Shin Yomogida

Juntendo University, Edo, Tōkyō, Japan

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Publications (24)53 Total impact

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    ABSTRACT: Glucosamine, a naturally occurring amino monosaccharide, is present in the connective and cartilage tissues as a component of glycosaminoglycans. Thus, glucosamine has been widely used to treat osteoarthritis, a joint disease characterized by cartilage degeneration, in humans. In addition, glucosamine is expected to exert an anti-inflammatory action, since glucosamine suppresses inflammatory cell activation. To further extend the anti-inflammatory actions of glucosamine, we investigated the effects of glucosamine on synovial cells, endothelial cells and intestinal epithelial cells using in vitro and in vivo systems. Firstly, glucosamine suppressed the IL-1β-induced activation of synovial cells in vitro. Furthermore, glucosamine administration repressed synovial cell hyperplasia, cartilage destruction and inflammatory cell infiltration in rat adjuvant arthritis. Secondary, glucosamine suppressed the TNF-α-induced activation of intestinal epithelial cell HT-29 in vitro. In addition, glucosamine administration improved the clinical symptoms, and colonic inflammation and tissue injury in dextran sulfate sodium-induced colitis in rats. Finally, glucosamine suppressed the TNF-α-induced activation of endothelial cells in vitro. Moreover, glucosamine administration repressed the formation of atherosclerotic lesion and infiltration of inflammatory cells into the lesion in spontaneously hyperlipidemic mice B6 KOR Aposhl. Together these observations support the idea that glucosamine can function as not only a chondroprotective agent but also an anti-inflammatory molecule in the body.
    Carbohydrate Polymers 03/2011; 84(2):825-830. DOI:10.1016/j.carbpol.2010.04.007 · 3.92 Impact Factor
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    ABSTRACT: To investigate the in vivo effect of glucosamine on articular cartilage in osteoarthritis (OA), we evaluated serum biomarkers such as CTX-II (type II collagen degradation) and CPII (type II collagen synthesis) as well as histopathological changes (Mankin score, toluidine blue staining of proteoglycans in an experimental OA model using rats. OA was surgically induced in the knee joint by anterior cruciate ligament transection (ACLT) in rats. Animals were divided into three groups: sham-operated group (Sham), ACLT group without GlcN administration (-GlcN) and ACLT group with oral administration of glucosamine hydrochloride (+GlcN; 1000mg/kg/day for 56days). ACLT induced macroscopic erosive changes on the surfaces of articular cartilage and histological damages such as increase of Mankin score. Of note, glucosamine administration substantially suppressed the macroscopic changes, although the effect on Mankin score was not significant. In addition, serum CTX-II levels were elevated in -GlcN group compared to that in Sham group after the operation. Of importance, the increase of CTX-II was significantly suppressed by GlcN administration. Moreover, serum CP-II levels were substantially increased in +GlcN group compared to those in Sham and -GlcN groups after the operation. GlcN has a potential to exert a chondroprotective action on OA by inhibiting type II collagen degradation and enhancing type II collagen synthesis in the articular cartilage.
    Life sciences 02/2010; 86(13-14):538-43. DOI:10.1016/j.lfs.2010.02.015 · 2.30 Impact Factor
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    ABSTRACT: Mammalian myeloid and epithelial cells express various peptide antibiotics (such as defensin and cathelicidin) that contribute to the innate host defense against invading microorganisms. Among these, guinea pig cathelicidin CAP11 (G1-I43) possesses potent antibacterial activities against Gram-positive and -negative bacteria, and also lipopolysaccharide-neutralizing activity. We previously revealed that the active region with antibacterial activity is localized at G1 to R18 of CAP11. In this study, to develop peptide derivatives with enhanced antimicrobial actions, we utilized the amphipathic 18-mer peptide (G1-R18) as a template. Anti-microbial activities of the peptides were assessed by alamarBlue assay (Escherichia coli, Staphylococcus aureus and Candida albicans) and colony formation assay (Porphyromonas gingivalis). Furthermore, the membrane-permeabilization activities were determined by using E. coli ML-35p as a target. By substituting K5, T9, R10, R12, and G17 with five L residues, the hydrophobicity of the peptide (1-18m1) was increased, and by substituting G1, and Q14 with K and R residues, respectively, the hydrophilicity (positive charge) of the peptide (1-18m2) was enhanced. Among the peptides, 1-18m2 exhibits the most potent antimicrobial and membrane-permeabilizing activities against the microorganisms examined. Thus, the antimicrobial activities of the amphipathic CAP11-derived 18-mer peptide can be augmented by modifying its hydrophobicity and hydrophilicity (positive charge), and 1-18m2 is the most potent among the peptide derivatives with therapeutic potential for Gram-positive and -negative bacterial, and fungal infections.
