Inhibition of Endothelial Growth by Homocysteine

Summary

Principal Investigator: Hong Wang
Affiliation: Temple University
Country: USA
Abstract: Hyperhomocysteinemia is an independent risk for cardiovascular disease. Most of the reported biological effects of homocysteine (Hcy) in vascular cells have been attributed to oxidative mechanisms, which were observed at Hcy concentrations higher than 1mM, and can be mimicked by cysteine, another non-pathogenic biothiol. Thus, a biochemical mechanism unique to Hcy remains to be identified. Our previous work has demonstrated that Hcy at 10-50 muM, but not cysteine, arrests endothelial cell (EC) p21/ras, suppress cyclin A transcription in cell type specific manner. The basic hypothesis of this proposed project is that Hcy, at growth through a hypomethylation related mechanism, which blocks cell cycle progression and endothelium regeneration. This project will study this hypothesis utilizing three linked specific aims. First, in Aim 1, experiments are designed to elucidate the role of Ras demethylation-independent Ras over-expression on EC growth, and on cyclin A expression and promoter activity. Cell growth will be determine by thymidine uptake, flow cytometry and cell counting. Cyclin A expression and promoter activity will be determined by Northern, Western blot analysis and reporter gene transfection. Alternatively, DNA microarray will be used to identify other potential targets in Hcy signaling. Second, in Aim 2, studies are proposed to determine the biochemical mechanisms by which Hcy suppress cyclin A transcription. Experiments will be performed to study the RB phosphorylation and E2F expression, and the role of E2F and other transcription factors on cyclin A transcription by Western blot, reporter gene transfection, gel mobility shift, adenovirus-transduced E2F expression. The role of cyclin A in maintaining RB phosphorylation will be assessed by RNA interference. The promoter methylation pattern of cyclin A genes will be examined by bisufite genomic sequence and methylation sensitive restriction enzyme digestion. Finally, in Aim 3, a mouse endothelial denudation and regeneration model will be used in cystathionine beta-synthase (CBS) knockout and diet-induced hyperhomocysteinemic mice to assess the effect of Hcy in endothelial regeneration. Mouse blood will e examined for the concentrations of Hcy and SAH/SAM. Immunohistochemistry staining for leukocytes, macrophages, EC and smooth muscle cells will be performed on vessel sections to analyze the cellular composition of the lesion. In situ hybridization of immunohistochemistry staining for cyclin A will be performed to assess its involvement. The broad, long-term objective of this proposal i to elucidate Hcy signaling in EC growth inhibition, and to evaluate its importance on the role of atherogenesis in hyperhomocysteinemia. If we identify the key events in Hcy-induced arteriosclerosis, genetic or biochemical approaches to block these steps could lead to therapeutic advantage.
Funding Period: 2002-04-05 - 2008-03-31
more information: NIH RePORT

Top Publications

  1. pmc An evolving new paradigm: endothelial cells--conditional innate immune cells
    Jietang Mai
    Center of Metabolic Disease Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    J Hematol Oncol 6:61. 2013
  2. pmc Severe hyperhomocysteinemia promotes bone marrow-derived and resident inflammatory monocyte differentiation and atherosclerosis in LDLr/CBS-deficient mice
    Daqing Zhang
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Circ Res 111:37-49. 2012
  3. pmc Endothelial progenitor cells in atherosclerosis
    Fuyong Du
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 17:2327-49. 2012
  4. pmc MicroRNAs and toll-like receptor/interleukin-1 receptor signaling
    Anthony Virtue
    Cardiovascular Research Center and Department of Pharmacology, Temple University School of Medicine, 3500 North Broad Street, MERB 1059, Philadelphia, PA 19140, USA
    J Hematol Oncol 5:66. 2012
  5. pmc Inflammasomes: sensors of metabolic stresses for vascular inflammation
    Ying Yin
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, 3500 North Broad Street, MERB 1059, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 18:638-49. 2013
  6. pmc Homocysteine induces inflammatory transcriptional signaling in monocytes
    Shu Meng
    Department of Pharmacology, Temple University School of Medicine, 3500 North Broad Street, 10th Floor, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 18:685-95. 2013
  7. pmc Targeting mitochondrial reactive oxygen species as novel therapy for inflammatory diseases and cancers
    Xinyuan Li
    Cardiovascular Research Center, Department of Pharmacology and Thrombosis Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA
    J Hematol Oncol 6:19. 2013
  8. pmc Identification of novel pretranslational regulatory mechanisms for NF-κB activation
    Xiao Huang
    Cardiovascular Research Center, Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
    J Biol Chem 288:15628-40. 2013
  9. pmc IL-35 is a novel responsive anti-inflammatory cytokine--a new system of categorizing anti-inflammatory cytokines
    Xinyuan Li
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
    PLoS ONE 7:e33628. 2012
  10. pmc MicroRNAs and other mechanisms regulate interleukin-17 cytokines and receptors
    Jietang Mai
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Elite Ed) 4:1478-95. 2012

