Products of the Parkinson's disease-related glyoxalase DJ-1, D-lactate and glycolate, support mitochondrial membrane potential and neuronal survival

Abstract Background:Mitochondrial dysfunction plays a prominent role in the pathogenesis of Parkinson’s disease (PD), and several genes linked to familial PD, including PINK1 and PARK2, are directly involved in processes such as mitophagy that maintain mitochondrial health. The dominant p.D620N variant in VPS35 has also been associated to familial PD but has not been functionally connected to PINK1 and PARK2. Methods: To better mimic and study the patient situation, we used CRISPR-Cas9 to generate heterozygous human SH-SY5Y cells carrying the PD-associated D620N variant in VPS35. These cells were treated with the protonophore CCCP to induce PINK1/Parkin-mediated mitophagy, which was assessed using biochemical and microscopy approaches. Results:Mitochondria in VPS35-D620N cells exhibited reduced mitochondrial membrane potential and appeared to already be damaged at steady state. As a result, the mitochondria of these cells were desensitized to CCCP-induced collapse in mitochondrial potential, as they displayed altered fragmentation and were unable to accumulate PINK1 at their surface upon this insult. Consequently, Parkin recruitment to the cell surface was inhibited and initiation of PINK1/Parkin-dependent mitophagy is impaired. Conclusion:Our findings extend the pool of evidence that the p.D620N mutant VPS35 causes mitochondrial dysfunction and suggest a converging pathogenic mechanism between VPS35, PINK1 and Parkin in PD.

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Parkinson’s disease–associated VPS35 mutant reduces mitochondrial membrane potential and impairs PINK1/Parkin-mediated mitophagy

Translational Neurodegeneration ◽

10.1186/s40035-021-00243-4 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Kai Yu Ma ◽

Michiel R. Fokkens ◽

Fulvio Reggiori ◽

Muriel Mari ◽

Dineke S. Verbeek

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Membrane Potential ◽

Mitochondrial Dysfunction ◽

Mitochondrial Membrane Potential ◽

Ubiquitin Ligase ◽

Mitochondrial Membrane ◽

Mitochondrial Potential ◽

Carbonyl Cyanide ◽

Vacuolar Protein

Abstract Background Mitochondrial dysfunction plays a prominent role in the pathogenesis of Parkinson’s disease (PD), and several genes linked to familial PD, including PINK1 (encoding PTEN-induced putative kinase 1 [PINK1]) and PARK2 (encoding the E3 ubiquitin ligase Parkin), are directly involved in processes such as mitophagy that maintain mitochondrial health. The dominant p.D620N variant of vacuolar protein sorting 35 ortholog (VPS35) gene is also associated with familial PD but has not been functionally connected to PINK1 and PARK2. Methods To better mimic and study the patient situation, we used CRISPR-Cas9 to generate heterozygous human SH-SY5Y cells carrying the PD-associated D620N variant of VPS35. These cells were treated with a protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) to induce the PINK1/Parkin-mediated mitophagy, which was assessed using biochemical and microscopy approaches. Results Mitochondria in the VPS35-D620N cells exhibited reduced mitochondrial membrane potential and appeared to already be damaged at steady state. As a result, the mitochondria of these cells were desensitized to the CCCP-induced collapse in mitochondrial potential, as they displayed altered fragmentation and were unable to accumulate PINK1 at their surface upon this insult. Consequently, Parkin recruitment to the cell surface was inhibited and initiation of the PINK1/Parkin-dependent mitophagy was impaired. Conclusion Our findings extend the pool of evidence that the p.D620N mutation of VPS35 causes mitochondrial dysfunction and suggest a converging pathogenic mechanism among VPS35, PINK1 and Parkin in PD.

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Products of the Parkinson's-disease related glyoxalase DJ-1, D-lactate and glycolate, support mitochondrial membrane potential and neuronal survival

10.1101/006916 ◽

2014 ◽

Author(s):

Yusuke Toyoda ◽

Cihan Erkut ◽

Francisco Pan-Montojo ◽

Sebastian Boland ◽

Martin P. Stewart ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Dopaminergic Neurons ◽

