Stem cell-like memory T(TSCM)cells possess stem cell properties including multipotency and self-renewal and are being recognized as emerging players in various human diseases.Advanced technologies such as multiparamet...Stem cell-like memory T(TSCM)cells possess stem cell properties including multipotency and self-renewal and are being recognized as emerging players in various human diseases.Advanced technologies such as multiparametric flowcytometry and single cell sequencing have enabled their identification and molecular characterization.In case of chronic viral diseases such as human immunodeficiency virus-1,CD4+T_(SCM) cells,serve as major reservoirs of the latent virus.However,during immune activation and functional exhaustion of effector T cells,these cells also possess the potential to replenish the pool of functional effector cells to curtail the infection.More recently,these cells are speculated to play important role in protective immunity following acute viral infections such as coronavirus disease 2019 and might be amenable for therapeutics by ex vivo expansion.Similarly,studies are also investigating their pathological role in driving autoimmune responses.However,there are several gaps in the understanding of the role of T_(SCM) cells in viral and autoimmune diseases to make them potential therapeutic targets.In this minireview,we have attempted an updated compilation of the dyadic role of these complex T_(SCM) cells during such human diseases along with their biology and transcriptional programs.展开更多
Mesenchymal stromal/stem cells(MSCs)have garnered significant attention in the field of regenerative medicine due to their remarkable therapeutic potential.MSCs play a pivotal role in maintaining tissue homeostasis an...Mesenchymal stromal/stem cells(MSCs)have garnered significant attention in the field of regenerative medicine due to their remarkable therapeutic potential.MSCs play a pivotal role in maintaining tissue homeostasis and possess diverse functions in tissue repair and recovery in various organs.These cells are charac-terized by easy accessibility,few ethical concerns,and adaptability to in vitro cultures,making them a valuable resource for cell therapy in several clinical conditions.Over the years,it has been shown that the true therapeutic power of MSCs lies not in cell engraftment and replacement but in their ability to produce critical paracrine factors,including cytokines,growth factors,and exosomes(EXOs),which modulate the tissue microenvironment and facilitate repair and regeneration processes.Consequently,MSC-derived products,such as condi-tioned media and EXOs,are now being extensively evaluated for their potential medical applications,offering advantages over the long-term use of whole MSCs.However,the efficacy of MSC-based treatments varies in clinical trials due to both intrinsic differences resulting from the choice of diverse cell sources and non-standardized production methods.To address these concerns and to enhance MSC therapeutic potential,researchers have explored many priming strategies,including exposure to inflammatory molecules,hypoxic conditions,and three-dimensional culture techniques.These approaches have optimized MSC secretion of functional factors,empowering them with enhanced immunomodulatory,angiogenic,and regenerative properties tailored to specific medical conditions.In fact,various priming strategies show promise in the treatment of numerous diseases,from immune-related disorders to acute injuries and cancer.Currently,in order to exploit the full therapeutic potential of MSC therapy,the most important challenge is to optimize the modulation of MSCs to obtain adapted cell therapy for specific clinical disorders.In other words,to unlock the complete potential of MSCs in regenerative medicine,it is crucial to identify the most suitable tissue source and develop in vitro manipulation protocols specific to the type of disease being treated.展开更多
The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like canc...The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem cells.To address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast cancer.The key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like phenotype.Highly sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse model.Overall,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies.展开更多
