Knockdown of metallothionein 1 and 2 does not affect atrophy or oxidant activity in a novel in vitro model

Skeletal muscle atrophy is a significant health problem that results in decreased muscle size and function and has been associated with increases in oxidative stress. The molecular mechanisms that regulate muscle atrophy, however, are largely unknown. The metallothioneins (MT), a family of genes with antioxidant properties, have been found to be consistently upregulated during muscle atrophy, although their function during muscle atrophy is unknown. Therefore, we hypothesized that MT knockdown would result in greater oxidative stress and an enhanced atrophy response in C2C12 myotubes subjected to serum reduction (SR), a novel atrophy-inducing stimulus. Forty-eight hours before SR, myotubes were transfected with small interfering RNA (siRNA) sequences designed to decrease MT expression. Muscle atrophy and oxidative stress were then measured at baseline and for 72 h following SR. Muscle atrophy was quantified by immunocytochemistry and myotube diameter measurements. Oxidative stress was measured using the fluorescent probe 5-(and-6)-carboxy-2′,7′-dichlorodihydrofluorescein. SR resulted in a significant increase in oxidative stress and a decrease in myotube size and protein content. However, there were no differences observed in the extent of muscle atrophy or oxidant activity following MT knockdown. We therefore conclude that the novel SR model results in a strong atrophy response and an increase in oxidant activity in cultured myotubes and that knockdown of MT does not affect that response.

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Camphene Attenuates Skeletal Muscle Atrophy by Regulating Oxidative Stress and Lipid Metabolism in Rats

Nutrients ◽

10.3390/nu12123731 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3731

Author(s):

Suji Baek ◽

Jisu Kim ◽

Byung Seok Moon ◽

Sun Mi Park ◽

Da Eun Jung ◽

...

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Lipid Metabolism ◽

Muscle Atrophy ◽

Gas Analysis ◽

Skeletal Muscle Atrophy ◽

Ros Scavenging ◽

In Vivo Models

Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro and in vivo. We treated L6 myoblast cells with camphene and then examined the ROS-related oxidative stress using Mito TrackerTM Red FM and anti-8-oxoguanine antibody staining. To investigate lipid metabolism, we performed real-time polymerase chain reactions, holotomographic microscopy, and respiratory gas analysis. Rat muscle atrophy in in vivo models was observed using 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography and immunocytochemistry. Camphene reversed the aberrant cell size and muscle morphology of L6 myoblasts under starvation and in in vivo models. Camphene also attenuated E3 ubiquitin ligase muscle RING-finger protein-1, mitochondrial fission, and 8-oxoguanine nuclear expression in starved myotubes and hydrogen peroxide (H2O2)-treated cells. Moreover, camphene significantly regulated lipid metabolism in H2O2-treated cells and in vivo models. These findings suggest that camphene may potentially affect skeletal muscle atrophy by regulating oxidative stress and lipid metabolism.

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Blockade of Metallothioneins 1 and 2 Increases Skeletal Muscle Mass and Strength

Molecular and Cellular Biology ◽

10.1128/mcb.00305-16 ◽

2016 ◽

Vol 37 (5) ◽

Cited By ~ 25

Author(s):

Serge Summermatter ◽

Anais Bouzan ◽

Eliane Pierrel ◽

Stefan Melly ◽

Daniela Stauffer ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Mass ◽

Muscle Atrophy ◽

Skeletal Muscle Atrophy ◽

Intracellular Zinc ◽

Beneficial Effects ◽

And Function ◽

Zinc Storage

ABSTRACT Metallothioneins are proteins that are involved in intracellular zinc storage and transport. Their expression levels have been reported to be elevated in several settings of skeletal muscle atrophy. We therefore investigated the effect of metallothionein blockade on skeletal muscle anabolism in vitro and in vivo. We found that concomitant abrogation of metallothioneins 1 and 2 results in activation of the Akt pathway and increases in myotube size, in type IIb fiber hypertrophy, and ultimately in muscle strength. Importantly, the beneficial effects of metallothionein blockade on muscle mass and function was also observed in the setting of glucocorticoid addition, which is a strong atrophy-inducing stimulus. Given the blockade of atrophy and the preservation of strength in atrophy-inducing settings, these results suggest that blockade of metallothioneins 1 and 2 constitutes a promising approach for the treatment of conditions which result in muscle atrophy.

