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Sneha NP, Dharshini SAP, Taguchi YH, Gromiha MM. Investigating Neuron Degeneration in Huntington's Disease Using RNA-Seq Based Transcriptome Study. Genes (Basel) 2023; 14:1801. [PMID: 37761940 PMCID: PMC10530489 DOI: 10.3390/genes14091801] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 09/02/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused due to a CAG repeat expansion in the huntingtin (HTT) gene. The primary symptoms of HD include motor dysfunction such as chorea, dystonia, and involuntary movements. The primary motor cortex (BA4) is the key brain region responsible for executing motor/movement activities. Investigating patient and control samples from the BA4 region will provide a deeper understanding of the genes responsible for neuron degeneration and help to identify potential markers. Previous studies have focused on overall differential gene expression and associated biological functions. In this study, we illustrate the relationship between variants and differentially expressed genes/transcripts. We identified variants and their associated genes along with the quantification of genes and transcripts. We also predicted the effect of variants on various regulatory activities and found that many variants are regulating gene expression. Variants affecting miRNA and its targets are also highlighted in our study. Co-expression network studies revealed the role of novel genes. Function interaction network analysis unveiled the importance of genes involved in vesicle-mediated transport. From this unified approach, we propose that genes expressed in immune cells are crucial for reducing neuron death in HD.
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Affiliation(s)
- Nela Pragathi Sneha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India; (N.P.S.); (S.A.P.D.)
| | - S. Akila Parvathy Dharshini
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India; (N.P.S.); (S.A.P.D.)
| | - Y.-h. Taguchi
- Department of Physics, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan;
| | - M. Michael Gromiha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India; (N.P.S.); (S.A.P.D.)
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2
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Endoplasmic Reticulum Stress-Regulated Chaperones as a Serum Biomarker Panel for Parkinson's Disease. Mol Neurobiol 2023; 60:1476-1485. [PMID: 36478320 PMCID: PMC9899193 DOI: 10.1007/s12035-022-03139-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022]
Abstract
Examination of post-mortem brain tissues has previously revealed a strong association between Parkinson's disease (PD) pathophysiology and endoplasmic reticulum (ER) stress. Evidence in the literature regarding the circulation of ER stress-regulated factors released from neurons provides a rationale for investigating ER stress biomarkers in the blood to aid diagnosis of PD. The levels of ER stress-regulated proteins in serum collected from 29 PD patients and 24 non-PD controls were measured using enzyme-linked immunosorbent assays. A panel of four biomarkers, protein disulfide-isomerase A1, protein disulfide-isomerase A3, mesencephalic astrocyte-derived neurotrophic factor, and clusterin, together with age and gender had higher ability (area under the curve 0.64, sensitivity 66%, specificity 57%) and net benefit to discriminate PD patients from the non-PD group compared with other analyzed models. Addition of oligomeric and total α-synuclein to the model did not improve the diagnostic power of the biomarker panel. We provide evidence that ER stress-regulated proteins merit further investigation for their potential as diagnostic biomarkers of PD.
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3
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Review on the interactions between dopamine metabolites and α-Synuclein in causing Parkinson's disease. Neurochem Int 2023; 162:105461. [PMID: 36460239 DOI: 10.1016/j.neuint.2022.105461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022]
Abstract
Parkinson's disease (PD) is characterized by an abnormal post-translational modifications (PTM) in amino acid sequence and aggregation of alpha-synuclein (α-Syn) protein. It is generally believed that dopamine (DA) metabolite in dopaminergic (DAergic) neurons promotes the aggregation of toxic α-Syn oligomers and protofibrils, whereas DA inhibits the formation of toxic fibers and even degrades the toxic fibers. Therefore, the study on interaction between DA metabolites and α-Syn oligomers is one of the current hot topics in neuroscience, because this effect may have direct relevance to the selective DAergic neuron loss in PD. Several mechanisms have been reported for DA metabolites induced α-Syn oligomers viz. i) The reactive oxygen species (ROS) released during the auto-oxidation or enzymatic oxidation of DA changes the structure of α-Syn by the oxidation of amino acid residue leading to misfolding, ii) The oxidized DA metabolites directly interact with α-Syn through covalent or non-covalent bonding leading to the formation of oligomers, iii) DA interacts with lipid or autophagy related proteins to decreases the degradation efficiency of α-Syn aggregates. However, there is no clear-cut mechanism proposed for the interaction between DA and α-Syn. However, it is believed that the lysine (Lys) side chain of α-Syn sequence is the initial trigger site for the oligomer formation. Herein, we review different chemical mechanism involved during the interaction of Lys side chain of α-Syn with DA metabolites such as dopamine-o-quinone (DAQ), dopamine-chrome (DAC), dopamine-aldehyde (DOPAL) and neuromelanin. This review also provides the promotive effect of divalent Cu2+ ions on DA metabolites induced α-Syn oligomers and its inhibition effect by antioxidant glutathione (GSH).
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4
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Dewanjee S, Chakraborty P, Bhattacharya H, Chacko L, Singh B, Chaudhary A, Javvaji K, Pradhan SR, Vallamkondu J, Dey A, Kalra RS, Jha NK, Jha SK, Reddy PH, Kandimalla R. Altered glucose metabolism in Alzheimer's disease: Role of mitochondrial dysfunction and oxidative stress. Free Radic Biol Med 2022; 193:134-157. [PMID: 36206930 DOI: 10.1016/j.freeradbiomed.2022.09.032] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/16/2022] [Accepted: 09/29/2022] [Indexed: 12/06/2022]
Abstract
Increasing evidence suggests that abnormal cerebral glucose metabolism is largely present in Alzheimer's disease (AD). The brain utilizes glucose as its main energy source and a decline in its metabolism directly reflects on brain function. Weighing on recent evidence, here we systematically assessed the aberrant glucose metabolism associated with amyloid beta and phosphorylated tau accumulation in AD brain. Interlink between insulin signaling and AD highlighted the involvement of the IRS/PI3K/Akt/AMPK signaling, and GLUTs in the disease progression. While shedding light on the mitochondrial dysfunction in the defective glucose metabolism, we further assessed functional consequences of AGEs (advanced glycation end products) accumulation, polyol activation, and other contributing factors including terminal respiration, ROS (reactive oxygen species), mitochondrial permeability, PINK1/parkin defects, lysosome-mitochondrial crosstalk, and autophagy/mitophagy. Combined with the classic plaque and tangle pathologies, glucose hypometabolism with acquired insulin resistance and mitochondrial dysfunction potentiate these factors to exacerbate AD pathology. To this end, we further reviewed AD and DM (diabetes mellitus) crosstalk in disease progression. Taken together, the present work discusses the emerging role of altered glucose metabolism, contributing impact of insulin signaling, and mitochondrial dysfunction in the defective cerebral glucose utilization in AD.