Retinal degenerations are the leading causes of irreversible visual loss worldwide. Many pathologies included under this umbrella involve progressive degeneration and ultimate loss of the photoreceptor cells, with age...Retinal degenerations are the leading causes of irreversible visual loss worldwide. Many pathologies included under this umbrella involve progressive degeneration and ultimate loss of the photoreceptor cells, with age-related macular degeneration and inherited and ischemic retinal diseases the most relevant. These diseases greatly impact patients' daily lives, with accompanying marked social and economic consequences. However, the currently available treatments only delay the onset or slow progression of visual impairment, and there are no cures for these photoreceptor diseases. Therefore, new therapeutic strategies are being investigated, such as gene therapy, optogenetics, cell replacement, or cell-based neuroprotection. Specifically, stem cells can secrete neurotrophic, immunomodulatory, and anti-angiogenic factors that potentially protect and preserve retinal cells from neurodegeneration. Further, neuroprotection can be used in different types of retinal degenerative diseases and at different disease stages, unlike other potential therapies. This review summarizes stem cell-based paracrine neuroprotective strategies for photoreceptor degeneration, which are under study in clinical trials, and the latest preclinical studies. Effective retinal neuroprotection could be the next frontier in photoreceptor diseases, and the development of novel neuroprotective strategies will address the unmet therapeutic needs.展开更多
BACKGROUND: S100 protein can promote axonal growth. Therefore, transplantation of induced bone marrow-derived mesenchymal stem cells (MSCs) that can secrete S100 may provide a beneficial microenvironment for neural...BACKGROUND: S100 protein can promote axonal growth. Therefore, transplantation of induced bone marrow-derived mesenchymal stem cells (MSCs) that can secrete S100 may provide a beneficial microenvironment for neural regeneration. OBJECTIVE: To explore the changes in S100 expression during rat MSCs differentiation into Schwann ceils in vitro. DESIGN, TIME AND SETTING: This cytology experiment was performed at the Jiangsu Key Laboratory of Neuroregeneration, Nantong University in China, from January 2006 to May 2007. MATERIALS: The rabbit anti-S100 polyclonal antibody was purchased from Dako, Denmark; the mouse anti-rat S100 monoclonal antibody was purchased from Sigma, USA. METHODS: MSCs were cultured from adult Sprague-Dawley rat femur and tibia. Cell proliferation was determined by the MTT method and CD markers, and cell cycle was measured by flow cytometry. MSCs were induced to differentiate into SC cells. SC cells were stained for S100 protein, glial fibrillary acidic protein, and low-affinity nerve growth factor receptor. S100 protein and mRNA levels were evaluated by flow cytometry, Western blot, and reverse transcription-polymerase chain reaction. MAIN OUTCOME MEASURES: S100 protein and mRNA expression. RESULTS: MSCs exhibited high amplification potential over eight passages. Prior to induction, the majority of MSCs were at the G0/G1 phase of the cell cycle. After induction, MSCs displayed morphology changes similar to Schwann cells. Moreover, induction increased S100 mRNA levels. Immunofluorescence showed that MSCs expressed S100 protein, glial fibrillary acidic protein, and low-affinity nerve growth factor receptor at 7 days of induction. Induction also increased S100 protein levels compared with untreated MSCs. CONCLUSION: MSCs are capable of differentiating into Schwann cells-like cells under conditional induction in vitro, with increasing S100 mRNA and protein expression.展开更多
BACKGROUND: It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells (BMSCs) can in vitro induce and differentiate into t...BACKGROUND: It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells (BMSCs) can in vitro induce and differentiate into the cells possessing the properties of nerve cells. But the functions of BMSCs-derived neural stem cells(NSCs) and the differentiated neuron-like cells are still unclear. OBJECTIVE: To observe whether bone marrow-derived NSCs can secrete norepinephrine (NE) under the condition of in vitro culture, induce and differentiation, and analyze the biochemical properties of BMSCs-derived NSCs. DESIGN: A non-randomized and controlled experimental observation SETTING : Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University MATERIALS: This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5- month-old healthy New Zealand white rabbits. METHODS: This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5 month-old healthy New Zealand white rabbits. BMSCs of rabbits were isolated and performed in vitro culture, induce and differentiation with culture medium of NSCs and differentiation-inducing factor, then identified with immunocytochemical method. Experimental grouping: ①Negative control group: L-02 hepatic cell and RPMI1640 culture medium were used. ② Background culture group: Only culture medium of NSCs as culture solution was added into BMSCs to perform culture, and 0.1 volume fraction of imported fetal bovine serum was supplemented 72 hours later. ③Differentiation inducing factor group: After culture for 72 hours, retinoic acid and glial cell line-derived neurotrophic factors were added in the culture medium of BMSCs and NSCs as corresponding inducing factors. The level of NE in each group was detected on the day of culture and 5, 7, 14 and 20 days after culture with high performance liquid chromatography (HPLC). The procedure was conducted 3 times in each group.Standard working curve was made