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Biomedical subjects

M Miyasaka

Publications and source records attributed to M Miyasaka.

At least 73 records · Page 4Linked to original sources
PubMed1998

Human eotaxin induces alpha 4 and beta 2 integrin-dependent eosinophil accumulation in rat skin in vivo: delayed generation of eotaxin in response to IL-4.

The CC chemokine eotaxin, originally purified from bronchoalveolar lavage fluid of sensitized guinea pigs following allergen challenge, is a potent eosinophil-selective chemoattractant. In the present study, we have used (111)In-eosinophils and human eotaxin to characterize the profile of chemokine-induced eosinophil accumulation in vivo in rat skin. Intradermally injected eotaxin caused a dose-dependent accumulation of (111)In-eosinophils. Time course studies indicated that the response was rapid, since all the accumulation occurred within the first 1 to 2 h of eotaxin injection. The i.v. administration of anti-intercellular adhesion molecule-1, anti-vascular cell adhesion molecule-1, or anti-alpha4 integrin mAbs significantly inhibited the eosinophil accumulation induced by 100 pmol of human eotaxin by 73, 43, and 67%, respectively. Further, when (111)In-eosinophils were pretreated in vitro with anti-alpha4 integrin or anti-beta2 integrin mAbs, or with a combination of both mAbs, eotaxin-induced responses in vivo were reduced by 52, 49, and 68%, respectively. Eosinophil accumulation induced by intradermal IL-4, but not that induced by TNF-alpha or leukotriene B4, appeared to be mediated in part by endogenously generated eotaxin. Anti-eotaxin Abs significantly inhibited (54%) the later phases (24-28 h) but not the early phase (0-4 h) of the response to IL-4. This was consistent with eotaxin mRNA expression peaking at 18 h after IL-4 injection. Our findings show that human eotaxin is a potent inducer of eosinophil accumulation in vivo, this response being dependent on alpha4 integrin/vascular cell adhesion molecule-1 and beta2 integrin/intercellular adhesion molecule-1 adhesion pathways. Further, the eosinophil accumulation in response to IL-4 is partly mediated by endogenously generated eotaxin.

Animals↗
PubMed1998

Cloning and characterization of the rat MAdCAM-1 cDNA and gene.

A cDNA clone for rat MAdCAM-1 homologue was isolated from mesenteric lymph nodes by RT-PCR using primers prepared from the exon sequences of the gene isolated from a genomic library of the WKAH rat, using mouse cDNA as a probe. A 1279 bp cDNA fragment contained an open reading frame (ORF) for a protein of 394 amino acids. Homology of nucleotide sequences between the mouse and rat MAdCAM-1 ORF was 85.1% with an amino acid identity of 80.5%. The rat MAdCAM-1 had two immunoglobulin-like domains, a mucinlike domain and the third immunoglobulin-like domain with a homology to alpha 3 domain of the rat MHC class I molecule. Northern blot analysis demonstrated transcripts in Peyer's patches and mesenteric lymph nodes but not in spleen. Organization of the gene in the rat was similar to that in the mouse, consisting of 5 exons located at about a 4 kbp genomic region.

Amino Acid Sequence↗
PubMed1998

Glomerular injury induced by cationic 70-kD staphylococcal protein; specific immune response is not involved in early phase in rats.

A highly cationic staphylococal protein (designated p70, MW 70 kD, pI > 10) belongs to the groups of bacterial proteins that can bind immunoglobulin without specific antigen-antibody recognition; heparin inhibition tests indicated a charge interaction. This study evaluated the nephritogenicity of p70, which has affinity for the glomerular basement membrane (GBM), and the influence of various mediator systems on the induction of glomerulonephritis by p70. The left kidneys of intact rats, rats given cobra venom factor (complement-depleted), or rats given anti-adhesion molecules (ICAM-1 and LFA-1a) were perfused with p70. Proteinuria started within 24 h and persisted at day 5. Intraglomerular infiltration of cells was seen as early as 15 min, peaking at day 1. Deposits of rat IgG and C3 were seen in a subendothelial location 15 min after p70 perfusion in the left kidney and were found in a predominantly subepithelial location from 1 day onwards. Complement depletion and blockade of adhesion molecules suppressed proteinuria from day 2 onwards; these manipulations also prevented the recruitment of infiltrating cells and partially hindered the transfer of IgG across the GBM and the accumulation of IgG in the subepithelial region. In the non-perfused right kidneys, deposits of IgG and C3 were comparable to those in the left kidneys, suggesting that p70-IgG complexes formed in the circulation may also contribute to the deposits in the GBM. Heparin inhibition tests indicated an electrostatic interaction between p70 and immunoglobulin. Complement and inflammatory mediator systems (granulocytes, monocytes/macrophages, and/or lymphocytes) were required to provoke glomerular injury. p70 might play a role in acute glomerulonephritis following Staphylococcus aureus infection.

