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| Critical role of tissue mast cells in controlling long-term glucose sensor function in vivo.
March 17, 2010 at 6:39 AM
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| | Critical role of tissue mast cells in controlling long-term glucose sensor function in vivo. Biomaterials. 2010 Mar 10; Authors: Klueh U, Kaur M, Qiao Y, Kreutzer DL Little is known about the specific cells, mediators and mechanisms involved in the loss of glucose sensor function (GSF) in vivo. Since mast cells (MC) are known to be key effector cells in inflammation and wound healing, we hypothesized that MC and their products are major contributors to the skin inflammation and wound healing that controls GSF at sites of sensor implantation. To test this hypothesis we utilized a murine model of continuous glucose monitoring (CGM) in vivo in both normal C57BL/6 mice (mast cell sufficient), as well as mast cell deficient B6.Cg-Kit(W-sh)/HNihrJaeBsmJ (Sash) mice over a 28 day CGM period. As expected, both strains of mice displayed excellent CGM for the first 7 days post sensor implantation (PSI). CGM in the mast cell sufficient C57BL/6 mice was erratic over the remaining 21 days PSI. CGM in the mast cell deficient Sash mice displayed excellent sensor function for the entire 28 day of CGM. Histopathologic evaluation of implantatio! n sites demonstrated that tissue reactions in Sash mice were dramatically less compared to the reactions in normal C57BL/6 mice. Additionally, mast cells were also seen to be consistently associated with the margins of sensor tissue reactions in normal C57BL/6 mice. Finally, direct injection of bone marrow derived mast cells at sites of sensor implantation induced an acute and dramatic loss of sensor function in both C57BL/6 and Sash mice. These results demonstrate the key role of mast cells in controlling glucose sensor function in vivo. PMID: 20226521 [PubMed - as supplied by publisher] | | |
| Plasma-induced polymerization as a tool for surface functionalization of polymer scaffolds for bone tissue engineering: an in vitro study.
March 17, 2010 at 6:39 AM
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| | Plasma-induced polymerization as a tool for surface functionalization of polymer scaffolds for bone tissue engineering: an in vitro study. Acta Biomater. 2010 Mar 9; Authors: López-Pérez PM, da Silva RM, A Sousa R, Pashkuleva I, Reis RL A commonly applied strategy in tissue engineering (TE) field is the use of temporary three dimensional scaffolds for supporting and guiding tissue formation in various in vitro strategies and in vivo regeneration approaches. The interactions of these scaffolds with the highly sensitive bioentities such as living cells and tissues primary occur through the material surface. Hence, surface chemistry and topological features have the principal role in coordinating biological events at molecular, cellular and tissue levels on time scales ranging from seconds to weeks. However, tailoring the surface properties of scaffolds with complex shape and architecture remains a challenge in the materials science. Commonly applied wet chemical treatments often involve the use of toxic solvents whose oddments in the construct could be fatal in the subsequent application. Aiming to shorten the culture time in vitro (i.e. prior the implantation of the construct), in this work we pro! pose a modification of previously described bone TE scaffolds made from a blend of starch with polycaprolactone (SPCL). The modification method involves surface grafting of sulfonic or phosphonic groups via plasma-induced polymerization of vinyl sulfonic and vinyl phosphonic acid, respectively. We demonstrate herein that the presence of these anionic functional groups can modulate cell adhesion mediated through the adsorbed proteins (from the culture medium). At the studied conditions, both vitronectin adsorption and osteoblasts proliferation and viability increase in the following order SPCL<< sulfonic grafted SPCL< phosphonic grafted SPCL. The results revealed that plasma induced polymerization is an excellent alternative route, when compared to the commonly used wet chemical treatments, for the surface functionalization of biodevices with complex shape and porosity. PMID: 20226283 [PubMed - as supplied by publisher] | | |
| Bioengineering of the silica-polymerizing enzyme silicatein-alpha for a targeted application to hydroxyapatite.
March 17, 2010 at 6:39 AM
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| | Bioengineering of the silica-polymerizing enzyme silicatein-alpha for a targeted application to hydroxyapatite. Acta Biomater. 2010 Mar 9; Authors: Natalio F, Link T, Müller WE, Schröder HC, Cui FZ, Wang X, Wiens M Since its discovery, numerous biotechnological approaches aim to explore the silica-polymerizing catalytic activity of the enzyme silicatein. In vivo, silicatein catalyzes polymerization of amorphous silica nanospheres from soluble precursors. In vitro, it directs the formation of nanostructured biosilica. This is of interest for various applications that strive to benefit from both the advantages of the biological system (i.e., silica synthesis under physiological conditions) and the cell mineralization-stimulating effect of biosilica. However, so far immobilization of silicatein was hampered by a complex multistep procedure. In addition, the chemical surface modifications involved not only restrict the choice of carrier materials but also render application of silicatein to hydroxyapatite (HA) of mineralized tissue impossible. Here we describe bioengineering of silicatein, adapted for application in the fields of bone regeneration, tissue engineering, and dental! care. Inspired by Glu-rich sequences of mammalian proteins that confer binding affinity to HA, a novel protein-tag was developed, the Glu-tag. Following expression of Glu-tagged silicatein the HA-binding capacity of the enzyme is demonstrated in combination with synthetic and dental HA. Furthermore, immobilized Glu-tagged silicatein catalyzes synthesis of biosilica coatings on both synthetic HA nanofibrils and dental HA. Hence, Glu-tagged silicatein reveals a considerable biomedical potential with regenerative and prophylactic implementations. PMID: 20226280 [PubMed - as supplied by publisher] | | |
| Cortical plasticity induced by inhibitory neuron transplantation.
March 17, 2010 at 6:39 AM
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| | Cortical plasticity induced by inhibitory neuron transplantation. Science. 2010 Feb 26;327(5969):1145-8 Authors: Southwell DG, Froemke RC, Alvarez-Buylla A, Stryker MP, Gandhi SP Critical periods are times of pronounced brain plasticity. During a critical period in the postnatal development of the visual cortex, the occlusion of one eye triggers a rapid reorganization of neuronal responses, a process known as ocular dominance plasticity. We have shown that the transplantation of inhibitory neurons induces ocular dominance plasticity after the critical period. Transplanted inhibitory neurons receive excitatory synapses, make inhibitory synapses onto host cortical neurons, and promote plasticity when they reach a cellular age equivalent to that of endogenous inhibitory neurons during the normal critical period. These findings suggest that ocular dominance plasticity is regulated by the execution of a maturational program intrinsic to inhibitory neurons. By inducing plasticity, inhibitory neuron transplantation may facilitate brain repair. PMID: 20185728 [PubMed - indexed for MEDLINE] | | |
| Island osteoperiosteal flap for alveolar bone reconstruction.
March 17, 2010 at 6:39 AM
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| | Island osteoperiosteal flap for alveolar bone reconstruction. J Oral Maxillofac Surg. 2010 Mar;68(3):539-46 Authors: Jensen OT, Mogyoros R, Owen Z, Cottam JR, Alterman M, Casap N The island osteoperiosteal flap (I-flap) is introduced as a modified alveolar split bone grafting technique used to gain width and modify the facial or buccal bone plate position. Three case examples are shown as well as animal histology indicating the possible development of this new surgical procedure as an adjunct for alveolar augmentation and implant therapy. PMID: 20171473 [PubMed - indexed for MEDLINE] | | |
| Sprouty1 regulates reversible quiescence of a self-renewing adult muscle stem cell pool during regeneration.