according to the corresponding relationship of NE concentration and peak area. The concentration of NE every 1×10^7 cells was calculated according to standard curve and cell counting. MAIN OUTCOME MEASURES : The level of NE of cultured cells was detected with HPLC; immunocytochemistrical identification of Nestin and neuron specific nuclear protein was performed. RESULTS: ① On the 14^th day after cell culture, BMSCs turned into magnus and round cells which presented Nestin-positive antigen, then changed into neuron-like cells with long processus and presented neuron specific nuclear protein -positive antigen at the 20^th day following culture. ② The ratio of NE concentration and peak area has good linear relationship, and regression equation was Y=1.168 36+0.000 272 8X,r=-0.998 4. Coefficient variation (CV) was 〈 5% and the recovery rate was 92.39%( Y referred to concentration and X was peak area).③NE was well detached within 10 minutes under the condition of this experiment. ④ NE was detected in NSCs and their culture mediums, which were cultured for 7, 14 and 20 days respectively, but no NE in BMSCs, NSCs-free culture medium and L-02 hepatic cell which were as negative control under the HPLC examination. Analysis of variance showed that the level of NE gradually increased following the elongation of culture time (P 〈 0.01 ). No significant difference in the level of NE existed at the same time between differentiation inducing factor group and basic culture group(P 〉 0.05). CONCLUSION : BMSCs of rabbits can proliferate in vitro and express Nestin antigen; They can differentiate into neuron-like cells, express specific neucleoprotein of mature neurons, synthesize and secrete NE as a kind of neurotransmitter.展开更多
Tissue engineering is a multidisciplinary field that applies the principles of engineering and life-sciencesfor regeneration of damaged tissues. Stem cells have attracted much interest in tissue engineering as a cell ...Tissue engineering is a multidisciplinary field that applies the principles of engineering and life-sciencesfor regeneration of damaged tissues. Stem cells have attracted much interest in tissue engineering as a cell source due to their ability to proliferate in an undifferentiated state for prolonged time and capability of differentiating to different cell types after induction. Scaffolds play an important role in tissue engineering as a substrate that can mimic the native extracellular matrix and the properties of scaffolds have been shown to affect the cell behavior such as the cell attachment, proliferation and differentiation. Here, we focus on the recent reports that investigated the various aspects of scaffolds including the materials used for scaffold fabrication, surface modification of scaffolds, topography and mechanical properties of scaffolds towards stem cells differentiation effect. We will present a more detailed overview on the effect of mechanical properties of scaffolds on stem cells fate.展开更多
Mesenchymal stromal/stem cells(MSCs)have shown significant therapeutic potential,and have therefore been extensively investigated in preclinical studies of regenerative medicine.However,while MSCs have been shown to b...Mesenchymal stromal/stem cells(MSCs)have shown significant therapeutic potential,and have therefore been extensively investigated in preclinical studies of regenerative medicine.However,while MSCs have been shown to be safe as a cellular treatment,they have usually been therapeutically ineffective in human diseases.In fact,in many clinical trials it has been shown that MSCs have moderate or poor efficacy.This inefficacy appears to be ascribable primarily to the heterogeneity of MSCs.Recently,specific priming strategies have been used to improve the therapeutic properties of MSCs.In this review,we explore the literature on the principal priming approaches used to enhance the preclinical inefficacy of MSCs.We found that different priming strategies have been used to direct the therapeutic effects of MSCs toward specific pathological processes.Particularly,while hypoxic priming can be used primarily for the treatment of acute diseases,inflammatory cytokines can be used mainly to prime MSCs in order to treat chronic immune-related disorders.The shift in approach from regeneration to inflammation implies,in MSCs,a shift in the production of functional factors that stimulate regenerative or anti-inflammatory pathways.The opportunity to fine-tune the therapeutic properties of MSCs through different priming strategies could conceivably pave the way for optimizing their therapeutic potential.展开更多
The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg alloys.The current work employs high angle annular dark field-scanning transmission electron microscopy(...The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg alloys.The current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-Y/Sm ternary alloys after extended isothermal annealing.Depending on the alloying elements and their concentrations,Mg-Ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg insertions.HAADF-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(Y/Sm)_(8) clusters.In addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding layers.These results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.展开更多
