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Elkhateeb N, Hyde S, Hogg SL, Allsop D, Shankar A, Deegan P, Tan CY. Paracetamol toxicity in classic homocystinuria: Effect of N-acetylcysteine on total homocysteine. JIMD Rep 2023; 64:238-245. [PMID: 37151359 PMCID: PMC10159864 DOI: 10.1002/jmd2.12363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/06/2023] Open
Abstract
Classical homocystinuria (HCU) is caused by cystathionine β-synthase deficiency leading to impaired homocysteine transsulfuration and accumulation of homocysteine and methionine. Patients present with a wide spectrum of manifestations including ocular, skeletal, neuropsychiatric, and vascular manifestations. We report a 48-year-old female with pyridoxine-unresponsive HCU treated with betaine, cyanocobalamin, and folate. Her diet was non-restricted due to intolerance of low-methionine diet. She was admitted to hospital following a fall, with multiple fractures and subsequently developed acute liver failure with encephalopathy. Shock, sepsis, and liver ischaemia/thrombosis were excluded. In the context of glutathione depletion expected in HCU, hepatic dysfunction was presumed to be due to iatrogenic paracetamol toxicity, despite paracetamol intake at conventional therapeutic dose, with role of hypermethioninemia as a contributing factor being uncertain. Betaine was discontinued on hospital admission. N-Acetylcysteine (NAC) infusion was initiated. Plasma total homocysteine (tHcy) was 3.4 μmol/L 9 days following initiation of NAC treatment with a markedly elevated plasma methionine of 1278 μmol/L. tHcy concentration returned to pre-admission baseline after NAC was discontinued. Recovery following this episode was slow with a prolonged cholestatic phase and gradual improvement in jaundice and coagulopathy. We recommend that paracetamol should be administered cautiously in HCU patients due to underlying glutathione depletion and risk of toxicity even at therapeutic doses. NAC is clearly effective in lowering tHcy in classical HCU in the short-term however further research is required to assess clinical efficacy and use as a potential therapy in classical HCU.
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Affiliation(s)
- Nour Elkhateeb
- Department of Metabolic MedicineCambridge University hospitals NHS Foundation TrustCambridgeUK
- Department of Clinical GeneticsCambridge University hospitals NHS Foundation TrustCambridgeUK
| | - Sarah Hyde
- Department of GastroenterologyNorfolk and Norwich University Hospital NHS TrustNorwichUK
| | - Sarah L. Hogg
- Biochemical Genetics UnitCambridge University Hospitals NHS Foundation TrustCambridgeUK
| | - Daniel Allsop
- Department of HistopathologyNorfolk and Norwich University Hospitals NHS TrustNorwichUK
| | - Arun Shankar
- Department of GastroenterologyNorfolk and Norwich University Hospital NHS TrustNorwichUK
| | - Patrick Deegan
- Department of Metabolic MedicineCambridge University hospitals NHS Foundation TrustCambridgeUK
| | - Chong Y. Tan
- Department of Metabolic MedicineCambridge University hospitals NHS Foundation TrustCambridgeUK
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2
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Mele S, Martelli F, Lin J, Kanca O, Christodoulou J, Bellen HJ, Piper MDW, Johnson TK. Drosophila as a diet discovery tool for treating amino acid disorders. Trends Endocrinol Metab 2023; 34:85-105. [PMID: 36567227 DOI: 10.1016/j.tem.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
Amino acid disorders (AADs) are a large group of rare inherited conditions that collectively impact one in 6500 live births, often resulting in rapid neurological decline and death during infancy. For several AADs, including phenylketonuria, dietary modification prevents physiological deterioration and ameliorates symptoms. Despite this remarkable potential for treatment success, dietary therapy for most AADs remains largely unexplored. Although animal models have provided novel insights into AAD mechanisms, few have been used for therapeutic diet discovery. Here, we find that of all the animal models, Drosophila is particularly well suited for nutrigenomic disease modelling, having amino acid pathways conserved with humans, exceptional genetic tractability, and the unique availability of a synthetic customisable diet.
