Background Several muscle-specific microRNAs (myomiRs) are differentially expressed during cellular senescence. However, the role of dietary compounds on myomiRs remains elusive. This study aimed to elucidate the modulatory role of tocotrienol-rich fraction (TRF) on myomiRs and myogenic genes during differentiation of human myoblasts. Young and senescent human skeletal muscle myoblasts (HSMM) were treated with 50 μg/mL TRF for 24 h before and after inducing differentiation. Results The fusion index and myotube surface area were higher (p < 0.05) on days 3 and 5 than that on day 1 of differentiation. Ageing reduced the differentiation rate, as observed by a decrease in both fusion index and myotube surface area in senescent cells (p < 0.05). Treatment with TRF significantly increased differentiation at days 1, 3 and 5 of young and senescent myoblasts. In senescent myoblasts, TRF increased the expression of miR-206 and miR-486 and decreased PTEN and PAX7 expression. However, the expression of IGF1R was upregulated during early differentiation and decreased at late differentiation when treated with TRF. In young myoblasts, TRF promoted differentiation by modulating the expression of miR-206, which resulted in the reduction of PAX7 expression and upregulation of IGF1R. Conclusion TRF can potentially promote myoblast differentiation by modulating the expression of myomiRs, which regulate the expression of myogenic genes.

中文翻译：

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通过富含生育三烯酚的部分靶向 myomiRs 以促进成肌细胞分化。

背景 几种肌肉特异性 microRNA (myomiRs) 在细胞衰老过程中差异表达。然而，膳食化合物对 myomiRs 的作用仍然难以捉摸。本研究旨在阐明富含生育三烯酚的组分 (TRF) 在人成肌细胞分化过程中对 myomiRs 和成肌基因的调节作用。在诱导分化前后，用 50 μg/mL TRF 处理年轻和衰老的人类骨骼肌成肌细胞 (HSMM) 24 小时。结果分化第3天和第5天融合指数和肌管表面积均高于第1天（p < 0.05）。衰老降低了分化率，正如衰老细胞中融合指数和肌管表面积的减少所观察到的那样 (p < 0.05)。用 TRF 治疗在第 1 天显着增加分化，3个和5个年轻和衰老的成肌细胞。在衰老的成肌细胞中，TRF 增加了 miR-206 和 miR-486 的表达，并降低了 PTEN 和 PAX7 的表达。然而，当用 TRF 处理时，IGF1R 的表达在早期分化过程中上调，而在分化晚期则下降。在年轻的成肌细胞中，TRF 通过调节 miR-206 的表达促进分化，导致 PAX7 表达降低和 IGF1R 上调。结论 TRF可能通过调节myomiRs的表达促进成肌细胞分化，myomiRs调节肌源基因的表达。当用 TRF 处理时，IGF1R 的表达在早期分化过程中上调，在分化晚期降低。在年轻的成肌细胞中，TRF 通过调节 miR-206 的表达促进分化，导致 PAX7 表达降低和 IGF1R 上调。结论 TRF可能通过调节myomiRs的表达促进成肌细胞分化，myomiRs调节肌源基因的表达。当用 TRF 处理时，IGF1R 的表达在早期分化过程中上调，在分化晚期降低。在年轻的成肌细胞中，TRF 通过调节 miR-206 的表达促进分化，导致 PAX7 表达降低和 IGF1R 上调。结论 TRF可能通过调节myomiRs的表达促进成肌细胞分化，myomiRs调节肌源基因的表达。