It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes a...It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes are lower than that of an ordinary dish, while the elastic modulus of SMI silicone membrane is lower than that of Tiansu silicone membrane. Neural stem cells from the cerebral cortex of embryonic day 16 Sprague-Dawley rats were seeded onto ordinary dishes as well as Tiansu silicone membrane and SMI silicone membrane. Light microscopy showed that neural stem cells on all three carriers show improved adherence. After 7 days of differentiation, neuron specific enolase, glial fibrillary acidic protein, and myelin basic protein expression was detected by immunofluorescence. Moreover, flow cytometry revealed a higher rate of neural stem cell differentiation into astrocytes on Tiansu and SMI silicone membranes than on the ordinary dish, which was also higher on the SMI than the Tiansu silicone membrane. These findings con- firm that all three cell carrier types have good biocompatibility, while SMI and Tiansu silicone membranes exhibit good mechanical homogenization. Thus, elastic modulus affects neural stem cell differentiation into various nerve cells. Within a certain range, a smaller elastic modulus re- sults in a more obvious trend of cell differentiation into astrocytes.展开更多
文摘Stem cell-like memory T(TSCM)cells possess stem cell properties including multipotency and self-renewal and are being recognized as emerging players in various human diseases.Advanced technologies such as multiparametric flowcytometry and single cell sequencing have enabled their identification and molecular characterization.In case of chronic viral diseases such as human immunodeficiency virus-1,CD4+T_(SCM) cells,serve as major reservoirs of the latent virus.However,during immune activation and functional exhaustion of effector T cells,these cells also possess the potential to replenish the pool of functional effector cells to curtail the infection.More recently,these cells are speculated to play important role in protective immunity following acute viral infections such as coronavirus disease 2019 and might be amenable for therapeutics by ex vivo expansion.Similarly,studies are also investigating their pathological role in driving autoimmune responses.However,there are several gaps in the understanding of the role of T_(SCM) cells in viral and autoimmune diseases to make them potential therapeutic targets.In this minireview,we have attempted an updated compilation of the dyadic role of these complex T_(SCM) cells during such human diseases along with their biology and transcriptional programs.
文摘Mesenchymal stromal/stem cells(MSCs)have garnered significant attention in the field of regenerative medicine due to their remarkable therapeutic potential.MSCs play a pivotal role in maintaining tissue homeostasis and possess diverse functions in tissue repair and recovery in various organs.These cells are charac-terized by easy accessibility,few ethical concerns,and adaptability to in vitro cultures,making them a valuable resource for cell therapy in several clinical conditions.Over the years,it has been shown that the true therapeutic power of MSCs lies not in cell engraftment and replacement but in their ability to produce critical paracrine factors,including cytokines,growth factors,and exosomes(EXOs),which modulate the tissue microenvironment and facilitate repair and regeneration processes.Consequently,MSC-derived products,such as condi-tioned media and EXOs,are now being extensively evaluated for their potential medical applications,offering advantages over the long-term use of whole MSCs.However,the efficacy of MSC-based treatments varies in clinical trials due to both intrinsic differences resulting from the choice of diverse cell sources and non-standardized production methods.To address these concerns and to enhance MSC therapeutic potential,researchers have explored many priming strategies,including exposure to inflammatory molecules,hypoxic conditions,and three-dimensional culture techniques.These approaches have optimized MSC secretion of functional factors,empowering them with enhanced immunomodulatory,angiogenic,and regenerative properties tailored to specific medical conditions.In fact,various priming strategies show promise in the treatment of numerous diseases,from immune-related disorders to acute injuries and cancer.Currently,in order to exploit the full therapeutic potential of MSC therapy,the most important challenge is to optimize the modulation of MSCs to obtain adapted cell therapy for specific clinical disorders.In other words,to unlock the complete potential of MSCs in regenerative medicine,it is crucial to identify the most suitable tissue source and develop in vitro manipulation protocols specific to the type of disease being treated.
