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| Day 153 of the Weschler-Reya Affair: Near Silence from All Quarters
July 21, 2010 at 6:10 PM
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| California's $6 million, long-running courtship of a pair of Duke Blue Devils has apparently not been consummated.
But, like many other consummations, it is not easy to tell. Silence is the watchword on the part of those who know.
Last April, the California stem cell agency offered a $6 million signing bonus to Robert Weschler-Reya, a researcher at Duke University, to move to La Jolla's | | |
| Resident Cardiac Progenitor Cells: At the Heart of Regeneration.
July 21, 2010 at 8:27 AM
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| | Resident Cardiac Progenitor Cells: At the Heart of Regeneration. J Mol Cell Cardiol. 2010 Jul 16; Authors: Bollini S, Smart N, Riley PR Stem cell therapy has recently emerged as an innovative strategy over conventional cardiovascular treatments to restore cardiac function in patients affected by ischemic heart disease. Various stem cell populations have been tested and their potential for cardiac repair analyzed. Embryonic stem cells retain the greatest differentiation potential, but concerns persist with regard to their immunogenic and teratogenic effects. Although adult somatic stem cells are not tumourigenic and easier to use in an autologous setting, they exist in small numbers and possess reduced differentiation potential. Traditionally the heart was considered to be a post-mitotic organ; however, this dogma has recently been challenged with the identification of a reservoir of resident stem cells, defined as cardiac progenitor cells (CPCs). These endogenous progenitors may represent the best candidates for cardiovascular cell therapy, as they are tissue-specific, often pre-committed to a cardiac fate, and display a greater propensity to differentiate towards cardiovascular lineages. This review will focus on current research into the biology of CPCs and their regenerative potential. PMID: 20643135 [PubMed - as supplied by publisher] | | |
| Bio-electrospraying and aerodynamically assisted bio-jetting whole human blood: Interrogating cell surface marker integrity.
July 21, 2010 at 7:21 AM
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| | Bio-electrospraying and aerodynamically assisted bio-jetting whole human blood: Interrogating cell surface marker integrity. Biomicrofluidics. 2010;4(1):11101 Authors: Joly P, Chavda N, Eddaoudi A, Jayasinghe SN Bio-electrospraying and aerodynamically assisted bio-jetting are two direct cell handling approaches recently pioneered, which have demonstrated significant applicability to the life sciences. These two bioprotocols have undergone scientific rigor, which have seen these techniques been explored in conjunction with a wide range of immortalized, primary and stem cells, and those whole organisms. Those studies have demonstrated a cellular population of >70% viable post-treatment in comparison with controls. Although, these studies assessed cellular viability, cell surface molecules play a critical role in several cellular functions, in particular, have importance to tissue engineering and regenerative medicine. Thus, in the studies reported herein, we demonstrate post-treated viable cells retain their cell surface marker expression levels in comparison to controls, over both short and long time points. Therefore, these studies further push back the frontiers of both bio-electrosprays and aerodynamically assisted bio-jetting in their endeavor as novel strategies for tissue engineering and regenerative biologymedicine with possible targeted clinical utility. PMID: 20644660 [PubMed - in process] | | |
| Cell type of origin influences the molecular and functional properties of mouse induced pluripotent stem cells.
July 21, 2010 at 7:21 AM
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| | Cell type of origin influences the molecular and functional properties of mouse induced pluripotent stem cells. Nat Biotechnol. 2010 Jul 19; Authors: Polo JM, Liu S, Figueroa ME, Kulalert W, Eminli S, Tan KY, Apostolou E, Stadtfeld M, Li Y, Shioda T, Natesan S, Wagers AJ, Melnick A, Evans T, Hochedlinger K Induced pluripotent stem cells (iPSCs) have been derived from various somatic cell populations through ectopic expression of defined factors. It remains unclear whether iPSCs generated from different cell types are molecularly and functionally similar. Here we show that iPSCs obtained from mouse fibroblasts, hematopoietic and myogenic cells exhibit distinct transcriptional and epigenetic patterns. Moreover, we demonstrate that cellular origin influences the in vitro differentiation potentials of iPSCs into embryoid bodies and different hematopoietic cell types. Notably, continuous passaging of iPSCs largely attenuates these differences. Our results suggest that early-passage iPSCs retain a transient epigenetic memory of their somatic cells of origin, which manifests as differential gene expression and altered differentiation capacity. These observations may influence ongoing attempts to use iPSCs for disease modeling and could also be exploited in potential therapeutic applications to enhance differentiation into desired cell lineages. PMID: 20644536 [PubMed - as supplied by publisher] | | |
| Isolating stem cells from soft musculoskeletal tissues.
