Molecular Characterization of Unique Junctional Complexes as Communication Pathways among Mesenchymal Stem Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1399-1399 ◽  
Author(s):  
Patrick Wuchter ◽  
Judit Boda-Heggemann ◽  
Beate Straub ◽  
Ulf Krause ◽  
Anja Seckinger ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Light And Electron Microscopy ◽  
Beta Catenin ◽  
Unique Type ◽  
Hematopoietic Stem ◽  
Junctional Complexes ◽  
Adhering Junctions

Abstract The interaction between stem cells and their niche is essential for the balance between self-renewal and differentiation. Mesenchymal stem cells (MSC) from bone marrow are able to differentiate into various tissues, such as bone, cartilage, muscle and fat. We have characterized the intercellular contacts among MSC and previously demonstrated the occurrence of a novel kind of adhering junction, consisting of villiform-to-vermiform cell projections (processus adhaerentes). The molecular compositions of these junctions have now been elucidated. Using a panel of antibodies specific for various components of tight, gap and adhering junctions (the latter comprising desmosomes and adhering junctions), we systematically analyzed the junctional complexes of MSC obtained from bone marrow aspirates from healthy voluntary donors and compared the data to bone marrow tissue in situ. Light and electron microscopy was used and several biochemical analyses were applied, including immunoprecipitation and RT-PCR. We could show that intercellular connections in MSC are realized in vitro by occasional gap junctions and frequent adhering junctions. Intercellular projections are noted, often deeply intruding into the neighbouring cell. These findings have been confirmed in situ in bone marrow biopsy material. Furthermore, we analyzed the molecular composition of these junctions and cell-projections. In most of them, we found the transmembrane glycoproteins cadherin 11 and N-cadherin, together with the cytoplasmic plaque proteins alpha- and beta-catenin and protein p120ctn. Interestingly, similar junctions had been already noted in primary mesenchymal stem cells of day 7 to 8.5 mouse embryos. Our hypothesis is that this junction type might be a prerequisite for early mesenchymal cells. Our findings indicate that intercellular communication in MSC in human marrow is realized through a unique type of junctional complexes not described before. These structures are crucial for the long-term fate and differentiation of the cells and might have significant impact on the interaction with hematopoietic stem cells.

Molecular Composition of Intercellular Contacts in Human Mesenchymal Stem Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2332-2332
Author(s):  
Patrick Wuchter ◽  
Judit Boda ◽  
Beate Straub ◽  
Ulf Krause ◽  
Anja Seckinger ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Gap Junctions ◽  
Light And Electron Microscopy ◽  
Human Mesenchymal Stem Cells ◽  
Molecular Composition ◽  
Cell Contact ◽  
Intercellular Contacts ◽  
Adhering Junctions

Abstract The long-term fate of stem cells depends on their interaction with the niche. Mesenchymal stem cells (MSC) from human bone marrow have been demonstrated to differentiate into various tissues, such as bone, cartilage, muscle and fat. As the interaction with the microenvironment plays a major role in differentiation, we have characterized the cell-cell contact among MSC. We have demonstrated the occurrence of a novel kind of adhering junction, consisting of slender, villiform-to-vermiform cell projections (processus adhaerentes). In this study, we have systematically analyzed the molecular composition of these junctions. A panel of antibodies specific for various components of tight junctions, gap junctions, adherens junctions and desmosomes was used. The expression of these antigens was verified by light and electron microscopy and by biochemical analysis, including immunoprecipitation and RT-PCR. MSC from two different sources were analyzed: MSC obtained from bone marrow aspirates from healthy voluntary donors and additionally MSC originating from umbilical cord blood donated for scientific research. We have also shown the presence of vimentin-positive retothelial cells (which are probably the source of MSC) in situ in fresh bone marrow samples. We demonstrate that MSC were interconnected by occasional gap junctions and frequent adhering junctions. Additionally, we found a unique molecular composition of these adhering junctions, as they comprise the transmembrane glycoproteins cadherin 11, N-cadherin and syndecan-1, together with the cytoplasmic plaque proteins α- and β-catenin and p120ctn. Constitutive complexes of these molecules have been identified. Our data indicate that MSC communicate with each other through junctions and junctional complexes. We hypothesize that MSC can embark on alternative differentiation pathways with specific junctional and cytoskeletal patterns. Characterization of and understanding the role of such intercellular contacts and their correlation to specific differentiation programs are being conducted.

