In eukaryotic organisms, the most common internal modification of messenger RNA (mRNA) is N6-methyladenosine (m6A). This modification can be dynamically and reversibly controlled by specific enzymes known as m6A writers and erasers. The fat-mass and obesity-associated protein (FTO) catalyzes RNA demethylation and plays a critical role in various physiological and pathological processes. Our research identified dynamic alterations in both m6A and FTO during the assembly of primordial follicles, with an inverse relationship observed for m6A levels and nuclear-localized FTO expression. Application of Fto small interfering RNA (siRNA) altered the expression of genes related to cell proliferation, hormone regulation, and cell chemotaxis, and affected RNA alternative splicing. Overexpression of the full-length Fto gene led to changes in m6A levels, alternative splicing of Cdk5, cell proliferation, cell cycle progression, and proportion of primordial follicles. Conversely, overexpression of Fto lacking a nuclear localization signal (NLS) did not significantly alter m6A levels or primordial follicle assembly. These findings suggest that FTO, localized in the nucleus but not in the cytoplasm, regulates RNA m6A demethylation and plays a role in cell proliferation, cell cycle progression, and primordial follicle assembly. These results highlight the potential of m6A and its eraser FTO as possible biomarkers and therapeutic targets.
在真核生物中，N6-甲基腺苷（m6A）是信使RNA（mRNA）最常见的内部修饰。m6A的动态可逆调节由m6A 的甲基转移酶“写入”和脱甲基酶“擦除”。脂肪质量和肥胖相关蛋白（FTO）催化RNA去甲基化，并在各种生理和病理过程中发挥关键作用。该研究发现，在原始卵泡组装过程中，m6A和FTO都发生了动态变化，而m6A水平和细胞核定位FTO的表达呈负相关。 Fto的降低表达（siRNA）改变了细胞增殖、激素调节和细胞趋化相关基因的表达，同时影响RNA的选择性剪接。此外，全长 Fto基因的过表达导致了m6A水平和 Cdk5选择性剪接形式比例的变化，影响细胞增殖、细胞周期进程和原始卵泡的比例。然而，缺乏核定位信号（NLS）的 Fto过表达对m6A水平或原始卵泡组装没有明显的改变。该研究发现表明，定位于细胞核而非细胞质中的FTO，通过调节RNA m6A去甲基化，参与细胞增殖、细胞周期进程，从而在原始卵泡组装中发挥作用。这一结果突出了m6A及其“擦除”蛋白FTO作为可能的生物标志物和治疗靶点的潜力。.
Keywords: Alternative splicing; FTO; Ovary; Primordial follicle assembly; m6A.