Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation....Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation.Here, we compared the osteogenic potential of MSCs from young and adult rats under three rounds of 2 h of cyclic stretch of 2.5% elongation at 1 Hz on 3 consecutive days. Cyclic stretch induced a significant osteogenic differentiation of MSCs from young rats, while a compromised osteogenesis in MSCs from the adult rats.Accordingly, there were much more reactive oxygen species（ROS） production in adult MSCs under cyclic stretch compared to young MSCs. Moreover, ROS scavenger N-acetylcysteine rescued the osteogenic differentiation of adult MSCs under cyclic stretch. Gene expression analysis revealed that superoxide dismutase 1（SOD1） was significantly downregulated in those MSCs from adult rats. In summary, our data suggest that reduced SOD1 may result in excessive ROS production in adult MSCs under cyclic stretch, and thus manipulation of the MSCs from the adult donors with antioxidant would improve their osteogenic ability.展开更多
Osteoporosis is a common disease that affects patient quality of life, especially among the elderly population. Although inflammation contributes significantly to osteoporosis, the underlying mechanism is unclear. In ...Osteoporosis is a common disease that affects patient quality of life, especially among the elderly population. Although inflammation contributes significantly to osteoporosis, the underlying mechanism is unclear. In this study, we found that tumor necrosis factor （TNF）-a, an inflammatory environment mimic, inhibits osteogenesis of bone mesenchymal stem ceils （BMSCs）, induces miR-146a and decreases Smad4. Moreover, overexpression of miR-146a inhibited the osteogenic ability of BMSCs, whereas blocking miR-146a partially rescued the osteogenesis deficiency under TNF-a treatment. Molecularly, miR-146a decreased Smad4 expression at the protein level by binding to an element located in the Smad4 3＇-untranslated region, and restoration of Smad4 reversed the inhibitory effects of miR-146a on osteogenesis. Together, our results showed that the inflammatory environment mimic TNF-ol inhibits osteogenesis via upregulation of miR-146a and subsequent downregulation of Smad4, thus suggesting that therapeutic manipulation of miR-146a maybe a potential strategy to improve osteogenesis in the context of osteoporosis.展开更多
The recent decade has witnessed an upsurge in the demands of intelligent and simplified Internet of Things(IoT)networks that provide ultra-low-power communication for numerous miniaturized devices.Although the researc...The recent decade has witnessed an upsurge in the demands of intelligent and simplified Internet of Things(IoT)networks that provide ultra-low-power communication for numerous miniaturized devices.Although the research community has paid great attention to wireless protocol designs for these networks,researchers are handicapped by the lack of an energy-efficient software-defined radio(SDR)platform for fast implementation and experimental evaluation.Current SDRs perform well in battery-equipped systems,but fail to support miniaturized IoT devices with stringent hardware and power constraints.This paper takes the first step toward designing an ultra-low-power SDR that satisfies the ultra-low-power or even battery-free requirements of intelligent and simplified IoT networks.To achieve this goal,the core technique is the effective integration ofµW-level backscatter in our SDR to sidestep power-hungry active radio frequency chains.We carefully develop a novel circuit design for efficient energy harvesting and power control,and devise a competent solution for eliminating the harmonic and mirror frequencies caused by backscatter hardware.We evaluate the proposed SDR using different modulation schemes,and it achieves a high data rate of 100 kb/s with power consumption less than 200µW in the active mode and as low as 10µW in the sleep mode.We also conduct a case study of railway inspection using our platform,achieving 1 kb/s battery-free data delivery to the monitoring unmanned aerial vehicle at a distance of 50 m in a real-world environment,and provide two case studies on smart factories and logistic distribution to explore the application of our platform.展开更多
基金financially supported by National Natural Science Foundation of China (81100240)‘985’ project of Sun Yat-Sen University grant+2 种基金Sun Yat-Sen university young teachers training project (13YKPY42)Natural Science Foundation of Guangdong Province,China(S2012010009495)Science and Technology Planning Project of Guangdong Province,China(2012B031800185)
文摘Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation.Here, we compared the osteogenic potential of MSCs from young and adult rats under three rounds of 2 h of cyclic stretch of 2.5% elongation at 1 Hz on 3 consecutive days. Cyclic stretch induced a significant osteogenic differentiation of MSCs from young rats, while a compromised osteogenesis in MSCs from the adult rats.Accordingly, there were much more reactive oxygen species（ROS） production in adult MSCs under cyclic stretch compared to young MSCs. Moreover, ROS scavenger N-acetylcysteine rescued the osteogenic differentiation of adult MSCs under cyclic stretch. Gene expression analysis revealed that superoxide dismutase 1（SOD1） was significantly downregulated in those MSCs from adult rats. In summary, our data suggest that reduced SOD1 may result in excessive ROS production in adult MSCs under cyclic stretch, and thus manipulation of the MSCs from the adult donors with antioxidant would improve their osteogenic ability.
