Effects of PPARγ on the cholesterol efflux of C57 mice peritoneal macrophage in inflammatory conditions / 中国现代普通外科进展

Objective:To explore the effects of PPARγ on the cholesterol efflux of C57 mice peritoneal macrophage.Methods:Firstly constructing C57 mice model under different metabolic situation including high-fat diet and acute inflammation then isolate and culture its peritoneal macrophage,observing the expressions of PPARγ and IκB-α,identify the character of macrophage cholesterol efflux in every group.Then pretreat the normol C57 mice peritoneal macrophage with PPARγ ligand ciglitazone and PPARγ antisense oligonucleotide,observing the effect to cholesterol efflux after simulated with LPS in vitro.Results:The level of mice serum lipids of high fat diet group was significantly higher than that of normal diet group.The results of Western-blotting showed that the expression of PPARγ protein in groups of HFD and stimulated by LPS were significantly higher than that of control group.The expression in groups stimulated by LPS was all lower significantly than in control grouph.The determination of cholesterol efflux showed that this function of macrophage with HFD was more enhanced than that of control group but was inhibited in group stimulated by LPS.To normol peritoneal macrophage pretreat with PPARγ antisense oligonucleotide and stimulated by LPS,the expression of PPARγ protein was lower than that of control group but the expression of IκB-α was depressed obviously.Conclusion:The PPARγ ligand ciglitazone can increase the cholesterol efflux of C57 mice peritoneal macrophage and weaken the inhibition stimulated by LPS.The PPARγ antisense oligonucleotide can depress it and aggravate the inhibition.

The protection mechanisms of glycine against liver injury induced by lipopolysaccharides / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the protective mechanisms of glycine (Gly) on lipopolysaccharides (LPS) induced liver injury.</p><p><b>METHODS</b>BABL/c mice were randomly divided into a LPS group, in which the animals were intraperitoneally injected with 10 mg/kg LPS, and a Gly group, in which the mice were pretreated with a 5% Gly-containing diet for 3 days before receiving the same dose of LPS. The livers of the mice were examined for histopathological changes. The TNF alpha and interleukin-10 (IL-10) levels in the blood plasma were measured using ELISA analysis. The mRNA expression of TNF alpha, IL-10 and Toll-like receptor 4 (TLR4) in hepatic tissues were detected using RT-PCR analysis. Protein expression of TLR4 in livers was detected using immunohistochemistry.</p><p><b>RESULTS</b>The Gly group mice had an improved survival rate and attenuated LPS-induced pathological changes in the liver tissues in comparison with those of the LPS group animals. The TNF alpha levels [(1,852.80+/-126.64) pg/ml vs (708.83+/-51.29) pg/ml, P<0.05] in plasma, as well as the expression of TNF alpha (A 1.59+/-0.14 vs. 0.91+/-0.11, P<0.05) and TLR4 (A 0.97+/-0.12 vs. 0.53+/-0.11, P<0.05) mRNA in liver tissues were decreased. However, the levels of plasma interleukin-10 [(344.09+/-31.70) pg/ml vs (418.64+/-38.86) pg/ml, P<0.05] were significantly increased and the peaking time left, shifted.</p><p><b>CONCLUSIONS</b>Gly pretreatment could attenuate LPS -induced liver injury in mice, which may be associated with its role in down-regulating TLR4 expression and up-regulating IL-10 production.</p>

Expression changes of interleukin-1 receptor associated kinase-4 during endotoxin tolerance development in kupffer cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the mechanism of endotoxin tolerance (ET) through observing the expression of interleukin 1 receptor associated kinase-4 (IRAK-4) during endotoxin tolerance development in Kupffer cells (KCs).</p><p><b>METHODS</b>Isolated KCs of Balb/c mouse were divided into two groups: the non-endotoxin tolerance (NET) group and the endotoxin tolerance (ET) group, which were pretreated with 10 ng/ml lipopolysaccharide (LPS) for 24 h. Then, the two groups were treated with 100 ng/ml LPS. The expressions of IRAK-4 gene and protein level were determined by RT-PCR and Western blot. The activities of NF-kappaB of KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h after LPS stimulation.</p><p><b>RESULTS</b>The ultimate level of IRAK-4, the activities of NF-kappaB and the TNFalpha level were evidently lower in the ET group than those in the NET group (t = 12.4, 17.4 and 138.9 respectively, P<0.01).</p><p><b>CONCLUSIONS</b>Pretreatment with LPS on KCs could induce endotoxin tolerance of KCs and inhibition of IRAK-4 expression may be one of the reasons for its development.</p>

The mechanism and treatment phases chosen of glycine for inhibition lipopolysaccharide induced Kupffer cells activation / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the possible mechanism and optimal treatment phase of glycine for inhibition lipopolysaccharide (LPS) induced Kupffer cells (KCs) activation.</p><p><b>METHODS</b>The KCs were isolated from 40 BALB/c mice and divided into four groups: the endotoxin group, the prevention group, the early treatment group and the later treatment group (n = 10). The endotoxin group was treated with 10 mg/L LPS, and in the other three groups, glycine (1 mmol/L) was given 24 h before, or at 0 h or 4 h respectively after LPS stimulation. At 0 h, 1 h, 2 h, 6 h and 12 h after LPS stimulation, the mRNA levels and protein expression of interleukin-1 receptor associated kinase-4 (IRAK-4) were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot respectively, and nuclear factor-kappaB (NF-kappaB) activities as well as tumor necrosis factor alpha (TNF-alpha) levels were also detected by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The climax values of IRAK-4, NF-kappaB and TNF-alpha were significantly higher in the endotoxin group and the later treatment group than that in the other two groups (t = 3.17, 4.33, 2.47, 126.73, P < 0.01).</p><p><b>CONCLUSION</b>The results indicated that prophylactic or simultaneous treatment with glycine could effectively inhibit LPS-induced KCs activation by inhibiting IRAK-4 expression.</p>

An experimental study of the inhibitory effects on the activation of endotoxin-induced Kupffer cells through short hairpin RNA targeting interleukin-1 receptor associated kinase-4 gene / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the inhibitory effects on the activation of endotoxin-induced Kupffer cells (KCs) through short hairpin RNA (shRNA) targeting interleukin-1 receptor associated kinase-4 (IRAK-4) gene.</p><p><b>METHODS</b>Two effective transfection shRNA plasmid (pSIIRAK-4-A, pSIIRAK-4-B) and one invalidated plasmids (pSIIRAK-4-C) targeting IRAK-4 gene were constructed. The isolated mouse KCs were divided into three groups: the normal control group, the RNAi control group (pSIIRAK-4-C) and the RNAi effective group (pSIIRAK-4-A, pSIIRAK-4-B). Then KCs were stimulated with 0.1 microg/ml lipopolysaccharide (LPS) after 24 h transfection with the constructed plasmid. The expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blot at 6 h after LPS stimulation, and the activities of NF-kappaB in KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h.</p><p><b>RESULTS</b>The level of IRAK-4, the activities of NF-kappaB and the TNF-alpha level in the RNAi effective group were evidently lower than those in normal and RNAi control groups (P < 0.01) at 1 h, 3 h, and 6 h. Especially, the pSIIRAK-4-A group in which the changes of the above indices were of no difference (P > 0.05), had better inhibited effects than that of the pSIIRAK-4-B group (P < 0.01).</p><p><b>CONCLUSION</b>The shRNA targeting IRAK-4 gene could effectively inhibit the activation of endotoxin-induced KCs.</p>