Apoptotic DNA fragmentation may be a cooperative activity between caspase-activated deoxyribonuclease and the poly(ADP-ribose) polymerase-regulated DNAS1L3, an endoplasmic reticulum-localized endonuclease that translocates to the nucleus during apoptosis.

Caspase-activated DNase (CAD) is the most favorable candidate for chromatin degradation during apoptosis. Ca(2+)-dependent endonucleases are equally important in internucleosomal DNA fragmentation (INDF), including the PARP-1-regulated DNAS1L3. Despite the elaborate work on these endonucleases, the question of whether these enzymes cooperate during INDF was not addressed.

Phosphorylation of p50 NF-kappaB at a single serine residue by DNA-dependent protein kinase is critical for VCAM-1 expression upon TNF treatment.

The DNA binding activity of NF-κB is critical for VCAM-1 expression during inflammation. DNA-dependent protein kinase (DNA-PK) is thought to be involved in NF-κB activation. Here we show that DNA-PK is required for VCAM-1 expression in response to TNF.

Phenoxodiol inhibits growth of metastatic prostate cancer cells.

Background: Phenoxodiol, a synthetic analog of Genistein, is being assessed in several clinical studies against a range of cancer types and was shown to have a good efficacy and safety profile. In this study we tested the effects of Phenoxodiol against prostate cancer cell lines.

Methods: Cell-cycle analysis, plasmatic membrane damage, clonogenic assay, comet assay, and Western blot methodologies were employed to assess the effects of Phenoxodiol on prostate cancer cell lines.

Polyubiquitylation of PARP-1 through ubiquitin K48 is modulated by activated DNA, NAD+, and dipeptides.

Poly(ADP-ribose) polymerase-1 (PARP-1) is the most abundant and the best-studied isoform of a family of enzymes that catalyze the polymerization of ADP-ribose from NAD(+) onto target proteins. PARP-1 is well known to involve in DNA repair, genomic stability maintenance, transcription regulation, apoptosis, and necrosis. Polyubiquitylation targets proteins towards degradation and regulates cell cycle progression, transcription, and apoptosis.

Prolonged poly(ADP-ribose) polymerase-1 activity regulates JP-8-induced sustained cytokine expression in alveolar macrophages.

Environmental pollutants inducing oxidative stress stimulate chronic inflammatory responses in the lung leading to pulmonary tissue dysfunction. In response to oxidative stress, alveolar macrophages produce both reactive oxygen species and reactive nitrogen species, which induce the expression of a wide variety of immune-response genes. We found that a prolonged exposure of alveolar macrophages to a nonlethal dose (8 microg/ml) of JP-8, the kerosene-based hydrocarbon jet fuel, induced the persistent expression of IL-1, iNOS, and COX-2, as well as cell adhesion molecules (ICAM-1 and VCAM-1).

Differential regulation of CXC ligand 1 transcription in melanoma cell lines by poly(ADP-ribose) polymerase-1.

The continuous production of the CXC ligand 1 (CXCL1) chemokine by melanoma cells is a major effector of tumor growth. We have previously shown that the constitutive expression of this chemokine is dependent upon transcription factors nuclear factor-kappa B (NF-kappaB), stimulating protein-1 (SP1), high-mobility group-I/Y (HMGI/Y), CAAT displacement protein (CDP) and poly(ADP-ribose) polymerase-1 (PARP-1). In this study, we demonstrate for the first time the mechanism of transcriptional regulation of CXCL1 through PARP-1 in melanoma cells.

Expression of JP-8-induced inflammatory genes in AEII cells is mediated by NF-kappaB and PARP-1.

Lung epithelial cells are critical in the regulation of airway inflammation in response to environmental pollutants. Altered activation of NF-kappaB is associated with expression of several proinflammatory factors in respiratory epithelial cells in response to an insult. Here we show that a low threshold dose (8 microg/ml) of the jet fuel JP-8 induces in a rat alveolar epithelial cell line (RLE-6TN) a prolonged activation of NF-kappaB as well as the increased expression of the proinflammatory cytokines TNF-alpha and IL-8, which are regulated by NF-kappaB.

