Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Keratinocyte migration is critical to reepithelialization during wound repair. The motility response is promoted by growth factors, cytokines, and cytokines produced in the wound bed, including those that activate the epidermal growth factor (EGF) receptor. The Alu-Leu-Arg-negative CXC chemokine interferon-inducible protein 9 (IP-9; also known as CXCL11, I-TAC, beta-R1, and H-174) is produced by keratinocytes in response to injury. As keratinocytes also express the receptor, CXCR3, this prompted us to examine the role and molecular mechanism by which IP-9 regulates keratinocyte motility. Unexpectedly, as CXCR3 liganding blocks growth factor-induced motility in fibroblasts, IP-9 alone promoted motility in undifferentiated keratinocytes (37 +/- 6% of the level of the highly motogenic EGF) as determined in a two-dimensional in vitro wound healing assay. IP-9 even enhanced EGF-induced motility in undifferentiated keratinocytes (116 +/- 5%; P < 0.05 compared to EGF alone), suggesting two separate mechanisms of action. IP-9-increased motility and -decreased adhesiveness required the intracellular protease calpain. The increases in both motility and calpain activity by IP-9 were blocked by pharmacological and molecular inhibition of phospholipase C-beta3 and chelation of calcium, which prevented an intracellular calcium flux. Molecular downregulation or RNA interference-mediated depletion of mu-calpain (calpain 1) but not M-calpain (calpain 2) blocked IP-9-induced calpain activation and motility. In accord with elimination of IP-9-induced de-adhesion, RNA interference-mediated depletion of calpain 1 but not calpain 2 prevented cleavage of the focal adhesion component focal adhesion kinase and disassembly of vinculin aggregates. In comparison, EGF-induced motility of the same undifferentiated keratinocytes requires the previously described extracellular signal-regulated kinase to the M-calpain pathway. These data demonstrate that while both EGF- and IP-9-induced motility in keratinocytes requires calpain activity, the isoform of calpain triggered depends on the nature of the receptor for the particular ligand. Interestingly, physiological nonapoptotic calcium fluxes were capable of activating mu-calpain, implying that the calcium requirement of mu-calpain for activation is attained during cell signaling. This is also the first demonstration of differential activation of the two ubiquitous calpain isoforms in the same cell by different signals.
 ...
PMID:Interferon-inducible protein 9 (CXCL11)-induced cell motility in keratinocytes requires calcium flux-dependent activation of mu-calpain. 1571 46

The hypertrophy of vascular smooth muscle cells (VSMCs) is critical in vascular remodeling associated with hypertension, atherosclerosis, and restenosis. Recently, leptin has appeared to play a pivotal role in vascular remodeling. However, the mechanism by which leptin induces hypertrophy in vascular smooth muscle cells is still unknown. We studied the role of leptin as a potential hypertrophic factor in rat VSMCs. In the present study, leptin significantly increased [(3)H]leucine incorporation and the total protein/DNA ratio in VSMCs. The maximal hypertrophic effect was at 100ng/ml of leptin. Leptin induced phosphorylation and activation of p38 mitogen-activated protein (p38 MAP) kinase and of signal transducers and activators of transcription 3 in a concentration- and time-dependent manner. A p38 MAP kinase inhibitor SB203580 significantly inhibited leptin-induced hypertrophy, AG490 (a JAK2 inhibitor) partially inhibited it, and other MAP kinase inhibitors, PD98059 (an ERK inhibitor) and SP600125 (a JNK inhibitor), had no effect. These results indicate that leptin directly stimulates cellular hypertrophy via p38 MAP kinase in rat VSMCs.
 ...
PMID:Leptin induces hypertrophy via p38 mitogen-activated protein kinase in rat vascular smooth muscle cells. 1572 Dec 67

Excessive angiogenesis is involved in many human diseases, and inhibiting angiogenesis is an important area of drug development. There have been conflicting reports as to whether decorin could function as an angiogenic inhibitor when used as an extracellular soluble factor. In this study, we demonstrated that not only purified decorin but also the 26-residue leucine-rich repeat 5 (LRR5) of decorin core protein functions as angiogenesis inhibitor by inhibiting both vascular endothelial growth factor (VEGF) and basic fibroblast growth factor-induced angiogenesis. Peptide LRR5 inhibited angiogenesis through multiple mechanisms, including inhibiting VEGF-stimulated endothelial cell (EC) migration, tube formation on Matrigel, cell attachment to fibronectin, as well as induction of EC apoptosis without significantly affecting their proliferation. We further demonstrated that different subregions of LRR5 inhibited different aspects of angiogenesis, with the middle region (LRR5M, 12 residues) inhibiting endothelial cell tube formation up to 1000 times more potently than LRR5. Although the C-terminal region (LRR5C) potently inhibited VEGF-stimulated endothelial cell migration, the N-terminal region (LRR5N) is as active as LRR5 in inhibiting endothelial cell attachment to fibronectin. Although both LRR5M and LRR5N induced EC apoptosis dose-dependently similar to LRR5 through a caspase-dependent pathway, LRR5C has no such function. We further showed that the inhibition of tube formation by LRR5 and LRR5M is linked with their ability to suppress VEGF-induced focal adhesion kinase phosphorylation and the assembly of focal adhesions and actin stress fibers in ECs, but not their ability to interfere with endothelial cell attachment to the matrix. Circular dichroism studies revealed that LRR5 undergoes an inter-conversion between 3(10) helix and beta-sheet structure in solution, a characteristic potentially important for its anti-angiogenic activity. Peptide LRR5 and its derivatives are therefore novel angiogenesis inhibitors that may serve as prototypes for further development into anti-angiogenic drugs.
 ...
PMID:Peptides derived from human decorin leucine-rich repeat 5 inhibit angiogenesis. 1592 92

