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

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

Peroxynitrite formation by rat alveolar macrophages activated with phorbol 12-myristate 13-acetate was assayed by the Cu,Zn superoxide dismutase-catalyzed nitration of 4-hydroxyphenylacetate. The inhibitor of nitric oxide synthesis N-methyl-L-arginine prevented the Cu,Zn superoxide dismutase-catalyzed nitration of 4-hydroxyphenylacetate by stimulated macrophages, while Cu-depleted Zn superoxide dismutase did not catalyze the formation of 3-nitro-4-hydroxyphenylacetate either in vitro or in the presence of activated macrophages. The rate of phenolic nitration by activated macrophages was 9 +/- 2 pmol x 10(6) cells-1 x min-1 (mean +/- STD). Only 8% of synthetic peroxynitrite was trapped by superoxide dismutase, which suggested that the rate of peroxynitrite formation may have been as high as 0.11 nmol x 10(6) cells-1 x min-1. This upper estimate was consistent with N-methyl-L-arginine increasing the amount of superoxide detected with cytochrome c by 0.12 nmol x 10(6) cells-1 x min-1. The rate of nitrite and nitrate accumulation was 0.10 +/- 0.001 nmol x 10(6) cells-1 x min-1, suggesting that the majority of nitric oxide produced by activated macrophages may have been converted to peroxynitrite. The formation of a relatively long lived, strong oxidant from the reaction of nitric oxide and superoxide in activated macrophages may contribute to inflammatory cell-mediated tissue injury.
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PMID:Peroxynitrite formation from macrophage-derived nitric oxide. 132 57

The selective induction of effector functions of a T-cell clone (DB14), specific to pigeon cytochrome c 43-58 (p 43-58) and restricted to I-Ab, was analyzed using a professional antigen-presenting cell, B hybridoma (Th 2.58), and various non-professional antigen-presenting cells (APC), L cells transfected with I-Ab (I-Ab L cells), a medullary thymic epithelial cell line (m-TEC) and a cortical thymic epithelial cell line (c-TEC). The m-TEC, and c-TEC expressed I-Ab upon induction with interferon gamma (IFN-gamma). When stimulated with p 43-58 in the presence of I-Ab L cells as well as Th 2.58 cells, the DB14 cells showed marked proliferation and, after 18 hr of culturing, exhibited significant cytotoxicity against the APC. By contrast, in the presence of m, c-TEC, the DB14 cells showed neither proliferation nor cytotoxicity against these TEC but exhibited considerable detachment activity towards them. Furthermore, DB14 cells became expressed activation markers CD69 or CD44) following stimulation with p 43-58 plus m-TEC or c-TEC. The addition of rIL-2 to the culture of DC14 cells, p 43-58 and m-TEC or c-TEC, restored the proliferative responses. However, it was shown that anergy was not involved in the negligible proliferative responses of DB14 cells after stimulation with p 43-58 plus m, c-TEC. The present findings indicate that differences in APC functions are present among the non-professional APC and suggest that the selective induction of T-cell functions can be achieved using the appropriate non-professional APC. The characteristic activation of T cells by TEC may be related to their functional roles in situ.
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PMID:Detachment activity but not cytotoxicity induced in a T-cell clone following antigen presentation in the presence of thymic epithelial cells. 908 68

