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Objective To investigate the anti-injury and anti-inflammation protective effects of metformin in acute-liver-injury SD rat model induced by D-galactosamine and Pam3CSK4 .Methods Eighteen male Sprague-Dawley rats were treated with the mixture of D-galactosamine (350 mg/kg ) and Pam3CSK4 (50 μg/kg ) by intraperitoneal injection (i .p .) to construct acute liver injury model .The rats in intervention group were given PBS and metformin ,respectively .The liver and body weight were measured and the ratio of liver weight to body weight was calculated .HE staining was used to observe the pathological changes of the liver .Fasting serum was collected for detection of serological parameters .ELISA and RT-qPCR were used to determine the expression levels of IL-6 and TNF-α.Finally , activation of MAPK signal pathway in rat liver was detected by Western blot .Results Compared with those in control group , the ratio of body weight to liver weight , serum transaminase and proinflammatory cytokines IL-6 and TNF-a were all significantly increased in the two intervention groups .Meanwhile , hepatic degeneration and hepatic interstitial exudation indicated that D -galactosamine combined with Pam3CSK4 successfully constructed acute liver injury model in the SD rats.Compared with PBS group, the ratio of body weight to liver weight , hepatic damage , serum transaminase levels.and the expressions of proinflammatory cytokines IL-6 and TNF-a were significantly decreased in metformin-treated group.Meanwhile,the expressions of p-ERKl/2,p-SAPK/JNK and p-P38 MAPK decreased in liver tissues by metformin pretreatment,suggesting that metformin may play an anti-inflammatory effect by suppressing MAPK signaling pathway.Conclusion Metformin attenuated inflammatory reactions in SD rats with acute liver injury induced by D -galactosamine and Pam3CSK4.
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Objective:To observe whether pretreatment with Pam3CSK4,a TLR2 agonist,could decrease the inflammation response in kidney from mice with systemic MRSA infection,and to investigate the mechanism of the attenuation of inflammation with Pam3CSK4 pretreatment. Methods:BALB/c mice were pretreated with Pam3CSK4 (10 μg/100 μl/each mouse) or PBS via tail vein once daily for two consecutive days. All mice were infected with live MRSA (ATCC43300) at 2×107 CFU/each mouse (via tail vein) 24 h after the second treatment. The levels of cytokines in kidney were measured by ELISA and real-time PCR,respectively. The relative expression of TLR2,IRAKs etc. were detected by real-time PCR. Western blot was performed to detect the phosphorylation of NF-κB, the expression of IRAK-M and A20,respectively. Results:The level of TNF-α,IL-6,IL-1β,CCL3 and IFN-γ in renal tissue from mice pretreated with Pam3CSK4 was decreased significantly compared with that from PBS-treated mice,respectively. Pam3CSK4 pretreatment down-regulated the relative expression of TLR2, inhibited the expression of IRAK-1 and the phosphorylation of NF-κB post infection. The expression of IRAK-M,one of the negative regulators in TLRs signaling pathway was increased significantly in renal tissue from Pam3CSK4-treated mice post infection. Conclusion:Pam3CSK4 pretreatment attenuated the inflammation response in kidney from mice with systemic MRSA infection,and these attenuation is related with up-regulation of IRAK-M.
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Objective:To observe whether pretreatment with Pam3CSK4,a TLR2 agonist,could decrease the inflammation response in kidney from mice with systemic MRSA infection,and to investigate the mechanism of the attenuation of inflammation with Pam3CSK4 pretreatment. Methods:BALB/c mice were pretreated with Pam3CSK4 (10 μg/100 μl/each mouse) or PBS via tail vein once daily for two consecutive days. All mice were infected with live MRSA (ATCC43300) at 2×107 CFU/each mouse (via tail vein) 24 h after the second treatment. The levels of cytokines in kidney were measured by ELISA and real-time PCR,respectively. The relative expression of TLR2,IRAKs etc. were detected by real-time PCR. Western blot was performed to detect the phosphorylation of NF-κB, the expression of IRAK-M and A20,respectively. Results:The level of TNF-α,IL-6,IL-1β,CCL3 and IFN-γ in renal tissue from mice pretreated with Pam3CSK4 was decreased significantly compared with that from PBS-treated mice,respectively. Pam3CSK4 pretreatment down-regulated the relative expression of TLR2, inhibited the expression of IRAK-1 and the phosphorylation of NF-κB post infection. The expression of IRAK-M,one of the negative regulators in TLRs signaling pathway was increased significantly in renal tissue from Pam3CSK4-treated mice post infection. Conclusion:Pam3CSK4 pretreatment attenuated the inflammation response in kidney from mice with systemic MRSA infection,and these attenuation is related with up-regulation of IRAK-M.
ABSTRACT
Objective:To evaluate immune response of murine peritoneal macrophage challenging by methicillin-resistant S.aureus(MRSA)after pretreatment with Pam3Csk4(TLR2 agonist).Methods: Murine peritoneal macrophage was pretreated with Pam3Csk4(1 μg/ml).Following pretreatment 12 h later,heat-killed MRSA( HK-MRSA) was added and incubated for another 2 or 6 hours.The protein and mRNA level of TNF-α, IL-6 and IL-1 were determined by ELISA and Q-PCR, respectively.To estimate phagocytosis of macrophage,HK-MRSA/MSSA labeled with FITC( FITC-HK-MRSA/MSSA) were added to well and incubated for 30 min.After washing 5 times with PBS,intracellular FITC-HK-MRSA was detected by flow cytometry.To estimate antimicrobal activity of macrophage,live MRSA and MSSA were added to well and incubated at indication time,the CFU of s.aureus was estimated via a 10-fold serial dilution on agar media.cDNA was further quantitative assessed using primers for mouse FCR-Ⅰ,FCR-Ⅲ,CR-1,CR-3,iNOS and LL37 by Q-PCR .Results: Compared with saline-pretreated cell, the protein and mRNA level of TNF-α, IL-6 and IL-1 were markely reduced, respectively.However, both the phagocytosis and antimicrobal activity to S.aureus were significantly increased in macrophages pretreated with Pam3Csk4.Further study found that the macrophages had higher FCR-Ⅰ,FCR-Ⅲ,CR-1,CR-3,iNOS and LL37 expression at 6 h and 12 h post-stimulation Pam3Csk4.Conclusion: The results suggest that Pam3Csk4 could activate murine antimicrobal activity of peritoneal macrophage challenging by methicillin-resistant Saureus via increasing opsonophagocytosis in depended antibodies, complements manners.The results suggest Pam3Csk4 probably be a novel immunotherapy candidate against MRSA.