基金supported by the National Natural Science Foundation of China (81570803)Guangzhou Foundation for Science and Technology Planning Project, China (201704030083)+1 种基金Science and Technology Planning Project of Guangdong Province, China (2017A050501013)the Fundamental Research Funds for the Central Universities (17ykjc21)
文摘Osteoporosis is a common disease that affects patient quality of life, especially among the elderly population. Although inflammation contributes significantly to osteoporosis, the underlying mechanism is unclear. In this study, we found that tumor necrosis factor （TNF）-a, an inflammatory environment mimic, inhibits osteogenesis of bone mesenchymal stem ceils （BMSCs）, induces miR-146a and decreases Smad4. Moreover, overexpression of miR-146a inhibited the osteogenic ability of BMSCs, whereas blocking miR-146a partially rescued the osteogenesis deficiency under TNF-a treatment. Molecularly, miR-146a decreased Smad4 expression at the protein level by binding to an element located in the Smad4 3＇-untranslated region, and restoration of Smad4 reversed the inhibitory effects of miR-146a on osteogenesis. Together, our results showed that the inflammatory environment mimic TNF-ol inhibits osteogenesis via upregulation of miR-146a and subsequent downregulation of Smad4, thus suggesting that therapeutic manipulation of miR-146a maybe a potential strategy to improve osteogenesis in the context of osteoporosis.
基金Project supported by the National Key R&D Program of China(Nos.2020YFB1806606 and 2016YFB1200100)the National Natural Science Foundation of China(No.62071194)。
文摘The recent decade has witnessed an upsurge in the demands of intelligent and simplified Internet of Things(IoT)networks that provide ultra-low-power communication for numerous miniaturized devices.Although the research community has paid great attention to wireless protocol designs for these networks,researchers are handicapped by the lack of an energy-efficient software-defined radio(SDR)platform for fast implementation and experimental evaluation.Current SDRs perform well in battery-equipped systems,but fail to support miniaturized IoT devices with stringent hardware and power constraints.This paper takes the first step toward designing an ultra-low-power SDR that satisfies the ultra-low-power or even battery-free requirements of intelligent and simplified IoT networks.To achieve this goal,the core technique is the effective integration ofµW-level backscatter in our SDR to sidestep power-hungry active radio frequency chains.We carefully develop a novel circuit design for efficient energy harvesting and power control,and devise a competent solution for eliminating the harmonic and mirror frequencies caused by backscatter hardware.We evaluate the proposed SDR using different modulation schemes,and it achieves a high data rate of 100 kb/s with power consumption less than 200µW in the active mode and as low as 10µW in the sleep mode.We also conduct a case study of railway inspection using our platform,achieving 1 kb/s battery-free data delivery to the monitoring unmanned aerial vehicle at a distance of 50 m in a real-world environment,and provide two case studies on smart factories and logistic distribution to explore the application of our platform.
