1
|
Zhang L, Xu R, Ma X, Zhang X, Gong J, Li Z. Mechanism of arterial injury exacerbated by hyperhomocysteinemia in spontaneously hypertensive rats. Sci Rep 2023; 13:2482. [PMID: 36774389 PMCID: PMC9922276 DOI: 10.1038/s41598-023-28731-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 01/24/2023] [Indexed: 02/13/2023] Open
Abstract
Hypertension associated with hyperhomocysteinemia (HHcy) accounts for 75% of hypertension in China. HHcy plays a synergistic role with hypertension in vascular injury and significantly increases the incidence of cardiovascular and cerebrovascular diseases. The present study aimed to explore the molecular mechanism of HHcy-induced arterial injury in hypertension. Spontaneously hypertensive rats (SHR) were injected intraperitoneally with DL-homocysteine (Hcy) to construct the model of hypertension associated with HHcy (HHcy + SHR). Biological network was employed to identify the material basis of arterial injury in hypertension associated with HHcy. The prediction molecules in oxidative stress and inflammation pathways were experimentally verified by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) analysis. The HHcy + SHR group significantly increased oxidative stress pathway molecules: nicotinamide adenine dinucleotide phosphate oxidase (Nox); inflammatory pathway molecules: vascular adhesion protein-1 (VAP-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a); as well as inflammatory pathway regulatory factors: nuclear factor-κ-gene binding (NF-κB) p65 and protein kinase B (Akt1). Among them, IL-6 was also significantly increased in the HHcy group. Both oxidative stress and inflammation contributed to the arterial injury of hypertension associated with HHcy, and inflammation mechanism might play a leading role in HHcy aggravating arterial injury, at least partially through the Akt1/NF-κB p65/IL-6 signaling pathway.
Collapse
Affiliation(s)
- Lihua Zhang
- Department of Medicine, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Rui Xu
- Department of Cardiology, Central Hospital Affiliated to Shandong First Medical University, Jinan, 250013, Shandong, People's Republic of China.
| | - Xiaoshan Ma
- Department of Medicine, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Xia Zhang
- Laboratory Department, Jinan Maternity and Child Care Hospital, Jinan, China
| | - Jun Gong
- Department of Women Healthcare, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Zhongliang Li
- Department of Women Healthcare, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, China
| |
Collapse
|
2
|
Farrugia A, Mori F. Therapeutic solutions of human albumin - The possible effect of process-induced molecular alterations on clinical efficacy and safety. J Pharm Sci 2022; 111:1292-1308. [PMID: 35276228 DOI: 10.1016/j.xphs.2022.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 12/14/2022]
Abstract
Human albumin solutions were developed as therapeutic during the Second World War to address blood loss due to battlefield injury. This indication was based on the recognition that albumin provided most of the oncotic capacity of human plasma. For the succeeding sixty years, this formed the basis for the use of albumin in traumatology and emergency medicine. In more recent times, the pharmacological properties arising from albumin's complex structure have become a focus of attention by clinical researchers. In particular, albumin, through anti-inflammatory and anti-oxidant properties, has been proposed as an agent for the treatment of sepsis, cirrhosis and other inflammatory states. Some evidence for these indications has accrued from a number of small clinical trials and observational studies. These studies have not been confirmed in other large trials. Together with other investigators, we have shown that the process of plasma fractionation results in alterations in the structure of albumin, including those parts of the molecule involved in anti-oxidant and anti-inflammatory effects. Albumin products from diverse manufacturers show heterogeneity in their ability to address these effects. In this article, we review the historical development of albumin solutions, pointing out the variations in fractionation chemistries which different manufacturers have adopted. We suggest ways by which the manufacturing processes have contributed to variations in the physico-chemical properties of molecule. We review the outcomes of clinical studies assessing the role of albumin in ameliorating conditions such as sepsis and cirrhosis, and we speculate as to the extent which heterogeneity in the products may have contributed to variable clinical outcomes. Finally, we argue for a change in the perception of the plasma product industry and its regulatory overseers. Historically, albumin has been viewed as a generic commodity, with different preparations being interchangeable in their clinical application. We suggest that this implied biosimilarity is not necessarily applicable for different albumin solutions. The use of albumin, in indications other than its historical role as a plasma expander, can only be validated by clinical investigation of each separate albumin product.
Collapse
Affiliation(s)
- Albert Farrugia
- Faculty of Health and Medical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Perth, Australia.
| | - Filippo Mori
- Kedrion S.p.A., Research and Innovation Department, Via di Fondovalle, Loc., Bolognana 55027, Gallicano (LU), Italy
| |
Collapse
|
3
|
Włoczkowska O, Perła-Kaján J, Smith AD, de Jager C, Refsum H, Jakubowski H. Anti- N-homocysteine-protein autoantibodies are associated with impaired cognition. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2021; 7:e12159. [PMID: 33816764 PMCID: PMC8010366 DOI: 10.1002/trc2.12159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/07/2021] [Accepted: 02/05/2021] [Indexed: 01/31/2023]
Abstract
Introduction Elevated homocysteine (Hcy) and related metabolites accelerate Alzheimer's disease. Hcy-lowering B vitamins slow brain atrophy/cognitive decline in mild cognitive impairment (MCI). Modification with Hcy-thiolactone generates auto-immunogenic N-Hcy-protein. We tested a hypothesis that anti-N-Hcy-protein autoantibodies predict cognition in individuals with MCI participating in a randomized, double-blind, placebo-controlled VITACOG trial of B vitamins. Methods Participants with MCI (n = 196, 76.8 years old, 60% women) were randomly assigned to receive a daily dose of folic acid (0.8 mg), vitamin B12 (0.5 mg), and B6 (20 mg) (n = 98) or placebo (n = 98) for 2 years. Cognition was analyzed by neuropsychological tests. Brain atrophy was quantified in a subset of patients (n = 167) by magnetic resonance imaging. Anti N-Hcy-protein auto-antibodies were quantified by enzyme-linked immunosorbent assay. Associations among anti-N-Hcy-protein autoantibodies, cognition, and brain atrophy were examined by multiple regression analysis. Results At baseline, anti-N-Hcy-protein autoantibodies were significantly associated with impaired global cognition (Mini-Mental State Examination [MMSE]), episodic memory (Hopkins Verbal Learning Test-revised), and attention/processing speed (Map Search). At the end of the study, anti-N-Hcy-protein autoantibodies were associated with impaired global cognition (MMSE) and attention/processing speed (Trail Making A). In the placebo group, baseline anti-N-Hcy-protein autoantibodies predicted, independently of Hcy, global cognition (Telephone Inventory for Cognitive Status modified [TICS-m]; MMSE) and attention/processing speed (Trail Making A) but not brain atrophy, at the end of study. B-vitamin treatment abrogated association of anti-N-Hcy-protein autoantibodies with cognition. Discussion These findings suggest that anti-N-Hcy-protein autoantibodies can impair functional (attention/processing speed and global cognition), but not structural (brain atrophy), aspects of cognition. Anti-N-Hcy-protein autoantibodies are a new factor associated with impaired cognition, which could be ameliorated by B vitamins.
