1
|
Shen B, Yang L, Jia X, Kong D, Jing L, Gao Y, Gao S, Chen R, Chen F, Zhao C, Li Y, Tan R, Zhao X. Contribution of platelets to disruption of the blood-brain barrier during arterial baroreflex dysfunction. Microvasc Res 2024; 154:104681. [PMID: 38493885 DOI: 10.1016/j.mvr.2024.104681] [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: 12/27/2023] [Revised: 03/07/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND Arterial baroreflex dysfunction, like many other central nervous system disorders, involves disruption of the blood-brain barrier, but what causes such disruption in ABR dysfunction is unclear. Here we explored the potential role of platelets in this disruption. METHODS ABR dysfunction was induced in rats using sinoaortic denervation, and the effects on integrity of the blood-brain barrier were explored based on leakage of Evans blue or FITC-dextran, while the effects on expression of CD40L in platelets and of key proteins in microvascular endothelial cells were explored using immunohistochemistry, western blotting and enzyme-linked immunosorbent assay. Similar experiments were carried out in rat brain microvascular endothelial cell line, which we exposed to platelets taken from rats with ABR dysfunction. RESULTS Sinoaortic denervation permeabilized the blood-brain barrier and downregulated zonula occludens-1 and occludin in rat brain, while upregulating expression of CD40L on the surface of platelets and stimulating platelet aggregation. Similar effects of permeabilization and downregulation were observed in healthy rats that received platelets from animals with ABR dysfunction, and in rat brain microvascular endothelial cells, but only in the presence of lipopolysaccharide. These effects were associated with activation of NF-κB signaling and upregulation of matrix metalloprotease-9. These effects of platelets from animals with ABR dysfunction were partially blocked by neutralizing antibody against CD40L or the platelet inhibitor clopidogrel. CONCLUSION During ABR dysfunction, platelets may disrupt the blood-brain barrier when CD40L on their surface activates NF-kB signaling within cerebral microvascular endothelial cells, leading to upregulation of matrix metalloprotease-9. Our findings imply that targeting CD40L may be effective against cerebral diseases involving ABR dysfunction.
Collapse
Affiliation(s)
- Bowen Shen
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Lili Yang
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Xiaoli Jia
- Department of Pharmacy, Liaocheng People's Hospital Affiliated to Shandong First Medical University & Shandong Academy of Medical Sciences, Liao'cheng 252000, China
| | - Deping Kong
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Lei Jing
- Department of Pharmacy, Dongping People's Hospital, Tai'an 271500, China
| | - Yongfeng Gao
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Shan Gao
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Ruimin Chen
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Fengbao Chen
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Chunyu Zhao
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Yue Li
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China
| | - Rui Tan
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China.
| | - Xiaomin Zhao
- Institute of Pharmacology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an 271016, China.
| |
Collapse
|
2
|
Gebeshuber CA, Daniel-Fischer L, Regele H, Schachner H, Aufricht C, Kornauth C, Ley M, Alper SL, Herzog R, Kratochwill K, Perco P. Computational drug repositioning of clopidogrel as a novel therapeutic option for focal segmental glomerulosclerosis. Transl Res 2023:S1931-5244(23)00057-9. [PMID: 37059330 DOI: 10.1016/j.trsl.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/13/2023] [Accepted: 04/04/2023] [Indexed: 04/16/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a glomerular lesion often associated with nephrotic syndrome. It is also associated with a high risk of progression to end-stage kidney disease. Current treatment of FSGS is limited to systemic corticosteroids or calcineurin inhibition, along with inhibitors of the renin-angiotensin-aldosterone system. FSGS is heterogeneous in etiology, and novel therapies targeting specific, dysregulated molecular pathways represent a major unmet medical need. We have generated a network-based molecular model of FSGS pathophysiology using previously established systems biology workflows to allow computational evaluation of compounds for their predicted interference with molecular processes contributing to FSGS. We identified the anti-platelet drug clopidogrel as a therapeutic option to counterbalance dysregulated FSGS pathways. This prediction of our computational screen was validated by testing clopidogrel in the adriamycin FSGS mouse model. Clopidogrel improved key FSGS outcome parameters and significantly reduced urinary albumin to creatinine ratio (p<0.01) and weight loss (p<0.01), and ameliorated histopathological damage (p<0.05). Clopidogrel is used to treat several cardiovascular diseases linked to chronic kidney disease. Clopidogrel's favorable safety profile and its efficacy in the adriamycin mouse FSGS model thus recommend it as an attractive drug repositioning candidate for clinical trial in FSGS.
