甲状旁腺素对大鼠系膜细胞增殖及凋亡的影响

Effect of parathyroid hormone on proliferation and apoptosis of rat glomerular mesangial cells cultured in vitro

目的观察甲状旁腺素(PTH)对体外培养的大鼠肾小球系膜细胞(GMC)增殖及凋亡的影响,并探讨其作用的可能机制。方法体外培养的大鼠系膜细胞经不同浓度的PTH作用后,采用噻唑蓝(MTT)法检测细胞增殖,流式细胞仪测定细胞周期及凋亡,吖啶橙荧光活体染色观察细胞凋亡形态,免疫细胞化学结合计算机图文分析系统检测c-jun、c-fos表达。结果PTH持续刺激GMC6h、12h时,10-11～10-9mol/L浓度范围内,促进细胞增殖(P<0.05);10-9mol/L在12h达高峰,并可使G0～G1期细胞减少,S+G2M期细胞增多,并能明显促进c-jun、c-fos的表达(P<0.01),而10-8mol/L无明显作用;刺激24h时各浓度均无作用;刺激48h各浓度明显抑制大鼠系膜细胞增殖(P<0.01),且使细胞阻滞在G0～G1期,不能进入S期,并能明显抑制c-jun、c-fos的表达(P<0.01)。PTH不诱导GMC凋亡。结论PTH体外刺激GMC增殖与作用时间及剂量相关,低浓度短时间作用刺激GMC增殖,持续作用抑制GMC增殖,其作用与c-jun、c-fos的表达有关,并影响细胞周期。PTH对体外培养的大鼠GMC凋亡无诱导作用。甲状旁腺机能亢进可能参与了慢性肾病残余肾功能进一步恶化的病理过程。

Objective To investigate the effect of PTH on proliferation and apoptosis of rat mesangial cells glomerular(GMC)cultured in vitro and explore its possible mechanism.Methods Rat GMCs were incubated with different concentrations of PTH and different times.Cell proliferation was assessed by MTT colorimetric assay.Cell cycle and apoptosis was analyzed by flow cytometry. Form of apoptosis was examined by vital staining of alcidine orange.The expression of c jun and c fos was determined by immunocytochemistry and computed video text analysis system.Results Incubation with 10-11～10-9mol/L PTH for 6 h and 12 h promoted the proliferation of GMC(P< 0 05)and the most remarkable proliferation effect was observed by 10-9mol/L for 12 h.It also decreased the cell in G0～G1 phase and increased the cell in S+G2M phase ,and markedly promoted expression of c Jun and c fos(P< 0 01). No obvious effects were found in 10-8mol/L for 6～12 h and in each concentration at 24 h,while GMC proliferation was significantly inhibited at 48 h(P< 0 01),and cells were blocked at G0～G1 stage.In addition,PTH could markedly inhibit the expression of c jun and c fos(P< 0 01),and could not induce apoptosis of GMC. Conclusions PTH possesses an effect on proliferation of rat GMC cultured in vitro,which was associated with time and dose. It can stimulate the proliferation in lower concentration and shorter time, and inhibit the proliferation in longer time. These effects,which can affect cell cycle,may be related to the expression of c Jun and c fos. PTH dose not induce apoptosis of rat GMCs cultured in vitro. Hyperparathyroidism may take part in the pathologic progress in remnant renal function of the chronic kidney disease.