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Affiliation(s)
- Saikat Dewanjee
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700 032, West Bengal, India
| | - Pratik Chakraborty
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700 032, West Bengal, India
| | - Hiranmoy Bhattacharya
- Advanced Pharmacognosy Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700 032, West Bengal, India
| | - Leena Chacko
- BioAnalytical Lab, Meso Scale Discovery, 1601 Research Blvd, Rockville, MD, USA
| | - Birbal Singh
- ICAR-Indian Veterinary Research Institute (IVRI), Regional Station, Palampur, 176061, Himachal Pradesh, India
| | - Anupama Chaudhary
- Orinin-BioSystems, LE-52, Lotus Road 4, CHD City, Karnal, 132001, Haryana, India
| | - Kalpana Javvaji
- CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, India
| | | | | | - Abhijit Dey
- Department of Life Sciences, Presidency University, Kolkata, 700073, India
| | - Rajkumar Singh Kalra
- Immune Signal Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, 9040495, Japan
| | - Niraj Kumar Jha
- Department of Biotechnology, School of Engineering & Technology (SET), Sharda University, UP, 201310, India; Department of Biotechnology Engineering and Food Technology, Chandigarh University, Mohali, 140413, India; Department of Biotechnology, School of Applied & Life Sciences (SALS), Uttaranchal University, Dehradun, 248007, India
| | - Saurabh Kumar Jha
- Department of Biotechnology, School of Engineering & Technology (SET), Sharda University, UP, 201310, India; Department of Biotechnology Engineering and Food Technology, Chandigarh University, Mohali, 140413, India; Department of Biotechnology, School of Applied & Life Sciences (SALS), Uttaranchal University, Dehradun, 248007, India
| | - P Hemachandra Reddy
- Internal Medicine Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology Departments School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Ramesh Kandimalla
- CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, India; Department of Biochemistry, Kakatiya Medical College, Warangal, India.
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5
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Inhibition of mTOR improves malnutrition induced hepatic metabolic dysfunction. Sci Rep 2022; 12:19948. [PMID: 36402829 PMCID: PMC9675758 DOI: 10.1038/s41598-022-24428-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/15/2022] [Indexed: 11/21/2022] Open
Abstract
Severe malnutrition accounts for half-a-million deaths annually in children under the age of five. Despite improved WHO guidelines, inpatient mortality remains high and is associated with metabolic dysfunction. Previous studies suggest a correlation between hepatic metabolic dysfunction and impaired autophagy. We aimed to determine the role of mTORC1 inhibition in a murine model of malnutrition-induced hepatic dysfunction. Wild type weanling C57/B6 mice were fed a 18 or 1% protein diet for two weeks. A third low-protein group received daily rapamycin injections, an mTORC1 inhibitor. Hepatic metabolic function was assessed by histology, immunofluorescence, gene expression, metabolomics and protein levels. Low protein-fed mice manifested characteristics of severe malnutrition, including weight loss, hypoalbuminemia, hypoglycemia, hepatic steatosis and cholestasis. Low protein-fed mice had fewer mitochondria and showed signs of impaired mitochondrial function. Rapamycin prevented hepatic steatosis, restored ATP levels and fasted plasma glucose levels compared to untreated mice. This correlated with increased content of LC3-II, and decreased content mitochondrial damage marker, PINK1. We demonstrate that hepatic steatosis and disturbed mitochondrial function in a murine model of severe malnutrition can be partially prevented through inhibition of mTORC1. These findings suggest that stimulation of autophagy could be a novel approach to improve metabolic function in severely malnourished children.
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6
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Harapas CR, Idiiatullina E, Al-Azab M, Hrovat-Schaale K, Reygaerts T, Steiner A, Laohamonthonkul P, Davidson S, Yu CH, Booty L, Masters SL. Organellar homeostasis and innate immune sensing. Nat Rev Immunol 2022; 22:535-549. [PMID: 35197578 DOI: 10.1038/s41577-022-00682-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2022] [Indexed: 02/06/2023]
Abstract
A cell is delimited by numerous borders that define specific organelles. The walls of some organelles are particularly robust, such as in mitochondria or endoplasmic reticulum, but some are more fluid such as in phase-separated stress granules. Either way, all organelles can be damaged at times, leading their contents to leak out into the surrounding environment. Therefore, an elegant way to construct an innate immune defence system is to recognize host molecules that do not normally reside within a particular compartment. Here, we provide several examples where organellar homeostasis is lost, leading to the activation of a specific innate immune sensor; these include NLRP3 activation owing to a disrupted trans-Golgi network, Pyrin activation due to cytoskeletal damage, and cGAS-STING activation following the leakage of nuclear or mitochondrial DNA. Frequently, organelle damage is observed downstream of pathogenic infection but it can also occur in sterile settings as associated with auto-inflammatory disease. Therefore, understanding organellar homeostasis is central to efforts that will identify new innate immune pathways, and therapeutics that balance organellar homeostasis, or target the breakdown pathways that trigger innate immune sensors, could be useful treatments for infection and chronic inflammatory diseases.
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Affiliation(s)
- Cassandra R Harapas
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Elina Idiiatullina
- Immunology Laboratory, Guangzhou Institute of Paediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou, Guangdong, China
| | - Mahmoud Al-Azab
- Immunology Laboratory, Guangzhou Institute of Paediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou, Guangdong, China
| | - Katja Hrovat-Schaale
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Thomas Reygaerts
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Annemarie Steiner
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Institute of Structural Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Pawat Laohamonthonkul
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Sophia Davidson
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Chien-Hsiung Yu
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Lee Booty
- Immunology Network, Immunology Research Unit, GSK, Stevenage, UK
| | - Seth L Masters
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia. .,Immunology Laboratory, Guangzhou Institute of Paediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou, Guangdong, China.
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7
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Lewoniewska S, Oscilowska I, Forlino A, Palka J. Understanding the Role of Estrogen Receptor Status in PRODH/POX-Dependent Apoptosis/Survival in Breast Cancer Cells. BIOLOGY 2021; 10:biology10121314. [PMID: 34943229 PMCID: PMC8698543 DOI: 10.3390/biology10121314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/29/2021] [Accepted: 12/07/2021] [Indexed: 04/15/2023]
Abstract
It has been suggested that activation of estrogen receptor α (ER α) stimulates cell proliferation. In contrast, estrogen receptor β (ER β) has anti-proliferative and pro-apoptotic activity. Although the role of estrogens in estrogen receptor-positive breast cancer progression has been well established, the mechanism of their effect on apoptosis is not fully understood. It has been considered that ER status of breast cancer cells and estrogen availability might determine proline dehydrogenase/proline oxidase (PRODH/POX)-dependent apoptosis. PRODH/POX is a mitochondrial enzyme that converts proline into pyrroline-5-carboxylate (P5C). During this process, ATP (adenosine triphosphate) or ROS (reactive oxygen species) are produced, facilitating cell survival or death, respectively. However, the critical factor in driving PRODH/POX-dependent functions is proline availability. The amount of this amino acid is regulated at the level of prolidase (proline releasing enzyme), collagen biosynthesis (proline utilizing process), and glutamine, glutamate, α-ketoglutarate, and ornithine metabolism. Estrogens were found to upregulate prolidase activity and collagen biosynthesis. It seems that in estrogen receptor-positive breast cancer cells, prolidase supports proline for collagen biosynthesis, limiting its availability for PRODH/POX-dependent apoptosis. Moreover, lack of free proline (known to upregulate the transcriptional activity of hypoxia-inducible factor 1, HIF-1) contributes to downregulation of HIF-1-dependent pro-survival activity. The complex regulatory mechanism also involves PRODH/POX expression and activity. It is induced transcriptionally by p53 and post-transcriptionally by AMPK (AMP-activated protein kinase), which is regulated by ERs. The review also discusses the role of interconversion of proline/glutamate/ornithine in supporting proline to PRODH/POX-dependent functions. The data suggest that PRODH/POX-induced apoptosis is dependent on ER status in breast cancer cells.