Scientific Experts

  • Hieronim Jakubowski
  • Xiao Feng Yang
  • Eugen Brailoiu
  • Hong Wang
  • Xiaohua Jiang
  • Jietang Mai
  • Anthony Virtue
  • Xinyuan Li
  • William Durante
  • Ying Yin
  • Andrew I Schafer
  • Fan Yang
  • Xiao Huang
  • Shu Meng
  • Daqing Zhang
  • Ren Gong
  • Tran Tran
  • Pu Fang
  • Meghana Pansuria
  • Jerry Shen
  • Hongmei Tan
  • Dan Liao
  • Warren D Kruger
  • Eric T Choi
  • Muniswamy Madesh
  • Fuyong Du
  • Karthik Mallilankaraman
  • Zhongjian Cheng
  • Erin Maley
  • Natalie C Chen
  • Michael Jan
  • Sapna Gupta
  • M D S Jamaluddin
  • Zhaohui Li
  • D A Tulis
  • Juan F Granada
  • Anh H Tran
  • Irene H Yang
  • Jahaira Lopez Pastrana
  • Stephen Ciment
  • Ramon Cueto
  • Hung Pham
  • Jodene K Moore
  • Andrew Frisch
  • Jun Nelson
  • Imani Hodge
  • Stefanie Gutchigian
  • Steven R Houser
  • Remus M Berretta
  • Xiaojin Sha
  • Jun Zhou
  • Domenico Pratico
  • Louis M Capecci
  • Xinyu Xiong
  • Ziyu Gu
  • Najam Us Saqib
  • Jingshan Liu
  • Yan Yan
  • Jian Song
  • Xiaoming Liu
  • Irene Chen
  • Nae J Dun
  • Lawrence Chan
  • Rutai Hui
  • Henry J Pownall
  • John Gaubatz
  • Mark J Magera
  • JoAnn Trial
  • H Wang
  • Amit N Keswani
  • Rolando E Rumbaut
  • W Durante
  • Mohammed A Azam
  • Jaspreet K Randhawa
  • Grzegorz L Kaluza
  • A I Schafer
  • K J Peyton
  • Kelly J Peyton
  • Diana Ensenat
  • Albert E Raizner
  • Xiao ming Liu
  • Robert M Bryan
  • A N Keswani

