Synergistic Ototoxicity of Gentamicin and Low-Dose Irradiation: Molecular Basis and Clinical Significance

2019 ◽  
Vol 25 (3) ◽  
pp. 111-119
Author(s):  
Wong Kein Low ◽  
Siaw Wei Teng ◽  
Michelle G.K. Tan
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Molecular Mechanisms ◽  
Low Dose ◽  
Combined Treatment ◽  
Autophagic Flux ◽  
Cell Viability Assay ◽  
Akt Phosphorylation ◽  
Dose Irradiation

Background: Inner ear structures may be included in the radiation fields when irradiation is used to treat patients with head and neck cancers. These patients may also have concurrent infections that require gentamicin treatment. Radiation and gentamicin are both potentially ototoxic, and their combined use has been shown to result in synergistic ototoxicity in animals. Objective: We aimed to confirm the synergistic ototoxicity of combined gentamicin and low-dose irradiation treatment and identify the underlying molecular mechanisms using an in vitro model. Method: We compared the ototoxic effects of gentamicin, low-dose irradiation, and their combination in the OC-k3 mouse cochlear cell line using cell viability assay, live/dead stain, apoptosis detection assay, oxidative stress detection, and studied the molecular mechanisms involved using immunoblot analysis. Results: Combined treatment led to prolonged oxidative stress, reduced cell viability, and synergistic apoptosis. Gentamicin induced the concurrent accumulation of LC3b-II and SQSTM1/p62, suggesting an impairment of autophagic flux. Low-dose irradiation induced transient p53 phosphorylation and persistent Akt phosphorylation in response to DNA damage. In combined treatment, gentamicin attenuated irradiation-induced Akt activation. Conclusions: Besides increased oxidative stress, synergistic apoptosis observed in combined treatment could be attributed to gentamicin-induced perturbation of autophagic flux and attenuation of Akt phosphorylation, which led to an impairment of radiation-induced DNA repair response.

scholarly journals Amlexanox Enhances Temozolomide-Induced Anti-Tumor Effects In Human Glioblastoma Cells By Inhibiting Ikbke And The Akt-mtor Signaling Pathway

2020 ◽  
Author(s):  
Jinbiao Xiong ◽  
Gaochao Guo ◽  
Lianmei Guo ◽  
Zengguang Wang ◽  
Zhijuan Chen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cell Viability ◽  
Glioma Cell ◽  
Combined Therapy ◽  
Combined Treatment ◽  
Migration And Invasion ◽  
Cell Viability Assay ◽  
Primary Glioma

Abstract Background: Temozolomide (TMZ), as the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM), often fails to improve the prognosis of GBM patients due to the quick development of resistance. The need for more effective management of GBM is urgent. The aim of this study is to evaluate the efficacy of combined therapy with TMZ and amlexanox, a selective inhibitor of inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKBKE), for GBM.Methods: in vitro, cell viability assay, apoptosis analysis, western blot, migration and invasion assay were used. In vivo, intracranial tumor models were constructed and the immunohistochemistry were used. Results: We found that combined treatment resulted in significant induction of cellular apoptosis and the inhibition of cell viability, migration and invasion in primary glioma cell and in the human glioma cell line, U87 MG. TMZ enhanced expression of phosphoration of adenosine 5‘-monophosphate-activated protein kinase (p-AMPK) and amlexanox led to reduction of IKBKE, with no impact on p-AMPK. Furthermore, we demonstrated that, compared to other groups treated with each component alone, TMZ combined with amlexanox effectively inhibited phosphorylation of protein kinase B (AKT) and mammalian target of rapamycin (mTOR). In addition, the combination treatment also clearly reduced in vivo tumor volume and prolonged median survival time in the xenograft mouse model. Conclusion: These results suggest that amlexanox sensitized primary glioma cell and U87 MG cell to TMZ at least partially though the suppression of IKBKE activation and the attenuation of AKT activation. Overall, combined treatment with TMZ and amlexanox may provide a promising possibility for improving the prognosis of glioblastoma patients in clinical practice.

scholarly journals PXDN reduces autophagic flux in insulin-resistant cardiomyocytes via modulating FoxO1

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Chan Li ◽  
Zhaoya Liu ◽  
Qian Xu ◽  
Huihui Peng ◽  
Jing Cao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Cell Viability ◽  
Essential Role ◽  
Degradation Process ◽  
Autophagic Flux ◽  
Lysosomal Degradation ◽  
Akt Phosphorylation ◽  
Insulin Resistant ◽  
Forkhead Box

