miR-302b promotes bovine preadipocyte differentiation and inhibits proliferation by targeting CDK2.

MicroRNAs have been recently reported to act as key regulators of adipogenesis, a multifactorial complex process. One miRNA, miR-302b, is an important regulator of cell proliferation and differentiation and controls cancer development, but we speculate that miR-302b may also regulate bovine adipogenesis. Herein we have evaluated the role of this miRNA in bovine adipocyte differentiation using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), Oil Red O staining, a dual-luciferase reporter. CDK2 was identified as the target gene of miR-302b, and miR-302b agomir promoted mRNA and protein expression levels of adipocyte-specific genes. In addition, a CCK-8 kit was used to show that miR-302b agomir, but not the negative control, inhibits preadipocyte proliferation. In conclusion, miR-302b promotes bovine preadipocyte differentiation and inhibits proliferation by targeting CDK2.

Tissue Expression Analysis, Cloning, and Characterization of the 5'-Regulatory Region of the Bovine LATS1 Gene.

As a member of the large tumor suppressor (LATS) gene family, LATS1 plays an important role in regulating muscle growth and development. In this study, we determined the distinct exhibit patterns of tissue expression of bovine LATS1. Further, we determined the functional proximal minimal promoter of bovine LATS1 and identified the key transcription factors in the core promoter region to elucidate its molecular regulation mechanism. The results showed that bovine LATS1 was highly expressed in the longissimus thoracis and upregulation in infancy muscle. An electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay in combination with site-directed mutation and small interfering RNA (siRNA) interference demonstrated that myogenic differentiation 1 (Myod1) and myocyte enhancer factor 2A (MEF2A) binding in the core promoter region (-298/-123 bp) play important roles in the transcriptional regulation of the bovine LATS1 promoter. Taken together, these interactions provide insight into the regulatory mechanisms of LATS1 transcription in mediating skeletal muscle growth in cattle.