1
|
Szymczak M, Heidecke H, Żabińska M, Rukasz D, Wiśnicki K, Kujawa K, Kościelska-Kasprzak K, Krajewska M, Banasik M. Angiotensin II Type 2 Receptor Antibodies in Glomerular Diseases. Arch Immunol Ther Exp (Warsz) 2024; 72:aite-2024-0017. [PMID: 39166802 DOI: 10.2478/aite-2024-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 06/24/2024] [Indexed: 08/23/2024]
Abstract
We evaluated the concentration of AT2R antibodies in 136 patients with primary and secondary glomerular diseases: membranous nephropathy (n = 18), focal and segmental glomerulosclerosis (n = 25), systemic lupus erythematosus (n = 17), immunoglobulin A (IgA) nephropathy (n = 14), mesangial (non-IgA) proliferative nephropathy (n = 6), c-ANCA vasculitis (n = 40), perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) vasculitis (n = 16), and compared it with a healthy control group (22 patients). Serum creatinine levels, proteinuria, serum albumin, and total protein concentrations were prospectively recorded for 2 years. The mean levels of AT2R antibodies in the lupus nephropathy group were significantly higher compared to the control group, 64.12 ± 26.95 units/mL and 9.72 ± 11.88 units/mL, respectively. There was no association between this level and the clinical course of the disease. The AT2R levels in other kinds of glomerular disease were no different from the control group. We found significant correlations between AT1R and AT2R in patients with membranous nephropathy (r = 0.66), IgA nephropathy (r = 0.61), and c-ANCA vasculitis (r = 0.63). Levels of AT2R antibodies in systemic lupus erythematosus are higher compared to other types of glomerulonephritis, vasculitis, and a healthy control group. Levels of AT2R antibodies correlate with AT1R antibodies in the groups of patients with membranous nephropathy, IgA nephropathy, and c-ANCA vasculitis. These kinds of AT2R antibodies have a stimulative effect on AT2R, but we have not found the influence of these antibodies on the clinical course of glomerular diseases.
Collapse
MESH Headings
- Humans
- Female
- Male
- Middle Aged
- Adult
- Receptor, Angiotensin, Type 2/immunology
- Receptor, Angiotensin, Type 2/metabolism
- Autoantibodies/blood
- Autoantibodies/immunology
- Aged
- Kidney Glomerulus/immunology
- Kidney Glomerulus/pathology
- Glomerulonephritis, Membranous/immunology
- Glomerulonephritis, Membranous/blood
- Glomerulonephritis/immunology
- Glomerulonephritis/blood
- Antibodies, Antineutrophil Cytoplasmic/immunology
- Antibodies, Antineutrophil Cytoplasmic/blood
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/blood
- Glomerulonephritis, IGA/immunology
- Glomerulonephritis, IGA/blood
- Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/immunology
- Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/blood
- Lupus Nephritis/immunology
- Receptor, Angiotensin, Type 1/immunology
- Young Adult
- Kidney Diseases/immunology
Collapse
Affiliation(s)
- Maciej Szymczak
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | | | - Marcelina Żabińska
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Dagna Rukasz
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Krzysztof Wiśnicki
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Krzysztof Kujawa
- 3Statistical Analysis Centre, Wroclaw Medical University, Wroclaw, Poland
| | | | - Magdalena Krajewska
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Mirosław Banasik
- 1Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| |
Collapse
|
2
|
Jang S, Kim JY, Kim CW, Kim I. Hypertonic Salt Solution Enhances Inflammatory Responses in Cultured Splenic T-Cells from Dahl Salt-Sensitive Rats but Not Dahl Salt-Resistant Rats. J Cardiovasc Dev Dis 2023; 10:414. [PMID: 37887861 PMCID: PMC10607114 DOI: 10.3390/jcdd10100414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/12/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
This study aimed to delineate the effect of sodium chloride on the induction of inflammatory responses and the development of hypertension in Dahl salt-sensitive (SS) and salt-resistant (SR) rats. Splenocytes were isolated from the spleens of SS and SR rats, and cultured on anti-CD3-coated plates for 5 days. The cultured splenic T-cells were challenged with a hypertonic salt solution (0, 20, or 40 mM) in the absence or presence of IL-6 (0, 20, or 60 ng/mL), TGF-β (0, 5, or 15 ng/mL), or IL-23 (0, 10, or 30 ng/mL), and analyzed via ELISA, flow cytometry, and immunofluorescence. The hypertonic salt solution potentiated IL-17A production, as well as the differentiation of Th17 cells via IL-6/TGF-β/IL-23, exclusively in SS rats. However, it did not affect IL-10 production or the differentiation of Treg cells in any of the groups. Furthermore, it potentiated the signal of RORγt in IL-6-treated splenic T-cells from SS rats. To summarize, cultured splenic T-cells exhibited enhanced inflammatory responses on exposure to a hypertonic salt solution in SS rats only, which indicated that sodium chloride and inflammatory cytokines synergistically drove the induction of pathogenic Th17 cells and the development of hypertension in this group only.
