1
|
De Koning DJ, Dominguez-Gasca N, Fleming RH, Gill A, Kurian D, Law A, McCormack HA, Morrice D, Sanchez-Rodriguez E, Rodriguez-Navarro AB, Preisinger R, Schmutz M, Šmídová V, Turner F, Wilson PW, Zhou R, Dunn IC. An eQTL in the cystathionine beta synthase gene is linked to osteoporosis in laying hens. Genet Sel Evol 2020; 52:13. [PMID: 32093603 PMCID: PMC7038551 DOI: 10.1186/s12711-020-00532-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Skeletal damage is a challenge for laying hens because the physiological adaptations required for egg laying make them susceptible to osteoporosis. Previously, we showed that genetic factors explain 40% of the variation in end of lay bone quality and we detected a quantitative trait locus (QTL) of large effect on chicken chromosome 1. The aim of this study was to combine data from the commercial founder White Leghorn population and the F2 mapping population to fine-map this QTL and understand its function in terms of gene expression and physiology. RESULTS Several single nucleotide polymorphisms on chromosome 1 between 104 and 110 Mb (galGal6) had highly significant associations with tibial breaking strength. The alternative genotypes of markers of large effect that flanked the region had tibial breaking strengths of 200.4 vs. 218.1 Newton (P < 0.002) and, in a subsequent founder generation, the higher breaking strength genotype was again associated with higher breaking strength. In a subsequent generation, cortical bone density and volume were increased in individuals with the better bone genotype but with significantly reduced medullary bone quality. The effects on cortical bone density were confirmed in a further generation and was accompanied by increased mineral maturity of the cortical bone as measured by infrared spectrometry and there was evidence of better collagen cross-linking in the cortical bone. Comparing the transcriptome of the tibia from individuals with good or poor bone quality genotypes indicated four differentially-expressed genes at the locus, one gene, cystathionine beta synthase (CBS), having a nine-fold higher expression in the genotype for low bone quality. The mechanism was cis-acting and although there was an amino-acid difference in the CBS protein between the genotypes, there was no difference in the activity of the enzyme. Plasma homocysteine concentration, the substrate of CBS, was higher in the poor bone quality genotype. CONCLUSIONS Validated markers that predict bone strength have been defined for selective breeding and a gene was identified that may suggest alternative ways to improve bone health in addition to genetic selection. The identification of how genetic variants affect different aspects of bone turnover shows potential for translational medicine.
Collapse
Affiliation(s)
| | | | - Robert H Fleming
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - Andrew Gill
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK.,School of Chemistry, The University of Lincoln, Lincoln, LN6 7TS, England, UK
| | - Dominic Kurian
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - Andrew Law
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - Heather A McCormack
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - David Morrice
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | | | | | | | | | - Veronica Šmídová
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK.,Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, CZ-613 00, Brno, Czech Republic
| | - Frances Turner
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - Peter W Wilson
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK
| | - Rongyan Zhou
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK.,Hebei Agricultural University, Baoding, 071001, Hebei, China
| | - Ian C Dunn
- The Roslin Institute, University of Edinburgh, Edinburgh, EH25 9RG, Scotland, UK.
| |
Collapse
|
2
|
Szabo C, Papapetropoulos A. International Union of Basic and Clinical Pharmacology. CII: Pharmacological Modulation of H 2S Levels: H 2S Donors and H 2S Biosynthesis Inhibitors. Pharmacol Rev 2017; 69:497-564. [PMID: 28978633 PMCID: PMC5629631 DOI: 10.1124/pr.117.014050] [Citation(s) in RCA: 278] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Over the last decade, hydrogen sulfide (H2S) has emerged as an important endogenous gasotransmitter in mammalian cells and tissues. Similar to the previously characterized gasotransmitters nitric oxide and carbon monoxide, H2S is produced by various enzymatic reactions and regulates a host of physiologic and pathophysiological processes in various cells and tissues. H2S levels are decreased in a number of conditions (e.g., diabetes mellitus, ischemia, and aging) and are increased in other states (e.g., inflammation, critical illness, and cancer). Over the last decades, multiple approaches have been identified for the therapeutic exploitation of H2S, either based on H2S donation or inhibition of H2S biosynthesis. H2S donation can be achieved through the inhalation of H2S gas and/or the parenteral or enteral administration of so-called fast-releasing H2S donors (salts of H2S such as NaHS and Na2S) or slow-releasing H2S donors (GYY4137 being the prototypical compound used in hundreds of studies in vitro and in vivo). Recent work also identifies various donors with regulated H2S release profiles, including oxidant-triggered donors, pH-dependent donors, esterase-activated donors, and organelle-targeted (e.g., mitochondrial) compounds. There are also approaches where existing, clinically approved drugs of various classes (e.g., nonsteroidal anti-inflammatories) are coupled with H2S-donating groups (the most advanced compound in clinical trials is ATB-346, an H2S-donating derivative of the non-steroidal anti-inflammatory compound naproxen). For pharmacological inhibition of H2S synthesis, there are now several small molecule compounds targeting each of the three H2S-producing enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase. Although many of these compounds have their limitations (potency, selectivity), these molecules, especially in combination with genetic approaches, can be instrumental for the delineation of the biologic processes involving endogenous H2S production. Moreover, some of these compounds (e.g., cell-permeable prodrugs of the CBS inhibitor aminooxyacetate, or benserazide, a potentially repurposable CBS inhibitor) may serve as starting points for future clinical translation. The present article overviews the currently known H2S donors and H2S biosynthesis inhibitors, delineates their mode of action, and offers examples for their biologic effects and potential therapeutic utility.
Collapse
Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, Texas (C.S.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Zografou, Greece (A.P.); and Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece (A.P.)
| | - Andreas Papapetropoulos
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, Texas (C.S.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Zografou, Greece (A.P.); and Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece (A.P.)
| |
Collapse
|
3
|
Weber GJ, Pushpakumar S, Tyagi SC, Sen U. Homocysteine and hydrogen sulfide in epigenetic, metabolic and microbiota related renovascular hypertension. Pharmacol Res 2016; 113:300-312. [PMID: 27602985 DOI: 10.1016/j.phrs.2016.09.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 12/18/2022]
Abstract
Over the past several years, hydrogen sulfide (H2S) has been shown to be an important player in a variety of physiological functions, including neuromodulation, vasodilation, oxidant regulation, inflammation, and angiogenesis. H2S is synthesized primarily through metabolic processes from the amino acid cysteine and homocysteine in various organ systems including neuronal, cardiovascular, gastrointestinal, and kidney. Derangement of cysteine and homocysteine metabolism and clearance, particularly in the renal vasculature, leads to H2S biosynthesis deregulation causing or contributing to existing high blood pressure. While a variety of environmental influences, such as diet can have an effect on H2S regulation and function, genetic factors, and more recently epigenetics, also have a vital role in H2S regulation and function, and therefore disease initiation and progression. In addition, new research into the role of gut microbiota in the development of hypertension has highlighted the need to further explore these microorganisms and how they influence the levels of H2S throughout the body and possibly exploiting microbiota for use of hypertension treatment. In this review, we summarize recent advances in the field of hypertension research emphasizing renal contribution and how H2S physiology can be exploited as a possible therapeutic strategy to ameliorate kidney dysfunction as well as to control blood pressure.
Collapse
Affiliation(s)
- Gregory J Weber
- Department of Physiology, University of Louisville, School of Medicine, Louisville, KY 40202, United States
| | - Sathnur Pushpakumar
- Department of Physiology, University of Louisville, School of Medicine, Louisville, KY 40202, United States
| | - Suresh C Tyagi
- Department of Physiology, University of Louisville, School of Medicine, Louisville, KY 40202, United States
| | - Utpal Sen
- Department of Physiology, University of Louisville, School of Medicine, Louisville, KY 40202, United States.
| |
Collapse
|
4
|
Vacek TP, Rehman S, Neamtu D, Yu S, Givimani S, Tyagi SC. Matrix metalloproteinases in atherosclerosis: role of nitric oxide, hydrogen sulfide, homocysteine, and polymorphisms. Vasc Health Risk Manag 2015; 11:173-83. [PMID: 25767394 PMCID: PMC4354431 DOI: 10.2147/vhrm.s68415] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Atherosclerosis is an inflammatory process that involves activation of matrix metalloproteinases (MMPs); MMPs degrade collagen and allow for smooth-muscle cell migration within a vessel. Moreover, this begets an accumulation of other cellular material, resulting in occlusion of the vessel and ischemic events to tissues in need of nutrients. Homocysteine has been shown to activate MMPs via an increase in oxidative stress and acting as a signaling molecule on receptors like the peroxisome proliferator activated receptor-γ and N-methyl-D-aspartate receptor. Nitric oxide has been shown to be beneficial in some cases of deactivating MMPs. However, in other cases, it has been shown to be harmful. Further studies are warranted on the scenarios that are beneficial versus destructive. Hydrogen sulfide (H2S) has been shown to decrease MMP activities in all cases in the literature by acting as an antioxidant and vasodilator. Various MMP-knockout and gene-silencing models have been used to determine the function of the many different MMPs. This has allowed us to discern the role that each MMP has in promoting or alleviating pathological conditions. Furthermore, there has been some study into the MMP polymorphisms that exist in the population. The purpose of this review is to examine the role of MMPs and their polymorphisms on the development of atherosclerosis, with emphasis placed on pathways that involve nitric oxide, hydrogen sulfide, and homocysteine.
