|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | Identification of a novel HLA-B allele, B*56:31, by sequence-based typing in a Lithuanian individual. Tissue Antigens. 2011 Mar;77(3):262-3 Authors: Jakubauskas A, Vilkeviciene R, Juskevicius D, Griskevicius L A novel allele HLA-B*56:31 differs from HLA-B*56:18 by three nucleotide substitutions resulting in a missense mutation Tyr171His (TAC to CAC) encoded in exon 3 and two silent substitutions at codon 188His (CAC to CAT) and codon 228Thr (ACT to ACC) encoded in exon 4. PMID: 21299538 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Embryonic stem cells for osteo-degenerative diseases. Methods Mol Biol. 2011;690:1-30 Authors: zur Nieden NI Current orthopedic practice to treat osteo-degenerative diseases, such as osteoporosis, calls for antiresorptive therapies and anabolic bone medications. In some cases, surgery, in which metal rods are inserted into the bones, brings symptomatic relief. As these treatments may ameliorate the symptoms, but cannot cure the underlying dysregulation of the bone, the orthopedic field seems ripe for regenerative therapies using transplantation of stem cells. Stem cells bring with them the promise of completely curing a disease state, as these are the cells that normally regenerate tissues in a healthy organism. This chapter assembles reports that have successfully used stem cells to generate osteoblasts, osteoclasts, and chondrocytes - the cells that can be found in healthy bone tissue - in culture, and review and collate studies about animal models that were employed to test the function of these in vitro "made" cells. A particular emphasis is placed on embryonic stem cells, the most versatile of all stem cells. Due to their pluripotency, embryonic stem cells represent the probably most challenging stem cells to bring into the clinic, and therefore, the associated problems are discussed to put into perspective where the field currently is and what we can expect for the future. PMID: 21042982 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Allogeneic periodontal ligament stem cell therapy for periodontitis in swine. Stem Cells. 2010 Oct;28(10):1829-38 Authors: Ding G, Liu Y, Wang W, Wei F, Liu D, Fan Z, An Y, Zhang C, Wang S Periodontitis is one of the most widespread infectious diseases in humans. It is the main cause of tooth loss and associated with a number of systemic diseases. Until now, there is no appropriate method for functional periodontal tissue regeneration. Here, we establish a novel approach of using allogeneic periodontal ligament stem cells (PDLSCs) sheet to curing periodontitis in a miniature pig periodontitis model. Significant periodontal tissue regeneration was achieved in both the autologous and the allogeneic PDLSCs transplantation group at 12 weeks post-PDLSCs transplantation. Based on clinical assessments, computed tomography (CT) scanning, and histological examination, there was no marked difference between the autologous and allogeneic PDLSCs transplantation groups. In addition, lack of immunological rejections in the animals that received the allogeneic PDLSCs transplantation was observed. Interestingly, we found that human PDLSCs fail to express human leukocyte antigen (HLA)-II DR and costimulatory molecules. PDLSCs were not able to elicit T-cell proliferation and inhibit T-cell proliferation when stimulated with mismatched major histocompatibility complex molecules. Furthermore, we found that prostaglandin E2 (PGE2) plays a crucial role in PDLSCs-mediated immunomodulation and periodontal tissue regeneration in vitro and in vivo. Our study demonstrated that PDLSCs possess low immunogenicity and marked immunosuppression via PGE2-induced T-cell anergy. We developed a standard technological procedure of using allogeneic PDLSCs to cure periodontitis in swine. PMID: 20979138 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Initial cell pre-cultivation can maximize ECM mineralization by human mesenchymal stem cells on silk fibroin scaffolds. Acta Biomater. 2011 Feb 4; Authors: Thimm BW, Wüst S, Hofmann S, Hagenmüller H, Müller R Fast remineralization of bone defects by means of tissue engineering is one of many targets in orthopedic regeneration. This study investigated into the influence of a range of pre-culture durations for human bone marrow derived mesenchymal stem cells (hMSC) before inducing differentiation into osteoblast-like cells. The aim was to find the condition that lead to maximal extracellular matrix (ECM) mineralization both in terms of amount and best distribution. Additionally, the influence of silk fibroin scaffold pore size on mineralization was assessed. The formation of mineralized ECM by hMSCs cultured in osteogenic medium on silk fibroin scaffolds was monitored and quantified up to 72 days in culture using non-invasive time-lapsed micro-computed tomography (micro-CT). ECM mineralization increased linearly three weeks after the beginning of the experiment with the addition of the differentiation medium. Biochemical