共查询到20条相似文献,搜索用时 31 毫秒
1.
Lu B Wang L Medan D Toledo D Huang C Chen F Shi X Rojanasakul Y 《American journal of physiology. Cell physiology》2002,283(3):C831-C838
The APO-1/Fasligand (FasL) and tumor necrosis factor- (TNF-) are twofunctionally related molecules that induce apoptosis ofsusceptible cells. Although the two molecules have been reported toinduce apoptosis via distinct signaling pathways, we have shown that FasL can also upregulate the expression of TNF-, raising thepossibility that TNF- may be involved in FasL-inducedapoptosis. Because TNF- gene expression is under the controlof nuclear factor-B (NF-B), we investigated whether FasL caninduce NF-B activation and whether such activation plays a role inFasL-mediated cell death in macrophages. Gene transfection studiesusing NF-B-dependent reporter plasmid showed that FasL did activateNF-B promoter activity. Gel shift studies also revealed that FasLmobilized the p50/p65 heterodimeric form of NF-B. Inhibition ofNF-B by a specific NF-B inhibitor, caffeic acid phenylethylester, or by dominant expression of the NF-B inhibitory subunitIB caused an increase in FasL-induced apoptosis and areduction in TNF- expression. However, neutralization of TNF- byspecific anti-TNF- antibody had no effect on FasL-inducedapoptosis. These results indicate that FasL-mediated cell deathin macrophages is regulated through NF-B and is independent ofTNF- activation, suggesting the antiapoptotic role of NF-Band a separate death signaling pathway mediated by FasL. 相似文献
2.
Zernecke Alma; Weber Kim S. C.; Weber Christian 《American journal of physiology. Cell physiology》2001,281(6):C1881
The activation of nuclear factor-B(NF-B) is required for the induction of many of the adhesionmolecules and chemokines involved in the inflammatory leukocyterecruitment to the kidney. Here we studied the effects of NF-Binhibition on the machinery crucial for monocyte infiltration of theglomerulus during inflammation. In mesangial cells (MC), the proteaseinhibitors MG-132 and N--tosyl-L-lysine chloromethyl ketone or adenoviral overexpression of IB- prevented the complete IB- degradation following tumor necrosis factor- (TNF-) stimulation. This resulted in a marked inhibition ofTNF--induced expression of mRNA and protein for the immunoglobulinmolecules intracellular adhesion molecule-1 and vascular cell adhesionmolecule-1 and the chemokines growth-related oncogene-, monocytechemoattractant protein-1, interleukin-8, or fractalkine in MC.Finally, the inhibition of IB- degradation or IB-overexpression suppressed the chemokine-induced transendothelialmonocyte chemotaxis toward MC and the chemokine-triggered firm adhesionof monocytic cells to MC. The inhibition of NF-B by pharmacologicalintervention or gene transfer may present a multimodal approach tocontrol the machinery propagating inflammatory recruitment of monocytesduring glomerular disease. 相似文献
3.
Lum Hazel; Hao Zengping; Gayle Dave; Kumar Priyadarsini; Patterson Carolyn E.; Uhler Michael D. 《American journal of physiology. Cell physiology》2002,282(1):C59
First published September 5, 2001;10.1152/ ajpcell.00256.2001.The expression and function of theendogenous inhibitor of cAMP-dependent protein kinase (PKI) inendothelial cells are unknown. In this study, overexpression of rabbitmuscle PKI gene into endothelial cells inhibited the cAMP-mediatedincrease and exacerbated thrombin-induced decrease in endothelialbarrier function. We investigated PKI expression in human pulmonaryartery (HPAECs), foreskin microvessel (HMECs), and brain microvesselendothelial cells (HBMECs). RT-PCR using specific primers for humanPKI, human PKI, and mouse PKI sequences detectedPKI and PKI mRNA in all three cell types. Sequencing and BLASTanalysis indicated that forward and reverse DNA strands for PKI andPKI were of >96% identity with database sequences. RNaseprotection assays showed protection of the 542 nucleotides in HBMEC andHPAEC PKI mRNA and 240 nucleotides in HBMEC, HPAEC, and HMEC PKImRNA. Western blot analysis indicated that PKI protein was detectedin all three cell types, whereas PKI was found in HBMECs. Insummary, endothelial cells from three different vascular beds expressPKI and PKI, which may be physiologically important inendothelial barrier function. 相似文献
4.
