 2 α -/- mice (4042 ± 306.07 to 3372.5 ± 43.27), and proteinuria (mg/24hr) increased to a greater extent in cPLA 2 α +/+ mice (2.07 ± 0.11 to 6.99 ± 0.34 P < 0.05) vs. cPLA 2 α -/- mice (1.95 ± 0.07 to 3.03 ± 0.20 in cPLA 2 α -/- ). These data suggest that cPLA 2 α contributes to Ang II-induced hypertension, associated renal dysfunction and end organ damage, most likely due to release of arachidonic acid, activation of NADPH oxidase and generation of ROS. Thus, cPLA 2 α could serve as a potential therapeutic target in the treatment of hypertension and end organ damage.

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Abstract P135: 2-methoxyestradiol Minimizes Angiotensin II-induced Hypertension and Renal Dysfunction in Ovariectomized Female and Intact Male Mice

Hypertension ◽

10.1161/hyp.68.suppl_1.p135 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Ajeeth K Pingili ◽

Shyamala Thirunavukkarasu ◽

Nayaab S Khan ◽

Akemi Katsurada ◽

Dewan S Majid ◽

...

Keyword(s):

Angiotensin Ii ◽

Renal Dysfunction ◽

Organ Damage ◽

Ang Ii ◽

Male Mice ◽

Intact Male ◽

Female Mice ◽

End Organ Damage ◽

Induced Hypertension ◽

Post Menopausal

Men and post-menopausal females are more prone to develop hypertension and renal dysfunction as compared to pre-menopausal females. It is well documented that in various experimental models of hypertension, the protection against hypertension in females is lost following ovariectomy (OVX). Recently we have shown that CYP1B1 protects against angiotensin II (Ang II)-induced hypertension and associated cardiovascular changes in female mice, most likely via production of 2-methoxyestradiol (2-ME). This study was conducted to determine if 2-ME reduces Ang II-induced hypertension, renal dysfunction and end organ damage in OVX female, and intact male mice. Treatment of OVX Cyp1b1 +/+ and Cyp1b1 -/- female mice with 2-ME (1.5 mg/kg/day i.p., for 2 weeks) reduced Ang II-induced increase in systolic blood pressure (SBP) (182±5.1 vs. 143± 2.4 mmHg, 179±6.4 vs. 140± 8.6 mmHg, P < 0.05, n= 5), water consumption, urine output and osmolality, and proteinuria (5.5±0.7 vs. 3.3±0.5 mg/24 hrs, 8.4±1.3 vs. 4.4 ±0.9 mg/24 hrs) respectively. 2-ME also reduced Ang II-induced increase in SBP (188±2.6 vs. 143± 2.7 mmHg, P < 0.05, n= 5) in intact male mice. 2-ME did not alter water consumption and urine osmolality, but reduced urine output and sodium excretion, and proteinuria (14.4±2.0 vs. 6.0±0.5 mg/24 hrs) in intact Cyp1b1 +/+ male mice. Treatment with 2-ME attenuated Ang II-induced end-organ damage (actin and collagen accumulation) in OVX Cyp1b1 +/+ and Cyp1b1 -/- female and Cyp1b1 +/+ male mice. 2-ME mitigated urinary excretion of angiotensinogen in OVX Cyp1b1 +/+ and Cyp1b1 -/- female mice infused with Ang II. These data suggest that 2-ME reduces Ang II- induced hypertension and associated renal dysfunction and end-organ damage in OVX Cyp1b1 +/+ and Cyp1b1 -/- female, and intact male mice. Therefore, 2-ME could serve as a therapeutic agent for treatment of hypertension and associated pathogenesis in post-menopausal females, and intact males.

