In adults, adipose tissue is abundant and can be easily sampled using liposuction. Largely involved in obesity and associated metabolic disorders, it is now described as a reservoir of immature stromal cells. These ce...In adults, adipose tissue is abundant and can be easily sampled using liposuction. Largely involved in obesity and associated metabolic disorders, it is now described as a reservoir of immature stromal cells. These cells, called adipose-derived stromal cells (ADSCs) must be distinguished from the crude stromal vascular fraction (SVF) obtained after digestion of adipose tissue. ADSCs share many features with mesenchymal stem cells derived from bone marrow, including paracrine activity, but they also display some specific features, including a greater angiogenic potential. Their angiogenic properties as well as their paracrine activity suggest a putative tumor-promoting role for ADSCs although contradictory data have been published on this issue. Both SVF cells and ADSCs are currently being investigated in clinical trials in several fields (chronic inflammation, ischemic diseases, etc. ). Apart from a phase Ⅲ trial on the treatment of fistula,most of these are in phaseⅠand use autologous cells. In the near future, the end results of these trials should provide a great deal of data on the safety of ADSC use.展开更多
Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multipl...Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multiple cytokines as well as several cell types and a variety of signaling pathways. When liver fibrosis is not well controlled, it can progress to liver cirrhosis, but it is reversible in principle. Thus far, no efficient therapy is available for treatment of liver fibrosis. Although liver transplantation is the preferred strategy, there are many challenges remaining in this approach, such as shortage of donor organs, immunological rejection, and surgical complications. Hence, there is a great need for an alternative therapeutic strategy. Currently, mesenchymal stem cell (MSC) therapy is considered a promising therapeutic strategy for the treatment of liver fibrosis;advantageously, the characteristics of MSCs are continuous self-renewal, proliferation, multipotent differentiation, and immunomodulatory activities. The human umbilical cord-derived (hUC)-MSCs possess not only the common attributes of MSCs but also more stable biological characteristics, relatively easy accessibility, abundant source, and no ethical issues (e.g., bone marrow being the adult source), making hUC-MSCs a good choice for treatment of liver fibrosis. In this review, we summarize the biological characteristics of hUC-MSCs and their paracrine effects, exerted by secretion of various cytokines, which ultimately promote liver repair through several signaling pathways. Additionally, we discuss the capacity of hUC-MSCs to differentiate into hepatocyte-like cells for compensating the function of existing hepatocytes, which may aid in amelioration of liver fibrosis. Finally, we discuss the current status of the research field and its future prospects.展开更多
Cell-based regenerative medicine is of growing interest in biomedical research. The role of stem cells in this context is under intense scrutiny and may help to define principles of organ regeneration and develop inno...Cell-based regenerative medicine is of growing interest in biomedical research. The role of stem cells in this context is under intense scrutiny and may help to define principles of organ regeneration and develop innovative therapeutics for organ failure. Utilizing stem and progenitor cells for organ replacement has been conducted for many years when performing hematopoietic stem cell transplantation. Since the first successful transplantation of umbilical cord blood to treat hematological malignancies, non-hematopoietic stem and progenitor cell populations have recently been identified within umbilical cord blood and other perinatal and fetal tissues. A cell population entitled mesenchymal stromal cells (MSCs) emerged as one of the most intensely studied as it subsumes a variety of capacities: MSCs can differentiate into various subtypes of the mesodermal lineage, they secrete a large array of trophic factors suitable of recruiting endogenous repair processes and they are immunomodulatory.Focusing on perinatal tissues to isolate MSCs, we will discuss some of the challenges associated with these cell types concentrating on concepts of isolation and expansion, the comparison with cells derived from other tissue sources, regarding phenotype and differentiation capacity and finally their therapeutic potential.展开更多
Background： Fat grafting technologies are popularly used in plastic and reconstructive surgery. Due to its size limitation, it is hard to directly inject untreated iht tissue into the dermal layer. Nanolht, which was...Background： Fat grafting technologies are popularly used in plastic and reconstructive surgery. Due to its size limitation, it is hard to directly inject untreated iht tissue into the dermal layer. Nanolht, which was introduced by Tonnard, solves this problem by mechanically emulsifying fat tissue. However, the viability of the cells was greatly destroyed. In this study, we reported a new method by ＂gently＂ digesting the fat tissue to produce viable adipocytes, progenitors, and stromal stem cells using collagenase I digestion and centrifugation. This was named ＂Vivo nanofat＂. Methods： Human liposuction aspirates were obtained from five healthy female donors with mean age of 28.7±5.6 years. Colony-forming assay, flow