Mesenchymal stem/stromal cells (MSCs) have the potential to form colonies in culture and reside i... more Mesenchymal stem/stromal cells (MSCs) have the potential to form colonies in culture and reside in adult tissues. Because MSCs have been defined using cells cultured in vitro, discrepancies have arisen between studies concerning their properties. There are also differences between populations obtained using different isolation methods. This review article focuses on recent developments in the identification of novel MSC markers for the in vivo localization and prospective isolation of human MSCs. The prospective isolation method described in this study represents an important strategy for the isolation of MSCs in a short period of time, and may find applications for regenerative medicine. Purified MSCs can be tailored according to their intended clinical therapeutic applications. Lineage tracing methods define the MSC phenotype and can be used to investigate the physiological roles of MSCs in vivo. These findings may facilitate the development of effective stem cell treatments.
The senescence-associated secretory phenotype (SASP) has attracted attention as a mechanism that ... more The senescence-associated secretory phenotype (SASP) has attracted attention as a mechanism that connects cellular senescence to tissue dysfunction, and specific SASP factors have been identified as systemic pro-aging factors. However, little is known about the age-dependent changes in the secretory properties of stem cells. Young, but not old, mesenchymal stem/stromal cells (MSCs) are a well-known source of critical regenerative factors, but the identity of these factors remains elusive. In this study, we identified growth differentiation factor 6 (Gdf6; also known as Bmp13 and CDMP-2) as a regenerative factor secreted from young MSCs. The expression of specific secretory factors, including Gdf6, was regulated by the microRNA (miRNA) miR-17, whose expression declined with age. Upregulation of Gdf6 restored the osteogenic capacity of old MSCs in vitro and exerted positive effects in vivo on aging-associated pathologies such as reduced lymphopoiesis, insufficient muscle repair, reduced numbers of neural progenitors in the brain, and chronic inflammation. Our results suggest that manipulation of miRNA could enable control of the SASP, and that regenerative factors derived from certain types of young cells could be used to treat geriatric diseases.
Fibrosis of organs is observed in systemic autoimmune disease. Using a scleroderma mouse, we show... more Fibrosis of organs is observed in systemic autoimmune disease. Using a scleroderma mouse, we show that transplantation of MHC compatible, minor antigen mismatched bone marrow stromal/stem cells (BMSCs) play a role in the pathogenesis of fibrosis. Removal of donor BMSCs rescued mice from disease. Freshly isolated PDGFRα(+) Sca-1(+) BMSCs expressed MHC class II following transplantation and activated host T cells. A decrease in FOXP3(+) CD25(+) Treg population was observed. T cells proliferated and secreted IL-6 when stimulated with mismatched BMSCs in vitro. Donor T cells were not involved in fibrosis because transplanting T cell-deficient RAG2 knock out mice bone marrow still caused disease. Once initially triggered by mismatched BMSCs, the autoimmune phenotype was not donor BMSC dependent as the phenotype was observed after effector T cells were adoptively transferred into naïve syngeneic mice. Our data suggest that minor antigen mismatched BMSCs trigger systemic fibrosis in this a...
Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical r... more Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical role in embryonic hematopoiesis, as its insufficiency caused late embryonic lethality associated with defective hematopoiesis and angiogenesis. In the present study, we generated hematopoietic- and endothelial cell-specific Prep1-deficient mice and demonstrated that expression of Prep1 in the hematopoietic cell compartment is not essential for either embryonic or adult hematopoiesis, although its absence causes significant hematopoietic abnormalities in the adult bone marrow. Loss of Prep1 promotes cell cycling of hematopoietic stem/progenitor cells (HSPC), leading to the expansion of the HSPC pool. Prep1 deficiency also results in the accumulation of lineage-committed progenitors, increased monocyte/macrophage differentiation and arrested erythroid maturation. Maturation of T cells and B cells is also perturbed in Prep-deficient mice. These findings provide novel insight into the pleiotropic roles of Prep1 in adult hematopoiesis that were unrecognized in previous studies using germline Prep1 hypomorphic mice.