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Affiliation(s)
- Sylwia Lewoniewska
- Department of Medicinal Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland;
| | - Ilona Oscilowska
- Department of Analysis and Bioanalysis of Medicines, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland;
| | - Antonella Forlino
- Department of Molecular Medicine, University of Pavia, Viale Taramelli 3/B, 27100 Pavia, Italy;
| | - Jerzy Palka
- Department of Medicinal Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland;
- Correspondence: ; Tel.: +48-85-748-5706
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8
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Oscilowska I, Huynh TYL, Baszanowska W, Prokop I, Surazynski A, Galli M, Zabielski P, Palka J. Proline oxidase silencing inhibits p53-dependent apoptosis in MCF-7 breast cancer cells. Amino Acids 2021; 53:1943-1956. [PMID: 34085157 PMCID: PMC8651586 DOI: 10.1007/s00726-021-03013-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/28/2021] [Indexed: 02/02/2023]
Abstract
Proline oxidase (POX) is mitochondrial proline-degrading enzyme of dual apoptosis/survival function. POX expression and proline availability are considered an underlying mechanism for differential POX functions. The mechanism for POX-dependent regulation of cell death/survival was studied in wild-type (MCF-7WT) and shRNA POX-silenced breast cancer cells (MCF-7iPOX). Proline concentration and proteomic analyses were determined by LC/MS/QTOF and LC/MS/ORBITRA, respectively. Inhibition of collagen biosynthesis (proline utilizing process) by 2-methoxyestradiol (2ME) contributed to induction of apoptosis in MCF-7WT cells, as detected by increase in the expression of active caspase-3, -9 and p53. The process was not shown in MCF-7iPOX. In MCF-7iPOX cells prolidase activity and expression as well as proline concentration were drastically increased, compared to MCF-7WT cells. Down-regulation of p53 in MCF-7iPOX cells was corroborated by proteomic analysis showing decrease in the expression of p53-related proteins. The mechanism for down-regulation of p53 expression in MCF-7iPOX cells was found at the level of p53-PEPD complex formation that was counteracted by hydrogen peroxide treatment. In this study, we found that silencing POX modulate pro-survival phenotype of MCF-7 cells and suggest that the mechanism of this process undergoes through down-regulation of p53-dependent signaling.
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Affiliation(s)
- Ilona Oscilowska
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland
| | - Thi Y L Huynh
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland
| | - Weronika Baszanowska
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland
| | - Izabela Prokop
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland
| | - Arkadiusz Surazynski
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland
| | - Mauro Galli
- Department of Medical Biology, Medical University of Bialystok, Mickiewicza 2C, 15-222, Bialystok, Poland
| | - Piotr Zabielski
- Department of Medical Biology, Medical University of Bialystok, Mickiewicza 2C, 15-222, Bialystok, Poland
| | - Jerzy Palka
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-222, Bialystok, Poland.
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Neutral lipids as early biomarkers of cellular fate: the case of α-synuclein overexpression. Cell Death Dis 2021; 12:52. [PMID: 33414430 PMCID: PMC7791139 DOI: 10.1038/s41419-020-03254-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
α-synuclein (α-syn) accumulation and aggregation is a common pathological factor found in synucleinopathies, a group of neurodegenerative disorders that includes Parkinson´s disease (PD). It has been proposed that lipid dyshomeostasis is responsible for the occurrence of PD-related processes, however, the precise role of lipids in the onset and progression of neurodegenerative disorders remains unclear. Our aim was to investigate the effect of α-syn overexpression on neutral lipid metabolism and how this impacts on neuronal fate. We found lipid droplet (LD) accumulation in cells overexpressing α-syn to be associated with a rise in triacylglycerol (TAG) and cholesteryl ester (CE) levels. α-syn overexpression promoted diacylglycerol acyltransferase 2 upregulation and acyl-CoA synthetase activation, triggering TAG buildup, that was accompanied by an increase in diacylglycerol acylation. Moreover, the CE increment was associated with higher activity of acyl-CoA:cholesterol acyltransferase. Interestingly, α-syn overexpression increased cholesterol lysosomal accumulation. We observed that sterol regulatory element-binding protein (SREBP)-1 and SREBP-2 were differentially regulated by α-syn overexpression. The latter gave rise to a reduction in SREBP-1 nuclear translocation and consequently in fatty acid synthase expression, whereas it produced an increase in SREBP-2 nuclear localization. Surprisingly, and despite increased cholesterol levels, SREBP-2 downstream genes related to cholesterolgenesis were not upregulated as expected. Notably, phospholipid (PL) levels were diminished in cells overexpressing α-syn. This decrease was related to the activation of phospholipase A2 (PLA2) with a concomitant imbalance of the PL deacylation-acylation cycle. Fatty acids released from PLs by iPLA2 and cPLA2 action were esterified into TAGs, thus promoting a biological response to α-syn overexpression with uncompromised cell viability. When the described steady-state was disturbed under conditions favoring higher levels of α-syn, the response was an enhanced LD accumulation, this imbalance ultimately leading to neuronal death.
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Chattopadhyay A, Kwartler CS, Kaw K, Li Y, Kaw A, Chen J, LeMaire SA, Shen YH, Milewicz DM. Cholesterol-Induced Phenotypic Modulation of Smooth Muscle Cells to Macrophage/Fibroblast-like Cells Is Driven by an Unfolded Protein Response. Arterioscler Thromb Vasc Biol 2021; 41:302-316. [PMID: 33028096 PMCID: PMC7752246 DOI: 10.1161/atvbaha.120.315164] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Vascular smooth muscle cells (SMCs) dedifferentiate and initiate expression of macrophage markers with cholesterol exposure. This phenotypic switching is dependent on the transcription factor Klf4 (Krüppel-like factor 4). We investigated the molecular pathway by which cholesterol induces SMC phenotypic switching. Approach and Results: With exposure to free cholesterol, SMCs decrease expression of contractile markers, activate Klf4, and upregulate a subset of macrophage and fibroblast markers characteristic of modulated SMCs that appear with atherosclerotic plaque formation. These phenotypic changes are associated with activation of all 3 pathways of the endoplasmic reticulum unfolded protein response (UPR), Perk (protein kinase RNA-like endoplasmic reticulum kinase), Ire (inositol-requiring enzyme) 1α, and Atf (activating transcription factor) 6. Blocking the movement of cholesterol from the plasma membrane to the endoplasmic reticulum prevents free cholesterol-induced UPR, Klf4 activation, and upregulation of the majority of macrophage and fibroblast markers. Cholesterol-induced phenotypic switching is also prevented by global UPR inhibition or specific inhibition of Perk signaling. Exposure to chemical UPR inducers, tunicamycin and thapsigargin, is sufficient to induce these same phenotypic transitions. Finally, analysis of published single-cell RNA sequencing data during atherosclerotic plaque formation in hyperlipidemic mice provides preliminary in vivo evidence of a role of UPR activation in modulated SMCs. CONCLUSIONS Our data demonstrate that UPR is necessary and sufficient to drive phenotypic switching of SMCs to cells that resemble modulated SMCs found in atherosclerotic plaques. Preventing a UPR in hyperlipidemic mice diminishes atherosclerotic burden, and our data suggest that preventing SMC transition to dedifferentiated cells expressing macrophage and fibroblast markers contributes to this decreased plaque burden.