5-[4-Acridin-9-ylamino]phenyl]-5-methyl-3-methylenedihydrofuran-2-one (CYL-26z) inhibited the formyl-Met-Leu-Phe (fMLP)-stimulated phospholipase D (PLD) activity, which was assessed by the production of phosphatidylethanol (PEt) in the presence of ethanol, in rat neutrophils (IC50 1.2+/-0.2 microM). CYL-26z caused a slight but significant attenuation of the global protein tyrosine phosphorylation stimulated by fMLP only at concentrations of CYL-26z up to 30 microM. CYL-26z blocked the membrane recruitment of protein kinase C-alpha (PKC-alpha) at concentrations of CYL-26z > or =3 microM, but failed to affect the membrane association of PKC-betaI and -betaII. The translocation of RhoA to the membrane was attenuated by CYL-26z (IC50 3.8+/-0.8 microM) in fMLP-stimulated neutrophils, whereas CYL-26z caused no significant inhibition of the membrane recruitment of ADP-ribosylation factor (Arf). CYL-26z inhibited the activation of RhoA and dissociation of the RhoA-Rho guanine nucleotide dissociation inhibitor (GDI) complex in fMLP-stimulated neutrophils (IC50 1.8+/-1.0 microM and 1.8+/-0.9 microM, respectively). In a cell-free system, CYL-26z effectively attenuated the membrane association of RhoA in response to GTPgammaS (IC50 1.3+/-0.5 microM). In contrast, the GTPgammaS-stimulated translocation of Arf to membrane was suppressed only at concentrations of CYL-26z up to 30 microM. CYL-26z inhibited the fMLP-stimulated membrane expression of CD11b, CD45 and CD63, and the release of lysozyme and beta-glucuronidase. These results indicate that CYL-26z inhibited the fMLP-stimulated PLD activity, mainly through the blockade of RhoA activation, and degranulation in rat neutrophils.
 ...
PMID:Inhibition of phospholipase D activation by CYL-26z in formyl peptide-stimulated neutrophils involves the blockade of RhoA activation. 1602 1

Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide (CGRP). The present study aimed to investigate the cardiovascular effects of IMDs (IMD1-47 and IMD8-47) in rats. Intravenous administration of 150 nmol IMDs continuously decreased mean arterial pressure and inhibited cardiac function. Administration with IMDs decreased left ventricular end-systolic pressure (LVESP) and maximal rate of left-ventricle pressure development (+/-LVdp/dt(max)), and elevated left ventricular end-diastolic pressure (LVEDP). Changes with IMD1-47 treatment were close to that with IMD8-47 (P>0.05). Perfusion of isolated rat hearts in vitro with IMD8-47 (10(-8) and 10(-7)mol/L) resulted in lower LVSP, by 40 and 56% (P<0.01); lower +LVdp/dt (max), by 33 and 47% (P<0.01); lower -LVdp/dt(max), by 25 and 39% (P<0.01); but higher coronary perfusion flow (CPF), by 25% (P<0.05) and 33% (P<0.01), respectively, than controls. However, both IMD8-47 and IMD1-47 (from 10(-13) to 10(-7)mol/L) relaxed preconstricted aortic rings in a dose-dependent manner. Intravenous administration of IMD1-47 and IMD8-47 (10(-7)mol/L) in vivo increased the cyclic adenosine monophosphate (cAMP) content by 68 and 150% (both P<0.01), respectively, in myocardia and 320 and 281% (both P<0.01), respectively, in aortas, compared with controls. Perfusion of isolated hearts with IMD1-47 and IMD8-47 (10(-7)mol/L) enhanced cAMP content by 24% (P<0.05) and 73% (P<0.01), respectively, compared with controls. IMDs inhibited 3H-Leucine incorporation in cardiomyocytes in a concentration-dependent manner. IMD1-47 and IMD8-47 (10(-7) and 10(-8)mol/L) decreased 3H-Leucine incorporation by 12-25% (P<0.01) and 14-18% (P<0.01), respectively. IMD mRNA was detected in cultured neonatal cardiomyocytes and isoproterenol-induced hypertrophic myocardia but not normal myocardia of adult rats. These results suggest that IMD might be a regulatory factor for cardiovascular function and myocardial hypertrophy as a cardiovascular active peptide.
 ...
PMID:Cardiovascular effects of newly discovered peptide intermedin/adrenomedullin 2. 1611 4

