Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical ...Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical applications,the probability of failure,degradation and revision is undesirably high,especially for the patients with low bone density,insufficient quantity of bone or osteoporosis,which renders the studies on surface modification of Ti still active to further improve clinical results.It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants.Therefore,it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration.This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical,physical and chemical treatments based on the formation mechanism of the modified coatings.Such conventional methods are able to improve bioactivity of Ti implants,but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues.Hence,beyond traditional static design,dynamic responsive avenues are then emerging.The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers.In short,this review surveys recent developments in the surface engineering of Ti materials,with a specific emphasis on advances in static to dynamic functionality,which provides perspectives for improving bioactivity and biocompatibility of Ti implants.展开更多
BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance...BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance of negative regulator of antiviral response(NRAV)in PDAC is unclear.AIM To study the regulatory role of lncRNA NRAV in PDAC.METHODS GEPIA analyzed lncRNA NRAV and miRNA(miR-299-3p)expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time.The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis,Cell Counting Kit-8 and Transwell analysis.The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics,RNA immunoassay,and fluorescence enzyme analysis.In vivo experiments included transplantation of simulated tumor cells under naked mice.RESULTS The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients.Functionally,overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells,while knockdown of NRAV reversed these effects.Finally,NRAV was performed as a molecular sponge of miR-299-3p.Moreover,overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells.CONCLUSION NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.展开更多
The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soy...The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soybean is limited.Genome-wide analysis and expression profiling of the ARR-Bs gene family were performed in the soybean genome.31 ARR-Bs genes(namely GmARR-B1-31)were identified,containing conserved catalytic domains with protein lengths and molecular weights ranging from 246 to 699 amino acids(aa)and 28.30 to 76.86 kDa,respectively.Phylogenetic analysis grouped ARR-Bs genes into three clusters—Cluster I,Cluster II,and Cluster III—which included 15,12,and 4 genes,respectively,and were asymmetrically distributed on 17 chromosomes.Tissue specific expression analysis of GmARR-Bs family revealed a high transcription level in flowers,roots and seeds.The subcellular localization of GmARR5,GmARR14 were observed in the nucleus,and the promoter region of them included low-temperature responsive element(LTR),the C-repeat/dehydration responsive element(DRE),MBS,ABRE,MYB,MEJA and TCA-elements,which possibly participate in abiotic stress and hormones responses.qRTPCR analysis showed that the expression of GmARR-B genes were affected by different abiotic stresses,especially cold stress and salt stress,and GmARR-B5 and GmARR-B14 were significantly induced by cold stress.This suggested that ARR-Bs genes were involved in multiple abiotic stress response pathways and acted as a positive factor under cold stress.展开更多
Due to the selective permeability of the cytomembrane,high-yield fumaric acid strains form a steep difference between intra-and extracellular concentrations.Intracellular biosensors cannot detect the real concentratio...Due to the selective permeability of the cytomembrane,high-yield fumaric acid strains form a steep difference between intra-and extracellular concentrations.Intracellular biosensors cannot detect the real concentration change of extracellular fumaric acid.To overcome this limitation,a two-component biosensor(TCB)that could respond to extracellular fumaric acid was designed based on the DcuS-DcuR two-component system.The two-component system consists of a histidine kinase(SK)and response regulator.SK is a transmembrane histidine kinase sensor that can detect concentration changes in extracellular compounds.To improve the dynamic range of the constructed fumaric acid TCB,we optimized the expression ratio and expression intensity of dcuS and dcuR.We found that the optimum expression ratio of dcuS:dcuR was 46:54.Under this ratio,the higher was the expression level,the greater the dynamic range.In addition,we modified the ATP-binding site on the DcuS,and the final dynamic range of the TCB reached 6.6-fold.Overall,the obtained fumaric acid-responsive TCB with a high dynamic range is reported for the first time,providing a synthetic biology tool for high-throughput screening and dynamic metabolic regulation of fumaric acid cell factories.展开更多
