| Please add updates@feedmyinbox.com to your address book to make sure you receive these messages in the future. | |
| Labeling and tracking of mesenchymal stromal cells with EdU.
June 4, 2010 at 7:32 AM
|
| | Labeling and tracking of mesenchymal stromal cells with EdU. Cytotherapy. 2009;11(7):864-73 Authors: Lin G, Huang YC, Shindel AW, Banie L, Wang G, Lue TF, Lin CS BACKGROUND AIMS: The thymidine analog bromodeoxyuridine (5-bromo-2-deoxyuridine; BrdU) has been used widely to label cells in culture and in tissue. The labeled cells can also be tracked when transplanted into a suitable host. In the present study we tested a new thymidine analog, 5-ethynyl-2-deoxyuridine (EdU), for labeling and tracking of mesenchymal stromal cells (MSC), specifically adipose tissue-derived stem cells (ADSC). METHODS: Labeling of ADSC was examined for the dosage effect of EdU and stability of label by Alexa-594 staining followed by fluorescence microscopy. Labeling of various organs/tissues was done by intraperitoneal injection of EdU and examined by histology and fluorescence microscopy. Tracking of ADSC was done by intratissue or intravenous transplantation of EdU-labeled ADSC into various tissues and examined by histology and fluorescence microscopy. RESULTS: EdU was incorporated specifically into the nucleus in approximately 50% of ADSC and t! he percentage of cells that remained fully labeled declined with time. Peritoneal injection of EdU resulted in the appearance of EdU-positive cells in most organs and tissues. In the intestine, EdU-positive cells were found in both the epithelium and connective tissues 7 h after injection. Long-term (2-6 week) follow-ups found EdU-positive cells only in the connective tissue. Tracking of ADSC was successful in tissues 10 weeks after intratissue or intravenous transplantation. CONCLUSIONS: Cell labeling with EdU in culture or living animals can be performed easily. The detection of EdU label requires no harsh treatment or immunologic reaction, as detection of BrdU label does. EdU can be used for long-term tracking of ADSC. PMID: 19903099 [PubMed - indexed for MEDLINE] | | |
| Designer self-assembling peptide nanofiber biological materials.
June 4, 2010 at 6:38 AM
|
| | Designer self-assembling peptide nanofiber biological materials. Chem Soc Rev. 2010 Jun 3; Authors: Hauser CA, Zhang S Scientists and bioengineers have dreamed of designing materials from the bottom up with the finest detail and ultimate control at the single molecular level. The discovery of a class of self-assembling peptides that spontaneously undergo self-organization into well-ordered structures opened a new avenue for molecular fabrication of biological materials. Since this discovery, diverse classes of short peptides have been invented with broad applications, including 3D tissue cell culture, reparative and regenerative medicine, tissue engineering, slow drug release and medical device development. Molecular design of new materials using short peptides is poised to become increasingly important in biomedical research, biomedical technology and medicine, and is covered in this tutorial review. PMID: 20520907 [PubMed - as supplied by publisher] | | |
| Functional Heterogeneity of Embryonic Stem Cells Revealed through Translational Amplification of an Early Endodermal Transcript.
June 4, 2010 at 6:38 AM
|
| | Functional Heterogeneity of Embryonic Stem Cells Revealed through Translational Amplification of an Early Endodermal Transcript. PLoS Biol. 2010;8(5):e1000379 Authors: Canham MA, Sharov AA, Ko MS, Brickman JM ES cells are defined as self-renewing, pluripotent cell lines derived from early embryos. Cultures of ES cells are also characterized by the expression of certain markers thought to represent the pluripotent state. However, despite the widespread expression of key markers such as Oct4 and the appearance of a characteristic undifferentiated morphology, functional ES cells may represent only a small fraction of the cultures grown under self-renewing conditions. Thus phenotypically "undifferentiated" cells may consist of a heterogeneous population of functionally distinct cell types. Here we use a transgenic allele designed to detect low level transcription in the primitive endoderm lineage as a tool to identify an immediate early endoderm-like ES cell state. This reporter employs a tandem array of internal ribosomal entry sites to drive translation of an enhanced Yellow Fluorescent Protein (Venus) from the transcript that normally encodes for the early endodermal ma! rker Hex. Expression of this Venus transgene reports on single cells with low Hex transcript levels and reveals the existence of distinct populations of Oct4 positive undifferentiated ES cells. One of these cells types, characterized by both the expression of the Venus transgene and the ES cells marker SSEA-1 (V(+)S(+)), appears to represent an early step in primitive endoderm specification. We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self-renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts. Interestingly, while these subpopulations are equivalently and clonally interconvertible under self-renewing conditions, when induced to differentiate both in vivo and in vitro they exhibit diffe! rent behaviours. Most strikingly when introduced back into mor! ulae or blastocysts, the V(+)S(+) population is not effective at contributing to the epiblast and can contribute to the extra-embryonic visceral and parietal endoderm, while the V(-)S(+) population generates high contribution chimeras. Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo. PMID: 20520791 [PubMed - in process] | | |
| Loss of stromal caveolin-1 leads to oxidative stress, mimics hypoxia and drives inflammation in the tumor microenvironment, conferring the "reverse Warburg effect": A transcriptional informatics analysis with validation.
