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Bai Y, Zhang Q, Chen Q, Zhou Q, Zhang Y, Shi Z, Nong H, Liu M, Zeng G, Zong S. Conditional knockout of the PDK-1 gene in osteoblasts affects osteoblast differentiation and bone formation. J Cell Physiol 2020; 236:5432-5445. [PMID: 33377210 DOI: 10.1002/jcp.30249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 12/22/2022]
Abstract
Osteoblasts are the main functional cells of bone formation, and they are responsible for the synthesis, secretion, and mineralization of the bone matrix. Phosphatidylinositol-3-kinase/Akt is an important signaling pathway involved in the regulation of cell proliferation, death, and survival. Some studies have shown that 3-phosphoinositide-dependent protein kinase-1 (PDK-1) plays an important role in the phosphorylation of Akt. In the present study, an osteocalcin (OCN) promoter-driven Cre-LoxP system was established to specifically delete the PDK-1 gene in osteoblasts. It was found that the size and weight of PDK-1 conditional gene knockout (cKO) mice were significantly reduced. von Kossa staining and microcomputed tomography showed that the trabecular thickness, trabecular number, and bone volume were significantly decreased, whereas trabecular separation was increased, as compared with wide-type littermates, which were characterized by a decreased bone mass. A model of distal femoral defect was established, and it was found that cKO mice delayed bone defect repair. In osteoblasts derived from PDK-1 cKO mice, the alkaline phosphatase (ALP) secretion and ability of calcium mineralization were significantly decreased, and the expressions of osteoblast-related proteins, runt-related transcription factor 2, OCN, and ALP were also clearly decreased. Moreover, the phosphorylation level of Akt and downstream factor GSK3β and their response to insulin-like growth factor-1 (IGF-1) decreased clearly. Therefore, we believe that PDK-1 plays a very important role in osteoblast differentiation and bone formation by regulating the PDK-1/Akt/GSK3β signaling pathway.
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Affiliation(s)
- Yiguang Bai
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Department of Orthopaedics, Nanchong Central Hospital, The Second Clinical Institute of North Sichuan Medical College, Nanchong, Sichuan, China
| | - Qiong Zhang
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi, China
| | - Qiaoling Chen
- Department of Oncology, Nanchong Central Hospital, The Second Clinical Institute of North Sichuan Medical College, Nanchong, Sichuan, China
| | - Quan Zhou
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi, China.,Department of Emergency, The Hongqi Hospital Affiliated to Mudanjiang Medical University, Mudanjiang, Heilongjiang, China
| | - Yanan Zhang
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Zhuohua Shi
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Haibin Nong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Mingfu Liu
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Gaofeng Zeng
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi, China
| | - Shaohui Zong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Research Centre for Regenerative Medicine and Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
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Bai Y, Zhang Q, Zhou Q, Zhang Y, Nong H, Liu M, Shi Z, Zeng G, Zong S. Effects of inhibiting PDK‑1 expression in bone marrow mesenchymal stem cells on osteoblast differentiation in vitro. Mol Med Rep 2020; 23:118. [PMID: 33300048 PMCID: PMC7751487 DOI: 10.3892/mmr.2020.11757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/02/2020] [Indexed: 01/22/2023] Open
Abstract
Osteoblasts are the main functional cells in bone formation, which are responsible for the synthesis, secretion and mineralization of bone matrix. The PI3K/AKT signaling pathway is strongly associated with the differentiation and survival of osteoblasts. The 3-phosphoinositide-dependent protein kinase-1 (PDK-1) protein is considered the master upstream lipid kinase of the PI3K/AKT cascade. The present study aimed to investigate the role of PDK-1 in the process of mouse osteoblast differentiation in vitro. In the BX-912 group, BX-912, a specific inhibitor of PDK-1, was added to osteoblast induction medium (OBM) to treat bone marrow mesenchymal stem cells (BMSCs), whereas the control group