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Inhibition of lethal inflammatory responses through the targeting of membrane-associated Toll-like receptor 4 signaling complexes with a Smad6-derived peptide.

Lee YS, Park JS, Jung SM, Kim SD, Kim JH, Lee JY, Jung KC, Mamura M, Lee S, Kim SJ, Bae YS, Park SH - EMBO Mol Med (2015)

Bottom Line: Here, we developed Smaducin-6, a novel membrane-tethered palmitic acid-conjugated Smad6-derived peptide composed of amino acids 422-441 of Smad6.Smaducin-6 interacted with Pellino-1, located in the inner membrane, thereby disrupting the formation of IRAK1-, RIP1-, IKKε-mediated TLR4 signaling complexes.Our findings provide clues to develop new peptide-based drugs to target Pellino-1 protein in TLR4 signaling pathway for the treatment of sepsis.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea.

No MeSH data available.


Related in: MedlinePlus

Smaducin-6 reduces sepsis-induced apoptosisA, B Quantitative analysis of (A) TUNEL-positive cells and (B) caspase-3-positive cells in IHC in the spleens of CLP + PBS, CLP + Pal-Scram #1, and CLP + Smaducin-6 mice. Three independent experiments (n = 3 mice per group per experiments) were performed. At least five hot spots in a section of TUNEL and IHC per experiment were selected, and average count was determined. The data were expressed as a mean percentage of total cell numbers and statistically analyzed by a t-test and show the mean ± SD of three independent experiments. **P < 0.005, ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).C ELISA showing that Smaducin-6 treatment reduced IFN-β1 levels in peritoneal lavage fluids compared to Pal-Scram #1-treated CLP mice. n = 10 mice per group per experiment. Data were statistically analyzed by the Dunnett's multiple comparison test (one-way ANOVA). ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).D, E IFN-β1 (D) and TRAIL (E) expression detected by FACS in splenocytes is decreased in Smaducin-6-treated CLP mice compared to scrambled peptide-treated CLP mice. Data are representative of three independent experiments.F Decreased expression of TRAIL was detected by IHC in the spleen of CLP-induced mice treated with Smaducin-6 compared to mice treated with Pal-Scram. Scale bar, 100 μm (magnification, 200×). Data are representative of three independent experiments.
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fig07: Smaducin-6 reduces sepsis-induced apoptosisA, B Quantitative analysis of (A) TUNEL-positive cells and (B) caspase-3-positive cells in IHC in the spleens of CLP + PBS, CLP + Pal-Scram #1, and CLP + Smaducin-6 mice. Three independent experiments (n = 3 mice per group per experiments) were performed. At least five hot spots in a section of TUNEL and IHC per experiment were selected, and average count was determined. The data were expressed as a mean percentage of total cell numbers and statistically analyzed by a t-test and show the mean ± SD of three independent experiments. **P < 0.005, ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).C ELISA showing that Smaducin-6 treatment reduced IFN-β1 levels in peritoneal lavage fluids compared to Pal-Scram #1-treated CLP mice. n = 10 mice per group per experiment. Data were statistically analyzed by the Dunnett's multiple comparison test (one-way ANOVA). ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).D, E IFN-β1 (D) and TRAIL (E) expression detected by FACS in splenocytes is decreased in Smaducin-6-treated CLP mice compared to scrambled peptide-treated CLP mice. Data are representative of three independent experiments.F Decreased expression of TRAIL was detected by IHC in the spleen of CLP-induced mice treated with Smaducin-6 compared to mice treated with Pal-Scram. Scale bar, 100 μm (magnification, 200×). Data are representative of three independent experiments.

Mentions: Extensive apoptosis of immune effector cells impairs immune responses in the pathogenesis of sepsis (Hotchkiss et al, 1999; Hotchkiss & Nicholson, 2006). In particular, rectification of the immunosuppressive state caused by extensive apoptosis has recently been shown as therapeutic for sepsis (Hotchkiss & Nicholson, 2006). Thus, we next examined the effects of Smaducin-6 peptide treatment on apoptosis in CLP-induced sepsis. Treatment with Smaducin-6 significantly reduced the numbers of TUNEL-positive cells in the spleens of CLP mice compared to the scrambled peptide-treated controls (Fig7A; Supplementary Fig S14A). Immunohistochemical analysis of caspase-3 expression also showed consistent results (Fig7B; Supplementary Fig S14B). Because the TRIF-mediated pathway via interaction with RIP1 has been reported to be more prominent in apoptosis than the MyD88-dependent pathway (Kaiser & Offermann, 2005), and Pellino-1 has been reported to bind to RIP (Chang et al, 2009), the inhibitory effect of Smaducin-6 on apoptosis in septic mice can be explained by disruption of the RIP1-mediated signaling complex (Fig3H).