Collapse
Affiliation(s)
- Sungmin Jang
- Department of Pharmacology, School of Medicine, Daegu, 41944, Republic of Korea; (S.J.); (J.Y.K.); (C.-W.K.)
- Cardiovascular Research Institute, Daegu 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Daegu 41944, Republic of Korea
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Jee Young Kim
- Department of Pharmacology, School of Medicine, Daegu, 41944, Republic of Korea; (S.J.); (J.Y.K.); (C.-W.K.)
- Cardiovascular Research Institute, Daegu 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Daegu 41944, Republic of Korea
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Cheong-Wun Kim
- Department of Pharmacology, School of Medicine, Daegu, 41944, Republic of Korea; (S.J.); (J.Y.K.); (C.-W.K.)
- Cardiovascular Research Institute, Daegu 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Daegu 41944, Republic of Korea
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Inkyeom Kim
- Department of Pharmacology, School of Medicine, Daegu, 41944, Republic of Korea; (S.J.); (J.Y.K.); (C.-W.K.)
- Cardiovascular Research Institute, Daegu 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Daegu 41944, Republic of Korea
- Department of Biomedical Science, The Graduate School, Kyungpook National University, Daegu 41944, Republic of Korea
| |
Collapse
|
3
|
Cohen-Segev R, Nativ O, Kinaneh S, Aronson D, Kabala A, Hamoud S, Karram T, Abassi Z. Effects of Angiotensin 1-7 and Mas Receptor Agonist on Renal System in a Rat Model of Heart Failure. Int J Mol Sci 2023; 24:11470. [PMID: 37511227 PMCID: PMC10380355 DOI: 10.3390/ijms241411470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/09/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Congestive heart failure (CHF) is often associated with impaired kidney function. Over- activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid salt/water retention and cardiac hypertrophy in CHF. While the deleterious effects of angiotensin II (Ang II) in CHF are well established, the biological actions of angiotensin 1-7 (Ang 1-7) are not fully characterized. In this study, we assessed the acute effects of Ang 1-7 (0.3, 3, 30 and 300 ng/kg/min, IV) on urinary flow (UF), urinary Na+ excretion (UNaV), glomerular filtration rate (GFR) and renal plasma flow )RPF) in rats with CHF induced by the placement of aortocaval fistula. Additionally, the chronic effects of Ang 1-7 (24 µg/kg/h, via intra-peritoneally implanted osmotic minipumps) on kidney function, cardiac hypertrophy and neurohormonal status were studied. Acute infusion of either Ang 1-7 or its agonist, AVE 0991, into sham controls, but not CHF rats, increased UF, UNaV, GFR, RPF and urinary cGMP. In the chronic protocols, untreated CHF rats displayed lower cumulative UF and UNaV than their sham controls. Chronic administration of Ang 1-7 and AVE 0991 exerted significant diuretic, natriuretic and kaliuretic effects in CHF rats, but not in sham controls. Serum creatinine and aldosterone levels were significantly higher in vehicle-treated CHF rats as compared with controls. Treatment with Ang 1-7 and AVE 0991 reduced these parameters to comparable levels observed in sham controls. Notably, chronic administration of Ang 1-7 to CHF rats reduced cardiac hypertrophy. In conclusion, Ang 1-7 exerts beneficial renal and cardiac effects in rats with CHF. Thus, we postulate that ACE2/Ang 1-7 axis represents a compensatory response to over-activity of ACE/AngII/AT1R system characterizing CHF and suggest that Ang 1-7 may be a potential therapeutic agent in this disease state.
