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Sun Y, Hao M, Wu H, Zhang C, Wei D, Li S, Song Z, Tao Y. Unveiling the role of CaMKII in retinal degeneration: from biological mechanism to therapeutic strategies. Cell Biosci 2024; 14:59. [PMID: 38725013 PMCID: PMC11084033 DOI: 10.1186/s13578-024-01236-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 04/18/2024] [Indexed: 05/12/2024] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a family of broad substrate specificity serine (Ser)/threonine (Thr) protein kinases that play a crucial role in the Ca2+-dependent signaling pathways. Its significance as an intracellular Ca2+ sensor has garnered abundant research interest in the domain of neurodegeneration. Accumulating evidences suggest that CaMKII is implicated in the pathology of degenerative retinopathies such as diabetic retinopathy (DR), age-related macular degeneration (AMD), retinitis pigmentosa (RP) and glaucoma optic neuropathy. CaMKII can induce the aberrant proliferation of retinal blood vessels, influence the synaptic signaling, and exert dual effects on the survival of retinal ganglion cells and pigment epithelial cells. Researchers have put forth multiple therapeutic agents, encompassing small molecules, peptides, and nucleotides that possess the capability to modulate CaMKII activity. Due to its broad range isoforms and splice variants therapeutic strategies seek to inhibit specifically the CaMKII are confronted with considerable challenges. Therefore, it becomes crucial to discern the detrimental and advantageous aspects of CaMKII, thereby facilitating the development of efficacious treatment. In this review, we summarize recent research findings on the cellular and molecular biology of CaMKII, with special emphasis on its metabolic and regulatory mechanisms. We delve into the involvement of CaMKII in the retinal signal transduction pathways and discuss the correlation between CaMKII and calcium overload. Furthermore, we elaborate the therapeutic trials targeting CaMKII, and introduce recent developments in the zone of CaMKII inhibitors. These findings would enrich our knowledge of CaMKII, and shed light on the development of a therapeutic target for degenerative retinopathy.
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Affiliation(s)
- Yuxin Sun
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Mengyu Hao
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Hao Wu
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Chengzhi Zhang
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Dong Wei
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Siyu Li
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China
| | - Zongming Song
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China.
| | - Ye Tao
- Department of Ophthalmology, Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China.
- College of Medicine, Zhengzhou University, Zhengzhou, 450001, China.
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Ermakova E, Shaidullova K, Gafurov O, Kabirova A, Nurmieva D, Sitdikova G. Implications of high homocysteine levels in migraine pain: An experimental study of the excitability of peripheral meningeal afferents in rats with hyperhomocysteinemia. Headache 2024; 64:533-546. [PMID: 38650105 DOI: 10.1111/head.14710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/23/2024] [Accepted: 02/28/2024] [Indexed: 04/25/2024]
Abstract
OBJECTIVES Investigation of chronic homocysteine action on the excitability and N-methyl-D-aspartate (NMDA) sensitivity of the peripheral trigeminovascular system of rats. BACKGROUND Migraine is a neurological disease that affects 15%-20% of the general population. Epidemiological observations show that an increase of the sulfur-containing amino acid homocysteine in plasma-called hyperhomocysteinemia-is associated with a high risk of migraine, especially migraine with aura. In animal studies, rats with hyperhomocysteinemia demonstrated mechanical allodynia, photophobia, and anxiety, and higher sensitivity to cortical spreading depression. In addition, rats with hyperhomocysteinemia were more sensitive in a model of chronic migraine induced by nitroglycerin which indicated the involvement of peripheral nociceptive mechanisms. The present work aimed to analyze the excitability of meningeal afferents and neurons isolated from the trigeminal ganglion of rats with prenatal hyperhomocysteinemia. METHODS Experiments were performed on male rats born from females fed with a methionine-rich diet before and during pregnancy. The activity of meningeal afferents was recorded extracellularly in hemiskull preparations ex vivo and action potentials were characterized using cluster analysis. The excitability of trigeminal ganglion neurons was assessed using whole-cell patch clamp recording techniques and calcium imaging studies. Meningeal mast cells were stained using toluidine blue. RESULTS The baseline extracellular recorded electrical activity of the trigeminal nerve was higher in the hyperhomocysteinemia group with larger amplitude action potentials. Lower concentrations of KCl caused an increase in the frequency of action potentials of trigeminal afferents recorded in rat hemiskull ex vivo preparations. In trigeminal ganglion neurons of rats with hyperhomocysteinemia, the current required to elicit at least one action potential (rheobase) was lower, and more action potentials were induced in response to stimulus of 2 × rheobase. In controls, short-term application of homocysteine and its derivatives increased the frequency of action potentials of the trigeminal nerve and induced Ca2+ transients in neurons, which are associated with the activation of NMDA receptors. At the same time, in rats with hyperhomocysteinemia, we did not observe an increased response of the trigeminal nerve to NMDA. Similarly, the parameters of Ca2+ transients induced by NMDA, homocysteine, and its derivatives were not changed in rats with hyperhomocysteinemia. Acute incubation of the meninges in homocysteine and homocysteinic acid did not change the state of the mast cells, whereas in the model of hyperhomocysteinemia, an increased degranulation of mast cells in the meninges was observed. CONCLUSIONS Our results demonstrated higher excitability of the trigeminal system of rats with hyperhomocysteinemia. Together with our previous finding about the lower threshold of generation of cortical spreading depression in rats with hyperhomocysteinemia, the present data provide evidence of homocysteine as a factor that increases the sensitivity of the peripheral migraine mechanisms, and the control of homocysteine level may be an important strategy for reducing the risk and/or severity of migraine headache attacks.
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Affiliation(s)
- Elizaveta Ermakova
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
| | - Kseniia Shaidullova
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
| | - Oleg Gafurov
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
| | - Alsu Kabirova
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
| | - Dinara Nurmieva
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
| | - Guzel Sitdikova
- Institute of Fundamental Medicine and Biology, Department of Human and Animal Physiology, Kazan Federal University, Kazan, Russia
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Ebrahimi M, Ebrahimi M, Vergroesen JE, Aschner M, Sillanpää M. Environmental exposures to cadmium and lead as potential causes of eye diseases. J Trace Elem Med Biol 2024; 82:127358. [PMID: 38113800 DOI: 10.1016/j.jtemb.2023.127358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/21/2023]
Abstract
Humans are exposed to cadmium and lead in various regions of the world daily due to industrial development and climate change. Increasing numbers of preclinical and clinical studies indicate that heavy metals, such as cadmium and lead, play a role in the pathogenesis of eye diseases. Excessive exposure to heavy metals such as cadmium and lead can increase the risk of impaired vision. Therefore, it is essential to better characterize the role of these non-essential metals in disease etiology and progression. This article discusses the potential role of cadmium and lead in the development of age-related eye diseases, including age-related macular degeneration, cataracts, and glaucoma. Furthermore, we discuss how cadmium and lead affect ocular cells and provide an overview of putative pathological mechanisms associated with their propensity to damage the eye.
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Affiliation(s)
- Moein Ebrahimi
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Network of Immunity in Infection, Malignancy, and Autoimmunity, Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Maryam Ebrahimi
- Cancer Immunology Project (CIP), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Joëlle E Vergroesen
- Department of Ophthalmology, Erasmus MC University Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands; Department of Epidemiology, Erasmus MC University Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands.
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Mika Sillanpää
- Department of Chemical Engineering, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, P. O. Box 17011, Doornfontein 2028, South Africa; International Research Centre of Nanotechnology for Himalayan Sustainability (IRCNHS), Shoolini University, Solan 173212, Himachal Pradesh, India; Zhejiang Rongsheng Environmental Protection Paper Co. LTD, NO.588 East Zhennan Road, Pinghu Economic Development Zone, Zhejiang 314213, PR China; Department of Civil Engineering, University Centre for Research & Development, Chandigarh University, Gharuan, Mohali, Punjab, India
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Lee JY, Choi JA, Park SP, Jee D. Association Between High Blood Folate Levels and Glaucoma in a Representative Korean Population. Invest Ophthalmol Vis Sci 2024; 65:6. [PMID: 38170538 PMCID: PMC10768708 DOI: 10.1167/iovs.65.1.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/19/2023] [Indexed: 01/05/2024] Open
Abstract
Purpose This study aimed to investigate the association between folate levels and the prevalence of glaucoma. Methods This nationwide population-based cross-sectional study included 1790 participants aged ≥40 years. We analyzed data regarding the participants obtained in the 2016-2018 Korean National Health and Nutrition Examination Survey. The diagnosis of glaucoma was defined according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses were used to investigate the relationship between blood folate levels and glaucoma. Results There was a significantly lower prevalence of glaucoma in the highest quartile of blood folate levels than in the lowest quartile, after adjusting for confounding factors such as age, sex, systemic hypertension, diabetes, hypercholesterolemia, and smoking (odds ratio [OR] = 0.470; 95% confidence interval [CI], 0.291-0.759; P for trend = 0.017). There was a significantly lower risk of glaucoma in the highest quartile of blood folate levels than in the lowest quartile among women (OR = 0.188; 95% CI, 0.099-0.357; P for trend <0.001) and younger participants (OR =0.443; 95% CI, 0.229-0.856; P for trend = 0.045). Conclusions Our findings indicate a strong inverse correlation between blood folate levels and glaucoma.
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Affiliation(s)
- Ji Young Lee
- Department of Ophthalmology and Visual Science, College of Medicine, Daejeon St. Marys’ Hospital, Catholic University of Korea, Seoul, Korea
| | - Jin A. Choi
- Department of Ophthalmology and Visual Science, College of Medicine, St. Vincent's Hospital, Catholic University of Korea, Seoul, Korea
| | - Sung Pyo Park
- Department of Ophthalmology, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea
| | - Donghyun Jee
- Department of Ophthalmology and Visual Science, College of Medicine, St. Vincent's Hospital, Catholic University of Korea, Seoul, Korea
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Kaur B, Sharma PK, Chatterjee B, Bissa B, Nattarayan V, Ramasamy S, Bhat A, Lal M, Samaddar S, Banerjee S, Roy SS. Defective quality control autophagy in Hyperhomocysteinemia promotes ER stress and consequent neuronal apoptosis through proteotoxicity. Cell Commun Signal 2023; 21:258. [PMID: 37749555 PMCID: PMC10518934 DOI: 10.1186/s12964-023-01288-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/19/2023] [Indexed: 09/27/2023] Open
Abstract
Homocysteine (Hcy), produced physiologically in all cells, is an intermediate metabolite of methionine and cysteine metabolism. Hyperhomocysteinemia (HHcy) resulting from an in-born error of metabolism that leads to accumulation of high levels of Hcy, is associated with vascular damage, neurodegeneration and cognitive decline. Using a HHcy model in neuronal cells, primary cortical neurons and transgenic zebrafish, we demonstrate diminished autophagy and Hcy-induced neurotoxicity associated with mitochondrial dysfunction, fragmentation and apoptosis. We find this mitochondrial dysfunction is due to Hcy-induced proteotoxicity leading to ER stress. We show this sustained proteotoxicity originates from the perturbation of upstream autophagic pathways through an aberrant activation of mTOR and that protetoxic stress act as a feedforward cues to aggravate a sustained ER stress that culminate to mitochondrial apoptosis in HHcy model systems. Using chemical chaperones to mitigate sustained ER stress, Hcy-induced proteotoxicity and consequent neurotoxicity were rescued. We also rescue neuronal lethality by activation of autophagy and thereby reducing proteotoxicity and ER stress. Our findings pave the way to devise new strategies for the treatment of neural and cognitive pathologies reported in HHcy, by either activation of upstream autophagy or by suppression of downstream ER stress. Video Abstract.
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Affiliation(s)
- Bhavneet Kaur
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
| | - Pradeep Kumar Sharma
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
- CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Barun Chatterjee
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
| | - Bhawana Bissa
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Present address: Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, India
| | - Vasugi Nattarayan
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
| | - Soundhar Ramasamy
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
| | - Ajay Bhat
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
| | - Megha Lal
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India
| | | | | | - Soumya Sinha Roy
- CSIR-Institute of Genomics & Integrative Biology, Mathura Road, Sukhdev Vihar, New Delhi, 110020, India.
- Academy of Scientific & Innovative Research, Ghaziabad, 201002, India.
