title: The role of selenium in insulin-like growth factor I receptor (IGF-IR) expression and regulation of apoptosis in mouse osteoblasts.
abstract: Selenium (Se) is an essential component for animals and human beings. The chemoprotective role of Se, via the regulation of the cell cycle, stimulation of apoptosis and activation of some cytokines among others, is well known; however, the comprehensive effects of Se on the expression of IGF-IR and its regulation of apoptosis have not been investigated. Thus the aim of this study was to report on the effects that different concentrations of Se extert on body weight, blood serum IGF-IR levels and histopathology in mice; and on IGF-IR expression, proliferation and apoptosis in mouse osteoblasts. In vivo experiments showed a significant decrease in body weight, serum levels of IGF-IR and prominent toxicant effects on the liver, kidney, heart and spleen following the administration of defined concentrations of Se for 30 d. However, moderate levels (0.1 mg/kg) of Se gradually improved weight and serum IGF-IR. In vitro osteoblast experiments revealed that at concentrations of 5 × 10(-6) and 10(-5) mol/L Se, MTT activity decreased in comparison with control cells. Cell cycle, TEM and caspase-3 activity supported these observations including an increase in the sub-G1 phase and notable apoptosis in osteoblasts, along with a decrease in the expression of mRNA and protein levels of IGF-IR. Moreover, the MTT activity, mRNA and protein levels of IGF-IR in osteoblasts were decreased and caspase-3 activity was increased in siRNA groups as compared with non-siRNA groups. These data suggest that Se significantly affects IGF-IR expression, and that it contributes to the proliferation and regulation of apoptosis in osteoblasts.
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Gaixian
authors.initials: G
authors.lastname: Ren
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Tariq
authors.initials: T
authors.lastname: Ali
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Han
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Gu
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Shiyao
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Laidi
authors.initials: L
authors.lastname: Ding
authors.affiliation: UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Séamus
authors.initials: S
authors.lastname: Fanning
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China. Electronic address: hanbo@cau.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Han
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008807:Mice, Inbred BALB C; D009206:Myocardium / Q000473:pathology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D012643:Selenium / Q000494:pharmacology*; D013154:Spleen / Q000187:drug effects / Q000473:pathology
chemical_list: D012333:RNA, Messenger; D017526:Receptor, IGF Type 1; D053148:Caspase 3; D012643:Selenium
keywords: Apoptosis; IGF-IR; Mice; Osteoblast; Proliferation; Selenium