Upregulation of alpha(8)beta(1)-integrin in cardiac fibroblast by angiotensin II and transforming growth factor-beta1 总被引:3,自引:0,他引:3
Thibault G Lacombe MJ Schnapp LM Lacasse A Bouzeghrane F Lapalme G 《American journal of physiology. Cell physiology》2001,281(5):C1457-C1467
Using a novel pharmacological tool with125I-echistatin to detect integrins on the cell, we haveobserved that cardiac fibroblasts harbor five different RGD-bindingintegrins: 81,31, 51, v1, and v3.Stimulation of cardiac fibroblasts by angiotensin II (ANG II) ortransforming growth factor-1 (TGF-1) resulted in an increase ofprotein and heightening by 50% of the receptor density of81-integrin. The effect of ANG II wasblocked by an AT1, but not an AT2, receptorantagonist, or by an anti-TGF-1 antibody. ANG II and TGF-1increased fibronectin secretion, smooth muscle -actin synthesis, andformation of actin stress fibers and enhanced attachment of fibroblaststo a fibronectin matrix. The 8- and1-subunits were colocalized by immunocytochemistry with vinculin or 3-integrin at focal adhesion sites.These results indicate that 81-integrinis an abundant integrin on rat cardiac fibroblasts. Its positivemodulation by ANG II and TGF-1 in a myofibroblast-likephenotype suggests the involvement of81-integrin in extracellularmatrix protein deposition and cardiac fibroblast adhesion. 相似文献
5.
p38 MAPK mediates renal tubular cell TNF-{alpha} production and TNF-{alpha}-dependent apoptosis during simulated ischemia 总被引:4,自引:0,他引:4
Meldrum K. K.; Meldrum D. R.; Hile K. L.; Yerkes E. B.; Ayala A.; Cain M. P.; Rink R. C.; Casale A. J.; Kaefer M. A. 《American journal of physiology. Cell physiology》2001,281(2):C563
Ischemia causes renal tubular cellloss through apoptosis; however, the mechanisms of this processremain unclear. Using the renal tubular epithelial cell lineLLC-PK1, we developed a model of simulated ischemia(SI) to investigate the role of p38 MAPK (mitogen-activated proteinkinase) in renal cell tumor necrosis factor- (TNF-) mRNAproduction, protein bioactivity, and apoptosis. Resultsdemonstrate that 60 min of SI induced maximal TNF- mRNA productionand bioactivity. Furthermore, 60 min of ischemia induced renaltubular cell apoptosis at all substrate replacement time pointsexamined, with peak apoptotic cell death occurring after either 24 or 48 h. p38 MAPK inhibition abolished TNF- mRNA production andTNF- bioactivity, and both p38 MAPK inhibition and TNF- neutralization (anti-porcine TNF- antibody) preventedapoptosis after 60 min of SI. These results constitute theinitial demonstration that 1) renal tubular cells produceTNF- mRNA and biologically active TNF- and undergoapoptosis in response to SI, and 2) p38 MAPKmediates renal tubular cell TNF- production and TNF--dependent apoptosis after SI. 相似文献
6.
The gamma-subunit of ENaC is more important for channel surface expression than the beta-subunit 总被引:4,自引:0,他引:4
The amiloride-sensitiveepithelial sodium channel (ENaC) plays a critical role in fluid andelectrolyte homeostasis and is composed of three homologous subunits:, , and . Only heteromultimeric channels made of ENaCare efficiently expressed at the cell surface, resulting in maximallyamiloride-sensitive currents. To study the relative importance ofvarious regions of the - and -subunits for the expression offunctional ENaC channels at the cell surface, we constructedhemagglutinin (HA)-tagged --chimeric subunits composed of -and -subunit regions and coexpressed them with HA-tagged - and-subunits in Xenopus laevis oocytes. The whole cellamiloride-sensitive sodium current (Iami) andsurface expression of channels were assessed in parallel using thetwo-electrode voltage-clamp technique and a chemiluminescence assay.Because coexpression of ENaC resulted in largerIami and surface expression compared withcoexpression of ENaC, we hypothesized that the -subunit ismore important for ENaC trafficking than the -subunit. Usingchimeras, we demonstrated that channel activity is largely preservedwhen the highly conserved second cysteine rich domains (CRD2) of the- and -subunits are exchanged. In contrast, exchanging the wholeextracellular loops of the - and the -subunits largely reducedENaC currents and ENaC expression in the membrane. This indicates thatthere is limited interchangeability between molecular regions of thetwo subunits. Interestingly, our chimera studies demonstrated that theintracellular termini and the two transmembrane domains of ENaC aremore important for the expression of functional channels at the cellsurface than the corresponding regions of ENaC. 相似文献
7.
