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Vashishth S, Ambasta RK, Kumar P. Deciphering the microbial map and its implications in the therapeutics of neurodegenerative disorder. Ageing Res Rev 2024; 100:102466. [PMID: 39197710 DOI: 10.1016/j.arr.2024.102466] [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: 07/31/2024] [Revised: 08/19/2024] [Accepted: 08/19/2024] [Indexed: 09/01/2024]
Abstract
Every facet of biological anthropology, including development, ageing, diseases, and even health maintenance, is influenced by gut microbiota's significant genetic and metabolic capabilities. With current advancements in sequencing technology and with new culture-independent approaches, researchers can surpass older correlative studies and develop mechanism-based studies on microbiome-host interactions. The microbiota-gut-brain axis (MGBA) regulates glial functioning, making it a possible target for the improvement of development and advancement of treatments for neurodegenerative diseases (NDDs). The gut-brain axis (GBA) is accountable for the reciprocal communication between the gastrointestinal and central nervous system, which plays an essential role in the regulation of physiological processes like controlling hunger, metabolism, and various gastrointestinal functions. Lately, studies have discovered the function of the gut microbiome for brain health-different microbiota through different pathways such as immunological, neurological and metabolic pathways. Additionally, we review the involvement of the neurotransmitters and the gut hormones related to gut microbiota. We also explore the MGBA in neurodegenerative disorders by focusing on metabolites. Further, targeting the blood-brain barrier (BBB), intestinal barrier, meninges, and peripheral immune system is investigated. Lastly, we discuss the therapeutics approach and evaluate the pre-clinical and clinical trial data regarding using prebiotics, probiotics, paraprobiotics, fecal microbiota transplantation, personalised medicine, and natural food bioactive in NDDs. A comprehensive study of the GBA will felicitate the creation of efficient therapeutic approaches for treating different NDDs.
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Affiliation(s)
- Shrutikirti Vashishth
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Delhi 110042, India
| | - Rashmi K Ambasta
- Department of Medicine, School of Medicine, VUMC, Vanderbilt University, TN, USA
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Delhi 110042, India.
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2
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Stone TW, Darlington LG, Badawy AAB, Williams RO. The Complex World of Kynurenic Acid: Reflections on Biological Issues and Therapeutic Strategy. Int J Mol Sci 2024; 25:9040. [PMID: 39201726 PMCID: PMC11354734 DOI: 10.3390/ijms25169040] [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: 07/23/2024] [Revised: 08/13/2024] [Accepted: 08/14/2024] [Indexed: 09/03/2024] Open
Abstract
It has been unequivocally established that kynurenic acid has a number of actions in a variety of cells and tissues, raising, in principle, the possibility of targeting its generation, metabolism or sites of action to manipulate those effects to a beneficial therapeutic end. However, many basic aspects of the biology of kynurenic acid remain unclear, potentially leading to some confusion and misinterpretations of data. They include questions of the source, generation, targets, enzyme expression, endogenous concentrations and sites of action. This essay is intended to raise and discuss many of these aspects as a source of reference for more balanced discussion. Those issues are followed by examples of situations in which modulating and correcting kynurenic acid production or activity could bring significant therapeutic benefit, including neurological and psychiatric conditions, inflammatory diseases and cell protection. More information is required to obtain a clear overall view of the pharmacological environment relevant to kynurenic acid, especially with respect to the active concentrations of kynurenine metabolites in vivo and changed levels in disease. The data and ideas presented here should permit a greater confidence in appreciating the sites of action and interaction of kynurenic acid under different local conditions and pathologies, enhancing our understanding of kynurenic acid itself and the many clinical conditions in which manipulating its pharmacology could be of clinical value.
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Affiliation(s)
- Trevor W. Stone
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK;
| | - L. Gail Darlington
- Worthing Hospital, University Hospitals Sussex NHS Foundation Trust, Worthing BN11 2DH, UK
| | - Abdulla A.-B. Badawy
- Formerly School of Health Sciences, Cardiff Metropolitan University, Cardiff CF5 2YB, UK
| | - Richard O. Williams
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford OX3 7FY, UK;
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3
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Kondo T, Okada Y, Shizuya S, Yamaguchi N, Hatakeyama S, Maruyama K. Neuroimmune modulation by tryptophan derivatives in neurological and inflammatory disorders. Eur J Cell Biol 2024; 103:151418. [PMID: 38729083 DOI: 10.1016/j.ejcb.2024.151418] [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: 12/25/2023] [Revised: 05/02/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024] Open
Abstract
The nervous and immune systems are highly developed, and each performs specialized physiological functions. However, they work together, and their dysfunction is associated with various diseases. Specialized molecules, such as neurotransmitters, cytokines, and more general metabolites, are essential for the appropriate regulation of both systems. Tryptophan, an essential amino acid, is converted into functional molecules such as serotonin and kynurenine, both of which play important roles in the nervous and immune systems. The role of kynurenine metabolites in neurodegenerative and psychiatric diseases has recently received particular attention. Recently, we found that hyperactivity of the kynurenine pathway is a critical risk factor for septic shock. In this review, we first outline neuroimmune interactions and tryptophan derivatives and then summarized the changes in tryptophan metabolism in neurological disorders. Finally, we discuss the potential of tryptophan derivatives as therapeutic targets for neuroimmune disorders.
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Affiliation(s)
- Takeshi Kondo
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Hokkaido 060-8636, Japan
| | - Yuka Okada
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama 641-0012, Japan
| | - Saika Shizuya
- Department of Ophthalmology, Wakayama Medical University School of Medicine, Wakayama 641-0012, Japan
| | - Naoko Yamaguchi
- Department of Pharmacology, School of Medicine, Aichi Medical University, Aichi 480-1195, Japan
| | - Shigetsugu Hatakeyama
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Hokkaido 060-8636, Japan
| | - Kenta Maruyama
- Department of Pharmacology, School of Medicine, Aichi Medical University, Aichi 480-1195, Japan.
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Lautrup S, Hou Y, Fang EF, Bohr VA. Roles of NAD + in Health and Aging. Cold Spring Harb Perspect Med 2024; 14:a041193. [PMID: 37848251 PMCID: PMC10759992 DOI: 10.1101/cshperspect.a041193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
NAD+, the essential metabolite involved in multiple reactions such as the regulation of cellular metabolism, energy production, DNA repair, mitophagy and autophagy, inflammation, and neuronal function, has been the subject of intense research in the field of aging and disease over the last decade. NAD+ levels decline with aging and in some age-related diseases, and reduction in NAD+ affects all the hallmarks of aging. Here, we present an overview of the discovery of NAD+, the cellular pathways of producing and consuming NAD+, and discuss how imbalances in the production rate and cellular request of NAD+ likely contribute to aging and age-related diseases including neurodegeneration. Preclinical studies have revealed great potential for NAD+ precursors in promotion of healthy aging and improvement of neurodegeneration. This has led to the initiation of several clinical trials with NAD+ precursors to treat accelerated aging, age-associated dysfunctions, and diseases including Alzheimer's and Parkinson's. NAD supplementation has great future potential clinically, and these studies will also provide insight into the mechanisms of aging.
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Affiliation(s)
- Sofie Lautrup
- Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, 1478 Lørenskog, Norway
| | - Yujun Hou
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Evandro F Fang
- Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, 1478 Lørenskog, Norway
- The Norwegian Centre on Healthy Ageing (NO-Age), Oslo, Norway
| | - Vilhelm A Bohr
- DNA Repair Section, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
- Danish Center for Healthy Aging, University of Copenhagen, 2200 Copenhagen, Denmark
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Dehhaghi M, Heng B, Guillemin GJ. The kynurenine pathway in traumatic brain injuries and concussion. Front Neurol 2023; 14:1210453. [PMID: 37360356 PMCID: PMC10289013 DOI: 10.3389/fneur.2023.1210453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
Up to 10 million people per annum experience traumatic brain injury (TBI), 80-90% of which are categorized as mild. A hit to the brain can cause TBI, which can lead to secondary brain injuries within minutes to weeks after the initial injury through unknown mechanisms. However, it is assumed that neurochemical changes due to inflammation, excitotoxicity, reactive oxygen species, etc., that are triggered by TBI are associated with the emergence of secondary brain injuries. The kynurenine pathway (KP) is an important pathway that gets significantly overactivated during inflammation. Some KP metabolites such as QUIN have neurotoxic effects suggesting a possible mechanism through which TBI can cause secondary brain injury. That said, this review scrutinizes the potential association between KP and TBI. A more detailed understanding of the changes in KP metabolites during TBI is essential to prevent the onset or at least attenuate the severity of secondary brain injuries. Moreover, this information is crucial for the development of biomarker/s to probe the severity of TBI and predict the risk of secondary brain injuries. Overall, this review tries to fill the knowledge gap about the role of the KP in TBI and highlights the areas that need to be studied.
