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:2.7.11.1 (protein kinase)
81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previously it has been shown that thymocytes undergo apoptosis, a form of programmed cell death, in response to glucocorticoids. This classic form of apoptosis is prevented by inhibition of protein synthesis. The current paper demonstrates that mature T cells also undergo apoptosis, but that the regulation of apoptosis in spleen T cells differs from that of thymocytes. Mature mouse spleen T cells were shown to die by apoptosis, not necrosis, when cultured without an added stimulus. Assays for apoptosis included internucleosomal DNA cleavage by gel electrophoresis, percent fragmentation of DNA by the diphenylamine method, and percent of cells with hypodiploid DNA by flow cytometry. The percent of apoptotic cells was 2% in fresh spleen T cells, and increased at least until 16 h, when 21% were apoptotic. Dexamethasone caused apoptosis in both thymus and spleen T cells, but only thymocytes showed a requirement for protein synthesis in dexamethasone-induced death. Cycloheximide increased apoptosis in spleen T cells, indicating that apoptosis was controlled by newly synthesized protective proteins. Spontaneous apoptosis was decreased in spleen T cells by protein kinase C activation, and was increased by H7 and staurosporine, which inhibits protein kinases, in contrast with the behavior of thymocytes. The protein kinase A/G inhibitor HA1004 also decreased spleen T cell apoptosis. The contrasting effects of cycloheximide on thymocytes and spleen T cells occurred over the same concentration range, and the same was true for PMA. The dexamethasone dose-response curves were similar, except that a greater proportion of spleen T cells were dexamethasone-resistant. These data support the hypothesis that the apoptosis program in T cells undergoes a transition during their maturation, such that apoptosis in mature T cells is regulated more like that of mature B cells than that of thymocytes.
...
PMID:Regulation of apoptosis in vitro in mature murine spleen T cells. 837 90

To explore the role of glomerular endothelial cells (GEN) in the pathogenesis of glomerulonephritis, the in vitro production of monocyte chemoattractant protein-1 (MCP-1) by bovine GEN was determined by chemotaxis assay, and Western blot analysis, and immunocytochemistry. Monocyte chemotactic activity of GEN-conditioned media was detectable by a chemotaxis assay using human peripheral blood monocytes. Exposure to human recombinant interleukin-1 beta (IL-1 beta) and phorbol myristate acetate (PMA) significantly increased the chemotactic activity of GEN-conditioned media. A checkerboard analysis showed that the response of monocytes to GEN-conditioned media was truly chemotactic. Immunoadsorption with a monoclonal antibody to human MCP-1 reduced the chemotactic activity of GEN-conditioned media by 85%. Northern blot analysis revealed that MCP-1 mRNA was constitutively expressed by GEN and that IL-1 beta and tumor necrosis factor-alpha (TNF-alpha) increased MCP-1 mRNA levels in a dose- and time-dependent manner. Furthermore, PMA induced an increase in MCP-1 mRNA levels, whereas dibutyryl cyclic AMP and forskolin had minimal effects. Inhibition study using protein kinase inhibitors revealed that MCP-1 mRNA expression induced by IL-1 beta and TNF-alpha was suppressed by the tyrosine kinase inhibitor genistein, not by the protein kinase C inhibitors staurosporine or H-7, or the protein kinase A inhibitor H-89, suggesting an important role of tyrosine kinase in the cytokine-induced MCP-1 gene expression. Dexamethasone had a small inhibitory effect on constitutive MCP-1 mRNA expression, but no effect on the induction by TNF-alpha. By immunoperoxidase staining and Western blot analysis using an anti-MCP-1 monoclonal antibody. MCP-1 protein was detected in untreated GEN and increased by exposure to TNF-alpha. These results demonstrate the cytokine-induced production of MCP-1 by GEN at gene and protein levels as well as bioactivity, and suggest that GEN may participate in the development of glomerulonephritis through the production of MCP-1.
...
PMID:Production of monocyte chemoattractant protein-1 by bovine glomerular endothelial cells. 858 46

