1
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Witucki Ł, Jakubowski H. Homocysteine metabolites inhibit autophagy, elevate amyloid beta, and induce neuropathy by impairing Phf8/H4K20me1-dependent epigenetic regulation of mTOR in cystathionine β-synthase-deficient mice. J Inherit Metab Dis 2023; 46:1114-1130. [PMID: 37477632 DOI: 10.1002/jimd.12661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/10/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
The loss of cystathionine β-synthase (CBS), an important homocysteine (Hcy)-metabolizing enzyme or the loss of PHF8, an important histone demethylase participating in epigenetic regulation, causes severe intellectual disability in humans. Similar neuropathies were also observed in Cbs-/- and Phf8-/- mice. How CBS or PHF8 depletion can cause neuropathy was unknown. To answer this question, we examined a possible interaction between PHF8 and CBS using Cbs-/- mouse and neuroblastoma cell models. We quantified gene expression by RT-qPCR and western blotting, mTOR-bound H4K20me1 by chromatin immunoprecipitation (CHIP) assay, and amyloid β (Aβ) by confocal fluorescence microscopy using anti-Aβ antibody. We found significantly reduced expression of Phf8, increased H4K20me1, increased mTOR expression and phosphorylation, and increased App, both on protein and mRNA levels in brains of Cbs-/- mice versus Cbs+/- sibling controls. Autophagy-related Becn1, Atg5, and Atg7 were downregulated while p62, Nfl, and Gfap were upregulated on protein and mRNA levels, suggesting reduced autophagy and increased neurodegeneration in Cbs-/- brains. In mouse neuroblastoma N2a or N2a-APPswe cells, treatments with Hcy-thiolactone, N-Hcy-protein or Hcy, or Cbs gene silencing by RNA interference significantly reduced Phf8 expression and increased total H4K20me1 as well as mTOR promoter-bound H4K20me1. This led to transcriptional mTOR upregulation, autophagy downregulation, and significantly increased APP and Aβ levels. The Phf8 gene silencing increased Aβ, but not APP, levels. Taken together, our findings identify Phf8 as a regulator of Aβ synthesis and suggest that neuropathy of Cbs deficiency is mediated by Hcy metabolites, which transcriptionally dysregulate the Phf8 → H4K20me1 → mTOR → autophagy pathway thereby increasing Aβ accumulation.
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Affiliation(s)
- Łukasz Witucki
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
| | - Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
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2
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Zhou L, Guo T, Meng L, Zhang X, Tian Y, Dai L, Niu X, Li Y, Liu C, Chen G, Liu C, Ke W, Zhang Z, Bao A, Zhang Z. N-homocysteinylation of α-synuclein promotes its aggregation and neurotoxicity. Aging Cell 2023; 22:e13745. [PMID: 36437524 PMCID: PMC10014048 DOI: 10.1111/acel.13745] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/07/2022] [Accepted: 11/09/2022] [Indexed: 11/29/2022] Open
Abstract
The aggregation of α-synuclein plays a pivotal role in the pathogenesis of Parkinson's disease (PD). Epidemiological evidence indicates that high level of homocysteine (Hcy) is associated with an increased risk of PD. However, the molecular mechanisms remain elusive. Here, we report that homocysteine thiolactone (HTL), a reactive thioester of Hcy, covalently modifies α-synuclein on the K80 residue. The levels of α-synuclein K80Hcy in the brain are increased in an age-dependent manner in the TgA53T mice, correlating with elevated levels of Hcy and HTL in the brain during aging. The N-homocysteinylation of α-synuclein stimulates its aggregation and forms fibrils with enhanced seeding activity and neurotoxicity. Intrastriatal injection of homocysteinylated α-synuclein fibrils induces more severe α-synuclein pathology and motor deficits when compared with unmodified α-synuclein fibrils. Increasing the levels of Hcy aggravates α-synuclein neuropathology in a mouse model of PD. In contrast, blocking the N-homocysteinylation of α-synuclein ameliorates α-synuclein pathology and degeneration of dopaminergic neurons. These findings suggest that the covalent modification of α-synuclein by HTL promotes its aggregation. Targeting the N-homocysteinylation of α-synuclein could be a novel therapeutic strategy against PD.