Animals↗
PubMed1998

Sulfatide protects rat skin flaps against ischemia-reperfusion injury.

Monoclonal antibodies to adhesion molecules have been used in many trials to prevent ischemia-reperfusion injury. Sulfatide reacts strongly with P- and L-selectin, which play an important role in the initiation of neutrophil-endothelial interactions occurring in injured or inflamed tissues. The purpose of this study was to evaluate the effect of sulfatide on ischemia-reperfusion injury of the rat skin flap. Sulfatide was administered intravenously just before elevation of the right abdominal epigastric flap. The femoral artery and vein were clamped above and below the epigastric vessels for 10 or 11 h and then the clamp was released. Administration of sulfatide augmented significantly the flap area surviving in the 10-h ischemic model (7.18 +/- 0.47 cm2 versus control 5.15 +/- 0.39 cm2. P = 0.01). In the 11-h ischemic model the area was 4.59 +/- 0. 36 cm2 versus control 1.73 +/- 0.31 cm2 (P = 0.001). The ATP levels in the flap gradually increased after release of the clamp in the rat administered sulfatide, and the increase was significant at 48 h (P = 0.006). Histological examination 48 h after surgery showed greater leukocyte invasion into the control flap than into the flap of the rat administered sulfatide. Myeloperoxidase activity was significantly reduced 48 h after reperfusion in the 11-h ischemic model. This study indicates that sulfatide has a significant protective effect against ischemia and reperfusion in rat epigastric flaps.

Adenosine Triphosphate↗
PubMed1998

Cytokine and adhesion molecule requirements for neutrophil recruitment during glycogen-induced peritonitis.

OBJECTIVE: Requirements for cytokines and adhesion molecules for peritoneal neutrophil recruitment during glycogen-induced peritonitis in rats were systematically defined. SUBJECTS: Male Long Evans rats (275-300 g). METHODS: Four hours after intraperitoneal injection of 25 mg oyster glycogen, neutrophilic exudates were harvested. Effects of blocking reagents (injected intravenously) to rat E-, L- and P-selectins, beta1 (VLA-4) and beta2 integrins (LFA-1 and Mac-1), ICAM-1, and the cytokines TNFalpha, IL- and IL-8 were assessed. RESULTS: Administration of synthetic sialyl Lewis(x) oligosaccharide reduced neutrophil recruitment to the peritoneum by 26%. Antibody to E-selectin reduced neutrophil accumulation by 71%, while anti-L-selectin reduced neutrophil accumulation by 59%, and anti-P-selectin was without an effect. Similar patterns of inhibition were found when selectin-Ig chimeras were employed. Antibodies to LFA-1 (CD11a), Mac-1 (CD11b) or CD18 reduced neutrophil accumulation by 62 percent, 59 percent and 86%, respectively, while anti-VLA-4 was without effect. Anti-ICAM-1 reduced cell influx by 65%. IL-1 receptor antagonist and antibodies to IL-1 and human IL-8 reduced neutrophil accumulation by 43alpha, 40% and 62 percent, respectively. Unexpectedly, blockade of TNFalpha had no effect. CONCLUSIONS: These studies identify requirements for selectins, beta2 integrins, IL-1 and a rat chemokine(s) similar to human IL-8 for neutrophil recruitment during glycogen-induced peritonitis. The lack of participation of VLA-4, P-selectin and TNFalpha suggests organ-specific cytokine and adhesion molecule requirements for neutrophil recruitment.