Collapse
Affiliation(s)
- Ravit Cohen-Segev
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Omri Nativ
- Department of Urology, Rambam Health Center, Haifa 3109601, Israel
| | - Safa Kinaneh
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Doron Aronson
- Cardiology, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Aviva Kabala
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Shadi Hamoud
- Department of Internal Medicine E, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Tony Karram
- Vascular Surgery, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Zaid Abassi
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
- Laboratory Medicine, Rambam Health Care Campus, Haifa 31096, Israel
| |
Collapse
|
4
|
Hong NJ, Gonzalez-Vicente A, Saez F, Garvin JL. Mechanisms of decreased tubular flow-induced nitric oxide in Dahl salt-sensitive rat thick ascending limbs. Am J Physiol Renal Physiol 2021; 321:F369-F377. [PMID: 34308669 PMCID: PMC8530749 DOI: 10.1152/ajprenal.00124.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/09/2021] [Accepted: 07/22/2021] [Indexed: 12/21/2022] Open
Abstract
Dahl salt-sensitive (SS) rat kidneys produce less nitric oxide (NO) than those of salt-resistant (SR) rats. Thick ascending limb (TAL) NO synthase 3 (NOS3) is a major source of renal NO, and luminal flow enhances its activity. We hypothesized that flow-induced NO is reduced in TALs from SS rats primarily due to NOS uncoupling and diminished NOS3 expression rather than scavenging. Rats were fed normal-salt (NS) or high-salt (HS) diets. We measured flow-induced NO and superoxide in perfused TALs and performed Western blots of renal outer medullas. For rats on NS, flow-induced NO was 35 ± 6 arbitrary units (AU)/min in TALs from SR rats but only 11 ± 2 AU/min in TALs from SS (P < 0.008). The superoxide scavenger tempol decreased the difference in flow-induced NO between strains by about 36% (P < 0.020). The NOS inhibitor N-nitro-l-arginine methyl ester (l-NAME) decreased flow-induced superoxide by 36 ± 8% in TALs from SS rats (P < 0.02) but had no effect in TALs from SR rats. NOS3 expression was not different between strains on NS. For rats on HS, the difference in flow-induced NO between strains was enhanced (SR rats: 44 ± 10 vs. SS: 9 ± 2 AU/min, P < 0.005). Tempol decreased the difference in flow-induced NO between strains by about 37% (P < 0.012). l-NAME did not significantly reduce flow-induced superoxide in either strain. HS increased NOS3 expression in TALs from SR rats but not in TALs from SS rats (P < 0.003). We conclude that 1) on NS, flow-induced NO is diminished in TALs from SS rats mainly due to NOS3 uncoupling such that it produces superoxide and 2) on HS, the difference is enhanced due to failure of TALs from SS rats to increase NOS3 expression.NEW & NOTEWORTHY The Dahl rat has been used extensively to study the causes and effects of salt-sensitive hypertension. Our study suggests that more complex processes other than simple scavenging of nitric oxide (NO) by superoxide lead to less NO production in thick ascending limbs of the Dahl salt-sensitive rat. The predominant mechanism involved depends on dietary salt. Impaired flow-induced NO production in thick ascending limbs most likely contributes to the Na+ retention associated with salt-sensitive hypertension.
