scholarly journals 6-OHDA-induced dopaminergic neurodegeneration in C. elegans is promoted by the engulfment pathway and inhibited by the transthyretin-related protein TTR-33

2017 ◽  
Author(s):  
Sarah-Lena Offenburger ◽  
Xue Yan Ho ◽  
Theresa Tachie-Menson ◽  
Sean Coakley ◽  
Massimo A. Hilliard ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dopaminergic Neurons ◽  
Oxygen Species ◽  
Related Protein ◽  
Mapk Kinase ◽  
C Elegans ◽  
Dopaminergic Neurodegeneration ◽  
Cell Corpse ◽  
6 Hydroxydopamine ◽  
Corpse Engulfment

AbstractOxidative stress is linked to many pathological conditions including the loss of dopaminergic neurons in Parkinson’s disease. The vast majority of disease cases appear to be caused by a combination of genetic mutations and environmental factors. We screened for genes protecting Caenorhabditis elegans dopaminergic neurons from oxidative stress induced by the neurotoxin 6-hydroxydopamine (6-OHDA) and identified the transthyretin-related gene ttr-33. The only described C. elegans transthyretin-related protein to date, TTR-52, has been shown to mediate corpse engulfment as well as axon repair. We demonstrate that TTR-52 and TTR-33 have distinct roles. TTR-33 is likely produced in the posterior arcade cells in the head of C. elegans larvae and is predicted to be a secreted protein. TTR-33 protects C. elegans from oxidative stress induced by paraquat or H2O2 at an organismal level. The increased oxidative stress sensitivity of ttr-33 mutants is alleviated by mutations affecting the KGB-1 MAPK kinase pathway, whereas it is enhanced by mutation of the JNK-1 MAPK kinase. Finally, we provide genetic evidence that the C. elegans cell corpse engulfment pathway is required for the degeneration of dopaminergic neurons after exposure to 6-OHDA. In summary, we describe a new neuroprotective mechanism and demonstrate that TTR-33 normally functions to protect dopaminergic neurons from oxidative stress-induced degeneration, potentially by acting as a secreted sensor or scavenger of oxidative stress.Author summaryAnimals employ multiple mechanisms to prevent their cells from damage by reactive oxygen species, chemically reactive molecules containing oxygen. Oxidative stress, caused by the overabundance of reactive oxygen species or a decreased cellular defence against these chemicals, is linked to a variety of neurodegenerative conditions, including the loss of dopaminergic neurons in Parkinson’s disease. In this study, we discovered a novel protective molecule that functions to prevent dopaminergic neurodegeneration caused by oxidative stress induced by the neurotoxin 6-hydroxydopamine (6-OHDA). We used the nematode C. elegans, a well-characterised model in which mechanisms can be studied on an organismal level. When C. elegans is exposed to 6-OHDA, its dopaminergic neurons gradually die. Our major findings include (i) mutations of the transthyretin-related gene ttr-33 causes highly increased dopaminergic neurodegeneration after 6-OHDA exposure; (ii) TTR-33 is likely produced and secreted by several cells in the head of the animal; (iii) TTR-33 protects against oxidative stress induced by other compounds; (iv) mutations in the KGB-1 MAP kinase stress pathway alleviate dopaminergic neuron loss in the ttr-33 mutant; and (v) the cell corpse engulfment pathway is required for dopaminergic neurodegeneration. We hypothesise that TTR-33 protects dopaminergic neurons against 6-OHDA-induced oxidative stress by acting as an oxygen sensor or scavenger.

scholarly journals Mutations in C. elegans neuroligin-like glit-1, the apoptosis pathway and the calcium chaperone crt-1 increase dopaminergic neurodegeneration after 6-OHDA treatment

2017 ◽  
Author(s):  
Sarah-Lena Offenburger ◽  
Elisabeth Jongsma ◽  
Anton Gartner
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Dopaminergic Neurons ◽  
Apoptosis Pathway ◽  
C Elegans ◽  
Dopaminergic Neurodegeneration ◽  
Cell Death Pathway ◽  
6 Hydroxydopamine