    International Journal of Molecular Medicine 05/2009; 23(4):501-8. DOI:10.3892/ijmm_00000157 · 1.88 Impact Factor
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    ABSTRACT: High mobility group box-1 (HMGB1) is extracellularly released from mononuclear phagocytes by lipopolysaccharide (LPS)-stimulation accompanied with cell death, and plays an important role in septic/endotoxin shock as a late phase mediator. Notably, CAP11 (cationic antibacterial polypeptide of 11-kDa), a member of cathelicidin family of antimicrobial peptides, has a potential to bind with LPS and neutralize the biological activity of LPS. In this context, we previously revealed that CAP11 can suppress the elevation of serum HMGB1 level in mouse endotoxin shock model and protect mice from endotoxin lethality. In the present study, to clarify the inhibitory mechanism of CAP11 on HMGB1 release, we evaluated the effect of CAP11 on the LPS-induced HMGB1 release and apoptotic/necrotic cell death using a murine macrophage cell line RAW264.7. The results indicated that LPS-stimulation induced the release of HMGB1 from RAW264.7 cells, accompanied with both apoptotic and necrotic cell death. Of interest, CAP11 markedly inhibited the binding of LPS to target RAW264.7 cells, and suppressed HMGB1 release as well as necrotic cell death; however, CAP11 could not affect the LPS-induced apoptotic cell death. These observations clearly indicate that CAP11 can efficiently abolish necrotic cell death via the inhibition of LPS-binding to target cells, thereby suppressing the release of HMGB1. Thus, CAP11 could be a therapeutic agent for septic/endotoxin shock, with a potential to regulate the release of HMGB1 from LPS-stimulated mononuclear phagocytes via the suppression of LPS-binding to target cells and prevention of necrotic cell death due to its potent LPS-binding activity.
    International Journal of Molecular Medicine 04/2009; 23(3):341-6. DOI:10.3892/ijmm_00000137 · 1.88 Impact Factor
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    ABSTRACT: Glucosamine, a naturally occurring amino monosaccharide, is widely used to treat osteoarthritis in humans. Furthermore, glucosamine exhibits an anti-inflammatory action by inhibiting the activation of neutrophils, chondrocytes and synoviocytes. Recently, we revealed that glucosamine suppresses cytokine-induced activation of intestinal epithelial cells in vitro. In the present study therefore, we investigated whether glucosamine exhibits the anti-inflammatory effect in vivo, using dextran sulfate sodium (DSS)-induced colitis in rats, a model of inflammatory bowel diseases (IBD). The results indicated that glucosamine improved the clinical symptoms (evaluated by disease activity index), and suppressed colonic inflammation (evaluated by colon length and weight/length ratio) and tissue injury (evaluated by histological damage score) in DSS-induced colitis. Furthermore, glucosamine inhibited the activation of intestinal epithelial cells, as evidenced by the suppressed phosphorylation of NF-kappaB in the intestinal mucosa of DSS-induced colitis. Collectively, these observations suggest that glucosamine is likely to suppress the activation of intestinal epithelial cells in vivo, thereby possibly exhibiting anti-inflammatory action in a DSS-induced rat colitis model. Thus, glucosamine could prove to be a useful agent for IBD.