July 21, 2010 at 7:21 AM
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| | Isolating stem cells from soft musculoskeletal tissues. J Vis Exp. 2010;(41): Authors: Li Y, Pan H, Huard J Adult stem cells have long been discussed in regards to their application in regenerative medicine. Adult stem cells have generated a great deal of excitement for treating injured and diseased tissues due to their impressive capabilities to undergo multi-lineage cell differentiation and their self-renewal ability. Most importantly, these qualities have made them advantageous for use in autologous cell transplantation therapies. The current protocol will introduce the readers to the modified preplate technique where soft tissues of the musculoskeletal system, e.g. tendon and muscle, are 1(st) enzymatically dissociated and then placed in collagen coated flasks with medium. The supernatant, which is composed of medium and the remaining floating cells, is serially transferred daily to new flasks. The stem cells are the slowest to adhere to the flasks which is usually takes 5-7 days (serial transfers or preplates) . By using this technique, adult stem cells present in these tissues can be easily harvested through fairly non-invasive procedures. PMID: 20644509 [PubMed - in process] | | |
| Aggregation of human mesenchymal stromal cells (MSCs) into 3D spheroids enhances their antiinflammatory properties.
July 21, 2010 at 7:21 AM
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| | Aggregation of human mesenchymal stromal cells (MSCs) into 3D spheroids enhances their antiinflammatory properties. Proc Natl Acad Sci U S A. 2010 Jul 19; Authors: Bartosh TJ, Ylöstalo JH, Mohammadipoor A, Bazhanov N, Coble K, Claypool K, Lee RH, Choi H, Prockop DJ Previous reports suggested that culture as 3D aggregates or as spheroids can increase the therapeutic potential of the adult stem/progenitor cells referred to as mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs). Here we used a hanging drop protocol to prepare human MSCs (hMSCs) as spheroids that maximally expressed TNFalpha stimulated gene/protein 6 (TSG-6), the antiinflammatory protein that was expressed at high levels by hMSCs trapped in the lung after i.v. infusion and that largely explained the beneficial effects of hMSCs in mice with myocardial infarcts. The properties of spheroid hMSCs were found to depend critically on the culture conditions. Under optimal conditions for expression of TSG-6, the hMSCs also expressed high levels of stanniocalcin-1, a protein with both antiinflammatory and antiapoptotic properties. In addition, they expressed high levels of three anticancer proteins: IL-24, TNFalpha-related apoptosis inducing ligand, and CD82. The spheroid hMSCs were more effective than hMSCs from adherent monolayer cultures in suppressing inflammatory responses in a coculture system with LPS-activated macrophages and in a mouse model for peritonitis. In addition, the spheroid hMSCs were about one-fourth the volume of hMSCs from adherent cultures. Apparently as a result, larger numbers of the cells trafficked through the lung after i.v. infusion and were recovered in spleen, liver, kidney, and heart. The data suggest that spheroid hMSCs may be more effective than hMSCs from adherent cultures in therapies for diseases characterized by sterile tissue injury and unresolved inflammation and for some cancers that are sensitive to antiinflammatory agents. PMID: 20643923 [PubMed - as supplied by publisher] | | |
| Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model.
July 21, 2010 at 7:21 AM
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| | Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model. Head Face Med. 2010 Jul 19;6(1):17 Authors: Kleinheinz J, Jung S, Wermker K, Fischer C, Joos U ABSTRACT: BACKGROUND: Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the complex in a circulation model. METHODS: Release kinetics of VEGF165 complexed in different quantities in a collagen matrix were determined in a circulation model by quantifying protein concentration with ELISA over a period of 5 days. The structural changes of the collagen matrix were assessed with light microscopy, native scanning electron microscopy (SEM) as well as with immuno-gold-labelling technique in scanning and transmission electron microscopy (TEM). RESULTS: We established a biological half-life for VEGF165 of 90 minutes. In a half-logarithmic presentation the VEGF165 release showed a linear declining gradient; the release kinetics were not depending on VEGF165 concentrations. After 12 hours VEGF release reached a plateau, after 48 hours VEGF165 was no longer detectable in the complexes charged with lower doses, but still measurable in the 80 ug sample. At the beginning of the study a smear layer was visible on the surface of the complex. After the wash out of the protein in the first days the natural structure of the collagen appeared and did not change over the test period. CONCLUSIONS: By defining the pharmacological and morphological profile of a cytokine collagen complex in a circulation model our data paves the way for further in-vivo studies where additional biological side effects will have to be considered. VEGF165 linked to collagen fibrils shows its improved stability in direct electron microscopic imaging as well as in prolonged release from the matrix. Our in-vitro trial substantiates the position of cytokine collagen complexes as innovative and effective treatment tools in regenerative medicine and and may initiate further clinical research. PMID: 20642842 [PubMed - as supplied by publisher] | | |
| Selective culture of different types of human parotid gland cells.
