摘要目的 本文探讨基质细胞趋化因子1α (stromal cell-derived factor-1,SDF-1α)对人肾小管上皮细胞(HK细胞)细胞外基质(Ⅳ型胶原)表达的影响.方法 不同浓度的葡萄糖培养HK细胞,分为正常葡萄糖组(NG组:含5.5 mmol/L葡萄糖)和高糖组(HG组:含25.0 mmol/L葡萄糖),分别用转化生长因子β1 (TGF-β1)和SDF-1α干预HK细胞12h,再分为空白对照组(NC组)、阴性对照组(DMSO组)、T组(TGF-β1组)、S组(SDF-1α组)、T+S组(TGF-β1和SDF-1α共同干预组),采用实时定量聚合酶链反应(RT-PCR)和Western blotting分别检测Ⅳ型胶原mRNA和蛋白的表达.两组间比较采用t检验.结果 (1)HK细胞能持续表达SDF-1α和其受体CXCR4 mRNA.高糖条件下SDF-1α和CXCR4mRNA表达呈时间梯度增加,24 h两者表达量达到高峰.24 h CXCR4 mRNA表达量是12h表达量的1.2倍(t=6.08,P＜0.05),SDF-1αmRNA表达量是12h的1.58倍(t=7.52,P＜0.05).(2)高糖条件下SDF-1α抑制HK细胞Ⅳ型胶原mRNA和蛋白的表达,并能降低由TGF-β1诱导的Ⅳ型胶原表达.S+T组Ⅳ型胶原mRNA表达量是T组的0.33倍(t=12.57,P＜0.05),蛋白表达量是T组的0.47倍(t=14.23,P＜0.05).但在正常葡萄糖条件下,SDF-1α对由TGF-β1诱导的Ⅳ型胶原表达没有影响.(3)TGF-β1促进HK细胞Ⅳ型胶原mRNA和蛋白表达,高糖条件下其促进作用更为显著.T组Ⅳ型胶原mRNA是正常对照组的6.63倍(t=19.21,P＜0.05),蛋白表达量是其2.59倍(t=15.71,P＜0.05).结论 高糖条件下SDF-1α能减轻TGF-β1诱导的HK细胞Ⅳ型胶原表达,可能由此改善肾脏纤维化.TGF-β1促进HK细胞Ⅳ型胶原的表达,促进肾脏纤维化的发生发展.

abstractsObjective To explore the effect of stromal cell-derived factor-1α (SDF-1α) on extracellular matrix (type Ⅳ collagen) in human renal proximal tubular epithelial cells (HKC) with the different glucose conditions.Methods HK cell were cultured exposed to SDF-1α and transform growth factor-β1(TGF-β1) of the different concentration with normal (NG group:5.5 mmol/L glocuse) or high (HG group:25.0 mmol/L glucose) glucose.With the stimulation of TGF-β1 and SDF-1α for 12 hours later,the HKC were divided to the following groups:control group(NC group),S group (SDF-1α alone),T group (TGF-β 1 alone),S+T group(SDF-1α and TGF-β1 together).Real-time PCR and Western blotting were used to detect the m RNA and protein expression of type Ⅳ collagen in HKC.Comparison between two groups was using t test.Results (1)The m RNA expression of SDF-1α and CXCR4 mRNA was detected continuously in HKC.High glucose could increase the expression of SDF-1α and CXCR4 mRNA in HKC with a time-dependent manner,which reached the highest level at 24 h.The mRNA level of CXCR4 at 24 h was 1.2 times of those at 12 h(t-6.08,P＜0.05),meanwhile the mRNA level of SDF-1α at 24 h was 1.58 times of those at 12 h(t=7.52,P＜0.05).(2)With high glucose SDF-1α suppressed the mRNA and protein expression of type Ⅳ collagen induced by TGF-β1 in HKC.The mRNA and protein expression level of type Ⅳ collagen in S+T group were 0.33 times (t=12.57,P＜0.05),and 0.47 times (t=14.23,P＜0.05) of those in T group,respectively.Under the normal glucose condition,SDF-1α had no effect on the expression of type Ⅳ collagen induced by TGF-β1.(3)TGF-β1 stimulated mRNA and protein expression of type Ⅳ collagen in HKC,especially in high glucose.The mRNA and protein expression level of type Ⅳ collagen in T group were 6.63 times (t=19.21,P＜0.05),and 2.59 times (t=15.71,P＜0.05) of those in control group respectively.Conclusions (1)SDF-1α maybe attenuate the renal fibrosis by suppressing the expression of type Ⅳ collagen induced by TGF-β1 in high glucose.(2)TGF-β1 promotes the development of DN by increasing the expression of type Ⅳ collagen in HKC.