Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulatio...Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.展开更多
KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts ...KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.展开更多
基金supported by grants from the National Natural Science Foundation of China(81200763 to WG and 81070809 to YZ)the Program for New Century Excellent Talents(NCET)at the University from Ministry of Education of China(NCET-11-0026)+1 种基金the PKU School of Stomatology for Talented Young Investigators(PKUSS20150107)the Construction Program for the National Key Clinical Specialty from the National Health and Family Planning Commission of China(2011)
文摘Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.
文摘KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.