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Khatoon S, Kalam N, Rashid S, Bano G. Effects of gut microbiota on neurodegenerative diseases. Front Aging Neurosci 2023; 15:1145241. [PMID: 37323141 PMCID: PMC10268008 DOI: 10.3389/fnagi.2023.1145241] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 04/12/2023] [Indexed: 06/17/2023] Open
Abstract
A progressive degradation of the brain's structure and function, which results in a reduction in cognitive and motor skills, characterizes neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). The morbidity linked to NDs is growing, which poses a severe threat to human being's mental and physical ability to live well. The gut-brain axis (GBA) is now known to have a crucial role in the emergence of NDs. The gut microbiota is a conduit for the GBA, a two-way communication system between the gut and the brain. The myriad microorganisms that make up the gut microbiota can affect brain physiology by transmitting numerous microbial chemicals from the gut to the brain via the GBA or neurological system. The synthesis of neurotransmitters, the immunological response, and the metabolism of lipids and glucose have all been demonstrated to be impacted by alterations in the gut microbiota, such as an imbalance of helpful and harmful bacteria. In order to develop innovative interventions and clinical therapies for NDs, it is crucial to comprehend the participation of the gut microbiota in these conditions. In addition to using antibiotics and other drugs to target particular bacterial species that may be a factor in NDs, this also includes using probiotics and other fecal microbiota transplantation to maintain a healthy gut microbiota. In conclusion, the examination of the GBA can aid in understanding the etiology and development of NDs, which may benefit the improvement of clinical treatments for these disorders and ND interventions. This review indicates existing knowledge about the involvement of microbiota present in the gut in NDs and potential treatment options.
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Affiliation(s)
- Saima Khatoon
- Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India
| | - Nida Kalam
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Summya Rashid
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Gulnaz Bano
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
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Yulug B, Altay O, Li X, Hanoglu L, Cankaya S, Lam S, Velioglu HA, Yang H, Coskun E, Idil E, Nogaylar R, Ozsimsek A, Bayram C, Bolat I, Oner S, Tozlu OO, Arslan ME, Hacimuftuoglu A, Yildirim S, Arif M, Shoaie S, Zhang C, Nielsen J, Turkez H, Borén J, Uhlén M, Mardinoglu A. Combined metabolic activators improve cognitive functions in Alzheimer's disease patients: a randomised, double-blinded, placebo-controlled phase-II trial. Transl Neurodegener 2023; 12:4. [PMID: 36703196 PMCID: PMC9879258 DOI: 10.1186/s40035-023-00336-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/09/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is associated with metabolic abnormalities linked to critical elements of neurodegeneration. We recently administered combined metabolic activators (CMA) to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals. CMA promotes mitochondrial fatty acid uptake from the cytosol, facilitates fatty acid oxidation in the mitochondria, and alleviates oxidative stress. METHODS Here, we designed a randomised, double-blinded, placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients. One-dose CMA included 12.35 g L-serine (61.75%), 1 g nicotinamide riboside (5%), 2.55 g N-acetyl-L-cysteine (12.75%), and 3.73 g L-carnitine tartrate (18.65%). AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84. The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms. The secondary aim of this study was to evaluate the safety and tolerability of CMA. A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients. RESULTS We showed a significant decrease of AD Assessment Scale-cognitive subscale (ADAS-Cog) score on day 84 vs day 0 (P = 0.00001, 29% improvement) in the CMA group. Moreover, there was a significant decline (P = 0.0073) in ADAS-Cog scores (improvement of cognitive functions) in the CMA compared to the placebo group in patients with higher ADAS-Cog scores. Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis. Moreover, the plasma levels of proteins and metabolites associated with NAD + and glutathione metabolism were significantly improved after CMA treatment. CONCLUSION Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters associated with phenomics, metabolomics, proteomics and imaging analysis. Trial registration ClinicalTrials.gov NCT04044131 Registered 17 July 2019, https://clinicaltrials.gov/ct2/show/NCT04044131.
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Affiliation(s)
- Burak Yulug
- Department of Neurology and Neuroscience, Faculty of Medicine, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Ozlem Altay
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Xiangyu Li
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Lutfu Hanoglu
- Department of Neurology, Faculty of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Seyda Cankaya
- Department of Neurology and Neuroscience, Faculty of Medicine, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Simon Lam
- Centre for Host-Microbiome Interaction's, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Halil Aziz Velioglu
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
- Functional Imaging and Cognitive-Affective Neuroscience Lab, Istanbul Medipol University, Istanbul, Turkey
| | - Hong Yang
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Ebru Coskun
- Department of Neurology, Faculty of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Ezgi Idil
- Department of Neurology and Neuroscience, Faculty of Medicine, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Rahim Nogaylar
- Department of Neurology and Neuroscience, Faculty of Medicine, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Ahmet Ozsimsek
- Department of Neurology and Neuroscience, Faculty of Medicine, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Cemil Bayram
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Ismail Bolat
- Department of Pathology, Veterinary Faculty, Ataturk University, Erzurum, Turkey
| | - Sena Oner
- Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, Erzurum, Turkey
| | - Ozlem Ozdemir Tozlu
- Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, Erzurum, Turkey
| | - Mehmet Enes Arslan
- Department of Molecular Biology and Genetics, Faculty of Science, Erzurum Technical University, Erzurum, Turkey
| | - Ahmet Hacimuftuoglu
- Department of Medical Pharmacology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Serkan Yildirim
- Department of Pathology, Veterinary Faculty, Ataturk University, Erzurum, Turkey
| | - Muhammad Arif
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Saeed Shoaie
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
- Centre for Host-Microbiome Interaction's, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK
| | - Cheng Zhang
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Hasan Turkez
- Department of Medical Biology, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| | - Jan Borén
- Department of Molecular and Clinical Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Mathias Uhlén
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
| | - Adil Mardinoglu
- Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
- Centre for Host-Microbiome Interaction's, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
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Ostapiuk A, Urbanska EM. Kynurenic acid in neurodegenerative disorders-unique neuroprotection or double-edged sword? CNS Neurosci Ther 2022; 28:19-35. [PMID: 34862742 PMCID: PMC8673711 DOI: 10.1111/cns.13768] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 12/24/2022] Open
Abstract
AIMS The family of kynurenine pathway (KP) metabolites includes compounds produced along two arms of the path and acting in clearly opposite ways. The equilibrium between neurotoxic kynurenines, such as 3-hydroxykynurenine (3-HK) or quinolinic acid (QUIN), and neuroprotective kynurenic acid (KYNA) profoundly impacts the function and survival of neurons. This comprehensive review summarizes accumulated evidence on the role of KYNA in Alzheimer's, Parkinson's and Huntington's diseases, and discusses future directions of potential pharmacological manipulations aimed to modulate brain KYNA. DISCUSSION The synthesis of specific KP metabolites is tightly regulated and may considerably vary under physiological and pathological conditions. Experimental data consistently imply that shift of the KP to neurotoxic branch producing 3-HK and QUIN formation, with a relative or absolute deficiency of KYNA, is an important factor contributing to neurodegeneration. Targeting specific brain regions to maintain adequate KYNA levels seems vital; however, it requires the development of precise pharmacological tools, allowing to avoid the potential cognitive adverse effects. CONCLUSIONS Boosting KYNA levels, through interference with the KP enzymes or through application of prodrugs/analogs with high bioavailability and potency, is a promising clinical approach. The use of KYNA, alone or in combination with other compounds precisely influencing specific populations of neurons, is awaiting to become a significant therapy for neurodegenerative disorders.
