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Feng W, Guan Z, Ying WZ, Xing D, Ying KE, Sanders PW. Matrix metalloproteinase-9 regulates afferent arteriolar remodeling and function in hypertension-induced kidney disease. Kidney Int 2023; 104:740-753. [PMID: 37423509 PMCID: PMC10854403 DOI: 10.1016/j.kint.2023.06.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 06/01/2023] [Accepted: 06/22/2023] [Indexed: 07/11/2023]
Abstract
This study tested if matrix metalloproteinase (MMP)-9 promoted microvascular pathology that initiates hypertensive (HT) kidney disease in salt-sensitive (SS) Dahl rats. SS rats lacking Mmp9 (Mmp9-/-) and littermate control SS rats were studied after one week on a normotensive 0.3% sodium chloride (Pre-HT SS and Pre-HT Mmp9-/-) or a hypertension-inducing diet containing 4.0% sodium chloride (HT SS and HT Mmp9-/-). Telemetry-monitored blood pressure of both the HT SS and HT Mmp9-/- rats increased and did not differ. Kidney microvessel transforming growth factor-beta 1 (Tgfb1) mRNA did not differ between Pre-HT SS and Pre-HT Mmp9-/- rats, but with hypertension and expression of Mmp9 and Tgfb1 increased in HT SS rats, along with phospho-Smad2 labeling of nuclei of vascular smooth muscle cells, and with peri-arteriolar fibronectin deposition. Loss of MMP-9 prevented hypertension-induced phenotypic transformation of microvascular smooth muscle cells and the expected increased microvascular expression of pro-inflammatory molecules. Loss of MMP-9 in vascular smooth muscle cells in vitro prevented cyclic strain-induced production of active TGF-β1 and phospho-Smad2/3 stimulation. Afferent arteriolar autoregulation was impaired in HT SS rats but not in HT Mmp9-/- rats or the HT SS rats treated with doxycycline, an MMP inhibitor. HT SS but not HT Mmp9-/- rats showed decreased glomerular Wilms Tumor 1 protein-positive cells (a marker of podocytes) along with increased urinary podocin and nephrin mRNA excretion, all indicative of glomerular damage. Thus, our findings support an active role for MMP-9 in a hypertension-induced kidney microvascular remodeling process that promotes glomerular epithelial cell injury in SS rats.
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Affiliation(s)
- Wenguang Feng
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Zhengrong Guan
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wei-Zhong Ying
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Dongqi Xing
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kai Er Ying
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Paul W Sanders
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA; Birmingham Veterans Affairs Health Care System, Birmingham, Alabama, USA.
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2
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Staniszewska-Slezak E, Mateuszuk L, Chlopicki S, Baranska M, Malek K. Alterations in plasma biochemical composition in NO deficiency induced by L-NAME in mice analysed by Fourier Transform Infrared Spectroscopy. JOURNAL OF BIOPHOTONICS 2016; 9:1098-1108. [PMID: 27440215 DOI: 10.1002/jbio.201600141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 06/06/2023]
Abstract
Mouse model of nitric oxide deficiency, induced by prolonged treatment with NG -nitro-L-arginine methyl ester (L-NAME) was used for infrared spectroscopy (FTIR) analysis of plasma. L-NAME leads to increased peripheral resistance and systemic hypertension. Classification of spectral response was by principal component analysis (PCA) and linear discriminant analysis (LDA). PCA allowed to separate each animal group showing that FTIR spectra are sensitive to development of NO-deficiency on contrary to blood pressure values indicating hypertension. Globally, the most pronounced spectral alternations were observed in the second and third week of L-NAME treatment indicating that infrared signature of blood plasma can serve as indicator of early and late stages of the disease. The PLS-DA method provided >95% classification accuracy. Spectral features characteristic for L-NAME treatment were mainly associated with an elevated level of proteins accompanied by a decrease of a tyrosine content and changes in lipids/phospholipid concentration. In our work we discuss these changes for which statistically significant differences (p < 0.05 - 0.005) were observed between spectra collected for each time-point of the L-NAME treatment versus control subjects. We demonstrated for the first time that NO-deficiency and hypertension resulted in changes in biochemical profile of plasma that was detected by FTIR spectroscopy.
