scholarly journals Tryptophan-2,3-dioxygenase (TDO) inhibition ameliorates neurodegeneration by modulation of kynurenine pathway metabolites

2016 ◽  
Vol 113 (19) ◽  
pp. 5435-5440 ◽  
Author(s):  
Carlo Breda ◽  
Korrapati V. Sathyasaikumar ◽  
Shama Sograte Idrissi ◽  
Francesca M. Notarangelo ◽  
Jasper G. Estranero ◽  
...  
Keyword(s):  
Quinolinic Acid ◽  
Neurodegenerative Disorders ◽  
Kynurenic Acid ◽  
Therapeutic Potential ◽  
Fruit Fly ◽  
Kynurenine Pathway ◽  
Locomotor Performance ◽  
Potential Treatment ◽  
Regulatory Enzymes ◽  
Therapeutic Benefits

Metabolites of the kynurenine pathway (KP) of tryptophan (TRP) degradation have been closely linked to the pathogenesis of several neurodegenerative disorders. Recent work has highlighted the therapeutic potential of inhibiting two critical regulatory enzymes in this pathway—kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO). Much evidence indicates that the efficacy of KMO inhibition arises from normalizing an imbalance between neurotoxic [3-hydroxykynurenine (3-HK); quinolinic acid (QUIN)] and neuroprotective [kynurenic acid (KYNA)] KP metabolites. However, it is not clear if TDO inhibition is protective via a similar mechanism or if this is instead due to increased levels of TRP—the substrate of TDO. Here, we find that increased levels of KYNA relative to 3-HK are likely central to the protection conferred by TDO inhibition in a fruit fly model of Huntington’s disease and that TRP treatment strongly reduces neurodegeneration by shifting KP flux toward KYNA synthesis. In fly models of Alzheimer’s and Parkinson’s disease, we provide genetic evidence that inhibition of TDO or KMO improves locomotor performance and ameliorates shortened life span, as well as reducing neurodegeneration in Alzheimer's model flies. Critically, we find that treatment with a chemical TDO inhibitor is robustly protective in these models. Consequently, our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits.

scholarly journals Kynurenic Acid Levels are Increased in the CSF of Alzheimer’s Disease Patients

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 571 ◽  
Author(s):  
Marta González-Sánchez ◽  
Javier Jiménez ◽  
Arantzazu Narváez ◽  
Desiree Antequera ◽  
Sara Llamas-Velasco ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Neurodegenerative Disorders ◽  
Healthy Subjects ◽  
Kynurenic Acid ◽  
Kynurenine Pathway ◽  
Healthy Controls ◽  
Specific Increase ◽  
Normal Controls ◽  
Lateral Sclerosis

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.

scholarly journals Imbalanced Kynurenine Pathway in Schizophrenia

2014 ◽  
Vol 7 ◽  
pp. IJTR.S16800 ◽  
Author(s):  
Magdalena E. Kegel ◽  
Maria Bhat ◽  
Elisabeth Skogh ◽  
Martin Samuelsson ◽  
Kristina Lundberg ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cerebrospinal Fluid ◽  
Liquid Chromatography ◽  
Quinolinic Acid ◽  
Kynurenic Acid ◽  
Kynurenine Pathway ◽  
The Other ◽  
Healthy Controls ◽  
Liquid Chromatography Mass Spectrometry ◽  
Csf Levels

Several studies suggest a role for kynurenic acid (KYNA) in the pathophysiology of schizophrenia. It has been proposed that increased brain KYNA levels in schizophrenia result from a pathological shift in the kynurenine pathway toward enhanced KYNA formation, away from the other branch of the pathway leading to quinolinic acid (QUIN). Here we investigate the levels of QUIN in cerebrospinal fluid (CSF) of patients with schizophrenia and healthy controls, and relate those to CSF levels of KYNA and other kynurenine metabolites from the same individuals. CSF QUIN levels from stable outpatients treated with olanzapine (n = 22) and those of controls (n = 26) were analyzed using liquid chromatography-mass spectrometry. No difference in CSF QUIN levels between patients and controls was observed (20.6 ± 1.5 nM vs. 18.2 ± 1.1 nM, P = 0.36). CSF QUIN was positively correlated to CSF kynurenine and CSF KYNA in patients but not in controls. The CSF QUIN/KYNA ratio was lower in patients than in controls ( P = 0.027). In summary, the present study offers support for an over-activated and imbalanced kynurenine pathway, favoring the production of KYNA over QUIN in patients with schizophrenia.

scholarly journals Kynurenines in the Pathogenesis of Multiple Sclerosis: Therapeutic Perspectives