Mohan S Hamuro M Sorescu GP Koyoma K Sprague EA Jo H Valente AJ Prihoda TJ Natarajan M 《American journal of physiology. Cell physiology》2003,284(4):C1039-C1047
We have investigated the role ofinhibitor B (IB) in the activation of nuclear factor B(NF-B) observed in human aortic endothelial cells (HAEC) undergoinga low shear stress of 2 dynes/cm2. Low shear for 6 hresulted in a reduction of IB levels, an activation of NF-B,and an increase in B-dependent vascular cell adhesion molecule 1 (VCAM-1) mRNA expression and endothelial-monocyte adhesion.Overexpression of IB in HAEC attenuated all of these shear-induced responses. These results suggest that downregulation ofIB is the major factor in the low shear-induced activation ofNF-B in HAEC. We then investigated the role of nitric oxide (NO) inthe regulation of IB/NF-B. Overexpression of endothelial nitric oxide synthase (eNOS) inhibited NF-B activation in HAEC exposed to 6 h of low shear stress. Addition of the structurally unrelated NO donors S-nitrosoglutathione (300 µM) orsodium nitroprusside (1 mM) before low shear stress significantlyincreased cytoplasmic IB and concomitantly reduced NF-Bbinding activity and B-dependent VCAM-1 promoter activity. Together,these data suggest that NO may play a major role in the regulation ofIB levels in HAEC and that the application of low shear flowincreases NF-B activity by attenuating NO generation and thusIB levels. 相似文献
8.
Protein kinase Calpha participates in activation of store-operated Ca2+ channels in human glomerular mesangial cells 总被引:2,自引:0,他引:2
Protein kinase C (PKC) plays animportant role in activating store-operated Ca2+ channels(SOC) in human mesangial cells (MC). The present study was performed todetermine the specific isoform(s) of conventional PKC involved inactivating SOC in MC. Fura 2 fluorescence ratiometry showed that thethapsigargin-induced Ca2+ entry (equivalent to SOC) wassignificantly inhibited by 1 µM Gö-6976 (a specific PKC andI inhibitor) and PKC antisense treatment (2.5 nM for 24-48h). However, LY-379196 (PKC inhibitor) and2,2',3,3',4,4'-hexahydroxy-1,1'-biphenyl-6,6'-dimethanoldimethyl ether(HBDDE; PKC and inhibitor) failed to affect thapsigargin-evoked activation of SOC. Single-channel analysis in the cell-attached configuration revealed that Gö-6976 and PKC antisensesignificantly depressed thapsigargin-induced activation of SOC.However, LY-379196 and HBDDE did not affect the SOC responses. Ininside-out patches, application of purified PKC or I, but notII or , significantly rescued SOC from postexcision rundown.Western blot analysis revealed that thapsigargin evoked a decrease incytosolic expression with a corresponding increase in membraneexpression of PKC and . However, the translocation from cytosolto membranes was not detected for PKCI or II. These resultssuggest that PKC participates in the intracellular signaling pathwayfor activating SOC upon release of intracellular stores ofCa2+. 相似文献
9.
Kunz-Schughart LA Wenninger S Neumeier T Seidl P Knuechel R 《American journal of physiology. Cell physiology》2003,284(1):C209-C219
Transforming growth factor-(TGF-) is known to induce -smooth muscle actin (-SMA) infibroblasts and is supposed to play a role in myofibroblastdifferentiation and tumor desmoplasia. Our objective was to elucidatethe impact of TGF-1 on -SMA expression in fibroblasts in athree-dimensional (3-D) vs. two-dimensional (2-D) environment. Inmonolayer culture, all fibroblast cultures responded in a similarfashion to TGF-1 with regard to -SMA expression. In fibroblastspheroids, -SMA expression was reduced and induction by TGF-1 washighly variable. This difference correlated with a differentialregulation in the TGF- receptor (TGFR) expression, in particularwith a reduction in TGF-RII in part of the fibroblast types. Ourdata indicate that 1) sensitivity to TGF-1-induced -SMA expression in a 3-D environment is fibroblast-type specific, 2) fibroblast type-independent regulatory mechanisms, suchas a general reduction/loss in TGF-RIII, contribute to an altered TGFR expression profile in spheroid compared with monolayer culture, and 3) fibroblast type-specific alterations in TGFR typesI and II determine the sensitivity to TGF-1-induced -SMAexpression in the 3-D setting. We suggest that fibroblasts that can beinduced by TGF-1 to produce -SMA in spheroid culture reflect a"premyofibroblastic" phenotype. 相似文献
10.