Selective induction of effector functions in a T cell clone, DB14, specific for pigeon cytochrome c 43-58 (p43-58) and restricted to I Ab was analyzed using professional antigen presenting cells (APC), B hybridoma (Th2.58), and various non professional APC, L cells transfected with I Ab (I-Ab L cells), a medullary thymic epithelial cell line (m-TEC) and a cortical thymic epithelial cell line (c-TEC). The m-TEC and c-TEC (m, c-TEC) expressed I-Ab after culturing with interferon-gamma (IFN-gamma). When stimulated with p43-58 in the presence of I-Ab L cells as well as Th2.58 cells, the DB14 cells showed marked proliferation and exhibited significant cytotoxicity against these APC after 18 hr of culture. By contrast, in the presence of m, c-TEC the DB14 cells showed neither proliferation nor cytotoxicity against these TEC but exhibited considerable detachment activity against them. Furthermore DB14 cells became expressed activation markers (CD69 and CD44) after antigen (p43-58) stimulation with m-TEC or c-TEC. Addition of rIL-2 to the culture of DB14 cells, p43-58 and m, c-TEC restored the proliferative responses. However, it was shown that anergy was not involved in the lack of proliferative response of DB14 cells after antigen stimulation with m, c-TEC. The present findings indicate that differences in APC function are present among non-professional APC and suggest that the selective induction of T cell functions can be achieved using appropriate non-professional APC. The characteristic activation of T cells by TEC may be related to their functional roles in situ.
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PMID:[Selective induction of effector functions in a T cell clone following antigen presentation in the presence of thymic epithelial cells]. 914 12

Selective activation among several effector functions of a T cell clone, DB14, specific for pigeon cytochrome c 43-58 (p43-58) and restricted to I-Ab/d was induced by antigen (Ag) presentation with nonprofessional Ag-presenting cells (APC), cortical thymic epithelial cells (c-TEC) (B7-1- CD40-), whereas full activation of the DB14 was induced with another nonprofessional APC, I-Ab L cell (B7-1+ CD40+). In the present study, to elucidate the mechanism underlying the selective activation of DB14 cells by c-TEC, we established c-TEC transfected with human CD40 alone (huCD40-c-TEC) or both human CD40 and murine B7-1 (huCD40/mB7-1-c-TEC), and compared the APC functions with those of the original c-TEC and I-Ab L cell. IFN-gamma production but not the proliferative response of DB14 was elevated by Ag presentation with huCD40-c-TEC as compared with unmanipulated c-TEC. On the other hand, upon stimulation with Ag plus huCD40/mB7-1-c-TEC both a significant proliferative response and IFN-gamma production were induced in DB14. However, the level of these responses did not reach that induced in the presence of I-Ab L cell. A similar pattern of APC functions was demonstrated with the other B7-independent T cell clone, PAB3, or T cell hybridomas (DBhy22 and BD7-5) which are basically independent of costimulation for the activation. The present finding along with our previous report that several structural differences of I-Ab molecules are present between c-TEC and I-Ab L cell suggests that the distinct APC activity of c-TEC is attributable not only to a lack of B7-1 and CD40 but also to inefficient presentation of MHC-peptide complex on the c-TEC.
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PMID:Selective antigen presenting activity of cortical thymic epithelial cells against CD4+ T cells associated with both lack of costimulatory molecules and inefficient presentation of MHC-peptide ligands. 939 3

CGP 57148 is a potent inhibitor of the ABL protein tyrosine kinase and a promising new compound for the treatment of a variety of BCR-ABL-positive leukemias. We used this enzyme inhibitor to characterize the biological effects of BCR-ABL in primary cells and two growth factor-dependent BCR-ABL-transfected cell lines. The effect of CGP 57148 on primary cells is dependent on the stage of differentiation. The growth of maturing chronic myeloid leukemia cells is independent of BCR-ABL in the presence of growth factors. However, the proliferation of leukemic immature cobblestone-forming area cells is almost completely blocked after the inhibition of the BCR-ABL kinase. In the BCR-ABL-transfected cell lines, M07/ p210 and Ba/F3/p185, CGP 57148 induces apoptosis by releasing cytochrome c, activating caspase 3, and cleavage of PARP. No alteration of the expression level of the apoptosis regulator BCL-2 was observed. In contrast, BCL-X was down-regulated after exposure to CGP 57148. Inhibitors of signal transduction proteins such as PI-3 kinase, mitogen-activated protein/extracellular signal-regulated kinase kinase, and Janus-activated kinase 2 pathways were not capable of a comparable down-regulation of BCL-X. The Fas/Fas ligand system was not involved either in the induction of apoptosis by CGP 57148. We conclude that the inhibition of the BCR-ABL kinase by CGP 57148 (a) preferentially inhibits the growth of immature leukemic precursor cells, (b) efficiently reverts the antiapoptotic effects of BCR-ABL by down-regulation of BCL-X, and (c) is more effective than the inhibition of the downstream signal transduction pathways of PI-3 kinase, mitogen-activated protein/extracellular signal-regulated kinase kinase, and Janus-activated kinase 2.
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PMID:The tyrosine kinase inhibitor CGP 57148 (ST1 571) induces apoptosis in BCR-ABL-positive cells by down-regulating BCL-X. 1081 21

