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Kuang J, Kafetzopoulos V, Deth R, Kocsis B. Dopamine D4 Receptor Agonist Drastically Increases Delta Activity in the Thalamic Nucleus Reuniens: Potential Role in Communication between Prefrontal Cortex and Hippocampus. Int J Mol Sci 2023; 24:15289. [PMID: 37894968 PMCID: PMC10607171 DOI: 10.3390/ijms242015289] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/11/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Network oscillations are essential for all cognitive functions. Oscillatory deficits are well established in psychiatric diseases and are recapitulated in animal models. They are significantly and specifically affected by pharmacological interventions using psychoactive compounds. Dopamine D4 receptor (D4R) activation was shown to enhance gamma rhythm in freely moving rats and to specifically affect slow delta and theta oscillations in the urethane-anesthetized rat model. The goal of this study was to test the effect of D4R activation on slow network oscillations at delta and theta frequencies during wake states, potentially supporting enhanced functional connectivity during dopamine-induced attention and cognitive processing. Network activity was recorded in the prefrontal cortex (PFC), hippocampus (HC) and nucleus reuniens (RE) in control conditions and after injecting the D4R agonist A-412997 (3 and 5 mg/kg; systemic administration). We found that A-412997 elicited a lasting (~40 min) wake state and drastically enhanced narrow-band delta oscillations in the PFC and RE in a dose-dependent manner. It also preferentially enhanced delta synchrony over theta coupling within the PFC-RE-HC circuit, strongly strengthening PFC-RE coupling. Thus, our findings indicate that the D4R may contribute to cognitive processes, at least in part, through acting on wake delta oscillations and that the RE, providing an essential link between the PFC and HC, plays a prominent role in this mechanism.
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Affiliation(s)
- J. Kuang
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; (J.K.); (V.K.)
| | - V. Kafetzopoulos
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; (J.K.); (V.K.)
- Department of Psychiatry, Medical School, University of Ioannina, 45110 Ioannina, Greece
| | - Richard Deth
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, FL 33328, USA;
| | - B. Kocsis
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; (J.K.); (V.K.)
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Tran T, Cruz C, Chan A, Awad S, Rajasingh J, Deth R, Gurusamy N. Mesenchymal Stem Cell-Derived Long Noncoding RNAs in Cardiac Injury and Repair. Cells 2023; 12:2268. [PMID: 37759491 PMCID: PMC10527806 DOI: 10.3390/cells12182268] [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] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/05/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
Cardiac injury, such as myocardial infarction and heart failure, remains a significant global health burden. The limited regenerative capacity of the adult heart poses a challenge for restoring its function after injury. Mesenchymal stem cells (MSCs) have emerged as promising candidates for cardiac regeneration due to their ability to differentiate into various cell types and secrete bioactive molecules. In recent years, attention has been given to noncoding RNAs derived from MSCs, particularly long noncoding RNAs (lncRNAs), and their potential role in cardiac injury and repair. LncRNAs are RNA molecules that do not encode proteins but play critical roles in gene regulation and cellular responses including cardiac repair and regeneration. This review focused on MSC-derived lncRNAs and their implications in cardiac regeneration, including their effects on cardiac function, myocardial remodeling, cardiomyocyte injury, and angiogenesis. Understanding the molecular mechanisms of MSC-derived lncRNAs in cardiac injury and repair may contribute to the development of novel therapeutic strategies for treating cardiovascular diseases. However, further research is needed to fully elucidate the potential of MSC-derived lncRNAs and address the challenges in this field.
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Affiliation(s)
- Talan Tran
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
| | - Claudia Cruz
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
| | - Anthony Chan
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
| | - Salma Awad
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
| | - Johnson Rajasingh
- Department of Bioscience Research, University of Tennessee Health Science Center, 847 Monroe Avenue, Memphis, TN 38163, USA
| | - Richard Deth
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
| | - Narasimman Gurusamy
- Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA
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Shrestha N, Chaturvedi P, Zhu X, Dee MJ, George V, Janney C, Egan JO, Liu B, Foster M, Marsala L, Wong P, Cubitt CC, Foltz JA, Tran J, Schappe T, Hsiao K, Leclerc GM, You L, Echeverri C, Spanoudis C, Carvalho A, Kanakaraj L, Gilkes C, Encalada N, Kong L, Wang M, Fang B, Wang Z, Jiao J, Muniz GJ, Jeng EK, Valdivieso N, Li L, Deth R, Berrien‐Elliott MM, Fehniger TA, Rhode PR, Wong HC. Immunotherapeutic approach to reduce senescent cells and alleviate senescence-associated secretory phenotype in mice. Aging Cell 2023; 22:e13806. [PMID: 36967480 PMCID: PMC10186597 DOI: 10.1111/acel.13806] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 03/29/2023] Open
Abstract
Accumulation of senescent cells (SNCs) with a senescence-associated secretory phenotype (SASP) has been implicated as a major source of chronic sterile inflammation leading to many age-related pathologies. Herein, we provide evidence that a bifunctional immunotherapeutic, HCW9218, with capabilities of neutralizing TGF-β and stimulating immune cells, can be safely administered systemically to reduce SNCs and alleviate SASP in mice. In the diabetic db/db mouse model, subcutaneous administration of HCW9218 reduced senescent islet β cells and SASP resulting in improved glucose tolerance, insulin resistance, and aging index. In naturally aged mice, subcutaneous administration of HCW9218 durably reduced the level of SNCs and SASP, leading to lower expression of pro-inflammatory genes in peripheral organs. HCW9218 treatment also reverted the pattern of key regulatory circadian gene expression in aged mice to levels observed in young mice and impacted genes associated with metabolism and fibrosis in the liver. Single-nucleus RNA Sequencing analysis further revealed that HCW9218 treatment differentially changed the transcriptomic landscape of hepatocyte subtypes involving metabolic, signaling, cell-cycle, and senescence-associated pathways in naturally aged mice. Long-term survival studies also showed that HCW9218 treatment improved physical performance without compromising the health span of naturally aged mice. Thus, HCW9218 represents a novel immunotherapeutic approach and a clinically promising new class of senotherapeutic agents targeting cellular senescence-associated diseases.