Collapse
Affiliation(s)
- Nancy J Hong
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | | | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
5
|
Miyoshi M, Imakado Y, Otani L, Kaji M, Aanzai Y, Sugimoto N, Murakami T, Fukuoka M, Hohjoh H, Jia H, Kato H. Maternal protein restriction induces renal AT2R promoter hypomethylation in salt-sensitive, hypertensive rats. Food Sci Nutr 2021; 9:1452-1459. [PMID: 33747459 PMCID: PMC7958563 DOI: 10.1002/fsn3.2113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/08/2020] [Accepted: 12/28/2020] [Indexed: 11/06/2022] Open
Abstract
SCOPE We previously demonstrated that protein restriction in utero induced salt-sensitive hypertension and changed renal levels of angiotensin type 2 receptor (AT2R) in Stroke-Prone Spontaneously Hypertensive Rat (SHRSP). Here, we investigated if this characteristic alteration of AT2R is related to AT2R DNA methylation profiles. METHODS AND RESULTS First, we examined the relation between AT2R DNA methylation and its promoter activity in vitro. Luciferase assays revealed a negative correlation between these two variables. Next, we fed SHRSP dams and grand-dams a control 20% casein diet or a 9% casein diet during pregnancy. Adult offspring and grand-offspring were supplied either water or 1% saline solution for 2 weeks. Renal AT2R promoter DNA near the TATA-box was hypomethylated, mRNA expression was suppressed, and protein expression tended to be higher, in adult offspring of mothers fed a low casein diet. Moreover, adult grand-offspring exhibited high blood pressure after salt loading, along with suppressed transcription of AT2R mRNA and elevated translated protein. CONCLUSIONS Under a fetal environment of protein restriction, the increase in protein expression due to hypomethylation of the AT2R promoter region occurs as a response to increased salt sensitivity, and controlling this mechanism may be important for the prevention of hypertension.
Collapse
Affiliation(s)
- Moe Miyoshi
- Health NutritionGraduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan
| | - Yasuhisa Imakado
- Health NutritionGraduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan
| | - Lila Otani
- Health NutritionGraduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan
- Department of Food Science and NutritionFaculty of AgricultureKinki UniversityNaraJapan
| | - Misa Kaji
- Department of Food Science and NutritionFaculty of AgricultureKinki UniversityNaraJapan
| | - Yuki Aanzai
- Department of Food Science and NutritionFaculty of AgricultureKinki UniversityNaraJapan
| | - Naoya Sugimoto
- Department of Food Science and NutritionFaculty of AgricultureKinki UniversityNaraJapan
| | - Tetsuo Murakami
- Department of Food Science and NutritionFaculty of AgricultureKinki UniversityNaraJapan
| | | | | | - Huijuan Jia
- Health NutritionGraduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan
| | - Hisanori Kato
- Health NutritionGraduate School of Agricultural and Life SciencesUniversity of TokyoTokyoJapan
| |
Collapse
|
6
|
Zicha J, Hojná S, Vaňourková Z, Kopkan L, Vaněčková I. Is renal ß-adrenergic-WNK4-NCC pathway important in salt hypertension of Dahl rats? Physiol Res 2019; 68:873-882. [PMID: 31647304 DOI: 10.33549/physiolres.934334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In 2011 Fujita and coworkers proposed that ß-adrenergic stimulation causes decreased serine/threonine-protein kinase WNK4 transcription leading to the activation of Na-Cl cotransporter (NCC) which participates in salt sensitivity and salt hypertension development in rodents. The aim of our study was to investigate whether the above hypothesis is also valid for salt hypertension of Dahl rats, which are characterized by high sympathetic tone and abnormal renal sodium handling. Male 8-week-old salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) Dahl rats were fed either low-salt diet (LS, 0.4 % NaCl) or high-salt diet (HS, 4 % NaCl) for 6 weeks. Half of the animals on either diet were chronically treated with non-selective ß-blocker propranolol (100 mg/kg/day). At the end of the experiment diuresis and sodium excretion were measured prior and after hydrochlorothiazide injection (HCTZ, 10 mg/kg i.p.). Furthermore, blood pressure (BP), heart rate (HR), sympathetic (pentolinium 5 mg/kg i.v.) and NO-dependent (L-NAME 30 mg/kg i.v.) BP components were determined. Chronic HS diet feeding increased BP through sympathoexcitation in SS/Jr but not in SR/Jr rats. Concomitant propranolol treatment did not lower BP in either experimental group. Under the conditions of low salt intake HCTZ increased diuresis, natriuresis and fractional sodium excretion in SR/Jr but not in SS/Jr rats. HS diet feeding attenuated renal response to HCT in SR/Jr rats, whereas no HCTZ effect was observed in SS/Jr rats fed HS diet. Propranolol treatment did not modify diuresis or natriuresis in any experimental group. In conclusions, our present data do not support the idea on the essential importance of renal ß-adrenergic-WNK4-NCC pathway in pathogenesis and/or maintenance of salt hypertension in Dahl rats.