Simonin Marie-Agnes; Bordji Karim; Boyault Sandrine; Bianchi Arnaud; Gouze Elvire; Becuwe Philippe; Dauca Michel; Netter Patrick; Terlain Bernard 《American journal of physiology. Cell physiology》2002,282(1):C125
This work demonstrated the constitutive expressionof peroxisome proliferator-activated receptor (PPAR)- and PPAR-in rat synovial fibroblasts at both mRNA and protein levels. A decrease in PPAR- expression induced by 10 µg/ml lipopolysaccharide (LPS) was observed, whereas PPAR- mRNA expression was not modified. 15-Deoxy-12,14-prostaglandin J2(15d-PGJ2) dose-dependently decreased LPS-induced cyclooxygenase (COX)-2 (80%) and inducible nitric oxide synthase (iNOS) mRNA expression (80%), whereas troglitazone (10 µM) only inhibited iNOS mRNA expression (50%). 15d-PGJ2 decreasedLPS-induced interleukin (IL)-1 (25%) and tumor necrosis factor(TNF)- (40%) expression. Interestingly, troglitazone stronglydecreased TNF- expression (50%) but had no significant effect onIL-1 expression. 15d-PGJ2 was able to inhibitDNA-binding activity of both nuclear factor (NF)-B and AP-1.Troglitazone had no effect on NF-B activation and was shown toincrease LPS-induced AP-1 activation. 15d-PGJ2 andtroglitazone modulated the expression of LPS-induced iNOS, COX-2, andproinflammatory cytokines differently. Indeed, troglitazone seems tospecifically target TNF- and iNOS pathways. These results offer newinsights in regard to the anti-inflammatory potential of the PPAR-ligands and underline different mechanisms of action of15d-PGJ2 and troglitazone in synovial fibroblasts. 相似文献
11.
Müller-Ehmsen J Juvvadi P Thompson CB Tumyan L Croyle M Lingrel JB Schwinger RH McDonough AA Farley RA 《American journal of physiology. Cell physiology》2001,281(4):C1355-C1364
HumanNa+-K+-ATPase11,21, and 31heterodimers were expressed individually in yeast, and ouabainbinding and ATP hydrolysis were measured in membrane fractions. Theouabain equilibrium dissociation constant was 13-17 nM for11 and 31at 37°C and 32 nM for 21, indicatingthat the human -subunit isoforms have a similar high affinity forcardiac glycosides. K0.5 values for antagonism of ouabain binding by K+ were ranked in order as follows:2 (6.3 ± 2.4 mM) > 3(1.6 ± 0.5 mM) 1 (0.9 ± 0.6 mM),and K0.5 values for Na+ antagonismof ouabain binding to all heterodimers were 9.5-13.8 mM. Themolecular turnover for ATP hydrolysis by11 (6,652 min1) was abouttwice as high as that by 31 (3,145 min1). These properties of the human heterodimersexpressed in yeast are in good agreement with properties of the humanNa+-K+-ATPase expressed in Xenopusoocytes (G Crambert, U Hasler, AT Beggah, C Yu, NN Modyanov, J-DHorisberger, L Lelievie, and K Geering. J Biol Chem275: 1976-1986, 2000). In contrast to Na+ pumpsexpressed in Xenopus oocytes, the21 complex in yeast membranes wassignificantly less stable than 11 or31, resulting in a lower functionalexpression level. The 21 complex was also more easily denatured by SDS than was the11 or the31 complex. 相似文献
12.
