title: Transcriptional changes of secreted Wnt antagonists in hindlimb skeletal muscle during the lifetime of the C57BL/6J mouse.
abstract: The canonical Wnt pathway plays a critical role in myogenesis and age-related inefficient muscle regeneration. To gain insights into changes in Wnt signaling in muscle during the lifetime of a mouse, mRNA levels of secreted Wnt antagonists were investigated. Among 13 analyzed antagonists, seven genes were found to be down-regulated in skeletal muscles of adult and old mice. Epigenetic modifications at the promoter regions of these seven Wnt antagonists were then examined to understand how these correlate with this transcriptional repression. DNA methylation was stably maintained, while chromatin modifications changed to transcriptionally inactive states over the course of a lifetime. Similar patterns of changes in chromatin modifications were observed at the promoters of all of the studied genes. The observations indicated that an upstream factor might regulate the chromatin states and the transcriptional repression of Wnt antagonists. Several bioinformatic analyses revealed that a FOXD3 binding motif is present within promoter regions of the seven antagonists. Furthermore, age-dependent differential FOXD3 binding is observed at the motifs of the seven gene promoters. Our results suggest that FOXD3 as a potential epigenetic regulator may mediate the transcriptional repression of the seven antagonists, possibly through regulation of histone modifications.
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, South Korea.
authors.forename: Soo Hee
authors.initials: SH
authors.lastname: Ryu
authors.forename: Taekyung
authors.initials: T
authors.lastname: Yoo
authors.forename: Keunsoo
authors.initials: K
authors.lastname: Kang
authors.forename: Seung-Yeol
authors.initials: SY
authors.lastname: Park
authors.forename: Cheol O
authors.initials: CO
authors.lastname: Joe
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Chung
mesh_terms: D000375:Aging / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D044127:Epigenesis, Genetic; D051858:Forkhead Transcription Factors / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D024510:Muscle Development / Q000235:genetics; D018482:Muscle, Skeletal / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D051153:Wnt Proteins / Q000037:antagonists & inhibitors; D060449:Wnt Signaling Pathway / Q000235:genetics*
chemical_list: D051858:Forkhead Transcription Factors; C101757:Foxd3 protein, mouse; D012333:RNA, Messenger; D012097:Repressor Proteins; D051153:Wnt Proteins