scholarly journals Mutant A53T α-Synuclein Induces Neuronal Death by Increasing Mitochondrial Autophagy

2011 ◽  
Vol 286 (12) ◽  
pp. 10814-10824 ◽  
Author(s):  
Vinay Choubey ◽  
Dzhamilja Safiulina ◽  
Annika Vaarmann ◽  
Michal Cagalinec ◽  
Przemyslaw Wareski ◽  
...  
Keyword(s):  
Parkinson Disease ◽  
Mitochondrial Dysfunction ◽  
Cortical Neurons ◽  
Neuronal Degeneration ◽  
Neuronal Cell Death ◽  
Lewy Bodies ◽  
Neuronal Cell ◽  
Dominant Negative ◽  
Contributing Factors ◽  
Mitofusin 2

Parkinson disease is characterized by the accumulation of aggregated α-synuclein as the major component of the Lewy bodies. α-Synuclein accumulation in turn leads to compensatory effects that may include the up-regulation of autophagy. Another common feature of Parkinson disease (PD) is mitochondrial dysfunction. Here, we provide evidence that the overactivation of autophagy may be a link that connects the intracellular accumulation of α-synuclein with mitochondrial dysfunction. We found that the activation of macroautophagy in primary cortical neurons that overexpress mutant A53T α-synuclein leads to massive mitochondrial destruction and loss, which is associated with a bioenergetic deficit and neuronal degeneration. No mitochondrial removal or net loss was observed when we suppressed the targeting of mitochondria to autophagosomes by silencing Parkin, overexpressing wild-type Mitofusin 2 and dominant negative Dynamin-related protein 1 or blocking autophagy by silencing autophagy-related genes. The inhibition of targeting mitochondria to autophagosomes or autophagy was also partially protective against mutant A53T α-synuclein-induced neuronal cell death. These data suggest that overactivated mitochondrial removal could be one of the contributing factors that leads to the mitochondrial loss observed in PD models.

Oxidative Stress: Major Threat in Traumatic Brain Injury

2018 ◽  
Vol 17 (9) ◽  
pp. 689-695 ◽  
Author(s):  
Nidhi Khatri ◽  
Manisha Thakur ◽  
Vikas Pareek ◽  
Sandeep Kumar ◽  
Sunil Sharma ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mitochondrial Dysfunction ◽  
Calcium Influx ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Physical Assault ◽  
Mortality And Morbidity ◽  
Primary Injury

Background & Objective: Traumatic Brain Injury (TBI) is one of the major causes of mortality and morbidity worldwide. It represents mild, moderate and severe effects of physical assault to brain which may cause sequential, primary or secondary ramifications. Primary injury can be due to the first physical hit, blow or jolt to one of the brain compartments. The primary injury is then followed by secondary injury which leads to biochemical, cellular, and physiological changes like blood brain barrier disruption, inflammation, excitotoxicity, necrosis, apoptosis, mitochondrial dysfunction and generation of oxidative stress. Apart from this, there is also an immediate increase in glutamate at the synapses following severe TBI. Excessive glutamate at synapses in turn activates corresponding NMDA and AMPA receptors that facilitate excessive calcium influx into the neuronal cells. This leads to the generation of oxidative stress which further leads to mitochondrial dysfunction, lipid peroxidation and oxidation of proteins and DNA. As a consequence, neuronal cell death takes place and ultimately people start facing some serious disabilies. Conclusion: In the present review we provide extensive overview of the role of reactive oxygen species (ROS)-induced oxidative stress and its fatal effects on brain after TBI.

Abstract 3115: Low-Level Laser Therapy Protects Against OGD-induced Neurotoxicity Of Primary Cultured Mouse Cortical Neurons

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Zhanyang Yu ◽  
Ning Liu ◽  
Eng H Lo ◽  
Thomas J McCarthy ◽  
Xiaoying Wang
Keyword(s):  
Laser Therapy ◽  
Mitochondrial Function ◽  
Cortical Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Low Level Laser Therapy ◽  
Primary Neurons ◽  
Novel Therapy ◽  
Low Level ◽  
Mtt Reduction

