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Query: UNIPROT:P05412 (
c-Jun
)
11,453
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Previously, we reported that mitogenicity in L6 muscle cells was stimulated by insulin but inhibited by reactive oxygen/nitrogen species (
ROS
/RNS; []) and that preincubation with sodium ascorbate (ASC) protected from either the impaired DNA synthesis and/or loss of cell viability. Now, we addressed the question how ascorbate (AA) rescued DNA synthesis in L6 muscle cells being challenged with
ROS
/RNS. We assumed that AA might be able to influence insulin signaling. We found that insulin elevated the protein levels of both PKB/Akt kinase phosphorylated at Serine(473) (pS473-Akt), and
c-Jun
phosphorylated at Serine63, Serine73 (pS63, pS73-
c-Jun
) residues, respectively. A short-term treatment experiment (0 - 45 min) revealed that either insulin (0.1 muM) or hydrogen peroxide (0.1, 0.5 mM; H2O2) increased the pS473-Akt and pS63, pS73-
c-Jun
protein levels, although the effect of
ROS
/RNS peaked earlier (5 min) than that of insulin (45 min). Astonishingly, the elevated levels of both pS473-Akt and pS63, pS73-
c-Jun
in response to insulin were reduced by the concomitant treatment with H2O2 in a dose-dependent fashion. In contrast, a 4-hour preincubation with ASC (1 mM) augmented the signal from pS473-Akt and pS63, pS73-
c-Jun
, when both insulin and H2O2 were added. Moreover, a 24 h preincubation with ASC also elevated the pS473-Akt and pS63, pS73-
c-Jun
levels in response to insulin irrespective to
ROS
/RNS co-treatment. During chronic treatment studies,
ROS
/RNS stimulated neither phosphorylation of Akt nor
c-Jun
, indicating that
ROS
/RNS-dependent activation of the above-mentioned proteins was short-term and transient. Furthermore, higher levels of pS473 Akt and pS63, pS73-
c-Jun
after preincubation with ASC suggest that by this route AA could protect insulin-induced mitogenicity. Basal levels of Akt and its target p70(S6K) remained constant regardless of treatment. These results suggest that AA defends the insulin-stimulated mitogenicity hampered by
ROS
/RNS most likely by the amplification of insulin signal at the level of pS473-Akt and pS63, pS73-
c-Jun
, respectively.
...
PMID:Preincubation with sodium ascorbate potentiates insulin-dependent PKB/Akt and c-Jun phosphorylation in L6 rat myoblasts challenged with reactive oxygen/nitrogen species. 1590 68
Chlorogenic acid, the ester of caffeic acid with quinic acid, is one of the most abundant polyphenols in the human diet. The antioxidant and anticarcinogenic properties of chlorogenic acid have been established in animal studies. However, little is known about the molecular mechanisms through which chlorogenic acid inhibits carcinogenesis. In this study, we found that chlorogenic acid inhibited the proliferation of A549 human cancer cells in vitro. The results of the soft agar assay indicated that chlorogenic acid suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation of JB6 P+ cells in a dose-dependent manner. Pretreatment of JB6 cells with chlorogenic acid blocked UVB- or TPA-induced transactivation of AP-1 and NF-kappaB over the same dose range. At low concentrations, chlorogenic acid decreased the phosphorylation of
c-Jun
NH2-terminal kinases, p38 kinase, and MAPK kinase 4 induced by UVB/12-O-tetradecanoylphorbol-13-acetate, yet higher doses were required to inhibit extracellular signal-regulated kinases. Chlorogenic acid also increased the enzymatic activities of glutathione S-transferases (GST) and NAD(P)H: quinone oxidoreductase. Further studies indicated that chlorogenic acid could stimulate the nuclear translocation of Nrf2 (NF-E2-related factor) as well as subsequent induction of GSTA1 antioxidant response element (ARE)-mediated GST activity. The phosphatidylinositol 3-kinase pathway might be involved in the activation of Nrf2 translocation. These results provide the first evidence that chlorogenic acid could protect against environmental carcinogen-induced carcinogenesis and suggest that the chemopreventive effects of chlorogenic acid may be through its up-regulation of cellular antioxidant enzymes and suppression of
ROS
-mediated NF-kappaB, AP-1, and MAPK activation.
...