March 17, 2010 at 6:39 AM
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| | Sprouty1 regulates reversible quiescence of a self-renewing adult muscle stem cell pool during regeneration. Cell Stem Cell. 2010 Feb 5;6(2):117-29 Authors: Shea KL, Xiang W, LaPorta VS, Licht JD, Keller C, Basson MA, Brack AS Satellite cells are skeletal muscle stem cells capable of self-renewal and differentiation after transplantation, but whether they contribute to endogenous muscle fiber repair has been unclear. The transcription factor Pax7 marks satellite cells and is critical for establishing the adult satellite cell pool. By using a lineage tracing approach, we show that after injury, quiescent adult Pax7(+) cells enter the cell cycle; a subpopulation returns to quiescence to replenish the satellite cell compartment, while others contribute to muscle fiber formation. We demonstrate that Sprouty1 (Spry1), a receptor tyrosine kinase signaling inhibitor, is expressed in quiescent Pax7(+) satellite cells in uninjured muscle, downregulated in proliferating myogenic cells after injury, and reinduced as Pax7(+) cells re-enter quiescence. We show that Spry1 is required for the return to quiescence and homeostasis of the satellite cell pool during repair. Our results therefore define a ! role for Spry1 in adult muscle stem cell biology and tissue repair. PMID: 20144785 [PubMed - indexed for MEDLINE] | | |
| Development and validation of a multiplex bead assay for measuring growth mediators in wound fluid.
March 17, 2010 at 6:39 AM
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| | Development and validation of a multiplex bead assay for measuring growth mediators in wound fluid. Analyst. 2010 Jan;135(1):182-8 Authors: Rakmanee T, Olsen I, Griffiths GS, Donos N Large amounts of biological samples are usually required to measure multiple components by the enzyme-linked immunosorbant assay. However, the amounts of many tissue extracts and fluids, including gingival crevicular fluid (GCF), are generally extremely small. The aim of this study was, therefore, to develop and validate a novel multiplex bead assay (MBA) to simultaneously measure a profile of healing-related mediators in the GCF of treated periodontal wounds. An MBA was developed and validated by assessment of assay selectivity, recovery, precision and sensitivity, using eight recombinant human growth mediators as assay standards. GCF samples were collected on paper strips from healing wound (test) and healthy unaffected (control) sites of 15 patients with periodontitis, seven days post-periodontal surgery. Each GCF sample was eluted and the levels of the mediators measured using the MBA and antibody pairs specific for angiopoietin-1, vascular endothelial growth-! factor, bone morphogenetic protein-2, osteoprotegerin, tissue inhibitor of metalloprotease-1 (TIMP-1), basic fibroblast growth-factor, keratinocyte growth-factor, and platelet derived growth-factor. Less than 1.8% of cross-reactivity was observed between antibodies and the eight different analytes, for which the recovery was more than 85%. Mean intra- and inter-assay precision were within the acceptance criteria of 20% and 25%, respectively. Detection of all mediators was highly sensitive (<or=70 ng/L) except for TIMP-1 (215 ng/L). Angiogenic factors were the most highly secreted in the GCF seven days post-surgery. This new MBA can simultaneously measure small amounts of eight different growth mediators in the GCF of healing periodontal wounds. It might also be a valuable tool for evaluating the components of wound fluids as a prognostic indicator of the success of therapeutic intervention. PMID: 20024200 [PubMed - indexed for MEDLINE] | | |
| An overview on stem cell research: a report on the 7th Annual Meeting of the International Society for Stem Cell Research.
March 17, 2010 at 6:39 AM
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| | An overview on stem cell research: a report on the 7th Annual Meeting of the International Society for Stem Cell Research. Drug News Perspect. 2009 Oct;22(8):504-8 Authors: Romano G The focus of the seventh annual meeting of the International Society for Stem Cell Research was placed on several topics, such as cancer stem cells, stem cell transplantation, tissue regeneration, biology of embryonic and adult stem cells of various species and production of induced pluripotent stem cells via reprogramming of mammalian somatic cells. This report provides an overview of stem cell research, based on the proceedings of the meeting. PMID: 20016860 [PubMed - indexed for MEDLINE] | | |
| Construction of modular novel bioartificial liver support system.
March 17, 2010 at 6:39 AM
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| | Construction of modular novel bioartificial liver support system. Conf Proc IEEE Eng Med Biol Soc. 2009;2009:3095-8 Authors: Liu J, Song T, Jiang W, Zhang Y, Lv G, Zhao L, Zhang G, Li L A modular novel bioartificial liver support system was designed and constructed in order to simplify tedious operation of artificial liver treatment and to improve the applicability in the system. The design ideas, structure composition, system function, and etc, were described in detail. In this system, the variety of the therapy modes could be conveniently connected by the interface of modular structure. Industrial control computer was used as the main control platform, and physical of control parameters such as pressure, pump speed, dissolved oxygen, temperature, and etc, were transmitted into computer, then according to the instruction, process of the treatment was accomplished by the executing units implemented by main control system. Touch screen of human-computer interface was adopted, which made the system better operational and more comfortable. The system has passed the spot function test, and all indexes can meet requirements for the clinical treatment ! requested. It has the character such as modular design, systematic distribution, building-block structure, and etc, which supports a great novel operation platform for artificial therapy. PMID: 19963564 [PubMed - indexed for MEDLINE] | | |
| [Efficient production of transfected human keratinocytes under serum-free and feeder layer-free conditions]
March 17, 2010 at 6:39 AM
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| | [Efficient production of transfected human keratinocytes under serum-free and feeder layer-free conditions] Handchir Mikrochir Plast Chir. 2009 Dec;41(6):333-40 Authors: Radtke C, Reimers K, Allmeling C, Vogt PM PURPOSE/BACKGROUND: Keratinocyte transplantation after burn injury and in chronic wound treatment is a potentially useful method in clinical practice. As transfer of keratinocytes is easily monitored and gene expression is controllable by topical administration of inductors, keratinocyte cultures are an especially interesting medium for gene therapeutic approaches far above of wound healing applications. A major obstacle is the standardization of keratinocyte preparation and maintenance of pure proliferative cultures for clinical application. The best outcomes in previous protocols were obtained using fibroblasts as a feeder layer, a requirement for long-term expanded cultures. Cell expansion and a high purity of keratinocytes are prerequisites for clinical transfer studies. Here, we describe a human keratinocytes preparation method that allows cell proliferation and expansion in culture without a feeder layer. MATERIALS AND METHODS: Human keratinocytes were prepa! red from skin biopsies and cultured on untreated plastic culture dishes using Waymouth medium the first days followed by a change to a commercially available serum-free keratinocyte medium. The cells were characterized morphologically followed by transfection. For positive selection, transfected cells were selected by the cotransfection system pMACS Kk and magnetic cell sorting. RESULTS: Transfection rates were determined by expression of GFP vector which were 35%. The usage of magnetic cell sorting resulted in positive selection of transfected cells. Positive cells were able to adhere and proliferate after the sorting procedure. High viability and expansion of plastic adherent keratinocytes was achieved allowing up to 5 passages without signs of senescence and the doubling times were 3-5 days. The cells displayed typical keratinocyte morphology and immunostaining confirmed high keratinocyte purity. The number of contaminating fibroblasts was low. CONCLUSION: Here, we descr! ibe an efficient and inexpensive method for a standardized hum! an kerat inocyte isolation without the need of a fibroblast feeder layer. This protocol may facilitate the clinical application of cell based therapies in burn injuries or chronic wounds using keratinocytes. PMID: 19859870 [PubMed - indexed for MEDLINE] | | |
| [Development of an engraftable skin equivalent based on matriderm with human keratinocytes and fibroblasts]
March 17, 2010 at 6:39 AM
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| | [Development of an engraftable skin equivalent based on matriderm with human keratinocytes and fibroblasts] Handchir Mikrochir Plast Chir. 2009 Dec;41(6):327-32 Authors: Golinski PA, Zöller N, Kippenberger S, Menke H, Bereiter-Hahn J, Bernd A A cell-based wound coverage with keratinocytes and fibroblasts on the basis of a commercially available dermal substitute (Matriderm ((R)), Kollagen/Elastin matrix) was generated, in order to treat wide burn wounds. First the expansion of keratinocytes was optimised and the culturing time was minimised. Raw material was 1-2 cm (2) split skin. Dermis and epidermis were separated by enzymatic treatment with thermolysin. After treatment of both compartments with trypsin and collagenase I, keratinocytes and fibroblasts were isolated and expanded in collagen I coated dishes. After 10 days fibroblasts were seeded on Matriderm ((R)). After cultivation of the fibroblasts-containing matrix for one week keratinocytes were seeded on top. After an additional week of submersed cultivation the matrix was lifted up to the air-liquid interface to initiate epidermal cell differentiation. After 16 days in the air-liquid interphase the matrix was fixed and underwent immunohistochemi! cal and electron microscopic analysis. Histological analysis showed a regularly stratification of the epidermal part. We observed collagen IV, a marker for the basement membrane, between epidermis and dermis. Desmoglein and the differentiation markers involucrine and cytokeratin 10 were found in the suprabasal layers of the epidermis. Electron microscopic analysis showed the basement membrane in the epidermal junction zone as well as cell-cell connections in the form of desmosomes. Late differentiation characteristics, like granular structures and the cornified layer, were found in the stratum granulosum and stratum corneum. Our results demonstrate that a skin equivalent can be generated by using a collagen/elastin matrix, with an expansion rate of 50-100-fold. This skin equivalent may be useful for covering deep wounds. PMID: 19711256 [PubMed - indexed for MEDLINE] | | |
| Rolling autogenetic dermis up to form a tube may be used as scaffold in tissue-engineered blood vessels.