Insulin-like growth factor-1, IGF-1, is believed to be an important anabolic modulator of cartilage metabolism and its bioactivity and bioavailability is regulated, in part, by IGF-1 binding protein 3 (IGFBP-3). Prostaglandin E2 (PGE2) stimulates IGF-1 production by articular chondrocytes and we determined whether the eicosanoid could regulate IGFBP-3 and, as such, act as a modifier of IGF-1 action at a different level. Using human articular chondrocytes in high density primary culture, Western and Western ligand blotting to measure secreted IGFBP-3 protein, and Northern analysis to monitor IGFBP-3 mRNA levels, we demonstrated that PGE2 provoked a 3.9 +/- 1.1 (n = 3) fold increase in IGFBP-3 mRNA and protein. This effect was reversed by the Ca++ channel blockers, verapamil and nifedipine, and the Ca++/calmodulin inhibitor, W-7. The Ca+2 ionophore, ionomycin, mimicked the effects of PGE2 as did the phorbol ester PMA, which activates Ca++/-phospholipid-dependent protein kinase C (PKC). Cyclic AMP mimetics, such as forskolin, IBMX, Ro-20-1724, and Sp-cAMP, inhibited the expression and synthesis of the binding protein. PGE2 did not increase the levels of cAMP or protein kinase A (PKA) activity in chondrocytes. The PGE2 secretagogue, IL-1 beta, down-regulated control levels of IGFBP-3 which could be completely abrogated by pre-incubation with the tyrosine kinase inhibitor, erbstatin, and partially reversed (50 +/- 8%) by KT-5720, a PKA inhibitor. These observations suggested that PGE2 does not mediate the effect of its secretagogue and that IL-1 beta signalling in chondrocytes may involve multiple kinases of diverse substrate specificities. Dexamethasone down-regulated control, constitutive levels of IGFBP-3 mRNA and protein eliminating the previously demonstrated possibility of cross-talk between glucocorticoid receptor (GR) and PGE2 receptor signalling pathways. Taken together, our results suggest that PGE2 modulates IGFBP-3 expression, protein synthesis, and secretion, and that such regulation may modify human chondrocyte responsiveness to IGF-1 and influence cartilage metabolism.
...
PMID:Prostaglandin E2 up-regulates insulin-like growth factor binding protein-3 expression and synthesis in human articular chondrocytes by a c-AMP-independent pathway: role of calcium and protein kinase A and C. 891 83

The early response to inflammation is characterized by the synthesis of a variety of proteins under cytokine and glucocorticoid control. During episodes of infection or inflammation, a secretory phospholipase A2 (sPLA2) appears in the circulation along with a variety of acute-phase proteins (APP), suggesting possible common regulatory elements amongst sPLA2 and APP. Using the human hepatoma line, HepG2, regulation of sPLA2 expression was examined in relation to synthesis of HP and ACH. The patterns of induction of sPLA2, HP and ACH were distinct for each of IL- 1, tumour necrosis factor (TNF) and IL-6, oncostatin M, IL-11 and leukaemia inhibitory factor. Dexamethasone had an enhancing effect on IL-6-induced expression of HP and ACH, but inhibited sPLA2 expression by 50%. Both 8-bromo-cAMP and dibutyryl cAMP increased sPLA2 expression (48.8-fold and 64.2-fold, respectively), whereas KT5720, an inhibitor of protein kinase A, down-regulated cytokine-induced sPLA2 synthesis by 51%. These data show that a panel of cytokines induced varying patterns of up-regulation of sPLA2, ACH and HP. Although dexamethasone potentiated IL-6-induced APP expression in HepG2 cells, it suppressed sPLA2 expression in a dose-dependent manner. In several respects, sPLA2 regulation is similar to that of HP and ACH, but a notable difference is the reciprocal effect of glucocorticoids on sPLA2 expression compared with that of ACH and HP.
...
PMID:Coordinate expression of group II phospholipase A2 and the acute-phase proteins haptoglobin (HP) and alpha1-anti-chymotrypsin (ACH) by HepG2 cells. 909 27

Corticotropin releasing hormone (CRH) plays a primary role in mediating suprapituitary activation of the hypothalamic-pituitary-adrenal axis and is an important physiologic target of negative feedback regulation by glucocorticoids. We sought to define cis-acting regions of the CRH promoter responsible for cAMP-dependent activation and glucocorticoid-dependent repression of CRH promoter activity. In transiently transfected AtT-20 cells, cAMP-dependent transcriptional activation was mediated largely through a classical, consensus, cAMP-response element (CRE) at - 224 bp. Dexamethasone (DEX) produced a specific 2-3-fold repression of cAMP-stimulated, but not basal, CRH promoter activity. Using a series of 5' nested deletions, dexamethasone-dependent repression of cAMP-stimulated CRH promoter activity was localized to promoter sequences between -278 and -249 bp. Specific, high-affinity binding of glucocorticoid receptor (GR) DNA-binding domain to this promoter region was observed using an eletrophoretic mobility shift assay (EMSA). We conclude that (i) cAMP dependent activation of the CRH promoter is mediated primarily by the CRE at -224 bp, (ii) glucocorticoid-dependent repression is specific for the CRH promoter, and not a generalized effect of glucocorticoid signaling or interference with the protein kinase A (PKA) signaling pathway, (iii) a highly conserved region between -278 and -249 bp is critical for glucocorticoid dependent repression, and (iv) GR is capable of interacting directly with this functionally defined negative glucocorticoid response element of the CRH promoter.
...
PMID:Localization of a negative glucocorticoid response element of the human corticotropin releasing hormone gene. 909 14