PMID:Inhibition of activator protein-1, NF-kappaB, and MAPKs and induction of phase 2 detoxifying enzyme activity by chlorogenic acid. 1594 51
Bone sialoprotein (BSP), a major protein in the extracellular matrix of bone, is expressed almost exclusively by bone cells and by cancer cells that have a propensity to metastasize to bone. Previous studies have shown that v-src stimulates basal transcription of bsp in osteosarcoma (
ROS
17/2.8) cells by targeting the inverted CCAAT element (ICE) in the proximal promoter. To identify possible downstream effectors of Src we studied the effects of the proto-oncogene c-jun, which functions downstream of Src, on basal transcription of bsp using transient transfection assays. Increased expression of endogenous
c-Jun
induced by the tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate and ectopic expression of
c-Jun
increased basal transcription of chimeric reporter constructs encompassing the proximal promoter by 1.5-3-fold in
ROS
17/2.8 osteosarcoma cells, with more modest effects in a normal bone cell line, RBMC-D8. The effects of
c-Jun
were abrogated by mutations in the ICE box and by co-expression of dominant negative nuclear factor Y, subunit A (NF-YA). The increase in bsp transcription did not require phosphorylation of
c-Jun
and was not altered by trichostatin treatment or by ectopic expression of p300/CREB-binding protein (CBP) or mutated forms lacking histone acetyltransferase (HAT) activity. Similarly, ectopic expression of p300/CBP-associated factor (P/CAF), which transduces p300/CBP effects, or of HAT-defective P/CAF did not influence the c-jun effects. Surprisingly, E1A, which competes with P/CAF binding to p300/CBP, also stimulated BSP transcription through NF-Y independently of c-jun, p300/CBP, and P/CAF. Collectively, these studies show that
c-Jun
and E1A regulate basal transcription of bsp in osteosarcoma cells by recruiting the NF-Y transcriptional complex to the ICE box in a mechanism that is independent of p300/CBP and P/CAF HAT activities.
...
PMID:Recruitment of nuclear factor Y to the inverted CCAAT element (ICE) by c-Jun and E1A stimulates basal transcription of the bone sialoprotein gene in osteosarcoma cells. 1608 80
Rosmarinic acid (RA) is a naturally occurring polyphenolic and is found in several herbs in the Lamiaceae family, such as, Perilla frutescens. ADR is a potent anti-tumor drug, but is unfortunately potently cardiotoxic. This study was undertaken to investigate the inhibitory effect of RA on ADR-induced apoptosis in H9c2 cardiac muscle cells at a mechanistic level. In vitro, ADR significantly decreased the viabilities of H9c2 cells, and this was accompanied by apoptotic features, such as a change in nuclear morphology and caspase protease activation. RA was found to markedly inhibit these apoptotic characteristics by reducing intracellular
ROS
generation and by recovering the mitochondria membrane potential (delta psi). In addition, RA reversed the downregulations of GSH, SOD and Bcl-2 by ADR. In the present study, ADR was found to activate c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), transcriptional factor-activator-protein (AP)-1. We found that c-fos, Jun-B, Jun-D and p-
c-Jun
were super shifted by ADR, indicating that these proteins have an important role in the ADR-induced AP-1 activation. The inhibitions of JNK and ERK using appropriate inhibitors or dominant negative cell lines reduced ADR-induced apoptosis in H9c2 cardiac muscle cells. Taken together, these results suggest that RA can inhibit ADR-induced apoptosis in H9C2 cardiac muscle cells by inhibiting
ROS
generation and JNK and ERK activation. Thus, we propose that RA should be viewed as a potential chemotherapeutic that inhibits cardiotoxicity in ADR-exposed patients.
...
PMID:Inhibitory effects of rosmarinic acid on adriamycin-induced apoptosis in H9c2 cardiac muscle cells by inhibiting reactive oxygen species and the activations of c-Jun N-terminal kinase and extracellular signal-regulated kinase. 1610 32
Trilinolein, isolated from the traditional Chinese herb Sanchi (Panax notoginseng), has been shown to have myocardial protective effects via its antioxidant ability. However, the cellular and molecular mechanisms of the protective effect of trilinolein in the heart remain to be elucidated. Oxidative mechanisms have been implicated in neonatal cardiomyocyte hypertrophy. We previously reported that ET-1 induces
ROS
generation via the ET(A) receptor and
ROS
modulates c-fos gene expression. We have therefore examined whether trilinolein attenuates
ROS
production and ET-1-induced c-fos gene expression in cardiomyocytes. Cultured neonatal rat cardiomyocytes were stimulated with ET-1 (10 nM), and c-fos gene expression was examined. Trilinolein (1 and 10 microM) inhibited ET-1-induced c-fos gene expression in cardiomyocytes. We also examined the effects of trilinolein on ET-1-increased NADPH oxidase activity and superoxide formation. Trilinolein inhibited ET-1-increased NADPH oxidase activity and superoxide formation in a concentration-dependent manner. This increase in superoxide production by ET-1 was significantly inhibited by trilinolein, diphenyleneiodonium, or N-acetylcysteine. Trilinolein also decreased ET-1- or H2O2-induced extracellular signal-regulated kinase (ERK) phosphorylation,
c-Jun
NH2-terminal kinase (JNK) phosphorylation, and activator protein-1 activation. These data indicate that trilinolein inhibits ET-1-induced ERK phosphorylation, JNK phosphorylation, and c-fos gene expression via attenuating superoxide production in cardiomyocytes.