Animals↗
PubMed1998

Protection of islet allografts transplanted together with Fas ligand expressing testicular allografts.

Fas ligand (FasL) is highly expressed in testicular tissues and thought to be responsible for protection from allograft rejection by inducing apoptosis of anti-graft activated T cells. FasL-expressing islets have been shown to induce a granulocyte-mediated inflammatory reaction. We investigated whether a graft can be protected from alloimmune responses by manipulating the Fas/FasL-system. We transplanted allogeneic islets under the kidney capsule of streptozotocin-induced diabetic mice together with testicular tissue. Significant prolongation of survival of C3H islet allograft was observed in C57BL/6 (B6) recipients transplanted with C3H testicular tissue, but not in those transplanted with C3H-gld testicular tissue expressing non-functional FasL. No significant prolongation was observed in B6-lpr recipients expressing non-functional Fas. Immunohistochemical staining of C3H testicular tissue in the composite graft showed a high expression of FasL, but not that of the C3H-gld testicular tissue. In situ terminal deoxynucleotidyl transferase-mediated dUDP-biotin catalysed DNA nick-end labelling (TUNEL) staining of a composite graft of C3H islet and testicular tissue in B6 recipients demonstrated extensive apoptosis of infiltrating mononuclear cells around the graft. The protective effect of C3H testicular tissue was abrogated when anti-FasL monoclonal antibody was administered i.p. postoperatively. Our results suggest that FasL-positive testicular allografts protect composite islet allografts and indicate that manipulation of Fas/FasL mediated apoptosis is a suitable strategy for controlling rejection of islet allografts.

Animals↗
PubMed1998

Transplantation tolerance by a combined therapy with sulfatide, anti-LFA-1/ICAM-1 monoclonal antibodies and FK506 in rat cardiac transplantation.

Selectins promote a rolling phenomenon of leukocytes along activated endothelial surfaces, which is the first step in the events that ultimately lead to leukocyte transmigration at acute inflammatory sites. Our previous study revealed that sulfatide, which is one of the selectin inhibitors, prolonged graft survival in rat cardiac allografts. In the present study, to obtain a longer graft acceptance, we examined a combination treatment of sulfatide, monoclonal antibodies (mAbs) against LFA-1/ICAM-1, and FK506 in a Fischer 344 (F344, RT1lvl) to Lewis (LEW, RT1l) rat heart transplantation. FK506 alone (n = 6) and FK506/sulfatide-treated LEW rats (n = 6) rejected F344 heart grafts with an MST of 49 and 55.2 days, respectively. Otherwise, four out of six heart grafts treated with sulfatide, mAbs against LFA-1/ICAM-1, and FK506 (n = 6) survived for over 100 days after transplantation. The proliferative response of alloreactive T cells obtained from tolerant rats against both F344 alloantigen and third-party alloantigen on day 104 postgrafting was significantly suppressed as compared to that from naive LEW rats. On light microscopic examination, specimens of tolerant rat on day 104 postgrafting showed an almost normal appearance. Our results suggested that blocking both each step of leukocyte entry and recognition of alloantigens by a combination treatment of sulfatide, mAbs against LFA-1/ICAM-1, and FK506 could lead to tolerance.

Animals↗
PubMed1998

Cell-to-cell interaction is required to induce proteinuria in in situ immune complex glomerulonephritis.

This experiment was performed to study the roles of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), and another adhesion molecule, selectin, in the development of cationized antigen-induced in situ immune complex glomerulonephritis (CAICGN). CAICGN was induced in preimmunized rats by perfusing cationized human immunoglobulin G (CaIgG) through the left kidney. Albuminuria developed within 2 days of CaIgG perfusion and peaked around day 7. Marked polymorphonuclear leukocyte (PMN) infiltration was observed in the glomeruli 1 hour after CaIgG perfusion, but the infiltrate resolved by day 7. Immunofluorescent studies disclosed linear deposition of rat IgG and C3 along glomerular capillary walls 1 hour after CaIgG perfusion. Treatment with monoclonal antibodies (mAbs) to both ICAM-1 and LFA-1, as well as with a sulfatide, a ligand of L- and P-selectin, started within 2 days after CaIgG perfusion completely suppressed the development of proteinuria without affecting the glomerular deposition of immunoreactants. Although sulfatide attenuated the PMN response 1 hour after CaIgG perfusion, ICAM-1 and LFA-1 mAb treatment did not alter PMN infiltration. Treatment with ICAM-1 and LFA-1 mAbs started on day 5, or treatment with sulfatide started on day 4, after CaIgG perfusion did not affect albuminuria. These findings suggest that adhesion molecules play an important role in the development of proteinuria in CAICGN. The contribution of these molecules was evident for only a short interval after the induction of nephritis, when a significant infiltration of PMNs was observed.