Seed weight is usually associated with seed size and is one of the important agronomic traits that determine yield.Understanding of seed weight control is limited,especially in soybean plants.Here we show that Glycine...Seed weight is usually associated with seed size and is one of the important agronomic traits that determine yield.Understanding of seed weight control is limited,especially in soybean plants.Here we show that Glycine max JASMONATEZIM DOMAIN 3(GmJAZ3),a gene identified through gene co-expression network analysis,regulates seed-related traits in soybean.Overexpression of GmJAZ3 promotes seed size/weight and other organ sizes in stable transgenic soybean plants likely by increasing cell proliferation.GmJAZ3 interacted with both G.max RESPONSE REGULATOR 18a(GmRR18a)and GmMYC2a to inhibit their transcriptional activation of cytokinin oxidase gene G.max CYTOKININ OXIDASE 3-4(GmCKX3-4),which usually affects seed traits.Meanwhile,the GmRR18a binds to the promoter of GmMYC2a and activates GmMYC2a gene expression.In GmJAZ3-overexpressing soybean seeds,the protein contents were increased while the fatty acid contents were reduced compared to those in the control seeds,indicating that the GmJAZ3 affects seed size/weight and compositions.Natural variation in JAZ3 promoter region was further analyzed and Hap3 promoter correlates with higher promoter activity,higher gene expression and higher seed weight.The Hap3 promoter may be selected and fixed during soybean domestication.JAZ3 orthologs from other plants/crops may also control seed size and weight.Taken together,our study reveals a novel molecular module GmJAZ3-GmRR18a/GmMYC2a-GmCKXs for seed size and weight control,providing promising targets during soybean molecular breeding for better seed traits.展开更多
Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specif...Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specific transporters.However,the mechanisms underlying the regulation of these ion transporters have not been fully elucidated.Loss-of-function mutants of OsHKT2;1,which is involved in sodium uptake,exhibit strong salt stress-resistant phenotypes.In this study,OsHKT2;1 was identified as a transcriptional target of the type-B response regulator OsRR22.Loss-of-function osrr22 mutants showed resilience to salt stress,and OsRR22-overexpression plants were sensitive to salt stress.OsRR22 was found to activate the expression of OsHKT2;1 by directly binding to the promoter region of OsHKT2;1 via a consensus cis-element of type-B response regulators.Moreover,rice DELLA protein OsSLR1 directly interacted with OsRR22 and functioned as a transcriptional co-activator.This study has uncovered a novel transcriptional regulatory mechanism by which a type-B response regulator controls sodium transport under salinity stress.展开更多
The continuous development of hydrogen-electrolyser and fuel-cell technologies not only reduces their investment and operating costs but also improves their technical performance to meet fast-acting requirements of el...The continuous development of hydrogen-electrolyser and fuel-cell technologies not only reduces their investment and operating costs but also improves their technical performance to meet fast-acting requirements of electrical grid balancing services such as frequency-response services.In order to project the feasibility of co-locating a hydrogen-storage system with a wind farm for the dynamic regulation frequency-response provision in Great Britain,this paper develops a modelling framework to coordinate the wind export and frequency responses to the main grid and manage the interaction of the electrolyser,compressor,storage tank and fuel cell within the hydrogen-storage system by respecting the market mechanisms and the balance and conversion of power and hydrogen flows.Then the revenue of frequency-response service provision and a variety of costs induced by the hydrogen-storage system are translated into the net profit of the co-location system,which is maximized by optimizing the capacities of hydrogen-storage-system components,hydrogen-storage levels that guide the hydrogen restoration via operational baselines and the power interchange between a wind-farm and hydrogen-storage system,as well as the capacities tendered for low-and high-frequency dynamic regulation services.The developed modelling framework is tested based on a particular 432-MW offshore wind farm in Great Britain combined with the techno-economics of electrolysers and fuel cells projected for 2030 and 2050 scenarios.The optimized system configuration and operation are compared between different operating scenarios and discussed alongside the prospect of applying hydrogen-storage systems for frequency-response provision.展开更多
Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades.However,optimal cell types and transplantation methods remain unclear.This study evaluated the therapeutic effects of human umbil...Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades.However,optimal cell types and transplantation methods remain unclear.This study evaluated the therapeutic effects of human umbilical cord mesenchymal stem cell(hUCMSC)sheet on myocardial infarction(MI).Methods:hUCMSCs expressing luciferase were generated by lentiviral transduction for in vivo bio-luminescent imaging tracking of cells.We applied a temperature-responsive cell culture surface-based method to form the hUCMSC sheet.Cell retention was evaluated using an in vivo bio-luminescent imaging tracking system.Unbiased transcriptional profiling of infarcted hearts and further immunohistochemical assessment of monocyte and macrophage subtypes were used to determine the mechanisms underlying the therapeutic effects of the hUCMSC sheet.Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function,angiogenesis and left ventricular remodelling.Results:When transplanted to the infarcted mouse hearts,hUCMSC sheet significantly improved the retention and survival compared with cell suspension.At the early stage of MI,hUCMSC sheet modulated inflammation by decreasing Mcp1-positive monocytes and CD68-positive macrophages and increasing Cx3cr1-positive non-classical macrophages,preserving the cardiomyocytes from acute injury.Moreover,the extracellular matrix produced by hUCMSC sheet then served as bioactive scaffold for the host cells to graft and generate new epicardial tissue,providing mechanical support and routes for revascularsation.These effects of hUCMSC sheet treatment significantly improved the cardiac function at days 7 and 28 post-MI.Conclusions:hUCMSC sheet formation dramatically improved the biological functions of hUCMSCs,mitigating adverse post-MI remodelling by modulating the inflammatory response and providing bioactive scaffold upon transplantation into the heart.Translational perspective:Due to its excellent availability as well as superior local cellular retention and survival,allogenic transplantation of hUCMSC sheets can more effectively acquire the biological functions of hUCMSCs,such as modulating inflammation and enhancing angiogenesis.Moreover,the hUCMSC sheet method allows the transfer of an intact extracellular matrix without introducing exogenous or synthetic biomaterial,further improving its clinical applicability.展开更多