Collapse
Affiliation(s)
- Thomas P Vacek
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Shahnaz Rehman
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Diana Neamtu
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Shipeng Yu
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Srikanth Givimani
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Suresh C Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA
| |
Collapse
|
5
|
Huang A, Pinto JT, Froogh G, Kandhi S, Qin J, Wolin MS, Hintze TH, Sun D. Role of homocysteinylation of ACE in endothelial dysfunction of arteries. Am J Physiol Heart Circ Physiol 2014; 308:H92-100. [PMID: 25416191 DOI: 10.1152/ajpheart.00577.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The direct impact of de novo synthesis of homocysteine (Hcy) and its reactive metabolites, Hcy-S-S-Hcy and Hcy thiolactone (HCTL), on vascular function has not been fully elucidated. We hypothesized that Hcy synthesized within endothelial cells affects activity of angiotensin-converting enzyme (ACE) by direct homocysteinylation of its amino- and/or sulfhydryl moieties. This covalent modification enhances ACE reactivity toward angiotensin II (ANG II)-NADPH oxidase-superoxide-dependent endothelial dysfunction. Mesenteric and coronary arteries isolated from normal rats were incubated for 3 days with or without exogenous methionine (Met, 0.1-0.3 mM), a precursor to Hcy. Incubation of arteries in Met-free media resulted in time-dependent decreases in vascular Hcy formation. By contrast, vessels incubated with Met produced Hcy in a dose-dependent manner. There was a notably greater de novo synthesis of Hcy from endothelial than from smooth muscle cells. Enhanced levels of Hcy production significantly impaired shear stress-induced dilation and release of nitric oxide, events that are associated with elevated production of vascular superoxide. Each of these processes was attenuated by ANG II type I receptor blocker or ACE and NADPH oxidase inhibitors. In addition, in vitro exposure of purified ACE to Hcy-S-S-Hcy/HCTL resulted in formation of homocysteinylated ACE and an enhanced ACE activity. The enhanced ACE activity was confirmed in isolated coronary and mesenteric arteries that had been exposed directly to Hcy-S-S-Hcy/HCTL or after Met incubation. In conclusion, vasculature-derived Hcy initiates endothelial dysfunction that, in part, may be mediated by ANG II-dependent activation of NADPH oxidase in association with homocysteinylation of ACE.
Collapse
Affiliation(s)
- An Huang
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - John T Pinto
- Department of Biochemistry, New York Medical College, Valhalla, New York
| | - Ghezal Froogh
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - Sharath Kandhi
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - Jun Qin
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - Michael S Wolin
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - Thomas H Hintze
- Department of Physiology, New York Medical College, Valhalla, New York; and
| | - Dong Sun
- Department of Physiology, New York Medical College, Valhalla, New York; and
| |
Collapse
|
6
|
Muradashvili N, Tyagi R, Metreveli N, Tyagi SC, Lominadze D. Ablation of MMP9 gene ameliorates paracellular permeability and fibrinogen-amyloid beta complex formation during hyperhomocysteinemia. J Cereb Blood Flow Metab 2014; 34:1472-82. [PMID: 24865997 PMCID: PMC4158659 DOI: 10.1038/jcbfm.2014.102] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 04/22/2014] [Accepted: 05/01/2014] [Indexed: 12/23/2022]
Abstract
Increased blood level of homocysteine (Hcy), called hyperhomocysteinemia (HHcy) accompanies many cognitive disorders including Alzheimer's disease. We hypothesized that HHcy-enhanced cerebrovascular permeability occurs via activation of matrix metalloproteinase-9 (MMP9) and leads to an increased formation of fibrinogen-β-amyloid (Fg-Aβ) complex. Cerebrovascular permeability changes were assessed in C57BL/6J (wild type, WT), cystathionine-β-synthase heterozygote (Cbs+/-, a genetic model of HHcy), MMP9 gene knockout (Mmp9-/-), and Cbs and Mmp9 double knockout (Cbs+/-/Mmp9-/-) mice using a dual-tracer probing method. Expression of vascular endothelial cadherin (VE-cadherin) and Fg-Aβ complex formation was assessed in mouse brain cryosections by immunohistochemistry. Short-term memory of mice was assessed with a novel object recognition test. The cerebrovascular permeability in Cbs+/- mice was increased via mainly the paracellular transport pathway. VE-cadherin expression was the lowest and Fg-Aβ complex formation was the highest along with the diminished short-term memory in Cbs+/- mice. These effects of HHcy were ameliorated in Cbs+/-/Mmp9-/- mice. Thus, HHcy causes activation of MMP9 increasing cerebrovascular permeability by downregulation of VE-cadherin resulting in an enhanced formation of Fg-Aβ complex that can be associated with loss of memory. These data may lead to the identification of new targets for therapeutic intervention that can modulate HHcy-induced cerebrovascular permeability and resultant pathologies.
Collapse
Affiliation(s)
- Nino Muradashvili
- Department of Physiology and Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - Reeta Tyagi
- Department of Physiology and Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - Naira Metreveli
- Department of Physiology and Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - Suresh C Tyagi
- Department of Physiology and Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| | - David Lominadze
- Department of Physiology and Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA
| |
Collapse
|
7
|
Homocysteine in renovascular complications: hydrogen sulfide is a modulator and plausible anaerobic ATP generator. Nitric Oxide 2014; 41:27-37. [PMID: 24963795 DOI: 10.1016/j.niox.2014.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 11/23/2022]
Abstract
Homocysteine (Hcy) is a non-protein amino acid derived from dietary methionine. High levels of Hcy, known as hyperhomocysteinemia (HHcy) is known to cause vascular complications. In the mammalian tissue, Hcy is metabolized by transsulfuration enzymes to produce hydrogen sulfide (H2S). H2S, a pungent smelling gas was previously known for its toxic effects in the central nervous system, recent studies however has revealed protective effects in a variety of diseases including hypertension, diabetes, inflammation, atherosclerosis, and renal disease progression and failure. Interestingly, under stress conditions including hypoxia, H2S can reduce metabolic demand and also act as a substrate for ATP production. This review highlights some of the recent advances in H2S research as a potential therapeutic agent targeting renovascular diseases associated with HHcy.
Collapse
|
8
|
Narayanan N, Pushpakumar SB, Givvimani S, Kundu S, Metreveli N, James D, Bratcher AP, Tyagi SC. Epigenetic regulation of aortic remodeling in hyperhomocysteinemia. FASEB J 2014; 28:3411-22. [PMID: 24739303 DOI: 10.1096/fj.14-250183] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hyperhomocysteinemia (HHcy) is prevalent in patients with hypertension and is an independent risk factor for aortic pathologies. HHcy is known to cause an imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), leading to the accumulation of collagen in the aorta and resulting in stiffness and development of hypertension. Although the exact mechanism of extracellular matrix (ECM) remodeling is unclear, emerging evidence implicates epigenetic regulation involving DNA methylation. Our purpose was to investigate whether 5-aza-2'-deoxycytidine (Aza), a DNA methyltransferase (DNMT1) inhibitor, reduces high blood pressure (BP) by regulating aortic ECM remodeling in HHcy. Wild-type and cystathionine β-synthase (CBS)(+/-) HHcy mice were treated with Aza (0.5 mg/kg body weight). In HHcy mice, Aza treatment normalized the plasma homocysteine (Hcy) level and BP. Thoracic and abdominal aorta ultrasound revealed a reduction in the resistive index and wall-to-lumen ratio. Vascular response to phenylephrine, acetylcholine, and sodium nitroprusside improved after Aza in HHcy mice. Histology showed a marked reduction in collagen deposition in the aorta. Aza treatment decreased the expression of DNMT1, MMP9, TIMP1, and S-adenosyl homocysteine hydrolase (SAHH) and upregulated methylene tetrahydrofolate reductase (MTHFR). We conclude that reduction of DNA methylation by Aza in HHcy reduces adverse aortic remodeling to mitigate hypertension.