July 21, 2010 at 6:58 AM
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| | Selective culture of different types of human parotid gland cells. Head Neck. 2010 Jul 19; Authors: Chan YH, Huang TW, Young TH, Lou PJ BACKGROUND.: Advances in salivary gland tissue engineering can benefit patients diagnosed with xerostomia. Complexity of the gland explains the urgent demand for a reliable protocol to isolate and expand various gland cells that can be used for further study. METHODS.: Three cells with different morphologies were isolated from the same human parotid glands using different culture medium systems and then were identified by the expressions from mRNA to the protein level. RESULTS.: Among the 34 specimens, parotid gland acinar cells, myoepithelial cells, and fibroblasts expressing specific markers that belonged to individual cell types, were successfully isolated and expanded from 30 specimens without a complex mechanical process and expensive flow technique. CONCLUSION.: The proposed protocol is simple with a high success rate to culture various gland cells, making it highly promising for use in future tissue engineering studies. (c) 2010 Wiley Periodicals, Inc. Head Neck, 2010. PMID: 20645288 [PubMed - as supplied by publisher] | | |
| Evaluation of early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffold. An experimental study in Wistar rats.
July 21, 2010 at 6:58 AM
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| | Evaluation of early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffold. An experimental study in Wistar rats. Oral Maxillofac Surg. 2010 Jul 20; Authors: Alhag M, Farrell E, Toner M, Claffey N, Lee TC, O'Brien F PURPOSE: Tissue engineering using cell-seeded biodegradable scaffolds offers a new bone regenerative approach that might circumvent many of the limitations of current therapeutic modalities. The aim of this experiment was to study the early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds. METHODS: The 5-mm critical size defects were created in the calvarial bones of 41 Wistar rats. The defects were either left empty to serve as controls (n = 11), filled with cell-free scaffolds (n = 12), cell-seeded scaffolds that were maintained in standard culture medium (n = 9), or cell-seeded scaffolds that were maintained in osteoinductive factor-supplemented medium (n = 9). The animals were sacrificed at 7 days after surgery, and specimens were prepared for histological analysis. Early healing events such as host cell penetration, blood vessel in-growth, and scaffold integration were observed. The degree of inflammatory cell infiltrate was assessed. RESULTS: While defects in the control group healed with a thin fibrous tissue, the collagen-glycosaminoglycan scaffold in the test groups preserved the three-dimensional form of the defects. After 7 days in vivo, the scaffold maintained its integrity and appeared populated with host cells. The cell-seeded scaffold induced more inflammatory response compared to the cell-free scaffolds. New blood vessels and areas of early bone formation were also evident in the cell-seeded scaffolds. CONCLUSIONS: In conclusion, the findings show that mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds have good tissue tolerance and exhibit an osteoinductive effect as indicated by early stage healing. PMID: 20644972 [PubMed - as supplied by publisher] | | |
| Bio-electrospraying and aerodynamically assisted bio-jetting whole human blood: Interrogating cell surface marker integrity.
July 21, 2010 at 6:58 AM
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| | Bio-electrospraying and aerodynamically assisted bio-jetting whole human blood: Interrogating cell surface marker integrity. Biomicrofluidics. 2010;4(1):11101 Authors: Joly P, Chavda N, Eddaoudi A, Jayasinghe SN Bio-electrospraying and aerodynamically assisted bio-jetting are two direct cell handling approaches recently pioneered, which have demonstrated significant applicability to the life sciences. These two bioprotocols have undergone scientific rigor, which have seen these techniques been explored in conjunction with a wide range of immortalized, primary and stem cells, and those whole organisms. Those studies have demonstrated a cellular population of >70% viable post-treatment in comparison with controls. Although, these studies assessed cellular viability, cell surface molecules play a critical role in several cellular functions, in particular, have importance to tissue engineering and regenerative medicine. Thus, in the studies reported herein, we demonstrate post-treated viable cells retain their cell surface marker expression levels in comparison to controls, over both short and long time points. Therefore, these studies further push back the frontiers of both bio-electrosprays and aerodynamically assisted bio-jetting in their endeavor as novel strategies for tissue engineering and regenerative biologymedicine with possible targeted clinical utility. PMID: 20644660 [PubMed - in process] | | |
| Isolation of Human Umbilical Arterial Smooth Muscle Cells (HUASMC).
