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Alves LDF, Moore JB, Kell DB. The Biology and Biochemistry of Kynurenic Acid, a Potential Nutraceutical with Multiple Biological Effects. Int J Mol Sci 2024; 25:9082. [PMID: 39201768 PMCID: PMC11354673 DOI: 10.3390/ijms25169082] [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: 07/19/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/03/2024] Open
Abstract
Kynurenic acid (KYNA) is an antioxidant degradation product of tryptophan that has been shown to have a variety of cytoprotective, neuroprotective and neuronal signalling properties. However, mammalian transporters and receptors display micromolar binding constants; these are consistent with its typically micromolar tissue concentrations but far above its serum/plasma concentration (normally tens of nanomolar), suggesting large gaps in our knowledge of its transport and mechanisms of action, in that the main influx transporters characterized to date are equilibrative, not concentrative. In addition, it is a substrate of a known anion efflux pump (ABCC4), whose in vivo activity is largely unknown. Exogeneous addition of L-tryptophan or L-kynurenine leads to the production of KYNA but also to that of many other co-metabolites (including some such as 3-hydroxy-L-kynurenine and quinolinic acid that may be toxic). With the exception of chestnut honey, KYNA exists at relatively low levels in natural foodstuffs. However, its bioavailability is reasonable, and as the terminal element of an irreversible reaction of most tryptophan degradation pathways, it might be added exogenously without disturbing upstream metabolism significantly. Many examples, which we review, show that it has valuable bioactivity. Given the above, we review its potential utility as a nutraceutical, finding it significantly worthy of further study and development.
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Affiliation(s)
- Luana de Fátima Alves
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
| | - J. Bernadette Moore
- School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK;
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
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Orzeł-Gajowik K, Milewski K, Zielińska M. miRNA-ome plasma analysis unveils changes in blood-brain barrier integrity associated with acute liver failure in rats. Fluids Barriers CNS 2023; 20:92. [PMID: 38066639 PMCID: PMC10709860 DOI: 10.1186/s12987-023-00484-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Hepatic encephalopathy (HE) symptoms associated with liver insufficiency are linked to the neurotoxic effects of ammonia and other toxic metabolites reaching the brain via the blood-brain barrier (BBB), further aggravated by the inflammatory response. Cumulative evidence documents that the non-coding single-stranded RNAs, micro RNAs (miRs) control the BBB functioning. However, miRs' involvement in BBB breakdown in HE is still underexplored. Here, we hypothesized that in rats with acute liver failure (ALF) or rats subjected to hyperammonemia, altered circulating miRs affect BBB composing proteins. METHODS Transmission electron microscopy was employed to delineate structural alterations of the BBB in rats with ALF (thioacetamide (TAA) intraperitoneal (ip.) administration) or hyperammonemia (ammonium acetate (OA) ip. administration). The BBB permeability was determined with Evans blue dye and sodium fluorescein assay. Plasma MiRs were profiled by Next Generation Sequencing (NGS), followed by in silico analysis. Selected miRs, verified by qRT-PCR, were examined in cultured rat brain endothelial cells. Targeted protein alterations were elucidated with immunofluorescence, western blotting, and, after selected miR mimics transfection, through an in vitro resistance measurement. RESULTS Changes in BBB structure and increased permeability were observed in the prefrontal cortex of TAA rats but not in the brains of OA rats. The NGS results revealed divergently changed miRNA-ome in the plasma of both rat models. The in silico analysis led to the selection of miR-122-5p and miR-183-5p with their target genes occludin and integrin β1, respectively, as potential contributors to BBB alterations. Both proteins were reduced in isolated brain vessels and cortical homogenates in TAA rats. We documented in cultured primary brain endothelial cells that ammonia alone and, in combination with TNFα increases the relative expression of NGS-selected miRs with a less pronounced effect of TNFα when added alone. The in vitro study also confirmed miR-122-5p-dependent decrease in occludin and miR-183-5p-related reduction in integrin β1 expression. CONCLUSION This work identified, to our knowledge for the first time, potential functional links between alterations in miRs residing in brain endothelium and BBB dysfunction in ALF.