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MESH Headings
- Activating Transcription Factor 4/metabolism
- Animals
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Cell Line
- Cell Transdifferentiation/drug effects
- Cholesterol/toxicity
- Endoplasmic Reticulum Stress/drug effects
- Eukaryotic Initiation Factor-2/metabolism
- Female
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Kruppel-Like Factor 4
- Kruppel-Like Transcription Factors/metabolism
- Macrophages/drug effects
- Macrophages/metabolism
- Macrophages/pathology
- Male
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Phenotype
- Plaque, Atherosclerotic
- Unfolded Protein Response/drug effects
- eIF-2 Kinase/metabolism
- Mice
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Affiliation(s)
- Abhijnan Chattopadhyay
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
| | - Callie S. Kwartler
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
| | - Kaveeta Kaw
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
| | - Yanming Li
- Division of Cardiothoracic Surgery, Baylor College of Medicine, Houston, TX (.L., S.A.L., Y.H.S.)
| | - Anita Kaw
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
| | - Jiyuan Chen
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
| | - Scott A. LeMaire
- Division of Cardiothoracic Surgery, Baylor College of Medicine, Houston, TX (.L., S.A.L., Y.H.S.)
| | - Ying H. Shen
- Division of Cardiothoracic Surgery, Baylor College of Medicine, Houston, TX (.L., S.A.L., Y.H.S.)
| | - Dianna M. Milewicz
- Division of Medical Genetics, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX (A.C., C.S.K., K.K., A.K., J.C., D.M.M.)
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11
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Li L, Yang F, Jia R, Yan P, Ma L. Velvet antler polypeptide prevents the disruption of hepatic tight junctions via inhibiting oxidative stress in cholestatic mice and liver cell lines. Food Funct 2020; 11:9752-9763. [PMID: 33073799 DOI: 10.1039/d0fo01899f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The present study aims to examine the protective effects and mechanism of a velvet antler polypeptide (VAP) against lithocholic acid (LCA)-induced cholestatic liver injury in mice. A 7.0 kDa VAP was orally administered at doses of 10 and 20 mg kg-1 day-1. Hematoxylin and eosin (H&E) staining of the liver showed that VAP7.0 reduced LCA-induced infiltration of inflammatory cells and areas of necrotic hepatocytes. In addition, VAP7.0 greatly reduced the levels of alanine aminotransferase (ALT), total bile acid (TBA) and total bilirubin (TBIL) in LCA mouse serum and prolonged the survival time of mice with LCA. VAP7.0 reduced the production of reactive oxygen species (ROS), decreased malondialdehyde (MDA) and increased the superoxide dismutase (SOD) levels in LCA mice. VAP7.0 also reduced OGG1 expression, which is a biochemical indicator of oxidative stress. Mechanistic analysis revealed that VAP7.0 significantly inhibited LCA-induced disruption of tight junction integrity, as determined by observing the morphology of the bile canaliculus, and this finding was confirmed by observation of the bile canalicular structure and tight junction proteins Occludin and ZO-1 expression. Moreover, we also found that VAP7.0 maintained the stability of hepatic paracellular permeability, as determined by Evans blue dye assays and horseradish peroxidase (HRP) tracer distribution through inhibiting the activation of the PI3K pathway in LCA mouse livers. In addition, VAP7.0 ameliorated H2O2-induced barrier dysfunction and tight junction disruption via inhibiting the PI3K activity in human HepG2 and SMMC7721 cells, which was confirmed by the PI3K activator 740Y-P. H2O2 disturbed the localization of the tight junction proteins ZO-1 and Occludin, resulting in the transfer of these proteins from the membrane to the cytoplasm of cells, whereas pretreatment of cells with VAP7.0 prevented the disruption of the localization of these proteins, as determined by immunofluorescence staining and western blot analysis. These results demonstrate that VAP7.0 reduces liver injury by inhibiting oxidative stress and maintains the stability of hepatic tight junctions via suppressing the activation of the intracellular signaling molecule PI3K in LCA mice and hepatocellular carcinoma cells.
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Affiliation(s)
- Lihua Li
- Department of Cell Biology, Taizhou University, Taizhou, PR China.
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12
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Li M, Zhang Y, Wang J. Endoplasmic reticulum stress regulates cell injury in lipopolysaccharide-induced nerve cells. J Int Med Res 2020; 48:300060520949762. [PMID: 32910707 PMCID: PMC7488914 DOI: 10.1177/0300060520949762] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE Sepsis-associated encephalopathy (SAE) is a common complication of sepsis, and excessive endoplasmic reticulum (ER) stress is closely correlated with the cell injury caused by sepsis. This study aimed to analyze the possible role of ER stress in SAE cell models. METHODS PC12 and MES23.5 cells were treated with increasing concentrations of lipopolysaccharides (LPS). The Cell Counting Kit-8 assay was used to detect cell viability and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess cell apoptosis. In addition, the protein expression levels of ER stress markers [GRP78, CHOP, inositol-requiring enzyme 1 (IRE1), and PKR-like ER kinase (PERK)] and apoptosis-related proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) were analyzed using western blotting. RESULTS LPS treatment activated ER stress markers in both the PC12 and MES23.5 cells. The overexpression of GRP78 significantly reduced cell viability and enhanced cell apoptosis in a time-dependent manner. An ER stress inhibitor, 4-PBA, significantly enhanced cell viability and inhibited the cell apoptosis induced by LPS. Therefore, an enhanced unfolded protein response (UPR) and UPR suppression may regulate cell apoptosis. CONCLUSIONS UPR was shown to be involved in regulating LPS-induced neuron injury. UPR could be a potential therapeutic target in SAE.