Collapse
Affiliation(s)
| | - Lisa Daniel-Fischer
- Division of Pediatric Nephrology and Gastroenterology, Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Heinz Regele
- Division of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Helga Schachner
- Division of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Christoph Aufricht
- Division of Pediatric Nephrology and Gastroenterology, Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Christoph Kornauth
- Division of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Matthias Ley
- Delta 4 GmbH, Alserstrasse 23 / 30, 1080 Vienna, Austria
| | - Seth L Alper
- Division of Nephology and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA 02215
| | - Rebecca Herzog
- Division of Pediatric Nephrology and Gastroenterology, Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Klaus Kratochwill
- Delta 4 GmbH, Alserstrasse 23 / 30, 1080 Vienna, Austria; Division of Pediatric Nephrology and Gastroenterology, Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Paul Perco
- Delta 4 GmbH, Alserstrasse 23 / 30, 1080 Vienna, Austria.
| |
Collapse
|
3
|
Chen J, Tang Y, Zhong Y, Wei B, Huang XR, Tang PMK, Xu A, Lan HY. P2Y12 inhibitor clopidogrel inhibits renal fibrosis by blocking macrophage-to-myofibroblast transition. Mol Ther 2022; 30:3017-3033. [PMID: 35791881 PMCID: PMC9481993 DOI: 10.1016/j.ymthe.2022.06.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/07/2022] [Accepted: 06/29/2022] [Indexed: 11/20/2022] Open
Abstract
Clopidogrel, a P2Y12 inhibitor, is a novel anti-fibrosis agent for chronic kidney disease (CKD), but its mechanisms remain unclear, which we investigated by silencing P2Y12 or treating unilateral ureteral obstruction (UUO) in LysM-Cre/Rosa Tomato mice with clopidogrel in vivo and in vitro. We found that P2Y12 was significantly increased and correlated with progressive renal fibrosis in CKD patients and UUO mice. Phenotypically, up to 82% of P2Y12-expressing cells within the fibrosing kidney were of macrophage origin, identified by co-expressing CD68/F4/80 antigens or a macrophage-lineage-tracing marker Tomato. Unexpectedly, more than 90% of P2Y12-expressing macrophages were undergoing macrophage-to-myofibroblast transition (MMT) by co-expressing alpha smooth muscle actin (α-SMA), which was also confirmed by single-cell RNA sequencing. Functionally, clopidogrel improved the decline rate of the estimated glomerular filtration rate (eGFR) in patients with CKD and significantly inhibited renal fibrosis in UUO mice. Mechanistically, P2Y12 expression was induced by transforming growth factor β1 (TGF-β1) and promoted MMT via the Smad3-dependent mechanism. Thus, silencing or pharmacological inhibition of P2Y12 was capable of inhibiting TGF-β/Smad3-mediated MMT and progressive renal fibrosis in vivo and in vitro. In conclusion, P2Y12 is highly expressed by macrophages in fibrosing kidneys and mediates renal fibrosis by promoting MMT via TGF-β/Smad3 signaling. Thus, P2Y12 inhibitor maybe a novel and effective anti-fibrosis agent for CKD.
Collapse
Affiliation(s)
- Junzhe Chen
- Department of Nephrology, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China; Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Ying Tang
- Department of Nephrology, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China
| | - Yu Zhong
- Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Biao Wei
- Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Xiao-Ru Huang
- Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China; Guangdong-Hong Kong Joint Laboratory for Immunity and Genetics of Chronic Kidney Disease, Guangdong Academy of Medical Science, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Patrick Ming-Kuen Tang
- Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China; Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China.
| | - Anping Xu
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
| | - Hui-Yao Lan
- Departments of Medicine & Therapeutics, Li Ka Shing Institute of Health Sciences, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China; Guangdong-Hong Kong Joint Laboratory for Immunity and Genetics of Chronic Kidney Disease, Guangdong Academy of Medical Science, Guangdong Provincial People's Hospital, Guangzhou, China.