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Affiliation(s)
- Sarah Mele
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Felipe Martelli
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Jiayi Lin
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Duncan Neurological Research Institute of Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - John Christodoulou
- Murdoch Children's Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Duncan Neurological Research Institute of Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - Matthew D W Piper
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
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Al-Shabrawey M, Elmarakby A, Samra Y, Moustafa M, Looney SW, Maddipati KR, Tawfik A. Hyperhomocysteinemia dysregulates plasma levels of polyunsaturated fatty acids-derived eicosanoids. LIFE RESEARCH 2022; 5:14. [PMID: 36341141 PMCID: PMC9632953 DOI: 10.53388/2022-0106-103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Hyperhomocysteinemia (HHcy) contributes to the incidence of many cardiovascular diseases (CVD). Our group have previously established crucial roles of eicosanoids and homocysteine in the incidence of vascular injury in diabetic retinopathy and renal injury. Using cystathionine-β-synthase heterozygous mice (cβs+/-) as a model of HHcy, the current study was designed to determine the impact of homocysteine on circulating levels of lipid mediators derived from polyunsaturated fatty acids (PUFA). Plasma samples were isolated from wild-type (WT) and cβs+/- mice for the assessment of eicosanoids levels using LC/MS. Plasma 12/15-lipoxygenase (12/15-LOX) activity significantly decreased in cβs+/- vs. WT control mice. LOX-derived metabolites from both omega-3 and omega-6 PUFA were also reduced in cβs+/- mice compared to WT control (P < 0.05). Contrary to LOX metabolites, cytochrome P450 (CYP) metabolites from omega-3 and omega-6 PUFA were significantly elevated in cβs+/- mice compared to WT control. Epoxyeicosatrienoic acids (EETs) are epoxides derived from arachidonic acid (AA) metabolism by CYP with anti-inflammatory properties and are known to limit vascular injury, however their physiological role is limited by their rapid degradation by soluble epoxide hydrolase (sEH) to their corresponding diols (DiHETrEs). In cβs+/- mice, a significant decrease in the plasma EETs bioavailability was obvious as evident by the decrease in EETs/ DiHETrEs ratio relative to WT control mice. Cyclooxygenase (COX) metabolites were also significantly decreased in cβs+/- vs. WT control mice. These data suggest that HHcy impacts eicosanoids metabolism through decreasing LOX and COX metabolic activities while increasing CYP metabolic activity. The increase in AA metabolism by CYP was also associated with increase in sEH activity and decrease in EETs bioavailability. Dysregulation of eicosanoids metabolism could be a contributing factor to the incidence and progression of HHcy-induced CVD.
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Affiliation(s)
- Mohamed Al-Shabrawey
- Department of Foundational Medical Studies and Eye Research Center, Oakland University William Beaumont School of Medicine, Rochester, Michigan, USA
- Eye Research Institute, Oakland University, Rochester, Michigan, USA
| | - Ahmed Elmarakby
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, Georgia, USA
- Departments of Pharmacology & Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Yara Samra
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, Georgia, USA
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Egypt
| | - Mohamed Moustafa
- Department of Foundational Medical Studies and Eye Research Center, Oakland University William Beaumont School of Medicine, Rochester, Michigan, USA
- Eye Research Institute, Oakland University, Rochester, Michigan, USA
| | - Stephen W. Looney
- Department of Population Health Sciences, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Krishna Rao Maddipati
- Bioactive Lipids Research Program, Department of Pathology, Wayne State University, Michigan, USA
| | - Amany Tawfik
- Department of Foundational Medical Studies and Eye Research Center, Oakland University William Beaumont School of Medicine, Rochester, Michigan, USA
- Eye Research Institute, Oakland University, Rochester, Michigan, USA
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4
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Shaposhnikov MV, Zakluta AS, Zemskaya NV, Guvatova ZG, Shilova VY, Yakovleva DV, Gorbunova AA, Koval LA, Ulyasheva NS, Evgen'ev MB, Zatsepina OG, Moskalev AA. Deletions of the cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) genes, involved in the control of hydrogen sulfide biosynthesis, significantly affect lifespan and fitness components of Drosophila melanogaster. Mech Ageing Dev 2022; 203:111656. [PMID: 35247392 DOI: 10.1016/j.mad.2022.111656] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/02/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022]
Abstract
The gasotransmitter hydrogen sulfide (H2S) is an important biological mediator, playing an essential role in many physiological and pathological processes. It is produced by transsulfuration - an evolutionarily highly conserved pathway for the metabolism of sulfur-containing amino acids methionine and cysteine. Cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) enzymes play a central role in cysteine metabolism and H2S production. Here we investigated the fitness components (longevity, stress resistance, viability of preimaginal stages, and reproductive function parameters) in D. melanogaster lines containing deletions of the CBS and CSE genes. Surprisingly, in most tests, CSE deletion improved, and CBS worsened the fitness. Lines with deletion of both CBS and CSE demonstrated better stress resistance and longevity than lines with single CBS deletion. At the same time, deletion of both CBS and CSE genes causes more serious disturbances of reproductive function parameters than single CBS deletion. Thus, a complex interaction of H2S-producing pathways and cellular stress response in determining the lifespan and fitness components of the whole organism was revealed.