AbstractAutophagy, a well-observed intracellular lysosomal degradation process, is particularly important to the cell viability in diabetic cardiomyopathy (DCM). Peroxidasin (PXDN) is a heme-containing peroxidase that augments oxidative stress and plays an essential role in cardiovascular diseases, while whether PXDN contributes to the pathogenesis of DCM remains unknown. Here we reported the suppression of cell viability and autophagic flux, as shown by autophagosomes accumulation and increased expression level of LC3-II and p62 in cultured H9C2 and human AC16 cells that treated with 400 μM palmitate acid (PA) for 24 h. Simultaneously, PXDN protein level increased. Moreover, cell death, autophagosomes accumulation as well as increased p62 expression were suppressed by PXDN silence. In addition, knockdown of PXDN reversed PA-induced downregulated forkhead box-1 (FoxO1) and reduced FoxO1 phosphorylation, whereas did not affect AKT phosphorylation. Not consistent with the effects of si-PXDN, double-silence of PXDN and FoxO1 significantly increased cell death, suppressed autophagic flux and declined the level of FoxO1 and PXDN, while the expression of LC3-II was unchanged under PA stimulation. Furthermore, inhibition of FoxO1 in PA-untreated cells induced cell death, inhibited autophagic flux, and inhibited FoxO1 and PXDN expression. Thus, we come to conclusion that PXDN plays a key role in PA-induced cell death by impairing autophagic flux through inhibiting FoxO1, and FoxO1 may also affect the expression of PXDN. These findings may develop better understanding of potential mechanisms regarding autophagy in insulin-resistant cardiomyocytes.

THE TARGET-CHEMOTHERAPY DIRECTED BY THE RADIATION

2005 ◽  
Vol 15 (03n04) ◽  
pp. 221-224 ◽  
Author(s):  
S. HARADA ◽  
K. ISHII ◽  
H. YAMAZAKI ◽  
S. MATSUYAMA ◽  
K. MIZUMA ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Low Dose ◽  
Combined Treatment ◽  
Leukemic Cell ◽  
Human Leukemic Cell ◽  
Dose Irradiation ◽  
Therapeutic Gain ◽  
Γ Ray

The target-chemetherpy directed by the radiation was tested by the two methods; 1) facilitate the carboplatin; and 2) the capsules that is decomposed by irradiation IN VITRO. The human leukemic cell (OCI/M2) cultured in RPMI 1640 was treated by the 0.5 Gy of 60 Co γ ray after the 4μmol of carboplatin administration. The uptake of carboplatin expressed as Pt signal was measured by the micro PIXE camera. The increased uptake of carboplatin was observed in the cell. There was also an increased uptake of Cu . The chelating of Cu resulted in the maximum uptake of carboplatin under the combined treatment of radiation and carboplatin. As for the capsules, it was prepared by polymerizing the alginate by CaCl 2, whose core was carboplatin. The 0.5 Gy irradiation was performed to the capsules. The carboplatin's emission was observed using a micro PIXE camera. As a result, the carboplatin was emitted from capsules, which was almost 10 %. Those two methods (increased uptake of carboplatin by low dose irradiation and the capsules decomposed by irradiation) is considered to be useful for the better therapeutic gain and less adverse effect.

scholarly journals Anethole Dithiolethione Increases Glutathione in Kidney by Inhibiting γ-Glutamyltranspeptidase: Biochemical Interpretation and Pharmacological Consequences

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Daniela Giustarini ◽  
Federico Galvagni ◽  
Isabella Dalle-Donne ◽  
Aldo Milzani ◽  
Monica Lucattelli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Low Dose ◽  
Ex Vivo ◽  
Rat Kidney ◽  
Oral Treatment ◽  
Proximal Tubule Cells ◽  
Perfused Rat Kidney ◽  
Biomarkers Of Oxidative Stress

Aims. Anethole dithiolethione (ADT) is a marketed drug to treat xerostomia. Its mechanism of action is still unknown, but several preclinical studies indicate that it is able to increase intracellular glutathione (GSH) and protect against oxidative stress. Here, we investigated the molecular mechanisms behind these effects. Results. Oral treatment of rats confirmed the GSH enhancing properties of ADT; among the different organs examined in this study, only the kidney showed a significant GSH increase that was already observed at low-dose treatments. The increase in GSH correlated with a decrease in γ-glutamyltranspeptidase (γ-GT) activity of the different tissues. In vitro and ex vivo experiments with tubular renal cells and isolated perfused rat kidney showed that the cellular uptake of intact GSH was correlated with the extracellular concentrations of GSH. Conclusions. The prominent in vivopharmacological effect of ADT was a marked increase of GSH concentration in the kidney and a decrease of some systemic and renal biomarkers of oxidative stress. In particular, by inhibition of γ-GT activity, it decreased the production cysteinylglycine, a thiol that has prooxidant effects as the consequence of its autooxidation. The activity of ADT as GSH enhancer in both the circulation and the kidney was long-lasting. All these characteristics make ADT a promising drug to protect the kidney, and in particular proximal tubule cells, from xenobiotic-induced damage.

scholarly journals Amlexanox enhances temozolomide-induced anti-tumor effects in human glioblastoma cells by inhibiting IKBKE and the Akt-mTOR signaling pathway

