Intraepithelial CD8+ T-cell-count becomes a prognostic factor after a longer follow-up period in human colorectal carcinoma: possible association with suppression of micrometastasis

T-cell infiltration into human cancer tissues can be a manifestation of host immune responses to cancer cells. The present study was undertaken to explore the clinicopathological significance of intraepithelial CD8⁺ T cells using 371 consecutively sampled human colorectal carcinomas. By univariate analysis, we noted that the survival curves by intraepithelial CD8⁺ T cells became separated only after 1 to 2 years postoperation. Multivariate analyses revealed that the beneficial effect of this factor becomes significant only after a longer (more than 2 year), but not after a shorter (less than 2 year) follow-up period. Furthermore, the number of intraepithelial CD8⁺ T cells was significantly higher in patients alive for more than 5 years than in patients who either died of cancer after a curative operation or patients who underwent a noncurative operation. Patients' cancer-specific death long after a curative operation is thought to be caused by the growth of micrometastases in other organs or near the primary sites. The effects of intraepithelial CD8⁺ T cells, therefore, may be mediated by suppression of micrometastasis, rather than suppression of growth in the primary tumour. In conclusion, our data support a hypothesis on the presence of systemic immunosurveillance against micrometastasis of cancer cells.

Orientation and distribution of collagen fibers in the sagittal plane of the human adult calcaneus

Human right calcaneus bone, consisting of hydroxyapatite and collagen fibers, was cut in the sagittal plane which was parallel to the long axes of the calcaneus bone and the human lower limb, into samples approximately 1.5 mm thick. The angular dependence of transmitted microwave intensity at 12 GHz was measured for each sample, using Osaki's microwave method. The direction and the degree of collagen-fiber orientation for the cut specimens changed with changing position from the heel end to the anterior, along to the long axis of the calcaneus bone. The direction of orientation deviated by about -60 degrees from the direction of the long axis of the human lower limb, in the region between the heel end and the middle, and by about 60 degrees near the anterior. The position at which the orientation angle changed drastically from negative to positive corresponded to the neck defined as the position where a posterior face of the talus contacts the calcaneus. The results suggest that the mechanical stress applied to the neck of the calcaneus bone from the lower limb may effectively disperse, on average, in two different directions where the collagen fibers are oriented at the neck.

Design and evaluation of a single-pivot supported centrifugal blood pump

In order to develop a centrifugal blood pump that meets the requirements of a long-term, implantable circulatory support device, in this study a single-pivot bearing supported centrifugal blood pump was designed to evaluate its basic performance. The single-pivot structure consisted of a ceramic ball male pivot mounted on the bottom surface of the impeller and a polyethylene female pivot incorporated in the bottom pump casing. The follower magnet mounted inside the impeller was magnetically coupled to the driver magnet mounted on the shaft of the direct current brushless motor. As the motor rotated, the impeller rotated supported entirely by a single-pivot bearing system. The static pump performance obtained in the mock circulatory loop revealed an acceptable performance as a left ventricular assist device in terms of flow and head pressure. The pump flow of 5 L/min against the head pressure of 100 mm Hg was obtained at rotational speeds of 2,000 to 2,200 rpm. The maximum pump flow was 9 L/min with 2,200 rpm. The maximum electrical-to-hydraulic power conversion efficiency was around 14% at pump flows of 4 to 5 L/min. The stability of the impeller was demonstrated at the pump rpm higher than 1,400 with a single-pivot bearing without an additional support at its top. The single-pivot supported centrifugal pump can provide adequate flow and pressure as a ventricular assist device, but its mechanical stability and hemolytic as well as thrombotic performances must be tested prior to clinical use.

Inhibition of prostalglandin E2 production by 2'-hydoxychalcone derivatives and the mechanism of action

The effects of 14 synthetic 2'-hydroxychalcone derivatives on prostaglandin E2 (PGE2) production in rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), were examined to clarify the structure-activity relationship. 2',4-Dihydroxy-4'-methoxychalcone (compound 3), 2',4-dihydroxy-6'-methoxychalcone (compound 8) and 2'-hydroxy-4'-methoxychalcone (compound 9) suppressed PGE2 production more potently than the other compounds. The IC50 (50% Inhibitory concentration) value for compounds 3, 8 and 9 was calculated to be 3 microM. The activity of cyclooxygenase (COX)-1 was inhibited slightly by compound 9, but that of COX-2 was not inhibited. At concentrations that inhibited the production of PGE2, compound 9 had no effect on the release of radioactivity from [3H]arachidonic acid-labelled macrophages stimulated by TPA. Western-blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by compound 9 in parallel with the inhibition of PGE2 production. Compounds 3 and 8 had similar effects. These findings suggest that 4'-methoxyl and 6'-methoxyl groups are required for the expression of more potent inhibitory activity against PGE2 production, and that the inhibition of PGE2 production by these 2'-hydroxychalcone derivatives is due to the inhibition of TPA-induced COX-2 protein expression.

Estimation of left ventricular recovery level based on the motor current waveform analysis on circulatory support with centrifugal blood pump

In a mock circulatory loop simulating the left heart bypass using a centrifugal blood pump, analysis of the motor current waveform of the centrifugal pump was performed to derive a useful parameter to evaluate the status of ventricular function. The relationship between the peak, amplitude, and the peak of the fundamental frequency of the power spectral density of the periodic motor current waveform (MCpsdP) that reflected the pulsatile ventricular pressure, and the peak of the left ventricular pressure (LVP) was examined. Although both peak and amplitude of the motor current waveform showed an excellent correlation with the peak LVP, they failed to predict the opening of the aortic valve. The MCpsdP that corresponds to the frequency of the heart rate showed an excellent correlation with the peak LVP throughout the LVP levels, but the slope between them changed with the opening of the aortic valve. Thus, it is possible to follow the change in the LVP and detect even the opening of the aortic valve, and, hence, the recovery of the left ventricle. However, the slope of the linear regression equation varied, depending on the pump speed. This result implies that the MCpsdP can be possibly used to follow the change of ventricular function during circulatory assistance with a centrifugal blood pump as well as to control the pump speed in response to varying ventricular function.

Mice lacking histidine decarboxylase exhibit abnormal mast cells

Histidine decarboxylase (HDC) synthesizes histamine from histidine in mammals. To evaluate the role of histamine, we generated HDC-deficient mice using a gene targeting method. The mice showed a histamine deficiency and lacked histamine-synthesizing activity from histidine. These HDC-deficient mice are viable and fertile but exhibit a decrease in the numbers of mast cells while the remaining mast cells show an altered morphology and reduced granular content. The amounts of mast cell granular proteases were tremendously reduced. The HDC-deficient mice provide a unique and promising model for studying the role of histamine in a broad range of normal and disease processes.