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Affiliation(s)
- Lingyan Zhou
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Tao Guo
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xingyu Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ye Tian
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lijun Dai
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xuan Niu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yiming Li
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Congcong Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Guiqin Chen
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.,Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Chaoyang Liu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.,Research Center for Environment and Health, Zhongnan University of Economics and Law, Wuhan, China
| | - Wei Ke
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Anyu Bao
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.,TaiKang Center for Life and Medical Science, Wuhan University, Wuhan, China
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3
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Witucki Ł, Jakubowski H. Depletion of Paraoxonase 1 (Pon1) Dysregulates mTOR, Autophagy, and Accelerates Amyloid Beta Accumulation in Mice. Cells 2023; 12. [PMID: 36899882 DOI: 10.3390/cells12050746] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Paraoxonase 1 (PON1), a homocysteine (Hcy)-thiolactone detoxifying enzyme, has been associated with Alzheimer's disease (AD), suggesting that PON1 plays an important protective role in the brain. To study the involvement of PON1 in the development of AD and to elucidate the mechanism involved, we generated a new mouse model of AD, the Pon1-/-xFAD mouse, and examined how Pon1 depletion affects mTOR signaling, autophagy, and amyloid beta (Aβ) accumulation. To elucidate the mechanism involved, we examined these processes in N2a-APPswe cells. We found that Pon1 depletion significantly downregulated Phf8 and upregulated H4K20me1; mTOR, phospho-mTOR, and App were upregulated while autophagy markers Bcln1, Atg5, and Atg7 were downregulated at the protein and mRNA levels in the brains of Pon1─/─5xFAD vs. Pon1+/+5xFAD mice. Pon1 depletion in N2a-APPswe cells by RNA interference led to downregulation of Phf8 and upregulation of mTOR due to increased H4K20me1-mTOR promoter binding. This led to autophagy downregulation and significantly increased APP and Aβ levels. Phf8 depletion by RNA interference or treatments with Hcy-thiolactone or N-Hcy-protein metabolites similarly increased Aβ levels in N2a-APPswe cells. Taken together, our findings define a neuroprotective mechanism by which Pon1 prevents Aβ generation.
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4
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Tsiasioti A, Zacharis CK, Tzanavaras PD. Single-Step Hydrolysis and Derivatization of Homocysteine Thiolactone Using Zone Fluidics: Simultaneous Analysis of Mixtures with Homocysteine Following Separation by Fluorosurfactant-Modified Gold Nanoparticles. Molecules 2022; 27:molecules27072040. [PMID: 35408439 PMCID: PMC9000217 DOI: 10.3390/molecules27072040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/15/2022] [Accepted: 03/20/2022] [Indexed: 11/16/2022] Open
Abstract
Herein, we report a new automated flow method based on zone fluidics for the simultaneous determination of homocysteine and homocysteine thiolactone using fluorimetric detection (λext = 370 nm/λem = 480 nm). Homocysteine thiolactone is hydrolyzed on-line in alkaline medium (1 mol L−1 NaOH) to yield homocysteine, followed by reaction with o-phthalaldehyde in a single step. Derivatization is rapid without the need of elevated temperatures and stopped-flow steps, while specificity is achieved through a unique reaction mechanism in the absence of nucleophilic compounds. Mixtures of the analytes can be analyzed quantitatively after specific separation with fluorosurfactant-capped gold nanoparticles that are selectively aggregated by homocysteine, leaving the thiolactone analogue in solution. As low as 100 nmol L−1 of the analyte(s) can be quantified in aqueous solutions, while concentrations > 2 μmol L−1 can be analyzed in artificial and real urine matrix following 20-fold dilution. The percent recoveries ranged between 87 and 119%.
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Affiliation(s)
- Apostolia Tsiasioti
- Laboratory of Analytical Chemistry, School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Constantinos K. Zacharis
- Laboratory of Pharmaceutical Analysis, Department of Pharmaceutical Technology, School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Paraskevas D. Tzanavaras
- Laboratory of Analytical Chemistry, School of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
- Correspondence: ; Tel.: +30-23-1099-7721
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5
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Piechocka J, Litwicka N, Głowacki R. Identification and Determination of 1,3-Thiazinane-4-carboxylic Acid in Human Urine-Chromatographic Studies. Int J Mol Sci 2022; 23:598. [PMID: 35054809 PMCID: PMC8776240 DOI: 10.3390/ijms23020598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/23/2021] [Accepted: 01/04/2022] [Indexed: 11/27/2022] Open
Abstract
It is well established that homocysteine (Hcy) and its thiolactone (HTL) are reactive towards aldehydes in an aqueous environment, forming substituted thiazinane carboxylic acids. This report provides evidence that Hcy/HTL and formaldehyde (FA) adduct, namely 1,3-thiazinane-4-carboxylic acid (TCA) is formed in vivo in humans. In order to provide definitive proof, a gas chromatography-mass spectrometry (GC-MS) based method was elaborated to identify and quantify TCA in human urine. The GC-MS assay involves chemical derivatization with isobutyl chloroformate (IBCF) in the presence of pyridine as a catalyst, followed by an ethyl acetate extraction of the obtained isobutyl derivative of TCA (TCA-IBCF). The validity of the method has been demonstrated based upon United States Food and Drug Administration recommendations. The assay linearity was observed within a 1-50 µmol L-1 range for TCA in urine, while the lowest concentration on the calibration curve was recognized as the limit of quantification (LOQ). Importantly, the method was successfully applied to urine samples delivered by apparently healthy volunteers (n = 15). The GC-MS assay may provide a new analytical tool for routine clinical analysis of the role of TCA in living systems in the near future.