Collapse
Affiliation(s)
- Olga Włoczkowska
- Department of Biochemistry and Biotechnology Poznań University of Life Sciences Poznań Poland
| | - Joanna Perła-Kaján
- Department of Biochemistry and Biotechnology Poznań University of Life Sciences Poznań Poland
| | - A David Smith
- OPTIMA Department of Pharmacology University of Oxford Oxford UK
| | - Celeste de Jager
- OPTIMA Department of Pharmacology University of Oxford Oxford UK
| | - Helga Refsum
- Department of Nutrition Institute of Basic Medical Sciences University of Oslo Oslo Norway
| | - Hieronim Jakubowski
- Department of Biochemistry and Biotechnology Poznań University of Life Sciences Poznań Poland.,Department of Microbiology Biochemistry and Molecular Genetics New Jersey Medical School International Center for Public Health Rutgers University Newark New Jersey USA
| |
Collapse
|
4
|
Immune Dysfunction and Albumin-Related Immunity in Liver Cirrhosis. Mediators Inflamm 2019; 2019:7537649. [PMID: 30930689 PMCID: PMC6410448 DOI: 10.1155/2019/7537649] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/15/2019] [Accepted: 01/26/2019] [Indexed: 02/07/2023] Open
Abstract
Liver cirrhosis yearly causes 1.2 million deaths worldwide, ranking as the 10th leading cause of death in the most developed countries. High susceptibility to infections along with a significant risk for infection-related mortality justifies the description of liver cirrhosis as the world's most common immunodeficiency syndrome. Liver cirrhosis is an end-stage organic disease hallmarked by a multifaceted immune dysfunction due to deterioration of antimicrobial recognition and elimination mechanisms in macrophages along with an impaired antigen presentation ability in circulating monocytes. Bacterial translocation supports—and is supported by—uncontrolled activation of immune cell responses and/or loss of toll-like receptor (TLR) tolerance, which can turn exaggerated inflammatory responses to systemic inflammation. Lipopolysaccharide (LPS) or endotoxin boosts systemic inflammatory activity through activation of TLR-2- and TLR-4-dependent pathways and facilitate a massive production of cytokines. This, in turn, results into elevated secretion of reactive oxygen species (ROS), which further enhances intestinal hyperpermeability and thus sustains a vicious circle of events widely known as “leaky gut.” Albumin can be of particular benefit in cirrhotic patients with spontaneous bacterial peritonitis and/or hepatorenal syndrome type of acute kidney injury (HRS-AKI) due to anti-inflammatory and antioxidative stress as well as volume-expanding properties and endothelial-stabilizing attributes. However, presence of autoantibodies against albumin in patients with liver cirrhosis has been described. Although previous research suggested that these antibodies should be regarded as naturally occurring antibodies (NOA), the origin of the antialbumin immune response is obscure. High occurrence of NAO/albumin complexes in patients with liver disease might reflect a limited clearance capacity due to bypassing portal circulation. Moreover, high burden of oxidized albumin is associated with less favorable outcome in patients with liver cirrhosis. To date, there is no data available as to whether oxidized forms of albumin result in neoepitopes recognized by the immune system. Nevertheless, it is reasonable to hypothesize that these alterations may have the potential to induce antialbumin immune responses and thus favor systemic inflammation.
Collapse
|
5
|
Jakubowski H. Homocysteine Modification in Protein Structure/Function and Human Disease. Physiol Rev 2019; 99:555-604. [PMID: 30427275 DOI: 10.1152/physrev.00003.2018] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B12, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health , Newark, New Jersey ; and Department of Biochemistry and Biotechnology, Poznań University of Life Sciences , Poznań , Poland
| |
Collapse
|
6
|
Borowczyk K, Piechocka J, Głowacki R, Dhar I, Midtun Ø, Tell GS, Ueland PM, Nygård O, Jakubowski H. Urinary excretion of homocysteine thiolactone and the risk of acute myocardial infarction in coronary artery disease patients: the WENBIT trial. J Intern Med 2019; 285:232-244. [PMID: 30193001 PMCID: PMC6378604 DOI: 10.1111/joim.12834] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES No individual homocysteine (Hcy) metabolite has been studied as a risk marker for coronary artery disease (CAD). Our objective was to examine Hcy-thiolactone, a chemically reactive metabolite generated by methionyl-tRNA synthetase and cleared by the kidney, as a risk predictor of incident acute myocardial infarction (AMI) in the Western Norway B-Vitamin Intervention Trial. DESIGN Single centre, prospective double-blind clinical intervention study, randomized in a 2 × 2 factorial design. SUBJECTS AND METHODS Patients with suspected CAD (n = 2049, 69.8% men; 61.2-year-old) were randomized to groups receiving daily (i) folic acid (0.8 mg)/vitamin B12 (0.4 mg)/vitamin B6 (40 mg); (ii) folic acid/vitamin B12 ; (iii) vitamin B6 or (iv) placebo. Urinary Hcy-thiolactone was quantified at baseline, 12 and 38 months. RESULTS Baseline urinary Hcy-thiolactone/creatinine was significantly associated with plasma tHcy, ApoA1, glomerular filtration rate, potassium and pyridoxal 5'-phosphate (positively) and with age, hypertension, smoking, urinary creatinine, plasma bilirubin and kynurenine (negatively). During median 4.7-years, 183 patients (8.9%) suffered an AMI. In Cox regression analysis, Hcy-thiolactone/creatinine was associated with AMI risk (hazard ratio = 1.58, 95% confidence interval = 1.10-2.26, P = 0.012 for trend; adjusted for age, gender, tHcy). This association was confined to patients with pyridoxic acid below median (adjusted HR = 2.72, 95% CI = 1.47-5.03, P = 0.0001; Pinteraction = 0.020). B-vitamin/folate treatments did not affect Hcy-thiolactone/creatinine and its AMI risk association. CONCLUSIONS Hcy-thiolactone/creatinine ratio is a novel AMI risk predictor in patients with suspected CAD, independent of traditional risk factors and tHcy, but modified by vitamin B6 catabolism. These findings lend a support to the hypothesis that Hcy-thiolactone is mechanistically involved in cardiovascular disease.
Collapse
Affiliation(s)
- K Borowczyk
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health, Newark, NJ, USA.,Department of Environmental Chemistry, Faculty of Chemistry, University of Łódź, Łódź, Poland
| | - J Piechocka
- Department of Environmental Chemistry, Faculty of Chemistry, University of Łódź, Łódź, Poland
| | - R Głowacki
- Department of Environmental Chemistry, Faculty of Chemistry, University of Łódź, Łódź, Poland
| | - I Dhar
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - G S Tell
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway
| | - P M Ueland
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - O Nygård
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Institute of Medicine, University of Bergen, Bergen, Norway
| | - H Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health, Newark, NJ, USA.,Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
| |
Collapse
|
7
|
Xuan C, Li H, Li LL, Tian QW, Wang Q, Zhang BB, Guo JJ, He GW, Lun LM. Screening and Identification of Pregnancy Zone Protein and Leucine-Rich Alpha-2-Glycoprotein as Potential Serum Biomarkers for Early-Onset Myocardial Infarction using Protein Profile Analysis. Proteomics Clin Appl 2018; 13:e1800079. [PMID: 30411527 DOI: 10.1002/prca.201800079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 10/19/2018] [Indexed: 12/29/2022]
Abstract
PURPOSE The present study aims to discover novel serum biomarkers of early-onset myocardial infarction (MI) using proteomic analysis. EXPERIMENTAL DESIGN In the first stage, the iTRAQ-coupled LC-MS/MS technique is utilized to investigate protein profiles of patients with early-onset MI. In the second stage, these candidate proteins are validated using ELISA. RESULTS A total of 538 proteins are quantified, with pregnancy zone protein (PZP), leucine-rich α-2-glycoprotein (LRG) and Apolipoprotein C-I (Apo C-I) being upregulated and Apolipoprotein A-I (Apo A-I) and Apolipoprotein A-IV (Apo A-IV) downregulated in early-onset MI patients. Results from the validation stage demonstrate that the serum concentrations of PZP and LRG are significantly increased in the early-onset MI group. The correlation between the concentrations of C-reactive protein (CRP) and the two candidate biomarkers is positive. Area under the curve values used to diagnose early-onset MI for LRG and PZP are 0.939 and 0.874, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Five differential serum proteins are identified in early-onset MI using proteomic analysis. Lipoprotein-related biomarkers further demonstrate the close relationship between lipid metabolism and the disease. Inflammation-associated LRG and PZP may be novel biomarkers of the disease. In addition, changes in these proteins may partly reveal the possible mechanisms in the pathogenesis and pathophysiology of early-onset MI.