June 4, 2010 at 6:38 AM
|
| | Loss of stromal caveolin-1 leads to oxidative stress, mimics hypoxia and drives inflammation in the tumor microenvironment, conferring the "reverse Warburg effect": A transcriptional informatics analysis with validation. Cell Cycle. 2010 Jun 22;9(11) Authors: Pavlides S, Tsirigos A, Vera I, Flomenberg N, Frank PG, Casimiro MC, Wang C, Fortina P, Addya S, Pestell RG, Martinez-Outschoorn UE, Sotgia F, Lisanti MP Cav-1 (-/-) deficient stromal cells are a new genetic model for myofibroblasts and cancer-associated fibroblasts. Using an unbiased informatics analysis of the transcriptional profile of Cav-1 (-/-) deficient mesenchymal stromal cells, we have now identified many of the major signaling pathways that are activated by a loss of Cav-1, under conditions of metabolic restriction (with low glucose media). Our informatics analysis suggests that a loss of Cav-1 induces oxidative stress, which mimics a constitutive pseudo-hypoxic state, leading to (1) aerobic glycolysis and (2) inflammation in the tumor stromal microenvironment. This occurs via the activation of 2 major transcription factors, namely HIF (aerobic glycolysis) and NFkappaB (inflammation) in Cav-1 (-/-) stromal fibroblastic cells. Experimentally, we show that Cav-1 deficient stromal cells may possess defective mitochondria, due to the over-production of nitric oxide (NO), resulting in the tyrosine nitration of! the mitochondrial respiratory chain components (such as complex I). Elevated levels of nitro-tyrosine were observed both in Cav-1 (-/-) stromal cells, and via acute knock-down with siRNA targeting Cav-1. Finally, metabolic restriction with mitochondrial (complex I) and glycolysis inhibitors was synthetically lethal with a Cav-1 (-/-) deficiency in mice. As such, Cav-1 deficient mice show a dramatically reduced mitochondrial reserve capacity. Thus, a mitochondrial defect in Cav-1 deficient stromal cells could drive oxidative stress, leading to aerobic glycolysis, and inflammation, in the tumor microenvironment. These stromal alterations may underlie the molecular basis of the "Reverse Warburg Effect", and could provide the key to targeted anti-cancer therapies using metabolic inhibitors. In direct support of these findings, the transcriptional profile of Cav-1 (-/-) stromal cells overlaps significantly with Alzheimer's disease, which is characterized by oxidative stress, NO! over-production (peroxynitrite formation), inflammation, hypo! xia and mitochondrial dysfunction. We conclude that Cav-1 (-/-) deficient mice are a new whole-body animal model for an activated lethal tumor microenvironment, i.e., "tumor stroma" without the tumor. Since Cav-1 (-/-) mice are also an established animal model for profibrotic disease, our current results may have implications for understanding the pathogenesis of scleroderma (systemic sclerosis) and pulmonary fibrosis, which are also related to abnormal mesenchymal stem cell function. PMID: 20519932 [PubMed - as supplied by publisher] | | |
| A G-CSF functionalized scaffold for stem cells seeding: a differentiating device for cardiac purposes.
June 4, 2010 at 6:38 AM
|
| | A G-CSF functionalized scaffold for stem cells seeding: a differentiating device for cardiac purposes. J Cell Mol Med. 2010 Jun 1; Authors: Spadaccio C, Rainer A, Trombetta M, Centola M, Lusini M, Chello M, Covino E, De Marco F, Coccia R, Toyoda Y, Genovese JA Abstract Myocardial infarction and its consequences represent one of the most demanding challenges in cell therapy and regenerative medicine. Transfer of skeletal myoblasts into decompensated hearts has been performed through intramyocardial injection. However, the achievement of both a cardiomyocyte differentiation and a precise integration of the injected cells into the myocardial wall, in order to augment synchronized contractility and avoid potentially life-threatening alterations in the electrical conduction of the heart, still remains a major target to be pursued. Recently, Granulocytes Colony-Stimulating Factor (G-CSF) fueled the interest of researchers for its direct effect on cardiomyocytes, inhibiting both apoptosis and remodelling in the failing heart and protecting from ventricular arrhythmias through the upregulation of Connexin 43 (Cx43). We propose a tissue engineering approach concerning the fabrication of an electrospun cardiac graft functionalize! d with G-CSF, in order to provide the correct signalling sequence to orientate myoblast differentiation and exert important systemic and local effects, positively modulating the infarction microenvironment. Poly-L-lactide electrospun scaffolds were seeded with C2C12 murine skeletal myoblast for 48 hours. Biological assays demonstrated the induction of Cx43 expression along with morphostructural changes resulting in cell elongation and appearance of cellular junctions resembling the usual cardiomyocyte arrangement at the ultrastructural level. The possibility of fabricating extracellular matrix-mimicking scaffolds able to promote myoblast precommitment towards myocardiocyte lineage and mitigate the hazardous environment of the damaged myocardium represents an interesting strategy in cardiac tissue engineering. PMID: 20518852 [PubMed - as supplied by publisher] | | |
| Very small embryonic-like stem cells for regenerative medicine: WO2010039241.
