scholarly journals Anti-Apoptosis and Autophagy Effects of Melatonin Protect Rat Chondrocytes against Oxidative Stress via Regulation of AMPK/Foxo3 Pathways

Cartilage ◽  
2021 ◽  
pp. 194760352110387
Author(s):  
Zhaoxun Chen ◽  
Chen Zhao ◽  
Pengcheng Liu ◽  
Haohan Huang ◽  
Shuhong Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Western Blotting ◽  
Redox Homeostasis ◽  
Cartilage Degeneration ◽  
Cell Counting ◽  
Autophagic Flux ◽  
Sprague Dawley ◽  
Melatonin Treatment ◽  
Age Related

Objective Emerging evidence has indicated that excessive reactive oxygen species (ROS) have detrimental effects on osteoarthritis (OA). This study aimed to elucidate the effects of melatonin (MT), an antioxidant indolamine secreted from the pineal gland, on chondrocyte senescence and cartilage degeneration, thereby clarifying the underlying mechanisms of ROS-induced OA pathogenesis. Design Hydrogen peroxide (H2O2) was used to induce oxidative stress in rat chondrocytes. ROS levels were evaluated using cytometry and immunofluorescence. Cell viability was detected using the Cell Counting Kit-8 (CCK-8) assay. Western blotting and qPCR (Quantiative Real-Time Polymerase Chain Reaction) were used to examine apoptosis and autophagy. For in vivo experiments, male Sprague-Dawley rats were randomly divided into a sham-operated group, DMM (destabilization of the medial meniscus) surgery group, and surgery groups that received melatonin. Knee joints were collected and stained for histological analysis. Results The data demonstrated that melatonin treatment significantly suppressed H2O2-induced matrix degradation and apoptosis, and maintained mitochondrial redox homeostasis. In addition, an enhancement of autophagic flux was observed through western blotting. These findings corresponded with activation of the AMPK/Foxo3 signaling pathways upon melatonin treatment. Histological staining and transmission electron microscopy (TEM) micrographs also demonstrated that melatonin alleviated cartilage ossification and chondrocyte hypertrophy in vivo. Conclusions Our results indicated that melatonin protected chondrocytes via mitochondrial redox homeostasis and autophagy. The effects of melatonin on senescence may apply to other age-related diseases. Thus, melatonin may have multiple potential therapeutic applications.

Targeting PPARalpha in Alzheimer's Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
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.

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

Antioxidants ◽  
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.

Extracellular signal-regulated kinase inhibition prevents venous adaptive remodeling via regulation of Eph-B4

Vascular ◽  
2021 ◽  
pp. 170853812199985
Author(s):  
Yuanyuan Guo ◽  
Fan Zhu ◽  
Xiong Zhang ◽  
Guangmin Wu ◽  
Pinting Fu ◽  
...  
Keyword(s):  
Western Blotting ◽  
Vein Graft ◽  
Artery Bypass ◽  
Bypass Graft ◽  
Graft Loss ◽  
Elastic Fibers ◽  
Sprague Dawley ◽  
Vein Grafts ◽  
Graft Stenosis

Objectives Vein graft adaptation (VGA) is a process that vein as a vascular graft conduits in arterial reconstructive surgery; VGA can lead to postoperative vein graft stenosis (VGS) and complications after coronary artery bypass graft and other peripheral artery bypass surgeries. VGA is characterized by vein graft loss the venous features without exhibiting arterial features; furthermore, the activation of ERK inhibited the maintenance of venous properties of the vein graft. We hypothesized that ERK inhibition can affect vein VGS through regulating the expression of EphB4. Methods Rat vein transplantation model was established using wild-type and EphB4+/− Sprague-Dawley rats. Hematoxylin-eosin, Masson, Verhoeff, actin staining, and immunohistochemistry were applied to observe the structure of the vein grafts. Vascular smooth muscle cells (VSMCs) were isolated from the vein and vein grafts. Western blotting was used to determine the expression of p-ERK1/2 and EphB4, and immunofluorescence was applied to detect the expression and location of EphB4. Cell wound scratch assay and CCK8 assay were used to determine the migration and proliferation of VSMCs. Real-time polymerase chain reaction was used to determine the mRNA expression of EphB4. Results Western blotting in vein sample and vein graft sample detected p-ERK1/2 and ERK1/2 expression in both EphB4+/+ and EphB4+/− rats. The expression of p-ERK was increased in vein graft compared to vein. Immunofluorescence in VSMCs form EphB4+/+ and EphB4+/− rats detected EphB4 expression in both cells, and the expression of EphB4 was increased in VSMCs form EphB4+/+ rats. SCH772984 reduces the proliferation and migration of VSMCs. Inhibition of ERK suppressed the increase of vein graft wall thickness, and the expression of collagen fibers, elastic fibers, and α-actin was decreased. Vein graft from EphB4+/− rats reduces the expression of EphB4, and SCH772984 suppressed the decrease of EphB4 in vivo. Vein graft from EphB4+/− rats increased the expression of EphB4, and SCH772984 suppressed the increase of EphB4 in vivo. Conclusions The inhibition of ERK1/2 suppressed the process of VGS by decreasing the proliferation of VSMCs. The ERK-inhibitor SCH772984 suppressed the level of VGS by extending the time of EphB4 expression during the process of VGA, thus maintaining the venousization of vein graft. The mechanism may be that the inhibitor SCH772984 suppresses the level of VGS by extending the time of EphB4 expression during the process of VGA. Therefore, our research provides a new target of VGS treatment by inhibiting the expression of ERK1/2 through the process of VGA.