| |
Collapse
|
4
|
Wu SJ, Shi ZW, Wang X, Ren FF, Xie ZY, Lei L, Chen P. Activation of the Cholinergic Anti-inflammatory Pathway Attenuated Angiotension II-Dependent Hypertension and Renal Injury. Front Pharmacol 2021; 12:593682. [PMID: 33815099 PMCID: PMC8010129 DOI: 10.3389/fphar.2021.593682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Background: Angiotensin II (AngII) induces renal fibrosis, characterized by fibroblast proliferation, inflammatory cell infiltration and excessive extracellular matrix deposition, all of which was relevant closely to hypertension. The vagus nerve-related cholinergic anti-inflammatory pathway (CAP) modulates local and systemic inflammatory responses. The aim of present study was to determine the effect of CAP on renal inflammation and fibrosis. Methods and Results: AngII-induced hypertension was induced in vivo by 14-days low-dose AngII infusion from osmotic minipumps. We used GTS-21 dihydrochloride, a selective nicotinic acetylcholine receptor agonist. Daily intraperitoneal GTS-21 injection and/or vagotomy started after hypertension was confirmed and continued for 4 weeks. The elevated blood pressure caused by AngII was significantly attenuated by GTS-21. Improved baroreflex sensitivity was observed after GTS-21 administration. Masson stain and immunoblotting revealed that deposition of excessive fibrosis and overexpression of inflammatory cytokines induced by AngII was reduced by GTS-21. To determine the role of autonomic control in CAP, unilateral vagotomy was performed. Vagotomy weakened the effect of CAP on AngII-induced hypertension. In vitro, GTS-21 suppressed NF-κB activation, attenuated AngII-induced epithelial-mesenchymal transition and reduced inflammation and fibrosis in NRK-52E cells; α-bungarotoxin (α-Bgt, an α7-nAChR selective antagonist) partly inhibited these effects. Conclusion: CAP protected against AngII-induced hypertension via improvement in autonomic control, suppression of NF-κB activation, and reduction of renal fibrosis and inflammatory response.
Collapse
Affiliation(s)
- Shu-Jie Wu
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhe-Wei Shi
- Department of Cardiology, Zhuji Affiliated Hospital of Shaoxing University, Zhuji, China
| | - Xue Wang
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Fang-Fang Ren
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zuo-Yi Xie
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Li Lei
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Peng Chen
- Department of Cardiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
5
|
Monaghan MLT, Bailey MA, Unwin RJ. Purinergic signalling in the kidney: In physiology and disease. Biochem Pharmacol 2020; 187:114389. [PMID: 33359067 DOI: 10.1016/j.bcp.2020.114389] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 02/06/2023]
Abstract
Historically, the control of renal vascular and tubular function has, for the most part, concentrated on neural and endocrine regulation. However, in addition to these extrinsic factors, it is now appreciated that several complex humoral control systems exist within the kidney that can act in an autocrine and/or paracrine fashion. These paracrine systems complement neuroendocrine regulation by dynamically fine-tuning renal vascular and tubular function to buffer rapid changes in nephron perfusion and flow rate of tubular fluid. One of the most pervasive is the extracellular nucleotide/P2 receptor system, which is central to many of the intrinsic regulatory feedback loops within the kidney such as renal haemodynamic autoregulation and tubuloglomerular feedback (TGF). Although physiological actions of extracellular adenine nucleotides were reported almost 100 years ago, the conceptual framework for purinergic regulation of renal function owes much to the work of Geoffrey Burnstock. In this review, we reflect on our >20-year collaboration with Professor Burnstock and highlight the research that is still unlocking the potential of the renal purinergic system to understand and treat kidney disease.
Collapse
Affiliation(s)
- Marie-Louise T Monaghan
- British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom
| | - Matthew A Bailey
- British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom
| | - Robert J Unwin
- The Department of Renal Medicine, University College London, United Kingdom.
| |
Collapse
|
6
|
Ramirez LA, Gillis EE, Musall JB, Mohamed R, Snyder E, El-Marakby A, Sullivan JC. Hypertensive female Sprague-Dawley rats require an intact nitric oxide synthase system for compensatory increases in renal regulatory T cells. Am J Physiol Renal Physiol 2020; 319:F192-F201. [PMID: 32597687 DOI: 10.1152/ajprenal.00228.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We have previously shown that hypertensive female rats have more regulatory T cells (Tregs), which contribute more to blood pressure (BP) control in female versus male rats. Based on known protective properties of Tregs, the goal of the present study was to investigate the mechanisms by which female rats maintain Tregs. The present study was designed to 1) compare the impact of three hypertension models on the percentage of renal Tregs and 2) test the hypothesis that nitric oxide synthase (NOS) inhibition prevents increases in renal Tregs and exacerbates renal damage in female Sprague-Dawley rats. Rats (11-14 wk old) were randomized to one of the following four groups: control, norepinephrine (NE) infusion, angiotensin II infusion, or the NOS inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) in drinking water. BP was measured via tail cuff. After 2 wk of treatment, kidneys were isolated and processed to measure Tregs via flow cytometric analysis and renal injury via urinary albumin excretion, plasma creatinine, and histological analyses. Hypertensive treatments increased BP in all experimental animals. Increases in BP in norepinephrine-and angiotensin II-treated rats were associated with increases in renal Tregs versus control. In contrast, l-NAME treatment decreased Tregs compared with all groups. l-NAME treatment modestly increased albumin excretion. However, plasma creatinine was comparable among the groups, and there was no histological evidence of glomerular or tubular injury. This study provides insights into the mechanisms regulating renal Tregs and supports that an intact NOS system is crucial for female rats to have BP-related increases in renal Tregs.
