title: mRNA expression characteristics are different in irreversibly atrophic intrinsic muscles of the forepaw compared with reversibly atrophic biceps in a rat model of obstetric brachial plexus palsy (OBPP).
abstract: In obstetric brachial plexus palsy (OBPP), irreversible muscle atrophy occurs much faster in intrinsic muscles of the hand than in the biceps. To elucidate the mechanisms involved, mRNA expression profiles of denervated intrinsic muscles of the forepaw (IMF) and denervated biceps were determined by microarray using the rat model of OBPP where atrophy of IMF is irreversible while atrophy of biceps is reversible. Relative to contralateral control, 446 dysregulated mRNAs were detected in denervated IMF and mapped to 51 KEGG pathways, and 830 dysregulated mRNAs were detected in denervated biceps and mapped to 52 KEGG pathways. In denervated IMF, 10 of the pathways were related to muscle regulation; six with down-regulated and one with up-regulated mRNAs. The remaining three pathways had both up- and down-regulated mRNAs. In denervated biceps, 13 of the pathways were related to muscle regulation, six with up-regulated and seven with down-regulated mRNAs. Five of the pathways with up-regulated mRNAs were related to regrowth and differentiation of muscle cells. Among the 23 pathways with dysregulated mRNAs, 13 were involved in regulation of neuromuscular junctions. Our results demonstrated that mRNAs expression characteristics in irreversibly atrophic denervated IMF were different from those in reversibly atrophic denervated biceps; dysregulated mRNAs in IMF were associated with inactive pathways of muscle regulation, and in biceps they were associated with active pathways of regrowth and differentiation. Lack of self-repair potential in IMF may be a major reason why atrophy of IMF becomes irreversible much faster than atrophy of biceps after denervation.
authors.affiliation: Department of Hand Surgery, Huashan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, 200040, China.|Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200040, China.
authors.forename: Ji-Xin
authors.initials: JX
authors.lastname: Wu
authors.affiliation: Department of Hand Surgery, Huashan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, 200040, China. liangchen1960@163.com.|Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200040, China. liangchen1960@163.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, 226001, China. dingfei@ntu.edu.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Ding
authors.affiliation: Department of Plastic and Peripheral Vascular Surgery, Guangdong General Hospital and Guangdong Academy of Medical Science, Guangzhou, 510080, China.
authors.forename: Le-Zi
authors.initials: LZ
authors.lastname: Chen
authors.affiliation: Department of Hand Surgery, Huashan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, 200040, China.|Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200040, China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Gu
mesh_terms: D000818:Animals; D001917:Brachial Plexus; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D006614:Hindlimb / Q000378:metabolism / Q000473:pathology; D009124:Muscle Proteins / Q000096:biosynthesis*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009133:Muscular Atrophy / Q000378:metabolism* / Q000473:pathology; D010243:Paralysis / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D009124:Muscle Proteins
keywords: Biceps; Denervation; Intrinsic muscle of the hand; Neuromuscular junction; mRNA profile