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Ramires Júnior OV, Silveira JS, Dos Santos TM, Ferreira FS, Vizuete AFK, Gonçalves CA, Wyse ATS. Homocysteine May Decrease Glucose Uptake and Alter the Akt/GSK3β/GLUT1 Signaling Pathway in Hippocampal Slices: Neuroprotective Effects of Rivastigmine and Ibuprofen. Mol Neurobiol 2023; 60:5468-5481. [PMID: 37314655 DOI: 10.1007/s12035-023-03408-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/25/2023] [Indexed: 06/15/2023]
Abstract
Homocysteine (Hcy) is a risk factor for neurodegenerative diseases, such as Alzheimer's Disease, and is related to cellular and tissue damage. In the present study, we verified the effect of Hcy on neurochemical parameters (redox homeostasis, neuronal excitability, glucose, and lactate levels) and the Serine/Threonine kinase B (Akt), Glucose synthase kinase-3β (GSK3β) and Glucose transporter 1 (GLUT1) signaling pathway in hippocampal slices, as well as the neuroprotective effects of ibuprofen and rivastigmine alone or in combination in such effects. Male Wistar rats (90 days old) were euthanized and the brains were dissected. The hippocampus slices were pre-treated for 30 min [saline medium or Hcy (30 µM)], then the other treatments were added to the medium for another 30 min [ibuprofen, rivastigmine, or ibuprofen + rivastigmine]. The dichlorofluorescein formed, nitrite and Na+, K+-ATPase activity was increased by Hcy at 30 µM. Ibuprofen reduced dichlorofluorescein formation and attenuated the effect of Hcy. The reduced glutathione content was reduced by Hcy. Treatments with ibuprofen and Hcy + ibuprofen increased reduced glutathione. Hcy at 30 µM caused a decrease in hippocampal glucose uptake and GLUT1 expression, and an increase in Glial Fibrillary Acidic Protein-protein expression. Phosphorylated GSK3β and Akt levels were reduced by Hcy (30 µM) and co-treatment with Hcy + rivastigmine + ibuprofen reversed these effects. Hcy toxicity on glucose metabolism can promote neurological damage. The combination of treatment with rivastigmine + ibuprofen attenuated such effects, probably by regulating the Akt/GSK3β/GLUT1 signaling pathway. Reversal of Hcy cellular damage by these compounds may be a potential neuroprotective strategy for brain damage.
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Affiliation(s)
- Osmar Vieira Ramires Júnior
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Neuroproteção e Doenças Neurometabólicas, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Josiane Silva Silveira
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Neuroproteção e Doenças Neurometabólicas, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Tiago Marcon Dos Santos
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Neuroproteção e Doenças Neurometabólicas, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Fernanda Silva Ferreira
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Neuroproteção e Doenças Neurometabólicas, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Adriana Fernanda K Vizuete
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Proteínas Ligantes de Cálcio no SNC, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Carlos Alberto Gonçalves
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Laboratório de Proteínas Ligantes de Cálcio no SNC, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil
| | - Angela T S Wyse
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
- Laboratório de Neuroproteção e Doenças Neurometabólicas, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil.
- Laboratory of Neuroprotection and Neurometabolic Diseases (Wyse´s Lab), Department of Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035003, Brazil.
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Washington J, Ritch R, Liu Y. Homocysteine and Glaucoma. Int J Mol Sci 2023; 24:10790. [PMID: 37445966 DOI: 10.3390/ijms241310790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 06/10/2023] [Accepted: 06/11/2023] [Indexed: 07/15/2023] Open
Abstract
Elevated levels of homocysteine (Hcy), a non-proteinogenic amino acid, may lead to a host of manifestations across the biological systems, particularly the nervous system. Defects in Hcy metabolism have been associated with many neurodegenerative diseases including glaucoma, i.e., the leading cause of blindness. However, the pathophysiology of elevated Hcy and its eligibility as a risk factor for glaucoma remain unclear. We aimed to provide a comprehensive review of the relationship between elevated Hcy levels and glaucoma. Through a systemic search of the PubMed and Google Scholar databases, we found that elevated Hcy might play an important role in the pathogenesis of glaucoma. Further research will be necessary to help clarify the specific contribution of elevated Hcy in the pathogenesis of glaucoma. A discovery and conceptual understanding of Hcy-associated glaucoma could be the keys to providing better therapeutic treatment, if not prophylactic treatment, for this disease.
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Affiliation(s)
- Joshua Washington
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Robert Ritch
- New York Eye & Ear Infirmary, New York, NY 10003, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- James & Jean Culver Vision Discovery Institute, 4 Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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Zhang ZY, Zuo ZY, Liang Y, Zhang SM, Zhang CX, Chi J, Fan B, Li GY. Promotion of axon regeneration and protection on injured retinal ganglion cells by rCXCL2. Inflamm Regen 2023; 43:31. [PMID: 37340465 DOI: 10.1186/s41232-023-00283-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 05/31/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND In addition to rescuing injured retinal ganglion cells (RGCs) by stimulating the intrinsic growth ability of damaged RGCs in various retinal/optic neuropathies, increasing evidence has shown that the external microenvironmental factors also play a crucial role in restoring the survival of RGCs by promoting the regrowth of RGC axons, especially inflammatory factors. In this study, we aimed to screen out the underlying inflammatory factor involved in the signaling of staurosporine (STS)-induced axon regeneration and verify its role in the protection of RGCs and the promotion of axon regrowth. METHODS We performed transcriptome RNA sequencing for STS induction models in vitro and analyzed the differentially expressed genes. After targeting the key gene, we verified the role of the candidate factor in RGC protection and promotion of axon regeneration in vivo with two RGC-injured animal models (optic nerve crush, ONC; retinal N-methyl-D-aspartate, NMDA damage) by using cholera toxin subunit B anterograde axon tracing and specific immunostaining of RGCs. RESULTS We found that a series of inflammatory genes expressed upregulated in the signaling of STS-induced axon regrowth and we targeted the candidate CXCL2 gene since the level of the chemokine CXCL2 gene elevated significantly among the top upregulated genes. We further demonstrated that intravitreal injection of rCXCL2 robustly promoted axon regeneration and significantly improved RGC survival in ONC-injured mice in vivo. However, different from its role in ONC model, the intravitreal injection of rCXCL2 was able to simply protect RGCs against NMDA-induced excitotoxicity in mouse retina and maintain the long-distance projection of RGC axons, yet failed to promote significant axon regeneration. CONCLUSIONS We provide the first in vivo evidence that CXCL2, as an inflammatory factor, is a key regulator in the axon regeneration and neuroprotection of RGCs. Our comparative study may facilitate deciphering the exact molecular mechanisms of RGC axon regeneration and developing high-potency targeted drugs.
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Affiliation(s)
- Zi-Yuan Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Yang Liang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Si-Ming Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Chun-Xia Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Jing Chi
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Bin Fan
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
| | - Guang-Yu Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
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Chen GL, Zeng B, Jiang H, Daskoulidou N, Saurabh R, Chitando RJ, Xu SZ. Ca 2+ Influx through TRPC Channels Is Regulated by Homocysteine-Copper Complexes. Biomolecules 2023; 13:952. [PMID: 37371532 DOI: 10.3390/biom13060952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/29/2023] Open
Abstract
An elevated level of circulating homocysteine (Hcy) has been regarded as an independent risk factor for cardiovascular disease; however, the clinical benefit of Hcy lowering-therapy is not satisfying. To explore potential unrevealed mechanisms, we investigated the roles of Ca2+ influx through TRPC channels and regulation by Hcy-copper complexes. Using primary cultured human aortic endothelial cells and HEK-293 T-REx cells with inducible TRPC gene expression, we found that Hcy increased the Ca2+ influx in vascular endothelial cells through the activation of TRPC4 and TRPC5. The activity of TRPC4 and TRPC5 was regulated by extracellular divalent copper (Cu2+) and Hcy. Hcy prevented channel activation by divalent copper, but monovalent copper (Cu+) had no effect on the TRPC channels. The glutamic acids (E542/E543) and the cysteine residue (C554) in the extracellular pore region of the TRPC4 channel mediated the effect of Hcy-copper complexes. The interaction of Hcy-copper significantly regulated endothelial proliferation, migration, and angiogenesis. Our results suggest that Hcy-copper complexes function as a new pair of endogenous regulators for TRPC channel activity. This finding gives a new understanding of the pathogenesis of hyperhomocysteinemia and may explain the unsatisfying clinical outcome of Hcy-lowering therapy and the potential benefit of copper-chelating therapy.
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Affiliation(s)
- Gui-Lan Chen
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Bo Zeng
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Hongni Jiang
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Nikoleta Daskoulidou
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Rahul Saurabh
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Rumbidzai J Chitando
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Shang-Zhong Xu
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
- Diabetes, Endocrinology and Metabolism, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
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Zhang H, Shen H, Gong W, Sun X, Jiang X, Wang J, Jin L, Xu X, Luo D, Wang X. Plasma homocysteine and macular thickness in older adults-the Rugao Longevity and Aging Study. Eye (Lond) 2022; 36:1050-1060. [PMID: 33976397 PMCID: PMC9046221 DOI: 10.1038/s41433-021-01549-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 03/08/2021] [Accepted: 04/09/2021] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES To determine the association of plasma homocysteine levels with retinal layer thickness in a large community cohort of older adults. METHODS The Rugao Longevity and Ageing Study is an observational, prospective and community-based cohort study. A total of 989 older adults who underwent spectral-domain optical coherence tomography (SD-OCT) were included and analyzed. Foveal, macular retinal nerve fibre layer (mRNFL) and ganglion cell layer plus inner plexiform layer (GC-IPL) thicknesses were measured by SD-OCT. Plasma homocysteine levels were measured using chemiluminescence immunoassay. Linear regression analyses were performed to evaluate the relationship between plasma homocysteine and retinal layer thickness while controlling for confounding factors. RESULTS Of the 989 participants, 500 (50.56%) were men. The mean age was 78.26 (4.58) years, and the mean plasma homocysteine level was 16.38 (8.05) μmol/L. In multivariable analyses, each unit increase in plasma homocysteine was associated with an 8.84 × 10-2 (95% CI: -16.54 × 10-2 to -1.15 × 10-2, p = 0.032) μm decrease in the average inner thickness of the GC-IPL after controlling for confounding factors. The association remained significant even in participants without major cardiovascular disease or diabetes (β = -10.33 × 10-2, 95% CI: -18.49 × 10-2 to -2.18 × 10-2, p = 0.013). No significant associations of plasma homocysteine levels with macular thickness or mRNFL were found in primary and sensitivity analyses (p > 0.05). CONCLUSIONS Increased plasma homocysteine levels are associated with a thinner GC-IPL. Plasma homocysteine may be a risk factor for thinner retinas in older adults.
