Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Complex cellular networks regulate regeneration, detoxification and differentiation of hepatocytes. By combining experimental data with mathematical modelling, systems biology holds great promises to elucidate the key regulatory mechanisms involved and predict targets for efficient intervention. For the generation of high-quality quantitative data suitable for mathematical modelling a standardised in vitro system is essential. Therefore the authors developed standard operating procedures for the preparation and cultivation of primary mouse hepatocytes. To reliably monitor the dynamic induction of signalling pathways, the authors established starvation conditions and evaluated the extent of starvation-associated stress by quantifying several metabolic functions of cultured primary hepatocytes, namely activities of glutathione-S-transferase, glutamine synthetase, CYP3A as well as secretion of lactate and urea into the culture medium. Establishment of constant metabolic activities after an initial decrease compared with freshly isolated hepatocytes showed that the cultured hepatocytes achieve a new equilibrium state that was not affected by our starving conditions. To verify the highly reproducible dynamic activation of signalling pathways in the in vitro system, the authors examined the JAK-STAT, SMAD, PI3 kinase, MAP kinase, NF-kappaB and Wnt/beta-catenin signalling pathways. For the induction of gp130, JAK1 and STAT3 phosphorylation IL6 was used, whereas TGFbeta was applied to activate the phosphorylation of SMAD1, SMAD2 and SMAD3. Both Akt/PKB and ERK1/2 phosphorylation were stimulated by the addition of hepatocyte growth factor. The time-dependent induction of a pool of signalling competent beta-catenin was monitored in response to the inhibition of GSK3beta. To analyse whether phosphorylation is actually leading to transcriptional responses, luciferase reporter gene constructs driven by multiple copies of TGFbeta-responsive motives were applied, demonstrating a dose-dependent increase in luciferase activity. Moreover, the induction of apoptosis by the TNF-like cytokine Fas ligand was studied in the in vitro system. Thus, the mouse hepatocyte in vitro system provides an important basis for the generation of high-quality quantitative data under standardised cell culture conditions that is essential to elucidate critical hepatocellular functions by the systems biology approach.
...
PMID:Primary mouse hepatocytes for systems biology approaches: a standardized in vitro system for modelling of signal transduction pathways. 1718 5

Activation of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5) pathway by GH is terminated by the suppressors of cytokine signaling (SOCSs) and protein tyrosine phosphatases, Src homology 2 domain-containing protein tyrosine phosphatase (SHP)-1 and SHP-2. Based on our recent report that estrogen inhibits GH signaling by stimulating SOCS-2 expression, we investigated the effects of selective estrogen receptor modulators (SERMs) on GH signaling in human embryonic kidney (HEK293) and breast cancer (MDA-MB-231) cells expressing human GH receptor and estrogen receptor-alpha. 17beta-estradiol (E(2)) suppressed GH activation of a STAT5-responsive luciferase reporter and JAK2 phosphorylation in both cell models. 4-hydroxytamoxifen and raloxifene augmented these actions of GH in HEK293 cells but not breast cancer cells. SOCS-2 expression in both cell types was stimulated by E(2) but unaffected by SERMs. In HEK293 cells, SHP-1 was inhibited by raloxifene and 4-hydroxytamoxifen, whereas the latter additionally inhibited SHP-2. The phosphatases were unaffected by E(2). In breast cancer cells, phosphatase activity was not altered by SERMs or E(2). In summary, estrogen inhibited the JAK2/STAT5 signaling of GH and stimulated SOCS-2 expression in both HEK293 and breast cancer cells. By contrast, SERMs augmented GH signaling by reducing SHP activities in HEK293 cells and had no effect on both in breast cancer cells. We provide the first evidence for a novel mechanism regulating GH signaling, in which SERMs enhance GH activation of the JAK2/STAT5 pathway in a cell-type-dependent manner by attenuating protein tyrosine phosphatase activities.
...
PMID:Regulation of growth hormone signaling by selective estrogen receptor modulators occurs through suppression of protein tyrosine phosphatases. 1727 97