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Affiliation(s)
- Aleksandra Ostapiuk
- Laboratory of Cellular and Molecular PharmacologyDepartment of Experimental and Clinical PharmacologyMedical University of LublinLublinPoland
- Present address:
Department of Clinical Digestive OncologyKU LeuvenLeuvenBelgium
| | - Ewa M. Urbanska
- Laboratory of Cellular and Molecular PharmacologyDepartment of Experimental and Clinical PharmacologyMedical University of LublinLublinPoland
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Sun P, Su L, Zhu H, Li X, Guo Y, Du X, Zhang L, Qin C. Gut Microbiota Regulation and Their Implication in the Development of Neurodegenerative Disease. Microorganisms 2021; 9:microorganisms9112281. [PMID: 34835406 PMCID: PMC8621510 DOI: 10.3390/microorganisms9112281] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/19/2021] [Accepted: 10/27/2021] [Indexed: 12/12/2022] Open
Abstract
In recent years, human gut microbiota have become one of the most promising areas of microorganism research; meanwhile, the inter-relation between the gut microbiota and various human diseases is a primary focus. As is demonstrated by the accumulating evidence, the gastrointestinal tract and central nervous system interact through the gut–brain axis, which includes neuronal, immune-mediated and metabolite-mediated pathways. Additionally, recent progress from both preclinical and clinical studies indicated that gut microbiota play a pivotal role in gut–brain interactions, whereas the imbalance of the gut microbiota composition may be associated with the pathogenesis of neurological diseases (particularly neurodegenerative diseases), the underlying mechanism of which is insufficiently studied. This review aims to highlight the relationship between gut microbiota and neurodegenerative diseases, and to contribute to our understanding of the function of gut microbiota in neurodegeneration, as well as their relevant mechanisms. Furthermore, we also discuss the current application and future prospects of microbiota-associated therapy, including probiotics and fecal microbiota transplantation (FMT), potentially shedding new light on the research of neurodegeneration.
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Affiliation(s)
- Peilin Sun
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Lei Su
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Hua Zhu
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Xue Li
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Yaxi Guo
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Xiaopeng Du
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Ling Zhang
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
| | - Chuan Qin
- NHC Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China; (P.S.); (L.S.); (H.Z.); (X.L.); (Y.G.); (X.D.); (L.Z.)
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Chinese Academy of Medical Sciences (CAMS), Beijing 100021, China
- Correspondence: ; Tel.: +86-10-8777-8141
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10
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Braidy N, Alicajic H, Pow D, Smith J, Jugder BE, Brew BJ, Nicolazzo JA, Guillemin GJ. Potential Mechanism of Cellular Uptake of the Excitotoxin Quinolinic Acid in Primary Human Neurons. Mol Neurobiol 2020; 58:34-54. [PMID: 32894500 DOI: 10.1007/s12035-020-02046-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/28/2020] [Indexed: 01/18/2023]
Abstract
In Alzheimer's disease (AD), excessive amounts of quinolinic acid (QUIN) accumulate within the brain parenchyma and dystrophic neurons. QUIN also regulates glutamate uptake into neurons, which may be due to modulation of Na+-dependent excitatory amino acid transporters (EAATs). To determine the biological relationships between QUIN and glutamate dysfunction, we first quantified the functionality and kinetics of [3H]QUIN uptake in primary human neurons using liquid scintillation. We then measured changes in the protein expression of the glutamate transporter EAAT3 and EAAT1b in primary neurons treated with QUIN and the EAAT inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (2,4-PDC) using western blotting and immunohistochemistry. Immunohistochemistry was further used to elucidate intracellular transport of exogenous QUIN and the lysosomal-associated membrane protein 2 (LAMP2). Structural insights into the binding between QUIN and EAAT3 were further investigated using molecular docking techniques. We report significant temperature-dependent high-affinity transport leading to neuronal uptake of [3H]QUIN with a Km of 42.2 μM, and a Vmax of 9.492 pmol/2 min/mg protein, comparable with the uptake of glutamate. We also found that QUIN increases expression of the EAAT3 monomer while decreasing the functional trimer. QUIN uptake into primary neurons was shown to involve EAAT3 as uptake was significantly attenuated following EAAT inhibition. We also demonstrated that QUIN increases the expression of aberrant EAAT1b protein in neurons further implicating QUIN-induced glutamate dysfunction. Furthermore, we demonstrated that QUIN is metabolised exclusively in lysosomes. The involvement of EAAT3 as a modulator for QUIN uptake was further confirmed using molecular docking. This study is the first to characterise a mechanism for QUIN uptake into primary human neurons involving EAAT3, opening potential targets to attenuate QUIN-induced excitotoxicity in neuroinflammatory diseases.
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Affiliation(s)
- Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia.
- School of Medicine, Huzhou University, Wuxing District, Huzhou, Zhejiang, China.
| | - Hayden Alicajic
- Neuropharmacology group, MND and Neurodegenerative diseases Research Centre, Macquarie University, Sydney, NSW, 2019, Australia
| | - David Pow
- University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Jason Smith
- Department of Chemistry and Biomolecular sciences, Macquarie University, Sydney, NSW, Australia
| | - Bat-Erdene Jugder
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Bruce J Brew
- St Vincent's Centre for Applied Medical Research, Sydney, Australia
- Department of Neurology and HIV Medicine, St Vincent's Hospital, Sydney, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - Gilles J Guillemin
- Neuropharmacology group, MND and Neurodegenerative diseases Research Centre, Macquarie University, Sydney, NSW, 2019, Australia.
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11
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Kynurenic Acid Levels are Increased in the CSF of Alzheimer's Disease Patients. Biomolecules 2020; 10:biom10040571. [PMID: 32276479 PMCID: PMC7226436 DOI: 10.3390/biom10040571] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/28/2022] Open
Abstract
Kynurenic acid (KYNA) is a product of the tryptophan (TRP) metabolism via the kynurenine pathway (KP). This pathway is activated in neurodegenerative disorders, such as Alzheimer´s disease (AD). KYNA is primarily produced by astrocytes and is considered neuroprotective. Thus, altered KYNA levels may suggest an inflammatory response. Very recently, significant increases in KYNA levels were reported in cerebrospinal fluid (CSF) from AD patients compared with normal controls. In this study, we assessed the accuracy of KYNA in CSF for the classification of patients with AD, cognitively healthy controls, and patients with a variety of other neurodegenerative diseases, including frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and progressive supranuclear palsy (PSP). Averaged KYNA concentration in CSF was higher in patients with AD when compared with healthy subjects and with all the other differentially diagnosed groups. There were no significant differences in KYNA levels in CSF between any other neurodegenerative groups and controls. These results suggest a specific increase in KYNA concentration in CSF from AD patients not seen in other neurodegenerative diseases.
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12
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Huang YS, Ogbechi J, Clanchy FI, Williams RO, Stone TW. IDO and Kynurenine Metabolites in Peripheral and CNS Disorders. Front Immunol 2020; 11:388. [PMID: 32194572 PMCID: PMC7066259 DOI: 10.3389/fimmu.2020.00388] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/18/2020] [Indexed: 12/12/2022] Open
Abstract
The importance of the kynurenine pathway in normal immune system function has led to an appreciation of its possible contribution to autoimmune disorders such as rheumatoid arthritis. Indoleamine-2,3-dioxygenase (IDO) activity exerts a protective function, limiting the severity of experimental arthritis, whereas deletion or inhibition exacerbates the symptoms. Other chronic disorder with an inflammatory component, such as atherosclerosis, are also suppressed by IDO activity. It is suggested that this overall anti-inflammatory activity is mediated by a change in the relative production or activity of Th17 and regulatory T cell populations. Kynurenines may play an anti-inflammatory role also in CNS disorders such as Huntington's disease, Alzheimer's disease and multiple sclerosis, in which signs of inflammation and neurodegeneration are involved. The possibility is discussed that in Huntington's disease kynurenines interact with other anti-inflammatory molecules such as Human Lymphocyte Antigen-G which may be relevant in other disorders. Kynurenine involvement may account for the protection afforded to animals with cerebral malaria and trypanosomiasis when they are treated with an inhibitor of kynurenine-3-monoxygenase (KMO). There is some evidence that changes in IL-10 may contribute to this protection and the relationship between kynurenines and IL-10 in arthritis and other inflammatory conditions should be explored. In addition, metabolites of kynurenine downstream of KMO, such as anthranilic acid and 3-hydroxy-anthranilic acid can influence inflammation, and the ratio of these compounds is a valuable biomarker of inflammatory status although the underlying molecular mechanisms of the changes require clarification. Hence it is essential that more effort be expended to identify their sites of action as potential targets for drug development. Finally, we discuss increasing awareness of the epigenetic regulation of IDO, for example by DNA methylation, a phenomenon which may explain differences between individuals in their susceptibility to arthritis and other inflammatory disorders.