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Affiliation(s)
- Hui Zhang
- grid.8547.e0000 0001 0125 2443State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China ,grid.8547.e0000 0001 0125 2443Human Phenome Institute, Fudan University, Shanghai, China
| | - Hangqi Shen
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China ,Shanghai Engineering Center for Visual Science and Photomedicin, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China ,grid.412478.c0000 0004 1760 4628National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Wei Gong
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China ,Shanghai Engineering Center for Visual Science and Photomedicin, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China ,grid.412478.c0000 0004 1760 4628National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Xuehui Sun
- grid.8547.e0000 0001 0125 2443State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China ,grid.8547.e0000 0001 0125 2443Human Phenome Institute, Fudan University, Shanghai, China
| | - Xiaoyan Jiang
- grid.24516.340000000123704535Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai, China
| | - Jiucun Wang
- grid.8547.e0000 0001 0125 2443State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China ,grid.8547.e0000 0001 0125 2443Human Phenome Institute, Fudan University, Shanghai, China
| | - Li Jin
- grid.8547.e0000 0001 0125 2443State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China ,grid.8547.e0000 0001 0125 2443Human Phenome Institute, Fudan University, Shanghai, China
| | - Xun Xu
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China ,Shanghai Engineering Center for Visual Science and Photomedicin, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China ,grid.412478.c0000 0004 1760 4628National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Dawei Luo
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China ,Shanghai Engineering Center for Visual Science and Photomedicin, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China ,grid.412478.c0000 0004 1760 4628National Clinical Research Center for Eye Diseases, Shanghai, China
| | - Xiaofeng Wang
- grid.8547.e0000 0001 0125 2443State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China ,grid.8547.e0000 0001 0125 2443Human Phenome Institute, Fudan University, Shanghai, China ,grid.413597.d0000 0004 1757 8802Shanghai Key Laboratory of Clinical Geriatric Medicine and Huadong Hospital Clinical Research Center for Geriatric Medicine, Shanghai, China ,grid.8547.e0000 0001 0125 2443National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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Effect of long-term chronic hyperhomocysteinemia on retinal structure and function in the cystathionine-β-synthase mutant mouse. Exp Eye Res 2022; 214:108894. [PMID: 34906600 PMCID: PMC9251730 DOI: 10.1016/j.exer.2021.108894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 02/03/2023]
Abstract
Elevated levels of the excitatory amino acid homocysteine (Hcy) have been implicated in retinal diseases in humans including glaucoma and macular degeneration. It is not clear whether elevated Hcy levels are pathogenic. Models of hyperhomocysteinemia (Hhcy) have proven useful in addressing this including mice with deficiency in the enzyme cystathionine β-synthase (CBS). Cbs+/- mice have a ∼two-fold increase in plasma and retinal Hcy levels. Previous studies of visual function and structure in Cbs+/- mice during the first 10 months of life revealed mild ganglion cell loss, but minimal electrophysiological alterations. It is not clear whether extended, chronic exposure to moderate Hhcy elevation will lead to visual function loss and retinal pathology. The present study addressed this by performing comprehensive analyses of retinal function/structure in 20 month Cbs+/- and Cbs+/+ (WT) mice including IOP, SD-OCT, scotopic and photopic ERG, pattern ERG (pERG), and visual acuity. Eyes were harvested for histology and immunohistochemical analysis of Brn3a (ganglion cells), dihydroethidium (oxidative stress) and GFAP (gliosis). The analyses revealed no difference in IOP between groups for age/strain. Visual acuity measured ∼0.36c/d for mice at 20 months in Cbs+/- and WT mice; contrast sensitivity did not differ between groups at either age. Similarly SD-OCT, scotopic/photopic ERG and pERG revealed no differences between 20 month Cbs+/- and WT mice. There was minimal disruption in retinal structure when eyes were examined histologically. Morphometric analysis revealed no significant differences in retinal layers. Immunohistochemistry revealed ∼5 RGCs/100 μm retinal length in both Cbs+/- and WT mice at 20 months. While there was greater oxidative stress and gliosis in older (20 month) mice versus young (4 month) mice, there was no difference in these parameters between the 20 month Cbs+/- and WT mice. We conclude that chronic, moderate Hhcy (at least due to deficiency of Cbs) is not accompanied by retinal structural/functional changes that differ significantly from age-matched WT littermates. Despite considerable evidence that severe Hhcy is toxic to retina, moderate Hhcy appears tolerated by retina suggesting compensatory cellular survival mechanisms.
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12
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Tomić M, Vrabec R, Ljubić S, Bulum T, Rahelić D. Plasma homocysteine is associated with nonproliferative retinopathy in patients with type 2 diabetes without renal disease. Diabetes Metab Syndr 2022; 16:102355. [PMID: 34920196 DOI: 10.1016/j.dsx.2021.102355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND AIMS This study aimed to assess the role of plasma homocysteine (Hcy) in the development of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes (T2DM) without chronic kidney disease. METHODS This was a cross-sectional study that included 94 T2DM. Hcy, serum 25-hydroxy (25-OH) vitamin D, vitamin B12, and folate were determined by the CMIA method. NPDR was determined according to the EURODIAB retinal photography methodology and optical coherence tomography (OCT) of the macula. RESULTS Compared to patients without NPDR, patients with NPDR had longer diabetes duration (p < 0.001), higher Hcy (p < 0.001), lower vitamin B12 (p = 0.028) and lower estimated glomerular filtration rate (eGFR) (p = 0.004). NPDR was positively associated with diabetes duration (p < 0.001), HbA1c (p = 0.049) and Hcy (p < 0.001), and negatively with vitamin B12 (p = 0.027) and eGFR (p = 0.005). Logistic regression analyses showed that diabetes duration (OR = 1.13, p < 0.001), Hcy (OR = 1.06, p = 0.047), and eGFR (OR = 0.96, p = 0.004) were the main predictors of NPDR in T2DM. Stepwise regression analyses showed that the best model for predicting Hcy (R2 = 0.104) included vitamins B12 and D. CONCLUSIONS Higher Hcy is associated with NPDR and may play a role as a risk factor for its development in T2DM. Vitamins B12 and D seem to modify this association.
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Affiliation(s)
- Martina Tomić
- Department of Ophthalmology, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Merkur University Hospital, Zagreb, Croatia
| | - Romano Vrabec
- Department of Ophthalmology, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Merkur University Hospital, Zagreb, Croatia
| | - Spomenka Ljubić
- Department of Diabetes and Endocrinology, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Merkur University Hospital, Zagreb, Croatia; School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Tomislav Bulum
- Department of Diabetes and Endocrinology, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Merkur University Hospital, Zagreb, Croatia; School of Medicine, University of Zagreb, Zagreb, Croatia.
| | - Dario Rahelić
- Department of Diabetes and Endocrinology, Vuk Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases, Merkur University Hospital, Zagreb, Croatia; School of Medicine, University of Zagreb, Zagreb, Croatia
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13
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Mohamad MHN, Abu IF, Fazel MF, Agarwal R, Iezhitsa I, Juliana N, Mellor IR, Franzyk H. Neuroprotection Against NMDA-Induced Retinal Damage by Philanthotoxin-343 Involves Reduced Nitrosative Stress. Front Pharmacol 2022; 12:798794. [PMID: 34970151 PMCID: PMC8714026 DOI: 10.3389/fphar.2021.798794] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/10/2021] [Indexed: 01/18/2023] Open
Abstract
N-methyl-D-aspartate receptor (NMDAR) overstimulation is known to mediate neurodegeneration, and hence represents a relevant therapeutic target for neurodegenerative disorders including glaucoma. This study examined the neuroprotective effects of philanthotoxin (PhTX)-343 against NMDA-induced retinal injury in rats. Male Sprague Dawley rats were divided into three groups; group 1 received phosphate buffer saline as the negative control, group 2 was injected with NMDA (160 nM) to induce retinal excitotoxic injury, and group 3 was pre-treated with PhTX-343 (160 nM) 24 h before NMDA exposure. All treatments were given intravitreally and bilaterally. Seven days post-treatment, rats were subjected to visual behaviour assessments using open field and colour recognition tests. Rats were then euthanized, and the retinas were harvested and subjected to haematoxylin and eosin (H&E) staining for morphometric analysis and 3-nitrotyrosine (3-NT) ELISA protocol as the nitrosative stress biomarker. PhTX-343 treatment prior to NMDA exposure improved the ability of rats to recognize visual cues and preserved visual functions (i.e., recognition of objects with different colours). Morphological examination of retinal tissues showed that the fractional ganglion cell layer thickness within the inner retina (IR) in the PhTX-343 treated group was greater by 1.28-fold as compared to NMDA-treated rats (p < 0.05) and was comparable to control rats (p > 0.05). Additionally, the number of retinal cell nuclei/100 μm2 in IR for the PhTX-343-treated group was greater by 1.82-fold compared to NMDA-treated rats (p < 0.05) and was comparable to control group (p > 0.05). PhTX-343 also reduced the retinal 3-NT levels by 1.74-fold compared to NMDA-treated rats (p < 0.05). In conclusion, PhTX-343 pretreatment protects against NMDA-induced retinal morphological changes and visual impairment by suppressing nitrosative stress as reflected by the reduced retinal 3-NT level.
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Affiliation(s)
| | - Izuddin Fahmy Abu
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Muhammad Fattah Fazel
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Renu Agarwal
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Igor Iezhitsa
- School of Medicine, International Medical University, Kuala Lumpur, Malaysia.,Department of Pharmacology and Bioinformatics, Volgograd State Medical University, Volgograd, Russian Federation
| | - Norsham Juliana
- Faculty of Medicine and Health Sciences, Universiti Sains Islam Malaysia, Negeri Sembilan, Malaysia
| | - Ian R Mellor
- School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Loughman J, Loskutova E, Butler JS, Siah WF, O’Brien C. Macular Pigment Response to Lutein, Zeaxanthin, and Meso-zeaxanthin Supplementation in Open-Angle Glaucoma. OPHTHALMOLOGY SCIENCE 2021; 1:100039. [PMID: 36247822 PMCID: PMC9562333 DOI: 10.1016/j.xops.2021.100039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 01/30/2023]
Abstract
Purpose To evaluate macular pigment response to carotenoid supplementation in glaucomatous eyes. Design Double-masked, randomized, placebo-controlled clinical trial, the European Nutrition in Glaucoma Management Study (ClinicalTrials.gov identifier, NCT04460365). Participants Sixty-two participants (38 men, 24 women) with a diagnosis of open-angle glaucoma were enrolled. Forty-two were randomized to receive the active supplement, 20 participants were allocated to placebo. Methods Macular pigment optical density (MPOD) was measured by autofluorescence using the Heidelberg Spectralis scanning laser ophthalmoscope. Macular pigment optical density volume within the central 6° of retinal eccentricity as well as MPOD at 0.23°, 0.51°, 0.74°, and 1.02° were recorded at baseline and at 6-month intervals over 18 months. Visual function was assessed using visual acuity, mesopic and photopic contrast sensitivity under glare conditions, photo stress recovery time, microperimetry, and Glaucoma Activities Limitation 9 questionnaire. Advanced glaucoma module scans of retinal nerve fiber layer thickness and ganglion cell complex thickness over the central 6° of retinal eccentricity also were completed at each study visit. Main Outcome Measures Change in MPOD after supplementation with 10 mg lutein, 2 mg zeaxanthin, and 10 mg meso-zeaxanthin or placebo over 18 months. Results A mixed-model repeated measures analysis of variance revealed a statistically significant increase in MPOD volume (significant time effect: F(3,111) = 89.31, mean square error (MSE) = 1656.9; P < 0.01). Post hoc t tests revealed a significant difference in MPOD volume at each study visit for the treatment group (P < 0.01 for all), but no change in the placebo group (P > 0.05 for all). A statistically significant increase in mesopic contrast sensitivity under glare conditions was noted at 18 months in the treatment group, but not placebo. No other structural or functional changes were observed. No serious adverse events were noted during the trial. Conclusions Macular pigment can be augmented in glaucomatous eyes by supplementation with a formulation containing the carotenoids lutein, zeaxanthin, and meso-zeaxanthin. The greatest relative benefit was observed in those with the lowest baseline levels, but increases were noted across all participants and each retinal eccentricity. The potential benefits of MP augmentation for macular health in glaucoma merit further long-term evaluation.
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15
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Mild Hyperhomocysteinemia Causes Anxiety-like Behavior and Brain Hyperactivity in Rodents: Are ATPase and Excitotoxicity by NMDA Receptor Overstimulation Involved in this Effect? Cell Mol Neurobiol 2021; 42:2697-2714. [PMID: 34324129 DOI: 10.1007/s10571-021-01132-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 07/18/2021] [Indexed: 10/20/2022]
Abstract
Mild hyperhomocysteinemia is a risk factor for psychiatric and neurodegenerative diseases, whose mechanisms between them are not well-known. In the present study, we evaluated the emotional behavior and neurochemical pathways (ATPases, glutamate homeostasis, and cell viability) in amygdala and prefrontal cortex rats subjected to mild hyperhomocysteinemia (in vivo studies). The ex vivo effect of homocysteine on ATPases and redox status, as well as on NMDAR antagonism by MK-801 in same structures slices were also performed. Wistar male rats received a subcutaneous injection of 0.03 µmol Homocysteine/g of body weight or saline, twice a day from 30 to 60th-67th days of life. Hyperhomocysteinemia increased anxiety-like behavior and tended to alter locomotion/exploration of rats, whereas sucrose preference and forced swimming tests were not altered. Glutamate uptake was not changed, but the activities of glutamine synthetase and ATPases were increased. Cell viability was not altered. Ex vivo studies (slices) showed that homocysteine altered ATPases and redox status and that MK801, an NMDAR antagonist, protected amygdala (partially) and prefrontal cortex (totally) effects. Taken together, data showed that mild hyperhomocysteinemia impairs the emotional behavior, which may be associated with changes in ATPase and glutamate homeostasis, including glutamine synthetase and NMDAR overstimulation that could lead to excitotoxicity. These findings may be associated with the homocysteine risk factor on psychiatric disorders development and neurodegeneration.