Insulin-like growth factor-1, IGF-1, is believed to be an important anabolic modulator of cartilage metabolism whose action is mediated by high affinity cell surface receptors and bioactivity and bioavailability regulated, in part, by IGF-1 binding proteins (IGFBPs). Prostaglandin E2 (PGE2) stimulates collagen and proteoglycan synthesis in cartilage via an autocrine feedback loop involving IGF-1. We determined whether the eicosanoid could regulate IGFBP-4, a major form expressed by chondrocytes and, as such, act as a modifier of IGF-1 action at another level. Using human articular chondrocytes in high-density primary culture, Western and Western ligand blotting to measure secreted IGFBP-4 protein, and Northern analysis to monitor IGFBP-4 mRNA levels, we demonstrated that PGE2 provoked a 2.7 +/- 0.3- and 3.8 +/- 0.5- (n = 3) fold increase in IGFBP-4 mRNA and protein, respectively. This effect was reversed by the Ca(++) channel blocker, verapamil, and the Ca(++)/calmodulin inhibitor, W-7. The Ca(++)ionophore, ionomycin, mimicked the effects of PGE2. The phorbol ester, PMA, which activated phospholipid-dependent protein kinase C (PKC) in chondrocytes, had no effect on IGFBP-4 production. Cyclic AMP mimetics and PKA activators, IBMX, and Sp-cAMP, inhibited the expression of the binding protein as did the PGE2 secretagogue, interleukin-1 beta (IL-beta). The inhibitory effect of the latter cytokine was mediated by a erbstatin/genistein (tyrosine) sensitive kinase. Dexamethasone, an inhibitor of cyclooxygenase (COX-2) expression and PGE2 synthesis, down-regulated control, constitutive levels of IGFBP-4 mRNA and protein, eliminating the previously demonstrated possibility of cross-talk between glucocorticoid receptor (GR) and PGE2-receptor signalling pathways. The results suggest that extracellular signals control IGFBP-4 production by a number of different transducing networks with changes in Ca(++) and calmodulin activity exerting a strong positive influence, possibly maintaining the constitutivity of IGFBP-4 synthesis under basal conditions. PGE2 activation of the IGF-1/IGFBP axis may play a pivotal role in the metabolism of cartilage and possibly connective tissues in general. Eicosanoid biosynthesis may be a rate-limiting step in cartilage repair processes.
...
PMID:Prostaglandin E2 stimulates insulin-like growth factor binding protein-4 expression and synthesis in cultured human articular chondrocytes: possible mediation by Ca(++)-calmodulin regulated processes. 913 96

Amygdalar CRF has been implicated in the mediation of stress behaviors. The signal transduction pathways that regulate amygdalar CRF are not well understood. In this report, we have examined the effect of protein kinase A and C activators, dexamethasone, and interleukin 6 on CRF messenger RNA (mRNA) and CRF peptide expression in dissociated amygdalar cultures. The amygdala from E19 rat pups was dissected out bilaterally and dissociated in 0.25% trypsin for 10-15 min and plated. On day 17 in culture, CRF mRNA and peptide were measured following treatment with the following agents: forskolin, the phorbol ester-phorbol 12 myristate 13-acetate (TPA), dexamethasone, and interleukin-6 (IL6). Both forskolin and IL6, but not TPA, increased CRF mRNA in a time- and dose-dependent manner. Secretion and intracellular content of the CRF peptide also increased with both forskolin and IL6 treatment but not with TPA. Dexamethasone treatment did not alter the expression of CRF message or peptide. Transfection of the primary cultures with a rat CRF promoter-luciferase reporter construct followed by treatment with all four agents produced alterations in luciferase expression that were consistent with changes observed at the level of CRF mRNA and peptide. The results suggest that CRF regulation in the amygdala differs from that known to occur in the hypothalamus, and that elevation of IL6 levels within the central nervous system may directly act to stimulate CRF production and secretion from limbic structures such as the amygdala, to promote subsequent behavioral changes.
...
PMID:Regulation of corticotropin-releasing factor (CRF) messenger ribonucleic acid and CRF peptide in the amygdala: studies in primary amygdalar cultures. 934 5