Collapse
Affiliation(s)
- Lindsey A Ramirez
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ellen E Gillis
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Jacqueline B Musall
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Riyaz Mohamed
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Elizabeth Snyder
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ahmed El-Marakby
- Dental College of Georgia, Department of Oral Biology and Diagnostic Sciences, Augusta University, Augusta, Georgia
| | - Jennifer C Sullivan
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| |
Collapse
|
7
|
Guan Z, Makled MN, Inscho EW. Purinoceptors, renal microvascular function and hypertension. Physiol Res 2020; 69:353-369. [PMID: 32301620 DOI: 10.33549/physiolres.934463] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Proper renal blood flow (RBF) and glomerular filtration rate (GFR) are critical for maintaining normal blood pressure, kidney function and water and electrolyte homeostasis. The renal microvasculature expresses a multitude of receptors mediating vasodilation and vasoconstriction, which can influence glomerular blood flow and capillary pressure. Despite this, RBF and GFR remain quite stable when arterial pressure fluctuates because of the autoregulatory mechanism. ATP and adenosine participate in autoregulatory control of RBF and GFR via activation of two different purinoceptor families (P1 and P2). Purinoceptors are widely expressed in renal microvasculature and tubules. Emerging data show altered purinoceptor signaling in hypertension-associated kidney injury, diabetic nephropathy, sepsis, ischemia-reperfusion induced acute kidney injury and polycystic kidney disease. In this brief review, we highlight recent studies and new insights on purinoceptors regulating renal microvascular function and renal hemodynamics. We also address the mechanisms underlying renal microvascular injury and impaired renal autoregulation, focusing on purinoceptor signaling and hypertension-induced renal microvascular dysfunction. Interested readers are directed to several excellent and comprehensive reviews that recently covered the topics of renal autoregulation, and nucleotides in kidney function under physiological and pathophysiological conditions (Inscho 2009, Navar et al. 2008, Carlstrom et al. 2015, Vallon et al. 2020).
Collapse
Affiliation(s)
- Z Guan
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, South Birmingham, USA.
| | | | | |
Collapse
|
8
|
Franco M, Pérez-Méndez O, Kulthinee S, Navar LG. Integration of purinergic and angiotensin II receptor function in renal vascular responses and renal injury in angiotensin II-dependent hypertension. Purinergic Signal 2019; 15:277-285. [PMID: 31183668 PMCID: PMC6635571 DOI: 10.1007/s11302-019-09662-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 05/30/2019] [Indexed: 12/24/2022] Open
Abstract
Glomerular arteriolar vasoconstriction and tubulointerstitial injury are observed before glomerular damage occurs in models of hypertension. High interstitial ATP concentrations, caused by the increase in arterial pressure, alter renal mechanisms involved in the long-term control of blood pressure, autoregulation of glomerular filtration rate and blood flow, tubuloglomerular feedback (TGF) responses, and sodium excretion. Elevated ATP concentrations and augmented expression of P2X receptors have been demonstrated under a genetic background or induction of hypertension with vasoconstrictor peptides. In addition to the alterations of the microcirculation in the hypertensive kidney, the vascular actions of elevated intrarenal angiotensin II levels may be mitigated by the administration of broad purinergic P2 antagonists or specific P2Y12, P2X1, and P2X7 receptor antagonists. Furthermore, the prevention of tubulointerstitial infiltration with immunosuppressor compounds reduces the development of salt-sensitive hypertension, indicating that tubulointerstitial inflammation is essential for the development and maintenance of hypertension. Inflammatory cells also express abundant purinergic receptors, and their activation by ATP induces cytokine and growth factor release that in turn contributes to augment tubulointerstitial inflammation. Collectively, the evidence suggests a pathophysiological activation of purinergic P2 receptors in angiotensin-dependent hypertension. Coexistent increases in intrarenal angiotensin II and activates Ang II AT1 receptors, which interacts with over-activated purinergic receptors in a complex manner, suggesting convergence of their post-receptor signaling processes.