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1564 ◽  
Author(s):  
Tamás Biernacki ◽  
Dániel Sandi ◽  
Krisztina Bencsik ◽  
László Vécsei
Keyword(s):  
Multiple Sclerosis ◽  
Immune System ◽  
Quinolinic Acid ◽  
Nicotinamide Adenine Dinucleotide ◽  
Kynurenic Acid ◽  
Picolinic Acid ◽  
Kynurenine Pathway ◽  
Current Evidence ◽  
Therapeutic Approaches ◽  
The Past

Over the past years, an increasing amount of evidence has emerged in support of the kynurenine pathway’s (KP) pivotal role in the pathogenesis of several neurodegenerative, psychiatric, vascular and autoimmune diseases. Different neuroactive metabolites of the KP are known to exert opposite effects on neurons, some being neuroprotective (e.g., picolinic acid, kynurenic acid, and the cofactor nicotinamide adenine dinucleotide), while others are toxic to neurons (e.g., 3-hydroxykynurenine, quinolinic acid). Not only the alterations in the levels of the metabolites but also disturbances in their ratio (quinolinic acid/kynurenic acid) have been reported in several diseases. In addition to the metabolites, the enzymes participating in the KP have been unearthed to be involved in modulation of the immune system, the energetic upkeep of neurons and have been shown to influence redox processes and inflammatory cascades, revealing a sophisticated, intertwined system. This review considers various methods through which enzymes and metabolites of the kynurenine pathway influence the immune system, the roles they play in the pathogenesis of neuroinflammatory diseases based on current evidence with a focus on their involvement in multiple sclerosis, as well as therapeutic approaches.

scholarly journals Effects of Tranilast on the Urinary Excretion of Kynurenic and Quinolinic Acid under Conditions of L Tryptophan Loading

2013 ◽  
Vol 6 ◽  
pp. IJTR.S12797 ◽  
Author(s):  
Rowland R. Noakes
Keyword(s):  
Urinary Excretion ◽  
Quinolinic Acid ◽  
Kynurenic Acid ◽  
Competitive Inhibitor ◽  
Kynurenine Pathway ◽  
Tryptophan Metabolism ◽  
Autoimmune Response ◽  
Current Therapy ◽  
Indoleamine 2 ◽  
Hydroxyanthranilic Acid

The pathogenesis of morphea and other cutaneous sclerosing disorders remain poorly understood. Although they are considered to be autoimmune disorders, abnormal tryptophan metabolism may be involved. Current therapy is directed to supressing the autoimmune response. Demonstration of a therapeutic response to manipulation of the kynurenine pathway would both support a role for abnormal tryptophan metabolism and offer additional targets for therapy. Tranilast is a 3-hydroxyanthranilic acid derivative known to target the kynurenine pathway. The aim of this study was to see if tranilast lowered the urinary excretion of the kynurenine metabolites kynurenic and quinolinic acid under condition of L tryptophan loading in a volunteer. Mean baseline value for kynurenic acid and quinolinic acid were 1.1 and 2.1 mmol/mol creatinine, respectively. This rose to 5.6 and 3.8 mmol/mol creatinine respectively under conditions of L tryptophan loading 2 grams daily. Adding 1 g of tranilast daily lowered the values to 2.0 and 2.9 mmol/mol creatinine, respectively. These data suggest that tranilast acts as a competitive inhibitor of either indoleamine 2, 3-dioxygenase (IDO), tryptophan 2, 3 di-oxygenase (TDO) or both. As it involved only 1 subject, the results may not be representative of the larger population and must be considered preliminary.

scholarly journals Plasma neurofilament light chain and amyloid-β are associated with the kynurenine pathway metabolites in preclinical Alzheimer’s disease

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Pratishtha Chatterjee ◽  
Henrik Zetterberg ◽  
Kathryn Goozee ◽  
Chai K. Lim ◽  
Kelly R. Jacobs ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Light Chain ◽  
Quinolinic Acid ◽  
Anthranilic Acid ◽  
Kynurenic Acid ◽  
Amyloid Β ◽  
Kynurenine Pathway ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Elderly Individuals