March 17, 2010 at 6:39 AM
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| | Rolling autogenetic dermis up to form a tube may be used as scaffold in tissue-engineered blood vessels. Med Hypotheses. 2010 Jan;74(1):85-6 Authors: Diao JS, Yang S, Xia WS, Yi W, Xia W, Shu MG, Zhang X, Guo SZ Coronary and peripheral artery bypass grafting are widely being used to deal with vascular deficiencies currently, and a man-made synthetic tube or autogenous arteries or veins are needed a lot. But one's autogenous arteries or veins are limited, and artificial graft substitute isn't yet available in clinical applications because of many disadvantages. Various polymeric materials have been used as scaffolds, but without satisfying results due to intimal hyperplasia and the rate of degradation. Autogenetic dermis, which has the advantages of resistance to immunogenicity, good biocompatibility, and appropriate mechanical and physiological properties, has gained our attention to use it as a scaffold for tissue-engineered blood vessels. What is more, autogenetic dermis can be harvested easily. So we postulate that autogenetic dermis rolled up to form a tube may be an ideal scaffold for tissue-engineered blood vessels. PMID: 19682804 [PubMed - indexed for MEDLINE] | | |
| Stem-cell-activated organ following ultrasound exposure: better transplant option for organ transplantation.
March 17, 2010 at 6:39 AM
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| | Stem-cell-activated organ following ultrasound exposure: better transplant option for organ transplantation. Med Hypotheses. 2010 Jan;74(1):147-9 Authors: Wang S, Li Y, Ji YC, Lin CM, Man C, Zheng XX Although doctors try their best to protect transplants during surgery, there remain great challenges for the higher survival rate and less rejection of transplants after organ transplantation. Growing evidence indicates that the stem cells could function after injury rather than aging, implying that suitable injury may activate the stem cells of damaged organs. Furthermore, it has been revealed that stem cells can be used to induce tolerance in transplantation and the ultrasound has great biological effects on organs. Basing on these facts, we hypothesize that the stem cells within the transplants can be activated by ultrasound with high-frequency and medium-intensity. Therefore, the stem-cell-activated organs (SCAO) can be derived, and the SCAO will be better transplant option for organ transplantation. We postulate the ultrasound can change the molecular activity and/or quantity of the stem cells, the membrane permeability, the cell-cell junctions, and their sur! rounding microenvironments. As a result, the stem cells are activated, and the SCAO will acquire more regenerative capacity and less rejection. In the paper, we also discuss the process, methods and models for verifying the theory, and the consequences. We believe the theory may provide a practical method for the clinical application of the ultrasound and stem cells in organ transplantation. PMID: 19665313 [PubMed - indexed for MEDLINE] | | |
| Immunization with Bin1b decreases sperm motility with compromised fertility in rats.
March 17, 2010 at 6:39 AM
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| | Immunization with Bin1b decreases sperm motility with compromised fertility in rats. Fertil Steril. 2010 Feb;93(3):952-958.e1 Authors: Xu W, Zhang X, Chen W, Fok KL, Rowlands DK, Chui YL, Chan HC OBJECTIVE: To evaluate the contraceptive ability of a synthetic Bin1b peptide in vivo in the rat. DESIGN: Basic research. SETTING: University laboratory animal service center. ANIMAL(S): A peptide-based immunization model was developed; rats were injected with the Bin1b specific peptide. INTERVENTION(S): A synthetic peptide segment, MCRSGERKGDICSDP-conjugated with KLH (Bin1b), was used to immunize male wistar rats. Freund's complete adjuvant was used as a control. MAIN OUTCOME MEASURE(S): Anti-Bin1b levels in sera were evaluated by enzyme-linked immunosorbent assay (ELISA). Anti-Bin1b and control antisera were used to evaluate sperm function inhibition in vitro. The fertility of immunized rats was determined by mating experiment. The testis and epididymides were analyzed by histology. RESULT(S): Histological studies showed no evidence of orchitis or epididymitis in Bin1b-immunized animals. ELISA results revealed that the titers of anti-Bin1b antibodies in serum in! creased with the immunization process in immunized rats. Sperm recovered from the corpus epididymidis of the Bin1b-immunized animals exhibited a significant decrease in motility. Immunization of Bin1b also caused a reduction (25%) in fertility after the mating experiment. CONCLUSION(S): The present study has demonstrated that immunization with Bin1b peptide specifically interferes with sperm motility, resulting in a compromised fertilizing capacity of sperm. PMID: 19135192 [PubMed - indexed for MEDLINE] | | |
| Effect of encapsulation or grafting on release kinetics of recombinant human bone morphogenetic protein-2 from self-assembled poly(lactide-co-glycolide ethylene oxide fumarate) nanoparticles.
March 17, 2010 at 6:39 AM
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| | Effect of encapsulation or grafting on release kinetics of recombinant human bone morphogenetic protein-2 from self-assembled poly(lactide-co-glycolide ethylene oxide fumarate) nanoparticles. Microsc Res Tech. 2010 Mar 15; Authors: Mercado AE, Jabbari E The objective of this work was to compare the release characteristics of Recombinant human bone morphogenetic protein-2 (rhBMP-2) encapsulated in thermally self-assembled poly(lactide ethylene oxide fumarate) (PLEOF) nanoparticles (NPs) with rhBMP-2 grafted to succinimide-terminated poly(lactide fumarate) (PLAF-NHS) or poly(lactide-co-glycolide fumarate) (PLGF-NHS) NPs. The amphiphilic PLEOF NPs had average size of 110 +/- 50 nm. The hydrophobic PLAF-NHS and PLGF-NHS NPs had average size of 242 +/- 67 and 195 +/- 42 nm, respectively. PLEOF NPs had rhBMP-2 encapsulation efficiency ranging from 65 to 93%. Grafting efficiency of rhBMP-2 to PLAF-NHS and PLGF-NHS NPs was 97% +/- 1% and 98% +/- 1%, respectively. PLEOF NPs displayed a relatively high-release rate of rhBMP-2 in the first week, which rapidly dropped to zero after 10 days. PLEOF NPs grafted with 10 and 20 mug/mL rhBMP-2 released 67 and 80% of the protein in the active conformation after degradation. PLGF-NH! S NPs displayed sustained release of rhBMP-2 in the first 2 weeks but dropped to almost zero rate (<3 ng/day) after 20 days. PLAF-NHS NPs showed the longest period of sustained release of active rhBMP-2 at two rates: a high rate of 25-35 ng/mL in the first 2 weeks followed by a low rate of 5-10 ng/mL from 2 to 6 weeks. Nearly, 25 and 50% of the rhBMP-2 released from PLGF-NHS and PLAF-NHS NPs, respectively, were enzymatically active after degradation of the NPs. PLEOF NPs provided a fast release of rhBMP-2 for 1 week, whereas PLAF-NHS NPs provided a slow release for up to 6 weeks. Microsc. Res. Tech., 2010. (c) 2010 Wiley-Liss, Inc. PMID: 20232367 [PubMed - as supplied by publisher] | | |
| The ERK5 and ERK1/2 signaling pathways play opposing regulatory roles during chondrogenesis of adult human bone marrow-derived multipotent progenitor cells.