Background: Low level light (or laser) therapy (LLLT) has been studied and practiced for promoting wound healing, reducing pain, inflammation, and ischemic tissue damage. Recently, a series of experimental and clinical investigations have suggested that LLLT may be a novel therapy against hypoxic/ischemic brain damage. A clinical trial of LLLT therapy for ischemic stroke is now on going. However, the molecular mechanism of LLLT-conferred neuroprotection remains poorly defined. In this study, we tested our hypothesis that LLLT may attenuate impairments of mitochondrial function induced by hypoxic/ischemic insults in primary cultured mouse cortical neurons. Method: At day 9 of culture, primary neurons were subjected to 4 hr OGD followed by reoxygenation. One 810-nm LLLT treatment was applied for 2 minutes at 2 hr after reoxygenation. Neurotoxicity was measured after 20 hr after reoxygenation by LDH release assay. We also measured MTT reduction and mitochondria membrane potential (MMP) at 2 hr after LLLT treatment as markers of mitochondrial function. Results: The neurotoxicity study showed that 4 hr OGD plus 20 hr reoxygenation caused 33.8± 3.4% neuronal cell death, while LLLT treatment significantly reduced the neuronal death rate to 23.6± 2.9% (30.2% reduction, n=6, p smaller than 0.05). Mitochondrial functional assays showed OGD decreased MTT reduction to 75.9± 2.68%, but LLLT treatment significantly rescued MTT reduction to 87.6±4.55% (15.4% improvement, n=6, p smaller than 0.05). Furthermore, after OGD, MMP was reduced to 48.9±4.39%, while LLLT treatment significantly ameliorated this reduction to 89.6± 13.9% (83% improvement, n=4, p smaller than 0.05) compared to normoxic controls. Conclusion: The present study suggests that LLLT treatment is protective against OGD-induced neurotoxicity of primary neurons and that this protection may be conferred through preservation or rescue of mitochondrial function.

scholarly journals Neuroprotective Effects of Gagam-Sipjeondaebo-Tang, a Novel Herbal Formula, against MPTP-Induced Parkinsonian Mice and MPP+-Induced Cell Death in SH-SY5Y Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jade Heejae Ko ◽  
Ju-Hee Lee ◽  
Bobin Choi ◽  
Ju-Yeon Park ◽  
Young-Won Kwon ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Apoptotic Cell ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Motor Dysfunction ◽  
Herbal Formula ◽  
Neuroprotective Effects

Parkinson’s disease is a neurodegenerative disease characterized by progressive cell death of dopaminergic neuron and following neurological disorders. Gagam-Sipjeondaebo-Tang (GST) is a novel herbal formula made of twelve medicinal herbs derived from Sipjeondaebo-Tang, which has been broadly used in a traditional herbal medicine. In the present study, we investigated the effects of GST against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor abnormalities in mice and 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity in SH-SY5Y cell. First, we found that GST alleviated motor dysfunction induced by MPTP, and the result showed dopaminergic neurons recovery in substantia nigra. In the cell experiment, pretreatment with GST increased the cell viability and attenuated apoptotic cell death in MPP+-treated SH-SY5Y cells. GST also inhibited reactive oxygen species production and restored the mitochondrial membrane potential loss, which were induced by MPP+. Furthermore, GST extract significantly activated ERK and Akt, cell survival-related proteins, in SH-SY5Y cells. The effect of GST preventing mitochondrial dysfunction was antagonized by pretreatment of PD98059 and LY294002, selective inhibitors of ERK and Akt, respectively. Taken together, GST alleviated abnormal motor functions and recovered neuronal cell death, mitochondrial dysfunction, possibly via ERK and Akt activation. Therefore, we suggest that GST may be a candidate for the treatment and prevention of Parkinson’s disease.

scholarly journals Overexpression of Mitochondrial Calcium Uniporter Causes Neuronal Death

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Veronica Granatiero ◽  
Marco Pacifici ◽  
Anna Raffaello ◽  
Diego De Stefani ◽  
Rosario Rizzuto
Keyword(s):  
Cell Fate ◽  
Neuronal Death ◽  
Cortical Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Neuronal Loss ◽  
Calcium Uniporter ◽  
Organelle Morphology

Neurodegenerative diseases are a large and heterogeneous group of disorders characterized by selective and progressive death of specific neuronal subtypes. In most of the cases, the pathophysiology is still poorly understood, although a number of hypotheses have been proposed. Among these, dysregulation of Ca2+ homeostasis and mitochondrial dysfunction represent two broadly recognized early events associated with neurodegeneration. However, a direct link between these two hypotheses can be drawn. Mitochondria actively participate to global Ca2+ signaling, and increases of [Ca2+] inside organelle matrix are known to sustain energy production to modulate apoptosis and remodel cytosolic Ca2+ waves. Most importantly, while mitochondrial Ca2+ overload has been proposed as the no-return signal, triggering apoptotic or necrotic neuronal death, until now direct evidences supporting this hypothesis, especially in vivo, are limited. Here, we took advantage of the identification of the mitochondrial Ca2+ uniporter (MCU) and tested whether mitochondrial Ca2+ signaling controls neuronal cell fate. We overexpressed MCU both in vitro, in mouse primary cortical neurons, and in vivo, through stereotaxic injection of MCU-coding adenoviral particles in the brain cortex. We first measured mitochondrial Ca2+ uptake using quantitative genetically encoded Ca2+ probes, and we observed that the overexpression of MCU causes a dramatic increase of mitochondrial Ca2+ uptake both at resting and after membrane depolarization. MCU-mediated mitochondrial Ca2+ overload causes alteration of organelle morphology and dysregulation of global Ca2+ homeostasis. Most importantly, MCU overexpression in vivo is sufficient to trigger gliosis and neuronal loss. Overall, we demonstrated that mitochondrial Ca2+ overload is per se sufficient to cause neuronal cell death both in vitro and in vivo, thus highlighting a potential key step in neurodegeneration.