Collapse
Affiliation(s)
- J Zicha
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | | | | | | | | |
Collapse
|
7
|
Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
Collapse
Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| |
Collapse
|
8
|
Saez F, Hong NJ, Garvin JL. NADPH oxidase 4-derived superoxide mediates flow-stimulated NKCC2 activity in thick ascending limbs. Am J Physiol Renal Physiol 2018; 314:F934-F941. [PMID: 29672130 DOI: 10.1152/ajprenal.00631.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Luminal flow augments Na+ reabsorption in the thick ascending limb more than can be explained by increased ion delivery. This segment reabsorbs 30% of the filtered load of Na+, playing a key role in its homeostasis. Whether flow elevations enhance Na+-K+-2Cl- cotransporter (NKCC2) activity and the second messenger involved are unknown. We hypothesized that raising luminal flow augments NKCC2 activity by enhancing superoxide ([Formula: see text]) production by NADPH oxidase 4 (NOX4). NKCC2 activity was measured in thick ascending limbs perfused at either 5 or 20 nl/min with and without inhibitors of [Formula: see text] production. Raising luminal flow from 5 to 20 nl/min enhanced NKCC2 activity from 4.8 ± 0.9 to 6.3 ± 1.2 arbitrary fluorescent units (AFU)/s. Maintaining flow at 5 nl/min did not alter NKCC2 activity. The superoxide dismutase mimetic manganese (III) tetrakis (4-benzoic acid) porphyrin chloride blunted NKCC2 activity from 3.5 ± 0.4 to 2.5 ± 0.2 AFU/s when flow was 20 nl/min but not 5 nl/min. When flow was 20 nl/min, NKCC2 activity showed no change with time. The selective NOX1/4 inhibitor GKT-137831 blunted NKCC2 activity when thick ascending limbs were perfused at 20 nl/min from 7.2 ± 1.1 to 4.5 ± 0.8 AFU/s but not at 5 nl/min. The inhibitor also prevented luminal flow from elevating [Formula: see text] production. Allopurinol, a xanthine oxidase inhibitor, had no effect on NKCC2 activity when flow was 20 nl/min. Tetanus toxin prevents flow-induced stimulation of NKCC2 activity. We conclude that elevations in luminal flow enhance NaCl reabsorption in thick ascending limbs by stimulating NKCC2 via NOX4 activation and increased [Formula: see text]. NKCC2 activation is primarily the result of insertion of new transporters in the membrane.
Collapse
Affiliation(s)
- Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Nancy J Hong
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| |
Collapse
|
9
|
Angiotensin II type 2 receptor (AT2R) in renal and cardiovascular disease. Clin Sci (Lond) 2017; 130:1307-26. [PMID: 27358027 DOI: 10.1042/cs20160243] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/06/2016] [Indexed: 12/14/2022]
Abstract
Angiotensin II (Ang II) is well-considered to be the principal effector of the renin-angiotensin system (RAS), which binds with strong affinity to the angiotensin II type 1 (AT1R) and type 2 (AT2R) receptor subtype. However, activation of both receptors is likely to stimulate different signalling mechanisms/pathways and produce distinct biological responses. The haemodynamic and non-haemodynamic effects of Ang II, including its ability to regulate blood pressure, maintain water-electrolyte balance and promote vasoconstriction and cellular growth are well-documented to be mediated primarily by the AT1R. However, its biological and functional effects mediated through the AT2R subtype are still poorly understood. Recent studies have emphasized that activation of the AT2R regulates tissue and organ development and provides in certain context a potential counter-regulatory mechanism against AT1R-mediated actions. Thus, this review will focus on providing insights into the biological role of the AT2R, in particular its actions within the renal and cardiovascular system.
