Senescent Phenotype of Astrocytes Leads to Microglia Activation and Neuronal Death

Abstract Astrocyte, the most abundant cell type in the central nervous system, is increasingly recognized and is thought to depend on curial and diverse roles in maintaining brain homeostasis, the blood-brain barrier, ion homeostasis, secrete neurotrophic factors and regulate synaptic transmission which is essential to tune individual-to-network neuronal activity. Senescence in astrocytes has been discovered to be an important contributor to several age-related neurological diseases like Alzheimer's and Parkinson's disease. However, the latest research about astrocytes from aged subjects or aged astrocytes in vitro is not yet adequate to be well elucidated on their curial process in the regulation of brain function. In this study, an in vitro cell model of aged astrocytes was constructed by serial passaging until passage 20-25, and those passages within 1-5 were used as young astrocytes. Meanwhile, oxidative induced astrocyte senescence model was also constructed by H2O2 induction. Our results indicate that after serial passaging or oxidative stress-induced astrocytes, all showed manifest changes in several established markers of cellular senescence like P53, P21, the release of inflammatory cytokine IL-6 and SA-β-gal positive cells. Results also showed mitochondrial dysfunction in the oxidative stress-induced astrocyte senescence model and treatment of berberine could reverse these alterations. What’s more interests us is that those two types of senescent astrocytes’ conditioned medium co-cultured with neuronal cells could do impact on neuron apoptosis no matter in direct or indirect ways. This study may help us better understand the fundamental role of astrocyte senescence on the regulation of normal and pathological brain aging.

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Implication of Hyperhomocysteinemia in Blood Retinal Barrier (BRB) Dysfunction

Biomolecules ◽

10.3390/biom10081119 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1119 ◽

Cited By ~ 2

Author(s):

Amany Tawfik ◽

Yara A. Samra ◽

Nehal M. Elsherbiny ◽

Mohamed Al-Shabrawey

Keyword(s):

Oxidative Stress ◽

Risk Factor ◽

Vision Loss ◽

Neurological Diseases ◽

Brain Inflammation ◽

Age Related Macular Degeneration ◽

Matrix Remodeling ◽

Blood Retinal Barrier ◽

Age Related

Elevated plasma homocysteine (Hcy) level, known as hyperhomocysteinemia (HHcy) has been linked to different systemic and neurological diseases, well-known as a risk factor for systemic atherosclerosis and cardiovascular disease (CVD) and has been identified as a risk factor for several ocular disorders, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Different mechanisms have been proposed to explain HHcy-induced visual dysfunction, including oxidative stress, upregulation of inflammatory mediators, retinal ganglion cell apoptosis, and extracellular matrix remodeling. Our previous studies using in vivo and in vitro models of HHcy have demonstrated that Hcy impairs the function of both inner and outer blood retinal barrier (BRB). Dysfunction of BRB is a hallmark of vision loss in DR and AMD. Our findings highlighted oxidative stress, ER stress, inflammation, and epigenetic modifications as possible mechanisms of HHcy-induced BRB dysfunction. In addition, we recently reported HHcy-induced brain inflammation as a mechanism of blood–brain barrier (BBB) dysfunction and pathogenesis of Alzheimer’s disease (AD). Moreover, we are currently investigating the activation of glutamate receptor N-methyl-d-aspartate receptor (NMDAR) as the molecular mechanism for HHcy-induced BRB dysfunction. This review focuses on the studied effects of HHcy on BRB and the controversial role of HHcy in the pathogenesis of aging neurological diseases such as DR, AMD, and AD. We also highlight the possible mechanisms for such deleterious effects of HHcy.

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Impact of Polyphenolic-Food on Longevity: An Elixir of Life. An Overview

Antioxidants ◽

10.3390/antiox10040507 ◽

2021 ◽

Vol 10 (4) ◽

pp. 507

Author(s):

Rosaria Meccariello ◽

Stefania D’Angelo

Keyword(s):

Oxidative Stress ◽

Food Sources ◽

Preventive Action ◽

Nutritional Interventions ◽

Beneficial Effects ◽

Age Related ◽

Macromolecular Damage ◽

And Oxidative Stress

Aging and, particularly, the onset of age-related diseases are associated with tissue dysfunction and macromolecular damage, some of which can be attributed to accumulation of oxidative damage. Recently, growing interest has emerged on the beneficial effects of plant-based diets for the prevention of chronic diseases including obesity, diabetes, and cardiovascular disease. Several studies collectively suggests that the intake of polyphenols and their major food sources may exert beneficial effects on improving insulin resistance and related diabetes risk factors, such as inflammation and oxidative stress. They are the most abundant antioxidants in the diet, and their intake has been associated with a reduced aging in humans. Polyphenolic intake has been shown to be effective at ameliorating several age-related phenotypes, including oxidative stress, inflammation, impaired proteostasis, and cellular senescence, both in vitro and in vivo. In this paper, effects of these phytochemicals (either pure forms or polyphenolic-food) are reviewed and summarized according to affected cellular signaling pathways. Finally, the effectiveness of the anti-aging preventive action of nutritional interventions based on diets rich in polyphenolic food, such as the diets of the Blue zones, are discussed.