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Rudzki L, Stone TW, Maes M, Misiak B, Samochowiec J, Szulc A. Gut microbiota-derived vitamins - underrated powers of a multipotent ally in psychiatric health and disease. Prog Neuropsychopharmacol Biol Psychiatry 2021; 107:110240. [PMID: 33428888 DOI: 10.1016/j.pnpbp.2020.110240] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023]
Abstract
Despite the well-established roles of B-vitamins and their deficiencies in health and disease, there is growing evidence indicating a key role of those nutrients in functions of the central nervous system and in psychopathology. Clinical data indicate the substantial role of B-vitamins in various psychiatric disorders, including major depression, bipolar disorder, schizophrenia, autism, and dementia, including Alzheimer's and Parkinson's diseases. As enzymatic cofactors, B-vitamins are involved in many physiological processes such as the metabolism of glucose, fatty acids and amino acids, metabolism of tryptophan in the kynurenine pathway, homocysteine metabolism, synthesis and metabolism of various neurotransmitters and neurohormones including serotonin, dopamine, adrenaline, acetylcholine, GABA, glutamate, D-serine, glycine, histamine and melatonin. Those vitamins are highly involved in brain energetic metabolism and respiration at the cellular level. They have a broad range of anti-inflammatory, immunomodulatory, antioxidant and neuroprotective properties. Furthermore, some of those vitamins are involved in the regulation of permeability of the intestinal and blood-brain barriers. Despite the fact that a substantial amount of the above vitamins is acquired from various dietary sources, deficiencies are not uncommon, and it is estimated that micronutrient deficiencies affect about two billion people worldwide. The majority of gut-resident microbes and the broad range of bacteria available in fermented food, express genetic machinery enabling the synthesis and metabolism of B-vitamins and, consequently, intestinal microbiota and fermented food rich in probiotic bacteria are essential sources of B-vitamins for humans. All in all, there is growing evidence that intestinal bacteria-derived vitamins play a significant role in physiology and that dysregulation of the "microbiota-vitamins frontier" is related to various disorders. In this review, we will discuss the role of vitamins in mental health and explore the perspectives and potential of how gut microbiota-derived vitamins could contribute to mental health and psychiatric treatment.
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Affiliation(s)
- Leszek Rudzki
- The Charleston Centre, 49 Neilston Road, Paisley PA2 6LY, UK.
| | | | - Michael Maes
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Bulgaria; IMPACT Strategic Research Center, Deakin University, Geelong, Australia
| | - Błażej Misiak
- Department of Psychiatry, Wroclaw Medical University, Pasteura 10 Street, 50-367 Wroclaw, Poland
| | - Jerzy Samochowiec
- Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26 Street, 71-460 Szczecin, Poland
| | - Agata Szulc
- Department of Psychiatry, Medical University of Warsaw, Poland
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17
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Muzurović E, Kraljević I, Solak M, Dragnić S, Mikhailidis DP. Homocysteine and diabetes: Role in macrovascular and microvascular complications. J Diabetes Complications 2021; 35:107834. [PMID: 33419630 DOI: 10.1016/j.jdiacomp.2020.107834] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/23/2020] [Accepted: 12/17/2020] [Indexed: 01/12/2023]
Abstract
Diabetes mellitus (DM) can lead to the development of macro- and microvascular complications. Homocysteine (Hcy) may play a role in the development of cardiovascular (CV) diseases (CVDs). The role of Hcy in the development of the vascular complications associated with DM is not clearly defined. Despite a strong initial assumption regarding the importance of Hcy in DM and its complications, over time "enthusiasm has waned" because several studies showed unconvincing and occasionally contradictory results. A universal conclusion is not easy to draw given the diversity of studies (e.g. number of patients, design, folic acid and vitamin B status, ethnic differences, genetic background). For some complications, most results encourages further investigation. Impaired renal function is a major independent determinant of high total Hcy (tHcy) levels. However, the role of hyperhomocysteinaemia (HHcy) in the development of diabetic kidney disease (DKD) has yet to be determined. Hcy-lowering therapies can significantly decrease Hcy levels but their effects on CVD risk reduction are conflicting. Further studies are needed to determine the influence of Hcy-lowering therapy on CVD risk reduction, especially in patients with DM.
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Affiliation(s)
- Emir Muzurović
- Department of Internal Medicine, Endocrinology Section, Clinical Centre of Montenegro, Faculty of Medicine, University of Montenegro, Ljubljanska bb, 81000 Podgorica, Montenegro.
| | - Ivana Kraljević
- Department of Endocrinology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Mirsala Solak
- Department of Endocrinology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Siniša Dragnić
- Department of Cardiology, Clinical Centre of Montenegro, Faculty of Medicine, University of Montenegro, Ljubljanska bb, 81000 Podgorica, Montenegro
| | - Dimitri P Mikhailidis
- Department of Clinical Biochemistry, Royal Free Hospital Campus, University College London Medical School, University College London (UCL), Pond Street, London NW3 2QG, UK
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Involvements of Hyperhomocysteinemia in Neurological Disorders. Metabolites 2021; 11:metabo11010037. [PMID: 33419180 PMCID: PMC7825518 DOI: 10.3390/metabo11010037] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/27/2020] [Accepted: 01/01/2021] [Indexed: 12/14/2022] Open
Abstract
Homocysteine (HCY), a physiological amino acid formed when proteins break down, leads to a pathological condition called hyperhomocysteinemia (HHCY), when it is over a definite limit. It is well known that an increase in HCY levels in blood, can contribute to arterial damage and several cardiovascular disease, but the knowledge about the relationship between HCY and brain disorders is very poor. Recent studies demonstrated that an alteration in HCY metabolism or a deficiency in folate or vitamin B12 can cause altered methylation and/or redox potentials, that leads to a modification on calcium influx in cells, or into an accumulation in amyloid and/or tau protein involving a cascade of events that culminate in apoptosis, and, in the worst conditions, neuronal death. The present review will thus summarize how much is known about the possible role of HHCY in neurodegenerative disease.
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Tawfik A, Mohamed R, Kira D, Alhusban S, Al-Shabrawey M. N-Methyl-D-aspartate receptor activation, novel mechanism of homocysteine-induced blood-retinal barrier dysfunction. J Mol Med (Berl) 2021; 99:119-130. [PMID: 33159240 PMCID: PMC7785674 DOI: 10.1007/s00109-020-02000-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/18/2020] [Accepted: 10/27/2020] [Indexed: 12/14/2022]
Abstract
Elevated levels of amino acid homocysteine (Hcy) recognized as hyperhomocysteinemia (HHcy) was reported in several human visual disorders, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Breakdown of blood-retinal barrier (BRB) is concomitant with vision loss in DR and AMD. We previously reported that HHcy alters BRB. Here, we tested the hypothesis that HHcy alters BRB via activation of N-methyl-D-aspartate receptor (NMDAR). Human retinal endothelial cells subjected to high level of Hcy and mouse model of HHcy were used. We injected Hcy intravitreal and used a mouse model of HHcy that lacks cystathionine-β-synthase (CBS). RT-PCR, western blot, and immunofluorescence showed that retinal endothelial cells (RECs) express NMDAR at the gene and protein levels both in vitro and in vivo and this was increased by HHcy. We assessed BRB function and retinal morphology using fluorescein angiogram and optical coherence tomography (OCT) under HHcy with and without pharmacological inhibition of NMDAR by (MK801) or in mice lacking endothelial NMDAR (NMDARE-/- mouse). Additionally, retinal albumin leakage and tight junction proteins ZO-1 and occludin were assessed by western blotting analysis. Inhibition or elimination of NMDAR was able to improve the altered retinal hyperpermeability and morphology under HHcy as indicated by significant decrease in retinal albumin leakage and restoration of tight junction proteins ZO-1 and occludin. Our findings underscore a potential role for endothelial NMDAR in mediating Hcy-induced breakdown of BRB and subsequently as a potential therapeutic target in retinal diseases associated with HHcy such as DR and AMD. KEY MESSAGES: • Elevated levels of homocysteine (Hcy) are defined as hyperhomocysteinemia (HHcy). • HHcy is implicated in diabetic retinopathy and age-related macular degeneration. • HHcy alters BRB via activation of N-methyl-D-aspartate receptor.
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Affiliation(s)
- Amany Tawfik
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA.
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA.
- Department of Cellular Biology and Anatomy, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA.
- Department of Ophthalmology, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA.
| | - Riyaz Mohamed
- Department of Physiology Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
| | - Dina Kira
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
| | - Suhib Alhusban
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
| | - Mohamed Al-Shabrawey
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
- Department of Cellular Biology and Anatomy, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
- Department of Ophthalmology, Medical College of Georgia (MCG), Augusta University, Augusta, GA, 30912, USA
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Flores-Flores M, Moreno-García L, Castro-Martínez F, Nahmad M. Cystathionine β-synthase Deficiency Impairs Vision in the Fruit Fly, Drosophila melanogaster. Curr Eye Res 2020; 46:600-605. [PMID: 32865440 DOI: 10.1080/02713683.2020.1818262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Deficiency in Cystathionine β-synthase (CBS) leads to an abnormal accumulation of homocysteine and results in classical homocystinuria, a multi-systemic disorder that affects connective tissue, muscles, the central nervous system, and the eyes. However, the genetic players and mechanisms underlying vision alterations in patients with homocystinuria are little understood. MATERIALS AND METHODS The fruit fly, Drosophila melanogaster, is a useful system to investigate the genetic basis of several human diseases, but no study to date has used Drosophila as model of homocystinuria. Here, we use Drosophila genetic tools to down-regulate CBS expression and evaluate its behavioral response to light. RESULTS We show that CBS-deficient flies do not display the normal stereotypical behavior of attraction towards a luminous source, known as phototaxis. This behavior cannot be attributed to a motor or olfactory deficiency, but it is most likely related to a lower visual acuity. CBS-deficient flies are overall smaller, but smaller eyes do not explain their lack of phototactic response. CONCLUSIONS The vision phenotype of CBS knock-down flies is consistent with severe myopia in homocystinuria patients. We propose to use Drosophila as a model to investigate ocular manifestations underlying homocystinuria.
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Affiliation(s)
- Marycruz Flores-Flores
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Leonardo Moreno-García
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Felipe Castro-Martínez
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Marcos Nahmad
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
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21
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Implication of Hyperhomocysteinemia in Blood Retinal Barrier (BRB) Dysfunction. Biomolecules 2020; 10:biom10081119. [PMID: 32751132 PMCID: PMC7463551 DOI: 10.3390/biom10081119] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 02/07/2023] Open
Abstract
Elevated plasma homocysteine (Hcy) level, known as hyperhomocysteinemia (HHcy) has been linked to different systemic and neurological diseases, well-known as a risk factor for systemic atherosclerosis and cardiovascular disease (CVD) and has been identified as a risk factor for several ocular disorders, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Different mechanisms have been proposed to explain HHcy-induced visual dysfunction, including oxidative stress, upregulation of inflammatory mediators, retinal ganglion cell apoptosis, and extracellular matrix remodeling. Our previous studies using in vivo and in vitro models of HHcy have demonstrated that Hcy impairs the function of both inner and outer blood retinal barrier (BRB). Dysfunction of BRB is a hallmark of vision loss in DR and AMD. Our findings highlighted oxidative stress, ER stress, inflammation, and epigenetic modifications as possible mechanisms of HHcy-induced BRB dysfunction. In addition, we recently reported HHcy-induced brain inflammation as a mechanism of blood–brain barrier (BBB) dysfunction and pathogenesis of Alzheimer’s disease (AD). Moreover, we are currently investigating the activation of glutamate receptor N-methyl-d-aspartate receptor (NMDAR) as the molecular mechanism for HHcy-induced BRB dysfunction. This review focuses on the studied effects of HHcy on BRB and the controversial role of HHcy in the pathogenesis of aging neurological diseases such as DR, AMD, and AD. We also highlight the possible mechanisms for such deleterious effects of HHcy.
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22
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Relationship between homocysteine levels, anterior chamber depth, and pseudoexfoliation glaucoma in patients with pseudoexfoliation. Int Ophthalmol 2020; 40:1731-1737. [PMID: 32212027 DOI: 10.1007/s10792-020-01341-4] [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: 11/08/2019] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE This study investigates the relationship between plasma homocysteine levels, anterior chamber depth (ACD), and pseudoexfoliation glaucoma (PEXG) in patients with pseudoexfoliation syndrome. METHODS Sixty patients (F:M = 35:25) with pseudoexfoliation (PEX) were divided into two groups based on their plasma homocysteine levels; group 1 (< 20 µmol/L, normal) and group 2 (≥ 20 µmol/L, high). Intraocular pressure (IOP) and ACD values as well as plasma homocysteine levels were compared between the two groups. Moreover, the mean values for ACD and IOP were compared between patients stratified according to the reference upper limit for the homocysteine level (above and below 14 μmol/L), and the prevalence of high IOP was estimated. RESULTS Groups 1 and 2 showed no statistically significant differences in the mean ACD (3.04 ± 0.28 vs. 3.07 ± 0.31 mm, respectively) and mean IOP (20.63 ± 10.22 vs. 21.67 ± 7.55 mmHg, respectively). Patients with PEX and homocysteine levels > 14 μmol/L had a significantly increased prevalence (P < 0.05) of high IOP (≥ 22 mmHg). CONCLUSIONS Patients with PEX and high homocysteine levels have an increased prevalence of high IOP. No relationship exists between plasma homocysteine levels and ACD. Thus, PEXG should be suspected in patients with PEX and high plasma homocysteine levels. Plasma homocysteine levels could be helpful for the diagnosis of PEXG, although larger sample studies are required to confirm this finding.
