1
|
Spencer PS, Valdes Angues R, Palmer VS. Nodding syndrome: A role for environmental biotoxins that dysregulate MECP2 expression? J Neurol Sci 2024; 462:123077. [PMID: 38850769 DOI: 10.1016/j.jns.2024.123077] [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: 10/01/2023] [Revised: 05/15/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
Nodding syndrome is an epileptic encephalopathy associated with neuroinflammation and tauopathy. This initially pediatric brain disease, which has some clinical overlap with Methyl-CpG-binding protein 2 (MECP2) Duplication Syndrome, has impacted certain impoverished East African communities coincident with local civil conflict and internal displacement, conditions that forced dependence on contaminated food and water. A potential role in Nodding syndrome for certain biotoxins (freshwater cyanotoxins plus/minus mycotoxins) with neuroinflammatory, excitotoxic, tauopathic, and MECP2-dysregulating properties, is considered here for the first time.
Collapse
Affiliation(s)
- Peter S Spencer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda.
| | - Raquel Valdes Angues
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| | - Valerie S Palmer
- Department of Neurology, School of Medicine and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA; Gulu University School of Medicine, Gulu, Uganda
| |
Collapse
|
2
|
Nguyen YND, Jeong JH, Sharma N, Tran NKC, Tran HYP, Dang DK, Park JH, Byun JK, Ko SK, Nah SY, Kim HC, Shin EJ. Ginsenoside Re protects against kainate-induced neurotoxicity in mice by attenuating mitochondrial dysfunction through activation of the signal transducers and activators of transcription 3 signaling. Free Radic Res 2024; 58:276-292. [PMID: 38613520 DOI: 10.1080/10715762.2024.2341885] [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: 09/13/2023] [Accepted: 03/21/2024] [Indexed: 04/15/2024]
Abstract
It was demonstrated that ginsenosides exert anti-convulsive potentials and interleukin-6 (IL-6) is protective from excitotoxicity induced by kainate (KA), a model of temporal lobe epilepsy. Ginsenosides-mediated mitochondrial recovery is essential for attenuating KA-induced neurotoxicity, however, little is known about the effects of ginsenoside Re (GRe), one of the major ginsenosides. In this study, GRe significantly attenuated KA-induced seizures in mice. KA-induced redox changes were more evident in mitochondrial fraction than in cytosolic fraction in the hippocampus of mice. GRe significantly attenuated KA-induced mitochondrial oxidative stress (i.e. increases in reactive oxygen species, 4-hydroxynonenal, and protein carbonyl) and mitochondrial dysfunction (i.e. the increase in intra-mitochondrial Ca2+ and the decrease in mitochondrial membrane potential). GRe or mitochondrial protectant cyclosporin A restored phospho-signal transducers and activators of transcription 3 (STAT3) and IL-6 levels reduced by KA, and the effects of GRe were reversed by the JAK2 inhibitor AG490 and the mitochondrial toxin 3-nitropropionic acid (3-NP). Thus, we used IL-6 knockout (KO) mice to investigate whether the interaction between STAT3 and IL-6 is involved in the GRe effects. Importantly, KA-induced reduction of manganese superoxide dismutase (SOD-2) levels and neurodegeneration (i.e. astroglial inhibition, microglial activation, and neuronal loss) were more prominent in IL-6 KO than in wild-type (WT) mice. These KA-induced detrimental effects were attenuated by GRe in WT and, unexpectedly, IL-6 KO mice, which were counteracted by AG490 and 3-NP. Our results suggest that GRe attenuates KA-induced neurodegeneration via modulating mitochondrial oxidative burden, mitochondrial dysfunction, and STAT3 signaling in mice.