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Affiliation(s)
- Mikhail V Shaposhnikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation; Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Alexey S Zakluta
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Nadezhda V Zemskaya
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Zulfiya G Guvatova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Victoria Y Shilova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Daria V Yakovleva
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Anastasia A Gorbunova
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Liubov A Koval
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Natalia S Ulyasheva
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.
| | - Mikhail B Evgen'ev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Olga G Zatsepina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
| | - Alexey A Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation; Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation; Center for Precision Genome Editing and Genetic Technologies for Biomedicine Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation.
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5
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Vitamin B 12 Attenuates Acute Pancreatitis by Suppressing Oxidative Stress and Improving Mitochondria Dysfunction via CBS/SIRT1 Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7936316. [PMID: 34925701 PMCID: PMC8677375 DOI: 10.1155/2021/7936316] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/22/2021] [Accepted: 11/06/2021] [Indexed: 02/07/2023]
Abstract
Acute pancreatitis is an inflammatory disorder of the pancreas associated with substantial morbidity and mortality, which is characterized by a rapid depletion of glutathione (GSH). Cysthionine-β-synthase (CBS) is a key coenzyme in GSH synthesis, and its deficiency is related to a variety of clinical diseases. However, whether CBS is involved in the pathogenesis of acute pancreatitis remains unclear. First, we found that CBS was downregulated in both in vivo and in vitro AP models. The pancreatic damage and acinar cell necrosis related to CBS deficiency were significantly improved by VB 12, which stimulated clearance of reactive oxygen species (ROS) by conserving GSH. Furthermore, EX-527 (a specific inhibitor of SIRT1) exposure counteracted the protective effect of VB 12 by promoting oxidative stress and aggravating mitochondrial damage without influencing CBS, indicating that vitamin B12 regulates SIRT1 to improve pancreatical damage by activating CBS. In conclusion, we found that VB 12 protected acute pancreatitis associated with oxidative stress via CBS/SIRT1 pathway.
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6
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Sokolov AS, Nekrasov PV, Shaposhnikov MV, Moskalev AA. Hydrogen sulfide in longevity and pathologies: Inconsistency is malodorous. Ageing Res Rev 2021; 67:101262. [PMID: 33516916 DOI: 10.1016/j.arr.2021.101262] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/18/2021] [Accepted: 01/24/2021] [Indexed: 02/08/2023]
Abstract
Hydrogen sulfide (H2S) is one of the biologically active gases (gasotransmitters), which plays an important role in various physiological processes and aging. Its production in the course of methionine and cysteine catabolism and its degradation are finely balanced, and impairment of H2S homeostasis is associated with various pathologies. Despite the strong geroprotective action of exogenous H2S in C. elegans, there are controversial effects of hydrogen sulfide and its donors on longevity in other models, as well as on stress resistance, age-related pathologies and aging processes, including regulation of senescence-associated secretory phenotype (SASP) and senescent cell anti-apoptotic pathways (SCAPs). Here we discuss that the translation potential of H2S as a geroprotective compound is influenced by a multiplicity of its molecular targets, pleiotropic biological effects, and the overlapping ranges of toxic and beneficial doses. We also consider the challenges of the targeted delivery of H2S at the required dose. Along with this, the complexity of determining the natural levels of H2S in animal and human organs and their ambiguous correlations with longevity are reviewed.