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Affiliation(s)
- Emilia Staniszewska-Slezak
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348, Krakow, Poland
| | - Lukasz Mateuszuk
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348, Krakow, Poland
| | - Stefan Chlopicki
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348, Krakow, Poland
- Department of Experimental Pharmacology (Chair of Pharmacology), Jagiellonian University, Grzegorzecka 16, Krakow, 31-531, Poland
| | - Malgorzata Baranska
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348, Krakow, Poland
| | - Kamilla Malek
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060, Krakow, Poland.
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Bobrzynskiego 14, 30-348, Krakow, Poland.
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3
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Kobori H, Mori H, Masaki T, Nishiyama A. Angiotensin II blockade and renal protection. Curr Pharm Des 2013; 19:3033-42. [PMID: 23176216 DOI: 10.2174/1381612811319170009] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/20/2012] [Indexed: 12/15/2022]
Abstract
Current national guidelines have recommended the use of renin-angiotensin system inhibitors, including angiotensin II type 1 receptor blockers (ARBs), in preference to other antihypertensive agents for treating hypertensive patients with chronic kidney disease. However, the mechanisms underlying the renoprotective effects of ARBs are multiple and complex. Blood pressure reduction by systemic vasodilation with an ARB contributes to its beneficial effects in treating kidney disease. Furthermore, ARB-induced renal vasodilation results in an increase in renal blood flow, leading to improvement of renal ischemia and hypoxia. ARBs are also effective in reducing urinary albumin excretion through a reduction in intraglomerular pressure and the protection of glomerular endothelium and/or podocyte injuries. In addition to blocking angiotensin II-induced renal cell and tissue injuries, ARBs can decrease intrarenal angiotensin II levels by reducing proximal tubular angiotensinogen and production of collecting duct renin, as well as angiotensin II accumulation in the kidney. In this review, we will briefly summarize our current understanding of the pharmacological effects of an ARB in the kidney. We will also discuss the possible mechanisms responsible for the renoprotective effects of ARBs on type 2 diabetic nephropathy.
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Affiliation(s)
- Hiroyuki Kobori
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Ikenobe 1750-1, Miki, Kita, Kagawa 761-0793, Japan
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4
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Kobori H, Urushihara M. Augmented intrarenal and urinary angiotensinogen in hypertension and chronic kidney disease. Pflugers Arch 2012; 465:3-12. [PMID: 22918624 DOI: 10.1007/s00424-012-1143-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/03/2012] [Accepted: 08/06/2012] [Indexed: 12/22/2022]
Abstract
Activated intrarenal renin-angiotensin system plays a cardinal role in the pathogenesis of hypertension and chronic kidney disease. Angiotensinogen is the only known substrate for renin, which is the rate-limiting enzyme of the renin-angiotensin system. Because the levels of angiotensinogen are close to the Michaelis-Menten constant values for renin, angiotensinogen levels as well as renin levels can control the renin-angiotensin system activity, and thus, upregulation of angiotensinogen leads to an increase in the angiotensin II levels and ultimately increases blood pressure. Recent studies using experimental animal models have documented the involvement of angiotensinogen in the intrarenal renin-angiotensin system activation and development of hypertension. Enhanced intrarenal angiotensinogen mRNA and/or protein levels were observed in experimental models of hypertension and chronic kidney disease, supporting the important roles of angiotensinogen in the development and the progression of hypertension and chronic kidney disease. Urinary excretion rates of angiotensinogen provide a specific index of the intrarenal renin-angiotensin system status in angiotensin II-infused rats. Also, a direct quantitative method has been developed recently to measure urinary angiotensinogen using human angiotensinogen enzyme-linked immunosorbent assay. These data prompted us to measure urinary angiotensinogen in patients with hypertension and chronic kidney disease, and investigate correlations with clinical parameters. This short article will focus on the role of the augmented intrarenal angiotensinogen in the pathophysiology of hypertension and chronic kidney disease. In addition, the potential of urinary angiotensinogen as a novel biomarker of the intrarenal renin-angiotensin system status in hypertension and chronic kidney disease will be also discussed.