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Salissou MTM, Mahaman YAR, Zhu F, Huang F, Wang Y, Xu Z, Ke D, Wang Q, Liu R, Wang JZ, Zhang B, Wang X. Methanolic extract of Tamarix Gallica attenuates hyperhomocysteinemia induced AD-like pathology and cognitive impairments in rats. Aging (Albany NY) 2019; 10:3229-3248. [PMID: 30425189 PMCID: PMC6286848 DOI: 10.18632/aging.101627] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/27/2018] [Indexed: 12/20/2022]
Abstract
Although few drugs are available today for the management of Alzheimer’s disease (AD) and many plants and their extracts are extensively employed in animals’ studies and AD patients, yet no drug or plant extract is able to reverse AD symptoms adequately. In the present study, Tamarix gallica (TG), a naturally occurring plant known for its strong antioxidative, anti-inflammatory and anti-amyloidogenic properties, was evaluated on homocysteine (Hcy) induced AD-like pathology and cognitive impairments in rats. We found that TG attenuated Hcy-induced oxidative stress and memory deficits. TG also improved neurodegeneration and neuroinflammation by upregulating synaptic proteins such as PSD95 and synapsin 1 and downregulating inflammatory markers including CD68 and GFAP with concomitant decrease in proinflammatory mediators interlukin-1β (IL1β) and tumor necrosis factor α (TNFα). TG attenuated tau hyperphosphorylation at multiple AD-related sites through decreasing some kinases and increasing phosphatase activities. Moreover, TG rescued amyloid-β (Aβ) pathology through downregulating BACE1. Our data for the first time provide evidence that TG attenuates Hcy-induced AD-like pathological changes and cognitive impairments, making TG a promising candidate for the treatment of AD-associated pathological changes.
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Affiliation(s)
- Maibouge Tanko Mahamane Salissou
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yacoubou Abdoul Razak Mahaman
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University, Shenzhen, 518001, Guangdong Province, China
| | - Feiqi Zhu
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University, Shenzhen, 518001, Guangdong Province, China
| | - Fang Huang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuman Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhendong Xu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS, 226001, China
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Kumar M, Sandhir R. Hydrogen sulfide attenuates hyperhomocysteinemia-induced mitochondrial dysfunctions in brain. Mitochondrion 2019; 50:158-169. [PMID: 31751655 DOI: 10.1016/j.mito.2019.11.004] [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] [Received: 03/27/2019] [Revised: 08/04/2019] [Accepted: 11/11/2019] [Indexed: 12/17/2022]
Abstract
Hyperhomocysteinemia (HHcy) has been implicated in the development of neurodegenerative conditions and mild cognitive disorders. Mitochondrial dysfunctions are the major mechanisms involved in homocysteine (Hcy)-induced neurotoxicity. Although, hydrogen sulfide has been reported as potent antioxidant, its effects on Hcy-induced mitochondrial dysfunctions have not been studied. Therefore, the present study has been designed to evaluate the protective effect of NaHS on Hcy-induced mitochondrial dysfunctions in brain. NaHS supplementation decreased reactive oxygen species and nitrite levels in the cortex and hippocampus of animals with HHcy. NaHS supplementation increased the activity of mitochondrial electron transport chain components; NADH dehydrogenase, cytochrome c oxidase and F0-F1 ATPase in the cortex and hippocampus of HHcy animals along with in-gel activity of complex I - complex V in the mitochondria isolated from the cortex and hippocampus of HHcy animals. Moreover, NaHS supplementation also increased the mitochondrial complex I, II and IV mediated oxygen consumption rate in Hcy treated mitochondria. NaHS administration prevented the Hcy-induced mitochondrial damage as suggested by the decreased mitochondrial swelling in the cortex and hippocampus of HHcy animals. NaHS supplementation decreased the activity of lactate dehydrogenase isozymes (1-5) in the brain regions of HHcy animals. The expression of protein kinase c δ was also decreased in the brain regions of HHcy animals following NaHS supplementation. This was accompanied by reduced activity of caspase-3 indicating anti-apoptotic effect of H2S. Taken together, the findings suggest that H2S supplementation ameliorates Hcy-induced oxidative stress and mitochondrial dysfunctions suggesting H2S releasing drugs may be a novel therapeutic approach to treat HHcy associated neurological disorders.
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Affiliation(s)
- Mohit Kumar
- Department of Biochemistry, Basic Medical Science Block-II, Panjab University, Chandigarh 160014, India
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Science Block-II, Panjab University, Chandigarh 160014, India.
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25
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Tawarayama H, Feng Q, Murayama N, Suzuki N, Nakazawa T. Cyclin-Dependent Kinase Inhibitor 2b Mediates Excitotoxicity-Induced Death of Retinal Ganglion Cells. ACTA ACUST UNITED AC 2019; 60:4479-4488. [DOI: 10.1167/iovs.19-27396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Hiroshi Tawarayama
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Division of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Qiwei Feng
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Namie Murayama
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Noriyuki Suzuki
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
- Division of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
- Division of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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26
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Narayanan SP, Shosha E, D Palani C. Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy. Pharmacol Res 2019; 147:104299. [PMID: 31207342 PMCID: PMC7011157 DOI: 10.1016/j.phrs.2019.104299] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/23/2019] [Accepted: 06/05/2019] [Indexed: 12/20/2022]
Abstract
Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.
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Affiliation(s)
- S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; VA Medical Center, Augusta, GA, United States.
| | - Esraa Shosha
- Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; Clinical Pharmacy Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Chithra D Palani
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States
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27
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Cho HK, Kim S, Lee EJ, Kee C. Neuroprotective Effect of Ginkgo Biloba Extract Against Hypoxic Retinal Ganglion Cell Degeneration In Vitro and In Vivo. J Med Food 2019; 22:771-778. [PMID: 31268403 DOI: 10.1089/jmf.2018.4350] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Hypoxia-induced oxidative stress and disturbed microvascular circulation are both associated with pathogenesis of glaucoma. Ginkgo biloba extract (GBE) has been reported to have positive pharmacological effects on oxidative stress and impaired vascular circulation. This study aimed to investigate the neuroprotective effect of GBE against hypoxic injury to retinal ganglion cells (RGCs) both in vitro and in vivo. The rat RGC line was used, and oxidative stress was induced by hydrogen peroxide (H2O2) in vitro. EGb 761, a standardized GBE, or vehicle was applied to RGCs. Hypoxic optic nerve injury in vivo was induced by clamping the optic nerve of rats with a "microserrefine clip" with an applicator, which was applied without crushing the optic nerve. This method is different from "optic nerve crush model" and does not involve elevation of intraocular pressure, and may serve as a possible normal tension glaucoma animal model. EGb 761 at various concentrations or vehicle was administered intraperitoneally. RGC density was measured to estimate the survival both in vitro and in vivo. The survival of RGCs was significantly (P < .001) higher upon treatment with 1 or 5 μg/mL of EGb 761 compared with vehicle after oxidative stress in vitro. RGC density upon treatment with EGb 761 of 100 mg/kg (1465.6 ± 175 cells/mm2) or 250 mg/kg (1307.6 ± 213 cells/mm2) was significantly higher (P < .01, P < .05, respectively) than that obtained with vehicle (876.3 ± 136 cells/mm2) in vivo. Our results suggest that GBE has neuroprotective effect on RGCs against hypoxic injury both in vitro and in vivo.
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Affiliation(s)
- Hyun-Kyung Cho
- 1Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Gyeongsang National University, School of Medicine, Changwon, Korea
| | - Sibum Kim
- 2Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Eun Jung Lee
- 2Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Changwon Kee
- 2Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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28
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Mahaman YAR, Huang F, Wu M, Wang Y, Wei Z, Bao J, Salissou MTM, Ke D, Wang Q, Liu R, Wang JZ, Zhang B, Chen D, Wang X. Moringa Oleifera Alleviates Homocysteine-Induced Alzheimer's Disease-Like Pathology and Cognitive Impairments. J Alzheimers Dis 2019; 63:1141-1159. [PMID: 29710724 PMCID: PMC6004908 DOI: 10.3233/jad-180091] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer’s disease (AD) is multifactorial with unclear etiopathology. Due to the complexity of AD, many attempted single therapy treatments, like Aβ immunization, have generally failed. Therefore, there is a need for drugs with multiple benefits. Naturally occurring phytochemicals with neuroprotective, anti-amyloidogenic, antioxidative, and anti-inflammatory properties could be a possible way out. In this study, the effect of Moringa oleifera (MO), a naturally occurring plant with high antioxidative, anti-inflammatory, and neuroprotective effects, was evaluated on hyperhomocysteinemia (HHcy) induced AD-like pathology in rats. Homocysteine (Hcy) injection for 14 days was used to induce AD-like pathology. Simultaneous MO extract gavage followed the injection as a preventive treatment or, after injection completion, MO gavage was performed for another 14 days as a curative treatment. MO was found to not only prevent but also rescue the oxidative stress and cognitive impairments induced by Hcy treatment. Moreover, MO recovered the decreased synaptic proteins PSD93, PSD95, Synapsin 1 and Synaptophysin, and improved neurodegeneration. Interestingly, MO decreased the Hyc-induced tau hyperphosphorylation at different sites including S-199, T-231, S-396, and S-404, and at the same time decreased Aβ production through downregulation of BACE1. These effects in HHcy rats were accompanied by a decrease in calpain activity under MO treatment, supporting that calpain activation might be involved in AD pathogenesis in HHcy rats. Taken together, our data, for the first time, provided evidence that MO alleviates tau hyperphosphorylation and Aβ pathology in a HHcy AD rat model. This and previous other studies support MO as a good candidate for, and could provide new insights into, the treatment of AD and other tauopathies.
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Affiliation(s)
- Yacoubou Abdoul Razak Mahaman
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Huang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mengjuan Wu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuman Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhen Wei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian Bao
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Maibouge Tanko Mahamane Salissou
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dan Chen
- School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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George AK, Master K, Majumder A, Homme RP, Laha A, Sandhu HS, Tyagi SC, Singh M. Circular RNAs constitute an inherent gene regulatory axis in the mammalian eye and brain. Can J Physiol Pharmacol 2019; 97:463-472. [DOI: 10.1139/cjpp-2018-0505] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Circular RNAs (circRNAs) are being hailed as a newly rediscovered class of covalently closed transcripts that are produced via alternative, noncanonical pre-mRNA back-splicing events. These single-stranded RNA molecules have been identified in organisms ranging from the worm (Cortés-López et al. 2018. BMC Genomics, 19: 8; Ivanov et al. 2015. Cell Rep. 10: 170–177) to higher eukaryotes (Yang et al. 2017. Cell Res. 27: 626–641) to plants (Li et al. 2017. Biochem. Biophys. Res. Commun. 488: 382–386). At present, research on circRNAs is an active area because of their diverse roles in development, health, and diseases. Partly because their circularity makes them resistant to degradation, they hold great promise as unique biomarkers for ocular and central nervous system (CNS) disorders. We believe that further work on their applications could help in developing them as “first-in-class” diagnostics, therapeutics, and prognostic targets for numerous eye conditions. Interestingly, many circRNAs play key roles in transcriptional regulation by acting as miRNAs sponges, meaning that they serve as master regulators of RNA and protein expression. Since the retina is an extension of the brain and is part of the CNS, we highlight the current state of circRNA biogenesis, properties, and function and we review the crucial roles that they play in the eye and the brain. We also discuss their regulatory roles as miRNA sponges, regulation of their parental genes or linear mRNAs, translation into micropeptides or proteins, and responses to cellular stress. We posit that future advances will provide newer insights into the fields of RNA metabolism in general and diseases of the aging eye and brain in particular. Furthermore, in keeping pace with the rapidly evolving discipline of RNA“omics”-centered metabolism and to achieve uniformity among researchers, we recently introduced the term “cromics” (circular ribonucleic acids based omics) (Singh et al. 2018. Exp. Eye Res. 174: 80–92).