Albuminuria↗
PubMed1998

Cytokine and adhesion molecule requirements for lung injury induced by anti-glomerular basement membrane antibody.

Acute hemorrhagic lung injury occurs in humans with anti-GBM antibody (Goodpasture's syndrome), however, the mechanism of this injury is still largely unknown. To date, treatment has been confined to steroids and plasmaphoresis. Infusion of anti-GBM antibody into rats caused lung injury with intra-alveolar hemorrhage and intrapulmonary accumulation of neutrophils. Lung injury was dependent on the presence of neutrophils and complement and required both TNF alpha and IL-1. Experiments employing blocking antibodies to adhesion molecules demonstrated requirements for the beta 1 integrin VLA-4, beta 2 integrins LFA-1 and Mac-1, and L-selection. The endothelial cell adhesion molecules, E-selectin and ICAM-1, were also required for the full development of lung injury. Inhibition of TNF alpha or IL-1 or adhesion molecules reduced both lung injury and tissue neutrophil accumulation. Thus, this study underscores cytokine and adhesion molecule requirements for neutrophil mediated injury in lung and kidney caused by anti-GBM, suggesting potential targets for the treatment of Goodpasture's syndrome in humans.

Animals↗
PubMed1998

Therapeutic effects of prostacyclin analog on crescentic glomerulonephritis of rat.

Prostacyclin (PGI2) is known to have a relaxative action on vascular smooth muscle, an inhibitory action against platelet activation and neutrophil function. Previous studies showed the preventive effects of PGI2 on lupus nephritis and Thy-1 nephritis, although the mechanism has not been clarified. Glomerular endothelial expression of intercellular adhesion molecule-1 (ICAM-1) is up-regulated in experimental and human glomerular diseases, and is known to facilitate leukocyte infiltration into the glomeruli, which ultimately induces the various glomerular injuries. In the present study, we evaluated the therapeutic effects of PGI2 on a rat model for crescentic glomerulonephritis and investigated its putative mechanism in relation to ICAM-1-mediated leukocyte recruitment. Wistar-Kyoto (WKY) rats were injected with nephrotoxic serum and received continuous intraperitoneal infusion of PGI2. PGI2 dramatically decreased proteinuria (123.0 +/- 18.8 vs. 31.6 +/- 4.5), crescent formation and deposition of fibrinogen in the glomeruli, while the deposition of rabbit IgG, rat IgG and rat C3 along the capillary walls was not changed. Furthermore, intraglomerular expression of ICAM-1 and infiltration of macrophages were significantly suppressed by administration with PGI2. In contrast, influx of CD4 or CD8 positive cells was not altered. The present results suggest that PGI2 shows the preventive effects on experimental crescentic glomerulonephritis by inhibiting intraglomerular coagulation and ICAM-1-mediated macrophage-glomerular endothelial cell adhesive pathway.

Animals↗
PubMed1998

In vitro and in vivo selectin-blocking activities of sulfated lipids and sulfated sialyl compounds.

There is accumulating evidence that sulfated lipids, sulfated oligosaccharides and other sulfated compounds are reactive with selectins in a manner that interferes with selectin interactions with their natural ligands. In the report we describe the ability of sulfated lipids (sulfatides and gangliosides) and multimeric forms of sulfated sialic acid to block binding of P- and E-selectin-Ig to neutrophils. The in vivo ability of these compounds to block lung injury in rats following i.v. infusion of purified cobra venom factor (CVF), which induces injury that is L- and P-selectin dependent, was also determined as well as effects on recruitment of neutrophils, as measured by lung myeloperoxidase. There was a significant correlation between the ability of sulfated lipids and sialyl compounds to interfere in vitro with P-selectin-Ig binding to neutrophils and to protect against P-selectin-dependent acute lung injury induced by CVF. The biological effects of these sulfated compounds were also associated with diminished accumulation of neutrophils. The protective effects of these compounds may be linked to their ability to interfere with P-selectin binding to counter-receptors on neutrophils.

