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Query: EC:2.7.7.49 (
reverse transcriptase
)
31,746
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Carnosol, a constant constituent of Rosmarinus officinalis extracts, is a phenolic diterpene shown to have antioxidant and anticarcinogen properties. In our studies, carnosol inhibited the invasion of highly metastatic mouse melanoma B16/F10 cells in vitro. First, the antimetastatic potentials of carnosol were examined by soft agar colony formation assay. Second, carnosol dose-dependently inhibited B16/F10 cell migration and invasion by in vitro transwell assay. Third, the decreasing activity of metalloproteinase was observed by zymographic assay. The result revealed that the treatment of carnosol could diminish the activity of MMP-9 more than MMP-2. Next, we analyzed the amounts of MMP-9 and MMP-2 proteins in the cells. The data indicated MMP-9 protein was also suppressed by carnosol in the same manner. In accordance with the above data, the results of
reverse transcriptase
polymerase chain reaction (RT-PCR) analysis showed a reduced level of MMP-9 mRNA. Furthermore, carnosol significantly inhibited the tyrosine phosphorylation of
extracellular signal-regulated kinase
(
ERK
) 1/2, AKT, p38,
JNK
and inhibition of activation of transcription factors NFkappa-B and c-Jun. These results lead us to conclude that carnosol could restrict the invasive ability of B16/F10 mouse melanoma cells by reducing MMP-9 expression and activity through suppressing (
ERK
) 1/2, AKT, p38, and
JNK
signaling pathway and inhibition of NF-kappaB and AP-1 binding activity. Taken together, these results indicate that carnosol targets MMP-mediated cellular events in cancer cells and provides a new mechanism for its anticancer activity.
...
PMID:Carnosol inhibits the invasion of B16/F10 mouse melanoma cells by suppressing metalloproteinase-9 through down-regulating nuclear factor-kappa B and c-Jun. 1562 74
Increased expression of transforming growth factor (TGF)-beta(1) and tumor necrosis factor (TNF)-alpha are thought to play important roles in the development of pulmonary fibrosis. We recently reported that TNF-alpha upregulates TGF-beta(1) expression in primary mouse lung fibroblasts (MLFs), a key cell population in fibrogenesis. In the present study, we have investigated signal transduction pathways involved in TNF-alpha upregulation of TGF-beta(1) in both primary MLFs and the Swiss 3T3 fibroblast cell line. Treatment of fibroblasts with TNF-alpha resulted in a significant increase in TGF-beta(1) protein as measured by ELISA. The increase in protein was preceded by a 200-400% increase in TGF-beta(1) mRNA detected by quantitative, real-time,
reverse transcriptase
-polymerase chain reaction. Western blot analysis showed that TNF-alpha activated the
extracellular signal-regulated kinase
(
ERK
), and inhibitors of the
ERK
-specific
mitogen-activated protein kinase
pathway (PD98059 or U0126) blocked TNF-alpha induction of TGF-beta(1) mRNA and protein. mRNA stability experiments showed that TNF-alpha increased the half-life of TGF-beta(1) mRNA to more than 24 h compared with approximately 15 h in unstimulated cells. Expression of constitutively active MEK1 that selectively phosphorylates
ERK
was sufficient for TGF-beta(1) mRNA stabilization in Swiss 3T3 fibroblasts. These results indicate that TNF-alpha activates the
ERK
-specific
mitogen-activated protein kinase
pathway leading to increased TGF-beta(1) production in fibroblasts, primarily via a post-transcriptional mechanism that involves stabilization of the TGF-beta(1) transcript.
...
PMID:Tumor necrosis factor-alpha induces transforming growth factor-beta1 expression in lung fibroblasts through the extracellular signal-regulated kinase pathway. 1565 32
It has been demonstrated that exposure to cocaine increases cell death in the fetal CNS. To examine the molecular mechanisms of this effect, we employed mouse oligo microarrays followed by real-time
reverse transcriptase
-polymerase chain reaction (real-time RT-PCR) to compare expressions of apoptosis-related genes in the cerebral wall of 18-day-old (E18) fetuses from cocaine-treated (20 mg/kg cocaine, s.c., b.i.d., E8th-E18th) and drug-naive (saline, s.c.) mice. Out of approximately 400 relevant genes in the arrays, 53 showed alterations in expression in cocaine-exposed fetuses. Upregulation was observed in 35 proapoptotic and 8 antiapoptotic genes; 4 proapoptotic and 6 antiapoptotic genes were down-regulated. The affected genes encode a wide range of apoptosis-related proteins, including death receptors (NTF-R1, NTF-R2, DR3, DR5, LTbeta-R, GITR, P57 TR-1) and their adaptor and regulatory proteins (MASGE-D1, TRAF-2, SIVA, MET, FLIP, FAIM, IAP1, ATFA), members of transcription regulatory pathways (
JNK
, NF-kappaB, P53), members of BCL-2 family of proteins (BID, BAD, BAX, BIK, NIP21, NIP3, NIX, BCL-2), DNA damage sensor (PARP-1), caspases and their substrates and regulatory proteins (caspases 8, 4, 9, and 3, ACINUS, CIDE-A, CIDE-B, GAS2), mitochondrially released factors (cytochrome c, AIF, PRG3), specific endoplasmic reticulum- and oxidative stress-associated factors (BACH2, ABL1, ALG2, CHOP), members of cell survival AKT and HSP70 pathways (PIK3GA, PTEN, HSP70, BAG1, BAG2), and others. This suggests that cocaine affects survival of developing cerebral cells via multiple apoptosis-regulating mechanisms.
