lncBNIP3 knockdown enhances bovine myoblast proliferation by modulating DNA replication and cell cycle pathways

Myogenesis, a multistep process involving myoblast proliferation and differentiation, is critical for determining the economic value of beef cattle. While long noncoding RNAs (lncRNAs) are known to regulate myoblast proliferation, their specific mechanisms remain unclear. This study investigates the role of lncBNIP3 in bovine myoblast proliferation and examines the effects of its knockdown on cellular biological characteristics. Using quantitative real-time PCR (qRT-PCR), lncBNIP3 expression was observed to be higher in muscle tissues compared to other tissues in both 1-day-old and 24-month-old Qinchuan cattle. Knockdown of lncBNIP3 expression upregulated the mRNA levels of proliferation-related genes, as confirmed by qRT-PCR, and subsequently enhanced cellular proliferation, as demonstrated through EdU assays, flow cytometry, and CCK-8 analysis. Transcriptomic sequencing of myoblasts revealed that differentially expressed genes (DEGs) were significantly enriched in pathways associated with DNA replication and the cell cycle. Shared DEGs were primarily enriched in the minichromosome maintenance (MCM) gene family. Additionally, qRT-PCR and transcriptomic sequencing results revealed that the knockdown of lncBNIP3 expression significantly upregulated the mRNA levels of MCM family genes, including MCM2 and MCM3. Fluorescence activity assays further showed that lncBNIP3 knockdown significantly enhanced the promoter activities of MCM2 and MCM3. These findings suggest that interference with lncBNIP3 expression promotes the proliferation of bovine myoblasts, potentially through transcriptional regulation of the MCM gene family. This study provides novel insights into the regulatory functions of lncRNAs in muscle development.