March 17, 2010 at 6:39 AM
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| | The ERK5 and ERK1/2 signaling pathways play opposing regulatory roles during chondrogenesis of adult human bone marrow-derived multipotent progenitor cells. J Cell Physiol. 2010 Mar 15; Authors: Bobick BE, Matsche AI, Chen FH, Tuan RS Adult human bone marrow-derived multipotent progenitor cells (MPCs) are able to differentiate into a variety of specialized cell types, including chondrocytes, and are considered a promising candidate cell source for use in cartilage tissue engineering. In this study, we examined the regulation of MPC chondrogenesis by mitogen-activated protein kinases in an attempt to better understand how to generate hyaline cartilage in the laboratory that more closely resembles native tissue. Specifically, we employed the high-density pellet culture model system to assess the roles of ERK5 and ERK1/2 pathway signaling in MPC chondrogenesis. Western blotting revealed that high levels of ERK5 phosphorylation correlate with low levels of MPC chondrogenesis and that as TGF-beta3-enhanced MPC chondrogenesis proceeds, phospho-ERK5 levels steadily decline. Conversely, levels of phospho-ERK1/2 paralleled the progression of MPC chondrogenesis. siRNA-mediated knockdown of ERK5 pathway c! omponents MEK5 and ERK5 resulted in increased MPC pellet mRNA transcript levels of the cartilage-characteristic marker genes SOX9, COL2A1, AGC, L-SOX5, and SOX6, as well as enhanced accumulation of SOX9 protein, collagen type II protein, and Alcian blue-stainable proteoglycan. In contrast, knockdown of ERK1/2 pathway members MEK1 and ERK1 decreased expression of all chondrogenic markers tested. Finally, overexpression of MEK5 and ERK5 also depressed MPC chondrogenesis, as indicated by diminished activity of a co-transfected collagen II promoter-luciferase reporter construct. In conclusion, our results suggest a novel role for the ERK5 pathway as an important negative regulator of adult human MPC chondrogenesis and illustrate that the ERK5 and ERK1/2 kinase cascades play opposing roles regulating MPC cartilage formation. J. Cell. Physiol. (c) 2010 Wiley-Liss, Inc. PMID: 20232315 [PubMed - as supplied by publisher] | | |
| Membrane vesicles containing matrix metalloproteinase-9 and fibroblast growth factor-2 are released into the extracellular space from mouse mesoangioblast stem cells.
March 17, 2010 at 6:39 AM
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| | Membrane vesicles containing matrix metalloproteinase-9 and fibroblast growth factor-2 are released into the extracellular space from mouse mesoangioblast stem cells. J Cell Physiol. 2010 Mar 15; Authors: Candela ME, Geraci F, Turturici G, Taverna S, Albanese I, Sconzo G Certain proteins, including fibroblast growth factor-2 (FGF-2) and matrix metalloproteinase-9 (MMP-9), have proved very effective in increasing the efficacy of mesoangioblast stem cell therapy in repairing damaged tissue. We provide the first evidence that mouse mesoangioblast stem cells release FGF-2 and MMP-9 in their active form through the production of membrane vesicles. These vesicles are produced and turned over continuously, but are stable for some time in the extracellular milieu. Mesoangioblasts shed membrane vesicles even under oxygen tensions that are lower than those typically used for cell culture and more like those of mouse tissues. These findings suggest that mesoangioblasts may themselves secrete paracrine signals and factors that make damaged tissues more amenable to cell therapy through the release of membrane vesicles. J. Cell. Physiol. (c) 2010 Wiley-Liss, Inc. PMID: 20232295 [PubMed - as supplied by publisher] | | |
| Structural and cellular features in metaphyseal and diaphyseal periosteum of osteoporotic rats.
March 17, 2010 at 6:39 AM
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| | Structural and cellular features in metaphyseal and diaphyseal periosteum of osteoporotic rats. J Mol Histol. 2010 Mar 16; Authors: Fan W, Bouwense SA, Crawford R, Xiao Y Despite the important physiological role of periosteum in the pathogenesis and treatment of osteoporosis, little is known about the structural and cellular characteristics of periosteum in osteoporosis. To study the structural and cellular differences in both diaphyseal and metaphyseal periosteum of osteoporotic rats, samples from the right femur of osteoporotic and normal female Lewis rats were collected and tissue sections were stained with hematoxylin and eosin, antibodies or staining kit against tartrate resistant acid phosphatase (TRAP), alkaline phosphatase (ALP), vascular endothelial growth factor (VEGF), von Willebrand (vWF), tyrosine hydroxylase (TH) and calcitonin gene-related peptide (CGRP). The results showed that the osteoporotic rats had much thicker and more cellular cambial layer of metaphyseal periosteum compared with other periosteal areas and normal rats (P < 0.001). The number of TRAP(+) osteoclasts in bone resorption pits, VEGF(+) cells and! the degree of vascularization were found to be greater in the cambial layer of metaphyseal periosteum of osteoporotic rats (P < 0.05), while no significant difference was detected in the number of ALP(+) cells between the two groups. Sympathetic nerve fibers identified by TH staining were predominantly located in the cambial layer of metaphyseal periosteum of osteoporotic rats. No obvious difference in the expression of CGRP between the two groups was found. In conclusion, periosteum may play an important role in the cortical bone resorption in osteoporotic rats and this pathological process may be regulated by the sympathetic nervous system. PMID: 20232237 [PubMed - as supplied by publisher] | | |
| Electro-spinning of PLGA/PCL blends for tissue engineering and their biocompatibility.
March 17, 2010 at 6:39 AM
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| | Electro-spinning of PLGA/PCL blends for tissue engineering and their biocompatibility. J Mater Sci Mater Med. 2010 Mar 16; Authors: Hiep NT, Lee BT In this study, an electro-spun co-polymer PLGA/PCL blend was fabricated using various percentages of PLGA in the blend PLGA/PCL solutions. The PLGA/PCL ratios used to fabricate the electrospun fibrous mats were reflected in the FT-IR (Fourier Transform Infrared Spectroscopy) data. Experimental results from the MTT assay showed that the biocompatibility of the electro-spun co-polymer increased at increasing percentages of PLGA. In vitro cells adhesion and proliferation of fibroblast cells on electro-spun mats were characterized by SEM morphology. In addition, we found that increasing PLGA concentrations affected the mechanical properties of electro-spun membranes and increased the biocompatibility of PLGA/PCL electro-spun fibrous mats. PMID: 20232234 [PubMed - as supplied by publisher] | | |
| Preparation and characterization of collagen microspheres for sustained release of VEGF.
