12-Lipoxygenase is increased in glucose-stimulated mesangial cells and in experimental diabetic nephropathy
12-Lipoxygenase is increased in glucose-stimulated mesangial cells and in experimental diabetic nephropathy
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DOI：
10.1046/j.1523-1755.2001.0590041354.x
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发表时间：
2001-04-01
影响因子：
19.6
通讯作者：
Natarajan, R
中科院分区：
文献类型：
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作者：
Kang, SW;Adler, SG;Natarajan, R
背景资料。花生四烯酸衍生的12-脂氧合酶(12-LO)产物具有强大的生长和趋化特性。本研究旨在探讨高糖对体外培养的大鼠肾小球系膜细胞(MC)是否诱导12-LO和纤维连接蛋白的表达，以及它们在实验性糖尿病肾病中的表达。为探讨高糖对MC 12-LO基因和蛋白表达的影响，用含100 mg/dL和450 mg/dL葡萄糖的RPMI培养液孵育大鼠肾小球系膜细胞。在动物研究中，大鼠被注射稀释剂(对照)或链脲佐菌素。后者不接受治疗(DM)或胰岛素治疗(DM+I)。4个月后处死动物，用竞争性逆转录聚合酶链式反应(RT-PCR)检测肾小球(G)中GAPDH、12-LO和纤维连接蛋白(FN)的表达。肾切片用免疫组织化学方法对糖尿病的改变和12-LO和纤维连接蛋白进行半定量评分(0~4+)。HG(12.71+/-1.17attm/mul)和DM G(1.78+/-0.65x10(-3)attm/肾小球)培养的MC的12-LO基因表达显著高于NG培养液(6.71+/-0.78attm/mul)和中央G(0.34+/-0.12×10(-3)attm/肾小球，P<；0.005)。Western印迹显示MC和G12-LO蛋白表达分别增加1.7倍和2.8倍(P<；0.05)。糖尿病组和糖尿病+I组G12-LO免疫组织化学评分和糖尿病肾病评分均显著高于对照组。MC和G-GAPDHm RNA无明显变化。在暴露于HG的MC和糖尿病大鼠肾小球中，12-LO基因和蛋白的增加与糖尿病肾病模型的改变有关。这些发现提示12-LO通路在糖尿病肾病的发病机制中起作用。
Background. Arachidonic acid-derived 12-lipoxygenase (12-LO) products have potent growth and chemotactic properties. The present studies examined whether 12-LO and fibronectin are induced in cultured rat mesangial cells (MCs) exposed to high glucose and whether they are expressed in experimental diabetic nephropathy.Methods. To determine the effect of high glucose on MC 12-LO mRNA and protein expression, rat MCs were incubated with RPMI medium containing 100 (NG) or 450 mg/dL glucose (HG). For animal studies, rats were injected with diluent (control) or streptozotocin. The latter were left untreated (DM) or treated with insulin (DM + I). At sacrifice after four months, GAPDH, 12-LO, and fibronectin mRNA were measured by competitive reverse transcription-polymerase chain reaction (RT-PCR) in microdissected glomeruli (G). Renal sections were semiquanlitatively scored (0 to 4+) for diabetic changes and for 12-LO and fibronectin by immunohistochemistry.Results. 12-LO mRNA expression in MC exposed to HG (12.71 +/- 1.17 attm/mul) and DM G (1.78 +/- 0.65 x 10(-3) attm/ glomerulus) was significantly higher than those of MCs in NG media (6.71 +/- 0.78 attm/muL) and central G (0.34 +/- 0.12 X 10(-3) attm/glomerulus, P < 0.005), respectively. Western blot revealed a 1.7- and a 2.8-fold increase in MC and G 12-LO protein expression, respectively (P < 0.05). The immunohistochemistry score for G 12-LO and diabetic nephropathy score was significantly greater in DM and DM + I than controls. MC and G GAPDH mRNA remained unchanged.Conclusions. In MCs exposed to HG and in diabetic rat glomeruli, increments in 12-LO mRNA and protein are associated with changes modeling diabetic nephropathy. These findings suggest a role for the 12-LO pathway in the pathogenesis of diabetic nephropathy.