Expression and purification of recombinant rat eosinophil-associated ribonucleases, homologues of human eosinophil cationic protein and eosinophil-derived neurotoxin, and their characterization

BACKGROUND

Human eosinophils contain two eosinophil ribonucleases, eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). In rats, 8 homologues of human ECP and EDN have been identified. To clarify the biological activity of rat eosinophil ribonucleases, we cloned rat eosinophil-associated ribonuclease (EAR)-1/rat ribonuclease 7 and rat EAR-2/rat ribonuclease 4, and produced recombinant rat pre-EAR-1 and pre-EAR-2 in a bacterial expression system.

METHODS

As we have already cloned the complete nucleotide sequence for rat EAR-1, we determined that for rat EAR-2 cDNA by the rapid amplification of cDNA ends procedure. Recombinant rat pre-EAR-1 and pre-EAR-2 were expressed in Escherichia coli as N-terminal 6 x histidine-tagged proteins, isolated from the insoluble fraction of the cell lysate and purified by a single-step method using an Ni-NTA resin column after solubilization with a 6 M guanidine solution.

RESULTS

The deduced amino acid sequence revealed that the molecular weight of EAR-2 containing the signal peptide is 17.3 kD and the isoelectric point is 8.59. The homology in amino acid sequence between rat pre-EAR-2, and human pre-ECP and human pre-EDN is 51 and 53%, respectively. The purified and refolded recombinant rat pre-EAR-1 and pre-EAR-2 showed bactericidal activity against E. coli and Staphylococcus aureus.

CONCLUSIONS

These findings suggest that rat EAR-1 and EAR-2 act as host defense factors against bacterial infection in rats.

Novel roles of CpG oligodeoxynucleotides as a leader for the sampling and presentation of CpG-tagged antigen by dendritic cells

Oligodeoxynucleotides containing CpG motifs have been highlighted as potent Th1 activators. We previously reported that Ag and CpG, when conjugated together, synergistically promoted the Ag-specific Th1 development and inhibited the Th2-mediated airway eosinophilia. In this study, we examined the mechanisms underlying the synergism of the covalent conjugation. The CpG-OVA conjugate enhanced the Th1 activation and development. These characteristic features of the conjugate could not be ascribed to the polymerization of OVA, but mirrored the augmented binding of the CpG-tagged Ag to dendritic cells (DCs) in a CpG-guided manner, because phycobiliprotein, R-PE, conjugated to CpG stained a higher proportion of DCs with higher intensity than the mixture. R-PE fluorescence was emitted from cytoplasmic portions of the DCs, which simultaneously expressed costimulatory molecules and IL-12. The CpG-conjugated R-PE trafficking described above actually served as a potent Ag. These results indicate that CpG conjugated to Ag exhibit novel joint properties as promoters of Ag uptake and DC activators, thereby potentiating the ability of DCs to generate Th1 cells. The DNA-mediated promotion of Ag uptake would be advantageous for evoking host immune responses against invading microorganisms.

[Regulation of histamine production in macrophages]

Stimulating cells of the mouse macrophage-like cell line RAW 264.7 with the Ca(2+)-ATPase inhibitor thapsigargin increased histamine production. Thapsigargin increased the levels of histidine decarboxylase (HDC) mRNA at 4 h and the expression of 74-kDa HDC protein at 8 h. PD98059, a specific inhibitor of MEK-1 which phosphorylates p44/p42 MAP kinase, strongly suppressed the thapsigargin-induced histamine production, the increase in HDC mRNA level and 74-kDa HDC protein expression. In contrast, SB203580, an inhibitor of p38 MAP kinase, showed only a partial inhibition of histamine production. TPA and LPS also induced histamine production in RAW 264.7 cells, and the histamine production induced by TPA or LPS was also inhibited by PD98059, but the effect of SB203580 was partial. The synthetic glucocorticoid dexamethasone inhibited thapsigargin-induced histamine production, 74-kDa HDC protein expression and the activation of p44/p42 MAP kinases. In conclusion, the increase in histamine production in macrophages stimulated with inflammatory stimulants is due to the increased expression of 74-kDa HDC, which is positively regulated by activated p44/p42 MAP kinases. Dexamethasone inhibits thapsigargin-induced HDC protein expression and histamine production by inhibiting the MAP kinase activation.

Inhibition of prostaglandin E2 production by platycodin D isolated from the root of Platycodon grandiflorum

Platycodin D, isolated from the root of Platycodon grandiflorum A. DC. (Campanulaceae) suppressed prostaglandin E2 production at 10 and 30 microM in rat peritoneal macrophages stimulated by the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Platycodin D3 and oleanolic acid showed no effect at these concentrations. Western blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by platycodin D in parallel with the inhibition of prostaglandin E2 production. Platycodin D showed no direct effect on COX-1 and COX-2 activities. TPA-induced release of [3H]arachidonic acid from pre-labeled macrophages was also not inhibited by platycodin D.

Control strategy for rotary blood pumps

The control strategy for ventricular support with a centrifugal blood pump was examined in this study. The control parameter was the pump rpm that determines pump flow. Optimum control of pump rpm that reflects the body's demand is important for long-term, effective, and safe circulatory support. Moreover, continuous, reliable monitoring of ventricular function will help successfully wean the patients from the ventricular assist device (VAD). The control strategy in this study includes determination of the target pump rpm that can provide the flow required by the body, fine-rpm-tuning to minimize deleterious effects such as suction in the ventricle, and assessment of ventricular function for successful weaning from VADs. To determine the target pump rpm, we proposed to use the relation between the native heart rate and cardiac output, and the relation between the pump rpm and centrifugal pump output. For fine-tuning of the pump rpm, the motor current waveform was used. We computed the power spectral density of the motor current waveform and calculated the ratio of the fundamental to the higher order components. When this ratio was larger than approximately 0.2, we assumed there would be a suction effect in the ventricle. As for assessment of ventricular function, we used the amplitude of the motor current waveform. The control system implemented using a DSP functioned properly in the mock circulatory loop as well as in acute animal experiments. The motor current also showed a good correlation with the ventricular pressure in acute animal experiments.

