Adipose tissue is a rich, ubiquitous and easily acces-sible source for multipotent stromal/stem cells and has, therefore, several advantages compared to other sourc-es of mesenchymal stromal/stem cells. Several studie...Adipose tissue is a rich, ubiquitous and easily acces-sible source for multipotent stromal/stem cells and has, therefore, several advantages compared to other sourc-es of mesenchymal stromal/stem cells. Several studies have tried to identify the origin of the stromal/stem cell population within adipose tissue in situ. This is a complicated attempt because no marker has currently been described which unambiguously identifies native adipose-derived stromal/stem cells(ASCs). Isolated and cultured ASCs are a non-uniform preparation consisting of several subsets of stem and precursor cells. Cultured ASCs are characterized by their expression of a panel of markers(and the absence of others), whereas their in vitro phenotype is dynamic. Some markers were ex-pressed de novo during culture, the expression of some markers is lost. For a long time, CD34 expression was solely used to characterize haematopoietic stem and progenitor cells, but now it has become evident that it is also a potential marker to identify an ASC subpopula-tion in situ and after a short culture time. Nevertheless, long-term cultured ASCs do not express CD34, perhaps due to the artificial environment. This review gives an update of the recently published data on the origin and phenotype of ASCs both in vivo and in vitro. In addition, the composition of ASCs(or their subpopula-tions) seems to vary between different laboratories andpreparations. This heterogeneity of ASC preparationsmay result from different reasons. One of the main problems in comparing results from different laborato-ries is the lack of a standardized isolation and culture protocol for ASCs. Since many aspects of ASCs, suchas the differential potential or the current use in clinical trials, are fully described in other recent reviews, this review further updates the more basic research issues concerning ASCs' subpopulations, heterogeneity andculture standardization.展开更多
Background Human adipose tissue-derived stromal cells （hADSCs） can be induced to differentiate along an osteoblastic lineage under stimulation of dexamethasone （DEX）. Recent studies, however, have questioned the e...Background Human adipose tissue-derived stromal cells （hADSCs） can be induced to differentiate along an osteoblastic lineage under stimulation of dexamethasone （DEX）. Recent studies, however, have questioned the efficacy of glucocorticoids such as DEX in mediating the osteogenesis process of skeletal progenitor cells and processed lipoaspirate cells. Is it possible to find a substitute for DEX？ Therefore, this study was designed to investigate osteogenic capacity and regulating mechanisms for osteoblastic differentiation of hADSCs by comparing osteogenic media （OM） containing either 1, 25-dihydroxyvitamin D3 （VD） or DEX and determine if VD was an ideal substitute for DEX as an induction agent for the osteogenesis of hADSCs. Methods Osteogenic differentiation of hADSCs was induced by osteogenic medium （OM） containing either 10 nmol/L VD or 100 nmol/L DEX. Differentiation of hADSCs into osteoblastic lineage was identified by alkaline phosphatase （ALP） staining, von Kossa staining, and reverse transcription-polymerase chain reaction assays for mRNA expression of osteogenesis-related genes such as type Ⅰ collagen （COL Ⅰ）, bone sialoprotein （BSP）, osteocalcin （OC）, bone morphogenetic protein （BMP）-2, BMP-4, BMP-6, BMP-7, runt-related transcription factor 2/core binding factor α1 （Runx2/Cbfal）, osterix （Osx）, and LIM mineralization protein- 1 （LMP- 1）. Results von Kossa staining revealed that the differentiated cells induced by both VD and DEX were mineralized in vitro. They also expressed osteoblast-related markers, such as ALP, COL Ⅰ, BSP, and OC. Runx2/Cbfal, Osx, BMP-6, and LMP-1 were upregulated during VD and DEX-induced hADSC osteoblastic differentiation, but BMP-4, BMP-7 were not. BMP-2 was only expressed in VD-induced differentiated cells. Conclusions VD or DEX-induced hADSCs differentiate toward the osteoblastic lineage in vitro. Runx2/Cbfal, Osx, BMP-2, BMP-6, and LMP-1 are involved in regulating osteoblastic differentiation of hADSCs, but BMP-4, BMP-7 are not. VD, but not DEX, induces expression of BMP-2 during osteogenic induction of hADSCs. VD is an ideal substitute for DEX for osteogenic induction of hADSCs.展开更多