Collapse
Affiliation(s)
- Yen Nhi Doan Nguyen
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
| | - Ji Hoon Jeong
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Naveen Sharma
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Ngoc Kim Cuong Tran
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
| | - Hoang-Yen Phi Tran
- Department of Physical Chemistry, University of Medicine and Pharmacy at Ho Chi Minh City, Viet Nam, Ho Chi Minh City
| | - Duy-Khanh Dang
- Department of Pharmacy, Can Tho University of Medicine and Pharmacy, Can Tho City, Viet Nam, Ho Chi Minh City
| | - Jung Hoon Park
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
| | - Jae Kyung Byun
- Korea Society of Forest Environmental Research, Namyangju, Republic of Korea
| | - Sung Kwon Ko
- Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, Republic of Korea
| | - Seung-Yeol Nah
- Ginsentology Research Laboratory and Department of Physiology, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea
| |
Collapse
|
3
|
Li B, Wang Z, Chuan H, Li J, Xie P, Liu Y. Introducing fluorescent probe technology for detecting microcystin-LR in the water and cells. Anal Chim Acta 2024; 1288:342188. [PMID: 38220314 DOI: 10.1016/j.aca.2023.342188] [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: 10/21/2023] [Revised: 12/14/2023] [Accepted: 12/29/2023] [Indexed: 01/16/2024]
Abstract
BACKGROUND For a long time, the environment hazards caused by cyanobacteria bloom and associated microcystins have attracted attention worldwide. Microcystin-LR (MC-LR) is the most widely distributed and most toxic toxin. At present, numerous MC-LR detection methods exist many drawbacks. Therefore, a quick and accurate method for identifying and detecting MC-LR is crucial and necessary. In this work, we strived to introduce a novel fluorescence assay to detect MC-LR in the water and cells. RESULTS According to the special spatial configuration and physicochemical properties of MC-LR, we designed and constructed six fluorescent probes. The design concepts of the probes were exhaustively elaborated. MC-YdTPA, MC-YdTPE, MC-RdTPA, and MC-RdTPE could show significant fluorescence enhancement in MC-LR solution. Significantly, MC-YdTPA, MC-YdTPE, and MC-RdTPA could also response well in the cells treated with MC-LR, demonstrating these fluorescent probes' values. The recognition mechanism between probes and MC-LR were also deeply explored: (1) The polyphenylene ring structure of probes may have nested or hydrogen bond weak interaction with the ring structure of MC-LR. (2) The probes can generate a reaction to the hydrogen ions ionized by MC-LR. SIGNIFICANCE We proposed the novel ideas for designing MC-LR probes. This research can provide valuable experiences and important assistance in synthesizing MC-LR fluorescent probes. We expect that this work may bring new ideas to develop fluorescent probes for researching MC-LR in vivo and in vitro.
Collapse
Affiliation(s)
- Bingyan Li
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650500, PR China
| | - Zhaomin Wang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650500, PR China
| | - Huiyan Chuan
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650500, PR China
| | - Jing Li
- Yunnan International Joint R&D Center of Smart Agriculture and Water Security, School of Water Conservancy, Yunnan Agricultural University, Kunming, 650201, PR China
| | - Ping Xie
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650500, PR China; Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Yong Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Sciences, Yunnan University, Kunming, 650500, PR China.
| |
Collapse
|
4
|
Park JH, Hwang Y, Nguyen YND, Kim HC, Shin EJ. Ramelteon attenuates hippocampal neuronal loss and memory impairment following kainate-induced seizures. J Pineal Res 2024; 76:e12921. [PMID: 37846173 DOI: 10.1111/jpi.12921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/18/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023]
Abstract
Evidence suggests that the neuroprotective effects of melatonin involve both receptor-dependent and -independent actions. However, little is known about the effects of melatonin receptor activation on the kainate (KA) neurotoxicity. This study examined the effects of repeated post-KA treatment with ramelteon, a selective agonist of melatonin receptors, on neuronal loss, cognitive impairment, and depression-like behaviors following KA-induced seizures. The expression of melatonin receptors decreased in neurons, whereas it was induced in astrocytes 3 and 7 days after seizures elicited by KA (0.12 μg/μL) in the hippocampus of mice. Ramelteon (3 or 10 mg/kg, i.p.) and melatonin (10 mg/kg, i.p.) mitigated KA-induced oxidative stress and impairment of glutathione homeostasis and promoted the nuclear translocation and DNA binding activity of Nrf2 in the hippocampus after KA treatment. Ramelteon and melatonin also attenuated microglial activation but did not significantly affect astroglial activation induced by KA, despite the astroglial induction of melatonin receptors after KA treatment. However, ramelteon attenuated KA-induced proinflammatory phenotypic changes in astrocytes. Considering the reciprocal regulation of astroglial and microglial activation, these results suggest ramelteon inhibits microglial activation by regulating astrocyte phenotypic changes. These effects were accompanied by the attenuation of the nuclear translocation and DNA binding activity of nuclear factor κB (NFκB) induced by KA. Consequently, ramelteon attenuated the KA-induced hippocampal neuronal loss, memory impairment, and depression-like behaviors; the effects were comparable to those of melatonin. These results suggest that ramelteon-mediated activation of melatonin receptors provides neuroprotection against KA-induced neurotoxicity in the mouse hippocampus by activating Nrf2 signaling to attenuate oxidative stress and restore glutathione homeostasis and by inhibiting NFκB signaling to attenuate neuroinflammatory changes.