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Affiliation(s)
| | | | | | | | | | | | | | - Bai Liu
- HCW Biologics Inc.MiramarFloridaUSA
| | - Mark Foster
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Lynne Marsala
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Pamela Wong
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Celia C. Cubitt
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Jennifer A. Foltz
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Jennifer Tran
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Timothy Schappe
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Karin Hsiao
- Department of Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFloridaUSA
| | | | | | | | | | | | | | | | | | - Lin Kong
- HCW Biologics Inc.MiramarFloridaUSA
| | | | | | | | | | | | | | | | | | - Richard Deth
- Department of Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFloridaUSA
| | | | - Todd A. Fehniger
- Division of OncologyWashington University School of MedicineSt. LouisMissouriUSA
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Schrier M, Zhang Y, Trivedi M, Deth R. Decreased Cortical Nrf2 Gene Expression in Autism Spectrum Disorder and its Relationship to Thiol and Cobalamin status. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.05411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Matthew Schrier
- Pharmaceutical SciencesNova Southeastern UniversityFt. LauderdaleFL
| | | | - Malav Trivedi
- Pharmaceutical SciencesNova Southeastern UniversityFt. LauderdaleFL
| | - Richard Deth
- Pharmaceutical SciencesNova Southeastern UniversityFt. LauderdaleFL
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Dixon S, Deth R, Dong J, Tran A, Schrier M, Trivedi M. Metformin Induced Oxidative Stress Alters Transsulfuration Pathway and Inhibits Prostate Cancer Cell Growth. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.04944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sashana Dixon
- Pharmaceutical ScienceNova Southeastern UniversityFort LauderdaleFL
| | - Richard Deth
- Pharmaceutical ScienceNova Southeastern UniversityFort LauderdaleFL
| | - Jianan Dong
- Pharmaceutical ScienceNova Southeastern UniversityFort LauderdaleFL
| | - Alice Tran
- Halmos College of Arts and SciencesNova Southeastern UniversityFort LauderdaleFL
| | - Matthew Schrier
- Pharmaceutical ScienceNova Southeastern UniversityFort LauderdaleFL
| | - Malav Trivedi
- Pharmaceutical ScienceNova Southeastern UniversityFort LauderdaleFL
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Yamada C, Akkaoui J, Ho A, Duarte C, Deth R, Kawai T, Nichols F, Lakshmana MK, Movila A. Potential Role of Phosphoglycerol Dihydroceramide Produced by Periodontal Pathogen Porphyromonas gingivalis in the Pathogenesis of Alzheimer's Disease. Front Immunol 2020; 11:591571. [PMID: 33329577 PMCID: PMC7719741 DOI: 10.3389/fimmu.2020.591571] [Citation(s) in RCA: 5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/20/2020] [Indexed: 11/21/2022] Open
Abstract
Background Among different types of sphingolipids produced by human cells, the possible engagement of ceramide species in the pathogenesis of Alzheimer’s disease (AD) has attracted recent attention. While ceramides are primarily generated by de novo synthesis in mammalian cells, only a limited number of bacterial species, produce ceramides, including phosphoglycerol dihydroceramide (PGDHC) that is produced by the key periodontal pathogen Porphyromonas gingivalis. Emerging evidence indicates that virulence factors produced by P. gingivalis, such as lipopolysaccharide and gingipain, may be engaged in the initiation and/or progression of AD. However, the potential role of PGDHC in the pathogenesis of AD remains unknown. Therefore, the aim of this study was to evaluate the influence of PGDHC on hallmark findings in AD. Material and Methods CHO-7WD10 and SH-SY-5Y cells were exposed to PGDHC and lipopolysaccharide (LPS) isolated from P. gingivalis. Soluble Aβ42 peptide, amyloid precursor protein (APP), phosphorylated tau and senescence-associated secretory phenotype (SASP) factors were quantified using ELISA and Western blot assays. Results Our results indicate that P. gingivalis (Pg)-derived PGDHC, but not Pg-LPS, upregulated secretion of soluble Aβ42 peptide and expression of APP in CHO-7WD10 cells. Furthermore, hyperphosphorylation of tau protein was observed in SH-SY-5Y cells in response to PGDHC lipid. In contrast, Pg-LPS had little, or no significant effect on the tau phosphorylation induced in SH-SY-5Y cells. However, both PGDHC and Pg-LPS contributed to the senescence of SH-SY5Y cells as indicated by the production of senescence-associated secretory phenotype (SASP) markers, including beta-galactosidase, cathepsin B (CtsB), and pro-inflammatory cytokines TNF-α, and IL-6. Additionally, PGDHC diminished expression of the senescence-protection marker sirtuin-1 in SH-SY-5Y cells. Conclusions Altogether, our results indicate that P. gingivalis-derived PGDHC ceramide promotes amyloidogenesis and hyperphosphorylation, as well as the production of SASP factors. Thus, PGDHC may represent a novel class of bacterial-derived virulence factors for AD associated with periodontitis.
