title: Analysis of MicroRNA Expression Profiles in Weaned Pig Skeletal Muscle after Lipopolysaccharide Challenge.
abstract: MicroRNAs (miRNAs) constitute a class of non-coding RNAs that play a crucial regulatory role in skeletal muscle development and disease. Several acute inflammation conditions including sepsis and cancer are characterized by a loss of skeletal muscle due primarily to excessive muscle catabolism. As a well-known inducer of acute inflammation, a lipopolysaccharide (LPS) challenge can cause serious skeletal muscle wasting. However, knowledge of the role of miRNAs in the course of inflammatory muscle catabolism is still very limited. In this study, RNA extracted from the skeletal muscle of pigs injected with LPS or saline was subjected to small RNA deep sequencing. We identified 304 conserved and 114 novel candidate miRNAs in the pig. Of these, four were significantly increased in the LPS-challenged samples and five were decreased. The expression of five miRNAs (ssc-miR-146a-5p, ssc-miR-221-5p, ssc-miR-148b-3p, ssc-miR-215 and ssc-miR-192) were selected for validation by quantitative polymerase chain reaction (qPCR), which found that ssc-miR-146a-5p and ssc-miR-221-5p were significantly upregulated in LPS-challenged pig skeletal muscle. Moreover, we treated mouse C2C12 myotubes with 1000 ng/mL LPS as an acute inflammation cell model. Expression of TNF-α, IL-6, muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1) mRNA was strongly induced by LPS. Importantly, miR-146a-5p and miR-221-5p also showed markedly increased expression in LPS-treated C2C12 myotubes, suggesting the two miRNAs may be involved in muscle catabolism systems in response to acute inflammation caused by a LPS challenge. To our knowledge, this study is the first to examine miRNA expression profiles in weaned pig skeletal muscle challenged with LPS, and furthers our understanding of miRNA function in the regulation of inflammatory muscle catabolism.
authors.affiliation: Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China. judyzhang1103@126.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Wuhan Institute of Animal Husbandry and Veterinary Science, Wuhan Academy of Agricultural Science & Technology, Wuhan 430208, China. fushulin@webmail.hzau.edu.cn.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Fu
authors.affiliation: Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China. sharonliuyan@126.com.|College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China. sharonliuyan@126.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China. yulanflower@126.com.
authors.forename: Yu-Lan
authors.initials: YL
authors.lastname: Liu
authors.affiliation: College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, China. hustwsir@126.com.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D002460:Cell Line; D007249:Inflammation / Q000209:etiology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity*; D035683:MicroRNAs / Q000235:genetics*; D018482:Muscle, Skeletal / Q000254:growth & development / Q000378:metabolism*; D034421:Sus scrofa; D059467:Transcriptome
chemical_list: D008070:Lipopolysaccharides; D035683:MicroRNAs
keywords: LPS; microRNA; pig; skeletal muscle wasting; small RNA sequencing