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Lewis KE, Sharan K, Takumi T, Yadav VK. Skeletal Site-specific Changes in Bone Mass in a Genetic Mouse Model for Human 15q11-13 Duplication Seen in Autism. Sci Rep 2017; 7:9902. [PMID: 28851986 PMCID: PMC5575059 DOI: 10.1038/s41598-017-09921-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/01/2017] [Indexed: 12/13/2022] Open
Abstract
Children suffering from autism have been reported to have low bone mineral density and increased risk for fracture, yet the cellular origin of the bone phenotype remains unknown. Here we have utilized a mouse model of autism that duplicates 6.3 Mb region of chromosome 7 (Dp/+) corresponding to a region of chromosome 15q11-13, duplication of which is recurrent in humans to characterize the bone phenotype. Paternally inherited Dp/+ (patDp/+) mice showed expected increases in the gene expression in bone, normal postnatal growth and body weight acquisition compared to the littermate controls. Four weeks-old patDp/+ mice develop a low bone mass phenotype in the appendicular but not the axial skeleton compared to the littermate controls. This low bone mass in the mutant mice was secondary to a decrease in the number of osteoblasts and bone formation rate while the osteoclasts remained relatively unaffected. Further in vitro cell culture experiments and gene expression analysis revealed a major defect in the proliferation, differentiation and mineralization abilities of patDp/+ osteoblasts while osteoclast differentiation remained unchanged compared to controls. This study therefore characterizes the structural and cellular bone phenotype in a mouse model of autism that can be further utilized to investigate therapeutic avenues to treat bone fractures in children with autism.
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Affiliation(s)
- Kirsty E Lewis
- Department of Mouse and Zebrafish Genetics, Wellcome Trust Sanger Institute, Cambridge, CB10 1SA, United Kingdom.,Department of Physiology, Pharmacology, Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Kunal Sharan
- Department of Mouse and Zebrafish Genetics, Wellcome Trust Sanger Institute, Cambridge, CB10 1SA, United Kingdom.,Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute, Mysore, India
| | - Toru Takumi
- RIKEN Brain Science Institute (BSI), Wako, Saitama, Japan.,Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima, Japan
| | - Vijay K Yadav
- Department of Mouse and Zebrafish Genetics, Wellcome Trust Sanger Institute, Cambridge, CB10 1SA, United Kingdom. .,Metabolic Research Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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Ren G, Ali T, Chen W, Han D, Zhang L, Gu X, Zhang S, Ding L, Fanning S, Han B. The role of selenium in insulin-like growth factor I receptor (IGF-IR) expression and regulation of apoptosis in mouse osteoblasts. CHEMOSPHERE 2016; 144:2158-2164. [PMID: 26595309 DOI: 10.1016/j.chemosphere.2015.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 10/18/2015] [Accepted: 11/01/2015] [Indexed: 06/05/2023]
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.
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Affiliation(s)
- Gaixian Ren
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Tariq Ali
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Wei Chen
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Dandan Han
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Limei Zhang
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Xiaolong Gu
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Shiyao Zhang
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Laidi Ding
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Bo Han
- College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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Liu J, Yang J. Uncarboxylated osteocalcin inhibits high glucose-induced ROS production and stimulates osteoblastic differentiation by preventing the activation of PI3K/Akt in MC3T3-E1 cells. Int J Mol Med 2015; 37:173-81. [PMID: 26719856 DOI: 10.3892/ijmm.2015.2412] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 11/16/2015] [Indexed: 11/05/2022] Open
Abstract
Uncarboxylated osteocalcin, an osteoblast-derived protein, plays an important role in the regulation of glucose metabolism. It has previously been demonstrated that high glucose levels inhibit osteoblast proliferation and differentiation. However, the mechanisms through which uncarboxylated osteocalcin regulates osteoblast proliferation and differentiation under high glucose conditions remain unclear. Thus, in the present study, we aimed to examine the effects of uncarboxylated osteocalcin on the proliferation and differentiation of MC3T3-E1 cells under high glucose conditions. We demonstrated that high glucose levels induced the production of reactive oxygen species (ROS) in MC3T3-E1 cells, and this production was inhibited by treatment with uncarboxylated osteocalcin and N-acetyl-L-cysteine (NAC), a ROS scavenger. In addition, we found that uncarboxylated osteocalcin reduced high glucose‑induced oxidative stress and increased the mRNA expression of the osteogenic markers, runt-related transcription factor 2 (Runx2), osterix and osteocalcin, as well as the formation of mineralized nodules; it also inhibited adipogenic differentiation, as shown by a decrease in the mRNA expression of the adipogenic markers, peroxisome proliferator‑activated receptor γ (PPARγ), adipocyte fatty acid-binding protein (adipocyte protein 2; aP2) and fatty acid synthase (FAS), and reduced lipid drop accumulation. Furthermore, we found that uncarboxylated osteocalcin inhibited PI3K/Akt signaling which was induced by ROS and facilitated the osteogenic differentiation of MC3T3-E1 cells under high glucose conditions. Taken together and to the best of ou knowledge, our results demonstrate for the first time that uncarboxylated osteocalcin inhibits high glucose-induced ROS production and stimulates osteoblastic differentiation by inhibiting the activation of PI3K/Akt in MC3T3-E1 cells. Therefore, we suggest that uncarboxylated osteocalcin may be a potential therapeutic agent for diabetes-related osteoporosis.
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Affiliation(s)
- Jingli Liu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Jianhong Yang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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