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Vascular Dysfunction Induced by Mercury Exposure

International Journal of Molecular Sciences ◽

10.3390/ijms20102435 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2435 ◽

Cited By ~ 4

Author(s):

Tetsuya Takahashi ◽

Takayoshi Shimohata

Keyword(s):

Oxidative Stress ◽

Vascular Dysfunction ◽

Brain Parenchyma ◽

Transport Systems ◽

Mehg Exposure ◽

In Vivo Models ◽

The Central Nervous System ◽

The Brain

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.

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Antioxidative 1,4-Dihydropyridine Derivatives Modulate Oxidative Stress and Growth of Human Osteoblast-Like Cells In Vitro

Antioxidants ◽

10.3390/antiox7090123 ◽

2018 ◽

Vol 7 (9) ◽

pp. 123 ◽

Cited By ~ 8

Author(s):

Lidija Milkovic ◽

Tea Vukovic ◽

Neven Zarkovic ◽

Franz Tatzber ◽

Egils Bisenieks ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Growth ◽

Cell Model ◽

Second Messengers ◽

Human Osteoblast ◽

Tert Butyl Hydroperoxide ◽

Human Stress ◽

Set Up ◽

Dihydropyridine Derivatives

Oxidative stress has been implicated in pathophysiology of different human stress- and age-associated disorders, including osteoporosis for which antioxidants could be considered as therapeutic remedies as was suggested recently. The 1,4-dihydropyridine (DHP) derivatives are known for their pleiotropic activity, with some also acting as antioxidants. To find compounds with potential antioxidative activity, a group of 27 structurally diverse DHPs, as well as one pyridine compound, were studied. A group of 11 DHPs with 10-fold higher antioxidative potential than of uric acid, were further tested in cell model of human osteoblast-like cells. Short-term combined effects of DHPs and 50 µM H2O2 (1-h each), revealed better antioxidative potential of DHPs if administered before a stressor. Indirect 24-h effect of DHPs was evaluated in cells further exposed to mild oxidative stress conditions induced either by H2O2 or tert-butyl hydroperoxide (both 50 µM). Cell growth (viability and proliferation), generation of ROS and intracellular glutathione concentration were evaluated. The promotion of cell growth was highly dependent on the concentrations of DHPs used, type of stressor applied and treatment set-up. Thiocarbatone III-1, E2-134-1 III-4, Carbatone II-1, AV-153 IV-1, and Diethone I could be considered as therapeutic agents for osteoporosis although further research is needed to elucidate their bioactivity mechanisms, in particular in respect to signaling pathways involving 4-hydroxynoneal and related second messengers of free radicals.

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Multiphoton NAD(P)H FLIM reveals metabolic changes in individual cell types of the intact cochlea upon sensorineural hearing loss

Scientific Reports ◽

10.1038/s41598-019-55329-x ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Paromita Majumder ◽

Thomas S. Blacker ◽

Lisa S. Nolan ◽

Michael R. Duchen ◽

Jonathan E. Gale

Keyword(s):

Oxidative Stress ◽

Hearing Loss ◽

Cell Model ◽

Organ Of Corti ◽

Cell Types ◽

Fluorescence Lifetime Imaging ◽

Noise Induced Hearing Loss ◽

Label Free ◽

Age Related ◽

The Individual

AbstractAn increasing volume of data suggests that changes in cellular metabolism have a major impact on the health of tissues and organs, including in the auditory system where metabolic alterations are implicated in both age-related and noise-induced hearing loss. However, the difficulty of access and the complex cyto-architecture of the organ of Corti has made interrogating the individual metabolic states of the diverse cell types present a major challenge. Multiphoton fluorescence lifetime imaging microscopy (FLIM) allows label-free measurements of the biochemical status of the intrinsically fluorescent metabolic cofactors NADH and NADPH with subcellular spatial resolution. However, the interpretation of NAD(P)H FLIM measurements in terms of the metabolic state of the sample are not completely understood. We have used this technique to explore changes in metabolism associated with hearing onset and with acquired (age-related and noise-induced) hearing loss. We show that these conditions are associated with altered NAD(P)H fluorescence lifetimes, use a simple cell model to confirm an inverse relationship between τbound and oxidative stress, and propose such changes as a potential index of oxidative stress applicable to all mammalian cell types.