endpoint assays measured the amount of DNA, calcium deposits, alkaline phosphatase and cell metabolic activity to corroborate the hypothesis that an initial pre-culture period of hMSCs on silk fibroin scaffolds can accelerate mineralized ECM formation. According to micro-CT analysis, mineralization on silk fibroin scaffolds with pores of 112 - 224 μm in diameter was most efficient with an initial cell pre-culture period of nine days showing 6.87 ± 0.81-times higher mineralization values during the whole cultivation period than without an initial cell pre-culture period. PMID: 21300186 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Update on stem cell therapy for cerebral palsy. Expert Opin Biol Ther. 2011 Feb 8; Authors: Carroll JE, Mays RW Introduction: Due to the publicity about stem cell transplantation for the treatment of cerebral palsy, many families seek information on treatment, and many travel overseas for cell transplantation. Even so, there is little scientific confirmation of benefit, and therefore existing knowledge in the field must be summarized. Areas covered: This paper addresses the clinical protocols examining the problem, types of stem cells available for transplant, experimental models used to test the benefit of the cells, possible mechanisms of action, potential complications of cell treatment and what is needed in the field to help accelerate cell-based therapies. Expert opinion: While stem cells may be beneficial in acute injuries of the CNS the biology of stem cells is not well enough understood in chronic injuries or disorders such as cerebral palsy. More work is required at the basic level of stem cell biology, in the development of animal models, and finally in well-conceived clinical trials. PMID: 21299445 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Homing of endogenous stem/progenitor cells for in situ tissue regeneration: Promises, strategies, and translational perspectives. Biomaterials. 2011 Feb 5; Authors: Chen FM, Wu LA, Zhang M, Zhang R, Sun HH Stem cell-based therapy has been one of the best documented approaches in regenerative medicine, promising cures for a multitude of diseases and disorders. However, the ex vivo expansion of stem cells and their in vivo delivery are restricted by the limited availability of stem cell sources, the excessive cost of commercialization, and the anticipated difficulties of clinical translation and regulatory approval. An alternative to adoptively transferred stem cells are cell populations already present in a patient's body, including stem/progenitor cells, which can be actively attracted to sites of injury. This technique, known as endogenous cell homing, has the potential to provide new therapeutic options for in situ tissue regeneration. Such options would be less costly and complex than approaches that require substantial ex vivo cell manipulation and that use artificial vehicles for cell delivery. Tissue regeneration methods that rely on endogenous stem/progenitor cell homing, local tissue responses, and functional stimulation thus offer new insights into in vivo tissue engineering and hold great promise for the future of translational medicine. Although such methods that take advantage of the latent endogenous regenerative potential of the patient are promising for the repair of damaged tissue, they are in need of further experimental support before application in late-stage diseases or severe tissue injury. This review is not meant to be exhaustive but gives a brief outlook on the promises, strategies, and current applications of endogenous stem cell homing for in situ tissue regeneration, with particular emphasis placed upon pharmacological means based on cell-instructive scaffolds and release technology to direct cell mobilization and recruitment. In the future these exciting paradigms are likely to help reconcile the clinical and commercial pressures in regenerative medicine. PMID: 21300401 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A multicenter, prospective, randomized, controlled trial evaluating the safety and efficacy of intracoronary cell infusion mobilized with granulocyte colony-stimulating factor and darbepoetin after acute myocardial infarction: study design and rationale of the 'MAGIC cell-5-combination cytokine trial' Trials. 