Gateways for Glutamate Neuroprotection in Parkinson’s Disease (PD): Essential Role of EAAT3 and NCX1 Revealed in an In Vitro Model of PD

Increasing evidence suggests that metabolic alterations may be etiologically linked to neurodegenerative disorders such as Parkinson’s disease (PD) and in particular empathizes the possibility of targeting mitochondrial dysfunctions to improve PD progression. Under different pathological conditions (i.e., cardiac and neuronal ischemia/reperfusion injury), we showed that supplementation of energetic substrates like glutamate exerts a protective role by preserving mitochondrial functions and enhancing ATP synthesis through a mechanism involving the Na+-dependent excitatory amino acid transporters (EAATs) and the Na+/Ca2+ exchanger (NCX). In this study, we investigated whether a similar approach aimed at promoting glutamate metabolism would be also beneficial against cell damage in an in vitro PD-like model. In retinoic acid (RA)-differentiated SH-SY5Y cells challenged with α-synuclein (α-syn) plus rotenone (Rot), glutamate significantly improved cell viability by increasing ATP levels, reducing oxidative damage and cytosolic and mitochondrial Ca2+ overload. Glutamate benefits were strikingly lost when either EAAT3 or NCX1 expression was knocked down by RNA silencing. Overall, our results open the possibility of targeting EAAT3/NCX1 functions to limit PD pathology by simultaneously favoring glutamate uptake and metabolic use in dopaminergic neurons.

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Crocetin Alleviates Inflammation in MPTP-Induced Parkinson’s Disease Models through Improving Mitochondrial Functions

Parkinson s Disease ◽

10.1155/2020/9864370 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Na Dong ◽

Zhong Dong ◽

Ying Chen ◽

Xiaosu Gu

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mitochondrial Permeability Transition ◽

Therapeutic Potential ◽

Adenine Nucleotide ◽

Motor Deficits ◽

Dependent Manner ◽

Cyclophilin D ◽

Mitochondrial Functions

Parkinson’s disease (PD) is the second most common neurodegenerative disease. Crocetin, derived from saffron, exerts multiple pharmacological properties, such as anti-inflammatory, antioxidant, antifatigue, and anticancer effects. However, the effect of crocetin on PD remains unclear. In this study, we designed experiments to investigate the effect of crocetin against MPTP-induced PD models and the underlying mechanisms. Our results showed that crocetin treatment attenuates MPTP-induced motor deficits and protects dopaminergic neurons. Both in vivo and in vitro experiments demonstrated that crocetin treatment decreased the expression of inflammatory associated genes and inflammatory cytokines. Furthermore, crocetin treatment protected mitochondrial functions against MPP+ induced damage by regulating the mPTP (mitochondrial permeability transition pore) viability in the interaction of ANT (adenine nucleotide translocase) and Cyp D (Cyclophilin D) dependent manner. Therefore, our results demonstrate that crocetin has therapeutic potential in Parkinson’s disease.

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Regulation of Actg1 and Gsta2 is possible mechanism by which capsaicin alleviates apoptosis in cell model of 6-OHDA-induced Parkinson's disease

Bioscience Reports ◽

10.1042/bsr20191796 ◽

2020 ◽

Vol 40 (6) ◽

Cited By ~ 1

Author(s):

Jiahui Liu ◽

Hong Liu ◽

Zhenxiang Zhao ◽

Jianfeng Wang ◽

Dandan Guo ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cell Model ◽

Cell Damage ◽

Glutathione S Transferase ◽

Expression Arrays ◽

Transcriptional Changes ◽

Molecular Mechanism Of Action ◽

Disease Cell

Abstract The present study aimed to identify the gene expression changes conferred by capsaicin in the cell model of 6-OHDA-induced Parkinson's disease, to disclose the molecular mechanism of action of capsaicin. We used capsaicin-treated and paraffin-embedded wax blocks containing substantia nigra tissue from 6-OHDA-induced Parkinson's disease rats to analyze transcriptional changes using Affymetrix GeneChip Whole Transcript Expression Arrays. A total of 108 genes were differentially expressed in response to capsaicin treatment, and seven of these genes were selected for further analysis: Olr724, COX1, Gsta2, Rab5a, Potef, Actg1, and Acadsb, of which Actg1 (actin gamma 1) was down-regulated and Gsta2 (Glutathione S-transferase alpha 2) was up-regulated. We successfully overexpressed Actg1 and Gsta2 in vitro. CCK-8 detection and flow cytometry demonstrated that overexpression of Actg1 and Gsta2 increased apoptosis in the 6-OHDA-induced Parkinson's disease cell model. The imbalance between Actg1 and Gsta2 may be one of the mechanisms of cell damage in Parkinson's disease (PD). Capsaicin can protect the cells and reduce the apoptosis rate by regulating Actg1 and Gsta2.

