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    <title>Hoogduijn, M.J.</title>
    <link>http://repub.eur.nl/res/aut/19765/</link>
    <description>List of Publications</description>
    <language>en</language>
    <image>
      <url>http://repub.eur.nl/static-eur/img/logo.png</url>
      <title>RePub, Erasmus University Rotterdam</title>
      <link>http://repub.eur.nl</link>
    </image>
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      <title>Bone marrow-derived mesenchymal stromal cells from patients with end-stage renal disease are suitable for autologous therapy (Article)</title>
      <link>http://repub.eur.nl/res/pub/40251/</link>
      <pubDate>2013-06-01T00:00:00Z</pubDate>
      <description>Background aims: Mesenchymal stromal cells (MSCs) are pluripotent cells that have immunosuppressive and reparative properties in vitro and in vivo. Although autologous bone marrow (BM)-derived MSCs are already clinically tested in transplant recipients, it is unclear whether these BM cells are affected by renal disease. We assessed whether renal failure affected the function and therapeutic potential of BM-MSCs. Methods: MSCs from 10 adults with end-stage renal disease (ESRD) and 10 age-matched healthy controls were expanded from BM aspirates and tested for phenotype and functionality in vitro. Results: MSCs from ESRD patients were &gt;90% positive for CD73, CD90 and CD105 and negative for CD34 and CD45 and showed a similar morphology and differentiation capacity as MSCs from healthy controls. Of importance for their clinical utility, growth characteristics were similar in both groups, and sufficient numbers of MSCs were obtained within 4 weeks. Messenger RNA expression levels of self-renewal genes and factors involved in repair and inflammation were also comparable between both groups. Likewise, microRNA expression profiling showed a broad overlap between ESRD and healthy donor MSCs. ESRD MSCs displayed the same immunosuppressive capacities as healthy control MSCs, demonstrated by a similar dose-dependent inhibition of peripheral blood mononuclear cell proliferation, similar inhibition of proinflammatory cytokines tumor necrosis factor-α and interferon-γ production and a concomitant increase in the production of interleukin-10. Conclusions: Expanded BM-MSCs procured from ESRD patients and healthy controls are both phenotypically and functionally similar. These findings are important for the potential autologous clinical application of BM-MSCs in transplant recipients. </description>
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      <title>Effect of arthritic synovial fluids on the expression of immunomodulatory factors by mesenchymal stem cells: An explorative in vitro study (Article)</title>
      <link>http://repub.eur.nl/res/pub/39299/</link>
      <pubDate>2012-12-01T00:00:00Z</pubDate>
      <description>Background:In diseased joints, the catabolic environment results in progressive joint damage. Mesenchymal stem cells (MSCs) can have immunomodulatory effects by secreting anti-inflammatory factors. To exert these effects, MSCs need to be triggered by proinflammatory cytokines. To explore the potential of MSCs as a treatment for diseased joints, we studied the effect of synovial fluid (SF) from donors with different joint diseases and donors without joint pathology on the immunomodulatory capacities of human MSCs in vitro. We hypothesized that SF of diseased joints influences the immunomodulatory effects of MSCs. Materials and Methods: MSCs were cultured in medium with SF of six osteoarthritis (OA) or six rheumatoid arthritis (RA) donors and three donors without joint pathology were used as control. Gene expressions of IL-6, HGF, TNFa, TGFb1, and indoleamine 2,3-dioxygenase (IDO) were analyzed. L-kynurenine concentration in conditioned medium (CM) by MSCs with SF was determined as a measure of IDO activity by MSCs. Furthermore, the effect of CM with SF on proliferation of activated lymphocytes was analyzed. Results: Addition of SF significantly up-regulated the mRNA expression of IL-6 and IDO in MSCs. SF(OA) induced significantly higher expression of IDO than SF(control), although no difference in IDO activity of the MSCs could be shown with a L-kynurenine assay. Medium conditioned by MSCs with SF(OA or RA) suppressed activated lymphocyte proliferation in vitro more than medium conditioned by MSCs without SF or with SF(control). Discussion: SF can influence the expression of genes involved in immunomodulation by MSCs and the effect on lymphocyte proliferation. We found indications for disease-specific differences between SFs but the variation between donors, even within one disease group was high. These data warrant further research to examine the potential application of MSC therapy in arthritic joints. </description>
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      <title>Mesenchymal stem cells derived from adipose tissue are not affected by renal disease (Article)</title>
      <link>http://repub.eur.nl/res/pub/37384/</link>
