977 resultados para Bone Marrow Cells
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Background: The aim was to test the hypothesis that the blood serum of rats subjected to recurrent airway obstructions mimicking obstructive sleep apnea (OSA) induces early activation of bone marrow-derived mesenchymal stem cells (MSC) and enhancement of endothelial wound healing. Methods: We studied 30 control rats and 30 rats subjected to recurrent obstructive apneas (60 per hour, lasting 15 s each, for 5 h). The migration induced in MSC by apneic serum was measured by transwell assays. MSC-endothelial adhesion induced by apneic serum was assessed by incubating fluorescent-labelled MSC on monolayers of cultured endothelial cells from rat aorta. A wound healing assay was used to investigate the effect of apneic serum on endothelial repair. Results: Apneic serum showed significant increase in chemotaxis in MSC when compared with control serum: the normalized chemotaxis indices were 2.20 +- 0.58 (m +- SE) and 1.00 +- 0.26, respectively (p < 0.05). MSC adhesion to endothelial cells was greater (1.75 +- 0.14 -fold; p < 0.01) in apneic serum than in control serum. When compared with control serum, apneic serum significantly increased endothelial wound healing (2.01 +- 0.24 -fold; p < 0.05). Conclusions: The early increases induced by recurrent obstructive apneas in MSC migration, adhesion and endothelial repair suggest that these mechanisms play a role in the physiological response to the challenges associated to OSA.
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Chronic inhalation of grain dust is associated with asthma and chronic bronchitis in grain worker populations. Exposure to fungal particles was postulated to be an important etiologic agent of these pathologies. Fusarium species frequently colonize grain and straw and produce a wide array of mycotoxins that impact human health, necessitating an evaluation of risk exposure by inhalation of Fusarium and its consequences on immune responses. Data showed that Fusarium culmorum is a frequent constituent of aerosols sampled during wheat harvesting in the Vaud region of Switzerland. The aim of this study was to examine cytokine/chemokine responses and innate immune sensing of F. culmorum in bone-marrow-derived dendritic cells and macrophages. Overall, dendritic cells and macrophages responded to F. culmorum spores but not to its secreted components (i.e., mycotoxins) by releasing large amounts of macrophage inflammatory protein (MIP)-1α, MIP-1β, MIP-2, monocyte chemoattractant protein (MCP)-1, RANTES, and interleukin (IL)-12p40, intermediate amounts of tumor necrosis factor (TNF), IL-6, IL-12p70, IL-33, granulocyte colony-stimulating factor (G-CSF), and interferon gamma-induced protein (IP-10), but no detectable amounts of IL-4 and IL-10, a pattern of mediators compatible with generation of Th1 or Th17 antifungal protective immune responses rather than with Th2-dependent allergic responses. The sensing of F. culmorum spores by dendritic cells required dectin-1, the main pattern recognition receptor involved in β-glucans detection, but likely not MyD88 and TRIF-dependent Toll-like receptors. Taken together, our results indicate that F. culmorum stimulates potently innate immune cells in a dectin-1-dependent manner, suggesting that inhalation of F. culmorum from grain dust may promote immune-related airway diseases in exposed worker populations.
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Background. Mycosis Fungoides (MF) is the most common cutaneous T-cell lymphoma, and large cell trasformation (tMF) is an adverse prognostic event. Extra-cutaneous dissemination can occur in the course of the disease, but dissemination to the central nervous system (CNS) is uncommon. Moreover, CNS lymphomas are overall rare and most often of B-cell phenotype. We report a case of CNS large T-cell lymphoma presenting as multiple cerebral lesions in a patient with a history of MF. Methods. We report a case of a 33-year-old woman, known since the age of 16 for erythematous plaques thought to be atopic dermatitis, who developed, end 2012, multiple nodular skin lesions and peripheral adenopathies. Two skin lesions were biopsied simultaneously, and diagnosed as MF and tMF. A lymph node biopsy showed dermatopathic changes without lymphoma (Stage IIB). She received local treatment (UVB, PUVA and radiation therapy) and interferon therapy, and experienced almost complete remission. In 2015 neurological symptoms lead to evidence multiple cerebral lesions, suspicious for lymphoma, evaluated by stereotaxic biopsies. We compared histopathological and molecular features of these with previous skin specimens. After negative bone marrow staging biopsy, she was recently started on chemotherapy (MATRIX). Short follow-up shows rapidly worsening clinical conditions. Results. One of the initial skin biopsies showed atypical lymphoid cells with epidermotropism, Pautrier abcesses and CD4+ CD30- phenotype; the other revealed diffuse dermal infiltration by predominantly large cerebriform tumor cells with high proliferative fraction, and CD2−CD3 −CD4+/−CD7−CD30+ALK- EMA- non-cytotoxic immunophenotype. Altogether, these results led us to diagnose MF and tMF, respectively. The brain was infiltrated by large atypical lymphoid cells with cerebriform nuclei, somewhat anaplastic features and perivascular distribution. By immunohistochemistry, tumor cells were highly proliferative, with a CD2−CD3+CD5−CD7+CD30+ activated cytotoxic immunophenotype. A diagnosis of CD30+ cytotoxic peripheral T-cell lymphoma was retained. TRG and TRB clonality analyses revealed clonal rearrangements in skin and CNS biopsies, with identical patterns in both skin specimens but only minimally overlapping profiles when compared to the CNS sample. Der Pathologe 6 ? 2015 | 633 Conclusions. The reported case illustrates an uncommon finding of a CNS T-cell lymphoma in a patient with previous MF, questioning the clonal relationship between the two diseases and challenging the adequate classification of this CNS lymphoma as either a progression or a de novo lymphoma. Despite differences in immunophenotype and clonality patterns, this CNS lymphoma could possibly represent an aggressive divergent evolution of a primary cutaneous T-cell lymphoma. Additional sequencing is ongoing to try to solve the question.