Collapse
Affiliation(s)
- Chao Xuan
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hui Li
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Le-Le Li
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qing-Wu Tian
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qing Wang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Bei-Bei Zhang
- Department of Molecular Microbiology, Oslo University Hospital, Oslo, Norway
| | - Jun-Jie Guo
- Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Guo-Wei He
- Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital,, Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.,Department of Surgery, Oregon Health and Science University, Portland, Oregon
| | - Li-Min Lun
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| |
Collapse
|
8
|
Mei XY, He XD, Huang L, Qi DS, Nie J, Li Y, Si W, Zhao SM. Dehomocysteinylation is catalysed by the sirtuin-2-like bacterial lysine deacetylase CobB. FEBS J 2016; 283:4149-4162. [PMID: 27696686 DOI: 10.1111/febs.13912] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/04/2016] [Accepted: 09/28/2016] [Indexed: 01/15/2023]
Abstract
Hyperhomocysteinemia, which is characterized by elevated blood levels of the non-protein amino acid homocysteine (Hcy), is an independent risk factor for many diseases, including cardiovascular diseases, neurodegenerative diseases and birth defects. The incorporation of homocysteine into proteins, known as protein N-homocysteinylation, has been considered a major mechanism that contributes to hyperhomocysteinemia. However, the process of dehomocysteinylation, the N-homocysteinylation substrates and the regulatory enzyme(s) remain largely unknown. In this study, we observed that the dehomocysteinylation reaction is a spontaneous process that can be inhibited by blocking -SH groups, which have been demonstrated to be critical for non-enzymatic dehomocysteinylation reactions. We also report that CobB, a known Sir2-like bacterial lysine deacetylase, catalyzes lysine dehomocysteinylation reactions both in vitro and in vivo. Our work provides insight into how this non-enzymatic modification might be removed from affected proteins, supplies potential targets for developing identification methods for N-homocysteine proteins, and identifies CobB as the first prokaryotic dehomocysteinylation enzyme.
Collapse
Affiliation(s)
- Xin-Yu Mei
- School of Life Sciences, Fudan University, Shanghai, China.,Interdisciplinary Center on Biology and Chemistry and Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
| | - Xia-Di He
- School of Life Sciences, Fudan University, Shanghai, China
| | - Lei Huang
- School of Life Sciences, Fudan University, Shanghai, China
| | - Da-Shi Qi
- Department of Genetics, Xuzhou Medical University, Jiangsu, China
| | - Ji Nie
- School of Life Sciences, Fudan University, Shanghai, China
| | - Yang Li
- School of Life Sciences, Fudan University, Shanghai, China
| | - Wen Si
- Qingdao University of Science and Technology, College of Chemistry and Molecular Engineering, China
| | - Shi-Min Zhao
- School of Life Sciences, Fudan University, Shanghai, China
| |
Collapse
|
9
|
Perła-Kajan J, Utyro O, Rusek M, Malinowska A, Sitkiewicz E, Jakubowski H. N-Homocysteinylation impairs collagen cross-linking in cystathionine β-synthase-deficient mice: a novel mechanism of connective tissue abnormalities. FASEB J 2016; 30:3810-3821. [PMID: 27530978 DOI: 10.1096/fj.201600539] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/27/2016] [Indexed: 02/04/2023]
Abstract
Cystathionine β-synthase (CBS) deficiency, a genetic disorder in homocysteine (Hcy) metabolism in humans, elevates plasma Hcy-thiolactone and leads to connective tissue abnormalities that affect the cardiovascular and skeletal systems. However, the underlying mechanism of these abnormalities is not understood. Hcy-thiolactone has the ability to form isopeptide bonds with protein lysine residues, which generates N-homocysteinylated protein. Because lysine residues are involved in collagen cross-linking, N-homocysteinylation of these lysines should impair cross-linking. Using a Tg-I278T Cbs-/- mouse model of hyperhomocysteinemia (HHcy) which replicates the connective tissue abnormalities observed in CBS-deficient patients, we found that N-Hcy-collagen was elevated in bone, tail, and heart of Cbs-/- mice, whereas pyridinoline cross-links were significantly reduced. Plasma deoxypyridinoline cross-link and cross-linked carboxyterminal telopeptide of type I collagen were also significantly reduced in the Cbs-/- mice. Lysine oxidase activity and mRNA level were not reduced by the Cbs-/- genotype. We also showed that collagen carries S-linked Hcy bound to the thiol of N-linked Hcy. In vitro experiments showed that Hcy-thiolactone modifies lysine residues in collagen type I α-1 chain. Residue K160, located in the nonhelical N-telopeptide region and involved in pyridinoline cross-link formation, was also N-homocysteinylated in vivo Taken together, our findings showed that N-homocysteinylation of collagen in Cbs-/- mice impairs its cross-linking. These findings explain, at least in part, connective tissue abnormalities observed in HHcy.-Perła-Kajan, J., Utyro, O., Rusek, M., Malinowska, A., Sitkiewicz, E., Jakubowski, H. N-Homocysteinylation impairs collagen cross-linking in cystathionine β-synthase-deficient mice: a novel mechanism of connective tissue abnormalities.
Collapse
Affiliation(s)
- Joanna Perła-Kajan
- Department of Biochemistry and Biotechnology, University of Life Sciences, Poznań, Poland
| | - Olga Utyro
- Institute of Bioorganic Chemistry, Poznań, Poland
| | - Marta Rusek
- Department of Microbiology, Biochemistry and Molecular Genetics, International Center for Public Health, Rutgers-New Jersey Medical School, Rutgers University, Newark, New Jersey, USA; and
| | - Agata Malinowska
- Proteomics Laboratory, Biophysics Department, Institute of Biochemistry and Biophysics, Warsaw, Poland
| | - Ewa Sitkiewicz
- Proteomics Laboratory, Biophysics Department, Institute of Biochemistry and Biophysics, Warsaw, Poland
| | - Hieronim Jakubowski
- Department of Biochemistry and Biotechnology, University of Life Sciences, Poznań, Poland; .,Institute of Bioorganic Chemistry, Poznań, Poland.,Department of Microbiology, Biochemistry and Molecular Genetics, International Center for Public Health, Rutgers-New Jersey Medical School, Rutgers University, Newark, New Jersey, USA; and
| |
Collapse
|
10
|
Denny KJ, Kelly CF, Kumar V, Witham KL, Cabrera RM, Finnell RH, Taylor SM, Jeanes A, Woodruff TM. Autoantibodies against homocysteinylated protein in a mouse model of folate deficiency-induced neural tube defects. ACTA ACUST UNITED AC 2016; 106:201-7. [PMID: 26900104 DOI: 10.1002/bdra.23483] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Periconceptional supplementation with folic acid results in a significant reduction in the incidence of neural tube defects (NTDs). Nonetheless, NTDs remain a leading cause of perinatal morbidity and mortality worldwide, and the mechanism(s) by which folate exerts its protective effects are unknown. Homocysteine is an amino acid that accumulates under conditions of folate-deficiency, and is suggested as a risk factor for NTDs. One proposed mechanism of homocysteine toxicity is its accumulation into proteins in a process termed homocysteinylation. METHODS & RESULTS Herein, we used a folate-deficient diet in pregnant mice to demonstrate that there is: (i) a significant inverse correlation between maternal serum folate levels and serum homocysteine; (ii) a significant positive correlation between serum homocysteine levels and titers of autoantibodies against homocysteinylated protein; and (iii) a significant increase in congenital malformations and NTDs in mice deficient in serum folate. Furthermore, in mice administered the folate-deplete diet before conception, supplementation with folic acid during the gestational period completely rescued the embryos from congenital defects, and resulted in homocysteinylated protein titers at term that are comparable to that of mice administered a folate-replete diet throughout both the pre- and postconception period. These results demonstrate that a low-folate diet that induces NTDs also increases protein homocysteinylation and the subsequent generation of autoantibodies against homocysteinylated proteins. CONCLUSION These data support the hypotheses that homocysteinylation results in neo-self antigen formation under conditions of maternal folate deficiency, and that this process is reversible with folic acid supplementation.