2011 Feb 7;12(1):33 Authors: Kang HJ, Kim MK, Kim MG, Choi DJ, Yoon JH, Park YB, Kim HS ABSTRACT: BACKGROUND: Bone marrow derived stem/progenitor cell transplantation after acute myocardial infarction is safe and effective for improving left ventricular systolic function. However, the improvement of left ventricular systolic function is limited. This study will evaluate novel stem/progenitor cell therapy with combination cytokine treatment of the long-acting erythropoietin analogue, darbepoetin, and granulocyte colony-stimulating factor (G-CSF) in patients with acute myocardial infarction. METHODS: The 'MAGIC Cell-5-Combination Cytokine Trial' is a multicenter, prospective, randomized, 3-arm, controlled trial with blind evaluation of the endpoints. A total of 116 patients will randomly receive one of the following three treatments: an intravenous darbepoetin infusion and intracoronary infusion of peripheral blood stem cells mobilized with G-CSF (n=58), an intracoronary infusion of peripheral blood stem cells mobilized with G-CSF alone (n=29), or conventional therapy (n=29) at phase I. Patients with left ventricular ejection fraction <45% at 6 months, in the patients who received stem cell therapy at phase I, will receive repeated cell therapy at phase II. The objectives of this study are to evaluate the safety and efficacy of combination cytokine therapy with erythropoietin and G-CSF (phase I) and repeated progenitor/stem cell treatment (phase II). DISCUSSION: This is the first study to evaluate the safety and efficacy of combination cytokine based progenitor/stem cell treatment. Trial registration: www.ClinicalTrials.gov identifier: NCT00501917. PMID: 21299845 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Reconstruction of lymph vessel by lymphatic endothelial cells combined with polyglycolic acid scaffolds: a pilot study. J Biotechnol. 2010 Oct 1;150(1):182-9 Authors: Dai T, Jiang Z, Li S, Zhou G, Kretlow JD, Cao W, Liu W, Cao Y Restoration of lymphatic drainage using lymph vessels or tissue grafting is becoming an efficient method for alleviating obstructive lymphedema. However, the lack of ideal lymphatic grafts is the key problem that limits the application of lymphatic transplantation, but now that may be resolved with tissue-engineered lymph vessels. In this study, the feasibility of reconstructing lymph vessels was explored using lymphatic endothelial cells (LECs) combined with polyglycolic acid (PGA) scaffolds. The highly purified human dermal LECs can be isolated from human dermis by immunomagnetic bead sorting and multiplied in culture. The viability and growth potential of subcultured LECs make it possible to obtain large amount of cells in vitro. Light and scanning electron microscopy (SEM) showed that the prefabricated PGA scaffolds, with three-dimensional structure, can support cell adhesion, growth and spreading. The constructs formed with LECs combined with PGA scaffolds were cultured in vitro for 10 days and then implanted subcutaneously into nude mice. Six weeks after implantation, the portions of implanted tubules were harvested. Gross and histological observation demonstrated that the tubular structure still remained in the experimental groups but not in the control groups. Immunohistochemical staining and RT-PCR assay of the implanted vessels revealed positive staining in experimental groups for the lymphatic specific markers Podoplanin, VEGFR-3 and LYVE-1. The results indicate that LECs can serve as seed cells and be successfully combined with PGA scaffolds, and the tissue-engineered tubular structure using implanted LECs-PGA compounds showed preliminary characteristics of lymph vessels. A gap between the nearly normal or functional lymph vessel still exists as we have only the endothelial cell-lined duct, but this study demonstrates that it is feasible to construct tissue-engineered lymph vessels using LECs combined with a biodegradable material. PMID: 20691226 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Overexpression of BCL2 enhances survival of human embryonic stem cells during stress and obviates the requirement for serum factors. Proc Natl Acad Sci U S A. 2011 Feb 7; Authors: Ardehali R, Inlay MA, Ali SR, Tang C, Drukker M, Weissman IL The promise of pluripotent stem cells as a research and therapeutic tool is partly undermined by the technical challenges of generating and maintaining these cells in culture. Human embryonic stem cells (hESCs) are exquisitely sensitive to culture conditions, and require constant signaling by growth factors and cell-cell and cell-matrix interactions to prevent apoptosis, senescence, and differentiation. Previous work from our laboratory demonstrated that overexpression of the prosurvival gene BCL2 in mouse embryonic stem cells overrode the requirement of serum factors and feeder cells to maintain mESCs in culture. To determine whether this prosurvival gene could similarly protect hESCs, we generated hESC lines that constitutively or inducibly express BCL2. We find that BCL2 overexpression significantly decreases dissociation-induced apoptosis, resulting in enhanced colony formation from sorted single cells, and enhanced embryoid body formation. In addition, BCL2-hESCs exhibit normal growth in the absence of serum, but require basic fibroblast growth factor to remain undifferentiated. Furthermore, they maintain their pluripotency markers, form teratomas in vivo, and differentiate into all three germ layers. Our data suggest that the BCL2 signaling pathway plays an important role in inhibiting hESC apoptosis, such that its overexpression in hESCs offers both a survival benefit in conditions of stress by resisting apoptosis and obviates the requirement for serum or a feeder layer for maintenance. PMID: 21300885 