Early gene response in lithium chloride induced apoptosis

Zhang, W. V.; Jüllig, Mia; Connolly, Ashley R.; Stott, N. Susan

doi:10.1007/s10495-005-6063-x

Cited by 38 publications

(28 citation statements)

References 70 publications

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“…Within a population of one cell type, a large proportion of cells that expressed eGFP-PCV1ORF3 did not undergo cell death. Similarly, it has been reported that cells from different origins vary in their tolerance and responses to apoptosis-inducing agents, such as lithium chloride (15,35). Therefore, it is possible that ORF3 is proapoptotic but that it is the state of the cellular host that determines the final outcome of virus-cell interactions.…”

Section: Resultsmentioning

confidence: 97%

Cytotoxicity of ORF3 Proteins from a Nonpathogenic and a Pathogenic Porcine Circovirus

Chaiyakul

Hsu²,

Dardari³

et al. 2010

J Virol

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Porcine circovirus type 2 (PCV2) infection is associated with significant and serious swine diseases worldwide, while PCV1 appears to be a nonpathogenic virus. Previous studies demonstrated that the ORF3 protein of PCV2 (PCV2ORF3) was involved in PCV2 pathogenesis via its proapoptotic capability (J. Liu, I. Chen, Q. Du, H. Chua, and J. Kwang, J. Virol. 80:5065-5073, 2006). If PCV2ORF3-induced apoptosis is a determinant of virulence, PCV1ORF3 is hypothesized to lack this ability. The properties of PCV1 and PCV2 ORF3, expressed as fusion proteins to an enhanced green fluorescent protein (eGFP), were characterized with regard to their ability to cause cellular morphological changes, detachment, death, and apoptosis. PCV1ORF3 significantly induced more apoptotic cell death and was toxic to more different cell types than PCV2ORF3 was. PCV1ORF3-associated cell death was caspase dependent. PCV1ORF3 also induced poly(ADP-ribose) polymerase 1 (PARP) cleavage; however, whether PARP was involved in cell death requires further studies. Truncation of PCV1 and elongation of PCV2 ORF3 proteins revealed that the first 104 amino acids contain a domain capable of inducing cell death, whereas the C terminus of PCV1ORF3 contains a domain possibly responsible for enhancing cell death. These results suggest that the pathogenicity of PCV2 for pigs is either not determined or not solely determined by the ORF3 protein.Lymphocyte depletion and the presence of porcine circovirus type 2 (PCV2) genome and antigens (4, 6, 21) are hallmarks of PCV-associated disease (PCVAD), a wasting and immunosuppressive ailment of postweaned pigs. Despite two decades of research, little is known about the molecular pathogenesis of PCVAD.PCV2 is the smallest known autonomous vertebrate virus containing a 1.7-kb single-stranded, ambisense DNA genome (32). The virus has two major open reading frames (ORFs) that encode the replication proteins (Rep and RepЈ) involved in the initiation of virus replication (17) and a capsid protein (Cap), forming the capsid of the virion (32). A third ORF encodes an ORF3 protein that has been characterized as an inducer of apoptosis (14). Abrogation of ORF3 expression attenuated PCV2 pathogenesis in BALB/c mice (13) and specific-pathogen-free piglets (9). This led to the hypothesis that ORF3 is involved in PCV2 pathogenesis by inducing apoptosis in infected lymphocytes, leading to lymphocyte depletion and ultimately immunosuppression (13, 25). The closely related, yet nonpathogenic porcine circovirus type 1 (PCV1) also has a third open reading frame, but the properties of the ORF3 protein of PCV1 (PCV1ORF3) have not been characterized. Analysis of over 250 PCV2 variants and 30 PCV1 variants shows a consistent single-nucleotide substitution in the ORF3 coding sequence of PCV2 (PCV2ORF3), resulting in a stop codon and a protein that is half the size of PCV1ORF3 (PCV2ORF3 is made up of 104 amino acids [aa] compared to PCV1ORF3, which is made up of 206 aa). A comparison between PCV1 and PCV2 ORF3 translated regions reveals only 60%...