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Affiliation(s)
- Hiroyuki Kobori
- Department of Physiology, Tulane University Health Sciences Center, 1430 Tulane Avenue, #SL39, New Orleans, LA 70112-2699, USA.
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5
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Weng J, Liao M, Zou S, Bao J, Zhou J, Qu L, Feng R, Feng X, Zhao Z, Jing Z. Downregulation of FHL1 Expression in Thoracic Aortic Dissection: Implications in Aortic Wall Remodeling and Pathogenesis of Thoracic Aortic Dissection. Ann Vasc Surg 2011; 25:240-7. [DOI: 10.1016/j.avsg.2010.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 09/29/2010] [Accepted: 10/04/2010] [Indexed: 11/28/2022]
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Immunoglobulin light chains activate nuclear factor-κB in renal epithelial cells through a Src-dependent mechanism. Blood 2010; 117:1301-7. [PMID: 21098396 DOI: 10.1182/blood-2010-08-302505] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
One of the major attendant complications of multiple myeloma is renal injury, which contributes significantly to morbidity and mortality in this disease. Monoclonal immunoglobulin free light chains (FLCs) are usually directly involved, and tubulointerstitial renal injury and fibrosis are prominent histologic features observed in myeloma. The present study examined the role of monoclonal FLCs in altering the nuclear factor κ light chain enhancer of activated B cells (NF-κB) activity of renal epithelial cells. Human proximal tubule epithelial cells exposed to 3 different human monoclonal FLCs demonstrated Src kinase-dependent activation of the NF-κB pathway, which increased production of monocyte chemoattractant protein-1 (MCP-1). Tyrosine phosphorylation of inhibitor of κB kinases (IKKs) IKKα and IKKβ and a concomitant increase in inhibitor of κB (IκB) kinase activity in cell lysates were observed. Time-dependent, Src kinase-dependent increases in serine and tyrosine phosphorylation of IκBα and NF-κB activity were also demonstrated. Proteasome inhibition partially blocked FLC-induced MCP-1 production. These findings fit into a paradigm characterized by FLC-induced redox-signaling events that activated the canonical and atypical (IKK-independent) NF-κB pathways to promote a proinflammatory, profibrotic renal environment.
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Lin YS, Hsieh M, Lee YJ, Liu KL, Lin TH. AH23848 accelerates inducible nitric oxide synthase degradation through attenuation of cAMP signaling in glomerular mesangial cells. Nitric Oxide 2007; 18:93-104. [PMID: 18039475 DOI: 10.1016/j.niox.2007.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 10/23/2007] [Accepted: 10/31/2007] [Indexed: 01/23/2023]
Abstract
Excessive release of nitric oxide (NO) by mesangial cells contributes to the pathogenesis of glomerulonephritis. Prostaglandin E(2) (PGE(2)) produced at inflammatory sites regulates the release of NO through its downstream signaling. In glomerular mesangial cells (MES-13 cells), PGE(2) modulated NO production mainly through EP4 receptor in a cAMP-dependent manner. Lipopolysaccharide and interferon-gamma (LPS+IFNgamma)-induced NO production, inducible nitric oxide synthase (iNOS) gene and protein expression were greatly inhibited by AH23848, an EP4 antagonist. Further investigation indicated that AH23848 attenuated endogenous cAMP accumulation in MES-13 cells and modulated NO production through declination of iNOS gene expression and acceleration of iNOS protein degradation. AH23848 downregulated the iNOS protein in MES-13 cells through protein kinase A (PKA) since KT5720, a PKA-specific inhibitor, reduced iNOS protein stability. A short exposure of activated MES-13 cells to okadaic acid augmented iNOS activity. AH23848 and KT5720 attenuated serine/threonine phosphorylation of iNOS protein in LPS + IFNgamma-stimulated MES-13 cells. The results of this study led us to speculate that cAMP might regulate iNOS-stimulated NO synthesis through posttranslational mechanisms. Attenuation of cAMP signaling and the phosphorylation status of the iNOS protein may account for the effect of AH23848 in accelerating iNOS protein degradation in MES-13 cells.