July 21, 2010 at 6:58 AM
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| | Isolation of Human Umbilical Arterial Smooth Muscle Cells (HUASMC). J Vis Exp. 2010;(41) Authors: Ribeiro MP, Relvas R, Chiquita S, Correia ID The human umbilical cord (UC) is a biological sample that can be easily obtained just after birth. This biological sample is, most of the time, discarded and their collection does not imply any added risk to the newborn or mother s health. Moreover no ethical concerns are raised. The UC is composed by one vein and two arteries from which both endothelial cells (ECs) (1) and smooth muscle cells (SMCs) (2), two of the main cellular components of blood vessels, can be isolated. In this project the SMCs were obtained after enzymatic treatment of the UC arteries accordingly the experimental procedure previously described by Jaffe et al (3). After cell isolation they were kept in t-flash with DMEM-F12 supplemented with 5% of fetal bovine serum and were cultured for several passages. Cells maintained their morphological and other phenotypic characteristics in the different generations. The aim of this study was to isolate smooth muscle cells in order to use them as models for future assays with constrictor drugs, isolate and structurally characterize L-type calcium channels, to study cellular and molecular aspects of the vascular function (4) and to use them in tissue engineering. PMID: 20644508 [PubMed - as supplied by publisher] | | |
| Mapping the first stages of mesoderm commitment during differentiation of human embryonic stem cells.
July 21, 2010 at 6:58 AM
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| | Mapping the first stages of mesoderm commitment during differentiation of human embryonic stem cells. Proc Natl Acad Sci U S A. 2010 Jul 19; Authors: Evseenko D, Zhu Y, Schenke-Layland K, Kuo J, Latour B, Ge S, Scholes J, Dravid G, Li X, Maclellan WR, Crooks GM Our understanding of how mesodermal tissue is formed has been limited by the absence of specific and reliable markers of early mesoderm commitment. We report that mesoderm commitment from human embryonic stem cells (hESCs) is initiated by epithelial-to-mesenchymal transition (EMT) as shown by gene expression profiling and by reciprocal changes in expression of the cell surface proteins, EpCAM/CD326 and NCAM/CD56. Molecular and functional assays reveal that the earliest CD326(-)CD56(+) cells, generated from hESCs in the presence of activin A, BMP4, VEGF, and FGF2, represent a multipotent mesoderm-committed progenitor population. CD326(-)CD56(+) progenitors are unique in their ability to generate all mesodermal lineages including hematopoietic, endothelial, mesenchymal (bone, cartilage, fat, fibroblast), smooth muscle, and cardiomyocytes, while lacking the pluripotency of hESCs. CD326(-)CD56(+) cells are the precursors of previously reported, more lineage-restricted mesodermal progenitors. These findings present a unique approach to study how germ layer specification is regulated and offer a promising target for tissue engineering. PMID: 20643952 [PubMed - as supplied by publisher] | | |
| Synergic effects of crypt-like topography and ECM proteins on intestinal cell behavior in collagen based membranes.
July 21, 2010 at 6:58 AM
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| | Synergic effects of crypt-like topography and ECM proteins on intestinal cell behavior in collagen based membranes. Biomaterials. 2010 Jul 17; Authors: Wang L, Murthy SK, Barabino GA, Carrier RL The basement membrane of small intestinal epithelium possesses complex topography at multiple scales ranging from the mesoscale to nanoscale. Specifically, intestinal crypt-villus units are comprised of hundred-micron-scale well-like invaginations and finger-like projections; intestinal cell phenotype is related to location on this crypt-villus unit. A biomimetic intestinal cell culture system composed of type I collagen based permeable cell culture membranes incorporating both micron-scale intestinal crypt-like topography and nanometer scale topography was fabricated. Membranes were pre-incubated with either laminin (Ln) or fibronectin (Fn), inoculated with intestinal epithelial Caco-2 cells and cultured for 1-21 days to study the relative significance of influence of crypt-like topography and biomimetic substrate chemistry on cell phenotype. Crypt-like topography inhibited Caco-2 differentiation during early culture, as evidenced by slower cell spreading and lower brush border enzyme activity. For example, alanine aminopeptidase activity was lower on Ln-coated patterned collagen ( approximately 3.4+/-0.24mU/mg) compared to flat collagen (10.84+/-0.55mU/mg) at day 7. Caco-2 cultured on Fn-coated collagen started to spread earlier (1 day vs 3 days) and formed longer protrusions than on Ln-coated collagen. Pre-coating of Ln enhanced cell differentiation, as the maximum activity of a cell differentiation marker (alkaline phosphatase) was 2-3 times higher than on Fn-coated collagen, and maintained differentiated phenotype in long term (up to 21 days) culture. In general, compared to substrate topography, coating with ECM protein had more prominent and longer effect on cell behavior. Crypt-like topography affected Caco-2 spreading and differentiation during early culture, however the effect diminished as culture progressed. This information will benefit intestinal tissue engineering scaffold design, and modification of in vitro intestinal cell models. PMID: 20643478 [PubMed - as supplied by publisher] | | |
| Reconstruction of the auricle. Preface.
July 21, 2010 at 6:58 AM
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| | Reconstruction of the auricle. Preface. Adv Otorhinolaryngol. 2010;68:VI-VIII Authors: Staudenmaier R PMID: 20586133 [PubMed - indexed for MEDLINE] | | | | 
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