title: MicroRNA-21 Regulates PI3K/Akt/mTOR Signaling by Targeting TGFβI during Skeletal Muscle Development in Pigs.
abstract: MicroRNAs (miRNAs), which are short (22-24 base pairs), non-coding RNAs, play critical roles in myogenesis. Using Solexa deep sequencing, we detected the expression levels of 229 and 209 miRNAs in swine skeletal muscle at 90 days post-coitus (E90) and 100 days postnatal (D100), respectively. A total of 138 miRNAs were up-regulated on E90, and 31 were up-regulated on D100. Of these, 9 miRNAs were selected for the validation of the small RNA libraries by quantitative RT-PCR (RT-qPCR). We found that miRNA-21 was down-regulated by 17-fold on D100 (P<0.001). Bioinformatics analysis suggested that the transforming growth factor beta-induced (TGFβI) gene was a potential target of miRNA-21. Both dual luciferase reporter assays and western blotting demonstrated that the TGFβI gene was regulated by miRNA-21. Co-expression analysis revealed that the mRNA expression levels of miRNA-21 and TGFβI were negatively correlated (r = -0.421, P = 0.026) in skeletal muscle during the 28 developmental stages. Our results revealed that more miRNAs are expressed in prenatal than in postnatal skeletal muscle. The miRNA-21 is a novel myogenic miRNA that is involved in skeletal muscle development and regulates PI3K/Akt/mTOR signaling by targeting the TGFβI gene.
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China; Agricultural Genome Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
authors.forename: Lijing
authors.initials: L
authors.lastname: Bai
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Ruyi
authors.initials: R
authors.lastname: Liang
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Yalan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Hou
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Zishuai
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Shiyun
authors.initials: S
authors.lastname: Zhu
authors.affiliation: National Engineering Laboratory for Animal Breeding, Key Laboratory of Agricultural Animal Genetics and Breeding, Department of Animal Breeding and Genetics, College of Animal Sciences and Technology, China Agricultural University, Beijing, China.
authors.forename: Chuduan
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China; Agricultural Genome Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Tang
authors.affiliation: State Key Laboratory for Animal Nutrition, Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Li
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018507:Gene Expression Regulation, Developmental; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017423:Sequence Analysis, RNA; D015398:Signal Transduction; D013552:Swine; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D016212:Transforming Growth Factor beta