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Characterization of the Angiogenic Potential of Human Regulatory Macrophages (Mreg) after Ischemia/Reperfusion Injury In Vitro

Stem Cells International ◽

10.1155/2019/3725863 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Lars Hummitzsch ◽

Karina Zitta ◽

Rene Rusch ◽

Jochen Cremer ◽

Markus Steinfath ◽

...

Keyword(s):

Treatment Option ◽

Ischemia Reperfusion Injury ◽

Cell Damage ◽

Ischemia Reperfusion ◽

Surrogate Marker ◽

Tube Formation ◽

Blood Monocytes ◽

Angiogenic Potential ◽

Angiogenic Proteins

Ischemia/reperfusion- (I/R-) induced organ damage represents one of the main causes of death worldwide, and new strategies to reduce I/R injury are urgently needed. We have shown that programmable cells of monocytic origin (PCMO) respond to I/R with the release of angiogenic mediators and that transplantation of PCMO results in increased neovascularization. Human regulatory macrophages (Mreg), which are also of monocytic origin, have been successfully employed in clinical transplantation studies due to their immunomodulatory properties. Here, we investigated whether Mreg also possess angiogenic potential in vitro and could represent a treatment option for I/R-associated illnesses. Mreg were differentiated using peripheral blood monocytes from different donors (N=14) by incubation with M-CSF and human AB serum and stimulation with INF-gamma. Mreg cultures were subjected to 3 h of hypoxia and 24 h of reoxygenation (resembling I/R) or the respective nonischemic control. Cellular resilience, expression of pluripotency markers, secretion of angiogenic proteins, and influence on endothelial tube formation as a surrogate marker for angiogenesis were investigated. Mreg showed resilience against I/R that did not lead to increased cell damage. Mreg express DHRS9 as well as IDO and display a moderate to low expression pattern of several pluripotency genes (e.g., NANOG, OCT-4, and SOX2). I/R resulted in an upregulation of IDO (p<0.001) while C-MYC and KLF4 were downregulated (p<0.001andp<0.05). Proteome profiling revealed the secretion of numerous angiogenic proteins by Mreg of which several were strongly upregulated by I/R (e.g., MIP-1alpha, 19.9-fold; GM-CSF, 19.2-fold; PTX3, 5.8-fold; IL-1β, 5.2-fold; and MCP-1, 4.7-fold). The angiogenic potential of supernatants from Mreg subjected to I/R remains inconclusive. While Mreg supernatants from 3 donors induced tube formation, 2 supernatants were not effective. We suggest that Mreg may prove beneficial as a cell therapy-based treatment option for I/R-associated illnesses. However, donor characteristics seem to crucially influence the effectiveness of Mreg treatment.

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Glutamic Acid Transporters: Targets for Neuroprotective Therapies in Parkinson’s Disease

Frontiers in Neuroscience ◽

10.3389/fnins.2021.678154 ◽

2021 ◽

Vol 15 ◽

Author(s):

Xiang Li ◽

Wenjun Wang ◽

Jianghong Yan ◽

Fancai Zeng

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Glutamic Acid ◽

Drug Targets ◽

Excitatory Amino Acid ◽

Glutamate Transporter ◽

Glutamate Transporters ◽

Symptomatic Treatment ◽

Amino Acid Transporters ◽

Functional Roles

Parkinson’s disease (PD) is a common neurodegenerative disease in middle-aged and elderly individuals. At present, no effective drug has been developed to treat PD. Although a variety of drugs exist for the symptomatic treatment of PD, they all have strong side effects. Most studies on PD mainly focus on dopaminergic neurons. This review highlights the function of glutamic acid transporters (GLTs), including excitatory amino acid transporters (EAATs) and vesicular glutamate transporters (VGLUTs), during the development of PD. In addition, using bioinformatics, we compared the expression of different types of glutamate transporter genes in the cingulate gyrus of PD patients and healthy controls. More importantly, we suggest that the functional roles of glutamate transporters may prove beneficial in the treatment of PD. In summary, VGLUTs and EAATs may be potential targets in the treatment of PD. VGLUTs and EAATs can be used as clinical drug targets to achieve better efficacy. Through this review article, we hope to enable future researchers to improve the condition of PD patients.

