Effects In Different Cell Lines Research Articles

MPA-capped CdTequantum dots induces endoplasmic reticulum stress-mediated autophagy and apoptosis through generation of reactive oxygen species in human liver normal cell and liver tumor cell

The rapid developments in nanotechnology have brought increased attention to the safety of Quantum Dots (QDs). Exploring their mechanisms of toxicity and characterizing their toxic effects in different cell lines will help us better understand and apply QDs appropriately. This study aims to elucidate the importance of reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress-induced autophagy for CdTe QDs toxicity, that is, the importance of the nanoparticles in mediating cellular uptake and consequent intracellular stress effects inside the cell. The results of the study showed that cancer cells and normal cells have different cell outcomes as a result of intracellular stress effects. In normal human liver cells (L02), CdTe QDs leads to ROS generation and prolong ER stress. The subsequent autophagosome accumulation eventually triggers apoptosis by activating proapoptotic signaling pathways and the expression of proapoptotic Bax. In contrast, in human liver cancer cells (HepG2 cells), expression of UPR restrains proapoptotic signaling and downregulates Bax, and activated protective cellular autophagy, as a result of protecting these liver cancer cells from CdTe QDs-induced apoptosis. In summary, we assess the safety of CdTe QDs and recounted the molecular mechanism underlying its nanotoxicity in normal and cancerous cells. Notwithstanding, additional detailed studies on the deleterious effects of these nanoparticles in the organisms of interest are required to ensure low-risk application.

Characterization of a strain of quaranfil virus isolated from soft ticks in India. Is quaranfil virus an unrecognized cause of disease in human and animals?”

The soft ticks collected during a field survey in Karnataka state, India, in 1983, yielded a novel virus isolate, which caused mortality in an infant mouse upon inoculation. Attempts at characterizing the virus using the conventional methods were unsuccessful, which prompted us to study it by Next-Generation Sequencing (NGS). This virus isolate was obtained from the viral repository of National Institute of Virology, and an initial virus stock was prepared as a mouse brain homogenate. The virus stock showed cytopathic effects in different cell-lines and was used in NGS. Based on the complete genome sequence, obtained using de novo and reference mapping approach, the virus isolate was identified as a Quaranfil virus (QRFV) belonging to the family Orthomyxoviridae, genus Quaranjavirus. The genome size of the virus is 11,427 nucleotides which consist of 6 segments encoding six proteins. Homology analysis suggested this isolate as similar to QRFV of Afghanistan. In silico analysis showed the HA protein secondary structure to be a class III penetrance similar to Thogotovirus. QRFV was first isolated in 1953 from ticks [Cairo, Egypt] and subsequently reported from other geographical areas. This is the first report describing the presence of QRFV from India. This discovery emphasizes the need for investigating mild febrile illness cases with influenza-like symptoms, particularly in the area of high risk for tick bites.

An investigation of methyl tert‑butyl ether‑induced cytotoxicity and protein profile in Chinese hamster ovary cells.

Methyl tert-butyl ether (MTBE) is widely used as an oxygenating agent in gasoline to reduce harmful emissions. However, previous studies have demonstrated that MTBE is a cytotoxic substance that has harmful effects in vivo and in vitro. Although remarkable progress has been made in elucidating the mechanisms underlying the MTBE-induced reproductive toxicological effect in different cell lines, the precise mechanisms remain far from understood. The present study aimed to evaluate whether mammalian ovary cells were sensitive to MTBE exposure in vitro by assessing cell viability, lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) content and antioxidant enzyme activities. In addition, the effect of MTBE exposure on differential protein expression profiles was examined by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. MTBE exposure induced significant effects on cell viability, LDH leakage, plasma membrane damage and the activity of antioxidant enzymes. In the proteomic analysis, 24 proteins were demonstrated to be significantly affected by MTBE exposure. Functional analysis indicated that these proteins were involved in catalytic activity, binding, structural molecule activity, metabolic processes, cellular processes and localization, highlighting the fact that the cytotoxic mechanisms resulting from MTBE exposure are complex and diverse. The altered expression levels of two representative proteins, heat shock protein family A (Hsp70) members 8 and 9, were further confirmed by western blot analysis. The results revealed that MTBE exposure affects protein expression in Chinese hamster ovary cells and that oxidative stress and altered protein levels constitute the mechanisms underlying MTBE-induced cytotoxicity. These findings provided novel insights into the biochemical mechanisms involved in MTBE-induced cytotoxicity in the reproductive system.

Comparative pathogenicity of Coxsackievirus A16 circulating and noncirculating strains in vitro and in a neonatal mouse model.

