Filtered By:
Source: Toxicology Letters

This page shows you your search results in order of date. This is page number 5.

Order by Relevance | Date

Total 86 results found since Jan 2013.

p-Cresol mediates autophagic cell death in renal proximal tubular cells.
Abstract Higher serum level of p-cresol (PC) in chronic kidney disease (CKD) patients has been linked with CKD progression. The toxic effect of PC on diverse cells has been reported by prior studies, except for renal tubular cells. Both autophagy and apoptosis contribute to renal tubular cell death, yet evidence of its response to PC is limited and their crosstalk is still unclear. Autophagy is an important cellular process involved in toxin-induced cell death. Renal tubular cell death in tubular injury is thought to be one of the key events causing the progression of CKD. Thus, we treated rat (NRK-52E) and human ...
Source: Toxicology Letters - February 7, 2015 Category: Toxicology Authors: Lin HH, Huang CC, Lin TY, Lin CY Tags: Toxicol Lett Source Type: research

Role of autophagy in arsenite-induced neurotoxicity: the involvement of α-synuclein.
Abstract In the present study, the role of autophagy in sodium arsenite (arsenite)-induced neurotoxicity was investigated in rat primary cultured cortical neurons. Incubation with arsenite concentration-dependently increased LC3-II levels (a biomarker of autophagy), indicating that arsenite is capable of inducing autophagy. Co-localization of fluorescent puncta of monodansylcadaverine (a fluorescent dye of autophagic vacuoles) and LysoTracker Red (a fluorescent dye of lysosomes) as well as chloroquine-induced enhancement of arsenite-elevated LC3-II levels suggest that arsenite induced autolysosome formation in pri...
Source: Toxicology Letters - January 29, 2015 Category: Toxicology Authors: Teng YC, Jeng CJ, Huang HJ, Lin AM Tags: Toxicol Lett Source Type: research

Pifithrin-alpha has a p53-independent cytoprotective effect on docosahexaenoic acid-induced cytotoxicity in human hepatocellular carcinoma HepG2 cells.
In this report, we examined the inhibitory effects of PFT against docosahexaenoic acid (DHA)-induced cytotoxicity in the human hepatocellular carcinoma (HCC) cell line HepG2. PFT significantly abrogated DHA-induced cytotoxicity in wild-type HepG2 cells (normal expression of p53) and after p53-knockdown by siRNA, as well as in Hep3B (p53 null) and Huh7 (p53 mutant) cells. DHA-induced cytotoxicity is mediated by induction of oxidative stress, and PFT inhibited this event, but it does not exert antioxidant effects. PFT significantly suppressed the release of cytochrome c from mitochondria to cytosol, as well as changes in the...
Source: Toxicology Letters - November 18, 2014 Category: Toxicology Authors: Kanno SI, Kurauchi K, Tomizawa A, Yomogida S, Ishikawa M Tags: Toxicol Lett Source Type: research

17-beta estradiol inhibits oxidative stress-induced accumulation of AIF into nucleolus and PARP1-dependent cell death via estrogen receptor alpha.
Abstract Oxidative stress-induced DNA damage results in over-activation of poly(ADP-ribose) polymerase 1 (PARP1), leading to parthanatos, a newly discovered cell elimination pathway. Inhibition of PARP1-dependent cell death has shown to improve the outcome of diseases, including stroke, heart ischemia, and neurodegenerative diseases. In the present study we aimed to detect whether estrogen plays a protective role in inhibiting parthanatos. We utilized human mammary adenocarcinoma cells (MCF7) that abundantly express the estrogen receptor alpha and beta (ERα and ERβ). Parthanatos was induced by challenging the ce...
Source: Toxicology Letters - September 30, 2014 Category: Toxicology Authors: Batnasan E, Wang R, Wen J, Ke Y, Li X, Bohio AA, Zeng X, Huo H, Han L, Boldogh I, Ba X Tags: Toxicol Lett Source Type: research

Nanomolar levels of PAHs in extracts from urban air induce MAPK signaling in HepG2cells.
This study has investigated intracellular MAPK signaling in response to PAHs in extracts from urban air collected in Stockholm, Sweden and Limeira, Brazil, in comparison to BP in HepG2cells. Nanomolar concentrations of PAHs in the extracts induced activation of MEK4 signaling with down-stream increased gene expression of several important stress response mediators. Involvement of the MEK4/JNK pathway was confirmed using siRNA and an inhibitor of JNK signaling resulting in significantly reduced MAPK signaling transactivated by the AP-1 transcription factors ATF2 and cJun. ATF2 was also identified as a sensitive stress respo...
Source: Toxicology Letters - June 6, 2014 Category: Toxicology Authors: Jarvis IW, Bergvall C, Morales DA, Kummrow F, Umbuzeiro GA, Westerholm R, Stenius U, Dreij K Tags: Toxicol Lett Source Type: research