DNA transitions induced by binding of PARP-1 to cruciform structures in supercoiled plasmids.

Background: Poly(ADP-ribose)polymerase-1 (PARP-1) binds to single and double-stranded breaks in DNA, but less well known is its affinity for undamaged DNA. Previously, we have shown that PARP-1 also binds to the hairpin structures in DNA models. The mechanism underlying these interactions remains to be defined.

Regulation of alpha-synuclein expression by poly (ADP ribose) polymerase-1 (PARP-1) binding to the NACP-Rep1 polymorphic site upstream of the SNCA gene.

Alleles at NACP-Rep1, the polymorphic microsatellite repeat located approximately 10 kb upstream of the alpha -synuclein gene (SNCA), are associated, in some reports, with differing risks of sporadic Parkinson disease (PD). We showed previously that NACP-Rep1 acts as a negative modulator of SNCA transcription, with an effect that varied threefold among different NACP-Rep1 alleles. Given that duplications and triplications of SNCA have been implicated in familial Parkinson disease (PD), even a 1.

Protection by antioxidants against toxicity and apoptosis induced by the sulphur mustard analog 2-chloroethylethyl sulphide (CEES) in Jurkat T cells and normal human lymphocytes.

1. The mechanism of toxicity of sulphur mustard was investigated by examining the biochemical effects of the analog 2-chloroethylethyl sulphide (CEES) in both human Jurkat cells as well as normal human lymphocytes. 2.

PARP-1 binds E2F-1 independently of its DNA binding and catalytic domains, and acts as a novel coactivator of E2F-1-mediated transcription during re-entry of quiescent cells into S phase.

The transcription factor E2F-1 is implicated in the activation of S-phase genes as well as induction of apoptosis, and is regulated by interactions with Rb and by cell cycle-dependent alterations in E2F-1 abundance. We earlier demonstrated a pivotal role for poly(ADP-ribose) polymerase-1 (PARP-1) in the regulation of E2F-1 expression and promoter activity during S-phase re-entry when quiescent cells re-enter the cell cycle. We now investigate the putative mechanism(s) by which PARP-1 may upregulate E2F-1 promoter activity during S-phase re-entry.

Gene knockout or pharmacological inhibition of poly(ADP-ribose) polymerase-1 prevents lung inflammation in a murine model of asthma.

Airway inflammation is a central feature of asthma and chronic obstructive pulmonary disease. Reactive oxygen species (ROS) contribute to inflammation by damaging DNA, which, in turn, results in the activation of poly(ADP-ribose) polymerase-1 (PARP-1) and depletion of its substrate, nicotinamide adenine dinucleotide. Here we show that prevention of PARP-1 activation protects against both ROS-induced airway epithelial cell injury in vitro and airway inflammation in vivo.

Gene therapy for prostate cancer by targeting poly(ADP-ribose) polymerase.

Poly(ADP-ribose) polymerase (PARP) has strong affinity for DNA strand breaks and cycles on and off the DNA ends to allow DNA repair. A DNA-binding domain of PARP (PARP-DBD) acts as a dominant-negative mutant by binding to DNA strand breaks irreversibly and sensitizing mammalian cells to DNA-damaging agents. Therefore, expression of PARP-DBD in prostate carcinoma cells offers a strategy to achieve sensitization to genotoxic treatments.

A novel in vivo post-translational modification of p53 by PARP-1 in MPTP-induced parkinsonism.

Sporadic Parkinson's disease (PD) affects primarily dopaminergic neurons of the substantia nigra pars compacta. There is evidence of necrotic and apoptotic neuronal death in PD, but the mechanisms behind selected dopaminergic neuronal death remain unknown. The tumor suppressor protein p53 functions to selectively destroy stressed or abnormal cells during life and development by means of necrosis and apoptosis.

