Moderate consumption of red wine (cabernet sauvignon) improves ischemia-induced neovascularization in ApoE-deficient mice: effect on endothelial progenitor cells and nitric oxide.
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Moderate consumption of red wine is associated with a decreased incidence of cardiovascular diseases in populations with relatively high amount of fat in the diet. However, the mechanisms involved in this protective effect are not completely understood. Here we show that moderate consumption of red wine (equivalent to 2 glasses/day in humans) but not ethanol only, improves blood flow recovery by 32% after hindlimb ischemia in hypercholesterolemic ApoE-deficient mice. In ischemic tissues, red wine consumption reduces oxidative stress and increases capillary density by 46%. Endothelial progenitor cells (EPCs) have been shown to have an important role in postnatal neovascularization. We found that the number of EPCs is increased by 60% in ApoE mice exposed to red wine. Moreover, the migratory capacity of EPCs is significantly improved in red wine-drinking mice. The wine used in our study is a cabernet sauvignon from Languedoc-Roussillon, France, which contains a relatively high concentration (4-6 mg/L) of the polyphenolic antioxidant resveratrol. We demonstrate that resveratrol can rescue oxidized low-density lipoprotein (oxLDL)-induced impairment of in vitro angiogenic activities in human umbilical vein endothelial cells (HUVECs). Resveratrol exposure is also associated with increased activation of Akt/eNOS together with a restoration of nitric oxide production in HUVECs exposed to oxLDL. Our study suggests that moderate consumption of red wine improves ischemia-induced neovascularization in high-cholesterol conditions by increasing the number and the functional activities of EPCs and by restoring the Akt-eNOS-NO pathway. (+info)
Mesenchymal stem cells from ischemic heart disease patients improve left ventricular function after acute myocardial infarction.
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Mesenchymal stem cells (MSCs) from healthy donors improve cardiac function in experimental acute myocardial infarction (AMI) models. However, little is known about the therapeutic capacity of human MSCs (hMSCs) from patients with ischemic heart disease (IHD). Therefore, the behavior of hMSCs from IHD patients in an immune-compromised mouse AMI model was studied. Enhanced green fluorescent protein-labeled hMSCs from IHD patients (hMSC group: 2 x 10(5) cells in 20 microl, n = 12) or vehicle only (medium group: n = 14) were injected into infarcted myocardium of NOD/scid mice. Sham-operated mice were used as the control (n = 10). Cardiac anatomy and function were serially assessed using 9.4-T magnetic resonance imaging (MRI); 2 wk after cell transplantation, immunohistological analysis was performed. At day 2, delayed-enhancement MRI showed no difference in myocardial infarction (MI) size between the hMSC and medium groups (33 +/- 2% vs. 36 +/- 2%; P = not significant). A comparable increase in left ventricular (LV) volume and decrease in ejection fraction (EF) was observed in both MI groups. However, at day 14, EF was higher in the hMSC than in the medium group (24 +/- 3% vs. 16 +/- 2%; P < 0.05). This was accompanied by increased vascularity and reduced thinning of the infarct scar. Engrafted hMSCs (4.1 +/- 0.3% of injected cells) expressed von Willebrand factor (16.9 +/- 2.7%) but no stringent cardiac or smooth muscle markers. hMSCs from patients with IHD engraft in infarcted mouse myocardium and preserve LV function 2 wk after AMI, potentially through an enhancement of scar vascularity and a reduction of wall thinning. (+info)
Sox17 dependence distinguishes the transcriptional regulation of fetal from adult hematopoietic stem cells.
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Fetal stem cells differ phenotypically and functionally from adult stem cells in diverse tissues. However, little is known about how these differences are regulated. To address this we compared the gene expression profiles of fetal versus adult hematopoietic stem cells (HSCs) and discovered that the Sox17 transcriptional regulator is specifically expressed in fetal and neonatal but not adult HSCs. Germline deletion of Sox17 led to severe fetal hematopoietic defects, including a lack of detectable definitive HSCs. Conditional deletion of Sox17 from hematopoietic cells led to the loss of fetal and neonatal but not adult HSCs. HSCs stopped expressing Sox17 approximately 4 weeks after birth. During this transition, loss of Sox17 expression correlated with slower proliferation and the acquisition of an adult phenotype by individual HSCs. Sox17 is thus required for the maintenance of fetal and neonatal HSCs and distinguishes their transcriptional regulation from adult HSCs. (+info)
In vitro cardiomyogenic differentiation of adult human bone marrow mesenchymal stem cells. The role of 5-azacytidine.
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The aim of this study is to investigate the ability of adult human bone marrow mesenchymal stem cells to differentiate towards a cardiomyogenic phenotype in vitro. Bone marrow samples have been aspirated from 30 patients undergoing open heart surgery. Mesenchymal stem cells were isolated and cultured in enriched medium. Second passaged cells were treated with 10 microM 5-azacytidine for 24 h. Selected surface antigens were analyzed by flow cytometry. Morphologic characteristics were analyzed by confocal and electron microscopy. Expression of cytoskeletal protein vimentin and muscle specific myosin heavy chain were analyzed by immunohistochemistry. Expression of alpha-cardiac actin, beta-myosin heavy chain and cardiac troponin-T was detected by reverse transcriptase polymerase chain reaction. Mesenchymal stem cells were spindle-shaped with irregular processes. Cells treated with 5-azacytidine have assumed a stick-like morphology. They were connecting with adjoining cells forming myotube-like structures. Numerous myofilaments were detected in induced cells running in a parallel fashion without forming sarcomeres that were immunohistochemically positive for myosin heavy chain and vimentin. The mRNAs of alpha-cardiac actin, beta-myosin heavy chain and troponin-T were expressed in both induced and uninduced cells. These results indicate that adult human bone marrow mesenchymal stem cells can differentiate towards a cardiomyogenic lineage in vitro. (+info)
Comparative transcriptome analysis of embryonic and adult stem cells with extended and limited differentiation capacity.