Collapse
Affiliation(s)
- Nithya Narayanan
- Department of Physiology and Biophysics, University of Louisville School of Medicine, and
| | | | - Srikanth Givvimani
- Department of Physiology and Biophysics, University of Louisville School of Medicine, and
| | - Sourav Kundu
- Department of Physiology and Biophysics, University of Louisville School of Medicine, and
| | - Naira Metreveli
- Department of Physiology and Biophysics, University of Louisville School of Medicine, and
| | - Dexter James
- Department of Exercise Physiology, University of Louisville, Louisville, Kentucky, USA
| | - Adrienne P Bratcher
- Department of Exercise Physiology, University of Louisville, Louisville, Kentucky, USA
| | - Suresh C Tyagi
- Department of Physiology and Biophysics, University of Louisville School of Medicine, and
| |
Collapse
|
9
|
Pushpakumar SB, Kundu S, Metreveli N, Sen U. Folic acid mitigates angiotensin-II-induced blood pressure and renal remodeling. PLoS One 2013; 8:e83813. [PMID: 24386282 PMCID: PMC3873386 DOI: 10.1371/journal.pone.0083813] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 11/08/2013] [Indexed: 12/11/2022] Open
Abstract
Clinical data suggests an association between systolic hypertension, renal function and hyperhomocysteinemia (HHcy). HHcy is a state of elevated plasma homocysteine (Hcy) levels and is known to cause vascular complications. In this study, we tested the hypothesis whether Ang II-induced hypertension increases plasma Hcy levels and contributes to renovascular remodeling. We also tested whether folic acid (FA) treatment reduces plasma Hcy levels by enhancing Hcy remethylation and thus mitigating renal remodeling. Hypertension was induced in WT mice by infusing Ang II using Alzet mini osmotic pumps. Blood pressure, Hcy level, renal vascular density, oxidative stress, inflammation and fibrosis markers, and angiogenic- and anti-angiogenic factors were measured. Ang II hypertension increased plasma Hcy levels and reduced renal cortical blood flow and microvascular density. Elevated Hcy in Ang II hypertension was associated with decreased 4, 5-Diaminofluorescein (DAF-2DA) staining suggesting impaired endothelial function. Increased expression of Nox-2, -4 and dihydroethidium stain revealed oxidative stress. Excess collagen IV deposition in the peri-glomerular area and increased MMP-2, and -9 expression and activity indicated renal remodeling. The mRNA and protein expression of asymmetric dimethylarginine (ADMA) was increased and eNOS protein was decreased suggesting the involvement of this pathway in Hcy mediated hypertension. Decreased expressions of VEGF and increased anti-angiogenic factors, angiostatin and endostatin indicated impaired vasculogenesis. FA treatment partially reduced hypertension by mitigating HHcy in Ang II-treated animals and alleviated pro-inflammatory, pro-fibrotic and anti-angiogenic factors. These results suggest that renovascular remodeling in Ang II-induced hypertension is, in part, due to HHcy.
Collapse
Affiliation(s)
- Sathnur B. Pushpakumar
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Sourav Kundu
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Naira Metreveli
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Utpal Sen
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
10
|
Kundu S, Pushpakumar SB, Tyagi A, Coley D, Sen U. Hydrogen sulfide deficiency and diabetic renal remodeling: role of matrix metalloproteinase-9. Am J Physiol Endocrinol Metab 2013; 304:E1365-78. [PMID: 23632630 PMCID: PMC3680700 DOI: 10.1152/ajpendo.00604.2012] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Matrix metalloproteinase-9 (MMP-9) causes adverse remodeling, whereas hydrogen sulfide (H2S) rescues organs in vascular diseases. The involvement of MMP-9 and H2S in diabetic renovascular remodeling is, however, not well characterized. We determined whether MMP-9 regulates H2S generation and whether H2S modulates connexin through N-methyl-d-aspartate receptor (NMDA-R)-mediated pathway in the diabetic kidney. Wild-type (WT, C57BL/6J), diabetic (Akita, C57BL/6J-Ins2(Akita)), MMP-9(-/-) (M9KO), double knockout (DKO) of Akita/MMP-9(-/-) mice and in vitro cell culture were used in our study. Hyperglycemic Akita mice exhibited increased level of MMP-9 and decreased production of H2S. H2S-synthesizing enzymes cystathionine-β-synthase and cystathionine-γ-lyase were also diminished. In addition, increased expressions of NMDA-R1 and connexin-40 and -43 were observed in diabetic kidney. As expected, MMP-9 mRNA was not detected in M9KO kidneys. However, very thin protein expression and activity were detected. No other changes were noticed in M9KO kidney. In DKO mice, all the above molecules showed a trend toward baseline despite hyperglycemia. In vitro, glomerular endothelial cells treated with high glucose showed induction of MMP-9, attenuated H2S production, NMDA-R1 induction, and dysregulated conexin-40 and -43 expressions. Silencing MMP-9 by siRNA or inhibition of NMDA-R1 by MK801 or H2S treatment preserved connexin-40 and -43. We conclude that in diabetic renovascular remodeling MMP-9 plays a major role and that H2S has therapeutic potential to prevent adverse diabetic renal remodeling.
Collapse
MESH Headings
- Animals
- Cells, Cultured
- Diabetic Nephropathies/genetics
- Diabetic Nephropathies/metabolism
- Dizocilpine Maleate/pharmacology
- Endothelial Cells/cytology
- Excitatory Amino Acid Antagonists/pharmacology
- Glycosuria, Renal/genetics
- Glycosuria, Renal/metabolism
- Hydrogen Sulfide/metabolism
- Kidney Glomerulus/blood supply
- Kidney Glomerulus/cytology
- Kidney Tubules, Proximal/blood supply
- Kidney Tubules, Proximal/cytology
- Matrix Metalloproteinase 9/genetics
- Matrix Metalloproteinase 9/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- RNA, Small Interfering/genetics
- Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
Collapse
Affiliation(s)
- Sourav Kundu
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | | | | | | | | |
Collapse
|
11
|
Givvimani S, Munjal C, Narayanan N, Aqil F, Tyagi G, Metreveli N, Tyagi SC. Hyperhomocysteinemia decreases intestinal motility leading to constipation. Am J Physiol Gastrointest Liver Physiol 2012; 303:G281-90. [PMID: 22595990 PMCID: PMC3423105 DOI: 10.1152/ajpgi.00423.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Elevated levels of plasma homocysteine (Hcy) called hyperhomocysteinemia (HHcy) have been implicated in inflammation and remodeling in intestinal vasculature, and HHcy is also known to aggravate the pathogenesis of inflammatory bowel disease (IBD). Interestingly, colon is the pivotal site that regulates Hcy levels in the plasma. We hypothesize that HHcy decreases intestinal motility through matrix metalloproteinase-9 (MMP-9)-induced intestinal remodeling leading to constipation. To verify this hypothesis, we used C57BL/6J or wild-type (WT), cystathionine β-synthase (CBS(+/-)), MMP-9(-/-), and MMP-9(-/-) + Hcy mice. Intestinal motility was assessed by barium meal studies and daily feces output. Plasma Hcy levels were measured by HPLC. Expression of ICAM-1, inducible nitric oxide synthase, MMP-9, and tissue inhibitors of MMPs was studied by Western blot and immunohistochemistry. Reactive oxygen species (ROS) including super oxide were measured by the Invitrogen molecular probe method. Tissue nitric oxide levels were assessed by a commercially available kit. Plasma Hcy levels in the treated MMP-9 group mice were comparable to CBS(+/-) mice. Barium meal studies suggest that intestinal motility is significantly decreased in CBS(+/-) mice compared with other groups. Fecal output-to-body weight ratio was significantly reduced in CBS(+/-) mice compared with other groups. There was significant upregulation of MMP-9, iNOS, and ICAM-1 expression in the colon from CBS(+/-) mice compared with WT mice. Levels of ROS, superoxide, and inducible nitric oxide were elevated in the CBS(+/-) mice compared with other groups. Results suggest that HHcy decreases intestinal motility due to MMP-9-induced intestinal remodeling leading to constipation.