Mitochondrial Membrane ◽

Mitochondrial Activity ◽

Mitochondrial Potential ◽

Environmental Toxin ◽

Lactic Acids

Parkinson's disease is associated with mitochondrial decline in dopaminergic neurons of the substantia nigra. One of the genes, DJ- 1/PARK7, linked with the onset of Parkinson’s disease, belongs to a novel glyoxalase family and influences mitochondrial activity. It has been assumed that glyoxalases fulfill this task by detoxifying aggressive aldehyde by-products of metabolism. Here we show that supplying either D-lactate or glycolate, products of DJ-1, rescues the requirement for the enzyme in maintenance of mitochondrial potential. We further show that glycolic acid and D-lactic acid can elevate lowered mitochondrial membrane potential caused by silencing PINK-1, another Parkinson's related gene, as well as by paraquat, an environmental toxin known to be linked with Parkinson's disease. We propose that DJ-1 and consequently its products are components of a novel pathway that stabilizes mitochondria during cellular stress. We go on to show that survival of cultured mesencephalic dopaminergic neurons, defective in Parkinson's disease, is enhanced by glycolate and D-lactate. Because glycolic and D-lactic acids occur naturally, they are therefore a potential therapeutic route for treatment or prevention of Parkinson's disease.

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The NAD+ Precursor Nicotinamide Governs Neuronal Survival During Oxidative Stress Through Protein Kinase B Coupled to FOXO3a and Mitochondrial Membrane Potential

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/01.wcb.0000122746.72175.0e ◽

2004 ◽

Vol 24 (7) ◽

pp. 728-743 ◽

Cited By ~ 73

Author(s):

Zhao Zhong Chong ◽

Shi-Hua Lin ◽

Kenneth Maiese

Keyword(s):

Oxidative Stress ◽

Membrane Potential ◽

Protein Kinase ◽

Mitochondrial Membrane Potential ◽

Hippocampal Neurons ◽

Mitochondrial Membrane ◽

Caspase 3 ◽

Protein Kinase B ◽

Neuronal Survival ◽

Dominant Negative

Nicotinamide, a ß-nicotinamide adenine dinucleotide (NAD+) precursor and an essential nutrient for cell growth and function, may offer critical insights into the specific cellular mechanisms that determine neuronal survival, since this agent significantly impacts upon both neuronal and vascular integrity in the central nervous system. The authors show that nicotinamide provides broad, but concentration-specific, protection against apoptotic genomic DNA fragmentation and membrane phosphatidylserine exposure during oxidative stress to secure cellular integrity and prevent phagocytic cellular demise. Activation of the protein kinase B (Akt1) pathway is a necessary requirement for nicotinamide protection, because transfection of primary hippocampal neurons with a plasmid encoding a kinase-deficient dominant-negative Akt1 as well as pharmacologic inhibition of phosphatidylinositol-3-kinase phosphorylation of Akt1 eliminates cytoprotection by nicotinamide. Nicotinamide fosters neuronal survival through a series of intimately associated pathways. At one level, nicotinamide directly modulates mitochondrial membrane potential and pore formation to prevent cytochrome c release and caspase-3–and 9–like activities through mechanisms that are independent of the apoptotic protease activating factor-1. At a second level, nicotinamide maintains an inhibitory phosphorylation of the forkhead transcription factor FOXO3a at the regulatory sites of Thr32 and Ser253 and governs a unique regulatory loop that prevents the degradation of phosphorylated FOXO3a by caspase-3. Their work elucidates some of the unique neuroprotective pathways used by the essential cellular nutrient nicotinamide that may direct future therapeutic approaches for neurodegenerative disorders.

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Baicalein Mediates Mitochondrial Autophagy via miR-30b and the NIX/BNIP3 Signaling Pathway in Parkinson’s Disease

Biochemistry Research International ◽

10.1155/2021/2319412 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Min Chen ◽

Li Peng ◽

Ping Gong ◽

Xiaoli Zheng ◽

Tao Sun ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Membrane Potential ◽

Mitochondrial Membrane ◽

Neurodegenerative Disorder ◽

Neuronal Damage ◽

Protein Levels ◽

Neurological Score ◽

6 Hydroxydopamine ◽

Related Proteins

Parkinson’s disease (PD) is regarded as a severe neurodegenerative disorder. Baicalein is involved in the treatment of PD. This study explored the mechanism of baicalein in PD. The PD rat model was established using 6-hydroxydopamine. The neurologic score, dopamine (DA) content, apoptotic cells, and neuronal damage were evaluated after rats were treated with baicalein. Autophagy in PD rats was inhibited using 3-methyladenine (3-MA). The mitochondrial membrane potential (MMP) and autophagy-related proteins (LC3, P62) were detected. Next, agomiR-30b was transfected into PD rats. The targeting relation between miR-30b and NIX was predicted and verified. Then, sh-NIX was transfected into PD rats, and the effects of miR-30b and NIX on MMP, LC3, and P62 were assessed. When miR-30b was overexpressed using agomiR-30b, the NIX and BNIP3 levels were detected. Baicalein increased the neurological score and restored DA content, neurons, MMP, and mitochondrial autophagy protein levels. Baicalein inhibited miR-30b expression and miR-30b targeted NIX. miR-30b upregulation or NIX silencing reversed the effect of baicalein on MMP and mitochondrial autophagy. Baicalein upregulated NIX and BNIP3 expressions, while miR-30b overexpression inhibited NIX and BNIP3 expressions. In summary, baicalein mediated mitochondrial autophagy and restored neuronal activity by downregulating miR-30b and activating the NIX/BNIP3 pathway, thus protecting against PD.

