Signal Transduction Pathway on .BETA.-Glucans-Triggered Hydrogen Peroxide Production by Murine Peritoneal Macrophages in Vitro.

Okazaki, Mitsuhiro; Chiba, Norihisa; Adachi, Yoshiyuki; Ohno, Naohito; Yadomae, Toshiro

doi:10.1248/bpb.19.18

Cited by 19 publications

(10 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, AMB reduces the production of superoxide anions induced by both LPS and phorbol myristate acetate (PMA; an activator of PKC), inhibits LPS-induced production of hydrogen peroxide (H 2 O 2 ) from A-MFs [54, 55], and attenuates the spontaneous and PMA-induced production of superoxide anions by BAL cells (>90% of which are A-MFs) in mice and guinea pigs [56, 57]. These inhibitory effects of AMB might result from inhibition of activated PKC, because the direct scavenging action of AMB against these ROS is weak and statistically insignificant [54, 58, 59], and the production of H 2 O 2 is also mediated by PKC activation [60, 61]. These investigations were performed at concentrations corresponding well to those of AMB and LPS in our experiment.…”

Section: Discussionmentioning

confidence: 99%

Effects of N-Acetylcysteine and Ambroxol on the Production of IL-12 and IL-10 in Human Alveolar Macrophages

et al. 2000

View full text Add to dashboard Cite

Background: N-acetylcysteine (NAC) and ambroxol (AMB) have recently been proposed as possible therapeutic agents in the treatment of pulmonary disorders. IL-12 plays an important role in host resistance to infection and the development of Th-1 cells. In contrast, IL-10 is involved in anti-inflammatory and immunoregulatory mechanisms. Objective: We investigated the effects of NAC and AMB on secretions of IL-12 and IL-10 from human alveolar macrophages. Methods: Alveolar macrophages were obtained from 7 healthy nonsmokers by bronchoalveolar lavage. The cells were first incubated with either NAC or AMB for 2 h and then cultured in lipopolysaccharide (LPS) solution for 24 h. IL-12 and IL-10 secretions were measured by ELISA. Result: Both NAC and AMB enhanced LPS-induced secretion of IL-12. NAC also enhanced LPS-induced IL-10 secretion, while AMB did not. The ratio IL-12/IL-10 secretion was increased by AMB, but NAC did not affect it. Conclusions: The results suggest that NAC enhances inflammatory and immune responses and prevents excessive responses reciprocally, through keeping local balance of IL-12 and IL-10 production in alveolar macrophages at inflammatory sites of bacterial pneumonia. AMB appears to strengthen inflammatory responses and cell-mediated immunity, facilitating the development of Th-1 cells, through shifting the local balance to IL-12 dominance.

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of N-Acetylcysteine and Ambroxol on the Production of IL-12 and IL-10 in Human Alveolar Macrophages

et al. 2000

View full text Add to dashboard Cite

show abstract

“…However, laminarin is an oligomeric water-soluble fi-1,3-glucan not necessarily identical to other polymeric more complex &1,3-glucans. Laminarin is known to be random coil while more complex &1,3-glucans can be single-or triple-helix conformers [23]. One fi-1,3-glucan of great value for detecting various, enzymes is the alkaliinsoluble baker's yeast fi-1,3-glucan.…”

Section: Discussionmentioning

confidence: 99%

Detection of enzymes active on various β‐1, 3‐glucans after denaturing polyacrylamide gel electrophoresis

