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Geranylgeranylacetone ameliorates inflammatory response to lipopolysaccharide (LPS) in murine macrophages: inhibition of LPS binding to the cell surface.

Mochida S, Matsura T, Yamashita A, Horie S, Ohata S, Kusumoto C, Nishida T, Minami Y, Inagaki Y, Ishibe Y, Nakada J, Ohta Y, Yamada K - J Clin Biochem Nutr (2007)

Bottom Line: GGA (80 microM) treatment 2 h before LPS addition significantly suppressed TNF-alpha and NO productions at 12 h and 24 h after LPS, respectively, indicating that GGA inhibits activation of macrophages.When it was examined whether GGA interacts with LPS and/or affects expression of Toll-like receptor 4 (TLR4) and CD14 on the cell surface, GGA inhibited the binding of LPS to the cell surface, while GGA did not affect TLR4 and CD14 expressions.These results indicate that GGA suppresses the binding of LPS to the cell surface of macrophages, resulting in inhibiting signal transduction downstream of TLR4.

View Article: PubMed Central - PubMed

Affiliation: Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, Tottori University Faculty of Medicine, 86 Nishi-cho, Yonago 683-8503, Japan.

ABSTRACT
We investigated whether pretreatment with geranylgeranylacetone (GGA), a potent heat shock protein (HSP) inducer, could inhibit proinflammatory cytokine liberation and nitric oxide (NO) production in lipopolysaccharide (LPS)-treated murine macrophages. The levels of NO and tumor necrosis factor-alpha (TNF-alpha) released from murine macrophage RAW 264 cells were increased dose- and time-dependently following treatment with LPS (1 microg/ml). GGA (80 microM) treatment 2 h before LPS addition significantly suppressed TNF-alpha and NO productions at 12 h and 24 h after LPS, respectively, indicating that GGA inhibits activation of macrophages. However, replacement by fresh culture medium before LPS treatment abolished the inhibitory effect of GGA on NO production in LPS-treated cells. Furthermore, GGA inhibited both HSP70 and inducible NO synthase expressions induced by LPS treatment despite an HSP inducer. When it was examined whether GGA interacts with LPS and/or affects expression of Toll-like receptor 4 (TLR4) and CD14 on the cell surface, GGA inhibited the binding of LPS to the cell surface, while GGA did not affect TLR4 and CD14 expressions. These results indicate that GGA suppresses the binding of LPS to the cell surface of macrophages, resulting in inhibiting signal transduction downstream of TLR4.

No MeSH data available.


Related in: MedlinePlus

Effect of GGA on HSP70 induction in RAW 264 cells. (A) Cells were incubated in the presence or absence of LPS (1 µg/ml) for 24 h at 37°C under a 5% CO2 and 95% air atmosphere. GGA (0, 20, 40, or 80 µM) was added 2 h before the addition of LPS. (B) Cells were incubated in the presence or absence of GGA (80 µM) for 2 h at 37°C under a 5% CO2 and 95% air atmosphere. HSP70 level was analyzed by Western blotting, quantified densitometrically and expressed as relative density to control cells. Data points represent the means ± SE (n = 3). ap<0.01 vs control, bp<0.01 vs LPS alone-treated cells.
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Figure 5: Effect of GGA on HSP70 induction in RAW 264 cells. (A) Cells were incubated in the presence or absence of LPS (1 µg/ml) for 24 h at 37°C under a 5% CO2 and 95% air atmosphere. GGA (0, 20, 40, or 80 µM) was added 2 h before the addition of LPS. (B) Cells were incubated in the presence or absence of GGA (80 µM) for 2 h at 37°C under a 5% CO2 and 95% air atmosphere. HSP70 level was analyzed by Western blotting, quantified densitometrically and expressed as relative density to control cells. Data points represent the means ± SE (n = 3). ap<0.01 vs control, bp<0.01 vs LPS alone-treated cells.

Mentions: Overexpression of HSP70 reportedly inhibited the production of cytokines in macrophages activated by LPS [18]. Since GGA is well known to be a potent HSP70 inducer [12, 13], we investigated whether the inhibitory effect of GGA on LPS-induced NO and TNF-α production in RAW 264 cells was ascribed to HSP70 induction by GGA treatment (Fig. 5A). Treatment with GGA 2 h before LPS administration inhibited LPS-triggered HSP70 induction in a dose-dependent manner. Specifically, 80 µM GGA suppressed the increase in HSP70 content by LPS to the control level. Treating the cells with 80 µM GGA alone for 2 h did not enhance HSP70 protein expression (Fig. 5B).