cytometry analysis, and adipogenic and osteogenic induction of the adherent cells from the Vivo nanofat were used to characterize the adipose mesenchymal stem cells （MSCs）. To investigate in vivo survival, we respectively injected Vivo nanofat and nanofat subcutaneously to the back of 8-week-old male BALB/c nude mice. Samples were harvested 2 days, 2 weeks, and 4 weeks postiniection for measurement, hematoxylin and eosin staining, and immunostaining. Results： Our results showed that the Vivo nanofat contained a large number ofcolony-fbrming cells. These cells expressed MSC markers and had multi-differentiative potential. In vivo transplantation showed that the Vivo nanofat had lower resorption ratio than that of nanofat. The size of the transplanted nanofat was obviously smaller than that of Vivo nanofat 4 weeks postinjection （0.50±0.17 cm vs. 0.81 ± 0.07 cm, t = -5783, P- 0.01）. Conclusion： Vivo nanofat may serve as a cell fraction injectable through a fine needle; this could be used for cosmetic applications.展开更多
Neglected for years, astrocytes are now recognized to fulfill and support many, if not all, homeostatic functionsof the healthy central nervous system(CNS). During neurodegenerative diseases such as amyotrophic latera...Neglected for years, astrocytes are now recognized to fulfill and support many, if not all, homeostatic functionsof the healthy central nervous system(CNS). During neurodegenerative diseases such as amyotrophic lateral sclerosis(ALS) and spinal cord injury(SCI), astrocytes in the vicinity of degenerating areas undergo both morphological and functional changes that might compromise their intrinsic properties. Evidence from human and animal studies show that deficient astrocyte functions or loss-of-astrocytes largely contribute to increased susceptibility to cell death for neurons, oligodendrocytes and axons during ALS and SCI disease progression. Despite exciting advances in experimental CNS repair, most of current approaches that are translated into clinical trials focus on the replacement or support of spinal neurons through stem cell transplantation, while none focus on the specific replacement of astroglial populations. Knowing the important functions carried out by astrocytes in the CNS, astrocyte replacement-based therapies might be a promising approach to alleviate overall astrocyte dysfunction, deliver neurotrophic support to degenerating spinal tissue and stimulate endogenous CNS repair abilities. Enclosed in this review, we gathered experimental evidence that argue in favor of astrocyte transplantation during ALS and SCI. Based on their intrinsic properties and according to the cell type transplanted, astrocyte precursors or stem cell-derived astrocytes promote axonal growth, support mechanisms and cells involved in myelination, are able to modulate the host immune response, deliver neurotrophic factors and provide protective molecules against oxidative or excitotoxic insults, amongst many possible benefits. Embryonic or adult stem cells can even be genetically engineered in order to deliver missing gene products and therefore maximize the chance of neuroprotection and functional recovery. However, before broad clinical translation, further preclinical data on safety, reliability and therapeutic efficien展开更多
Progressively loss of neural and glial cells is the key event that leads to nervous system dysfunctions and diseases. Several neurodegenerative diseases, for instance Alzheimer's disease, Parkinson's disease, ...Progressively loss of neural and glial cells is the key event that leads to nervous system dysfunctions and diseases. Several neurodegenerative diseases, for instance Alzheimer's disease, Parkinson's disease, and Huntington's disease, are associated to aging and suggested to be a consequence of deficiency of neural stem cell pool in the affected brain regions. Endogenous neural stem cells exist throughout life and are found inspecific niches of human brain. These neural stem cells are responsible for the regeneration of new neurons to restore, in the normal circumstance, the functions of the brain. Endogenous neural stem cells can be isolated, propagated, and, notably, differentiated to most cell types of the brain. On the other hand, other types of stem cells, such as mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells can also serve as a source for neural stem cell production, that hold a great promise for regeneration of the brain. The replacement of neural stem cells, either endogenous or stem cell-derived neural stem cells, into impaired brain is highly expected as a possible therapeutic mean for neurodegenerative diseases. In this review, clinical features and current routinely treatments of agerelated neurodegenerative diseases are documented. Noteworthy, we presented the promising evidence of neural stem cells and their derivatives in curing such diseases, together with the remaining challenges to achieve the best outcome for patients.展开更多