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Affiliation(s)
- Justyna Piechocka
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Łódź, Poland;
| | | | - Rafał Głowacki
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Łódź, Poland;
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6
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Purgat K, Kośka I, Kubalczyk P. The Use of Single Drop Microextraction and Field Amplified Sample Injection for CZE Determination of Homocysteine Thiolactone in Urine. Molecules 2021; 26:5687. [PMID: 34577158 DOI: 10.3390/molecules26185687] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 12/03/2022] Open
Abstract
Two cheap, simple and reproducible methods for the electrophoretic determination of homocysteine thiolactone (HTL) in human urine have been developed and validated. The first method utilizes off-line single drop microextraction (SDME), whereas the second one uses off-line SDME in combination with field amplified sample injection (FASI). The off-line SDME protocol consists of the following steps: urine dilution with 0.2 mol/L, pH 8.2 phosphate buffer (1:2, v/v), chloroform addition, drop formation and extraction of HTL. The pre-concentration of HTL inside a separation capillary was performed by FASI. For sample separation, the 0.1 mol/L pH 4.75 phosphate buffer served as the background electrolyte, and HTL was detected at 240 nm. A standard fused-silica capillary (effective length 55.5 cm, 75 μm id) and a separation voltage of 21 kV (~99 μA) were used. Electrophoretic separation was completed within 7 min, whereas the LOD and LOQ for HTL were 0.04 and 0.1 μmol/L urine, respectively. The calibration curve in urine was linear in the range of 0.1–0.5 μmol/L, with R2 = 0.9991. The relative standard deviation of the points of the calibration curve varied from 2.4% to 14.9%. The intra- and inter-day precision and recovery were 6.4–10.2% (average 6.0% and 6.7%) and 94.9–102.7% (average 99.7% and 99.5%), respectively. The analytical procedure was successfully applied to the analysis of spiked urine samples obtained from apparently healthy volunteers.
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7
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Perl A-Kaján J, Malinowska A, Zimny JA, Cysewski D, Suszyńska-Zajczyk J, Jakubowski H. Proteome-Wide Analysis of Protein Lysine N-Homocysteinylation in Saccharomyces cerevisiae. J Proteome Res 2021; 20:2458-2476. [PMID: 33797904 DOI: 10.1021/acs.jproteome.0c00937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein N-homocysteinylation by a homocysteine (Hcy) metabolite, Hcy-thiolactone, is an emerging post-translational modification (PTM) that occurs in all tested organisms and has been linked to human diseases. The yeast Saccharomyces cerevisiae is widely used as a model eukaryotic organism in biomedical research, including studies of protein PTMs. However, patterns of global protein N-homocysteinylation in yeast are not known. Here, we identified 68 in vivo and 197 in vitro N-homocysteinylation sites at protein lysine residues (N-Hcy-Lys). Some of the N-homocysteinylation sites overlap with other previously identified PTM sites. Protein N-homocysteinylation in vivo, induced by supplementation of yeast cultures with Hcy, which elevates Hcy-thiolactone levels, was accompanied by significant changes in the levels of 70 yeast proteins (38 up-regulated and 32 down-regulated) involved in the ribosomal structure, amino acid biosynthesis, and basic cellular pathways. Our study provides the first global survey of N-homocysteinylation and accompanying changes in the yeast proteome caused by elevated Hcy level. These findings suggest that protein N-homocysteinylation and dysregulation of cellular proteostasis may contribute to the toxicity of Hcy in yeast. Homologous proteins and N-homocysteinylation sites are likely to be involved in Hcy-related pathophysiology in humans and experimental animals. Data are available via ProteomeXchange with identifier PXD020821.