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7
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Eyob W, George AK, Homme RP, Stanisic D, Sandhu H, Tyagi SC, Singh M. Regulation of the parental gene GRM4 by circGrm4 RNA transcript and glutamate-mediated neurovascular toxicity in eyes. Mol Cell Biochem 2020; 476:663-673. [PMID: 33074445 DOI: 10.1007/s11010-020-03934-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/07/2020] [Indexed: 01/30/2023]
Abstract
Epigenetic memory plays crucial roles in gene regulation. It not only modulates the expression of specific genes but also has ripple effects on transcription as well as translation of other genes. Very often an alteration in expression occurs either via methylation or demethylation. In this context, "1-carbon metabolism" assumes a special significance since its dysregulation by higher levels of homocysteine; Hcy (known as hyperhomocysteinemia; HHcy), a byproduct of "1-Carbon Metabolism" during methionine biosynthesis leads to serious implications in cardiovascular, renal, cerebrovascular systems, and a host of other conditions. Currently, the circular RNAs (circRNAs) generated via non-canonical back-splicing events from the pre-mRNA molecules are at the center stage for their essential roles in diseases via their epigenetic manifestations. We recently identified a circular RNA transcript (circGRM4) that is significantly upregulated in the eye of cystathionine β-synthase-deficient mice. We also discovered a concurrent over-expression of the mGLUR4 receptor in the eyes of these mice. In brief, circGRM4 is selectively transcribed from its parental mGLUR4 receptor gene (GRM4) functions as a "molecular-sponge" for the miRNAs and results into excessive turnover of the mGLUR4 receptor in the eye in response to extremely high circulating glutamate concentration. We opine that this epigenetic manifestation potentially predisposes HHcy people to retinovascular malfunctioning.
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Affiliation(s)
- Wintana Eyob
- College of Arts and Sciences, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA
| | - Akash K George
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Rubens P Homme
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Dragana Stanisic
- Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Harpal Sandhu
- Department of Ophthalmology and Visual Sciences and Kentucky Lions Eye Center, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Suresh C Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
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8
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Zuhra K, Augsburger F, Majtan T, Szabo C. Cystathionine-β-Synthase: Molecular Regulation and Pharmacological Inhibition. Biomolecules 2020; 10:E697. [PMID: 32365821 PMCID: PMC7277093 DOI: 10.3390/biom10050697] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/11/2022] Open
Abstract
Cystathionine-β-synthase (CBS), the first (and rate-limiting) enzyme in the transsulfuration pathway, is an important mammalian enzyme in health and disease. Its biochemical functions under physiological conditions include the metabolism of homocysteine (a cytotoxic molecule and cardiovascular risk factor) and the generation of hydrogen sulfide (H2S), a gaseous biological mediator with multiple regulatory roles in the vascular, nervous, and immune system. CBS is up-regulated in several diseases, including Down syndrome and many forms of cancer; in these conditions, the preclinical data indicate that inhibition or inactivation of CBS exerts beneficial effects. This article overviews the current information on the expression, tissue distribution, physiological roles, and biochemistry of CBS, followed by a comprehensive overview of direct and indirect approaches to inhibit the enzyme. Among the small-molecule CBS inhibitors, the review highlights the specificity and selectivity problems related to many of the commonly used "CBS inhibitors" (e.g., aminooxyacetic acid) and provides a comprehensive review of their pharmacological actions under physiological conditions and in various disease models.
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Affiliation(s)
- Karim Zuhra
- Chair of Pharmacology, Section of Medicine, University of Fribourg, 1702 Fribourg, Switzerland; (K.Z.); (F.A.)
| | - Fiona Augsburger
- Chair of Pharmacology, Section of Medicine, University of Fribourg, 1702 Fribourg, Switzerland; (K.Z.); (F.A.)
| | - Tomas Majtan
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Csaba Szabo
- Chair of Pharmacology, Section of Medicine, University of Fribourg, 1702 Fribourg, Switzerland; (K.Z.); (F.A.)