AbstractThe loss of dopaminergic neurons is a hallmark of Parkinson’s disease, the aetiology of which is associated with increased levels of oxidative stress. We used C. elegans to screen for genes that protect dopaminergic neurons against oxidative stress and isolated glit-1 (gliotactin (Drosophila neuroligin-like) homologue). Loss of the C. elegans neuroligin-like glit-1 causes increased dopaminergic neurodegeneration after treatment with 6-hydroxydopamine (6-OHDA), an oxidative- stress inducing drug that is specifically taken up into dopaminergic neurons. Furthermore, glit-1 mutants exhibit increased sensitivity to oxidative stress induced by H2O2 and paraquat. We provide evidence that GLIT-1 acts in the same genetic pathway as the previously identified tetraspanin TSP-17. After exposure to 6-OHDA and paraquat, glit-1 and tsp-17 mutants show almost identical, non-additive hypersensitivity phenotypes and exhibit highly increased induction of oxidative stress reporters. TSP-17 and GLIT-1 are both expressed in dopaminergic neurons. In addition, the neuroligin-like GLIT-1 is expressed in pharynx, intestine and several unidentified cells in the head. GLIT-1 is homologous, but not orthologous to neuroligins, transmembrane proteins required for the function of synapses. The Drosophila GLIT-1 homologue Gliotactin in contrast is required for epithelial junction formation. We report that GLIT-1 likely acts in multiple tissues to protect against 6-OHDA, and that the epithelial barrier of C. elegans glit-1 mutants does not appear to be compromised. We further describe that hyperactivation of the SKN-1 oxidative stress response pathway alleviates 6-OHDA-induced neurodegeneration. In addition, we find that mutations in the canonical apoptosis pathway and the calcium chaperone crt-1 cause increased 6-OHDA-induced dopaminergic neuron loss. In summary, we report that the neuroligin-like GLIT-1, the canonical apoptosis pathway and the calreticulin CRT-1 are required to prevent 6-OHDA-induced dopaminergic neurodegeneration.Author summaryNeurons use dopamine as a chemical messenger to mediate diverse behaviours. The gradual loss of dopaminergic neurons in specific brain areas is a hallmark of Parkinson’s disease. The increased occurrence of highly reactive oxygen radicals, also called oxidative stress, is assumed to contribute to the demise of dopaminergic neurons. In this study we searched for genes that protect dopaminergic neurons against oxidative stress. We used the nematode C. elegans, a well- characterised model organism whose dopamine signalling system is very similar to that of humans. When C. elegans is exposed to 6-hydroxydopamine, an oxidative stress-inducing compound, dopaminergic neurons gradually die. Our major findings include: (i) absence of the neuroligin-like gene glit-1 causes highly increased cell death of dopaminergic neurons after 6-OHDA exposure; (ii) GLIT-1 acts in a similar manner as the previously identified tetraspanin TSP-17; (iii) GLIT-1 and TSP-17 also protect C. elegans from other types of oxidative stress; and (iv) the programmed cell death pathway and a calcium chaperone protect dopaminergic neurons as well. Collectively, this study shows that apoptosis proteins, the calcium chaperone CRT-1 and the neuroligin-like GLIT-1 protect against neurodegeneration after oxidative stress exposure.

A dibenzoylmethane derivative protects dopaminergic neurons against both oxidative stress and endoplasmic reticulum stress

2007 ◽  
Vol 293 (6) ◽  
pp. C1884-C1894 ◽  
Author(s):  
Katsura Takano ◽  
Yasuko Kitao ◽  
Yoshiyuki Tabata ◽  
Hikari Miura ◽  
Kosuke Sato ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Dopaminergic Neurons ◽  
Brefeldin A ◽  
Substantia Nigra Pars Compacta ◽  
Oxygen Species ◽  
Oxidative Property ◽  
6 Hydroxydopamine

The enhancement of intracellular stresses such as oxidative stress and endoplasmic reticulum (ER) stress has been implicated in several neurodegenerative disorders including Parkinson's disease (PD). During a search for compounds that regulate ER stress, a dibenzoylmethane (DBM) derivative 14-26 (2,2′-dimethoxydibenzoylmethane) was identified as a novel neuroprotective agent. Analysis in SH-SY5Y cells and in PC12 cells revealed that the regulation of ER stress by 14-26 was associated with its anti-oxidative property. 14-26 prevented the production of reactive oxygen species (ROS) when the cells were exposed to oxidants such as hydrogen peroxide and 6-hydroxydopamine (6-OHDA) or an ER stressor brefeldin A (BFA). 14-26 also prevented ROS-induced damage in both the ER and the mitochondria, including the protein carbonylation in the microsome and the reduction of the mitochondrial membrane potential. Further examination disclosed the presence of the iron-chelating activity in 14-26. In vivo, 14-26 suppressed both oxidative stress and ER stress and prevented neuronal death in the substantia nigra pars compacta (SNpc) after injection of 6-OHDA in mice. These results suggest that 14-26 is an antioxidant that protects dopaminergic neurons against both oxidative stress and ER stress and could be a therapeutic candidate for the treatment of PD.

