ABSTRACT
Objective To investigate the antiproliferative effect of rosiglitazone, a thiazolidinedione (TZD) on autosomal dominant polycystic kidney disease (ADPKD) cystic lining epithelial cells and to explore the underlying molecular mechanism. Methods ADPKD cysticlining immortalized epithelial (WT9-12) cells were stimulated by rosiglitazone with different concentrations. After treatment, MTT method was performed to detect the level of proliferation; flow cytometry was used to determine the cell cycle distribution and the apoptosis rate. Western blotting was used to detect the protein expressions of mTOR, p70S6K, 4E-Bp1, PPARγ PPARγ siRNA was transfected into WT9-12 cells to knock down the expression of PPARγ Results Treatment of WT9-12 cells with rosiglitazone resulted in a dose-dependent and time-dependent strong inhibition of cell proliferation, an accumulation of cells in the G0/G1 phase (rosiglitazone 50 μmol/L 65.43%,rosiglitazone 100 μmol/L 64.02%, control 49.65% ) and 6% apoptosis at high concentration (rosiglitazone 200 μmol/L). Rosiglitazone reduced the phosphorylation of p70S6K in a dosedependent and time-dependent manner. The levels of phosphorylated mTOR and 4E-Bp1, the latter being a downstream substrate of mTOR related mRNA translation initiation, were not changed by rosiglitazone. Cells were pre-incubated with GW9662, a PPARγ antagonist, before the treatment with rosiglitazone, the inhibition of p70S6 kinase phosphorylation by rosiglitazone was partially prevented by GW9662 (P＜0.01). Then PPARγ siRNA was transfected into WT9-12 cells, in contrast to untransfected control or cells transfected with an irrelevant siRNA, rosiglitazone did not cause an obvious inhibition of p70S6 kinase phosphorylation in PPARγ knock-down.Conclusion Rosiglitazone inhibits the proliferation of ADPKD cystic lining epithelial cells, and down-regulates p70S6 kinase phosphorylation through mTOR-independent and PPARγ-dependent signal pathway.
ABSTRACT
Objective To investigate the safety and tolerability of darbepoetin alfa.a long-lasting erythmpoietin,single intravenous administration in maintenance hemodialysis(MHD) patients. Methods A single center,open clinical trial was carried out.Forty-three stable MHD patients were divided into 5 groups and received darbepoetin α at dosage of 0.225,0.45,0.9,1.8,3.6 μg/kg respectively.The vital signs,symptoms,ECG and laboratory examinations were monitored and detected before and after administration. Results Of the 43 patients (male 26and female 17),the largest tolerable dosage of darbepoetin alfa was 3.6 μg/kg.During the study,the main side effect associated with darbepoetin was hypertension aggravation(7%).One patient died but that was not associated with darbepoetin alfa. Conclusion Darbepoetin alfa is sale and well tolerated.