Due to global climate change, temperature stress has become one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms in plants, particularly ...Due to global climate change, temperature stress has become one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms in plants, particularly in the identification of temperature stress responsive protein-coding genes. Recently discovered micro RNAs(mi RNAs) and endogenous small-interfering RNAs(si RNAs) have also been demonstrated as simportant players in plant temperature stress response.Using high-throughput sequencing, many small RNAs,especially mi RNAs, have been identified to be triggered by cold or heat. Subsequently, several studies have shown an important functional role for these small RNAs in cold or heat tolerance. These findings greatly broaden our understanding of endogenous small RNAs in plant stress response control. Here, we highlight new findings regarding the roles of mi RNAs and si RNAs in plant temperature stress response and acclimation. We also review the current understanding of the regulatory mechanisms of small RNAs in temperature stress response, and explore the outlook for the use of these small RNAs in molecular breeding for improvement of temperature stress tolerance in plants.展开更多
基金supported by National Key Research and Development Program of China(grant Nos.2020YFC2004900,2016YFC1100300)the National Natural Science Foundation of China(grant Nos.21773199,51571169,52001265).
文摘Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical applications,the probability of failure,degradation and revision is undesirably high,especially for the patients with low bone density,insufficient quantity of bone or osteoporosis,which renders the studies on surface modification of Ti still active to further improve clinical results.It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants.Therefore,it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration.This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical,physical and chemical treatments based on the formation mechanism of the modified coatings.Such conventional methods are able to improve bioactivity of Ti implants,but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues.Hence,beyond traditional static design,dynamic responsive avenues are then emerging.The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers.In short,this review surveys recent developments in the surface engineering of Ti materials,with a specific emphasis on advances in static to dynamic functionality,which provides perspectives for improving bioactivity and biocompatibility of Ti implants.
基金Supported by the National Natural Science Foundation of China,No.81974372
文摘BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance of negative regulator of antiviral response(NRAV)in PDAC is unclear.AIM To study the regulatory role of lncRNA NRAV in PDAC.METHODS GEPIA analyzed lncRNA NRAV and miRNA(miR-299-3p)expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time.The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis,Cell Counting Kit-8 and Transwell analysis.The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics,RNA immunoassay,and fluorescence enzyme analysis.In vivo experiments included transplantation of simulated tumor cells under naked mice.RESULTS The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients.Functionally,overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells,while knockdown of NRAV reversed these effects.Finally,NRAV was performed as a molecular sponge of miR-299-3p.Moreover,overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells.CONCLUSION NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.
基金This work was financially supported by the National Modern Agricultural Industrial Technology System(CARS-04-01A).
文摘The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soybean is limited.Genome-wide analysis and expression profiling of the ARR-Bs gene family were performed in the soybean genome.31 ARR-Bs genes(namely GmARR-B1-31)were identified,containing conserved catalytic domains with protein lengths and molecular weights ranging from 246 to 699 amino acids(aa)and 28.30 to 76.86 kDa,respectively.Phylogenetic analysis grouped ARR-Bs genes into three clusters—Cluster I,Cluster II,and Cluster III—which included 15,12,and 4 genes,respectively,and were asymmetrically distributed on 17 chromosomes.Tissue specific expression analysis of GmARR-Bs family revealed a high transcription level in flowers,roots and seeds.The subcellular localization of GmARR5,GmARR14 were observed in the nucleus,and the promoter region of them included low-temperature responsive element(LTR),the C-repeat/dehydration responsive element(DRE),MBS,ABRE,MYB,MEJA and TCA-elements,which possibly participate in abiotic stress and hormones responses.qRTPCR analysis showed that the expression of GmARR-B genes were affected by different abiotic stresses,especially cold stress and salt stress,and GmARR-B5 and GmARR-B14 were significantly induced by cold stress.This suggested that ARR-Bs genes were involved in multiple abiotic stress response pathways and acted as a positive factor under cold stress.
