Estrogen regulation of uterine microRNAs: Novel factors in MMP-9 regulation

描述(由申请人提供)：基质金属蛋白酶-9(MMP9)被认为从出生后子宫发育到妊娠确立和随后的分娩期间在子宫内发挥重要作用。此外，基质金属蛋白酶-9的过度表达或基质金属蛋白酶-9与组织抑制物(TIMP)的比例失衡与功能失调性子宫出血、子宫内膜异位症、不孕症和子宫内膜癌等子宫病变有关。尽管这种基质金属蛋白酶在正常子宫生理和子宫疾病中的重要性被提出，但对基质金属蛋白酶-9的类固醇调节还不是很清楚。目前应用中的初步数据表明，这种基质金属蛋白酶的调节还有另一层复杂性。我们提出了令人信服的证据，表明早期雌激素治疗后，基质金属蛋白酶-9的转录表达减少，但蛋白质和基质金属蛋白酶-9的活性显著增加。这些观察表明，据我们所知，子宫基质金属蛋白酶-9的雌激素诱导机制是新颖而复杂的，这种机制确实存在于其他器官或细胞系统中。因此，这项建议的目标是探索在子宫内传递这一独特的调节系统的机制。我们假设雌激素通过一种包括microRNAs(MiRNAs)的机制来调节子宫基质金属蛋白酶-9的翻译。为了验证这一假说，我们提出了两个特定的目标，这将1)表征子宫miRNA对雌激素治疗的响应，以及2)从功能上证明这些已识别的miRNA调节子宫内基质金属蛋白酶-9的翻译。通过这样做，新的曙光将揭示这一重要的子宫基质金属蛋白酶的雌激素调节以及子宫miRNA系统在雌激素治疗中的潜在作用。总之，拟议研究的结果将扩大我们对基质金属蛋白酶-9表达调控机制的认识，并为子宫miRNA图谱提供开创性的文献资料。这些结果将导致对子宫内这一系统的进一步探索，并为更好地了解子宫MMPs如何调节以及miRNAs在这个重要的女性器官中可能发挥的功能提供了更好的理解。摘要：基质金属蛋白酶-9的受控表达对于正常的子宫生理至关重要，而基质金属蛋白酶-9的异常表达与子宫疾病密切相关。尽管基质金属蛋白酶-9在子宫中很重要，但人们对其调控知之甚少。这项拟议的研究将检验子宫内基质金属蛋白酶-9的复杂调节，并破译microRNAs在调节这种蛋白水解酶中的新作用。加强我们对基质金属蛋白酶-9表达调控的了解，可能会导致建立新的方法来对抗这种蛋白水解酶的错误表达以及与之相关的疾病。

DESCRIPTION (provided by applicant): Matrix metalloproteinase-9 (MMP-9) is proposed to play an important role within the uterus from the time of post-natal uterine development through the period of establishment of pregnancy and subsequent parturition. Further, over-expression of MMP-9 or an imbalance in the MMP-9 to tissue inhibitor (TIMP) ratio has been associated with uterine pathologies such as dysfunctional uterine bleeding, endometriosis, infertility and endometrial carcinoma. Despite the proposed importance of this MMP in normal uterine physiology and uterine diseases, the steroidal regulation of MMP-9 is not clearly understood. Preliminary data in the current application suggest yet another layer of complexity in the regulation of this MMP. We present compelling evidence that MMP-9 transcript expression is decreased in response to early estrogen treatment, but protein and MMP-9 activity significantly increase. These observations suggest a novel and complex mechanism for estrogenic induction of uterine MMP-9 which, to the best of our knowledge, does exist in other organ or cell systems. As such, the objective of this proposal is to explore the mechanisms which impart this unique regulatory system within the uterus. We hypothesize that estrogen regulates uterine MMP-9 translation via a mechanism which includes microRNAs (miRNAs). To test this hypothesis, we propose two Specific Aims which will 1) characterize uterine miRNA expression in response to estrogen treatment, and 2) functionally demonstrate that those identified miRNA regulate MMP-9 translation within the uterus. In doing so, new light will be shed upon the estrogenic regulation of this important uterine MMP as well as the potential role of the uterine miRNA system in response to estrogen treatment. Collectively, the findings from the proposed studies will expand our knowledge on regulatory mechanisms for MMP-9 expression and provide the pioneering documentation of the uterine miRNA profile. These results will lead to further exploration of this system within the uterus and provide a better understanding on how uterine MMPs may be regulated and what functions miRNAs may play in this vital female organ. Summary: Controlled expression of matrix metalloproteinase-9 (MMP-9) is vital for normal uterine physiology while abnormal expression of MMP-9 is associated with uterine disease. Despite the importance of MMP-9 within the uterus, its regulation is poorly understood. The proposed studies will examine the complex regulation of MMP-9 within the uterus and decipher the novel role of microRNAs in the regulation of this protease. Enhancing our understanding on the regulation of MMP-9 expression may lead to the establishment of novel approaches to counteract mis-expression of this protease and the diseases associated with it.