|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | Last week, we wrote about whether "feeding the well-fed" would produce the kind of results desired by the California stem cell agency.
The starting point was an item by UC Davis stem cell researcher Paul Knoepfler who discussed on his blog the general grant-making process in the world of science. He said that the process rewards those who are already well-funded while greater impact could be | | | | | | | | | | | | | | | | | | | | | | | | | Generation of an osteogenic graft from human placenta and placenta-derived mesenchymal stem cells. Reprod Sci. 2010 Nov;17(11):1006-15 Authors: Mohr S, Portmann-Lanz CB, Schoeberlein A, Sager R, Surbek DV The objective of the study was to determine the feasibility of generating a biodegradable, stem cell-loaded osteogenic composite graft from human placenta. Initially, a scaffold from human chorion membrane was produced. Human placenta mesenchymal stem cells (MSCs) derived from either first-trimester chorionic villi or term chorion membrane were differentiated osteogenically on this scaffold. Outgrowth, adherence, and osteogenic differentiation of cells were assessed by immunohistochemistry (IHC), scanning electron microscopy, protein expression, and real-time polymerase chain reaction (RT-PCR). Our results showed that a cell-free extracellular matrix scaffold can be generated from human chorion. Seeded MSCs densely adhered to that scaffold and were osteogenically differentiated. Calcium and alkaline phosphatase were detected in the cell-scaffold constructs as a proof of mineralization and findings were confirmed by IHC and RT-PCR results. This study shows for the first time that generation of an osteogenic composite graft using placental tissue is feasible. It might allow therapeutic application of autologous or allogeneic grafts in congenital skeletal defects by means of a composite graft. PMID: 20940246 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Osteogenic activity of bone marrow-derived mesenchymal stem cells (BMSCs) seeded on irradiated allogenic bone. J Tissue Eng Regen Med. 2011 Feb 15; Authors: Tohma Y, Dohi Y, Ohgushi H, Tadokoro M, Akahane M, Tanaka Y Allogenic bone grafting, a technique used in orthopaedic surgery, has several problems, including low osteogenic activity. To overcome the problem, this study aimed to determine whether in vivo osteogenesis could be enhanced using allogenic irradiated bone grafts after seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs). The allogenic bone cylinders were extracted from ACI rats and sterilized by irradiation. Donor BMSCs were obtained from fresh Fischer 344 (F344) rat bone marrow by cell culture. The allogenic bone with or without BMSCs were transplanted subcutaneously into syngeneic F344 rats. At 4 weeks after transplantation, high alkaline phosphatase (ALP) activity, bone-specific osteocalcin mRNA expression and newly formed bone were detected in the allogenic bone with BMSCs. The origin of the newly formed bone was derived from cultured donor BMSCs. However, none of these identifiers of osteogenesis were detected in either the fresh or the irradiated allogenic bone without BMSCs. These results indicate the availability of autologous BMSCs to heighten the osteogenic response of allogenic bone. Our present tissue-engineering method might contribute to a wide variety of allogenic bone grafting techniques in clinical settings. Copyright © 2011 John Wiley & Sons, Ltd. PMID: 21322118 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A procedure for identifying stem cell compartments with multi-lineage differentiation potential. Analyst. 2011 Feb 14; Authors: Amin HD, Olsen I, Knowles J, Donos N Stem cells isolated from adult human tissue have received increasing attention because of their potential to repair and/or regenerate damaged tissue. However, identification and characterization of such cell populations have been limited due to the lack of adequate methodology for assessing their multi-lineage potential. In the present study, using adult human ligament tissue as a model, we have developed a combination of methods which together can be used to identify adult stem cell compartments based on their ability to undergo a range of differentiation pathways, including osteogenesis, adipogenesis, chondrogenesis, myogenesis, vasculogenesis, angiogenesis, neurogenesis and gliogenesis in vitro. This was carried out using the conventional reverse transcription polymerase chain reaction technique to assess the expression of selected key lineage-associated marker genes and by using histological, immunological and morphological criteria to assess characteristic features of lineage-specific 'terminal' differentiation in vitro. PMID: 21321687 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | The California stem cell agency has unveiled the results of a survey of its directors concerning their own performance and desired criteria for a new chair of the $3 billion research effort.