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Affiliation(s)
- Yi-Shu Huang
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Joy Ogbechi
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Felix I Clanchy
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Richard O Williams
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
| | - Trevor W Stone
- The Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, United Kingdom
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13
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Overexpression of Kynurenine 3-Monooxygenase Correlates with Cancer Malignancy and Predicts Poor Prognosis in Canine Mammary Gland Tumors. JOURNAL OF ONCOLOGY 2019; 2019:6201764. [PMID: 31186637 PMCID: PMC6521384 DOI: 10.1155/2019/6201764] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/08/2019] [Indexed: 12/01/2022]
Abstract
Tumor biomarkers are developed to indicate tumor status, clinical outcome, or prognosis. Since currently there are no effective biomarkers for canine mammary tumor (CMT), this study intended to verify whether kynurenine 3-monooxygenase (KMO), one of the key enzymes involved in tryptophan catabolism, is competent for predicting prognosis in patients with CMT. By investigating a series of 86 CMT clinical cases, we found that both gene and protein expression of KMO discriminated malignant from benign CMTs and was significantly higher in stage IV and V tumors than in lower-stage CMTs. About 73.7% of malignant CMTs showed strong expression of KMO which correlated with lower overall survival rates in patients. Further, downregulation of KMO activity significantly inhibited cell proliferation of CMT cells. Taken together, the findings indicated that KMO is a potential biomarker for tumor diagnosis, and this might open up new perspectives for clinical applications of CMT.
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14
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Rubin LH, Sundermann EE, Moore DJ. The current understanding of overlap between characteristics of HIV-associated neurocognitive disorders and Alzheimer's disease. J Neurovirol 2019; 25:661-672. [PMID: 30671777 DOI: 10.1007/s13365-018-0702-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/04/2018] [Accepted: 11/13/2018] [Indexed: 12/11/2022]
Abstract
The advent of effective antiretroviral medications (ARVs) has led to an aging of the HIV population with approximately 50% of people with HIV (PWH) being over the age of 50 years. Neurocognitive complications, typically known as HIV-associated neurocognitive disorders (HAND), persist in the era of ARVs and, in addition to risk of HAND, older PWH are also at risk for age-associated, neurodegenerative disorders including Alzheimer's disease (AD). It has been postulated that risk for AD may be greater among PWH due to potential compounding effects of HIV and aging on mechanisms of neural insult. We are now faced with the challenge of disentangling AD from HAND, which has important prognostic and treatment implications given the more rapidly debilitating trajectory of AD. Herein, we review the evidence to date demonstrating both parallels and differences in the profiles of HAND and AD. We specifically address similarities and difference of AD and HAND as it relates to (1) neuropsychological profiles (cross-sectional/longitudinal), (2) AD-associated neuropathological features as evidenced from neuropathological, cerebrospinal fluid and neuroimaging assessments, (3) biological mechanisms underlying cortical amyloid deposition, (4) parallels in mechanisms of neural insult, and (5) common risk factors. Our current understanding of the similarities and dissimilarities of AD and HAND should be further delineated and leveraged in the development of differential diagnostic methods that will allow for the early identification of AD and more suitable and effective treatment interventions among graying PWH.
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Affiliation(s)
- Leah H Rubin
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Erin E Sundermann
- Department of Psychiatry, University of California, San Diego (UCSD) School of Medicine, La Jolla, CA, USA.
| | - David J Moore
- Department of Psychiatry, University of California, San Diego (UCSD) School of Medicine, La Jolla, CA, USA
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15
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Parthasarathy A, Cross PJ, Dobson RCJ, Adams LE, Savka MA, Hudson AO. A Three-Ring Circus: Metabolism of the Three Proteogenic Aromatic Amino Acids and Their Role in the Health of Plants and Animals. Front Mol Biosci 2018; 5:29. [PMID: 29682508 PMCID: PMC5897657 DOI: 10.3389/fmolb.2018.00029] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 03/21/2018] [Indexed: 12/19/2022] Open
Abstract
Tyrosine, phenylalanine and tryptophan are the three aromatic amino acids (AAA) involved in protein synthesis. These amino acids and their metabolism are linked to the synthesis of a variety of secondary metabolites, a subset of which are involved in numerous anabolic pathways responsible for the synthesis of pigment compounds, plant hormones and biological polymers, to name a few. In addition, these metabolites derived from the AAA pathways mediate the transmission of nervous signals, quench reactive oxygen species in the brain, and are involved in the vast palette of animal coloration among others pathways. The AAA and metabolites derived from them also have integral roles in the health of both plants and animals. This review delineates the de novo biosynthesis of the AAA by microbes and plants, and the branching out of AAA metabolism into major secondary metabolic pathways in plants such as the phenylpropanoid pathway. Organisms that do not possess the enzymatic machinery for the de novo synthesis of AAA must obtain these primary metabolites from their diet. Therefore, the metabolism of AAA by the host animal and the resident microflora are important for the health of all animals. In addition, the AAA metabolite-mediated host-pathogen interactions in general, as well as potential beneficial and harmful AAA-derived compounds produced by gut bacteria are discussed. Apart from the AAA biosynthetic pathways in plants and microbes such as the shikimate pathway and the tryptophan pathway, this review also deals with AAA catabolism in plants, AAA degradation via the monoamine and kynurenine pathways in animals, and AAA catabolism via the 3-aryllactate and kynurenine pathways in animal-associated microbes. Emphasis will be placed on structural and functional aspects of several key AAA-related enzymes, such as shikimate synthase, chorismate mutase, anthranilate synthase, tryptophan synthase, tyrosine aminotransferase, dopachrome tautomerase, radical dehydratase, and type III CoA-transferase. The past development and current potential for interventions including the development of herbicides and antibiotics that target key enzymes in AAA-related pathways, as well as AAA-linked secondary metabolism leading to antimicrobials are also discussed.
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Affiliation(s)
- Anutthaman Parthasarathy
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - Penelope J. Cross
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Renwick C. J. Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Lily E. Adams
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - Michael A. Savka
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - André O. Hudson
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
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16
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Involvement of the kynurenine pathway in the pathogenesis of Parkinson’s disease. Prog Neurobiol 2017; 155:76-95. [DOI: 10.1016/j.pneurobio.2015.12.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/18/2015] [Accepted: 12/30/2015] [Indexed: 12/14/2022]
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17
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Kim YK, Won E. The influence of stress on neuroinflammation and alterations in brain structure and function in major depressive disorder. Behav Brain Res 2017; 329:6-11. [DOI: 10.1016/j.bbr.2017.04.020] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 12/14/2022]
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18
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Won E, Kim YK. Stress, the Autonomic Nervous System, and the Immune-kynurenine Pathway in the Etiology of Depression. Curr Neuropharmacol 2017; 14:665-73. [PMID: 27640517 PMCID: PMC5050399 DOI: 10.2174/1570159x14666151208113006] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/17/2015] [Accepted: 11/01/2015] [Indexed: 12/27/2022] Open
Abstract
The autonomic nervous system is one of the major neural pathways activated by stress. In situations that are often associated with chronic stress, such as major depressive disorder, the sympathetic nervous system can be continuously activated without the normal counteraction of the parasympathetic nervous system. As a result, the immune system can be activated with increased levels of pro-inflammatory cytokines. These inflammatory conditions have been repeatedly observed in depression. In the search for the mechanism by which the immune system might contribute to depression, the enhanced activity of indoleamine 2,3-dioxygenase by pro-inflammatory cytokines has been suggested to play an important role. Indoleamine 2,3-dioxygenase is the first enzyme in the kynurenine pathway that converts tryptophan to kynurenine. Elevated activity of this enzyme can cause imbalances in downstream kynurenine metabolites. This imbalance can induce neurotoxic changes in the brain and create a vulnerable glial-neuronal network, which may render the brain susceptible to depression. This review focuses on the interaction between stress, the autonomic nervous system and the immune system which can cause imbalances in the kynurenine pathway, which may ultimately lead to major depressive disorder.