    International Journal of Molecular Medicine 10/2008; 22(3):317-23. DOI:10.3892/ijmm_00000025 · 1.88 Impact Factor
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    ABSTRACT: Intestinal epithelial cells play an important role in the mucosal immune reaction in inflammatory bowel diseases via the production and expression of chemokines and adhesion molecules, such as interleukin-8 (IL-8) and intercellular adhesion molecule-1 (ICAM-1), which are involved in the neutrophil infiltration and tissue damage in the inflamed colon. Notably, glucosamine, a naturally-occurring amino monosaccharide, has been shown to exhibit an anti-inflammatory action by inhibiting neutrophil functions. In the present study, to evaluate the anti-inflammatory action of glucosamine on intestinal epithelial cells, we examined the effects of glucosamine on the activation of a human colonic epithelial cell line HT-29. The results revealed that glucosamine suppressed the IL-8 production and ICAM-1 expression by TNF-alpha-activated HT-29 cells. Furthermore, glucosamine inhibited the TNF-alpha-induced phosphorylation of p38MAPK and NF-kappaB p65, and the nuclear translocation of NF-kappaB in the cells. Thus, glucosamine demonstrates inhibitory actions on the inflammatory and signaling molecules (IL-8, ICAM-1, p38MAPK and NF-kappaB) in intestinal epithelial cells. However, glucosamine did not essentially affect the binding of TNF-alpha to its receptor on HT-29 cells. Together, these observations suggest that glucosamine may have the potential to exhibit an anti-inflammatory action on intestinal epithelial cells, by possibly interfering with the activation signaling downstream of the ligand/receptor binding.
    International Journal of Molecular Medicine 08/2008; 22(2):205-11. · 1.88 Impact Factor
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    ABSTRACT: The action of antibacterial cathelicidin peptide CAP11 on the anandamide production from mononuclear phagocytes was examined. Lipopolysaccharide (LPS)-stimulation induced the anandamide production from macrophage-like RAW264.7, accompanied with the enhanced anandamide-synthesizing enzyme activity; however, the anandamide-degrading enzyme activity was not changed by LPS-stimulation. Importantly, CAP11 suppressed the LPS-induced anandamide production and the increase of anandamide-synthesizing enzyme activity. Furthermore, CAP11 abrogated the LPS-binding to CD14-positive RAW264.7. These observations indicate that CAP11 inhibits the binding of LPS to CD14-positive mononuclear phagocytes, thereby suppressing the anandamide synthesizing enzyme activity and the anandamide production from the cells.
    FEBS Letters 02/2007; 581(1):140-4. DOI:10.1016/j.febslet.2006.12.017 · 3.34 Impact Factor
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    ABSTRACT: Previously, we revealed that a cationic antibacterial polypeptide of 11 kDa (CAP11), a member of the cathelicidins isolated from guinea pig neutrophils, exhibits not only potent antibacterial activity but also lipopolysaccharide (LPS)-neutralizing activity. In this study, to determine the biologically active regions of CAP11, we isolated or synthesized the partial peptides of CAP11 and evaluated their antibacterial and LPS-neutralizing activities. Although CAP11 has a unique homodimeric structure with a disulfide bridge, the biological activities of dimeric and monomeric forms of CAP11 were almost the same. Moreover, the G(1)-E(33) peptide of CAP11 showed the same activities as CAP11, whereas the C-terminal region (Y(34) to I(43)) possessed no biological activities. In addition, the three 18-mer peptides (G(1)-R(18), T(9)-K(26), and L(16)-E(33)) with overlapping sequences were synthesized, and their activities were determined. The three 18-mer peptides retained the antibacterial activities, and G(1)-R(18) was the most potent. In contrast, the LPS-neutralizing activities of these peptides were markedly reduced. Together, these observations indicate that the active region with antibacterial activity is localized at G(1) to R(18) of CAP11, whereas longer sequences (such as G(1) to E(33)) would be required for the expression of LPS-neutralizing activity. Furthermore, the C-terminal region (Y(34) to I(43)) and a disulfide bridge are not essential for the antibacterial and LPS-neutralizing activities of CAP11.