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Affiliation(s)
- Karolina Orzeł-Gajowik
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Krzysztof Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
- Laboratory of Cellular Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura St. 3, 02-093, Warsaw, Poland
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
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Zhou Y, Wei M, Fan M, Liu Z, Wang A, Liu Y, Men L, Pi Z, Liu Z, Song F. Pharmacokinetic and metabolomics approach based on UHPLC-MS to evaluate therapeutic effect of lignans from S. Chinensis in alzheimer's disease. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1178:122859. [PMID: 34274605 DOI: 10.1016/j.jchromb.2021.122859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 06/17/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
Lignans from Schisandra chinensis (Turcz.) Baill (LFS) has been proved to improve impaired cognitive ability thereby show potential in treating Alzheimer's disease (AD). In this study, UHPLC-Q-TOF-MS and UHPLC-QQQ-MS were adopted cooperatively to establish a method synchronously detecting 10 kinds of LFS monomers in rat plasma samples. And this method was further applied for pharmacokinetic study to compare the metabolism of LFS in normal and AD rats. The results indicated that AD rats showed an observably better absorption of LFS compared to normal rats. Based on time-varying plasma concentration of LFS, metabolomics was used to establish a plasma concentration-time-endogenous metabolite connection. In total 54 time-varying endogenous metabolites were screened and most of which were closely associated with AD. And LFS exerted a concentration dependent regulating effect to most of these metabolites. Through biomarker related pathways and biological function analysis, LFS might treat AD through neuroprotection, antioxidant damage and regulating the metabolism of unsaturated fatty acids. This is the first study connecting LFS absorbtion and endogenous metabolite changes with the time lapse. The pharmacokinetics and metabolic profile differences between normal and AD rats were firstly investigated as well. This study provides a novel perspective in exploring the effect and mechanism of LFS in treating AD.
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Affiliation(s)
- Yuan Zhou
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China; School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Mengying Wei
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China; State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun, Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; Department of Osteoporosis Care and Control, Xiaoshan Affiliated Hospital of Wenzhou Medical University, Hangzhou 311200, China
| | - Meiling Fan
- College of Pharmacy, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Zhongying Liu
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China.
| | - Aimin Wang
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun, Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Yuanyuan Liu
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China
| | - Lihui Men
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China
| | - Zifeng Pi
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun, Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; College of Pharmacy, Changchun University of Chinese Medicine, Changchun 130117, China.
| | - Zhiqiang Liu
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun, Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Fengrui Song
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun, Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
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Zhao C, Wu K, Bao L, Chen L, Feng L, Liu Z, Wang Y, Fu Y, Zhang N, Hu X. Kynurenic acid protects against mastitis in mice by ameliorating inflammatory responses and enhancing blood-milk barrier integrity. Mol Immunol 2021; 137:134-144. [PMID: 34247099 DOI: 10.1016/j.molimm.2021.06.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/06/2021] [Accepted: 06/29/2021] [Indexed: 12/15/2022]
Abstract
Mastitis is one of the most serious diseases in humans and animals, especially in the modern dairy industry. Seeking safe and effective mastitis prevention strategies is urgent since food safety and drug residues in milk remain an enormous concern, despite the contribution of antibiotics to control mastitis. Kynurenic acid (KYNA), derived from the kynurenine pathway of tryptophan metabolism, has been shown to exhibit anti-inflammatory and immunomodulatory effects in many diseases. Recently, it was reported that impaired KYNA levels were associated with mastitis. However, the physiological role of KYNA in mastitis has not yet been elucidated. Therefore, the aim of this study was to investigate the protective role of KYNA in pathogen-induced mastitis in mice, as well as the underlying mechanism of this effect. We first evaluated the effects of KYNA on LPS-induced mastitis in mice. Additionally, the underlying anti-inflammatory mechanism of KYNA was investigated in mammary epithelial cells (MMECs). Furthermore, we examined the effects of KYNA on S. aureus and E. coli induced mastitis in mice. Our results demonstrated that KYNA alleviated LPS-induced mastitis by reducing inflammatory responses and enhancing blood-milk barrier integrity. The fundamental mechanisms involved the inhibition of NF-κB and activation of Nrf2/Ho-1, which is probably mediated by G protein-coupled receptor 35 but not aryl hydrocarbon receptor. Notably, KYNA also protected against S. aureus and E. coli induced mastitis in mice. In conclusion, our results highlight the role of KYNA in mastitis and serve as a basis for using endogenous metabolite as a novel preventative or therapeutic strategy for disease intervention.