Abstract Background Blood markers indicative of neurodegeneration (neurofilament light chain; NFL), Alzheimer’s disease amyloid pathology (amyloid-β; Aβ), and neuroinflammation (kynurenine pathway; KP metabolites) have been investigated independently in neurodegenerative diseases. However, the association of these markers of neurodegeneration and AD pathology with neuroinflammation has not been investigated previously. Therefore, the current study examined whether NFL and Aβ correlate with KP metabolites in elderly individuals to provide insight on the association between blood indicators of neurodegeneration and neuroinflammation. Methods Correlations between KP metabolites, measured using liquid chromatography and gas chromatography coupled with mass spectrometry, and plasma NFL and Aβ concentrations, measured using single molecule array (Simoa) assays, were investigated in elderly individuals aged 65–90 years, with normal global cognition (Mini-Mental State Examination Score ≥ 26) from the Kerr Anglican Retirement Village Initiative in Ageing Health cohort. Results A positive correlation between NFL and the kynurenine to tryptophan ratio (K/T) reflecting indoleamine 2,3-dioxygenase activity was observed (r = .451, p < .0001). Positive correlations were also observed between NFL and kynurenine (r = .364, p < .0005), kynurenic acid (r = .384, p < .0001), 3-hydroxykynurenine (r = .246, p = .014), anthranilic acid (r = .311, p = .002), and quinolinic acid (r = .296, p = .003). Further, significant associations were observed between plasma Aβ40 and the K/T (r = .375, p < .0005), kynurenine (r = .374, p < .0005), kynurenic acid (r = .352, p < .0005), anthranilic acid (r = .381, p < .0005), and quinolinic acid (r = .352, p < .0005). Significant associations were also observed between plasma Aβ42 and the K/T ratio (r = .215, p = .034), kynurenic acid (r = .214, p = .035), anthranilic acid (r = .278, p = .006), and quinolinic acid (r = .224, p = .027) in the cohort. On stratifying participants based on their neocortical Aβ load (NAL) status, NFL correlated with KP metabolites irrespective of NAL status; however, associations between plasma Aβ and KP metabolites were only pronounced in individuals with high NAL while associations in individuals with low NAL were nearly absent. Conclusions The current study shows that KP metabolite changes are associated with biomarker evidence of neurodegeneration. Additionally, the association between KP metabolites and plasma Aβ seems to be NAL status dependent. Finally, the current study suggests that an association between neurodegeneration and neuroinflammation manifests in the periphery, suggesting that preventing cytoskeleton cytotoxicity by KP metabolites may have therapeutic potential.

Therapeutic Potential of Cannabinoids in Neurodegenerative Disorders: A Selective Review

2014 ◽  
Vol 20 (13) ◽  
pp. 2218-2230 ◽  
Author(s):  
Latha Velayudhan ◽  
Erik Diepen ◽  
Mangesh Marudkar ◽  
Oliver Hands ◽  
Srinivas Suribhatla ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Therapeutic Potential ◽  
Selective Review

The Potential of Milk-derived Exosomes for Drug Delivery

2020 ◽  
Vol 17 ◽  
Author(s):  
Shuyuan Li ◽  
Yue Tang ◽  
Yushun Dou
Keyword(s):  
Drug Delivery ◽  
Oral Delivery ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Biological Fluids ◽  
Drug Loading ◽  
Drug Carriers ◽  
Current Application ◽  
Therapeutic Benefits ◽  
Loading Methods

Background: Exosomes, one of the extracellular vesicles, are widely present in all biological fluids and play an important role in intercellular communication. Because of its hydrophobic lipid bilayer and aqueous hydrophilic core structure, it is considered a possible alternative to liposome drug delivery systems. Not only do they protect the cargo like liposomes during delivery, they are less toxic and better tolerated. However, due to the lack of sources and methods for obtaining enough exosomes, the therapeutic application of exosomes as drug carriers is limited. Methods: A literature search was performed using the ScienceDirect and PubMed electronic databases to obtain information from published literature on milk exosomes related to drug delivery. Results: Here, we briefly reviewed the current knowledge of exosomes, expounded the advantages of milk-derived exosomes over other delivery vectors, including a higher yield, the oral delivery characteristic and additional therapeutic benefits. The purification and drug loading methods of milk exosomes, and the current application of milk exosomes were also introduced. Conclusion: The emergence of milk-derived exosomes is expected to break through the limitations of exosomes as therapeutic carriers of drugs. We hope to raise awareness of the therapeutic potential of milk-derived exosomes as a new drug delivery system.

