scholarly journals Gold Nanoparticles Promote Oxidant-Mediated Activation of NF-κB and 53BP1 Recruitment-Based Adaptive Response in Human Astrocytes

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jennifer Mytych ◽  
Anna Lewinska ◽  
Jacek Zebrowski ◽  
Maciej Wnuk

Nanogold-based materials are promising candidate tools for nanobased medicine. Nevertheless, no conclusive information on their cytotoxicity is available. In the present study, we investigated the effects of gold nanoparticles (AuNPs) on human astrocytesin vitro. Nanogold treatment in a wide range of concentrations did not result in cytotoxicity. In contrast, nanogold provoked changes in the astrocyte cell cycle and induced senescence-associatedβ-galactosidase activity. AuNPs promoted oxidative stress and caused activation of NF-κB pathway. After nanogold treatment, an inverse correlation between the formation of 53BP1 foci and micronuclei generation was observed. The robust 53BP1 recruitment resulted in reduced micronuclei production. Thus, nanogold treatment stimulated an adaptive response in a human astrocyte cell.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2173
Author(s):  
Martin Kello ◽  
Tomas Kuruc ◽  
Klaudia Petrova ◽  
Michal Goga ◽  
Zuzana Michalova ◽  
...  

Acute lymphoblastic leukemia (ALL) is the most frequently diagnosed type of leukemia among children. Although chemotherapy is a common treatment for cancer, it has a wide range of serious side effects, including myelo- and immunosuppression, hepatotoxicity and neurotoxicity. Combination therapies using natural substances are widely recommended to attenuate the adverse effects of chemotherapy. The aim of the present study was to investigate the anti-leukemic potential of extract from the lichen Pseudevernia furfuracea (L.) Zopf (PSE) and isolated physodic acid (Phy) in an in vitro ALL model. A screening assay, flow cytometry and Western blotting were used to analyze apoptosis occurrence, oxidative stress, DNA damage and stress/survival/apoptotic pathway modulation induced by the tested substances in Jurkat cells. We demonstrate for the first time that PSE and Phy treatment-induced intrinsic caspase-dependent cell death was associated with increased oxidative stress, DNA damage and cell cycle arrest with the activation of cell cycle checkpoint proteins p53, p21 and p27 and stress/survival kinases p38 MAPK, JNK and PI3K/Akt. Moreover, using peripheral T lymphocytes, we confirmed that PSE and Phy treatment caused minimal cytotoxicity in normal cells, and therefore, these naturally occurring lichen secondary metabolites could be promising substances for ALL therapy.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xiaohong Zhou ◽  
Christina Monnie ◽  
Maria DeLucia ◽  
Jinwoo Ahn

Abstract Background Vpr is a virion-associated protein that is encoded by lentiviruses and serves to counteract intrinsic immunity factors that restrict infection. HIV-1 Vpr mediates proteasome-dependent degradation of several DNA repair/modification proteins. Mechanistically, Vpr directly recruits cellular targets onto DCAF1, a substrate receptor of Cullin 4 RING E3 ubiquitin ligase (CRL4) for poly-ubiquitination. Further, Vpr can mediate poly-ubiquitination of DCAF1-interacting proteins by the CRL4. Because Vpr-mediated degradation of its known targets can not explain the primary cell-cycle arrest phenotype that Vpr expression induces, we surveyed the literature for DNA-repair-associated proteins that interact with the CRL4-DCAF1. One such protein is SIRT7, a deacetylase of histone 3 that belongs to the Sirtuin family and regulates a wide range of cellular processes. We wondered whether Vpr can mediate degradation of SIRT7 via the CRL4-DCAF1. Methods HEK293T cells were transfected with cocktails of plasmids expressing DCAF1, DDB1, SIRT7 and Vpr. Ectopic and endogeneous levels of SIRT7 were monitered by immunoblotting and protein–protein interactions were assessed by immunoprecipitation. For in vitro reconstitution assays, recombinant CRL4-DCAF1-Vpr complexes and SIRT7 were prepared and poly-ubiqutination of SIRT7 was monitored with immunoblotting. Results We demonstrate SIRT7 polyubiquitination and degradation upon Vpr expression. Specifically, SIRT7 is shown to interact with the CRL4-DCAF1 complex, and expression of Vpr in HEK293T cells results in SIRT7 degradation, which is partially rescued by CRL inhibitor MNL4924 and proteasome inhibitor MG132. Further, in vitro reconstitution assays show that Vpr induces poly-ubiquitination of SIRT7 by the CRL4-DCAF1. Importantly, we find that Vpr from several different HIV-1 strains, but not HIV-2 strains, mediates SIRT7 poly-ubiquitination in the reconstitution assay and degradation in cells. Finally, we show that SIRT7 degradation by Vpr is independent of the known, distinctive phenotype of Vpr-induced cell cycle arrest at the G2 phase, Conclusions Targeting histone deacetylase SIRT7 for degradation is a conserved feature of HIV-1 Vpr. Altogether, our findings reveal that HIV-1 Vpr mediates down-regulation of SIRT7 by a mechanism that does not involve novel target recruitment to the CRL4-DCAF1 but instead involves regulation of the E3 ligase activity.


