ABSTRACT
<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>
Subject(s)
Animals , Male , Mice , Cells, Cultured , Drug Interactions , Glycine , Pharmacology , Interleukin-1 Receptor-Associated Kinases , Intracellular Signaling Peptides and Proteins , Genetics , Metabolism , Kupffer Cells , Metabolism , Lipopolysaccharides , Pharmacology , Mice, Inbred BALB C , NF-kappa B , Metabolism , Protein Serine-Threonine Kinases , Genetics , Metabolism , RNA, Messenger , Metabolism , Time Factors , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study the expression of lipopolysaccharide (LPS) receptor CD14 and Toll-like receptor 4 (TLR4) on Kupffer cells and its role in ischemia-reperfusion injury (IRI) on rat liver graft.</p><p><b>METHODS</b>The Kupffer cells following IRI were isolated and divided into control, ischemia-reperfusion (IR), and anti-CD14 antibody group. The mRNA and protein expression of CD14 and TLR4, nuclear factor kappa B (NF-kappaB) activity and TNF-alpha level in supernatant were measured.</p><p><b>RESULTS</b>The mRNA and protein expression of CD14 and TLR4 in IR group were significantly higher than those in control group (P < 0.01). The NF-kappaB activity and TNF-alpha level in IR group were significantly higher than those in control group (P < 0.01), and they greatly decreased after anti CD14 antibody treatment (compared with IR group, P < 0.05), but were still significantly higher than those in control group (P < 0.01).</p><p><b>CONCLUSIONS</b>LPS following IRI could up-regulate CD14 and TLR4 gene and protein expression on Kupffer cells, and subsequently activate NF-kappaB to produce cytokines, but other signal transduction pathways might also participate in the IRI.</p>