Collapse
Affiliation(s)
- S. Givvimani
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - C. Munjal
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - N. Narayanan
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - F. Aqil
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - G. Tyagi
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - N. Metreveli
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| | - S. C. Tyagi
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky
| |
Collapse
|
12
|
Li C, Han J, Shang D, Li J, Wang Y, Wang Y, Zhang Y, Yao Q, Zhang C, Li K, Li X. Identifying disease related sub-pathways for analysis of genome-wide association studies. Gene 2012; 503:101-9. [DOI: 10.1016/j.gene.2012.04.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 02/17/2012] [Accepted: 04/18/2012] [Indexed: 12/29/2022]
|
13
|
Kim YR, Kim CS, Naqvi A, Kumar A, Kumar S, Hoffman TA, Irani K. Epigenetic upregulation of p66shc mediates low-density lipoprotein cholesterol-induced endothelial cell dysfunction. Am J Physiol Heart Circ Physiol 2012; 303:H189-96. [PMID: 22661506 DOI: 10.1152/ajpheart.01218.2011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypercholesterolemia characterized by elevation of low-density lipoprotein (LDL) cholesterol is a major risk factor for atherosclerotic vascular disease. p66shc mediates hypercholesterolemia-induced endothelial dysfunction and atheromatous plaque formation. We asked if LDL upregulates endothelial p66shc via changes in the epigenome and examined the role of p66shc in LDL-stimulated endothelial cell dysfunction. Human LDL stimulates human p66shc promoter activity and p66shc expression in human endothelial cells. LDL leads to hypomethylation of two CpG dinucleotides and acetylation of histone 3 in the human p66shc promoter. These two CpG dinucleotides mediate LDL-stimulated p66shc promoter activity. Inhibition or knock down of DNA methyltransferases negates LDL-induced endothelial p66shc expression. p66shc mediates LDL-stimulated increase in expression of endothelial intercellular adhesion molecule-1 (ICAM1) and decrease in expression of thrombomodulin (TM). Mirroring these changes in ICAM1 and TM expression, p66shc mediates LDL-stimulated adhesion of monocytes to endothelial cells and plasma coagulation on endothelial cells. These findings indicate that LDL cholesterol upregulates human endothelial p66shc expression via hypomethylation of CpG dinucleotides in the p66shc promoter. Moreover, they show that LDL-stimulated p66shc expression mediates a dysfunctional endothelial cell surface, with proadhesive and procoagulant features.
Collapse
Affiliation(s)
- Young-Rae Kim
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
Kim CS, Kim YR, Naqvi A, Kumar S, Hoffman TA, Jung SB, Kumar A, Jeon BH, McNamara DM, Irani K. Homocysteine promotes human endothelial cell dysfunction via site-specific epigenetic regulation of p66shc. Cardiovasc Res 2011; 92:466-75. [PMID: 21933910 PMCID: PMC3211975 DOI: 10.1093/cvr/cvr250] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 09/01/2011] [Accepted: 09/14/2011] [Indexed: 12/31/2022] Open
Abstract
AIMS Hyperhomocysteinaemia is an independent risk factor for atherosclerotic vascular disease and is associated with vascular endothelial dysfunction. Homocysteine modulates cellular methylation reactions. P66shc is a protein that promotes oxidative stress whose expression is governed by promoter methylation. We asked if homocysteine induces endothelial p66shc expression via hypomethylation of CpG dinucleotides in the p66shc promoter, and whether p66shc mediates homocysteine-stimulated endothelial cell dysfunction. METHODS AND RESULTS Homocysteine stimulates p66shc transcription in human endothelial cells and hypomethylates specific CpG dinucleotides in the human p66shc promoter. Knockdown of p66shc inhibits the increase in reactive oxygen species, and decrease in nitric oxide, elicited by homocysteine in endothelial cells and prevents homocysteine-induced up-regulation of endothelial intercellular adhesion molecule-1. In addition, knockdown of p66shc mitigates homocysteine-induced adhesion of monocytes to endothelial cells. Inhibition of DNA methyltransferase activity or knockdown of DNA methyltransferase 3b abrogates homocysteine-induced up-regulation of p66shc. Comparison of plasma homocysteine in humans with coronary artery disease shows a significant difference between those with highest and lowest p66shc promoter CpG methylation in peripheral blood leucocytes. CONCLUSION Homocysteine up-regulates human p66shc expression via hypomethylation of specific CpG dinucleotides in the p66shc promoter, and this mechanism is important in homocysteine-induced endothelial cell dysfunction.
Collapse
Affiliation(s)
- Cuk-Seong Kim
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Young-Rae Kim
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Asma Naqvi
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Santosh Kumar
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Timothy A. Hoffman
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Saet-Byel Jung
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Ajay Kumar
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Byeong-Hwa Jeon
- Department of Physiology, Chungnam National University School of Medicine, Daejeon, Republic of Korea
| | - Dennis M. McNamara
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Kaikobad Irani
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Scaife S620, 200 Lothrop St, Pittsburgh, PA 15213, USA
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
- Vascular Medicine Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| |
Collapse
|
15
|
Pushpakumar SB, Perez-Abadia G, Soni C, Wan R, Todnem N, Patibandla PK, Fensterer T, Zhang Q, Barker JH, Maldonado C. Enhancing complement control on endothelial barrier reduces renal post-ischemia dysfunction. J Surg Res 2011; 170:e263-70. [PMID: 21816416 DOI: 10.1016/j.jss.2011.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 04/25/2011] [Accepted: 06/07/2011] [Indexed: 11/16/2022]
Abstract
BACKGROUND Excessive complement activation is an integral part of ischemia and reperfusion (IR) injury (IRI) of organs. In kidney transplantation, the pathologic consequence of IRI and complement activation can lead to delayed graft function, which in turn is associated with acute rejection. Previous strategies to reduce complement-induced IRI required systemic administration of agents, which can lead to increased susceptibility to infections/immune diseases. The objective of this study was to determine whether an increase in complement control defenses of rat kidney endothelium reduces IRI. We hypothesized that increased complement control on the endothelial barrier reduces IR-mediated complement activation and reduces kidney dysfunction. MATERIALS AND METHODS Fischer 344 rats underwent left kidney ischemia for 45 min and treatment with a novel fusogenic lipid vesicle (FLVs) delivery system to decorate endothelial cells with vaccinia virus complement control protein (VCP), followed by reperfusion for 24 h. Assessment included renal function by serum creatinine and urea, myeloperoxidase assay for neutrophil infiltration, histopathology, and quantification of C3 production in kidneys. RESULTS Animals in which the kidney endothelium was bolstered by FLVs+VCP treatment had better renal function with a significant reduction in serum creatinine compared with vehicle controls (P < 0.05). Also, C3 production was significantly reduced (P < 0.05) in treated animals compared with vehicle controls. CONCLUSION Increasing complement control at the endothelial barrier with FLVs+VCP modulates complement activation/production during the first 24 h, reducing renal dysfunction following IRI.
Collapse
Affiliation(s)
- Sathnur B Pushpakumar
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Grobelny BT, Ducruet AF, DeRosa PA, Kotchetkov IS, Zacharia BE, Hickman ZL, Fernandez L, Narula R, Claassen J, Lee K, Badjatia N, Mayer SA, Connolly ES. Gain-of-function polymorphisms of cystathionine β-synthase and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. J Neurosurg 2011; 115:101-7. [DOI: 10.3171/2011.2.jns101414] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Cystathionine β-synthase (CBS) is an enzyme that metabolizes homocysteine to form H2S in the brain. Hydrogen sulfide functions as a vasodilator as well as a regulator of neuronal ion channels and multiple intracellular signaling pathways. Given the myriad effects of H2S, the authors hypothesized that patients possessing gain-of-function polymorphisms of the CBS gene will experience a decreased incidence of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH).
Methods
Patients were enrolled in a prospective observational database of aSAH outcomes. DNA was extracted from buccal swabs and sequenced for 3 functional polymorphisms of the CBS gene (699C→T, 844ins68, and 1080C→T) by polymerase chain reaction. Serum homocysteine levels (μmol/L) were assayed. Multivariate analysis was used to determine the relationship between CBS genotype and occurrence of both angiographic vasospasm and DCI.
Results
There were 87 patients included in the study. None of the polymorphisms investigated were significantly associated with the incidence of angiographic vasospasm. However, after controlling for admission hypertension, patients with the gain-of-function 844 WT/ins genotypes were less likely to experience DCI relative to those with the 844 WT/WT genotype (86 patients, p = 0.050), while the decrease-in-function genotype 1080 TT was more likely to experience DCI relative to those with 1080 CC and CT genotypes (84 patients, p = 0.042). Serum homocysteine levels did not correlate with the extent of either angiographic vasospasm or DCI in this analysis.