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Affiliation(s)
- Chiaki Yamada
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Juliet Akkaoui
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Anny Ho
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Carolina Duarte
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Richard Deth
- College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Toshihisa Kawai
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
| | - Frank Nichols
- School of Dental Medicine, The University of Connecticut Health Center, Farmington, CT, United States
| | - Madepalli K Lakshmana
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Alexandru Movila
- College of Dental Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States.,Institute for Neuro-Immune Medicine, Nova Southeastern University, Ft. Lauderdale, FL, United States
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Deth R, Schrier M, Dong J, Lemle M, Trivedi M. Age‐dependence of Methylation, Transsulfuration and Glutathione Synthesis Pathways in Human Frontal Cortex. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.543.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Richard Deth
- Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFL
| | - Matthew Schrier
- Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFL
| | - Jianan Dong
- Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFL
| | - Marian Lemle
- Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFL
| | - Malav Trivedi
- Pharmaceutical SciencesNova Southeastern UniversityFort LauderdaleFL
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Ye Q, Trivedi M, Zhang Y, Böhlke M, Alsulimani H, Chang J, Maher T, Deth R, Kim J. Brain iron loading impairs DNA methylation and alters GABAergic function in mice. FASEB J 2019; 33:2460-2471. [PMID: 30277817 PMCID: PMC6338660 DOI: 10.1096/fj.201801116rr] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 09/04/2018] [Indexed: 12/12/2022]
Abstract
Iron deficiency is closely associated with altered GABA metabolism and affective behavior. While mutation in the hemochromatosis ( HFE) gene disrupts iron homeostasis and promotes oxidative stress that increases the risk of neurodegeneration, it is largely unknown whether HFE mutation modifies GABAergic homeostasis and emotional behavior. The goal of our study was to investigate the impact of HFE on GABAergic neurochemistry and redox-epigenetic regulation in the brain using H67D HFE-mutant mice that recapitulates the H63D-HFE mutation in humans. H67D mice displayed elevated redox-active iron levels in the brain by 32% compared to age-matched wild-type mice. Moreover, the H67D brain had increased isoprostane and decreased glutathione, indicating elevated oxidative stress. Additionally, the H67D brain had decreased global methylation and attenuated DNA methyltransferase (DNMT) activity. Direct addition of iron to purified DNMT in vitro decreased enzyme activity in a concentration-dependent manner. Last, H67D mice exhibited decreased anxiety-like behavior, which was associated with increased expression of the GABAA receptor α2 subunits by 93%, and these changes were also observed in H67D mice fed a low-iron diet. Taken together, our results suggest a putative role of HFE in regulating labile iron status in the brain, and mutation in H67D perturbs redox-methylation status, contributing to GABAergic dysfunction.-Ye, Q., Trivedi, M., Zhang, Y., Böhlke, M., Alsulimani, H., Chang, J., Maher, T., Deth, R., Kim, J. Brain iron loading impairs DNA methylation and alters GABAergic function in mice.
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Affiliation(s)
- Qi Ye
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Malav Trivedi
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, Florida, USA; and
| | - Yiting Zhang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Mark Böhlke
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Science (MCPHS) University, Boston, Massachusetts, USA
| | - Helal Alsulimani
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, USA
| | - JuOae Chang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Timothy Maher
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Science (MCPHS) University, Boston, Massachusetts, USA
| | - Richard Deth
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, Florida, USA; and
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts, USA
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Deth R, Clarke A, Ni J, Trivedi M. Clinical evaluation of glutathione concentrations after consumption of milk containing different subtypes of β-casein: results from a randomized, cross-over clinical trial. Nutr J 2016; 15:82. [PMID: 27680716 PMCID: PMC5041571 DOI: 10.1186/s12937-016-0201-x] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/15/2016] [Indexed: 12/17/2022] Open
Abstract
Abstract This study reports the plasma glutathione concentrations in a double-blind, randomized, controlled, 2 × 2 cross-over study in which healthy participants consumed conventional milk (2 × 250 mL per day) containing both A1 and A2 types of β-casein, or milk containing only A2 type β-casein. Beta-casomorphin-7 (BCM-7), a peptide uniquely derived from the A1 type of β-casein, was previously reported to downregulate glutathione expression in human gut epithelial and neuronal cell lines by limiting cysteine uptake. The current human study demonstrates that consumption of milk containing only A2 β-casein was associated with a greater increase in plasma glutathione concentrations compared with the consumption of milk containing both β-casein types, and did not increase plasma BCM-7 concentrations compared with the washout diet in the study participants. Thus, milk containing only A2 β-casein and not A1 β-casein has the potential to promote the production of the antioxidant glutathione in humans. Clinical Trial Registration ClinicalTrials.gov; identifier: NCT02406469 Electronic supplementary material The online version of this article (doi:10.1186/s12937-016-0201-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard Deth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Rm # 1382, Terry Building, Fort Lauderdale, FL, 33317, USA
| | | | - Jiayi Ni
- S.P.R.I.M. China (Shanghai) Consulting Co., Ltd., Shanghai, China
| | - Malav Trivedi
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Rm # 1382, Terry Building, Fort Lauderdale, FL, 33317, USA.
