The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal...The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal stem cells （MSCs） has gained much attention. However, the underlying cellular mechanisms of MSC therapy are still not fully understood. Although paracrine effects of MSCs on residual cardiomyocytes have been discussed, the amelioration of fibrosis was rarely studied as the hostile environment cannot support the survival of most cell populations and impairs the diffusion of soluble factors. Here in order to decipher the potential mecha- nism of MSC therapy for cardiac fibrosis, we investi- gated the interplay between MSCs and cardiac myofibroblasts （mFBs） using interactive co-culture method, with comparison to paracrine approaches, namely treatment by MSC conditioned medium and gap co-culture method. Various fibrotic features of mFBs were analyzed and the most prominent anti-fibrosis effects were always obtained using direct co-culture that allowed cell-to-cell contacts. Hepatocyte growth factor （HGF）, a well-known anti-fibrosis factor, was demonstrated to be a major contributor for MSCs＇ anti-fibrosisfunction. Moreover, physical contacts and tube-like structures between MSCs and mFBs were observed by live cell imaging and TEM which demonstrate the direct cellular interactions.展开更多
We develop a two dimensional model of a vesicle adhered on a curved substrate via long-range molecular interactions while subjected to a detachment force. The relationship between the force and displacement of the ves...We develop a two dimensional model of a vesicle adhered on a curved substrate via long-range molecular interactions while subjected to a detachment force. The relationship between the force and displacement of the vesicle is investigated as a function of the substrate shape. It is shown that both the force- displacement relationship and the maximum force at pull-off are significantly dependent on the substrate shape. The results suggest that probes with different tip shapes may be designed for cell manipulation. For example, we demonstrate that a vesicle can be pulled off a fiat surface using a probe with a curved tip.展开更多
目的观察不同浓度条件下,细胞接触对骨髓间充质干细胞(BMSCs)分化为心肌细胞(CM)的诱导作用。方法利用表达绿色荧光蛋白(GFP)的转基因大鼠的BMSCs与CM以不同比例(1∶1、1∶10、1∶20、1∶40)共培养1周,分别采用免疫荧光染色及流式细胞...目的观察不同浓度条件下,细胞接触对骨髓间充质干细胞(BMSCs)分化为心肌细胞(CM)的诱导作用。方法利用表达绿色荧光蛋白(GFP)的转基因大鼠的BMSCs与CM以不同比例(1∶1、1∶10、1∶20、1∶40)共培养1周,分别采用免疫荧光染色及流式细胞计数分析检测肌钙蛋白Ⅰ(cTnI)、α-sarcom eric actin in和MEF-2C等心肌特异性蛋白,采用膜片钳技术检测分化细胞的电生理功能。结果在共培养条件下,部分GFP-BMSCs可表达一系列心肌表面标记物,如心肌特异性cTnI蛋白等,且获得心肌分化表型的数量随着CM数量的增加而增加。部分GFP-BMSCs与CM一起同步搏动,并可获得与CM相似的膜电位。结论细胞接触可诱导BMSCs获得有功能的心肌分化表型,其数量与心肌的数量不同浓度有相对的依赖性,随着心肌数量的增加而增加。展开更多
The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La...The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La（ Ⅲ ） at concentrations ranging from 1.00 × 10^-5 to 1.00 × 10^-8 mol·L^-1 show no effect on mature OC number （P 〉 0.05）. In the OC-OB coculture systems without La（Ⅲ ）, osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not （ P 〉 0.05）. Under the OC-OB not-in-contact condition, the effect of La（ Ⅲ ） on the bone-resorbing activity of OCs was similar to that of La（Ⅲ） in the absence of OBs （P 〉 0.05）. However, while OCs were in direct contact with OBs, the inhibitory effects of La（ Ⅲ ） on OCs＇ bone-resorbing activity decreased at the concentrations of 1.00 × 10^-5, 1.00×10^-6 and 1.00×10^-7mol·L^-1, and the promotion effects increased at 1.00×10^-8mol·L^-1 （P 〈0.05）. The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La（ Ⅲ ）.展开更多
Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fib...Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fibrous,or tubular forms encompassing specific molecular compositions.In addition to contact guidance,ECM composition and structures also exert its effect on neuronal differentiation.This short report reviewed the native ECM structure and composition in central nervous system and peripheral nervous system,and their impact on neural regeneration and neuronal differentiation.Using topographies,stem cells have been differentiated to neurons.Further,focussing on engineered biomimicking topographies,we highlighted the role of anisotropic topographies in stem cell differentiation to neurons and its recent temporal application for efficient neuronal differentiation.展开更多