Animals↗
PubMed1998

A functional epitope on P-selectin that supports binding of P-selectin to P-selectin glycoprotein ligand-1 but not to sialyl Lewis X oligosaccharides.

P-selectin mediates the adhesion of leukocytes to activated platelets and endothelial cells. To characterize the functional domains of P-selectin for ligand recognition, we established nine hybridoma cell lines secreting anti-rat P-selectin mAb. Among them, the mAb C215 bound both rat and human P-selectins, and inhibited binding of rat and human P-selectins to P-selectin glycoprotein ligand-1 (PSGL-1) from HL-60 cells. In contrast, mAb C215 failed to inhibit the binding of rat and human P-selectin-IgG to sialyl Lewis X (sLe(x)) oligosaccharides. Epitope mapping of mAb C215 using synthetic decapeptides revealed that mAb C215 binds specifically to an eight-residue epitope that spans amino acids 76-83 of rat P-selectin, a region completely conserved by human P-selectin. Synthetic peptides containing the mAb C215 epitope inhibited binding of P-selectin to PSGL-1, but not to sLe(x) oligosaccharides, suggesting that the C215 epitope on P-selectin may directly interact with a particular site on the PSGL-1 core protein essential for interaction with P-selectin, such as sulfated tyrosine residues. Our results suggest the presence of two ligand recognition sites on P-selectin necessary for binding to PSGL-1--one recognizes sLe(x), while the other recognises the PSGL-1 core protein.

Amino Acid Sequence↗
PubMed1998

Intracellular Signal-transducing elements involved in transendothelial migration of lymphoma cells.

To investigate the molecular mechanisms underlying transendothelial migration of tumor cells, an essential process for their hematogenous dissemination, we developed an in vitro model system that allows the separate monitoring of cell adhesion and transmigration processes. This system uses a human pre-B lymphoma cell line, Nalm-6, and a cultured mouse endothelial cell line, KOP2.16. Nalm-6 cells rapidly adhered to KOP2.16 and subsequently transmigrated underneath them. Using this model, we examined the effects on transendothelial migration, of various reagents which specifically interfere with the function of intracellular signal transduction molecules. Treatment of Nalm-6 cells with wortmannin (WMN), herbimycin A, pertussis toxin, or C3 exoenzyme of Clostridium botulinum, which specifically inhibit P13 kinase and/or myosin light chain kinase, herbimycin-sensitive tyrosine kinases, heterotrimeric G proteins, and the small G proteins, and the small G proteins rho/rac, respectively, reduced transmigration in a dose-dependent manner, Pretreatment of KOP2.16 endothelial cells with WMN also reduced transmigration in a dose-dependent manner. Binding of Nalm-6 binding to KOp2.16 was not affected, even when Nalm-6 or KOP2.16 cells were pretreated with these inhibitors, indicating that the reduction of transmigration was not due to a reduction of Nalm-6 to KOP2.16. These results also indicate that the signal transduction pathway(s) involved in transmigration can be dissociated from that of adhesion. Our results support the notion that endothelial cells are not a passive barrier in lymphoma extravasation, but that they assist lymphoma cell extravasation.

Androstadienes↗
PubMed1998

Effects of the anti-ICAM-1 monoclonal antibody on dextran sodium sulphate-induced colitis in rats.

Increased expression of intercellular adhesion molecule-1 (ICAM-1) in the colon of inflammatory bowel disease (IBD) has been reported. We evaluated the effects of monoclonal antibodies to ICAM-1 on acute colitis induced by dextran sodium sulphate (DSS) in rats. Colitis was induced by feeding rats 3% DSS for 7 days. Anti-ICAM-1 antibody or vehicle alone was injected intraperitoneally in rats daily from day 0 to day 6. On day 7 the rats were killed and colitis was evaluated histologically. Prophylactic treatment with anti-ICAM-1 significantly attenuated colonic damage, neutrophil infiltration and the shortening of the colon in DSS colitis. Our findings demonstrate that ICAM-1 plays an important role in this model of inflammatory bowel disease. Although this study does not directly address the effect of anti-ICAM-1 therapy in IBD, our findings encourage experiments using therapies that target ICAM-1 in rats with already developed disease.