Detail Information

Publications26

  1. pmc An evolving new paradigm: endothelial cells--conditional innate immune cells
    Jietang Mai
    Center of Metabolic Disease Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    J Hematol Oncol 6:61. 2013
    ..Based on these novel EC functions, we propose a new paradigm that ECs are conditional innate immune cells. This paradigm provides a novel insight into the functions of ECs in inflammatory/immune pathologies. ..
  2. pmc Severe hyperhomocysteinemia promotes bone marrow-derived and resident inflammatory monocyte differentiation and atherosclerosis in LDLr/CBS-deficient mice
    Daqing Zhang
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Circ Res 111:37-49. 2012
    ..However, its causative role in atherosclerosis is not well established and its effect on vascular inflammation has not been studied. The underlying mechanism is unknown...
  3. pmc Endothelial progenitor cells in atherosclerosis
    Fuyong Du
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 17:2327-49. 2012
    ....
  4. pmc MicroRNAs and toll-like receptor/interleukin-1 receptor signaling
    Anthony Virtue
    Cardiovascular Research Center and Department of Pharmacology, Temple University School of Medicine, 3500 North Broad Street, MERB 1059, Philadelphia, PA 19140, USA
    J Hematol Oncol 5:66. 2012
    ..In addition, we will discuss the modulation of miRNAs' expression by TLR and IL-1R signaling through positive and negative feedback loops...
  5. pmc Inflammasomes: sensors of metabolic stresses for vascular inflammation
    Ying Yin
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, 3500 North Broad Street, MERB 1059, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 18:638-49. 2013
    ....
  6. pmc Homocysteine induces inflammatory transcriptional signaling in monocytes
    Shu Meng
    Department of Pharmacology, Temple University School of Medicine, 3500 North Broad Street, 10th Floor, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 18:685-95. 2013
    ..We conclude that Hcy is a pro-inflammatory amino acid and induces inflammatory transcriptional signal pathways mediated by class 1 TF. We term class 1 TF as putative Hcy-responsive TFs...
  7. pmc Targeting mitochondrial reactive oxygen species as novel therapy for inflammatory diseases and cancers
    Xinyuan Li
    Cardiovascular Research Center, Department of Pharmacology and Thrombosis Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA
    J Hematol Oncol 6:19. 2013
    ..Thorough understanding of this topic and the application of mtROS-targeting drugs in the research is significant towards development of better therapies to combat inflammatory diseases and inflammatory malignancies...
  8. pmc Identification of novel pretranslational regulatory mechanisms for NF-κB activation
    Xiao Huang
    Cardiovascular Research Center, Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
    J Biol Chem 288:15628-40. 2013
    ..Our findings provide important insight into the mechanism of NF-κB activation, which may contribute to cardiovascular disease, inflammatory diseases, and immunological disorders...
  9. pmc IL-35 is a novel responsive anti-inflammatory cytokine--a new system of categorizing anti-inflammatory cytokines
    Xinyuan Li
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
    PLoS ONE 7:e33628. 2012
    ..Our in-depth analyses of molecular events that regulate the production of IL-35 as well as the new categorization system of anti-inflammatory cytokines are important for the design of new strategies of immune therapies...
  10. pmc MicroRNAs and other mechanisms regulate interleukin-17 cytokines and receptors
    Jietang Mai
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Elite Ed) 4:1478-95. 2012
    ..These results provide an insight into the roles of IL-17 in mediating inflammation and immunity...
  11. pmc Hyperhomocysteinemia impairs endothelium-derived hyperpolarizing factor-mediated vasorelaxation in transgenic cystathionine beta synthase-deficient mice
    Zhongjian Cheng
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Blood 118:1998-2006. 2011
    ..Our results suggest that HHcy impairs EDHF relaxation in SMAs by inhibiting SK/IK activities via oxidation- and tyrosine nitration-related mechanisms...
  12. pmc Structural evidence of anti-atherogenic microRNAs
    Anthony Virtue
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 16:3133-45. 2011
    ..These results indicate a critical role of anti-inflammatory microRNAs in suppressing pro-atherogenic inflammatory gene expression...
  13. pmc Th 17 cells interplay with Foxp3+ Tregs in regulation of inflammation and autoimmunity
    Jietang Mai
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Front Biosci (Landmark Ed) 15:986-1006. 2010