2014 ◽  
Vol 37 (1) ◽  
pp. 141-149 ◽  
Author(s):  
Daotong Li ◽  
Yaqiong Ye ◽  
Shaoqing Lin ◽  
Li Deng ◽  
Xiaolong Fan ◽  
...  

2000 ◽  
Vol 88 (6) ◽  
pp. 2054-2061 ◽  
Author(s):  
Leo M. A. Heunks ◽  
Aalt Bast ◽  
Cees L. A. van Herwaarden ◽  
Guido R. M. M. Haenen ◽  
P. N. Richard Dekhuijzen

Loading of skeletal muscles is associated with increased generation of oxidants, which in turn may impair muscle contractility. We investigated whether the load on the hamster diaphragm imposed by pulmonary emphysema induces oxidative stress, as indicated by glutathione oxidation, and whether the degree of glutathione oxidation is correlated with contractility of the diaphragm. In addition, the effect of 12 wk of treadmill exercise training on contractility and glutathione content in the normal (NH) and emphysematous hamster (EH) diaphragm was investigated. Training started 6 mo after elastase instillation. After the training period, glutathione content and in vitro contractility of the diaphragm were determined. Twitch force and maximal tetanic force were significantly reduced (by ∼30 and ∼15%, respectively) in EH compared with NH. In sedentary hamsters, the GSSG-to-GSH ratio was significantly elevated in the EH compared with the NH diaphragm. A significant inverse correlation was found between GSSG-to-GSH ratio and twitch force in the diaphragm ( P < 0.01). Training improved maximal tetanic force and reduced fatigability of the EH diaphragm but did not alter its glutathione content. In conclusion, 1) emphysema induces oxidative stress in the diaphragm, 2) training improves the contractile properties of the EH diaphragm, and 3) this improvement is not accompanied by changes in glutathione redox status.


2018 ◽  
Vol 10 (5) ◽  
pp. 153 ◽  
Author(s):  
Balashanmugam P. ◽  
Mosa Christas K. ◽  
Kowsalya E.

Objective: The biogenic gold nanoparticles are considered to be extremely impressive for its wide range of applications in pharmaceutics and therapeutics. The present study was aimed at the biogenic synthesis of gold nanoparticles (AuNPs) from Marsilea quadrifolia aqueous extract and to investigate its antioxidant property and cytotoxic effect on human ovarian teratocarcinoma (PA-1) and lung adenocarcinoma (A549) cell lines.Methods: The biogenic AuNPs was synthesized using an aqueous extract of Marsilea quadrifolia. The synthesized biogenic AuNPs were characterized by ultraviolet (UV) visible spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD). The biogenic AuNPs was assessed for its stability over a period of time and antioxidant activity. The cytotoxicity of biogenic AuNPs against PA-1 and A549 cell lines was studied using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Results: The synthesized biogenic AuNPs showed peculiar ruby red color and a surface plasmon resonance (SPR) peak at 544 nm in the UV-Vis spectrum. The characterization of biogenic AuNPs by TEM, EDX and XRD revealed well dispersed spherical particles ranging from 10-40 nm and the presence of elemental gold and its crystalline nature, respectively. The AuNPs showed good stability and the scavenging activity at 50 μg/ml. The in vitro cytotoxicity of biogenic AuNPs against PA-1 and A549 cell lines recorded half maximal inhibitory concentration (IC50) of 45.88 μg/ml and 52.015 μg/ml, respectively.Conclusion: The biogenic AuNPs demonstrated superior antioxidant and antiproliferative activities against cancer cell lines.


2018 ◽  
Vol 30 (12) ◽  
pp. 1728 ◽  
Author(s):  
M. Arias-Álvarez ◽  
R. M. García-García ◽  
J. López-Tello ◽  
P. G. Rebollar ◽  
A. Gutiérrez-Adán ◽  
...  

The developmental competence of in vitro maturation (IVM) oocytes can be enhanced by antioxidant agents. The present study investigated, for the first time in the rabbit model, the effect of adding α-tocopherol (0, 100, 200 and 400 µM) during IVM on putative transcripts involved in antioxidant defence (superoxide dismutase 2, mitochondrial (SOD2), glutathione peroxidase 1 (GPX1), catalase (CAT)), cell cycle regulation and apoptosis cascade (apoptosis tumour protein 53 (TP53), caspase 3, apoptosis-related cysteine protease (CASP3)), cell cycle progression (cellular cycle V-Akt murine thymoma viral oncogene homologue 1 (AKT1)), cumulus expansion (gap junction protein, alpha 1, 43 kDa (GJA1) and prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclo-oxygenase) (PTGS2)) and metabolism (glucose-6-phosphate dehydrogenase (G6PD)). Meiotic progression, mitochondrial reallocation, cumulus cell apoptosis and the developmental competence of oocytes after IVF were also assessed. Expression of SOD2, CAT, TP53, CASP3 and GJA1 was downregulated in cumulus–oocyte complexes (COCs) after IVM with 100 μM α-tocopherol compared with the group without the antioxidant. The apoptotic rate and the percentage of a non-migrated mitochondrial pattern were lower in COCs cultured with 100 μM α-tocopherol, consistent with better-quality oocytes. In fact, early embryo development was improved when 100 μM α-tocopherol was included in the IVM medium, but remained low compared with in vivo-matured oocytes. In conclusion, the addition of 100 μM α-tocopherol to the maturation medium is a suitable approach to manage oxidative stress and apoptosis, as well as for increasing the in vitro developmental competence of rabbit oocytes.