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Abstract 250: 6β-hydroxytestosterone, A Cytochrome P450 1b1-derived Metabolite Of Testosterone, Mediates Increase In Thirst, Renal Dysfunction, And End Organ Damage Associated With Angiotensin II-induced Hypertension In Male Mice

Hypertension ◽

10.1161/hyp.64.suppl_1.250 ◽

2014 ◽

Vol 64 (suppl_1) ◽

Author(s):

Ajeeth K Pingili ◽

Mehmet Kara ◽

Brett L Jennings ◽

Anne M Estes ◽

Kafait U Malik

Keyword(s):

Oxidative Stress ◽

Renal Function ◽

Cytochrome P450 ◽

Renal Fibrosis ◽

Organ Damage ◽

Ang Ii ◽

Male Mice ◽

End Organ Damage ◽

Cytochrome P450 1B1 ◽

Induced Hypertension

Recently, we showed that 6β-hydroxytestosterone (6β-OHT), a cytochrome P450 1B1 (CYP1B1)-derived metabolite of testosterone, contributes to the development of angiotensin II (Ang II)-induced hypertension and associated cardiovascular pathophysiology. In view of the critical role of Ang II in renal homeostasis and end organ damage, we determined the contribution of 6β-OHT to Ang II actions on water consumption and renal function in male Cyp1b1 +/+ and Cyp1b1 -/- mice. Eight weeks old male Cyp1b1 +/+ and Cyp1b1 -/- intact or castrated mice were injected with 6β-OHT (15 μg/g, i.p. every 3 rd day) or vehicle (DMSO, 50 μl), and infused with Ang II (700 ng/kg/min) or vehicle for 2 weeks. Urine was collected for 24 hours on the final day of experiment. Castration attenuated Ang II-induced increase in water consumption and urine output, proteinuria and decrease in osmolality in both Cyp1b1 +/+ , and Cyp1b1 -/- mice (Table 1). 6β-OHT did not alter Ang II-induced increase in water intake, urine output, proteinuria and decrease in osmolality in Cyp1b1 +/+ mice, but restored these effects of Ang II in Cyp1b1 -/- or castrated mice (Table 1). Cyp1b1 gene disruption or castration prevented Ang II-induced renal fibrosis, inflammation, and oxidative stress. 6β-OHT did not alter Ang II-induced renal fibrosis, inflammation or oxidative stress in Cyp1b1 +/+ mice, however in Cyp1b1 -/- or castrated mice it restored these effects of Ang II. These data suggest that 6β-OHT, contributes to increased thirst, impairment of renal function and end organ damage associated with Ang II-induced hypertension in male mice, and that CYP1B1 could serve as a novel target for the treatment of renal disease and hypertension.

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Puerarin protects against endothelial dysfunction and end-organ damage in Ang II-induced hypertension

Clinical and Experimental Hypertension ◽

10.1080/10641963.2016.1200603 ◽

2017 ◽

Vol 39 (1) ◽

pp. 58-64 ◽

Cited By ~ 15

Author(s):

Xiaojie Li ◽

Yuhan Lin ◽

Hongyu Zhou ◽

Yao Li ◽

Aimei Wang ◽

...

Keyword(s):

Endothelial Dysfunction ◽

Organ Damage ◽

Ang Ii ◽

End Organ Damage ◽

Induced Hypertension

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The complement receptor C5aR1 contributes to renal damage but protects the heart in angiotensin II-induced hypertension

AJP Renal Physiology ◽

10.1152/ajprenal.00040.2016 ◽

2016 ◽

Vol 310 (11) ◽

pp. F1356-F1365 ◽

Cited By ~ 20

Author(s):

Sebastian Weiss ◽

Alva Rosendahl ◽

Daniel Czesla ◽

Catherine Meyer-Schwesinger ◽

Rolf A. K. Stahl ◽

...