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Affiliation(s)
| | - Yong-Ku Kim
- Department of Psychiatry, Korea University Ansan Hospital, College of Medicine, 123 Jeokgeum-ro, Danwon-gu, Ansan 425-021, Republic of Korea
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19
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O'Farrell K, Harkin A. Stress-related regulation of the kynurenine pathway: Relevance to neuropsychiatric and degenerative disorders. Neuropharmacology 2015; 112:307-323. [PMID: 26690895 DOI: 10.1016/j.neuropharm.2015.12.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/02/2015] [Accepted: 12/08/2015] [Indexed: 02/08/2023]
Abstract
The kynurenine pathway (KP), which is activated in times of stress and infection has been implicated in the pathophysiology of neurodegenerative and psychiatric disorders. Activation of this tryptophan metabolising pathway results in the production of neuroactive metabolites which have the potential to interfere with normal neuronal functioning which may contribute to altered neuronal transmission and the emergence of symptoms of these brain disorders. This review investigates the involvement of the KP in a range of neurological disorders, examining recent in vitro, in vivo and clinical discoveries highlights evidence to indicate that the KP is a potential therapeutic target in both neurodegenerative and stress-related neuropsychiatric disorders. Furthermore, this review identifies gaps in our knowledge with regard to this field which are yet to be examined to lead to a more comprehensive understanding of the role of KP activation in brain health and disease. This article is part of the Special Issue entitled 'The Kynurenine Pathway in Health and Disease'.
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Affiliation(s)
- Katherine O'Farrell
- Neuropsychopharmacology Research Group, School of Pharmacy and Pharmaceutical Sciences & Trinity College Institute of Neuroscience, Trinity College Dublin, Ireland
| | - Andrew Harkin
- Neuropsychopharmacology Research Group, School of Pharmacy and Pharmaceutical Sciences & Trinity College Institute of Neuroscience, Trinity College Dublin, Ireland; Neuroimmunology Research Group, Department of Physiology, School of Medicine & Trinity College Institute of Neuroscience, Trinity College Dublin, Ireland.
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20
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Yan EB, Frugier T, Lim CK, Heng B, Sundaram G, Tan M, Rosenfeld JV, Walker DW, Guillemin GJ, Morganti-Kossmann MC. Activation of the kynurenine pathway and increased production of the excitotoxin quinolinic acid following traumatic brain injury in humans. J Neuroinflammation 2015; 12:110. [PMID: 26025142 PMCID: PMC4457980 DOI: 10.1186/s12974-015-0328-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 05/20/2015] [Indexed: 12/14/2022] Open
Abstract
Abstract During inflammation, the kynurenine pathway (KP) metabolises the essential amino acid tryptophan (TRP) potentially contributing to excitotoxicity via the release of quinolinic acid (QUIN) and 3-hydroxykynurenine (3HK). Despite the importance of excitotoxicity in the development of secondary brain damage, investigations on the KP in TBI are scarce. In this study, we comprehensively characterised changes in KP activation by measuring numerous metabolites in cerebrospinal fluid (CSF) from TBI patients and assessing the expression of key KP enzymes in brain tissue from TBI victims. Acute QUIN levels were further correlated with outcome scores to explore its prognostic value in TBI recovery. Methods Twenty-eight patients with severe TBI (GCS ≤ 8, three patients had initial GCS = 9–10, but rapidly deteriorated to ≤8) were recruited. CSF was collected from admission to day 5 post-injury. TRP, kynurenine (KYN), kynurenic acid (KYNA), QUIN, anthranilic acid (AA) and 3-hydroxyanthranilic acid (3HAA) were measured in CSF. The Glasgow Outcome Scale Extended (GOSE) score was assessed at 6 months post-TBI. Post-mortem brains were obtained from the Australian Neurotrauma Tissue and Fluid Bank and used in qPCR for quantitating expression of KP enzymes (indoleamine 2,3-dioxygenase-1 (IDO1), kynurenase (KYNase), kynurenine amino transferase-II (KAT-II), kynurenine 3-monooxygenase (KMO), 3-hydroxyanthranilic acid oxygenase (3HAO) and quinolinic acid phosphoribosyl transferase (QPRTase) and IDO1 immunohistochemistry. Results In CSF, KYN, KYNA and QUIN were elevated whereas TRP, AA and 3HAA remained unchanged. The ratios of QUIN:KYN, QUIN:KYNA, KYNA:KYN and 3HAA:AA revealed that QUIN levels were significantly higher than KYN and KYNA, supporting increased neurotoxicity. Amplified IDO1 and KYNase mRNA expression was demonstrated on post-mortem brains, and enhanced IDO1 protein coincided with overt tissue damage. QUIN levels in CSF were significantly higher in patients with unfavourable outcome and inversely correlated with GOSE scores. Conclusion TBI induced a striking activation of the KP pathway with sustained increase of QUIN. The exceeding production of QUIN together with increased IDO1 activation and mRNA expression in brain-injured areas suggests that TBI selectively induces a robust stimulation of the neurotoxic branch of the KP pathway. QUIN’s detrimental roles are supported by its association to adverse outcome potentially becoming an early prognostic factor post-TBI.
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Affiliation(s)
- Edwin B Yan
- Department of Physiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Tony Frugier
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia
| | - Chai K Lim
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Benjamin Heng
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Gayathri Sundaram
- Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St Vincent's Centre for Applied Medical Research, Sydney, Australia
| | - May Tan
- Hospital Queen Elizabeth, Karung Berkunci No. 2029, 88586, Kota Kinabalu, Sabah, Malaysia
| | - Jeffrey V Rosenfeld
- Department of Neurosurgery, The Alfred Hospital, Melbourne, Australia.,Department of Surgery, Central Clinical School and Monash Institute of Medical Engineering, Monash University, Melbourne, Australia
| | - David W Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Monash Medical Centre, Melbourne, Australia
| | - Gilles J Guillemin
- Neuroinflammation group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Maria Cristina Morganti-Kossmann
- Australian New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.,Department of Child Health, Barrow Neurological Institute, University of Arizona, Phoenix, AZ, USA
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21
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Azizi G, Mirshafiey A. The potential role of proinflammatory and antiinflammatory cytokines in Alzheimer disease pathogenesis. Immunopharmacol Immunotoxicol 2012; 34:881-95. [DOI: 10.3109/08923973.2012.705292] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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22
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Tan L, Yu JT, Tan L. The kynurenine pathway in neurodegenerative diseases: mechanistic and therapeutic considerations. J Neurol Sci 2012; 323:1-8. [PMID: 22939820 DOI: 10.1016/j.jns.2012.08.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/10/2012] [Accepted: 08/08/2012] [Indexed: 12/11/2022]
Abstract
The kynurenine pathway (KP), the primary route of tryptophan degradation in mammalian cells, consists of many metabolites including kynurenic acid (KYNA), quinolinic acid (QUIN), 3-hydroxykynurenine (3-HK) and picolinic acid (PIC). The former two are neuroactive, while the latter two are molecules with pro-oxidants and antioxidants properties. These agents are considered to be involved in aging and numerous neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). Several studies have demonstrated that altered kynurenine metabolism plays an important role in the pathogenesis of this group of diseases. The important metabolites and key enzymes show significant importance in those disorders. Both analogs of the neuroprotective metabolites and small molecule enzyme inhibitors preventing the formation of neurotoxic compounds may have potential therapeutic significance. In this review we discuss the mechanistic and therapeutic considerations of KP in aging and the main neurodegenerative diseases and review the updated knowledge in this therapeutic field.
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Affiliation(s)
- Lin Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, China.