基金supported by the National Key R&D Program of China(2019YFA0905502)the National Natural Science Foundation of China(31900066 and 21877053)+2 种基金the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-015)the Fundamental Research Funds for the Central Universities(JUSRP12056 and JUSRP51705A)the China Postdoctoral Science Foundation(2021M690533).
文摘Due to the selective permeability of the cytomembrane,high-yield fumaric acid strains form a steep difference between intra-and extracellular concentrations.Intracellular biosensors cannot detect the real concentration change of extracellular fumaric acid.To overcome this limitation,a two-component biosensor(TCB)that could respond to extracellular fumaric acid was designed based on the DcuS-DcuR two-component system.The two-component system consists of a histidine kinase(SK)and response regulator.SK is a transmembrane histidine kinase sensor that can detect concentration changes in extracellular compounds.To improve the dynamic range of the constructed fumaric acid TCB,we optimized the expression ratio and expression intensity of dcuS and dcuR.We found that the optimum expression ratio of dcuS:dcuR was 46:54.Under this ratio,the higher was the expression level,the greater the dynamic range.In addition,we modified the ATP-binding site on the DcuS,and the final dynamic range of the TCB reached 6.6-fold.Overall,the obtained fumaric acid-responsive TCB with a high dynamic range is reported for the first time,providing a synthetic biology tool for high-throughput screening and dynamic metabolic regulation of fumaric acid cell factories.
基金supported by the National Key R&D Project(2021YFF1001201,2021YFF1000104-2)the National Natural Science Foundation of China(32090062,32090063)+2 种基金the Chinese Academy of Science leading project(XDA24010105)the State Key Lab of Plant Genomicsthe Qilu Zhongke Academy of Modern Microbiology Technology。
文摘Seed weight is usually associated with seed size and is one of the important agronomic traits that determine yield.Understanding of seed weight control is limited,especially in soybean plants.Here we show that Glycine max JASMONATEZIM DOMAIN 3(GmJAZ3),a gene identified through gene co-expression network analysis,regulates seed-related traits in soybean.Overexpression of GmJAZ3 promotes seed size/weight and other organ sizes in stable transgenic soybean plants likely by increasing cell proliferation.GmJAZ3 interacted with both G.max RESPONSE REGULATOR 18a(GmRR18a)and GmMYC2a to inhibit their transcriptional activation of cytokinin oxidase gene G.max CYTOKININ OXIDASE 3-4(GmCKX3-4),which usually affects seed traits.Meanwhile,the GmRR18a binds to the promoter of GmMYC2a and activates GmMYC2a gene expression.In GmJAZ3-overexpressing soybean seeds,the protein contents were increased while the fatty acid contents were reduced compared to those in the control seeds,indicating that the GmJAZ3 affects seed size/weight and compositions.Natural variation in JAZ3 promoter region was further analyzed and Hap3 promoter correlates with higher promoter activity,higher gene expression and higher seed weight.The Hap3 promoter may be selected and fixed during soybean domestication.JAZ3 orthologs from other plants/crops may also control seed size and weight.Taken together,our study reveals a novel molecular module GmJAZ3-GmRR18a/GmMYC2a-GmCKXs for seed size and weight control,providing promising targets during soybean molecular breeding for better seed traits.
基金supported by the National Natural Science Foundation of China (32001448,32272027)。
文摘Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specific transporters.However,the mechanisms underlying the regulation of these ion transporters have not been fully elucidated.Loss-of-function mutants of OsHKT2;1,which is involved in sodium uptake,exhibit strong salt stress-resistant phenotypes.In this study,OsHKT2;1 was identified as a transcriptional target of the type-B response regulator OsRR22.Loss-of-function osrr22 mutants showed resilience to salt stress,and OsRR22-overexpression plants were sensitive to salt stress.OsRR22 was found to activate the expression of OsHKT2;1 by directly binding to the promoter region of OsHKT2;1 via a consensus cis-element of type-B response regulators.Moreover,rice DELLA protein OsSLR1 directly interacted with OsRR22 and functioned as a transcriptional co-activator.This study has uncovered a novel transcriptional regulatory mechanism by which a type-B response regulator controls sodium transport under salinity stress.