Repeated and dramatic pregnancy-induced uterine enlargement and remodeling throughout reproductiv... more Repeated and dramatic pregnancy-induced uterine enlargement and remodeling throughout reproductive life suggests the existence of uterine smooth muscle stem/progenitor cells. The aim of this study was to isolate and characterize stem/progenitor-like cells from human myometrium through identification of specific surface markers. We here identify CD49f and CD34 as markers to permit selection of the stem/progenitor cell-like population from human myometrium and show that human CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells exhibit stem cell-like properties. These include side population phenotypes, an undifferentiated status, high colony forming ability, multi-lineage differentiation into smooth muscle cells, osteoblasts, adipocytes and chondrocytes, and in vivo myometrial tissue reconstitution following xenotransplantation. Furthermore, CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells proliferate under hypoxic conditions in vitro and, comp...
Although meniscus defects and degeneration are strongly correlated with the later development of ... more Although meniscus defects and degeneration are strongly correlated with the later development of osteoarthritis, the promise of regenerative medicine strategies is to prevent and/or delay the disease's progression. Meniscal reconstruction has been shown in animal models with tendon grafting and transplantation of mesenchymal stem cells (MSCs); however, these procedures have not shown the same efficacy in clinical studies. Here, our aim was to investigate the ability of tendon grafts pretreated with exogenous synovial-derived MSCs to prevent cartilage degeneration in a rat partial meniscus defect model. We removed the anterior half of the medial meniscus and grafted autologous Achilles tendons with or without a 10-minute pretreatment of the tendon with synovial MSCs. The meniscus and surrounding cartilage were evaluated at 2, 4, and 8 weeks (n = 5). Tendon grafts increased meniscus size irrespective of synovial MSCs. Histological scores for regenerated menisci were better in the ...
Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to... more Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to renew themselves without malignant changes, and thus hold potential for many clinical applications. However, it has not been well characterized how different the properties of MSCs are depending on the tissue source in which they resided. We previously reported a novel technique for the prospective MSC isolation from bone marrow, and revealed that a combination of cell surface markers (LNGFR and THY-1) allows the isolation of highly enriched MSC populations. In this study, we isolated LNGFR+ THY-1 + MSCs from synovium using flow cytometry. The results show that the synovium tissue contained a significantly larger percentage of LNGFR + THY-1 + MSCs. We examined the colony formation and differentiation abilities of bone marrow-derived MSCs (BM-MSCs) and synovium-derived MSCs (SYN-MSCs) isolated from the same patients. Both types of MSCs exhibited a marked propensity to differentiate into ...
Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regenera... more Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular function remains unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4 deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Further, we found an accelerated activation of satellite cells in the regenerated Ten-4 deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of mus...
Although mesenchymal stem/stromal cells (MSCs) are an important component of the hematopoietic ni... more Although mesenchymal stem/stromal cells (MSCs) are an important component of the hematopoietic niche, the markers that correlate with their physiological functions have not been defined. In this issue of Cell Stem Cell, Zhou et al. (2014) identify the Leptin Receptor as a marker for prospective identification and in vivo fate mapping of bone marrow MSCs.
ABSTRACT Mesenchymal stem cells (MSCs) are currently defined as cells that undergo sustained in v... more ABSTRACT Mesenchymal stem cells (MSCs) are currently defined as cells that undergo sustained in vitro growth and can give rise to multiple mesenchymal lineages. Traditional MSCs isolation methods require prolonged in vitro culture on plastic plates, which reduces their differentiation potential and proliferative ability. Furthermore, this process alters MSCs-phenotype, making it difficult to identify specific MSCs-markers that could be used for their in vivo localization and prospective isolation. These limitations have hindered investigations into the biology and function of MSCs. This review article focuses on recent developments in the MSC-research field including the identification of novel surface markers for the prospective isolation of both murine and human MSCs. Prospectively isolated MSCs are more proliferative than MSCs prepared by conventional plastic adherence, provide a better substrate for studying MSCs biology and have more poten- tial for regenerative therapy.