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Effects of Mdivi-1 on Neural Mitochondrial Dysfunction and Mitochondria-Mediated Apoptosis in Ischemia-Reperfusion Injury After Stroke: A Systematic Review of Preclinical Studies

Frontiers in Molecular Neuroscience ◽

10.3389/fnmol.2021.778569 ◽

2021 ◽

Vol 14 ◽

Author(s):

Nguyen Thanh Nhu ◽

Qing Li ◽

Yijie Liu ◽

Jian Xu ◽

Shu-Yun Xiao ◽

...

Keyword(s):

Systematic Review ◽

Ischemic Stroke ◽

Brain Injury ◽

Mitochondrial Dysfunction ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Atp Depletion ◽

Mitochondrial Functions

This systematic review sought to determine the effects of Mitochondrial division inhibitor-1 (Mdivi-1) on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in ischemia/reperfusion (I/R) injury after ischemic stroke. Pubmed, Web of Science, and EMBASE databases were searched through July 2021. The studies published in English language that mentioned the effects of Mdivi-1 on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in I/R-induced brain injury were included. The CAMARADES checklist (for in vivo studies) and the TOXRTOOL checklist (for in vitro studies) were used for study quality evaluation. Twelve studies were included (median CAMARADES score = 6; TOXRTOOL scores ranging from 16 to 18). All studies investigated neural mitochondrial functions, providing that Mdivi-1 attenuated the mitochondrial membrane potential dissipation, ATP depletion, and complexes I-V abnormalities; enhanced mitochondrial biogenesis, as well as inactivated mitochondrial fission and mitophagy in I/R-induced brain injury. Ten studies analyzed neural mitochondria-mediated apoptosis, showing that Mdivi-1 decreased the levels of mitochondria-mediated proapoptotic factors (AIF, Bax, cytochrome c, caspase-9, and caspase-3) and enhanced the level of antiapoptotic factor (Bcl-2) against I/R-induced brain injury. The findings suggest that Mdivi-1 can protect neural mitochondrial functions, thereby attenuating neural mitochondria-mediated apoptosis in I/R-induced brain injury. Our review supports Mdivi-1 as a potential therapeutic compound to reduce brain damage in ischemic stroke (PROSPERO protocol registration ID: CRD42020205808).Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42020205808].

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Tetramethylpyrazine nitrone exerts neuroprotection via PGC-1α/Nrf2 activation and α-synuclein clearance in Parkinson’s disease models

10.21203/rs.3.rs-32864/v1 ◽

2020 ◽

Author(s):

Baojian Guo ◽

Chengyou Zheng ◽

Jie Cao ◽

Shangming Li ◽

Fangcheng Luo ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Transgenic Mice ◽

Dopaminergic Neurons ◽

Radical Scavenger ◽

Related Factor ◽

Mice Model ◽

Mitochondrial Functions ◽

Nrf2 Signaling Pathway

Abstract Background: The peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) and Nuclear factor erythroid 2-related factor 2 (Nrf2) are key regulators controlling antioxidant defense, mitochondrial biogenesis and cellular proteostasis. Dysfunction of these processes has been implicated in the pathogenesis of Parkinson’s disease (PD). Activation of PGC-1α/Nrf2 might improve mitochondrial dysfunction, promote α-synuclein (α-syn) clearance and attenuate degeneration of nigral dopaminergic neurons in PD. Methods: Neurotoxin-induced in vitro PD model, 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-treated mice model, unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA)-lesioned rat model, and transgenic mice overexpression of human A53T mutant α-synuclein were used to evaluate the neuroprotective and neurorescue effect of tetramethylpyrazine nitrone (TBN), a free radical scavenger, and its regulation on PGC-1α/Nrf2 pathway. Results: TBN protected against 1-methyl-4-phenylpyridinium (MPP + ) and 6-OHDA insult in cultured primary midbrain neurons. TBN promoted α-syn clearance by autophagy and proteasomal pathways in cell models overexpressing the human A53T mutant α-syn. In MPTP-treated mice, unilateral 6-OHDA-lesioned rats, and the α-syn transgenic mice model, TBN improved motor impairment, increased survival of nigral dopaminergic neurons, and elevated striatal dopamine levels while decreasing the products of oxidative damage. Importantly, TBN down-regulated the α-syn level in the brain and serum of α-syn-transgenic mice. These in vitro and in vivo improvements were associated with activation of the PGC-1α/Nrf2 signaling pathway, resulting in reduced oxidative stress, and enhanced mitochondrial functions. Conclusions: Our work demonstrates that TBN activates PGC-1α/Nrf2 and increases the survival of nigral dopaminergic neurons. These results suggest that TBN warrants further development as a potential new PD treatment.