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9
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Imbalance of Homocysteine and H 2S: Significance, Mechanisms, and Therapeutic Promise in Vascular Injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7629673. [PMID: 31885816 PMCID: PMC6893243 DOI: 10.1155/2019/7629673] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/16/2019] [Indexed: 12/28/2022]
Abstract
While the role of hyperhomocysteinemia in cardiovascular pathogenesis continuously draws attention, deficiency of hydrogen sulfide (H2S) has been growingly implicated in cardiovascular diseases. Generation of H2S is closely associated with the metabolism of homocysteine via key enzymes such as cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE). The level of homocysteine and H2S is regulated by each other. Metabolic switch in the activity of CBS and CSE may occur with a resultant operating preference change of these enzymes in homocysteine and H2S metabolism. This paper presented an overview regarding (1) linkage between the metabolism of homocysteine and H2S, (2) mutual regulation of homocysteine and H2S, (3) imbalance of homocysteine and H2S in cardiovascular disorders, (4) mechanisms underlying the protective effect of H2S against homocysteine-induced vascular injury, and (5) the current status of homocysteine-lowering and H2S-based therapies for cardiovascular disease. The metabolic imbalance of homocysteine and H2S renders H2S/homocysteine ratio a potentially reliable biomarker for cardiovascular disease and development of drugs or interventions targeting the interplay between homocysteine and H2S to maintain the endogenous balance of these two molecules may hold an even bigger promise for management of vascular disorders than targeting homocysteine or H2S alone.
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10
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Majtan T, Park I, Cox A, Branchford BR, di Paola J, Bublil EM, Kraus JP. Behavior, body composition, and vascular phenotype of homocystinuric mice on methionine-restricted diet or enzyme replacement therapy. FASEB J 2019; 33:12477-12486. [PMID: 31450979 DOI: 10.1096/fj.201901203r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Classic homocystinuria (HCU) is an inherited disorder characterized by elevated homocysteine (Hcy) in plasma and tissues resulting from cystathionine β-synthase (CBS) deficiency. There is no cure, and patients are predominantly managed by methionine-restricted diet (MRD) to limit the production of Hcy. In this study, we used the I278T mouse model of HCU to evaluate the long-term impact of a novel enzyme replacement therapy [truncated human CBS C15S mutant modified with linear 20-kDa N-hydroxysuccinimide ester polyethylene glycol (OT-58)] on clinical end points relevant to human patients with HCU. In addition, we compared its efficacy on a background of either MRD or normal methionine intake [regular diet (REG)] to that of MRD alone. We found that, compared with untreated I278T mice, OT-58 treatment of I278T mice fed with the REG diet resulted in a 90% decrease in plasma Hcy concentrations and correction of learning/cognition, endothelial dysfunction, hemostasis, bone mineralization, and body composition. On background of the MRD, OT-58 performed equally well with plasma Hcy entirely normalized. The MRD alone decreased plasma Hcy by 67% and corrected the HCU phenotype in I278T mice. However, the MRD increased anxiety and reduced bone mineral content in both I278T mice and wild-type controls. This study shows that OT-58 is a highly efficacious novel treatment for HCU on the background of either normal or restricted methionine intake.-Majtan, T., Park, I., Cox, A., Branchford, B. R., di Paola, J., Bublil, E. M., Kraus, J. P. Behavior, body composition, and vascular phenotype of homocystinuric mice on methionine-restricted diet or enzyme replacement therapy.