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Affiliation(s)
- Yu-Sheng Lin
- Institute of Oral Medicine, Chung Shan Medical University, Taiwan, Republic of China
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8
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Sjakste T, Poudziunas I, Ninio E, Perret C, Pirags V, Nicaud V, Lazdins M, Evans A, Morrison C, Cambien F, Sjakste N. SNPs of the PSMA6 gene: Investigation of possible association with myocardial infarction and type 2 diabetes mellitus. RUSS J GENET+ 2007. [DOI: 10.1134/s102279540704014x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ying WZ, Zhang HG, Sanders PW. EGF receptor activity modulates apoptosis induced by inhibition of the proteasome of vascular smooth muscle cells. J Am Soc Nephrol 2006; 18:131-42. [PMID: 17151333 DOI: 10.1681/asn.2006040333] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The observation that intracellular protein turnover rates participate directly in cell viability led to the development and clinical use of potent proteasome inhibitors. This study determined that the mechanism of apoptosis that is induced by inhibition of the proteasome of vascular smooth muscle cells (VSMC) was related to the intracellular accumulation of Bad, a BH3-only member of the Bcl-2 family of apoptosis regulators. Experiments confirmed that the apoptotic process was mitochondria- and caspase-dependent. Ubiquitination and accumulation of Bad in VSMC followed inhibition of the proteasome, and depletion of Bad using RNA interference prevented apoptosis that was induced by proteasome inhibition with PS-341. EGF receptor (EGFR) activation produced posttranslational modifications of Bad, providing the pro-survival signals that prevented apoptosis of smooth muscle cells during proteasome inhibition. Antagonists of the EGFR potentiated the apoptotic rate. In summary, the activities of the EGFR and the proteasome focused on Bad and the intrinsic apoptotic pathway and were involved integrally in determining viability of VSMC. These findings might prove useful in the management of diseases in which proliferation of vascular smooth muscle cells plays a central role.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/physiology
- Boronic Acids/pharmacology
- Bortezomib
- Caspases/metabolism
- Cell Proliferation
- Cells, Cultured
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Mitochondria/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Protease Inhibitors/pharmacology
- Proteasome Inhibitors
- Protein Processing, Post-Translational
- Pyrazines/pharmacology
- Quinazolines/pharmacology
- RNA Interference
- Rats
- bcl-Associated Death Protein/antagonists & inhibitors
- bcl-Associated Death Protein/genetics
- bcl-Associated Death Protein/metabolism
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Affiliation(s)
- Wei-Zhong Ying
- Division of Nephrology/Department of Medicine, niversity of Alabama at Birmingham, Birmingham, AL 35294-0007, USA
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10
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Ray JCJ, Kirschner DE. Requirement for multiple activation signals by anti-inflammatory feedback in macrophages. J Theor Biol 2006; 241:276-94. [PMID: 16460764 DOI: 10.1016/j.jtbi.2005.11.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 10/25/2005] [Accepted: 11/26/2005] [Indexed: 12/19/2022]
Abstract
Pathogen killing is one of the primary roles of macrophages, utilizing potent effectors such as nitric oxide (NO) and involving other cellular machinery including iron regulatory apparatus. Macrophages become strongly activated upon receipt of appropriate signaling with cytokines and pathogen-derived endotoxins. However, they must resist activation in the absence of decisive signaling due to the energetic demands of activation coupled with the toxic nature of effector molecules to surrounding tissues. We have developed a mathematical model of the modular biochemical network of macrophages involved with activation, pathogen killing and iron regulation. This model requires synergistic interaction of multiple activation signals to overcome the quiescent state. To achieve a trade-off between macrophage quiescence and activation, strong activation signals are modulated via negative regulation by NO. In this way a single activation signal is insufficient for complete activation. In addition, our results suggest that iron regulation is usually controlled by activation signals. However, under conditions of partial macrophage activation, exogenous iron levels play a key role in regulating NO production. This model will be useful for evaluating macrophage control of intracellular pathogens in addition to the biochemical mechanisms examined here.
