title: miR-16 controls myoblast proliferation and apoptosis through directly suppressing Bcl2 and FOXO1 activities.
abstract: Myogenesis mainly involves several steps including myoblast proliferation, differentiation, apoptosis and fusion. Except for muscle specific regulators, few miRNAs were proved to coordinate this complex process. Here, we reported that miR-16 inhibited myoblast proliferation and promoted myoblast apoptosis by directly targeting Bcl2 and FOXO1. The expression level of miR-16 was significantly decreased in the hypertrophic pectoral muscle compared to the normal pectoral muscle in chicken. In vitro, elevating miR-16 significantly inhibited myoblast proliferation and promoted myoblast apoptosis, resulting in about 11.2% cells arrested in G1 phase and 12.3% apoptotic cells in the early stage. Bioinformatic and biochemical analyses revealed Bcl2 and FOXO1 as direct targets of miR-16. Consist to the effect of miR-16 on myogenesis, specific inhibition of Bcl2 or FOXO1 significantly suppressed myoblast proliferation and induced myoblast apoptosis, indicating that both Bcl2 and FOXO1 contributed to miR-16 regulatory function in myogenesis. Interestingly, FOXO1, as the core target, mediated multiple growth-related pathways induced by miR-16 such as PI3K-AKT-MAPK and PI3K-AKT-mTOR. Chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) revealed that 234 annotated genes bound by FOXO1 in the early-differentiated myoblasts, which were significantly enriched in myogenic proliferation, death and hypotrophy. Altogether, we proposed that miR-16 acted as a coordinated mediator to suppress myogenesis in avian through the control of myoblast proliferation and apoptosis. These findings have provided a novel mechanism whereby miR-16 represses Bcl2 and FOXO1 expression to maintain myoblast growth and skeletal muscle mass.
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China.
authors.forename: Xinzheng
authors.initials: X
authors.lastname: Jia
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China.
authors.forename: Hongjia
authors.initials: H
authors.lastname: Ouyang
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China.
authors.forename: Bahareldin Ali
authors.initials: BA
authors.lastname: Abdalla
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China. Electronic address: nqinghua@scau.edu.cn.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Nie
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, Guangdong 510642, China.
authors.forename: Xiquan
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D049109:Cell Proliferation / Q000502:physiology*; D002645:Chickens; D000071161:Forkhead Box Protein O1 / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*
chemical_list: D000071161:Forkhead Box Protein O1; D035683:MicroRNAs; D019253:Proto-Oncogene Proteins c-bcl-2; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D020929:Mitogen-Activated Protein Kinase Kinases
keywords: Apoptosis; Bcl2; FOXO1; Myoblast proliferation; miR-16