基金the National Natural Science Foundation of China(grant nos.81972799 and 81871449)the Natural Science Foundation of Shanghai(grant no.23ZR1421400).
文摘The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem cells.To address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast cancer.The key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like phenotype.Highly sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse model.Overall,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies.
基金supported by Fundación Carolina,Madrid,SpainFondo Europeo de Desarrollo Regional,Fondo Social Europeo and Consejería de Educación(Grant VA077P17),Junta de Castilla y León,SpainCentro en Red de Medicina Regenerativa y Terapia Celular,Junta de Castilla y León,Spain,respectively
文摘Retinal degenerations are the leading causes of irreversible visual loss worldwide. Many pathologies included under this umbrella involve progressive degeneration and ultimate loss of the photoreceptor cells, with age-related macular degeneration and inherited and ischemic retinal diseases the most relevant. These diseases greatly impact patients' daily lives, with accompanying marked social and economic consequences. However, the currently available treatments only delay the onset or slow progression of visual impairment, and there are no cures for these photoreceptor diseases. Therefore, new therapeutic strategies are being investigated, such as gene therapy, optogenetics, cell replacement, or cell-based neuroprotection. Specifically, stem cells can secrete neurotrophic, immunomodulatory, and anti-angiogenic factors that potentially protect and preserve retinal cells from neurodegeneration. Further, neuroprotection can be used in different types of retinal degenerative diseases and at different disease stages, unlike other potential therapies. This review summarizes stem cell-based paracrine neuroprotective strategies for photoreceptor degeneration, which are under study in clinical trials, and the latest preclinical studies. Effective retinal neuroprotection could be the next frontier in photoreceptor diseases, and the development of novel neuroprotective strategies will address the unmet therapeutic needs.
基金the National High-Tech Research & Development Program of China, No. 2006AA02A128the National Natural Science Foundation of China, No. 30670667
文摘BACKGROUND: S100 protein can promote axonal growth. Therefore, transplantation of induced bone marrow-derived mesenchymal stem cells (MSCs) that can secrete S100 may provide a beneficial microenvironment for neural regeneration. OBJECTIVE: To explore the changes in S100 expression during rat MSCs differentiation into Schwann ceils in vitro. DESIGN, TIME AND SETTING: This cytology experiment was performed at the Jiangsu Key Laboratory of Neuroregeneration, Nantong University in China, from January 2006 to May 2007. MATERIALS: The rabbit anti-S100 polyclonal antibody was purchased from Dako, Denmark; the mouse anti-rat S100 monoclonal antibody was purchased from Sigma, USA. METHODS: MSCs were cultured from adult Sprague-Dawley rat femur and tibia. Cell proliferation was determined by the MTT method and CD markers, and cell cycle was measured by flow cytometry. MSCs were induced to differentiate into SC cells. SC cells were stained for S100 protein, glial fibrillary acidic protein, and low-affinity nerve growth factor receptor. S100 protein and mRNA levels were evaluated by flow cytometry, Western blot, and reverse transcription-polymerase chain reaction. MAIN OUTCOME MEASURES: S100 protein and mRNA expression. RESULTS: MSCs exhibited high amplification potential over eight passages. Prior to induction, the majority of MSCs were at the G0/G1 phase of the cell cycle. After induction, MSCs displayed morphology changes similar to Schwann cells. Moreover, induction increased S100 mRNA levels. Immunofluorescence showed that MSCs expressed S100 protein, glial fibrillary acidic protein, and low-affinity nerve growth factor receptor at 7 days of induction. Induction also increased S100 protein levels compared with untreated MSCs. CONCLUSION: MSCs are capable of differentiating into Schwann cells-like cells under conditional induction in vitro, with increasing S100 mRNA and protein expression.
