Nox4 NAD(P)H oxidase mediates hypertrophy and fibronectin expression in the diabetic kidney
Nox4 NAD(P)H oxidase mediates hypertrophy and fibronectin expression in the diabetic kidney
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DOI：
10.1074/jbc.m502412200
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发表时间：
2005-11-25
影响因子：
4.8
通讯作者：
Abboud, HE
中科院分区：
文献类型：
--
作者：
Gorin, Y;Block, K;Abboud, HE
肾脏肥大和细胞外基质积聚是糖尿病肾病的早期特征。我们研究了NAD(P) H氧化酶Nox4在链脲佐菌素诱导的1型糖尿病大鼠模型中活性氧（ROS）的产生、肥厚和纤维连接蛋白表达中的作用。在链脲佐菌素治疗72小时后，用渗透性微型泵给予Nox4的磷酸化反义（AS）或义寡核苷酸2周。与非糖尿病对照组相比，Nox4蛋白在糖尿病肾皮质中的表达增加，而在as处理的动物中表达下调。AS寡核苷酸抑制肾皮质和肾小球匀浆中nadph依赖性ROS的产生。与as处理动物的肾小球相比，糖尿病动物的完整离体肾小球产生的ROS增加。AS治疗减轻了整个肾脏和肾小球的肥大。此外，as治疗的糖尿病大鼠肾皮质包括肾小球中纤维连接蛋白的表达明显减少。Akt/蛋白激酶B和ERK1/2是两种对细胞生长和肥大至关重要的蛋白激酶，在糖尿病中被激活，而AS治疗几乎消除了它们的激活。在培养的系膜细胞中，高葡萄糖增加了NADPH氧化酶活性和纤维连接蛋白的表达，这种作用在转染AS寡核苷酸的细胞中被阻止。这些数据证实了Nox4在糖尿病早期肾脏中作为ROS的主要来源所起的作用，并证实了Nox4衍生的ROS介导肾肥大和纤维连接蛋白表达的增加。
Renal hypertrophy and extracellular matrix accumulation are early features of diabetic nephropathy. We investigated the role of the NAD(P) H oxidase Nox4 in generation of reactive oxygen species (ROS), hypertrophy, and fibronectin expression in a rat model of type 1 diabetes induced by streptozotocin. Phosphorothioated antisense (AS) or sense oligonucleotides for Nox4 were administered for 2 weeks with an osmotic minipump 72 h after streptozotocin treatment. Nox4 protein expression was increased in diabetic kidney cortex compared with non-diabetic controls and was down-regulated in AS-treated animals. AS oligonucleotides inhibited NADPH-dependent ROS generation in renal cortical and glomerular homogenates. ROS generation by intact isolated glomeruli from diabetic animals was increased compared with glomeruli isolated from AS-treated animals. AS treatment reduced whole kidney and glomerular hypertrophy. Moreover, the increased expression of fibronectin protein was markedly reduced in renal cortex including glomeruli of AS-treated diabetic rats. Akt/protein kinase B and ERK1/2, two protein kinases critical for cell growth and hypertrophy, were activated in diabetes, and AS treatment almost abolished their activation. In cultured mesangial cells, high glucose increased NADPH oxidase activity and fibronectin expression, effects that were prevented in cells transfected with AS oligonucleotides. These data establish a role for Nox4 as the major source of ROS in the kidneys during early stages of diabetes and establish that Nox4-derived ROS mediate renal hypertrophy and increased fibronectin expression.