Geranylgeranylacetone ameliorates inflammatory response to lipopolysaccharide (LPS) in murine macrophages: inhibition of LPS binding to the cell surface.

Mochida S, Matsura T, Yamashita A, Horie S, Ohata S, Kusumoto C, Nishida T, Minami Y, Inagaki Y, Ishibe Y, Nakada J, Ohta Y, Yamada K - J Clin Biochem Nutr (2007)

Effect of GGA on HSP70 induction in RAW 264 cells. (A) Cells were incubated in the presence or absence of LPS (1 µg/ml) for 24 h at 37°C under a 5% CO2 and 95% air atmosphere. GGA (0, 20, 40, or 80 µM) was added 2 h before the addition of LPS. (B) Cells were incubated in the presence or absence of GGA (80 µM) for 2 h at 37°C under a 5% CO2 and 95% air atmosphere. HSP70 level was analyzed by Western blotting, quantified densitometrically and expressed as relative density to control cells. Data points represent the means ± SE (n = 3). ap<0.01 vs control, bp<0.01 vs LPS alone-treated cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 5: Effect of GGA on HSP70 induction in RAW 264 cells. (A) Cells were incubated in the presence or absence of LPS (1 µg/ml) for 24 h at 37°C under a 5% CO2 and 95% air atmosphere. GGA (0, 20, 40, or 80 µM) was added 2 h before the addition of LPS. (B) Cells were incubated in the presence or absence of GGA (80 µM) for 2 h at 37°C under a 5% CO2 and 95% air atmosphere. HSP70 level was analyzed by Western blotting, quantified densitometrically and expressed as relative density to control cells. Data points represent the means ± SE (n = 3). ap<0.01 vs control, bp<0.01 vs LPS alone-treated cells.
Mentions: Overexpression of HSP70 reportedly inhibited the production of cytokines in macrophages activated by LPS [18]. Since GGA is well known to be a potent HSP70 inducer [12, 13], we investigated whether the inhibitory effect of GGA on LPS-induced NO and TNF-α production in RAW 264 cells was ascribed to HSP70 induction by GGA treatment (Fig. 5A). Treatment with GGA 2 h before LPS administration inhibited LPS-triggered HSP70 induction in a dose-dependent manner. Specifically, 80 µM GGA suppressed the increase in HSP70 content by LPS to the control level. Treating the cells with 80 µM GGA alone for 2 h did not enhance HSP70 protein expression (Fig. 5B).

Bottom Line: GGA (80 microM) treatment 2 h before LPS addition significantly suppressed TNF-alpha and NO productions at 12 h and 24 h after LPS, respectively, indicating that GGA inhibits activation of macrophages.When it was examined whether GGA interacts with LPS and/or affects expression of Toll-like receptor 4 (TLR4) and CD14 on the cell surface, GGA inhibited the binding of LPS to the cell surface, while GGA did not affect TLR4 and CD14 expressions.These results indicate that GGA suppresses the binding of LPS to the cell surface of macrophages, resulting in inhibiting signal transduction downstream of TLR4.

View Article: PubMed Central - PubMed

Affiliation: Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, Tottori University Faculty of Medicine, 86 Nishi-cho, Yonago 683-8503, Japan.

ABSTRACT
We investigated whether pretreatment with geranylgeranylacetone (GGA), a potent heat shock protein (HSP) inducer, could inhibit proinflammatory cytokine liberation and nitric oxide (NO) production in lipopolysaccharide (LPS)-treated murine macrophages. The levels of NO and tumor necrosis factor-alpha (TNF-alpha) released from murine macrophage RAW 264 cells were increased dose- and time-dependently following treatment with LPS (1 microg/ml). GGA (80 microM) treatment 2 h before LPS addition significantly suppressed TNF-alpha and NO productions at 12 h and 24 h after LPS, respectively, indicating that GGA inhibits activation of macrophages. However, replacement by fresh culture medium before LPS treatment abolished the inhibitory effect of GGA on NO production in LPS-treated cells. Furthermore, GGA inhibited both HSP70 and inducible NO synthase expressions induced by LPS treatment despite an HSP inducer. When it was examined whether GGA interacts with LPS and/or affects expression of Toll-like receptor 4 (TLR4) and CD14 on the cell surface, GGA inhibited the binding of LPS to the cell surface, while GGA did not affect TLR4 and CD14 expressions. These results indicate that GGA suppresses the binding of LPS to the cell surface of macrophages, resulting in inhibiting signal transduction downstream of TLR4.

No MeSH data available.


Related in: MedlinePlus