title: [The role of Bmi-1 gene in submandibular gland of mice].
abstract: OBJECTIVE
  To determine the role of Bmi-1 in the submandibular gland (SMG) of mice.
  
  
  METHODS
  SMG of 4-week wild-type (WT) and Bmi-1 null (Bmi-1(-/-)) mice was analyzed on the weight, salivary flow rate, hematoxylin-eosin staining morphological differences and the changes in proliferation and aging by histology, immunohistochemistry and Western blotting.
  
  
  RESULTS
  Compared with WT mice, the average static salivary flow rate [WT:(0.21 ± 0.02) µg/min,Bmi-1(-/-): (0.10 ± 0.02) µg/min] (P = 0.001) and the submandibular gland weight [WT: (1.89 ± 0.15) µg], Bmi-1(-/-): [(1.34 ± 0.07)µg] (P = 0.003) of the male Bmi-1(-/-) mice were significantly decreased, the number of gland duct increased, and the granular convoluted duct showed reduced diameter and branches. More senescence-associated β-galactosidase positive cells existed in SMG of Bmi-1(-/-)mice (WT:0.00, Bmi-1(-/-): 0.18 ± 0.02), and Ki-67 immunopositive cells decreased in SMG of Bmi-1(-/-) mice (WT:0.40 ∼ 0.47, Bmi-1(-/-): 0.18 ∼ 0.20) (P = 0.000). The expression of p16 (WT:1.00 ± 0.12, Bmi-1(-/-): 0.00 ± 0.00) (P = 0.003) and p19 (WT:0.97 ± 0.09, Bmi-1(-/-): 5.09 ± 0.21) (P = 0.004) were up-regulated dramatically in SMG of the Bmi-1(-/-) mice.
  
  
  CONCLUSIONS
  Bmi-1 gene deficiency causes abnormal function of SMG by inducing senescence phenotype of SMG.
authors: Institute of Stomatology, Nanjing Medical University & Department of Implant, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.
authors: Fen
authors: F
authors: Miao
authors: Ming
authors: M
authors: Shen
authors: Xianhui
authors: X
authors: Lyu
authors: Xiuliang
authors: X
authors: Dai
authors: Quanquan
authors: Q
authors: Yan
authors: Email: njcn@njmu.edu.cn.
authors: Ning
authors: N
authors: Chen
mesh_terms: D000818:Animals; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D063150:Polycomb Repressive Complex 1 / Q000096:biosynthesis* / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D013363:Submandibular Gland / Q000254:growth & development* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: C489421:Bmi1 protein, mouse; D011518:Proto-Oncogene Proteins; D063150:Polycomb Repressive Complex 1