    Antimicrobial Agents and Chemotherapy 09/2006; 50(8):2602-7. DOI:10.1128/AAC.00331-06 · 4.45 Impact Factor
  • Inflammation and Regeneration 01/2006; 26(6):513-518. DOI:10.2492/inflammregen.26.513
  • Inflammation and Regeneration 01/2006; 26(2):101-106. DOI:10.2492/inflammregen.26.101
  • I Nagaoka, S Yomogida, H Tamura, M Hirata
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    ABSTRACT: The action of antibacterial cathelicidin CAP11 (cationic antibacterial polypeptide of 11 kDa) on the lipopolysaccharide (LPS)-induced suppression of neutrophil apoptosis was evaluated in vitro. Human neutrophils (10(6) cells/ml) were incubated alone or with mononuclear cells (6 x 10(5) cells/ml) in the presence of LPS (10 ng/ml) and CAP 11 (0.1 approximately 10 microg/ml), and neutrophil apoptosis was determined. LPS suppressed neutrophil apoptosis, accompanied with the activation of NF-kappaB, phosphorylation of extracellular signal-related protein kinase (ERK), expression of Bcl-XL (an anti-apoptotic protein) and inhibition of caspase 3 activity. Interestingly, CAP11 (> 1 microg/ml) reversed the actions of LPS to trigger these changes, and induced neutrophil apoptosis (p < 0.0001). Moreover, neutralizing antibodies against Mac-1 (CD11b/CD18) and Toll-like receptor (TLR) 4 completely blocked the LPS-induced suppression of neutrophil apoptosis (p < 0.0001), suggesting a major role of Mac-1 and TLR4 in the LPS-mediated neutrophil activation. In addition, LPS activated monocytes to produce proinflammatory cytokines (IL-1beta, TNF-alpha and IL-8) and inhibited neutrophil apoptosis. Importantly, CAP11 (> 1 microg/ml) reduced the cytokine production, thereby inducing neutrophil apoptosis (p < 0.0001). Finally, CAP11 (> 1 microg/ml) strongly suppressed the LPS-binding to neutrophils and monocytes (p < 0.01). CAP11 is able to block the LPS-induced survival of neutrophils via the suppression of anti-apoptotic signaling in neutrophils and cytokine production from monocytes by inhibiting the binding of LPS to target cells.
    Inflammation Research 11/2004; 53(11):609-22. DOI:10.1007/s00011-004-1300-2 · 2.14 Impact Factor
  • Ensho Saisei 01/2004; 24(3):166-172. DOI:10.2492/jsir.24.166
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    ABSTRACT: Activated neutrophils extracellularly release antibacterial defensins and cathelicidins from the granules. In this study, to elucidate the interactions between defensins and cathelicidins in the extracellular environment, we evaluated the individual and synergistic actions of defensins and cathelicidins in the presence of physiological concentration of NaCl (150 mM). Antibacterial activities against Escherichia coli and Staphylococcus aureus were assessed using human and guinea pig defensins and cathelicidins. Furthermore, the effect of defensins and cathelicidins on membrane permeabilization was examined using E. coli ML-35p, as a target organism. In the absence of NaCl, human defensin (HNP-1) and guinea pig defensins (GNCPs) exhibited the antibacterial activities in a dose-dependent manner (0.1-10 microg/ml); however, their activities were completely lost in the presence of 150 mM NaCl. In contrast, the antibacterial activities of human cathelicidin (CAP18/LL-37) and guinea pig cathelicidin (CAP11) were resistant to NaCl. Interestingly, HNP-1 and GNCPs synergized with CAP18/LL-37 and CAP11 to enhance the antibacterial activities against E. coli and S. aureus in the presence of 150 mM NaCl (p<0.05). Similarly, HNP-1 and GNCPs were synergistic with CAP18/LL-37 and CAP11 to potentiate the outer and inner membrane permeabilization of E. coli ML-35p (p<0.05). Together these observations indicate that when extracellularly released from neutrophils, defensins cannot function as antibacterial molecules by themselves, but can synergistically work with cathelicidins to exert the antibacterial activity in the extracellular milieu by augmenting the membrane permeabilization of target cells.