The Poly(ADP-ribose) polymerase-1-regulated endonuclease DNAS1L3 is required for etoposide-induced internucleosomal DNA fragmentation and increases etoposide cytotoxicity in transfected osteosarcoma cells.

The cytotoxic effect of the chemotherapeutic drug etoposide (VP-16) is thought to result from its ability to induce DNA damage and thereby to trigger apoptosis. Internucleosomal DNA fragmentation occurs late during apoptosis in many cell types. However, whereas human osteosarcoma cells undergo internucleosomal DNA fragmentation during staurosporine-induced apoptosis, they fail to do so in response to VP-16.

Acetaminophen induces a caspase-dependent and Bcl-XL sensitive apoptosis in human hepatoma cells and lymphocytes.

Acetaminophen is a widely used analgesic and antipyretic drug that exhibits toxicity at high doses to the liver and kidneys. This toxicity has been attributed to cytochrome P-450-generated metabolites which covalently modify target proteins. Recently, acetaminophen, in its unmetabolized form, has been shown to affect a variety of cells and tissues, for instance, testicular and lymphoid tissues and lymphocyte cell lines.

Roles of oxidative stress and glutathione depletion in JP-8 jet fuel-induced apoptosis in rat lung epithelial cells.

The toxic jet fuel JP-8 induces morphological and biochemical changes characteristic of apoptosis in rat lung epithelial (RLE-6TN) cells. The mechanism of JP-8 toxicity in these cells was further investigated in an attempt to identify potential therapeutic interventions. Given that oxidative stress and changes in the concentrations of endogenous antioxidants, such as glutathione (GSH), have been associated with the cellular damage elicited by numerous toxicants, the possibility that JP-8 induces cellular oxidative stress was investigated.

PARP determines the mode of cell death in skin fibroblasts, but not keratinocytes, exposed to sulfur mustard.

Sulfur mustard is cytotoxic to dermal fibroblasts as well as epidermal keratinocytes. We demonstrated that poly(ADP-ribose) polymerase (PARP) modulates Fas-mediated apoptosis, and other groups and we have shown that PARP plays a role in the modulation of other types of apoptotic and necrotic cell death. We have now utilized primary dermal fibroblasts, immortalized fibroblasts, and keratinocytes derived from PARP(-/-) mice and their wildtype littermates (PARP(+/+)) to determine the contribution of PARP to sulfur mustard toxicity.

Rapid activation of poly(ADP-ribose) polymerase contributes to Sindbis virus and staurosporine-induced apoptotic cell death.

Poly(ADP-ribose) polymerase-1 (PARP-1) is a chromatin-associated enzyme that is activated by DNA strand breaks and catalyzes the transfer of ADP-ribose groups from NAD to itself and other nuclear proteins. Although caspase-mediated PARP-1 cleavage occurs during almost all forms of apoptosis, the contribution of PARP-1 activation and cleavage to this cell death process remains unclear. Using immortalized fibroblasts from wild-type (PARP-1(+/+)) and PARP-1 knockout (PARP-1(-/-)) mice, and a mouse neuroblastoma cell line (N18), the role that poly(ADP-ribosyl)ation plays in Sindbis virus (SV)-induced apoptosis was examined.

Roles of DNA fragmentation factor and poly(ADP-ribose) polymerase-1 in sensitization of fibroblasts to tumor necrosis factor-induced apoptosis.

DNA fragmentation factor (DFF) comprises DFF45 and DFF40 subunits, the former of which acts as an inhibitor of the latter (the catalytic subunit) and whose cleavage by caspase-3 results in DFF activation. Disruption of the DFF45 gene blocks the generation of 50-kb DNA fragments and confers resistance to apoptosis. We recently suggested that the early fragmentation of DNA by DFF and the consequent activation of poly(ADP-ribose) polymerase-1 (PARP-1), mitochondrial dysfunction, and activation of caspase-3 contribute to an amplification loop in the apoptotic process.