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23
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Feng Y, Bowden BF, Kapoor V. Ianthellamide A, a selective kynurenine-3-hydroxylase inhibitor from the Australian marine sponge Ianthella quadrangulata. Bioorg Med Chem Lett 2012; 22:3398-401. [PMID: 22525315 DOI: 10.1016/j.bmcl.2012.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/29/2012] [Accepted: 04/02/2012] [Indexed: 12/27/2022]
Abstract
Ianthellamide A (1), a novel octopamine derivative, was isolated from the Australian marine sponge Ianthella quadrangulata. Compound 1 selectively inhibited the activity of kynurenine 3-hydroxylase with an IC(50) value of 1.5 μM. It also significantly increased the level of endogenous kynurenic acid in rat brain and hence has the potential as a neuroprotective agent in the treatment of neurodegenerative disorders.
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Affiliation(s)
- Yunjiang Feng
- Eskitis Institute, Griffith University, Brisbane, QLD 4111, Australia.
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24
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Abstract
Over the last two decades, evidence for the involvement of quinolinic acid (QUIN) in neuroinflammatory diseases has been exponentially increasing. Within the brain, QUIN is produced and released by infiltrating macrophages and activated microglia, the very cells that are prominent during neuroinflammation. QUIN acts as an agonist of the N-methyl-D-aspartate receptor and as such is considered to be a brain endogenous excitotoxin. Since the discovery of the excitotoxic activity of QUIN in the early 1980s, several other cytotoxic mechanisms have been identified. We know today that QUIN acts as a neurotoxin, gliotoxin, proinflammatory mediator, pro-oxidant molecule and can alter the integrity and cohesion of the blood-brain barrier. This paper aims to review some of the most recent findings about the effects of QUIN and its mode of action.
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Affiliation(s)
- Gilles J Guillemin
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
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25
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Klinge PM, Harmening K, Miller MC, Heile A, Wallrapp C, Geigle P, Brinker T. Encapsulated native and glucagon-like peptide-1 transfected human mesenchymal stem cells in a transgenic mouse model of Alzheimer's disease. Neurosci Lett 2011; 497:6-10. [PMID: 21507341 DOI: 10.1016/j.neulet.2011.03.092] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 03/26/2011] [Accepted: 03/30/2011] [Indexed: 11/28/2022]
Abstract
Encapsulated human mesenchymal stem cells(MSC) are studied in a double transgenic mouse model of Alzheimer's disease (AD) after intraventricular implantation at 3 months of age. Abeta 40/42 deposition, and glial (GFAP) and microglial (CD11b) immunoreactivity were investigated 2 months after transplantation of either native MSC or MSC transfected with glucagon-like peptide-1 (GLP-1). CD11b immunostaining in the frontal lobes was significantly decreased in the GLP-1 MSC group compared to the untreated controls. Also, the plaque associated GFAP immunoreactivity was only observed in one of four animals in the GLP-1 MSC group. Abeta 40 whole brain ELISA was decreased in the MSC group: 86.06±5.2 pg/ml (untreated control) vs. 78.67±11.2 pg/ml (GLP-1 MSC group) vs.70.9±11.1 pg/ml (MSC group, p<0.05). Intraventricular transplantation of native and GLP-1 transfected MSC has been shown effective. Decreased amyloid deposition or suppression of glial and microglial responses were observed. However, encapsulation of MSC may alter their biological activity.
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Affiliation(s)
- Petra M Klinge
- Neurosurgery Foundation, Rhode Island Hospital/Warren Alpert Medical School, Brown University, Providence, RI, USA
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26
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Dantzer R, O'Connor JC, Lawson MA, Kelley KW. Inflammation-associated depression: from serotonin to kynurenine. Psychoneuroendocrinology 2011; 36:426-36. [PMID: 21041030 PMCID: PMC3053088 DOI: 10.1016/j.psyneuen.2010.09.012] [Citation(s) in RCA: 527] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 08/21/2010] [Accepted: 09/29/2010] [Indexed: 01/28/2023]
Abstract
In the field of depression, inflammation-associated depression stands up as an exception since its causal factors are obvious and it is easy to mimic in an animal model. In addition, quasi-experimental studies can be carried out in patients who are treated chronically with recombinant cytokines for a medical condition since these patients can be studied longitudinally before, during and after stimulation of the immune system. These clinical studies have revealed that depression is a late phenomenon that develops over a background of early appearing sickness. Incorporation of this feature in animal models of inflammation-associated depression has allowed the demonstration that alterations of brain serotoninergic neurotransmission do not play a major role in the pathogenesis. This is in contrast to the activation of the tryptophan degrading enzyme indoleamine 2,3-dioxygenase that generates potentially neurotoxic kynurenine metabolites such as 3-hydroxy kynurenine and quinolinic acid. Although the relative importance of peripherally versus centrally produced kynurenine and the cellular source of production of this compound remain to be determined, these findings provide new targets for the treatment of inflammation-associated depression that could be extended to other psychiatric conditions mediated by activation of neuroimmune mechanisms.
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Affiliation(s)
- Robert Dantzer
- Integrative Immunology and Behavior Program, Department of Animal Sciences, 227 Edward R. Madigan Laboratory, 1201 West Gregory Drive, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Srinivasan V, Kaur C, Pandi-Perumal S, Brown GM, Cardinali DP. Melatonin and its agonist ramelteon in Alzheimer's disease: possible therapeutic value. Int J Alzheimers Dis 2010; 2011:741974. [PMID: 21197086 PMCID: PMC3004402 DOI: 10.4061/2011/741974] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 10/08/2010] [Accepted: 10/27/2010] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is an age-associated neurodegenerative disease characterized by the progressive loss of cognitive function, loss of memory and insomnia, and abnormal behavioral signs and symptoms. Among the various theories that have been put forth to explain the pathophysiology of AD, the oxidative stress induced by amyloid β-protein (Aβ) deposition has received great attention. Studies undertaken on postmortem brain samples of AD patients have consistently shown extensive lipid, protein, and DNA oxidation. Presence of abnormal tau protein, mitochondrial dysfunction, and protein hyperphosphorylation all have been demonstrated in neural tissues of AD patients. Moreover, AD patients exhibit severe sleep/wake disturbances and insomnia and these are associated with more rapid cognitive decline and memory impairment. On this basis, the successful management of AD patients requires an ideal drug that besides antagonizing Aβ-induced neurotoxicity could also correct the disturbed sleep-wake rhythm and improve sleep quality. Melatonin is an effective chronobiotic agent and has significant neuroprotective properties preventing Aβ-induced neurotoxic effects in a number of animal experimental models. Since melatonin levels in AD patients are greatly reduced, melatonin replacement has the potential value to be used as a therapeutic agent for treating AD, particularly at the early phases of the disease and especially in those in whom the relevant melatonin receptors are intact. As sleep deprivation has been shown to produce oxidative damage, impaired mitochondrial function, neurodegenerative inflammation, and altered proteosomal processing with abnormal activation of enzymes, treatment of sleep disturbances may be a priority for arresting the progression of AD. In this context the newly introduced melatonin agonist ramelteon can be of much therapeutic value because of its highly selective action on melatonin MT1/MT2 receptors in promoting sleep.
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Affiliation(s)
- Venkatramanujam Srinivasan
- Sri Sathya Sai Medical Educational and Research Foundation, Prasanthi Nilayam, 40- Kovai Thirunagar, Coimbatore 641014, India
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Davies NW, Guillemin G, Brew BJ. Tryptophan, Neurodegeneration and HIV-Associated Neurocognitive Disorder. Int J Tryptophan Res 2010; 3:121-40. [PMID: 22084594 PMCID: PMC3195234 DOI: 10.4137/ijtr.s4321] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This review presents an up-to-date assessment of the role of the tryptophan metabolic and catabolic pathways in neurodegenerative disease and HIV-associated neurocognitive disorder. The kynurenine pathway and the effects of each of its enzymes and products are reviewed. The differential expression of the kynurenine pathway in cells within the brain, including inflammatory cells, is explored given the increasing recognition of the importance of inflammation in neurodegenerative disease. An overview of common mechanisms of neurodegeneration is presented before a review and discussion of the evidence for a pathogenetic role of the kynurenine pathway in Alzheimer's disease, HIV-associated neurocognitive disorder, Huntington's disease, motor neurone disease, and Parkinson's disease.