Conclusions
Polymorphisms of the CBS gene that impart gain-of-function may be associated with a reduced risk of DCI after aSAH, independent of serum homocysteine. Signaling through H2S may mediate protection from DCI following aSAH through a mechanism that does not involve macrovascular vasodilation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Luis Fernandez
- 3Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | | | - Jan Claassen
- 3Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Kiwon Lee
- 3Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Neeraj Badjatia
- 3Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Stephan A. Mayer
- 3Neurology, Columbia University College of Physicians and Surgeons, New York, New York
| | | |
Collapse
|
17
|
Tyagi N, Vacek TP, Fleming JT, Vacek JC, Tyagi SC. Hyperhomocysteinemia decreases bone blood flow. Vasc Health Risk Manag 2011; 7:31-5. [PMID: 21339911 PMCID: PMC3037087 DOI: 10.2147/vhrm.s15844] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Elevated plasma levels of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), are associated with osteoporosis. A decrease in bone blood flow is a potential cause of compromised bone mechanical properties. Therefore, we hypothesized that HHcy decreases bone blood flow and biomechanical properties. To test this hypothesis, male Sprague–Dawley rats were treated with Hcy (0.67 g/L) in drinking water for 8 weeks. Age-matched rats served as controls. At the end of the treatment period, the rats were anesthetized. Blood samples were collected from experimental or control rats. Biochemical turnover markers (body weight, Hcy, vitamin B12, and folate) were measured. Systolic blood pressure was measured from the right carotid artery. Tibia blood flow was measured by laser Doppler flow probe. The results indicated that Hcy levels were significantly higher in the Hcy-treated group than in control rats, whereas vitamin B12 levels were lower in the Hcy-treated group compared with control rats. There was no significant difference in folate concentration and blood pressure in Hcy-treated versus control rats. The tibial blood flow index of the control group was significantly higher (0.78 ± 0.09 flow unit) compared with the Hcy-treated group (0.51 ± 0.09). The tibial mass was 1.1 ± 0.1 g in the control group and 0.9 ± 0.1 in the Hcy-treated group. The tibia bone density was unchanged in Hcy-treated rats. These results suggest that Hcy causes a reduction in bone blood flow, which contributes to compromised bone biomechanical properties.
Collapse
Affiliation(s)
- Neetu Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, KY, USA.
| | | | | | | | | |
Collapse
|
18
|
Sen U, Givvimani S, Abe OA, Lederer ED, Tyagi SC. Cystathionine β-synthase and cystathionine γ-lyase double gene transfer ameliorate homocysteine-mediated mesangial inflammation through hydrogen sulfide generation. Am J Physiol Cell Physiol 2011; 300:C155-63. [PMID: 20943958 PMCID: PMC3023186 DOI: 10.1152/ajpcell.00143.2010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 10/08/2010] [Indexed: 11/22/2022]
Abstract
Elevated level of homocysteine (Hcy) induces chronic inflammation in vascular bed, including glomerulus, and promotes glomerulosclerosis. In this study we investigated in vitro mechanism of Hcy-mediated monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) induction and determined the regulatory role of hydrogen sulfide (H₂S) to ameliorate inflammation. Mouse glomerular mesangial cells (MCs) were incubated with Hcy (75 μM) and supplemented with vehicle or with H₂S (30 μM, in the form of NaHS). Inflammatory molecules MCP-1 and MIP-2 were measured by ELISA. Cellular capability to generate H₂S was measured by colorimetric chemical method. To enhance endogenous production of H₂S and better clearance of Hcy, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) genes were delivered to the cells. Oxidative NAD(P)H p47(phox) was measured by Western blot analysis and immunostaining. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH₂-terminal kinase (JNK1/2) were measured by Western blot analysis. Our results demonstrated that Hcy upregulated inflammatory molecules MCP-1 and MIP-2, whereas endogenous production of H₂S was attenuated. H₂S treatment as well as CBS and CSE doubly cDNA overexpression markedly reduced Hcy-induced upregulation of MCP-1 and MIP-2. Hcy-induced upregulation of oxidative p47(phox) was attenuated by H₂S supplementation and CBS/CSE overexpression as well. In addition to that we also detected Hcy-induced MCP-1 and MIP-2 induction was through phosphorylation of ERK1/2 and JNK1/2. Either H₂S supplementation or CBS and CSE doubly cDNA overexpression attenuated Hcy-induced phosphorylation of these two signaling molecules and diminished MCP-1 and MIP-2 expressions. Similar results were obtained by inhibition of ERK1/2 and JNK1/2 using pharmacological and small interferring RNA (siRNA) blockers. We conclude that H₂S plays a regulatory role in Hcy-induced mesangial inflammation and that ERK1/2 and JNK1/2 are two signaling pathways involved this process.
Collapse
Affiliation(s)
- Utpal Sen
- Department of Physiology & Biophysics, University of Louisville, KY 40202, USA.
| | | | | | | | | |
Collapse
|
19
|
Yang RX, Huang SY, Yan FF, Lu XT, Xing YF, Liu Y, Liu YF, Zhao YX. Danshensu protects vascular endothelia in a rat model of hyperhomocysteinemia. Acta Pharmacol Sin 2010; 31:1395-400. [PMID: 20871618 DOI: 10.1038/aps.2010.167] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIM To examine whether danshensu could protect vascular endothelia in a rat model of hyperhomocysteinemia. METHODS The model was established by feeding rats with a methionine-rich diet (1 g·kg⁻¹·d⁻¹) for 3 months. Immediately following the discontinuation of methionine-rich diet, rats were treated with danshensu (67.5 mg·kg⁻¹·d⁻¹, po) or saline for 3 additional months. One group of rats receiving vitamin mixture (folic acid, vitamin B12 and vitamin B6) was included as a positive control. One group of rats not exposed to methionine-rich diet was also included as a blank control. The expression of tumor necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecule-1 (ICAM-1) protein in the descending aorta was examined using immunohistochemistry and Western blot. Homocysteine and blood concentration of endothelin and nitric oxide (NO) was also examined. RESULTS Methionine-rich diet resulted in accumulation of "foam cells", up-regulated expression of TNF-alpha and ICAM-1 in the descending aorta, and significantly increased serum homocysteine. Plasma endothelin concentration was significantly increased; NO was decreased. Danshensu treatment, either simultaneous to methionine-rich diet or afterwards, attenuated the above mentioned changes. CONCLUSION Chronic treatment with danshensu could prevent/attenuate the formation of atherosclerosis. Potential mechanisms include inhibited expression of representative proinflammatory cytokines and adhesion molecules in arterial endothelia. Changes in homocysteine and circulating molecules that control vascular contraction/relaxation via endothelial cells (eg, endothelin and NO) were also implicated.
Collapse
|
20
|
Mishra PK, Tyagi N, Sen U, Joshua IG, Tyagi SC. Synergism in hyperhomocysteinemia and diabetes: role of PPAR gamma and tempol. Cardiovasc Diabetol 2010; 9:49. [PMID: 20828387 PMCID: PMC2944245 DOI: 10.1186/1475-2840-9-49] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 09/09/2010] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Hyperhomocysteinemia (HHcy) and hyperglycemia cause diabetic cardiomyopathy by inducing oxidative stress and attenuating peroxisome proliferator- activated receptor (PPAR) gamma. However, their synergistic contribution is not clear. METHODS Diabetic Akita (Ins2+/-) and hyperhomocysteinemic cystathionine beta synthase mutant (CBS+/-) were used for M-mode echocardiography at the age of four and twenty four weeks. The cardiac rings from WT, Akita and hybrid (Ins2+/-/CBS+/-) of Akita and CBS+/- were treated with different doses of acetylcholine (an endothelial dependent vasodilator). High performance liquid chromatography (HPLC) was performed for determining plasma homocysteine (Hcy) level in the above groups. Akita was treated with ciglitazone (CZ) - a PPAR gamma agonist and tempol-an anti-oxidant, separately and their effects on cardiac remodeling were assessed. RESULTS At twenty four week, Akita mice were hyperglycemic and HHcy. They have increased end diastolic diameter (EDD). In their heart PPAR gamma, tissue inhibitor of metalloproteinase-4 (TIMP-4) and anti-oxidant thioredoxin were attenuated whereas matrix metalloproteinase (MMP)-9, TIMP-3 and NADPH oxidase 4 (NOX4) were induced. Interestingly, they showed synergism between HHcy and hyperglycemia for endothelial-myocyte (E-M) uncoupling. Additionally, treatment with CZ alleviated MMP-9 activity and fibrosis, and improved EDD. On the other hand, treatment with tempol reversed cardiac remodeling in part by restoring the expressions of TIMP-3,-4, thioredoxin and MMP-9. CONCLUSIONS Endogenous homocysteine exacerbates diabetic cardiomyopathy by attenuating PPAR gamma and inducing E-M uncoupling leading to diastolic dysfunction. PPAR gamma agonist and tempol mitigates oxidative stress and ameliorates diastolic dysfunction in diabetes.