Collapse
Affiliation(s)
- Martha Franco
- Department of Nephrology, Renal Pathophysiology Laboratory, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano No.1, 14080 Mexico City, DF Mexico
| | - Oscar Pérez-Méndez
- Department Molecular Biology, Instituto Nacional de Cardiología “Ignacio Chávez”, Mexico City, Mexico
| | - Supaporn Kulthinee
- Department of Physiology and Hypertension and Renal Center, Tulane University School of Medicine, New Orleans, LA USA
- Department of Cardiovascular and Thoracic Technology, Chulabhorn International College of Medicine, Thammasat University, Rangsit, Pathum Thani Thailand
| | - L. Gabriel Navar
- Department of Physiology and Hypertension and Renal Center, Tulane University School of Medicine, New Orleans, LA USA
| |
Collapse
|
9
|
Wang X, Han X, Li M, Han Y, Zhang Y, Zhao S, Li Y. Ticagrelor protects against AngII-induced endothelial dysfunction by alleviating endoplasmic reticulum stress. Microvasc Res 2018; 119:98-104. [PMID: 29777791 DOI: 10.1016/j.mvr.2018.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 04/23/2018] [Accepted: 05/13/2018] [Indexed: 12/21/2022]
Abstract
Ticagrelor has been reported to decrease cardiovascular mortality compared with clopidogrel. This benefit cannot be fully explained by the more efficient platelet inhibition. Many studies demonstrated that ticagrelor improved endothelial function, leaving the mechanism elusive though. The present study aims to investigate whether ticagrelor protects against endothelial dysfunction induced by angiotensinII (AngII) through alleviating endoplasmic reticulum (ER) stress. Male Sprague Dawley rats were infused with AngII or vehicle and administrated with ticagrelor or vehicle for 14 days. Reactive oxygen species (ROS) was detected. Aortas from normal mice were incubated with endoplasmic reticulum stress inducer tunicamycin with or without ticagrelor. Vasorecactivity was measured on wire myography. Rat aortic endothelial cells (RAECs) were pretreated with ticagrelor followed by AngII or tunicamycin. Endothelial nitric oxide synthase (eNOS) phosphorylation and ER stress markers were determined by western blotting. Impaired endothelial function, induction of ER stress, reduced eNOS phosphorylation and elevated ROS generation was restored by ticagrelor treatment in vivo. In addition, tunicamycin induced endothelial dysfunction was improved by ticagrelor. In vitro, the induction of ER stress and inhibited eNOS phosphorylation in REACs exposed to AngII as well as tunicamycin was reversed by co-culturing with ticagrelor. In conclusion, ticagrelor protects against AngII-induced endothelial dysfunction via alleviating ER stress.
Collapse
Affiliation(s)
- Xiaoyu Wang
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Xuejie Han
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Minghui Li
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Yu Han
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Yun Zhang
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Shiqi Zhao
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
| | - Yue Li
- Department of Cardiology, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China; Key Laboratory of Cardiac Diseases and Heart Failure, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China.
| |
Collapse
|
10
|
Clopidogrel Partially Counteracts Adenosine-5'-Diphosphate Effects on Blood Pressure and Renal Hemodynamics and Excretion in Rats. Am J Med Sci 2018; 356:287-295. [PMID: 30293555 DOI: 10.1016/j.amjms.2018.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 04/21/2018] [Accepted: 04/25/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Adenosine-5'-diphosphate (ADP) can influence intrarenal vascular tone and tubular transport, partly through activation of purine P2Y12 receptors (P2Y12-R), but their actual in vivo role in regulation of renal circulation and excretion remains unclear. METHODS The effects of intravenous ADP infusions of 2-8mg/kg/hour were examined in anesthetized Wistar rats that were untreated or chronically pretreated with clopidogrel, 20mg/kg/24hours, a selective P2Y12-R antagonist. Renal blood flow (transonic probe) and perfusion of the superficial cortex and medulla (laser-Doppler fluxes) were measured, together with urine osmolality (Uosm), diuresis (V), total solute (UosmV), sodium (UNaV) and potassium (UKV) excretion. RESULTS ADP induced a gradual, dose-dependent 15% decrease of mean arterial pressure, a sustained increase of renal blood flow and a 25% decrease in renal vascular resistance. Clopidogrel pretreatment attenuated the mean arterial pressure decrease, and did not significantly alter renal blood flow or renal vascular resistance. Renal medullary perfusion was not affected by ADP whereas Uosm decreased from 1,080 ± 125 to 685 ± 75 mosmol/kg H20. There were also substantial significant decreases in UosmV, UNaV and UKV; all these changes were attenuated or abolished by clopidogrel pretreatment. Two-weeks' clopidogrel treatment decreased V while UosmUosmV and UNaV increased, most distinctly after 7 days. Acute clopidogrel infusion modestly decreased mean arterial pressure and significantly increased outer- and decreased inner-medullary perfusion. CONCLUSIONS Our functional studies show that ADP can cause systemic and renal vasodilation and a decrease in mean arterial pressure, an action at least partly mediated by P2Y12 receptors. We confirmed that these receptors exert tonic action to reduce tubular water reabsorption and urine concentration.