Decreased 5alpha-dihydrotestosterone catabolism suppresses T lymphocyte functions in males after trauma-hemorrhage 总被引:1,自引:0,他引:1
Zheng R Samy TS Schneider CP Rue LW Bland KI Chaudry IH 《American journal of physiology. Cell physiology》2002,282(6):C1332-C1338
Trauma-hemorrhage producesprofound immunosuppression in males but not in proestrus females.Prior castration or flutamide treatment of males followingtrauma-hemorrhage prevents immunosuppression, implicating5-dihydrotestosterone for the immunosuppressive effects. 5-Dihydrotestosterone, a high-affinity androgen receptor-binding steroid, is synthesized in tissues as needed and seldom accumulates. The presence of steroidogenic enzymes in T lymphocytes suggests bothsynthesis and catabolism of 5-dihydrotestosterone. We hypothesized, therefore, that the basis for high 5-dihydrotestosterone activity inT lymphocytes of males following trauma-hemorrhage is due to decreasedcatabolism. Accordingly, catabolism of 5-dihydrotestosterone wasassessed in splenic T lymphocytes by examining the activity andexpression of enzymes involved. Analysis showed increased synthesis anddecreased catabolism of 5-dihydrotestosterone in intact male Tlymphocytes following trauma-hemorrhage. In contrast, reduced5-reductase activity and increased expression of17-hydroxysteroid dehydrogenase oxidative isomers suggestinactivation of 5-dihydrotestosterone in precastrated males. Thusour study suggests increased synthesis and decreased catabolism of5-dihydrotestosterone as a reason for loss of T lymphocyte functionsin intact males following trauma-hemorrhage, as evidenced by decreasedrelease of interleukin-2 and -6. 相似文献
13.
Agonist-specific cross talk between ERKs and p38(mapk) regulates PGI(2) synthesis in endothelium 总被引:1,自引:0,他引:1
Houliston RA Pearson JD Wheeler-Jones CP 《American journal of physiology. Cell physiology》2001,281(4):C1266-C1276
We have examined the mechanisms regulatingprostacyclin (PGI2) synthesis after acute exposure of humanumbilical vein endothelial cells (HUVEC) to interleukin-1 (IL-1).IL-1 evoked an early (30 min) release of PGI2 and[3H]arachidonate that was blocked by the cytosolicphospholipase A2 (cPLA2) inhibitorarachidonyl trifluoromethyl ketone. IL-1-mediated activationof extracellular signal-regulated kinase 1/2 (ERK1/2; p42/p44mapk) coincided temporally with phosphorylation ofcPLA2 and with the onset of PGI2synthesis. The mitogen-activated protein kinase (MAPK) kinase (MEK)inhibitors, PD-98059 and U-0126, blocked IL-1-induced ERKactivation and partially attenuated cPLA2phosphorylation and PGI2 release, suggesting thatERK-dependent and -independent pathways regulate cPLA2phosphorylation. SB-203580 treatment enhanced IL-1-induced MEK,p42/44mapk, and cPLA2 phosphorylation butreduced thrombin-stimulated MEK and p42/44mapk activation.IL-1, but not thrombin, activated Raf-1 as assessed byimmune-complex kinase assay, as did SB-203580 alone. These results showthat IL-1 causes an acute upregulation of PGI2generation in HUVEC, establish a role for theMEK/ERK/cPLA2 pathway in this early release, and provideevidence for an agonist-specific cross talk between p38mapkand p42/44mapk that may reflect receptor-specificdifferences in the signaling elements proximal to MAPK activation. 相似文献
14.
Tumor necrosis factor- (TNF-), oneof the major inflammatory cytokines, is known to influence endothelialcell migration. In this study, we demonstrate that exposure of calfpulmonary artery endothelial cells to TNF- caused an increase in theformation of membrane protrusions and cell migration. Fluorescencemicroscopy revealed an increase in v3focal contacts but a decrease in 51 focalcontacts in TNF--treated cells. In addition, both cell-surface andtotal cellular expression of v3-integrinsincreased significantly, whereas the expression of51-integrins was unaltered. Only focalcontacts containing v3- but not51-integrins were present in membraneprotrusions of cells at the migration front. In contrast, robust focalcontacts containing 51-integrins were present in cells behind the migration front. A blocking antibody tov3, but not a blocking antibody to5-integrins, significantly inhibited TNF--inducedcell migration. These results indicate that in response to TNF-,endothelial cells may increase the activation and ligation ofv3 while decreasing the activation andligation of 51-integrins to facilitatecell migration, a process essential for vascular wound healing and angiogenesis. 相似文献
15.
