scholarly journals Platelet mitochondrial membrane potential in Parkinson's disease

2014 ◽  
Vol 2 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Paul M. A. Antony ◽  
Olga Boyd ◽  
Christophe Trefois ◽  
Wim Ammerlaan ◽  
Marek Ostaszewski ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane

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

2020 ◽  
Author(s):  
Kai Yu Ma ◽  
Michiel R Fokkens ◽  
Fulvio Reggiori ◽  
Muriel Mari ◽  
Dineke S Verbeek
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Steady State ◽  
Membrane Potential ◽  
Cell Surface ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Pathogenic Mechanism ◽  
Mitochondrial Potential

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.

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

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.

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

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.

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

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.

Platelets apoptosis in rats after global brain ischemia

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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