scholarly journals Mohr-Tranebjaerg Syndrome is an X-linked Recessive Disorder Characterized by Mitochondrial Dysfunction Associated with Neuronal Cell Death

2000 ◽  
Vol 2 (1) ◽  
pp. 107-107
Author(s):  
L Tranebjaerg ◽  
S Lindal ◽  
S Merchant ◽  
O Ingebretsen ◽  
B Hamel ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Neuronal Cell Death ◽  
Neuronal Cell

Oleuropein isolated from Fraxinus rhynchophylla inhibits glutamate-induced neuronal cell death by attenuating mitochondrial dysfunction

2017 ◽  
Vol 21 (7) ◽  
pp. 520-528 ◽  
Author(s):  
Mi Hye Kim ◽  
Ju-Sik Min ◽  
Joon Yeop Lee ◽  
Unbin Chae ◽  
Eun-Ju Yang ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Dysfunction ◽  
Neuronal Cell Death ◽  
Neuronal Cell

scholarly journals Heme–Hemopexin Complex Attenuates Neuronal Cell Death and Stroke Damage

2009 ◽  
Vol 29 (5) ◽  
pp. 953-964 ◽  
Author(s):  
Rung-chi Li ◽  
Sofiyan Saleem ◽  
Gehua Zhen ◽  
Wangsen Cao ◽  
Hean Zhuang ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Artery Occlusion ◽  
Neuronal Cultures ◽  
Tert Butyl Hydroperoxide ◽  
Primary Mouse ◽  
Free Heme ◽  
Cerebral Artery Occlusion ◽  
The Brain

Hemoproteins undergo degradation during hypoxic/ischemic conditions, but the prooxidant free heme that is released cannot be recycled and must be degraded. The extracellular heme associates with its high-affinity binding protein, hemopexin (HPX). Hemopexin is shown here to be expressed by cortical neurons and it is present in mouse cerebellum, cortex, hippocampus, and striatum. Using the transient ischemia model (90-min middle cerebral artery occlusion followed by 96-h survival), we provide evidence that HPX is protective in the brain, as neurologic deficits and infarct volumes were significantly greater in HPX−/− than in wild-type mice. Addressing the potential protective HPX cellular pathway, we observed that exogenous free heme decreased cell survival in primary mouse cortical neuron cultures, whereas the heme bound to HPX was not toxic. Heme-HPX complexes induce HO1 and, consequently, protect primary neurons against the toxicity of both heme and prooxidant tert-butyl hydroperoxide; such protection was decreased in HO1−/− neuronal cultures. Taken together, these data show that HPX protects against heme-induced toxicity and oxidative stress and that HO1 is required. We propose that the heme-HPX system protects against stroke-related damage by maintaining a tight balance between free and bound heme. Thus, regulating extracellular free heme levels, such as with HPX, could be neuroprotective.

scholarly journals Oxidative Damage to the Endoplasmic Reticulum is Implicated in Ischemic Neuronal Cell Death

2003 ◽  
Vol 23 (10) ◽  
pp. 1117-1128 ◽  
Author(s):  
Takeshi Hayashi ◽  
Atsushi Saito ◽  
Shuzo Okuno ◽  
Michel Ferrand-Drake ◽  
Robert L Dodd ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Protein Modification ◽  
Neuronal Degeneration ◽  
Neuronal Damage ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Transgenic Animals ◽  
Initiation Factor