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Affiliation(s)
- Min Li
- Department of Neurology, People's Hospital of Gaotang County, Liaocheng, Shandong, China
| | - Ying Zhang
- Department of Neurology, People's Hospital of Gaotang County, Liaocheng, Shandong, China
| | - Jixing Wang
- Department of Neurology, Ningbo Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Ningbo, China
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13
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Noncanonical Roles of h α-syn (A53T) in the Pathogenesis of Parkinson's Disease: Synaptic Pathology and Neuronal Aging. Neural Plast 2020; 2020:6283754. [PMID: 32273890 PMCID: PMC7115172 DOI: 10.1155/2020/6283754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 01/04/2020] [Accepted: 01/31/2020] [Indexed: 12/26/2022] Open
Abstract
The motor and nonmotor symptoms of PD involve several brain regions. However, whether α-syn pathology originating from the SNc can directly lead to the pathological changes in distant cerebral regions and induce PD-related symptoms remains unclear. Here, AAV9-synapsin-mCherry-human SNCA (A53T) was injected into the unilateral SNc of mice. Motor function and olfactory sensitivity were evaluated. Our results showed that AAV9-synapsin-mCherry-human SNCA was continuously expressed in SNc. The animals showed mild motor and olfactory dysfunction at 7 months after viral injection. The pathology in SNc was characterized by the loss of dopaminergic neurons accompanied by ER stress. In the striatum, hα-syn expression was high, CaMKβ-2 and NR2B expression decreased, and active synapses reduced. In the olfactory bulb, hα-syn expression was high, and aging cells in the mitral layer increased. The results suggested that hα-syn was transported in the striatum and OB along the nerve fibers that originated from the SNc and induced pathological changes in the distant cerebral regions, which contributed to the motor and nonmotor symptoms of PD.
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14
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Malerba A, Roth F, Harish P, Dhiab J, Lu-Nguyen N, Cappellari O, Jarmin S, Mahoudeau A, Ythier V, Lainé J, Negroni E, Abgueguen E, Simonelig M, Guedat P, Mouly V, Butler-Browne G, Voisset C, Dickson G, Trollet C. Pharmacological modulation of the ER stress response ameliorates oculopharyngeal muscular dystrophy. Hum Mol Genet 2020; 28:1694-1708. [PMID: 30649389 DOI: 10.1093/hmg/ddz007] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/03/2019] [Accepted: 01/03/2019] [Indexed: 12/23/2022] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a rare late onset genetic disease leading to ptosis, dysphagia and proximal limb muscles at later stages. A short abnormal (GCN) triplet expansion in the polyA-binding protein nuclear 1 (PABPN1) gene leads to PABPN1-containing aggregates in the muscles of OPMD patients. Here we demonstrate that treating mice with guanabenz acetate (GA), an FDA-approved antihypertensive drug, reduces the size and number of nuclear aggregates, improves muscle force, protects myofibers from the pathology-derived turnover and decreases fibrosis. GA targets various cell processes, including the unfolded protein response (UPR), which acts to attenuate endoplasmic reticulum (ER) stress. We demonstrate that GA increases both the phosphorylation of the eukaryotic translation initiation factor 2α subunit and the splicing of Xbp1, key components of the UPR. Altogether these data show that modulation of protein folding regulation is beneficial for OPMD and promote the further development of GA or its derivatives for treatment of OPMD in humans. Furthermore, they support the recent evidences that treating ER stress could be therapeutically relevant in other more common proteinopathies.
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Affiliation(s)
- Alberto Malerba
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Fanny Roth
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Pradeep Harish
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Jamila Dhiab
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Ngoc Lu-Nguyen
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Ornella Cappellari
- Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
| | - Susan Jarmin
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Alexandrine Mahoudeau
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Victor Ythier
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Jeanne Lainé
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Elisa Negroni
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | | | - Martine Simonelig
- Institute of Human Genetics, CNRS UMR9002-University of Montpellier, mRNA Regulation and Development, Montpellier, France
| | | | - Vincent Mouly
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Gillian Butler-Browne
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Cécile Voisset
- UMR1078 'Genetic, Functional Genomic and Biotechnologies', INSERM, EFS, Brest University, IBSAM, Brest, France
| | - George Dickson
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Capucine Trollet
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
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15
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Marvian AT, Koss DJ, Aliakbari F, Morshedi D, Outeiro TF. In vitro models of synucleinopathies: informing on molecular mechanisms and protective strategies. J Neurochem 2019; 150:535-565. [PMID: 31004503 DOI: 10.1111/jnc.14707] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 02/06/2023]
Abstract
Alpha-synuclein (α-Syn) is a central player in Parkinson's disease (PD) and in a spectrum of neurodegenerative diseases collectively known as synucleinopathies. The protein was first associated with PD just over 20 years ago, when it was found to (i) be a major component of Lewy bodies and (ii) to be also associated with familial forms of PD. The characterization of α-Syn pathology has been achieved through postmortem studies of human brains. However, the identification of toxic mechanisms associated with α-Syn was only achieved through the use of experimental models. In vitro models are highly accessible, enable relatively rapid studies, and have been extensively employed to address α-Syn-associated neurodegeneration. Given the diversity of models used and the outcomes of the studies, a cumulative and comprehensive perspective emerges as indispensable to pave the way for further investigations. Here, we subdivided in vitro models of α-Syn pathology into three major types: (i) models simulating α-Syn fibrillization and the formation of different aggregated structures in vitro, (ii) models based on the intracellular expression of α-Syn, reporting on pathogenic conditions and cellular dysfunctions induced, and (iii) models using extracellular treatment with α-Syn aggregated species, reporting on sites of interaction and their downstream consequences. In summary, we review the underlying molecular mechanisms discovered and categorize protective strategies, in order to pave the way for future studies and the identification of effective therapeutic strategies. This article is part of the Special Issue "Synuclein".
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Affiliation(s)
- Amir Tayaranian Marvian
- Department of Neurology, School of Medicine, Technical University of Munich, Munich, Germany.,Department of Translational Neurodegeneration, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - David J Koss
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle Upon Tyne, UK
| | - Farhang Aliakbari
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.,Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Dina Morshedi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Tiago Fleming Outeiro
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle Upon Tyne, UK.,Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,University Medical Center Göttingen, Göttingen, Germany.,Max Planck Institute for Experimental Medicine, Göttingen, Germany
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16
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GRP78/BIP/HSPA5 as a Therapeutic Target in Models of Parkinson's Disease: A Mini Review. Adv Pharmacol Sci 2019; 2019:2706783. [PMID: 30949202 PMCID: PMC6425347 DOI: 10.1155/2019/2706783] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/21/2019] [Accepted: 02/12/2019] [Indexed: 01/09/2023] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by selective loss of dopamine neurons in the substantia nigra pars compacta of the midbrain. Reports from postmortem studies in the human PD brain, and experimental PD models reveal that endoplasmic reticulum (ER) stress is implicated in the pathogenesis of PD. In times of stress, the unfolded or misfolded proteins overload the folding capacity of the ER to induce a condition generally known as ER stress. During ER stress, cells activate the unfolded protein response (UPR) to handle increasing amounts of abnormal proteins, and recent evidence has demonstrated the activation of the ER chaperone GRP78/BiP (78 kDa glucose-regulated protein/binding immunoglobulin protein), which is important for proper folding of newly synthesized and partly folded proteins to maintain protein homeostasis. Although the activation of this protein is essential for the initiation of the UPR in PD, there are inconsistent reports on its expression in various PD models. Consequently, this review article aims to summarize current knowledge on neuroprotective agents targeting the expression of GRP78/BiP in the regulation of ER stress in experimental PD models.