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Affiliation(s)
- Nicholas W.S. Davies
- Department of Neurology, and
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
| | - Gilles Guillemin
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
| | - Bruce J. Brew
- Department of Neurology, and
- St Vincent’s Centre for Applied Medical Research, St Vincent’s Hospital, Darlinghurst, Sydney, Australia
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29
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Duleu S, Mangas A, Sevin F, Veyret B, Bessede A, Geffard M. Circulating Antibodies to IDO/THO Pathway Metabolites in Alzheimer's Disease. Int J Alzheimers Dis 2010; 2010. [PMID: 20721333 PMCID: PMC2915656 DOI: 10.4061/2010/501541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 12/22/2009] [Accepted: 01/20/2010] [Indexed: 01/18/2023] Open
Abstract
In Alzheimer's disease, indoleamine 2,3-dioxygenase and tryptophan hydroxylase are known to induce an overproduction of neurotoxic compounds, such as quinolinic acid and 3-hydroxykynurenine from the former, and 5-hydroxytryptophol and 5-methoxytryptophol from the latter. Other compounds, such as kynurenic acid, serotonin, and melatonin are produced via the same pathways. An improved ELISA method identified circulating antibodies directed against these compounds, linked to proteins, as previously described for other chronic diseases. This describes how only the A isotype of circulating immunoglobulins recognized a pattern of conjugated tryptophan metabolites in the sera of Alzheimer patients. These data indirectly confirmed the involvement of tryptophan derivatives in the pathogenic processes of Alzheimer's disease. Further studies are required to evaluate the relevance of these antibody patterns in monitoring this disease.
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Affiliation(s)
- S Duleu
- IDRPHT, 33400 Talence, France
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30
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Ting KK, Brew BJ, Guillemin GJ. Effect of quinolinic acid on human astrocytes morphology and functions: implications in Alzheimer's disease. J Neuroinflammation 2009; 6:36. [PMID: 20003262 PMCID: PMC2797503 DOI: 10.1186/1742-2094-6-36] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/10/2009] [Indexed: 02/06/2023] Open
Abstract
The excitotoxin quinolinic acid (QUIN) is synthesized through the kynurenine pathway (KP) by activated monocyte lineage cells. QUIN is likely to play a role in the pathogenesis of several major neuroinflammatory diseases including Alzheimer's disease (AD). The presence of reactive astrocytes, astrogliosis, increased oxidative stress and inflammatory cytokines are important pathological hallmarks of AD. We assessed the stimulatory effects of QUIN at low physiological to high excitotoxic concentrations in comparison with the cytokines commonly associated with AD including IFN-γ and TNF-α on primary human astrocytes. We found that QUIN induces IL-1β expression, a key mediator in AD pathogenesis, in human astrocytes. We also explored the effect of QUIN on astrocyte morphology and functions. At low concentrations, QUIN treatment induced concomitantly a marked increase in glial fibrillary acid protein levels and reduction in vimentin levels compared to controls; features consistent with astrogliosis. At pathophysiological concentrations QUIN induced a switch between structural protein expressions in a dose dependent manner, increasing VIM and concomitantly decreasing GFAP expression. Glutamine synthetase (GS) activity was used as a functional metabolic test for astrocytes. We found a significant dose-dependent reduction in GS activity following QUIN treatment. All together, this study showed that QUIN is an important factor for astroglial activation, dysregulation and cell death with potential relevance to AD and other neuroinflammatory diseases.
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Affiliation(s)
- Ka Ka Ting
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
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31
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Wu M, Audet A, Cusic J, Seeger D, Cochran R, Ghribi O. Broad DNA repair responses in neural injury are associated with activation of the IL-6 pathway in cholesterol-fed rabbits. J Neurochem 2009; 111:1011-21. [PMID: 19765189 DOI: 10.1111/j.1471-4159.2009.06390.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The importance of DNA repair in the pathogenic mechanism of Alzheimer's Disease (AD) is still poorly understood. Here, we report that a broad range of responses by DNA repair proteins plays a critical role in the regulation of inflammatory response in rabbits fed with cholesterol-rich diet, a model system for AD. We found accumulation of oxodG DNA adduct in the brain of rabbits fed with cholesterol-enriched diets compared to control diets, which subsequently induced a broad range of DNA repair protein activities. Also, the hippocampus was identified as the primary site of oxidative DNA damage and elevated OGG1 activity. In addition, a physical interaction between XPB and OGG1 may account for a potential mechanism involving these DNA repair responses. DNA repair proteins also impact activation of various signaling cascades, including Src in response to cholesterol oxidation. Furthermore, OGG1 deficient mice showed no IL-6 activation as seen in wt mice but a drastic increase of TNF-alpha, a pro-inflammatory cytokine. Thus, OGG1 may be associated with cytokine production induced by high cholesterol levels, impacting neurodegeneration. Together, our studies suggest that critical DNA repair proteins are associated with development of AD, and may serve as potential targets for the treatment of AD.
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Affiliation(s)
- Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58203, USA.
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32
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Abdul-Hay SO, Luo J, Ashghodom RT, Thatcher GRJ. NO-flurbiprofen reduces amyloid-beta, is neuroprotective in cell culture, and enhances cognition in response to cholinergic blockade. J Neurochem 2009; 111:766-76. [PMID: 19702655 DOI: 10.1111/j.1471-4159.2009.06353.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The non-steroidal anti-inflammatory drug flurbiprofen is a selective amyloid lowering agent which has been studied clinically in Alzheimer's disease. HCT-1026 is an ester prodrug of flurbiprofen incorporating a nitrate carrier moiety that in vivo provides NO bioactivity and an improved safety profile. In vitro, HCT-1026 retained the cyclooxygenase inhibitory and non-steroidal anti-inflammatory drug activity of flurbiprofen, but at concentrations at which levels of amyloid-beta 1-42 amino acid were lowered by flurbiprofen, amyloid-beta 1-42 amino acid levels were elevated 200% by HCT-1026. Conversely, at lower concentrations, HCT-1026 behaved as a selective amyloid lowering agent with greater potency than flurbiprofen. The difference in concentration-responses between flurbiprofen and HCT-1026 in vitro suggests different cellular targets; and in no case did a combination of nitrate drug with flurbiprofen provide similar actions. In vivo, HCT-1026 was observed to reverse cognitive deficits induced by scopolamine in two behavioral assays; activity that was also shown by a classical nitrate drug, but not by flurbiprofen. The ability to restore aversive memory and spatial working and reference memory after cholinergic blockade has been demonstrated by other agents that stimulate NO/cGMP signaling. These observations add positively to the preclinical profile of HCT-1026 and NO chimeras in Alzheimer's disease.
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Affiliation(s)
- Samer O Abdul-Hay
- Department of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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Braun A, Dang J, Johann S, Beyer C, Kipp M. Selective regulation of growth factor expression in cultured cortical astrocytes by neuro-pathological toxins. Neurochem Int 2009; 55:610-8. [PMID: 19524632 DOI: 10.1016/j.neuint.2009.06.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 06/02/2009] [Accepted: 06/03/2009] [Indexed: 12/14/2022]
Abstract
Astrocytes are integrated in the complex regulation of neurodegeneration and neuronal damage in the CNS. It is well-known that astroglia produces a plethora of growth factors which might be protective for neurons. Growth factors prevent neurons from cell death and promote proliferation and differentiation of precursor cells. Previous data suggest that astrocytes may respond to toxic stimuli by a selective mobilization of guarding molecules. In the present study, we have investigated the potency of different pathological stimuli such as lipopolysaccharides, tumor necrosis factor alpha, glutamate, and hydrogen peroxide to activate cultured cortical astroglia and stimulate growth factor expression. Astroglial cultures were exposed to the above factors for 24h at non-toxic concentrations for astrocytes. Growth factor expression was analyzed by real-time PCR, oligo-microarray technique, and ELISA. Insulin-like growth factor-1 was selectively down-regulated by lipopolysaccharides and tumor necrosis factor alpha, bone morphogenetic protein 6 by all stimuli. In contrast, lipopolysaccharides, tumor necrosis factor alpha, and glutamate increased leukemia inhibitory factor. Fibroblast growth factor 2 was up-regulated by lipopolysaccharides and tumor necrosis factor alpha and down-regulated by hydrogen peroxide. Besides hydrogen peroxide, all other stimuli promoted vascular epithelial growth factor A mRNA and protein expression. It appears that lipopolysaccharides but not tumor necrosis factor alpha effects on vascular epithelial growth factor A depend on the classic NFkappaB pathway. Our data clearly demonstrate that astroglia actively responses to diverse pathological compounds by a selective expression pattern of growth factors. These findings make astrocytes likely candidates to participate in disease-specific characteristics of neuronal support or damage.
