title: Development of hair cells in inner ear is associated with expression and promoter methylation of Notch-1 in postnatal mice.
abstract: The present study was designed to investigate the correlation among the number of hair cells in inner ear, Notch-1 gene expression levels and its methylation status of the promoter region in the postnatal mice. The hair cells in inner ear were collected from postnatal mice at day 0, 4, 8 and 16 and counted by immunofluorescence. Notch-1 mRNA expression were measured by real-time quantitative polymerize chain reaction (PCR). Methylation levels of CpG islands in Notch-1 promoters were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The results showed that the number of hair cells in the inner ear increased gradually after birth, which were positively correlated to Notch-1 mRNA expression. However, analysis on methylation of CpG sites in Notch-1 promoter showed that the methylation rates increased gradually after births, which were correlated with the decreased expression of Notch-1. Drug lesion induced the loss of hair cells, and stimulated the expression of Notch-1 mRNA expression, but didn't influence the methylation rates of Notch-1 promoter. We concluded that the Notch-1 mRNA expression level in inner ear tissues is correlated with the development of hair cells. CpG islands in Notch-1 promoter region manifest hypermethylation status when hair cells in inner ear are mature.
authors.affiliation: Kunming Sanatorium of Chengdu Military Region Fengshan Door, Wenquan, Anning 650300, Yunnan, China.
authors.forename: Yanghui
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Xianbao
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Xijun
authors.initials: X
authors.lastname: Xue
authors.affiliation: Disease prevention and Control Center of Chengdu Military Region 168 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Ziliang
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Disease prevention and Control Center of Chengdu Military Region 168 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Quanshui
authors.initials: Q
authors.lastname: Fan
authors.affiliation: Disease prevention and Control Center of Chengdu Military Region 168 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Feng
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Chengqiong
authors.initials: C
authors.lastname: Xia
authors.affiliation: Department of Head-Neck Otolaryngology of General Hospital of Chengdu Military Region 212 Grand View Road, Kunming 650000, Yunnan, China.
authors.forename: Yingkun
authors.initials: Y
authors.lastname: Cheng
keywords: Hair cells; Notch-1; inner ear; methylation; postnatal mice