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Section: Resultsmentioning

confidence: 97%

Cytotoxicity of ORF3 Proteins from a Nonpathogenic and a Pathogenic Porcine Circovirus

Chaiyakul

Hsu²,

Dardari³

et al. 2010

J Virol

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“…Although LiCl is used clinically as a neuroprotectant, at concentrations as high as 20 mM, it can cause apoptosis of hippocampal neurons (Song et al 2004;Zhang et al 2005). Therefore, we tried to determined whether the combination treatment could hinder the proliferation of glioma cells at relatively lower cytotoxicity.…”

Section: Combination Treatment Inhibited the Proliferation Of C6 Gliomentioning

confidence: 99%

A potential strategy for high-grade gliomas: combination treatment with lithium chloride and BmK CT

Zheng

Huang

et al. 2011

Biotechnol Lett

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Therapies for high-grade gliomas (HHG) that have strong tendency of infiltration and resistance to chemotherapies are currently unavailable. Here, we report that lower-dose combination therapy of Buthus martensii Karsch (BmK) CT, a type of scorpion toxin peptide, and LiCl, clinically used as mood stabilizer, could synergistically inhibit the migration, invasion and proliferation of C6 glioma cells. The decreased invasiveness of C6 glioma cells was accompanied by inhibited activation, catalytic activity and/or expression of matrix metalloproteinase-2. Moreover, TOPfalsh luciferase reporter and immunofluorescence staining showed altered localization pattern of β-catenin at the leading edge of 2D scratch. Our results suggested that the combination treatment of lithium and BmK CT may constitute a novel and potential strategy for HHG therapy.

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“…The sequences of the primers and the probe used for Noxa and 18SrRNA were designed using Primer Express (Applied Biosystems, USA) and Amplify software and synthesized by Applied Biosystems (Applied Biosystems, USA) and have previously been described. 28 The PCR was developed on the ABI PRISM 7700 Sequence Detection system instrument (Applied Biosystems), using the standard protocol supplied by the manufacturer. The thermal cycling conditions comprised of an initial denaturation step at 95 • C for 10 min and 50 cycles of two-step PCR, including 15 sec of denaturation at 95 • C and 1 min of annealing-elongation at 60 • C. All experiments were repeated in triplicate.…”

Section: Real-time Rt Pcrmentioning

confidence: 99%

MG132 induced apoptosis is associated with p53-independent induction of pro-apoptotic Noxa and transcriptional activity of β-catenin

et al. 2006

Self Cite

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Noxa is a pro-apoptotic BH3-only member of the Bcl-2 family of proteins that is up-regulated at a transcriptional level by the nuclear protein p53 in response to cellular stresses such as DNA damage or growth factor deprivation. Noxa is able to interact with anti-apoptotic members of the Bcl-2 family and causes release of cytochrome c into the cytosol, leading to the activation of caspases and induction of apoptosis. Here we demonstrate that MG132, a proteasomal inhibitor, rapidly induces Noxa mRNA and protein in two human cell lines, T/C28a and Saos2. The induction of Noxa is associated with a significant reduction in the number of metabolically active cells over the first 24 h of exposure to MG132 and progressive activation of caspase-3, a hallmark of caspase-dependent apoptosis. Partial rescue of the phenotype is observed when cells are transfected with Noxa siRNA prior to treatment with MG132, indicating functional significance of the induction of Noxa. p53 has previously been shown to be non-functional in the T/C28a cell line and is absent by Western blotting in Saos2 cells, suggesting that the induction of Noxa is through a p53 independent mechanism. Western blotting and confocal microscopy showed that total beta-catenin protein is increased in both cell lines at the time of Noxa induction, with the bulk of the beta-catenin present in the nucleus. Transfection with the Tcf reporter vector pTOPFLASH confirms that treatment with MG132 leads to early increased transcriptional activity of beta-catenin in both T/C28a and Saos2 cells. However, although over-expression of transcriptionally active beta-catenin in T/C28a cells also induced apoptosis through a p53-independent mechanism, the levels of Noxa protein were unchanged, suggesting that beta-catenin mediated signaling and Noxa may play independent roles in MG132 induced apoptosis. In summary, our results demonstrate that MG132 induces the pro-apoptotic protein Noxa via a p53-independent mechanism that leads to caspase-dependent apoptosis. This is the first report showing that treatment with MG132 induces Noxa. This study also provides further evidence for a link between beta-catenin mediated signaling and the induction of apoptosis.

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Early gene response in lithium chloride induced apoptosis

Cited by 38 publications

References 70 publications

Cytotoxicity of ORF3 Proteins from a Nonpathogenic and a Pathogenic Porcine Circovirus

Cytotoxicity of ORF3 Proteins from a Nonpathogenic and a Pathogenic Porcine Circovirus

A potential strategy for high-grade gliomas: combination treatment with lithium chloride and BmK CT

MG132 induced apoptosis is associated with p53-independent induction of pro-apoptotic Noxa and transcriptional activity of β-catenin

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