Possible participation of a JAK2 signaling pathway in recombinant rat interleukin-5-induced prolongation of rat eosinophil survival

Recombinant rat interleukin (IL)-5-induced prolongation of rat eosinophil survival in culture was inhibited in a concentration-dependent manner by the protein synthesis inhibitor cycloheximide, the DNA-dependent RNA synthesis inhibitor actinomycin D, and the tyrosine kinase inhibitor herbimycin A when examined 96 h after incubation. The MEK-1 inhibitor PD98059 inhibited IL-5-induced phosphorylation of both p44 and p42 MAP kinases, but the IL-5-induced prolongation of eosinophil survival was not inhibited. In contrast, the JAK2 inhibitor AG490 inhibited the IL-5-induced prolongation of eosinophil survival. Treatment of eosinophils with IL-5 resulted in phosphorylation of STAT5 but not STAT1, and the IL-5-induced phosphorylation of STAT5 was inhibited by AG490. These findings suggest that the activation of JAK2 tyrosine kinase and protein synthesis are required for the prolongation of rat eosinophil survival induced by recombinant rat IL-5. STAT5 phosphorylation might also participate in the IL-5-induced survival of rat eosinophils.

Expression of 74-kDa histidine decarboxylase protein in a macrophage-like cell line RAW 264.7 and inhibition by dexamethasone

Stimulation of RAW 264.7 cells with the Ca(2+)-ATPase inhibitor thapsigargin increased histamine production. Immunoblot analyses revealed that thapsigargin increased the expression of 74-kDa histidine decarboxylase protein although rat mast cell line RBL-2H3 cells express both 74- and 53-kDa histidine decarboxylase proteins. The inhibition of histamine production by the mitogen-activated protein kinase-extracellular signal-regulated kinase kinase (MEK) inhibitors PD98059 (2'-amino-3'-methoxyflavone) and U0126 (1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene) and by the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole) was correlated with the inhibition of the expression of thapsigargin-induced 74-kDa histidine decarboxylase protein. The synthetic glucocorticoid dexamethasone inhibited thapsigargin-induced histamine production and 74-kDa histidine decarboxylase protein expression. The thapsigargin-induced activation of p42/p44 MAP kinase and p38 MAP kinase was also inhibited by dexamethasone. These findings indicate that the induction of histamine production by thapsigargin in RAW 264.7 cells is due to the increased expression of 74-kDa histidine decarboxylase protein and that dexamethasone inhibits thapsigargin-induced histidine decarboxylase protein expression and histamine production via inhibition of MAP kinase activation.

Inhibition by retinoids of antigen-induced IL-4 production in rat mast cell line RBL-2H3

The retinoic acid receptor (RAR) agonists, Re80 and Am80, partially inhibited the antigen-induced IL-4 production by rat mast cell line RBL-2H3 in a concentration-dependent manner (0.1 to 1000 nM). Both Re80 and Am80 also reduced the antigen-induced increase in IL-4 mRNA levels. The RAR antagonist LE540 at 4 microM reversed Re80 (100 nM)- and Am80 (100 nM)-induced inhibition of IL-4 production. The retinoid X receptor agonist HX600 (1 microM) by itself did not affect IL-4 production, but enhanced the inhibitory effect of Re80 (10 nM) and of Am80 (10 nM). Cyclosporin A suppressed the antigen-induced IL-4 production almost completely at 0.3 microM. These findings indicated that the antigen-induced IL-4 production by RBL-2H3 cells is partially inhibited by retinoids via RAR-dependent mechanisms.

Cyclooxygenase-2-mediated angiogenesis in carrageenin-induced granulation tissue in rats

The possible participation of cyclooxygenase (COX)-2 in angiogenesis in granulation tissue was analyzed using an air pouch-type carrageenin-induced inflammation model in rats. Injection of carrageenin solution into an air pouch induced gradual increases in the pouch fluid volume and granulation tissue weight as well as angiogenesis in granulation tissue. NS-398 (10-100 microg) inhibited all of these parameters in a dose-dependent manner. NS-398 (100 microg), indomethacin (100 microg), and dexamethasone (10 microg) markedly reduced prostaglandin (PG) E(2) levels in the pouch fluid at day 6. NS-398 and indomethacin did not affect protein levels of COX-1 and COX-2 but dexamethasone significantly reduced the level of COX-2 in granulation tissue at day 6. Protein levels of vascular endothelial growth factor (VEGF) in granulation tissue and in the pouch fluid were higher at day 6 than at day 3, and the levels were decreased by treatment with NS-398 (10-100 microg) in a dose-dependent manner. The inhibitory effects of NS-398 (100 microg) were almost the same as those of indomethacin (100 microg). Dexamethasone (10 microg) also reduced VEGF protein levels in granulation tissue at day 6. To clarify the role of PGE(2) in VEGF production, minced granulation tissue obtained 3 days after carrageenin injection from the indomethacin-treated rats was incubated in the presence of various concentrations of PGE(2). It was shown that VEGF mRNA and protein levels in the minced granulation tissue were increased by PGE(2) in a concentration-dependent manner. These findings suggest that COX-2-derived PGE(2) plays a significant role in angiogenesis in the carrageenin-induced granulation tissue through VEGF formation.

Altered endothelium-dependent and -independent hyperpolarization and endothelium-dependent relaxation in carotid arteries isolated from streptozotocin-induced diabetic rats

We examined endothelium-dependent and -independent hyperpolarizations and endothelium-dependent relaxation responses in carotid arteries isolated from streptozotocin-induced diabetic rats and age-matched controls. The resting membrane potentials were not significantly different between control and diabetic carotid arteries. The endothelium-dependent hyperpolarization induced by acetylcholine, which was inhibited by TEA but not by glibenclamide or by treatment with either a high concentration of glucose or pertussis toxin, was significantly weaker in diabetic arteries than in the controls. The relaxation responses to acetylcholine in carotid artery rings were significantly decreased in streptozotocin-diabetic rats. Treatment with NG-nitro-L-arginine (L-NOARG) inhibited the acetylcholine-induced maximal relaxation by 80% and 30% in control and streptozotocin-diabetic rats, respectively, and the simultaneous application of L-NOARG and indomethacin had a more potent inhibitory effect on this relaxation in both groups. The release of 6-keto-prostaglandin F1alpha and that of thromboxane A2 in response to methoxamine or methoxamine plus acetylcholine were both markedly decreased in diabetic rats. The cromakalim-induced hyperpolarization of the carotid artery, which was completely prevented by glibenclamide, was also significantly weaker in diabetic arteries than in the controls. These results suggest that changes in (1) various K+ channels on smooth muscle, (2) the biosynthesis of cyclooxygenase products and (3) endothelium-dependent relaxation may be important factors in the development of diabetic complications in the carotid artery.