March 17, 2010 at 6:39 AM
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| | Preparation and characterization of collagen microspheres for sustained release of VEGF. J Mater Sci Mater Med. 2010 Mar 16; Authors: Nagai N, Kumasaka N, Kawashima T, Kaji H, Nishizawa M, Abe T In this study, we prepared injectable collagen microspheres for the sustained delivery of recombinant human vascular endothelial growth factor (rhVEGF) for tissue engineering. Collagen solution was formed into microspheres under a water-in-oil emulsion condition, followed by crosslinking with water-soluble carbodiimide. Various sizes of collagen microspheres in the range of 1-30 mum diameters could be obtained by controlling the surfactant concentration and rotating speed of the emulsified mixture. Particle size proportionally decreased with increasing the rotating speed (1.8 mum per 100 rpm increase in the range of 300-1,200 rpm) and surfactant concentration (3.1 mum per 0.1% increase in the range of 0.1-0.5%). The collagen microspheres showed a slight positive charge of 8.86 and 3.15 mV in phosphate-buffered saline and culture medium, respectively. Release study showed the sustained release of rhVEGF for 4 weeks. Released rhVEGF was able to induce capillary form! ation of human umbilical vein endothelial cells, indicating the maintenance of rhVEGF bioactivity after release. In conclusion, the results suggest that the collagen microspheres have potential for sustained release of rhVEGF. PMID: 20232232 [PubMed - as supplied by publisher] | | |
| Rem2 GTPase maintains survival of human embryonic stem cells as well as enhancing reprogramming by regulating p53 and cyclin D1.
March 17, 2010 at 6:39 AM
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| | Rem2 GTPase maintains survival of human embryonic stem cells as well as enhancing reprogramming by regulating p53 and cyclin D1. Genes Dev. 2010 Mar 15;24(6):561-73 Authors: Edel MJ, Menchon C, Menendez S, Consiglio A, Raya A, Izpisua Belmonte JC Human pluripotent stem cells, such as embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), have the unique abilities of differentiation into any cell type of the organism (pluripotency) and indefinite self-renewal. Here, we show that the Rem2 GTPase, a suppressor of the p53 pathway, is up-regulated in hESCs and, by loss- and gain-of-function studies, that it is a major player in the maintenance of hESC self-renewal and pluripotency. We show that Rem2 mediates the fibroblastic growth factor 2 (FGF2) signaling pathway to maintain proliferation of hESCs. We demonstrate that Rem2 effects are mediated by suppressing the transcriptional activity of p53 and cyclin D(1) to maintain survival of hESCs. Importantly, Rem2 does this by preventing protein degradation during DNA damage. Given that Rem2 maintains hESCs, we also show that it is as efficient as c-Myc by enhancing reprogramming of human somatic cells into iPSCs eightfold. Rem2 does this by accele! rating the cell cycle and protecting from apoptosis via its effects on cyclin D(1) expression/localization and suppression of p53 transcription. We show that the effects of Rem2 on cyclin D(1) are independent of p53 function. These results define the cell cycle and apoptosis as a rate-limiting step during the reprogramming phenomena. Our studies highlight the possibility of reprogramming somatic cells by imposing hESC-specific cell cycle features for making safer iPSCs for cell therapy use. PMID: 20231315 [PubMed - in process] | | |
| Why we need semisolid decalcification system in bone tissue engineering? A story begins with honeycomb.
March 17, 2010 at 6:39 AM
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| | Why we need semisolid decalcification system in bone tissue engineering? A story begins with honeycomb. Med Hypotheses. 2010 Mar 13; Authors: Jiang S, Jiang QL, Zhang Y, Li L, Zhao PR, Pan YF, Chang W, Liu LJ, Pei GX The repair of large segmental bone defects remains a tough problem disturbing surgeons and researchers. Bone tissue engineering brings some new sight in this field. However, it has not been effectively applied in clinics, for the reason that the involved mechanism is not well understood. Thus, we need to know the osteogenesis process of the tissue-engineered bone including distribution, proliferation and interaction among seed cells pre-inoculated in biomaterials as well as the function of surrounding tissues. As a matter of fact, the tissue-engineered bone or the biomaterials are solid and opaque, which makes the study difficult. Here, inspired by the structure of honeycomb and amber, we hypothesize a semisolid decalcification protocol to solve this problem. PMID: 20231059 [PubMed - as supplied by publisher] | | |
| Retinoic Acid Regulates Differentiation of the Secondary Heart Field and TGFbeta-Mediated Outflow Tract Septation.
March 17, 2010 at 6:39 AM
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| | Retinoic Acid Regulates Differentiation of the Secondary Heart Field and TGFbeta-Mediated Outflow Tract Septation. Dev Cell. 2010 Mar 16;18(3):480-485 Authors: Li P, Pashmforoush M, Sucov HM In many experimental models and clinical examples, defects in the differentiation of the second heart field (SHF) and heart outflow tract septation defects are combined, although the mechanistic basis for this relationship has been unclear. We found that as the initial SHF population incorporates into the outflow tract, it is replenished from the surrounding progenitor territory. In retinoic acid (RA) receptor mutant mice, this latter process fails, and the outflow tract is shortened and misaligned as a result. As an additional consequence, the outflow tract is misspecified along its proximal-distal axis, which results in ectopic expression of TGFbeta2 and ectopic mesenchymal transformation of the endocardium. Reduction of TGFbeta2 gene dosage in the RA receptor-deficient background restores septation but does not rescue alignment defects, indicating that excess TGFbeta causes septation defects. This may be a common pathogenic pathway when second heart field and s! eptation defects are coupled. PMID: 20230754 [PubMed - as supplied by publisher] | | |
| Cellular Plasticity within the Pancreas- Lessons Learned from Development.
March 17, 2010 at 6:39 AM
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| | Cellular Plasticity within the Pancreas- Lessons Learned from Development. Dev Cell. 2010 Mar 16;18(3):342-356 Authors: Puri S, Hebrok M The pancreas has been the subject of intense research due to the debilitating diseases that result from its dysfunction. In this review, we summarize current understanding of the critical tissue interactions and intracellular regulatory events that take place during formation of the pancreas from a small cluster of cells in the foregut domain of the mouse embryo. Importantly, an understanding of principles that govern the development of this organ has equipped us with the means to manipulate both embryonic and differentiated adult cells in the context of regenerative medicine. The emerging area of lineage modulation within the adult pancreas is of particular interest, and this review summarizes recent findings that exemplify how lessons learned from development are being applied to reveal the potential of fully differentiated cells to change fate. PMID: 20230744 [PubMed - as supplied by publisher] | | |
| [Effects of UO-126 on proliferation and fbw7 expression of HeLa cells.]
March 17, 2010 at 6:39 AM
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| | [Effects of UO-126 on proliferation and fbw7 expression of HeLa cells.] Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2010 Feb;26(2):138-40 Authors: Sun D, Shen Y, Wang SH, Xiang ZW, Xie YS, Jiang X AIM: To observe the effects of UO-126 on the expression of F-box and WD repeat domain-containing protein 7(FBW7)and on the proliferation of human Cervical cancer cell lines (HeLa cells). METHODS: HeLa cells were treated with different concentrations of UO-126, MTT assay was used to observe the proliferation of HeLa cells.Immunofluorescence showed the lacation and expression of FBW7 in HeLa cells.The mRNA and protein expression of FBW7 were detected by RT-PCR and Western blot before and after mitogen-activated protein kinases (MAPK)signal was blocked by UO-126 a MAPK inhibitor. RESULTS: MTT results showed that the concentration range of MAPK signaling pathway inhibitor UO-126 inhibited the proliferation of HeLa cells in a concentration-and time-dependent manner(P<0.05). Immunofluorescence showed that the expression of positive FBW7 had increased after HeLa cells were treated with UO-126. RT-PCR and Western blot exhibited that the FBW7 mRNA and protein expression! had significantly increased before and after HeLa cells were treated with UO-126(P<0.05). CONCLUSION: UO-126 could inhibit HeLa cells proliferation, FBW7 lied downstream of MAPK signaling pathway. PMID: 20230673 [PubMed - in process] | | |
| Spontaneous reversal of the developmental aging of normal human cells following transcriptional reprogramming.