Objective To review the biological behaviour of endothelial progenitor cells and their role in vascular diseases. Data sources The data used in this review were mainly from Medline and PubMed for relevant English lang...Objective To review the biological behaviour of endothelial progenitor cells and their role in vascular diseases. Data sources The data used in this review were mainly from Medline and PubMed for relevant English language articles published from 1985 to March 2007. The search term was ＂endothelial progenitor cells＂. Study selection Articles about the biological behaviour of endothelial progenitor cells and their roles in the pathogenesis of vascular diseases such as atherogenesis were used. Results Progenitor cells in bone marrow, peripheral blood and adventitia can differentiate into mature endothelial cells （ECs）. The progenitor cells, which express certain surface markers including AC133, CD34 and KDR, enable restoration of the microcirculation and ECs when injury or ischaemia occurs. Endothelial progenitor cells used in experimental models and clinical trials for ischaemic syndromes could restore endothelial integrity and inhibit neointima development. Moreover, their number and functional properties are influenced by certain cytokines and atherosclerotic risk factors. Impairment of the progenitor cells might limit the regenerative capacity, even lead to the development of atherosclerosis or other vascular diseases. Conclusions Endothelial progenitor cells have a particular role in prevention and treatment of certain cardiovascular diseases. However, many challenges remain in understanding differentiation of endothelial progenitor cells, their mobilization and revascularization.展开更多
Pluripotent stem cells derived from somatic cells through such processes as nuclear transfer or induced pluripotent stem(iPS) cells present an important model for biomedical research and provide potential resources fo...Pluripotent stem cells derived from somatic cells through such processes as nuclear transfer or induced pluripotent stem(iPS) cells present an important model for biomedical research and provide potential resources for cell replacement therapies.However,the overall efficiency of the conversional nuclear transfer is very low and the safety issue remains a major concern for iPS cells.Embryonic stem cells(ESCs) generated from parthenogenetic embryos are one attractive alternative as a source of histocompatible cells and tissues for cell therapy.Recent studies on human parthenogenetic embryonic stem cells(hPG ESCs) have revealed that these ESCs are very similar to the hESCs derived from IVF or in vivo produced blastocysts in gene expression and other characteristics,but full differentiation and development potential of these hPG ESCs have to be further investigated before clinical research and therapeutic interventions.To generate various pluripotent stem cells,diverse reprogramming techniques and approaches will be developed and integrated.This may help elucidate the fundamental mechanisms underlying reprogramming and stem cell biology,and ultimately benefit cell therapy and regenerative medicine.展开更多
文摘In adults, adipose tissue is abundant and can be easily sampled using liposuction. Largely involved in obesity and associated metabolic disorders, it is now described as a reservoir of immature stromal cells. These cells, called adipose-derived stromal cells (ADSCs) must be distinguished from the crude stromal vascular fraction (SVF) obtained after digestion of adipose tissue. ADSCs share many features with mesenchymal stem cells derived from bone marrow, including paracrine activity, but they also display some specific features, including a greater angiogenic potential. Their angiogenic properties as well as their paracrine activity suggest a putative tumor-promoting role for ADSCs although contradictory data have been published on this issue. Both SVF cells and ADSCs are currently being investigated in clinical trials in several fields (chronic inflammation, ischemic diseases, etc. ). Apart from a phase Ⅲ trial on the treatment of fistula,most of these are in phaseⅠand use autologous cells. In the near future, the end results of these trials should provide a great deal of data on the safety of ADSC use.
基金Supported by the Natural Science Foundation of Jilin Province of China,No.20190201010JC
文摘Liver fibrosis is a wound-healing response to chronic injuries, characterized by the excessive accumulation of extracellular matrix or scar tissue within the liver;in addition, its formation is associated with multiple cytokines as well as several cell types and a variety of signaling pathways. When liver fibrosis is not well controlled, it can progress to liver cirrhosis, but it is reversible in principle. Thus far, no efficient therapy is available for treatment of liver fibrosis. Although liver transplantation is the preferred strategy, there are many challenges remaining in this approach, such as shortage of donor organs, immunological rejection, and surgical complications. Hence, there is a great need for an alternative therapeutic strategy. Currently, mesenchymal stem cell (MSC) therapy is considered a promising therapeutic strategy for the treatment of liver fibrosis;advantageously, the characteristics of MSCs are continuous self-renewal, proliferation, multipotent differentiation, and immunomodulatory activities. The human umbilical cord-derived (hUC)-MSCs possess not only the common attributes of MSCs but also more stable biological characteristics, relatively easy accessibility, abundant source, and no ethical issues (e.g., bone marrow being the adult source), making hUC-MSCs a good choice for treatment of liver fibrosis. In this review, we summarize the biological characteristics of hUC-MSCs and their paracrine effects, exerted by secretion of various cytokines, which ultimately promote liver repair through several signaling pathways. Additionally, we discuss the capacity of hUC-MSCs to differentiate into hepatocyte-like cells for compensating the function of existing hepatocytes, which may aid in amelioration of liver fibrosis. Finally, we discuss the current status of the research field and its future prospects.