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Affiliation(s)
- Caijun Zhao
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Keyi Wu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Lijuan Bao
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Luotong Chen
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Lianjun Feng
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Zhuoyu Liu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Ying Wang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Yunhe Fu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Naisheng Zhang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China
| | - Xiaoyu Hu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, China.
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Zhang Y, Jiao Y, Tao Y, Li Z, Yu H, Han S, Yang Y. Monobutyl phthalate can induce autophagy and metabolic disorders by activating the ire1a-xbp1 pathway in zebrafish liver. JOURNAL OF HAZARDOUS MATERIALS 2021; 412:125243. [PMID: 33524730 DOI: 10.1016/j.jhazmat.2021.125243] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/01/2021] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
Monobutyl phthalate (MBP) can exist in biological organisms for a long time because of its excellent fat solubility, and it has been found to have certain toxic effects. In this study, the acute effects of MBP on endoplasmic reticulum (ER) stress and metabolism in the zebrafish liver were studied. After continuous exposure to MBP (5 and 10 mg / L) for 96 h, ER damage and the appearance of apoptotic bodies and autophagosomes were found in liver. This is because MBP stimulated the ire-xbp1 pathway of ER stress, thus leading to apoptosis and autophagy. Also, through analysis of metabolic enzymes and genes, it was found that the activated ire-xbp1 pathway could promote lipid synthesis and cause the accumulation of lipid droplets. The gene pparγ related to lipid storage affected the level of insulin, which can also further affect the glucose metabolism process, that is, glycolysis and aerobic respiration were inhibited. And the pentose phosphate pathway (PPP) was activated as a compensation mechanism to alleviate glycogen accumulation. The abnormal supply of energy and the death of excessive cells will eventually severely damage the zebrafish liver. This study will enrich the knowledge about the toxic effects of MBP.
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Affiliation(s)
- Ying Zhang
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China.
| | - Yaqi Jiao
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Yue Tao
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Zixu Li
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Hui Yu
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Siyue Han
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Yang Yang
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
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Rac1/Wave2/Arp3 Pathway Mediates Rat Blood-Brain Barrier Dysfunction under Simulated Microgravity Based on Proteomics Strategy. Int J Mol Sci 2021; 22:ijms22105165. [PMID: 34068233 PMCID: PMC8153163 DOI: 10.3390/ijms22105165] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 01/09/2023] Open
Abstract
The blood-brain barrier (BBB) is critical to maintaining central nervous system (CNS) homeostasis. However, the effects of microgravity (MG) on the BBB remain unclear. This study aimed to investigate the influence of simulated MG (SMG) on the BBB and explore its potential mechanism using a proteomic approach. Rats were tail-suspended to simulate MG for 21 days. SMG could disrupt the BBB, including increased oxidative stress levels, proinflammatory cytokine levels, and permeability, damaged BBB ultrastructure, and downregulated tight junctions (TJs) and adherens junctions (AJs) protein expression in the rat brain. A total of 554 differentially expressed proteins (DEPs) induced by SMG were determined based on the label-free quantitative proteomic strategy. The bioinformatics analysis suggested that DEPs were mainly enriched in regulating the cell–cell junction and cell–extracellular matrix biological pathways. The inhibited Ras-related C3 botulinum toxin substrate 1 (Rac1)/Wiskott–Aldrich syndrome protein family verprolin-homologous protein 2 (Wave2)/actin-related protein 3 (Arp3) pathway and the decreased ratio of filamentous actin (F-actin) to globular actin contributed to BBB dysfunction induced by SMG. In the human brain microvascular endothelial cell (HBMECs), SMG increased the oxidative stress levels and proinflammatory cytokine levels, promoted apoptosis, and arrested the cell cycle phase. Expression of TJs and AJs proteins were downregulated and the distribution of F-actin was altered in SMG-treated HBMECs. The key role of the Rac1/Wave2/Arp3 pathway in BBB dysfunction was confirmed in HBMECs with a specific Rac1 agonist. This study demonstrated that SMG induced BBB dysfunction and revealed that Rac1/Wave2/Arp3 could be a potential signaling pathway responsible for BBB disruption under SMG. These results might shed a novel light on maintaining astronaut CNS homeostasis during space travel.