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Faculty Opinions recommendation of Little change in markers of protein breakdown and oxidative stress in humans in immobilization-induced skeletal muscle atrophy.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.7808956.8146054 ◽

2011 ◽

Author(s):

Roberto Bottinelli

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Muscle Atrophy ◽

Skeletal Muscle Atrophy ◽

Protein Breakdown ◽

And Oxidative Stress

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Targeting PPARalpha in Alzheimer's Disease

Current Alzheimer Research ◽

10.2174/1567205014666170505094549 ◽

2018 ◽

Vol 15 (4) ◽

pp. 345-354 ◽

Cited By ~ 13

Author(s):

Barbara D'Orio ◽

Anna Fracassi ◽

Maria Paola Cerù ◽

Sandra Moreno

Keyword(s):

Oxidative Stress ◽

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Molecular Mechanisms ◽

Redox Homeostasis ◽

Antioxidant Response ◽

Peroxisome Proliferator ◽

Prevailing Paradigm

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.

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Isobornylchalcones as Scaffold for the Synthesis of Diarylpyrazolines with Antioxidant Activity

Molecules ◽

10.3390/molecules26123579 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3579

Author(s):

Svetlana A. Popova ◽

Evgenia V. Pavlova ◽

Oksana G. Shevchenko ◽

Irina Yu. Chukicheva ◽

Aleksandr V. Kutchin

Keyword(s):

Antioxidant Activity ◽

Antioxidant Properties ◽

Biological Properties ◽

High Reactivity ◽

Biologically Active ◽

Brain Lipids ◽

Wide Range ◽

Privileged Structure ◽

Vitro Model

The pyrazoline ring is defined as a “privileged structure” in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system. At the same time, bicyclic monoterpenoids deserve special attention as a source of a key structural block or as one of the pharmacophore components of biologically active molecules. A series of new diarylpyrazoline derivatives based on isobornylchalcones with different substitutes (MeO, Hal, NO2, N(Me)2) was synthesized. Antioxidant properties of the obtained compounds were comparatively evaluated using in vitro model Fe2+/ascorbate-initiated lipid peroxidation in the substrate containing brain lipids of laboratory mice. It was demonstrated that the combination of the electron-donating group in the para-position of ring B and OH-group in the ring A in the structure of chalcone fragment provides significant antioxidant activity of synthesized diarylpyrazoline derivatives.

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Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽

10.3390/molecules26061676 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1676

Author(s):

Giulia Rossi ◽

Martina Placidi ◽

Chiara Castellini ◽

Francesco Rea ◽

Settimio D'Andrea ◽

...

Keyword(s):

In Vitro Model ◽

Molecular Mechanisms ◽

Biological Effects ◽

Cellular Damage ◽

X Rays ◽

Adolescent Cancer ◽

Radiation Induced ◽

Vitro Model ◽

Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

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Alcohol-and-HIV-Induced Lysosomal Dysfunction Regulates Extracellular Vesicles Secretion in Vitro and in Liver-Humanized Mice

Biology ◽

10.3390/biology10010029 ◽

2021 ◽

Vol 10 (1) ◽

pp. 29

Author(s):

Raghubendra Singh Dagur ◽

Moses New-Aaron ◽

Murali Ganesan ◽

Weimin Wang ◽

Svetlana Romanova ◽

...

Keyword(s):