...
PMID:Cocaine-induced changes in the expression of apoptosis-related genes in the fetal mouse cerebral wall. 1568 Nov 17
We investigated whether lipid peroxidation might influence activation of the mitogen activated protein kinase (MAPK) extracellular regulated kinase (
ERK1
/2) and
c-Jun N-terminal kinase
(JNK) in neointimal hyperplasia induced by flow interruption of carotid artery in mice. C57/BL6 mice were subjected to a complete ligation of the left common carotid artery or to a sham ligation. Animals were randomized to receive either IRFI-042, a Vitamin E-like inhibitor of lipid peroxidation (20 mg/kg/i.p., immediately after artery occlusion) or its vehicle (1 ml/kg of a NaCl-DMSO solution). The extent of lipid peroxidation (investigated by the means of conjugated dienes levels) and JNK and ERK activation were evaluated by Western blot analysis after blood flow interruption. ICAM-1 expression in injured arteries was investigated 4 days after artery ligation by the means of
reverse transcriptase
polymerase chain reaction (RT-PCR) and quantification of the ICAM-1 protein levels. Morphometric analysis of the structural alteration caused by the disruption of the arterial blood flow was performed 4 weeks after surgery. Flow interruption in the carotid artery resulted at 10 min, following occlusion in a marked increase in conjugated dienes tissue levels (5.8+/-0.44 DeltaABS/mg protein), caused at 30 min after occlusion peak increase in both
ERK1
/2 (45+/-8 integrated intensity) and JNK (38+/-6 integrated intensity) activities, enhanced ICAM-1 expression (1.5+/-0.45 relative amount of ICAM-1 mRNA) and ICAM-1 protein levels (55+/-12 pg/mg protein) and produced a marked neointimal hyperplasia (mean intimal area=101+/-14 microm2). Injured arteries harvested from IRFI-042-treated mice had reduced conjugated dienes tissue levels (2.9+/-0.5 DeltaABS/mg protein), attenuated
ERK1
/2 (19+/-6 integrated intensity) and JNK (2.9+/-0.5 integrated intensity) activities, blunted ICAM-1 expression (0.38+/-0.1 relative amount of ICAM-1 mRNA) and protein levels (26+/-8 pg/mg protein) and decreased neointimal hyperplasia (mean intimal area=4.5+/-1.5 microm2). Our data indicate that
ERK1
/2 and JNK kinases play a crucial role in neointimal hyperplasia induced by flow cessation in the mouse carotid artery. Furthermore, the present data suggest that lipid peroxidation triggers ERK and JNK activation.
...
PMID:Lipid peroxidation triggers both c-Jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK) activation and neointimal hyperplasia induced by cessation of blood flow in the mouse carotid artery. 1569 37
In the United States, oral cancer accounts for more deaths annually than cervical cancer, leukemias, or Hodgkin's lymphoma. Studies have shown that aberrations of chromosome 18q develop with tumor progression and are associated with significantly decreased survival in head and neck cancer patients. The G-protein-coupled receptor, galanin receptor 1 (GALR1), maps to this region of chromosome 18q. Although the role of GALR1 has been well characterized in neuronal cells, little is known regarding this receptor in non-neuronal cells. In this study, the expression, mitogenic function, and signaling mechanism of GALR1 are investigated in normal and malignant oral epithelial cells. mRNA expression was determined via
reverse transcriptase
-PCR. Protein quantification was done via immunoblot analysis and enzyme-linked immunosorbent assay. For functional and signaling studies, an inhibitory antibody was generated to the N-terminal ligand binding domain of GALR1. GALR1 protein and mRNA expression and GAL secretion were detected at variable levels in immortalized human oral keratinocytes and human oropharyngeal squamous cell carcinoma cell lines. Upon competitive inhibition of GALR1, proliferation was up-regulated in immortalized and malignant keratinocytes. Furthermore, studies with the inhibitory antibody and U0126, the
MAPK
inhibitor, show that GALR1 inhibits proliferation in immortalized and malignant keratinocytes by inactivating the
MAPK
pathway. GALR1s inhibitory effects on proliferation in epithelial cells raises the possibility that inactivation or disregulation of this receptor can lead to uncontrolled proliferation and neoplastic transformation.