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Lo YC, Lin CL, Fang WY, Lőrinczi B, Szatmári I, Chang WH, Fülöp F, Wu SN. Effective Activation by Kynurenic Acid and Its Aminoalkylated Derivatives on M-Type K + Current. Int J Mol Sci 2021; 22:ijms22031300. [PMID: 33525680 PMCID: PMC7865226 DOI: 10.3390/ijms22031300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/24/2022] Open
Abstract
Kynurenic acid (KYNA, 4-oxoquinoline-2-carboxylic acid), an intermediate of the tryptophan metabolism, has been recognized to exert different neuroactive actions; however, the need of how it or its aminoalkylated amide derivative N-(2-(dimethylamino)ethyl)-3-(morpholinomethyl)-4-oxo-1,4-dihydroquinoline-2-carboxamide (KYNA-A4) exerts any effects on ion currents in excitable cells remains largely unmet. In this study, the investigations of how KYNA and other structurally similar KYNA derivatives have any adjustments on different ionic currents in pituitary GH3 cells and hippocampal mHippoE-14 neurons were performed by patch-clamp technique. KYNA or KYNA-A4 increased the amplitude of M-type K+ current (IK(M)) and concomitantly enhanced the activation time course of the current. The EC50 value required for KYNA- or KYNA-A4 -stimulated IK(M) was yielded to be 18.1 or 6.4 μM, respectively. The presence of KYNA or KYNA-A4 shifted the relationship of normalized IK(M)-conductance versus membrane potential to more depolarized potential with no change in the gating charge of the current. The voltage-dependent hysteretic area of IK(M) elicited by long-lasting triangular ramp pulse was observed in GH3 cells and that was increased during exposure to KYNA or KYNA-A4. In cell-attached current recordings, addition of KYNA raised the open probability of M-type K+ channels, along with increased mean open time of the channel. Cell exposure to KYNA or KYNA-A4 mildly inhibited delayed-rectifying K+ current; however, neither erg-mediated K+ current, hyperpolarization-activated cation current, nor voltage-gated Na+ current in GH3 cells was changed by KYNA or KYNA-A4. Under whole-cell, current-clamp recordings, exposure to KYNA or KYNA-A4 diminished the frequency of spontaneous action potentials; moreover, their reduction in firing frequency was attenuated by linopirdine, yet not by iberiotoxin or apamin. In hippocampal mHippoE-14 neurons, the addition of KYNA also increased the IK(M) amplitude effectively. Taken together, the actions presented herein would be one of the noticeable mechanisms through which they modulate functional activities of excitable cells occurring in vivo.
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Affiliation(s)
- Yi-Ching Lo
- Department of Pharmacology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (W.-Y.F.); (W.-H.C.)