Collapse
|
11
|
Ikeme JC, Pergola PE, Scherzer R, Shlipak MG, Benavente OR, Peralta CA. Post Hoc Analyses of Randomized Clinical Trial for the Effect of Clopidogrel Added to Aspirin on Kidney Function. Clin J Am Soc Nephrol 2017; 12:1040-1047. [PMID: 28446537 PMCID: PMC5498342 DOI: 10.2215/cjn.00100117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/30/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Despite the high burden of CKD, few specific therapies are available that can halt disease progression. In animal models, clopidogrel has emerged as a potential therapy to preserve kidney function. The effect of clopidogrel on kidney function in humans has not been established. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The Secondary Prevention of Small Subcortical Strokes Study randomized participants with prior lacunar stroke to treatment with aspirin or aspirin plus clopidogrel. We compared annual eGFR decline and incidence of rapid eGFR decline (≥30% from baseline) using generalized estimating equations and interval-censored proportional hazards regression, respectively. We also stratified our analyses by baseline eGFR, systolic BP target, and time after randomization. RESULTS At randomization, median age was 62 (interquartile range, 55-71) years old; 36% had a history of diabetes, 90% had hypertension, and the median eGFR was 81 (interquartile range, 65-94) ml/min per 1 m2. Persons receiving aspirin plus clopidogrel had an average annual change in kidney function of -1.39 (95% confidence interval, -1.15 to -1.62) ml/min per 1.73 m2 per year compared with -1.52 (95% confidence interval, -1.30 to -1.74) ml/min per 1.73 m2 per year among persons receiving aspirin only (P=0.42). Rapid kidney function decline occurred in 21% of participants receiving clopidogrel plus aspirin compared with 22% of participants receiving aspirin plus placebo (hazard ratio, 0.94; 95% confidence interval, 0.79 to 1.10; P=0.42). Findings did not vary by baseline eGFR, time after randomization, or systolic BP target (all P values for interaction were >0.3). CONCLUSIONS We found no effect of clopidogrel added to aspirin compared with aspirin alone on kidney function decline among persons with prior lacunar stroke.
Collapse
Affiliation(s)
- Jesse C. Ikeme
- The Kidney Health Research Collaborative, University of California, San Francisco, California
- San Francisco Veterans Affairs Medical Center, San Francisco, California
| | - Pablo E. Pergola
- University of Texas Health Science Center at San Antonio, San Antonio, Texas; and
| | - Rebecca Scherzer
- The Kidney Health Research Collaborative, University of California, San Francisco, California
- San Francisco Veterans Affairs Medical Center, San Francisco, California
| | - Michael G. Shlipak
- The Kidney Health Research Collaborative, University of California, San Francisco, California
- San Francisco Veterans Affairs Medical Center, San Francisco, California
| | | | - Carmen A. Peralta
- The Kidney Health Research Collaborative, University of California, San Francisco, California
- San Francisco Veterans Affairs Medical Center, San Francisco, California
| |
Collapse
|
12
|
Bhat SA, Goel R, Shukla R, Hanif K. Platelet CD40L induces activation of astrocytes and microglia in hypertension. Brain Behav Immun 2017; 59:173-189. [PMID: 27658543 DOI: 10.1016/j.bbi.2016.09.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/16/2016] [Accepted: 09/17/2016] [Indexed: 12/20/2022] Open
Abstract
Studies have demonstrated separately that hypertension is associated with platelet activation in the periphery (resulting in accumulation and localized inflammatory response) and glial activation in the brain. We investigated the contribution of platelets in brain inflammation, particularly glial activation in vitro and in a rat model of hypertension. We found that HTN increased the expression of adhesion molecules like JAM-1, ICAM-1, and VCAM-1 on brain endothelium and resulted in the deposition of platelets in the brain. Platelet deposition in hypertensive rats was associated with augmented CD40 and CD40L and activation of astrocytes (GFAP expression) and microglia (Iba-1 expression) in the brain. Platelets isolated from hypertensive rats had significantly higher sCD40L levels and induced more prominent glial activation than platelets from normotensive rats. Activation of platelets with ADP induced sCD40L release and activation of astrocytes and microglia. Moreover, CD40L induced glial (astrocytes and microglia) activation, NFкB and MAPK inflammatory signaling, culminating in neuroinflammation and neuronal injury (increased apoptotic cells). Importantly, injection of ADP-activated platelets into normotensive rats strongly induced activation of astrocytes and microglia and increased plasma sCD40L levels compared with control platelets. On the contrary, inhibition of platelet activation by Clopidogrel or disruption of CD40 signaling prevented astrocyte and microglial activation and provided neuroprotection in both in vivo and in vitro conditions. Thus, we have identified platelet CD40L as a key inflammatory molecule for the induction of astrocyte and microglia activation, the major contributors to inflammation-mediated injury in the brain.
