The role of myeloid differentiation protein-2 in lipopolysaccharide-induced cellular activation of human endothelial cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the expression of myeloid differentiation protein-2 (MD-2) in the human endothelial cells and its role in lipopolysaccharide (LPS)-induced NF-kappaB activation in endothelial cells.</p><p><b>METHODS</b>In vitro cultured human umbilical vein endothelial cells (HUVEC) were employed in the study. The expression of MD-2 mRNA and protein, and the effect of LPS on the expression of its mRNA and protein were assessed with RT-PCR and Western blotting. The role of MD-2 in LPS-induced NF-kappaB activation and IL-8 production were investigated with gene transfection of mutant MD-2 cDNA (0.5, 1.0, 2.0 microg), pEF-BOS vacant vector (2.0 microg) and MD-2 plasmid (2.0 microg) into HUVEC, respectively.</p><p><b>RESULTS</b>There was MD-2 mRNA and protein expression in HUVECs before LPS stimulation, and it could be obviously upregulated by LPS in time and dose-dependent manner (MD-2 protein absorbency was 25 196 +/- 1 723 without LPS stimulation, which was obviously lower than that stimulated with 0.01 mg/L LPS (58 817 +/- 3 241, P < 0.01) for 6 hours. Transfection of mutant MD-2 cDNA could remarkably inhibit LPS-induced NF-kappaB activation and IL-8 production in endothelial cells.</p><p><b>CONCLUSION</b>MD-2 might play an important role in the LPS-induced NF-kappaB activation in HUVECs.</p>

Novel multi-probe RNase protection assay set for detection of endotoxin associated receptors gene expression / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To construct the multi-probe ribonuclease protection assay (RPA) template set to be used for detecting expression patterns of MD-2, TLR4, CD14 mRNAs in human peripheral blood mononuclear cells.</p><p><b>METHODS</b>The designed cDNA fragments of the three genes were generated by polymerase chain reaction (PCR) using specific primers and directionally cloned into EcoR I and Hind III sites of expression plasmid pSP72 containing the T7 promoter, the linearized plasmids was used as template to synthesize anti-sense RNA probes. Then we extracted total RNA from peripheral blood mononuclear cells (PBMC) and detected the dynamic expression patterns of the three genes with RPA method.</p><p><b>RESULTS</b>The proper sequence and orientation of the template set were confirmed by sequencing and the template set was successfully used to assay TLR4, MD-2 and CD14 mRNAs in human PBMC. The results showed that the three detected genes decreased transiently 1-3 hours after 100 ng/ml LPS stimulation.</p><p><b>CONCLUSIONS</b>These new RPA multi-probe set provided valuable tool for the simultaneous quantitative determination of expression of TLR4, CD14 and MD-2 mRNAs in both constitutive and inducible types.</p>