Mechanisms underlying the attenuation of endothelium-dependent vasodilatation in the mesenteric arterial bed of the streptozotocin-induced diabetic rat

Experiments were designed to investigate the mechanisms underlying the diabetes-related impairment of the vasodilatations of the perfused mesenteric arterial bed induced by acetylcholine (ACh) and K(+). In streptozotocin (STZ)-diabetic rats, the ACh-induced endothelium-dependent vasodilatation was attenuated. The dose-response curves for ACh in control and diabetic rats were each shifted to the right by N(G)-nitro-L-arginine (L-NOARG) and by isotonic high K(+) (60 mM). The ACh dose-response curves under isotonic high K(+) were not different between control and diabetic rats. We also examined the vasodilatation induced by K(+), which is a putative endothelium-derived hyperpolarizing factor (EDHF). The mesenteric vasodilatation induced by a single administration of K(+) was greatly impaired in STZ-induced diabetic rats. Treatment with charybdotoxin plus apamin abolished the ACh-induced vasodilatation but enhanced the K(+)-induced response in controls and diabetic rats. After pretreatment with ouabain plus BaCl(2), the ACh-induced vasodilatation was significantly impaired and the K(+)-induced relaxation was abolished in both control and diabetic rats. The impairment of the endothelium-dependent vasodilatation of the mesenteric arterial bed seen in STZ-induced diabetic rats may be largely due to a defective vascular response to EDHF. It is further suggested that K(+) is one of the endothelium-derived hyperpolarizing factors and that the vasodilatation response to K(+) is impaired in the mesenteric arterial bed from diabetic rats.

Analysis of the prolongation of rat eosinophil survival induced by recombinant rat interleukin-5

Rat eosinophil survival was prolonged by recombinant rat IL-5 prepared by the baculovirus expression system. The IL-5-induced prolongation of eosinophil survival was dose-dependently inhibited by the protein synthesis inhibitor cycloheximide, the DNA-dependent RNA synthesis inhibitor actinomycin D, and the tyrosine kinase inhibitor herbimycin A. The MEK-1 inhibitor PD98059 inhibited IL-5-induced phosphorylation of both p44 and p42 MAP kinases, but the IL-5-induced prolongation of eosinophil survival was not inhibited. In contrast, the JAK2 inhibitor AG490 inhibited the IL-5-induced prolongation of eosinophil survival. Treatment of eosinophils with IL-5 resulted in phosphorylation of STAT5 but not STAT1, and the IL-5-induced phosphorylation of STAT5 was inhibited by AG490. These findings suggest that recombinant rat IL-5 activates JAK2 tyrosine kinase, which phosphorylates STAT5, and induces protein synthesis required for the prolongation of rat eosinophil survival.

Generation of rat eosinophils by recombinant rat interleukin-5 in vitro and in vivo

The addition of recombinant rat interleukin-5 (IL-5), which was purified from the hemolymph of silkworm Bombyx mori larvae infected with IL-5-expressing recombinant virus, to cultures of rat bone marrow cells resulted in an increase in the number of Luxol-fast-blue staining eosinophils in a time- and concentration-dependent manner. After 6 days culture with 100 pM recombinant rat IL-5, more than 90% of the bone marrow cells were eosinophil. The contents of major basic protein (MBP) in the bone marrow cells determined by Western blot analysis using a polyclonal antibody to rat MBP were also increased by recombinant rat IL-5 (100 pM). Furthermore, intravenous injections of recombinant rat IL-5 twice a day for six consecutive days increased the population of eosinophils in peripheral blood cells and in bone marrow cells. These findings indicate that rat IL-5 induces terminal differentiation and proliferation of progenitor cells to mature eosinophils in rats.

Analysis of histamine-producing cells at the late phase of allergic inflammation in rats

To identify histamine-producing cells at the late phase of allergic inflammation, the expression of L-histidine decarboxylase (HDC) was examined in the infiltrating leucocytes in the inflammatory locus. HDC activity and HDC mRNA levels in the infiltrating leucocytes in the pouch fluid of the immunized rats (that were injected with the antigen solution into the air pouch) were increased compared with those in the infiltrating leucocytes of the non-immunized rats. When infiltrating leucocytes collected 8 hr after antigen injection were cultured, histamine production by the cells from the immunized rats was higher than that from the non-immunized rats. In situ hybridization of HDC mRNA revealed that almost all the infiltrating leucocytes of the immunized rats, 4 hr after injection of the antigen, expressed HDC mRNA with high intensity, while those of the non-immunized rats showed only a weak intensity of HDC mRNA. In the immunized rats, approximately 90% of leucocytes infiltrating in the pouch fluid at 4 hr were neutrophils and 8% were monocytes/macrophages. Neither mast cells nor basophils were detected in the infiltrating leucocytes. When rat peritoneal neutrophils were incubated in the presence of 12-O-tetradecanoylphorbol 13-acetate, histamine production was significantly increased. These findings suggest that the leucocytes, mainly neutrophils, infiltrating at the inflammatory locus are responsible for histamine production at the late phase of allergic inflammation.

Signal transduction cascade in staurosporine-induced prostaglandin E(2) production by rat peritoneal macrophages

The possible participation of phosphatidylinositol (PI) 3-kinase, p44/42 mitogen-activated protein (MAP) kinases and protein kinase C (PKC) in staurosporine-induced prostaglandin E(2) (PGE(2)) production was investigated pharmacologically in rat peritoneal macrophages. When the cells were incubated in the presence of staurosporine (63 nM), phosphorylation of p44/42 MAP kinases and cytosolic phospholipase A(2) (cPLA(2)) was induced at 15 min and increased until 60 min, whereas PGE(2) production and expression of cyclooxygenase-2 (COX-2) protein began to increase at 2 h and increased thereafter. Both PD98059 and U0126, MAP kinase/extracellular signal-regulated kinase (ERK) kinase inhibitors, and LY294002, a PI 3-kinase inhibitor, inhibited staurosporine-induced phosphorylation of p44/42 MAP kinases and cPLA(2) and PGE(2) production. Moreover, U0126 inhibited staurosporine-induced arachidonic acid release at 1 h. Although PD98059 and U0126 at 30 microM partially inhibited staurosporine-induced COX-2 protein expression, they completely inhibited staurosporine-induced PGE(2) production. LY294002 at 100 microM did not inhibit staurosporine-induced expression of COX-2 protein. In contrast, Ro-31-8220, a PKC inhibitor, completely inhibited staurosporine-induced PGE(2) production and COX-2 protein expression at 8 h but did not inhibit staurosporine-induced phosphorylation of p44/42 MAP kinases and cPLA(2). These findings suggest that staurosporine induces PGE(2) production by two mechanisms. One is cPLA(2) phosphorylation through a signal transduction pathway from PI 3-kinase to p44/42 MAP kinases, by which arachidonic acid, a substrate for COX-1 and COX-2, is increased. The other is COX-2 protein expression, which is induced mainly by activation of PKC and partially by activation of p44/42 MAP kinases; thus, arachidonic acid is metabolized to PGE(2).