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Affiliation(s)
- Joanna Perl A-Kaján
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań 60-632, Poland
| | - Agata Malinowska
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, PAS, Warsaw 02-106, Poland
| | - Jarosl Aw Zimny
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań 60-632, Poland
| | - Dominik Cysewski
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, PAS, Warsaw 02-106, Poland
| | - Joanna Suszyńska-Zajczyk
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań 60-632, Poland
| | - Hieronim Jakubowski
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań 60-632, Poland.,International Center for Public Health, Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, New Jersey 07103, United States
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8
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Piechocka J, Wieczorek M, Głowacki R. Gas Chromatography-Mass Spectrometry Based Approach for the Determination of Methionine-Related Sulfur-Containing Compounds in Human Saliva. Int J Mol Sci 2020; 21:ijms21239252. [PMID: 33291575 PMCID: PMC7729597 DOI: 10.3390/ijms21239252] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/28/2020] [Accepted: 12/02/2020] [Indexed: 12/12/2022] Open
Abstract
Gas chromatography-mass spectrometry technique (GC-MS) is mainly recognized as a tool of first choice when volatile compounds are determined. Here, we provide the credible evidence that its application in analysis can be extended to non-volatile sulfur-containing compounds, to which methionine (Met), homocysteine (Hcy), homocysteine thiolactone (HTL), and cysteine (Cys) belong. To prove this point, the first method, based on GC-MS, for the identification and quantification of Met-related compounds in human saliva, has been elaborated. The assay involves simultaneous disulfides reduction with tris(2-carboxyethyl)phosphine (TCEP) and acetonitrile (MeCN) deproteinization, followed by preconcentration by drying under vacuum and treatment of the residue with a derivatizing mixture containing anhydrous pyridine, N-trimethylsilyl-N-methyl trifluoroacetamide (MSTFA), and trimethylchlorosilane (TMCS). The validity of the method was demonstrated based upon US FDA recommendations. The assay linearity was observed over the range of 0.5-20 µmol L-1 for Met, Hcy, Cys, and 1-20 µmol L-1 for HTL in saliva. The limit of quantification (LOQ) equals 0.1 µmol L-1 for Met, Hcy, Cys, while its value for HTL was 0.05 µmol L-1. The method was successfully applied to saliva samples donated by apparently healthy volunteers (n = 10).
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Affiliation(s)
- Justyna Piechocka
- Correspondence: (J.P.); (R.G.); Tel.: +48-42-635-58-46 (J.P.); +48-42-635-58-35 (R.G.)
| | | | - Rafał Głowacki
- Correspondence: (J.P.); (R.G.); Tel.: +48-42-635-58-46 (J.P.); +48-42-635-58-35 (R.G.)
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9
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Parada-Turska J, Wójcicka G, Beltowski J. Paraoxonase 1 Phenotype and Protein N-Homocysteinylation in Patients with Rheumatoid Arthritis: Implications for Cardiovascular Disease. Antioxidants (Basel) 2020; 9:antiox9090899. [PMID: 32967340 PMCID: PMC7555791 DOI: 10.3390/antiox9090899] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/13/2022] Open
Abstract
Paraoxonase 1 (PON1) is the high density lipoprotein-associated esterase which inhibits the development of atherosclerosis by metabolizing lipid peroxidation products as well as hydrolyzing proatherogenic metabolite of homocysteine (Hcy), Hcy thiolactone, which otherwise reacts with lysine groups of proteins, thus forming N-Hcy-protein in a process referred to as protein N-homocysteinylation. Rheumatoid arthritis (RA) is the chronic inflammatory autoimmune disease associated with increased risk of cardiovascular complications, but the underlying mechanisms are incompletely understood. We examined PON1 status and N-homocysteinylation of serum proteins in patients with RA. Blood was collected from 74 RA patients and 70 control subjects. PON1 activity was measured toward synthetic (paraoxon, phenyl acetate) and natural (Hcy thiolactone) substrates. PON1 protein concentration was measured by ELISA. Total Hcy as well as N-Hcy-protein were measured in serum as well. PON1 activity toward Hcy thiolactone was lower in RA patients than in control subjects which was accompanied by increased concentration of N-Hcy-protein despite normal total Hcy concentration. PON1 protein concentration was unchanged in the RA group, but the specific enzyme activity was reduced. When RA patients were categorized according to the DAS28-ESR score, PON1 concentration and enzymatic activity were lower whereas N-Hcy-protein was higher in those with high disease activity. PON1 activity and Hcy thiolactone were correlated with DAS28-ESR score and myeloperoxidase concentration. In conclusion, RA is associated with deficiency of PON1 activity and increased protein N-homocyseinylation which may contribute to accelerated development of cardiovascular diseases.
