|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Integrin Activation Promotes Axon Growth on Inhibitory Chondroitin Sulfate Proteoglycans by Enhancing Integrin Signaling. J Neurosci. 2011 Apr 27;31(17):6289-6295 Authors: Tan CL, Kwok JC, Patani R, Ffrench-Constant C, Chandran S, Fawcett JW Chondroitin sulfate proteoglycans (CSPGs) are upregulated after CNS lesions, where they inhibit axon regeneration. In order for axon growth and regeneration to occur, surface integrin receptors must interact with surrounding extracellular matrix molecules. We have explored the hypothesis that CSPGs inhibit regeneration by inactivating integrins and that forcing integrins into an active state might overcome this inhibition. Using cultured rat sensory neurons, we show that the CSPG aggrecan inhibits laminin-mediated axon growth by impairing integrin signaling via decreasing phosphorylated FAK (pFAK) and pSrc levels, without affecting surface integrin levels. Forcing integrin activation and signaling by manganese or an activating antibody TS2/16 reversed the inhibitory effect of aggrecan on mixed aggrecan/laminin surfaces, and enhanced axon growth from cultured rat sensory neurons (manganese) and human embryonic stem cell-derived motoneurons (TS2/16). The inhibitory effect of Nogo-A can also be reversed by integrin activation. These results suggest that inhibition by CSPGs can act via inactivation of integrins, and that activation of integrins is a potential method for improving axon regeneration after injury. PMID: 21525268 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Claudins and Cancer Stem Cells. Stem Cell Rev. 2011 Apr 28; Authors: Turksen K It is now believed that most epithelial tumors are maintained by a subpopulation of cells called cancer stem cells (CSCs) or tumor initiating cells (TICs) with stem cell-like properties, including self-renewal and multilineage differentiation capacity. Recently new insights into this population have emerged in certain epithelial tumor types, including their Claudin(low) phenotype and its importance to the epithelial-mesenchymal transition (EMT) process. Taken together, CSCs, EMT and Claudins appear to constitute an axis-of-evil in cancer, for which better understanding may lead to new therapeutic platforms. PMID: 21526417 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Rapid induction and long-term self-renewal of primitive neural precursors from human embryonic stem cells by small molecule inhibitors. Proc Natl Acad Sci U S A. 2011 Apr 27; Authors: Li W, Sun W, Zhang Y, Wei W, Ambasudhan R, Xia P, Talantova M, Lin T, Kim J, Wang X, Kim WR, Lipton SA, Zhang K, Ding S Human embryonic stem cells (hESCs) hold enormous promise for regenerative medicine. Typically, hESC-based applications would require their in vitro differentiation into a desirable homogenous cell population. A major challenge of the current hESC differentiation paradigm is the inability to effectively capture and, in the long-term, stably expand primitive lineage-specific stem/precursor cells that retain broad differentiation potential and, more importantly, developmental stage-specific differentiation propensity. Here, we report synergistic inhibition of glycogen synthase kinase 3 (GSK3), transforming growth factor β (TGF-β), and Notch signaling pathways by small molecules can efficiently convert monolayer cultured hESCs into homogenous primitive neuroepithelium within 1 wk under chemically defined condition. These primitive neuroepithelia can stably self-renew in the presence of leukemia inhibitory factor, GSK3 inhibitor (CHIR99021), and TGF-β receptor inhibitor (SB431542); retain high neurogenic potential and responsiveness to instructive neural patterning cues toward midbrain and hindbrain neuronal subtypes; and exhibit in vivo integration. Our work uniformly captures and maintains primitive neural stem cells from hESCs. PMID: 21525408 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cell therapy: A challenge to periodontist. Indian J Dent Res. 2011 Jan-Feb;22(1):132-9 Authors: Mudda JA, Bajaj M Periodontitis is an inflammatory disease which manifests clinically as loss of supporting periodontal tissues including periodontal ligament, cementum, and alveolar bone, and periodontal therapy is aimed at achieving complete regeneration of these structures. To date, this goal has been tried to accomplish using various bone grafts, growth factors, and barrier membranes. Stem cells are the most fascinating area of biology today and have been used clinically in the field of medicine to treat many incurable diseases. Various human and animal studies have confirmed the presence of stem cells in dental tissues including periodontal ligament. This has opened new avenues aiming toward complete periodontal regeneration using cell-based therapies. This review provides an overview of various types of stem cells in medicine and dentistry and their potential uses especially pertaining to periodontal regeneration. PMID: 21525691 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Characterisation of chondrogenic differentiation of human mesenchymal stem cells using synchrotron FTIR microspectroscopy. Analyst. 