Transforming growth factor beta (TGF-beta)-mediated apoptosis is one of the major death processes in the liver. We have previously shown that epidermal growth factor (EGF) is an important survival signal for TGF-beta-induced apoptosis in fetal hepatocytes (Fabregat et al., FEBS Lett 1996;384:14-18). In this work we have studied the intracellular signaling implicated in the protective effect of EGF. We show here that EGF activates p42 and p44 mitogen-activated protein kinases (MAPK). However, mitogen extracellular kinase (MEK) inhibitors do not block the survival effect of EGF. EGF also activates phosphoinositide 3-kinase (PI 3-kinase) and protein kinase B (PKB/AKT) in these cells. The presence of PI 3-kinase inhibitors blocks the protective effect of EGF on cell viability, DNA fragmentation, and caspase-3 activity. We have found that TGF-beta disrupts the mitochondrial transmembrane potential (DeltaPsi(m))( )and activates the release of cytochrome c, this effect being blocked by EGF, via a PI 3-kinase-dependent pathway. A detailed study on bcl-2 superfamily gene expression shows that TGF-beta produces a decrease in the messenger RNA (mRNA) and protein levels of bcl-x(L), an antiapoptotic member of this family, capable of preventing cytochrome c release. EGF is able to maintain bcl-x(L) levels even in the presence of TGF-beta. PI 3-kinase inhibitors completely block the protective effect of EGF on TGF-beta-induced bcl-x(L )down-regulation. We conclude that PI 3-kinase mediates the survival effect of EGF on TGF-beta-induced death by acting upstream from the mitochondrial changes, i.e., preventing bcl-x(L) down-regulation, cytochrome c release, and activation of caspase-3.
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PMID:Epidermal growth factor impairs the cytochrome C/caspase-3 apoptotic pathway induced by transforming growth factor beta in rat fetal hepatocytes via a phosphoinositide 3-kinase-dependent pathway. 1096 Apr 45

Detachment of epithelial cells from extracellular matrix results in induction of apoptosis ('anoikis') which can be blocked by expression of activated Ras or PKB/Akt. Here we show that detachment causes release of cytochrome c from mitochondria in MDCK cells. This is blocked by caspase inhibitors, suggesting a role for caspases upstream of mitochondria in the initiation of anoikis, in accord with the ability of dominant negative FADD to inhibit this form of cell death. Bulk activation of caspase-8 following detachment lags behind cytochrome c release, and is likely the result of a mitochondrial positive feed back loop. Matrix detachment also induces Bax translocation to mitochondria in a caspase-dependent manner. Expression of activated Ras or PKB/Akt blocks all the detectable events on the detachment-induced apoptosis signalling pathway, suggesting that PKB/Akt acts at an early point in the pathway, providing the signal normally generated by matrix attachment. Strong activation of Raf can also protect MDCK cells from detachment induced apoptosis, but this occurs at a point downstream of cytochrome c release from mitochondria, and is clearly distinct from the effect of PKB/Akt. Oncogene (2000) 19, 4461 - 4468.
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PMID:Matrix detachment induces caspase-dependent cytochrome c release from mitochondria: inhibition by PKB/Akt but not Raf signalling. 1100 18