scholarly journals Astragalus Polysaccharide Suppresses 6-Hydroxydopamine-Induced Neurotoxicity in Caenorhabditis elegans

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Haifeng Li ◽  
Ruona Shi ◽  
Fei Ding ◽  
Hongyu Wang ◽  
Wenjing Han ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Protective Effect ◽  
Therapeutic Potential ◽  
Neuroprotective Effect ◽  
Acetylcholinesterase Activity ◽  
Apoptosis Pathway ◽  
Acidic Polysaccharide ◽  
C Elegans ◽  
6 Hydroxydopamine

Astragalus membranaceus is a medicinal plant traditionally used in China for a variety of conditions, including inflammatory and neural diseases. Astragalus polysaccharides are shown to reduce the adverse effect of levodopa which is used to treat Parkinson’s disease (PD). However, the neuroprotective effect of Astragalus polysaccharides per se in PD is lacking. Using Caenorhabditis elegans models, we investigated the protective effect of astragalan, an acidic polysaccharide isolated from A. membranaceus, against the neurotoxicity of 6-hydroxydopamine (6-OHDA), a neurotoxin that can induce parkinsonism. We show that 6-OHDA is able to degenerate dopaminergic neurons and lead to the deficiency of food-sensing behavior and a shorter lifespan in C. elegans. Interestingly, these degenerative symptoms can be attenuated by astragalan treatment. Astragalan is also shown to alleviate oxidative stress through reducing reactive oxygen species level and malondialdehyde content and increasing superoxide dismutase and glutathione peroxidase activities and reduce the expression of proapoptotic gene egl-1 in 6-OHDA-intoxicated nematodes. Further studies reveal that astragalan is capable of elevating the decreased acetylcholinesterase activity induced by 6-OHDA. Together, our results demonstrate that the protective effect of astragalan against 6-OHDA neurotoxicity is likely due to the alleviation of oxidative stress and regulation of apoptosis pathway and cholinergic system and thus provide an important insight into the therapeutic potential of Astragalus polysaccharide in neurodegeneration.

scholarly journals Lipid-Mediated Oxidative Stress and Inflammation in the Pathogenesis of Parkinson's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Tahira Farooqui ◽  
Akhlaq A. Farooqui
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Platelet Activating Factor ◽  
Lipid Mediators ◽  
Unknown Etiology ◽  
Oxygen Species ◽  
Progressive Loss ◽  
Progressive Neurodegeneration

Parkinson's disease (PD) is a neurodegenerative movement disorder of unknown etiology. PD is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, depletion of dopamine in the striatum, abnormal mitochondrial and proteasomal functions, and accumulation ofα-synuclein that may be closely associated with pathological and clinical abnormalities. Increasing evidence indicates that both oxidative stress and inflammation may play a fundamental role in the pathogenesis of PD. Oxidative stress is characterized by increase in reactive oxygen species (ROS) and depletion of glutathione. Lipid mediators for oxidative stress include 4-hydroxynonenal, isoprostanes, isofurans, isoketals, neuroprostanes, and neurofurans. Neuroinflammation is characterized by activated microglial cells that generate proinflammatory cytokines, such as TNF-αand IL-1β. Proinflammatory lipid mediators include prostaglandins and platelet activating factor, together with cytokines may play a prominent role in mediating the progressive neurodegeneration in PD.

scholarly journals T-2 Toxin Induces Oxidative Stress, Apoptosis and Cytoprotective Autophagy in Chicken Hepatocytes

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 90 ◽  
Author(s):  
Huadong Yin ◽  
Shunshun Han ◽  
Yuqi Chen ◽  
Yan Wang ◽  
Diyan Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanism ◽  
Regulatory Mechanism ◽  
Fusarium Species ◽  
Cereal Grains ◽  
Oxygen Species ◽  
Related Protein ◽  
Pathological Changes ◽  
Toxicological Effect ◽  
Type A Trichothecenes