Among the 10 human Toll-like receptors (TLRs), TLR2 appears to be unique in its requirement for cooperation with other TLRs, namely TLR1 and TLR6, to mediate cell signaling. Through reconstitution experiments, we have defined more precisely the function of these human TLRs. Human colonic epithelial cells cotransfected with TLR1 and -2 preferentially respond to a synthetic tripalmitoylated bacterial lipopeptide analogue (Pam(3)CSK(4)). However, examination of a wide variety of lipopeptide derivatives indicates that recognition by human TLR1 and -2 does not strictly correlate with the number or position of the acyl chains on the modified cysteine residue. Conversely, human TLR2 and -6 exclusively respond to lipopeptides possessing a diacylglycerol group. Most surprisingly, we have found that an R stereoisomer of diacylated macrophage-activating lipopeptide 2 (MALP-2) exclusively activates epithelial cells through TLR6 and -2 but not through TLR1 and -2. These results suggest that the chirality of the central carbon of the diacylglycerol group of these agonists is a structural determinant for human TLR recognition. Examination of chimeric receptors, generated by domain exchange between TLR1 and -6, has revealed that leucine-rich repeats 9-12 of the extracellular domain enable these receptors to discriminate between structurally similar lipopeptides. However, additional chimeric constructs reveal that this region alone is not sufficient to generate receptors that can functionally cooperate with TLR2. Our results support the idea that TLR1 and TLR6 diverged during evolution to differentially recognize natural lipoprotein structures and that this function has been conserved with respect to the human receptors.
 ...
PMID:Domain exchange between human toll-like receptors 1 and 6 reveals a region required for lipopeptide discrimination. 1612 84

Podocytes or glomerular epithelial cells (GECs) are important targets of the diabetic microenvironment. Podocyte foot process effacement and widening, loss of GECs and hypertrophy are pathological features of this disease. ANG II and oxidative stress are key mediators of renal hypertrophy in diabetes. The cellular mechanisms responsible for GEC hypertrophy in diabetes are incompletely characterized. We investigated the effect of high glucose on protein synthesis and GEC hypertrophy. Exposure of GECs to high glucose dose dependently stimulated [(3)H]leucine incorporation, but not [(3)H]thymidine incorporation. High glucose resulted in the activation of ERK1/2 and Akt/PKB. ERK1/2 pathway inhibitor or the dominant negative mutant of Akt/PKB inhibited high glucose-induced protein synthesis. High glucose elicited a rapid generation of reactive oxygen species (ROS). The stimulatory effect of high glucose on ROS production, ERK1/2, and Akt/PKB activation was prevented by the antioxidants catalase, diphenylene iodonium, and N-acetylcysteine. Exposure of the cells to hydrogen peroxide mimicked the effects of high glucose. In addition, ANG II resulted in the activation of ERK1/2 and Akt/PKB and GEC hypertrophy. Moreover, high glucose and ANG II exhibited additive effects on ERK1/2 and Akt/PKB activation as well as protein synthesis. These additive responses were abolished by treatment of the cells with the antioxidants. These data demonstrate that high glucose stimulates GEC hypertrophy through a ROS-dependent activation of ERK1/2 and Akt/PKB. Enhanced ROS generation accounts for the additive effects of high glucose and ANG II, suggesting that this signaling cascade contributes to GEC injury in diabetes.
 ...
PMID:Redox dependence of glomerular epithelial cell hypertrophy in response to glucose. 1623 11

