LncRNA XLOC_015548 affects the proliferation and differentiation of myoblasts via the MAPK signaling pathway

In recent years, an increasing number of studies have reported that long non-coding RNAs (lncRNAs) play essential regulatory roles in myogenic differentiation. In this study, a specific LncRNA XLOC_015548 (Lnc000280) was identified. However, little research has explored its mechanism of action by constructing XLOC_015548 gene editing cell models. In this study, relevant sequences were obtained according to the RNA-seq results. Subsequently, XLOC_015548 knockdown and over-expression lentiviral vectors were constructed, and the C2C12 myoblast cell line was transfected to prepare the XLOC_015548 gene-edited myoblast model. The in vitro analysis revealed that over-expression of XLOC_015548 significantly promoted the proliferation and differentiation of myoblasts and the formation of myotubes, whereas the opposite result was obtained in the knockdown group. XLOC_015548 regulated myogenic differentiation and affected the expression of myogenic differentiation regulators such as Myod, myogenin, and MyHC. Regarding the signaling pathway, we found that XLOC_015548 correlated with the phosphorylation level of MAPK/MEK/ERK pathway proteins. And the degree of phosphorylation was positively correlated with the protein expression of myogenic differentiation regulators. In conclusion, a new gene-edited myoblast model was constructed based on the lncRNA regulator XLOC_015548. The in vitro cell experiments verified that XLOC_015548 had regulatory effects on muscle growth and myoblast differentiation. These findings provide a laboratory foundation for the clinical application of lncRNAs as regulatory factors in the treatment of disuse muscle atrophy.