Overexpression of a DENND1A isoform produces a polycystic ovary syndrome theca phenotype
Overexpression of a DENND1A isoform produces a polycystic ovary syndrome theca phenotype
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DOI：
10.1073/pnas.1400574111
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发表时间：
2014-04-15
影响因子：
11.1
通讯作者：
Strauss, Jerome F., III
中科院分区：
文献类型：
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作者：
McAllister, Jan M.;Modi, Bhavi;Strauss, Jerome F., III
多囊卵巢综合征（PCOS）的特征是卵巢雄激素生物合成增加、无排卵和不孕，影响5-7%的育龄妇女。全基因组关联研究确定了PCOS候选基因座，这些基因座在随后的报告中得到了复制，包括DENND 1A，它编码一种与细胞表面受体所在的网格蛋白包被的凹坑相关的蛋白质。然而，这些研究没有提供关于DEND 1A在PCOS发病机制中的功能作用的信息。DEND 1A蛋白定位于卵泡膜细胞的细胞质和细胞核中，提示可能在基因调控中起作用。DEND 1A在PCOS卵巢卵泡膜中表达较强。使用从正常周期和PCOS妇女分离和增殖的卵泡膜细胞，我们发现DENND 1A变体2（DENND1A.V2）蛋白和mRNA水平在PCOS卵泡膜细胞中增加。与正常骑自行车的妇女相比，PCOS妇女尿液中的外泌体DEND1A.V2 RNA显著升高。在正常卵泡膜细胞中，DENND1A.V2的强制过表达导致了CYP 17 A1和CYP 11 A1基因转录、mRNA丰度和雄激素生物合成增加的PCOS表型。在PCOS卵泡膜细胞中敲低DENND1A.V2可降低雄激素生物合成以及CYP 17 A1和CYP 11 A1基因转录。当添加到培养的PCOS卵泡膜细胞的培养基中时，对DENND1A.V2特异性的IgG也降低雄激素生物合成和CYP 17和CYP 11 A1 mRNA。我们的结论是，PCOS候选基因，DEND 1A，在高雄激素血症与PCOS中起着关键作用。这些观察结果对这种常见疾病具有诊断和治疗意义。
Polycystic ovary syndrome (PCOS), characterized by increased ovarian androgen biosynthesis, anovulation, and infertility, affects 5-7% of reproductive-age women. Genome-wide association studies identified PCOS candidate loci that were replicated in subsequent reports, including DENND1A, which encodes a protein associated with clathrin-coated pits where cell-surface receptors reside. However, these studies provided no information about functional roles for DENND1A in the pathogenesis of PCOS. DENND1A protein was located in the cytoplasm as well as nuclei of theca cells, suggesting a possible role in gene regulation. DENND1A immunostaining was more intense in the theca of PCOS ovaries. Using theca cells isolated and propagated from normal cycling and PCOS women, we found that DENND1A variant 2 (DENND1A.V2) protein and mRNA levels are increased in PCOS theca cells. Exosomal DENND1A.V2 RNA was significantly elevated in urine from PCOS women compared with normal cycling women. Forced overexpression of DENND1A.V2 in normal theca cells resulted in a PCOS phenotype of augmented CYP17A1 and CYP11A1 gene transcription, mRNA abundance, and androgen biosynthesis. Knock-down of DENND1A.V2 in PCOS theca cells reduced androgen biosynthesis and CYP17A1 and CYP11A1 gene transcription. An IgG specific to DENND1A.V2 also reduced androgen biosynthesis and CYP17 and CYP11A1 mRNA when added to the medium of cultured PCOS theca cells. We conclude that the PCOS candidate gene, DENND1A, plays a key role in the hyperandrogenemia associated with PCOS. These observations have both diagnostic and therapeutic implications for this common disorder.