MicroRNA 21 Blocks Apoptosis in Mouse Periovulatory Granulosa Cells
MicroRNA 21 Blocks Apoptosis in Mouse Periovulatory Granulosa Cells
复制标题
DOI：
10.1095/biolreprod.109.081448
复制
发表时间：
2010-08-01
影响因子：
3.6
通讯作者：
Christenson, Lane K.
中科院分区：
文献类型：
--
作者：
Carletti, Martha Z.;Fiedler, Stephanie D.;Christenson, Lane K.
microRNAs（miRNAs）在细胞分化和凋亡等发育过程中发挥重要作用。促黄体生成素（LH）的排卵峰导致卵巢颗粒细胞增殖向终末分化的黄体细胞的转变，其细胞形态和功能发生迅速而显著的变化。MicroRNA 21（miR-21，官方符号Mir 21）是小鼠颗粒细胞中LH诱导的三种高度miRNA之一，在此我们研究了颗粒细胞向黄体细胞转变时Mir 21的功能和时间表达。用阻断（2 '-O-甲基）和锁核酸（LNA-21）寡核苷酸转染颗粒细胞，成熟的Mir 21表达分别降低至其基础表达的九分之一和二十七分之一。LNA-21耗竭培养颗粒细胞中的Mir 21活性诱导细胞凋亡。在体内，卵泡颗粒细胞表现出减少裂解半胱天冬酶3，细胞凋亡的标志，6小时后，LH/人绒毛膜促性腺激素激增，与成熟的Mir 21的最高表达。为了检查Mir 21是否参与体内细胞凋亡的调节，用硫代磷酸酯修饰的LNA-21寡核苷酸处理小鼠，并检查颗粒细胞凋亡。与对侧对照组相比，LNA-21处理的卵巢中细胞凋亡增加，并且LNA-21处理的卵巢中排卵率降低。我们已经研究了一些在其他系统中鉴定的Mir 21凋亡靶转录物;目前，这些似乎都没有在诱导卵巢颗粒细胞凋亡中发挥作用。这项研究是第一个暗示抗凋亡Mir 21（一种致癌miRNA）在正常组织功能中发挥明确的生理作用。
MicroRNAs (miRNAs) play important roles in many developmental processes, including cell differentiation and apoptosis. Transition of proliferative ovarian granulosa cells to terminally differentiated luteal cells in response to the ovulatory surge of luteinizing hormone (LH) involves rapid and pronounced changes in cellular morphology and function. MicroRNA 21 (miR-21, official symbol Mir21) is one of three highly LH-induced miRNAs in murine granulosa cells, and here we examine the function and temporal expression of Mir21 within granulosa cells as they transition to luteal cells. Granulosa cells were transfected with blocking (2'-O-methyl) and locked nucleic acid (LNA-21) oligonucleotides, and mature Mir21 expression decreased to one ninth and one twenty-seventh of its basal expression, respectively. LNA-21 depletion of Mir21 activity in cultured granulosa cells induced apoptosis. In vivo, follicular granulosa cells exhibit a decrease in cleaved caspase 3, a hallmark of apoptosis, 6 h after the LH/human chorionic gonadotropin surge, coincident with the highest expression of mature Mir21. To examine whether Mir21 is involved in regulation of apoptosis in vivo, mice were treated with a phospho thioate-modified LNA-21 oligonucleotide, and granulosa cell apoptosis was examined. Apoptosis increased in LNA-21-treated ovaries, and ovulation rate decreased in LNA-21-treated ovaries, compared with their contralateral controls. We have examined a number of Mir21 apoptotic target transcripts identified in other systems; currently, none of these appear to play a role in the induction of ovarian granulosa cell apoptosis. This study is the first to implicate the antiapoptotic Mir21 (an oncogenic miRNA) as playing a clear physiologic role in normal tissue function.