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Affiliation(s)
- Jolanta Parada-Turska
- Department of Rheumatology and Connective Tissue Diseases, Medical University, 20-090 Lublin, Poland;
| | - Grażyna Wójcicka
- Department of Pathophysiology, Medical University, 20-090 Lublin, Poland;
| | - Jerzy Beltowski
- Department of Pathophysiology, Medical University, 20-090 Lublin, Poland;
- Correspondence: ; Tel.: +48-81-4486500
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Dobrynin S, Kutseikin S, Morozov D, Krumkacheva O, Spitsyna A, Gatilov Y, Silnikov V, Angelovski G, Bowman MK, Kirilyuk I, Chubarov A. Human Serum Albumin Labelled with Sterically-Hindered Nitroxides as Potential MRI Contrast Agents. Molecules 2020; 25:E1709. [PMID: 32276437 DOI: 10.3390/molecules25071709] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 11/29/2022] Open
Abstract
Four albumin-nitroxide conjugates were prepared and tested as metal-free organic radical contrast agents (ORCAs) for magnetic resonance imaging (MRI). Each human serum albumin (HSA) carrier bears multiple nitroxides conjugated via homocysteine thiolactones. These molecular conjugates retain important physical and biological properties of their HSA component, and the resistance of their nitroxide groups to bioreduction was retained or enhanced. The relaxivities are similar for these four conjugates and are much greater than those of their individual components: the HSA or the small nitroxide molecules. This new family of conjugates has excellent prospects for optimization as ORCAs.
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11
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Gątarek P, Rosiak A, Borowczyk K, Głowacki R, Kałużna-Czaplińska J. Higher Levels of Low Molecular Weight Sulfur Compounds and Homocysteine Thiolactone in the Urine of Autistic Children. Molecules 2020; 25:E973. [PMID: 32098164 DOI: 10.3390/molecules25040973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 12/23/2022] Open
Abstract
In this study, the levels of concentration of homocysteine thiolactone (HTL), cysteine (Cys), and cysteinylglycine (CysGly) in the urine of autistic and non-autistic children were investigated and compared. HTL has never been analyzed in autistic children. The levels of low molecular weight sulfur compounds in the urine of both groups were determined by validated methods based on high-performance liquid chromatography with spectrofluorometric and diode-array detectors. The statistical data show a significant difference between the examined groups. Children with autism were characterized by a significantly higher level of HTL (p = 5.86 × 10−8), Cys (p = 1.49 × 10−10) and CysGly (p = 1.06 × 10−8) in urine compared with the control group. A difference in the p-value of <0.05 is statistically significant. Higher levels of HTL, Cys, and CysGly in the urine of 41 children with autism, aged 3 to 17, were observed. The obtained results may indicate disturbances in the metabolism of methionine, Cys, and glutathione in some autistic patients. These preliminary results suggest that further research with more rigorous designs and a large number of subjects is needed.
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12
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Perła-Kaján J, Jakubowski H. Dysregulation of Epigenetic Mechanisms of Gene Expression in the Pathologies of Hyperhomocysteinemia. Int J Mol Sci 2019; 20:E3140. [PMID: 31252610 DOI: 10.3390/ijms20133140] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 02/07/2023] Open
Abstract
Hyperhomocysteinemia (HHcy) exerts a wide range of biological effects and is associated with a number of diseases, including cardiovascular disease, dementia, neural tube defects, and cancer. Although mechanisms of HHcy toxicity are not fully uncovered, there has been a significant progress in their understanding. The picture emerging from the studies of homocysteine (Hcy) metabolism and pathophysiology is a complex one, as Hcy and its metabolites affect biomolecules and processes in a tissue- and sex-specific manner. Because of their connection to one carbon metabolism and editing mechanisms in protein biosynthesis, Hcy and its metabolites impair epigenetic control of gene expression mediated by DNA methylation, histone modifications, and non-coding RNA, which underlies the pathology of human disease. In this review we summarize the recent evidence showing that epigenetic dysregulation of gene expression, mediated by changes in DNA methylation and histone N-homocysteinylation, is a pathogenic consequence of HHcy in many human diseases. These findings provide new insights into the mechanisms of human disease induced by Hcy and its metabolites, and suggest therapeutic targets for the prevention and/or treatment.