During systemic inflammation, the liver becomes unresponsive to growth hormone (GH), resulting in decreased plasma insulin-like growth factor-I (IGF-I) with concomitant reductions in lean body mass. Transgenic mice that overexpress IL-6 also demonstrate impaired growth and decreased IGF-I. To determine whether IL-6 directly inhibits GH-inducible gene expression, CWSV-1 hepatocytes were incubated with IL-6 (10 ng/ml), then stimulated with recombinant human GH (500 ng/ml, 18 h). The increase in IGF-I and serine protease inhibitor 2.1 (Spi 2.1) mRNA in GH-treated cells was inhibited by treatment with IL-6 for 24 h. To investigate potential mechanisms, we examined the effects of IL-6 on GH receptor (GHR) expression and GH signaling via the JAK/signal transducer and activator of transcription (STAT) and MAP kinase pathways. Incubation of cells with IL-6 (10 ng/ml, 24 h) had no effect on GHR abundance or signaling proteins JAK2, STAT5b, and ERK1/2. Although GH transiently increased (2- to 5-fold) the tyrosine phosphorylation of GHR, JAK2, STAT5b, and ERK1/2, IL-6 did not alter these phosphorylation events. However, nuclear protein from IL-6-treated cells demonstrated reduced STAT5 DNA binding (by EMSA) at 15 min (-20%) and 60 min (-43%) after GH stimulation. To determine whether IL-6 inhibits GH-inducible promoter activity, CWSV-1 cells were transfected with Spi 2.1 or prolactin receptor promoter luciferase vectors, incubated with or without IL-6, then stimulated with GH. The induction of both Spi 2.1 (7.5-fold) and prolactin receptor (4-fold) promoter activity by GH was inhibited by IL-6. In summary, IL-6 mediates hepatic GH resistance by a time-dependent inhibition of GH-inducible promoter activity that is associated with reductions in STAT5 DNA binding.
...
PMID:Interleukin-6 inhibits growth hormone-mediated gene expression in hepatocytes. 1739 96

Obsessive-compulsive disorder (OCD) is a disease of complex aetiology with a marked genetic component. Impact of the serotonergic system has been reported but the contribution of additional transmitter systems to the pathogenesis seems likely. The extraneuronal monoamine transporter, EMT (SLC22A3), is implicated in non-neuronal termination of noradrenergic signalling in the central nervous system and a candidate gene for a variety of neuropsychiatric disorders. We conducted a case-control study of 84 Caucasian children and adolescents with OCD according to DSM-IV criteria, and healthy adults by comprehensive sequencing of the EMT gene. Additionally, targeted genotype analysis was done with patient-parent trios. Known polymorphisms and frequent haplotypes were not associated with OCD in the present sample. Transmission disequilibrium test was negative for the presumptive cryptic splice site 1233G>A polymorphism. However, we identified two novel independent mutations exclusively in affected patients. A thus far unknown -106/107delAG mutation was detected in three male patients of unaffected parents but was not prevalent in 204 healthy subjects (p=0.024). In a luciferase reporter assay the mutant allele conferred increased promoter activity by 36%. Furthermore, we describe the first non-synonymous substitution in the EMT gene, Met370Ile, in a family of affected female members that co-segregated with the disease. The residue exhibits a high degree of inter-species conservation. Heterologous expression of mutant cDNA revealed a 40% decline of transport capacity for norepinephrine. Rare mutations in the EMT gene suggest a causative or modulating role in genetic subtypes of OCD.
...
PMID:Novel mutations of the extraneuronal monoamine transporter gene in children and adolescents with obsessive-compulsive disorder. 1747 85

Interleukin 6 and the signal transducer and activator of transcription (STAT) 3 proteins have important roles in cancer cell survival and proliferation. Recent studies demonstrate that abnormal STAT3 activation promotes tumor growth and supports survival of many human cancers, and thus, this protein or the pathway responsible for its activation is a potential target for the new anticancer therapy. STAT3 is a DNA binding transcription factor, and therefore, its function depends on nuclear translocation. To discover inhibitors of the STAT3 pathway, we designed a cell-based screening assay capable of identifying small molecules that inhibit nuclear translocation. Among the 2000-compound National Cancer Institute Diversity set, we identified 8-benzyl-4-oxo-8-azabicyclo[3.2.1]oct-2-ene-6,7-dicarboxylic acid (SD-1008) as a micromolar inhibitor of interleukin-6 or oncostatin-induced STAT3 nuclear translocation. In addition, SD-1008 inhibits tyrosyl phosphorylation of STAT3, Janus kinase 2 (JAK2), and Src. SD-1008 also reduces STAT3-dependent luciferase activity. Biochemical studies with recombinant JAK2 proteins demonstrate that high concentrations of SD-1008 directly inhibit JAK2 kinase autophosphorylation. Exposure of various cell lines to SD-1008 decreases levels of the STAT3-dependent proteins, Bcl-X(L) and survivin, inducing apoptosis. SD-1008 also enhances apoptosis induced by paclitaxel in ovarian cancer cells. These results demonstrate that SD-1008 directly blocks the JAK-STAT3 signaling pathway in human cancer cells that express constitutively active Stat and add to the growing literature that identifies this pathway as a viable target for drug development. Finally, SD-1008 may be a suitable prototype for further chemical modification and exploration as a therapeutic agent.
...
PMID:8-benzyl-4-oxo-8-azabicyclo[3.2.1]oct-2-ene-6,7-dicarboxylic acid (SD-1008), a novel janus kinase 2 inhibitor, increases chemotherapy sensitivity in human ovarian cancer cells. 1767 86