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17
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Abstract
Parkinson’s disease (PD) is a neurodegenerative disease characterized by a progressive loss of dopaminergic neurons from the nigrostriatal pathway, formation of Lewy bodies, and microgliosis. During the past decades multiple cellular pathways have been associated with PD pathology (i.e., oxidative stress, endosomal-lysosomal dysfunction, endoplasmic reticulum stress, and immune response), yet disease-modifying treatments are not available. We have recently used genetic data from familial and sporadic cases in an unbiased approach to build a molecular landscape for PD, revealing lipids as central players in this disease. Here we extensively review the current knowledge concerning the involvement of various subclasses of fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, and lipoproteins in PD pathogenesis. Our review corroborates a central role for most lipid classes, but the available information is fragmented, not always reproducible, and sometimes differs by sex, age or PD etiology of the patients. This hinders drawing firm conclusions about causal or associative effects of dietary lipids or defects in specific steps of lipid metabolism in PD. Future technological advances in lipidomics and additional systematic studies on lipid species from PD patient material may improve this situation and lead to a better appreciation of the significance of lipids for this devastating disease.
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18
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Jiang P, Dickson DW. Parkinson's disease: experimental models and reality. Acta Neuropathol 2018; 135:13-32. [PMID: 29151169 PMCID: PMC5828522 DOI: 10.1007/s00401-017-1788-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 12/15/2022]
Abstract
Parkinson's disease (PD) is a chronic, progressive movement disorder of adults and the second most common neurodegenerative disease after Alzheimer's disease. Neuropathologic diagnosis of PD requires moderate-to-marked neuronal loss in the ventrolateral substantia nigra pars compacta and α-synuclein (αS) Lewy body pathology. Nigrostriatal dopaminergic neurodegeneration correlates with the Parkinsonian motor features, but involvement of other peripheral and central nervous system regions leads to a wide range of non-motor features. Nigrostriatal dopaminergic neurodegeneration is shared with other parkinsonian disorders, including some genetic forms of parkinsonism, but many of these disorders do not have Lewy bodies. An ideal animal model for PD, therefore, should exhibit age-dependent and progressive dopaminergic neurodegeneration, motor dysfunction, and abnormal αS pathology. Rodent models of PD using genetic or toxin based strategies have been widely used in the past several decades to investigate the pathogenesis and therapeutics of PD, but few recapitulate all the major clinical and pathologic features of PD. It is likely that new strategies or better understanding of fundamental disease processes may facilitate development of better animal models. In this review, we highlight progress in generating rodent models of PD based on impairments of four major cellular functions: mitochondrial oxidative phosphorylation, autophagy-lysosomal metabolism, ubiquitin-proteasome protein degradation, and endoplasmic reticulum stress/unfolded protein response. We attempt to evaluate how impairment of these major cellular systems contribute to PD and how they can be exploited in rodent models. In addition, we review recent cell biological studies suggesting a link between αS aggregation and impairment of nuclear membrane integrity, as observed during cellular models of apoptosis. We also briefly discuss the role of incompetent phagocytic clearance and how this may be a factor to consider in developing new rodent models of PD.
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Affiliation(s)
- Peizhou Jiang
- Neuropathology Laboratory, Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Dennis W Dickson
- Neuropathology Laboratory, Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
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19
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Xin JL, Zhang Y, Li Y, Zhang LZ, Lin Y, Zheng LW. Protective effects of Cervus nippon Temminck velvet antler polypeptides against MPP+‑induced cytotoxicity in SH‑SY5Y neuroblastoma cells. Mol Med Rep 2017; 16:5143-5150. [PMID: 28849030 PMCID: PMC5647048 DOI: 10.3892/mmr.2017.7303] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 05/02/2017] [Indexed: 12/20/2022] Open
Abstract
The aim of the present study was to examine the protective effects and mechanism of sika deer (Cervus nippon Temminck) velvet antler polypeptides (VAPs) against MPP+ exposure in the SH-SY5Y human neuroblastoma cell line. MPP+ cytotoxicity and the protective effects of VAPs on the SH-SY5Y cells were determined using an MTT assay. Cell apoptosis and mitochondrial membrane potential were detected using Hoechst 33342 and Rhodamine123 staining, respectively. Endoplasmic reticulum (ER) stress-related reactive oxygen species (ROS) production in the SH-SY5Y cells was detected using 2′,7′-dichlorodihydrofluorescein diacetate fluorescent probes. The expression levels of proteins, including caspase-12, glucose regulated protein 78 (GRP78), CCAAT/enhancer binding protein homologous protein (CHOP) and phosphorylated c-Jun N-terminal kinase (p-JNK) were detected using western blot analysis. The results showed that the half inhibitory concentration of MPP+ at 72 h was 120.9 µmol/l, and that 62.5, 125, and 250 µg/ml concentrations of VAPs protected the SH-SY5Y cells under MPP+ exposure. When exposed to 120.9 µmol/l MPP+, changes in cell nucleus morphology, mitochondrial membrane potential and intracellular ROS were observed. VAPs at concentrations of 62.5, 125, 250 µg/ml reduced this damage. Western blot analysis showed that protein expression levels of caspase-12, GRP78 and p-JNK were upregulated in the SH-SY5Y cells exposed to 120.9 µmol/l MPP+ for 72 h. In addition, 62.5, 125, and 250 µg/ml VAPs downregulated the expression levels of caspase-12 and p-JNK in a concentration- dependent manner, particularly the p-JNK pathway. The effects of VAPs on GRP78 and CHOP were weak. In conclusion, MPP+-induced SH-SY5Y cell death may be linked to ER stress. VAPs prevented MPP+-induced SH-SY5Y cell death by affecting the p-JNK pathway and caspase-12-mediated apoptosis. These findings assist in understanding the mechanism underlying the protective effect of VAPs on neurons.
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Affiliation(s)
- Ji-Le Xin
- Department of Biopharmacy, School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin 130022, P.R. China
| | - Yang Zhang
- Department of Biopharmacy, School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin 130022, P.R. China
| | - Yan Li
- Department of Rehabilitation, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, P.R. China
| | - Lian-Zhu Zhang
- College of Life Sciences and Ecology, Hainan Tropical Ocean University, Sanya, Hainan 572000, P.R. China
| | - Yong Lin
- Department of Neurology, Changchun Central Hospital, Changchun, Jilin 130051, P.R. China
| | - Lian-Wen Zheng
- Reproductive Medical Center, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
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20
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Friesen EL, De Snoo ML, Rajendran L, Kalia LV, Kalia SK. Chaperone-Based Therapies for Disease Modification in Parkinson's Disease. PARKINSON'S DISEASE 2017; 2017:5015307. [PMID: 28913005 PMCID: PMC5585656 DOI: 10.1155/2017/5015307] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 07/18/2017] [Indexed: 12/11/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder and is characterized by the presence of pathological intracellular aggregates primarily composed of misfolded α-synuclein. This pathology implicates the molecular machinery responsible for maintaining protein homeostasis (proteostasis), including molecular chaperones, in the pathobiology of the disease. There is mounting evidence from preclinical and clinical studies that various molecular chaperones are downregulated, sequestered, depleted, or dysfunctional in PD. Current therapeutic interventions for PD are inadequate as they fail to modify disease progression by ameliorating the underlying pathology. Modulating the activity of molecular chaperones, cochaperones, and their associated pathways offers a new approach for disease modifying intervention. This review will summarize the potential of chaperone-based therapies that aim to enhance the neuroprotective activity of molecular chaperones or utilize small molecule chaperones to promote proteostasis.