Chitosan has been shown to be a promising material for various applications in tissue engineering. Recently, adipose tissue derived stromal cells （ADSCs） have been investigated as an alternative source of seed cells...Chitosan has been shown to be a promising material for various applications in tissue engineering. Recently, adipose tissue derived stromal cells （ADSCs） have been investigated as an alternative source of seed cells for tissue engineering. The compatibility of chitosan and chitosan-gelatin complexes with ADSCs is not known. In the present study, ADSCs were isolated and characterized by phenotype using fluorescence-activated cell sorting （FACS）. The morphology, viability, and the ability of the ADSCs to differentiate on chitosan and chitosan-gelatin composite films with 60 wt.% gelatin were evaluated. Results show that the ADSCs are positive for CD29, CD44, and CD105, but negative for CD31, CD34, and CD45. ADSCs adhere and grow better on the composite films than on the chitosan films. The ability of ADSCs to differentiate into osteogenic and adipogenic lineage cells is not affected by their being cultured on chitosan-gelatin composite films. Therefore, chitosan-gelatin composite films are compatible with ADSCs and do not impair the ability of ADSCs to differentiate into osteogenic and adipogenic lineage cells.展开更多
In plastic and reconstructive surgery there is an increasing demand for malleable implants to repair soft tissue congenital defects, or those resulting from aging, traumatic injury and tumour resection. However, curre...In plastic and reconstructive surgery there is an increasing demand for malleable implants to repair soft tissue congenital defects, or those resulting from aging, traumatic injury and tumour resection. However, currently available methods present a number of limitations such as volume loss over time and eventual resorption of the graft. Tissue engineering techniques provide promising therapeutic solutions to these inconveniences through development of engineered equivalents that best imitate adipose tissue, both structurally and functionally. Here we review the latest achievements in the human adipose tissue engineering field, with a focus on its regenerative potential for a number of clinical applications.展开更多
With technological advances in basic research,the intricate mechanism of secondary delayed spinal cord injury(SCI)continues to unravel at a rapid pace.However,despite our deeper understanding of the molecular changes ...With technological advances in basic research,the intricate mechanism of secondary delayed spinal cord injury(SCI)continues to unravel at a rapid pace.However,despite our deeper understanding of the molecular changes occurring after initial insult to the spinal cord,the cure for paralysis remains elusive.Current treatment of SCI is limited to early administration of high dose steroids to mitigate the harmful effect of cord edema that occurs after SCI and to reduce the cascade of secondary delayed SCI.R ecent evident-based clinical studies have cast doubt on the clinical benefit of steroids in SCI and intense focus on stem cell-based therapy has yielded some encouraging results.An array of mesenchymal stem cells(MSCs)from various sources with novel and promising strategies are being developed to improve function after SCI.In this review,we briefly discuss the pathophysiology of spinal cord injuries and characteristics and the potential sources of MSCs that can be used in the treatment of SCI.We will discuss the progress of MSCs application in research,focusing on the neuroprotective properties of MSCs.Finally,we will discuss the results from preclinical and clinical trials involving stem cell-based therapy in SCI.展开更多
文摘Adipose tissue is a rich, ubiquitous and easily acces-sible source for multipotent stromal/stem cells and has, therefore, several advantages compared to other sourc-es of mesenchymal stromal/stem cells. Several studies have tried to identify the origin of the stromal/stem cell population within adipose tissue in situ. This is a complicated attempt because no marker has currently been described which unambiguously identifies native adipose-derived stromal/stem cells(ASCs). Isolated and cultured ASCs are a non-uniform preparation consisting of several subsets of stem and precursor cells. Cultured ASCs are characterized by their expression of a panel of markers(and the absence of others), whereas their in vitro phenotype is dynamic. Some markers were ex-pressed de novo during culture, the expression of some markers is lost. For a long time, CD34 expression was solely used to characterize haematopoietic stem and progenitor cells, but now it has become evident that it is also a potential marker to identify an ASC subpopula-tion in situ and after a short culture time. Nevertheless, long-term cultured ASCs do not express CD34, perhaps due to the artificial environment. This review gives an update of the recently published data on the origin and phenotype of ASCs both in vivo and in vitro. In addition, the composition of ASCs(or their subpopula-tions) seems to vary between different laboratories andpreparations. This heterogeneity of ASC preparationsmay result from different reasons. One of the main problems in comparing results from different laborato-ries is the lack of a standardized isolation and culture protocol for ASCs. Since many aspects of ASCs, suchas the differential potential or the current use in clinical trials, are fully described in other recent reviews, this review further updates the more basic research issues concerning ASCs' subpopulations, heterogeneity andculture standardization.
基金This study was supported by a grant from the National Natural Science Foundation of China (No. 30200319).
