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Laabbar W, Abbaoui A, Elgot A, Mokni M, Amri M, Masmoudi-Kouki O, Gamrani H. Aluminum induced oxidative stress, astrogliosis and cell death in rat astrocytes, is prevented by curcumin. J Chem Neuroanat 2020; 112:101915. [PMID: 33370573 DOI: 10.1016/j.jchemneu.2020.101915] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/21/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022]
Abstract
Aluminum (Al) is recognized potent neurotoxic metal, which causes oxidative stress leading to intracellular accumulation of reactive oxygen species (ROS) and neuronal cell death in various neurodegenerative diseases. Among several medicinal plants with beneficial effects on health, curcumin acts as a multi-functional drug with antioxidant activity. Thus, the purpose of the present study was to evaluate the protective effect of curcumin against aluminum induced-oxidative stress and astrocytes death, in vitro ad in vivo. Incubation of cultured rat astrocytes with two concentrations of Al (37 μM and 150 μM) for 1 h provoked a dose-dependent reduction of the number of living cells as evaluated by Fluorescein diacetate and lactate dehydrogenase assay. Al-treated cells exhibited a reduction of both superoxide dismutase (SOD) and catalase activities. Pretreatment of astrocytes with curcumin (81 μM) prevented Al-induced cell death. Regarding in vivo study, rats were exposed acutely during three consecutive days to three different doses of Al (25 mg/kg, 50 mg/kg and 100 mg/kg, i.p injection), together with curcumin treatment (30 mg/kg). For the chronic model, animals were exposed to Al (3 g/l) in drinking water from intrauterine age to 4 months ages, plus curcumin treatment (175 mg/kg). Data showed that both acute and chronic Al intoxication induced an obvious astrogliosis within motor cortex and hippocampus, while, such effects were restored by curcumin. We showed herein that Al was highly toxic, induced astrocytes death. Then, curcumin protected astrocytes against Al-toxicity. The cytoprotective potential of curcumin is initiated by stimulation of endogenous antioxidant system.
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Affiliation(s)
- Wafaa Laabbar
- Neurosciences, Pharmacology and Environment Team, Laboratory of Clinical, Experimental and Environmental Neurosciences, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakech, Morocco; Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Abdellatif Abbaoui
- Neurosciences, Pharmacology and Environment Team, Laboratory of Clinical, Experimental and Environmental Neurosciences, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakech, Morocco; Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco
| | - Abdeljalil Elgot
- Epidemiology and Biomedical Sciences Unit, Laboratory of Health Sciences and Technologies, Higher Institute of Health Sciences, Hassan First University of Settat, Settat, Morocco
| | - Meherzia Mokni
- University Tunis El Manar, Faculty of Science of Tunis, UR/11ES09 Laboratory of Functional Neurophysiology and Pathology, 2092 Tunis, Tunisia
| | - Mohamed Amri
- University Tunis El Manar, Faculty of Science of Tunis, UR/11ES09 Laboratory of Functional Neurophysiology and Pathology, 2092 Tunis, Tunisia.
| | - Olfa Masmoudi-Kouki
- University Tunis El Manar, Faculty of Science of Tunis, UR/11ES09 Laboratory of Functional Neurophysiology and Pathology, 2092 Tunis, Tunisia
| | - Halima Gamrani
- Neurosciences, Pharmacology and Environment Team, Laboratory of Clinical, Experimental and Environmental Neurosciences, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakech, Morocco; Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakesh, Morocco.
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Maina MB, Bailey LJ, Doherty AJ, Serpell LC. The Involvement of Aβ42 and Tau in Nucleolar and Protein Synthesis Machinery Dysfunction. Front Cell Neurosci 2018; 12:220. [PMID: 30123109 PMCID: PMC6086011 DOI: 10.3389/fncel.2018.00220] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/09/2018] [Indexed: 01/29/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia and is distinguished from other dementias by observation of extracellular Amyloid-β (Aβ) plaques and intracellular neurofibrillary tangles, comprised of fibrils of Aβ and tau protein, respectively. At early stages, AD is characterized by minimal neurodegeneration, oxidative stress, nucleolar stress, and altered protein synthesis machinery. It is generally believed that Aβ oligomers are the neurotoxic species and their levels in the AD brain correlate with the severity of dementia suggesting that they play a critical role in the pathogenesis of the disease. Here, we show that the incubation of differentiated human neuroblastoma cells (SHSY5Y) with freshly prepared Aβ42 oligomers initially resulted in oxidative stress and subtle nucleolar stress in the absence of DNA damage or cell death. The presence of exogenous Aβ oligomers resulted in altered nuclear tau levels as well as phosphorylation state, leading to altered distribution of nucleolar tau associated with nucleolar stress. These markers of cellular dysfunction worsen over time alongside a reduction in ribosomal RNA synthesis and processing, a decrease in global level of newly synthesized RNA and reduced protein synthesis. The interplay between Aβ and tau in AD remains intriguing and Aβ toxicity has been linked to tau phosphorylation and changes in localization. These findings provide evidence for the involvement of Aβ42 effects on nucleolar tau and protein synthesis machinery dysfunction in cultured cells. Protein synthesis dysfunction is observed in mild cognitive impairment and early AD in the absence of significant neuronal death.