was treated with OBM alone. Homozygote PDK1flox/flox mice were designed and generated, and were used to obtain BMSCsPDK1flox/flox. Subsequently, an adenovirus containing Cre recombinase enzyme (pHBAd-cre-EGFP) was used to disrupt the PDK-1 gene in BMSCsPDK1flox/flox; this served as the pHBAd-cre-EGFP group and the efficiency of the disruption was verified. Western blot analysis demonstrated that the protein expression levels of phosphorylated (p)-PDK1 and p-AKT were gradually increased during the osteoblast differentiation process. Notably, BX-912 treatment and disruption of the PDK-1 gene with pHBAd-cre-EGFP effectively reduced the number of alkaline phosphatase (ALP)-positive cells and the optical density value of ALP activity, as well as the formation of cell mineralization. The mRNA expression levels of PDK-1 in the pHBAd-cre-EGFP group were significantly downregulated compared with those in the empty vector virus group on days 3–7. The mRNA expression levels of the osteoblast-related genes RUNX2, osteocalcin and collagen I were significantly decreased in the BX-912 and pHBAd-cre-EGFP groups on days 7 and 21 compared with those in the control and empty vector virus groups. Overall, the results indicated that BX-912 and disruption of the PDK-1 gene in vitro significantly inhibited the differentiation and maturation of osteoblasts. These experimental results provided an experimental and theoretical basis for the role of PDK-1 in osteoblasts.
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Affiliation(s)
- Yiguang Bai
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Qiong Zhang
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Quan Zhou
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yanan Zhang
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Haibin Nong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Mingfu Liu
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Zhuohua Shi
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Gaofeng Zeng
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Shaohui Zong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
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Moseti D, Regassa A, Chen C, O K, Kim WK. 25-Hydroxycholesterol Inhibits Adipogenic Differentiation of C3H10T1/2 Pluripotent Stromal Cells. Int J Mol Sci 2020; 21:ijms21020412. [PMID: 31936485 PMCID: PMC7013583 DOI: 10.3390/ijms21020412] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 01/07/2023] Open
Abstract
Understanding of adipogenesis is important to find remedies for obesity and related disorders. In addition, it is also critical in bone disorders because there is a reciprocal relationship between adipogenesis and osteogenesis in bone micro-environment. Oxysterols are pro-osteogenic and anti-adipogenic molecules via hedgehog activation in pluripotent bone marrow stomal cells. However, no study has evaluated the role of specific oxysterols in C3H10T1/2 cells, which are a good cell model for studying osteogenesis and adipogenesis in bone-marrows. Thus, we investigated the effects of specific oxysterols on adipogenesis and expression of adipogenic transcripts in C3H10T1/2 cells. Treatment of cells with DMITro significantly induced mRNA expression of Pparγ. This induction was significantly inhibited by 25-HC. The expression of C/cepα, Fabp4 and Lpl was also inhibited by 25-HC. To determine the mechanism by which 25-HC inhibits adipogenesis, the effects of the hedgehog signalling pathway inhibitor, cyclopamine and CUR61414, were evaluated. Treatment of C3H10T1/2 cells with DMITro + cyclopamine or DMITro + CUR61414 for 96h did not modulate adipocyte differentiation; cyclopamine and CUR61414 did not reverse the inhibitory effects of 25-HC, suggesting that the canonical hedgehog signalling may not play a role in the anti-adipogenic effects of 25-HC in C3H10T1/2 cells. In addition, LXR agonist did not inhibit adipogenesis, but 25-HC strongly inhibits adipogenesis of C3H10T1/2 cells. Our observations showed that 25-HC was the most potent oxysterol in inhibiting adipogenesis and the expression of key adipogenic transcripts in C3H10T1/2 cells among the tested oxysterols, suggesting its potential application in providing an intervention in osteoporosis and obesity. We also report that the inhibitory effects of 25-HC on adipogenic differentiation in C3H10T1/2 cells are not mediated by hedgehog signaling and LXR.