Tyrosine phosphorylation of FAK (focal adhesion kinase) regulates signalling that results from the interaction of integrins with extracellular matrix and growth factor receptors. A critical step in this process is the phosphorylation of Tyr397 of FAK, which creates a binding site for Src family kinases, PI3K (phosphoinositide 3-kinase) and Shc (Src homology and collagen homology). An intact Tyr397 site is required for FAK-mediated regulation of cell migration, survival signals and full responsiveness to soluble growth factors. We showed previously that the adaptor protein paxillin is required for the overall tyrosine phosphorylation of FAK in embryonic stem cells [Wade, Bohl and Vande Pol (2002) Oncogene 21, 96-107]. In the present paper, we identify the minimal structural features of paxillin that are required to support overall FAK tyrosine phosphorylation and Tyr397 phosphorylation. Paxillin contains N-terminal leucine-rich LD motifs that bind directly to FAK and four LIM (Lin-11, Isl-1 and Mec-3) domains in the C-terminus. We show that paxillin LIM domains 1, 2 and 3 are each required for FAK tyrosine phosphorylation, while LIM4 is dispensable. In addition to paxillin LIM domains 1, 2 and 3, a single LD motif on paxillin is required to support FAK tyrosine phosphorylation in embryonic stem cells. Both sequence and spatial requirements exist for LD motifs to support FAK tyrosine phosphorylation. Interestingly, synthetic LD motifs that fail to bind FAK in vitro are able to fully support FAK tyrosine phosphorylation, indicating that minimal interactions of LD motifs with FAK suffice. Our results demonstrate at least four distinct structural domains of paxillin support at least three distinct functions that are each required for FAK tyrosine phosphorylation.
 ...
PMID:Minimal features of paxillin that are required for the tyrosine phosphorylation of focal adhesion kinase. 1625 16

In the absence of erythropoietin (Epo) cell surface Epo receptors (EpoR) are dimeric; dimerization is mediated mainly by the transmembrane domain. Binding of Epo changes the orientation of the two receptor subunits. This conformational change is transmitted through the juxtamembrane and transmembrane domains, leading to activation of JAK2 kinase and induction of proliferation and survival signals. To define the active EpoR conformation(s) we screened libraries of EpoRs with random mutations in the transmembrane domain and identified several point mutations that activate the EpoR in the absence of ligand, including changes of either of the first two transmembrane domain residues (Leu(226) and Ile(227)) to cysteine. Following this discovery, we performed cysteine-scanning mutagenesis in the EpoR juxtamembrane and transmembrane domains. Many mutants formed disulfide-linked receptor dimers, but only EpoR dimers linked by cysteines at positions 223, 226, or 227 activated EpoR signal transduction pathways and supported proliferation of Ba/F3 cells in the absence of cytokines. These data suggest that activation of dimeric EpoR by Epo binding is achieved by reorienting the EpoR transmembrane and the connected cytosolic domains and that certain disulfide-bonded dimers represent the activated dimeric conformation of the EpoR, constitutively activating downstream signaling. Based on our data and the previously determined structure of Epo bound to a dimer of the EpoR extracellular domain, we present a model of the active and inactive conformations of the Epo receptor.
 ...
PMID:Active conformation of the erythropoietin receptor: random and cysteine-scanning mutagenesis of the extracellular juxtamembrane and transmembrane domains. 1641 57

5-[4-Acridin-9-ylamino]phenyl]-5-methyl-3-methylenedihydrofuran-2-one (CYL-26z) inhibited the polymorphonuclear leukocyte (PMNL) infiltration and protein leakage into the lungs in lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice as determined on the basis of PMNL and protein contents in bronchoalveolar lavage (BAL) fluid and myeloperoxidase (MPO) content in whole lung extracts. CYL-26z also attenuated the formyl-Met-Leu-Phe (fMLP)-induced neutrophil chemotaxis and respiratory burst in vitro (IC(50) 8.4+/-0.9microM and 2.0+/-0.6microM, respectively). CYL-26z had no effect on superoxide anion (O(2)(-)) generation during dihydroxyfumaric acid autoxidation or on the NADPH oxidase activity in two cell-free systems (the arachidonic acid-induced assembly of NADPH oxidase and the preassembled oxidase caused by phorbol ester treatment), whereas it inhibited NaF-induced respiratory burst. Inhibition of respiratory burst by CYL-26z was readily reversible by washing. Only slight, but significant, inhibition of extracellular signal regulated kinase (ERK) phosphorylation and p38 mitogen-activated protein kinase (MAPK) activation in response to fMLP by CYL-26z up to 30microM was obtained. CYL-26z effectively blocked the formation of phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) as determined by immunofluorescence microscopy and flow cytometry assays and the dual phosphorylation of protein kinase B (PKB/Akt) on S473 and T308 residues in fMLP-stimulated neutrophils. The membrane recruitment of p110gamma and Ras, the Ras activation, and the association between p110gamma and Ras were also attenuated by CYL-26z. These results indicate that the blockade of Ras activation by CYL-26z attenuated the downstream phosphoinositide 3-kinase (PI3K) gamma signaling, which is involved in chemoattractant-induced neutrophil chemotaxis and respiratory burst, and may have a beneficial anti-inflammatory effect on ALI.
 ...
PMID:Effective attenuation of acute lung injury in vivo and the formyl peptide-induced neutrophil activation in vitro by CYL-26z through the phosphoinositide 3-kinase gamma pathway. 1688 2


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