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Trivedi M, Zhang Y, Lopez-Toledano M, Clarke A, Deth R. Differential neurogenic effects of casein-derived opioid peptides on neuronal stem cells: implications for redox-based epigenetic changes. J Nutr Biochem 2015; 37:39-46. [PMID: 27611101 DOI: 10.1016/j.jnutbio.2015.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/27/2015] [Accepted: 10/16/2015] [Indexed: 11/28/2022]
Abstract
Food-derived peptides, such as β-casomorphin BCM7, have potential to cross the gastrointestinal tract and blood-brain barrier and are associated with neurological disorders and neurodevelopmental disorders. We previously established a novel mechanism through which BCM7 affects the antioxidant levels in neuronal cells leading to inflammatory consequences. In the current study, we elucidated the effects of casein-derived peptides on neuronal development by using the neurogenesis of neural stem cells (NSCs) as an experimental model. First, the transient changes in intracellular thiol metabolites during NSC differentiation (neurogenesis) were investigated. Next, the neurogenic effects of food-derived opioid peptides were measured, along with changes in intracellular thiol metabolites, redox status and global DNA methylation levels. We observed that the neurogenesis of NSCs was promoted by human BCM7 to a greater extent, followed by A2-derived BCM9 in contrast to bovine BCM7, which induced increased astrocyte formation. The effect was most apparent when human BCM7 was administered for 1day starting on 3days postplating, consistent with immunocytochemistry. Furthermore, neurogenic changes regulated by bovine BCM7 and morphine were associated with an increase in the glutathione/glutathione disulfide ratio and a decrease in the S-adenosylmethionine/S-adenosylhomocysteine ratio, indicative of changes in the redox and the methylation states. Finally, bovine BCM7 and morphine decreased DNA methylation in differentiating NSCs. In conclusion, these results suggest that food-derived opioid peptides and morphine regulated neurogenesis and differentiation of NSCs through changes in the redox state and epigenetic regulation.
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Affiliation(s)
- Malav Trivedi
- Department of Pharmaceutical Sciences, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL, USA.
| | - Yiting Zhang
- Department of Pharmaceutical Sciences, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL, USA
| | - Miguel Lopez-Toledano
- Department of Biology, Fischer School of Medicine, Florida Atlantic University, Jupiter Campus, FL, USA
| | | | - Richard Deth
- Department of Pharmaceutical Sciences, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL, USA
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Trivedi MS, Deth R. Redox-based epigenetic status in drug addiction: a potential contributor to gene priming and a mechanistic rationale for metabolic intervention. Front Neurosci 2015; 8:444. [PMID: 25657617 PMCID: PMC4302946 DOI: 10.3389/fnins.2014.00444] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [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: 07/12/2014] [Accepted: 12/16/2014] [Indexed: 12/26/2022] Open
Abstract
Alcohol and other drugs of abuse, including psychostimulants and opioids, can induce epigenetic changes: a contributing factor for drug addiction, tolerance, and associated withdrawal symptoms. DNA methylation is a major epigenetic mechanism and it is one of more than 200 methylation reactions supported by methyl donor S-adenosylmethionine (SAM). Levels of SAM are controlled by cellular redox status via the folate and vitamin B12-dependent enzyme methionine synthase (MS). For example, under oxidative conditions MS is inhibited, diverting its substrate homocysteine (HCY) to the trans sulfuration pathway. Alcohol, dopamine, and morphine, can alter intracellular levels of glutathione (GSH)-based cellular redox status, subsequently affecting SAM levels and DNA methylation status. Here, existing evidence is presented in a coherent manner to propose a novel hypothesis implicating the involvement of redox-based epigenetic changes in drug addiction. Further, we discuss how a “gene priming” phenomenon can contribute to the maintenance of redox and methylation status homeostasis under various stimuli including drugs of abuse. Additionally, a new mechanistic rationale for the use of metabolic interventions/redox-replenishers as symptomatic treatment of alcohol and other drug addiction and associated withdrawal symptoms is also provided. Hence, the current review article strengthens the hypothesis that neuronal metabolism has a critical bidirectional coupling with epigenetic changes in drug addiction exemplified by the link between redox-based metabolic changes and resultant epigenetic consequences under the effect of drugs of abuse.