March 17, 2010 at 6:39 AM
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| | Spontaneous reversal of the developmental aging of normal human cells following transcriptional reprogramming. Regen Med. 2010 Mar 16; Authors: Vaziri H, Chapman K, Guigova A, Teichroeb J, Lacher M, Sternberg H, Singec I, Briggs L, Wheeler J, Sampathkumar J, Gonzalez R, Larocca D, Murai J, Snyder E, Andrews W, Funk W, West M Aim: To determine whether transcriptional reprogramming is capable of reversing the developmental aging of normal human somatic cells to an embryonic state. Materials & methods: An isogenic system was utilized to facilitate an accurate assessment of the reprogramming of telomere restriction fragment (TRF) length of aged differentiated cells to that of the human embryonic stem (hES) cell line from which they were originally derived. An hES-derived mortal clonal cell strain EN13 was reprogrammed by SOX2, OCT4 and KLF4. The six resulting induced pluripotent stem (iPS) cell lines were surveyed for telomere length, telomerase activity and telomere-related gene expression. In addition, we measured all these parameters in widely-used hES and iPS cell lines and compared the results to those obtained in the six new isogenic iPS cell lines. Results: We observed variable but relatively long TRF lengths in three widely studied hES cell lines (16.09-21.1 kb) but markedly s! horter TRF lengths (6.4-12.6 kb) in five similarly widely studied iPS cell lines. Transcriptome analysis comparing these hES and iPS cell lines showed modest variation in a small subset of genes implicated in telomere length regulation. However, iPS cell lines consistently showed reduced levels of telomerase activity compared with hES cell lines. In order to verify these results in an isogenic background, we generated six iPS cell clones from the hES-derived cell line EN13. These iPS cell clones showed initial telomere lengths comparable to the parental EN13 cells, had telomerase activity, expressed embryonic stem cell markers and had a telomere-related transcriptome similar to hES cells. Subsequent culture of five out of six lines generally showed telomere shortening to lengths similar to that observed in the widely distributed iPS lines. However, the clone EH3, with relatively high levels of telomerase activity, progressively increased TRF length over 60 days of serial cu! lture back to that of the parental hES cell line. Conclusion: ! Prematur ely aged (shortened) telomeres appears to be a common feature of iPS cells created by current pluripotency protocols. However, the spontaneous appearance of lines that express sufficient telomerase activity to extend telomere length may allow the reversal of developmental aging in human cells for use in regenerative medicine. PMID: 20230312 [PubMed - as supplied by publisher] | | |
| Curcumin Prevents Dopaminergic Neuronal Death Through Inhibition of the c-Jun N-Terminal Kinase Pathway.
March 17, 2010 at 6:39 AM
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| | Curcumin Prevents Dopaminergic Neuronal Death Through Inhibition of the c-Jun N-Terminal Kinase Pathway. Rejuvenation Res. 2010 Feb;13(1):55-64 Authors: Yu S, Zheng W, Xin N, Chi ZH, Wang NQ, Nie YX, Feng WY, Wang ZY Abstract Recent studies have shown that the c-Jun N-terminal kinase (JNK) signaling pathway is involved in dopaminergic neuronal degeneration, and direct blockade of JNK by specific inhibitors may prevent or effectively slow the progression of Parkinson disease (PD). Previous studies have revealed that the natural phenolic compound curcumin can reduce inflammation and oxidation, which makes it a potential therapeutic agent for neurodegenerative diseases. In this study, we investigated whether curcumin protects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP) or 1-methyl-4-phenylpyridnium ion- (MPP(+)) induced dopaminergic neurotoxicity in C57BL/6N mice or SH-SY5Y cells by inhibiting JNK pathways both in vivo and in vitro. Curcumin treatment significantly improved behavioral deficits, and enhanced the survival of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) in the MPTP-induced PD model mice. Most importantly, curcumin treatment sig! nificantly inhibited MPTP/MPP(+)-induced phosphorylation of JNK1/2 and c-Jun, and cleaved caspase-3. Our study suggests that the neuroprotective effect of curcumin is not related simply to its antiinflammatory and antioxidant properties, but involves other mechanisms, particularly by targeting the JNK pathways. PMID: 20230279 [PubMed - in process] | | |
| Establishment of immortalized mesenchymal stromal cells with red fluorescence protein expression for in vivo transplantation and tracing in the rat model with traumatic brain injury.
March 17, 2010 at 6:39 AM
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| | Establishment of immortalized mesenchymal stromal cells with red fluorescence protein expression for in vivo transplantation and tracing in the rat model with traumatic brain injury. Cytotherapy. 2010 Mar 15; Authors: Hung CJ, Yao CL, Cheng FC, Wu ML, Wang TH, Hwang SM Abstract Background aims. Human mesenchymal stromal cells (hMSC) play a crucial role in tissue engineering and regenerative medicine, and have important clinical potential for cell therapy. However, many hMSC studies have been restricted by limited cell numbers and difficult detection in vivo. To expand the lifespan, hMSC are usually immortalized by virus-mediated gene transfer. However, these genetically modified cells easily lose critical phenotypes and stable genotypes because of insertional mutagenesis. Methods. We used a non-viral transfection method to establish human telomerase reverse transcriptase-immortalized cord blood hMSC (hTERT-cbMSC). We also established red fluorescent protein (RFP)-expressing hTERT-cbMSC (hTERT/RFP-cbMSC) by the same non-viral transfection method, and these cells were injected into a rat model with traumatic brain injury for in vivo detection analysis. Results. The hTERT-cbMSC could grow more than 200 population doublings with a s! table doubling time and maintained differentiation capacities. hTERT/RFP-cbMSC could proliferate efficiently within 2 weeks at the injury location and could be detected easily under a fluorescent microscope. Importantly, both hTERT-cbMSC and hTERT/RFP-cbMSC showed no chromosomal abnormalities by karyotype analysis and no tumor formation in severe combined immunodeficient (SCID) mice by transplantation assay. Conclusions. We have developed immortalized cbMSC with hTERT expression and RFP expression, which will be useful tools for stem cell research and translational study. PMID: 20230225 [PubMed - as supplied by publisher] | | |
| Multidistrict human mesenchymal vascular cells: pluripotency and stemness characteristics.
March 17, 2010 at 6:39 AM
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| | Multidistrict human mesenchymal vascular cells: pluripotency and stemness characteristics. Cytotherapy. 2010 Mar 15; Authors: Pasquinelli G, Pacilli A, Alviano F, Foroni L, Ricci F, Valente S, Orrico C, Lanzoni G, Buzzi M, Luigi Tazzari P, Pagliaro P, Stella A, Paolo Bagnara G Abstract Background aims. The presence of ectopic tissues in the pathologic artery wall raises the issue of whether multipotent stem cells may reside in the vasculature itself. Recently mesenchymal stromal cells (MSC) have been isolated from different human vascular segments (VW MSC), belying the previous view that the vessel wall is a relatively quiescent tissue. Methods. Resident multipotent cells were recovered from fresh arterial segments (aortic arches, thoracic and femoral arteries) collected in a tissue-banking facility and used to establish an in situ and in vitro study of the stemness features and multipotency of these multidistrict MSC populations. Results. Notch-1(+), Stro-1(+), Sca-1(+) and Oct-4(+) cells were distributed along an arterial wall vasculogenic niche. Multidistrict VW MSC homogeneously expressed markers of stemness (Stro-1, Notch-1 and Oct-4) and MSC lineages (CD44, CD90, CD105, CD73, CD29 and CD166) whilst they were negative for hematopoi! etic and endothelial markers (CD34, CD45, CD31 and vWF). Each VW MSC population had characteristics of stem cells, i.e. a high efflux capability for Hoechst 33342 dye and the ability to form spheroids when grown in suspension and generate colonies when seeded at low density. Again, VW MSC cultured in induction media exhibited adipogenic, chondrogenic and leiomyogenic potential but less propensity to osteogenic differentiation, as documented by histochemical, immunohistochemical, molecular and electron microscopy analysis. Conclusions. Overall, these findings may enlighten the physiopathologic mechanisms of vascular wall diseases as well as having potential implications for cellular, genetic and tissue engineering approaches to treating vascular pathologies when these are unresponsive to medical and surgical therapies. PMID: 20230218 [PubMed - as supplied by publisher] | | |
| Bio-electrospraying: a potentially safe technique for delivering progenitor cells.
