Involvement of leukotrine B4 receptors in the inflammatory responses and immunological regulation in vitro / 中国应用生理学杂志

<p><b>AIM</b>BLT1 and BLT2 were both recently cloned and identified as two subtypes of leukotrine B4 (LTB4) receptors. With the usage of U-75302 and LY255283, the specific antagonists of BLT1 and BLT2 respectively, the involvement of BLT1 and BLT2 in the inflammatory and immunological responses was in vitro explored.</p><p><b>METHODS</b>(1) To investigate inhibition of U-75302 and LY255283 on the proliferation of rat synovial cells, 3H-TdR incorporation into the cells was quantified. (2) Flow cytometric assay for interferon-gamma (IFN-gamma) and interleukine 4 (IL-4) profiles in CD4+ T lymphocytes from rat spleen was carried out to determine the ratio of Th1/Th2.</p><p><b>RESULTS</b>(1) For inhibition on rat synovial cells proliferation, U-75302 exerted its effect only at a high concentration of 10 micromol/L and LY255283 at the concentrations of 10 micromol/L-10 micromol/L. (2) Both U-75302 and LY255283 could elevate the percentage of Th2, but could not influence that of Th1.</p><p><b>CONCLUSION</b>BLT1 and BLT2 were involved in the synovial cells proliferation change the ratio of Th1/Th2. Their meaning served as targets for prevention and treatment of infectious diseases should be emphasized.</p>

Molecular cloning, tissue distribution and expression in engineered cells of human orphan receptor GPR81 / 生物工程学报

The gpr81 was amplified by polymerase chain reaction (PCR) using human fetus kidney cDNA and whole blood genome DNA as template, respectively. The expression profile of gpr81 in human fetus was analyzed by RT-PCR and the result indicated GPR81 mRNA was most abundant in fetus liver and heart. In addition, the deduced amino acid of GPR81 was compared with other related molecules by Clustal w/x software, and a molecular phylogenetic tree was constructed with Treeview software. It was showed that GPR81 had the highest homology with nicotinic acid receptor in amino acids. After sequence identification, gpr81 was inserted into the plasmid pcDNA3. 1 (-)/his-mycA and then transfected into Chinese hamster ovary cell (CHO-K1). With the selection of G418, an engineered cell line which could stably express gpr81 was obtained by the indication of RT-PCR and Western-blot detection. The establishment of the cell line will serve as means for further study of GPR81.

Subcellular localization and tissues expression profile of hGPCRc: an orphan G protein-coupled receptor / 生物工程学报

As a member of orphan G protein-coupled receptors (oGPCRs), hGPCRc was cloned from human colon tissue and analyzed by bioinformatic softwares. It was showed that the corresponding amino acids of hGPCRc formed seven-transmembrane domains as the key characteristic of GPCRs. Then, the recombinant GFP-hGPCRc was constructed by fussing hGPCRc into pEGFP-N1 carrying green fluorescent protein (GFP) gene, and CHO-K1 cells were subsequently transfected with the GFP-hGPCRc or pEGFP-N1. The green fluorescence protein expression in the two different transfected cells was observed under the laser scanning confocal microscopy (LSCM). It was showed that green fluorescence protein was distributed in the whole bodies of the cells transfected with pEGFP-N1, but mainly distributed on the plasma membrane and cytoplasm membrane transfected with GFP-hGPCRc. Thus, the localization on the membrane of hGPCRc was accorded with the predication by bioinformatic analysis. The expression analysis of hGPCRc by RT-PCR indicated that hGPCRc was abundantly expressed in heart, kidney, cerebel and colon etc., but absent in liver, cerebra, small intestine and muscle etc. The expressing profile of hGPCRc could provide some useful clues to understanding its effects on embryonic development and physiological functions.