Collapse
Affiliation(s)
- Kerina J Denny
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | - Christina F Kelly
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Vinod Kumar
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Katey L Witham
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Robert M Cabrera
- Department of Nutritional Sciences, The University of Texas, Austin, Texas
| | - Richard H Finnell
- Department of Nutritional Sciences, The University of Texas, Austin, Texas
| | - Stephen M Taylor
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Angela Jeanes
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| |
Collapse
|
11
|
McCully KS. Homocysteine Metabolism, Atherosclerosis, and Diseases of Aging. Compr Physiol 2015; 6:471-505. [DOI: 10.1002/cphy.c150021] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
12
|
Eksin E, Erdem A. Electrochemical detection of N-homocysteinylated BSA in the fetal bovine serum medium. RSC Adv 2015. [DOI: 10.1039/c4ra13303j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The immobilization of bovine serum albumin (BSA), homocysteine-thiolactone (HTL) andN-homocysteinylated BSA (N-Hcy-BSA) onto the surface of each PGE was performed by passive adsorption and the electrochemical detection of these components was investigated individually.
Collapse
Affiliation(s)
- Ece Eksin
- Ege University
- Faculty of Pharmacy
- Analytical Chemistry Department
- Izmir
- Turkey
| | - Arzum Erdem
- Ege University
- Faculty of Pharmacy
- Analytical Chemistry Department
- Izmir
- Turkey
| |
Collapse
|
13
|
Głowacki R, Borowczyk K, Bald E. Determination of Nɛ-homocysteinyl-lysine and γ-glutamylcysteine in plasma by liquid chromatography with UV-detection. JOURNAL OF ANALYTICAL CHEMISTRY 2014. [DOI: 10.1134/s1061934814060082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
14
|
Genoud V, Castañon M, Lauricella AM, Quintana I. Characterization of N-homocysteinylated Albumin Adducts. Protein J 2014; 33:85-91. [DOI: 10.1007/s10930-013-9540-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
15
|
Effects of DL-homocysteine thiolactone on cardiac contractility, coronary flow, and oxidative stress markers in the isolated rat heart: the role of different gasotransmitters. BIOMED RESEARCH INTERNATIONAL 2013; 2013:318471. [PMID: 24350259 PMCID: PMC3857920 DOI: 10.1155/2013/318471] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 09/20/2013] [Accepted: 10/31/2013] [Indexed: 11/22/2022]
Abstract
Considering the adverse effects of DL-homocysteine thiolactone hydrochloride (DL-Hcy TLHC) on vascular function and the possible role of oxidative stress in these mechanisms, the aim of this study was to assess the influence of DL-Hcy TLHC alone and in combination with specific inhibitors of important gasotransmitters, such as L-NAME, DL-PAG, and PPR IX, on cardiac contractility, coronary flow, and oxidative stress markers in an isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique at a 70 cm H2O and administered 10 μM DL-Hcy TLHC alone or in combination with 30 μM L-NAME, 10 μM DL-PAG, or 10 μM PPR IX. The following parameters were measured: dp/dt max, dp/dt min, SLVP, DLVP, MBP, HR, and CF. Oxidative stress markers were measured spectrophotometrically in coronary effluent through TBARS, NO2, O2−, and H2O2 concentrations. The administration of DL-Hcy TLHC alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. DL-Hcy TLHC with L-NAME decreased CF, O2−, H2O2, and TBARS. The administration of DL-Hcy TLHC with DL-PAG significantly increased dp/dt max but decreased DLVP, CF, and TBARS. Administration of DL-Hcy TLHC with PPR IX caused a decrease in dp/dt max, SLVP, HR, CF, and TBARS.
Collapse
|
16
|
Nowakowska-Plaza A, Potaczek DP, Gluszko P, Undas A. Antibodies to N-homocysteinylated albumin and haemoglobin in patients with rheumatoid arthritis: a potential new marker of disease severity. Scand J Rheumatol 2013; 43:17-21. [PMID: 24015711 DOI: 10.3109/03009742.2013.811537] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To investigate whether anti-Nε-homocysteinylated albumin (anti-N-Hcy-Alb) and haemoglobin (anti-N-Hcy-Hb) antibodies occur in rheumatoid arthritis (RA) and whether they are associated with RA activity and/or severity. METHOD Plasma total homocysteine (tHcy) and serum anti-N-Hcy-Alb and -Hb antibodies levels were determined in 76 RA patients (12 men and 64 women, median age 56 years) and 80 age- and sex-matched controls. RESULTS RA patients compared to healthy controls demonstrated elevated tHcy [median (IQR), 13.20 (3.80) vs. 9.45 (3.25) μmol/L; p < 0.000001] and anti-N-Hcy-Alb and -Hb antibodies [absorbance at 490 nm, median (IQR), 0.546 (0.085) vs. 0.452 (0.056) and 0.649 (0.106) vs. 0.532 (0.057), respectively; all p < 0.000001]. In RA patients, RA radiological class was a strong independent predictor of tHcy [β (SE), 0.59 (0.11); p = 0.000001] and anti-N-Hcy-Alb [0.36 (0.12); p = 0.003] and -Hb [0.49 (0.11); p = 0.00007] antibodies. The number of swollen joints, but not C-reactive protein (CRP), interleukin 6 (IL-6), positive rheumatoid factor (RF), or anti-cyclic citrullinated peptide (anti-CCP) antibodies, showed independent effects on anti-N-Hcy-Alb [β (SE), 0.36 (0.11); p = 0.001] and -Hb [0.25 (0.11); p = 0.02] antibodies. Anti-N-Hcy-Hb antibodies, but not those against N-Hcy-Alb, were positively correlated with RA functional class and RA duration. No effect of any medications on tHcy or anti-N-Hcy-protein antibodies was observed. CONCLUSIONS This study is the first to show that RA is characterized by enhanced autoimmune response to Nε-homocysteinylated proteins detectable in circulating blood, which is related to some clinical measures of RA severity.
Collapse
|
17
|
Jakubowski H. The Mechanism and Consequences of Homocysteine Incorporation Into Protein in Humans. PHOSPHORUS SULFUR 2013. [DOI: 10.1080/10426507.2012.736104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hieronim Jakubowski
- a Department of Microbiology & Molecular Genetics, UMDNJ-New Jersey Medical School , International Center for Public Health , Newark , NJ , USA
- b Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, and Department of Biochemistry and Biotechnology , University of Life Sciences , Poznań , Poland
| |
Collapse
|
18
|
Stroylova YY, Chobert JM, Muronetz VI, Jakubowski H, Haertlé T. N-homocysteinylation of ovine prion protein induces amyloid-like transformation. Arch Biochem Biophys 2012; 526:29-37. [DOI: 10.1016/j.abb.2012.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/01/2012] [Accepted: 06/17/2012] [Indexed: 10/28/2022]
|
19
|
Yilmaz N. Relationship between paraoxonase and homocysteine: crossroads of oxidative diseases. Arch Med Sci 2012; 8:138-53. [PMID: 22457688 PMCID: PMC3309450 DOI: 10.5114/aoms.2012.27294] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/17/2011] [Accepted: 04/07/2011] [Indexed: 01/14/2023] Open
Abstract
Homocysteine (Hcy) is an accepted independent risk factor for several major pathologies including cardiovascular disease, birth defects, osteoporosis, Alzheimer's disease, and renal failure. Interestingly, many of the pathologies associated with homocysteine are also linked to oxidative stress. The enzyme paraoxonase (PON1) - so named because of its ability to hydrolyse the toxic metabolite of parathion, paraoxon - was also shown early after its identification to manifest arylesterase activity. Although the preferred endogenous substrate of PON1 remains unknown, lactones comprise one possible candidate class. Homocysteine-thiolactone can be disposed of by enzymatic hydrolysis by the serum Hcy-thiolactonase/paraoxonase carried on high-density lipoprotein (HDL). In this review, Hcy and the PON1 enzyme family were scrutinized from different points of view in the literature and the recent articles on these subjects were examined to determine whether these two molecular groups are related to each other like a coin with two different sides, so close and yet so different and so opposite.