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (Y.-C.L.); (S.-N.W.); Tel.: +886-7-3234686 (Y.-C.L.); +886-6-2353535-5334 (S.-N.W.); Fax: +886-7-3234686 (Y.-C.L.); +886-6-2362780 (S.-N.W.)
| | - Chih-Lung Lin
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan;
- Department of Neurosurgery, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Wei-Yu Fang
- Department of Pharmacology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (W.-Y.F.); (W.-H.C.)
| | - Bálint Lőrinczi
- Institute of Pharmaceutical Chemistry, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary; (B.L.); (I.S.); (F.F.)
| | - István Szatmári
- Institute of Pharmaceutical Chemistry, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary; (B.L.); (I.S.); (F.F.)
| | - Wan-Hsuan Chang
- Department of Pharmacology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (W.-Y.F.); (W.-H.C.)
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Ferenc Fülöp
- Institute of Pharmaceutical Chemistry, University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary; (B.L.); (I.S.); (F.F.)
- MTA-SZTE Stereochemistry Research Group, Hungarian Academy of Sciences, Eötvös u. 6, H-6720 Szeged, Hungary
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City 70101, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan City 70101, Taiwan
- Correspondence: (Y.-C.L.); (S.-N.W.); Tel.: +886-7-3234686 (Y.-C.L.); +886-6-2353535-5334 (S.-N.W.); Fax: +886-7-3234686 (Y.-C.L.); +886-6-2362780 (S.-N.W.)
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Salminen A. Hypoperfusion is a potential inducer of immunosuppressive network in Alzheimer's disease. Neurochem Int 2020; 142:104919. [PMID: 33242538 DOI: 10.1016/j.neuint.2020.104919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 10/12/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease which causes a non-reversible cognitive impairment and dementia. The primary cause of late-onset AD remains unknown although its pathology was discovered over a century ago. Recently, the vascular hypothesis of AD has received backing from evidence emerging from neuroimaging studies which have revealed the presence of a significant hypoperfusion in the brain regions vulnerable to AD pathology. In fact, hypoxia can explain many of the pathological changes evident in AD pathology, e.g. the deposition of β-amyloid plaques and chronic low-grade inflammation. Hypoxia-inducible factor-1α (HIF-1α) stimulates inflammatory responses and modulates both innate and adaptive immunity. It is known that hypoxia-induced inflammation evokes compensatory anti-inflammatory response involving tissue-resident microglia/macrophages and infiltrated immune cells. Hypoxia/HIF-1α induce immunosuppression by (i) increasing the expression of immunosuppressive genes, (ii) stimulating adenosinergic signaling, (iii) enhancing aerobic glycolysis, i.e. lactate production, and (iv) augmenting the secretion of immunosuppressive exosomes. Interestingly, it seems that these common mechanisms are also involved in the pathogenesis of AD. In AD pathology, an enhanced immunosuppression appears, e.g. as a shift in microglia/macrophage phenotypes towards the anti-inflammatory M2 phenotype and an increase in the numbers of regulatory T cells (Treg). The augmented anti-inflammatory capacity promotes the resolution of acute inflammation but persistent inflammation has crucial effects not only on immune cells but also harmful responses to the homeostasis of AD brain. I will examine in detail the mechanisms of the hypoperfusion/hypoxia-induced immunosuppressive state in general and especially, in its association with AD pathogenesis. These immunological observations support the vascular hypothesis of AD pathology.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
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Tao Y, Yang Y, Jiao Y, Wu S, Zhu G, Akindolie MS, Zhu T, Qu J, Wang L, Zhang Y. Monobutyl phthalate (MBP) induces energy metabolism disturbances in the gills of adult zebrafish (Danio rerio). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115288. [PMID: 32795888 DOI: 10.1016/j.envpol.2020.115288] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/13/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Monobutyl phthalate (MBP) is a primary metabolite of an environmental endocrine disruptor dibutyl phthalate (DBP), which poses a potential threat to living organisms. In this research, the acute toxicity of MBP on energy metabolism in zebrafish gills was studied. Transmission electron microscopy (TEM) results show that 10 mg L-1 MBP can induce mitochondrial structural damage of chloride cells after 96 h of continuous exposure. The activity of ion ATPase and the expression level of oxidative phosphorylation-related genes suggest that MBP interferes with ATP synthesis and ion transport. Further leading to a decrease in mitochondrial membrane potential (MMP) and cell viability, thereby mediating early-stage cell apoptosis. Through a comprehensive analysis of principal component analysis (PCA) and integrated biomarker response (IBR) scores, atp5a1, a subunit of mitochondrial ATP synthase, is mainly inhibited by MBP, followed by genes encoding ion ATPase (atp1b2 and atp2b1). Importantly, MBP inhibits aerobic metabolism by inhibiting the key enzyme malate dehydrogenase (MDH) in the TCA cycle, forcing zebrafish to maintain ATP supply by enhancing anaerobic metabolism.