...
PMID:Galanin receptor 1 has anti-proliferative effects in oral squamous cell carcinoma. 1576 48
Sex steroids and growth factors interact at the intracellular level in a variety of tissues to control numerous physiological functions. Oestrogen is known to stimulate prolactin synthesis and secretion, but the effect of insulin-like growth factor (IGF)-I is less clear. We used GH3 cells, a somatolactotroph cell line, to study the interaction of 17beta-oestradiol (E(2)) and IGF-I on prolactin protein levels and the intracellular mechanisms involved. Cell cultures were treated with E(2) (10 nM) and/or IGF-I (10 ng/ml) for 8 h. The real-time
reverse transcriptase
-polymerase chain reaction, Western blot and enzyme-immunoassay were used to determine changes in prolactin mRNA and protein levels. At this time-point, there were no significant changes in cell number, prolactin mRNA expression, or the amount of secreted prolactin. However, E(2) increased intracellular prolactin concentrations. IGF-I alone had no effect, but blocked the stimulatory effect of E(2).
MAPK
(
ERK1
/2) activation, as determined by Western blot analysis, increased with both E(2) and IGF-I, but not with the combination of these factors. The
MAPK
inhibitor PD98059 blocked the ability of E(2) to increase intracellular prolactin concentrations. Similarly, the IGF-I receptor antagonist, JB1, blocked the effect of E(2) on prolactin synthesis and
MAPK
activation, as did the oestrogen receptor antagonist ICI182 780. These results suggest that, to stimulate prolactin synthesis, E(2) activates the
MAPK
cascade and that this requires the presence of both oestrogen and IGF-I receptors.
...
PMID:Oestrogen requires the insulin-like growth factor-I receptor for stimulation of prolactin synthesis via mitogen-activated protein kinase. 1579 60
Lactoferrin (LF), a glycoprotein present in milk, mucosal secretions and neutrophils, contributes to host defense and immunomodulation. In the present study, we investigated the effect of bovine LF (bLF) on cytokine messenger RNA (mRNA) expression in concanavalin A (ConA)-stimulated feline peripheral blood mononuclear cells (PBMC). Semi-quantitative
reverse transcriptase
polymerase chain reaction (RT-PCR) and real-time PCR showed a ConA-induced increase of interferon-gamma (IFN-gamma) mRNA expression but not of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and IL-12 p40 mRNA in feline PBMC. This ConA-induced increase of IFN-gamma mRNA expression was inhibited by addition of bLF not only 30 min before ConA stimulation but also 10, 20 and 40 min after ConA stimulation. Western blotting showed that protein tyrosine kinase (PTK) and
extracellular signal-regulated kinase
(
ERK
) in feline PBMC were activated within 10 min after the ConA stimulation and that the activation of both kinases had almost disappeared by 40 min after stimulation. Moreover, the ConA-induced IFN-gamma mRNA expression was partly prevented by genistein, a global PTK inhibitor, and PD-98059, an
ERK
inhibitor, respectively. These results suggest that bLF is able to inhibit the ConA-induced IFN-gamma mRNA expression by abrogation of intracellular signaling activated after interaction between ConA and its receptor.
...