    ....
  14. pmc Regulation of homocysteine metabolism and methylation in human and mouse tissues
    Natalie C Chen
    Department of Pharmacology, Temple University School of Medicine, 3420 North Broad St, MRB, Philadelphia, PA 19140, USA
    FASEB J 24:2804-17. 2010
    ..Our study is the first to provide panoramic tissue gene expression profiles and mathematical models of tissue methylation regulation...
  15. pmc Caspase-1 recognizes extended cleavage sites in its natural substrates
    Jerry Shen
    Department of Pharmacology, Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, United States
    Atherosclerosis 210:422-9. 2010
    ..We attempted to solve this problem...
  16. pmc Genetic or nutritional disorders in homocysteine or folate metabolism increase protein N-homocysteinylation in mice
    Hieronim Jakubowski
    Department of Microbiology and Molecular Genetics, UMDNJ New Jersey Medical School, International Center for Public Health, 225 Warren St, Newark, NJ 07101 1709, USA
    FASEB J 23:1721-7. 2009
    ..These findings provide evidence that N-Hcy-protein is an important metabolite associated with Hcy pathophysiology in the mouse...
  17. ncbi Hyperhomocystinemia impairs endothelial function and eNOS activity via PKC activation
    Xiaohua Jiang
    Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
    Arterioscler Thromb Vasc Biol 25:2515-21. 2005
    ..A risk factor for cardiovascular disease, hyperhomocystinemia (HHcy), is associated with endothelial dysfunction. In this study, we examined the mechanistic role of HHcy in endothelial dysfunction...
  18. ncbi Hyperhomocysteinemia inhibits post-injury reendothelialization in mice
    Hongmei Tan
    Department of Medicine, Baylor College of Medicine, USA
    Cardiovasc Res 69:253-62. 2006
    ..In this study, we established a mouse model of endothelial injury and reendothelialization and examined the role and mechanism of HHcy in endothelial repair...
  19. pmc Local administration of carbon monoxide inhibits neointima formation in balloon injured rat carotid arteries
    D A Tulis
    Cardiovascular Disease Research Program, J L Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina 27707, USA
    Cell Mol Biol (Noisy-le-grand) 51:441-6. 2005
    ....
  20. ncbi Hyperhomocysteinemia decreases circulating high-density lipoprotein by inhibiting apolipoprotein A-I Protein synthesis and enhancing HDL cholesterol clearance
    Dan Liao
    Department of Medicine, Baylor College of Medicine, Houston, TX, USA
    Circ Res 99:598-606. 2006
    ..These findings indicate that HHcy inhibits reverse cholesterol transport by reducing circulating HDL via inhibiting apoA-I protein synthesis and enhancing HDL-C clearance...
  21. pmc Homocysteine inhibits endothelial cell growth via DNA hypomethylation of the cyclin A gene
    M D S Jamaluddin
    Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Blood 110:3648-55. 2007
    ..In conclusion, Hcy inhibits cyclin A transcription and cell growth by inhibiting DNA methylation through suppression of DNMT1 in ECs...
  22. ncbi Differential regulation of homocysteine transport in vascular endothelial and smooth muscle cells
    Xiaohua Jiang
    Temple University School of Medicine, Department of Pharmacology, 3420 North Broad Street, Philadelphia, PA 19140, USA
    Arterioscler Thromb Vasc Biol 27:1976-83. 2007
    ..This study characterized and directly compared Hcy transport in cultured human aortic ECs (HAECs) and smooth muscle cells (HASMCs)...
  23. pmc State-dependent calcium mobilization by urotensin-II in cultured human endothelial cells
    Eugen Brailoiu
    Department of Pharmacology, 3420 N Broad Street, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Peptides 29:721-6. 2008
    ..The result demonstrates a state-dependent effect of U-II in cultured HAEC, which may explain the variable responses to U-II under different experimental conditions...
  24. pmc Hyperhomocysteinemia promotes inflammatory monocyte generation and accelerates atherosclerosis in transgenic cystathionine beta-synthase-deficient mice
    Daqing Zhang
    Department of Pharmacology and Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
    Circulation 120:1893-902. 2009
    ..Monocytes display inflammatory and resident subsets and commit to specific functions in atherogenesis. In this study, we examined the hypothesis that HHcy modulates monocyte heterogeneity and leads to atherosclerosis...
  25. ncbi Single perivascular delivery of mitomycin C stimulates p21 expression and inhibits neointima formation in rat arteries
    Juan F Granada
    The Methodist Research Institute, Houston, Texas, USA
    Arterioscler Thromb Vasc Biol 25:2343-8. 2005
    ....