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Affiliation(s)
- Erik L. Friesen
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada
| | - Mitch L. De Snoo
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada
| | - Luckshi Rajendran
- Faculty of Medicine, University of British Columbia, 317-2194 Health Sciences Mall, Vancouver, BC, Canada
| | - Lorraine V. Kalia
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada
- Morton and Gloria Shulman Movement Disorders Clinic and The Edmond J. Safra Program in Parkinson's Disease, Division of Neurology, Department of Medicine, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, ON, Canada
- Division of Neurology, Department of Medicine and Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, 190 Elizabeth Street, Toronto, ON, Canada
| | - Suneil K. Kalia
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Avenue, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada
- Division of Neurosurgery, Department of Surgery, University of Toronto, 149 College Street, Toronto, ON, Canada
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Determining the Roles of Inositol Trisphosphate Receptors in Neurodegeneration: Interdisciplinary Perspectives on a Complex Topic. Mol Neurobiol 2016; 54:6870-6884. [PMID: 27771899 DOI: 10.1007/s12035-016-0205-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/11/2016] [Indexed: 02/06/2023]
Abstract
It is well known that calcium (Ca2+) is involved in the triggering of neuronal death. Ca2+ cytosolic levels are regulated by Ca2+ release from internal stores located in organelles, such as the endoplasmic reticulum. Indeed, Ca2+ transit from distinct cell compartments follows complex dynamics that are mediated by specific receptors, notably inositol trisphosphate receptors (IP3Rs). Ca2+ release by IP3Rs plays essential roles in several neurological disorders; however, details of these processes are poorly understood. Moreover, recent studies have shown that subcellular location, molecular identity, and density of IP3Rs profoundly affect Ca2+ transit in neurons. Therefore, regulation of IP3R gene products in specific cellular vicinities seems to be crucial in a wide range of cellular processes from neuroprotection to neurodegeneration. In this regard, microRNAs seem to govern not only IP3Rs translation levels but also subcellular accumulation. Combining new data from molecular cell biology with mathematical modelling, we were able to summarize the state of the art on this topic. In addition to presenting how Ca2+ dynamics mediated by IP3R activation follow a stochastic regimen, we integrated a theoretical approach in an easy-to-apply, cell biology-coherent fashion. Following the presented premises and in contrast to previously tested hypotheses, Ca2+ released by IP3Rs may play different roles in specific neurological diseases, including Alzheimer's disease and Parkinson's disease.
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ER Stress Induced by Tunicamycin Triggers α-Synuclein Oligomerization, Dopaminergic Neurons Death and Locomotor Impairment: a New Model of Parkinson’s Disease. Mol Neurobiol 2016; 54:5798-5806. [DOI: 10.1007/s12035-016-0114-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 09/09/2016] [Indexed: 11/27/2022]
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23
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Zeeshan HMA, Lee GH, Kim HR, Chae HJ. Endoplasmic Reticulum Stress and Associated ROS. Int J Mol Sci 2016; 17:327. [PMID: 26950115 PMCID: PMC4813189 DOI: 10.3390/ijms17030327] [Citation(s) in RCA: 567] [Impact Index Per Article: 70.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/21/2016] [Accepted: 02/24/2016] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is a fascinating network of tubules through which secretory and transmembrane proteins enter unfolded and exit as either folded or misfolded proteins, after which they are directed either toward other organelles or to degradation, respectively. The ER redox environment dictates the fate of entering proteins, and the level of redox signaling mediators modulates the level of reactive oxygen species (ROS). Accumulating evidence suggests the interrelation of ER stress and ROS with redox signaling mediators such as protein disulfide isomerase (PDI)-endoplasmic reticulum oxidoreductin (ERO)-1, glutathione (GSH)/glutathione disuphide (GSSG), NADPH oxidase 4 (Nox4), NADPH-P450 reductase (NPR), and calcium. Here, we reviewed persistent ER stress and protein misfolding-initiated ROS cascades and their significant roles in the pathogenesis of multiple human disorders, including neurodegenerative diseases, diabetes mellitus, atherosclerosis, inflammation, ischemia, and kidney and liver diseases.
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Affiliation(s)
- Hafiz Maher Ali Zeeshan
- Department of Pharmacology and New Drug Development Institute, School of Medicine, Chonbuk National University, Jeonju, Chonbuk 561-180, Korea.
| | - Geum Hwa Lee
- Department of Pharmacology and New Drug Development Institute, School of Medicine, Chonbuk National University, Jeonju, Chonbuk 561-180, Korea.
| | - Hyung-Ryong Kim
- Department of Dental Pharmacology and Wonkwang Biomaterial Implant Research Institute, School of Dentistry, Wonkwang University, Iksan, Chonbuk 570-749, Korea.
| | - Han-Jung Chae
- Department of Pharmacology and New Drug Development Institute, School of Medicine, Chonbuk National University, Jeonju, Chonbuk 561-180, Korea.
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24
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Jiang M, Yun Q, Shi F, Niu G, Gao Y, Xie S, Yu S. Downregulation of miR-384-5p attenuates rotenone-induced neurotoxicity in dopaminergic SH-SY5Y cells through inhibiting endoplasmic reticulum stress. Am J Physiol Cell Physiol 2016; 310:C755-63. [PMID: 26864693 DOI: 10.1152/ajpcell.00226.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 02/08/2016] [Indexed: 11/22/2022]
Abstract
Endoplasmic reticulum (ER) stress has been linked to the pathogenesis of Parkinson's disease (PD). However, the role of microRNAs (miRNAs) in this process involved in PD remains poorly understood. Recent studies indicate that miR-384-5p plays an important role for cell survival in response to different insults, but the role of miR-384-5p in PD-associated neurotoxicity remains unknown. In this study, we investigated the role of miR-384-5p in an in vitro model of PD using dopaminergic SH-SY5Y cells treated with rotenone. We found that miR-384-5p was persistently induced by rotenone in neurons. Also, the inhibition of miR-384-5p significantly suppressed rotenone-induced neurotoxicity, while overexpression of miR-384-5p aggravated rotenone-induced neurotoxicity. Through bioinformatics and dual-luciferase reporter assay, miR-384-5p was found to directly target the 3'-untranslated region of glucose-regulated protein 78 (GRP78), the master regulator of ER stress sensors. Quantitative polymerase chain reaction and Western blotting analysis showed that miR-384-5p negatively regulated the expression of GRP78. Inhibition of miR-384-5p remarkably suppressed rotenone-evoked ER stress, which was evident by a reduction in the phosphorylation of activating transcription factor 4 (ATF4) and inositol-requiring enzyme 1 (IRE1α). The downstream target genes of ER stress including CCAAT/enhancer-binding protein-homologous protein (CHOP) and X box-binding protein-1 (XBP-1) were also decreased by the miR-384-5p inhibitor. In contrast, overexpression of miR-384-5p enhanced ER stress signaling. In addition, knockdown of GRP78 significantly abrogated the inhibitory effect of miR-384-5p inhibitors on cell apoptosis and ER stress signaling. Moreover, we observed a significant increase of miR-384-5p expression in primary neurons induced by rotenone. Taken together, our results suggest that miR-384-5p mediated ER stress by negatively regulating GRP78 and that miR-384-5p inhibition might be a novel and promising approach for the treatment of PD.