Collapse
Affiliation(s)
- Shahnawaz Ali Bhat
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, U.P., India
| | - Ruby Goel
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, U.P., India
| | - Rakesh Shukla
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, U.P., India
| | - Kashif Hanif
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, U.P., India; National Institute of Pharmaceutical Education and Research, Rae Bareli, India.
| |
Collapse
|
13
|
Abstract
Antiplatelet agents represent a cornerstone in the management of patients at increased cardiovascular risk. Essential hypertension is considered a major public health problem leading to increased cardiovascular morbidity and mortality. The majority of patients with essential hypertension exhibit also additional cardiovascular risk factors and present with increased platelet activation. Despite recent innovations in the field of antiplatelet treatment and the introduction of novel agents, the role of antiplatelet treatment in patients with essential hypertension remains understudied. This review aims to shed light on novel experimental and clinical data in the evolving field of antiplatelet treatment in essential hypertension. In particular, recent data regarding aspirin, clopidogrel, novel P2Y12 inhibitors, and other agents with potential antiplatelet effects are critically reviewed.
Collapse
|
14
|
Fellner RC, Guan Z, Cook AK, Pollock DM, Inscho EW. Endothelin contributes to blunted renal autoregulation observed with a high-salt diet. Am J Physiol Renal Physiol 2015; 309:F687-96. [PMID: 26246513 DOI: 10.1152/ajprenal.00641.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 07/29/2015] [Indexed: 01/03/2023] Open
Abstract
Autoregulation of renal blood flow (RBF) is an essential function of the renal microcirculation that has been previously shown to be blunted by excessive dietary salt. Endogenous endothelin 1 (ET-1) is increased following a high-salt (HS) diet and contributes to the control of RBF but the differential effects of ET-1 on renal microvessel autoregulation in response to HS remain to be established. We hypothesized that a HS diet increases endothelin receptor activation in normal Sprague-Dawley rats and blunts autoregulation of RBF. The role of ET-1 in the blunted autoregulation produced by a HS diet was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. Using highly selective antagonists, we observed that blockade of either ETA or ETB receptors was sufficient to restore normal autoregulatory behavior in afferent arterioles from HS-fed rats. Additionally, normal autoregulatory behavior was restored in vivo in HS-fed rats by simultaneous ETA and ETB receptor blockade, whereas blockade of ETB receptors alone showed significant improvement of normal autoregulation of RBF. Consistent with this observation, autoregulation of RBF in ETB receptor-deficient rats fed HS was similar to both ETB-deficient rats and transgenic control rats on normal-salt diets. These data support the hypothesis that endogenous ET-1, working through ETB and possibly ETA receptors, contributes to the blunted renal autoregulatory behavior in rats fed a HS diet.
Collapse
Affiliation(s)
- Robert C Fellner
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Zhengrong Guan
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Anthony K Cook
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Section of Experimental Medicine, Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, Georgia; and Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Edward W Inscho
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
15
|
Zhang Y, Peti-Peterdi J, Müller CE, Carlson NG, Baqi Y, Strasburg DL, Heiney KM, Villanueva K, Kohan DE, Kishore BK. P2Y12 Receptor Localizes in the Renal Collecting Duct and Its Blockade Augments Arginine Vasopressin Action and Alleviates Nephrogenic Diabetes Insipidus. J Am Soc Nephrol 2015; 26:2978-87. [PMID: 25855780 DOI: 10.1681/asn.2014010118] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/27/2015] [Indexed: 11/03/2022] Open
Abstract
P2Y12 receptor (P2Y12-R) signaling is mediated through Gi, ultimately reducing cellular cAMP levels. Because cAMP is a central modulator of arginine vasopressin (AVP)-induced water transport in the renal collecting duct (CD), we hypothesized that if expressed in the CD, P2Y12-R may play a role in renal handling of water in health and in nephrogenic diabetes insipidus. We found P2Y12-R mRNA expression in rat kidney, and immunolocalized its protein and aquaporin-2 (AQP2) in CD principal cells. Administration of clopidogrel bisulfate, an irreversible inhibitor of P2Y12-R, significantly increased urine concentration and AQP2 protein in the kidneys of Sprague-Dawley rats. Notably, clopidogrel did not alter urine concentration in Brattleboro rats that lack AVP. Clopidogrel administration also significantly ameliorated lithium-induced polyuria, improved urine concentrating ability and AQP2 protein abundance, and reversed the lithium-induced increase in free-water excretion, without decreasing blood or kidney tissue lithium levels. Clopidogrel administration also augmented the lithium-induced increase in urinary AVP excretion and suppressed the lithium-induced increase in urinary nitrates/nitrites (nitric oxide production) and 8-isoprostane (oxidative stress). Furthermore, selective blockade of P2Y12-R by the reversible antagonist PSB-0739 in primary cultures of rat inner medullary CD cells potentiated the expression of AQP2 and AQP3 mRNA, and cAMP production induced by dDAVP (desmopressin). In conclusion, pharmacologic blockade of renal P2Y12-R increases urinary concentrating ability by augmenting the effect of AVP on the kidney and ameliorates lithium-induced NDI by potentiating the action of AVP on the CD. This strategy may offer a novel and effective therapy for lithium-induced NDI.
