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pubmed: adipose stem cell         Prolonged hypoxic culture and trypsinization increase the pro-angiogenic potential of human adipose tissue-derived stem cells. August 28, 2010 at 6:19 AM   Related Articles Prolonged hypoxic culture and trypsinization increase the pro-angiogenic potential of human adipose tissue-derived stem cells. Cytotherapy. 2010 Aug 26; Authors: Rasmussen JG, Frøbert O, Pilgaard L, Kastrup J, Simonsen U, Zachar V, Fink T Abstract Background aims. Transplantation of mesenchymal stromal cells (MSC), including adipose tissue-derived stem cells (ASC), is a promising option in the treatment of vascular disease. Short-term hypoxic culture of MSC augments secretion of anti-apoptotic and angiogenic cytokines. We hypothesized that prolonged hypoxic (1% and 5% oxygen) culture and trypsinization would augment ASC expression of anti-apoptotic and angiogenic cytokines and increase the angiogenic potential of ASC-conditioned media. Methods. The effects of prolonged hypoxic culture on growth and pro-angiogenic properties were investigated using human ASC cultured at 1%, 5% and 21% oxygen. The effect of trypsinization on the expression of pro-angiogenic genes was also determined. Results. Trypsinization induced up-regulation of the vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) genes independent of oxygen concentration. The expression of VEGF and IGF-1 was up-regulated in ASC cultured at 1% oxygen for 13 days compared with 4 days. The VEGF concentration in ASC-conditioned media was higher after prolonged hypoxic culture compared with short-term culture, while the IGF-1 and chemokine (CXC motif) ligand 12 (CXCL12) concentrations were unchanged. The VEGF receptor blocker SU5416 abolished angiogenesis in a cultured rat aortic ring model. Media from cells exposed to hypoxia increased angiogenesis, an effect that was dependent on factors other than just the VEGF concentration in the added media. Conclusions. Optimization of the angiogenic potential of stem cell-based therapy in the treatment of vascular disease is important. We have demonstrated that prolonged hypoxic culture and trypsinization augment the therapeutic angiogenic potential of ASC. PMID: 20795759 [PubMed - as supplied by publisher]         Adipose tissue-derived stem cells show both immunogenic and immunosuppressive properties after chondrogenic differentiation. August 28, 2010 at 6:19 AM   Related Articles Adipose tissue-derived stem cells show both immunogenic and immunosuppressive properties after chondrogenic differentiation. Cytotherapy. 2010 Aug 26; Authors: Technau A, Froelich K, Hagen R, Kleinsasser N Abstract Background aims. The chondrogenic differentiation potential of mesenchymal stromal cells (MSC), as well as their immunosuppressive properties, have been studied extensively. So far, only a few studies have addressed the question of whether MSC still retain their immunosuppressive qualities after transdifferentiation. In particular, the expression of immunogenic markers, such as human leukocyte antigen (HLA)-DR, after differentiation has never been investigated. Methods. Chondrogenic transdifferentiation was induced in human adipose tissue-derived stem cell (ADSC) pellet cultures derived from 10 different patients, using 10 ng/mL transforming growth factor (TGF)-beta3. Samples were harvested over a time-course of 28 days and analyzed by immunohistochemistry and reverse transcription (RT)-polymerase chain reaction (PCR). The cytokine levels in the supernatants of the samples were measured semi-quantitatively by dot-blots and quantitatively by enzyme-linked immunosorbant assays (ELISA). Results. Undifferentiated ADSC were negative for chondrogenic markers, as well as HLA-ABC and HLA-DR epitopes in immunofluorescence. In contrast, TGF-beta3-induced pellet cultures showed both expression of chondrogenic differentiation markers, such as transcription factor 9 (Sox 9), collagen type IIa and aggrecan, and an up-regulation of HLA-DR, beginning at day 7 after induction. Interferon-gamma (INF-gamma) is known to up-regulate HLA-DR. Therefore we measured INF-gamma levels in the supernatants of TGF-beta3-induced pellets and, indeed, INF-gamma was up-regulated during chondrogenesis in ADSC pellet cultures. However, both undifferentiated and TGF-beta3-induced ADSC also showed expression of immunosuppressive HLA-G and interleukin (IL)-10 up-regulation. Conclusions. These results suggest that the immunogenicity of adult stem cell-derived tissue should be tested in animal models before clinical trials for allogeneic engineered tissue are considered. PMID: 20795757 [PubMed - as supplied by publisher]             This email was sent to agupta1213+termsc@gmail.com. Delivered by Feed My Inbox 230 Franklin Road Suite 814 Franklin, TN 37064 Account Login Unsubscribe Here