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Affiliation(s)
- Akash K. George
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Kruyanshi Master
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India
| | - Avisek Majumder
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Rubens Petit Homme
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Anwesha Laha
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Harpal S. Sandhu
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
- 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
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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Navneet S, Zhao J, Wang J, Mysona B, Barwick S, Ammal Kaidery N, Saul A, Kaddour-Djebbar I, Bollag WB, Thomas B, Bollinger KE, Smith SB. Hyperhomocysteinemia-induced death of retinal ganglion cells: The role of Müller glial cells and NRF2. Redox Biol 2019; 24:101199. [PMID: 31026769 PMCID: PMC6482349 DOI: 10.1016/j.redox.2019.101199] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/05/2019] [Accepted: 04/10/2019] [Indexed: 12/23/2022] Open
Abstract
Hyperhomocysteinemia (Hhcy), or increased levels of the excitatory amino acid homocysteine (Hcy), is implicated in glaucoma, a disease characterized by increased oxidative stress and loss of retinal ganglion cells (RGCs). Whether Hhcy is causative or merely a biomarker for RGC loss in glaucoma is unknown. Here we analyzed the role of NRF2, a master regulator of the antioxidant response, in Hhcy-induced RGC death in vivo and in vitro. By crossing Nrf2−/− mice and two mouse models of chronic Hhcy (Cbs+/- and Mthfr+/- mice), we generated Cbs+/-Nrf2−/− and Mthfr+/-Nrf2−/− mice and performed systematic analysis of retinal architecture and visual acuity followed by assessment of retinal morphometry and gliosis. We observed significant reduction of inner retinal layer thickness and reduced visual acuity in Hhcy mice lacking NRF2. These functional deficits were accompanied by fewer RGCs and increased gliosis. Given the key role of Müller glial cells in maintaining RGCs, we established an ex-vivo indirect co-culture system using primary RGCs and Müller cells. Hhcy-exposure decreased RGC viability, which was abrogated when cells were indirectly cultured with wildtype (WT) Müller cells, but not with Nrf2−/− Müller cells. Exposure of WT Müller cells to Hhcy yielded a robust mitochondrial and glycolytic response, which was not observed in Nrf2−/− Müller cells. Taken together, the in vivo and in vitro data suggest that deleterious effects of Hhcy on RGCs are likely dependent upon the health of retinal glial cells and the availability of an intact retinal antioxidant response mechanism. Oxidative stress is linked to homocysteine (Hcy)-induced retinal ganglion cell death. NRF2's role in protecting ganglion cells from excess Hcy was studied in vitro/vivo. Hyper-Hcy mice were crossed with Nrf2−/− mice to study retinal function/structure. Ganglion cells co-cultured with primary WT Müller glial cells survived Hcy treatment. Nrf2−/− Müller cells did not afford neuroprotective advantage to Hcy-treated cells.
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Affiliation(s)
- Soumya Navneet
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Jing Zhao
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Barbara Mysona
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Shannon Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Navneet Ammal Kaidery
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
| | - Alan Saul
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Ismail Kaddour-Djebbar
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA, 30904, USA
| | - Wendy B Bollag
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA, 30904, USA
| | - Bobby Thomas
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA; Department of Drug Discovery, Medical University of South Carolina, Charleston, SC, USA
| | - Kathryn E Bollinger
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA.
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Hyperhomocysteinemia leads to exacerbation of ischemic brain damage: Role of GluN2A NMDA receptors. Neurobiol Dis 2019; 127:287-302. [PMID: 30885791 DOI: 10.1016/j.nbd.2019.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 02/19/2019] [Accepted: 03/14/2019] [Indexed: 11/24/2022] Open
Abstract
Hyperhomocysteinemia has been implicated in several neurodegenerative disorders including ischemic stroke. However, the pathological consequences of ischemic insult in individuals predisposed to hyperhomocysteinemia and the associated etiology are unknown. In this study, we evaluated the outcome of transient ischemic stroke in a rodent model of hyperhomocysteinemia, developed by subcutaneous implantation of osmotic pumps containing L-homocysteine into male Wistar rats. Our findings show a 42.3% mortality rate in hyperhomocysteinemic rats as compared to 7.7% in control rats. Magnetic resonance imaging of the brain in the surviving rats shows that mild hyperhomocysteinemia leads to exacerbation of ischemic injury within 24 h, which remains elevated over time. Behavioral studies further demonstrate significant deficit in sensorimotor functions in hyperhomocysteinemic rats compared to control rats. Using pharmacological inhibitors targeting the NMDAR subtypes, the study further demonstrates that inhibition of GluN2A-containing NMDARs significantly reduces ischemic brain damage in hyperhomocysteinemic rats but not in control rats, indicating that hyperhomocysteinemia-mediated exacerbation of ischemic brain injury involves GluN2A-NMDAR signaling. Complementary studies in GluN2A-knockout mice show that in the absence of GluN2A-NMDARs, hyperhomocysteinemia-associated exacerbation of ischemic brain injury is blocked, confirming that GluN2A-NMDAR activation is a critical determinant of the severity of ischemic damage under hyperhomocysteinemic conditions. Furthermore, at the molecular level we observe GluN2A-NMDAR dependent sustained increase in ERK MAPK phosphorylation under hyperhomocysteinemic condition that has been shown to be involved in homocysteine-induced neurotoxicity. Taken together, the findings show that hyperhomocysteinemia triggers a unique signaling pathway that in conjunction with ischemia-induced pathways enhance the pathology of stroke under hyperhomocysteinemic conditions.
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Homocysteine: A Potential Biomarker for Diabetic Retinopathy. J Clin Med 2019; 8:jcm8010121. [PMID: 30669482 PMCID: PMC6352029 DOI: 10.3390/jcm8010121] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 12/14/2022] Open
Abstract
Diabetic retinopathy (DR) is the most common cause of blindness in people under the age of 65. Unfortunately, the current screening process for DR restricts the population that can be evaluated and the disease goes undetected until irreversible damage occurs. Herein, we aimed to evaluate homocysteine (Hcy) as a biomarker for DR screening. Hcy levels were measured by enzyme-linked immuno sorbent assay (ELISA) and immunolocalization methods in the serum, vitreous and retina of diabetic patients as well as in serum and retina of different animal models of DM representing type 1 diabetes (streptozotocin (STZ) mice, Akita mice and STZ rats) and db/db mice which exhibit features of human type 2 diabetes. Our results revealed increased Hcy levels in the serum, vitreous and retina of diabetic patients and experimental animal models of diabetes. Moreover, optical coherence tomography (OCT) and fluorescein angiography (FA) were used to evaluate the retinal changes in mice eyes after Hcy-intravitreal injection into normal wild-type (WT) and diabetic (STZ) mice. Hcy induced changes in mice retina which were aggravated under diabetic conditions. In conclusion, our data reported Hcy as a strong candidate for use as a biomarker in DR screening. Targeting the clearance of Hcy could also be a future therapeutic target for DR.
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High sensitivity of cerebellar neurons to homocysteine is determined by expression of GluN2C and GluN2D subunits of NMDA receptors. Biochem Biophys Res Commun 2018; 506:648-652. [PMID: 30454701 DOI: 10.1016/j.bbrc.2018.10.140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 10/23/2018] [Indexed: 10/28/2022]
Abstract
Homocysteine (HCY) induced neurotoxicity largely depends on interaction of this endogenous amino acid with glutamate NMDA receptors (NMDARs). This receptor type is composed by GluN1 and different GluN2 (A, B, C or D) subunits. However, the receptor activity of HCY in brain regions which differ in relative contribution of GluN2 subunits was not tested so far. In the current study, we explored the action of HCY on cerebellar neurons which natively express GluN2C and GluN2D subunits of NMDARs and compared this with the action of HCY on cortical neurons which are mainly composed by GluN2A and GluN2B subunits. To validate obtained results, we also studied the responses to HCY in recombinant GluN1/2C and GluN1/2D NMDARs expressed in HEK293T cells. Responses to HCY were compared to membrane currents evoked by glutamate or by the specific agonist NMDA. First, we found that on HEK cells expressing GluN1/2C or GluN1/2D NMDARs, HCY was full agonist producing membrane currents similar in amplitude to currents induced by glutamate. The EC50 values for these particular receptor subtype activation were 80 μM and 31 μM, respectively. Then, we found that HCY similarly to NMDA, evoked large slightly desensitizing membrane currents in native NMDARs of cerebellar and cortical neurons. In cortical neurons, the ratio of the respective currents (IHCY/INMDA) was 0.16 and did not significantly change during in vitro maturation. In sharp contrast, in cerebellar neurons, the ratio of currents evoked by HCY and NMDA was dramatically increased from 0.31 to 0.72 from 7 to 21 day in culture. We show that least 75% of HCY-induced currents in cerebellum were mediated by GluN2C- or GluN2D-containing NMDARs. Thus, our data revealed a large population of cerebellar NMDA receptors highly sensitive to HCY which suggest potential vulnerability of this brain region to pathological conditions associated with enhanced levels of this neurotoxic amino acid.
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Nutritional supplementation in the treatment of glaucoma: A systematic review. Surv Ophthalmol 2018; 64:195-216. [PMID: 30296451 DOI: 10.1016/j.survophthal.2018.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 01/02/2023]
Abstract
Current treatment strategies for glaucoma are limited to halting disease progression and do not restore lost visual function. Intraocular pressure is the main risk factor for glaucoma, and intraocular pressure-lowering treatment remains the mainstay of glaucoma treatment, but even successful intraocular pressure reduction does not stop the progression of glaucoma in all patients. We review the literature to determine whether nutritional interventions intended to prevent or delay the progression of glaucoma could prove to be a valuable addition to the mainstay of glaucoma therapy. A total of 33 intervention trials were included in this review, including 21 randomized controlled trials. These suggest that flavonoids exert a beneficial effect in glaucoma, particularly in terms of improving ocular blood flow and potentially slowing progression of visual field loss. In addition, supplements containing forskolin have consistently demonstrated the capacity to reduce intraocular pressure beyond the levels achieved with traditional therapy alone; however, despite the strong theoretical rationale and initial clinical evidence for the beneficial effect of dietary supplementation as an adjunct therapy for glaucoma, the evidence is not conclusive. More and better quality research is required to evaluate the role of nutritional supplementation in glaucoma.
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Kang JH, Ivey KL, Boumenna T, Rosner B, Wiggs JL, Pasquale LR. Prospective study of flavonoid intake and risk of primary open-angle glaucoma. Acta Ophthalmol 2018. [PMID: 29536641 DOI: 10.1111/aos.13705] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the association between flavonoid intake and incident primary open-angle glaucoma (POAG). METHODS We followed 65 516 women from the Nurses' Health Study (from 1984) and 42 156 men from the Health Professionals Follow-up Study (from 1986) biennially to 2012, who were 40+ years old, free of POAG, and reported eye examinations. Dietary flavonoid intake was assessed with validated repeated semi-quantitative food frequency questionnaires. Incident POAG cases (n = 1575) were confirmed with medical record review. Cohort-specific multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were calculated and meta-analysed. RESULTS Total flavonoid intake was not associated with risk of POAG development [RR for highest (Q5: median ~645 mg/day) versus lowest quintile (Q1: ~130 mg/day) = 0.91 (95% CI = 0.77, 1.08); p for trend (p-trend) = 0.19]; the flavonoid subclasses of flavones, flavanones, polymeric flavanols or anthocyanidins were also not associated (Q5 versus Q1 comparison p-values ≥0.05 and p-trend ≥0.09). Higher intakes of flavonols and monomeric flavanols were nominally associated with lower POAG risk, based on the Q5 versus Q1 comparisons or p-trends. The Q5 versus Q1 comparison RRs were: for flavonols, 0.82 (95% CI = 0.69, 0.97; p-trend = 0.05; ~28 versus ~8 mg/day), and for monomeric flavanols, 0.86 (95% CI = 0.72, 1.02; p-trend=0.04; ~110 versus 10 mg/day). The food/beverage that contributed most to both the variation of flavonols and monomeric flavanols was tea; consuming ~2 cups/day was associated with 18% lower POAG risk (RR=0.82; 95% CI = 0.68, 0.99; p-trend = 0.02). CONCLUSION Total flavonoid intake was not associated with POAG risk. Greater intakes of flavonols and monomeric flavanols and of tea showed suggestive modest associations with lower risk; these results need confirmation.