Participation of mitogen-activated protein kinase in thapsigargin- and TPA-induced histamine production in murine macrophage RAW 264.7 cells

1. Stimulation of the murine macrophage cell line RAW 264.7 with thapsigargin, an endomembrane Ca(2+)-ATPase inhibitor, induced histamine production in a time- and concentration-dependent manner. 2. The protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), also enhanced histamine production. 3. alpha-Fluoromethylhistidine, a suicide substrate of L-histidine decarboxylase (HDC), suppressed the thapsigargin (30 nM)- and TPA (30 nM)-induced histamine production. 4. Both thapsigargin (30 nM) and TPA (30 nM) induced phosphorylation of p44/p42 MAP kinase and p38 MAP kinase. 5. PD98059, a specific inhibitor of MEK-1 which phosphorylates p44/p42 MAP kinase, strongly suppressed both the thapsigargin (30 nM)- and TPA (30 nM)-induced histamine production, whereas SB203580, a specific inhibitor of p38 MAP kinase, inhibited them only partially. 6. The other MEK-1 inhibitor, U-0126, also inhibited both the thapsigargin- and TPA-induced histamine production in a concentration-dependent manner. 7. Thapsigargin (30 nM) and TPA (30 nM) increased the levels of HDC mRNA at 4 h, but PD98059 suppressed both the thapsigargin- and TPA-induced increases in the HDC mRNA level. 8. These findings indicate that thapsigargin and TPA induce histamine production in RAW 264.7 cells by increasing the level of HDC mRNA, and that both the thapsigargin- and TPA-induced histamine production are regulated largely by p44/p42 MAP kinase and partially by p38 MAP kinase.

Involvement of a phosphatidylinositol 3-kinase-p38 mitogen activated protein kinase pathway in antigen-induced IL-4 production in mast cells

We studied the involvement of phosphatidylinositol 3-kinase (PI3-kinase) in the antigen-induced IL-4 production in a rat mast cell line, RBL-2H3. The stimulation of IgE-sensitized RBL-2H3 cells by the antigen resulted in increased IL-4 mRNA levels followed by increased IL-4 production. Wortmannin and LY294002, PI3-kinase inhibitors, partially reduced both the antigen-induced increases in the IL-4 mRNA levels and IL-4 production in a concentration-dependent manner. Extracellular signal-regulated kinase, p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK), which belong to the MAPK family, were activated by the antigen stimulation, and the activation of p38 MAPK in addition to JNK was suppressed markedly by wortmannin. The phosphorylation of endogenous activating transcription factor-2, a substrate of p38 MAPK, was also inhibited by wortmannin. The specific p38 MAPK inhibitor SB203580 partially inhibited the antigen-induced IL-4 production at mRNA levels, but the MEK-1 inhibitor PD98059 enhanced it. These findings suggest that the activation of PI3-kinase and p38 MAPK is partially responsible for the antigen-induced IL-4 production in RBL-2H3 cells.

Analysis of biological activities of recombinant rat interleukin-5

We analyzed the biological activities of recombinant rat interleukin-5 (IL-5). Purified recombinant rat IL-5 promoted the proliferation of T88-M cells in a concentration-dependent manner, and its effect was inhibited by an anti-murine IL-5-neutralizing polyclonal antibody. When bone marrow cells from normal rats were incubated with recombinant rat IL-5 in medium containing methylcellulose, the colony formation by eosinophilic cells was induced. Furthermore, when rat peritoneal eosinophils were incubated with recombinant rat IL-5, the spontaneous decrease in eosinophil viability was inhibited in a time- and concentration-dependent manner. In addition, the recombinant rat IL-5-induced eosinophil survival was inhibited by an anti-murine IL-5-neutralizing polyclonal antibody. These findings suggest that rat IL-5 acts as B cell growth factor II, eosinophil differentiation factor, and eosinophil survival-enhancing factor.

Preparation of recombinant rat interleukin-5 by baculovirus expression system and analysis of its biological activities

Rat interleukin-5 (IL-5) cDNA was subcloned from peritoneal cells collected 4 h after intraperitoneal injection of Ascaris suum antigen solution into the immunized rats. Cysteine proteinase-deleted (CPd) rat IL-5 recombinant virus was constructed by inserting rat IL-5 cDNA into CPd virus having a deletion in the cysteine proteinase gene of the silkworm Bombyx mori nuclear polyhedrosis virus. On infection with the CPd rat IL-5 recombinant virus, the silkworm B. mori larvae produced rat IL-5 as a dimeric form in hemolymph. Recombinant rat IL-5 was purified more than 95.5% by anion-exchange chromatography and hydrophobic chromatography. The purified recombinant rat IL-5 promoted the proliferation of T88-M cells in a concentration-dependent manner, and its effect was inhibited by an anti-murine IL-5 neutralizing polyclonal antibody. When bone marrow cells from normal rats were incubated with recombinant rat IL-5 in medium containing methylcellulose, the colony formation by eosinophilic cells was induced. Furthermore, when rat peritoneal eosinophils were incubated with recombinant rat IL-5, the spontaneous decrease in the eosinophil viability was inhibited in time- and concentration-dependent manners. In addition, the recombinant rat IL-5-induced eosinophil survival was inhibited by an anti-murine IL-5 neutralizing polyclonal antibody. These findings suggest that rat IL-5 acts as B-cell growth factor II (BCGF-II), eosinophil differentiation factor (EDF), and eosinophil survival-enhancing factor.