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Affiliation(s)
- J Christian J Ray
- Department of Microbiology and Immunology, The University of Michigan Medical School, Ann Arbor, MI 48109-0620, USA
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11
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Ying WZ, Sanders PW. Enhanced expression of EGF receptor in a model of salt-sensitive hypertension. Am J Physiol Renal Physiol 2005; 289:F314-21. [PMID: 15827348 DOI: 10.1152/ajprenal.00003.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic kidney disease in the Dahl/Rapp salt-sensitive (S) rat is related to an arteriolopathic process that occurs following the onset of hypertension and involves vascular smooth muscle cell (VSMC) hyperplasia and luminal constriction. Because previous studies have shown that activation of the epidermal growth factor receptor (EGFR) produces a mitogenic stimulus in VSMC and the EGFR participates integrally in the vasoconstrictor responses of renal arterioles, the present study analyzed the expression of EGFR in these animals. Compared with Sprague-Dawley (SD) rats, renal cortical expression of EGFR was increased in both prehypertensive and hypertensive S rats. Immunohistochemistry using a polyclonal antibody to EGFR demonstrated that EGFR expression was prominent in the renal vasculature, particularly in the media of afferent and efferent arterioles and the aorta of S rats. When examined, primary cultures of VSMC from S rats showed increased expression of EGFR, compared with VSMC from SD and Dahl/Rapp salt-resistant rats. Following addition of EGF, autophosphorylation of the EGFR was enhanced in cells from S rats, as was the downstream signaling events that included activation of p42/44 MAPK and Akt pathways. Thus in vivo and in vitro studies demonstrated augmented expression and functional activity of the EGFR in S rats.
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MESH Headings
- Animals
- Blotting, Northern
- Blotting, Western
- Cells, Cultured
- ErbB Receptors/biosynthesis
- Flow Cytometry
- Hypertension/chemically induced
- Hypertension/metabolism
- Immunohistochemistry
- Kidney/metabolism
- Kidney Cortex/drug effects
- Kidney Cortex/metabolism
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- RNA, Messenger/biosynthesis
- Rats
- Rats, Inbred Dahl
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Sodium Chloride/pharmacology
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Affiliation(s)
- Wei-Zhong Ying
- Nephrology Research and Training Center, Comprehensive Cancer Center, University of Alabama at Birmingham, 35294-0007, USA
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12
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Won JS, Im YB, Singh AK, Singh I. Dual role of cAMP in iNOS expression in glial cells and macrophages is mediated by differential regulation of p38-MAPK/ATF-2 activation and iNOS stability. Free Radic Biol Med 2004; 37:1834-44. [PMID: 15528042 DOI: 10.1016/j.freeradbiomed.2004.08.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Revised: 08/24/2004] [Accepted: 08/26/2004] [Indexed: 11/23/2022]
Abstract
We reported previously that cAMP analogues or cAMP synthesis activator (forskolin; FSK) inhibit lipopolysaccharide (LPS)-induced inducible nitric-oxide systase (iNOS) gene expression in astrocytes, while they enhance that in macrophages. Here, we report that the FSK-mediated inhibition of iNOS expression in C6 glial cells is due to its reduced transcriptional activity, while the FSK-mediated enhancement of iNOS expression in RAW264.7 macrophages is a result of increased stability of iNOS protein without transcriptional enhancement. The LPS/interferon-gamma (IFN)-induced iNOS transcription was inhibited by FSK via inhibition of p38-MAPK/ATF-2 activity in glial cells while it was not affected in macrophages. In both cell types, proteasome activities were required for the spontaneous degradation of iNOS protein, and the inhibition of proteasome activity by MG132 after maximum increase of iNOS protein levels further enhanced iNOS protein induction by LPS/IFN, suggesting the involvement of proteasome in iNOS degradation. More importantly, the iNOS protein levels were equalized by the MG132 posttreatment in macrophages treated with LPS/IFN alone and along with FSK, and ubiquitinated iNOS protein levels were reduced by FSK posttreatment, suggesting that the FSK-mediated inhibition of ubiquitination of iNOS protein and the following increased stability of iNOS protein are one of the mechanisms of cAMP-pathway-mediated enhancement of iNOS gene expression in macrophages. To our knowledge, this is the first evidence that cAMP regulates iNOS expression at the posttranslational level in macrophages.