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regenerative medicine in multiple sclerosis: identifying pharmacological targets of adult neural stem cell differentiation. Neurochem Int. 2011 Feb 4; Authors: Huang JK, Franklin RJ Progressive axonal loss from chronic demyelination in multiple sclerosis (MS) is the key contributor to clinical decline. Failure to regenerate myelin by adult oligodendrocyte precursor cells (OPCs), a widely distributed neural stem cell population in the adult brain, is one of the major causes of axonal degeneration. In order to develop successful therapies to protect the integrity of axons in MS, it is important to identify and understand the key molecular pathways involved in myelin regeneration (remyelination) by adult OPCs. This review highlights recent findings on the critical signaling pathways associated with OPC differentiation following CNS demyelination. We discuss the role of LINGO-1, Notch, Wnt, and retinoid X receptor (RXR) signaling, and how they might be useful pharmacological targets to overcoming remyelination failure in MS. PMID: 21300122 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Recent advances in particle and droplet manipulation for lab-on-a-chip devices based on surface acoustic waves. Lab Chip. 2011 Feb 8; Authors: Wang Z, Zhe J Manipulation of microscale particles and fluid liquid droplets is an important task for lab-on-a-chip devices for numerous biological researches and applications, such as cell detection and tissue engineering. Particle manipulation techniques based on surface acoustic waves (SAWs) appear effective for lab-on-a-chip devices because they are non-invasive, compatible with soft lithography micromachining, have high energy density, and work for nearly any type of microscale particles. Here we review the most recent research and development of the past two years in SAW based particle and liquid droplet manipulation for lab-on-a-chip devices including particle focusing and separation, particle alignment and patterning, particle directing, and liquid droplet delivery. PMID: 21301739 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Histone deacetylase regulates high mobility group A2-targeting microRNAs in human cord blood-derived multipotent stem cell aging. Cell Mol Life Sci. 2011 Jan;68(2):325-36 Authors: Lee S, Jung JW, Park SB, Roh K, Lee SY, Kim JH, Kang SK, Kang KS Cellular senescence involves a reduction in adult stem cell self-renewal, and epigenetic regulation of gene expression is one of the main underlying mechanisms. Here, we observed that the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) caused by inhibition of histone deacetylase (HDAC) activity leads to down-regulation of high mobility group A2 (HMGA2) and, on the contrary, to up-regulation of p16(INK)⁴(A), p21(CIP)¹(/WAF)¹ and p27(KIP)¹. We found that let-7a1, let-7d, let-7f1, miR-23a, miR-26a and miR-30a were increased during replicative and HDAC inhibitor-mediated senescence of hUCB-MSCs by microRNA microarray and real-time quantitative PCR. Furthermore, the configurations of chromatins beading on these miRNAs were prone to transcriptional activation during HDAC inhibitor-mediated senescence. We confirmed that miR-23a, miR-26a and miR-30a inhibit HMGA2 to accelerate the progress of senescence. These findings suggest that HDACs may play important roles in cellular senescence by regulating the expression of miRNAs that target HMGA2 through histone modification. PMID: 20652617 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Using immuno-scanning electron microscopy for the observation of focal adhesion-substratum interactions at the nano- and microscale in S-phase cells. Methods Mol Biol. 2011;695:53-60 Authors: Biggs MJ, Richards RG, Dalby MJ It is becoming clear that the nano/microtopography of a biomaterial in vivo is of first importance in influencing focal adhesion formation and subsequent cellular behaviour. When considering next-generation biomaterials, where the material's ability to elicit a regulated cell response will be key to device success, focal adhesion analysis is an useful indicator of cytocompatibility and can be used to determine functionality. Here, a methodology is described to allow simultaneous high-resolution imaging of focal adhesion sites and the material topography using field emission scanning electron microscopy. Furthermore, through the use of BrdU pulse labelling and immunogold detection, S-phase cells can be selected from a near-synchronised population of cells to remove artefacts due to cell cycle phase. This is a key factor in adhesion quantification as there is natural variation in focal adhesion density as cells progress through the cell cycle, which can skew the quantitative analysis of focal adhesion formation on fabricated biomaterials. PMID: 21042965 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Production of tissue-engineered skin and oral mucosa for clinical and experimental use. Methods Mol Biol. 2011;695:129-53 Authors: MacNeil S, Shepherd J, Smith L Since