Identification of MicroRNA-93 as a Novel Regulator of Vascular Endothelial Growth Factor in Hyperglycemic Conditions
Identification of MicroRNA-93 as a Novel Regulator of Vascular Endothelial Growth Factor in Hyperglycemic Conditions
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DOI：
10.1074/jbc.m110.136168
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发表时间：
2010-07-23
影响因子：
4.8
通讯作者：
Danesh, Farhad R.
中科院分区：
文献类型：
--
作者：
Long, Jianyin;Wang, Yin;Danesh, Farhad R.
血管内皮生长因子（VEGF）是一种二聚体糖蛋白，在糖尿病微血管并发症（包括糖尿病肾病）中起着至关重要的作用。然而，糖尿病环境中VEGF表达的精确调控机制仍知之甚少。在这里，我们提供的证据表明，microRNA-93（miR-93）调节血管内皮生长因子在体外和体内糖尿病实验模型的表达。比较microRNA表达谱阵列将miR-93鉴定为高血糖条件下的标志性microRNA。我们确定VEGF-A是肾脏中miR-93的假定靶点，在几个物种中miR-93和vegfa的3 '-非翻译区之间具有完美的互补性。当与含有小鼠vegfa 3 '-非翻译区的荧光素酶报告基因构建体共转染时，miR-93的表达显著降低荧光素酶活性。我们发现，在细胞中强制表达miR-93废除了VEGF蛋白的分泌。相反，抗miR-93抑制剂增加VEGF释放。miR-93的转染也阻止了高糖对VEGF下游靶点的影响。使用含有VEGF-LacZ双顺反子转录物的转基因小鼠，我们发现肽缀合的吗啉代寡聚体抑制肾小球miR-93引起VEGF表达增加。我们的研究结果还表明，高糖通过下调宿主MCM 7基因的启动子来降低miR-93的表达。综上所述，我们的发现为miR-93在VEGF信号通路中的作用提供了新的见解，并为预防糖尿病肾病的进展提供了潜在的新靶点。
Vascular endothelial growth factor (VEGF) is a dimeric glycoprotein that plays a crucial role in microvascular complications of diabetes, including diabetic nephropathy. However, the precise regulatory mechanisms governing VEGF expression in the diabetic milieu are still poorly understood. Here, we provide evidence that microRNA-93 (miR-93) regulates VEGF expression in experimental models of diabetes both in vitro and in vivo. Comparative microRNA expression profile arrays identified miR-93 as a signature microRNA in hyperglycemic conditions. We identified VEGF-A as a putative target of miR-93 in the kidney with a perfect complementarity between miR-93 and the 3'-untranslated region of vegfa in several species. When cotransfected with a luciferase reporter construct containing the mouse vegfa 3'-untranslated region, expression of miR-93 markedly decreased the luciferase activity. We showed that forced expression of miR-93 in cells abrogated VEGF protein secretion. Conversely, anti-miR-93 inhibitors increased VEGF release. Transfection of miR-93 also prevented the effect of high glucose on VEGF downstream targets. Using transgenic mice containing VEGF-LacZ bicistronic transcripts, we found that inhibition of glomerular miR-93 by peptide-conjugated morpholino oligomers elicited increased expression of VEGF. Our findings also indicate that high glucose decreases miR-93 expression by down-regulating the promoter of the host MCM7 gene. Taken together, our findings provide new insights into the role of miR-93 in VEGF signaling pathway and offer a potentially novel target in preventing the progression of diabetic nephropathy.