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Affiliation(s)
- Dorothy Moseti
- Department of Animal Science, University of Manitoba, 201 Animal Science building, Winnipeg, MB R3T 2N2, Canada (A.R.)
| | - Alemu Regassa
- Department of Animal Science, University of Manitoba, 201 Animal Science building, Winnipeg, MB R3T 2N2, Canada (A.R.)
| | - Chongxiao Chen
- Department of Poultry Science, University of Georgia, 303 Poultry Science building, Athens, GA 30602-2772, USA;
| | - Karmin O
- Department of Animal Science, University of Manitoba, 201 Animal Science building, Winnipeg, MB R3T 2N2, Canada (A.R.)
| | - Woo Kyun Kim
- Department of Poultry Science, University of Georgia, 303 Poultry Science building, Athens, GA 30602-2772, USA;
- Correspondence: ; Tel./Fax: +1-706-248-9584
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Xi JC, Zang HY, Guo LX, Xue HB, Liu XD, Bai YB, Ma YZ. The PI3K/AKT cell signaling pathway is involved in regulation of osteoporosis. J Recept Signal Transduct Res 2015; 35:640-5. [PMID: 26390889 DOI: 10.3109/10799893.2015.1041647] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Osteoporosis is a systemic skeletal disease with the high incidence, serious complications, financial burden, and heavily decrease in living quality. METHODS Proliferation of osteoblast was tested by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, alkaline phosphatase (ALP) activity of osteoblasts was tested by ALP REAGENT, Calcium level was determined by a colorimetric assay, mRNA expression of phosphoinositide-3 kinase (PI3K), 3-phosphoinositide-dependent protein kinase 1 (PDK1), Akt, Caspase-3, Caspase-7, Caspase-9, osteocalcin (OCN), Osterix and Runx2 of osteoblasts was tested by RNA preparation and quantitative reverse transcription polymerase chain reaction (RT-PCR), and protein expression of phospho-PI3K, phospho-PDK1 and phospho-Akt was measured by Western Blot analysis. RESULTS In osteoporosis model rats, it found that mRNA expression of PI3K, PDK1 and Akt showed no changes while protein expression of phospho-PI3K, phospho-PDK1 and phospho-Akt in bone tissue was decreased dramatically. To further characterize the molecular mechanisms that regulate osteoporosis, we examined the contribution of the PI3K/Akt cell signaling pathway in cultured osteoblasts. It suggested that, the blockade of PI3K activation by LY294002, a specific inhibitor of the PI3K/Akt signaling pathway in osteoblasts, heavily inhibited cell proliferation, ALP activity, calcium accumulation, and mRNA expression of OCN, Osterix and Runx2. However, mRNA expression of Caspase-3 and Caspase-9 was promoted accordingly. CONCLUSION The in vivo and in vitro studies indicated that the PI3K/Akt cell signaling pathway is involved in the inhibition of osteoporosis through promoting osteoblast proliferation, differentiation and bone formation.