Human Hematopoietic and Mesenchymal Stem Cells Are Interconnected by Cadherin-Catenin Based Junctions.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1410-1410
Author(s):  
Patrick Wuchter ◽  
Rainer Saffrich ◽  
Mario Schubert ◽  
Wolfgang Wagner ◽  
Heinrich Lannert ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Leukemia Stem Cells ◽  
Beta Catenin ◽  
Feeder Layer ◽  
Hematopoietic Stem ◽  
Alpha Beta ◽  
Junction Proteins ◽  
Cell Cell

Abstract The direct cell-cell contact between human hematopoietic stem cells (HSC) and their niche has been shown to control stem cell fate by regulating self-renewal versus differentiation. In previous studies we have demonstrated gap and adherens junctions arranged in complex villiform, vermiform, intercalating protrusions and invaginations among mesenchymal stem cells (MSC). Specific cadherin-catenin-molecules, among other junction proteins, were found in these contact systems. Using MSC-feeder-layer as an in vitro surrogate model for the hematopoietic stem cell niche, we have analyzed the intercellular junctional complexes between HSC and MSC in this study. Additionally, we characterized cell-cell-connections between leukemia stem cells (LSC) and MSC. MSC were derived from bone marrow aspirates from healthy voluntary donors. HSC were isolated from umbilical cord blood. Leukemia stem cells were obtained from bone marrow aspirates from patients suffering from acute myeloid leukemia either at the time of initial diagnosis or at relapse after chemotherapy. After 24–48 hours of co-cultivation, we have stained the cell-cell contacts with a panel of antibodies specific for various components of tight, gap and adherens junctions including alpha-/beta-catenin, N-cadherin, Cadherin 11, E-Cadherin, p120, Vinculin and Connexin 43. Using advanced confocal laser scanning microscopy in combination with deconvolution and volume rendering software, we were able to produce 3D-images of intercellular junctions between HSC/MSC as well as between LSC/MSC. We have confirmed previous observations that HSC demonstrated directed locomotion towards a MSC gradient. HSC then migrated around the MSC and some of them are then interconnected by podia formation to the MSC. These podia are directly linked to the MSC feeder layer and at the intimate contact zone we have identified N-cadherin as well as alpha-/beta-catenin as the main junction proteins. The specific function of this cadherin/catenin-complex is probably associated with redistribution of beta-catenin and hence to self-renewing division, similar to the findings in stem cells of drosophila model systems. Functional analyses are currently underway to confirm this hypothesis. We have also compared these findings with a similar setting consisting of human LSC co-cultured with MSC-feeder-layer.

Characterization of Intercellular Junctional Complexes between Human Hematopoietic and Mesenchymal Stem Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1396-1396
Author(s):  
Patrick Wuchter ◽  
Rainer Saffrich ◽  
Beate Straub ◽  
Judit Boda-Heggemann ◽  
Katrin Miesala ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adherens Junctions ◽  
Cellular Interaction ◽  
Bovine Bone ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Junctional Complexes ◽  
Intercellular Connections

Abstract The interaction between hematopoietic stem cells and their niche is essential for the balance between self-renewal and differentiation. We previously demonstrated that intercellular connections in mesenchymal stem cells (MSC) are realized by occasional gap junctions and frequent adherens junctions, comprising specific cadherin-catenin-complexes. Using MSC-feeder-layer as a surrogate model for the hematopoietic stem cell (HSC) niche, we have analyzed the intercellular junctional complexes between HSC and MSC. MSC were obtained from bone marrow aspirates from healthy voluntary donors. HSC were isolated from umbilical cord blood. Using advanced confocal laser scanning in combination with deconvolution and volume rendering software, we were able to produce 3D-images of intercellular junctions between HSC and MSC. We used a panel of antibodies specific for various components of tight, gap and adherens junctions. Additionally, we compared the data to human and bovine bone marrow tissue in situ. We could show that intercellular connections between HSC and MSC are mainly realized by podia formation of the HSC linking to the adjacent MSC. These podia vary greatly in length and shape (uropodia, filopodia). Along these podia and especially at the contact zone to the MSC, we have identified the cytoplasmic plaque proteins alpha- and beta-catenin and protein p120ctn, as well as the transmembrane glycoprotein N-cadherin. This study provided solid evidence for the direct and intimate cellular interaction of HSCs with their niche. Direct cell contact represents a key factor for the regulation of self-renewal versus differentiation. The examination of the specific function of catenins, p120ctn and N-cadherin in this process is concurrently underway.

scholarly journals Self-repopulating recipient bone marrow resident macrophages promote long-term hematopoietic stem cell engraftment

Blood ◽  
2018 ◽  
Vol 132 (7) ◽  
pp. 735-749 ◽  
Author(s):  
Simranpreet Kaur ◽  
Liza J. Raggatt ◽  
Susan M. Millard ◽  
Andy C. Wu ◽  
Lena Batoon ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hematopoietic Stem ◽  
Cell Engraftment ◽  
Key Points ◽  
Bone Marrow Engraftment

Key Points Recipient macrophages persist in hematopoietic tissues and self-repopulate via in situ proliferation after syngeneic transplantation. Targeted depletion of recipient CD169+ macrophages after transplant impaired long-term bone marrow engraftment of hematopoietic stem cells.

scholarly journals Conditioned Medium from Human Tonsil-Derived Mesenchymal Stem Cells Enhances Bone Marrow Engraftment via Endothelial Cell Restoration by Pleiotrophin

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 221
Author(s):  
Yu-Hee Kim ◽  
Kyung-Ah Cho ◽  
Hyun-Ji Lee ◽  
Minhwa Park ◽  
Sang-Jin Shin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Conditioned Medium ◽  
Histological Analysis ◽  
Conditioning Regimen ◽  
Mouse Bone Marrow ◽  
Human Tonsil ◽  
Hematopoietic Stem ◽  
Bone Marrow Engraftment