Collapse
Affiliation(s)
- Paras K Mishra
- Department of Physiology & Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky-40202, USA
| | - Neetu Tyagi
- Department of Physiology & Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky-40202, USA
| | - Utpal Sen
- Department of Physiology & Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky-40202, USA
| | - Irving G Joshua
- Department of Physiology & Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky-40202, USA
| | - Suresh C Tyagi
- Department of Physiology & Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky-40202, USA
| |
Collapse
|
21
|
Tyagi N, Vacek JC, Givvimani S, Sen U, Tyagi SC. Cardiac specific deletion of N-methyl-d-aspartate receptor 1 ameliorates mtMMP-9 mediated autophagy/mitophagy in hyperhomocysteinemia. J Recept Signal Transduct Res 2010; 30:78-87. [PMID: 20170426 DOI: 10.3109/10799891003614808] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Autophagy is an important process in the pathogenesis of cardiovascular diseases; however, the proximal triggers for mitochondrial autophagy were unknown. The N-methyl-d-aspartate receptor 1 (NMDA-R1) is a receptor for homocysteine (Hcy) and plays a key role in cardiac dysfunction. Cardiac-specific deletion of NMDA-R1 has been shown to ameliorate Hcy-induced myocyte contractility. Hcy activates mitochondrial matrix metalloproteinase-9 (mtMMP-9) and induces translocation of connexin-43 (Cxn-43) to the mitochondria (mtCxn-43). We sought to show cardiac-specific deletion of NMDA-R1 mitigates Hcy-induced mtCxn-43 translocation, mtMMP-9-mediated mtCxn-43 degradation, leading to mitophagy, in part, by decreasing mitochondrial permeability (MPT). Cardiac-specific knockout (KO) of NAMDA-R1 was generated using the cre/lox approach. The myocyte mitochondria were isolated from wild type (WT), WT + Hcy (1.8 g of DL-Hcy/L in the drinking water for 6 weeks), NMDA-R1 KO + Hcy, and NR1(fl/fl)/Cre (NR1(fl/fl)) genetic control mice. Mitochondrial respiratory capacity and MPT were measured by fluorescence-dye methods. The mitochondrial superoxide and peroxinitrite levels were detected by confocal microscopy using Mito-SOX and dihydrorhodamine-123. The mtMMP-9 activity and expression were detected by zymography and RT-PCR analyses. The mtCxn-43 translocation was detected by confocal microscopy. The degradation of mtCxn-43 and LC3-I/II (a marker of autophagy) were detected by Western blot. These results suggested that Hcy enhanced intramitochondrial nitrosative stress in myocytes. There was a robust increase in mtMMP-9 activity. An increase in translocation and degradation of mtCxn-43 was also noted. These increases led to mitophagy. The effects were ameliorated by cardiac-specific deletion of NMDA-R1. We concluded that HHcy increased mitochondrial nitrosative stress, thereby activating mtMMP-9 and inciting the degradation of mtCxn-43. This led to mitophagy, in part, by activating NMDA-R1. The findings of this study will lead to therapeutic ramifications for mitigating cardiovascular diseases by inhibiting the mitochondrial mitophagy and NMDA-R1 receptor.
Collapse
Affiliation(s)
- Neetu Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY 40292, USA
| | | | | | | | | |
Collapse
|
22
|
Sen U, Munjal C, Qipshidze N, Abe O, Gargoum R, Tyagi SC. Hydrogen sulfide regulates homocysteine-mediated glomerulosclerosis. Am J Nephrol 2010; 31:442-55. [PMID: 20395677 DOI: 10.1159/000296717] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 03/08/2010] [Indexed: 12/19/2022]
Abstract
BACKGROUND/AIMS In this study we tested the hypothesis that H(2)S regulates collagen deposition, matrix metalloproteinases (MMP) and inflammatory molecules during hyperhomocysteinemia (HHcy) resulting in attenuation of glomerulosclerosis and improved renal function. MATERIALS AND METHODS A genetic model of HHcy, cystathionine beta-synthase heterozygous (CBS+/-) and wild-type (WT) 2-kidney (2K) mice were used in this study and supplemented with or without NaHS (30 micromol/l, H(2)S donor) in drinking water for 8 weeks. To expedite the renal damage associated with HHcy, uninephrectomized (1K) mice of similar groups were also used. RESULTS Results demonstrated that NAD(P)H oxidase (p47(phox)subunit) and blood pressure were upregulated in WT 1K, CBS+/- 2K and CBS+/- 1K mice with downregulation of H(2)S production and reduced glomerular filtration rate. These changes were normalized with H(2)S supplementation. Both pro- and active MMP-2 and -9 and collagen protein expressions and glomerular depositions were also upregulated in WT 1K, CBS+/- 2K and CBS+/- 1K mice. Increased expressions of inflammatory molecules, intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1, as well as increased macrophage infiltration, were detected in WT 1K, CBS+/- 2K and CBS+/- 1K mice. These changes were ameliorated with H(2)S supplementation. CONCLUSION Together, these results suggest that increased oxidative stress and decreased H(2)S in HHcy causes matrix remodeling and inflammation resulting in glomerulosclerosis and reduced renal function.
Collapse
Affiliation(s)
- Utpal Sen
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA. u0sen001 @ louisville.edu
| | | | | | | | | | | |
Collapse
|
23
|
Vacek TP, Gillespie W, Tyagi N, Vacek JC, Tyagi SC. Hydrogen sulfide protects against vascular remodeling from endothelial damage. Amino Acids 2010; 39:1161-9. [PMID: 20352463 DOI: 10.1007/s00726-010-0550-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 02/26/2010] [Indexed: 12/12/2022]
Abstract
Remodeling by its very nature implied synthesis and degradation of extracellular matrix (ECM) proteins. Although oxidative stress, matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) have been implicated in vascular remodeling, the differential role of MMPs versus TIMPs and oxidative stress in vascular remodeling was unclear. TIMP-3 induced vascular cell apoptosis, therefore, we hypothesized that during vascular injury TIMP-3, MMP-9 and -12 (elastin-degrading MMP) were increased, whereas MMP-2 (constitutive MMP) and TIMP-4 (cardioprotective TIMP) decreased. Because of the potent anti-oxidant, vasorelaxing, anti-hypertensive agent, hydrogen sulfide (H2S) was used to mitigate the vascular remodeling due to the differential expression of MMP and TIMP. Carotid artery injury was created by inserting a PE-10 catheter and rotating several times before pulling out. The insertion hole was sealed. Mice were grouped: wild type (WT), wild-type damaged artery (WTD), WT+NaHS (sodium hydrogen sulfide, precursor of H2S) treatment (30 µmol/L in drinking water/6 weeks) and WTD+NaHS treatment. Carotid arteries were analyzed for oxidative stress and remodeling, by measuring super oxide dismutase-1 (SOD1), p47 (NADPH oxidase subunit), nitrotyrosine, MMPs and TIMPs by in situ immunolabeling and by Western blot analyses. The results suggested robust increase in p47, nitrotyrosine, MMP-9, MMP-12, TIMP-3 and decrease in SOD1 and MMP-2 levels in the injured arteries. The treatment with H2S ameliorated these effects. We concluded that p47, TIMP-3, MMP-9 and -12 were increased where as SOD-1, MMP-2 and TIMP-4 were decreased in the injured arteries. The treatment with H2S mitigated the vascular remodeling by normalizing the levels of redox stress, MMPs and TIMPs.
Collapse
Affiliation(s)
- Thomas P Vacek
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | | | | | | | | |
Collapse
|
24
|
Tyagi N, Givvimani S, Qipshidze N, Kundu S, Kapoor S, Vacek JC, Tyagi SC. Hydrogen sulfide mitigates matrix metalloproteinase-9 activity and neurovascular permeability in hyperhomocysteinemic mice. Neurochem Int 2009; 56:301-7. [PMID: 19913585 DOI: 10.1016/j.neuint.2009.11.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Accepted: 11/03/2009] [Indexed: 11/26/2022]
Abstract
An elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), was associated with neurovascular diseases. At physiological levels, hydrogen sulfide (H(2)S) protected the neurovascular system. Because Hcy was also a precursor of hydrogen sulfide (H(2)S), we sought to test whether the H(2)S protected the brain during HHcy. Cystathionine-beta-synthase heterozygous (CBS+/-) and wild type (WT) mice were supplemented with or without NaHS (30 microM/L, H(2)S donor) in drinking water. Blood flow and cerebral microvascular permeability in pial vessels were measured by intravital microscopy in WT, WT+NaHS, CBS-/+ and (CBS-/+)+NaHS-treated mice. The brain tissues were analyzed for matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) by Western blot and RT-PCR. The mRNA levels of CBS and cystathionine gamma lyase (CSE, enzyme responsible for conversion of Hcy to H(2)S) genes were measured by RT-PCR. The results showed a significant increase in MMP-2, MMP-9, TIMP-3 protein and mRNA in CBS (-/+) mice, while H(2)S treatment mitigated this increase. Interstitial localization of MMPs was also apparent through immunohistochemistry. A decrease in protein and mRNA expression of TIMP-4 was observed in CBS (-/+) mice. Microscopy data revealed increase in permeability in CBS (-/+) mice. These effects were ameliorated by H(2)S and suggested that physiological levels of H(2)S supplementation may have therapeutic potential against HHcy-induced microvascular permeability, in part, by normalizing the MMP/TIMP ratio in the brain.