基金Supported by Research Funds of the German Federal Ministry of Education and Research (01GN0531 and 01GN0939)Proj-ect Commissioned by the European Community ("CASCADE"HEALTH-F5-2009-223236).
文摘Cell-based regenerative medicine is of growing interest in biomedical research. The role of stem cells in this context is under intense scrutiny and may help to define principles of organ regeneration and develop innovative therapeutics for organ failure. Utilizing stem and progenitor cells for organ replacement has been conducted for many years when performing hematopoietic stem cell transplantation. Since the first successful transplantation of umbilical cord blood to treat hematological malignancies, non-hematopoietic stem and progenitor cell populations have recently been identified within umbilical cord blood and other perinatal and fetal tissues. A cell population entitled mesenchymal stromal cells (MSCs) emerged as one of the most intensely studied as it subsumes a variety of capacities: MSCs can differentiate into various subtypes of the mesodermal lineage, they secrete a large array of trophic factors suitable of recruiting endogenous repair processes and they are immunomodulatory.Focusing on perinatal tissues to isolate MSCs, we will discuss some of the challenges associated with these cell types concentrating on concepts of isolation and expansion, the comparison with cells derived from other tissue sources, regarding phenotype and differentiation capacity and finally their therapeutic potential.
文摘Background： Fat grafting technologies are popularly used in plastic and reconstructive surgery. Due to its size limitation, it is hard to directly inject untreated iht tissue into the dermal layer. Nanolht, which was introduced by Tonnard, solves this problem by mechanically emulsifying fat tissue. However, the viability of the cells was greatly destroyed. In this study, we reported a new method by ＂gently＂ digesting the fat tissue to produce viable adipocytes, progenitors, and stromal stem cells using collagenase I digestion and centrifugation. This was named ＂Vivo nanofat＂. Methods： Human liposuction aspirates were obtained from five healthy female donors with mean age of 28.7±5.6 years. Colony-forming assay, flow cytometry analysis, and adipogenic and osteogenic induction of the adherent cells from the Vivo nanofat were used to characterize the adipose mesenchymal stem cells （MSCs）. To investigate in vivo survival, we respectively injected Vivo nanofat and nanofat subcutaneously to the back of 8-week-old male BALB/c nude mice. Samples were harvested 2 days, 2 weeks, and 4 weeks postiniection for measurement, hematoxylin and eosin staining, and immunostaining. Results： Our results showed that the Vivo nanofat contained a large number ofcolony-fbrming cells. These cells expressed MSC markers and had multi-differentiative potential. In vivo transplantation showed that the Vivo nanofat had lower resorption ratio than that of nanofat. The size of the transplanted nanofat was obviously smaller than that of Vivo nanofat 4 weeks postinjection （0.50±0.17 cm vs. 0.81 ± 0.07 cm, t = -5783, P- 0.01）. Conclusion： Vivo nanofat may serve as a cell fraction injectable through a fine needle; this could be used for cosmetic applications.