Inhibition of lethal inflammatory responses through the targeting of membrane-associated Toll-like receptor 4 signaling complexes with a Smad6-derived peptide.

Lee YS, Park JS, Jung SM, Kim SD, Kim JH, Lee JY, Jung KC, Mamura M, Lee S, Kim SJ, Bae YS, Park SH - EMBO Mol Med (2015)

Smaducin-6 reduces sepsis-induced apoptosisA, B Quantitative analysis of (A) TUNEL-positive cells and (B) caspase-3-positive cells in IHC in the spleens of CLP + PBS, CLP + Pal-Scram #1, and CLP + Smaducin-6 mice. Three independent experiments (n = 3 mice per group per experiments) were performed. At least five hot spots in a section of TUNEL and IHC per experiment were selected, and average count was determined. The data were expressed as a mean percentage of total cell numbers and statistically analyzed by a t-test and show the mean ± SD of three independent experiments. **P < 0.005, ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).C ELISA showing that Smaducin-6 treatment reduced IFN-β1 levels in peritoneal lavage fluids compared to Pal-Scram #1-treated CLP mice. n = 10 mice per group per experiment. Data were statistically analyzed by the Dunnett's multiple comparison test (one-way ANOVA). ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).D, E IFN-β1 (D) and TRAIL (E) expression detected by FACS in splenocytes is decreased in Smaducin-6-treated CLP mice compared to scrambled peptide-treated CLP mice. Data are representative of three independent experiments.F Decreased expression of TRAIL was detected by IHC in the spleen of CLP-induced mice treated with Smaducin-6 compared to mice treated with Pal-Scram. Scale bar, 100 μm (magnification, 200×). Data are representative of three independent experiments.
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Related In: Results  -  Collection

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fig07: Smaducin-6 reduces sepsis-induced apoptosisA, B Quantitative analysis of (A) TUNEL-positive cells and (B) caspase-3-positive cells in IHC in the spleens of CLP + PBS, CLP + Pal-Scram #1, and CLP + Smaducin-6 mice. Three independent experiments (n = 3 mice per group per experiments) were performed. At least five hot spots in a section of TUNEL and IHC per experiment were selected, and average count was determined. The data were expressed as a mean percentage of total cell numbers and statistically analyzed by a t-test and show the mean ± SD of three independent experiments. **P < 0.005, ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).C ELISA showing that Smaducin-6 treatment reduced IFN-β1 levels in peritoneal lavage fluids compared to Pal-Scram #1-treated CLP mice. n = 10 mice per group per experiment. Data were statistically analyzed by the Dunnett's multiple comparison test (one-way ANOVA). ***P < 0.001 compared to sham or vehicle control (CLP + Pal-Scram #1).D, E IFN-β1 (D) and TRAIL (E) expression detected by FACS in splenocytes is decreased in Smaducin-6-treated CLP mice compared to scrambled peptide-treated CLP mice. Data are representative of three independent experiments.F Decreased expression of TRAIL was detected by IHC in the spleen of CLP-induced mice treated with Smaducin-6 compared to mice treated with Pal-Scram. Scale bar, 100 μm (magnification, 200×). Data are representative of three independent experiments.
Mentions: Extensive apoptosis of immune effector cells impairs immune responses in the pathogenesis of sepsis (Hotchkiss et al, 1999; Hotchkiss & Nicholson, 2006). In particular, rectification of the immunosuppressive state caused by extensive apoptosis has recently been shown as therapeutic for sepsis (Hotchkiss & Nicholson, 2006). Thus, we next examined the effects of Smaducin-6 peptide treatment on apoptosis in CLP-induced sepsis. Treatment with Smaducin-6 significantly reduced the numbers of TUNEL-positive cells in the spleens of CLP mice compared to the scrambled peptide-treated controls (Fig7A; Supplementary Fig S14A). Immunohistochemical analysis of caspase-3 expression also showed consistent results (Fig7B; Supplementary Fig S14B). Because the TRIF-mediated pathway via interaction with RIP1 has been reported to be more prominent in apoptosis than the MyD88-dependent pathway (Kaiser & Offermann, 2005), and Pellino-1 has been reported to bind to RIP (Chang et al, 2009), the inhibitory effect of Smaducin-6 on apoptosis in septic mice can be explained by disruption of the RIP1-mediated signaling complex (Fig3H).

Bottom Line: Here, we developed Smaducin-6, a novel membrane-tethered palmitic acid-conjugated Smad6-derived peptide composed of amino acids 422-441 of Smad6.Smaducin-6 interacted with Pellino-1, located in the inner membrane, thereby disrupting the formation of IRAK1-, RIP1-, IKKε-mediated TLR4 signaling complexes.Our findings provide clues to develop new peptide-based drugs to target Pellino-1 protein in TLR4 signaling pathway for the treatment of sepsis.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea.

No MeSH data available.


Related in: MedlinePlus