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Astrocytes improve neuronal health after cisplatin treatment through mitochondrial transfer

10.1101/2019.12.17.879924 ◽

2019 ◽

Author(s):

Krystal English ◽

Andrew Shepherd ◽

Ndidi-Ese Nzor ◽

Ronnie Trinh ◽

Annemieke Kavelaars ◽

...

Keyword(s):

Membrane Potential ◽

Mitochondrial Dysfunction ◽

Mitochondrial Membrane Potential ◽

Cortical Neurons ◽

Mitochondrial Membrane ◽

Neuronal Survival ◽

Calcium Dynamics ◽

Primary Cortical Neurons ◽

Mitochondrial Transfer

AbstractNeurodegenerative disorders, including chemotherapy-induced cognitive impairment, are associated with neuronal mitochondrial dysfunction. Cisplatin, a commonly used chemotherapeutic, induces neuronal mitochondrial dysfunction in vivo and in vitro. Astrocytes are key players in supporting neuronal development, synaptogenesis, axonal growth, metabolism and, potentially, mitochondrial health. We tested the hypothesis that astrocytes transfer healthy mitochondria to neurons after cisplatin treatment to restore neuronal health. We used an in vitro system in which astrocytes containing mito-mCherry-labeled mitochondria were co-cultured with primary cortical neurons damaged by cisplatin. Culture of primary cortical neurons with cisplatin reduced neuronal survival and depolarized neuronal mitochondrial membrane potential. Cisplatin induced abnormalities in neuronal calcium dynamics characterized by increased resting calcium levels, reduced calcium responses to stimulation with KCl, and slower calcium clearance. The same dose of cisplatin that caused neuronal damage did not affect astrocyte survival or astrocytic mitochondrial respiration. Co-culture of cisplatin-treated neurons with astrocytes increased neuronal survival, restored neuronal mitochondrial membrane potential, and normalized neuronal calcium dynamics especially in those neurons that had received mitochondria from astrocytes. These beneficial effects of astrocytes were associated with transfer of mitochondria from astrocytes to cisplatin-treated neurons. The Rho-GTPase Miro-1 is known to contribute to mitochondrial motility and transfer. We show that siRNA-mediated knockdown of Miro-1 in astrocytes reduced mitochondrial transfer from astrocytes to neurons and prevented the normalization of neuronal calcium dynamics.In conclusion, we identified transfer of mitochondria from astrocytes to neurons damaged by cisplatin as an important repair mechanism to protect cortical neurons against the toxic effects of this chemotherapeutic.Significance statementChemotherapy-induced neurotoxicity is a serious health problem and little is known about the underlying mechanisms. Especially neurons are very sensitive to cisplatin treatment. We show that astrocytes can protect neurons damaged by cisplatin by improving neuronal survival, mitochondrial health, and calcium dynamics in vitro. This beneficial effect of astrocytes is dependent on the transfer of mitochondria from astrocytes to the damaged neurons. Our findings provide evidence for an important endogenous protective neuro-glial mechanism that could contribute to prevention of neuronal death as a result of cisplatin treatment and thereby aid in sustaining brain health of patients during chemotherapy.

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Ca2+ Accumulation in Isolated Rat Heart Mitochondria under Maintenance of Mitochondrial Membrane Potential

International Journal of Physiology and Pathophysiology ◽

10.1615/intjphyspathophys.v7.i4.30 ◽

2016 ◽

Vol 7 (4) ◽

pp. 309-319

Author(s):

Alina Yu. Budko ◽

Nataliya A. Strutynska ◽

Iryna Yu. Okhay ◽

Olena M. Semenykhina ◽

Vadim F. Sagach

Keyword(s):

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Rat Heart ◽

Mitochondrial Membrane ◽

Isolated Rat Heart ◽

Heart Mitochondria ◽

Rat Heart Mitochondria ◽

Isolated Rat

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Platelets apoptosis in rats after global brain ischemia

ZHurnal «Patologicheskaia fiziologiia i eksperimental`naia terapiia» ◽

10.25557/0031-2991.2018.01.27-35 ◽

2018 ◽

pp. 27-35

Author(s):

А.А. Соколовская ◽

Э.Д. Вирюс ◽

В.В. Александрин ◽

А.С. Роткина ◽

К.А. Никифорова ◽

...