Collapse
|
10
|
Ali Q, Patel S, Hussain T. Angiotensin AT2 receptor agonist prevents salt-sensitive hypertension in obese Zucker rats. Am J Physiol Renal Physiol 2015; 308:F1379-85. [PMID: 25855512 PMCID: PMC4469886 DOI: 10.1152/ajprenal.00002.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/07/2015] [Indexed: 01/09/2023] Open
Abstract
High-sodium intake is a risk factor for the pathogenesis of hypertension, especially in obesity. The present study is designed to investigate whether angiotensin type 2 receptor (AT2R) activation with selective agonist C21 prevents high-sodium diet (HSD)-induced hypertension in obese animals. Male obese rats were treated with AT2R agonist C21 (1 mg·kg(-1)·day(-1), oral) while maintained on either normal-sodium diet (NSD; 0.4%) or HSD (4%) for 2 wk. Radiotelemetric recording showed a time-dependent increase in systolic blood pressure in HSD-fed obese rats, being maximal increase (∼27 mmHg) at day 12 of the HSD regimen. C21 treatment completely prevented the increase in blood pressure of HSD-fed rats. Compared with NSD controls, HSD-fed obese rats had greater natriuresis/diuresis and urinary levels of nitrates, and these parameters were further increased by C21 treatment. Also, C21 treatment improved glomerular filtration rate in HSD-fed rats. HSD-fed rats expressed higher level of cortical ANG II, which was reduced to 50% by C21 treatment. HSD feeding and/or C21 treatment had no effects on cortical renin activity and the expression of angiotensin-converting enzyme (ACE) and chymase, which are ANG II-producing enzymes. However, ANG(1-7) concentration and ACE2 activity in the renal cortex were reduced by HSD feeding, and C21 treatment rescued both the parameters. Also, C21 treatment reduced the cortical expression of AT1R in HSD-fed rats, but had no effect of AT2R expression. We conclude that chronic treatment with the AT2R agonist C21 prevents salt-sensitive hypertension in obese rats, and a reduction in the renal ANG II/AT1R and enhanced ACE2/ANG(1-7) levels may play a potential role in this phenomenon.
Collapse
Affiliation(s)
- Quaisar Ali
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Sanket Patel
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Tahir Hussain
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| |
Collapse
|
11
|
Ramseyer VD, Gonzalez-Vicente A, Carretero OA, Garvin JL. Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation. Am J Physiol Renal Physiol 2014; 308:F149-56. [PMID: 25377910 DOI: 10.1152/ajprenal.00279.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II -0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II -0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation.
Collapse
Affiliation(s)
- Vanesa D Ramseyer
- Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan; Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, Michigan
| | - Agustin Gonzalez-Vicente
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio; and Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Ciudad Autónoma de Buenos Aires, Argentina
| | - Oscar A Carretero
- Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan
| | - Jeffrey L Garvin
- Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan; Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio; and
| |
Collapse
|
12
|
Gonzalez-Vicente A, Cabral PD, Garvin JL. Resveratrol increases nitric oxide production in the rat thick ascending limb via Ca2+/calmodulin. PLoS One 2014; 9:e110487. [PMID: 25314136 PMCID: PMC4196991 DOI: 10.1371/journal.pone.0110487] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 09/19/2014] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (p<0.03). The NOS inhibitor L-NAME blunted resveratrol-stimulated NO bioavailability by 96±11% (p<0.03). The superoxide scavenger tempol had no effect. Resveratrol elevated Cai from 48±7 to 135±24 nM (p<0.01) in single tubules. In Ca2+-free media, the resveratrol-induced increase in NO was blunted by 60±20% (p<0.05) and the rise in Cai reduced by 80%. Calmodulin inhibition prevented the resveratrol-induced increase in NO (p<0.002). AMPK inhibition had no effect. Resveratrol did not increase SIRT1 activity. We conclude that resveratrol increases NO production in thick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects.