the early 1990s, our understanding of how epithelial and stromal cells interact in 3D tissue-engineered constructs has led to tissue-engineered skin and oral mucosa models, which are beginning to deliver benefit in the clinic (usually in small-scale reconstructive surgery procedures) but have a great deal to offer for in vitro investigations. These 3D tissue-engineered models can be used for a wide variety of purposes such as dermato- and mucotoxicity, wound healing, examination of pigmentation and melanoma biology, and in particular, a recent development from this laboratory, as a model of bacterially infected skin. Models can also be used to investigate specific skin disease processes. In this chapter, we describe the basic methodology for producing 3D tissue-engineered skin and oral mucosa based on de-epidermised acellular human dermis, and we give examples of how these models can be used for a variety of applications. PMID: 21042970 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Encapsulation of human articular chondrocytes into 3D hydrogel: phenotype and genotype characterization. Methods Mol Biol. 2011;695:167-81 Authors: Pereira RC, Gentili C, Cancedda R, Azevedo HS, Reis RL This chapter is intended to provide a summary of the current materials used in cell encapsulation technology as well as methods for evaluating the performance of cells encapsulated in a polymeric matrix. In particular, it describes the experimental procedure to prepare a hydrogel matrix based on natural polymers for encapsulating and culturing human articular chondrocytes with the interest in cartilage regeneration. Protocols to evaluate the viability, proliferation, differentiation, and matrix production of embedded cells are also described and include standard protocols such as the MTT and [3H] Thymidine assays, reverse transcription polymerase chain reaction (RT-PCR) technique, histology, and immunohistochemistry analysis. The assessment of cell distribution within the 3D hydrogel construct is also described using APoTome analysis. PMID: 21042972 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Influence of culture parameters on ear mesenchymal stem cells expanded on microcarriers. J Biotechnol. 2010 Oct 1;150(1):149-60 Authors: Sart S, Schneider YJ, Agathos SN Mesenchymal stem cells (MSCs) have an accrued potential as a tool for cell-based therapies, thanks largely to their trophic properties. The significant amounts of cells needed for this goal should be attainable through optimized bioreactor expansion of MSCs. However, because of the specific properties of these cell populations, there is a need to investigate novel cell culture strategies adapted from established bioreactor cultivation practices. Among these, stirred culture on microcarriers appears as an appropriate approach for the expansion of MSCs but its optimization requires the identification of key limiting parameters to achieve a further increase in growth span. In this work, among the physico-chemical and physiological parameters affecting the expansion of ear-derived MSCs (E-MSCs) on porous microcarriers, supply of growth factors was important in controlling their growth span. The apparent growth rate of E-MSCs was found to be correlated with the percentage of cells in the S phase of the cell cycle. Moreover, this percentage was directly linked with the fraction of growth factor/receptor complexes. Thus, controlling the percentage of E-MSCs in S phase with suitable growth factor feeds led to an increase of their growth span. Finally, in response to these adapted feeds the cells maintained the key properties defining their MSC phenotype in terms of expression of markers and in vitro differentiation potential. PMID: 20708046 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Development and Evaluation of a Perfusion Decellularization Porcine Heart Model. Circ J. 2011 Feb 2; Authors: Weymann A, Loganathan S, Takahashi H, Schies C, Claus B, Hirschberg K, Soós P, Korkmaz S, Schmack B, Karck M, Szabó G Background: Reports about the generation of 3-dimensional neoscaffolds for myocardial tissue engineering are limited. The architecture provided by perfusion decellularization of whole hearts would support the production of human-sized 3-dimensional living tissues from an acellular matrix. The aim of this study was to evaluate the potential of a perfusion decellularization model for whole heart tissue engineering. Methods and Results: Hearts were obtained from 12 German Landrace pigs from a selected abattoir. After preparation, the hearts were mounted and perfused on a modified Langendorff decellularization model specifically constructed for this reason. Decellularization was achieved by an ionic detergent-based perfusion protocol. The quality of the decellularization process was quantified by histology and fluorescence microscopy. Data regarding the presence of residual DNA within the decellularized hearts was measured with spectrophotometric quantification and compared to controls. After histological examination, all