scholarly journals The Designer Antimicrobial Peptide A-hBD-2 Facilitates Skin Wound Healing by Stimulating Keratinocyte Migration and Proliferation

2018 ◽  
Vol 51 (2) ◽  
pp. 647-663 ◽  
Author(s):  
Bobin Mi ◽  
Jing Liu ◽  
Yi Liu ◽  
Liangcong Hu ◽  
Yukun Liu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Wound Healing ◽  
Antimicrobial Peptide ◽  
Structural Stability ◽  
Cell Counting ◽  
Sprague Dawley ◽  
Skin Wound Healing ◽  
High Sodium

Background/Aims: Antimicrobial peptides are effective promoters of wound healing but are susceptible to degradation. In this study, we replaced the GIGDP unit on the N-terminal of the endogenous human antimicrobial peptide hBD-2 with APKAM to produce A-hBD-2 and analyzed the effect on wound healing both in vitro and in vivo. Methods: The effects of A-hBD-2 and hBD-2 on cytotoxicity and proliferation in keratinocytes were assessed by Cell Counting Kit-8 assay. The structural stability and antimicrobial activity of hBD-2 and A-hBD-2 were evaluated against Staphylococcus aureus. RNA and proteins levels were evaluated by real-time PCR and western blotting, respectively. Cell migration was evaluated using a transwell assay. Cell cycle analysis was performed by flow cytometry. Wound healing was assessed in Sprague-Dawley rats. Epidermal thickness was evaluated by hematoxylin and eosin staining. Results: We found that hBD-2 exhibited cytotoxicity at high concentrations and decreased the structural stability in the presence of high sodium chloride concentrations. A-hBD-2 exhibited increased structural stability and antimicrobial activity, and had lower cytotoxicity in keratinocytes. A-hBD-2 increased the migration and proliferation of keratinocytes via phosphorylation of EGFR and STAT3 and suppressed terminal differentiation of keratinocytes. We also found that A-hBD-2 elicited mobilization of intracellular Ca2+ and stimulated keratinocytes to produce pro- and anti-inflammatory cytokines and chemokines via phospholipase C activation. Furthermore, A-hBD-2 promoted wound healing in vivo. Conclusion: Our data suggest that A-hBD-2 may be a promising candidate therapy for wound healing.

scholarly journals Selective STAT3 Inhibitor Alantolactone Ameliorates Osteoarthritis via Regulating Chondrocyte Autophagy and Cartilage Homeostasis

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenbin Pei ◽  
Xiaojian Huang ◽  
Bowei Ni ◽  
Rui Zhang ◽  
Guangyi Niu ◽  
...  
Keyword(s):  
Western Blot ◽  
Inflammatory Responses ◽  
Cartilage Degeneration ◽  
Cartilage Destruction ◽  
Signaling Molecules ◽  
Inflammatory Factors ◽  
Signal Pathways ◽  
Autophagic Flux ◽  
Safranin O