Glucocorticoids can induce a G1 arrest in the cell cycle progression of BDS1 rat hepatoma cells. In these cells, dexamethasone, a synthetic glucocorticoid, stimulated a rapid and selective increase in expression of the p21 cyclin-dependent kinase (CDK) inhibitor mRNA and protein and virtually abolished CDK2 phosphorylation of the retinoblastoma protein. Expression of the p27 CDK inhibitor, and other G1-acting cell cycle proteins, remained unaffected. Dexamethasone stimulated p21 promoter activity in a p53-independent manner that required functional glucocorticoid receptors. Transforming growth factor-beta, which also induced a G1 cell cycle arrest of the hepatoma cells, failed to elicit this response. Analysis of 5' deletions of the p21 promoter uncovered a glucocorticoid responsive region between nucleotides -1481 and -1184, which does not contain a canonical glucocorticoid response element but which can confer dexamethasone responsiveness to a heterologous promoter. Fine mapping of this region uncovered three distinct 50-60-base pair transcriptional elements that likely function as targets of glucocorticoid receptor signaling. Finally, ectopic expression of p21 had no effect on hepatoma cell growth in the absence of glucocorticoids but facilitated the ability of dexamethasone to inhibit cell proliferation. Thus, our results have established a direct transcriptional link between glucocorticoid receptor signaling and the regulated promoter activity of a CDK inhibitor gene that is involved in the cell cycle arrest of hepatoma cells.
...
PMID:Glucocorticoids stimulate p21 gene expression by targeting multiple transcriptional elements within a steroid responsive region of the p21waf1/cip1 promoter in rat hepatoma cells. 944 36

We characterized the ontogeny of cAMP-dependent protein kinase (PKA) enzymatic activity and PKA subunit mRNA expression in developing lung. The lungs of fetal Sprague-Dawley rat pups were removed after 16, 18, or 20 days of gestation and at term. PKA activity was greatest in the 18- and 20-day gestation lungs. Tissue cAMP levels were lowest in the 16-day lungs and increased with lung maturity. We were able to detect only low levels of mRNA for the C beta subunit of PKA by northern blot analysis of total lung RNA and we were able to detect mRNA for the RI beta and RII beta subunits only by RT-PCR. Therefore, we limited our analysis of PKA subunit mRNA levels to those for C alpha, RI alpha and RII alpha. The mRNA levels for C alpha, were highest in the 16-day lung, decreased at 18 and 20 days, were lower in the newborn and lowest in the adult lung. RI alpha mRNA levels were also highest at 16 days and lowest in the adult lung. However, RII alpha mRNA levels were similar in the 18-day, 20-day and newborn lungs. Dexamethasone treatment of fetal lung explants resulted in a small decrease in RI alpha mRNA levels but was not associated with a change in PKA activity. We conclude that PKA activity and PKA subunit mRNA expression are developmentally regulated in fetal lung. Such regulation results in optimal PKA activity at the time of type II alveolar cell differentiation, presumably in preparation for air breathing. The absence of an effect of glucocorticoid on PKA activity suggests that glucocorticoids are not responsible for the increase in PKA activity which accompanies this critical time in lung maturation.
...
PMID:Cyclic AMP-dependent protein kinase (PKA) gene expression is developmentally regulated in fetal lung. 960 89

FSH action on granulosa cells involves the generation of cAMP and subsequent activation of the cAMP-dependent protein kinase (PKA). The PKA holoenzyme is targeted to specific subcellular sites through the interaction of the regulatory subunits with A-kinase anchoring proteins (AKAPs). We previously reported that FSH regulates expression of AKAPs. In this report we examine the relationship between AKAP expression and cell shape. Granulosa cells cultured in the absence of FSH tend to spread and flatten. Cell spreading is accompanied by an increased expression of a 140-kDa AKAP. This spreading/flattening phenotype is independent of the specific extracellular matrix proteins (fibronectin, polylysine, and gelatin) on which cells are plated. Addition of FSH prevents both cell spreading and induction of AKAP 140. Culturing cells on poly (2-hydroxyethyl methacrylate), a surface-coating agent that inhibits cell spreading and adhesion, also inhibits expression of AKAP 140. Addition of phorbol myristate acetate, an agent known to antagonize FSH actions, blocks FSH regulation of both cell shape and AKAP 140 expression. Addition of dexamethasone plus FSH causes a synergistic increase in progesterone levels but has no effect on cell shape or induction of AKAP 140. Dexamethasone produces a dose-dependent increase in AKAP 80 expression, which is blocked by FSH, suggesting cross talk between the glucocorticoid and FSH receptor signaling pathways. These data suggest that expression of AKAP 140 is linked to regulation of cell shape, and that changes in the expression of AKAPs are regulated by several different signaling pathways.
...
PMID:Regulation of expression of A-kinase anchoring proteins in rat granulosa cells. 962 11


<< Previous 1 2 3 4 5 6 7 Next >>

---