Collapse
Affiliation(s)
- Agustin Gonzalez-Vicente
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Pablo D. Cabral
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
- Universidad de Buenos Aires, Facultad de Medicina, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Jeffrey L. Garvin
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
- Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan, United States of America
- * E-mail:
| |
Collapse
|
13
|
Carey RM, Padia SH. Role of angiotensin AT(2) receptors in natriuresis: Intrarenal mechanisms and therapeutic potential. Clin Exp Pharmacol Physiol 2014; 40:527-34. [PMID: 23336117 DOI: 10.1111/1440-1681.12059] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/16/2013] [Accepted: 01/16/2013] [Indexed: 01/11/2023]
Abstract
The renin-angiotensin system is a coordinated hormonal cascade critical for the regulation of blood pressure (BP) and kidney function. Angiotensin (Ang) II, the major angiotensin effector peptide, binds to two major receptors, namely AT1 and AT2 receptors. The AT1 receptors engender antinatriuresis and raise BP, whereas AT2 receptors oppose these effects, inducing natriuresis and reducing BP. There is high AT2 receptor expression in the adult kidney, especially in the proximal tubule. In AT2 receptor-null mice, long-term AngII infusion results in pressor and antinatriuretic hypersensivivity compared with responses in wild-type mice. The major endogenous receptor ligand for AT2 receptor-mediated natriuretic responses appears to be des-aspartyl(1) -AngII (AngIII) instead of AngII. Recent studies have demonstrated that AngII requires metabolism to AngIII by aminopeptidase A to induce natriuresis and that inhibition of aminopeptidase N increases intrarenal AngIII and augments AngIII-induced natriuresis. The renal dopaminergic system is another important natriuretic pathway. Renal proximal tubule the D1 and D5 receptor subtypes (D1 -like receptors (D1LIKE R)) control approximately 50% of basal sodium excretion. Recently, we have found that natriuresis induced by proximal tubule D1LIKE R requires AT2 receptor activation and that D1LIKE R stimulation induces recruitment of AT2 receptors to the apical plasma membrane via a cAMP-dependent mechanism. Initial studies using the potent AT2 receptor non-peptide agonist Compound 21 demonstrate natriuresis in both the presence and absence of AT1 receptor blockade, indicating the therapeutic potential of this compound in fluid-retaining states and hypertension.
Collapse
Affiliation(s)
- Robert M Carey
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
| | | |
Collapse
|
14
|
Abstract
Hypertension is a complex and multifaceted disease, and there are well established sex differences in many aspects of blood pressure (BP) control. The intent of this review is to highlight recent work examining sex differences in the molecular mechanisms of BP control in hypertension to assess whether the "one-size-fits-all" approach to BP control is appropriate with regard to sex.
Collapse
|
15
|
Gonzalez-Vicente A, Garvin JL. Angiotensin II-induced hypertension increases plasma membrane Na pump activity by enhancing Na entry in rat thick ascending limbs. Am J Physiol Renal Physiol 2013; 305:F1306-14. [PMID: 23986517 DOI: 10.1152/ajprenal.00064.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Thick ascending limbs (TAL) reabsorb 30% of the filtered NaCl load. Na enters the cells via apical Na-K-2Cl cotransporters and Na/H exchangers and exits via basolateral Na pumps. Chronic angiotensin II (ANG II) infusion increases net TAL Na transport and Na apical entry; however, little is known about its effects on the basolateral Na pump. We hypothesized that in rat TALs Na pump activity is enhanced by ANG II-infusion, a model of ANG II-induced hypertension. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 7 days, and TAL suspensions were obtained. We studied plasma membrane Na pump activity by measuring changes in 1) intracellular Na (Nai) induced by ouabain; and 2) ouabain-sensitive oxygen consumption (QO2). We found that the ouabain-sensitive rise in Nai in TALs from ANG II-infused rats was 12.8 ± 0.4 arbitrary fluorescent units (AFU)·mg(-1)·min(-1) compared with only 9.9 ± 1.1 AFU·mg(-1)·min(-1) in controls (P < 0.024). Ouabain-sensitive oxygen consumption was 17 ± 5% (P < 0.043) greater in tubules from ANG II-treated than vehicle rats. ANG II infusion did not alter total Na pump expression, the number of Na pumps in the plasma membrane, or the affinity for Na. When furosemide (1.1 mg·kg(-1)·day(-1)) was coinfused with ANG II, no increase in plasma membrane Na pump activity was observed. We concluded that in ANG II-induced hypertension Na pump activity is increased in the plasma membrane of TALs and that this increase is caused by the chronically enhanced Na entry occurring in this model.