Collapse
Affiliation(s)
- Necat Yilmaz
- Central Laboratories of Antalya Education and Research Hospital of Ministry of Health, Antalya, Turkey
| |
Collapse
|
20
|
Borowczyk K, Tisończyk J, Jakubowski H. Metabolism and neurotoxicity of homocysteine thiolactone in mice: protective role of bleomycin hydrolase. Amino Acids 2012; 43:1339-48. [PMID: 22227865 DOI: 10.1007/s00726-011-1207-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 12/21/2011] [Indexed: 10/14/2022]
Abstract
Genetic or nutritional disorders in homocysteine (Hcy) metabolism elevate Hcy-thiolactone and cause heart and brain diseases. Hcy-thiolactone has been implicated in these diseases because it has the ability to modify protein lysine residues and generate toxic N-Hcy-proteins with auto-immunogenic, pro-thrombotic, and amyloidogenic properties. Bleomycin hydrolase (Blmh) has the ability to hydrolyze L-Hcy-thiolactone (but not D-Hcy-thiolactone) to Hcy in vitro, but whether this reflects a physiological function has been unknown. Here, we show that Blmh (-/-) mice excreted in urine 1.8-fold more Hcy-thiolactone than wild-type Blmh (+/+) animals (P = 0.02). Hcy-thiolactone was elevated 2.3-fold in brains (P = 0.004) and 2.0-fold in kidneys (P = 0.047) of Blmh (-/-) mice relative to Blmh (+/+) animals. Plasma N-Hcy-protein was elevated in Blmh (-/-) mice fed a normal (2.3-fold, P < 0.001) or hyperhomocysteinemic diet (1.5-fold, P < 0.001), compared with Blmh (+/+) animals. More intraperitoneally injected L-Hcy-thiolactone was recovered in plasma in Blmh (-/-) mice than in wild-type Blmh (+/+) animals (83.1 vs. 39.3 μM, P < 0.0001). In Blmh (+/+) mice injected intraperitoneally with D-Hcy-thiolactone, D,L-Hcy-thiolactone, or L-Hcy-thiolactone, 88, 47, or 6.3%, respectively, of the injected dose was recovered in plasma. The incidence of seizures induced by L-Hcy-thiolactone injections (3,700 nmol/g body weight) was higher in Blmh (-/-) than in Blmh (+/+) mice (93.8 vs. 29.5%, P < 0.001). Using the Blmh null mice, we provide the first direct evidence that a specific Hcy metabolite, Hcy-thiolactone, rather than Hcy itself, is neurotoxic in vivo. Taken together, our findings indicate that Blmh protects mice against L-Hcy-thiolactone toxicity by metabolizing it to Hcy and suggest a mechanism by which Blmh might protect against neurodegeneration associated with hyperhomocysteinemia and Alzheimer's disease.
Collapse
Affiliation(s)
- Kamila Borowczyk
- Department of Microbiology and Molecular Genetics, International Center for Public Health, UMDNJ-New Jersey Medical School, 225 Warren Street, Newark, NJ 07101, USA
| | | | | |
Collapse
|
21
|
Jakubowski H, Głowacki R. Chemical biology of homocysteine thiolactone and related metabolites. Adv Clin Chem 2011; 55:81-103. [PMID: 22126025 DOI: 10.1016/b978-0-12-387042-1.00005-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Protein-related homocysteine (Hcy) metabolism produces Hcy-thiolactone, N-Hcy-protein, and N epsilon-homocysteinyl-lysine (N epsilon-Hcy-Lys). Hcy-thiolactone is generated in an error-editing reaction in protein biosynthesis when Hcy is erroneously selected in place of methionine by methionyl-tRNA synthetase. Hcy-thiolactone, an intramolecular thioester, is chemically reactive and forms isopeptide bonds with protein lysine residues in a process called N-homocysteinylation, which impairs or alters the protein's biological function. The resulting protein damage is exacerbated by a thiyl radical-mediated oxidation. N-Hcy-proteins undergo structural changes leading to aggregation and amyloid formation. These structural changes generate proteins, which are toxic and which induce an autoimmune response. Proteolytic degradation of N-Hcy-proteins generates N epsilon-Hcy-Lys. Levels of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys increase under pathological conditions in humans and mice and have been linked to cardiovascular and brain disorders. This chapter reviews fundamental biological chemistry of Hcy-thiolactone, N-Hcy-protein, and N epsilon-Hcy-Lys and discusses their clinical significance.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, New Jersey, USA.
| | | |
Collapse
|
22
|
Jakubowski H. The role of paraoxonase 1 in the detoxification of homocysteine thiolactone. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 660:113-27. [PMID: 20221875 DOI: 10.1007/978-1-60761-350-3_11] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The thioester homocysteine (Hcy)-thiolactone, product of an error-editing reaction in protein biosynthesis, forms when Hcy is mistakenly selected by methionyl-tRNA synthetase. Accumulating evidence suggests that Hcy-thiolactone plays an important role in atherothrombosis. The thioester chemistry of Hcy-thiolactone underlies its ability to form isopeptide bonds with protein lysine residues, which impairs or alters protein function and has pathophysiological consequences including activation of an autoimmune response and enhanced thrombosis. Mammalian organisms, including human, have evolved the ability to eliminate Hcy-thiolactone. One such mechanism involves paraoxonase 1 (PON1), which has the ability to hydrolyze Hcy-thiolactone. This article outlines Hcy-thiolactone pathobiology and reviews evidence documenting the role of PON1 in minimizing Hcy-thiolactone and N-Hcy-protein accumulation.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Biochemistry and Biotechnology, University of Life Sciences, Poznań, Poland.
| |
Collapse
|
23
|
Chubarov AS, Shakirov MM, Koptyug IV, Sagdeev RZ, Knorre DG, Godovikova TS. Synthesis and characterization of fluorinated homocysteine derivatives as potential molecular probes for 19 F magnetic resonance spectroscopy and imaging. Bioorg Med Chem Lett 2011; 21:4050-3. [DOI: 10.1016/j.bmcl.2011.04.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 04/26/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022]
|
24
|
Zaąbczyk M, Głowacki R, Machnik A, Heród P, Kazek G, Jakubowski H, Undas A. Elevated concentrations of Nɛ-homocysteinyl-lysine isopeptide in acute myocardial infarction: links with ADMA formation. Clin Chem Lab Med 2011; 49:729-35. [DOI: 10.1515/cclm.2011.107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
25
|
Ferretti G, Bacchetti T, Masciangelo S, Bicchiega V. Effect of homocysteinylation on high density lipoprotein physico-chemical properties. Chem Phys Lipids 2010; 163:228-35. [DOI: 10.1016/j.chemphyslip.2009.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 11/14/2009] [Accepted: 11/27/2009] [Indexed: 01/27/2023]
|
26
|
Callegher E, Seraglia R, Vettore M, Puricelli L, Millioni R, Tessari P. Kinetics of albumin homocysteinylation measured with matrix-assisted laser/desorption ionization mass spectrometry versus with a radioactive tracer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3837-3842. [PMID: 19902417 DOI: 10.1002/rcm.4290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Homocysteinylation is a post-translational protein modification which involves homocysteine-thiolactone and may be responsible for many pathophysiological changes secondary to hyperhomocysteinemia. Therefore, methods to measure protein homocysteinylation in intact biological samples are required. We tested whether matrix assisted-laser/desorption ionization mass spectrometry (MALDI-MS) can detect time- and dose-dependent changes in in vitro homocysteine-thiolactone binding to human serum albumin. We have compared this method with a 35S-thiolactone radioactive binding assay. Incubations with and without dithiothreitol allowed measurement of the amide-linked and disulfide-linked thiolactone-protein adducts, respectively. A good correspondence in time- and dose-dependent protein-thiolactone formation was observed between the two methods. A maximum of 9 to 12 thiolactone residues were bound to each albumin molecule. The 35S-thiolactone bound albumin tightly, particularly at the lowest concentrations, with approximately 70% of the binding amide-linked. Although the results of the two methods were rather similar, the radioactive method appears to be more sensitive than the MALDI-MS technique.