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Affiliation(s)
- Mahmoud B Maina
- School of Life Sciences, University of Sussex, Brighton, United Kingdom.,Department of Human Anatomy, College of Medical Sciences, Gombe State University, Gombe, Nigeria
| | - Laura J Bailey
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Louise C Serpell
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
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Zhao Y, Cong L, Lukiw WJ. Lipopolysaccharide (LPS) Accumulates in Neocortical Neurons of Alzheimer's Disease (AD) Brain and Impairs Transcription in Human Neuronal-Glial Primary Co-cultures. Front Aging Neurosci 2017; 9:407. [PMID: 29311897 PMCID: PMC5732913 DOI: 10.3389/fnagi.2017.00407] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 11/24/2017] [Indexed: 11/26/2022] Open
Abstract
Several independent laboratories have recently reported the detection of bacterial nucleic acid sequences or bacterial-derived neurotoxins, such as highly inflammatory lipopolysaccharide (LPS), within Alzheimer’s disease (AD) affected brain tissues. Whether these bacterial neurotoxins originate from the gastrointestinal (GI) tract microbiome, a possible brain microbiome or some dormant pathological microbiome is currently not well understood. Previous studies indicate that the co-localization of pro-inflammatory LPS with AD-affected brain cell nuclei suggests that there may be a contribution of this neurotoxin to genotoxic events that support inflammatory neurodegeneration and failure in homeostatic gene expression. In this report we provide evidence that in sporadic AD, LPS progressively accumulates in neuronal parenchyma and appears to preferentially associate with the periphery of neuronal nuclei. Run-on transcription studies utilizing [α-32P]-uridine triphosphate incorporation into newly synthesized total RNA further indicates that human neuronal-glial (HNG) cells in primary co-culture incubated with LPS exhibit significantly reduced output of DNA transcription products. These studies suggest that in AD LPS may impair the efficient readout of neuronal genetic information normally required for the homeostatic operation of brain cell function and may contribute to a progressive disruption in the read-out of genetic information.
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Affiliation(s)
- Yuhai Zhao
- Neuroscience Center, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Departments of Anatomy and Cell Biology, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Lin Cong
- Neuroscience Center, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Neurology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Walter J Lukiw
- Neuroscience Center, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Neurology, Shengjing Hospital, China Medical University, Shenyang, China.,Department of Neurology, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Ophthalmology, Louisiana State University School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, United States
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Hill WD, Arai M, Cohen JA, Trojanowski JQ. Neurofilament mRNA is reduced in Parkinson's disease substantia nigra pars compacta neurons. J Comp Neurol 1993; 329:328-36. [PMID: 8459049 DOI: 10.1002/cne.903290304] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Lewy bodies are filamentous neuronal inclusions characteristic of Parkinson's disease, and neurofilament triplet proteins are the major components of the filaments in Lewy bodies. Since the neurofilament proteins found in Lewy bodies are abnormally phosphorylated and partially degraded, the formation of Lewy bodies may be due to the defective metabolism of these proteins, and this could lead to impairments in the structure and function of neurofilament rich neuronal processes (i.e., large caliber axons). To gain further insights into the metabolism of neurofilaments in Parkinson's disease, we evaluated neurofilament mRNA levels by semi-quantitative in situ hybridization histochemistry in postmortem tissues from Parkinson's disease and control subjects. Substantia nigra pars compacta neurons were examined with digoxigenin-UTP labeled cRNA probes to the heavy and light neurofilament mRNAs. The relative abundance of these mRNAs was measured by videodensitometric image analysis of chromogenic reaction product. Using this approach, we demonstrated that the levels of both heavy and light neurofilament mRNAs were reduced in Parkinson's disease substantia nigra pars compacta neurons. Additionally, the levels of heavy neurofilament mRNA were lowest in Lewy body containing neurons in the Parkinson's disease cases. These results suggest that the formation of neurofilament-rich Lewy bodies in substantia nigra pars compacta neurons is associated with reduced levels of the heavy and light neurofilament mRNAs in Parkinson's disease. Thus, it is possible that the accumulation of abnormal neurofilament proteins in Lewy bodies and diminished neurofilament mRNAs contribute to the degeneration of substantia nigra pars compacta neurons in Parkinson's disease.
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Affiliation(s)
- W D Hill
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta 30912-2000
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