T-2 toxin is type A trichothecenes mycotoxin, which produced by fusarium species in cereal grains. T-2 toxin has been shown to induce a series of toxic effects on the health of human and animal, such as immunosuppression and carcinogenesis. Previous study has proven that T-2 toxin caused hepatotoxicity in chicken, but the regulatory mechanism is unclear. In the present study, we assessed the toxicological effect of T-2 toxin on apoptosis and autophagy in hepatocytes. The total of 120 1-day-old healthy broilers were allocated randomly into four groups and reared for 21 day with complete feed containing 0 mg/kg, 0.5 mg/kg, 1 mg/kg or 2 mg/kg T-2 toxin, respectively. The results showed that the apoptosis rate and pathological changes degree hepatocytes were aggravated with the increase of T-2 toxin. At the molecular mechanism level, T-2 toxin induced mitochondria-mediated apoptosis by producing reactive oxygen species, promoting cytochrome c translocation between the mitochondria and cytoplasm, and thus promoting apoptosomes formation. Meanwhile, the expression of the autophagy-related protein, ATG5, ATG7 and Beclin-1, and the LC3-II/LC3-I ratio were increased, while p62 was downregulated, suggesting T-2 toxin caused autophagy in hepatocytes. Further experiments demonstrated that the PI3K/AKT/mTOR signal may be participated in autophagy induced by T-2 toxin in chicken hepatocytes. These data suggest a possible underlying molecular mechanism for T-2 toxin that induces apoptosis and autophagy in chicken hepatocytes

scholarly journals Genetic Defects in Mitochondrial Dynamics in Caenorhabditis elegans Impact Ultraviolet C Radiation- and 6-hydroxydopamine-Induced Neurodegeneration

2019 ◽  
Vol 20 (13) ◽  
pp. 3202 ◽  
Author(s):  
Jessica H. Hartman ◽  
Claudia Gonzalez-Hunt ◽  
Samantha M. Hall ◽  
Ian T. Ryde ◽  
Kim A. Caldwell ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Dopaminergic Neurons ◽  
Mitochondrial Dynamics ◽  
Environmental Pollutants ◽  
Model Organism ◽  
Mitochondrial Morphology ◽  
Dopaminergic Neurodegeneration ◽  
Gene By Environment Interactions ◽  
Ultraviolet C ◽  
6 Hydroxydopamine

Background: Parkinson’s disease (PD) is one of the most common neurodegenerative disorders involving devastating loss of dopaminergic neurons in the substantia nigra. Early steps in PD pathogenesis include mitochondrial dysfunction, and mutations in mitochondrial genes have been linked to familial forms of the disease. However, low penetrance of mutations indicates a likely important role for environmental factors in PD risk through gene by environment interactions. Herein, we study how genetic deficiencies in mitochondrial dynamics processes including fission, fusion, and mitophagy interact with environmental exposures to impact neurodegeneration. Methods: We utilized the powerful model organism Caenorhabditis elegans to study ultraviolet C radiation (UVC)- and 6-hydroxydopamine-induced degeneration of fluorescently-tagged dopaminergic neurons in the background of fusion deficiency (MFN1/2 homolog, fzo-1), fission deficiency (DMN1L homolog, drp-1), and mitochondria-specific autophagy (mitophagy) deficiency (PINK1 and PRKN homologs, pink-1 and pdr-1). Results: Overall, we found that deficiency in either mitochondrial fusion or fission sensitizes nematodes to UVC exposure (used to model common environmental pollutants) but protects from 6-hydroxydopamine-induced neurodegeneration. By contrast, mitophagy deficiency makes animals more sensitive to these stressors with an interesting exception—pink-1 deficiency conferred remarkable protection from 6-hydroxydopamine. We found that this protection could not be explained by compensatory antioxidant gene expression in pink-1 mutants or by differences in mitochondrial morphology. Conclusions: Together, our results support a strong role for gene by environment interactions in driving dopaminergic neurodegeneration and suggest that genetic deficiency in mitochondrial processes can have complex effects on neurodegeneration.

scholarly journals CED-10-WASP-Arp2/3 signaling axis regulates apoptotic cell corpse engulfment in C. elegans

2017 ◽  
Vol 428 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Dou Wu ◽  
Yongping Chai ◽  
Zhiwen Zhu ◽  
Wenjing Li ◽  
Guangshuo Ou ◽  
...  
Keyword(s):  
Apoptotic Cell ◽  
C Elegans ◽  
Signaling Axis ◽  
Cell Corpse ◽  
Corpse Engulfment

Chinese Medicine PaBing-II Protects Human iPSC Derived Dopaminergic Neurons from Oxygen Stress