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Affiliation(s)
- Je-Seong Won
- Developmental Neurogenetics, Department of Pediatrics; Department of Pathology, Medical University of South Carolina, 316 CSB, Charleston, SC 29425, USA
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13
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Kobori H, Nishiyama A. Effects of tempol on renal angiotensinogen production in Dahl salt-sensitive rats. Biochem Biophys Res Commun 2004; 315:746-50. [PMID: 14975764 PMCID: PMC3290764 DOI: 10.1016/j.bbrc.2004.01.120] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2004] [Indexed: 12/15/2022]
Abstract
We have recently reported that Dahl salt-sensitive rats (DS) on high salt diet (HS) have an inappropriate augmentation of intrarenal angiotensinogen. Recent studies also reported that the augmented superoxide anion formation plays important roles in this animal model of hypertension. This study was performed to address the hypothesis that an inappropriate augmentation of intrarenal angiotensinogen by HS is caused by the augmented reactive oxygen species. Male DS (200-220 g) were maintained on low salt diet LS (N = 7) or HS (N = 27) for 4 weeks. The HS group was subdivided into three subgroups to receive null (N = 12), superoxide dismutase mimetic, tempol (3 mmol/l, N = 8), or vasodilator, hydralazine (0.5 mmol/l, N = 7) in drinking water during the period. Systolic BP was significantly increased in the DS+HS group compared to the DS+LS group (184+/-7 mmHg vs. 107+/-5 at 4-week). Tempol or hydralazine treatment equivalently attenuated the hypertension (128+/-3 and 127+/-5 at 4-week, respectively). Urinary excretion of thiobarbituric acid reactive substances at 4-week was significantly increased in the DS+HS group compared to the DS+LS group (0.66+/-0.05 micromol/day vs. 0.14+/-0.01). Tempol treatment prevented this effect (0.24+/-0.04) but hydralazine treatment only partially prevented the effect (0.40+/-0.03). Kidney angiotensinogen levels, measured by Western blot analysis, were significantly increased in the DS+HS group compared to the DS+LS group (32+/-5 densitometric units vs. 21+/-1). Tempol (14+/-3) but not hydralazine (32+/-5) treatment prevented the intrarenal angiotensinogen augmentation. The evidence suggests that the enhanced intrarenal angiotensinogen in DS challenged with HS is associated with the augmented reactive oxygen species.
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Affiliation(s)
- Hiroyuki Kobori
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, USA.
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14
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Ying WZ, Sanders PW. Accelerated ubiquitination and proteasome degradation of a genetic variant of inducible nitric oxide synthase. Biochem J 2003; 376:789-94. [PMID: 12959638 PMCID: PMC1223806 DOI: 10.1042/bj20031058] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Revised: 09/05/2003] [Accepted: 09/08/2003] [Indexed: 11/17/2022]
Abstract
Biochemical and pharmacological studies have suggested that NOS2 (inducible nitric oxide synthase) has a functional role in the blood pressure response to increases in dietary salt intake. On a high-salt diet, the Dahl/Rapp salt-sensitive (S) strain of rat, a genetic model of salt-sensitive hypertension, did not show increased nitric oxide production. NOS2 from S rats possesses a point mutation that results in substitution of proline for serine at position 714. In the present study, rat NOS2 was shown to be ubiquitinated in vitro and in vivo and to be degraded by the proteasome; this process was accelerated for the S714P mutant. Accelerated degradation of the S714P mutant enzyme accounted for the diminished enzyme activity of this mutant. Hsp90 (heat-shock protein 90) associated with NOS2 and modulated degradation, but was not responsible for the accentuated degradation of the S714P mutant enzyme. The combined findings demonstrate the integral role of ubiquitination and degradation by the proteasome in the regulation of NO production by rat NOS2. Demonstrating that this process is responsible for the abnormal function of the S714P mutant NOS2 in S rats confirms the physiological importance of the proteasome in NOS2 function.