Collapse
Affiliation(s)
- Yue Zhang
- Nephrology Research and Department of Internal Medicine
| | - Janos Peti-Peterdi
- Zilkha Neurogenetic Institute and Department of Physiology and Biophysics, University of Southern California, Los Angeles, California
| | - Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany; and
| | - Noel G Carlson
- Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah; Department of Neurobiology and Anatomy, and Center on Aging, University of Utah Health Sciences Center, Salt Lake City, Utah
| | - Younis Baqi
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany; and Department of Chemistry, Faculty of Science, Sultan Qaboos University, Muscat, Oman
| | | | | | - Karie Villanueva
- Zilkha Neurogenetic Institute and Department of Physiology and Biophysics, University of Southern California, Los Angeles, California
| | | | - Bellamkonda K Kishore
- Nephrology Research and Department of Internal Medicine, Center on Aging, University of Utah Health Sciences Center, Salt Lake City, Utah;
| |
Collapse
|
16
|
Abstract
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
Collapse
Affiliation(s)
- Mattias Carlström
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher S Wilcox
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J Arendshorst
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| |
Collapse
|
17
|
Polichnowski AJ, Griffin KA, Picken MM, Licea-Vargas H, Long J, Williamson GA, Bidani AK. Hemodynamic basis for the limited renal injury in rats with angiotensin II-induced hypertension. Am J Physiol Renal Physiol 2014; 308:F252-60. [PMID: 25477472 DOI: 10.1152/ajprenal.00596.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ANG II is thought to increase the susceptibility to hypertension-induced renal disease (HIRD) via blood pressure (BP)-dependent and BP-independent pathways; however, the quantitative relationships between BP and HIRD have not been examined in ANG II-infused hypertensive rats. We compared the relationship between radiotelemetrically measured BP and HIRD in Sprague-Dawley rats (Harlan) chronically administered ANG II (300-500 ng·kg(-1)·min(-1), n = 19) for 4 wk versus another commonly employed pharmacological model of hypertension induced by the chronic administration of N(ω)-nitro-l-arginine methyl ester (l-NAME, 50 mg·kg(-1)·day(-1), n = 23). [DOSAGE ERROR CORRECTED]. Despite the significantly higher average systolic BP associated with ANG II (191.1 ± 3.2 mmHg) versus l-NAME (179.9 ± 2.5 mmHg) administration, the level of HIRD was very modest in the ANG II versus l-NAME model as evidenced by significantly less glomerular injury (6.6 ± 1.3% vs. 11.3 ± 1.5%, respectively), tubulointerstitial injury (0.3 ± 0.1 vs. 0.7 ± 0.1 injury score, respectively), proteinuria (66.3 ± 10.0 vs. 117.5 ± 10.1 mg/day, respectively), and serum creatinine levels (0.5 ± 0.04 vs. 0.9 ± 0.07 mg/dl, respectively). Given that HIRD severity is expected to be a function of renal microvascular BP transmission, BP-renal blood flow (RBF) relationships were examined in additional conscious rats administered ANG II (n = 7) or l-NAME (n = 8). Greater renal vasoconstriction was observed during ANG II versus l-NAME administration (41% vs. 23% decrease in RBF from baseline). Moreover, administration of ANG II, but not l-NAME, led to a unique BP-RBF pattern in which the most substantial decreases in RBF were observed during spontaneous increases in BP. We conclude that the hemodynamic effects of ANG II may mediate the strikingly low susceptibility to HIRD in the ANG II-infused model of hypertension in rats.
Collapse
Affiliation(s)
- Aaron J Polichnowski
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois;
| | - Karen A Griffin
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
| | - Maria M Picken
- Department of Pathology Loyola University, Maywood, Illinois
| | - Hector Licea-Vargas
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
| | - Jianrui Long
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Geoffrey A Williamson
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Anil K Bidani
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
| |
Collapse
|