June 4, 2010 at 6:38 AM
|
| | Very small embryonic-like stem cells for regenerative medicine: WO2010039241. Expert Opin Ther Pat. 2010 Jun 2; Authors: Taupin P Background: The application is in the field of stem cells and regenerative medicine. Objective: It aims at identifying and characterising a population of pluripotent stem cells present in adult tissues. Methods: Cells were isolated and purified using Fluorescence-Activated Cell Sorting and Direct ImageStream analysis from various adult and umbilical cord tissues of rodents and humans. Cells were propagated in the presence of trophic factors and feeder cell layers of C2C12 cells. Cells were characterised by electron microscopy and immunocytology. Results: A population of cells that do not express a panleukocytic antigen CD45 and are negative for other markers of haematopoietic lineages were isolated and purified. The isolated cells elicit morphological features of embryonic stem cells (ESCs). They express markers of pluripotent stem cells, such as Nanog, Oct-4 and SSEA-1. On culturing on feeder cell layers, the isolated and purified cells generate embryoid body-lik! e sphere. Conclusion: The identified and characterised cells elicit features of pluripotent stem cells and similarities with ESCs. They are termed very small embryonic-like stem cells (VSELs). The application claims the use of VSELs for cellular therapy and regenerative medicine. PMID: 20518618 [PubMed - as supplied by publisher] | | |
| Endothelial progenitor cells give rise to pro-angiogenic smooth muscle-like progeny.
June 4, 2010 at 6:38 AM
|
| | Endothelial progenitor cells give rise to pro-angiogenic smooth muscle-like progeny. Cardiovasc Res. 2010 Jun 1;86(3):506-15 Authors: Moonen JR, Krenning G, Brinker MG, Koerts JA, van Luyn MJ, Harmsen MC AIMS: Reciprocal plasticity exists between endothelial and mesenchymal lineages. For instance, mature endothelial cells adopt a smooth muscle-like phenotype through transforming growth factor beta-1 (TGFbeta1)-driven endothelial-to-mesenchymal transdifferentiation (EndMT). Peripheral blood contains circulating endothelial progenitor cells of which the endothelial colony-forming cells (ECFCs) harbour stem cell-like properties. Given the plasticity between endothelial and mesenchymal lineages and the stem cell-like properties of ECFCs, we hypothesized that ECFCs can give rise to smooth muscle-like progeny. METHODS AND RESULTS: ECFCs were stimulated with TGFbeta1, after which TGFbeta signalling cascades and their downstream effects were investigated. Indeed, EndMT of ECFCs resulted in smooth muscle-like progeniture. TGFbeta1-driven EndMT is mediated by ALK5 kinase activity, increased downstream Smad2 signalling, and reduced protein levels of inhibitor of DNA-binding ! protein 3. ECFCs lost expression of endothelial markers and endothelial anti-thrombogenic function. Simultaneously, mesenchymal marker expression was gained, cytoskeletal rearrangements occurred, and cells acquired a contractile phenotype. Transdifferentiated ECFCs were phenotypically stable and self-sustaining and, importantly, showed fibroblast growth factor-2 and angiopoietin-1-mediated pro-angiogenic paracrine properties. CONCLUSION: Our study is the first to demonstrate that ECFCs can give rise to smooth muscle-like progeny, with potential therapeutic benefits. These findings further illustrate that ECFCs are highly plastic, which by itself has implications for therapeutical use. PMID: 20083576 [PubMed - indexed for MEDLINE] | | | | 
| This email was sent to regenmd@gmail.com. Account Login
Don't want to receive this feed any longer? Unsubscribe here
This email was carefully delivered by Feed My Inbox. 230 Franklin Road Suite 814 Franklin, TN 37064 | |
No comments:
Post a Comment