基金the National Natural Science Foundation of China, No. 30270491 the Natural Science Foundation of Guangdong Province, No. 04020422 Science and Technology Plan Program of Guangdong Province, No. 2003A3020304
文摘BACKGROUND: It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells (BMSCs) can in vitro induce and differentiate into the cells possessing the properties of nerve cells. But the functions of BMSCs-derived neural stem cells(NSCs) and the differentiated neuron-like cells are still unclear. OBJECTIVE: To observe whether bone marrow-derived NSCs can secrete norepinephrine (NE) under the condition of in vitro culture, induce and differentiation, and analyze the biochemical properties of BMSCs-derived NSCs. DESIGN: A non-randomized and controlled experimental observation SETTING : Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University MATERIALS: This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5- month-old healthy New Zealand white rabbits. METHODS: This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5 month-old healthy New Zealand white rabbits. BMSCs of rabbits were isolated and performed in vitro culture, induce and differentiation with culture medium of NSCs and differentiation-inducing factor, then identified with immunocytochemical method. Experimental grouping: ①Negative control group: L-02 hepatic cell and RPMI1640 culture medium were used. ② Background culture group: Only culture medium of NSCs as culture solution was added into BMSCs to perform culture, and 0.1 volume fraction of imported fetal bovine serum was supplemented 72 hours later. ③Differentiation inducing factor group: After culture for 72 hours, retinoic acid and glial cell line-derived neurotrophic factors were added in the culture medium of BMSCs and NSCs as corresponding inducing factors. The level of NE in each group was detected on the day of culture and 5, 7, 14 and 20 days after culture with high performance liquid chromatography (HPLC). The procedure was conducted 3 times in each group.Standard working curve was made according to the corresponding relationship of NE concentration and peak area. The concentration of NE every 1×10^7 cells was calculated according to standard curve and cell counting. MAIN OUTCOME MEASURES : The level of NE of cultured cells was detected with HPLC; immunocytochemistrical identification of Nestin and neuron specific nuclear protein was performed. RESULTS: ① On the 14^th day after cell culture, BMSCs turned into magnus and round cells which presented Nestin-positive antigen, then changed into neuron-like cells with long processus and presented neuron specific nuclear protein -positive antigen at the 20^th day following culture. ② The ratio of NE concentration and peak area has good linear relationship, and regression equation was Y=1.168 36+0.000 272 8X,r=-0.998 4. Coefficient variation (CV) was 〈 5% and the recovery rate was 92.39%( Y referred to concentration and X was peak area).③NE was well detached within 10 minutes under the condition of this experiment. ④ NE was detected in NSCs and their culture mediums, which were cultured for 7, 14 and 20 days respectively, but no NE in BMSCs, NSCs-free culture medium and L-02 hepatic cell which were as negative control under the HPLC examination. Analysis of variance showed that the level of NE gradually increased following the elongation of culture time (P 〈 0.01 ). No significant difference in the level of NE existed at the same time between differentiation inducing factor group and basic culture group(P 〉 0.05). CONCLUSION : BMSCs of rabbits can proliferate in vitro and express Nestin antigen; They can differentiate into neuron-like cells, express specific neucleoprotein of mature neurons, synthesize and secrete NE as a kind of neurotransmitter.