Anacardic acid induces cell apoptosis associated with induction of ATF4-dependent endoplasmic reticulum stress.
Abstract Anacardic acid (6-pentadecylsalicylic acid, AA), a natural compound isolated from the traditional medicine Amphipterygium adstringens, has been reported to possess antitumor activities. However, its molecular targets have not been thoroughly studied. Here, we report that AA is a potent inducer of endoplasmic reticulum (ER) stress, leading to apoptosis in hepatoma HepG2 and myeloma U266 cells. Induction of ER stress by AA was supported by a dose- and time-dependent increase in expression of the ER signaling downstream molecules, such as GRP78/BiP, phosphorylated eIF2α, ATF4 and CHOP in both HepG2 and U266...
Source: Toxicology Letters - May 19, 2014 Category: Toxicology Authors: Huang H, Hua X, Liu N, Li X, Liu S, Chen X, Zhao C, Lan X, Yang C, Dou QP, Liu J Tags: Toxicol Lett Source Type: research

Salvianolic acid B protects against acute ethanol-induced liver injury through SIRT1-mediated deacetylation of p53 in rats.
This study aimed to investigate the effect of SalB on acute ethanol-induced hepatic injury in rats and to explore the role of SIRT1 in this process. The results showed that pretreatment with SalB significantly reduced ethanol-induced elevation in aminotransferase activities, decreased hepatotoxic cytokine levels such as Interleukin-6 (IL-6), and increased the antioxidant enzyme activity. Moreover, SalB pretreatment reversed the increase in NF-κB, cleaved caspase-3 and decrease in B-cell lymphoma-extra large (Bcl-xL) caused by ethanol exposure. Importantly, SalB pretreatment significantly increased the expression of SIRT1,...
Source: Toxicology Letters - April 21, 2014 Category: Toxicology Authors: Li M, Lu Y, Hu Y, Zhai X, Xu W, Jing H, Tian X, Lin Y, Gao D, Yao J Tags: Toxicol Lett Source Type: research

Ziyuglycoside II induces cell cycle arrest and apoptosis through activation of ROS/JNK pathway in human breast cancer cells.
In this study, the anti-proliferative effect of ziyuglycoside II in two classic human breast cancer cell lines, MCF-7 and MDA-MB-231, was extensively investigated. Our study indicated that ziyuglycoside II could effectively induce G2/M phase arrest and apoptosis in both cell lines. Cell cycle blocking was associated with the down-regulation of Cdc25C, Cdc2, cyclin A and cyclin B1 as well as the up-regulation of p21/WAF1, phospho-Cdc25C and phospho-Cdc2. Ziyuglycoside II treatment also induced reactive oxygen species (ROS) production and apoptosis by activating the extrinsic/Fas/FasL pathway as well as the intrinsic/mitocho...
Source: Toxicology Letters - March 27, 2014 Category: Toxicology Authors: Zhu X, Wang K, Zhang K, Zhu L, Zhou F Tags: Toxicol Lett Source Type: research

Zinc Oxide nanoparticles induce Apoptosis by enhancement of Autophagy via PI3K/Akt/mTOR inhibition.
This study demonstrates autophagy supports apoptosis on ZnO NPs exposure. PMID: 24614525 [PubMed - as supplied by publisher]
Source: Toxicology Letters - March 7, 2014 Category: Toxicology Authors: Roy R, Singh SK, Chauhan LK, Das M, Tripathi A, Dwivedi PD Tags: Toxicol Lett Source Type: research

Downregulation of Rad51 participates in OTA-induced DNA double-strand breaks in GES-1 cells in vitro.
Abstract Ochratoxin A (OTA), a mycotoxin produced by ubiquitous Aspergilli, is carcinogenic, teratogenic, and nephrotoxic in both humans and animals. Our previous study found that OTA induced DNA double-strand breaks (DSBs) and resulted in G2 phase arrest in human gastric epithelium immortalized (GES-1) cells. DSBs can cause genomic instability, mutations, and neoplastic transformations, and improper repair of DSBs may lead to the development of cancer. Rad51 is a key protein in the homologous recombination (HR) pathway of DSBs repair. The roles of Rad51 in the repair of DNA damage vary in response to different ty...
Source: Toxicology Letters - February 10, 2014 Category: Toxicology Authors: Lian H, Cui J, Wang Y, Liu J, Wang J, Shen H, Xing L, Wang J, Yan X, Zhang X Tags: Toxicol Lett Source Type: research