Keyword(s):

Cardiac Fibrosis ◽

Cardiac Injury ◽

Organ Damage ◽

Innate Immune ◽

Ang Ii ◽

End Organ Damage ◽

Induced Hypertension ◽

Infiltrating Cells ◽

Deficient Mice

Adaptive and innate immune responses contribute to hypertension and hypertensive end-organ damage. Here, we determined the role of anaphylatoxin C5a, a major inflammatory effector of the innate immune system that is generated in response to complement activation, in hypertensive end-organ damage. For this purpose, we assessed the phenotype of C5a receptor 1 (C5aR1)-deficient mice in ANG II-induced renal and cardiac injury. Expression of C5aR1 on infiltrating and resident renal as well as cardiac cells was determined using a green fluorescent protein (GFP)-C5aR1 reporter knockin mouse. Flow cytometric analysis of leukocytes isolated from the kidney of GFP-C5aR1 reporter mice showed that 28% of CD45-positive cells expressed C5aR1. Dendritic cells were identified as the major C5aR1-expressing population (88.5%) followed by macrophages and neutrophils. Using confocal microscopy, we detected C5aR1 in the kidney mainly on infiltrating cells. In the heart, only infiltrating cells stained C5aR1 positive. To evaluate the role of C5aR1 deficiency in hypertensive injury, an aggravated model of hypertension was used. Unilateral nephrectomy was performed followed by infusion of ANG II (1.5 ng·g−1·min−1) and salt in wild-type ( n = 34) and C5aR1-deficient mice ( n = 32). C5aR1-deficient mice exhibited less renal injury, as evidenced by significantly reduced albuminuria. In contrast, cardiac injury was accelerated with significantly increased cardiac fibrosis and heart weight in C5aR1-deficient mice after ANG II infusion. No effect was found on blood pressure. In summary, the C5a:C5aR1 axis drives end-organ damage in the kidney but protects from the development of cardiac fibrosis and hypertrophy in experimental ANG II-induced hypertension.

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Class switching and high-affinity immunoglobulin G production by B cells is dispensable for the development of hypertension in mice

Cardiovascular Research ◽

10.1093/cvr/cvaa187 ◽

2020 ◽

Author(s):

Yuhan Chen ◽

Bethany L Dale ◽

Matthew R Alexander ◽

Liang Xiao ◽

Mingfang Ao ◽

...

Keyword(s):

B Cells ◽

Immunoglobulin G ◽

Elevated Serum ◽

Organ Damage ◽

Causal Role ◽

Ang Ii ◽

End Organ Damage ◽

High Affinity ◽

Serum Immunoglobulins

Abstract Aims Elevated serum immunoglobulins have been associated with experimental and human hypertension for decades but whether immunoglobulins and B cells play a causal role in hypertension pathology is unclear. In this study, we sought to determine the role of B cells and high-affinity class-switched immunoglobulins on hypertension and hypertensive end-organ damage to determine if they might represent viable therapeutic targets for this disease. Methods and results We purified serum immunoglobulin G (IgG) from mice exposed to vehicle or angiotensin (Ang) II to induce hypertension and adoptively transferred these to wild type (WT) recipient mice receiving a subpressor dose of Ang II. We found that transfer of IgG from hypertensive animals does not affect blood pressure, endothelial function, renal inflammation, albuminuria, or T cell-derived cytokine production compared with transfer of IgG from vehicle infused animals. As an alternative approach to investigate the role of high-affinity, class-switched immunoglobulins, we studied mice with genetic deletion of activation-induced deaminase (Aicda−/−). These mice have elevated levels of IgM but virtual absence of class-switched immunoglobulins such as IgG subclasses and IgA. Neither male nor female Aicda−/− mice were protected from Ang II-induced hypertension and renal/vascular damage. To determine if IgM or non-immunoglobulin-dependent innate functions of B cells play a role in hypertension, we studied mice with severe global B-cell deficiency due to deletion of the membrane exon of the IgM heavy chain (µMT−/−). µMT−/− mice were also not protected from hypertension or end-organ damage induced by Ang II infusion or deoxycorticosterone acetate-salt treatment. Conclusions These results suggest that B cells and serum immunoglobulins do not play a causal role in hypertension pathology.