James Harrison of Remcho, Johansen and Purcell of San Leandro, outside counsel to the board, said in a memo to the board,
"The survey reveals that members have a wide range of views, especially in connection | | | | | | | | | | | | | | | | | | | | | | | | | Comparison of alternative mesenchymal stem cell sources for cell banking and musculoskeletal advanced therapies. J Cell Biochem. 2011 Feb 14; Authors: Cavallo C, Cuomo C, Fantini S, Ricci F, Tazzari PL, Lucarelli E, Donati D, Facchini A, Lisignoli G, Fornasari PM, Grigolo B, Moroni L With the continuous discovery of new alternative sources containing mesenchymal stem cells (MSCs), regenerative medicine therapies may find tailored applications in the clinics. Although these cells have been demonstrated to express specific mesenchymal markers and are able to differentiate into mesenchymal lineages in ad hoc culture conditions, it is still critical to determine the yield and differentiation potential of these cells in comparative studies under the same standardized culture environment. Moreover, the opportunity to use MSCs from bone marrow of multiorgan donors for cell banking is of relevant importance. In the attempt to establish the relative potential of alternative MSCs sources, we analyzed and compared the yield and differentiation potential of human MSCs from adipose and bone marrow tissues of cadaveric origins, and from fetal annexes (placenta and umbilical cord) after delivery using standardized isolation and culture protocols. Bone marrow contained a significantly higher amount of mononuclear cells (MNCs) compared to the other tissue sources. Nonetheless, a higher cell seeding density was needed for these cells to successfully isolate MSCs. The MNCs populations were highly heterogeneous and expressed variable MSCs markers with a large variation from donor to donor. After MSCs selection through tissue culture plastic adhesion, cells displayed a comparable proliferation capacity with distinct colony morphologies and were positive for a pool of typical MSCs markers. In vitro differentiation assays showed a higher osteogenic differentiation capacity of adipose tissue and bone marrow MSCs, and a higher chondrogenic differentiation capacity of bone marrow MSCs. J. Cell. Biochem. © 2011 Wiley-Liss, Inc. PMID: 21321995 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A comprehensive flow-cytometric analysis of graft infiltrating lymphocytes, draining lymph nodes and serum during the rejection phase in a fully allogeneic rat cornea transplant model. Mol Vis. 2011;17:420-9 Authors: Maenz M, Morcos M, Ritter T To establish a cornea transplant model in a pigmented rat strain and to define the immunologic reaction toward corneal allografts, by studying the cellular and humoral immune response after keratoplasty. PMID: 21321672 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Comparison of alternative mesenchymal stem cell sources for cell banking and musculoskeletal advanced therapies. J Cell Biochem. 2011 Feb 14; Authors: Cavallo C, Cuomo C, Fantini S, Ricci F, Tazzari PL, Lucarelli E, Donati D, Facchini A, Lisignoli G, Fornasari PM, Grigolo B, Moroni L With the continuous discovery of new alternative sources containing mesenchymal stem cells (MSCs), regenerative medicine therapies may find tailored applications in the clinics. Although these cells have been demonstrated to express specific mesenchymal markers and are able to differentiate into mesenchymal lineages in ad hoc culture conditions, it is still critical to determine the yield and differentiation potential of these cells in comparative studies under the same standardized culture environment. Moreover, the opportunity to use MSCs from bone marrow of multiorgan donors for cell banking is of relevant importance. In the attempt to establish the relative potential of alternative MSCs sources, we analyzed and compared the yield and differentiation potential of human MSCs from adipose and bone marrow tissues of cadaveric origins, and from fetal annexes (placenta and umbilical cord) after delivery using standardized isolation and culture protocols. Bone marrow contained a significantly higher amount of mononuclear cells (MNCs) compared to the other tissue sources. Nonetheless, a higher cell seeding density was needed for these cells to successfully isolate MSCs. The MNCs populations were highly heterogeneous and expressed variable MSCs markers with a large variation from donor to donor. After MSCs selection through tissue culture plastic adhesion, cells displayed a comparable proliferation capacity with distinct colony morphologies and were positive for a pool of typical MSCs markers. In vitro differentiation assays showed a higher osteogenic differentiation capacity of adipose tissue and bone marrow MSCs, and a higher chondrogenic differentiation capacity of bone marrow MSCs. J. Cell. Biochem. © 2011 Wiley-Liss, Inc. PMID: 21321995 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Reprogramming to pluripotency: stepwise resetting of the epigenetic landscape. Cell Res. 2011 Feb 15; Authors: Papp B, Plath K In 2006, the "wall came down" that limited the experimental conversion of differentiated cells into the pluripotent state. In a landmark report, Shinya Yamanaka's group described that a handful of transcription factors (Oct4, Sox2, Klf4 and c-Myc) can convert a differentiated cell back to pluripotency over the course of a few weeks, thus reprograming them into induced pluripotent stem (iPS) cells. The birth of iPS cells started off a rush among researchers to increase the efficiency of the reprogramming process, to reveal the underlying mechanistic events, and allowed the generation of patient- and disease-specific human iPS cells, which have the potential to be converted into relevant specialized cell types for replacement therapies and disease modeling. This review addresses the steps involved in resetting the epigenetic landscape during reprogramming. Apparently, defined events occur during the course of the reprogramming process. Immediately, upon expression of the reprogramming factors, some cells start to divide faster and quickly begin to lose their differentiated cell characteristics with robust downregulation of somatic genes. Only a subset of cells continue to upregulate the embryonic expression program, and finally, pluripotency genes are upregulated establishing an embryonic stem cell-like transcriptome and epigenome with pluripotent capabilities. Understanding reprogramming to pluripotency will inform mechanistic studies of lineage switching, in which differentiated cells from one lineage can be directly reprogrammed into another without going through a pluripotent intermediate.Cell Research advance online publication 15 February 2011; doi: 10.1038/cr.2011.28. PMID: 21321600 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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