Objective To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.Methods Sprague Dawley （SD） rats were randomly divided in...Objective To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.Methods Sprague Dawley （SD） rats were randomly divided into a baseline group, a control group, a hindlimb suspension group, a radiation group, a ultradian rhythms group and a combined-three-factor group. After four weeks of hindlimb suspension followed by X-ray exposure and/or ultradian rhythms, biomechanical properties, bone mineral density, histological analysis, microstructure parameters, and bone turnover markers were detected to evaluate bone loss in hindlimbs of rats.Results Simulated microgravity or combined-three factors treatment led to a significant decrease in the biomechanical properties of bones, reduction in bone mineral density, and deterioration of trabecular parameters. Ionizing radiation exposure also showed adverse impact while ultradian rhythms had no significant effect on these outcomes. Decrease in the concentration of the turnover markers bone alkaline phosphatase （bALP）, osteocalcin （OCN）, and tartrate-resistant acid phosphatase-5b （TRAP-Sb） in serum was in line with the changes in trabecular parameters.Conclusion Simulated microgravity is the main contributor of bone loss. Radiation also results in deleterious effects but ultradian rhythms has no significant effect. Combined-three factors treatment do not exacerbate bone loss when compared to simulated microgravity treatment alone.展开更多
Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during rad...Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during radiation-induced Epithelium-to-mesenchymal transition(EMT).Methods TGF-β1 or IR was used to induce EMT.After mi R-663 a transfection,cell migration and cell morphological changes were detected and the expression levels of mi R-663 a,TGF-β1,and EMT-related factors were quantified.Results Enhancement of cell migration and promotion of mesenchymal changes induced by either TGF-β1 or radiation were suppressed by mi R-663 a.Furthermore,both X-ray and carbon ion irradiation resulted in the upregulation of TGF-β1 and downregulation of mi R-663 a,while the silencing of TGF-β1 by mi R-663 a reversed the EMT process after radiation.Conclusion Our findings demonstrate an EMT-suppressing effect by mi R-663 a via TGF-β1 in radiationinduced EMT.展开更多
基金supported by the International Science&Technology Cooperation Program of China[No.2015DFR30940]the Science and Technology Research Project of Gansu Province[No.145RTSA012 and No.17JR5RA307]
文摘Objective To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.Methods Sprague Dawley （SD） rats were randomly divided into a baseline group, a control group, a hindlimb suspension group, a radiation group, a ultradian rhythms group and a combined-three-factor group. After four weeks of hindlimb suspension followed by X-ray exposure and/or ultradian rhythms, biomechanical properties, bone mineral density, histological analysis, microstructure parameters, and bone turnover markers were detected to evaluate bone loss in hindlimbs of rats.Results Simulated microgravity or combined-three factors treatment led to a significant decrease in the biomechanical properties of bones, reduction in bone mineral density, and deterioration of trabecular parameters. Ionizing radiation exposure also showed adverse impact while ultradian rhythms had no significant effect on these outcomes. Decrease in the concentration of the turnover markers bone alkaline phosphatase （bALP）, osteocalcin （OCN）, and tartrate-resistant acid phosphatase-5b （TRAP-Sb） in serum was in line with the changes in trabecular parameters.Conclusion Simulated microgravity is the main contributor of bone loss. Radiation also results in deleterious effects but ultradian rhythms has no significant effect. Combined-three factors treatment do not exacerbate bone loss when compared to simulated microgravity treatment alone.
基金funded by the National Natural Science Foundation of China[no.U1932208,YANG Kai]the Science and Technology Research Project of Gansu Province[no.17JR5RA307 and 145RTSA012,WANG Ju Fang]the Science and Technology Research Project of Gansu Province[no.21JR7RA108,DING Nan]
文摘Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during radiation-induced Epithelium-to-mesenchymal transition(EMT).Methods TGF-β1 or IR was used to induce EMT.After mi R-663 a transfection,cell migration and cell morphological changes were detected and the expression levels of mi R-663 a,TGF-β1,and EMT-related factors were quantified.Results Enhancement of cell migration and promotion of mesenchymal changes induced by either TGF-β1 or radiation were suppressed by mi R-663 a.Furthermore,both X-ray and carbon ion irradiation resulted in the upregulation of TGF-β1 and downregulation of mi R-663 a,while the silencing of TGF-β1 by mi R-663 a reversed the EMT process after radiation.Conclusion Our findings demonstrate an EMT-suppressing effect by mi R-663 a via TGF-β1 in radiationinduced EMT.