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Bone engineering is a rapidly developing area of reconstructive medicine where bone inducing factors and/or cells are combined with a scaffold material to regenerate the structure and function of the original tissue. The aim of this study was to compare the suitability of different macroporous scaffold types for bone engineering applications. The two scaffold categories studied were a) the mechanically strong and stable titanium fiber meshes and b) the elastic and biodegradable porous polymers. Furthermore, bioactive modifications were applied to these basic scaffold types, and their effect on the osteogenic responses was evaluated in cell culture and ectopic bone formation studies. The osteogenic phenotype of cultured cell-scaffold constructs was heightened with a sol-gel derived titania coating, but not with a mixed titania-silica coating. The latter coating also resulted in delayed ectopic bone formation in bone marrow stromal cell seeded scaffolds. However, the better bone contact in early implantation times and more even bone tissue distribution at later times indicated enhanced osteoconductivity of both the coated scaffold types. Overall, the most promising bone engineering results were obtained with titania coated fiber meshes. Elastic and biodegradable poly(ε-caprolactone/D,L-lactide) based scaffolds were also developed in this study. The degradation rates of the scaffolds in vitro were governed by the hydrophilicity of the polymer matrix, and the porous architecture was controlled by the amount and type of porogen used. A continuous phase macroporosity was obtained using a novel CaCl2 • 6H2O porogen. Dynamic culture conditions increased cell invasion, but decreased cell numbers and osteogenicity, within the scaffolds. Osteogenic differentiation in static cultures and ectopic bone formation in cell seeded scaffolds were enhanced in composites, with 30 wt-% of bioactive glass filler.
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Due to technical restrictions of the database system the title of the thesis does not show corretly on this page. Numbers in the title are in superscript. Please see the PDF-file for correct title. ---- Osteomyelitis is a progressive inflammatory disease of bone and bone marrow that results in bone destruction due to an infective microorganism, most frequently Staphylococcus aureus. Orthopaedic concern relates to the need for reconstructive and trauma-related surgical procedures in the fast grow¬ing population of fragile, aged patients, who have an increased susceptibility to surgical site infections. Depending on the type of osteomyelitis, infection may be acute or a slowly progressing, low-grade infection. Peri-implant infections lead to implant loosening. The emerging antibiotic resistance of com¬mon pathogens further complicates the situation. With current imaging methods, significant limitations exist in the diagnosing of osteomyelitis and implant-related infections. Positron emission tomography (PET) with a glucose analogue, 18F-fluoro¬deoxyglucose (18F-FDG), seems to facilitate a more accurate diagnosis of chronic osteomyelitis. The method is based on the increased glucose consumption of activated inflammatory cells. Unfortunately, 18F-FDG accumulates also in sterile inflammation regions and causes false-positive findings, for exam¬ple, due to post-operative healing processes. Therefore, there is a clinical need for new, more infection-specific tracers. In addition, it is still unknown why 18F-FDG PET imaging is less accurate in the detec¬tion of periprosthetic joint infections, most frequently due to Staphylococcus epidermidis. This doctoral thesis focused on testing novel PET tracers (68Ga-chloride and 68Ga-DOTAVAP-P1) for early detections of bone infections and evaluated the role of pathogen-related factors in the appli¬cations of 18F-FDG PET in the diagnostics of bone infections. For preclinical models of S. epidermidis and S. aureus bone/implant infections, the significance of the causative pathogen was studied with respect to 18F-FDG uptake. In a retrospective analysis of patients with confirmed bone infections, the significance of the presence or absence of positive bacterial cultures on 18F-FDG uptake was evalu¬ated. 18F-FDG and 68Ga-chloride resulted in a similar uptake in S. aureus osteomyelitic bones. However, 68Ga-chloride did not show uptake in healing bones, and therefore it may be a more-specific tracer in the early post-operative or post-traumatic phase. 68Ga-DOTAVAP-P1, a novel synthetic peptide bind¬ing to vascular adhesion protein 1 (VAP-1), was able to detect the phase of inflammation in healing bones, but the uptake of the tracer was elevated also in osteomyelitis. Low-grade peri-implant infec¬tions due to S. epidermidis were characterized by a low uptake of 18F-FDG, which reflects the virulence of the causative pathogen and the degree of leukocyte infiltration. In the clinical study, no relationship was found between the level of 18F-FDG uptake and the presence of positive or negative bacterial cul¬tures. Thus 18F-FDG PET may help to confirm metabolically active infection process in patients with culture-negative, histologically confirmed, low-grade osteomyelitis.