Obesity is a major global health problem and is associated with low-grade inflammation and, in a number of cases, poor iron status. We speculated that the adipokine leptin might play a role in regulating iron metabolism in the overweight population because it shares a number of common biological features with IL-6, a major factor in the development of the anemia of chronic disease via its stimulatory actions on the production and release of the iron regulatory hormone hepcidin. To test this hypothesis, we exposed HuH7 human hepatoma cells to leptin and measured hepcidin mRNA expression by quantitative PCR. HuH7 cells were also transfected with a hepcidin promoter-luciferase reporter gene construct to investigate transcriptional regulation of hepcidin. In leptin-treated cells, hepcidin mRNA expression was enhanced significantly. Preincubation with a Janus kinase (JAK) 2 inhibitor significantly diminished this response. Hepcidin promoter activity was also increased in the presence of leptin. This effect was decreased either by mutation of the signal transducer and activator of transcription (STAT) 3 binding motif in the hepcidin promoter or by coexpressing a dominant-negative STAT3 mutant. These data suggest that leptin upregulates hepatic hepcidin expression through the JAK2/STAT3 signaling pathway. As a consequence, the increased production of leptin in overweight individuals might be a major contributor to the aberrant iron status observed in these population groups.
...
PMID:Leptin increases the expression of the iron regulatory hormone hepcidin in HuH7 human hepatoma cells. 1795 71

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a high affinity ligand for the aryl hydrocarbon receptor (AhR). In this study, we investigated structure-dependent differences in activation of the AhR by a series of halogenated aromatic hydrocarbons. TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB126) induced CYP1A1-dependent activities in HEK293 human embryonic kidney, Panc1 pancreatic cancer, and Hepa1c1c7 mouse hepatoma cell lines. There was a structure-dependent difference in the efficacy of TCDF and PCB126 in HEK293 and Panc1 cells since induced CYP1A1 mRNA levels were lower than observed for the other congeners. A mammalian two-hybrid assay in cells transfected with GAL4-coactivator and AhR-VP16 chimeras was used to investigate structure-dependent interactions of these chimeras in Panc1, HEK293, and Hepa1c1c7 cells. The reporter construct pGAL4-luc contains five tandem GAL4 response elements linked to the luciferase gene and the GAL4-coactivator chimeras express several coactivators including steroid receptor coactivator 1 (SRC-1), SRC-2 and SRC-3, the mediator coactivator TRAP220, coactivator associated arginine methyl transferase 1 (CARM-1), and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1). Results of the mammalian two-hybrid studies clearly demonstrate that activation of pGAL4-luc in cells transfected with VP-AhR and GAL4-coactivator chimeras is dependent on the structure of the HAH congener, cell context, and coactivator, suggesting that the prototypical HAH congeners used in this study exhibit selective AhR modulator activity.
...
PMID:Ligand-dependent interactions of the Ah receptor with coactivators in a mammalian two-hybrid assay. 1804 71

Activating mutations in fibroblast growth factor receptor 3 (FGFR3) cause several human skeletal dysplasias as a result of attenuation of cartilage growth. It is believed that FGFR3 inhibits chondrocyte proliferation via activation of signal transducers and activators of transcription (STAT) proteins, although the exact mechanism of both STAT activation and STAT-mediated inhibition of chondrocyte growth is unclear. We show that FGFR3 interacts with STAT1 in cells and is capable of activating phosphorylation of STAT1 in a kinase assay, thus potentially serving as a STAT1 kinase in chondrocytes. However, as demonstrated by western blotting with phosphorylation-specific antibodies, imaging of STAT nuclear translocation, STAT transcription factor assays and STAT luciferase reporter assays, FGF does not activate STAT1 or STAT3 in RCS chondrocytes, which nevertheless respond to a FGF stimulus with potent growth arrest. Moreover, addition of active STAT1 and STAT3 to the FGF signal, by means of cytokine treatment, SRC-mediated STAT activation or expression of constitutively active STAT mutants does not sensitize RCS chondrocytes to FGF-mediated growth arrest. Since FGF-mediated growth arrest is rescued by siRNA-mediated downregulation of the MAP kinase ERK1/2 but not STAT1 or STAT3, our data support a model whereby the ERK arm but not STAT arm of FGF signaling in chondrocytes accounts for the growth arrest phenotype.
...
PMID:STAT1 and STAT3 do not participate in FGF-mediated growth arrest in chondrocytes. 1819 89

