Muscle development is regulated under a series of complicate processes, and non-coding RNAs, such as microRNAs (miRNAs) and circular RNAs (circRNAs), have been reported to play important roles in regulating myoblast proliferation and differentiation. We found that miR-107 expression was high in skeletal muscle of Qinchuan cattle. Overexpression of miR-107 inhibited bovine myoblasts differentiation and protected cells from apoptosis. Wnt3a was identified as a target of miR-107 by luciferase activity, real-time qPCR, and western blotting assays. Knockdown of Wnt3a inhibited bovine myoblasts differentiation and apoptosis, and this effect was similar to miR-107 overexpression. We also found circFGFR4 to promote myoblasts differentiation and to induce cell apoptosis. Via luciferase screening and RNA pull-down assays, circFGFR4 was observed to sponge miR-107. Overexpression of circFGFR4 increased the expression of Wnt3a, whereas this effect was abolished by miR-107. These results demonstrated that circFGFR4 binding miR-107 promotes cell differentiation via targeting Wnt3a in bovine primary myoblasts.

肌肉的发育受一系列复杂过程的调节，据报道，非编码RNA，例如microRNA（miRNA）和环状RNA（circRNA），在调节成肌细胞的增殖和分化中起着重要的作用。我们发现，miR-107在秦川牛骨骼肌中的表达较高。miR-107的过表达抑制牛成肌细胞的分化，并保护细胞免于凋亡。通过荧光素酶活性，实时定量PCR和Western印迹分析，Wnt3a被鉴定为miR-107的靶标。敲低Wnt3a抑制牛成肌细胞的分化和凋亡，这种作用类似于miR-107过表达。我们还发现circFGFR4促进成肌细胞分化并诱导细胞凋亡。通过萤光素酶筛选和RNA下拉测定，观察到circFGFR4使miR-107海绵化。circFGFR4的过表达增加了Wnt3a的表达，而miR-107取消了这种作用。这些结果表明，通过靶向Wnt3a在牛原代成肌细胞中，circFGFR4结合miR-107促进细胞分化。