文摘The continuous development of hydrogen-electrolyser and fuel-cell technologies not only reduces their investment and operating costs but also improves their technical performance to meet fast-acting requirements of electrical grid balancing services such as frequency-response services.In order to project the feasibility of co-locating a hydrogen-storage system with a wind farm for the dynamic regulation frequency-response provision in Great Britain,this paper develops a modelling framework to coordinate the wind export and frequency responses to the main grid and manage the interaction of the electrolyser,compressor,storage tank and fuel cell within the hydrogen-storage system by respecting the market mechanisms and the balance and conversion of power and hydrogen flows.Then the revenue of frequency-response service provision and a variety of costs induced by the hydrogen-storage system are translated into the net profit of the co-location system,which is maximized by optimizing the capacities of hydrogen-storage-system components,hydrogen-storage levels that guide the hydrogen restoration via operational baselines and the power interchange between a wind-farm and hydrogen-storage system,as well as the capacities tendered for low-and high-frequency dynamic regulation services.The developed modelling framework is tested based on a particular 432-MW offshore wind farm in Great Britain combined with the techno-economics of electrolysers and fuel cells projected for 2030 and 2050 scenarios.The optimized system configuration and operation are compared between different operating scenarios and discussed alongside the prospect of applying hydrogen-storage systems for frequency-response provision.
基金This work was supported by the Peking University Third Hospital Key Clinical Foundation[grant numbers BYSY2015007,BYSY2018039 and BYSYDL2019016 to Y.L.]the capital health research and development of special[grant number 2020-2-4096 to Y.L.]+1 种基金the Beijing Natural Science Foundation[grant number Z190013 to F.L.]the National Natural Science Foundation of China[grant number 81970205 to F.L.].
文摘Stem cell-based therapy has been used to treat ischaemic heart diseases for two decades.However,optimal cell types and transplantation methods remain unclear.This study evaluated the therapeutic effects of human umbilical cord mesenchymal stem cell(hUCMSC)sheet on myocardial infarction(MI).Methods:hUCMSCs expressing luciferase were generated by lentiviral transduction for in vivo bio-luminescent imaging tracking of cells.We applied a temperature-responsive cell culture surface-based method to form the hUCMSC sheet.Cell retention was evaluated using an in vivo bio-luminescent imaging tracking system.Unbiased transcriptional profiling of infarcted hearts and further immunohistochemical assessment of monocyte and macrophage subtypes were used to determine the mechanisms underlying the therapeutic effects of the hUCMSC sheet.Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function,angiogenesis and left ventricular remodelling.Results:When transplanted to the infarcted mouse hearts,hUCMSC sheet significantly improved the retention and survival compared with cell suspension.At the early stage of MI,hUCMSC sheet modulated inflammation by decreasing Mcp1-positive monocytes and CD68-positive macrophages and increasing Cx3cr1-positive non-classical macrophages,preserving the cardiomyocytes from acute injury.Moreover,the extracellular matrix produced by hUCMSC sheet then served as bioactive scaffold for the host cells to graft and generate new epicardial tissue,providing mechanical support and routes for revascularsation.These effects of hUCMSC sheet treatment significantly improved the cardiac function at days 7 and 28 post-MI.Conclusions:hUCMSC sheet formation dramatically improved the biological functions of hUCMSCs,mitigating adverse post-MI remodelling by modulating the inflammatory response and providing bioactive scaffold upon transplantation into the heart.Translational perspective:Due to its excellent availability as well as superior local cellular retention and survival,allogenic transplantation of hUCMSC sheets can more effectively acquire the biological functions of hUCMSCs,such as modulating inflammation and enhancing angiogenesis.Moreover,the hUCMSC sheet method allows the transfer of an intact extracellular matrix without introducing exogenous or synthetic biomaterial,further improving its clinical applicability.
基金supported by the National Youth Science Foundation of China(31201198)the Key Project of Guangdong Scientific and Technological Plan(2015B020231002)the Guangdong Modern Agricultural Creation Team Project(2016LM2148)
文摘Due to global climate change, temperature stress has become one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms in plants, particularly in the identification of temperature stress responsive protein-coding genes. Recently discovered micro RNAs(mi RNAs) and endogenous small-interfering RNAs(si RNAs) have also been demonstrated as simportant players in plant temperature stress response.Using high-throughput sequencing, many small RNAs,especially mi RNAs, have been identified to be triggered by cold or heat. Subsequently, several studies have shown an important functional role for these small RNAs in cold or heat tolerance. These findings greatly broaden our understanding of endogenous small RNAs in plant stress response control. Here, we highlight new findings regarding the roles of mi RNAs and si RNAs in plant temperature stress response and acclimation. We also review the current understanding of the regulatory mechanisms of small RNAs in temperature stress response, and explore the outlook for the use of these small RNAs in molecular breeding for improvement of temperature stress tolerance in plants.