Collapse
Affiliation(s)
- Elisabetta Callegher
- Department of Clinical and Experimental Medicine, Division of Metabolic Disease, University of Padova
| | | | | | | | | | | |
Collapse
|
27
|
Jakubowski H, Perla-Kaján J, Finnell RH, Cabrera RM, Wang H, Gupta S, Kruger WD, Kraus JP, Shih DM. Genetic or nutritional disorders in homocysteine or folate metabolism increase protein N-homocysteinylation in mice. FASEB J 2009; 23:1721-7. [PMID: 19204075 DOI: 10.1096/fj.08-127548] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Genetic disorders of homocysteine (Hcy) or folate metabolism or high-methionine diets elevate plasma Hcy and its atherogenic metabolite Hcy-thiolactone. In humans, severe hyperhomocysteinemia due to genetic alterations in cystathionine beta-synthase (Cbs) or methylenetetrahydrofolate reductase (Mthfr) results in neurological abnormalities and premature death from vascular complications. In mouse models, dietary or genetic hyperhomocysteinemia results in liver or brain pathological changes and accelerates atherosclerosis. Hcy-thiolactone has the ability to form isopeptide bonds with protein lysine residues, which generates modified proteins (N-Hcy-protein) with autoimmunogenic and prothrombotic properties. Our aim was to determine how N-Hcy-protein levels are affected by genetic or nutritional disorders in Hcy or folate metabolism in mice. We found that plasma N-Hcy-protein was elevated 10-fold in mice fed a high-methionine diet compared with the animals fed a normal commercial diet. We also found that inactivation of Cbs, Mthfr, or the proton-coupled folate transporter (Pcft) gene resulted in a 10- to 30-fold increase in plasma or serum N-Hcy-protein levels. Liver N-Hcy-protein was elevated 3.4-fold in severely and 11-fold in extremely hyperhomocysteinemic Cbs-deficient mice, 3.6-fold in severely hyperhomocysteinemic Pcft mice, but was not elevated in mildly hyperhomocysteinemic Mthfr-deficient animals, suggesting that mice have a capacity to prevent accumulation of N-Hcy-protein in their organs. These findings provide evidence that N-Hcy-protein is an important metabolite associated with Hcy pathophysiology in the mouse.
Collapse
Affiliation(s)
- 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.
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Jakubowski H, Boers GHJ, Strauss KA. Mutations in cystathionine beta-synthase or methylenetetrahydrofolate reductase gene increase N-homocysteinylated protein levels in humans. FASEB J 2008; 22:4071-6. [PMID: 18708589 DOI: 10.1096/fj.08-112086] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Severely elevated plasma homocysteine (Hcy) levels observed in genetic disorders of Hcy metabolism are associated with pathologies in multiple organs and lead to premature death due to vascular complications. In addition to elevating plasma Hcy, mutations in cystathionine beta-synthase (CBS) or methylenetetrahydrofolate reductase (MTHFR) gene lead to markedly elevated levels of circulating Hcy-thiolactone. The thiooester chemistry of Hcy-thiolactone underlies its ability to form isopeptide bonds with protein lysine residues (N-Hcy-protein), which may impair or alter the protein's function. However, it was not known whether genetic deficiencies in Hcy metabolism affect N-Hcy-protein levels in humans. Here we show that plasma N-Hcy-protein levels are significantly elevated in CBS- and MTHFR-deficient patients. We also show that CBS-deficient patients have significantly elevated plasma levels of prothrombotic N-Hcy-fibrinogen. These results provide a possible explanation for increased atherothrombosis observed in CBS-deficient patients.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology & Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, 225 Warren St., Newark, NJ 07101-1709, USA.
| | | | | |
Collapse
|
29
|
Jakubowski H. The molecular basis of homocysteine thiolactone-mediated vascular disease. Clin Chem Lab Med 2008; 45:1704-16. [PMID: 17937605 DOI: 10.1515/cclm.2007.338] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Accumulating evidence suggests that a metabolite of homocysteine (Hcy), the thioester Hcy-thiolactone, plays an important role in atherogenesis and thrombosis. Hcy-thiolactone levels are elevated in hyperhomocysteinemic humans and mice. The thioester chemistry of Hcy-thiolactone underlies its ability to form isopeptide bonds with protein lysine residues, which impairs or alters the protein's function. Protein targets for the modification by Hcy-thiolactone in human blood include fibrinogen, low-density lipoprotein, and high-density lipoprotein. Protein N-homocysteinylation leads to pathophysiological responses, including increased susceptibility to thrombogenesis caused by N-Hcy-fibrinogen, and an autoimmune response elicited by N-Hcy-proteins. Chronic activation of these responses in hyperhomocysteinemia over many years could lead to vascular disease. This article reviews recent evidence supporting the hypothesis that Hcy-thiolactone contributes to pathophysiological effects of Hcy on the vascular system.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, NJ 07101-1709, USA.
| |
Collapse
|
30
|
Lazzerini PE, Capecchi PL, Selvi E, Lorenzini S, Bisogno S, Galeazzi M, Laghi Pasini F. Hyperhomocysteinemia, inflammation and autoimmunity. Autoimmun Rev 2007; 6:503-9. [PMID: 17643940 DOI: 10.1016/j.autrev.2007.03.008] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 03/06/2007] [Accepted: 03/07/2007] [Indexed: 12/31/2022]
Abstract
Hyperhomocysteinemia is independently associated with the development of coronary, cerebral and peripheral vascular disease and deep-vein thrombosis in the general population. The evidence that cardiovascular involvement is particularly frequent and advanced in patients affected with several autoimmune diseases (AD), in which hyperhomocysteinemia represent a common finding, led to an intensive investigation on homocysteine (Hcy) as a putative risk factor for the development of cardiovascular disease in such subjects. Indeed, recent data intriguingly expanded the spectrum of the possible pathogenetic implications for hyperhomocysteinemia in the course of AD. In fact, a bi-directional link seems to connect Hcy and the immuno-inflammatory activation characterizing AD, in which immuno-inflammatory activation may contribute to Hcy increase, and Hcy, in its turn, may act as a pro-inflammatory and immuno-stimulating molecule putatively cooperating to the injury of the disease-specific target organs, at least in rheumatoid arthritis and inflammatory bowel disease. Moreover, Hcy may be also a trigger of autoimmune reactions through its capability to bind and structurally modify specific proteins, then resulting in neoantigens formation potentially relevant either in the onset of specific AD and in the progression of the associated cardiovascular damage. More investigation is necessary to fully define the clinical relevance of such phenomena.