文摘Background Human adipose tissue-derived stromal cells （hADSCs） can be induced to differentiate along an osteoblastic lineage under stimulation of dexamethasone （DEX）. Recent studies, however, have questioned the efficacy of glucocorticoids such as DEX in mediating the osteogenesis process of skeletal progenitor cells and processed lipoaspirate cells. Is it possible to find a substitute for DEX？ Therefore, this study was designed to investigate osteogenic capacity and regulating mechanisms for osteoblastic differentiation of hADSCs by comparing osteogenic media （OM） containing either 1, 25-dihydroxyvitamin D3 （VD） or DEX and determine if VD was an ideal substitute for DEX as an induction agent for the osteogenesis of hADSCs. Methods Osteogenic differentiation of hADSCs was induced by osteogenic medium （OM） containing either 10 nmol/L VD or 100 nmol/L DEX. Differentiation of hADSCs into osteoblastic lineage was identified by alkaline phosphatase （ALP） staining, von Kossa staining, and reverse transcription-polymerase chain reaction assays for mRNA expression of osteogenesis-related genes such as type Ⅰ collagen （COL Ⅰ）, bone sialoprotein （BSP）, osteocalcin （OC）, bone morphogenetic protein （BMP）-2, BMP-4, BMP-6, BMP-7, runt-related transcription factor 2/core binding factor α1 （Runx2/Cbfal）, osterix （Osx）, and LIM mineralization protein- 1 （LMP- 1）. Results von Kossa staining revealed that the differentiated cells induced by both VD and DEX were mineralized in vitro. They also expressed osteoblast-related markers, such as ALP, COL Ⅰ, BSP, and OC. Runx2/Cbfal, Osx, BMP-6, and LMP-1 were upregulated during VD and DEX-induced hADSC osteoblastic differentiation, but BMP-4, BMP-7 were not. BMP-2 was only expressed in VD-induced differentiated cells. Conclusions VD or DEX-induced hADSCs differentiate toward the osteoblastic lineage in vitro. Runx2/Cbfal, Osx, BMP-2, BMP-6, and LMP-1 are involved in regulating osteoblastic differentiation of hADSCs, but BMP-4, BMP-7 are not. VD, but not DEX, induces expression of BMP-2 during osteogenic induction of hADSCs. VD is an ideal substitute for DEX for osteogenic induction of hADSCs.
基金Supported by the National Key Basic Research and Development (973) Program of China (No. 2005CB623905), the National Natural Science Foundation of China (No. 30400099), and the Tsinghua-Yue-Yuen Medical Science Fund
文摘Chitosan has been shown to be a promising material for various applications in tissue engineering. Recently, adipose tissue derived stromal cells （ADSCs） have been investigated as an alternative source of seed cells for tissue engineering. The compatibility of chitosan and chitosan-gelatin complexes with ADSCs is not known. In the present study, ADSCs were isolated and characterized by phenotype using fluorescence-activated cell sorting （FACS）. The morphology, viability, and the ability of the ADSCs to differentiate on chitosan and chitosan-gelatin composite films with 60 wt.% gelatin were evaluated. Results show that the ADSCs are positive for CD29, CD44, and CD105, but negative for CD31, CD34, and CD45. ADSCs adhere and grow better on the composite films than on the chitosan films. The ability of ADSCs to differentiate into osteogenic and adipogenic lineage cells is not affected by their being cultured on chitosan-gelatin composite films. Therefore, chitosan-gelatin composite films are compatible with ADSCs and do not impair the ability of ADSCs to differentiate into osteogenic and adipogenic lineage cells.
文摘In plastic and reconstructive surgery there is an increasing demand for malleable implants to repair soft tissue congenital defects, or those resulting from aging, traumatic injury and tumour resection. However, currently available methods present a number of limitations such as volume loss over time and eventual resorption of the graft. Tissue engineering techniques provide promising therapeutic solutions to these inconveniences through development of engineered equivalents that best imitate adipose tissue, both structurally and functionally. Here we review the latest achievements in the human adipose tissue engineering field, with a focus on its regenerative potential for a number of clinical applications.
基金Supported by A grant from Illinois Neurological Institute to DHD
文摘With technological advances in basic research,the intricate mechanism of secondary delayed spinal cord injury(SCI)continues to unravel at a rapid pace.However,despite our deeper understanding of the molecular changes occurring after initial insult to the spinal cord,the cure for paralysis remains elusive.Current treatment of SCI is limited to early administration of high dose steroids to mitigate the harmful effect of cord edema that occurs after SCI and to reduce the cascade of secondary delayed SCI.R ecent evident-based clinical studies have cast doubt on the clinical benefit of steroids in SCI and intense focus on stem cell-based therapy has yielded some encouraging results.An array of mesenchymal stem cells(MSCs)from various sources with novel and promising strategies are being developed to improve function after SCI.In this review,we briefly discuss the pathophysiology of spinal cord injuries and characteristics and the potential sources of MSCs that can be used in the treatment of SCI.We will discuss the progress of MSCs application in research,focusing on the neuroprotective properties of MSCs.Finally,we will discuss the results from preclinical and clinical trials involving stem cell-based therapy in SCI.