hearts lacked intracellular components but retained various types of collagen, proteoglycan and elastin. Quantitative DNA analysis demonstrated a significant reduction of DNA in decellularized hearts compared to controls (84.32±3.99ng DNA/mg tissue vs. 470.13±18.77ng DNA/mg tissue (P<0.05)). Conclusions: The modified Langendorff perfusion decellularization model described here is applicable for whole porcine hearts by removing cellular content and DNA. The resulting 3-dimensional matrix provides an interesting tool for further studies in the field of whole heart tissue engineering. PMID: 21301134 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mesenchymal stem cells enhance the engraftment and myelinating ability of allogeneic oligodendrocyte progenitors in dysmyelinated mice. Stem Cells Dev. 2011 Feb 7; Authors: Cristofanilli M, Harris VK, Zigelbaum A, Goossens AM, Lu A, Rosenthal H, Sadiq SA Multiple sclerosis (MS) is an autoimmune disease characterized by demyelination and axonal loss throughout the central nervous system. No regenerative treatment exists for patients who fail to respond to conventional immunosuppressive and immunomodulating drugs. In this scenario, stem cell therapy poses as a rational approach for neurological regeneration. Transplantation of embryonic-derived oligodendroglial progenitors (OPCs) has been shown to promote remyelination and ameliorate animal models of neurodegenerative diseases. However, its therapeutic application is limited due to potential transplant rejection. In MS, an added concern is that transplant rejection would be most pronounced at sites of previous lesions, exacerbating a hyperactive immune response which could prevent remyelination and precipitate additional demyelination. Routine systemic immunosuppression may not be sufficient to prevent transplant rejection-associated immune reactions in the cerebral microenvironment. Mesenchymal stem cells (MSCs), due to their homing properties and inherent immunosuppressive nature, are a promising tool for clinical application targeted toward immunosuppression at sites of injury. In this study, we used a co-transplantation strategy to investigate the effect of syngeneic MSCs on the survival and remyelination abilities of allogeneic OPCs in adult non-immunosuppressed shiverer mice. At all time points examined, cotransplantation with MSCs increased OPC engraftment, migration, and maturation in myelinating oligodendrocytes, which produced widespread myelination in the host corpus callosum. In addition, MSCs reduced microglia activation and astrocytosis in the brain of transplanted animals as well as T-cell proliferation in vitro. These data suggest that combining the immunomodulatory and trophic properties of MSCs with the myelinating ability of OPCs might be a suitable strategy for promoting neurological regeneration in demyelinating diseases. PMID: 21299379 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Vascular bioprinting. Am J Cardiol. 2011 Jan;107(1):141-2 Authors: da Graca B, Filardo G PMID: 21146701 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | The effect of two and three dimensional cell culture on the chondrogenic potential of human adipose-derived mesenchymal stem cells after subcutaneous transplantation with an injectable hydrogel. Cell Transplant. 2011 Feb 3; Authors: Merceron C, Portron S, Masson M, Lesoeur J, Fellah BH, Gauthier O, Geffroy O, Weiss P, Guicheux J, Vinatier C Articular cartilage is an avascular tissue composed of chondrocytes, a unique cell type responsible for abundant matrix synthesis and maintenance. When damaged, it never heals spontaneously under physiological circumstances. Therefore, the delivery of mesenchymal stem cells using hydrogel has been considered for cartilage repair. This study aims at investigating the influence of in vitro chondrogenic differentiation of human adipose tissue-derived stem cells (hATSC) on in vivo cartilage formation when associated with a cellulose-based self-setting hydrogel (Si-HPMC). hATSC were characterized for their proliferation, surface marker expression and multipotency. The in vitro chondrogenic potential of hATSC cultured within Si-HPMC in control or chondrogenic medium was evaluated by measuring COL2A1 and ACAN expression by real time PCR. Alcian blue and type II collagen staining were also performed. To determine whether in vitro chondrogenically-differentiated hATSC may give rise to cartilage in vivo, cells differentiated as a monolayer or in pellets were finally associated with Si-HPMC and implanted subcutaneously into nude mice. Cartilage formation was assessed histologically by alcian blue and type II collagen staining. Our data demonstrate that hATSC exhibited proliferation and self-renewal. hATSC also expressed typical stem cell surface markers and were able to differentiate towards the adipo- osteo- and chondrogenic lineages. Real time-PCR and histological analysis indicated that Si-HPMC enabled chondrogenic differentiation of hATSC in inductive medium, as demonstrated