...
PMID:Inhibitory effect of trilinolein on endothelin-1-induced c-fos gene expression in cultured neonatal rat cardiomyocytes. 1618 2
Sensitive to apoptosis gene (SAG), a novel zinc RING finger protein, exhibits anti-apoptotic and antioxidant activity against a variety of redox reagents. In the present study, we have determined that SAG suppresses 1-methyl-4-phenylpyridinium ion (MPP(+))-induced neurotoxicity via the downregulation of
ROS
generation and c-Jun N-terminal kinase 1 (JNK1) activity. Both transient and constitutively overexpressed SAG were found to inhibit the MPP(+)-induced neurotoxicity of SH-SY5Y neuroblastoma cells. In the SAG-expressing cells, MPP(+) induced
ROS
generation was suppressed to a significant degree as compared to the cells treated only with MPP(+). MPP(+)-induced JNK1 activation was also determined to be suppressed markedly by SAG. Furthermore, SAG inhibits MEKK1 dependent
c-Jun
transcription activity in SH-SY5Y cells. Thus, we concluded that SAG is a cellular protective molecule, which appears to function as an antioxidant, suppressing MPP(+)-induced neurotoxicity.
...
PMID:SAG protects human neuroblastoma SH-SY5Y cells against 1-methyl-4-phenylpyridinium ion (MPP+)-induced cytotoxicity via the downregulation of ROS generation and JNK signaling. 1724 May 29
4-Hydroxynonenal (HNE) is one of the most abundant aldehyde components of ox-LDL and it exerts various effects on intracellular and extracellular signaling cascades. In this mini-review, a brief synopsis of HNE-modulated signaling pathways will be presented mainly focused on cell death, including recent studies from our laboratory. The results of a number of studies demonstrate the ability of HNE to induce apoptosis and
ROS
formation in a dose-dependent manner. Several signaling pathways have been shown to be modulated by HNE, including MAP kinases, PKC isoforms, cell-cycle regulators, receptor tyrosine kinases and caspases. In order to get insight into the mechanisms of apoptotic response by HNE, MAP kinase and caspase activation pathways have been studied in 3T3 fibroblasts; HNE induced early activation of JNK and p38 proteins but down-regulated the basal activity of ERK-1/2. We have shown that HNE-induced release of cytochrome c from mitochondria, caspase-9 and caspase-3 activation. Activation of AP-1 along with increased
c-Jun
and phospho-
c-Jun
levels could be inhibited by pretreatment of cells with certain molecules such as resveratrol. Additionally, overexpression of dominant negative
c-Jun
and JNK1 in 3T3 fibroblasts prevented HNE-induced apoptosis, which indicated a role for JNK-
c-Jun
/AP-1 pathway. JNK-dependent induction of
c-Jun
/AP-1 activation data in the literature indicates a critical potential role for JNK in the cellular response against toxic products of lipid peroxidation.
...
PMID:Apoptosis signalling by 4-hydroxynonenal: a role for JNK-c-Jun/AP-1 pathway. 1726 5
Induction of 17beta-estradiol (E2) and insulin-like growth factor-I (IGF-I) has been detected in breast carcinoma, however the interaction between E2 and IGF-I in the proliferation of breast carcinoma cells is still unclear. In the present study, we found that IGF-I enhances the E2-induced proliferation in MCF-7 human breast carcinoma cells in accordance with stimulation of colony formation via a soft agar assay. Activation of insulin receptor substrate-1 (IRS-1) protein and extracellular signal-related kinases (ERKs) and
c-Jun
N-terminal kinases (JNKs), but not p38 mitogen-activated protein kinase (MAPK), via phosphorylation induction was detected in MCF-7 cells treated with IGF-I plus E2 (E2/IGF-I). E2/IGF-I-induced proliferation was blocked by chemical inhibitors of ERKs (PD98059) and JNKs (SP600125). An increase in the expression of
c-Jun
protein was detected in E2/IGF-I-treated MCF-7 cells, and this was inhibited by PD98059 and SP600125. Transfection of the dominant negative MEKK and JNK plasmids significantly reduced E2/IGF-I-induced proliferation with suppression of
c-Jun
protein expression. An increase in peroxide production was detected in E2/IGF-I-treated cells, and N-acetyl-L-cysteine (NAC) and Tiron (TIR) addition significantly inhibited E2/IGF-I-induced cell proliferation with blocking of the phosphorylation of ERKs and JNKs, and the expression of
c-Jun
protein. Additionally, 3-OH flavone, baicalein, and quercetin showed effective inhibitory activities against E2/IGF-I-induced proliferation through suppressing proliferative events such as phosphorylation of IRS-1, ERKs, and JNKs proteins, and induction of
c-Jun
protein and colony formation. These results indicate that IGF-I interacts with E2 to promote the proliferation of breast carcinoma cells via
ROS
-dependent MAPK activation and
c-Jun
protein expression. The structure-related inhibition of E2/IGF-I-induced proliferative events by flavonoids is elucidated.