PMID:Reduction of concanavalin A-induced expression of interferon-gamma by bovine lactoferrin in feline peripheral blood mononuclear cells. 1579 77
The very low-density lipoprotein (VLDL) receptor is a member of the low-density lipoprotein (LDL) receptor gene family with distinct tissue distribution and function. VLDL receptors are also expressed in vascular smooth muscle cells (VSMCs) and have been shown to be upregulated in atherosclerotic lesions. In the present study, we examined the effects of interleukin-1beta (IL-1beta) on the uptake of betaVLDL and its receptor expression in rat VSMCs. IL-1beta downregulated expression of the VLDL receptor in a time and dose-dependent manner as shown by Western blotting, Northern blotting, and
reverse transcriptase
-polymerase chain reaction (RT-PCR) analysis. Treatment with IL-1beta significantly reduced the uptake of beta-VLDL but not LDL in VSMCs. Use of specific pharmacologic inhibitors indicated that the tyrosine kinase inhibitors, herbimycin A and geldanamycin, completely reversed IL-1beta-induced downregulation of the VLDL receptor expression. Another tyrosine kinase inhibitor, genistein, the protein kinase C inhibitors, GF109203X and H7, the mitogen-activated protein (MAP) kinase inhibitors (MEK inhibitor PD098059 for [MEK] and SB203580 for p38-
MAP kinase
), and the protein kinase A inhibitor, KT5270 all had no effect on receptor expression. In addition, the c-Src specific inhibitor PP2 or adenoviral-mediated gene transfer of kinase inactive (KI)-c-Src failed to reverse IL-1beta-induced downregulation of VLDL receptor expression. These results indicate that IL-1beta attenuates uptake of VLDL through downregulation of its receptor in VSMCs, and that this downregulation is mediated through a benzoquinone ansamycin-dependent but c-Src-independent pathway.
...
PMID:Interleukin-1beta attenuates beta-very low-density lipoprotein uptake and its receptor expression in vascular smooth muscle cells. 1580 40
Since both endothelin-1 (ET-1) and aldosterone have been shown to induce expression of several pro-inflammatory genes, including cyclooxygenase-2 (COX-2), in the vasculature as a cardiovascular risk hormone, the present study was undertaken to examine the effects of ET-1 and aldosterone on COX-2 gene expression as measured by a real-time
reverse transcriptase
-polymerase chain reaction in aortic endothelial cells. Treatment with ET-1(10 M) markedly upregulated COX-2 mRNA levels in rat endothelial cells, whereas aldosterone (10 M) did not show any effect. The ET-1-induced COX-2 upregulation was inhibited by pretreatment with a non-selective endothelin receptor antagonist (TAK044), a protein kinase C inhibitor (GF109203X), and a MEK inhibitor (PD98059). Furthermore, ET-1 increased intracellular reactive oxygen species generation as estimated by the measurement of dichlorofluorescein fluorescence, whose effect was blocked by a COX-2 inhibitor (NS398). Our data show that ET-1 induces COX-2 upregulation in rat endothelial cells via a protein kinase C-dependent and
extracellular signal-regulated kinase
-dependent pathway, which may largely contribute to the generation of intracellular reactive oxygen species.
...
PMID:Endothelin-1 induces cyclooxygenase-2 expression and generation of reactive oxygen species in endothelial cells. 1583 13
We have previously shown that, in bovine retina pericytes, amyloid beta(1-42) and its truncated form containing amino acids 25-35, after 24 h treatment, stimulate arachidonic acid (AA) release and phosphatidylcholine hydrolysis, by activation of both cytosolic (cPLA(2)) and Ca(2+)-independent (iPLA(2)) phospholipase A(2). A putative role for MAP kinases in this process emerged. Here we studied the role of the MAP-kinase family as well as both cPLA(2) and iPLA(2) mRNA expression by a semi-quantitative
reverse transcriptase
-polymerase chain reaction (RT-PCR) in the same sublethal model of amyloid-beta (Abeta) damage to pericytes in vitro. Abeta(25-35) peptide evoked AA release as well as stimulated phosphorylation of
ERK1
/2, p38 MAPKs and cPLA(2), but not
c-Jun N-terminal kinase
(
JNK
/
SAPK
). PD98059, an inhibitor of ERK-activating kinase MEK-1, and SB203580, an inhibitor of p38 protein kinase, abolished the stimulation of AA release and
MAPK
activities. In cells stimulated by Abeta(25-35) peptide, Western blotting and confocal microscopy analyses confirmed either an increase in the phosphorylated form of ERKs and p38 or their nuclear translocation. A complete inhibition of
MAPK
activation and AA release was also observed when pericytes were treated with GF109203X, a general PKC inhibitor, indicating the important role of both PKC and the two MAPKs in mediating the Abeta peptide response. Compared with samples untreated or treated with reverse Abeta(35-25) peptide, pretreatment with 50 microM Abeta(25-35) for 24 h significantly increased the level of constitutively expressed iPLA(2) mRNA by 25%, which seems to depend on the activation of kinases. By contrast, the level of cPLA(2) mRNA remained unchanged. Together, these data link either the stimulation of PKC-ERK-p38 cascades or PLA(2) activity by Abeta peptide to prooxidant mechanism induced by amyloid, which may initially stimulate the cell reaction as well as metabolic repair, such as during inflammation.
...
PMID:MAPKs mediate the activation of cytosolic phospholipase A2 by amyloid beta(25-35) peptide in bovine retina pericytes. 1586 64
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