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13
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Silla Y, Varshney S, Ray A, Basak T, Zinellu A, Sabareesh V, Carru C, Sengupta S. Hydrolysis of homocysteine thiolactone results in the formation of Protein-Cys-S-S-homocysteinylation. Proteins 2019; 87:625-634. [PMID: 30869815 DOI: 10.1002/prot.25681] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 01/31/2019] [Accepted: 02/17/2019] [Indexed: 11/07/2022]
Abstract
An increased level of homocysteine, a reactive thiol amino acid, is associated with several complex disorders and is an independent risk factor for cardiovascular disease. A majority (>80%) of circulating homocysteine is protein bound. Homocysteine exclusively binds to protein cysteine residues via thiol disulfide exchange reaction, the mechanism of which has been reported. In contrast, homocysteine thiolactone, the cyclic thioester of homocysteine, is believed to exclusively bind to the primary amine group of lysine residue leading to N-homocysteinylation of proteins and hence studies on binding of homocysteine thiolactone to proteins thus far have only focused on N-homocysteinylation. Although it is known that homocysteine thiolactone can hydrolyze to homocysteine at physiological pH, surprisingly the extent of S-homocysteinylation during the exposure of homocysteine thiolactone with proteins has never been looked into. In this study, we clearly show that the hydrolysis of homocysteine thiolactone is pH dependent, and at physiological pH, 1 mM homocysteine thiolactone is hydrolysed to ~0.71 mM homocysteine within 24 h. Using albumin, we also show that incubation of HTL with albumin leads to a greater proportion of S-homocysteinylation (0.41 mol/mol of albumin) than N-homocysteinylation (0.14 mol/mol of albumin). S-homocysteinylation at Cys34 of HSA on treatment with homocysteine thiolactone was confirmed using LC-MS. Further, contrary to earlier reports, our results indicate that there is no cross talk between the cysteine attached to Cys34 of albumin and homocysteine attached to lysine residues.
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Affiliation(s)
- Yumnam Silla
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, Delhi, India
| | - Swati Varshney
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, Delhi, India
| | - Arjun Ray
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, Delhi, India
| | - Trayambak Basak
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, Delhi, India
| | - Angelo Zinellu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Varatharajan Sabareesh
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
| | - Ciriaco Carru
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
- Quality Control Unit, University Hospital of Sassari (AOU Sassari), Sassari, Italy
| | - Shantanu Sengupta
- Department of Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, New Delhi, Delhi, India
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, Delhi, India
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14
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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15
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Gałczyński K, Bełtowski J, Nowakowski Ł, Vasilevska D, Rechberger T, Semczuk A. Serum paraoxonase 1 activity and protein N-homocysteinylation in primary human endometrial cancer. Tumour Biol 2018; 40:1010428318797869. [PMID: 30178714 DOI: 10.1177/1010428318797869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Paraoxonase 1 plays an important role in protection from oxidative stress and also decomposes homocysteine thiolactone, the toxic metabolite of homocysteine. A limited number of reports evaluated the role of paraoxonase 1 in women affected by female genital tract neoplasms, including endometrial cancer. This study aimed to analyze the paraoxonase activity in the group of endometrial cancer patients (n = 48) who underwent primary surgery and to compare the data available with a well-matched control group (n = 30). Due to the role of paraoxonase 1 in the metabolism of homocysteine (Hcy) thiolactone, the amount of Hcy-thiolactone as well as total serum Hcy concentrations was also measured. Serum paraoxonase 1 activity toward synthetic substrates, paraoxon and phenyl acetate, in the study group was significantly lower compared to the control one. The mean paraoxonase 1 activity toward homocysteine thiolactone tended to be lower in the endometrial cancer group but this difference was not significant. There was no relationship between endometrial cancer and Q192R polymorphism of PON1 assessed by the dual substrate method. No differences in paraoxonase 1 activity between endometrial cancer subgroups according to clinico-pathological features were detected. Total serum homocysteine and protein-bound homocysteine thiolactone did not differ between control and cancer groups. In conclusion, reduced paraoxonase 1 activity suggests diminished important antioxidant mechanisms during the development of primary endometrial cancers in humans. PON1 Q192R polymorphism is not associated with the risk of endometrial cancer. Despite lower paraoxonase 1 activity, homocysteine concentration, and protein N-homocysteinylation in endometrial cancers do not differ from matched controls.