Russo MP Bennett BL Manning AM Brenner DA Jobin C 《American journal of physiology. Cell physiology》2002,283(1):C347-C357
In this study, weexamined the role of the nuclear factor-B (NF-B)-inducing kinase(NIK) in distinct signaling pathways leading to NF-B activation. Weshow that a dominant-negative form of NIK (dnNIK) delivered byadenoviral (Ad5dnNIK) vector inhibits Fas-induced IBphosphorylation and NF-B-dependent gene expression in HT-29 and HeLacells. Interleukin (IL)-1- and tumor necrosis factor-(TNF-)-induced NF-B activation and B-dependent gene expressionare inhibited in HeLa cells but not in Ad5dnNIK-infected HT-29 cells.Moreover, Ad5dnNIK failed to sensitize HT-29 cells to TNF--inducedapoptosis at an early time point. However, cytokine- andFas-induced signals to NF-B are finally integrated by the IBkinase (IKK) complex, since IB phosphorylation, NF-B DNAbinding activity, and IL-8 gene expression were strongly inhibited inHT-29 and HeLa cells overexpressing dominant-negative IKK(Ad5dnIKK). Our findings support the concept that cytokine signalingto NF-B is redundant at the level of NIK. In addition, this studydemonstrates for the first time the critical role of NIK and IKK inFas-induced NF-B signaling cascade. 相似文献
16.
Translated Alu sequence determines nuclear localization of a novel catalytic subunit of casein kinase 2 总被引:3,自引:0,他引:3
Hilgard P Huang T Wolkoff AW Stockert RJ 《American journal of physiology. Cell physiology》2002,283(2):C472-C483
Casein kinase 2 (CK2) is atetrameric enzyme constitutively expressed in all eukaryotic tissues.The two known isoforms of the catalytic subunit, CK2 and CK2',have been reported to have distinct tissue-dependent subcellulardistributions. We recently described a third isoform of the catalyticsubunit, designated CK2", which is highly expressed in liver.Immunoblot analysis of HuH-7 human hepatoma cell fractions as well asimmunofluorescent microscopy revealed that CK2" was exclusivelylocalized to the nucleus and preferentially associated with the nuclearmatrix. CK2 and CK2' were found in nuclear, membrane, andcytosolic compartments. Deletion of the carboxy-terminal 32 amino acids from the CK2" sequence resulted in release of the truncated green fluorescent protein fusion protein from the nuclear matrix and redistribution to both the nucleus and the cytoplasm. Demonstration that the carboxy terminus is necessary but not sufficient for nuclearretention indicates that the underlying mechanism of CK2" nuclearlocalization is dependent on the secondary structure of the holoenzymedirected by the carboxy-terminal sequence. 相似文献
17.
Effect of interleukin-1beta and tumor necrosis factor-alpha on gene expression in human endothelial cells 总被引:6,自引:0,他引:6
Zhao B Stavchansky SA Bowden RA Bowman PD 《American journal of physiology. Cell physiology》2003,284(6):C1577-C1583
Interleukin-1(IL-1) and tumor necrosis factor- (TNF-) are two majorcytokines that rise to relatively high levels during systemicinflammation, and the endothelial cell (EC) response to these cytokinesmay explain some of the dysfunction that occurs. To better understandthe cytokine-induced responses of EC at the gene expression level,human umbilical vein EC were exposed to IL-1 or TNF- for varioustimes and subjected to cDNA microarray analyses to study alterations intheir mRNA expression. Of ~4,000 genes on the microarray, expressionlevels of 33 and 58 genes appeared to be affected by treatment withIL-1 and TNF-, respectively; 25 of these genes responded to bothtreatments. These results suggest that the effects of IL-1 andTNF- on EC are redundant and that it may be necessary to suppressboth cytokines simultaneously to ameliorate the systemic response. 相似文献
18.
