title: Profile of microRNAs associated with aging in rat liver.
abstract: Recent studies suggest that small non‑coding microRNAs (miRNAs or miRs) play an important role in the regulation of genes involved in various cellular and developmental processes. However, the expression of miRNAs during the aging process remains largely unknown. The aim of the present study was to analyze miRNA expression profiles in rat livers during the aging process. The livers of male Wistar rats at different stages of development (fetal, aged 3 days, and 1, 2, 4, 8 and 36 weeks of age) were used. Total RNA was extracted from the livers. We analyzed the expression levels of 679 rat miRNA probes. In addition, immunohistochemical staining for proliferating cell nuclear antigen (PCNA) was performed. Several up- and downregulated miRNAs were identified in the rat livers at 7 different fetal developmental stages and at 36 weeks of age. We observed the upregulation of miR‑29a, miR‑29c, miR‑195 and miR‑497, whereas miR‑301a, miR‑148b-3p, miR‑7a, miR‑93, miR‑106b, miR‑185, miR‑450a, miR‑539 and miR‑301b were downregulated in the aging rat livers. The number of PCNA-positive hepatocytes was decreased with age. In conclusion, our findings suggest that these up- and downregulated miRNAs play an important role in aging by regulating cell cycles that are involved in liver senescence. Further investigation is required to reveal additional target genes of the miRNAs expressed in the liver and the roles of miRNAs in the developmental process of aging in the liver.
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Shima
authors.initials: S
authors.lastname: Mimura
authors.affiliation: Department of Signal Transduction Sciences, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Iwama
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Kiyohito
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Yoneyama
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Miyoshi
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Joji
authors.initials: J
authors.lastname: Tani
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Asahiro
authors.initials: A
authors.lastname: Morishita
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Himoto
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Deguchi
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Nomura
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Maeda
authors.affiliation: Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Izuishi
authors.affiliation: Department of Signal Transduction Sciences, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Okano
authors.affiliation: Department of Signal Transduction Sciences, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Masaki
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D015153:Blotting, Western; D033481:Chromosomes, Mammalian / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D008099:Liver / Q000254:growth & development* / Q000378:metabolism*; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D017208:Rats, Wistar
chemical_list: D035683:MicroRNAs; D018809:Proliferating Cell Nuclear Antigen; D019938:Cyclin D1