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Affiliation(s)
- Jae H. Kang
- Channing Division of Network Medicine; Department of Medicine; Brigham & Women's Hospital/Harvard Medical School; Boston MA USA
| | - Kerry L. Ivey
- Department of Nutrition; Harvard T. H. Chan School of Public Health; Boston MA USA
- South Australian Health and Medical Research Institute; Infection and Immunity Theme; School of Medicine; Flinders University; Adelaide SA Australia
| | - Tahani Boumenna
- Glaucoma Service; Massachusetts Eye and Ear Infirmary; Boston MA USA
| | - Bernard Rosner
- Channing Division of Network Medicine; Department of Medicine; Brigham & Women's Hospital/Harvard Medical School; Boston MA USA
- Department of Biostatistics; Harvard T. H. Chan School of Public Health; Boston MA USA
| | - Janey L. Wiggs
- Glaucoma Service; Massachusetts Eye and Ear Infirmary; Boston MA USA
| | - Louis R. Pasquale
- Channing Division of Network Medicine; Department of Medicine; Brigham & Women's Hospital/Harvard Medical School; Boston MA USA
- Glaucoma Service; Massachusetts Eye and Ear Infirmary; Boston MA USA
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Navneet S, Cui X, Zhao J, Wang J, Kaidery NA, Thomas B, Bollinger KE, Yoon Y, Smith SB. Excess homocysteine upregulates the NRF2-antioxidant pathway in retinal Müller glial cells. Exp Eye Res 2018; 178:228-237. [PMID: 29608906 DOI: 10.1016/j.exer.2018.03.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/14/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
This study evaluated the effects of elevated homocysteine (Hcy) on the oxidative stress response in retinal Müller glial cells. Elevated Hcy has been implicated in retinal diseases including glaucoma and optic neuropathy, which are characterized by retinal ganglion cell (RGC) loss. To understand the mechanisms of Hcy-induced RGC loss, in vitro and in vivo models have been utilized. In vitro isolated RGCs are quite sensitive to elevated Hcy levels, while in vivo murine models of hyperhomocysteinemia (HHcy) demonstrate a more modest RGC loss (∼20%) over a period of many months. This differential response to Hcy between isolated cells and the intact retina suggests that the retinal milieu invokes mechanisms that buffer excess Hcy. Oxidative stress has been implicated as a mechanism of Hcy-induced neuron loss and NRF2 is a transcription factor that plays a major role in regulating cytoprotective responses to oxidative stress. In the present study we investigated whether HHcy upregulates NRF2-mediated stress responses in Müller cells, the chief retinal glial cell responsible for providing trophic support to retinal neurons. Primary Müller cells were exposed to L-Hcy-thiolactone [50μM-10mM] and assessed for viability, reactive oxygen species (ROS), and glutathione (GSH) levels. Gene/protein levels of Nrf2 and levels of NRF2-regulated antioxidants (NQO1, CAT, SOD2, HMOX1, GPX1) were assessed in Hcy-exposed Müller cells. Unlike isolated RGCs, isolated Müller cells are viable over a wide range of Hcy concentrations [50 μM - 1 mM]. Moreover, when exposed to elevated Hcy, Müller cells demonstrate decreased oxidative stress and decreased ROS levels. GSH levels increased by ∼20% within 24 h exposure to Hcy. Molecular analyses revealed 2-fold increase in Nrf2 expression. Expression of antioxidant genes Nqo1, Cat, Sod2, Hmox1, Gpx1 increased significantly. The consequences of Hcy exposure were evaluated also in Müller cells harvested from Nrf2-/- mice. In contrast to WT Müller cells, in which oxidative stress decreased upon exposure to Hcy, the Nrf2-/- Müller cells showed a significant increase in oxidative stress. Our data suggest that at least during early stages of Hhcy, a cytoprotective response may be in place, mediated in part by NRF2 in Müller cells.
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Affiliation(s)
- Soumya Navneet
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Jing Zhao
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Navneet Ammal Kaidery
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Bobby Thomas
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Kathryn E Bollinger
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yisang Yoon
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, United States.
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Sun H, Yang Y, Shao H, Sun W, Gu M, Wang H, Jiang L, Qu L, Sun D, Gao Y. Sodium Arsenite-Induced Learning and Memory Impairment Is Associated with Endoplasmic Reticulum Stress-Mediated Apoptosis in Rat Hippocampus. Front Mol Neurosci 2017; 10:286. [PMID: 28936164 PMCID: PMC5594089 DOI: 10.3389/fnmol.2017.00286] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/23/2017] [Indexed: 12/21/2022] Open
Abstract
Chronic arsenic exposure has been associated to cognitive deficits. However, mechanisms remain unknown. The present study investigated the neurotoxic effects of sodium arsenite in drinking water over different dosages and time periods. Based on results from the Morris water maze (MWM) and morphological analysis, an exposure to sodium arsenite could induce neuronal damage in the hippocampus, reduce learning ability, and accelerate memory impairment. Sodium arsenite significantly increased homocysteine levels in serum and brain. Moreover, sodium arsenite triggered unfolded protein response (UPR), leading to the phosphorylation of RNA-regulated protein kinase-like ER kinase (PERK) and eukaryotic translation initiation factor 2 subunit α (eIF2α), and the induction of activating transcription factor 4 (ATF4). Arsenite exposure also stimulated the expression of the endoplasmic reticulum (ER) stress markers, glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and the cleavage of caspase-12. Furthermore, exposure to arsenite enhanced apoptosis as demonstrated by expression of caspase-3 and TUNEL assay in the hippocampus. The results suggest that exposure to arsenite can significantly decrease learning ability and accelerate memory impairment. Potential mechanisms are related to enhancement of homocysteine and ER stress-induced apoptosis in the hippocampus.
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Affiliation(s)
- Hongna Sun
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Yanmei Yang
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Hanwen Shao
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Weiwei Sun
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Muyu Gu
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Hui Wang
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Lixin Jiang
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Lisha Qu
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Dianjun Sun
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China
| | - Yanhui Gao
- Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical UniversityHarbin, China.,Institution of Environmentally Related Diseases, Harbin Medical UniversityHarbin, China
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Maekawa S, Sato K, Fujita K, Daigaku R, Tawarayama H, Murayama N, Moritoh S, Yabana T, Shiga Y, Omodaka K, Maruyama K, Nishiguchi KM, Nakazawa T. The neuroprotective effect of hesperidin in NMDA-induced retinal injury acts by suppressing oxidative stress and excessive calpain activation. Sci Rep 2017; 7:6885. [PMID: 28761134 PMCID: PMC5537259 DOI: 10.1038/s41598-017-06969-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 06/22/2017] [Indexed: 12/21/2022] Open
Abstract
We found that hesperidin, a plant-derived bioflavonoid, may be a candidate agent for neuroprotective treatment in the retina, after screening 41 materials for anti-oxidative properties in a primary retinal cell culture under oxidative stress. We found that the intravitreal injection of hesperidin in mice prevented reductions in markers of the retinal ganglion cells (RGCs) and RGC death after N-methyl-D-aspartate (NMDA)-induced excitotoxicity. Hesperidin treatment also reduced calpain activation, reactive oxygen species generation and TNF-α gene expression. Finally, hesperidin treatment improved electrophysiological function, measured with visual evoked potential, and visual function, measured with optomotry. Thus, we found that hesperidin suppressed a number of cytotoxic factors associated with NMDA-induced cell death signaling, such as oxidative stress, over-activation of calpain, and inflammation, thereby protecting the RGCs in mice. Therefore, hesperidin may have potential as a therapeutic supplement for protecting the retina against the damage associated with excitotoxic injury, such as occurs in glaucoma and diabetic retinopathy.
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Affiliation(s)
- Shigeto Maekawa
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Kota Sato
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Kosuke Fujita
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Reiko Daigaku
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Hiroshi Tawarayama
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Namie Murayama
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Satoru Moritoh
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Takeshi Yabana
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Yukihiro Shiga
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Kazuko Omodaka
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Kazuichi Maruyama
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Koji M Nishiguchi
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Toru Nakazawa
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.
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Nutrition for diabetic retinopathy: plummeting the inevitable threat of diabetic vision loss. Eur J Nutr 2017; 56:2013-2027. [PMID: 28258307 DOI: 10.1007/s00394-017-1406-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 02/10/2017] [Indexed: 12/14/2022]
Abstract
Diabetic retinopathy (DR) is among the leading causes of preventable blindness. Hyperglycemia, hypertension, hyperlipidemia and anemia majorly predispose its pathogenesis. The current treatment modalities of DR include laser photocoagulation therapy, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents and vitreo-retinal surgery which are costly, highly invasive, unproven for prolonged use and opted in advanced stages of DR. By then retina already encounters a vast damage. Nutrients by their natural physiological, biochemical and molecular action can preserve retinal structure and functions by interfering with the various pathological steps prompting DR incidence, thereby altering the risk of developing this ocular morbidity. Nutrients can also play a central role in DR patients resistant towards the conventional medical treatments. However due to the byzantine interplay existing between nutrients and DR, the worth of nutrition in curbing this vision-threatening ocular morbidity remains silent. This review highlights how nutrients can halt DR development. A nutritional therapy, if adopted in the initial stages, can provide superior-efficacy over the current treatment modalities and can be a complementary, inexpensive, readily available, anodyne option to the clinically unmet requirement for preventing DR. Assessment of nutritional status is presently considered relevant in various clinical conditions except DR. Body Mass Index (BMI) conferred inconclusive results in DR subjects. Subjective Global Assessment (SGA) of nutritional status has recently furnished relevant association with DR status. By integrating nutritional strategies, the risk of developing DR can be reduced substantially. This review summarizes the subsisting knowledge on nutrition, potentially beneficial for preventing DR and sustaining good vision among diabetic subjects.
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Srivastav K, Saxena S, Mahdi AA, Shukla RK, Meyer CH, Akduman L, Khanna VK. Increased serum level of homocysteine correlates with retinal nerve fiber layer thinning in diabetic retinopathy. Mol Vis 2016; 22:1352-1360. [PMID: 27994434 PMCID: PMC5135738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/30/2016] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To study the correlation between serum levels of vitamin B12, folic acid, and homocysteine and the severity of diabetic retinopathy and the correlation with retinal nerve fiber layer (RNFL) thinning on spectral domain optical coherence tomography (SD-OCT). METHODS In a tertiary care center-based prospective cross-sectional study, 60 consecutive cases and 20 healthy controls in the age group of 40-65 years were included. The eyes of the cases were divided into three groups according to Early Treatment Diabetic Retinopathy Study (ETDRS) classification: diabetes mellitus without retinopathy (n = 20), non-proliferative diabetic retinopathy with macular edema (n = 20), and proliferative diabetic retinopathy with macular edema (n = 20). The serum levels of vitamin B12 and folic acid were measured using a standard protocol. The serum homocysteine assay was performed using an enzyme-linked immunosorbent assay (ELISA) kit. Average RNFL thickness was measured using SD-OCT. Statistical analysis was used to assess the correlations between the study variables. RESULTS Increased severity of diabetic retinopathy was found to correlate with an increase in the serum levels of homocysteine (F = 53.79; p<0.001). The mean serum levels of vitamin B12 and folic acid were found to be within the normal reference range. A positive correlation was found between retinal nerve fiber layer thinning and serum levels of homocysteine (p<0.001). CONCLUSIONS This study, for the first time, demonstrated a correlation between increased homocysteine with a decrease in RNFL thickness and increased severity of diabetic retinopathy.