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Affiliation(s)
- Alena Braun
- Institute of Neuroanatomy, RWTH Aachen University, Germany
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Lemire J, Mailloux R, Puiseux-Dao S, Appanna VD. Aluminum-induced defective mitochondrial metabolism perturbs cytoskeletal dynamics in human astrocytoma cells. J Neurosci Res 2009; 87:1474-83. [PMID: 19084901 DOI: 10.1002/jnr.21965] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Although aluminum (Al), a known environmental toxin, has been implicated in a variety of neurological disorders, the molecular mechanism responsible for these conditions is not fully understood. In this report, we demonstrate the ability of Al to trigger mitochondrial dysfunction and ineffective adenosine triphosphate (ATP) production. This situation severely affected cytoskeletal dynamics. Whereas the control cells had well-defined structures, the Al-exposed astrocytoma cells appeared as globular structures. Creatine kinase (CK) and profilin-2, two critical modulators of cellular morphology, were markedly diminished in the astrocytoma cells treated with Al. Antioxidants such as alpha-ketoglutarate and N-acetylcysteine mitigated the occurrence of the globular-shaped cells promoted by Al toxicity. Taken together, these data reveal an intricate link between ATP metabolism and astrocytic dysfunction and provide molecular insights into the pathogenesis of Al-induced neurological diseases.
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Affiliation(s)
- J Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
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35
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Braidy N, Grant R, Adams S, Brew BJ, Guillemin GJ. Mechanism for Quinolinic Acid Cytotoxicity in Human Astrocytes and Neurons. Neurotox Res 2009; 16:77-86. [DOI: 10.1007/s12640-009-9051-z] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 03/31/2009] [Accepted: 04/02/2009] [Indexed: 12/28/2022]
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36
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Costantino G. New promises for manipulation of kynurenine pathway in cancer and neurological diseases. Expert Opin Ther Targets 2009; 13:247-58. [PMID: 19236242 DOI: 10.1517/14728220802665734] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The kynurenine pathway (KP), the primary route of tryptophan degradation in mammalian cells, consists of a cascade of enzymatic reactions eventually leading to NAD(+) formation. Many metabolites along the route have biological activities, especially in the nervous and immune systems. OBJECTIVE/METHODS This review focuses on three therapeutic areas, tumor immunoediting, schizophrenia, and Huntington's disease, apparently disconnected but linked by preliminary proof-of-concept of KP involvement. The potential embedded in drug discovery programs aimed at the identification of selective inhibitors with optimized pharmacodynamic and pharmacokinetic properties for human studies is discussed. RESULTS/CONCLUSIONS Recent advances have shifted the attention on the kynurenine pathway from a scientific curiosity to a clinically relevant collection of targets. A relatively large number of ligands able to interfere with individual enzymes of the pathway have been made available, but none have so far proceeded into advanced clinical studies.
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Affiliation(s)
- Gabriele Costantino
- Università degli Studi di Parma, Dipartimento Farmaceutico, Via GP Usberti 27/A-Campus Universitario, 43100 Parma, Italy.
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37
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Kostrzewa RM. Evolution of neurotoxins: from research modalities to clinical realities. ACTA ACUST UNITED AC 2009; Chapter 1:Unit 1.18. [PMID: 19170022 DOI: 10.1002/0471142301.ns0118s46] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In the 1950s, the discovery of anti-nerve growth factor, an immunotoxin stunting sympathetic neural development, signaled the advent of neurotoxins as research modalities. Other selective neurotoxins were discovered in rapid succession. In the 1960s, 6-hydroxydopamine and 6-hydroxydopa were shown to destroy noradrenergic and dopaminergic nerves. Excitotoxins (glutamate, aspartate, and analogs) were discovered in the 1970s. DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine] proved to be selective for noradrenergic destruction, while 5,6- and 5,7-dihydroxytryptamines were relatively selective for serotonin neurons. Additional neurotoxins were discovered, but it was MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) that predominated neurotoxicity research in the 1980s. Eventually, Clostridium botulinum neurotoxin (BoNT), discovered as a "poisonous" principle in the late 1800s, resurfaced in purified and standardized forms as a clinically useful drug. Neurotoxins represent chemical tools, useful not only for discerning neuronal mechanisms and animal modeling of neurological disorders, but also for their use in medicine and potential as treatments for medical disorders. This unit reviews the early discovery of neurotoxins, describes categories of neurotoxins, and finally characterizes their usefulness--first as research tools, and eventually as clinical therapeutic agents.
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Affiliation(s)
- Richard M Kostrzewa
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
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Baran H, Kepplinger B. Cerebrolysin lowers kynurenic acid formation--an in vitro study. Eur Neuropsychopharmacol 2009; 19:161-8. [PMID: 19008081 DOI: 10.1016/j.euroneuro.2008.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Revised: 09/10/2008] [Accepted: 09/30/2008] [Indexed: 11/24/2022]
Abstract
The therapeutic effect of Cerebrolysin in the treatment of dementia and brain injury has been proposed because of neurotrophic properties of this compound. Since an increased kynurenine metabolism has been documented in several brain pathologies including dementia the aim of the present study was to investigate the biochemical properties of Cerebrolysin with respect to kynurenic acid (KYNA) formation in an in vitro study. KYNA is an endogenous metabolite of the kynurenine pathway of tryptophan degradation and is an antagonist of the glutamate ionotropic excitatory amino acid and of the nicotine cholinergic receptors. The activities of the KYNA synthesizing enzymes kynurenine aminotransferases I, II and III (KAT I, KAT II and KAT III) in rat liver, and rat and human brain homogenates were analysed in the presence of Cerebrolysin. KAT I, II and III activities were measured using a radio-enzymatic method in the presence of 1 mM pyruvate and 100 microM [H(3)]L-kynurenine. Cerebrolysin, dose-dependently and significantly reduced KAT I, KAT II and KAT III activities of rat liver homogenate. Furthermore, Cerebrolysin exerted a dose-dependent inhibition of rat and human brain KAT I, KAT II and KAT III activities, too. The inhibitory effect of Cerebrolysin was more pronounced for KAT I than for KAT II and KAT III. The present study for the first time demonstrates the ability of Cerebrolysin to lower KYNA formation in rat liver as well as in rat and human brain homogenates. We propose Cerebrolysin as a compound susceptible of therapeutic exploitation in some disorders associated with elevated KYNA metabolism in the brain and/or other tissues. We suggest that the anti-dementia effect of Cerebrolysin observed in Alzheimer patients could be in part due to Cerebrolysin induced reduction of KYNA levels, thus modulating the cholinergic and glutamatergic neurotransmissions.
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Affiliation(s)
- Halina Baran
- Neurophysiology, Institute of Physiology, Department for Biomedical Sciences, Veterinary Medical University Vienna, Vienna, Austria.
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Neurodegeneration and ageing in the HAART era. J Neuroimmune Pharmacol 2008; 4:163-74. [PMID: 19067177 DOI: 10.1007/s11481-008-9143-1] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 11/21/2008] [Indexed: 10/21/2022]
Abstract
Cognitive impairment and neurodegeneration still occur despite highly active antiretroviral therapy (HAART). While there are many potential reasons for this, there is increasing evidence that such impairment occurs in the absence of a clear cause. Furthermore, there are data that some neurodegenerative diseases, especially Alzheimer's or an Alzheimer-like illness, are becoming more common in the context of HAART-treated human immunodeficiency virus (HIV) disease. This review will critically examine the evidence underpinning these observations. Potential mechanisms will be discussed with particular emphasis on the effect of ageing and how it overlaps with the effects of HIV disease itself thereby leading to neurodegeneration. The nature of this overlap will then be explored for its potential role in the facilitated expression and development of neurodegenerative diseases. Lastly, there will be a brief discussion of interventions to minimize such neurodegeneration including optimization of HAART for brain entry.
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