Collapse
Affiliation(s)
- Neetu Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY 40202, USA.
| | | | | | | | | | | | | |
Collapse
|
25
|
Aramwit P, Kanokpanont S, De-Eknamkul W, Kamei K, Srichana T. The effect of sericin with variable amino-acid content from different silk strains on the production of collagen and nitric oxide. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2009; 20:1295-306. [PMID: 19520013 DOI: 10.1163/156856209x453006] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Although silk sericin (SS) enhances the growth and attachment of fibroblast cells, its toxicity remains questionable. We investigated the effect of SS extracted by heat with variable amino-acid content on in vitro collagen promotion and nitric oxide synthesis. After 24 h of incubation, SS, especially from the Chul 1/1 strain which has the most methionine and cysteine content, enhanced fibroblast growth. The molecular mass of heat-extracted SS from these three strains showed a slightly different range, but within 20-200 kDa, which were all identified as sericin. SS from all strains promoted type-I collagen production in a concentration-dependent manner, while SS from Chul 1/1 strain could induce the highest amount of collagen synthesis when compared to SS from other strains. Nitric oxide was found in the culture medium after activation by SS from the Chul 1/1 strain but reached a level that was not toxic to the cells. We conclude that SS is not toxic to fibroblast cells. Moreover, methionine and cysteine content in SS are important factors to promote cell growth and collagen synthesis.
Collapse
Affiliation(s)
- Pornanong Aramwit
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand.
| | | | | | | | | |
Collapse
|
26
|
Sen U, Basu P, Abe OA, Givvimani S, Tyagi N, Metreveli N, Shah KS, Passmore JC, Tyagi SC. Hydrogen sulfide ameliorates hyperhomocysteinemia-associated chronic renal failure. Am J Physiol Renal Physiol 2009; 297:F410-9. [PMID: 19474193 DOI: 10.1152/ajprenal.00145.2009] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), is associated with end-stage renal diseases. Hcy metabolizes in the body to produce hydrogen sulfide (H(2)S), and studies have demonstrated a protective role of H(2)S in end-stage organ failure. However, the role of H(2)S in HHcy-associated renal diseases is unclear. The present study was aimed to determine the role of H(2)S in HHcy-associated renal damage. Cystathionine-beta-synthase heterozygous (CBS+/-) and wild-type (WT, C57BL/6J) mice with two kidney (2-K) were used in this study and supplemented with or without NaHS (30 micromol/l, H(2)S donor) in the drinking water. To expedite the HHcy-associated glomerular damage, uninephrectomized (1-K) CBS(+/-) and 1-K WT mice were also used with or without NaHS supplementation. Plasma Hcy levels were elevated in CBS(+/-) 2-K and 1-K and WT 1-K mice along with increased proteinuria, whereas, plasma levels of H(2)S were attenuated in these groups compared with WT 2-K mice. Interestingly, H(2)S supplementation increased plasma H(2)S level and normalized the urinary protein secretion in the similar groups of animals as above. Increased activity of matrix metalloproteinase (MMP)-2 and -9 and apoptotic cells were observed in the renal cortical tissues of CBS(+/-) 2-K and 1-K and WT 1-K mice; however, H(2)S prevented apoptotic cell death and normalized increased MMP activities. Increased expression of desmin and downregulation of nephrin in the cortical tissue of CBS(+/-) 2-K and 1-K and WT 1-K mice were ameliorated with H(2)S supplementation. Additionally, in the kidney tissues of CBS(+/-) 2-K and 1-K and WT 1-K mice, increased superoxide (O(2)(*-)) production and reduced glutathione (GSH)-to-oxidized glutathione (GSSG) ratio were normalized with exogenous H(2)S supplementation. These results demonstrate that HHcy-associated renal damage is related to decreased endogenous H(2)S generation in the body. Additionally, here we demonstrate with evidence that H(2)S supplementation prevents HHcy-associated renal damage, in part, through its antioxidant properties.
Collapse
Affiliation(s)
- Utpal Sen
- Dept. of Physiology & Biophysics, Univ. of Louisville School of Medicine, 500 S. Preston St., Louisville, KY 40202, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Sen U, Tyagi N, Patibandla PK, Dean WL, Tyagi SC, Roberts AM, Lominadze D. Fibrinogen-induced endothelin-1 production from endothelial cells. Am J Physiol Cell Physiol 2009; 296:C840-7. [PMID: 19193866 DOI: 10.1152/ajpcell.00515.2008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously demonstrated that fibrinogen (Fg) binding to the vascular endothelial intercellular adhesion molecule-1 (ICAM-1) leads to microvascular constriction in vivo and in vitro. Although a role of endothelin-1 (ET-1) in this Fg-induced vasoconstriction was suggested, the mechanism of action was not clear. In the current study, we tested the hypothesis that Fg-induced vasoconstriction results from ET-1 production by vascular endothelial cells (EC) and is mediated by activation of extracellular signal-regulated kinase -1/2 (ERK-1/2). Confluent, rat heart microvascular endothelial cells (RHMECs) were treated with one of the following: Fg (2 or 4 mg/ml), Fg (4 mg/ml) with ERK-1/2 kinase inhibitors (PD-98059 or U-0126), Fg (4 mg/ml) with an antibody against ICAM-1, or medium alone for 45 min. The amount of ET-1 formed and the concentration of released von Willebrand factor (vWF) in the cell culture medium were measured by ELISAs. Fg-induced exocytosis of Weibel-Palade bodies (WPBs) was assessed by immunocytochemistry. Phosphorylation of ERK-1/2 was detected by Western blot analysis. Fg caused a dose-dependent increase in ET-1 formation and release of vWF from the RHMECs. This Fg-induced increase in ET-1 production was inhibited by specific ERK-1/2 kinase inhibitors and by anti-ICAM-1 antibody. Immunocytochemical staining showed that an increase in Fg concentration enhanced exocytosis of WPBs in ECs. A specific endothelin type B receptor blocker, BQ-788, attenuated the enhanced phosphorylation of ERK-1/2 in ECs caused by increased Fg content in the culture medium. The presence of an endothelin converting enzyme inhibitor, SM-19712, slightly decreased Fg-induced phosphorylation of ERK-1/2, but inhibited production of Fg-induced ET-1 production. These results suggest that Fg-induced vasoconstriction may be mediated, in part, by activation of ERK-1/2 signaling and increased production of ET-1 that further increases EC ERK-1/2 signaling. Thus, an increased content of Fg may enhance vasoconstriction through increased production of ET-1.
Collapse
Affiliation(s)
- Utpal Sen
- Dept. of Physiology, Univ. of Louisville, School of Medicine, Bldg. A, Rm. 1115, 500 South Preston St., Louisville, KY 40202, USA
| | | | | | | | | | | | | |
Collapse
|
28
|
Tyagi N, Moshal KS, Sen U, Vacek TP, Kumar M, Hughes WM, Kundu S, Tyagi SC. H2S protects against methionine-induced oxidative stress in brain endothelial cells. Antioxid Redox Signal 2009; 11:25-33. [PMID: 18837652 PMCID: PMC2742910 DOI: 10.1089/ars.2008.2073] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Homocysteine (Hcy) causes cerebrovascular dysfunction by inducing oxidative stress. However, to date, there are no strategies to prevent Hcy-induced oxidative damage. Hcy is an H2S precursor formed from methionine (Met) metabolism. We aimed to investigate whether H2S ameliorated Met-induced oxidative stress in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to Met treatment in the presence or absence of NaHS (donor of H2S). Met-induced cell toxicity increased the levels of free radicals in a concentration-dependent manner. Met increased NADPH-oxidase-4 (NOX-4) expression and mitigated thioredxion-1(Trx-1) expression. Pretreatment of bEnd3 with NaHS (0.05 mM) attenuated the production of free radicals in the presence of Met and protected the cells from oxidative damage. Furthermore, NaHS enhanced inhibitory effects of apocynin, N-acetyl-l-cysteine (NAC), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), Nomega-nitro-l-arginine methyl ester (L-NAME) on ROS production and redox enzymes levels induced by Met. In conclusion, the administration of H2S protected the cells from oxidative stress induced by hyperhomocysteinemia (HHcy), which suggested that NaHS/H2S may have therapeutic potential against Met-induced oxidative stress.