by increased expression of chondrogenic markers. In addition, histological analysis of implants showed that chondrogenically-differentiated hATSC (monolayers or pellets), have the ability to form cartilaginous tissue, as indicated by the presence of sulphated-glycosaminoglycans and type II collagen. This study therefore suggests that an in vitro induction of hATSC in 2D was sufficient to obtain cartilaginous tissue formation in vivo. Si-HPMC associated with autologous hATSC could thus be a significant tool for regenerative medicine in the context of cartilage damage. PMID: 21294960 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stromal-Epithelial Metabolic Coupling in Cancer: Integrating Autophagy and Metabolism in the Tumor Microenvironment. Int J Biochem Cell Biol. 2011 Feb 4; Authors: Martinez-Outschoorn UE, Pavlides S, Howell A, Pestell RG, Tanowitz HB, Sotgia F, Lisanti MP Cancer cells don't exist as pure homogeneous populations in vivo. Instead they are embedded in "cancer cell nests" that are surrounded by stromal cells, especially cancer associated fibroblasts. Thus, it is not unreasonable to suspect that stromal fibroblasts could influence the metabolism of adjacent cancer cells, and visa versa. In accordance with this idea, we have recently proposed that the Warburg effect in cancer cells may be due to culturing cancer cells by themselves, out of their normal stromal context or tumor microenvironment. In fact, when cancer cells are co-cultured with fibroblasts, then cancer cells increase their mitochondrial mass, while fibroblasts lose their mitochondria. An in depth analysis of this phenomenon reveals that aggressive cancer cells are "parasites" that use oxidative stress as a "weapon" to extract nutrients from surrounding stromal cells. Oxidative stress in fibroblasts induces the autophagic destruction of mitochondria, by mitophagy. Then, stromal cells are forced to undergo aerobic glycolysis, and produce energy-rich nutrients (such as lactate and ketones) to "feed" cancer cells. This mechanism would allow cancer cells to seed anywhere, without blood vessels as a food source, as they could simply induce oxidative stress wherever they go, explaining how cancer cells survive during metastasis. We suggest that stromal catabolism, via autophagy and mitophagy, fuels the anabolic growth of tumor cells, promoting tumor progression and metastasis. We have previously termed this new paradigm "The Autophagic Tumor Stroma Model of Cancer Metabolism", or the "Reverse Warburg Effect". We also discuss how glutamine addiction (glutaminolysis) in cancer cells fits well with this new model, by promoting oxidative mitochondrial metabolism in aggressive cancer cells. PMID: 21300172 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Evidence of specific characteristics and osteogenic potentiality in bone cells from Tibia. J Cell Physiol. 2011 Feb 1; Authors: Manferdini C, Gabusi E, Grassi F, Piacentini A, Cattini L, Zini N, Filardo G, Facchini A, Lisignoli G Human bone cells used for in vitro studies are mainly derived from bone marrow (BM) or trabecular bone (TB). There are no specific markers or procedures for isolation and growth of these cells. To validate the potentiality of these cells, we isolated human mesenchymal stromal cells (MSCs) and osteoblasts (OBs) from the tibial plateau of the same subject, grown in two different media (α-MEM and DMEM/F12) and analyzed for cell growth, proliferation, phenotype and osteogenic potential. We found that OBs grew well in both media tested, but MSCs were able to grow only in α-MEM medium. OBs in DMEM/F12 showed reduced proliferation capability and expressed a low level of alkaline phosphatase (AP), RUNX-2, osteocalcin (OC), bone sialoprotein (BSP), collagen type I (Col.I) compared with OBs in α-MEM but high level of collagen type XV (Col.XV). Compared with MSCs in α-MEM, OBs have an increased ability to proliferate and express more OC and BSP at molecular level but less AP, RUNX-2 and Col.I than MSCs. Time-course experiments to analyse the osteogenic potential of these cells showed that OBs were more efficient than MSCs. However, these cells obtained from tibial plateau showed a different trend of AP, OC and Col.I osteogenic markers compared to control MSCs from the iliac crest. This study shows that bone-adherent OBs grown in α-MEM medium are more efficient for osteogenic differentiation than BM MSCs and contribute to defining their phenotypic and functional characteristics, so providing a rationale for their use in bone tissue engineering or therapeutic purposes. © 2011 Wiley-Liss, Inc. PMID: 21302278 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human salivary gland acinar cells spontaneously form three-dimensional structures and change the protein expression patterns. J Cell Physiol. 