低密度脂蛋白对肾小球系膜细胞、TGF-β和FNmRNA表达的影响

Effects of low density lipoprotein on the growth of mesangial cells, the expression of transforming growth factor-β and fibronectin mRNA

目的 :观察低密度脂蛋白 (L DL )对体外培养的大鼠肾小球系膜细胞 (Ms C)生长及转化生长因子β(TGF-β)和纤维连接蛋白 (FN)基因表达的影响。 方法 :体外培养的 Ms C培养液中加入 L DL 共同孵育 ,采用 3H- Td R渗入法检测 Ms C增殖情况 ;应用 Northern blot检测 TGF- β m RNA和 FN m RNA的表达 ;应用斑点杂交法检测抗 TGF- β抗体对 FN m RNA表达的影响。结果 :(1) L DL 刺激 Ms C在小剂量以剂量依赖 (5 0～ 15 0 μg/ ml)和时间依赖 (2 4～ 72 h)促进增殖 (P<0 .0 5 ) ,大剂量 (2 0 0μg/ ml)抑制增殖 (P<0 .0 5 )。 (2 ) Northern blot显示 L DL 刺激 Ms C增殖 ,其 TGF- β和 FN m RNA表达以剂量和时间依赖方式增强。 TGF-β m RNA表达较 FN m RNA提前 2 4h。 (3) Dot blot显示 ,加入抗 TGF-β抗体后 ,FN m RNA的表达较未加前明显减弱。 结论 :L DL不仅可刺激肾小球 Ms C的增殖 ,并且增加 TGF-β和 FN m RNA的表达。

Objective: To study the effect of gow density lipoprotein (LDL) on the proliferation of glomerular mesangial cells (MsC) and the expression of transforming growth factor β (TGF β) and fibronectin (FN) mRNA in rat MsC. Methods: 3H TdR incorporation for the detection of MsC proliferation. Northern blot analysis for the determination of TGF β and FN mRNA expression were used. Results: (1) LDL had biphasic effect on MsC proliferation. Low concentration stimulated MsC proliferation in a concentration dependent (50 150 μg/L) and time dependent (25 72 hours) manner, whereas high concentration (200 μg/L) inhibited MsC proliferation. (2) Northern blot analysis revealed an increase of TGF β and FN mRNA levels in a concentration dependent and time dependent manner in MsC stimulated by LDL. The expression of TGF β mRNA was 24 hours earlier than that of FN mRNA. (3) The expression of FN mRNA in MsC cultured with media containing anti TGF β antibody decreased significantly. Conclusion: LDL can stimulate mesangial cell proliferation, enhance TGF β and FN mRNA expression.