2020 ◽  
Author(s):  
Jinbiao Xiong ◽  
Gaochao Guo ◽  
Lianmei Guo ◽  
Zengguang Wang ◽  
Zhijuan Chen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cell Viability ◽  
Glioma Cell ◽  
Combined Therapy ◽  
Combined Treatment ◽  
Migration And Invasion ◽  
Cell Viability Assay ◽  
Primary Glioma

Abstract Background: Temozolomide (TMZ), as the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM), often fails to improve the prognosis of GBM patients due to the quick development of resistance. The need for more effective management of GBM is urgent. The aim of this study is to evaluate the efficacy of combined therapy with TMZ and amlexanox, a selective inhibitor of inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKBKE), for GBM. Methods: in vitro, cell viability assay, apoptosis analysis, western blot, migration and invasion assay were used. In vivo, intracranial tumor models were constructed and the immunohistochemistry were used. Results: We found that combined treatment resulted in significant induction of cellular apoptosis and the inhibition of cell viability, migration and invasion in primary glioma cell and in the human glioma cell line, U87 MG. TMZ enhanced expression of phosphoration of adenosine 5‘-monophosphate-activated protein kinase (p-AMPK) and amlexanox led to reduction of IKBKE, with no impact on p-AMPK. Furthermore, we demonstrated that, compared to other groups treated with each component alone, TMZ combined with amlexanox effectively inhibited phosphorylation of protein kinase B (AKT) and mammalian target of rapamycin (mTOR). In addition, the combination treatment also clearly reduced in vivo tumor volume and prolonged median survival time in the xenograft mouse model. Conclusion: These results suggest that amlexanox sensitized primary glioma cell and U87 MG cell to TMZ at least partially though the suppression of IKBKE activation and the attenuation of AKT activation. Overall, combined treatment with TMZ and amlexanox may provide a promising possibility for improving the prognosis of glioblastoma patients in clinical practice.

MiR-485-5p Promotes Neuron Survival through Mediating Rac1/Notch2 Signaling Pathway after Cerebral Ischemia/Reperfusion

2020 ◽  
Vol 17 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Xuan Chen ◽  
Sumei Zhang ◽  
Peipei Shi ◽  
Yangli Su ◽  
Dong Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Therapeutic Option ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Small Gtpase ◽  
Luciferase Reporter ◽  
Pathological Feature ◽  
In Cells

Objective: Ischemia-reperfusion (I/R) injury is a pathological feature of ischemic stroke. This study investigated the regulatory role of miR-485-5p in I/R injury. Methods: SH-SY5Y cells were induced with oxygen and glucose deprivation/reoxygenation (OGD/R) to mimic I/R injury in vitro. Cells were transfected with designated constructs (miR-485- 5p mimics, miR-485-5p inhibitor, lentiviral vectors overexpressing Rac1 or their corresponding controls). Cell viability was evaluated using the MTT assay. The concentrations of lactate dehydrogenase, malondialdehyde, and reactive oxygen species were detected to indicate the degree of oxidative stress. Flow cytometry and caspase-3 activity assay were used for apoptosis assessment. Dual-luciferase reporter assay was performed to confirm that Rac family small GTPase 1 (Rac1) was a downstream gene of miR-485-5p. Results: OGD/R resulted in decreased cell viability, elevated oxidative stress, increased apoptosis, and downregulated miR-485-5p expression in SH-SY5Y cells. MiR-485-5p upregulation alleviated I/R injury, evidenced by improved cell viability, decreased oxidative markers, and reduced apoptotic rate. OGD/R increased the levels of Rac1 and neurogenic locus notch homolog protein 2 (Notch2) signaling-related proteins in cells with normal miR-485-5p expression, whereas miR- 485-5p overexpression successfully suppressed OGD/R-induced upregulation of these proteins. Furthermore, the delivery of vectors overexpressing Rac1 in miR-485-5p mimics-transfected cells reversed the protective effect of miR-485-5p in cells with OGD/R-induced injury. Conclusion: This study showed that miR-485-5p protected cells following I/R injury via targeting Rac1/Notch2 signaling suggest that targeted upregulation of miR-485-5p might be a promising therapeutic option for the protection against I/R injury.

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.

VDAC1 Mediated Anticancer Activity of Gallic Acid in Human Lung Adenocarcinoma A549 Cells

2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li
Keyword(s):  
Western Blot ◽  
Cell Viability ◽  
Gallic Acid ◽  
Molecular Mechanisms ◽  
A549 Cells ◽  
Dependent Manner ◽  
Lung Carcinoma Cells ◽  
Induced Apoptosis ◽  
The Impact

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.

scholarly journals Low-dose irradiation reduces forced swim test-induced immobility and oxidative stress in mice

2021 ◽  
Vol 165 ◽  
pp. 56-57
Author(s):  
Shota Naoe ◽  
Takahiro Kataoka ◽  
Hina Shuto ◽  
Junki Yano ◽  
Tetsuya Nakada ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Low Dose ◽  
Forced Swim Test ◽  
Swim Test ◽  
Dose Irradiation ◽  
Forced Swim ◽  
And Oxidative Stress
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