...
PMID:IGF-I plus E2 induces proliferation via activation of ROS-dependent ERKs and JNKs in human breast carcinoma cells. 1745 2
ACTX-6 is a protein isolated from Agkistrodon acutus snake venom and demonstrated cytotoxic activity to various cancer cells in vitro. In this paper the exact mechanism in ACTX-6-induced cell death was investigated and it was found that ACTX-6 could induce cell apoptosis. The results of Western blot and RT-PCR showed that ACTX-6 could induce Fas and FasL protein expression. When Fas signaling pathway was blocked by neutralizing antibodies to Fas or FasL, ACTX-6-induced apoptosis was inhibited. DISC formation was also detected by immunoprecipitation. These results suggested that Fas pathway was involved in ACTX-6-induced apoptosis. The activities of caspase-3, 8 and 9 were assayed and the activation of caspase-9 demonstrated that mitochondrial pathway was also involved in ACTX-6-induced apoptosis. Bid cleavage and dissipation of mitochondrial membrane potential (delta psi(m)) verified the involvement of mitochondria. ACTX-6 is an L-amino acid oxidase and can oxidize L-amino acid to generate hydrogen peroxide. The production of
ROS
in ACTX-6-treated cells was detected and the
ROS
scavenger catalase could inhibit ACTX-6-induced apoptosis. Western blot analysis showed that JNK was phosphorylated in ACTX-6-treated cells and
c-Jun
was also activated. JNK inhibitor SP600125 could inhibit ACTX-6-induced apoptosis and catalase could inhibit JNK and
c-Jun
phosphorylation. It could be concluded that JNK pathway was necessary in ACTX-6-induced apoptosis and the oxidative stress generated by ACTX-6 was responsible for the activation of JNK.
...
PMID:A cytotoxin isolated from Agkistrodon acutus snake venom induces apoptosis via Fas pathway in A549 cells. 1754 16
The mechanism of acacetin-induced apoptosis of human breast cancer MCF-7 cells was investigated. Acacetin caused 50% growth inhibition (IC50) of MCF-7 cells at 26.4% 0.7% M over 24 h in the MTT assay. Apoptosis was characterized by DNA fragmentation and an increase of sub-G1 cells and involved activation of caspase-7 and PARP (poly-ADP-ribose polymerase). Maximum caspase 7 activity was observed with 100 microM acacetin for 24 h. Caspase 8 and 9 activation cascades mediated the activation of caspase 7. Acacetin caused a reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c and apoptosis inducing factor (AIF) into the cytoplasm, enhancing
ROS
generation and subsequently resulting in apoptosis. Pretreatment of cells with N-acetylcysteine (NAC) reduced
ROS
generation and cell growth inhibition, and pretreatment with NAC or a caspase 8 inhibitor (Z-IETD-FMK) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c and AIF. Stress-activated protein kinase/
c-Jun
NH4-terminal kinase 1/2 (SAPK/ JNK1/2) and
c-Jun
were activated by acacetin but extracellular-regulated kinase 1/2 (Erk1/2) nor p38 mitogen-activated protein kinase (MAPK) were not. Our results show that acacetin-induced apoptosis of MCF-7 cells is mediated by caspase activation cascades,
ROS
generation, mitochondria-mediated cell death signaling and the SAPK/JNK1/2-
c-Jun
signaling pathway, activated by acacetin-induced
ROS
generation.
...
PMID:Acacetin-induced apoptosis of human breast cancer MCF-7 cells involves caspase cascade, mitochondria-mediated death signaling and SAPK/JNK1/2-c-Jun activation. 1784 3
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