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Affiliation(s)
- Yue Tao
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Yang Yang
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Yaqi Jiao
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Song Wu
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Guangxue Zhu
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Modupe Sarah Akindolie
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Tong Zhu
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jianhua Qu
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Lei Wang
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China
| | - Ying Zhang
- School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, PR China.
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Synthesis of New C-3 Substituted Kynurenic Acid Derivatives. Molecules 2020; 25:molecules25040937. [PMID: 32093108 PMCID: PMC7071119 DOI: 10.3390/molecules25040937] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 11/16/2022] Open
Abstract
The application of kynurenic acid (KYNA) as an electron-rich aromatic system in the modified Mannich reaction has been examined. The extension possibility of the reaction was tested by using amines occurring in a number of bioactive products, such as morpholine, piperidine, or N-methylpiperazine and aldehydes of markedly different reactivities, like formaldehyde and benzaldehyde. The influence of substituents attached to position 3 on the aminoalkylation was also investigated. Thus, reactions of 3-carbamoyl-substituted precursors with tertiary amine containing side-chains were also tested to afford new KYNA derivatives with two potential cationic centers. By means of NMR spectroscopic measurements, supported by DFT calculations, the dominant tautomer form of KYNA derivatives was also determined.
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Lee T, Park HS, Jeong JH, Jung TW. Kynurenic acid attenuates pro-inflammatory reactions in lipopolysaccharide-stimulated endothelial cells through the PPARδ/HO-1-dependent pathway. Mol Cell Endocrinol 2019; 495:110510. [PMID: 31319098 DOI: 10.1016/j.mce.2019.110510] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/21/2019] [Accepted: 07/15/2019] [Indexed: 01/10/2023]
Abstract
Kynurenic acid (KA) regulates energy homeostasis and alleviates inflammation in adipose tissue but how KA affects the atherosclerotic response in HUVECs remains unclear. We evaluated the effects of KA on lipopolysaccharide (LPS)-induced inflammation and apoptosis in HUVECs. KA enhanced peroxisome proliferator-activated receptor delta (PPARδ) expression in HUVECs and THP-1 cells and suppressed LPS-induced atherosclerotic responses through PPARδ-mediated signaling. Moreover, KA treatment mitigated LPS-induced phosphorylation of nuclear factor kappa B and pro-inflammatory cytokine release in HUVECs and THP-1 cells, and down-regulated adhesion molecules in HUVECs and adhesion of THP-1 cells to HUVECs following LPS treatment. KA treatment decreased LPS-induced inflammation and apoptosis, and also promoted heme oxygenase (HO)-1 expression, which suppresses inflammation in HUVECs. Suppression of PPARδ or HO-1 expression markedly mitigated the effects of KA on atherosclerotic responses in HUVECs. Thus, KA attenuates LPS-induced atherosclerotic responses by suppressing inflammation via the PPARδ/HO-1-dependent pathway.
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Affiliation(s)
- Taeseung Lee
- Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea; Department of Surgery, Seoul National University College of Medicine, Seoul, South Korea
| | - Hyung Sub Park
- Department of Surgery, Seoul National University College of Medicine, Seoul, South Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Tae Woo Jung
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea.
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