Collapse
Affiliation(s)
- Jung Hoon Park
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Yen Nhi Doan Nguyen
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, Republic of Korea
| |
Collapse
|
5
|
Cuong Tran NK, Jeong JH, Sharma N, Doan Nguyen YN, Phi Tran HY, Dang DK, Park JH, Byun JK, Jin D, Xiaoyan Z, Ko SK, Nah SY, Kim HC, Shin EJ. Ginsenoside Re blocks Bay k-8644-induced neurotoxicity via attenuating mitochondrial dysfunction and PKCδ activation in the hippocampus of mice: Involvement of antioxidant potential. Food Chem Toxicol 2023:113869. [PMID: 37308051 DOI: 10.1016/j.fct.2023.113869] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/01/2023] [Indexed: 06/14/2023]
Abstract
Although the anticonvulsant effects of ginsenosides are recognized, little is known about their effects on the convulsive behaviors induced by the activation of L-type Ca2+ channels. Here, we investigated whether ginsenoside Re (GRe) modulates excitotoxicity induced by the L-type Ca2+ channel activator Bay k-8644. GRe significantly attenuated Bay k-8644-induced convulsive behaviors and hippocampal oxidative stress in mice. GRe-mediated antioxidant potential was more pronounced in the mitochondrial fraction than cytosolic fraction. As L-type Ca2+ channels are thought to be targets of protein kinase C (PKC), we investigated the role of PKC under excitotoxic conditions. GRe attenuated Bay k-8644-induced mitochondrial dysfunction, PKCδ activation, and neuronal loss. The PKCδ inhibition and neuroprotection mediated by GRe were comparable to those by the ROS inhibitor N-acetylcysteine, the mitochondrial protectant cyclosporin A, the microglial inhibitor minocycline, or the PKCδ inhibitor rottlerin. Consistently, the GRe-mediated PKCδ inhibition and neuroprotection were counteracted by the mitochondrial toxin 3-nitropropionic acid or the PKC activator bryostatin-1. GRe treatment did not have additional effects on PKCδ gene knockout-mediated neuroprotection, suggesting that PKCδ is a molecular target of GRe. Collectively, our results suggest that GRe-mediated anticonvulsive/neuroprotective effects require the attenuation of mitochondrial dysfunction and altered redox status and inactivation of PKCδ.
Collapse
Affiliation(s)
- Ngoc Kim Cuong Tran
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea.
| | - Ji Hoon Jeong
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, College of Medicine, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Naveen Sharma
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea; Department of Global Innovative Drugs, Graduate School of Chung-Ang University, College of Medicine, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Yen Nhi Doan Nguyen
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea
| | - Hoang-Yen Phi Tran
- Physical Chemistry Department, University of Medicine and Pharmacy, Ho Chi Minh City, 760000, Viet Nam
| | - Duy-Khanh Dang
- Pharmacy Faculty, Can Tho University of Medicine and Pharmacy, Can Tho City, 900000, Viet Nam
| | - Jung Hoon Park
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea
| | - Jae Kyung Byun
- Korea Society of Forest Environmental Research, Namyangju, 12106, Republic of Korea
| | - Dezhong Jin
- Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, 27316, Republic of Korea
| | - Zeng Xiaoyan
- Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, 27316, Republic of Korea
| | - Sung Kwon Ko
- Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, 27316, Republic of Korea
| | - Seung-Yeol Nah
- Ginsentology Research Laboratory and Department of Physiology, College of Veterinary Medicine, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon, 24341, Republic of Korea.