March 17, 2010 at 6:39 AM
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| | Bio-electrospraying: a potentially safe technique for delivering progenitor cells. Biotechnol Bioeng. 2010 Mar 12; Authors: Sahoo S, Lee WC, Goh JC, Toh SL Bio-electrospraying is fast becoming an attractive tool for in situ cell delivery into scaffolds for tissue engineering applications, with several cell types been successfully electrosprayed. Bone marrow derived mesenchymal progenitor/stem cells (BMSC), which are an important cell source for tissue engineering, have not been explored in detail and the effect of electrospraying on their "stemness" is not known. This study therefore investigates the effects of electrospraying on BMSC viability, proliferation and multilineage differentiation potential. Electrospraying a BMSC suspension at flow rate of 6 ml/hr and voltages of 7.5 - 15 kV could successfully generate a continuous, stable and linearly directed electrospray of cells. Morphological observation, trypan blue tests and alamar blue based metabolic assays revealed about 88% of these electrosprayed cells were viable, and proliferated at rates similar to native BMSCs. However, at higher voltages, electrospraying ! became unstable and reduced cell viability, possibly due to electrical or thermal damage to the cells. BMSCs electrosprayed at 7.5 kV also retained their multipotency and could be successfully differentiated into adipogenic, chondrogenic and osteogenic lineages, demonstrating similar morphology and gene expression levels as induced native BMSCs. These results indicate that bio-electrospraying could be safely used as a progenitor/stem cell delivery technique for tissue engineering and regenerative medicine applications. (c) 2010 Wiley Periodicals, Inc. PMID: 20229515 [PubMed - as supplied by publisher] | | |
| The synergistic anti-asthmatic effects of glycyrrhizin and salbutamol.
March 17, 2010 at 6:39 AM
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| | The synergistic anti-asthmatic effects of glycyrrhizin and salbutamol. Acta Pharmacol Sin. 2010 Mar 15; Authors: Yang Y, Shi Q, Liu Z, Li RJ, Pan PW, Hou YY, Lu WG, Bai G AbstractAim:To investigate the efficacy of glycyrrhizin (GL) combined with salbutamol (SA) as an anti-asthma therapy.Methods:Rat lung beta2-adrenergic receptor (beta(2)-AR) mRNA level was measured by real-time RT PCR. Intracellular cAMP accumulation was evaluated with a reporter gene assay. An in vitro acetylcholine-induced guinea pig tracheal strip contraction model was used to test the relaxing effects of GL and SA. The anti-inflammatory effects of GL and SA were tested using tumor necrosis factor-alpha-induced NF-kappaB transcriptional activation reporter assay, I-kappaB Western blotting and interleukin-8 ELISA. An in vivo guinea pig asthma model was used to prove further the synergistic effect of GL and SA.Results:GL (0.3 mumol/L) increased mRNA levels of beta(2)-AR in vivo and the accumulation of cAMP in vitro. The combination of GL and SA also resulted in significant complementary anti-inflammatory effects via inhibition of NF-kappaB activation, degradation ! of I-kappaB and production of interleukin-8. A significant synergistic effect of the combination was detected both in vitro and in vivo in a guinea pig mode.Conclusion:The results demonstrate that GL and SA have synergistic anti-asthmatic effects and offer the possibility of a therapeutic application of GL in combination with beta(2)-AR agonists in the treatment of asthma. PMID: 20228825 [PubMed - as supplied by publisher] | | |
| Three-dimensional tissue culture based on magnetic cell levitation.
March 17, 2010 at 6:39 AM
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| | Three-dimensional tissue culture based on magnetic cell levitation. Nat Nanotechnol. 2010 Mar 14; Authors: Souza GR, Molina JR, Raphael RM, Ozawa MG, Stark DJ, Levin CS, Bronk LF, Ananta JS, Mandelin J, Georgescu MM, Bankson JA, Gelovani JG, Killian TC, Arap W, Pasqualini R Cell culture is an essential tool in drug discovery, tissue engineering and stem cell research. Conventional tissue culture produces two-dimensional cell growth with gene expression, signalling and morphology that can be different from those found in vivo, and this compromises its clinical relevance. Here, we report a three-dimensional tissue culture based on magnetic levitation of cells in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles and filamentous bacteriophage. By spatially controlling the magnetic field, the geometry of the cell mass can be manipulated, and multicellular clustering of different cell types in co-culture can be achieved. Magnetically levitated human glioblastoma cells showed similar protein expression profiles to those observed in human tumour xenografts. Taken together, these results indicate that levitated three-dimensional culture with magnetized phage-based hydrogels more closely recapitulates in vivo pro! tein expression and may be more feasible for long-term multicellular studies. PMID: 20228788 [PubMed - as supplied by publisher] | | |
| Sustained VEGF Delivery Via PLGA Nanoparticles Promotes Vascular Growth.
March 17, 2010 at 6:39 AM
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| | Sustained VEGF Delivery Via PLGA Nanoparticles Promotes Vascular Growth. Am J Physiol Heart Circ Physiol. 2010 Mar 12; Authors: Golub JS, Kim YT, Duvall CL, Bellamkonda RV, Gupta D, Lin AS, Weiss D, Taylor WR, Guldberg RE Technologies to increase tissue vascularity are critically important to the fields of tissue engineering and cardiovascular medicine. Currently, limited technologies exist to encourage angiogenesis and arteriogenesis in a controlled manner. We describe here an injectable controlled release system consisting of vascular endothelial growth factor (VEGF) encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP). The majority of VEGF was released gradually over 2-4 days from the NPs as determined by an ELISA release kinetics study. An in vitro aortic ring bioassay was used to verify the bioactivity of VEGF-NP compared to empty NP and no treatment. A mouse femoral artery ischemia model was then used to measure revascularization in VEGF-NP treated limbs compared to limbs treated with naked VEGF and saline. 129/Sv mice were anesthetized with isoflurane and a region of the common femoral artery and vein was ligated and excised. Mice were then injected with V! EGF-NP, naked VEGF, or saline. After four days, 3D microcomputed tomography (microCT) angiography was employed to quantify vessel growth and morphology. Mice receiving VEGF-NP treatment showed a significant increase in total vessel volume and vessel connectivity compared to 5 mug VEGF, 2.5 mug VEGF, and saline treatment (all p<0.001). When taking the yield of the fabrication process into account, VEGF-NPs were over an order of magnitude more potent than naked VEGF in increasing blood vessel volume. Differences between VEGF-NP and all other groups were even greater when analyzing only small-sized vessels under 300 mum diameter. In conclusion, sustained VEGF delivery via PLGA nanoparticles shows promise for encouraging blood vessel growth in tissue engineering and cardiovascular medicine applications. Key words: tissue engineering, nanoparticle, angiogenesis, arteriogenesis. PMID: 20228260 [PubMed - as supplied by publisher] | | |
| Comparative Expression Profiles of mRNAs and microRNAs Among Human Mesenchymal Stem Cells Derived From Breast, Face, and Abdominal Adipose Tissues.