2015 ◽  
Vol 27 (1) ◽  
pp. 93 ◽  
Author(s):  
D. Laskowski ◽  
Y. Sjunnesson ◽  
R. Båge ◽  
M. A. Sirard ◽  
H. Gustafsson ◽  
...  

Insulin as a key metabolic hormone has crucial functions in metabolic regulation in all mammals. Deviation of its physiological concentration occurs in metabolic disorders as obesity and diabetes in humans or negative energy balance and overfeeding in the cow. As these metabolic disorders are strongly correlated with reproductive disturbances, we investigated the effect of insulin during oocyte maturation on gene expression of bovine Day 8 blastocysts (BC8) by transcriptome analysis. Abattoir-derived oocytes (n = 882) were divided into 3 groups and in vitro matured for 22 h by adding insulin (H: High 10 µg mL–1; L: Low 0.1 µg mL–1 and Z: Zero, control). This was followed by standard in vitro production (IVP) and evaluation of developmental rates up to blastocyst stage. BC8 (n = 120) were pooled in groups of 10 and total RNA was extracted by parallel gDNA and total RNA-extraction (AllPrepDNA/RNA micro kit, cat no. 80284, Qiagen®, Valencia, CA, USA) for analyses of the transcriptome. All samples (4 biological replicates/group) resulted in RIN-values >7.5. RNA amplification, cDNA synthesis, purification, and labelling were performed and 825 ng of Cy3- and Cy5-labelled linearly amplified aRNA was hybridized on the Agilent-manufactured EmbryoGENE-slides in a 2-colour dye swap design. An empirical Bayes moderated t-test was applied to search for the differentially expressed transcripts (DET) between control and insulin-treated groups, using the ‘limma’ package in R (www.r-project.org). The DET were defined as having a 1.5-fold change difference between treatment and control and P < 0.05. Pathways and molecular functions influenced by insulin treatment were analysed by using Ingenuity Pathway Analysis (IPA; Ingenuity® Systems, www.ingenuity.com). As a global pattern, insulin treatment induced an up-regulation of genes. In total, 202 DET in the H and 142 DET in the L group were found where 104 DET were common in both insulin groups. Fifteen selected candidate genes chosen for qPCR validation and 12 (80%) showed similar expression patterns as the microarray data. DET relevant for following cellular functions were found in H: Cell Cycle, Cellular Compromise, Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry respective L: Cell Morphology, Cellular Growth and Proliferation, Cell Cycle, Carbohydrate Metabolism and Cellular Assembly and Organization. The top canonical pathways influenced were Epithelial Adherens Junction Signalling and Remodelling, Germ Cell Sertoli Cell Junction Signalling and NRF2-mediated Oxidative Stress Response. Correlatively, blastocyst rates on Day 8 were significantly lower in H and L v. Z (P < 0.05). The transcriptome data could explain the mechanisms behind the impaired development, as genes involved in cellular growth and energy metabolism in Day 8 blastocysts were affected. The fact that transcripts related to NRF2-mediated oxidative stress response and lipid metabolism are up-regulated suggests that insulin induces dysregulation of cellular functions and energy metabolism leading to impaired embryo developmental potential.Funded by FORMAS.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 504 ◽  
Author(s):  
Hainan Sun ◽  
Xiaoling Wang ◽  
Shumei Zhai

Radiotherapy (RT) has been widely used for cancer treatment. However, the intrinsic drawbacks of RT, such as radiotoxicity in normal tissues and tumor radioresistance, promoted the development of radiosensitizers. To date, various kinds of nanoparticles have been found to act as radiosensitizers in cancer radiotherapy. This review focuses on the current state of nanoradiosensitizers, especially the related biological mechanisms, and the key design strategies for generating nanoradiosensitizers. The regulation of oxidative stress, DNA damage, the cell cycle, autophagy and apoptosis by nanoradiosensitizers in vitro and in vivo is highlighted, which may guide the rational design of therapeutics for tumor radiosensitization.


PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e105359 ◽  
Author(s):  
Erika Söderstjerna ◽  
Patrik Bauer ◽  
Tommy Cedervall ◽  
Hodan Abdshill ◽  
Fredrik Johansson ◽  
...  

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