Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone l...Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone loss. Autogenous bone is the present gold standard of bone regeneration. However, disadvantages like donor site morbidity and its decreased availability limit its use. Even allografts and synthetic grafting materials have their own limitations. As certain specific stem cells can be directed to differentiate into an osteoblastic lineage in the presence of growth factors(GFs), it makes stem cells the ideal agents for bone regeneration.Furthermore, platelet-rich plasma(PRP), which can be easily isolated from whole blood, is often used for bone regeneration, wound healing and bone defect repair. When stem cells are combined with PRP in the presence of GFs, they are able to promote osteogenesis. This review provides in-depth knowledge regarding the use of stem cells and PRP in vitro, in vivo and their application in clinical studies in the future.展开更多
IFT20 is the smallest member of the intraflagellar transport protein（IFT） complex B. It is involved in cilia formation. Studies of IFT20 have been confined to ciliated cells. Recently, IFT20 was found to be also exp...IFT20 is the smallest member of the intraflagellar transport protein（IFT） complex B. It is involved in cilia formation. Studies of IFT20 have been confined to ciliated cells. Recently, IFT20 was found to be also expressed in non-ciliated T cells and have functions in immune synapse formation and signaling in vitro. However, how IFT20 regulates T-cell development and activation in vivo is still unknown. We deleted the IFT20 gene in early and later stages of T-cell development by crossing IFT20flox/flox（IFT20f/f） mice with Lck-Cre and CD4-Cre transgenic mice, and investigated the role of IFT20 in T-cell maturation and in the development of T cell-mediated collagen-induced arthritis（CIA）. We found that both Lck-Cre/IFT20f/f and CD4-Cre/IFT20f/f mice were indistinguishable from their wild-type littermates in body size, as well as in the morphology and weight of the spleen and thymus. However, the number of CD4- and CD8-positive cells was significantly lower in thymus and spleen in Lck-Cre/IFT20f/f mice. Meanwhile, the incidence and severity of CIA symptoms were significantly decreased, and inflammation in the paw was significantly inhibited in Lck-Cre/IFT20f/f mice compared to Lck-Cre/IFT201/1littermates. Deletion IFT20 in more mature T cells of CD4-Cre/IFT20f/f mice had only mild effects on the development of T cells and CIA. The expression of IL-1b, IL-6 and TGF-b1 were significantly downregulated in the paw of Lck-Cre/IFT20f/f mice, but just slight decreased in CD4-Cre/IFT20f/f mice. These results demonstrate that deletion of IFT20 in the early stage of T-cell development inhibited CIA development through regulating T-cell development and the expression of critical cytokines.展开更多
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases,and National Institute of Dental and Craniofacial Research under Award Numbers AR061052,AR066101 and DE023105 to S.Y
文摘Presently, there is a high paucity of bone grafts in the United States and worldwide. Regenerating bone is of prime concern due to the current demand of bone grafts and the increasing number of diseases causing bone loss. Autogenous bone is the present gold standard of bone regeneration. However, disadvantages like donor site morbidity and its decreased availability limit its use. Even allografts and synthetic grafting materials have their own limitations. As certain specific stem cells can be directed to differentiate into an osteoblastic lineage in the presence of growth factors(GFs), it makes stem cells the ideal agents for bone regeneration.Furthermore, platelet-rich plasma(PRP), which can be easily isolated from whole blood, is often used for bone regeneration, wound healing and bone defect repair. When stem cells are combined with PRP in the presence of GFs, they are able to promote osteogenesis. This review provides in-depth knowledge regarding the use of stem cells and PRP in vitro, in vivo and their application in clinical studies in the future.
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases,part of the National Institutes of Health,under Award Numbers AR055678,DE023105 and AR061052 to SY
文摘IFT20 is the smallest member of the intraflagellar transport protein（IFT） complex B. It is involved in cilia formation. Studies of IFT20 have been confined to ciliated cells. Recently, IFT20 was found to be also expressed in non-ciliated T cells and have functions in immune synapse formation and signaling in vitro. However, how IFT20 regulates T-cell development and activation in vivo is still unknown. We deleted the IFT20 gene in early and later stages of T-cell development by crossing IFT20flox/flox（IFT20f/f） mice with Lck-Cre and CD4-Cre transgenic mice, and investigated the role of IFT20 in T-cell maturation and in the development of T cell-mediated collagen-induced arthritis（CIA）. We found that both Lck-Cre/IFT20f/f and CD4-Cre/IFT20f/f mice were indistinguishable from their wild-type littermates in body size, as well as in the morphology and weight of the spleen and thymus. However, the number of CD4- and CD8-positive cells was significantly lower in thymus and spleen in Lck-Cre/IFT20f/f mice. Meanwhile, the incidence and severity of CIA symptoms were significantly decreased, and inflammation in the paw was significantly inhibited in Lck-Cre/IFT20f/f mice compared to Lck-Cre/IFT201/1littermates. Deletion IFT20 in more mature T cells of CD4-Cre/IFT20f/f mice had only mild effects on the development of T cells and CIA. The expression of IL-1b, IL-6 and TGF-b1 were significantly downregulated in the paw of Lck-Cre/IFT20f/f mice, but just slight decreased in CD4-Cre/IFT20f/f mice. These results demonstrate that deletion of IFT20 in the early stage of T-cell development inhibited CIA development through regulating T-cell development and the expression of critical cytokines.