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Within the complex cellular arrangement found in the bone marrow stroma there exists a subset of nonhematopoietic cells referred to as mesenchymal progenitor cells (MPC). These cells can be expanded ex vivo and induced, either in vitro or in vivo, to terminally differentiate into at least seven types of cells: osteocytes, chondrocytes, adipocytes, tenocytes, myotubes, astrocytes and hematopoietic-supporting stroma. This broad multipotentiality, the feasibility to obtain MPC from bone marrow, cord and peripheral blood and their transplantability support the impact that the use of MPC will have in clinical settings. However, a number of fundamental questions about the cellular and molecular biology of MPC still need to be resolved before these cells can be used for safe and effective cell and gene therapies intended to replace, repair or enhance the physiological function of the mesenchymal and/or hematopoietic systems.
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Mast cell progenitors arise in bone marrow and then migrate to peripheral tissues where they mature. It is presumed that integrin receptors are involved in their migration and homing. In the present study, the expression of various integrin subunits was investigated in three systems of adherent and nonadherent mast cells. Mesentery mast cells, freshly isolated bone marrow-derived mast cells (BMMC) and RBL-2H3 cells grown attached to tissue culture flasks are all adherent mast cells and peritoneal mast cells, and cultured BMMC and RBL-2H3 cells grown in suspension represent nonadherent mast cell populations. Pure populations of mast cells were immunomagnetically isolated from bone marrow, mesentery and peritoneal lavage using the mast cell-specific monoclonal antibody AA4. By immunomicroscopy, we could demonstrate that all of these mast cells expressed alpha4, alpha5, alpha6, ß1 and ß7 integrin subunits. The expression of the alpha4 integrin subunit was 25% higher in freshly isolated mesentery mast cells and BMMC. Consistent with the results obtained by immunomicroscopy, mesentery mast cells expressed 65% more mRNA for the alpha4 integrin subunit than peritoneal mast cells. In vitro studies were also conducted using the rat mast cell line RBL-2H3. RBL-2H3 cells grown attached to the tissue culture flasks or as suspension cultures expressed the same integrin subunits identified in bone marrow, mesenteric and peritoneal mast cells ex vivo. Similarly, the expression of alpha4 integrin was higher in adherent cells. Therefore, alpha4 integrins may play a critical role in the anchorage of mast cells to the extracellular matrix in bone marrow and in peripheral tissues.
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Bone marrow contains a population of stem cells that can support hematopoiesis and can differentiate into different cell lines including adipocytes, osteocytes, chondrocytes, myocytes, astrocytes, and tenocytes. These cells have been denoted mesenchymal stem cells. In the present study we isolated a cell population derived from the endothelium and subendothelium of the umbilical cord vein which possesses morphological, immunophenotypical and cell differentiation characteristics similar to those of mesenchymal stem cells isolated from bone marrow. The cells were isolated from three umbilical cords after treatment of the umbilical vein lumen with collagenase. The cell population isolated consisted of adherent cells with fibroblastoid morphology which, when properly stimulated, gave origin to adipocytes and osteocytes in culture. Immunophenotypically, this cell population was found to be positive for the CD29, CD13, CD44, CD49e, CD54, CD90 and HLA-class 1 markers and negative for CD45, CD14, glycophorin A, HLA-DR, CD51/61, CD106, and CD49d. The characteristics described are the same as those presented by bone marrow mesenchymal stem cells. Taken together, these findings indicate that the umbilical cord obtained from term deliveries is an important source of mesenchymal stem cells that could be used in cell therapy protocols.