Collapse
Affiliation(s)
- Pietro Enea Lazzerini
- Department of Clinical Medicine and Immunological Sciences, Division of Clinical Immunology, University of Siena, Italy.
| | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Chemical reactivity of homocysteine thiolactone (HTL) has been implicated in cardiovascular disease. Owing to its aminoacyl-thioester character, HTL undergoes facile electrophilic and nucleophilic reactions at its amino and activated-carboxyl group, respectively. To gain insight into the mechanism of the reactions involving its amino group, the kinetics of the condensation of homocysteine thiolactone with formaldehyde, acetaldehyde, and pyridoxal phosphate, were analyzed in the pH range from 5 to 10. The reactions were first order with respect to HTL, aldehyde, and hydroxide ion concentrations. Of the two ionic species of HTL (pKa=6.67+/-0.05), the acid form HTL+ was approximately 100-fold more reactive than the base form HTL(0). The reactions of HTL with aldehydes involve intermediate adducts. The conversion of the intermediate carbinolamine to a product, 1,3-tetrahydrothiazine-4-carboxylic acid or its 2-substituted analogue, occurs in a two-step reaction. The first step involves hydrolysis of the thioester bond in the intermediate, facilitated by anchimeric assistance by the oxygen of the carbinolamine group of the intermediate. The second step involves an attack of the liberated thiolate on the aldehyde-derived carbon of the intermediate, affording 1,3-tetrahydrothiazine-4-carboxylic acid or its 2-substituted analogue. An unusual feature of these reactions is that the formation of the carbinolamine group increases the reactivity of the thioester bond of HTL approximately 10(4)-fold. The facile formation of tetrahydrothiazines may contribute to HTL elimination from the human body.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey, Medical School, Newark, NJ 07101, USA.
| |
Collapse
|
32
|
Chwatko G, Boers GHJ, Strauss KA, Shih DM, Jakubowski H. Mutations in methylenetetrahydrofolate reductase or cystathionine beta-synthase gene, or a high-methionine diet, increase homocysteine thiolactone levels in humans and mice. FASEB J 2007; 21:1707-13. [PMID: 17327360 DOI: 10.1096/fj.06-7435com] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Genetic disorders of homocysteine (Hcy) metabolism or a high-methionine diet lead to elevations of plasma Hcy levels. In humans, severe genetic hyperhomocysteinemia results in premature death from vascular complications whereas dietary hyperhomocysteinemia is often used to induce atherosclerosis in animal models. Hcy is mistakenly selected in place of methionine by methionyl-tRNA synthetase during protein biosynthesis, which results in the formation of Hcy-thiolactone and initiates a pathophysiological pathway that has been implicated in human vascular disease. However, whether genetic deficiencies in Hcy metabolism or a high-methionine diet affect Hcy-thiolactone levels in mammals has been unknown. Here we show that plasma Hcy-thiolactone is elevated 59-fold and 72-fold in human patients with hyperhomocysteinemia secondary to mutations in methylenetetrahydrofolate reductase and cystathionine beta-synthase genes, respectively. We also show that mice, like humans, eliminate Hcy-thiolactone by urinary excretion; in contrast to humans, however, mice also eliminate significant amounts of plasma total Hcy (approximately 38%) by urinary excretion. In mice, hyperhomocysteinemia secondary to a high-methionine diet leads to 3.7-fold and 25-fold increases in plasma and urinary Hcy-thiolactone levels, respectively. Thus, we conclude that hyperhomocysteinemia leads to significant increases in the atherogenic metabolite Hcy-thiolactone in humans and mice.
Collapse
Affiliation(s)
- Grazyna Chwatko
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, 225 Warren St., Newark, NJ 07101-1709, USA
| | | | | | | | | |
Collapse
|
33
|
Matsuo K, Xiang Y, Nakamura H, Masuko K, Yudoh K, Noyori K, Nishioka K, Saito T, Kato T. Identification of novel citrullinated autoantigens of synovium in rheumatoid arthritis using a proteomic approach. Arthritis Res Ther 2007; 8:R175. [PMID: 17125526 PMCID: PMC1794520 DOI: 10.1186/ar2085] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 11/02/2006] [Accepted: 11/27/2006] [Indexed: 11/21/2022] Open
Abstract
Recently, autoantibodies to some citrullinated autoantigens have been reported to be specific for rheumatoid arthritis (RA). However, an entire profile of and autoimmunity of the citrullinated proteins have been poorly understood. To understand the profile, we examined citrullinated autoantigens by a proteomic approach and further investigated the significance of citrullination in antigenicity of one of the autoantigens. Specifically, we detected citrullinated autoantigens in synovial tissue of a patient with RA by two-dimensional electrophoresis and Western blotting by using pooled sera from five patients with RA and anti-citrulline antibodies. After identifying the detected autoantigens by mass spectrometry, we investigated the contribution of citrullination to autoantigenicity by using a recombinant protein with or without citrullination on one of the identified novel citrullinated autoantigens. As a result, we found 51 citrullinated protein spots. Thirty (58.8%) of these spots were autoantigenic. We identified 13 out of the 30 detected citrullinated autoantigenic proteins. They contained three fibrinogen derivatives and several novel citrullinated autoantigens (for example, asporin and F-actin capping protein α-1 subunit [CapZα-1]). We further analyzed the contribution of citrullination to autoantigenicity in one of the detected citrullinated autoantigens, CapZα-1. As a result, frequencies of autoantibodies to non-citrullinated CapZα-1 were 36.7% in the RA group tested, 10.7% in the osteoarthritis (OA) group, and 6.5% in healthy donors. On the other hand, those to citrullinated CapZα-1 were 53.3% in the RA group, 7.1% in the OA group, and 6.5% in the healthy donors. This shows that autoantigenicity of citrullinated or non-citrullinated CapZα-1 is relevant to RA. The antibody titers to the citrullinated CapZα-1 were significantly higher than those to the non-citrullinated CapZα-1 in 36.7% of patients; however, the other patients showed almost equal antibody titers to both citrullinated and non-citrullinated CapZα-1. Therefore, the autoantibodies would target citrulline-related and/or citrulline-unrelated epitope(s) of CapZα-1. In conclusion, we report a profile of citrullinated autoantigens for the first time. Even though citrullination is closely related to autoantigenicity, citrullination would not always produce autoantigenicity in RA. Citrullinated and non-citrullinated autoantigens/autoepitopes would have different pathological roles in RA.
Collapse
Affiliation(s)
- Kosuke Matsuo
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
- Musculoskeletal Science, Yokohama City University Graduate School of Medicine, Fukuura3-9, Kanazawa, Yokohama, Kanagawa 236-0004, Japan
| | - Yang Xiang
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| | - Hiroshi Nakamura
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| | - Kayo Masuko
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| | - Kazuo Yudoh
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| | - Koji Noyori
- Musculoskeletal Science, Yokohama City University Graduate School of Medicine, Fukuura3-9, Kanazawa, Yokohama, Kanagawa 236-0004, Japan
| | - Kusuki Nishioka
- Department of Frontier Medicine, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| | - Tomoyuki Saito
- Musculoskeletal Science, Yokohama City University Graduate School of Medicine, Fukuura3-9, Kanazawa, Yokohama, Kanagawa 236-0004, Japan
| | - Tomohiro Kato
- Department of Bioregulation & Proteomics, Institute of Medical Science, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae, Kawasaki, Kanagawa 216-8512, Japan
| |
Collapse
|
34
|
Perła-Kaján J, Twardowski T, Jakubowski H. Mechanisms of homocysteine toxicity in humans. Amino Acids 2007; 32:561-72. [PMID: 17285228 DOI: 10.1007/s00726-006-0432-9] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 06/30/2006] [Indexed: 12/01/2022]
Abstract
Homocysteine, a non-protein amino acid, is an important risk factor for ischemic heart disease and stroke in humans. This review provides an overview of homocysteine influence on endothelium function as well as on protein metabolism with a special respect to posttranslational modification of protein with homocysteine thiolactone. Homocysteine is a pro-thrombotic factor, vasodilation impairing agent, pro-inflammatory factor and endoplasmatic reticulum-stress inducer. Incorporation of Hcy into protein via disulfide or amide linkages (S-homocysteinylation or N-homocysteinylation) affects protein structure and function. Protein N-homocysteinylation causes cellular toxicity and elicits autoimmune response, which may contribute to atherogenesis.