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Affiliation(s)
- Mingfang Jiang
- Department of Neurology, Chinese PLA General Hospital, Beijing, China; Department of Neurology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Qiang Yun
- Department of Neurosurgery, Inner Mongolia People's Hospital, Hohhot, China
| | - Feng Shi
- Department of Radiology, Inner Mongolia Chinese Medicine Hospital, Hohhot, China; and
| | - Guangming Niu
- Department of Radiology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Yang Gao
- Department of Radiology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Shenghui Xie
- Department of Radiology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Shengyuan Yu
- Department of Neurology, Chinese PLA General Hospital, Beijing, China;
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25
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Ji K, Zhao Y, Yu T, Wang Z, Gong H, Yang X, Liu Y, Huang K. Inhibition effects of tanshinone on the aggregation of α-synuclein. Food Funct 2016; 7:409-16. [DOI: 10.1039/c5fo00664c] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Bioactive tanshinone compounds inhibit the aggregation of α-synuclein and extend the life span of aC. elegansmodel of Parkinson's disease.
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Affiliation(s)
- Kaige Ji
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Yudan Zhao
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Tianhong Yu
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Zhuoyi Wang
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Hao Gong
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Xin Yang
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
| | - Yang Liu
- Synergy Innovation Center of Biological Peptide Antidiabetics of Hubei Province
- School of Life Science
- Wuchang University of Technology
- Wuhan
- China
| | - Kun Huang
- Tongji School of Pharmacy
- Huazhong University of Science and Technology
- Wuhan
- China
- Center for Biomedicine Research
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26
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Choi J, Polcher A, Joas A. Systematic literature review on Parkinson's disease and Childhood Leukaemia and mode of actions for pesticides. ACTA ACUST UNITED AC 2016. [DOI: 10.2903/sp.efsa.2016.en-955] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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27
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Biasiotto G, Di Lorenzo D, Archetti S, Zanella I. Iron and Neurodegeneration: Is Ferritinophagy the Link? Mol Neurobiol 2015; 53:5542-74. [PMID: 26468157 DOI: 10.1007/s12035-015-9473-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/01/2015] [Indexed: 12/12/2022]
Abstract
Mounting evidence indicates that the lysosome-autophagy pathway plays a critical role in iron release from ferritin, the main iron storage cellular protein, hence in the distribution of iron to the cells. The recent identification of nuclear receptor co-activator 4 as the receptor for ferritin delivery to selective autophagy sheds further light on the understanding of the mechanisms underlying this pathway. The emerging view is that iron release from ferritin through the lysosomes is a general mechanism in normal and tumour cells of different tissue origins, but it has not yet been investigated in brain cells. Defects in the lysosome-autophagy pathway are often involved in the pathogenesis of neurodegenerative disorders, and brain iron homeostasis disruption is a hallmark of many of these diseases. However, in most cases, it has not been established whether iron dysregulation is directly involved in the pathogenesis of the diseases or if it is a secondary effect derived from other pathogenic mechanisms. The recent evidence of the crucial involvement of autophagy in cellular iron handling offers new perspectives about the role of iron in neurodegeneration, suggesting that autophagy dysregulation could cause iron dyshomeostasis. In this review, we recapitulate our current knowledge on the routes through which iron is released from ferritin, focusing on the most recent advances. We summarise the current evidence concerning lysosome-autophagy pathway dysfunctions and those of iron metabolism and discuss their potential interconnections in several neurodegenerative disorders, such as Alzheimer's, Parkinson's and Huntington's diseases; amyotrophic lateral sclerosis; and frontotemporal lobar dementia.
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Affiliation(s)
- Giorgio Biasiotto
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Diego Di Lorenzo
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Silvana Archetti
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Isabella Zanella
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
- Biotechnology Laboratory, Department of Diagnostics, Civic Hospital of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy.
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28
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Tsujii S, Ishisaka M, Hara H. Modulation of endoplasmic reticulum stress in Parkinson's disease. Eur J Pharmacol 2015; 765:154-6. [DOI: 10.1016/j.ejphar.2015.08.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 08/17/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
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29
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Zhou LX, Yang AN, Chen JK, Zhao L, Wang YH, Liu XM, Cai X, Zhang MH, Jiang YD, Cao J. Endoplasmic reticulum oxidoreductin 1α mediates homocysteine-induced hepatocyte endoplasmic reticulum stress. Shijie Huaren Xiaohua Zazhi 2014; 22:5228-5234. [DOI: 10.11569/wcjd.v22.i34.5228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess the role of endoplasmic reticulum oxidoreductin 1α (ERO1α) in homocysteine (Hcy)-induced endoplasmic reticulum stress (ERS).
METHODS: Hepatocytes were cultured in the presence or absence of Hcy (100 μmol/L), and ELISA was used to determine the concentrations of of glucose-regulated protein 78 (GRP78), X-box binding protein-1 (XBP-1), protein kinase RNA-like endoplasmic reticulum kinase (PERK) and activating transcription factor 6 (ATF6). Hepatocytes were then cultured with different concentrations of Hcy (0, 50, 100, 200, 500 μmol/L) and 100 μmol/L Hcy plus folic acid and vitamin B12, and the expression of ERO1α was detected by qRT-PCR and Western blot. ERO1α recombinant plasmid and ERO1α small interfering RNAs were then used to transfect hepatocytes, and the expression of ERO1α and the concentrations of GRP78, PERK, ATF6 and XBP-1 were measured.
RESULTS: Compared with non-treated cells, the concentrations of GRP78, PERK, ATF6 and XBP-1 significantly increased in Hcy-treated cells (P < 0.01, P < 0.01, P < 0.05, P < 0.01). Hcy decreased the expression of ERO1α at mRNA and protein levels (P < 0.01) in a dose-dependent manner. Transfection with ERO1α recombinant plasmid significantly increased the expression of ERO1α (P < 0.01), while transfection with three ERO1α small interfering RNAs significantly decreased the expression of ERO1α, with siRNA2 having the most significant effect (P < 0.01). Compared with the Hcy group, the concentrations of GRP78, PERK, ATF6 and XBP-1 significantly decreased in the Hcy + pERO1α recombinant plasmid group (P < 0.05), but increased in the Hcy + siRNA2 group (P < 0.01).
CONCLUSION: ERO1α may be involved in Hcy-induced hepatocyte ERS possibly by regulation of the GRP78-XBP-1/PERK/ATF6 signal pathway.
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