2011 Feb 2; Authors: Chan YH, Huang TW, Young TH, Lou PJ Applying tissue engineering principles to design an auto-secretory device is a potential solution for patients suffering loss of salivary gland function. However, the largest challenge in implementing this solution is the primary culture of human salivary gland cells, because the cells are highly differentiated and difficult to expand in vitro. This situation leads to the lack of reports on the in vitro cell biology and physiology of human salivary gland cells. This study used a low-calcium culture system to selectively cultivate human parotid gland acinar (PGAC) cells from tissues with high purity in cell composition. This condition enables PGAC cells to continuously proliferate and retain the phenotypes of epithelial acinar cells to express secreting products (α-amylase) and function-related proteins (aquaporin-3, aquaporins-5, and ZO-1). Notably, when the cells reached confluence, 3-dimensional cell aggregates were observed in crowded regions. These self-formed cell spheres were termed post-confluence structures (PCSs). Unexpectedly, despite being cultured in the same media, cells in PCSs exhibited higher expression levels and different expression patterns of function-related proteins compared to the 2-dimensional cells. Translocation of aquoporin-3 from cytosolic to alongside the cell boundaries, and of ZO-1 molecules to the boundary of the PCSs were also observed. These observations suggest that when PGAC cells cultured on the 2-dimensional substrate would form PCSs without the help of 3-dimensional scaffolds and retain certain differentiation and polarity. This phenomenon implies that it is possible to introduce 2-dimensional substrates instead of 3-dimensional scaffolds into artificial salivary gland tissue engineering. J. Cell. Physiol. © 2011 Wiley Periodicals, Inc. PMID: 21302307 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tracking nanoparticles in three-dimensional tissue-engineered models using confocal laser scanning microscopy. Methods Mol Biol. 2011;695:41-51 Authors: Hearnden V, MacNeil S, Battaglia G Here we describe a method for imaging the position of nanoparticles within a 3D tissue-engineered model using confocal laser scanning microscopy (CLSM). The ability to track diffusion of nanoparticles in vitro is an important part of trans-dermal and trans-mucosal drug delivery development as well as for intra-epithelial drug delivery. Using 3D tissue-engineered models enables us to image diffusion in vitro in a physiologically relevant way; not possible in two-dimensional monolayer cultures (MacNeil, Nature 445:874-880, 2007; Hearnden et al., Pharmaceutical Res. 26(7):1718-1728, 2009). CLSM enables imaging of viable in vitro models in three dimensions with good spatial and axial resolution (Georgakoudi et al., Tissue Eng 14:1-20, 2008; Schenke-Layland et al., Adv. Drug Del. Rev. 58:878-896, 2006). Here we show that fluorescently labelled nanoparticles can be visualised, quantified, and their position within the cell can be determined using CLSM. PMID: 21042964 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Autologous implantation of bilayered tissue-engineered respiratory epithelium for tracheal mucosal regenesis in a sheep model. Cells Tissues Organs. 2010;192(5):292-302 Authors: Mohd Heikal MY, Aminuddin BS, Jeevanan J, Chen HC, Sharifah SH, Ruszymah BH The objective of this study was to regenerate the tracheal epithelium using autologous nasal respiratory epithelial cells in a sheep model. Respiratory epithelium and fibroblast cells were harvested from nasal turbinates and cultured for 1 week. After confluence, respiratory epithelium and fibroblast cells were suspended in autologous fibrin polymerized separately to form a tissue-engineered respiratory epithelial construct (TEREC). A 3 × 2 cm² tracheal mucosal defect was created, and implanted with TEREC and titanium mesh as a temporary scaffold. The control groups were divided into 2 groups: polymerized autologous fibrin devoid of cells (group 1), and no construct implanted (group 2). All sheep were euthanized at 4 weeks of implantation. Gross observation of the trachea showed minimal luminal stenosis formation in the experimental group compared to the control groups. Macroscopic evaluation revealed significant mucosal fibrosis in control group 1 (71.8%) as compared to the experimental group (7%). Hematoxylin and eosin staining revealed the presence of minimal overgrowth of fibrous connective tissue covered by respiratory epithelium. A positive red fluorescence staining of PKH26 on engineered tissue 4 weeks after implantation confirmed the presence of cultured nasal respiratory epithelial cells intercalated with native tracheal epithelial cells. Scanning electron microscopy showed the presence of short microvilli representing immature cilia on the surface of the epithelium. Our study showed that TEREC was a good replacement for a tracheal mucosal defect and was able to promote natural regenesis of the tracheal epithelium with minimal fibrosis. This study highlighted a new technique in the treatment of tracheal stenosis. PMID: 20616535 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | |  | |  |
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