1998

View full text Add to dashboard Cite

Enzymes were assayed for glucanase activity after denaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in gels containing beta-1,3-glucans embedded as substrate. Lentinan, curdlan, paramylon, baker's yeast alkali-insoluble glucan, baker's yeast alkali-soluble glucan and carboxymethyl (CM)-pachyman were compared to oligomeric laminarin, which is the usual substrate for assaying beta-1,3-glucanase activities. Detecting enzyme activities by aniline blue fluorescent staining was also compared with the staining of released reducing sugars by 2,3,5-triphenyltetrazolium chloride (TTC). For the nonreduced proteins, the Driselase extract exhibited one major band at 32.5 kDa and one less intense band at 23 kDa for most substrates with the two detection procedures. No Lyticase enzyme was detected in either detection procedures for all tested substrates. For barley enzymes, no activity was revealed after aniline blue staining while one undescribed 19 kDa glucanase activity was best shown after TTC staining with curdlan, paramylon and CM-pachyman as substrates. In the case of reduced proteins, the Lyticase extract yielded three bands (33, 36 and 46 kDa) on several substrates with both detection procedures. This was the same for the barley leaf extract (32, 36 and 39 kDa). The Driselase extract showed one 42 kDa band. Many enzymes active on beta-1,3-glucans are thus best revealed when proteins are denatured and reduced and when protein renaturation after SDS-PAGE involves a pH 8.0 treatment and the inclusion of 1 mM cysteine in buffers. However, some enzymes are only detected when proteins are denatured without reduction. Finally, the use of various polymeric beta-1,3-glucan substrates different from oligomeric laminarin is necessary to detect new types of enzymes such as the 19 kDa barley glucanase.

show abstract

“…Zymosan is a yeast cell wall particle containing mainly polysaccharides, of which ␤-glucan and mannan are the major constituents (3). Zymosan can activate macrophages, monocytes, and leukocytes (4 -6), resulting in the stimulated secretion of inflammatory products including TNF-␣, IL-8, hydrogen peroxide, and arachidonic acid (7)(8)(9). Intratracheal challenge of zymosan has been shown to induce pulmonary inflammation in animal models (10).…”

mentioning

confidence: 99%

Direct Binding of Toll-Like Receptor 2 to Zymosan, and Zymosan-Induced NF-κB Activation and TNF-α Secretion Are Down-Regulated by Lung Collectin Surfactant Protein A

Sato

Sano

Iwaki

et al. 2003

The Journal of Immunology

332

220

View full text Add to dashboard Cite

The lung collectin surfactant protein A (SP-A) has been implicated in the regulation of pulmonary host defense and inflammation. Zymosan induces proinflammatory cytokines in immune cells. Toll-like receptor (TLR)2 has been shown to be involved in zymosan-induced signaling. We first investigated the interaction of TLR2 with zymosan. Zymosan cosedimented the soluble form of rTLR2 possessing the putative extracellular domain (sTLR2). sTLR2 directly bound to zymosan with an apparent binding constant of 48 nM. We next examined whether SP-A modulated zymosan-induced cellular responses. SP-A significantly attenuated zymosan-induced TNF-α secretion in RAW264.7 cells and alveolar macrophages in a concentration-dependent manner. Although zymosan failed to cosediment SP-A, SP-A significantly reduced zymosan-elicited NF-κB activation in TLR2-transfected human embryonic kidney 293 cells. Because we have shown that SP-A binds to sTLR2, we also examined whether SP-A affected the binding of sTLR2 to zymosan. SP-A significantly attenuated the direct binding of sTLR2 to zymosan in a concentration-dependent fashion. From these results, we conclude that 1) TLR2 directly binds zymosan, 2) SP-A can alter zymosan-TLR2 interaction, and 3) SP-A down-regulates TLR2-mediated signaling and TNF-α secretion stimulated by zymosan. This study supports an important role of SP-A in controlling pulmonary inflammation caused by microbial pathogens.

show abstract

Signal Transduction Pathway on .BETA.-Glucans-Triggered Hydrogen Peroxide Production by Murine Peritoneal Macrophages in Vitro.

Cited by 19 publications

References 1 publication

Effects of N-Acetylcysteine and Ambroxol on the Production of IL-12 and IL-10 in Human Alveolar Macrophages

Effects of N-Acetylcysteine and Ambroxol on the Production of IL-12 and IL-10 in Human Alveolar Macrophages

Detection of enzymes active on various β‐1, 3‐glucans after denaturing polyacrylamide gel electrophoresis

Direct Binding of Toll-Like Receptor 2 to Zymosan, and Zymosan-Induced NF-κB Activation and TNF-α Secretion Are Down-Regulated by Lung Collectin Surfactant Protein A

Contact Info

Product

Resources

About