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Affiliation(s)
- Malav S Trivedi
- Department of Pharmaceutical Sciences, Northeastern University Boston, MA, USA
| | - Richard Deth
- Department of Pharmaceutical Sciences, Northeastern University Boston, MA, USA
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Yeter D, Deth R, Kuo HC. Mercury promotes catecholamines which potentiate mercurial autoimmunity and vasodilation: implications for inositol 1,4,5-triphosphate 3-kinase C susceptibility in kawasaki syndrome. Korean Circ J 2014; 43:581-91. [PMID: 24174958 PMCID: PMC3808853 DOI: 10.4070/kcj.2013.43.9.581] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Previously, we reviewed biological evidence that mercury could induce autoimmunity and coronary arterial wall relaxation as observed in Kawasaki syndrome (KS) through its effects on calcium signaling, and that inositol 1,4,5-triphosphate 3-kinase C (ITPKC) susceptibility in KS would predispose patients to mercury by increasing Ca2+ release. Hg2+ sensitizes inositol 1,4,5-triphosphate (IP3) receptors at low doses, which release Ca2+ from intracellular stores in the sarcoplasmic reticulum, resulting in delayed, repetitive calcium influx. ITPKC prevents IP3 from triggering IP3 receptors to release calcium by converting IP3 to inositol 1,3,4,5-tetrakisphosphate. Defective IP3 phosphorylation resulting from reduced genetic expressions of ITPKC in KS would promote IP3, which increases Ca2+ release. Hg2+ increases catecholamine levels through the inhibition of S-adenosylmethionine and subsequently catechol-O-methyltransferase (COMT), while a single nucleotide polymorphism of the COMT gene (rs769224) was recently found to be significantly associated with the development of coronary artery lesions in KS. Accumulation of norepinephrine or epinephrine would potentiate Hg2+-induced calcium influx by increasing IP3 production and increasing the permeability of cardiac sarcolemma to Ca2+. Norepinephrine and epinephrine also promote the secretion of atrial natriuretic peptide, a potent vasodilator that suppresses the release of vasoconstrictors. Elevated catecholamine levels can induce hypertension and tachycardia, while increased arterial pressure and a rapid heart rate would promote arterial vasodilation and subsequent fatal thromboses, particularly in tandem. Genetic risk factors may explain why only a susceptible subset of children develops KS although mercury exposure from methylmercury in fish or thimerosal in pediatric vaccines is nearly ubiquitous. During the infantile acrodynia epidemic, only 1 in 500 children developed acrodynia whereas mercury exposure was very common due to the use of teething powders. This hypothesis mirrors the leading theory for KS in which a widespread infection only induces KS in susceptible children. Acrodynia can mimic the clinical picture of KS, leading to its inclusion in the differential diagnosis for KS. Catecholamine levels are often elevated in acrodynia and may also play a role in KS. We conclude that KS may be the acute febrile form of acrodynia.
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Trivedi M, Shah J, Hodgson N, Byun HM, Deth R. Morphine induces redox-based changes in global DNA methylation and retrotransposon transcription by inhibition of excitatory amino acid transporter type 3-mediated cysteine uptake. Mol Pharmacol 2014; 85:747-57. [PMID: 24569088 DOI: 10.1124/mol.114.091728] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Canonically, opioids influence cells by binding to a G protein-coupled opioid receptor, initiating intracellular signaling cascades, such as protein kinase, phosphatidylinositol 3-kinase, and extracellular receptor kinase pathways. This results in several downstream effects, including decreased levels of the reduced form of glutathione (GSH) and elevated oxidative stress, as well as epigenetic changes, especially in retrotransposons and heterochromatin, although the mechanism and consequences of these actions are unclear. We characterized the acute and long-term influence of morphine on redox and methylation status (including DNA methylation levels) in cultured neuronal SH-SY5Y cells. Acting via μ-opioid receptors, morphine inhibits excitatory amino acid transporter type 3-mediated cysteine uptake via multiple signaling pathways, involving different G proteins and protein kinases in a temporal manner. Decreased cysteine uptake was associated with decreases in both the redox and methylation status of neuronal cells, as defined by the ratios of GSH to oxidized forms of glutathione and S-adenosylmethionine to S-adenosylhomocysteine levels, respectively. Further, morphine induced global DNA methylation changes, including CpG sites in long interspersed nuclear elements (LINE-1) retrotransposons, resulting in increased LINE-1 mRNA. Together, these findings illuminate the mechanism by which morphine, and potentially other opioids, can influence neuronal-cell redox and methylation status including DNA methylation. Since epigenetic changes are implicated in drug addiction and tolerance phenomenon, this study could potentially extrapolate to elucidate a novel mechanism of action for other drugs of abuse.
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Affiliation(s)
- Malav Trivedi
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts (M.T., J.S., N.H., R.D.); Center for Molecular Biology and Biotechnology, Florida Atlantic University, Jupiter, Florida (R.D.); and Department of Environmental Epidemiology, Harvard School of Public Health, Boston, Massachusetts (H.-M.B.)
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14
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Hodgson N, Trivedi M, Muratore C, Li S, Deth R. Soluble oligomers of amyloid-β cause changes in redox state, DNA methylation, and gene transcription by inhibiting EAAT3 mediated cysteine uptake. J Alzheimers Dis 2013; 36:197-209. [PMID: 23579332 DOI: 10.3233/jad-130101] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oxidative stress, hyperhomocysteinemia, altered DNA methylation, and insulin resistance in the brain are associated with Alzheimer's disease (AD), but the role of amyloid-β (Aβ) in these events remains unclear. Intracellular cysteine is rate-limiting for synthesis of the antioxidant glutathione (GSH), and factors regulating cysteine uptake exert a powerful influence over cellular redox status, especially in mature neurons where cysteine synthesis via transsulfuration of homocysteine (HCY) is restricted. We investigated the effect of soluble Aβ oligomers (oAβ) on basal and insulin-like growth factor-1 (IGF-1)-induced cysteine uptake mediated by the excitatory amino acid transporter 3 (EAAT3) in cultured human neuronal cells. We also examined the effect of oAβ on intracellular thiol metabolite levels, DNA methylation, and the transcription status of redox and methylation-associated genes. oAβ inhibited EAAT3-mediated cysteine uptake, causing a decrease in intracellular cysteine and GSH levels. The ratio of the methyl donor S-adenosylmethionine to the methylation inhibitor S-adenosylhomocysteine was decreased, in association with an increase in HCY and a global decrease in DNA methylation, indicative of decreased activity of the redox-sensitive enzyme methionine synthase. These metabolic effects of oAβ coincided with changes in the expression of redox and methylation pathway genes. The ability of oAβ to modulate gene expression via their redox and methylation-dependent epigenetic effects may contribute to the pathology of AD and recognition of this mechanism may lead to novel treatment approaches. We describe a role of IGF-1 signaling in regulating redox and methylation homeostasis, and propose this to be a pathogenic target of oAβ.