Participation of protein kinases in staurosporine-induced interleukin-6 production by rat peritoneal macrophages

The incubation of rat peritoneal macrophages in the presence of staurosporine, a non-specific protein kinase inhibitor, induced interleukin-6 (IL-6) production in a time- and concentration-dependent manner at 6.3-63 nM, but at 210 nM, the stimulant effect on IL-6 production was reduced. The levels of IL-6 mRNA as determined by a reverse transcription-polymerase chain reaction were also increased by staurosporine in parallel with the ability to induce IL-6 production. Compounds structurally related to staurosporine including K-252a (non-specific protein kinase inhibitor) and KT-5720 (inhibitor of cyclic AMP-dependent protein kinase, PKA), did not increase IL-6 production by peritoneal macrophages. Staurosporine-induced increases in IL-6 production and expression of IL-6 mRNA were decreased by the PKC inhibitors, H-7 (2.7-27 microM), Ro 31-8425 (1-10 microM) and calphostin C (0.3-3 microM) and by the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor LY294002 (30-100 microM), but were further increased by the protein tyrosine kinase (PTK) inhibitor, genistein (12-37 microM). The staurosporine-induced increase in IL-6 production was not affected by the PKA inhibitor, H-89 (0.1-3 microM). These findings suggest that the induction of IL-6 production by staurosporine is secondary to elevation of IL-6 mRNA level, which, in turn, is positively regulated by the activation of PKC and PI 3-kinase and negatively regulated by the activation of PTK. PKA does not appear to play a significant role.

Possible participation of intracellular platelet-activating factor in tumor necrosis factor-alpha production by rat peritoneal macrophages

Stimulation of rat peritoneal macrophages by thapsigargin (46.1 nM) increased levels of tumor necrosis factor-alpha and prostaglandin E2 in the conditioned medium. Platelet-activating factor (PAF) was not detected in the conditioned medium, but the level of cell-associated PAF was increased transiently by thapsigargin. The PAF receptor antagonists such as E6123 ((S)-(+)-6-(2-chlorophenyl)-3-cyclopro-panecarbonyl-8,11-dim ethyl-2,3,4,5-tetrahydro-8 H-pyrido[4',3':4,5]thieno [3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine), L-652,73 1 (2,5-bis(3,4,5-trimethoxyphenyl) tetrahydrofuran) and CV-6209 (2-[N-acetyl-N-(2-methoxy-3-octadecyl-carbamoyloxy propoxycarbonyl)aminomethyl]-1-ethylpyridinium chloride) inhibited thapsigargin-induced production of tumor necrosis factor-alpha. The cyclooxygenase inhibitor indomethacin inhibited prostaglandin E2 production, and further enhanced thapsigargin-induced tumor necrosis factor-alpha production in parallel with further increase in cell-associated PAF production. The enhancement of tumor necrosis factor-alpha production induced by thapsigargin plus indomethacin was also inhibited by E6123, L-652,731 and CV-6209. However, exogenously added PAF up to 100 nM did not stimulate production of tumor necrosis factor-alpha. The level of tumor necrosis factor-alpha mRNA was increased by thapsigargin, but was lowered by the PAF receptor antagonist E6123, suggesting that the inhibition of tumor necrosis factor-alpha production by the PAF receptor antagonist is induced at the level of mRNA for tumor necrosis factor-alpha. These findings suggested that concurrently produced cell-associated PAF in thapsigargin-stimulated macrophages up-regulates production of tumor necrosis factor-alpha by acting as an intracellular signaling molecule and the PAF receptor antagonists might penetrate into the cells and antagonize the action of intracellular PAF.

Inhibition by tectorigenin and tectoridin of prostaglandin E2 production and cyclooxygenase-2 induction in rat peritoneal macrophages

Tectorigenin and tectoridin, isolated from the rhizomes of Korean Belamcanda chinensis (Iridaceae) which are used as Chinese traditional medicine for the treatment of inflammation, suppressed prostaglandin E2 production by rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), or the endomembrane Ca2+-ATPase inhibitor, thapsigargin. Tectorigenin inhibited prostaglandin E2 production more potently than tectoridin. Neither compound inhibited the release of radioactivity from [3H]arachidonic acid-labeled macrophages stimulated by TPA or thapsigargin. In addition, activities of isolated cyclooxygenase (COX)-1 and COX-2 were not inhibited by the two compounds. Western blot analysis revealed that the induction of COX-2 by TPA or thapsigargin was inhibited by the two compounds in parallel with the inhibition of prostaglandin E2 production. These findings suggest that one of the mechanisms of the anti-inflammatory activities of the rhizomes of Belamcanda chinensis is the inhibition of prostaglandin E2 production by tectorigenin and tectoridin due to the inhibition of the induction of COX-2 in the inflammatory cells.

Involvement of p38 MAPK and ERK/MAPK pathways in staurosporine-induced production of macrophage inflammatory protein-2 in rat peritoneal neutrophils

Stimulation of rat peritoneal neutrophils with staurosporine (64 nM) induced production of macrophage inflammatory protein-2 (MIP-2) and phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase/MAP kinase (ERK/MAPK). The staurosporine-induced MIP-2 production at 4 h was inhibited by the highly specific p38 MAPK inhibitor SB 203580 and the MAPK/ERK kinase (MEK-1) inhibitor PD 98059 in a concentration-dependent manner. By treatment with SB 203580 (1 microM) or PD 98059 (50 microM), the staurosporine-induced increase in the levels of mRNA for MIP-2 was only partially lowered, although the staurosporine-induced MIP-2 production was completely inhibited. Consistent with the inhibition by the protein synthesis inhibitor cycloheximide, SB 203580 and PD 98059 inhibited MIP-2 production at 4 h either when added simultaneously with staurosporine or 2 h after stimulation with staurosporine. In contrast, the DNA-dependent RNA polymerase inhibitor actinomycin D did not inhibit MIP-2 production at 4 h when it was added 2 h after staurosporine stimulation. Dot blot analysis demonstrated that treatment with SB 203580 or PD 98059 down-regulates the stability of MIP-2 mRNA. These results suggested that p38 MAPK and ERK/MAPK pathways are involved in translation of MIP-2 mRNA to protein and stabilization of MIP-2 mRNA.

Inhibition by auranofin of the production of prostaglandin E2 and nitric oxide in rat peritoneal macrophages

In rat peritoneal macrophages, 12-O-tetradecanoylphorbol 13-acetate (TPA) (16.2 nM) stimulated production of both prostaglandin E2 and nitric oxide. TPA also increased the levels of mRNA for cyclooxygenase-2 and inducible nitric oxide synthase, suggesting that the increase in the production of prostaglandin E2 and nitric oxide is due to the increase in the levels of mRNA for cyclooxygenase-2 and inducible nitric oxide synthase, respectively. The TPA-induced increase in prostaglandin E2 production was partially inhibited by the inhibitor of nitric oxide synthase L-N(G)-monomethyl-L-arginine acetate (L-NMMA), and the TPA-induced increase in nitric oxide production was partially inhibited by the cyclooxygenase inhibitor indomethacin, suggesting that both the production of prostaglandin E2 and nitric oxide in TPA-stimulated macrophages is influenced by each other. The orally active chrysotherapeutic agent auranofin, at 3 and 10 microM, inhibited the TPA-stimulated production of prostaglandin E2 and nitric oxide, and suppressed the TPA-induced increase in the levels of mRNA for cyclooxygenase-2 and inducible nitric oxide synthase. These findings indicate that the inhibition by auranofin of the TPA-stimulated production of prostaglandin E2 and nitric oxide is due to the decrease in the levels of mRNA for cyclooxygenase-2 and inducible nitric oxide synthase, respectively, and the interaction of the production between prostaglandin E2 and nitric oxide may partly be involved in the mechanism for the inhibition by auranofin of the production of both prostaglandin E2 and nitric oxide.