      <pubDate>2012-10-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells are a potential therapeutic agent in renal disease and kidney transplantation. Autologous cell use in kidney transplantation is preferred to avoid anti-HLA reactivity; however, the influence of renal disease on mesenchymal stem cells is unknown. To investigate the feasibility of autologous cell therapy in patients with renal disease, we isolated these cells from subcutaneous adipose tissue of healthy controls and patients with renal disease and compared them phenotypically and functionally. The mesenchymal stem cells from both groups showed similar morphology and differentiation capacity, and were both over 90% positive for CD73, CD105, and CD166, and negative for CD31 and CD45. They demonstrated comparable population doubling times, rates of apoptosis, and were both capable of inhibiting allo-antigen-and anti-CD3/CD28-activated peripheral blood mononuclear cell proliferation. In response to immune activation they both increased the expression of pro-inflammatory and anti-inflammatory factors. These mesenchymal stem cells were genetically stable after extensive expansion and, importantly, were not affected by uremic serum. Thus, mesenchymal stem cells of patients with renal disease have similar characteristics and functionality as those from healthy controls. Hence, our results indicate the feasibility of their use in autologous cell therapy in patients with renal disease. </description>
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      <title>Immunological aspects of allogeneic and autologous mesenchymal stem cell therapies (Article)</title>
      <link>http://repub.eur.nl/res/pub/34128/</link>
      <pubDate>2011-12-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSCs) have potential for therapeutic application as an immunomodulatory and regenerative agent. The immunogenicity and survival of MSCs after infusion are, however, not clear and evidence suggests that allogeneic but also autologous MSCs disappear rapidly after infusion. This may be associated with the susceptibility of MSCs to lysis by natural killer (NK) cells, possibly a result of culture-induced stress. In the present study we examined whether NK cell-mediated lysis of MSCs could be inhibited by immunosuppressive drugs. Human MSCs were isolated from adipose tissue and expanded in culture. Peripheral blood mononuclear cells were activated with interleukin (IL)-2 (200U/ml) and IL-15 (10ng/ml) for 7 days. CD3-CD16+CD56+NK cells were then isolated by fluorescence-activated cell sorting and added to europium-labeled MSCs for 4hr in the presence or absence of immunosuppressive drugs. Lysis of MSCs was determined by spectrophotometric measurement of europium release. Nonactivated NK cells were not capable of lysing MSCs. Cytokine-activated NK cells showed upregulated levels of granzyme B and perforin and efficiently lysed allogeneic and autologous MSCs. Addition of tacrolimus, rapamycin or sotrastaurin to the lysis assay did not inhibit MSC killing. Furthermore, preincubation of activated NK cells with the immunosuppressive drugs for 24hr before exposure to MSCs had no effect on MSC lysis. Last, addition of the immunosuppressants before and during the activation of NK cells, reduced NK cell numbers but did not affect their capacity to lyse MSCs. We conclude that the immunosuppressive drugs tacrolimus, rapamycin, and sotrastaurin are not capable of inhibiting the lysis of allogeneic and autologous MSCs by activated NK cells. Other approaches to controlling lysis of MSCs should be investigated, as controlling lysis may determine the efficacy of MSC therapy. </description>
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      <title>Features of synergism between mesenchymal stem cells and immunosuppressive drugs in a murine heart transplantation model (Article)</title>
      <link>http://repub.eur.nl/res/pub/31050/</link>
      <pubDate>2011-09-01T00:00:00Z</pubDate>
      <description>Background: Mesenchymal stem cells (MSCs) can be used for immunomodulation therapy after solid organ transplantation. Here, we focus on the immunoregulatory potential of combination therapies of MSCs and classic pharmacotherapy to mediate acceptance of solid organ grafts. Methods: To determine which drugs influence the immunosuppressive effect of MSCs, we assessed the interaction of MSCs and common clinical immunosuppresants (MMF, sirolimus [Srl], and ciclosporin A [CiA]) in a parent-into-F1 cell transfer model. In this model, the transfer of parental strain T cells into semi-allogeneic F1 recipients induces a graft-versus-host reaction (GvHR). Re-isolated CFSE-labelled T lymphocytes were analyzed by flow cytometry. These findings were compared to a fully allogeneic heart transplantation model. Results: We found that MSC treatment alone had no significant effect on allograft survival of heterotopic heart grafts. However, MSCs combined with short-term mycophenolate mofetil (MMF) significantly prolonged graft survival. Quantitative analysis of three different MSC - drug combinations in the F1 model revealed, that only the MSC-MMF combination led to a super-additive immunosuppressive effect. We also investigated the effect of MMF and CiA on IFNγ production of stimulated lymphocytes and found that MMF left the expression of IFNγ unaffected, whereas CiA completely abolished the production of IFNγ. Conclusion: Our data show that the type of concurrent immunosuppression strongly influences the immunosuppressive effect of MSC, most likely through differential secretion of IFNγ. A regimen combining MSCs and MMF was most immunosuppressive. </description>