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Affiliation(s)
- Wei-Zhong Ying
- Nephrology Research and Training Center, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 35294-0007, USA
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15
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Fernández AP, Serrano J, Castro S, Salazar FJ, López JC, Rodrigo J, Nava E. Distribution of nitric oxide synthases and nitrotyrosine in the kidney of spontaneously hypertensive rats. J Hypertens 2003; 21:2375-88. [PMID: 14654759 DOI: 10.1097/00004872-200312000-00027] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To study the cellular distribution and the expression of the major isoforms of NO synthase (NOS) and of nitrotyrosine in the kidney in spontaneous hypertension. DESIGN AND METHODS We have studied by immunohistochemistry the location of the endothelial (eNOS), neuronal (nNOS) and inducible (iNOS) isoforms and nitrotyrosine in kidney slices from normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) using specific antibodies. In order to quantify the expression of these proteins, we have analyzed dissected renal cortical and medullary sections by means of Western blot. RESULTS Tubular cells were immunoreactive to nNOS and more numerous in the renal medulla of the SHR compared with that of the WKY, specifically in the outer medulla and the papillary region. Western blot also showed higher expression of nNOS in the renal medulla, but not the renal cortex of the SHR. In contrast, iNOS and eNOS distribution and expression were similar in the kidneys of WKY rats and SHR. Immunohistochemistry showed immunoreactive cells to nitrotyrosine in a variety of renal cells similarly distributed in SHR and WKY kidneys. Western analysis detected three proteins of 14.5, 23.7 and 39 kDa immunoreactive to nitrotyrosine, showing a higher expression in the renal cortex compared to the renal medulla. CONCLUSIONS The expression of nNOS is higher in the renal medulla of the SHR, and the distribution of eNOS, iNOS and nitrotyrosine is similar in SHR and WKY rats. It is proposed that the higher expression of the neuronal isoform in the medullary tubular cells is a protective mechanism aimed to improve renal function in spontaneous hypertension.
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Habisch HJ, Gorren ACF, Liang H, Venema RC, Parkinson JF, Schmidt K, Mayer B. Pharmacological interference with dimerization of human neuronal nitric-oxide synthase expressed in adenovirus-infected DLD-1 cells. Mol Pharmacol 2003; 63:682-9. [PMID: 12606778 DOI: 10.1124/mol.63.3.682] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A recombinant adenovirus containing the cDNA of human neuronal nitric-oxide synthase (nNOS) was constructed to characterize the interaction of nNOS with N-[(1,3-benzodioxol-5-yl)methyl]-1-[2-(1H-imidazole-1-yl)pyrimidin-4-yl]-4-(methoxycarbonyl)-piperazine-2-acetamide (BBS-1), a potent inhibitor of inducible NOS dimerization [Proc Natl Acad Sci USA 97:1506-1511, 2000]. BBS-1 inhibited de novo expression of nNOS activity in virus-infected cells at a half-maximal concentration (IC(50)) of 40 +/- 10 nM in a reversible manner. Low-temperature gel electrophoresis showed that BBS-1 attenuated the formation of SDS-resistant nNOS dimers with an IC(50) of 22 +/- 5.2 nM. Enzyme inhibition progressively decreased with increasing time of addition after infection. BBS-1 did not significantly inhibit dimeric nNOS activity (IC(50) > 1 mM). Long-term incubation with BBS-1 of human embryonic kidney cells stably transfected with nNOS or endothelial NOS revealed a slow time- and concentration-dependent decrease of NOS activity with half-lives of 30 and 43 h and IC(50) values of 210 +/- 30 nM and 12 +/- 0.5 microM, respectively. These results establish that BBS-1 interferes with the assembly of active nNOS dimers during protein expression. Slow inactivation of constitutively expressed NOS in intact cells may reflect protein degradation and interference of BBS-1 with the de novo synthesis of functionally active NOS dimers. As time-dependent inhibitors of NOS dimerization, BBS-1 and related compounds provide a promising strategy to develop a new class of selective and clinically useful NOS inhibitors.