The NF-κB family member RelB regulates microRNA miR-146a to suppress cigarette smoke-induced COX-2 protein expression in lung fibroblasts.
In this study we tested whether RelB attenuation of cigarette smoke-induced COX-2 protein is due to miR-146a. Utilizing pulmonary fibroblasts deficient in RelB expression, together with siRNA knock-down of RelB, we show the essential role of RelB in diminishing smoke-induced COX-2 protein expression despite robust activation of the canonical NF-κB pathway and subsequent induction of Cox-2 mRNA. RelB did not regulate COX-2 protein expression at the level of mRNA stability. Basal levels of miR-146a were significantly lower in Relb-deficient cells and cigarette smoke increased miR-146a expression only in Relb-expressing cell...
Source: Toxicology Letters - January 25, 2014 Category: Toxicology Authors: Zago M, de Souza AR, Hecht E, Rousseau S, Hamid Q, Eidelman DH, Baglole CJ Tags: Toxicol Lett Source Type: research

Assessment of drug delivery and anticancer potentials of nanoparticles-loaded siRNA targeting STAT3 in lung cancer, in vitro and in vivo.
Abstract Activation of signal transducer and activator of transcription3 (STAT3) is a hallmark of several types of cancer. Failure to inhibit STAT3 expression by injection of siRNA for STAT3 directly to Balb/c mice led us to adopt alternative means. We formulated nanoparticle-based encapsulation of siRNA (NsiRNA) with polyethylenimine (PEI) and poly (lactide-co-glycolide) (PLGA) and characterized them. The siRNA treated and NsiRNA-treated cells were subjected separately to different assay systems. We also checked if NsiRNA could cross the Blood Brain Barrier (BBB). Cell viability reduced dramatically in A549 cells...
Source: Toxicology Letters - January 16, 2014 Category: Toxicology Authors: Das J, Das S, Paul A, Samadder A, Bhattacharyya SS, Khuda-Bukhsh AR Tags: Toxicol Lett Source Type: research

Celecoxib potentially inhibits metastasis of lung cancer promoted by surgery in mice, via suppression of the PGE2-modulated β-catenin pathway.
In conclusion, celecoxib inhibits metastasis of A549 cells in the circulation enhanced by PGE2 after surgery by not only inhibiting endogenous PGE2 expression, but also by suppression downstream of PGE2 via the GSK-3β-β-catenin pathway. PMID: 24374173 [PubMed - as supplied by publisher]
Source: Toxicology Letters - December 24, 2013 Category: Toxicology Authors: Zhang S, Da L, Yang X, Feng D, Yin R, Li M, Zhang Z, Jiang F, Xu L Tags: Toxicol Lett Source Type: research

Dichlorodiphenyltrichloroethane exposure induces the growth of hepatocellular carcinoma via Wnt/β-catenin pathway.
In this study, we evaluated the impact of p,p'-DDT on the growth of hepatocellular carcinoma using both in vitro and in vivo models. The present data indicated that the proliferation of HepG2 cells was strikingly promoted after exposed to p,p'-DDT for 4 days. In addition, reactive oxygen species (ROS) content was significantly elevated, accompanied with inhibitions of γ-glutamylcysteine synthetase (γ-GCS) and superoxide dismutase (SOD) activities. Interestingly, the levels of β-catenin and its downstream target genes (c-Myc and CyclinD1) were significantly up-regulated, and co-treatment of NAC, the ROS inhibitor, inhibi...
Source: Toxicology Letters - December 17, 2013 Category: Toxicology Authors: Jin XT, Song L, Zhao JY, Li ZY, Zhao MR, Liu WP Tags: Toxicol Lett Source Type: research

Involvement of CTR1 and ATP7A in Lead (Pb)-induced Copper (Cu) Accumulation in Choroidal Epithelial Cells.
This study investigated the roles of Cu transporter 1 (CTR1) and ATP7A, two Cu transporters, in Pb-induced Cu accumulation in the choroidal epithelial cells. Pb exposure resulted in increased intracellular (64)Cu retention, accompanying with up-regulated CTR1 level. Knockdown of CTR1 using siRNA before Pb exposure diminished the Pb-induced increase of (64)Cu uptake. The expression level of ATP7A was down-regulated following the Pb exposure. ATP7A siRNA knockdown, or PCMB treatment, inhibited the (64)Cu efflux from the cells, while the following additional incubation with Pb failed to further increase the intracellular (64)...
Source: Toxicology Letters - December 5, 2013 Category: Toxicology Authors: Zheng G, Zhang J, Xu Y, Shen X, Song H, Jing J, Luo W, Zheng W, Chen J Tags: Toxicol Lett Source Type: research