Akt/protein kinase B (Akt/PKB), which is activated by phosphatidylinositol-3 kinase (PI3-kinase), plays an important role in cell survival and cell proliferation. Using the well differentiated, clonal gonadotroph cell line, LbetaT2, we examined (1) whether Akt/PKB was activated by gonadotropin-releasing hormone (GnRH); (2) the contribution of PI3-kinase-Akt/PKB pathway in each of gonadotropin subunit gene expression; (3) crosstalk between extracellular signal-regulated kinase (ERK) and Akt/PKB pathways. Insulin-like growth factor-1 (IGF-1) was used as Akt/PKBs classic activator. Western blot analyses using antibodies specific for the phosphorylated forms of ERK and Akt/PKB demonstrated that both were rapidly phosphorylated following treatment with GnRH and IGF-1. Akt/PKB activation by GnRH and IGF-1 was completely eliminated in the presence of the PI3-kinase inhibitor, LY 294002, but not in the presence of an Akt/PKB inhibitor. Interestingly, the total amount of Akt/PKB protein was dramatically increased in the presence of LY 294002. Phosphorylation of ERK was significantly increased in the presence of LY 294002 alone, and was further increased when GnRH was used in combination with LY 294002. In experiments using a luciferase reporter construct containing the serum response element (SRE), a known target of the ERK pathway, LY 294002 but not the Akt/PKB inhibitor increased SRE-luciferase activity. GnRH-induced SRE-luciferase activity was significantly increased by LY 294002. GnRH stimulation resulted in gonadotropin LHbeta, FSHbeta, and alpha-subunit promoter activation, while IGF-1 failed to stimulate any of them. GnRH-induced gonadotropin promoter activities were not modulated in the presence of an Akt/PKB inhibitor, but treatment with LY 294002 or Wortmannin resulted in a significant increase in alpha- and FSHbeta-subunit promoter activation, both with and without GnRH. LY 294002, but not the Akt/PKB inhibitor, significantly inhibited cell proliferation. These results suggest that GnRH-induced gonadotropin gene expression is not regulated through the Akt/PKB pathway; however, PI3-kinase may be involved in the negative regulation of alpha- and FSHbeta-subunit gene expression as well as cell proliferation.
...
PMID:The involvement of phosphatidylinositol 3-kinase in gonadotropin-releasing hormone-induced gonadotropin alpha- and FSHbeta-subunit genes expression in clonal gonadotroph LbetaT2 cells. 1820 95

Endothelial dysfunction plays a central role in diabetic vascular disease, but its molecular bases are not completely defined. We showed previously that the actin-binding protein proflin-1 was increased in the diabetic endothelium and that attenuated expression of profilin-1 protected against atherosclerosis. Also 7-ketocholesterol up-regulated profilin-1 in endothelial cells via transcriptional mechanisms. The present study addressed the pathways responsible for profilin-1 gene expression in 7-ketocholesterol-stimulated endothelial cells and in the diabetic aorta. In luciferase reporter assays, the response to 7-ketocholesterol within the 5'-flanking region of profilin-1 was dependent on a single STAT response element. In aortic endothelial cells, 7-ketocholesterol enhanced STAT3 activation, which required JAK2 and tyrosine 394 phosphorylation of oxysterol-binding protein-1. These changes were recapitulated in the aorta of diabetic rats. Also 7-ketocholesterol in cultured endothelial cells and diabetes in the aorta elicited the recruitment of STAT3 and relevant coregulatory factors to the oxysterol-responsive region of the profilin-1 promoter. These events were required for profilin-1 up-regulation. These studies identify a previously unrecognized oxysterol-binding protein-mediated mode of activation of STAT3 that controls the expression of the proatherogenic protein profilin-1 in response to 7-ketocholesterol and the diabetic milieu.
...
PMID:Oxysterol and diabetes activate STAT3 and control endothelial expression of profilin-1 via OSBP1. 1823 Jun 13


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---