Cotransplantation of mesenchymal stem cells (MSCs) with hematopoietic stem cells (HSCs) has been widely reported to promote HSC engraftment and enhance marrow stromal regeneration. The present study aimed to define whether MSC conditioned medium could recapitulate the effects of MSC cotransplantation. Mouse bone marrow (BM) was partially ablated by the administration of a busulfan and cyclophosphamide (Bu–Cy)-conditioning regimen in BALB/c recipient mice. BM cells (BMCs) isolated from C57BL/6 mice were transplanted via tail vein with or without tonsil-derived MSC conditioned medium (T-MSC CM). Histological analysis of femurs showed increased BM cellularity when T-MSC CM or recombinant human pleiotrophin (rhPTN), a cytokine readily secreted from T-MSCs with a function in hematopoiesis, was injected with BMCs. Microstructural impairment in mesenteric and BM arteriole endothelial cells (ECs) were observed after treatment with Bu–Cy-conditioning regimen; however, T-MSC CM or rhPTN treatment restored the defects. These effects by T-MSC CM were disrupted in the presence of an anti-PTN antibody, indicating that PTN is a key mediator of EC restoration and enhanced BM engraftment. In conclusion, T-MSC CM administration enhances BM engraftment, in part by restoring vasculature via PTN production. These findings highlight the potential therapeutic relevance of T-MSC CM for increasing HSC transplantation efficacy.

Mesenchymal Stem Cells Self-Regulate Their Differentiation To Maintain the Bone Marrow Stromal System.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2335-2335
Author(s):  
Iekuni Oh ◽  
Akira Miyazato ◽  
Hiroyuki Mano ◽  
Tadashi Nagai ◽  
Kazuo Muroi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Expression Profiles ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Steady Level

Abstract Mesenchymal stem cells (MSCs) account for a very small population in bone marrow stroma as a non-hematopoietic component with multipotency of differentiation into adipocytes, osteocytes and chondrocytes. MSC-derived cells are known to have hematopoiesis-supporting and immunomodulatory abilities. Although clinical applications of MSCs have already been conducted for the suppression of graft versus host disease in allogeneic stem cell transplantation and for tissue regeneration, underlying mechanisms of the biological events are still obscure. Previously, we established a differentiation model of MSCs using a mouse embryo fibroblast cell line, C3H10T1/2 (10T1/2) (Nishikawa M et al: Blood81:1184–1192, 1993). Preadipocyte (A54) and myoblast (M1601) cell lines were cloned by treatment with 5-azacytidine. A54 cells and M1601 cells can terminally differentiate into adipocytes and myotubes, respectively, under appropriate conditions, while parent 10T1/2 cells remain undifferentiated. Moreover, A54 cells show a higher ability to support hematopoiesis compared with the other cell lines. In this study, we analyzed gene expression profiles of the three cell lines by using DNA microarray and real-time PCR to investigate molecular mechanisms for maintaining immaturity of parent 10T1/2 cells. In A54 cells, 202 genes were up-regulated, including those encoding critical factors for hematopoiesis such as SCF, Angiopoietin-1, and SDF-1 as well as genes known to be involved in adipocyte differentiation such as C/EBPα, C/EBPδ and PPAR-γ genes. These data are consistent with the hematopoiesis-supporting ability of A54 cells. During adipocyte differentiation, SCF and SDF-1 expression levels decreased in A54 cells while C/EBPα expression showed a steady level. Recently, osteoblasts have been reported to play crucial roles in “niche” for self-renewal of hematopoietic stem cells. Our results also implicate that precursor cells of non-hematopoietic components may have important roles for hematopoiesis in bone marrow. Meanwhile, in parent 10T1/2 cells, 105 genes were up-regulated, including CD90, Dlk, Wnt5α and many functionally unknown genes. Although C/EBPα expression was induced in 10T1/2 cells without differentiation under the adipocyte differentiation conditions, CD90 expression decreased, Dlk showed a steady level and Wnt5α was up-regulated. Assuming that some regulatory mechanisms are needed to keep an immature state of parent 10T1/2 cells even under the differentiation-inducible conditions, we performed following experiments. First, enforced Dlk expression in A54 cells did not inhibit terminal differentiation to adipocytes under the differentiation conditions. Second, when we cultured A54 cells in the conditioned media of parent 10T1/2 cells under the differentiation-inducible conditions, adipocyte differentiation was inhibited, suggesting that 10T1/2 cells produce some soluble molecules that can inhibit adipocyte differentiation. Since Wnt family is known to be involved in the regulation of self-renewal of several stem cells, Wnt5α may be one candidate for maintenance of “stemness” of MSCs. Taken together, the data of 10T1/2 cells suggest that MSCs can self-regulate their differentiation in the bone marrow stromal system. This concept may be important to investigate the fatty change of bone marrow in aging and in aplastic anemia.

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