Mesenchymal stem/stromal cells (MSCs) have the potential to form colonies in culture and reside i... more Mesenchymal stem/stromal cells (MSCs) have the potential to form colonies in culture and reside in adult tissues. Because MSCs have been defined using cells cultured in vitro, discrepancies have arisen between studies concerning their properties. There are also differences between populations obtained using different isolation methods. This review article focuses on recent developments in the identification of novel MSC markers for the in vivo localization and prospective isolation of human MSCs. The prospective isolation method described in this study represents an important strategy for the isolation of MSCs in a short period of time, and may find applications for regenerative medicine. Purified MSCs can be tailored according to their intended clinical therapeutic applications. Lineage tracing methods define the MSC phenotype and can be used to investigate the physiological roles of MSCs in vivo. These findings may facilitate the development of effective stem cell treatments.
The senescence-associated secretory phenotype (SASP) has attracted attention as a mechanism that ... more The senescence-associated secretory phenotype (SASP) has attracted attention as a mechanism that connects cellular senescence to tissue dysfunction, and specific SASP factors have been identified as systemic pro-aging factors. However, little is known about the age-dependent changes in the secretory properties of stem cells. Young, but not old, mesenchymal stem/stromal cells (MSCs) are a well-known source of critical regenerative factors, but the identity of these factors remains elusive. In this study, we identified growth differentiation factor 6 (Gdf6; also known as Bmp13 and CDMP-2) as a regenerative factor secreted from young MSCs. The expression of specific secretory factors, including Gdf6, was regulated by the microRNA (miRNA) miR-17, whose expression declined with age. Upregulation of Gdf6 restored the osteogenic capacity of old MSCs in vitro and exerted positive effects in vivo on aging-associated pathologies such as reduced lymphopoiesis, insufficient muscle repair, reduced numbers of neural progenitors in the brain, and chronic inflammation. Our results suggest that manipulation of miRNA could enable control of the SASP, and that regenerative factors derived from certain types of young cells could be used to treat geriatric diseases.
Fibrosis of organs is observed in systemic autoimmune disease. Using a scleroderma mouse, we show... more Fibrosis of organs is observed in systemic autoimmune disease. Using a scleroderma mouse, we show that transplantation of MHC compatible, minor antigen mismatched bone marrow stromal/stem cells (BMSCs) play a role in the pathogenesis of fibrosis. Removal of donor BMSCs rescued mice from disease. Freshly isolated PDGFRα(+) Sca-1(+) BMSCs expressed MHC class II following transplantation and activated host T cells. A decrease in FOXP3(+) CD25(+) Treg population was observed. T cells proliferated and secreted IL-6 when stimulated with mismatched BMSCs in vitro. Donor T cells were not involved in fibrosis because transplanting T cell-deficient RAG2 knock out mice bone marrow still caused disease. Once initially triggered by mismatched BMSCs, the autoimmune phenotype was not donor BMSC dependent as the phenotype was observed after effector T cells were adoptively transferred into naïve syngeneic mice. Our data suggest that minor antigen mismatched BMSCs trigger systemic fibrosis in this a...
Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical r... more Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical role in embryonic hematopoiesis, as its insufficiency caused late embryonic lethality associated with defective hematopoiesis and angiogenesis. In the present study, we generated hematopoietic- and endothelial cell-specific Prep1-deficient mice and demonstrated that expression of Prep1 in the hematopoietic cell compartment is not essential for either embryonic or adult hematopoiesis, although its absence causes significant hematopoietic abnormalities in the adult bone marrow. Loss of Prep1 promotes cell cycling of hematopoietic stem/progenitor cells (HSPC), leading to the expansion of the HSPC pool. Prep1 deficiency also results in the accumulation of lineage-committed progenitors, increased monocyte/macrophage differentiation and arrested erythroid maturation. Maturation of T cells and B cells is also perturbed in Prep-deficient mice. These findings provide novel insight into the pleiotropic roles of Prep1 in adult hematopoiesis that were unrecognized in previous studies using germline Prep1 hypomorphic mice.