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Affiliation(s)
- Khushboo Srivastav
- Retina Service, Department of Ophthalmology, King George’s Medical University, Lucknow, India
| | - Sandeep Saxena
- Retina Service, Department of Ophthalmology, King George’s Medical University, Lucknow, India
| | - Abbas A. Mahdi
- Department of Biochemistry, King George’s Medical University, Lucknow, India
| | | | | | - Levent Akduman
- Vitreoretinal and uveitis service, Department of Ophthalmology, Saint Louis University School of Medicine,St. Louis, MO
| | - Vinay K. Khanna
- CSIR - Indian Institute of Toxicology and Research, Lucknow, India
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Sibarov DA, Abushik PA, Giniatullin R, Antonov SM. GluN2A Subunit-Containing NMDA Receptors Are the Preferential Neuronal Targets of Homocysteine. Front Cell Neurosci 2016; 10:246. [PMID: 27847466 PMCID: PMC5088185 DOI: 10.3389/fncel.2016.00246] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/07/2016] [Indexed: 12/30/2022] Open
Abstract
Homocysteine (HCY) is an endogenous redox active amino acid, best known as contributor to various neurodegenerative disorders. Although it is known that HCY can activate NMDA receptors (NMDARs), the mechanisms of its action on receptors composed of different NMDA receptor subunits remains almost unknown. In this study, using imaging and patch clamp technique in cultured cortical neurons and heterologous expression in HEK293T cells we tested the agonist activity of HCY on NMDARs composed of GluN1 and GluN2A subunits (GluN1/2A receptors) and GluN1 and GluN2B subunits (GluN1/2B receptors). We demonstrate that the time courses of Ca2+ transients and membrane currents activated by HCY and NMDA in cortical neurons are drastically different. Application of HCY to cortical neurons induced responses, which in contrast to currents induced by NMDA (both in the presence of glycine) considerably decreased to steady state of small amplitude. In contrast to NMDA, HCY-activated currents at steady state were resistant to the selective GluN2B subunit inhibitor ifenprodil. In calcium-free external solution the decrease of NMDA evoked currents was abolished, suggesting the Ca2+-dependent NMDAR desensitization. Under these conditions HCY evoked currents still declined almost to the baseline suggesting Ca2+-independent desensitization. In HEK293T cells HCY activated NMDARs of GluN1/2A and GluN1/2B subunit compositions with EC50s of 9.7 ± 1.8 and 61.8 ± 8.9 μM, respectively. Recombinant GluN1/2A receptors, however, did not desensitize by HCY, whereas GluN1/2B receptors were almost fully desensitized by HCY. Thus, HCY is a high affinity agonist of NMDARs preferring the GluN1/2A subunit composition. Our data suggest that HCY induced native NMDAR currents in neurons are mainly mediated by the "synaptic type" GluN1/2A NMDARs. This implies that in hyperhomocysteinemia, a disorder with enlarged level of HCY in plasma, HCY may persistently contribute to post-synaptic responses mediated by GluN2A-containing NMDA receptors. On the other hand, HCY toxicity may be limited by desensitization typical for HCY-induced activation of GluN2B-containing extrasynaptic receptors. Our findings, therefore, provide an evidence for the physiological relevance of endogenous HCY, which may represent an effective endogenous modulator of the central excitatory neurotransmission.
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Affiliation(s)
- Dmitry A Sibarov
- Laboratory of Comparative Neurophysiology, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences Saint-Petersburg, Russia
| | - Polina A Abushik
- Laboratory of Comparative Neurophysiology, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences Saint-Petersburg, Russia
| | - Rashid Giniatullin
- Department of Neurobiology, University of Eastern FinlandKuopio, Finland; Laboratory of Neurobiology, Kazan Federal UniversityKazan, Russia
| | - Sergei M Antonov
- Laboratory of Comparative Neurophysiology, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences Saint-Petersburg, Russia
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Milyutina YP, Pustygina AV, Zaloznyaya IV, Arutjunyan AV. Age-related changes in biogenic amine content and oxidative stress profile in rat hypothalamus with hyperhomocysteinemia. ADVANCES IN GERONTOLOGY 2016. [DOI: 10.1134/s2079057016040111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Plasma Homocysteine, Serum Folic Acid, Serum Vitamin B12, Serum Vitamin B6, MTHFR, and Risk of Normal-Tension Glaucoma. J Glaucoma 2016; 25:e94-8. [PMID: 26171850 DOI: 10.1097/ijg.0000000000000269] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND This meta-analysis aims to comprehensively evaluate the association between total homocysteine (tHcy) levels, serum folic acid, vitamin B12, vitamin B6 levels, methylenetetrahydrofolate reductase (MTHFR) C677T genotype, and risk of normal-tension glaucoma (NTG). MATERIALS AND METHODS A systematic search of the EMBASE and PubMed databases was performed to evaluate plasma tHcy levels, serum folic acid, B vitamins' mean difference, and odds ratios of MTHFR C677T genotype between cases and controls. RESULTS A total of 7 studies including 458 cases and 555 controls meeting the inclusion criteria were involved in this meta-analysis. There were 4 studies for tHcy (149 cases and 148 controls), 2 studies for vitamin B6, vitamin B12, and folate (90 cases and 82 controls), and 4 studies for MTHFR (343 cases and 449 controls). Overall, the mean plasma tHcy levels, serum folic acids, vitamin B12, and vitamin B6 levels were 1.16 μmol/L [95% confidence interval (CI), -0.13, 2.45], -0.62 μmol/L (95% CI, -1.98, 0.74), 5.81 μmol/L (95% CI, -3.53, 15.14), and -16.79 μmol/L (95% CI, -86.09, 52.51). MTHFR TT genotype was found to be unrelated to NTG risk (odds ratio=1.08; 95% CI, 0.69, 1.69). CONCLUSION NTG is not associated with elevated plasma tHcy, serum folic acid, serum vitamin B12, serum vitamin B6, and MTHFR C677T genotype.
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Effect of memantine: A NMDA receptor blocker, on ethambutol-induced retinal injury. Ann Anat 2015; 204:86-92. [PMID: 26704355 DOI: 10.1016/j.aanat.2015.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 11/26/2015] [Accepted: 11/28/2015] [Indexed: 12/18/2022]
Abstract
Ethambutol (ETM)-induced retinal injury is associated with a deterioration in visual function caused by a mechanism similar to many other retinal injuries; i.e. glutamate-induced N-methyl-d-aspartate (NMDA) receptor hyperexitability. Therefore, the current study was carried out to investigate the effect of memantine (MEM), NMDA receptor blocker, on ETM-induced retinal injury. A total of 36 rats were divided equally into: group I, control, group II (ETM administration, 100mg/kg/d, orally for 4 weeks) and group III (administration of ETM+MEM, 100 and 5mg/kg/d, respectively, orally for 4 weeks). Specimens of the retina were prepared for histological study by haematoxylin, eosin (H&E) as well as for immunohistochemical study by Bcl-2, cleaved caspase-3 and glial fibrillary acidic protein (GFAP). In the ETM group, the neural retina became significantly thinner (p<0.05) and the ganglion cell layer (GCL) was the main layer affected in the form of a significant decrease (p<0.001) in its cellularity, along with an obvious increase in Bcl-2 and GFAP expression as well as caspase-3 and oxidative stress markers level compared with other groups. On the other hand, on combining MEM with ETM, the retinal thickness, NFL appearance and GCL cellularity returned to amounts nearly similar to the control group coupled with a significant decrease (p<0.05) in the detected caspase-3, Bcl-2 levels and minimal GFAP expression. Therefore, memantine could be an effective neuroprotective agent in ETM-induced retinal injury by a mechanism that may involve correction of the pro/anti-apoptotic pathways and normalization of the oxidative and Müller cell stress responses.
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Abushik PA, Karelina TV, Sibarov DA, Stepanenko YD, Giniatullin RA, Antonov SM. Homocysteine-induced membrane currents, calcium responses and changes in mitochondrial potential in rat cortical neurons. J EVOL BIOCHEM PHYS+ 2015. [DOI: 10.1134/s0022093015040055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Homocysteine in ocular diseases. Clin Chim Acta 2015; 450:316-21. [PMID: 26343924 DOI: 10.1016/j.cca.2015.09.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/01/2015] [Accepted: 09/03/2015] [Indexed: 11/21/2022]
Abstract
Homocysteine (Hcy) is a derived sulfur-containing and non-proteinogenic amino acid. The metabolism of Hcy occurs either through the remethylation to methionine or transsulfuration to cysteine. Studies have identified hyperhomocysteinemia (HHcy) as one of the possible risk factors for a multitude of diseases including vascular, neurodegenerative and ocular diseases. Association of HHcy with eye diseases such as retinopathy, pseudoexfoliative glaucoma maculopathy, cataract, optic atrophy and retinal vessel atherosclerosis is established. The molecular mechanism underlying these ocular diseases has been reported as impaired vascular endothelial function, apoptosis of retinal ganglion cells, extracellular matrix alterations, decreased lysyl oxidase activity and oxidative stress. The formed homocysteine-thiolactone in HHcy has stronger cytotoxicity and pro-inflammatory properties which can induce lens opacification and optic nerve damage. The metabolism of Hcy requires enzymes with vitamins such as folic acid, vitamins B12 and B6. Despite the mixed conclusion of various studies regarding the level of these vitamins in elder people, studies recommended the treatment with folate and B12 to reduce Hcy levels in subjects with or without any defect in the enzymes involved in its metabolism. The levels of Hcy, folate, B6 as well as B12 should be measured early in patients with visual impairment that would aid to screen patients for life-threatening disorders related with HHcy. Elder patients may supplement with these vitamins in order to attenuate the ocular damages. This article discusses the association of Hcy in ocular diseases and the possible mechanism in the pathogenesis.
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Paul R, Borah A. The potential physiological crosstalk and interrelationship between two sovereign endogenous amines, melatonin and homocysteine. Life Sci 2015; 139:97-107. [PMID: 26281918 DOI: 10.1016/j.lfs.2015.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/07/2015] [Accepted: 07/31/2015] [Indexed: 12/13/2022]
Abstract
The antioxidant melatonin and the non-proteinogenic excitotoxic amino acid homocysteine (Hcy) are very distinct but related reciprocally to each other in their mode of action. The elevated Hcy level has been implicated in several disease pathologies ranging from cardio- and cerebro-vascular diseases to neurodegeneration owing largely to its free radical generating potency. Interestingly, melatonin administration potentially normalizes the elevated Hcy level, thereby protecting the cells from the undesired Hcy-induced excitotoxicity and cell death. However, the exact mechanism and between them remain obscure. Through literature survey we have found an indistinct but a vital link between melatonin and Hcy i.e., the existence of reciprocal regulation between them, and this aspect has been thoroughly described herein. In this review, we focus on all the possibilities of co-regulation of melatonin and Hcy at the level of their production and metabolism both in basal and in pathological conditions, and appraised the potential of melatonin in ameliorating homocysteinemia-induced cellular stresses. Also, we have summarized the differential mode of action of melatonin and Hcy on health and disease states.
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Affiliation(s)
- Rajib Paul
- Cellular and Molecular Neurobiology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, Assam, India
| | - Anupom Borah
- Cellular and Molecular Neurobiology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, Assam, India.
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Activation of NMDA receptor by elevated homocysteine in chronic liver disease contributes to encephalopathy. Med Hypotheses 2015; 85:64-7. [DOI: 10.1016/j.mehy.2015.03.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/23/2015] [Accepted: 03/28/2015] [Indexed: 11/18/2022]
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Abstract
Glaucoma is increasingly recognized as a neurodegenerative disorder, characterized by the accelerated loss of retinal ganglion cells (RGCs) and their axons. Impaired axonal transport has been implicated as a pathogenic mechanism in a number of neurodegenerative diseases, including glaucoma. The long RGC axon, with its high metabolic demand and crucial role in conveying neurotrophic signals, relies heavily on intact axonal transport. In this mini review, we consider the evidence for transport disruption along RGCs in association with glaucoma and other intraocular pressure models. We give a brief overview of the axonal transport process and the methods by which it is assessed. Spatial and temporal patterns of axonal transport disruption are considered as well as the reversibility of these changes. Biomechanical, metabolic and cytoskeletal insults may underlie the development of axonal transport deficits, and there are multiple perspectives on the impact that transport disruption has on the RGC. Eliciting the role of impaired axonal transport in glaucoma pathogenesis may uncover novel therapeutic targets for protecting the optic nerve and preventing vision loss in glaucoma.
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Affiliation(s)
- Eamonn T Fahy
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Vicki Chrysostomou
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Jonathan G Crowston
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
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50
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Sharma M, Tiwari M, Tiwari RK. Hyperhomocysteinemia: Impact on Neurodegenerative Diseases. Basic Clin Pharmacol Toxicol 2015; 117:287-96. [DOI: 10.1111/bcpt.12424] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 05/19/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Meenakshi Sharma
- Dr. B. R. Ambedkar Centre for Biomedical Research; University of Delhi; Delhi India
- Chapman University School of Pharmacy; Harry and Diane Rinker Health Science Campus; Irvine CA USA
| | - Manisha Tiwari
- Dr. B. R. Ambedkar Centre for Biomedical Research; University of Delhi; Delhi India
| | - Rakesh Kumar Tiwari
- Chapman University School of Pharmacy; Harry and Diane Rinker Health Science Campus; Irvine CA USA
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