Objective： By establishing the indirect contact co-culture system, we studied the in vitro condition for MAPCs differentiating into epidermal cells and the transformation of MAPCs into epidermal cell phenotype. Meth...Objective： By establishing the indirect contact co-culture system, we studied the in vitro condition for MAPCs differentiating into epidermal cells and the transformation of MAPCs into epidermal cell phenotype. Methods： Cell culture insert membrane was used for substitute basal membrane and MAPCs, fibroblast cells （FCs） and mixture of MAPCs and epidermal cells and FCs were separately implanted into 2 sides of it. PKH26 was used to label cloned MAPCs; type IV collagen rapid adhering method was used to isolate and culture the skin epidermal cells from l-day-old SD rat. Results： Part of the MAPCs transformed into cells expressing keratin in the presence of peripheral epithelia and FCs. Type Ⅳ collagen rapid adhering method successfully selected rats＇ epidermal stem cells. The mixture of the 2 kinds of cells or indirect culture might promote the differentiation through mesenchymal factors secreted by dermis FC. Conclusion： We were the first to have established the in vitro model of MAPCs differentiation into epidermal cells, in which MAPCs were transformed into epithelium-like cells.展开更多
Stimulation of G protein-coupled receptors(GPCRs) can lead to the transactivation of the epidermal growth factor receptors(EGFR). The cross-communication between the two signaling pathways regulates several important ...Stimulation of G protein-coupled receptors(GPCRs) can lead to the transactivation of the epidermal growth factor receptors(EGFR). The cross-communication between the two signaling pathways regulates several important physiological or pathological processes. However, the molecule mechanism underlying EGFR transactivation remains poorly understood. Here, we aim to study the GPCR-mediated EGFR transactivation process using the single-molecule fluorescence imaging and tracking approach.We found that although EGFR existed as monomers at the plasma membrane of resting cells, they became dimers and thus diffused slower following the activation of β2-adrenergic receptor(β2-AR) by isoproterenol(ISO). We further proved thatβ2-AR-mediated changes of EGFR in stoichiometry and dynamics were mediated by Src kinase. Thus, the observations obtained via the single-molecule imaging and tracking methods shed new insights into the molecular mechanism of EGFR transactivation at single molecule level.展开更多
In this paper, a surface plasmon resonance imaging(SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance(SPR) signal from the interactions between cells and different stimuli. The sys...In this paper, a surface plasmon resonance imaging(SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance(SPR) signal from the interactions between cells and different stimuli. The system is constructed with a red laser light source, a P-polarizer, a glass prism, a 5× objective lens, a charge coupled device(CCD) camera, a gold sensor chip, a polydimethylsiloxane(PDMS) reaction well and a mechanical scanning device. The system is applied to mapping living cells in response to stimuli by characterization of the refractive index(RI) changes. Cell responses to K+ in KCl solutions with concentrations of 5 mmol/L, 20 mmol/L, 50 mmol/L and 100 mmol/L are collected, which indicates that the SPRI method can distinguish the concentration of the stimuli. Furthermore, cell responses to epidermal growth factor(EGF) and vascular endothelial growth factor(VEGF) are studied independently. The binding of EGF receptor(EGFR) and EGF is collected as the first signal, and the internal change in cells is recorded as the second signal. The cell response to VEGF is different from that to EGF, which indicates that the SPRI as a label-free, real-time, fast and quantitative method has a potential to distinguish the cell responses to different stimuli.展开更多
基金Supported by the National Natural Science Foundation of China(30600651)the Cooperation Foundation for Overseas Young Scientists (30428001)
文摘Objective： By establishing the indirect contact co-culture system, we studied the in vitro condition for MAPCs differentiating into epidermal cells and the transformation of MAPCs into epidermal cell phenotype. Methods： Cell culture insert membrane was used for substitute basal membrane and MAPCs, fibroblast cells （FCs） and mixture of MAPCs and epidermal cells and FCs were separately implanted into 2 sides of it. PKH26 was used to label cloned MAPCs; type IV collagen rapid adhering method was used to isolate and culture the skin epidermal cells from l-day-old SD rat. Results： Part of the MAPCs transformed into cells expressing keratin in the presence of peripheral epithelia and FCs. Type Ⅳ collagen rapid adhering method successfully selected rats＇ epidermal stem cells. The mixture of the 2 kinds of cells or indirect culture might promote the differentiation through mesenchymal factors secreted by dermis FC. Conclusion： We were the first to have established the in vitro model of MAPCs differentiation into epidermal cells, in which MAPCs were transformed into epithelium-like cells.
基金supported by the National Basic Research Program of China (2013CB933701)the National Natural Science Foundation of China (81530009, 21127901, 91213305)Chinese Academy of Science
文摘Stimulation of G protein-coupled receptors(GPCRs) can lead to the transactivation of the epidermal growth factor receptors(EGFR). The cross-communication between the two signaling pathways regulates several important physiological or pathological processes. However, the molecule mechanism underlying EGFR transactivation remains poorly understood. Here, we aim to study the GPCR-mediated EGFR transactivation process using the single-molecule fluorescence imaging and tracking approach.We found that although EGFR existed as monomers at the plasma membrane of resting cells, they became dimers and thus diffused slower following the activation of β2-adrenergic receptor(β2-AR) by isoproterenol(ISO). We further proved thatβ2-AR-mediated changes of EGFR in stoichiometry and dynamics were mediated by Src kinase. Thus, the observations obtained via the single-molecule imaging and tracking methods shed new insights into the molecular mechanism of EGFR transactivation at single molecule level.
基金supported by the National Basic Research Program of China(Nos.2011CB933202 and 2014CB744600)the National High Technology Research and Development Program of China(No.2014AA022303)the National Natural Science Foundation of China(Nos.61201079,61372055,81371711 and 31100820)
文摘In this paper, a surface plasmon resonance imaging(SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance(SPR) signal from the interactions between cells and different stimuli. The system is constructed with a red laser light source, a P-polarizer, a glass prism, a 5× objective lens, a charge coupled device(CCD) camera, a gold sensor chip, a polydimethylsiloxane(PDMS) reaction well and a mechanical scanning device. The system is applied to mapping living cells in response to stimuli by characterization of the refractive index(RI) changes. Cell responses to K+ in KCl solutions with concentrations of 5 mmol/L, 20 mmol/L, 50 mmol/L and 100 mmol/L are collected, which indicates that the SPRI method can distinguish the concentration of the stimuli. Furthermore, cell responses to epidermal growth factor(EGF) and vascular endothelial growth factor(VEGF) are studied independently. The binding of EGF receptor(EGFR) and EGF is collected as the first signal, and the internal change in cells is recorded as the second signal. The cell response to VEGF is different from that to EGF, which indicates that the SPRI as a label-free, real-time, fast and quantitative method has a potential to distinguish the cell responses to different stimuli.