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Abstract 070: AntagomiR-762 Prevents Angiotensin II Induced Aortic Fibrosis and Stiffening

Hypertension ◽

10.1161/hyp.66.suppl_1.070 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Kim Ramil C Montaniel ◽

Jing Wu ◽

Matthew R Bersi ◽

Liang Xiao ◽

Hana A Itani ◽

...

Keyword(s):

Angiotensin Ii ◽

Organ Damage ◽

Matrix Proteins ◽

Locked Nucleic Acid ◽

Ang Ii ◽

End Organ Damage ◽

Acid Inhibitor ◽

Vascular Stiffening ◽

Aortic Stiffening

We and others have shown that hypertension (HTN) is associated with a striking deposition of collagen in the vascular adventitia. This causes vascular stiffening, which increases pulse wave velocity and contributes to end-organ damage. Through a screen of vascular microRNAs (miRNAs), we found that miR-762 is the most upregulated miRNA in mice with angiotensin II (Ang II)-induced HTN. qRT-PCR confirmed that miR-762 is upregulated 6.35±1.22 (p=0.03) fold in aortas of Ang II-infused mice compared with controls. This was a direct effect of Ang II, as miR-762 upregulation was not eliminated by lowering blood pressure with hydralazine and hydrochlorothiazide and was increased only 2-fold in DOCA salt HTN. To study the role of miR-762 in HTN, we administered a locked nucleic acid inhibitor of miR-762 (antagomiR-762). AntagomiR-762 administration did not alter the hypertensive response to Ang II, yet it normalized stress-strain relationships and aortic energy storage that occurs in systole (Table). Further studies showed that antagomiR-762 dramatically affected vascular matrix proteins, reducing mRNA for several collagens and fibronectin and dramatically upregulating collagenases MMP1a, 8 and 13 (Table). Thus, miR-762 has a major role in modulating vascular stiffening and its inhibition dramatically inhibits pathological fibrosis, enhances matrix degradation and normalizes aortic stiffness. AntagomiR-762 might represent a new approach to prevent aortic stiffening and its consequent end-organ damage.

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Disruption of the cytochrome P-450 1B1 gene exacerbates renal dysfunction and damage associated with angiotensin II-induced hypertension in female mice

AJP Renal Physiology ◽

10.1152/ajprenal.00597.2014 ◽

2015 ◽

Vol 308 (9) ◽

pp. F981-F992 ◽

Cited By ~ 7

Author(s):

Brett L. Jennings ◽

Joseph A. Moore ◽

Ajeeth K. Pingili ◽

Anne M. Estes ◽

Xiao R. Fang ◽

...

Keyword(s):

Urinary Excretion ◽

Renal Dysfunction ◽

Urine Output ◽

Organ Damage ◽

Antioxidant Systems ◽

Ang Ii ◽

Female Mice ◽

Induced Hypertension ◽

17Β Estradiol ◽

Cytochrome P 450

Recently, we demonstrated in female mice that protection against ANG II-induced hypertension and associated cardiovascular changes depend on cytochrome P-450 (CYP)1B1. The present study was conducted to determine if Cyp1b1 gene disruption ameliorates renal dysfunction and organ damage associated with ANG II-induced hypertension in female mice. ANG II (700 ng·kg−1·min−1) infused by miniosmotic pumps for 2 wk in female Cyp1b1+/+ mice did not alter water consumption, urine output, Na+ excretion, osmolality, or protein excretion. However, in Cyp1b1−/− mice, ANG II infusion significantly increased ( P < 0.05) water intake (5.50 ± 0.42 ml/24 h with vehicle vs. 8.80 ± 0.60 ml/24 h with ANG II), urine output (1.44 ± 0.37 ml/24 h with vehicle vs. 4.30 ± 0.37 ml/24 h with ANG II), and urinary Na+ excretion (0.031 ± 0.016 mmol/24 h with vehicle vs. 0.099 ± 0.010 mmol/24 h with ANG II), decreased osmolality (2,630 ± 79 mosM/kg with vehicle vs. 1,280 ± 205 mosM/kg with ANG II), and caused proteinuria (2.60 ± 0.30 mg/24 h with vehicle vs. 6.96 ± 0.55 mg/24 h with ANG II). Infusion of ANG II caused renal fibrosis, as indicated by an accumulation of renal interstitial α-smooth muscle actin, collagen, and transforming growth factor-β in Cyp1b1−/− but not Cyp1b1+/+ mice. ANG II also increased renal production of ROS and urinary excretion of thiobarburic acid-reactive substances and reduced the activity of antioxidants and urinary excretion of nitrite/nitrate and the 17β-estradiol metabolite 2-methoxyestradiol in Cyp1b1−/− but not Cyp1b1+/+ mice. These data suggest that Cyp1b1 plays a critical role in female mice in protecting against renal dysfunction and end-organ damage associated with ANG II-induced hypertension, in preventing oxidative stress, and in increasing activity of antioxidant systems, most likely via generation of 2-methoxyestradiol from 17β-estradiol.

