摘要
Cell therapy is a promising treatment for diseases that are caused by cell degeneration or death. The cells for clinical transplantation are usually obtained by culturing healthy allogeneic or exogenous tissue invitro. However, for diseases of the eye, obtaining the adequate number of cells for clinical transplantation is difficult due to the small size of tissue donors and the frequent needs of long-term amplification of cells in vitro, which results in low cell viability after transplantation. In addition, the transplanted cells often develop fibrosis or degrade and have very low survival. Embryonic stem cells(ESCs) and induced pluripotent stem cells(i PS) are also promising candidates for cell therapy. Unfortunately, the differentiation of ESCs can bring immune rejection, tumorigenicity and undesired differentiated cells, limiting its clinical application. Although i PS cells can avoid the risk of immune rejection caused by ES cell differentiation post-transplantation, the low conversion rate, the risk of tumor formation and the potentially unpredictable biological changes that could occur through genetic manipulation hinder its clinical application. Thus, the desired clinical effect of cell therapy is impaired by these factors. Recent research findings recognize that the reason for low survival of the implanted cells not only depends on the seeded cells, but also on the cell microenvironment, which determines the cell survival, proliferation and even reverse differentiation. When used for cell therapy, the transplanted cells need a specific three-dimensional structure to anchor and specific extra cellular matrix components in addition to relevant cytokine signaling to transfer the required information to support their growth. These structures present in the matrix in which the stem cells reside are known as the stem cell microenvironment. The microenvironment interaction with the stem cells provides the necessary homeostasis for cell maintenance and growth. A large number of studies suggest that to explore ho
Cell therapy is a promising treatment for diseasesthat are caused by cell degeneration or death. Thecells for clinical transplantation are usually obtainedby culturing healthy allogeneic or exogenous tissue invitro . However, for diseases of the eye, obtaining theadequate number of cells for clinical transplantationis difficult due to the small size of tissue donors andthe frequent needs of long-term amplification ofcells in vitro , which results in low cell viability aftertransplantation. In addition, the transplanted cells oftendevelop fibrosis or degrade and have very low survival.Embryonic stem cells （ESCs） and induced pluripotentstem cells （iPS） are also promising candidates for celltherapy. Unfortunately, the differentiation of ESCs canbring immune rejection, tumorigenicity and undesireddifferentiated cells, limiting its clinical application.Although iPS cells can avoid the risk of immune rejectioncaused by ES cell differentiation post-transplantation,the low conversion rate, the risk of tumor formationand the potentially unpredictable biological changesthat could occur through genetic manipulation hinderits clinical application. Thus, the desired clinical effectof cell therapy is impaired by these factors. Recentresearch findings recognize that the reason for lowsurvival of the implanted cells not only depends on theseeded cells, but also on the cell microenvironment,which determines the cell survival, proliferation andeven reverse differentiation. When used for cell therapy,the transplanted cells need a specific three-dimensionalstructure to anchor and specific extra cellular matrixcomponents in addition to relevant cytokine signalingto transfer the required information to support theirgrowth. These structures present in the matrix inwhich the stem cells reside are known as the stem cellmicroenvironment. The microenvironment interactionwith the stem cells provides the necessary homeostasisfor cell maintenance and growth. A large number ofstudies suggest that to explore how to reconstructthe stem c
基金
Supported by National High Technology Research and Development Program(863 Program)of China,No.2012AA020507
Natural Sciences Foundation of China,No.81200659 and 81270971
Guangdong Natural Science Foundation,No.S2012010009113
Fundamental Research Funds of State Key Laboratory of Ophthalmology of China,No.2012PI05