Effects of Extracellular Vesicles Derived from Mesenchymal Stem/Stromal Cells on Liver Diseases

2019 ◽  
Vol 14 (5) ◽  
pp. 442-452 ◽  
Author(s):  
Wenjie Zheng ◽  
Yumin Yang ◽  
Russel Clive Sequeira ◽  
Colin E. Bishop ◽  
Anthony Atala ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Extracellular Vesicles ◽  
Stromal Cells ◽  
Liver Diseases ◽  
Therapeutic Potential ◽  
Mechanisms Of Action ◽  
Therapeutic Effects ◽  
Chronic Liver Injury ◽  
Mediated Effects ◽  
Therapeutic Benefits

Therapeutic effects of Mesenchymal Stem/Stromal Cells (MSCs) transplantation have been observed in various disease models. However, it is thought that MSCs-mediated effects largely depend on the paracrine manner of secreting cytokines, growth factors, and Extracellular Vesicles (EVs). Similarly, MSCs-derived EVs also showed therapeutic benefits in various liver diseases through alleviating fibrosis, improving regeneration of hepatocytes, and regulating immune activity. This review provides an overview of the MSCs, their EVs, and their therapeutic potential in treating various liver diseases including liver fibrosis, acute and chronic liver injury, and Hepatocellular Carcinoma (HCC). More specifically, the mechanisms by which MSC-EVs induce therapeutic benefits in liver diseases will be covered. In addition, comparisons between MSCs and their EVs were also evaluated as regenerative medicine against liver diseases. While the mechanisms of action and clinical efficacy must continue to be evaluated and verified, MSCs-derived EVs currently show tremendous potential and promise as a regenerative medicine treatment for liver disease in the future.

scholarly journals Natural Molecules and Neuroprotection: Kynurenic Acid, Pantethine and α-Lipoic Acid

2021 ◽  
Vol 22 (1) ◽  
pp. 403
Author(s):  
Fanni Tóth ◽  
Edina Katalin Cseh ◽  
László Vécsei
Keyword(s):  
Neurodegenerative Diseases ◽  
Lipoic Acid ◽  
Kynurenic Acid ◽  
Biological Activities ◽  
Neuroprotective Effect ◽  
Structural Diversity ◽  
Kynurenine Pathway ◽  
Glutamate Excitotoxicity ◽  
Neuroprotective Agents ◽  
Starting Point

The incidence of neurodegenerative diseases has increased greatly worldwide due to the rise in life expectancy. In spite of notable development in the understanding of these disorders, there has been limited success in the development of neuroprotective agents that can slow the progression of the disease and prevent neuronal death. Some natural products and molecules are very promising neuroprotective agents because of their structural diversity and wide variety of biological activities. In addition to their neuroprotective effect, they are known for their antioxidant, anti-inflammatory and antiapoptotic effects and often serve as a starting point for drug discovery. In this review, the following natural molecules are discussed: firstly, kynurenic acid, the main neuroprotective agent formed via the kynurenine pathway of tryptophan metabolism, as it is known mainly for its role in glutamate excitotoxicity, secondly, the dietary supplement pantethine, that is many sided, well tolerated and safe, and the third molecule, α-lipoic acid is a universal antioxidant. As a conclusion, because of their beneficial properties, these molecules are potential candidates for neuroprotective therapies suitable in managing neurodegenerative diseases.

scholarly journals Therapeutics potentiating microglial p21-Nrf2 axis can rescue neurodegeneration caused by neuroinflammation

2020 ◽  
Vol 6 (46) ◽  
pp. eabc1428
Author(s):  
A. Nakano-Kobayashi ◽  
A. Fukumoto ◽  
A. Morizane ◽  
D. T. Nguyen ◽  
T. M. Le ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Neuronal Survival ◽  
Disease Model ◽  
Neuronal Loss ◽  
Induced Pluripotent Stem Cell ◽  
Related Factor ◽  
Induced Pluripotent ◽  
Novel Therapeutic

Neurodegenerative disorders are caused by progressive neuronal loss, and there is no complete treatment available yet. Neuroinflammation is a common feature across neurodegenerative disorders and implicated in the progression of neurodegeneration. Dysregulated activation of microglia causes neuroinflammation and has been highlighted as a treatment target in therapeutic strategies. Here, we identified novel therapeutic candidate ALGERNON2 (altered generation of neurons 2) and demonstrate that ALGERNON2 suppressed the production of proinflammatory cytokines and rescued neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)–induced Parkinson’s disease model. ALGERNON2 stabilized cyclinD1/p21 complex, leading to up-regulation of nuclear factor erythroid 2–related factor 2 (Nrf2), which contributes to antioxidative and anti-inflammatory responses. Notably, ALGERNON2 enhanced neuronal survival in other neuroinflammatory conditions such as the transplantation of induced pluripotent stem cell–derived dopaminergic neurons into murine brains. In conclusion, we present that the microglial potentiation of the p21-Nrf2 pathway can contribute to neuronal survival and provide novel therapeutic potential for neuroinflammation-triggered neurodegeneration.

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