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      <title>Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I) (Article)</title>
      <link>http://repub.eur.nl/res/pub/34370/</link>
      <pubDate>2011-07-28T00:00:00Z</pubDate>
      <description>Background: Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.Methods: Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).Discussion: If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy. </description>
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      <title>The immunomodulatory properties of mesenchymal stem cells and their use for immunotherapy (Article)</title>
      <link>http://repub.eur.nl/res/pub/20544/</link>
      <pubDate>2010-12-01T00:00:00Z</pubDate>
      <description>There is growing interest in the use of mesenchymal stem cells (MSC) for immune therapy. Clinical trials that use MSC for treatment of therapy resistant graft versus host disease, Crohn's disease and organ transplantation have initiated. Nevertheless, the immunomodulatory effects of MSC are only partly understood. Clinical trials that are supported by basic research will lead to better understanding of the potential of MSC for immunomodulatory applications and to optimization of such therapies. In this manuscript we review some recent literature on the mechanisms of immunomodulation by MSC in vitro and animal models, present new data on the secretion of pro-inflammatory and anti-inflammatory cytokines, chemokines and prostaglandins by MSC under resting and inflammatory conditions and discuss the hopes and expectations of MSC-based immune therapy.</description>
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      <title>Human adipose tissue-derived mesenchymal stem cells induce explosive T-Cell proliferation (Article)</title>
      <link>http://repub.eur.nl/res/pub/33160/</link>
      <pubDate>2010-12-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSCs) inhibit the proliferation of allo-activated lymphocytes. This effect is primarily dependent on the secretion of anti-inflammatory factors by MSCs and is enhanced under inflammatory conditions. MSCs, however, also produce factors that can potentially activate resting immune cells. Full understanding of the behavior of MSCs under inflammatory and noninflammatory conditions is crucial when clinical application of MSCs is considered. Human adipose tissue-derived MSCs were cultured with nonactivated peripheral blood mononuclear cells (PBMCs) and the activation, proliferation, and function of PBMCs were examined. Seven days of coculture with autologous or allogeneic MSCs significantly increased the proliferation of PBMCs (3-fold). This effect was observed in both direct and transwell coculture systems. MSCs cocultured with PBMCs showed increased mRNA expression of the proinflammatory mediators interleukin-6 (IL-6), IL-8, tumor necrosis factor-Î±, the growth factors basic fibroblast growth factor and vascular endothelial growth factor-Î±, and the anti-inflammatory factor indoleamine 2,3-dioxygenase. After removal of MSCs, PBMCs showed a spectacular further increase in proliferation, with a maximum of 25-fold after 7 days. This increase in proliferation was not seen when PBMCs were kept in the presence of MSCs. The proliferating fraction of PBMCs largely consisted of CD4+T-cells with high CD25 expression and the proportion of CD127negFoxP3+regulatory T-cells significantly increased from 5.0% to 8.5% of total CD4+T-cells. The expanded T-cells demonstrated normal responses to mitogen or alloantigen stimulation. The CD25positivefraction of these cells had immunosuppressive capacity. In conclusion, MSCs can stimulate the activation and proliferation of resting T-cells and generate regulatory T-cells. These findings are important when MSCs are applied in the clinic. </description>
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      <title>Advancement of mesenchymal stem cell therapy in solid organ transplantation (MISOT) (Article)</title>
      <link>http://repub.eur.nl/res/pub/27295/</link>
      <pubDate>2010-07-27T00:00:00Z</pubDate>
      <description>There is evolving interest in the use of mesenchymal stem cells (MSC) in solid organ transplantation. Pre-clinical transplantation models show efficacy of MSC in prolonging graft survival and a number of clinical studies are planned or underway. At a recent meeting of the MISOT consortium (MSC In Solid Organ Transplantation) the advances of these studies were evaluated and mechanisms underlying the potential effects of MSC discussed. Continued discussion is required for definition of safety and eventually efficacy endpoints for MSC therapy in solid organ transplantation. </description>