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MiR-25 protects NRK-52E cells from apoptosis induced by renal IRI by targeting DKK3

10.21203/rs.3.rs-417907/v1 ◽

2021 ◽

Author(s):

Yu Zhang ◽

Xiangrong Zuo

Keyword(s):

Protective Effect ◽

Ischemia Reperfusion Injury ◽

Cell Damage ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Treatment Method ◽

Expression Level ◽

Iri Model ◽

Small Noncoding Rnas

Abstract Renal ischemia reperfusion injury (IRI) is one of the main causes of acute kidney injury (AKI). In recent years, there have been many studies on renal IRI, although an effective treatment method has not been developed. In recent years, growing evidence has shown that small noncoding RNAs play an important regulatory role in renal IRI. This article aims to explore whether microRNA-25 (miR-25) plays a role in the molecular mechanism of renal IRI. The results showed that the expression level of miR-25 was significantly downregulated in a rat renal IRI model, and this result was confirmed with in vitro experiments. After hypoxia-reoxygenation treatment, the apoptosis level of NRK-52E cells transfected with miR-25 mimics decreased significantly, and this antiapoptotic effect was antagonized by miR-25 inhibitors. In addition, we confirmed that DKK3 is a target of miR-25. MiR-25 exerts its protective effect against apoptosis on NRK-52E cells by inhibiting the expression of DKK3, and downregulating the expression level of miR-25 could disrupt this protective effect. In addition, we reconfirmed the role of miR-25 in rats. Therefore, we confirmed that miR-25 may target DKK3 to reduce renal cell damage caused by hypoxia and that miR-25 may be a new potential treatment for renal IRI.

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Expression and modulation of translocator protein and its partners by hypoxia reoxygenation or ischemia and reperfusion in porcine renal models

AJP Renal Physiology ◽

10.1152/ajprenal.90422.2008 ◽

2009 ◽

Vol 297 (1) ◽

pp. F177-F190 ◽

Cited By ~ 15

Author(s):

Frederic Favreau ◽

Ludivine Rossard ◽

Keqiang Zhang ◽

Thibault Desurmont ◽

Emilie Manguy ◽

...

Keyword(s):

Proximal Tubule ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Regulatory Protein ◽

Translocator Protein ◽

Mitochondrial Functions ◽

The Impact ◽

Tspo Expression

Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor, is an 18-kDa drug- and cholesterol-binding protein localized to the outer mitochondrial membrane and implicated in a variety of cell and mitochondrial functions. To determine the role of TSPO in ischemia-reperfusion injury (IRI), we used both in vivo and in vitro porcine models: an in vivo renal ischemia model where different conservation modalities were tested and an in vitro model where TSPO-transfected porcine proximal tubule LLC-PK1cells were exposed to hypoxia and oxidative stress. The expression of TSPO and its partners in steroidogenic cells, steroidogenic acute regulatory protein (StAR) and cytochrome P-450 side chain cleavage CYP11A1, as well as the impact of TSPO overexpression and exposure to TSPO ligands in vitro in hypoxia-ischemia conditions were investigated. Hypoxia induced caspase activation, reduction of ATP content, and LLC-PK1cell death. Transfection and overexpression of TSPO rescued the cells from the detrimental effects of hypoxia and reoxygenation. Moreover, TSPO overexpression was accompanied by a reduction of H2O2-induced necrosis. TSPO drug ligands did not affect TSPO-mediated functions. In vivo, TSPO expression was modulated by IRI and during regeneration particularly in proximal tubule cells, which do not express this protein at the basal level. Under the same conditions, StAR and CYP11A1 protein and gene expression was reduced without apparent relation to TSPO changes. Pregnenolone was identified and measured in the pig kidney. Pregnenolone synthesis was not affected by the experimental conditions used. Taken together, these results indicate that changes in TSPO expression in kidney regenerating tissue could be important for renal protection and maintenance of kidney function.