Collapse
Affiliation(s)
- J Perła-Kaján
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland.
| | | | | |
Collapse
|
35
|
Perna AF, Acanfora F, Luciano MG, Pulzella P, Capasso R, Satta E, Cinzia L, Pollastro RM, Iannelli S, Ingrosso D, De Santo NG. Plasma protein homocysteinylation in uremia. ACTA ACUST UNITED AC 2007; 45:1678-82. [DOI: 10.1515/cclm.2007.336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractProtein homocysteinylation is proposed as one of the mechanisms of homocysteine toxicity. It occurs through various means, such as the post-biosynthetic acylation of free amino groups (protein-N-homocysteinylation, mediated by homocysteine thiolactone) and the formation of a covalent -S-S- bond found primarily with cysteine residues (protein-S-homocysteinylation). Both protein modifications are a cause of protein functional derangements. Hemodialysis patients in the majority of cases are hyperhomocysteinemic, if not malnourished. Protein-N-homocysteinylation and protein-S-homocysteinylation are significantly increased in hemodialysis patients compared to controls. Oral folate treatment normalizes protein-N-homocysteinylation levels, while protein-S-homocysteinylation is significantly reduced. Albumin binding experiments after in vitro homocysteinylation show that homocysteinylated albumin is significantly altered at the diazepam, but not at the warfarin and salicilic acid binding sites.Clin Chem Lab Med 2007;45:1678–82.
Collapse
|
36
|
Undas A, Jakubowski H. Letter by Undas and Jakubowski Regarding Article, “Relationship Between Homocysteine and Mortality in Chronic Kidney Disease”. Circulation 2006; 114:e547; author reply e548. [PMID: 17043173 DOI: 10.1161/circulationaha.106.634691] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
37
|
Jakubowski H. Mechanism of the Condensation of Homocysteine Thiolactone with Aldehydes. Chemistry 2006. [DOI: 10.1002/chem.600785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
38
|
Zimny J, Sikora M, Guranowski A, Jakubowski H. Protective mechanisms against homocysteine toxicity: the role of bleomycin hydrolase. J Biol Chem 2006; 281:22485-92. [PMID: 16769724 DOI: 10.1074/jbc.m603656200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Homocysteine (Hcy) editing by methionyl-tRNA synthetase results in the formation of Hcy-thiolactone and initiates a pathway that has been implicated in human disease. In addition to being cleared from the circulation by urinary excretion, Hcy-thiolactone is detoxified by the serum Hcy-thiolactonase/paraoxonase carried on high density lipoprotein. Whether Hcy-thiolactone is detoxified inside cells was unknown. Here we show that Hcy-thiolactone is hydrolyzed by an intracellular enzyme, which we have purified to homogeneity from human placenta and identified by proteomic analyses as human bleomycin hydrolase (hBLH). We have also purified an Hcy-thiolactonase from the yeast Saccharomyces cerevisiae and identified it as yeast bleomycin hydrolase (yBLH). BLH belongs to a family of evolutionarily conserved cysteine aminopeptidases, and its only known biologically relevant function was deamidation of the anticancer drug bleomycin. Recombinant hBLH or yBLH, expressed in Escherichia coli, exhibits Hcy-thiolactonase activity similar to that of the native enzymes. Active site mutations, C73A for hBLH and H369A for yBLH, inactivate Hcy-thiolactonase activities. Yeast blh1 mutants are deficient in Hcy-thiolactonase activity in vitro and in vivo, produce more Hcy-thiolactone, and exhibit greater sensitivity to Hcy toxicity than wild type yeast cells. Our data suggest that BLH protects cells against Hcy toxicity by hydrolyzing intracellular Hcy-thiolactone.
Collapse
Affiliation(s)
- Jaroslaw Zimny
- Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, International Center for Public Health, Newark, New Jersey 07101, USA
| | | | | | | |
Collapse
|
39
|
Abstract
Elevated level of the nonprotein amino acid homocysteine (Hcy) is a risk factor for cardiovascular diseases, neurodegenerative diseases, and neural tube defects. However, it is not clear why excess Hcy is harmful. To explain Hcy toxicity, the "Hcy-thiolactone hypothesis" has been proposed. According to this hypothesis, metabolic conversion of Hcy to a chemically reactive metabolite, Hcy-thiolactone, catalyzed by methionyl-tRNA synthetase is the first step in a pathway that contributes to Hcy toxicity in humans. Plasma Hcy-thiolactone levels are elevated in human subjects with hyperhomocysteinemia caused by mutations in CBS or MTHFR genes. Plasma and urinary Hcy-thiolactone levels are also elevated in mice fed a high-methionine diet. Hcy-thiolactone can be detrimental because of its intrinsic ability to form N-Hcy-protein adducts, in which a carboxyl group of Hcy is N-linked to epsilon-amino group of a protein lysine residue. This article reviews recent studies of Hcy-thiolactone and N-Hcy-protein in the human body, including their roles in autoimmune response, cellular toxicity, and atherosclerosis. Potential utility of Hcy-thiolactone, N-Hcy-protein, or anti-N-Hcy-protein autoantibodies as markers of Hcy excess is discussed.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology & Molecular Genetics, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, NJ 07101, USA.
| |
Collapse
|
40
|
Perna AF, Satta E, Acanfora F, Lombardi C, Ingrosso D, De Santo NG. Increased plasma protein homocysteinylation in hemodialysis patients. Kidney Int 2006; 69:869-76. [PMID: 16395265 DOI: 10.1038/sj.ki.5000070] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hyperhomocysteinemia, an independent cardiovascular risk factor, is present in the majority of hemodialysis patients. Among the postulated mechanisms of toxicity, protein homocysteinylation is potentially able to cause significant alterations in protein function. Protein homocysteinylation occurs through various mechanisms, among which is the post-translational acylation of free amino groups (protein-N-homocysteinylation, mediated by homocysteine (Hcy) thiolactone). Another type of protein homocysteinylation occurs through the formation of a covalent -S-S- bond, found primarily with cysteine residues (protein-S-homocysteinylation). Scant data are available in the literature regarding the extent to which alterations in protein homocysteinylation are present in uremic patients on hemodialysis, and the effects of folate treatment are not known. Protein homocysteinylation was measured in a group of hemodialysis patients (n=28) compared to controls (n=14), with a new method combining protein reduction, gel filtration and Hcy derivatization. Chemical hydrolysis was performed, followed by high-pressure liquid chromatography separation. The effects of folate treatment on protein homocysteinylation, as well as in vitro binding characteristics were evaluated. Plasma Hcy, protein-N-homocysteinylation and protein-S-homocysteinylation were significantly higher in patients vs controls. Plasma Hcy and protein-S-homocysteinylation were significantly correlated. After 2 months of oral folate treatment, protein-N-homocysteinylation was normalized, and protein-S-homocysteinylation was significantly reduced. Studies on albumin-binding capacity after in vitro homocysteinylation show that homocysteinylated albumin is significantly altered at the diazepam-binding site. In conclusion, increased protein homocysteinylation is present in hemodialysis patients, with possible consequences in terms of protein function. This alteration can be partially reversed after folate treatment.
Collapse
Affiliation(s)
- A F Perna
- Division of Nephrology, Department of Biochemistry and Biophysics, F Cedrangolo and Cardiovascular Research Center, School of Medicine, Second University of Naples, Via Pansini 5, Ed. 17, 80131 Naples, Italy.
| | | | | | | | | | | |
Collapse
|