Osteoarthritis (OA), which is identified by chronic pain, impacts the quality of life. Cartilage degradation and inflammation are the most relevant aspects involved in its development. Signal transducer and activator of transcription 3(STAT3), a member of the STATs protein family, is associated with inflammation. Alantolactone (ALT), a sesquiterpene lactone compound, can selectively suppress the phosphorylation of STAT3. However, the pharmacological effect of ALT on OA is still imprecise. In this study, IL-1β (10 ng/ml) was applied to cartilage chondrocytes, which were treated with different concentrations of Alantolactone for 24 h. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2(COX2), matrix metalloproteinases (MMPs) and thrombospondin motifs-5 (ADAMTS5) were detected by western blot. Protein expression of Collagen Ⅱ was observed by western blot, safranin O staining and immunofluorescence. Manifestation of autophagy related proteins such as autophagy-related gene-5 (ATG5), P62, LC3Ⅱ/Ⅰ and PI3K/AKT/mTOR-related signaling molecules were measured by western blot and autophagic flux monitored by confocal microscopy. Expression of STAT3 and NF-κB-related signaling molecules were evaluated by western blot and immunofluorescence. In vivo, 2 mg/kg ALT or equal bulk of vehicle was engaged in the destabilization of medial meniscus (DMM) mouse models by intra-articular injection, the degree of cartilage destruction was classified by Safranin O/Fast green staining. Our findings reported that the enhance of inflammatory factors containing iNOS, COX2, MMPs and ADAMTS5 induced by IL-1β could be ameliorated by ALT. Additionally, the diminish of Collagen Ⅱ and autophagy which was stimulated by IL-1β could be alleviated by ALT. Mechanistically, STAT3, NF-κB and PI3K/AKT/mTOR signal pathways might be involved in the effect of ALT on IL-1β-induced mouse chondrocytes. In vivo, ALT protected cartilage in the DMM mouse model. Overall, this study illustrated that ALT attenuated IL-1β-induced inflammatory responses, relieved cartilage degeneration and promoted impaired autophagy via restraining of STAT3 and NF-κB signal pathways, implying its auspicious therapeutical effect for OA.

scholarly journals Antioxidants in erythrocytes in aging and dementia

2013 ◽  
Vol 59 (4) ◽  
pp. 443-451 ◽  
Author(s):  
E.A. Kosenko ◽  
L.A. Tikhonova ◽  
A.C. Poghosyan ◽  
Y.G. Kaminsky
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Glutathione Peroxidase ◽  
Antioxidant Status ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Age Related ◽  
Organic Hydroperoxides

Age of patients and brain oxidative stress may contribute to pathogenesis of Alzheimer's disease (AD). Erythrocytes (red blood cells, RBC) are considered as passive “reporter cells” for the oxidative status of the whole organism and are not well studied in AD. The aim of this work was to assess whether the antioxidant status of RBC changes in aging and AD. Blood was taken from AD and non-Alzheimer's dementia patients, aged-matched and younger controls. In vivo antioxidant status was assessed in each of the study subjects by measuring RBC levels of Н О , organic hydroperoxides, glutathione (GSH) and glutathione disulfide (GSSG), activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and glucose-6-phosphate dehydrogenase. In both aging and dementia, oxidative stress in RBC was shown to increase and to be expressed in elevated concentrations of H O and organic hydroperoxides, decreased the GSH/GSSG ratio and glutathione S-transferase activity. Decreased glutathione peroxidase activity in RBC may be considered as a new peripheral marker for Alzheimer’s disease while alterations of other parameters of oxidative stress reflect age-related events.

scholarly journals Silencing VEGF enhances the radiosensitivity of the radioresistant human nasopharyngeal carcinoma cell line CNE-2R by inhibiting autophagy through the activation of mTOR pathway

2020 ◽  
Author(s):  
Li Chen ◽  
Guoxiang Lin ◽  
Kaihua Chen ◽  
Fangzhu Wan ◽  
Yongchu Sun ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Western Blotting ◽  
Xenograft Model ◽  
Mtor Pathway ◽  
Angiogenic Factor ◽  
Cell Counting

Abstract Background: Vascular endothelial growth factor (VEGF) is an important pro-angiogenic factor. VEGF was reported to promote the occurrence of autophagy, which enhanced to the radioresistance of tumors. The purpose of our study was to investigate the influence of VEGF silencing on the radiosensitivity of nasopharyngeal carcinoma radioresistant cell line CNE-2R and the underlying mechanisms.Methods: The radiosensitivity of CNE-2R cells after silencing VEGF was detected by cell counting kit 8 (CCK-8) and clonogenic assay, cell cycle and apoptosis was subjected to flow cytometry. DNA damage and autophagy were observed by immunofluorescence and western blotting. The interaction between VEGF and mTOR was confirmed by western blotting and co-immunoprecipitation analysis. In vivo, the effect of VEGF on radiosensitivity of NPC cells was investigated through xenograft model, furthermore, immunohistochemistry and TUNEL assay were used to further verify the relationship between autophagy and radiosensitivity in NPC after VEGF depletion.Results: Downregulation of VEGF significantly inhibited cell proliferation and induced apoptosis of CNE-2R cells after radiotherapy in vitro and in vivo. In addition, VEGF knockdown not only decreased autophagy level, but also delayed the DNA damage repair in CNE-2R cells after irradiation. Mechanistically, silencing VEGF suppressed autophagy through the activation of mTOR pathway.Conclusion: VEGF depletion increased radiosensitivity of NPC radioresistant cell CNE-2R by suppressing autophagy via the activation of mTOR pathway.

scholarly journals A novel mitochondrial enriched antioxidant protects neurons against acute oxidative stress

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.

