Human pluripotent stem cells (hPSCs), like embryonic (hESCs) and induced pluripotent stem cells (hiPSCs), exhibit an unusual cell cycle structure characterized by a short G1 phase and cells being most of time in S phase. hPSCs are receptive to differentiation cues during their transition through G1 phase when lineage determination is decided. Although several MicroRNAs (miRNAs) have been shown to target transcripts that directly or indirectly coordinate the cell cycle of pluripotent cells, its temporal expression profile along hPSCs cell cycle remains poorly characterized. miR-145 and miR-296 are induced during differentiation and silence the self-renewal and pluripotency program. miR-302 family is essential for hPSCs stemness and its expression decreases during differentiation. We aimed to study how the aforementioned miRNAs are regulated along the cell cycle of hPSCs. We demonstrated by pharmacological synchronization and block and release experiments that miR-145, miR-296 and miR-302 family are periodically expressed in hPSCs. Importantly, miR-302 family expression is induced at G1/S boundary and remained high at S phase, presumably to impede differentiation onset. Besides, we confirmed by a gene ontology analysis that many validated miR-302 family target genes are involved in cell cycle regulation.

人类多能干细胞 (hPSCs)，如胚胎 (hESCs) 和诱导多能干细胞 (hiPSCs)，表现出不寻常的细胞周期结构，其特点是 G1 期短，细胞大部分时间处于 S 期。hPSC 在其通过 G1 阶段的过渡期间接受分化线索，当谱系决定被确定时。尽管已显示几种 MicroRNA (miRNA) 靶向直接或间接协调多能细胞细胞周期的转录物，但其沿 hPSC 细胞周期的时间表达谱仍不清楚。miR-145 和 miR-296 在分化过程中被诱导并使自我更新和多能性程序沉默。miR-302 家族对 hPSCs 干性至关重要，其表达在分化过程中降低。我们旨在研究上述 miRNA 如何在 hPSC 的细胞周期中受到调节。我们通过药理学同步和阻断和释放实验证明 miR-145、miR-296 和 miR-302 家族在 hPSC 中周期性表达。重要的是，miR-302 家族表达在 G1/S 边界处被诱导，并在 S 期保持高水平，大概是为了阻止分化开始。此外，我们通过基因本体分析证实，许多经过验证的 miR-302 家族靶基因参与细胞周期调控。