Repeated and dramatic pregnancy-induced uterine enlargement and remodeling throughout reproductiv... more Repeated and dramatic pregnancy-induced uterine enlargement and remodeling throughout reproductive life suggests the existence of uterine smooth muscle stem/progenitor cells. The aim of this study was to isolate and characterize stem/progenitor-like cells from human myometrium through identification of specific surface markers. We here identify CD49f and CD34 as markers to permit selection of the stem/progenitor cell-like population from human myometrium and show that human CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells exhibit stem cell-like properties. These include side population phenotypes, an undifferentiated status, high colony forming ability, multi-lineage differentiation into smooth muscle cells, osteoblasts, adipocytes and chondrocytes, and in vivo myometrial tissue reconstitution following xenotransplantation. Furthermore, CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells proliferate under hypoxic conditions in vitro and, comp...
Although meniscus defects and degeneration are strongly correlated with the later development of ... more Although meniscus defects and degeneration are strongly correlated with the later development of osteoarthritis, the promise of regenerative medicine strategies is to prevent and/or delay the disease's progression. Meniscal reconstruction has been shown in animal models with tendon grafting and transplantation of mesenchymal stem cells (MSCs); however, these procedures have not shown the same efficacy in clinical studies. Here, our aim was to investigate the ability of tendon grafts pretreated with exogenous synovial-derived MSCs to prevent cartilage degeneration in a rat partial meniscus defect model. We removed the anterior half of the medial meniscus and grafted autologous Achilles tendons with or without a 10-minute pretreatment of the tendon with synovial MSCs. The meniscus and surrounding cartilage were evaluated at 2, 4, and 8 weeks (n = 5). Tendon grafts increased meniscus size irrespective of synovial MSCs. Histological scores for regenerated menisci were better in the ...
Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to... more Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to renew themselves without malignant changes, and thus hold potential for many clinical applications. However, it has not been well characterized how different the properties of MSCs are depending on the tissue source in which they resided. We previously reported a novel technique for the prospective MSC isolation from bone marrow, and revealed that a combination of cell surface markers (LNGFR and THY-1) allows the isolation of highly enriched MSC populations. In this study, we isolated LNGFR+ THY-1 + MSCs from synovium using flow cytometry. The results show that the synovium tissue contained a significantly larger percentage of LNGFR + THY-1 + MSCs. We examined the colony formation and differentiation abilities of bone marrow-derived MSCs (BM-MSCs) and synovium-derived MSCs (SYN-MSCs) isolated from the same patients. Both types of MSCs exhibited a marked propensity to differentiate into ...
Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regenera... more Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular function remains unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4 deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Further, we found an accelerated activation of satellite cells in the regenerated Ten-4 deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of mus...
Although mesenchymal stem/stromal cells (MSCs) are an important component of the hematopoietic ni... more Although mesenchymal stem/stromal cells (MSCs) are an important component of the hematopoietic niche, the markers that correlate with their physiological functions have not been defined. In this issue of Cell Stem Cell, Zhou et al. (2014) identify the Leptin Receptor as a marker for prospective identification and in vivo fate mapping of bone marrow MSCs.
ABSTRACT Mesenchymal stem cells (MSCs) are currently defined as cells that undergo sustained in v... more ABSTRACT Mesenchymal stem cells (MSCs) are currently defined as cells that undergo sustained in vitro growth and can give rise to multiple mesenchymal lineages. Traditional MSCs isolation methods require prolonged in vitro culture on plastic plates, which reduces their differentiation potential and proliferative ability. Furthermore, this process alters MSCs-phenotype, making it difficult to identify specific MSCs-markers that could be used for their in vivo localization and prospective isolation. These limitations have hindered investigations into the biology and function of MSCs. This review article focuses on recent developments in the MSC-research field including the identification of novel surface markers for the prospective isolation of both murine and human MSCs. Prospectively isolated MSCs are more proliferative than MSCs prepared by conventional plastic adherence, provide a better substrate for studying MSCs biology and have more poten- tial for regenerative therapy.
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