The endoplasmic reticulum (ER), which plays important roles in apoptosis, is susceptible to oxidative stress. Because reactive oxygen species (ROS) are robustly produced in the ischemic brain, ER damage by ROS may be implicated in ischemic neuronal cell death. We induced global brain ischemia on wild-type and copper/zinc superoxide dismutase (SOD1) transgenic rats and compared ER stress and neuronal damage. Phosphorylated forms of eukaryotic initiation factor 2α (eIF2α) and RNA-dependent protein kinase-like ER eIF2α kinase (PERK), both of which play active roles in apoptosis, were increased in hippocampal CA1 neurons after ischemia but to a lesser degree in the transgenic animals. This finding, together with the finding that the transgenic animals showed decreased neuronal degeneration, indicates that oxidative ER damage is involved in ischemic neuronal cell death. To elucidate the mechanisms of ER damage by ROS, we analyzed glucose-regulated protein 78 (GRP78) binding with PERK and oxidative ER protein modification. The proteins were oxidatively modified and stagnated in the ER lumen, and GRP78 was detached from PERK by ischemia, all of which were attenuated by SOD1 overexpression. We propose that ROS attack and modify ER proteins and elicit ER stress response, which results in neuronal cell death.

scholarly journals Mechanisms of Neuronal Protection against Excitotoxicity, Endoplasmic Reticulum Stress, and Mitochondrial Dysfunction in Stroke and Neurodegenerative Diseases

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Howard Prentice ◽  
Jigar Pravinchandra Modi ◽  
Jang-Yen Wu
Keyword(s):  
Nitric Oxide ◽  
Endoplasmic Reticulum ◽  
Nmda Receptor ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Permeability Transition ◽  
Neuronal Damage ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Calcium Overload

In stroke and neurodegenerative disease, neuronal excitotoxicity, caused by increased extracellular glutamate levels, is known to result in calcium overload and mitochondrial dysfunction. Mitochondrial deficits may involve a deficiency in energy supply as well as generation of high levels of oxidants which are key contributors to neuronal cell death through necrotic and apoptotic mechanisms. Excessive glutamate receptor stimulation also results in increased nitric oxide generation which can be detrimental to cells as nitric oxide interacts with superoxide to form the toxic molecule peroxynitrite. High level oxidant production elicits neuronal apoptosis through the actions of proapoptotic Bcl-2 family members resulting in mitochondrial permeability transition pore opening. In addition to apoptotic responses to severe stress, accumulation of misfolded proteins and high levels of oxidants can elicit endoplasmic reticulum (ER) stress pathways which may also contribute to induction of apoptosis. Two categories of therapeutics are discussed that impact major pro-death events that include induction of oxidants, calcium overload, and ER stress. The first category of therapeutic agent includes the amino acid taurine which prevents calcium overload and is also capable of preventing ER stress by inhibiting specific ER stress pathways. The second category involves N-methyl-D-aspartate receptor (NMDA receptor) partial antagonists illustrated by S-Methyl-N, N-diethyldithiocarbamate sulfoxide (DETC-MeSO), and memantine. DETC-MeSO is protective through preventing excitotoxicity and calcium overload and by blocking specific ER stress pathways. Another NMDA receptor partial antagonist is memantine which prevents excessive glutamate excitation but also remarkably allows maintenance of physiological neurotransmission. Targeting of these major sites of neuronal damage using pharmacological agents is discussed in terms of potential therapeutic approaches for neurological disorders.

scholarly journals Kaempferol Has Potent Protective and Antifibrillogenic Effects for α-Synuclein Neurotoxicity In Vitro

2021 ◽  
Vol 22 (21) ◽  
pp. 11484
Author(s):  
Masatoshi Inden ◽  
Ayaka Takagi ◽  
Hazuki Kitai ◽  
Taisei Ito ◽  
Hisaka Kurita ◽  
...  
Keyword(s):  
Amyloid Fibril ◽  
Therapeutic Potential ◽  
Neuroprotective Effect ◽  
Neuronal Cell Death ◽  
Lewy Bodies ◽  
Neuronal Cell ◽  
Therapeutic Agents ◽  
Amyloid Fibril Formation ◽  
Transcription Factor Eb

Aggregation of α-synuclein (α-Syn) is implicated in the pathogenesis of Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Therefore, the removal of α-Syn aggregation could lead to the development of many new therapeutic agents for neurodegenerative diseases. In the present study, we succeeded in generating a new α-Syn stably expressing cell line using a piggyBac transposon system to investigate the neuroprotective effect of the flavonoid kaempferol on α-Syn toxicity. We found that kaempferol provided significant protection against α-Syn-related neurotoxicity. Furthermore, kaempferol induced autophagy through an increase in the biogenesis of lysosomes by inducing the expression of transcription factor EB and reducing the accumulation of α-Syn; thus, kaempferol prevented neuronal cell death. Moreover, kaempferol directly blocked the amyloid fibril formation of α-Syn. These results support the therapeutic potential of kaempferol in diseases such as synucleinopathies that are characterized by α-Syn aggregates.

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