MSCs are pluripotent stem cells which have multipotent differentiation potential and immunosuppressive ability.Therefore,MSCs play an important role in regenerative medicine;the study of their mechanisms of regulating...MSCs are pluripotent stem cells which have multipotent differentiation potential and immunosuppressive ability.Therefore,MSCs play an important role in regenerative medicine;the study of their mechanisms of regulating immune responses will also lead to new strategies for the treatment of immune-inflammatory diseases.Studies have shown that MSCs can modulate adaptive and innate immunity by secreting cytokines or cell-to-cell contact and play an immunosuppressive role.In addition,the secretion of extracellular vesicles by MSCs is also an important immunomodulatory mechanism.MSCs need to be cultured in vitro before they can be used to modulate immunity.It has been shown that pretreatment of MSCs during culture can improve cell survival rate and further enhance the ability of immunomodulation.In this paper,the mechanism of MSCs regulating immune response is discussed to deepen the understanding of MSCs regulating immunity.展开更多
For multicellular organisms,cell-cell communication is essential to numerous biological processes.Drawing upon the latest development of single-cell RNA-sequencing(scRNA-seq),high-resolution transcriptomic data have d...For multicellular organisms,cell-cell communication is essential to numerous biological processes.Drawing upon the latest development of single-cell RNA-sequencing(scRNA-seq),high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues,which enables systematic cell-cell communication studies at a single-cell level.We first summarize a common workflow of cell-cell communication study using scRNA-seq data,which often includes data preparation,construction of communication networks,and result validation.Two common strategies taken to uncover cell-cell communications are reviewed,e.g.,physically vicinal structure-based and ligand-receptor interaction-based one.To conclude,challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.展开更多
In this paper, we have investigated the design parameters of RF CMOS cells which will be used for switch in the wireless telecommunication systems. This RF switch is capable to select the data streams from the two ant...In this paper, we have investigated the design parameters of RF CMOS cells which will be used for switch in the wireless telecommunication systems. This RF switch is capable to select the data streams from the two antennas for both the transmitting and receiving processes. The results for the development of a cell-library which includes the basics of the circuit elements required for the radio frequency sub-systems of the integrated circuits such as V-I characteristics at low-voltages, contact resistance which is present in the switches and the potential barrier with contacts available in devices has been discussed.展开更多
A bonding process for space solar cells implemented by an automated coating and bonding system was theoretically investigated for future parametric studies to achieve better bonding quality. First, the mechanical prop...A bonding process for space solar cells implemented by an automated coating and bonding system was theoretically investigated for future parametric studies to achieve better bonding quality. First, the mechanical properties of silicone adhesive and the vacuum suction cup were experimentally analyzed. Based on the constitutive relationship of four parts in the bonding process, the dynamic bonding process was modeled systematically, and numerically simulated by a commercial finite element analysis code, Adina. The final bonding edge-alignment error and the thickness and uniformity of the adhesive layer were obtained from simulation and validated by experiments. A simulation platform was created for predicting the final bonding quality via adjusting bonding parameters when dimensions of the solar cells and adhesive were changed.展开更多
This paper aims at developing a stochastic-elastic model of a soft elastic body adhering on a wavy surface via a patch of molecular bonds. The elastic deformation of the system is modeled by using continuum contact me...This paper aims at developing a stochastic-elastic model of a soft elastic body adhering on a wavy surface via a patch of molecular bonds. The elastic deformation of the system is modeled by using continuum contact mechanics, while the stochastic behavior of adhesive bonds is modeled by using Bell＇s type of exponential bond association/dissociation rates. It is found that for sufficiently small adhesion patch size or stress concentration index, the adhesion strength is insensitive to the wavelength but decreases with the amplitude of surface undulation, and that for large adhesion patch size or stress concentration index, there exist optimal values of the surface wavelength and amplitude for maximum adhesion strength.展开更多