| |
Collapse
|
6
|
Antioxidant Therapy Significantly Attenuates Hepatotoxicity following Low Dose Exposure to Microcystin-LR in a Murine Model of Diet-Induced Non-Alcoholic Fatty Liver Disease. Antioxidants (Basel) 2022; 11:antiox11081625. [PMID: 36009344 PMCID: PMC9404967 DOI: 10.3390/antiox11081625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 12/15/2022] Open
Abstract
We have previously shown in a murine model of Non-alcoholic Fatty Liver Disease (NAFLD) that chronic, low-dose exposure to the Harmful Algal Bloom cyanotoxin microcystin-LR (MC-LR), resulted in significant hepatotoxicity including micro-vesicular lipid accumulation, impaired toxin metabolism as well as dysregulation of the key signaling pathways involved in inflammation, immune response and oxidative stress. On this background we hypothesized that augmentation of hepatic drug metabolism pathways with targeted antioxidant therapies would improve MC-LR metabolism and reduce hepatic injury in NAFLD mice exposed to MC-LR. We chose N-acetylcysteine (NAC, 40 mM), a known antioxidant that augments the glutathione detoxification pathway and a novel peptide (pNaKtide, 25 mg/kg) which is targeted to interrupting a specific Src-kinase mediated pro-oxidant amplification mechanism. Histological analysis showed significant increase in hepatic inflammation in NAFLD mice exposed to MC-LR which was attenuated on treatment with both NAC and pNaKtide (both p ≤ 0.05). Oxidative stress, as measured by 8-OHDG levels in urine and protein carbonylation in liver sections, was also significantly downregulated upon treatment with both antioxidants after MC-LR exposure. Genetic analysis of key drug transporters including Abcb1a, Phase I enzyme-Cyp3a11 and Phase II metabolic enzymes-Pkm (Pyruvate kinase, muscle), Pklr (Pyruvate kinase, liver, and red blood cell) and Gad1 (Glutamic acid decarboxylase) was significantly altered by MC-LR exposure as compared to the non-exposed control group (all p ≤ 0.05). These changes were significantly attenuated with both pNaKtide and NAC treatment. These results suggest that MC-LR metabolism and detoxification is significantly impaired in the setting of NAFLD, and that these pathways can potentially be reversed with targeted antioxidant treatment.
Collapse
|
7
|
Hwang Y, Kim HC, Shin EJ. Effect of rottlerin on astrocyte phenotype polarization after trimethyltin insult in the dentate gyrus of mice. J Neuroinflammation 2022; 19:142. [PMID: 35690821 PMCID: PMC9188234 DOI: 10.1186/s12974-022-02507-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 06/01/2022] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND It has been demonstrated that reactive astrocytes can be polarized into pro-inflammatory A1 phenotype or anti-inflammatory A2 phenotype under neurotoxic and neurodegenerative conditions. Microglia have been suggested to play a critical role in astrocyte phenotype polarization by releasing pro- and anti-inflammatory mediators. In this study, we examined whether trimethyltin (TMT) insult can induce astrocyte polarization in the dentate gyrus of mice, and whether protein kinase Cδ (PKCδ) plays a role in TMT-induced astrocyte phenotype polarization. METHODS Male C57BL/6 N mice received TMT (2.6 mg/kg, i.p.), and temporal changes in the mRNA expression of A1 and A2 phenotype markers were evaluated in the hippocampus. In addition, temporal and spatial changes in the protein expression of C3, S100A10, Iba-1, and p-PKCδ were examined in the dentate gyrus. Rottlerin (5 mg/kg, i.p. × 5 at 12-h intervals) was administered 3-5 days after TMT treatment, and the expression of A1 and A2 transcripts, p-PKCδ, Iba-1, C3, S100A10, and C1q was evaluated 6 days after TMT treatment. RESULTS TMT treatment significantly increased the mRNA expression of A1 and A2 phenotype markers, and the increased expression of A1 markers remained longer than that of A2 markers. The immunoreactivity of the representative A1 phenotype marker, C3 and A2 phenotype marker, S100A10 peaked 6 days after TMT insult in the dentate gyrus. While C3 was expressed evenly throughout the dentate gyrus, S100A10 was highly expressed in the hilus and inner molecular layer. In addition, TMT insult induced microglial p-PKCδ expression. Treatment with rottlerin, a PKCδ inhibitor, decreased Iba-1 and C3 expression, but did not affect S100A10 expression, suggesting that PKCδ inhibition attenuates microglial activation and A1 astrocyte phenotype polarization. Consistently, rottlerin significantly reduced the expression of C1q and tumor necrosis factor-α (TNFα), which has been suggested to be released by activated microglia and induce A1 astrocyte polarization. CONCLUSION We demonstrated the temporal and spatial profiles of astrocyte polarization after TMT insult in the dentate gyrus of mice. Taken together, our results suggest that PKCδ plays a role in inducing A1 astrocyte polarization by promoting microglial activation and consequently increasing the expression of pro-inflammatory mediators after TMT insult.
Collapse
Affiliation(s)
- Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| |
Collapse
|