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Affiliation(s)
- Nathaniel Hodgson
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
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15
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Kocsis B, Lee P, Deth R. Enhancement of gamma activity after selective activation of dopamine D4 receptors in freely moving rats and in a neurodevelopmental model of schizophrenia. Brain Struct Funct 2013; 219:2173-80. [PMID: 23839116 DOI: 10.1007/s00429-013-0607-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/26/2013] [Indexed: 01/03/2023]
Abstract
Dopamine D4 receptor (D4R) mechanisms have been implicated in several psychiatric diseases, including schizophrenia, attention-deficit hyperactivity disorder (ADHD), and autism, which are characterized by cognitive deficits. The cellular mechanisms are poorly understood but impaired neuronal synchronization within cortical networks in the gamma frequency band has been proposed to contribute to these deficits. A D4R polymorphism was recently linked to variations in gamma power in both normal and ADHD subjects, and D4R activation was shown to enhance kainate-induced gamma oscillations in brain slices in vitro. The goal of this study was to investigate the effect of D4R activation on gamma oscillations in freely moving rats during natural behavior. Field potentials were recorded in the frontal, prefrontal, parietal, and occipital cortex and hippocampus. Gamma power was assessed before and after subcutaneous injection of a D4R agonist, A-412997, in several doses between 0.3 and 10.0 mg/kg. The experiments were also repeated in a neurodevelopmental model of schizophrenia, in which rats are prenatally treated with methylazoxymethanol (MAM). We found that the D4R agonist increased gamma power in all regions at short latency and lasted for ~2 h, both in normal and MAM-treated rats. The effect was dose dependent indicated by the significant difference between the effects after 3 and 10 mg/kg in pair-wise comparison, whereas 0.3 and 1.0 mg/kg injections were ineffective. This study demonstrates the involvement of D4R in cortical gamma oscillations in vivo and identifies this receptor as potential target for pharmacological treatment of cognitive deficits.
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Affiliation(s)
- Bernat Kocsis
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA,
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16
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17
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Li Y, Deth R. Title: Effect of Insulin‐like Growth Factor 1 on Cobalamin Composition in Neuronal Cells. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.558.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Hodgson N, Trivedi M, Deth R. Soluble oligomers of amyloid β cause oxidative stress and alter redox/methylation‐linked gene transcription by disrupting EAAT3‐mediated cysteine uptake. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.795.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Malav Trivedi
- Pharmaceutical SciencesNortheastern UniversityBostonMA
| | - Richard Deth
- Pharmaceutical SciencesNortheastern UniversityBostonMA
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19
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20
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Yeter D, Deth R. ITPKC susceptibility in Kawasaki syndrome as a sensitizing factor for autoimmunity and coronary arterial wall relaxation induced by thimerosal's effects on calcium signaling via IP3. Autoimmun Rev 2012; 11:903-8. [DOI: 10.1016/j.autrev.2012.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/22/2012] [Indexed: 12/12/2022]
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21
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Dufault R, Lukiw WJ, Crider R, Schnoll R, Wallinga D, Deth R. A macroepigenetic approach to identify factors responsible for the autism epidemic in the United States. Clin Epigenetics 2012; 4:6. [PMID: 22490277 PMCID: PMC3378453 DOI: 10.1186/1868-7083-4-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/10/2012] [Indexed: 02/08/2023] Open
Abstract
The number of children ages 6 to 21 in the United States receiving special education services under the autism disability category increased 91% between 2005 to 2010 while the number of children receiving special education services overall declined by 5%. The demand for special education services continues to rise in disability categories associated with pervasive developmental disorders. Neurodevelopment can be adversely impacted when gene expression is altered by dietary transcription factors, such as zinc insufficiency or deficiency, or by exposure to toxic substances found in our environment, such as mercury or organophosphate pesticides. Gene expression patterns differ geographically between populations and within populations. Gene variants of paraoxonase-1 are associated with autism in North America, but not in Italy, indicating regional specificity in gene-environment interactions. In the current review, we utilize a novel macroepigenetic approach to compare variations in diet and toxic substance exposure between these two geographical populations to determine the likely factors responsible for the autism epidemic in the United States.
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Affiliation(s)
- Renee Dufault
- Food Ingredient and Health Research Institute, Ocean View, HI, USA.