Animals↗
PubMed1998

Engraftment of human myelodysplastic syndrome derived cell line in transgenic severe combined immunodeficient (TG-SCID) mice expressing human GM-CSF and IL-3.

A transgenic SCID (TG-SCID) mouse expressing the human cytokines interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) has been generated with the aim of making a model system allowing the in vivo proliferation of human hematopoietic cells. Using TG-SCID mice expressing high levels (30-35 ng/ml in the serum) of human GM-CSF and IL-3, we attempted to engraft a human myeloid leukemia cell line, F-36P, derived from a myelodysplastic syndrome (MDS) patient. When F-36P cells were transferred intravenously into sublethally irradiated TG-SCID mice, extensive proliferation of F-36P cells was found 4-6 wk later. Successful engraftment, however, required the preadministration of a monoclonal antibody to mouse interleukin-2 receptor (IL-2R) beta chain, neutralizing NK activity. Surprisingly, all the transplanted TG-SCID mice engrafted with F-36P cells developed hind leg paralysis approximately 6 wk after transfer. Histological analysis demonstrated extensive invasion and formation of osteolytic lesions by the F-36P cells in the vertebrae. These data indicate that transgenic SCID mice expressing human IL-3 and GM-CSF provide a useful system for the study of human leukemia. In addition, NK cells appear to play an important role in rejection of human cells.

Animals↗
PubMed1998

Intercellular adhesion molecule 1 mediates mononuclear cell infiltration into rat glomeruli after renal ablation.

Mononuclear cells, primarily macrophages and lymphocytes, infiltrate the renal glomeruli and are involved in the progression of various glomerular diseases. Intercellular adhesion molecule 1 (ICAM-1) is expressed on the vascular endothelium and mediates the infiltration of leukocytes into the site of inflammation. Although the expression of ICAM-1 can be induced by the stimulation of inflammatory cytokine, ICAM-1 expression can also be induced by such nonimmune mechanisms as shear stress. Glomerular hyperfiltration is a major mechanism that contributes to the progression of the glomerular sclerosis that results from the loss of functioning nephrons. In the present study, we examined the role of ICAM-1 for mononuclear cell infiltration in the glomeruli of the five-sixth nephrectomized rat as a model of glomerular hyperfiltration. The fluorescence intensity score of the staining for ICAM-1 in the glomeruli of the five-sixth nephrectomized rats was significantly increased as compared with that in the control (sham-operated) rats at 1 week (1.51 +/- 0.15 vs. 0.61 +/- 0.13; p < 0.01) and 2 weeks (1.31 +/- 0.17 vs. 0.51 +/- 0.09; p < 0.01). The number of leukocytes present in the glomeruli was significantly increased in the five-sixth nephrectomized rats compared with control (sham-operated) rats at 1 week (3.44 +/- 0.16 vs. 0.99 +/- 0.08; p < 0.01) and 2 weeks (3.14 +/- 0.14 vs. 0.89 +/- 0.07; p < 0.01). Leukocytes mainly consisted of macrophages in the five-sixth nephrectomized rats at 1 week (2.39 +/- 0.19) and 2 weeks (1.46 +/- 0.11). Anti-ICAM-1 monoclonal antibody effectively prevented the infiltration of macrophages into the glomeruli following nephrectomy. These results indicate that glomerular hyperfiltration may be involved in the induction of the expression of ICAM-1 and the infiltration of macrophages into the renal glomeruli following glomerular injury.

Animals↗
PubMed1998

Vascular and non-vascular ligands for L-selectin.

Ligands for L-selectin are expressed not only on vascular endothelial cells but also in the extravascular tissues. In this article, we summarize the current understanding of the "vascular" ligands for L-selectin. We also describe identification of "non-vascular" ligands for L-selectin and discuss their possible biological significance.

Animals↗