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Acute promyelocytic leukemia (APL) is characterized by the expansion of blasts that resemble morphologically promyelocytes and harbor a chromosomal translocation involving the retinoic acid receptor a (RARa) and the promyelocytic leukemia (PML) genes on chromosomes 17 and 15, respectively. The expression of the PML/RARa fusion gene is essential for APL genesis. In fact, transgenic mice (TM) expressing PML/RARa develop a form of leukemia that mimics the hematological findings of human APL. Leukemia is diagnosed after a long latency (approximately 12 months) during which no hematological abnormality is detected in peripheral blood (pre-leukemic phase). In humans, immunophenotypic analysis of APL blasts revealed distinct features; however, the precise immunophenotype of leukemic cells in the TM model has not been established. Our aim was to characterize the expression of myeloid antigens by leukemic cells from hCG-PML/RARa TM. In this study, TM (N = 12) developed leukemia at the mean age of 13.1 months. Morphological analysis of bone marrow revealed an increase of the percentage of immature myeloid cells in leukemic TM compared to pre-leukemic TM and wild-type controls (48.63 ± 16.68, 10.83 ± 8.11, 7.4 ± 5.46%, respectively; P < 0.05). Flow cytometry analysis of bone marrow and spleen from leukemic TM identified the asynchronous co-expression of CD34, CD117, and CD11b. This abnormal phenotype was rarely detected prior to the diagnosis of leukemia and was present at similar frequencies in hematologically normal TM and wild-type controls of different ages. The present results demonstrate that, similarly to human APL, leukemic cells from hCG-PML/RARa TM present a specific immunophenotype.
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The total number of CD34+ cells is the most relevant clinical parameter when selecting human umbilical cord blood (HUCB) for transplantation. The objective of the present study was to compare the two most commonly used CD34+ cell quantification methods (ISHAGE protocol and ProCount™ - BD) and analyze the CD34+ bright cells whose 7-amino actinomycin D (7AAD) analysis suggests are apoptotic or dead cells. Twenty-six HUCB samples obtained at the Placental Blood Program of New York Blood Center were evaluated. The absolute numbers of CD34+ cells evaluated by the ISHAGE (with exclusion of 7AAD+ cells) and ProCount™ (with exclusion of CD34+ bright cells) were determined. Using the ISHAGE protocol we found 35.6 ± 19.4 CD34+ cells/µL and with the ProCount™ method we found 36.6 ± 23.2 CD34+ cells/µL. With the ProCount™ method, CD34+ bright cell counts were 9.3 ± 8.2 cells/µL. CD34+ bright and regular cells were individually analyzed by the ISHAGE protocol. Only about 1.8% of the bright CD34+ cells are alive, whereas a small part (19.0%) is undergoing apoptosis and most of them (79.2%) are dead cells. Our study showed that the two methods produced similar results and that 7AAD is important to exclude CD34 bright cells. These results will be of value to assist in the correct counting of CD34+ cells and to choose the best HUCB unit for transplantation, i.e., the unit with the greatest number of potentially viable stem cells for the reconstitution of bone marrow. This increases the likelihood of success of the transplant and, therefore, the survival of the patient.
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Autoimmune diseases constitute a heterogeneous group of conditions commonly treated with anti-inflammatory, immunosuppressant and immunomodulating drugs, with satisfactory results in most cases. Nevertheless, some patients become resistant to conventional therapy. The use of high doses of drugs in such cases results in the need for bone marrow reconstitution, a situation which has stimulated research into the use of hematopoietic stem cells in autoimmune disease therapy. Stem cell transplantation in such diseases aims to destroy the self-reacting immune cells and produce a new functional immune system, as well as substitute cells for tissue damaged in the course of the disease. Significant results, such as the reestablishment of tolerance and a decrease in the recurrence of autoimmune disease, have been reported following stem cell transplantation in patients with autoimmune disease in Brazil and throughout the world. These results suggest that stem cell transplantation has the potential to become an important therapeutic approach to the treatment of various autoimmune diseases including rheumatoid arthritis, juvenile idiopathic arthritis, systemic lupus erythematosus, multiple sclerosis, systemic sclerosis, Crohn's disease, autoimmune blood cytopenias, and type I diabetes mellitus.