文摘The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal stem cells （MSCs） has gained much attention. However, the underlying cellular mechanisms of MSC therapy are still not fully understood. Although paracrine effects of MSCs on residual cardiomyocytes have been discussed, the amelioration of fibrosis was rarely studied as the hostile environment cannot support the survival of most cell populations and impairs the diffusion of soluble factors. Here in order to decipher the potential mecha- nism of MSC therapy for cardiac fibrosis, we investi- gated the interplay between MSCs and cardiac myofibroblasts （mFBs） using interactive co-culture method, with comparison to paracrine approaches, namely treatment by MSC conditioned medium and gap co-culture method. Various fibrotic features of mFBs were analyzed and the most prominent anti-fibrosis effects were always obtained using direct co-culture that allowed cell-to-cell contacts. Hepatocyte growth factor （HGF）, a well-known anti-fibrosis factor, was demonstrated to be a major contributor for MSCs＇ anti-fibrosisfunction. Moreover, physical contacts and tube-like structures between MSCs and mFBs were observed by live cell imaging and TEM which demonstrate the direct cellular interactions.
基金The project supported by the National Natural Science Foundation of China (10525210 and 10121202)the 973 Program
文摘We develop a two dimensional model of a vesicle adhered on a curved substrate via long-range molecular interactions while subjected to a detachment force. The relationship between the force and displacement of the vesicle is investigated as a function of the substrate shape. It is shown that both the force- displacement relationship and the maximum force at pull-off are significantly dependent on the substrate shape. The results suggest that probes with different tip shapes may be designed for cell manipulation. For example, we demonstrate that a vesicle can be pulled off a fiat surface using a probe with a curved tip.
文摘目的观察不同浓度条件下,细胞接触对骨髓间充质干细胞(BMSCs)分化为心肌细胞(CM)的诱导作用。方法利用表达绿色荧光蛋白(GFP)的转基因大鼠的BMSCs与CM以不同比例(1∶1、1∶10、1∶20、1∶40)共培养1周,分别采用免疫荧光染色及流式细胞计数分析检测肌钙蛋白Ⅰ(cTnI)、α-sarcom eric actin in和MEF-2C等心肌特异性蛋白,采用膜片钳技术检测分化细胞的电生理功能。结果在共培养条件下,部分GFP-BMSCs可表达一系列心肌表面标记物,如心肌特异性cTnI蛋白等,且获得心肌分化表型的数量随着CM数量的增加而增加。部分GFP-BMSCs与CM一起同步搏动,并可获得与CM相似的膜电位。结论细胞接触可诱导BMSCs获得有功能的心肌分化表型,其数量与心肌的数量不同浓度有相对的依赖性,随着心肌数量的增加而增加。
基金Project supported bythe National Natural Science Foundation of China (20031010 ,20271005)
文摘The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La（ Ⅲ ） at concentrations ranging from 1.00 × 10^-5 to 1.00 × 10^-8 mol·L^-1 show no effect on mature OC number （P 〉 0.05）. In the OC-OB coculture systems without La（Ⅲ ）, osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not （ P 〉 0.05）. Under the OC-OB not-in-contact condition, the effect of La（ Ⅲ ） on the bone-resorbing activity of OCs was similar to that of La（Ⅲ） in the absence of OBs （P 〉 0.05）. However, while OCs were in direct contact with OBs, the inhibitory effects of La（ Ⅲ ） on OCs＇ bone-resorbing activity decreased at the concentrations of 1.00 × 10^-5, 1.00×10^-6 and 1.00×10^-7mol·L^-1, and the promotion effects increased at 1.00×10^-8mol·L^-1 （P 〈0.05）. The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La（ Ⅲ ）.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC) Discovery(NSERC 2016040 to DJ,SM and EKFY)+4 种基金University of Waterloo start up fund(to DJ,SM and EKFY) for their generous fundingNSERC Undergraduate Student Research Awards(USRAto SM and EKFY)Collaborative Research and Training Experience(CREATE,401207296to SM and EKFY) for their generous partial funding
文摘Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fibrous,or tubular forms encompassing specific molecular compositions.In addition to contact guidance,ECM composition and structures also exert its effect on neuronal differentiation.This short report reviewed the native ECM structure and composition in central nervous system and peripheral nervous system,and their impact on neural regeneration and neuronal differentiation.Using topographies,stem cells have been differentiated to neurons.Further,focussing on engineered biomimicking topographies,we highlighted the role of anisotropic topographies in stem cell differentiation to neurons and its recent temporal application for efficient neuronal differentiation.