March 17, 2010 at 6:39 AM
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| | Comparative Expression Profiles of mRNAs and microRNAs Among Human Mesenchymal Stem Cells Derived From Breast, Face, and Abdominal Adipose Tissues. Kaohsiung J Med Sci. 2010 Mar;26(3):113-122 Authors: Wang KH, Kao AP, Singh S, Yu SL, Kao LP, Yun Tsai Z, Lin SD, Li SS We determined the expression of both mRNAs and microRNAs (miRNAs) from human mesenchymal stem cells BM19, FM30, and AM3, which is derived from breast, face, and abdominal adipose tissues, respectively. BM19, FM30, and AM3 cells exhibited considerably similar mRNA profiles, and their 1,038 abundantly common genes were involved in regulating six cell adhesion and three cytoskeleton remodeling processes among the top ten GeneGo canonical pathway maps. The 39 most abundant miRNAs in AM3 cells were expressed at very similar levels in BM19 cells. However, seven abundant miRNAs (miR-19b, miR-320, miR-186, miR-199a, miR-339, miR-99a, and miR-152) in AM3 cells were expressed at much lower levels than that in FM30 cells, and 38 genes targeted by these miRNAs were consequently upregulated more than 3-fold in FM30 cells compared with AM3 cells. Therefore, autologous abdominal adipose-derived mesenchymal stem cells are suitable for tissue engineering of breast reconstruction b! ecause of very similar expression profiles of mRNAs and miRNAs between AM3 and BM19 cells. Conversely, abdominal AM3 cells might not be suitable for facial rejuvenation, since the 38 highly expressed genes targeted by miRNAs in FM30 cells might play an important role(s) in the development of facial tissue. PMID: 20227650 [PubMed - as supplied by publisher] | | |
| The in-vivo Generation of Beta-cell-like Cells from CD34(+) cells differentiated from Human Embryonic Stem Cells.
March 17, 2010 at 6:39 AM
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| | The in-vivo Generation of Beta-cell-like Cells from CD34(+) cells differentiated from Human Embryonic Stem Cells. Exp Hematol. 2010 Mar 11; Authors: Goodrich AD, Ersek A, Varain NM, Groza D, Cenariu M, Thain DS, Almeida-Porada G, Porada CD, Zanjani ED OBJECTIVE: CD34(+) cells, present within the bone marrow, have previously been shown to possess pancreatic endocrine potential. Based on this observation, we explored the capacity of CD34(+) cells derived in culture from the differentiation of human embryonic stem cells (hESC), for their in-vivo pancreatic endocrine capacity. METHODS: Sheep were transplanted with hESC-derived CD34(+) cells, as well as non-sorted differentiated cultures. Transplantations were carried out with in-utero intraperitoneal injections prior to the development of the immune system in the fetus so that tolerance towards foreign antigens was acquired during gestation and persisted in the adult. RESULTS: All cell populations that were tested demonstrated human cellular activity and long-term presence up to 5 years. However, the in-vivo beta-cell-like activity achieved from the transplantation of the sorted CD34(+) cell population was not augmented by transplanting the entire cell population f! rom which the CD34(+) cells were isolated. Human DNA and insulin mRNA were detected in sheep pancreases. An average of 1.51 ng/mL human C-peptide was detected in serum from 8 animals transplanted with differentiated cell populations and assayed up to 55 months post-transplantation. Transplantation of as few as 23,500 cells resulted in long-term sustainable beta-cell like activity. Teratomas were absent in the transplanted animals. CONCLUSION: Our data suggest that hESC-derived CD34(+) cells have a potential for long term in-vivo endocrine cellular activity which could prove useful in regenerative medicine. Since the same cell population has previously been shown to contain hematopoietic potential, it could be used for the induction of immunological tolerance and bone marrow chimerism prior to cellular therapy for diabetes. PMID: 20227460 [PubMed - as supplied by publisher] | | |
| Ex vivo delivery of GDNF maintains motor function and prevents neuronal loss in a transgenic mouse model of Huntington's disease.
March 17, 2010 at 6:39 AM
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| | Ex vivo delivery of GDNF maintains motor function and prevents neuronal loss in a transgenic mouse model of Huntington's disease. Exp Neurol. 2010 Mar 11; Authors: Ebert AD, Barber AE, Heins BM, Svendsen CN Huntington's disease (HD) is an autosomal dominant disorder caused by expansion of polyglutamine repeats in the huntingtin gene leading to loss of striatal and cortical neurons followed by deficits in cognition and choreic movements. Growth factor delivery to the brain has shown promise in various models of neurodegenerative diseases, including HD, by reducing neuronal death and thus limiting motor impairment. Here we used mouse neural progenitor cells (mNPCs) as growth factor delivery vehicles in the N171-82Q transgenic mouse model of HD. mNPCs derived from the developing mouse striatum were isolated and infected with lentivirus expressing either glial cell line-derived neurotrophic factor (GDNF) or green fluorescent protein (GFP). Next, mNPCs(GDNF) or mNPCs(GFP) were transplanted bilaterally into the striatum of pre-symptomatic N171-82Q mice. We found that mNPCs(GDNF), but not mNPCs(GFP), maintained rotarod function and increased striatal neuron survival out to ! 3 months post-transplantation. Importantly, histological analysis showed GDNF expression through the duration of the experiment. Our data show that mNPCs(GDNF) can survive transplantation, secrete GDNF for several weeks and are able to maintain motor function in this model of HD. PMID: 20227407 [PubMed - as supplied by publisher] | | |
| On stiffness of scaffolds for bone tissue engineering-a numerical study.
March 17, 2010 at 6:39 AM
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| | On stiffness of scaffolds for bone tissue engineering-a numerical study. J Biomech. 2010 Mar 11; Authors: Sturm S, Zhou S, Mai YW, Li Q Tissue scaffolds are typically designed and fabricated to match native bone properties. However, it is unclear if this would lead to the best tissue ingrowth outcome within the scaffold as neo-tissue keeps changing the stiffness of entire construct. This paper presents a numerical method to address this issue for design optimization and assessment of tissue scaffolds. The elasticity tensors of two different types of bones are weighted by different multipliers before being used as the targets in scaffold design. A cost function regarding the difference between the effective elasticity tensor, calculated by the homogenization technique, and the target tensor, is minimized by using topology optimization procedure. It is found that different stiffnesses can lead to different remodeling results. The comparison confirms that bone remodeling is at its best when the scaffold elastic tensor matches or is slightly higher than the elastic properties of the host bone. PMID: 20227080 [PubMed - as supplied by publisher] | | |
| Abnormally up-regulated cystic fibrosis transmembrane conductance regulator expression and uterine fluid accumulation contribute to Chlamydia trachomatis-induced female infertility.
March 17, 2010 at 6:39 AM
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| | Abnormally up-regulated cystic fibrosis transmembrane conductance regulator expression and uterine fluid accumulation contribute to Chlamydia trachomatis-induced female infertility. Fertil Steril. 2010 Mar 11; Authors: He Q, Tsang LL, Ajonuma LC, Chan HC OBJECTIVE: To investigate whether abnormal expression of cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic adenosine 3':5' monophosphate (cAMP)-activated chloride channel, and uterine fluid accumulation upon Chlamydia trachomatis infection may result in implantation failure, thus contributing to C. trachomatis-induced female infertility. DESIGN: Experimental animal study. SETTING: University laboratory animal service center. ANIMAL(S): Adult female mice with regular estrous cycles. INTERVENTION(S): Intrauterine injection of C. trachomatis lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-alpha), and estrogen (E) at diestrus and preimplantation. MAIN OUTCOME MEASURE(S): The CFTR messenger RNA (mRNA) and protein levels were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively, in mouse uterus treated with C. trachomatis LPS, TNF-alpha or E. Endometrial electrolyte transport and uterine fluid! accumulation were determined by the short circuit current and uterine wet weight, respectively. Number of implanted embryos was also counted to demonstrate the effect of treatments. RESULT(S): Uterine C. trachomatis LPS infection induced up-regulation of CFTR expression with enhanced anion secretion, abnormal fluid accumulation in mouse uterus at diestrus, and reduced implantation rate. Administration of exogenous TNF-alpha to mouse uterus mimicked the C. trachomatis LPS infection-induced CFTR up-regulation, enhanced CFTR channel activity, and fluid accumulation. Abnormal uterine fluid accumulation and implantation failure were also observed when CFTR was up-regulated by E. CONCLUSION(S): The present results suggest that C. trachomatis infection-induced release of cytokines could abnormally up-regulate CFTR expression leading to abnormal uterine fluid accumulation, which may result in infertility often associated with C. trachomatis infection. PMID: 20227074 [PubMed - as supplied by publisher] | | | | 
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