Protective effect of grape seed proanthocyanidin on cultured RGC-5 cells against CoCl2-induced hypoxic injury / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the protective effects of grape seed proanthocyanidin extracts (GSPE) against CoCl2-induced hypoxic injury in cultured RGC-5 cells.</p><p><b>METHODS</b>CoCl2(400 μmol/L) was used to induce hypoxic injury in cultured RGC-5 cells; the cells were pretreated with 0,100,200,400 and 800μmol/L GSPE for 24h. The cell viability was assayed by MTT; the apoptosis was detected by Hoechst 33342 staining; the intracellular reactive oxygen species (ROS) was measured by H2DCFDA oxidative reaction. The mRNA expression of Bcl-2, caspase 9 and caspase 3 was determined by real-time PCR.</p><p><b>RESULTS</b>Compared to hypoxic control group, pretreatment with GSPE significantly increased viability of RGC-5 cells (P<0.001), reduced cell apoptosis (P<0 .001) and intracellular ROS(P <0 .001). In addition, GSPE significantly increased the mRNA expression of Bcl-2(P<0 .001) and decreased mRNA expression of caspase 9(P<0 .001) and caspase 3(P<0 .001) compared to hypoxic control group.</p><p><b>CONCLUSION</b>GSPE may have a protective effect against CoCl2-induced hypoxic injury in cultured RGC-5 cells. The decrease of intercellular ROS, up-regulation of Bcl-2 and down-regulation of caspase 9 and caspase 3 may be involved in the mechanism of the protective effect of GSPE.</p>

Construction of HEK293 cell lines expressing hCysLT₂ receptor and its application in screening of antagonists / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To construct HEK293 cell lines stably expressing hCysLT(2) receptor, and to evaluate its application in screening of synthetic compounds with antagonist activity.</p><p><b>METHODS</b>The recombinant plasmid pcDNA3.1(+)-hCysLT(2) was transfected into HEK293 cells using Lipofectamin 2000. The transfected HEK293 cells were selected in 96 well plates by limiting dilution with 600 μg/ml C418 for 8 weeks. The expression of human CysLT(2) receptor was detected by RT-PCR and immunofluorescence staining. In HEK293 cells stably transfected with hCysLT(2), the agonist LTD(4)-induced elevation of intracellular calcium concentration ([Ca2(+)]i) was measured as the index for screening compounds with antagonist activity.</p><p><b>RESULT</b>After selection in 96 well plates by limiting dilution, 12 monoclones were obtained and 11 of them highly expressed hCysLT(2) receptor. The positive control ATP at 50 μmol/L and LTD(4) at 100 nmol/L elevated [Ca2(+)]i in hCysLT(2)-HEK293 cells. AP-2100984 inhibited LTD(4)-induced [Ca2(+)]i elevation, but selective CysLT(1) receptor antagonists did not exert such an effect. The newly synthesized compounds DXW2, DXW3, DXW4, DXW5, DXW9, DXW25, DXW26, DXW29 and DXW35 at 1 μmol/L significantly inhibited LTD(4)-induced [Ca2(+)]i elevation. The IC(50) values of DXW4 and DXW5 were 0.25 μmol/L and 7.5 μmol/L.</p><p><b>CONCLUSION</b>HEK293 cell lines stably expressing hCysLT(2) receptor have been successfully constructed, and can be used to screen compounds with CysLT(2) receptor antagonist activity.</p>

Construction and identification of eukaryotic expression vector of rat GPR17 gene / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To construct the eukaryotic expression vector of rat GPR17 (rGPR17) cDNA,and to identify its function in HEK293 cells.</p><p><b>METHODS</b>Total RNA was extracted from rat brain tissue; full-length GPR17 cDNA was prepared by RT-PCR, and cloned into pcDNA3.1(+) plasmid. The recombinant plasmid was converted into E.coli DH5alpha and confirmed by PCR, double enzyme digestion analysis and DNA sequencing. The recombinant plasmid pcDNA3.1(+)-rGPR17 was transiently transfected into HEK293 cells using Lipofectamin 2000. Expression of rGPR17 gene was confirmed by RT-PCR and immunofluorescence staining. The exogenous LTD(4) enhanced intracellular calcium was measured using Fluo-4.</p><p><b>RESULT</b>RT-PCR, double enzyme digestion analysis and sequencing showed that the rGPR17 gene was cloned into recombinant vector, and the recombinant rGPR17 was expressed after transfection in HKE293 cells. LTD(4) increased intracellular calcium release in the transfected HEK293 cells.</p><p><b>CONCLUSION</b>The eukaryotic expression vector of rGPR17 cDNA has been constructed; it is functionally expressed in HEK293 cells. This work provides a basis for further research of the GPR17 receptor and its antagonists.</p>