Keyword(s):

Flow Cytometry ◽

Ischemic Stroke ◽

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Brain Ischemia ◽

Mitochondrial Membrane ◽

Male Rats ◽

Global Brain Ischemia ◽

Platelet Apoptosis ◽

Global Brain

Цель исследования. Ишемические повреждения головного мозга, являются одной из наиболее частой причин инвалидности и смертности во всем мире. Недавно была установлена роль апоптоза тромбоцитов в патофизиологии инсульта, однако его механизмы до сих пор остаются невыясненными. Несмотря на различные экспериментальные модели, направленные на мониторинг апоптоза тромбоцитов, результаты, относительно изучения и выявления апоптоза тромбоцитов при ишемии головного мозга у крыс, весьма немногочисленны. Цель исследования - анализ апоптоза тромбоцитов с помощью метода проточной цитофлуориметрии на модели глобальной ишемии мозга у крыс. Методика. В экспериментах использовано 6 крыс-самцов Вистар в возрасте от 5 до 6 мес., разделенных на 2 группы: интактный контроль (К) и глобальная ишемия головного мозга. Модель глобальной ишемии головного мозга у крыс воспроизводилась путём билатеральной окклюзии общих сонных артерий на фоне гипотензии. Уровень системного артериального давления снижали посредством кровопотери до 40-45 мм рт. ст. Суспензию тромбоцитов крыс получали методом гельфильтрации с использованием сефарозы 2B. Для анализа экстернализации фосфатидилсерина (ФС) тромбоциты крыс инкубировали с Аннексином V-PE в связывающем буфере. Для оценки митохондриального мембранного потенциала (ММП) тромбоциты инкубировали с катионным красителем JC-1. После инкубации образцы немедленно анализировали на проточном цитофлуориметре FACSCalibur (Becton Dickinson, США). Результаты. Согласно полученным данным, экстернализация ФС на тромбоцитах крыс, перенесших инсульт, была значительно выше (53,45 ± 4,21%), чем в контрольной группе крыс (5,27 ± 2,40%). Данный эффект подтверждается выраженной деполяризацией митохондриальных мембран (DYm). После экспериментальной ишемии мозга почти 40% тромбоцитов было деполяризовано. Заключение. Использованный в работе подбор методов и маркеров обеспечивает понимание механизмов апоптоза тромбоцитов как в экспериментальных, так и в клинических условиях. Полученные данные позволяют сделать заключение, что апоптоз тромбоцитов является одним из факторов развития глобальной ишемии головного мозга у крыс. Результаты могут быть использованы для понимания механизмов, участвующих в развитии ишемического повреждения, что, в свою очередь, может быть использовано при разработке новых терапевтических стратегий. Aim. Stroke is one of the most common causes of disability and mortality worldwide. Multiple experimental models of stroke have focused on monitoring of platelet apoptosis. However, studies on and detection of platelet apoptosis in rats with ischemic stroke are very scarce. We investigated platelet apoptosis in rats with global brain ischemia using flow cytometry. Methods. Experiments were carried out on healthy, adult Wistar male rats weighing 300-350 g. The rats were divided into the following 2 groups: intact rats and rats with global brain ischemia. Global brain ischemia was induced by two-vessel (2-VO) carotid occlusion in combination with hypotension. Systemic blood pressure was reduced by 40-45 mm Hg by inducing haemorrhage. Platelets were isolated by gel filtration on Sepharose 2B. For evaluation of phosphatidylserine (PS) externalization, platelets were incubated with Annexin V-PE and analyzed on FACSCalibur (BD Biosciences). Mitochondrial membrane potential (DY) was measured during platelets apoptosis using JC-1, a mitochondrial membrane potential indicator. Platelets were analyzed by flow cytometry immediately after the incubation. Results. PS externalization on platelets was significantly greater after global brain ischemia (53.45 ± 4.21%) than in the control group (5.27 ± 2.40%). Pronounced depolarization of mitochondrial membrane potential (DYm) confirmed this finding. In the rat group with experimental brain ischemia, almost 40% (35.24 ± 5.21%) of platelets were depolarized. Conclusion. Our results provide insight into mechanisms involved in platelet apoptosis during ischemic stroke and can be used in further development of new therapeutic strategies.

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