An enterovirus 71 (EV71) vaccine for the prevention of hand, foot, and mouth disease (HMFD) is available, but it is not known whether the EV71 vaccine cross-protects against Coxsackievirus (CV) infection. Furthermore, although an inactivated circulating CVA16 Changchun 024 (CC024) strain vaccine candidate is effective in newborn mice, the CC024 strain causes severe lesions in muscle and lung tissues. Therefore, an effective CV vaccine with improved pathogenic safety is needed. The aim of this study was to evaluate the in vivo safety and in vitro replication capability of a noncirculating CVA16 SHZH05 strain. The replication capacity of circulating CVA16 strains CC024, CC045, CC090 and CC163 and the noncirculating SHZH05 strain was evaluated by cytopathic effect in different cell lines. The replication capacity and pathogenicity of the CC024 and SHZH05 strains were also evaluated in a neonatal mouse model. Histopathological and viral load analyses demonstrated that the SHZH05 strain had an in vitro replication capacity comparable to the four CC strains. The CC024, but not the SHZH05 strain, became distributed in a variety of tissues and caused severe lesions and mortality in neonatal mice. The differences in replication capacity and in vivo pathogenicity of the CC024 and SHZH05 strains may result from differences in the nucleotide and amino acid sequences of viral functional polyproteins P1, P2 and P3. Our findings suggest that the noncirculating SHZH05 strain may be a safer CV vaccine candidate than the CC024 strain.

Abstract B64: Alternagin-C, an α2β1 integrin-binding disintegrin-like protein, induces distinct cell responses in fibroblasts, tumor breast and endothelial cells in vitro

Abstract Reciprocal interactions between tumor, stromal cells and the extracellular matrix (ECM) are considered crucial steps for tumor development and progression. Both tumor and stromal cells secrete metalloproteases (MMPs) that modify the tumor microenvironment by degrading the ECM and releasing growth factors that may induce tumor cell proliferation, migration and invasion. MMPs activation is stimulated by co-activation of integrins, major cell-surface adhesion receptors. Disintegrins are strong integrin inhibitors found in snake venoms and used as prototypes for angiogenesis inhibitors. Alternagin-C (Alt-C), a disintegrin-like, Cys-rich protein isolated from Bothrops alternatus snake venom, has strong affinity for α2β1 integrin. ALT-C inhibited adhesion to collagen I of a variety of tumor cell lines, and in low concentrations, it induces VEGF expression and angiogenesis in an in vivo matrigel model. However, its mechanism of action was not very clear and it seems to depend on the cell type. Here, we show that ALT-C inhibited MMP-9 activity and mRNA expression in human breast cancer (MDA-MB-231) and MMP-2 activity in human micro vascular endothelial cells (HMEC-1) conditioned media from monocultures. ALT-C also increased the expression of angiogenic genes such as VEGF-A in fibroblasts and tumor cells but not in HMEC-1. However, ALT-C upregulated c-MYC mRNA expression only in tumor cells. ALT-C (10, 40, 100 and 1000 nM) also inhibited transendothelial migration of MDA-MB-231 cells through a monolayer of HMEC-1. In conclusion, these results suggest that α2β1 integrin binding by ALT-C may induce distinct effects in different cell lines by modulating MMP activity and stimulating the expression of angiogenic factors that influence tumor progression. These results may be very useful for medical and biotechnological applications in the development of anti-angiogenic and anti-metastatic therapies. Support: FAPESP, CNPq, CAPES (Brazil) Citation Format: Lívia Mara Santosa, Tamires de Castro Vieira, Heloísa Sobreiro Selistre-de-Araújo. Alternagin-C, an α2β1 integrin-binding disintegrin-like protein, induces distinct cell responses in fibroblasts, tumor breast and endothelial cells in vitro. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr B64. doi:10.1158/1538-7445.CHTME14-B64

Hepatotoxicity and genotoxicity of patulin in mice, and its modulation by green tea polyphenols administration

Patulin (PAT) is a mycotoxin produced by certain species of Penicillium, Aspergillus, and Byssochlamys. Previous studies demonstrated its cytotoxic, genotoxic, and mutagenic effects in different cell lines. However, there is little information available concerning its toxic behavior in vivo. In the present study, we investigated PAT-induced hepatotoxicity and genotoxicity in mice. We also investigated the antioxidant and anti-genotoxicity efficiency of green tea polyphenols (GTP) against PAT-induced toxicity. We found that PAT-treatment induced serum alanine transaminase (ALT) and aspartate transaminase (AST) activities significantly. PAT-induced lipid peroxidation was confirmed with the elevation of thiobarbituric acid-reactive substances (TBARS). Moreover, the increasing of reactive oxygen species (ROS) and decreasing of GSH level implied its oxidative damage mechanism. In bone marrow cell, PAT was found to induce micronucleus and chromosomal aberration formation. In addition, our result suggested that GTP administration has dose-dependent antioxidative and antigenotoxic effect in against PAT-induced hepatotoxicity and genotoxicity.