文摘Tissue engineering is a multidisciplinary field that applies the principles of engineering and life-sciencesfor regeneration of damaged tissues. Stem cells have attracted much interest in tissue engineering as a cell source due to their ability to proliferate in an undifferentiated state for prolonged time and capability of differentiating to different cell types after induction. Scaffolds play an important role in tissue engineering as a substrate that can mimic the native extracellular matrix and the properties of scaffolds have been shown to affect the cell behavior such as the cell attachment, proliferation and differentiation. Here, we focus on the recent reports that investigated the various aspects of scaffolds including the materials used for scaffold fabrication, surface modification of scaffolds, topography and mechanical properties of scaffolds towards stem cells differentiation effect. We will present a more detailed overview on the effect of mechanical properties of scaffolds on stem cells fate.
文摘Mesenchymal stromal/stem cells(MSCs)have shown significant therapeutic potential,and have therefore been extensively investigated in preclinical studies of regenerative medicine.However,while MSCs have been shown to be safe as a cellular treatment,they have usually been therapeutically ineffective in human diseases.In fact,in many clinical trials it has been shown that MSCs have moderate or poor efficacy.This inefficacy appears to be ascribable primarily to the heterogeneity of MSCs.Recently,specific priming strategies have been used to improve the therapeutic properties of MSCs.In this review,we explore the literature on the principal priming approaches used to enhance the preclinical inefficacy of MSCs.We found that different priming strategies have been used to direct the therapeutic effects of MSCs toward specific pathological processes.Particularly,while hypoxic priming can be used primarily for the treatment of acute diseases,inflammatory cytokines can be used mainly to prime MSCs in order to treat chronic immune-related disorders.The shift in approach from regeneration to inflammation implies,in MSCs,a shift in the production of functional factors that stimulate regenerative or anti-inflammatory pathways.The opportunity to fine-tune the therapeutic properties of MSCs through different priming strategies could conceivably pave the way for optimizing their therapeutic potential.
基金the financial support provided by ANR(Project ANR-22-PEHY-0007)DGA(French Direction Générale des Armées,2018600045)Région Nouvelle Aquitaine(agreement 2018–1R10126).
文摘The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg alloys.The current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-Y/Sm ternary alloys after extended isothermal annealing.Depending on the alloying elements and their concentrations,Mg-Ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg insertions.HAADF-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(Y/Sm)_(8) clusters.In addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding layers.These results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.
基金supported by the National Natural Science Foundation(Youth Project)of China,No.11102235a grant from the Key Project of Tianjin Science and Technology Support Plan in China,No.14ZCZDGX00500+2 种基金the Key Project of Natural Science Foundation of Tianjin City of China,No.12JCZDJC24100the Science and Technology Foundation Project of Tianjin Municipal Health Bureau of China,No.2013KZ134,2014KZ135the Seed Foundation Project of Affiliated Hospital of Logistics University of People’s Armed Police Force of China,No.FYM201432
文摘It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes are lower than that of an ordinary dish, while the elastic modulus of SMI silicone membrane is lower than that of Tiansu silicone membrane. Neural stem cells from the cerebral cortex of embryonic day 16 Sprague-Dawley rats were seeded onto ordinary dishes as well as Tiansu silicone membrane and SMI silicone membrane. Light microscopy showed that neural stem cells on all three carriers show improved adherence. After 7 days of differentiation, neuron specific enolase, glial fibrillary acidic protein, and myelin basic protein expression was detected by immunofluorescence. Moreover, flow cytometry revealed a higher rate of neural stem cell differentiation into astrocytes on Tiansu and SMI silicone membranes than on the ordinary dish, which was also higher on the SMI than the Tiansu silicone membrane. These findings con- firm that all three cell carrier types have good biocompatibility, while SMI and Tiansu silicone membranes exhibit good mechanical homogenization. Thus, elastic modulus affects neural stem cell differentiation into various nerve cells. Within a certain range, a smaller elastic modulus re- sults in a more obvious trend of cell differentiation into astrocytes.