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Affiliation(s)
- Hans-Jörg Habisch
- Institut für Pharmakologie und Toxikologie, Karl-Franzens-Universität Graz, Graz, Austria
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Osawa Y, Lowe ER, Everett AC, Dunbar AY, Billecke SS. Proteolytic degradation of nitric oxide synthase: effect of inhibitors and role of hsp90-based chaperones. J Pharmacol Exp Ther 2003; 304:493-7. [PMID: 12538799 DOI: 10.1124/jpet.102.035055] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide synthase (NOS) is a highly regulated enzyme that produces nitric oxide, a critical messenger in many physiological processes. In this perspective, we explore the role of proteolytic degradation of NOS, in particular the inducible and neuronal isoforms of NOS, as a mechanism of regulation of the enzyme. The ubiquitin-proteasome and calpain pathways are the major proteolytic systems identified to date that are responsible for this regulated degradation. The degradation of NOS is affected by diverse agents, including glucocorticoids, caveolin, neurotoxic compounds, and certain NOS inhibitors. Some irreversible inactivators of NOS enhance the proteolytic degradation of the enzyme, and this property may be of great importance in understanding the biological effects of these inhibitors, some of which are being developed for clinical use. Analogies with the regulated degradation of liver microsomal cytochromes P450, which are related to NOS, provide a framework for understanding these processes. Finally, a new perspective on the regulation of NOS by hsp90-based chaperones is presented that involves facilitated heme insertion into the enzyme.
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Affiliation(s)
- Yoichi Osawa
- Department of Pharmacology, the University of Michigan Medical School, Ann Arbor, Michigan, USA.
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Szentiványi M, Zou AP, Mattson DL, Soares P, Moreno C, Roman RJ, Cowley AW. Renal medullary nitric oxide deficit of Dahl S rats enhances hypertensive actions of angiotensin II. Am J Physiol Regul Integr Comp Physiol 2002; 283:R266-72. [PMID: 12069953 DOI: 10.1152/ajpregu.00461.2001] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Studies were designed to examine the hypothesis that the renal medulla of Dahl salt-sensitive (Dahl S) rats has a reduced capacity to generate nitric oxide (NO), which diminishes the ability to buffer against the chronic hypertensive effects of small elevations of circulating ANG II. NO synthase (NOS) activity in the outer medulla of Dahl S rats (arginine-citrulline conversion assay) was significantly reduced. This decrease in NOS activity was associated with the downregulation of protein expression of NOS I, NOS II, and NOS III isoforms in this region as determined by Western blot analysis. In anesthetized Dahl S rats, we observed that a low subpressor intravenous infusion of ANG II (5 ng. kg(-1). min(-1)) did not increase the concentration of NO in the renal medulla as measured by a microdialysis with oxyhemoglobin trapping technique. In contrast, ANG II produced a 38% increase in the concentration of NO (87 +/- 8 to 117 +/- 8 nmol/l) in the outer medulla of Brown-Norway (BN) rats. The same intravenous dose of ANG II reduced renal medullary blood flow as determined by laser-Doppler flowmetry in Dahl S, but not in BN rats. A 7-day intravenous ANG II infusion at a dose of 3 ng. kg(-1). min(-1) did not change mean arterial pressure (MAP) in the BN rats but increased MAP in Dahl S rats from 120 +/- 2 to 138 +/- 2 mmHg (P < 0.05). ANG II failed to increase MAP after NO substrate was provided by infusion of L-arginine (300 microg. kg(-1). min(-1)) into the renal medulla of Dahl S rats. Intravenous infusion of L-arginine at the same dose had no effect on the ANG II-induced hypertension. These results indicate that an impaired NO counterregulatory system in the outer medulla of Dahl S rats makes them more susceptible to the hypertensive actions of small elevations of ANG II.
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Affiliation(s)
- Mátyás Szentiványi
- Clinical Research Department, 2nd Institute of Physiology, Semmelweis University of Medicine, H-1088 Budapest, Hungary
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