Pharmacological analysis of protein kinases responsible for chemotaxis of rat peritoneal neutrophils

Several types of kinase inhibitors were used to investigate the possible signaling pathways leading to the chemotaxis of rat peritoneal neutrophils toward macrophage inflammatory protein-2, cytokine-induced neutrophil chemoattractant-1, and platelet-activating factor. The chemotaxis and shape changes induced by each of these chemoattractants were strongly inhibited by a tyrosine kinase inhibitor (herbimycin A) and protein kinase C inhibitors (H-7 (1-(5-isoquinolinesulphonyl)-2-methylpiperazine dihydrochloride) and calphostin C). The formation of phosphatidyl 3,4,5-triphosphate in chemoattractant-stimulated neutrophils was completely inhibited by 100 nM of wortmannin, an inhibitor of phosphatidylinositol 3-kinase, whereas the chemotaxis toward each of these chemoattractants was partially inhibited (50% inhibition). The mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK-1) inhibitor PD 98059 did not inhibit the neutrophil chemotaxis. These findings suggest that the activation of tyrosine kinase and protein kinase C strongly participates in neutrophil chemotaxis and that the activation of phosphatidylinositol 3-kinase is partially involved, but that the activation of mitogen-activated protein kinase is not involved in neutrophil chemotaxis. The cross-linking of the signaling pathways for chemotaxis toward each chemoattractant was also examined.

Inhibition by dexamethasone of antigen-induced c-Jun N-terminal kinase activation in rat basophilic leukemia cells

Antigen stimulation of IgE-sensitized rat basophilic leukemia RBL-2H3 cells induced activation of c-Jun N-terminal kinase (JNK) within a few minutes with maximum activity attained 40 min later. The increase in JNK activity was accompanied with an increase in phosphorylation of c-Jun in the cells. The Ag-induced JNK activation was inhibited by the phosphatidylinositol 3-kinase inhibitors wortmannin (10-100 nM) and LY 294002 (100 microM) but not by the protein kinase C inhibitors calphostin C (1 and 3 microM) and Ro 31-8425 (1 and 3 microM). Pretreatment with dexamethasone (10 and 100 nM) for 18 h inhibited the Ag-induced increase in JNK activity in a concentration-dependent manner. At least 6 h of preincubation with dexamethasone was necessary to inhibit the Ag-induced JNK activation. The phosphorylation of c-Jun induced by the Ag stimulation was reduced by pretreatment with dexamethasone without reduction of the content of c-Jun protein. The Ag-induced activation of the JNK kinase kinase mitogen-activated protein kinase-extracellular signal-regulated kinase kinase-1 was also inhibited by pretreatment with dexamethasone at 10 and 100 nM. These findings indicate that dexamethasone reduces JNK protein level and inhibits the Ag-induced activation of JNK resulting in the inhibition of c-Jun phosphorylation.

Increase in histamine production by inflammatory exudate in the chronic phase of allergic inflammation in rats

In the air pouch-type allergic inflammation in rats, we reported that a sustained histamine production in the late phase is induced by a cytokine-like factor, named histamine-production-increasing factor (HPIF) (1). Recently, we found another type of histamine-production-increasing factor in the pouch fluid at the chronic phase of air pouch-type allergic inflammation. Although it did not increase histamine production by itself, it enhanced the HPIF-induced histamine production by rat bone marrow cells. It also increased GM-CSF-induced histamine production. The activity of this factor increased time-dependently from 3 to 7 days after the antigen challenge. Injection of the 5 day pouch fluid sample containing this factor into the pouch 4 h after the antigen challenge increased histamine contents in the pouch fluid at 24 h, indicating that this factor enhances HPIF-induced histamine production in vivo. Biochemical analysis of the 5 day pouch fluid sample indicated that this factor is a heat-labile and trypsin-sensitive protein of which pI value and molecular weight are 7-8 and about 100 kDa, respectively.

Expression of adhesion molecules in cultured human nasal mucosal microvascular endothelial cells activated by interleukin-1 beta or tumor necrosis factor-alpha: effects of dexamethasone

Adhesion molecules of microvascular endothelial cells play a key role in the inflammatory processes involved in nonallergic sinusitis. We investigated the cytokine-regulated expression of intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1 (VCAM-1), and the effect of dexamethasone on these expressions in cultured human nasal microvascular endothelial cells (HNMEC). ICAM-1 was enhanced, and E-selectin and VCAM-1 were induced in a dose-dependent fashion following stimulation with IL-1beta or TNF-alpha. HNMEC differed from human umbilical vein endothelila cells in that (1) maximal upregulation of ICAM-1 expression induced by IL-1beta or TNF-alpha required more time (2) TNF-alpha was more potent than IL-1beta in VCAM-1 expression, and (3) dexamethasone inhibited the upregulation of E-selectin expression alone. These findings contribute to a better understanding of the characteristic features of leukocyte infiltration into inflamed tissue and the effect of glucocorticoid in nonallergic chronic sinusitis.

Identification of cDNA for rat homologues of human major basic protein and eosinophil cationic protein

We have determined the complete nucleotide sequence for cDNA of rat homologues of human eosinophil major basic protein (MBP) and eosinophil cationic protein (ECP) using the rapid amplification of cDNA ends (RACE) procedure. Nucleotide sequence of cDNA of rat MBP revealed that mRNA of rat MBP encodes a protein containing 227 amino acids which has three functional domains; namely, the signal peptide, the acidic peptide that contains numerous acidic amino acids and the mature MBP, as in human, guinea pig and mouse MBP. In addition, cDNA of a rat homologue of human ECP was also cloned. The deduced amino acid sequence revealed that this gene encodes a putative protein with a molecular weight of 15.5 kD which has ribonuclease activity. The homology of amino acid sequence between the rat homologue and the murine eosinophil-associated ribonucleases (EARs) was high (65%). Therefore, we named this rat homologue 'rat EAR-1'.