Collapse
Affiliation(s)
- Neetu Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky 40202, USA.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
Elevated levels of homocysteine (Hcy) (known as hyperhomocysteinemia HHcy) are involved in dilated cardiomyopathy. Hcy chelates copper and impairs copper-dependent enzymes. Copper deficiency has been linked to cardiovascular disease. We tested the hypothesis that copper supplement regresses left ventricular hypertrophy (LVH), fibrosis and endothelial dysfunction in pressure overload DCM mice hearts. The mice were grouped as sham, sham + Cu, aortic constriction (AC), and AC + Cu. Aortic constriction was performed by transverse aortic constriction. The mice were treated with or without 20 mg/kg copper supplement in the diet for 12 weeks. The cardiac function was assessed by echocardiography and electrocardiography. The matrix remodeling was assessed by measuring matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinases (TIMPs), and lysyl oxidase (LOX) by Western blot analyses. The results suggest that in AC mice, cardiac function was improved with copper supplement. TIMP-1 levels decreased in AC and were normalized in AC + Cu. Although MMP-9, TIMP-3, and LOX activity increased in AC and returned to baseline value in AC + Cu, copper supplement showed no significant effect on TIMP-4 activity after pressure overload. In conclusion, our data suggest that copper supplement helps improve cardiac function in a pressure overload dilated cardiomyopathic heart.
Collapse
|
30
|
Sen U, Rodriguez WE, Tyagi N, Kumar M, Kundu S, Tyagi SC. Ciglitazone, a PPARgamma agonist, ameliorates diabetic nephropathy in part through homocysteine clearance. Am J Physiol Endocrinol Metab 2008; 295:E1205-12. [PMID: 18780770 PMCID: PMC2584817 DOI: 10.1152/ajpendo.90534.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 09/02/2008] [Indexed: 01/11/2023]
Abstract
Diabetes and hyperhomocysteinemia (HHcy) are two independent risk factors for glomeruloslerosis and renal insufficiency. Although PPARgamma agonists such as ciglitazone (CZ) are known to modulate diabetic nephropathy, the role of CZ in diabetes-associated HHcy and renopathy is incompletely defined. We tested the hypothesis that induction of PPARgamma by CZ decreases tissue Hcy level; this provides a protective role against diabetic nephropathy. C57BL/6J mice were administered alloxan to create diabetes. Mice were grouped to 0, 1, 10, 12, and 16 wk of treatment; only 12- and 16-wk animals received CZ in drinking water after a 10-wk alloxan treatment. In diabetes, PPARgamma cDNA, mRNA, and protein expression were repressed, whereas an increase in plasma and glomerular Hcy levels was observed. CZ normalized PPARgamma mRNA and protein expression and glomerular level of Hcy, whereas plasma level of Hcy remained unchanged. GFR was dramatically increased at 1-wk diabetic induction, followed by hypofiltration at 10 wk, and was normalized by CZ treatment. This result corroborated with glomerular and preglomerular arteriole histology. A steady-state increase of RVR in diabetic mice became normal with CZ treatment. CZ ameliorated decrease bioavailability of NO in the diabetic animal. Glomerular MMP-2 and MMP-9 activities as well as TIMP-1 expression were increased robustly in diabetic mice and normalized with CZ treatment. Interestingly, TIMP-4 expression was opposite to that of TIMP-1 in diabetic and CZ-treated groups. These results suggested that diabetic nephropathy exacerbated glomerular tissue level of Hcy, and this caused further deterioration of glomerulus. CZ, however, protected diabetic nephropathy in part by activating PPARgamma and clearing glomerular tissue Hcy.
Collapse
Affiliation(s)
- Utpal Sen
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40202, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Kumar M, Tyagi N, Moshal KS, Sen U, Kundu S, Mishra PK, Givvimani S, Tyagi SC. Homocysteine decreases blood flow to the brain due to vascular resistance in carotid artery. Neurochem Int 2008; 53:214-9. [PMID: 18725259 DOI: 10.1016/j.neuint.2008.07.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2008] [Revised: 07/24/2008] [Accepted: 07/25/2008] [Indexed: 02/02/2023]
Abstract
An elevated level of Homocysteine (Hcy) is a risk factor for vascular dementia and stroke. Cysthathionine beta Synthase (CBS) gene is involved in the clearance of Hcy. Homozygous individuals for (CBS-/-) die early, but heterozygous for (CBS-/+) survive with high levels of Hcy. The gamma-Amino Butyric Acid (GABA) presents in the central nervous system (CNS) and functions as an inhibitory neurotransmitter. Hcy competes with GABA at the GABA(A) receptor and affects the CNS function. We hypothesize that Hcy causes a decrease in blood flow to the brain due to increase in vascular resistance (VR) because of arterial remodeling in the carotid artery (CA). Blood pressure and blood flow in CA of wild type (WT), CBS-/+, CBS-/+ GABA(A)-/- double knockout, and GABA(A)-/- were measured. CA was stained with trichrome, and the brain permeability was measured. Matrix Metalloproteinases (MMP-2 and MMP-9), tissue inhibitor of metalloproteinase (TIMP-3, TIMP-4), elastin, and collagen-III expression were measured by real-time polymerase chain reaction (RT-PCR). Results showed an increase in VR in CBS-/+/GABA(A)-/-double knockout>CBS-/+/>GABA(A)-/- compared to WT mice. Increased MMP-2, MMP-9, collagen-III and TIMP-3 mRNA levels were found in GABA(A)-/-, CBS-/+, CBS-/+/GABA(A) double knockout compared to WT. The levels of TIMP-4 and elastin were decreased, whereas the levels of MMP-2, MMP-9 and TIMP-3 increased, which indirectly reflected the arterial resistance. These results suggested that Hcy caused arterial remodeling in part, by increase in collagen/elastin ratio thereby increasing VR leading to the decrease in CA blood flow.
Collapse
Affiliation(s)
- Munish Kumar
- Department of Physiology & Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Kumar M, Tyagi N, Moshal KS, Sen U, Pushpakumar SB, Vacek T, Lominadze D, Tyagi SC. GABAA receptor agonist mitigates homocysteine-induced cerebrovascular remodeling in knockout mice. Brain Res 2008; 1221:147-53. [PMID: 18547546 DOI: 10.1016/j.brainres.2008.04.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 04/03/2008] [Accepted: 04/06/2008] [Indexed: 11/15/2022]
Abstract
Individuals with homozygous deficiency in cystathionine-beta-synthase (CBS) develop high levels of homocysteine in plasma, a condition known as homocysteinuria. Mental retardation ensues with death in teens; the heterozygous live normally but develop vascular dementia and Alzheimer's disease (AD) in later part of life. The treatment with muscimol, a gamma amino butyric acid receptor-A (GABA(A)) agonist, mitigates the AD syndrome and vascular dementia. We tested the hypothesis that homocysteine (Hcy) antagonizes the GABA(A) receptor and behaves as an excitotoxic neurotransmitter that causes blood brain barrier (BBB) permeability and vascular dementia. The BBB permeability was measured by infusing Evan's blue dye (2% in saline 5 ml/kg concentration) in CBS-/+, GABA(A)-/-, CBS-/+/GABA(A)-/- double knockout, CBS-/+ mice treated with muscimol and wild type (WT) mice. Matrix Metalloproteinase (MMP-2, MMP-9), Tissue Inhibitor of Matrix Metalloproteinase (TIMP-3, TIMP-4), collagen-III and elastin levels were measured in whole brain by Western blot. These results suggested an increase in Evan's blue permeability: CBS-/+<GABA(A)-/-<CBS-/+/GABA(A)-/- compared to WT mice. Interestingly, in CBS-/+ mice treated with muscimol, BBB permeability was significantly decreased compared with the CBS-/+ group. There was a decrease in the TIMP-4 protein expression level, whereas the TIMP-3 level increased in CBS-/+, GABA(A)-/-, and CBS-/+/GABA(A)-/- mice compared to the WT. MMP-2 and MMP-9 expression significantly increased in all the groups compared to the wild type. The results suggested that Hcy caused cerebral interstitial remodeling in brain by distorting the extracellular matrix, thus increasing the blood brain permeability; treatment with muscimol mitigated BBB permeability.
Collapse
Affiliation(s)
- Munish Kumar
- Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA
| | | | | | | | | | | | | | | |
Collapse
|