    Inflammation Research 02/2000; 49(2):73-9. DOI:10.1007/s000110050561 · 2.14 Impact Factor
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    ABSTRACT: Neutrophils contain various antibacterial polypeptides and proteins in the granules that contribute to the killing of microorganisms. Recently, we have purified a cationic antibacterial polypeptide of 11 kDa (CAP11) from guinea pig neutrophil granules. CAP11 is a homodimer of G1LRKKFRKTRKRIQKLGRKIGKTGRKVWKAWREYGQIPYPCRI43 joined with one disulfide bond. In this study, to understand the regulation of CAP11 expression, we isolated and analyzed cDNA encoding CAP11. Furthermore, we investigated the expression of CAP11 mRNA during neutrophil maturation and localization of CAP11 among neutrophil granule subsets. Sequence analysis of CAP11 cDNA isolated from guinea pig bone marrow cells using rapid amplification of cDNA ends technique indicated that CAP11 is synthesized as a precursor comprising 178 amino acid residues, which is composed of a signal peptide (N-terminal 29 residues), a propeptide (106 residues), and a C-terminal mature peptide (43 residues). Interestingly, the predicted CAP11 precursor displayed the characteristic features of cathelicidins, a novel protein family of antibacterial polypeptides with a conserved cathelin-like pro-region and a variable C-terminal antibacterial domain. Northern blot and Western blot analyses using neutrophils, macrophages, eosinophils, mononuclear cells, and bone marrow cells revealed that only neutrophils and bone marrow cells expressed CAP11 mRNA and contained CAP11, suggesting that expression of CAP11 is neutrophil lineage-specific. Furthermore, Northern blot analysis using bone marrow cells separated according to their maturation stages showed that CAP11 mRNA was predominantly expressed in the cells at later stages of neutrophil maturation. Consistent with this, in situ hybridization using CAP11-specific cRNA probe demonstrated that CAP11 mRNA was primarily expressed at metamyelocyte stage. In addition, extracellular release assay revealed that CAP11 was readily released from neutrophils accompanied with gelatinase by low concentrations of N-formyl-Met-Leu-Phe without release of specific and azurophil granule components, and CAP11 was found to be exclusively present in the fraction containing gelatinase granules, prepared by Percoll density gradient centrifugation. Together these observations indicate that CAP11 is a member of cathelicidin family and its mRNA is preferentially expressed at the later stage of neutrophil maturation (i.e. metamyelocyte stage). Furthermore, CAP11 may be stored in the granule subset, possibly the gelatinase granule.
    Journal of Biological Chemistry 10/1997; 272(36):22742-50. DOI:10.1074/jbc.272.36.22742 · 4.60 Impact Factor
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    ABSTRACT: Neutrophils contain various antibacterial polypeptides and proteins in the granules. Defensins have been known as the major antimicrobial granular components. Recently, we have purified a novel cationic antibacterial polypeptide of 11 kDa (CAP11) from guinea pig neutrophil granules. In this study, we have examined the extracellular release and biological activity of CAP11, and compared with defensins. CAP11 was extracellularly released from neutrophils by N-formyl Met-Leu-Phe, phorbol 12-myristate 13-acetate, accompanied by the release of lysozyme, a specific and azurophil granule component, without release of beta-glucuronidase, an azurophil granule component, whereas defensins were released by phagocytosis, accompanied by the release of beta-glucuronidase, suggesting that the localization of CAP11 and defensins is different among neutrophil granules. Defensins increased neutrophil adhesion, and inhibited phagocytosis of opsonized zymosan particles and phagocytosis-associated superoxide anion generation. In contrast, CAP11 did not affect these neutrophil functions. Both CAP11 and defensins possessed the histamine-releasing activities for mast cells, but CAP11 was 10-fold less potent than defensins. CAP11 and defensins showed the antibacterial activities against both Escherichia coli and Staphylococcus aureus. However, the antibacterial activity of defensins was completely lost in the presence of physiological concentration of NaCl (0.15 M), although CAP11 retained the antibacterial activity even in the presence of NaCl. Furthermore, CAP11 exhibited the 10-fold more potent antiretroviral activity than defensins against Moloney murine leukemia viruses. Together these observations indicate that when released from neutrophils, CAP11 likely functions as an antimicrobial molecule in the extracellular milieu, whereas defensins may participate in the modulation of neutrophil function and mast cell histamine release.
    Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology 02/1997; 116(1):99-107. DOI:10.1016/S0305-0491(96)00222-2 · 1.90 Impact Factor
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    ABSTRACT: Defensin has been known as a major antimicrobial component of neutrophil granules. Recently, we have purified a novel cationic antibacterial polypeptide of 11 kDa (CAP11) from guinea pig neutrophilis. In this study, we have compared the biological activity and gene expression between CAP11 and defensin. When stimulated, CAP11 was extracellularly released from neutrophils, accompanied by the release of a specific granule component (lysozyme), whereas defensin was released, accompanied by the release of an azurophil granule component (β-glucoronidase) . Defensin modulated neutrophil functions such as adhesion, phagocytosis and superoxide anion generation. However, CAP11 did not affected the neutrophil functions. Both CAP11 and defensin possessed histamine-releasing activity for mast cells, but CAP11 was 10-fold less potent than defensins. CAP11 exhibited 8-fold more antibacterial activity against Escherichia coli than defensin, and the activity was retained even in the presence of physiological concentration of NaCl, although the activity of defensin was completely lost in the presence of NaCl. Sequence analysis of CAP11 cDNA showed that pre-prosequence of CAP11 was similar to the sequences of cathelicidin family polypeptides. Furthemore, in situ hybridization study revealed that CAP11 mRNA was highly expressed in metamyelocytes among bone marrow cells. In contrast, defensin mRNA was expressed in promyelocytes and myelocytes. Together these observations indicate that CAP11, a member of cathelicidin family, which is synthesized during the late stage of neutrophil maturation and stored possibly in the specific granules, is released from stimulated neutrophils and functions as an antibacterial molecule in the extracellular milieu, whereas defensin released from the azurophil granules likely participate in the modulation of neutrophil functions and mast cell histamine release.
    01/1997; 17(4):367-374. DOI:10.2492/jsir1981.17.367
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    ABSTRACT: It has been known that neutrophils contain various antimicrobial components in the granules, which contribute to the oxygen-independent host defense mechanism. In this study, we have isolated the two antimicrobial polypeptides from guinea pig neutrophil granules. Urea-SDS-PAGE analysis revealed that the molecular masses of the polypeptides were 11 and 5 kDa under nonreducing conditions. Under reducing conditions, the molecular mass of the 5-kDa polypeptide did not change, whereas the molecular mass of the 11-kDa polypeptide changed to about 5 kDa, suggesting that the 11-kDa polypeptide is a dimer composed of 5-kDa subunits joined with a disulfide bond. The amino acid composition and sequence data indicated that the 5-kDa subunit of the 11-kDa polypeptide contained 9 lysine, 8 arginine, and 1 cysteine residues and that the 11-kDa polypeptide was a homodimer of G1LRKKFRKTRKRIQKLGRKIGKTGRKVWKAWREYGQIPYPCRI43 (4599 Da) joined with one disulfide bond. Amino acid sequence of the 11-kDa polypeptide showed partial homology (19-30%) to the active peptides of rabbit and human cationic antimicrobial proteins of 18 kDa (CAP18), suggesting the 11-kDa polypeptide might be a homologue of CAP18. In contrast, the amino acid analysis of the 5-kDa antibacterial polypeptide revealed that the polypeptide was composed of 41 amino acids (5007 Da) containing 7 lysine, 10 arginine, and 2 cystine residues. However, sequence analysis indicated that the N-terminus of the 5-kDa polypeptide was likely blocked. The 11- and 5-kDa polypeptides showed almost the same antibacterial activities; ED50 values were 30-35 nM against Escherichia coli and 90-120 nM against Staphylococcus aureus, which were 4- to 20-fold lower than those of defensins. Furthermore, the 11- and 5-kDa polypeptide retained the antibacterial activities even at the physiological concentration of NaCl (0.15 M), although the antibacterial activity of defensin was completely lost in the presence of NaCl.