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BACKGROUND: Recently, several populations of postnatal stem cells, such as multipotent adult progenitor cells (MAPCs), have been described that have broader differentiation ability than classical adult stem cells. Here we compare the transcriptome of pluripotent embryonic stem cells (ESCs), MAPCs, and lineage-restricted mesenchymal stem cells (MSCs) to determine their relationship. RESULTS: Applying principal component analysis, non-negative matrix factorization and k-means clustering algorithms to the gene-expression data, we identified a unique gene-expression profile for MAPCs. Apart from the ESC-specific transcription factor Oct4 and other ESC transcripts, some of them associated with maintaining ESC pluripotency, MAPCs also express transcripts characteristic of early endoderm and mesoderm. MAPCs do not, however, express Nanog or Sox2, two other key transcription factors involved in maintaining ESC properties. This unique molecular signature was seen irrespective of the microarray platform used and was very similar for both mouse and rat MAPCs. As MSC-like cells isolated under MAPC conditions are virtually identical to MSCs, and MSCs cultured in MAPC conditions do not upregulate MAPC-expressed transcripts, the MAPC signature is cell-type specific and not merely the result of differing culture conditions. CONCLUSION: Multivariate analysis techniques clustered stem cells on the basis of their expressed gene profile, and the genes determining this clustering reflected the stem cells' differentiation potential in vitro. This comparative transcriptome analysis should significantly aid the isolation and culture of MAPCs and MAPC-like cells, and form the basis for studies to gain insights into genes that confer on these cells their greater developmental potency. (+info)
Adult bone marrow-derived stem cells for organ regeneration and repair.
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Stem cells have been recognized as a potential tool for the development of innovative therapeutic strategies. There are in general two types of stem cells, embryonic and adult stem cells. While embryonic stem cell therapy has been riddled with problems of allogeneic rejection and ethical concerns, adult stem cells have long been used in the treatment of hematological malignancies. With the recognition of additional, potentially therapeutic characteristics, bone marrow-derived stem cells have become a tool in regenerative medicine. The bone marrow is an ideal source of stem cells because it is easily accessible and harbors two types of stem cells. Hematopoietic stem cells give rise to all blood cell types and have been shown to exhibit plasticity, while multipotent marrow stromal cells are the source of osteocytes, chondrocytes, and fat cells and have been shown to support and generate a large number of different cell types. This review describes the general characteristics of these stem cell populations and their current and potential future applications in regenerative medicine. (+info)
Electrophysiological properties of human adipose tissue-derived stem cells.
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Human adipose tissue-derived stem cells (hASCs) represent a potentially valuable cell source for clinical therapeutic applications. The present study was designed to investigate properties of ionic channel currents present in undifferentiated hASCs and their impact on hASCs proliferation. The functional ion channels in hASCs were analyzed by whole-cell patch-clamp recording and their mRNA expression levels detected by RT-PCR. Four types of ion channels were found to be present in hASCs: most of the hASCs (73%) showed a delayed rectifier-like K(+) current (I(KDR)); Ca(2+)-activated K(+) current (I(KCa)) was detected in examined cells; a transient outward K(+) current (I(to)) was recorded in 19% of the cells; a small percentage of cells (8%) displayed a TTX-sensitive transient inward sodium current (I(Na.TTX)). RT-PCR results confirmed the presence of ion channels at the mRNA level: Kv1.1, Kv2.1, Kv1.5, Kv7.3, Kv11.1, and hEAG1, possibly encoding I(KDR); MaxiK, KCNN3, and KCNN4 for I(KCa); Kv1.4, Kv4.1, Kv4.2, and Kv4.3 for I(to) and hNE-Na for I(Na.TTX). The I(KDR) was inhibited by tetraethyl ammonium (TEA) and 4-aminopyridine (4-AP), which significantly reduced the proliferation of hASCs in a dose-dependent manner (P < 0.05), as suggested by bromodeoxyurindine (BrdU) incorporation. Other selective potassium channel blockers, including linopiridine, iberiotoxin, clotrimazole, and apamin also significantly inhibited I(KDR). TTX completely abolished I(Na.TTX). This study demonstrates for the first time that multiple functional ion channel currents such as I(KDR), I(KCa), I(to), and I(Na.TTX) are present in undifferentiated hASCs and their potential physiological function in these cells as a basic understanding for future in vitro experiments and in vivo clinical investigations. (+info)
Human adipose-derived adult stem cells upregulate palladin during osteogenesis and in response to cyclic tensile strain.
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Cell morphology may be an important stimulus during differentiation of human adipose-derived adult stem (hADAS) cells, but there are limited studies that have investigated the role of the cytoskeleton or associated proteins in hADAS cells undergoing differentiation. Palladin is an actin-associated protein that plays an integral role in focal adhesion and cytoskeleton organization. In this study we show that palladin was expressed by hADAS cells and was modulated during osteogenic differentiation and in response to cyclic tensile strain. Human ADAS cells expressed the 90- and 140-kDa palladin isoforms and upregulated expression of both isoforms after culture in conditions that promoted osteogenesis. Palladin mRNA expression levels were also increased in hADAS cells subjected to cyclic tensile strain. Knockdown of the palladin gene during osteogenesis resulted in decreased actin stress fibers and decreased protein levels of Eps8, an epidermal growth factor receptor tyrosine kinase that colocalizes with actin. Silencing the palladin gene, however, did not affect hADAS cells' commitment down the osteogenic lineage. (+info)