2011 Apr 28; Authors: Chonanant C, Jearanaikoon N, Leelayuwat C, Limpaiboon T, Tobin MJ, Jearanaikoon P, Heraud P A major limiting factor in stem cell therapy is the accurate identification of the differentiation state of cells destined for transplantation. This study aimed to evaluate the potential of synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy as a novel technique to probe the differentiation state of human mesenchymal stem cells (hMSCs) to chondrocytes over a period of 7, 14 and 21 days of induction. The chondrogenic markers were determined using reverse transcription polymerase chain reaction, histology and immunohistochemistry. The changes of average spectra located near 1338-1230 and 1175-960 cm(-1) indicated increased levels of collagen and aggrecan, respectively, in chondrocyte-induced hMSCs compared with control cells. Classification of independent test spectra using partial least squares discriminant analysis (PLS-DA) could distinguish control and chondrocyte-induced cells with 100% accuracy. We conclude that the SR-FTIR microspectroscopy technique is sensitive for monitoring the differentiation state of stem cells under chondrogenic induction particularly at an early stage. It provides biochemical information that is complimentary to that obtained from conventional techniques, and may give more unambiguous results particularly at the very early stage of cellular differentiation. In addition, the spectroscopic approach is more straightforward, non-destructive and requires less sample preparation compared with the conventional methodologies. PMID: 21526247 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Coupling of gelatin to inner surfaces of pore walls in spongy alginate-based scaffolds facilitates the adhesion, growth and differentiation of human bone marrow mesenchymal stromal cells. J Mater Sci Mater Med. 2011 Apr 28; Authors: Petrenko YA, Ivanov RV, Petrenko AY, Lozinsky VI We have developed a novel wide-pore scaffold for cell 3D culturing, based on the technology of freeze-drying of Ca-alginate and gelatin. Two different preparation methodologies were compared: (i) freeze-drying of Na-alginate + gelatin mixed solution followed by the incubation of dried polymer in saturated ethanolic solution of CaCl(2); (ii) freeze-drying of the Na-alginate solution followed by the chemical "activation" of polysaccharide core with divinylsulfone with subsequent gelatin covalent attachment to the inner surfaces of pore walls. The scaffolds produced using the first approach did not provide adhesion and proliferation of human bone marrow mesenchymal stromal cells (MSCs). Conversely, the second approach allowed to obtain scaffolds with a high adherence ability for the cells. When cultured within the latter type of scaffold, MSCs proliferated and were able to differentiate into adipogenic, osteogenic and chondrogenic cell lineages, in response to specific induction stimuli. The results indicate that Ca-alginate wide-pore scaffolds with covalently attached gelatin could be useful for stem cell-based bone, cartilage and adipose tissue engineering. PMID: 21526407 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Rosiglitazone-induced adipogenesis in a bone marrow mesenchymal stem cell line - biomed 2011. Biomed Sci Instrum. 2011;47:213-21 Authors: Wang D, Haile A, Jones LC In vitro modeling of adipose tissue is essential for the study of adipogenesis and related diseases as well as for the development of surgical reconstruction procedures and tissue-engineering applications. Peroxisome proliferator activated receptor ? (PPAR?) has been shown to play an integral role in stimulating adipogenesis. There are several established ligands for PPAR?, including rosiglitazone. D1 cells, a multipotential cell line derived from mouse bone marrow, were treated with increasing (0.1, 1, 10, and 30 µM) concentrations of rosiglitazone in DMEM for 48 hours followed by treatment by DMEM alone for up to 15 days. All doses of rosiglitazone stimulated the accumulation of lipids ,which was notable by day 6. The adipogenic effect of rosiglitazone was maximized at doses of 10 and 30 µM. Adipogenesis for rosiglitazone-treated cells was greater than that for cells treated with dexamethasone, a conventional method used to stimulate adipogenesis. Significantly higher levels of triglyceride-G (TG) and mature adipocyte markers (PPAR-, adipocyte fatty acid-binding protein) were observed with rosiglitazone treatment after 6 days. Cytokines in the supernatants were analyzed by multiplex-based ELISA assays at day 6 after treatment; these cells release adiponectin, resistin, PAI-1, MCP-1, and VEGF with either rosiglitazone or dexamethasone treatment. However, rosiglitazone treatment had lower osteocalcin release than did the control. This study provides evidence that rosiglitazone treatment is a reliable method that can be used to induce adipogenesis of D1 cells, a pluripotential cell line from mouse bone marrow. PMID: 21525623 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Therapeutic potentials of mesenchymal stem cells derived from human umbilical cord. Stem Cell Rev. 2011 Mar;7(1):195-207 Authors: Fan CG, Zhang QJ, Zhou JR Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs), isolated from discarded extra-embryonic tissue after birth, are promising candidate source of mesenchymal stem cells (MSCs). Apart from their prominent advantages in abundant supply, painless collection, and faster self-renewal, hUC-MSCs have shown the potencies to differentiate into a variety of cells of three germ layers (such as bone, cartilage, adipose, skeletal muscle, cardiomyocyte, endothelium, hepatocyte-like cluster, islet-like cluster, neuron, astrocyte and oligodendrocyte), to synthesize and secret a set of trophic factors and cytokines, to support the expansion and function of other cells (like hematopoietic stem cells, embryonic stem cells, natural killer cells, islet-like cell clusters, neurons and glial cells), to migrate toward and home to pathological areas, and to be readily transfected with conventional methods. Two excellent previous reviews documenting the characteristics of this cell population with special emphasis on its niche, isolation, surface markers and primitive properties have been published recently. In this review, we will firstly give a brief introduction of this cell population, and subsequently dwell on the findings of differential capacities with emphasis on its therapeutic potentials. PMID: 20676943 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
No comments:
Post a Comment