基金Supported by The NINDS,No.#1R01NS079702(to Angelo C Lepore)
文摘Neglected for years, astrocytes are now recognized to fulfill and support many, if not all, homeostatic functionsof the healthy central nervous system(CNS). During neurodegenerative diseases such as amyotrophic lateral sclerosis(ALS) and spinal cord injury(SCI), astrocytes in the vicinity of degenerating areas undergo both morphological and functional changes that might compromise their intrinsic properties. Evidence from human and animal studies show that deficient astrocyte functions or loss-of-astrocytes largely contribute to increased susceptibility to cell death for neurons, oligodendrocytes and axons during ALS and SCI disease progression. Despite exciting advances in experimental CNS repair, most of current approaches that are translated into clinical trials focus on the replacement or support of spinal neurons through stem cell transplantation, while none focus on the specific replacement of astroglial populations. Knowing the important functions carried out by astrocytes in the CNS, astrocyte replacement-based therapies might be a promising approach to alleviate overall astrocyte dysfunction, deliver neurotrophic support to degenerating spinal tissue and stimulate endogenous CNS repair abilities. Enclosed in this review, we gathered experimental evidence that argue in favor of astrocyte transplantation during ALS and SCI. Based on their intrinsic properties and according to the cell type transplanted, astrocyte precursors or stem cell-derived astrocytes promote axonal growth, support mechanisms and cells involved in myelination, are able to modulate the host immune response, deliver neurotrophic factors and provide protective molecules against oxidative or excitotoxic insults, amongst many possible benefits. Embryonic or adult stem cells can even be genetically engineered in order to deliver missing gene products and therefore maximize the chance of neuroprotection and functional recovery. However, before broad clinical translation, further preclinical data on safety, reliability and therapeutic efficien
文摘Progressively loss of neural and glial cells is the key event that leads to nervous system dysfunctions and diseases. Several neurodegenerative diseases, for instance Alzheimer's disease, Parkinson's disease, and Huntington's disease, are associated to aging and suggested to be a consequence of deficiency of neural stem cell pool in the affected brain regions. Endogenous neural stem cells exist throughout life and are found inspecific niches of human brain. These neural stem cells are responsible for the regeneration of new neurons to restore, in the normal circumstance, the functions of the brain. Endogenous neural stem cells can be isolated, propagated, and, notably, differentiated to most cell types of the brain. On the other hand, other types of stem cells, such as mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells can also serve as a source for neural stem cell production, that hold a great promise for regeneration of the brain. The replacement of neural stem cells, either endogenous or stem cell-derived neural stem cells, into impaired brain is highly expected as a possible therapeutic mean for neurodegenerative diseases. In this review, clinical features and current routinely treatments of agerelated neurodegenerative diseases are documented. Noteworthy, we presented the promising evidence of neural stem cells and their derivatives in curing such diseases, together with the remaining challenges to achieve the best outcome for patients.
基金This study was supported by a grant from the National Natural Science Foundation of China(No.30570720)
文摘Objective To review the biological behaviour of endothelial progenitor cells and their role in vascular diseases. Data sources The data used in this review were mainly from Medline and PubMed for relevant English language articles published from 1985 to March 2007. The search term was ＂endothelial progenitor cells＂. Study selection Articles about the biological behaviour of endothelial progenitor cells and their roles in the pathogenesis of vascular diseases such as atherogenesis were used. Results Progenitor cells in bone marrow, peripheral blood and adventitia can differentiate into mature endothelial cells （ECs）. The progenitor cells, which express certain surface markers including AC133, CD34 and KDR, enable restoration of the microcirculation and ECs when injury or ischaemia occurs. Endothelial progenitor cells used in experimental models and clinical trials for ischaemic syndromes could restore endothelial integrity and inhibit neointima development. Moreover, their number and functional properties are influenced by certain cytokines and atherosclerotic risk factors. Impairment of the progenitor cells might limit the regenerative capacity, even lead to the development of atherosclerosis or other vascular diseases. Conclusions Endothelial progenitor cells have a particular role in prevention and treatment of certain cardiovascular diseases. However, many challenges remain in understanding differentiation of endothelial progenitor cells, their mobilization and revascularization.
基金Supported by the National High Technology Research and Development Program of China (Grant No. 2006AA02A101)
文摘Pluripotent stem cells derived from somatic cells through such processes as nuclear transfer or induced pluripotent stem(iPS) cells present an important model for biomedical research and provide potential resources for cell replacement therapies.However,the overall efficiency of the conversional nuclear transfer is very low and the safety issue remains a major concern for iPS cells.Embryonic stem cells(ESCs) generated from parthenogenetic embryos are one attractive alternative as a source of histocompatible cells and tissues for cell therapy.Recent studies on human parthenogenetic embryonic stem cells(hPG ESCs) have revealed that these ESCs are very similar to the hESCs derived from IVF or in vivo produced blastocysts in gene expression and other characteristics,but full differentiation and development potential of these hPG ESCs have to be further investigated before clinical research and therapeutic interventions.To generate various pluripotent stem cells,diverse reprogramming techniques and approaches will be developed and integrated.This may help elucidate the fundamental mechanisms underlying reprogramming and stem cell biology,and ultimately benefit cell therapy and regenerative medicine.