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Phytochemicals from the Cocoa Shell Modulate Mitochondrial Function, Lipid and Glucose Metabolism in Hepatocytes via Activation of FGF21/ERK, AKT, and mTOR Pathways

Antioxidants ◽

10.3390/antiox11010136 ◽

2022 ◽

Vol 11 (1) ◽

pp. 136

Author(s):

Miguel Rebollo-Hernanz ◽

Yolanda Aguilera ◽

Maria A. Martin-Cabrejas ◽

Elvira Gonzalez de Gonzalez de Mejia

Keyword(s):

Oxidative Stress ◽

Mitochondrial Function ◽

Phosphoenolpyruvate Carboxykinase ◽

Fatty Acid Synthase ◽

Cell Model ◽

Fibroblast Growth Factor 21 ◽

Alcoholic Fatty Liver ◽

Atp Production ◽

Cocoa Shell

The cocoa shell is a by-product that may be revalorized as a source of bioactive compounds to prevent chronic cardiometabolic diseases. This study aimed to investigate the phytochemicals from the cocoa shell as targeted compounds for activating fibroblast growth factor 21 (FGF21) signaling and regulating non-alcoholic fatty liver disease (NAFLD)-related biomarkers linked to oxidative stress, mitochondrial function, and metabolism in hepatocytes. HepG2 cells treated with palmitic acid (PA, 500 µmol L−1) were used in an NAFLD cell model. Phytochemicals from the cocoa shell (50 µmol L−1) and an aqueous extract (CAE, 100 µg mL−1) enhanced ERK1/2 phosphorylation (1.7- to 3.3-fold) and FGF21 release (1.4- to 3.4-fold) via PPARα activation. Oxidative stress markers were reduced though Nrf-2 regulation. Mitochondrial function (mitochondrial respiration and ATP production) was protected by the PGC-1α pathway modulation. Cocoa shell phytochemicals reduced lipid accumulation (53–115%) and fatty acid synthase activity (59–93%) and prompted CPT-1 activity. Glucose uptake and glucokinase activity were enhanced, whereas glucose production and phosphoenolpyruvate carboxykinase activity were diminished. The increase in the phosphorylation of the insulin receptor, AKT, AMPKα, mTOR, and ERK1/2 conduced to the regulation of hepatic mitochondrial function and energy metabolism. For the first time, the cocoa shell phytochemicals are proved to modulate FGF21 signaling. Results demonstrate the in vitro preventive effect of the phytochemicals from the cocoa shell on NAFLD.

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Coenzyme Q10, Ageing and the Nervous System: An Overview

Antioxidants ◽

10.3390/antiox11010002 ◽

2021 ◽

Vol 11 (1) ◽

pp. 2

Author(s):

David Mantle ◽

Robert A. Heaton ◽

Iain P. Hargreaves

Keyword(s):

Oxidative Stress ◽

Coenzyme Q10 ◽

Neurological Disorders ◽

Neurological Disease ◽

Age Related ◽

Increased Risk ◽

Potential Therapeutic Role ◽

Ageing Brain ◽

And Oxidative Stress

The ageing brain is characterised by changes at the physical, histological, biochemical and physiological levels. This ageing process is associated with an increased risk of developing a number of neurological disorders, notably Alzheimer’s disease and Parkinson’s disease. There is evidence that mitochondrial dysfunction and oxidative stress play a key role in the pathogenesis of such disorders. In this article, we review the potential therapeutic role in these age-related neurological disorders of supplementary coenzyme Q10, a vitamin-like substance of vital importance for normal mitochondrial function and as an antioxidant. This review is concerned primarily with studies in humans rather than in vitro studies or studies in animal models of neurological disease. In particular, the reasons why the outcomes of clinical trials supplementing coenzyme Q10 in these neurological disorders is discussed.