Abstract 123: Age-Related Endothelial Senescence is Driven by Thrombospondin-1-Activated NADPH Oxidase Nox1

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Daniel N Meijles ◽  
Imad Al Ghouleh ◽  
Sanghamitra Sahoo ◽  
Jefferson H Amaral ◽  
Heather Knupp ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Vascular Diseases ◽  
Dependent Manner ◽  
Wild Type ◽  
Molecular Control ◽  
Redox Biology ◽  
Age Related ◽  
P53 Activation

Organismal aging represents an independent risk factor underlying many vascular diseases, including systemic and pulmonary hypertension, and atherosclerosis. While the mechanisms driving aging are largely elusive, a steady persistent increase in tissue oxidative stress has been associated with senescence. Previously we showed TSP1 elicits NADPH oxidase (Nox)-dependent vascular smooth muscle cell oxidative stress. However mechanisms by which TSP1 affects endothelial redox biology are unknown. Here, we tested the hypothesis that TSP1 induces endothelial oxidative stress-linked senescence in aging. Using rapid autopsy disease-free human pulmonary (PA) artery, we identified a significant positive correlation between age, protein levels of TSP1, Nox1 and the cell-cycle repressor p21cip (p<0.05). Age also positively associated with increased Amplex Red-detected PA hydrogen peroxide levels (p<0.05). Moreover, treatment of human PA endothelial cells (HPAEC) with TSP1 (2.2nM; 24h) increased expression (~1.9 fold; p<0.05) and activation of Nox1 (~1.7 fold; p<0.05) compared to control, as assessed by Western blot and SOD-inhibitable cytochrome c reduction. Western blotting and immunofluorescence showed a TSP1-mediated increase in p53 activation, indicative of the DNA damage response. Moreover, TSP1 significantly increased HPAEC senescence in a p53/p21cip/Rb-dependent manner, as assessed by immunofluorescent detection of subcellular localization and senescence-associated β-galactosidase staining. To explore this pathway in vivo, middle-aged (8-10 month) wild-type and TSP1-null mice were utilized. In the TSP1-null, reduced lung senescence, oxidative stress, Nox1 levels and p21cip expression were observed compared to wild-type supporting findings in human samples and cell experiments. Finally, prophylactic treatment with specific Nox1 inhibitor NoxA1ds (10μM) attenuated TSP1-induced HPAEC ROS, p53 activation, p21cip expression and senescence. Taken together, our results provide molecular insight into the functional interplay between TSP1 and Nox1 in the regulation of endothelial senescence, with implications for molecular control of the aging process.

scholarly journals Discovery of a dual inhibitor of NQO1 and GSTP1 for treating glioblastoma

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Kecheng Lei ◽  
Xiaoxia Gu ◽  
Alvaro G. Alvarado ◽  
Yuhong Du ◽  
Shilin Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Crystal Structures ◽  
Active Sites ◽  
Redox Homeostasis ◽  
Growth Factor Receptor ◽  
Quinone Oxidoreductase ◽  
Cancer Proliferation ◽  
Dual Inhibitor

Abstract Background Glioblastoma (GBM) is a universally lethal tumor with frequently overexpressed or mutated epidermal growth factor receptor (EGFR). NADPH quinone oxidoreductase 1 (NQO1) and glutathione-S-transferase Pi 1 (GSTP1) are commonly upregulated in GBM. NQO1 and GSTP1 decrease the formation of reactive oxygen species (ROS), which mediates the oxidative stress and promotes GBM cell proliferation. Methods High-throughput screen was used for agents selectively active against GBM cells with EGFRvIII mutations. Co-crystal structures were revealed molecular details of target recognition. Pharmacological and gene knockdown/overexpression approaches were used to investigate the oxidative stress in vitro and in vivo. Results We identified a small molecular inhibitor, “MNPC,” that binds to both NQO1 and GSTP1 with high affinity and selectivity. MNPC inhibits NQO1 and GSTP1 enzymes and induces apoptosis in GBM, specifically inhibiting the growth of cell lines and primary GBM bearing the EGFRvIII mutation. Co-crystal structures between MNPC and NQO1, and molecular docking of MNPC with GSTP1 reveal that it binds the active sites and acts as a potent dual inhibitor. Inactivation of both NQO1 and GSTP1 with siRNA or MNPC results in imbalanced redox homeostasis, leading to apoptosis and mitigated cancer proliferation in vitro and in vivo. Conclusions Thus, MNPC, a dual inhibitor for both NQO1 and GSTP1, provides a novel lead compound for treating GBM via the exploitation of specific vulnerabilities created by mutant EGFR.

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