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22
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Waly M, Guizani N, Ali A, Rahman MS, Deth R. Neuroprotective Effects of Papaya Epicarp Extract against Aluminum‐Induced Oxidative Stress in Human Neuronal (SHSY5Y) Cells. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.823.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mostafa Waly
- Food Science and NutritionSultan Qaboos UniversityMuscatOman
| | - Nejib Guizani
- Food Science and NutritionSultan Qaboos UniversityMuscatOman
| | - Amanat Ali
- Food Science and NutritionSultan Qaboos UniversityMuscatOman
| | | | - Richard Deth
- Pharmacology DepartmentNortheastern UniversityBostonMA
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23
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Mutter J, Curth A, Naumann J, Deth R, Walach H. Does inorganic mercury play a role in Alzheimer's disease? A systematic review and an integrated molecular mechanism. J Alzheimers Dis 2011; 22:357-74. [PMID: 20847438 DOI: 10.3233/jad-2010-100705] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mercury is one of the most toxic substances known to humans. It has been introduced into the human environment and has also been widely used in medicine. Since circumstantial evidence exists that the pathology of Alzheimer's disease (AD) might be in part caused or exacerbated by inorganic mercury, we conducted a systematic review using a comprehensive search strategy. Studies were screened according to a pre-defined protocol. Two reviewers extracted relevant data independent of each other. One thousand and forty one references were scrutinized, and 106 studies fulfilled the inclusion criteria. Most studies were case control or comparative cohort studies. Thirty-two studies, out of 40 testing memory in individuals exposed to inorganic mercury, found significant memory deficits. Some autopsy studies found increased mercury levels in brain tissues of AD patients. Measurements of mercury levels in blood, urine, hair, nails, and cerebrospinal fluid were inconsistent. In vitro models showed that inorganic mercury reproduces all pathological changes seen in AD, and in animal models inorganic mercury produced changes that are similar to those seen in AD. Its high affinity for selenium and selenoproteins suggests that inorganic mercury may promote neurodegenerative disorders via disruption of redox regulation. Inorganic mercury may play a role as a co-factor in the development of AD. It may also increase the pathological influence of other metals. Our mechanistic model describes potential causal pathways. As the single most effective public health primary preventive measure, industrial, and medical usage of mercury should be eliminated as soon as possible.
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Affiliation(s)
- Joachim Mutter
- Department of Environmental and Integrative Medicine, Constance, Germany
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24
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Waly MI, Kharbanda K, Deth R. Ethanol Inhibition of Methionine Synthase in Rat Liver and Cortex: Role of Glutathione Depletion and Different Cobalamin Cofactors. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.lb410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Kusum Kharbanda
- Department of Veterans Affairs Medical CenterVA Alcohol Research CenterOmahaNE
| | - Richard Deth
- Pharmaceutical SciencesNortheastern UniversityBostonMA
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25
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Benzecry J, Deth R, Holtzman D. 4. Are autistic spectrum disorders an expression of mitochondrial encephalopathies? Mitochondrion 2009. [DOI: 10.1016/j.mito.2008.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Deth R, Muratore C, Benzecry J, Power-Charnitsky VA, Waly M. How environmental and genetic factors combine to cause autism: A redox/methylation hypothesis. Neurotoxicology 2007; 29:190-201. [PMID: 18031821 DOI: 10.1016/j.neuro.2007.09.010] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 07/27/2007] [Accepted: 09/27/2007] [Indexed: 01/17/2023]
Abstract
Recently higher rates of autism diagnosis suggest involvement of environmental factors in causing this developmental disorder, in concert with genetic risk factors. Autistic children exhibit evidence of oxidative stress and impaired methylation, which may reflect effects of toxic exposure on sulfur metabolism. We review the metabolic relationship between oxidative stress and methylation, with particular emphasis on adaptive responses that limit activity of cobalamin and folate-dependent methionine synthase. Methionine synthase activity is required for dopamine-stimulated phospholipid methylation, a unique membrane-delimited signaling process mediated by the D4 dopamine receptor that promotes neuronal synchronization and attention, and synchrony is impaired in autism. Genetic polymorphisms adversely affecting sulfur metabolism, methylation, detoxification, dopamine signaling and the formation of neuronal networks occur more frequently in autistic subjects. On the basis of these observations, a "redox/methylation hypothesis of autism" is described, in which oxidative stress, initiated by environment factors in genetically vulnerable individuals, leads to impaired methylation and neurological deficits secondary to reductions in the capacity for synchronizing neural networks.
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Affiliation(s)
- Richard Deth
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02468, United States.
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27
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Tumas J, Deth R, Kloner RA. Effects of nisoldipine, a new calcium antagonist, on myocardial infarct size and cardiac dynamics following acute myocardial infarction. J Cardiovasc Pharmacol 1985; 7:361-7. [PMID: 2581092 DOI: 10.1097/00005344-198503000-00023] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