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A novel mitochondrial enriched antioxidant protects neurons against acute oxidative stress

10.1101/109439 ◽

2017 ◽

Author(s):

Nicola J. Drummond ◽

Nick O. Davies ◽

Janet E. Lovett ◽

Mark R. Miller ◽

Graeme Cook ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Damage ◽

Radical Scavenging ◽

Head Group ◽

Neural Cells ◽

Zebrafish Model ◽

Free System ◽

Age Related

AbstractExcessive reactive oxygen species (ROS) can damage proteins, lipids, and DNA, which result in cell damage and death. The outcomes can be acute, as seen in stroke, or more chronic as observed in age-related diseases such as Parkinson’s disease. Here we investigate the antioxidant ability of a novel synthetic flavonoid, Proxison (7-decyl-3-hydroxy-2-(3,4,5-trihydroxyphenyl)-4-chromenone), using a range of in vitro and in vivo approaches. We show that, while it has radical scavenging ability on par with other flavonoids in a cell-free system, Proxison is orders of magnitude more potent than natural flavonoids at protecting neural cells against oxidative stress and is capable of rescuing damaged cells. The unique combination of a lipophilic hydrocarbon tail with a modified polyphenolic head group promotes efficient cellular uptake and mitochondrial localisation of Proxison. Importantly, in vivo administration of Proxison demonstrated effective and well tolerated neuroprotection against oxidative stress in a zebrafish model of dopaminergic neuronal loss.

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Neuroinflammation in Aged Brain: Impact of the Oral Administration of Ellagic Acid Microdispersion

International Journal of Molecular Sciences ◽

10.3390/ijms21103631 ◽

2020 ◽

Vol 21 (10) ◽

pp. 3631 ◽

Cited By ~ 2

Author(s):

Raffaella Boggia ◽

Federica Turrini ◽

Alessandra Roggeri ◽

Guendalina Olivero ◽

Francesca Cisani ◽

...

Keyword(s):

Oral Administration ◽

Ellagic Acid ◽

Ex Vivo ◽

Behavioral Skills ◽

Aged Mice ◽

Age Related ◽

The Central Nervous System ◽

The Impact ◽

Old Mice

The immune system and the central nervous system message each other to preserving central homeostasis. Both systems undergo changes during aging that determine central age-related defects. Ellagic acid (EA) is a natural product which is beneficial in both peripheral and central diseases, including aging. We analyzed the impact of the oral administration of a new oral ellagic acid micro-dispersion (EAm), that largely increased the EA solubility, in young and old mice. Oral EAm did not modify animal weight and behavioral skills in young and old mice, but significantly recovered changes in “ex-vivo, in vitro” parameters in old animals. Cortical noradrenaline exocytosis decreased in aged mice. EAm administration did not modify noradrenaline overflow in young animals, but recovered it in old mice. Furthermore, GFAP staining was increased in the cortex of aged mice, while IBA-1 and CD45 immunopositivities were unchanged when compared to young ones. EAm treatment significantly reduced CD45 signal in both young and old cortical lysates; it diminished GFAP immunopositivity in young mice, but failed to affect IBA-1 expression in both young and old animals. Finally, EAm treatment significantly reduced IL1beta expression in old mice. These results suggest that EAm is beneficial to aging and represents a nutraceutical ingredient for elders.

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Glycation and Oxidative Stress Increase Autoantibodies in the Elderly

Molecules ◽

10.3390/molecules25163675 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3675

Author(s):

Mohd W.A. Khan ◽

Ahmed Al Otaibi ◽

Subuhi Sherwani ◽

Wahid A. Khan ◽

Eida M. Alshammari ◽

...

Keyword(s):

Oxidative Stress ◽

The Elderly ◽

Significant Inhibition ◽

Group Iv ◽

Blood Proteins ◽

Age Related ◽

Direct Binding ◽

Asymptomatic Individuals ◽

Immune Imbalance

Aging causes gradual changes in free radicals, antioxidants, and immune-imbalance in the elderly. This study aims to understand links among aging, gluco-oxidative stress, and autoantibodies in asymptomatic individuals. In vitro glycation of human serum albumin (Gly-HSA) induces appreciable biochemical changes. Significant inhibition of advanced glycation end products (AGEs) formation was achieved using garlic extract (53.75%) and epigallocatechin-3-gallate from green tea (72.5%). Increased amounts of serum carbonyl content (2.42 ± 0.5) and pentosidine (0.0321 ± 0.0029) were detected in IV-S (S represent smokers) vs. IV group individuals. Direct binding ELISA results exhibited significantly high autoantibodies against Gly-HSA in group IV-S (0.55 ± 0.054; p < 0.001) and III-S (0.40 ± 0.044; p < 0.01) individuals as compared to the age matched subjects who were non-smokers (group IV and III). Moreover, high average percent inhibition (51.3 ± 4.1%) was obtained against Gly-HSA in IV-S group individuals. Apparent association constant was found to be high for serum immunoglobulin-G (IgG) from group IV-S (1.18 × 10−6 M) vs. serum IgG from IV group (3.32 × 10−7 M). Aging induced gluco-oxidative stress and AGEs formation may generate neo-epitopes on blood-proteins, contributing to production of autoantibodies in the elderly, especially smokers. Use of anti-glycation natural products may reduce age-related pathophysiological changes.

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