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      <title>Embryonic stem cell marker expression pattern in human mesenchymal stem cells derived from bone marrow, adipose tissue, heart and dermis (Article)</title>
      <link>http://repub.eur.nl/res/pub/28598/</link>
      <pubDate>2010-01-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSCs) have been isolated from a variety of human tissues, e. g., bone marrow, adipose tissue, dermis, hair follicles, heart, liver, spleen, dental pulp. Due to their immunomodulatory and regenerative potential MSCs have shown promising results in preclinical and clinical studies for a variety of conditions, such as graft versus host disease (GvHD), Crohn's disease, osteogenesis imperfecta, cartilage damage and myocardial infarction. MSC cultures are composed of heterogeneous cell populations. Complications in defining MSC arise from the fact that different laboratories have employed different tissue sources, extraction, and cultivation methods. Although cell-surface antigens of MSCs have been extensively explored, there is no conclusive evidence that unique stem cells markers are associated with these adult cells. Therefore the aim of this study was to examine expression of embryonic stem cell markers Oct4, Nanog, SOX2, alkaline phosphatase and SSEA-4 in adult mesenchymal stem cell populations derived from bone marrow, adipose tissue, dermis and heart. Furthermore, we tested whether human mesenchymal stem cells preserve tissue-specific differences under in vitro culture conditions. We found that bone marrow MSCs express embryonic stem cell markers Oct4, Nanog, alkaline phosphatase and SSEA-4, adipose tissue and dermis MSCs express Oct4, Nanog, SOX2, alkaline phosphatase and SSEA-4, whereas heart MSCs express Oct4, Nanog, SOX2 and SSEA-4. Our results also indicate that human adult mesenchymal stem cells preserve tissue-specific differences under in vitro culture conditions during early passages, as shown by distinct germ layer and embryonic stem cell marker expression patterns. Studies are now needed to determine the functional role of embryonic stem cell markers Oct4, Nanog and SOX2 in adult human MSCs. </description>
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      <title>Cell contact interaction between adipose-derived stromal cells and allo-activated T lymphocytes (Article)</title>
      <link>http://repub.eur.nl/res/pub/24086/</link>
      <pubDate>2009-12-01T00:00:00Z</pubDate>
      <description>Mesenchymal stromal cells regulate immune cell function via the secretion of soluble factors. Cell membrane interactions between these cell types may play an additional role. Here, we demonstrate that subpopulations of allo-activated T cells are capable of binding to human adipose-derived stromal cells (ASC). The bound T-cell population contained CD8+T cells and was enriched for CD4-CD8-T cells, whereas the proportion of CD4+T cells was decreased compared with the non-bound T-cell population. Bound CD4+T cells had high proliferative activity and increased CD25 and FoxP3 expression. However, they also expressed CD127, excluding regulatory T-cell function. In CD8+T cells, IL-2 sensitivity, as determined by the analysis of phosphorylated STAT5, was lower in the presence of ASC and even lower in bound cells. In contrast, IL-2-induced phosphorylated STAT5 levels were higher in bound CD4+T cells than in non-bound CD4+T cells. Additionally, pro-proliferative TGF-β signalling via endoglin and SMAD1/5/8 phosphorylation was detected in bound CD4+T cells. Even after prolonged co-culture with ASC, the activated phenotype of bound CD4+T cells persisted. In conclusion, these results demonstrate that the binding of lymphocytes to ASC represents an immunomodulatory mechanism in which CD8+T cells are inhibited in their responsiveness to pro-inflammatory stimuli and reactive CD4+T cells are depleted from the immune response. </description>
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      <title>Toward MSC in solid organ transplantation: 2008 position paper of the MISOT study group (Article)</title>
      <link>http://repub.eur.nl/res/pub/27159/</link>
      <pubDate>2009-09-15T00:00:00Z</pubDate>
      <description>The following position paper summarizes the recommendations for early clinical trials and ongoing basic research in the field of mesenchymal stem cell-induced solid organ graft acceptance-agreed upon on the first meeting of the Mesenchymal Stem Cells In Solid Organ Transplantation (MISOT) study group in late 2008. Copyright </description>
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      <title>The authors' reply: Mesenchymal stem cells and immunosuppressive drug interactions (Article)</title>
      <link>http://repub.eur.nl/res/pub/27157/</link>
      <pubDate>2009-06-27T00:00:00Z</pubDate>
      <description></description>
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      <title>Potential of mesenchymal stem cells as immune therapy in solid-organ transplantation (Article)</title>
