The Study On Mechanical Of The Process Of Patella Tendon Stem Cell Differentiation

Cells generate internal tensile forces through actomyosin interactions and actin polymerization ,they exert tractions on extracellular matrix. This internal tensile forces is referred to as cell traction force(CTF). CTF is regulated by intracellular proteins such as alpha-smoothmuscle actin (α-SMA) and transforming growth factor-β(TGF-β), it is an important physical parameter and is vital for many biological processes, including metastasis,inflammation, wound healing,angiogenesis, cell shape maintenance, and mechanical signal generation. The study of cell traction forces enables us to better understand these cell and the mechanisms of the growth. In this study, Researcher want to find the mechanism of differentiation through measureing the CTF of Patella tendon stem cells before and after differentiation.Object :to find the mechanism of differentiation through measureing the CTF of Patella tendon stem cells before and after differentiation.,and provide new enlighten and thohght for physiology and pathology.Methods and conclusions:Culture cells . Obtaining the cell needed and culturing them in CO2 incubator.After three to four days, remove the cell which not anchorage. Observating the cells with inverted microscope and picking the growth of cells cloned, once every three days, until most cells has good state.The CTFM (Cell Traction Force Microscopy)methods, which use elastic PAG substrate in measuring CTF , using fluorescent beads when fabricate the PAG. and the displacement field can be determined based on the movement of markers on the surface of the PG,we could obtain a pair of"force loaded"and"null force"microscopy images,which is the images we obtain when the cells adhere on substrate and be off.finally, determining the CTF by using the MATLAB and the program which workout .Measureing (α-SMA) of Patella tendon stem cells before and after differentiation by western bloting.Results:CTF of the mouse Patella tendon stem cells were decreased obviously after differentiation when these cells change significantly in morphology. The average of magnitude of CTF were reduced by 30%. The amount of (α-SMA) also be reduced correspondingly.This suggest that the structure and component of Patella tendon stem cells have changed significantly and to a certain extent the expression of a gene.By fluorescent antibody technique to detect protein.Use of indirect fluorescence staining showed protein: Stem cells in mice before and after patellar tendon,the internal protein content has undergone an obvious change. Patellar tendon stem cells in mice after the first differentiation of the relative protein content was significantly reduced protein content, and protein content decreased, indicating that stem cells become smaller traction.