Collapse
Affiliation(s)
- Agustin Gonzalez-Vicente
- Dept. of Physiology and Biophysics, Case Western Reserve Univ. School of Medicine, 10900 Euclid Ave, MS 4970, Robbins-E-526, Cleveland, OH 44106-4970.
| | | |
Collapse
|
16
|
Staruschenko A, Palygin O, Ilatovskaya DV, Pavlov TS. Epidermal growth factors in the kidney and relationship to hypertension. Am J Physiol Renal Physiol 2013; 305:F12-20. [PMID: 23637204 DOI: 10.1152/ajprenal.00112.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Members of the epidermal growth factor (EGF)-family bind to ErbB (EGFR)-family receptors that play an important role in the regulation of various fundamental cell processes in many organs including the kidney. In this field, most of the research efforts are focused on the role of EGF-ErbB axis in cancer biology. However, many studies indicate that abnormal ErbB-mediated signaling pathways are critical in the development of renal and cardiovascular pathologies. The kidney is a major site of the EGF-family ligands synthesis, and it has been shown to express all four members of the ErbB receptor family. The study of kidney disease regulation by ErbB receptor ligands has expanded considerably in recent years. In vitro and in vivo studies have provided direct evidence of the role of ErbB signaling in the kidney. Recent advances in the understanding of how the proteins in the EGF-family regulate sodium transport and development of hypertension are specifically discussed here. Collectively, these results suggest that EGF-ErbB signaling pathways could be major determinants in the progress of renal lesions, including its effects on the regulation of sodium reabsorption in collecting ducts.
Collapse
Affiliation(s)
- Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
| | | | | | | |
Collapse
|
17
|
Carey RM. The intrarenal renin-angiotensin and dopaminergic systems: control of renal sodium excretion and blood pressure. Hypertension 2013; 61:673-80. [PMID: 23407646 DOI: 10.1161/hypertensionaha.111.00241] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Robert M Carey
- University of Virginia Health System, Charlottesville, VA, USA.
| |
Collapse
|
18
|
AT2 receptors: beneficial counter-regulatory role in cardiovascular and renal function. Pflugers Arch 2012; 465:99-110. [PMID: 22949090 DOI: 10.1007/s00424-012-1146-3] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/17/2012] [Accepted: 08/20/2012] [Indexed: 01/11/2023]
Abstract
The renin-angiotensin system (RAS) is a coordinated hormonal cascade intimately involved in cardiovascular and renal control and blood pressure regulation. Angiotensin II (Ang II), the major RAS effector peptide, binds two distinct receptors, the angiotensin type-1 receptor (AT(1)R) and the angiotensin type-2 (AT(2)R) receptor. The vast majority of the physiological actions of Ang II, almost all of them detrimental, are mediated by AT(1)Rs. In contrast, AT(2)Rs negatively modulate the actions of AT(1)Rs under the majority of circumstances and generally possess beneficial effects. AT(2)Rs induce vasodilation in both resistance and capacitance vessels, mediating natriuresis directly and via interactions with dopamine D1 receptors in the renal proximal tubule. AT(2)Rs inhibit renin biosynthesis and secretion and protect the kidneys from inflammation and ischemic injury. Our understanding of the exact role of AT(2)Rs in physiology and pathophysiology continues to expand; the purpose of this review is to provide an up-to-date summary of the functional role of AT(2)Rs at the organ, tissue, cellular, and subcellular levels with emphasis on the vascular and renal actions that bear on blood pressure regulation and hypertension.
Collapse
|