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Novel anti-inflammatory mechanisms ofN-Acetyl-Ser-Asp-Lys-Pro in hypertension-induced target organ damage

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00305.2007 ◽

2008 ◽

Vol 294 (3) ◽

pp. H1226-H1232 ◽

Cited By ~ 75

Author(s):

Umesh Sharma ◽

Nour-Eddine Rhaleb ◽

Saraswati Pokharel ◽

Pamela Harding ◽

Saman Rasoul ◽

...

Keyword(s):

Target Organ Damage ◽

Organ Damage ◽

Target Organ ◽

Collagen Deposition ◽

Ang Ii ◽

Activated Macrophages ◽

Tnf Α ◽

Induced Hypertension ◽

Galectin 3 ◽

Anti Inflammatory

High blood pressure (HBP) is an important risk factor for cardiac, renal, and vascular dysfunction. Excess inflammation is the major pathogenic mechanism for HBP-induced target organ damage (TOD). N-acetyl-Ser-Asp-Lys-Pro (Ac-SDKP), a tetrapeptide specifically degraded by angiotensin converting enzyme (ACE), reduces inflammation, fibrosis, and TOD induced by HBP. Our hypothesis is that Ac-SDKP exerts its anti-inflammatory effects by inhibiting: 1) differentiation of bone marrow stem cells (BMSC) to macrophages, 2) activation and migration of macrophages, and 3) release of the proinflammatory cytokine TNF-α by activated macrophages. BMSC were freshly isolated and cultured in macrophage growth medium. Differentiation of murine BMSC to macrophages was analyzed by flow cytometry using F4/80 as a marker of macrophage maturation. Macrophage migration was measured in a modified Boyden chamber. TNF-α release by activated macrophages in culture was measured by ELISA. Myocardial macrophage activation in mice with ANG II-induced hypertension was studied by Western blotting of Mac-2 (galectin-3) protein. Interstitial collagen deposition was measured by picrosirius red staining. We found that Ac-SDKP (10 nM) reduced differentiation of cultured BMSC to mature macrophages by 24.5% [F4/80 positivity: 14.09 ± 1.06 mean fluorescent intensity for vehicle and 10.63 ± 0.35 for Ac-SDKP; P < 0.05]. Ac-SDKP also decreased galectin-3 and macrophage colony-stimulating factor-dependent macrophage migration. In addition, Ac-SDKP decreased secretion of TNF-α by macrophages stimulated with bacterial LPS. In mice with ANG II-induced hypertension, Ac-SDKP reduced expression of galectin-3, a protein produced by infiltrating macrophages in the myocardium, and interstitial collagen deposition. In conclusion, this study demonstrates that part of the anti-inflammatory effect of Ac-SDKP is due to its direct effect on BMSC and macrophage, inhibiting their differentiation, activation, and cytokine release. These effects explain some of the anti-inflammatory and antifibrotic properties of Ac-SDKP in hypertension.

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