文摘MSCs are pluripotent stem cells which have multipotent differentiation potential and immunosuppressive ability.Therefore,MSCs play an important role in regenerative medicine;the study of their mechanisms of regulating immune responses will also lead to new strategies for the treatment of immune-inflammatory diseases.Studies have shown that MSCs can modulate adaptive and innate immunity by secreting cytokines or cell-to-cell contact and play an immunosuppressive role.In addition,the secretion of extracellular vesicles by MSCs is also an important immunomodulatory mechanism.MSCs need to be cultured in vitro before they can be used to modulate immunity.It has been shown that pretreatment of MSCs during culture can improve cell survival rate and further enhance the ability of immunomodulation.In this paper,the mechanism of MSCs regulating immune response is discussed to deepen the understanding of MSCs regulating immunity.
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.81774153 and 81973701)the Natural Science Foundation of Zhejiang Province(LZ20H290002)the National Youth Top-notch Talent Support Program(W02070098).
文摘For multicellular organisms,cell-cell communication is essential to numerous biological processes.Drawing upon the latest development of single-cell RNA-sequencing(scRNA-seq),high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues,which enables systematic cell-cell communication studies at a single-cell level.We first summarize a common workflow of cell-cell communication study using scRNA-seq data,which often includes data preparation,construction of communication networks,and result validation.Two common strategies taken to uncover cell-cell communications are reviewed,e.g.,physically vicinal structure-based and ligand-receptor interaction-based one.To conclude,challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.
文摘In this paper, we have investigated the design parameters of RF CMOS cells which will be used for switch in the wireless telecommunication systems. This RF switch is capable to select the data streams from the two antennas for both the transmitting and receiving processes. The results for the development of a cell-library which includes the basics of the circuit elements required for the radio frequency sub-systems of the integrated circuits such as V-I characteristics at low-voltages, contact resistance which is present in the switches and the potential barrier with contacts available in devices has been discussed.
基金the National Natural Science Foundation of China(60675040)the Specialized Researth Fund for the Doctoral Program of Higher Education(20070248021)
文摘A bonding process for space solar cells implemented by an automated coating and bonding system was theoretically investigated for future parametric studies to achieve better bonding quality. First, the mechanical properties of silicone adhesive and the vacuum suction cup were experimentally analyzed. Based on the constitutive relationship of four parts in the bonding process, the dynamic bonding process was modeled systematically, and numerically simulated by a commercial finite element analysis code, Adina. The final bonding edge-alignment error and the thickness and uniformity of the adhesive layer were obtained from simulation and validated by experiments. A simulation platform was created for predicting the final bonding quality via adjusting bonding parameters when dimensions of the solar cells and adhesive were changed.
基金supported by the National Natural Science Foundation of China(11032006,11072094,and 11121202)the Ph.D.Program Foundation of Ministry of Education of China(20100211110022)+1 种基金the program for New Century Excellent Talents in University(NCET-10-0445)the Fundamental Research Funds for the Central Universities (lzujbky- 2012-k06)
文摘This paper aims at developing a stochastic-elastic model of a soft elastic body adhering on a wavy surface via a patch of molecular bonds. The elastic deformation of the system is modeled by using continuum contact mechanics, while the stochastic behavior of adhesive bonds is modeled by using Bell＇s type of exponential bond association/dissociation rates. It is found that for sufficiently small adhesion patch size or stress concentration index, the adhesion strength is insensitive to the wavelength but decreases with the amplitude of surface undulation, and that for large adhesion patch size or stress concentration index, there exist optimal values of the surface wavelength and amplitude for maximum adhesion strength.