Expression of the xenobiotic metabolizing enzyme cytochrome P450 1B1 alters anti‐inflammatory activity of quercetin, kaempferol and taxifolin in macrophage and monocyte (830.25)

Diet‐derived flavonoids quercetin (Q), kaempferol (K) and taxifolin (T) were studied for their anti‐inflammatory property in J774A.1 mouse macrophage, undifferentiated‐ (u‐) and differentiated‐ (d‐) human THP‐1 cells. Cells were pre‐incubated with respective compound for 48 h followed by stimulation with bacterial lipopolysaccharide (LPS) to induce inflammatory response. All test compounds inhibited LPS induction of the pro‐inflammatory cytokines IL‐6 mRNA expressions in J774A.1 cells with EC50 at 6 µM for Q, 5 µM for K, and 16 µM for T, respectively. Interestingly, all compounds at concentration up to 10 µM exerted no inhibitory effect on LPS induction of IL‐6 mRNA expression in u‐THP‐1 cells. In d‐THP‐1 cells, Q and K significantly inhibited LPS stimulation of IL‐6 mRNA expression, while T showed no inhibitory effect. This differential effect in different cell lines appeared to be associated with differential ability of the compounds to inhibit expression of the xenobiotic metabolizing enzyme, cytochrome p450 1B1 (CYP1B1), with potency of inhibition ranked K>Q>>T. CYP1B1 mRNA was detected in both u‐ and d‐THP‐1, but absent in J774A.1. In summary, among the structurally similar flavonoids, K exhibited most potent anti‐inflammatory effects, and possessed the most potent inhibitory effect on CYP1B1 expression. Hence, the anti‐inflammatory efficacy of a compound is negatively related to CYP1B1 expression.

In vitro study of the cytotoxicity and antiproliferative effects of surfactants produced by Sphingobacterium detergens

The application of biosurfactants in the biomedical field is growing due to their antimicrobial activity, low cytotoxicity and ability to induce apoptosis in cancer cells. In the light of this therapeutic potential, as well as possible applications in cosmetics or as drug vehicles in pharmaceutical products, a new biosurfactant produced by Sphingobacterium detergens was investigated for its haemolytic activity and cytotoxic and antiproliferative effects in different cell lines. Fraction A showed 100% haemolysis in rabbit erythrocytes, but in Fraction B the rate was only 83%. When comparing cytotoxicity values (IC50) of the two fractions in model fibroblast and keratinocyte cell cultures, Fraction B was less cytotoxic, showing lower values than the reference compound SDS, indicating low skin irritability. Finally, in non-differentiated intestinal Caco-2 cultures, Fractions A and B reduced cell proliferation and induced apoptosis by 44% and 75%, respectively. According to these results, biosurfactants produced by S. detergens have potential application in cosmetic and pharmaceutical formulations.

Studies on Correlation of Antimutagenic and Antiproliferative Activities of Juglans regia L.

We investigated the effect of water and acetone extract of Juglans regia L. to evaluate its antimutagenic and antiproliferative activities. The antimutagenic study using TA98 and TA100 tester strains of Salmonella revealed the water and acetone extracts to be more effective than the benzene and chloroform extracts in inhibiting the revertants induced by 2-aminoflourene (2AF) in TA100 tester strains. The most effective extracts in the Ames assay were further evaluated using the Lucifer luciferase assay and in time course studies for antiproliferative activities using the Hoechst staining to observe apoptotic cell deaths. The acetone extract showed a correlation of antimutagenic activities in the Ames assay with its antiproliferative effect in different cell lines, while the water extract exerted its effect distinctly in each cell line. Further studies are still needed to evaluate the cytotoxicity in experiments carried out in vivo.

Non-opioid binding sites for beta-endorphin and in vitro effects in different cell lines

Different cell lines (SK-N-MC, SH-SY5Y, AtT-20, and U-1690) were investigated with regard to binding of 3 H-morphine and 125 I-beta-endorphin(1-31). 3 H-morphine binding was only detectable on membranes of SH-SY5Y cells All cell lines showed a specific binding of 125 I-beta endorphin to intact cells which was not displaced by morphine or naloxone but by N-acetyl-beta-endorphin and the C-terminal fragment Lys-Lys-Gly-Glu. No other opioid peptides competed with 125 I-beta-endorphin at this binding site. The kd of the beta-endorphin binding site ranged between 10 and 100 nmol, with about 500 binding sites per cell, and the bound beta-endorphin was partially internalized. There was no influence on cAMP accumulation after incubation with beta-endorphin