While some calcium antagonists are effective in reducing myocardial infarct size, this beneficial effect may be accompanied by negative inotropic effects. In the following study, a new dihydropyridine calcium antagonist, nisoldipine, was assessed for its effect on infarct size, hemodynamics, and regional function as assessed by percent systolic wall thickening of the left ventricle (SWT) by 2D echocardiography. Open-chest, anesthetized dogs were subjected to 6 h of coronary artery occlusion. After 10 min of coronary artery occlusion, the ischemic area at risk of infarction (AR; % of left ventricle) was determined by left atrial injection of 99mTc-labeled albumin microspheres with subsequent postmortem autoradiography. After 6 h, the hearts were excised, and the area of necrosis (AN) determined by incubation of left ventricular slices in triphenyltetrazolium chloride stain. Treated dogs received 0.005 mg/kg nisoldipine by intravenous infusion at 1.91 ml/min (lasting approximately 8.7 min) during three dosing periods: 15 min, 2 h, and 4 h postocclusion. The AR of eight controls (25.7 +/- 1.8%) was not significantly different from that of 11 treated dogs (25.1 +/- 1.9%). However, the AN/AR X 100 of treated dogs was significantly less than that of controls (62.8 +/- 9.3 vs. 91.6 +/- 7.0%; p less than 0.05). Mean arterial pressure fell in treated dogs by 15.7% (p less than 0.01) at 15 min and by 5.7% (p less than 0.05) at 4 h but not at 2 h postocclusion. Heart rate was not affected by nisoldipine.(ABSTRACT TRUNCATED AT 250 WORDS)
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28
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Abstract
The influence of Mn2+ and La3+ on alpha-receptor-stimulated Ca2+ movements was examined in arterial smooth muscle of the rabbit aorta. Both cations cause an inhibition of phenylephrine (PE) contractile response which exhibits a different pattern at low and high cation concentrations. At 0.1-1.0 mM inhibition by Mn2+ and La3+ was predominately due to a reduction in Ca2+ influx reflected as inhibition of the slow phase of contraction and reduction in PE-stimulated 45Ca uptake. PE log dose-response curves were shifted to the right in a non-parallel manner by 1 mM Mn2+ such that responses to lower PE concentrations were more inhibited. However, in the presence of 10 mM Mn2+ PE responses are equally inhibited at all PE levels. At 10 mM both Mn2+ and La3+ also inhibited PE-stimulated Ca2+ release resulting in a reduction in both the rapid phase of contraction and in the magnitude of PE stimulation of 45Ca efflux. The effects of Nm2+ (1 or 10 mM) on contraction and 45Ca efflux were rapidly reversible, while the effect of La3+ was not. Inhibition of Ca2+ release by 10 mM Mn2+ and La3+ was not caused by displacement of releasable Ca2+, but appeared to reflect their occupation of a superficially located receptor modulating site. The inhibition of Ca2+ influx by lower concentrations of Mn2+ may illustrate the functional consequence of configurational changes in the alpha 2-form of the receptor which have been recently described at lower concentrations of divalent cations.
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29
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Abstract
The distribution of Ca in the cellular compartment of smooth muscle cells of the rabbit aorta has been studied by analyzing the effect of norepinephrine, caffeine, and DNP on 45Ca exchange and on the pattern of tension development. These three substances increase the release of 45Ca from the tissue, but DNP acts more slowly than norepinephrine or caffeine. Also, the effect of norepinephrine and caffeine on tension development occurs almost immediately, while that of DNP appears only after a delay of 5 min. Study of the effect of these substances on the Ca efflux has shown that norepinephrine and caffeine act probably on the same Ca compartment, while DNP seems to act on a different compartment with a slower exchange rate. The difference between these two pools could be further demonstrated by studying Ca release after loading the tissues with tracer in either K-rich solution or in a solution with reduced [Ca]o. The K depolarization results in an excessive loading of the cells with 45Ca. Exposing these cells during the efflux procedure to a solution containing DNP causes a much larger release of 45Ca than that observed after a loading procedure in normal solution. In contrast, the release of 45Ca elicited in such tissues by norepinephrine or caffeine disappears. This disappearance is due to the prolonged increase of the Ca exchangeability induced by K depolarization. During initial exposure to PSS the increased exchangeability causes an accelerated loss of tracer from the tissue compartment on which norepinephrine and caffeine act, while the DNP sensitive compartment is not affected. It is suggested that noradrenaline and caffeine act on the same calcium pool close to the membrane and that DNP acts mainly on the mitochondria.
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Abstract
The effects of hormonal agonists (norepinephrine, angiotensin, and histamine) on 45Ca efflux from the rabbit aorta were studied using a Ca-EGTA buffered efflux medium. Each caused a transient stimulation of efflux rate which probably reflected the release of an intracellular 45Ca store. The size of the stimulation of efflux correlated with the size of the initial rapid phase of contraction. The norepinephrine-sensitive intracellular Ca fraction was estimated to be greater than 21 mumoles/Kg wet tissue weight. This fraction is separate from intracellular Ca which is accumulated during relaxation. Evidence is presented for the lack of cyclic nucleotide involvement in the release of Ca2+, and possible alternative modes of coupling are discussed.
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Deth R, van Breemen C. Relative contributions of Ca2+ influx and cellular Ca2+ release during drug induced activation of the rabbit aorta. Pflugers Arch 1974; 348:13-22. [PMID: 4367920 DOI: 10.1007/bf00587735] [Citation(s) in RCA: 179] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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van Breemen C, Farinas BR, Casteels R, Gerba P, Wuytack F, Deth R. Factors controlling cytoplasmic Ca 2+ concentration. Philos Trans R Soc Lond B Biol Sci 1973; 265:57-71. [PMID: 4144699 DOI: 10.1098/rstb.1973.0009] [Citation(s) in RCA: 200] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The study of cellular Ca
2+
exchange in smooth muscle has been severely limited by extensive extracellular Ga
2+
binding. This problem was solved by using La
3+
to trap Ca
2+
inside the cells while displacing extracellular bound Ca
2+
. It was then shown that cytoplasmic Ca
2+
could be raised by Ca
2+
influx during high K+ depolarization, Na+ elimination and high pH. Ca
2+
influx was inhibited by other multivalent cations, local anaesthetics and low pH. In the rabbit aortae norepinephrine and angiotensin increase cytoplasmic Ca
2+
by release from intracellular membrane surfaces. In this same smooth muscle relaxation is brought about by intracellular Ca
2+
binding. Evidence from vascular, uterine and intestinal smooth muscle demonstrates that the large transmembrane Ca
2+
gradient depends on cellular [ATP] but not on the Na+ gradient. ATP depletion abolishes the Ca
2+
gradient by increasing Ca
2+
influx.
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