    Archives of Biochemistry and Biophysics 05/1996; 328(2):219-26. DOI:10.1006/abbi.1996.0166 · 3.04 Impact Factor
  • S Yomogida, I Nagaoka, K Saito, T Yamashita
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    ABSTRACT: Defensins are known to be the microbicidal components of neutrophil granules, which contribute to oxygen-independent antimicrobial mechanisms. In this study, we have examined the effect of defensins on neutrophil functions, such as adhesion, superoxide anion generation, phagocytosis and chemotaxis. Guinea-pig defensins increased the expression of CD11b, CD11c and CD54 (intercellular adhesion molecule ICAM-1) on human neutrophils, and induced adhesion of guinea-pig and human neutrophils. When the effect of guinea-pig defensins on superoxide anion generation was examined, defensins inhibited superoxide anion generation during phagocytosis of complement-opsonized particles. Furthermore, defensins inhibited complement-dependent phagocytosis. However, they did not inhibit the binding of complement-opsonized particles to neutrophils, suggesting that defensins possibly inhibit complement-dependent phagocytosis by affecting the ingestion step but not the binding step. Defensins exhibited neither chemotactic nor chemokine activity. Interestingly, 10-20% of total defensins were released extracellularly from phagocytosing neutrophils. Together these observations indicate that, in addition to their antimicrobial activity, defensins may have the ability to modulate the functions of neutrophils at sites of infection or inflammation.
    Inflammation Research 03/1996; 45(2):62-7. DOI:10.1007/BF02265117 · 2.14 Impact Factor
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    S Yomogida, I Nagaoka, T Yamashita
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    ABSTRACT: Guinea pig neutrophil cationic peptides (GNCPs) are single-chain polypeptides with 31 amino acid residues containing six cysteine residues, which exhibit both antibacterial and histamine-releasing activities in vitro. In this study, the role of the sulfhydryl groups in defining the antibacterial and histamine-releasing activities of the active fragments of GNCP-1 (Arg-1 to Tyr-14 [Arg-1-Tyr-14] and Arg-15-Tyr-27 peptides) was examined by using peptides containing alkylated or nonalkylated sulfhydryl groups. Alkylation slightly increased the histamine-releasing activity of the Arg-15-Tyr-27 (RRLGTCIFQNRVY) peptide but abrogated the antibacterial activity. Alkylation of the Arg-1-Tyr-14 (RRCICTTRTCRFPY) peptide similarly reduced the antibacterial activity of this fragment but had minimal effect on the histamine-releasing activity. These findings suggest that cysteine residues with free sulfhydryl groups play an important role in the expression of the antibacterial activity of the active fragments of GNCP-1.
    Infection and Immunity 07/1995; 63(6):2344-6. · 4.16 Impact Factor
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    ABSTRACT: Guinea-pig neutrophil cationic peptides (GNCPs) are single polypeptides containing 31 amino acid residues and three intramolecular disulfide bonds, which show both antibacterial and histamine-releasing activities. Reduction and alkylation of the disulfide bonds of GNCP did not reduce both biological activities. When pyridylethylated GNCP was digested with trypsin, the biological activities were almost lost, whereas the chymotryptic digest retained the biological activities. Chymotrypsin digested fragments were purified by RP-HPLC, and three active peptide fragments containing two Arg residues at the N-terminal sequence were isolated. When the biological activities were examined using synthetic peptides containing various numbers of Arg residue at the N-terminus, the omission of the Arg residues was found to reduce remarkably the antibacterial and histamine-releasing activities. Together these observations indicate that the primary structures containing Arg residues at the N-terminus but not the intramolecular disulfide cross-linking are important for the expression of the biological activities of GNCP.
    Biochimica et Biophysica Acta 05/1995; 1243(3):295-9. DOI:10.1016/0304-4165(94)00139-O · 4.66 Impact Factor