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Affiliation(s)
| | - Jerzy Bełtowski
- 2 Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Łukasz Nowakowski
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
| | - Danuta Vasilevska
- 3 Centre of Obstetrics and Gynecology, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania
| | - Tomasz Rechberger
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
| | - Andrzej Semczuk
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
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16
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Jamroz-Wiśniewska A, Bełtowski J, Bartosik-Psujek H, Wójcicka G, Rejdak K. Processes of plasma protein N-homocysteinylation in multiple sclerosis. Int J Neurosci 2016; 127:709-715. [PMID: 27671515 DOI: 10.1080/00207454.2016.1241782] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Homocysteine thiolactone (HTL) is a cyclic thioester of homocysteine (Hcy) contributing to the toxicity of this amino acid. HTL spontaneously reacts with protein lysine residues leading to altered properties of target proteins and induction of immune response. HTL is hydrolyzed to Hcy by plasma enzyme, paraoxonase 1 (PON1). Although both Hcy and PON1 may be involved in the pathogenesis of multiple sclerosis (MS), protein modification by HTL in this disease has not been studied so far. Purpose/Aim: The aim of this study was to assess the level of Hcy, HTL and autoantibodies against N-homocysteinylated proteins as well as PON1 activity in patients with MS. METHODS The studies were performed in 61 MS patients with relapsing-remitting (RR group, n = 25) and secondary-progressive type of MS (SP group, n = 36), and in healthy people (C - control group, n = 44). RESULTS Homocysteine level was significantly higher in MS patients comparing to control group (C vs. RR p < 0.01; C vs. SP p < 0.05). The level of HTL tended to be higher in RR-MS in comparison to control group, but it did not reach the level of significance. The level of antibodies against N-homocysteinylated proteins did not differ significantly between studied groups. PON1 activity was significantly lower in SP type of MS (SP vs. C p < 0.05; SP vs. RR p < 0.05). CONCLUSIONS Although plasma Hcy concentration is higher in MS patients and PON1 activity is reduced in the SP form, MS is associated with minor or no changes in protein-attached HTL and anti-homocysteinylated protein immune response.
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Affiliation(s)
| | - J Bełtowski
- b Department of Pathophysiology , Lublin Medical University , Lublin , Poland
| | - H Bartosik-Psujek
- c Department of Neurology , University of Rzeszów , Rzeszów , Poland
| | - G Wójcicka
- b Department of Pathophysiology , Lublin Medical University , Lublin , Poland
| | - K Rejdak
- a Department of Neurology , Lublin Medical University , Lublin , Poland
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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18
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Stroylova YY, Semenyuk PI, Asriyantz RA, Gaillard C, Haertlé T, Muronetz VI. Creation of catalytically active particles from enzymes crosslinked with a natural bifunctional agent-- homocysteine thiolactone. Biopolymers 2016; 101:975-84. [PMID: 24912753 DOI: 10.1002/bip.22514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 01/18/2023]
Abstract
The current study describes an approach to creation of catalytically active particles with increased stability from enzymes by N-homocysteinylation, a naturally presented protein modification. Enzymatic activities and properties of two globular tetrameric enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH) were studied before and after N-homocysteinylation. Modification of these proteins concerns the accessible lysine residues and introduces an average of 2-2,5 homocysteine residues per protein monomer. Formation of a range of aggregates was observed for both enzymes, which assemble via formation of intermolecular noncovalent bonds and by disulfide bonds. It was demonstrated that both studied enzymes retain their catalytic activities on modification and the subsequent formation of oligomeric forms. At low concentrations of homocysteine thiolactone, modification of GAPDH leads not only to prevention of spontaneous inactivation but also increases thermal stability of this enzyme on heating to 80°C. A moderate reduction of the activity of GAPDH observed in case of its crosslinking with 50-fold excess of homocysteine thiolactone per lysine is probably caused by hindered substrate diffusion. Spherical particles of 100 nm and larger diameters were observed by transmission electron microscopy and atomic force microscope techniques after modification of GAPDH with different homocysteine thiolactone concentrations. In case of LDH, branched fibril-like aggregates were observed under the same conditions. Interestingly, crosslinked samples of both proteins were found to have reversible thermal denaturation profiles, indicating that modification with homocysteine thiolactone stabilizes the spatial structure of these enzymes.