Effects of glucocorticoids on apoptosis of infiltrated eosinophils and neutrophils in rats

The effects of glucocorticoids on the survival of rat eosinophils and neutrophils infiltrated into the peritoneal cavity were examined. Glucocorticoids including dexamethasone, prednisolone and hydrocortisone inhibited the survival of rat peritoneal eosinophils at 10(-6) M, whereas they prolonged survival of rat peritoneal neutrophils at 10(-8) M. Sex steroids including estradiol and progesterone did not affect cell survival. Dexamethasone decreased the viability of eosinophils after 3 days of incubation and maintained the viability of neutrophils until 4 days after incubation concentration dependently. The EC50 of dexamethasone for inhibition of the survival of eosinophils was 1.5 x 10(-8) M, and that for the spontaneous death of neutrophils was 6.4 x 10(-10) M, suggesting that glucocorticoids at concentrations that inhibit eosinophil survival prolong neutrophil survival. Analysis of DNA fragmentation of cultured eosinophils and neutrophils revealed that glucocorticoids enhance eosinophil apoptosis but inhibit neutrophil apoptosis. The effects of dexamethasone on viability and DNA fragmentation were counteracted by the glucocorticoid receptor antagonist, mifepristone, concentration dependently. These findings indicate that glucocorticoids induce contradictory effects via the glucocorticoid receptor on rat eosinophils and neutrophils extravasated to an inflammatory locus such as the peritoneal cavity by modulating apoptosis.

Identification of histamine-production-increasing factor produced by stimulated RBL-2H3 rat basophilic leukemia cells as granulocyte-macrophage colony-stimulating factor

When RBL-2H3 rat basophilic leukemia cells were stimulated by antigen or the Ca2+ ionophore A23187, the activity to increase histamine production by rat bone marrow cells in the conditioned medium increased time-dependently. To characterize the histamine-production-increasing factor (HPIF) produced by RBL-2H3 cells, the conditioned medium was collected 8 h after stimulation by A23187, and the factor was purified by three-step chromatography, the specific activity being increased by 9000-fold. The partial amino acid sequence of the peptide obtained by S. aureus V8 protease digestion was identical to the internal amino acid sequence of rat granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition, GM-CSF mRNA levels in RBL-2H3 cells were increased by A23187 with a peak at 4 h. Furthermore, recombinant rat GM-CSF increased histamine production by rat bone marrow cells. These findings suggested that HPIF produced by the stimulated RBL-2H3 cells is GM-CSF. Possible significant roles of HPIF at the late phase of allergic inflammation are discussed.

Inhibition of tumor necrosis factor-alpha production by SK&F 98625, a CoA-independent transacylase inhibitor, in cultured rat peritoneal macrophages

When rat peritoneal macrophages were incubated in medium containing thapsigargin, tumor necrosis factor-alpha (TNF-alpha) production was increased time-dependently. In the presence of SK&F 98625, a CoA-independent transacylase inhibitor, the thapsigargin-induced TNF-alpha production was inhibited dose-dependently. Platelet-activating factor (PAF) and prostaglandin E2 (PGE2) production were also inhibited by SK&F 98625. The SK&F 98625-induced inhibition of TNF-alpha production was not prevented by addition of PGE2. PAF antagonists such as E6123, L-652,731 and CV-6209 partially inhibited the thapsigargin-induced TNF-alpha production, suggesting that concurrently produced PAF in thapsigargin-stimulated macrophages up-regulates TNF-alpha production. The inhibition by SK&F 98625 of thapsigargin-induced TNF-alpha production might be partly due to the inhibition of PAF production.

Analysis of the expression of intercellular adhesion molecule-1 in cells of the human bronchial epithelial cell line NCI-H292

The mechanism of the expression of intercellular adhesion molecule-1 (ICAM-1) on epithelial cells was analyzed using NCI-H292 cells, a human bronchial epithelial cell line. Treatment with interferon-gamma (100 U/ml) or the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA) (16.2 nM) induced ICAM-1 expression. The interferon-gamma-induced ICAM-1 expression was reduced by the tyrosine kinase inhibitor genistein (4',5,7-trihydroxyisoflavone) (37 to 185 microM), but not by the protein kinase C inhibitor Ro 31-8425 ((3-[8-(aminomethyl)-6,7,8,9-tetrahydropyrido [1.2-a]indol-10-yl]-4-(1-methyl-1 H-pyrrole-2,3-dione) (10 microM). The TPA-induced ICAM-1 expression was reduced by the protein kinase C inhibitor Ro 31-8425 (1 to 10 microM), but not by the tyrosine kinase inhibitor genistein (185 microM). The protein kinase A inhibitor H-89 (N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide) did not affect the ICAM-1 expression induced by interferon-gamma or TPA. Pyrrolidine dithiocarbamate (1-pyrrolidinecarbodithioic acid) (100 microM), an inhibitor of nuclear factor kappaB (NF-kappaB) activation. enhanced the ICAM-1 expression induced by interferon-y, but reduced that induced by TPA. The changes in ICAM-1 expression on the cell surface were correlated with the changes in ICAM-1 mRNA levels. Combined treatment with interferon-gamma and TPA induced more than additive ICAM-1 expression. These findings suggest that interferon-gamma induces ICAM-1 expression by a tyrosine kinase-dependent mechanism, but that TPA induces it by a protein kinase C- and NF-kappaB-dependent mechanism.

Effects of JTE-522, a specific inhibitor of cyclooxygenase-2, on the recurrence of allergic inflammation in rats

JTE-522, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide , is a selective inhibitor of cyclooxygenase-2 at the enzyme level (IC50 is 6.4 x 10(-7) M for sheep cyclooxygenase-2, but it does not inhibit sheep cyclooxygenase-1 at concentrations up to 10(-4) M). In rat peritoneal macrophages in culture, it markedly inhibited cyclooxygenase-2-dependent prostaglandin E2 production and weakly inhibited cyclooxygenase-1-dependent prostaglandin E2 production, as did the selective cyclooxygenase-2 inhibitor NS-398 ([N-2(cyclohexyloxy-4-nitrophenyl)]-methanesulfonamide). In addition, the anti-inflammatory activity of JTE-522 was evaluated, using a model of recurrent air pouch-type allergic inflammation in rats. JTE-522, injected into the pouch just after a second antigen challenge, suppressed the accumulation of pouch fluid, the infiltration of leukocytes and the prostaglandin E2 content in the pouch fluid, as did NS-398 and indomethacin. These findings indicated that JTE-522 is a selective cyclooxygenase-2 inhibitor in cell culture systems and that the suppression by JTE-522 of the recurrence of allergic inflammation is due to the inhibition of cyclooxygenase-2.