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Affiliation(s)
- Tomas Majtan
- Section of Genetics, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Insun Park
- Section of Genetics, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Allaura Cox
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado, USA.,Hemophilia and Thrombosis Center, University of Colorado, Aurora, Colorado, USA
| | - Brian R Branchford
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado, USA.,Hemophilia and Thrombosis Center, University of Colorado, Aurora, Colorado, USA
| | - Jorge di Paola
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, University of Colorado, Aurora, Colorado, USA.,Hemophilia and Thrombosis Center, University of Colorado, Aurora, Colorado, USA
| | - Erez M Bublil
- Orphan Technologies Limited, Rapperswil, Switzerland
| | - Jan P Kraus
- Section of Genetics, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, USA
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11
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Majtan T, Bublil EM, Park I, Arning E, Bottiglieri T, Glavin F, Kraus JP. Pharmacokinetics and pharmacodynamics of PEGylated truncated human cystathionine beta-synthase for treatment of homocystinuria. Life Sci 2018. [PMID: 29526799 DOI: 10.1016/j.lfs.2018.03.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AIMS PEGylated human truncated cystathionine beta-synthase, lacking the C-terminal regulatory domain (PEG-CBS), is a promising preclinical candidate for enzyme replacement therapy in homocystinuria (HCU). It was designed to function as a metabolic sink to decrease the severely elevated plasma and tissue homocysteine concentrations. In this communication, we evaluated pharmacokinetics (PK), pharmacodynamics (PD) and sub-chronic toxicity of PEG-CBS in homocystinuric mice, wild type rats and monkeys to estimate the minimum human efficacious dose for clinical trials. MAIN METHODS Animal models received single or multiple doses of PEG-CBS. Activity of PEG-CBS and sulfur amino acid metabolites were determined in plasma and used to determine PK and PD. KEY FINDINGS The plasma half-lives of PEG-CBS after a single subcutaneous (SC) injection were approximately 20, 44 and 73 h in mouse, rat and monkey, respectively. The SC administration of PEG-CBS resulted in a significant improvement or full correction of metabolic imbalance in both blood and tissues of homocystinuric mice. The PD of PEG-CBS in mouse was dose-dependent, but less than dose-proportional, with the maximal efficacy achieved at 8 mg/kg. PEG-CBS was well-tolerated in mice and monkeys, but resulted in dose-dependent minimal-to-moderate inflammation at the injection sites and vacuolated macrophages in rats. Allometric scaling of animal data was linear and the estimated human efficacious dose was determined as 0.66 mg/kg administered once a week. SIGNIFICANCE These results provide critical preclinical data for the design of first-in-human PEG-CBS clinical trial.
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Affiliation(s)
- Tomas Majtan
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Erez M Bublil
- Orphan Technologies Ltd., Rapperswill CH-8640, Switzerland
| | - Insun Park
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Erland Arning
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA
| | - Teodoro Bottiglieri
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75226, USA
| | - Frank Glavin
- Orphan Technologies Ltd., Rapperswill CH-8640, Switzerland
| | - Jan P Kraus
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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12
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Homocysteine Induces Glial Reactivity in Adult Rat Astrocyte Cultures. Mol Neurobiol 2017; 55:1966-1976. [PMID: 28255907 DOI: 10.1007/s12035-017-0463-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/16/2017] [Indexed: 02/08/2023]
Abstract
Astrocytes are dynamic glial cells associated to neurotransmitter systems, metabolic functions, antioxidant defense, and inflammatory response, maintaining the brain homeostasis. Elevated concentrations of homocysteine (Hcy) are involved in the pathogenesis of age-related neurodegenerative disorders, such as Parkinson and Alzheimer diseases. In line with this, our hypothesis was that Hcy could promote glial reactivity in a model of cortical primary astrocyte cultures from adult Wistar rats. Thus, cortical astrocytes were incubated with different concentrations of Hcy (10, 30, and 100 μM) during 24 h. After the treatment, we analyzed cell viability, morphological parameters, antioxidant defenses, and inflammatory response. Hcy did not induce any alteration in cell viability; however, it was able to induce cytoskeleton rearrangement. The treatment with Hcy also promoted a significant decrease in the activities of Na+, K+ ATPase, superoxide dismutase (SOD), and glutathione peroxidase (GPx), as well as in the glutathione (GSH) content. Additionally, Hcy induced an increase in the pro-inflammatory cytokine release. In an attempt to elucidate the putative mechanisms involved in the Hcy-induced glial reactivity, we measured the nuclear factor kappa B (NFκB) transcriptional activity and heme oxygenase 1 (HO-1) expression, which were activated and inhibited by Hcy, respectively. In summary, our findings provide important evidences that Hcy modulates critical astrocyte parameters from adult rats, which might be associated to the aging process.
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