Integrin receptors mediate several functions including prevention of matrix detachment-induced apoptosis (anoikis) of several adherent cell types. We report here that antagonists of beta1 integrins trigger an apoptotic signaling pathway in adherent differentiated LAN-5 human neuroblastoma cells, a cell line which represents a model system for the study of human neurons. The pathway is characterized by cytochrome c release into the cytoplasm, and activation of caspase-9 and caspase-3, 4-6h after treatment; cleavage products of caspase-8 and caspase-2 were not detectable in the cells. Coordinate inactivation of cell survival pathways, including cleavage of focal adhesion kinase, decreased expression of protein kinase B, and reduced phosphorylation of the pro-apoptotic protein, Bad, also characterized the signaling pathway. These events occurred in adherent cells; DNA fragmentation and detachment followed as late events 18-24h after addition of beta1 integrin antagonists. zDEVD-fmk, an irreversible inhibitor of caspase-3-like enzymes, and cytochalasin D, an actin depolymerizing agent, blocked caspase-3 cleavage and delayed cell death. In contrast to these results, undifferentiated, adherent and dividing LAN-5 cells did not die in response to beta1 integrin antagonists. These studies identify a distinct apoptotic pathway which is triggered by antagonists of beta1 integrins on differentiated adherent neuronal cells.
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PMID:beta1 integrin antagonism on adherent, differentiated human neuroblastoma cells triggers an apoptotic signaling pathway. 1111 63

The serine/threonine kinase Akt/PKB is a major downstream effector of growth factor-mediated cell survival. Activated Akt, like Bcl-2 and Bcl-xL, prevents closure of a PT pore component, the voltage-dependent anion channel (VDAC); intracellular acidification; mitochondrial hyperpolarization; and the decline in oxidative phosphorylation that precedes cytochrome c release. However, unlike Bcl-2 and Bcl-xL, the ability of activated Akt to preserve mitochondrial integrity, and thereby inhibit apoptosis, requires glucose availability and is coupled to its metabolism. Hexokinases are known to bind to VDAC and directly couple intramitochondrial ATP synthesis to glucose metabolism. We provide evidence that such coupling serves as a downstream effector function for Akt. First, Akt increases mitochondria-associated hexokinase activity. Second, the antiapoptotic activity of Akt requires only the first committed step of glucose metabolism catalyzed by hexokinase. Finally, ectopic hexokinase expression mimics the ability of Akt to inhibit cytochrome c release and apoptosis. We therefore propose that Akt increases coupling of glucose metabolism to oxidative phosphorylation and regulates PT pore opening via the promotion of hexokinase-VDAC interaction at the outer mitochondrial membrane.
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PMID:Inhibition of early apoptotic events by Akt/PKB is dependent on the first committed step of glycolysis and mitochondrial hexokinase. 1139 Mar 60

Autophagy is a major catabolic process allowing the renewal of intracellular organelles by which cells maintain their homeostasis. We have previously shown that autophagy is controlled by two transduction pathways mediated by a heterotrimeric Gi3 protein and phosphatidylinositol 3-kinase activities in the human colon cancer cell line HT-29. Here, we show that 3-methyladenine, an inhibitor of autophagy, increases the sensitivity of HT-29 cells to apoptosis induced by sulindac sulfide, a nonsteroidal anti-inflammatory drug which inhibits the cyclooxygenases. Similarly, HT-29 cells overexpressing a GTPase-deficient mutant of the G(alpha i3) protein (Q204L), which have a low rate of autophagy, were more sensitive to sulindac sulfide-induced apoptosis than parental HT-29 cells. In both cell populations we did not observe differences in the expression patterns of COX-2, Bcl-2, Bcl(XL), Bax, and Akt/PKB activity. However, the rate of cytochrome c release was higher in Q204L-overexpressing cells than in HT-29 cells. These results suggest that autophagy could retard apoptosis in colon cancer cells by sequestering mitochondrial death-promoting factors such as cytochrome c.
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PMID:Autophagy delays sulindac sulfide-induced apoptosis in the human intestinal colon cancer cell line HT-29. 1147 40


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