Oshima T Pavlick KP Laroux FS Verma SK Jordan P Grisham MB Williams L Alexander JS 《American journal of physiology. Cell physiology》2001,281(4):C1096-C1105
Mucosal addressin cell adhesion molecule-1(MAdCAM-1) is a 60-kDa endothelial cell adhesion glycoprotein thatregulates lymphocyte trafficking to Peyer's patches and lymph nodes.Although it is widely agreed that MAdCAM-1 induction is involved inchronic gut inflammation, few studies have investigated regulation ofMAdCAM-1 expression. We used two endothelial lines [bEND.3 (brain) and SVEC (high endothelium)] to study the signal paths that regulate MAdCAM-1 expression in response to tumor necrosis factor (TNF)- using RT-PCR, blotting, adhesion, and immunofluorescence. TNF- induced both MAdCAM-1 mRNA and protein in a dose- and time-dependent manner. This induction was tyrosine kinase (TK), p42/44, p38mitogen-activated protein kinase (MAPK), and nuclear factor(NF)-B/poly-ADP ribose polymerase (PARP) dependent. Because MAdCAM-1is regulated via MAPKs, we examined mitogen/extracellularsignal-regulated kinase (MEK)-1/2 activation in SVEC. We found thatMEK-1/2 is activated by TNF- within minutes and is dependent on TKand p42/44 MAPKs. Similarly, TNF- activated NF-B through TK,p42/44, p38 MAPKs, and PARP pathways in SVEC cells. MAdCAM-1 was alsoshown to be frequently distributed to endothelial junctions both invitro and in vivo. Cytokines like TNF- stimulate MAdCAM-1 inhigh endothelium via TK, p38, p42/22 MAPKs, and NF-B/PARP.MAdCAM-1 expression requires NF-B translocation through both directp42/44 and indirect p38 MAPK pathways in high endothelial cells. 相似文献
19.
Giger JM Haddad F Qin AX Baldwin KM 《American journal of physiology. Cell physiology》2002,282(3):C518-C527
Functional overload (OL)of the rat plantaris muscle by the removal of synergistic musclesinduces a shift in the myosin heavy chain (MHC) isoform expressionprofile from the fast isoforms toward the slow type I, or, -MHCisoform. Different length rat -MHC promoters were linked to afirefly luciferase reporter gene and injected in control and OLplantaris muscles. Reporter activities of 3,500, 914, 408, and215 bp promoters increased in response to 1 wk of OL. The smallest171 bp promoter was not responsive to OL. Mutation analyses ofputative regulatory elements within the 171 and 408 bp region wereperformed. The 408 bp promoters containing mutations of the e1,distal muscle CAT (MCAT; e2), CACC, or A/T-rich (GATA), were stillresponsive to OL. Only the proximal MCAT (e3) mutation abolished theOL response. Gel mobility shift assays revealed a significantly higherlevel of complex formation of the e3 probe with nuclear protein fromOL plantaris compared with control plantaris. These results suggestthat the e3 site functions as a putative OL-responsive element inthe rat -MHC gene promoter. 相似文献
20.
Lung epithelial barrier function and wound healing are decreased by IL-4 and IL-13 and enhanced by IFN-gamma 总被引:3,自引:0,他引:3
Ahdieh Minoo; Vandenbos Tim; Youakim Adel 《American journal of physiology. Cell physiology》2001,281(6):C2029
To understand theeffects of cytokines on epithelial cells in asthma, we haveinvestigated the effects of interleukin (IL)-4, IL-13, and interferon(IFN)- on barrier function and wound healing in Calu-3 human lungepithelial cells. IL-4 and IL-13 treatment of Calu-3 cells grown onTranswell filters resulted in a 70-75% decrease in barrierfunction as assessed by electrophysiological and[14C]mannitol flux measurements. In contrast, IFN-enhanced barrier function threefold using these same parameters. Cellstreated concurrently with IFN- and IL-4 or IL-13 showed an initialdecline in barrier function that was reversed within 2 days, resulting in barrier levels comparable to control cells. Analysis of the tightjunction-associated proteins ZO-1 and occludin showed that IL-4 andIL-13 significantly reduced ZO-1 expression and modestly decreasedoccludin expression compared with controls. IFN-, quite unexpectedlygiven its enhancing effect on barrier function, reduced expression ofZO-1 and occludin to almost undetectable levels compared with controls.In wound-healing assays of cells grown on collagen I, IL-4 and IL-13decreased migration, whereas IFN- treatment enhanced migration,compared with control cells. Addition of IFN-, in combination withIL-4 or IL-13, restored migration of cells to control levels. Migrationdifferences observed between the various cytokine treatments wascorrelated with expression of the collagen I-binding21-integrin at the leading edge of cellsat the wound front; 21-integrinexpression was decreased in IFN--treated cells compared withcontrols, whereas it was highest in IL-4- and IL-13-treated cells.These results demonstrate that IL-4 and IL-13 diminish the capacity ofCalu-3 cells to maintain barrier function and repair wounds, whereasIFN- promotes epithelial restitution by enhancing barrier functionand wound healing. 相似文献