2021 ◽  
Author(s):  
Shouhai Wu ◽  
Tongxiang Lin ◽  
Yang Xu
Keyword(s):  
Oxidative Stress ◽  
Chinese Medicine ◽  
Pluripotent Stem Cells ◽  
Dopaminergic Neurons ◽  
Protective Effects ◽  
Midbrain Dopaminergic Neurons ◽  
Induced Pluripotent ◽  
6 Hydroxydopamine ◽  
Human Ipsc

Abstract BackgroundPaBing-II Formula (PB-II) is a traditional Chinese medicine developed to treat Parkinson's disease (PD). However, due to the complexity of PB-II and the difficulty of culturing human dopaminergic neurons (DAn) in vitro, the mechanism of PB-II to treat PD remains unclear. MethodsWe established the human induced pluripotent stem cells (iPSCs) and derived DAn from hiPSCs to study the protective effects of PB-II on DAn after oxidative stress, which plays an important role in PD pathogenesis. ResultsWe found that serum derived from rats that had ingested PB-II significantly protect hiPSC-derived DAn from reactive oxygen species (ROS). In addition, PB-II dependent serum can activate nuclear erythroid-derived factor 2 (Nrf2) responses, which are required for the neutralization of ROS. In addition, PB-II can activate the Nrf2/ARE signal pathway of midbrain dopaminergic neurons of PD rats induced with 6-hydroxydopamine (6-OHDA) injury, rescue DAn cells, and improve the symptoms of PD rats. ConclusionsPB-II significantly protects the DA neurons from oxidative stress by activating the Nrf2 pathway.

scholarly journals Suppression of 6-Hydroxydopamine-Induced Oxidative Stress by Hyperoside Via Activation of Nrf2/HO-1 Signaling in Dopaminergic Neurons

2019 ◽  
Vol 20 (23) ◽  
pp. 5832 ◽  
Author(s):  
Kwon ◽  
Lee ◽  
Park ◽  
Ra ◽  
Lee ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Neuronal Death ◽  
Dopaminergic Neurons ◽  
Neuronal Cell ◽  
Antioxidant Response ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Neuroprotective Effects ◽  
Ongoing Research ◽  
6 Hydroxydopamine

In our ongoing research to discover natural products with neuroprotective effects, hyperoside (quercetin 3-O-galactoside) was isolated from Acer tegmentosum, which has been used in Korean traditional medicine to treat liver-related disorders. Here, we demonstrated that hyperoside protects cultured dopaminergic neurons from death via reactive oxygen species (ROS)-dependent mechanisms, although other relevant mechanisms of hyperoside activity remain largely uncharacterized. For the first time, we investigated the neuroprotective effects of hyperoside on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in neurons, and the possible underlying mechanisms. Hyperoside significantly ameliorated the loss of neuronal cell viability, lactate dehydrogenase release, excessive ROS accumulation and mitochondrial membrane potential dysfunction associated with 6-OHDA-induced neurotoxicity. Furthermore, hyperoside treatment activated the nuclear erythroid 2-related factor 2 (Nrf2), an upstream molecule of heme oxygenase-1 (HO-1). Hyperoside also induced the expression of HO-1, an antioxidant response gene. Remarkably, we found that the neuroprotective effects of hyperoside were weakened by an Nrf2 small interfering RNA, which blocked the ability of hyperoside to inhibit neuronal death, indicating the vital role of HO-1. Overall, we show that hyperoside, via the induction of Nrf2-dependent HO-1 activation, suppresses neuronal death caused by 6-OHDA-induced oxidative stress. Moreover, Nrf2-dependent HO-1 signaling activation represents a potential preventive and therapeutic target in Parkinson′s disease management.

scholarly journals Mirtazapine exerts astrocyte-mediated dopaminergic neuroprotection

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ryo Kikuoka ◽  
Ikuko Miyazaki ◽  
Natsuki Kubota ◽  
Megumi Maeda ◽  
Daiki Kagawa ◽  
...  
Keyword(s):  
Dopaminergic Neurons ◽  
Neuronal Cultures ◽  
Neuroprotective Effects ◽  
Astrocyte Proliferation ◽  
Dopaminergic Neurodegeneration ◽  
Disease Modifying ◽  
Novel Target ◽  
6 Hydroxydopamine ◽  
Serotonergic Antidepressant ◽  
Stimulation Of

AbstractMirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson’s disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD.

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