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Affiliation(s)
- Jian-Cheng Xi
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
| | - Hai-Yu Zang
- b Outpatient Department , Command College of Land Force of People's Liberation Army , Shijiazhuang City , China
| | - Li-Xin Guo
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
| | - Hai-Bin Xue
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
| | - Xiang-Dong Liu
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
| | - Yi-Bing Bai
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
| | - Yuan-Zheng Ma
- a Orthopaedic Department , 309 Hospital of People's Liberation Army , Beijing , China and
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Lee JS, Yang JH, Hong JY, Jung UW, Yang HC, Lee IS, Choi SH. Early bone healing onto implant surface treated by fibronectin/oxysterol for cell adhesion/osteogenic differentiation: in vivo experimental study in dogs. J Periodontal Implant Sci 2014; 44:242-50. [PMID: 25368813 PMCID: PMC4216401 DOI: 10.5051/jpis.2014.44.5.242] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 09/28/2014] [Indexed: 01/17/2023] Open
Affiliation(s)
- Jung-Seok Lee
- Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea
| | - Jin-Hyuk Yang
- Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea
| | - Ji-Youn Hong
- Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea
| | - Ui-Won Jung
- Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea
| | - Hyeong-Cheol Yang
- Department of Dental Biomaterials Science, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea
| | - In-Seop Lee
- Atomic-Scale Surface Science Research Center, Yonsei University, Seoul, Korea
| | - Seong-Ho Choi
- Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea
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Chen C, Yang HC, Lee IS. Immobilizing hydroxycholesterol with apatite on titanium surfaces to induce ossification. Biomater Res 2014; 18:16. [PMID: 26331067 PMCID: PMC4552360 DOI: 10.1186/2055-7124-18-16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/05/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immobilizing bioactive molecules and osteoconductive apatite on titanium implants have investigated direct ossification. In this study, hydroxycholesterol (HC) was immobilized with apatite on titanium through simply adsorption or sandwich-like coating. Three kinds of hydroxycholesterol were chosen to induce ossification: 20α-hydroxycholesterol (20α- HC), 22(S)-hydroxycholesterol (22(S)-HC) and 25-hydroxycholesterol (25-HC).The effects of HC/apatite coating on ossification abilities were evaluated in vitro and in vivo. RESULTS At 6 d, adsorbed apatite/25-HC and apatite/22(S)-HC coating exhibited some cytotoxicity, while the cell viability of apatite/20α-HC coating was similar as apatite coating. Immobilizing HC with apatite significantly enhanced the ALP activities compared with apatite coating. There was no significant difference in ALP value between adsorbed apatite/HC coating and sandwich-like apatite/HC/apatite coating. When compared with apatite coating, the mineral deposition improved by adsorbed HC with apatite at higher concentration in vivo. CONCLUSIONS When compared with apatite coating, immobilizing HC with apatite coating induced the ossification in vitro and in vivo.
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Affiliation(s)
- Cen Chen
- Bio-X Center, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018 China
| | - Hyeong Cheol Yang
- Department of Dental Biomaterials Science, Seoul National University, Seoul, 110-749 Korea
| | - In-Seop Lee
- Bio-X Center, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018 China ; Institute of Natural Sciences, Yonsei University, Seoul, 120-749 Korea
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Witkowska-Zimny M, Walenko K, Wrobel E, Mrowka P, Mikulska A, Przybylski J. Effect of substrate stiffness on the osteogenic differentiation of bone marrow stem cells and bone-derived cells. Cell Biol Int 2013; 37:608-16. [DOI: 10.1002/cbin.10078] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Accepted: 02/07/2013] [Indexed: 01/13/2023]
Affiliation(s)
- Malgorzata Witkowska-Zimny
- Department of Biophysics and Human Physiology; Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
| | - Katarzyna Walenko
- Department of Histology and Embryology; Centre of Biostructure Research, Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
| | - Edyta Wrobel
- Department of Biophysics and Human Physiology; Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
| | - Piotr Mrowka
- Department of Biophysics and Human Physiology; Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
| | - Agnieszka Mikulska
- Department of Biophysics and Human Physiology; Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
| | - Jacek Przybylski
- Department of Histology and Embryology; Centre of Biostructure Research, Medical University of Warsaw; Chalubinskiego 5; 02-004; Warsaw; Poland
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Park PJ, Moon BS, Lee SH, Kim SN, Kim AR, Kim HJ, Park WS, Choi KY, Cho EG, Lee TR. Hair growth-promoting effect of Aconiti Ciliare Tuber extract mediated by the activation of Wnt/β-catenin signaling. Life Sci 2012; 91:935-43. [DOI: 10.1016/j.lfs.2012.09.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/31/2012] [Accepted: 09/07/2012] [Indexed: 01/13/2023]
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