      <link>http://repub.eur.nl/res/pub/18155/</link>
      <pubDate>2009-04-01T00:00:00Z</pubDate>
      <description>Over the last decade, there has been a rising interest in the use of mesenchymal stem cells (MSCs) for clinical applications. This interest stems from the beneficial properties of MSCs, which include multi-lineage differentiation and immunosuppressive ability, suggesting there is a role for MSC therapy for tissue regeneration and in immunologic disease. Despite recent clinical trials investigating the use of MSCs in treating immune-mediated disease, their applicability in solid-organ transplantation is still unknown. In this review, we identified topics that are important when considering MSC therapy in clinical organ transplantation. Whereas, from other clinical studies, it would appear that administration of MSCs is safe, issues like dosing, timing, route of administration, and in particular the use of autologous or donor-derived MSCs may be of crucial importance for the functional outcome of MSCs treatment in organ transplantation. We discuss these topics and assess the feasibility of MSCs therapy in organ transplantation.</description>
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      <title>Donor-derived mesenchymal stem cells suppress alloreactivity of kidney transplant patients (Article)</title>
      <link>http://repub.eur.nl/res/pub/16457/</link>
      <pubDate>2009-03-27T00:00:00Z</pubDate>
      <description>BACKGROUND.: Human mesenchymal stem cells (MSC) have immunosuppressive capacities. Although their efficacy is currently studied in graft-versus-host disease, their effect on alloreactivity in solid organ transplant patients is unknown. In this study, the immunosuppressive effect of MSC on recipient anti-donor reactivity was examined before and after clinical kidney transplantation. METHODS.: Anti-donor reactivity was established in pretransplant and posttransplant mixed lymphocyte reactions (MLR) of 14 living-kidney donor-recipient pairs. MSC from donors and third-party controls were added to the MLR in a ratio of 1:5. RESULTS.: MSC were isolated from donor perirenal fat and showed multilineage differentiation potential and the capacity to inhibit lymphocyte proliferation. The immunosuppressive effect of MSC was dose dependent and mediated by cell-membrane contact and soluble factors, including interleukin-10 and indoleamine 2,3-dioxygenase.Donor-derived MSC significantly inhibited the recipient anti-donor reactivity before and 1 month after transplantation. This effect was independent of human leukocyte antigen background of MSC. Flow cytometric analysis showed that MSC inhibited the proliferation of CD4 and CD8 T-lymphocyte subsets in pretransplant and posttransplant donor-directed MLR, whereas MSC had no effect on B- or natural killer-cell proliferation. CONCLUSION.: Donor MSC significantly inhibited the proliferation of alloactivated recipient T cells before and after kidney transplantation. We believe these findings should encourage MSC-based intervention in clinical organ transplantation.</description>
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      <title>Donor-derived mesenchymal stem cells remain present and functional in the transplanted human heart (Article)</title>
      <link>http://repub.eur.nl/res/pub/25110/</link>
      <pubDate>2009-01-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSC) are characterized by their multilineage differentiation capacity and immunosuppressive properties. They are resident in virtually all tissues and we have recently characterized MSC from the human heart. Clinical heart transplantation offers a model to study the fate of transplanted human MSC. In this study, we isolated and expanded MSC from heart tissue taken before, and 1 week up to 6 years after heart transplantation. MSC from posttransplantation tissue were all of donor origin, demonstrating the longevity of endogenous MSC and suggesting an absence of immigration of recipient MSC into the heart. MSC isolated from transplanted tissue showed an immunophenotype that was characteristic for MSC and maintained cardiomyogenic and osteogenic differentiation capacity. They furthermore preserved their ability to inhibit the proliferative response of donor-stimulated recipient peripheral blood mononuclear cells. In conclusion, functional MSC of donor origin remain present in the heart for several years after transplantation. </description>
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      <title>Functional nicotinic and muscarinic receptors on mesenchymal stem cells (Article)</title>
      <link>http://repub.eur.nl/res/pub/25461/</link>