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Therapy with bone marrow-derived cells has been used in ischemic patients with reported success. The aim of this study was to determine the therapeutic efficacy of fresh and frozen human umbilical cord blood cells (hUCB) in Wistar rats submitted to permanent occlusion of the left coronary artery. Three hours after myocardial infarction, 2 x 10(7) hUCB cells or vehicle were administered by intramyocardial injection. The animals were divided into five groups: control (N = 10), sham operated (N = 10), infarcted that received vehicle (N = 9), infarcted treated with cryopreserved hUCB (N = 7), and infarcted treated with fresh hUCB (N = 5). Cardiac function was evaluated by electrocardiogram (ECG) and echocardiogram (ECHO) before cell therapy, and by ECG, ECHO, cardiopulmonary test, and left ventricular pressure measurements 3 weeks later. After 3 weeks, both groups treated with hUCB still had Q wave present in L1, âQRS >90° and reduced shortening fraction (less than 50%). In addition, cardiac indexes of left ventricular contractility and relaxation were 5484 ± 875 and -4032 ± 643 mmHg (cryopreserved hUCB) and 4585 ± 955 and -2862 ± 590 mmHg (fresh hUCB), respectively. These values were not statistically different from those of saline-treated animals. Cardiopulmonary exercise test profile was typical of infarcted hearts; exercise time was about 14 min and maximal VO2 was 24.77 ± 5.00 mL·kg-1·min-1. These data show that hUCB therapy did not improve the cardiac function of infarcted animals or prevent cardiac remodeling.
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Our aim was to construct a recombinant adenovirus co-expressing truncated human prostate-specific membrane antigen (tPSMA) and mouse 4-1BBL genes and to determine its effect on dendritic cells (DCs) generated from bone marrow suspensions harvested from C57BL/6 mice for which the effect of 4-1BBL on DCs is not clear, especially during DCs processing tumor-associated antigen. Replication deficient adenovirus AdMaxTM Expression System was used to construct recombinant adenovirus Ad-tPSMA-internal ribosome entry site-mouse 4-1BBL (Ad-tPSMA-IRES-m4-1BBL) and Ad-enhanced green fluorescent protein. Day 7 proliferating DC aggregates generated from C57BL/6 mice were collected as immature DCs and further mature DCs were obtained by lipopolysaccharide activated immature DCs. After DCs were exposed to the recombinant adenovirus with 250 multiplicity of infection, the expression of tPSMA and m4-1BBL proteins were detected by Western blot, and the apoptosis and phenotype of DCs were analyzed by flow cytometry. Cytokines (IL-6 and IL-12) in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Proliferation of T cells was detected by allogeneic mixed lymphocyte reactions. The tPSMA and m4-1BBL proteins were expressed correctly. The apoptosis rate of DCs transfected with Ad-tPSMA-IRES-m4-1BBL was 14.6%, lower than that of control DCs. The expression of co-stimulatory molecules [CD80 (81.6 ± 5.4%) and CD86 (80.13 ± 2.81%)] up-regulated in Ad-tPSMA-IRES-m4-1BBL-pulsed DCs, and the level of IL-6 (3960.2 ± 50.54 pg/mL) and IL-12 (249.57 ± 12.51 pg/mL) production in Ad-tPSMA-IRES-m4-1BBL-transduced DCs were significantly higher (P < 0.05) than those in control DCs. Ad-tPSMA-IRES-m4-1BBL induced higher T-cell proliferation (OD450 = 0.614 ± 0.018), indicating that this recombinant adenovirus can effectively enhance the activity of DCs.
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Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.
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Epigenetic mechanisms such as DNA methylation and histone modification are important in stem cell differentiation. Methylation is principally associated with transcriptional repression, and histone acetylation is correlated with an active chromatin state. We determined the effects of these epigenetic mechanisms on adipocyte differentiation in mesenchymal stem cells (MSCs) derived from bone marrow (BM-MSCs) and adipose tissue (ADSCs) using the chromatin-modifying agents trichostatin A (TSA), a histone deacetylase inhibitor, and 5-aza-2′-deoxycytidine (5azadC), a demethylating agent. Subconfluent MSC cultures were treated with 5, 50, or 500 nM TSA or with 1, 10, or 100 µM 5azadC for 2 days before the initiation of adipogenesis. The differentiation was quantified and expression of the adipocyte genes PPARG and FABP4 and of the anti-adipocyte gene GATA2 was evaluated. TSA decreased adipogenesis, except in BM-MSCs treated with 5 nM TSA. Only treatment with 500 nM TSA decreased cell proliferation. 5azadC treatment decreased proliferation and adipocyte differentiation in all conditions evaluated, resulting in the downregulation of PPARG and FABP4 and the upregulation of GATA2. The response to treatment was stronger in ADSCs than in BM-MSCs, suggesting that epigenetic memories may differ between cells of different origins. As epigenetic signatures affect differentiation, it should be possible to direct the use of MSCs in cell therapies to improve process efficiency by considering the various sources available.