Oxidative Stress ◽

Extracellular Vesicles ◽

Treated Group ◽

Human Hepatocytes ◽

In Vivo Studies ◽

People Living With Hiv ◽

Humanized Mouse Model ◽

And Function

Background: Alcohol abuse is common in people living with HIV-1 and dramaticallyenhances the severity of HIV-induced liver damage by inducing oxidative stress and lysosomaldysfunction in the liver cells. We hypothesize that the increased release of extracellular vesicles(EVs) in hepatocytes and liver humanized mouse model is linked to lysosome dysfunction. Methods:The study was performed on primary human hepatocytes and human hepatoma RLWXP-GFP (Huh7.5 cells stably transfected with CYP2E1 and XPack-GFP) cells and validated on ethanol-fed liverhumanizedfumarylacetoacetate hydrolase (Fah)-/-, Rag2-/-, common cytokine receptor gamma chainknockout (FRG-KO) mice. Cells and mice were infected with HIV-1ADA virus. Results: We observedan increase in the secretion of EVs associated with a decrease in lysosomal activity and expressionof lysosomal-associated membrane protein 1. Next-generation RNA sequencing of primary humanhepatocytes revealed 63 differentially expressed genes, with 13 downregulated and 50 upregulatedgenes in the alcohol–HIV-treated group. Upstream regulator analysis of differentially expressedgenes through Ingenuity Pathway Analysis identified transcriptional regulators affecting downstreamgenes associated with increased oxidative stress, lysosomal associated disease, and function andEVs biogenesis. Our in vitro findings were corroborated by in vivo studies on human hepatocytetransplantedhumanized mice, indicating that intensive EVs’ generation by human hepatocytes andtheir secretion to serum was associated with increased oxidative stress and reduction in lysosomalactivities triggered by HIV infection and ethanol diet. Conclusion: HIV-and-ethanol-metabolisminducedEVs release is tightly controlled by lysosome status in hepatocytes and participates in thedevelopment of double-insult-induced liver injury.

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Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

BioMed Research International ◽

10.1155/2018/8584136 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 12

Author(s):

Lingyu Yang ◽

Dehai Xian ◽

Xia Xiong ◽

Rui Lai ◽

Jing Song ◽

...

Keyword(s):

Oxidative Stress ◽

Signaling Pathways ◽

Molecular Mechanisms ◽

Metabolic Diseases ◽

Low Cost ◽

Natural Agents ◽

Molecular Damage ◽

And Control

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerousin vitroandin vivostudies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

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Enhancing the Nrf2 Antioxidant Signaling Provides Protection Against Trichloroethene-mediated Inflammation and Autoimmune Response

Toxicological Sciences ◽

10.1093/toxsci/kfaa022 ◽

2020 ◽

Vol 175 (1) ◽

pp. 64-74 ◽

Cited By ~ 3

Author(s):

Nivedita Banerjee ◽

Hui Wang ◽

Gangduo Wang ◽

M Firoze Khan

Keyword(s):

Oxidative Stress ◽

T Cells ◽

Molecular Mechanisms ◽

Inflammatory Responses ◽

Autoimmune Response ◽

Mediated Effects ◽

Antioxidant Gene Expression ◽

Responsive Element

Abstract Trichloroethene (trichloroethylene, TCE) and one of its reactive metabolites dichloroacetyl chloride (DCAC) are associated with the induction of autoimmunity in MRL+/+ mice. Although oxidative stress plays a major role in TCE-/DCAC-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Nuclear factor (erythroid-derived 2)-like2 (Nrf2) is an oxidative stress-responsive transcription factor that binds to antioxidant responsive element (ARE) and provides protection by regulating cytoprotective and antioxidant gene expression. However, the potential of Nrf2 in the regulation of TCE-/DCAC-mediated autoimmunity is not known. This study thus focused on establishing the role of Nrf2 and consequent inflammatory responses in TCE-/DCAC-mediated autoimmunity. To achieve this, we pretreated Kupffer cells (KCs) or T cells with/without tert-butylhydroquinone (tBHQ) followed by treatment with DCAC. In both KCs and T cells, DCAC treatment significantly downregulated Nrf2 and HO-1 expression along with induction of Keap-1 and caspase-3, NF-κB (p65), TNF-α, and iNOS, whereas pretreatment of these cells with tBHQ attenuated these responses. The in vitro findings were further verified in vivo by treating female MRL+/+ mice with TCE along with/without sulforaphane. TCE exposure in mice also led to reduction in Nrf2 and HO-1 but increased phospho-NF-κB (p-p65) and iNOS along with increased anti-dsDNA antibodies. Interestingly, sulforaphane treatment led to amelioration of TCE-mediated effects, resulting in Nrf2 activation and reduction in inflammatory and autoimmune responses. Our results show that TCE/DCAC mediates an impairment in Nrf2 regulation. Attenuation of TCE-mediated autoimmunity via activation of Nrf2 supports that antioxidants sulforaphane/tBHQ could be potential therapeutic agents for autoimmune diseases.

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