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Role of EphrinA3 in HIV-1 Neuropathogenesis

ASN NEURO ◽

10.1177/17590914211044359 ◽

2021 ◽

Vol 13 ◽

pp. 175909142110443

Author(s):

Chitra Mohinder Singh Singal ◽

Paritosh Jaiswal ◽

Anuradha Mehta ◽

Kanza Saleem ◽

Pankaj Seth

Keyword(s):

Excitatory Amino Acid ◽

Neuronal Damage ◽

Glutamate Uptake ◽

Synaptic Activity ◽

Glutamate Excitotoxicity ◽

Amino Acid Transporters ◽

Extracellular Glutamate ◽

Hiv 1

Glial cells perform important supporting functions for neurons through a dynamic crosstalk. Neuron–glia communication is the major phenomenon to sustain homeostatic functioning of the brain. Several interactive pathways between neurons and astrocytes are critical for the optimal functioning of neurons, and one such pathway is the ephrinA3–ephA4 signaling. The role of this pathway is essential in maintaining the levels of extracellular glutamate by regulating the excitatory amino acid transporters, EAAT1 and EAAT2 on astrocytes. Human immunodeficiency virus-1 (HIV-1) and its proteins cause glutamate excitotoxicity due to excess glutamate levels at sites of high synaptic activity. This study unravels the effects of HIV-1 transactivator of transcription (Tat) from clade B on ephrinA3 and its role in regulating glutamate levels in astrocyte–neuron co-cultures of human origin. It was observed that the expression of ephrinA3 increases in the presence of HIV-1 Tat B, while the expression of EAAT1 and EAAT2 was attenuated. This led to reduced glutamate uptake and therefore high neuronal death due to glutamate excitotoxicity. Knockdown of ephrinA3 using small interfering RNA, in the presence of HIV-1 Tat B reversed the neurotoxic effects of HIV-1 Tat B via increased expression of glutamate transporters that reduced the levels of extracellular glutamate. The in vitro findings were validated in autopsy brain sections from acquired immunodeficiency syndrome patients and we found ephrinA3 to be upregulated in the case of HIV-1-infected patients. This study offers valuable insights into astrocyte-mediated neuronal damage in HIV-1 neuropathogenesis.

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Impact of Glucocorticoid on a Cellular Model of Parkinson’s Disease: Oxidative Stress and Mitochondrial Function

Brain Sciences ◽

10.3390/brainsci11081106 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1106

Author(s):

Silvia Claros ◽

Antonio Gil ◽

Mauro Martinelli ◽

Nadia Valverde ◽

Estrella Lara ◽

...

Keyword(s):

Oxidative Stress ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mitochondrial Function ◽

Cell Model ◽

Cell Damage ◽

Neuronal Cell ◽

Cellular Markers ◽

The Impact

Stress seems to contribute to the neuropathology of Parkinson’s disease (PD), possibly by dysregulation of the hypothalamic–pituitary–adrenal axis. Oxidative distress and mitochondrial dysfunction are key factors involved in the pathophysiology of PD and neuronal glucocorticoid-induced toxicity. Animal PD models have been generated to study the effects of hormonal stress, but no in vitro model has yet been developed. Our aim was to examine the impact of corticosterone (CORT) administration on a dopaminergic neuronal cell model of PD induced by the neurotoxin MPP+, as a new combined PD model based on the marker of endocrine response to stress, CORT, and oxidative-mitochondrial damage. We determined the impact of CORT, MPP+ and their co-incubation on reactive oxygen species production (O2−•), oxidative stress cellular markers (advanced-oxidation protein products and total antioxidant status), mitochondrial function (mitochondrial membrane potential and mitochondrial oxygen consumption rate) and neurodegeneration (Fluoro-Jade staining). Accordingly, the administration of MPP+ or CORT individually led to cell damage compared to controls (p < 0.05), as determined by several methods, whereas their co-incubation produced strong cell damage (p < 0.05). The combined model described here could be appropriate for investigating neuropathological hallmarks and for evaluating potential new therapeutic tools for PD patients suffering mild to moderate emotional stress.

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