      <pubDate>2009-01-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSCs) are under the control of a large number of signaling systems. In this study, the presence and functionality of the acetylcholine (ACh) signaling system in MSCs was examined. We detected the expression of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), and the presence of ACh in MSCs. MSCs also expressed the nicotinic acetylcholine receptor subunits α3, α5, α7, and the muscarinic acetylcholine receptor 2 (M2-receptor). The M2-receptor and the nicotinic α7 receptor subunits were expressed on distinct subpopulations of cells, indicating differential regulation of cholinergic signaling between MSCs. Stimulation of MSCs with the nicotinic receptor agonist nicotine and the muscarinic receptor agonist muscarine induced immediate and transient increases in intracellular Ca2+concentration. Furthermore, muscarine had an inhibiting effect on the production of the intracellular signaling molecule cyclic adenosine 3′,5′-monophosphate (cAMP). The AChE inhibitor chlorpyrifos, which is widely used as an agricultural insecticide, had similar effects on intracellular Ca2+and cAMP in MSCs. Nicotine, muscarine, and chlorpyrifos induced the phosphorylation of extracellular signal-regulated kinases 1 and 2. This study demonstrates that several components of a cholinergic signaling system are present and functional in MSCs. Environmental compounds such as nicotine and agricultural insecticides can interfere with this system and may affect cellular processes in the MSC. </description>
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      <title>Susceptibility of human mesenchymal stem cells to tacrolimus, mycophenolic acid, and rapamycin (Article)</title>
      <link>http://repub.eur.nl/res/pub/29225/</link>
      <pubDate>2008-11-15T00:00:00Z</pubDate>
      <description>BACKGROUND.: Mesenchymal stem cells (MSC) have multilineage differentiation and immunomodulatory capacities and are potentially useful for therapeutic applications, such as tissue regeneration and control of alloreactivity. MSC are present in most tissues including the transplantable organs. It is therefore unavoidable that MSC will be exposed to immunosuppressive drugs in a clinical transplantation setting. The molecular targets of these drugs are expressed in MSC, but the effect of their inhibition on MSC functioning is unknown. METHODS.: MSC were isolated and expanded from heart tissue and the effects of the calcineurin inhibitor tacrolimus, the cell cycle inhibitor mycophenolic acid (MPA), and the mammalian target of rapamycin inhibitor on MSC survival, proliferation, differentiation, and immunosuppressive capacity were examined. RESULTS.: Short-term exposure to the immunosuppressants did not induce toxicity or apoptosis in MSC, but high-dose tacrolimus induced toxicity after 7 days. MPA and rapamycin inhibited MSC proliferation at therapeutic doses. The immunosuppressants had differential effects on the differentiation capacity of MSC. Tacrolimus reduced the expression of troponin T type 2 and desmin during cardiomyogenic differentiation of MSC, whereas MPA decreased the deposition of calcified minerals during osteogenic differentiation. Rapamycin stimulated lipid production during adipogenic differentiation. Unexpectedly, MSC had adverse effects on the immunosuppressive efficacy of tacrolimus and rapamycin. There was no such effect of MSC on the function of MPA. Preincubation of MSC with tacrolimus increased the immunosuppressive capacity of MSC. DISCUSSION.: This study demonstrates that therapeutic concentrations of immunosuppressive drugs affect MSC function. MSC affect the efficacy of immunosuppressive medication. These findings are important for potential clinical use of MSC in combination with immunosuppressants. </description>
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      <title>Human heart, spleen, and perirenal fat-derived mesenchymal stem cells have immunomodulatory capacities (Article)</title>
      <link>http://repub.eur.nl/res/pub/36989/</link>
      <pubDate>2007-08-01T00:00:00Z</pubDate>
      <description>Mesenchymal stem cells (MSCs) have important tissue repair functions and show potent immunosuppressive capacities in vitro. Although usually isolated from the bone marrow, MSCs have been identified in other tissues, including the skin and liver. In the present study, we isolated and characterized MSCs from human heart, spleen, and perirenal adipose tissue. MSCs from these different tissue sites were similar to those derived from bone marrow in that they expressed comparable levels of the cell-surface markers CD90, CD105, CD166, and HLA class I, were negative for CD34, CD45, HLA class II, CD80, and CD86 expression, and were capable of osteogenic and adipogenic differentiation. Like bone marrow-derived MSCs, MSCs from these different tissue sources inhibited the proliferation of alloactivated peripheral blood mononuclear cells (PBMCs), giving 85%, 79%, 79%, and 81% inhibition, respectively. Also in line with bone marrow-derived MSCs they inhibited proliferative responses of PBMCs to phytohemagglutinin, a nonspecific stimulator of lymphocyte proliferation, and reduced-memory T lymphocyte responses to tetanus toxoid. The results of this study demonstrate that MSCs from various tissues have similar immunophenotypes, in vitro immunosuppressive properties, and differentiation potential. </description>
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