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Affiliation(s)
- Yulia Y Stroylova
- Faculty of Bioengineering and Bioinformatics, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234, Moscow, Russia
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19
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Wu S, Gao X, Yang S, Meng M, Yang X, Ge B. The role of endoplasmic reticulum stress in endothelial dysfunction induced by homocysteine thiolactone. Fundam Clin Pharmacol 2015; 29:252-9. [PMID: 25623775 DOI: 10.1111/fcp.12101] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 08/21/2014] [Accepted: 01/20/2015] [Indexed: 12/21/2022]
Abstract
Our and other studies have reported that homocysteine thiolactone (HTL) could induce endothelial dysfunction. However, the precise mechanism was largely unknown. In this study, we tested the most possible factor-endoplasmic reticulum (ER) stress, which was demonstrated to be involved in endothelial dysfunction in cardiovascular disease. Acetylcholine (Ach)-induced endothelium-dependent relaxation (EDR) and biochemical parameters were measured in rat isolated aorta. The level of reactive oxygen species (ROS) and NO was designed by specific fluorescent probe DCFH-DA and DAF-FM DA separately. The nuclear translocation of the NF-κB was studied by immune-fluorescence. The mRNA expression and protein expression of GRP78--a key indicator for the induction of ER stress--were assessed by real-time PCR and Western blot. Two ER stress inhibitors-4-PBA (5 mm) and Tudca (500 μg/mL)--significantly prevented HTL-impaired EDR and increased NO release, endothelial nitric oxide synthase (eNOS) and SOD activity, decreased ROS production, NADPH activity, NOX-4 mRNA and MDA level. We also found that 4-PBA and Tudca blocked HTL--induced NF-κB activation thus inhibiting the downstream target gene production including TNF-α and ICAM-1. Simultaneously, HTL increased the mRNA and protein level of GRP78. HTL could induce ER stress leading to a downstream enhancement of oxidative stress and inflammation, which finally caused vascular endothelial dysfunction.
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Affiliation(s)
- Shujin Wu
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
| | - Xiang Gao
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
| | - Shehua Yang
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
| | - Min Meng
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
| | - Xiaolai Yang
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
| | - Bin Ge
- Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China
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20
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Yang XH, Li P, Yin YL, Tu JH, Dai W, Liu LY, Wang SX. Rosiglitazone via PPARγ-dependent suppression of oxidative stress attenuates endothelial dysfunction in rats fed homocysteine thiolactone. J Cell Mol Med 2015; 19:826-35. [PMID: 25656735 PMCID: PMC4395197 DOI: 10.1111/jcmm.12510] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 11/17/2014] [Indexed: 02/03/2023] Open
Abstract
To explore whether rosiglitazone (RSG), a selective peroxisome proliferator-activated receptor γ (PPARγ) agonist, exerts beneficial effects on endothelial dysfunction induced by homocysteine thiolactone (HTL) and to investigate the potential mechanisms. Incubation of cultured human umbilical vein endothelial cells with HTL (1 mM) for 24 hrs significantly reduced cell viabilities assayed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, as well as enhanced productions of reactive oxygen species, activation of nuclear factor kappa B, and increased intercellular cell adhesion molecule-1 secretion. Pre-treatment of cells with RSG (0.001–0.1 mM), pyrollidine dithiocarbamate (PDTC, 0.1 mM) or apocynin (0.1 mM) for 1 hr reversed these effects induced by HTL. Furthermore, co-incubation with GW9662 (0.01 mM) abolished the protective effects of RSG on HTL-treated cells. In ex vivo experiments, exposure of isolated aortic rings from. rats to HTL (1 mM) for 1 hr dramatically impaired acetylcholine-induced endothelium-dependent relaxation, reduced release of nitric oxide and activity of superoxide dismutase, and increased malondialdehyde content in aortic tissues. Preincubation of aortic rings with RSG (0.1, 0.3, 1 mM), PDTC or apocynin normalized the disorders induced by HTL. In vivo analysis indicated that administration of RSG (20 mg/kg/d) remarkably suppressed oxidative stress and prevented endothelial dysfunction in rats fed HTL (50 mg/kg/d) for 8 weeks. RSG improves endothelial functions in rats fed HTL, which is related to PPARγ-dependent suppression of oxidative stress.
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Affiliation(s)
- Xu-Hong Yang
- Department of Pharmacology, Pharmaceutical College, Central South University, Changsha, China
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