Role of PFKFB3-Driven Glycolysis in Vessel Sprouting

Biocompatibility of hydrogel-based scaffolds for tissue engineering applications

Sarah AdlerDavid BasketterStuart CretonOlavi PelkonenJan van BenthemValerie Zuang • Klaus Ejner AndersenAlexandre Angers-LoustauAynur AptulaAnna Bal-PriceEmilio Benfenati • Ulrike BernauerJos BessemsFrederic Y. BoisAlan BoobisEsther BrandonSusanne Bremer • Thomas BroschardSilvia CasatiSandra CoeckeRaffaella CorviMark CroninGeorge Daston • Wolfgang DekantSusan FelterElise GrignardUrsula Gundert-RemyTuula HeinonenIan Kimber • Jos KleinjansHannu KomulainenReinhard KreilingJoachim KreysaSofia Batista LeiteGeorge Loizou • Gavin MaxwellPaolo MazzatortaSharon MunnStefan PfuhlerPascal PhrakonkhamAldert Piersma • Albrecht PothPilar PrietoGuillermo RepettoVera RogiersGreet SchoetersMichael Schwarz • Rositsa SerafimovaHanna TahtiEmanuela TestaiJoost van DelftHenk van LoverenMathieu Vinken • Andrew WorthJose ´-Manuel Zaldivar

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Alternative (non-animal) methods for cosmetics testing: current status and future prospects—2010

Myocardial infarction is a prevalent major cardiovascular event that arises from myocardial ischemia with or without reperfusion, and basic and translational research is needed to better understand...

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Guidelines for experimental models of myocardial ischemia and infarction.

Cardiac hypertrophy is a major risk factor for heart failure and associated patient morbidity and mortality. Research investigating the aberrant molecular processes that occur during cardiac hypertrophy uses primary cardiomyocytes from neonatal rat hearts as the standard experimental in vitro system. In addition, some studies make use of the H9C2 rat cardiomyoblast cell line, which has the advantage of being an animal-free alternative; however, the extent to which H9C2 cells can accurately mimic the hypertrophic responses of primary cardiac myocytes has not yet been fully established. To address this limitation, we have directly compared the hypertrophic responses of H9C2 cells with those of primary rat neonatal cardiomyocytes following stimulation with hypertrophic factors. Primary rat neonatal cardiomyocytes and H9C2 cells were cultured in vitro and treated with angiotensin II and endothelin-1 to promote hypertrophic responses. An increase in cellular footprint combined with rearrangement of cytoskeleton and induction of foetal heart genes were directly compared in both cell types using microscopy and real-time rtPCR. H9C2 cells showed almost identical hypertrophic responses to those observed in primary cardiomyocytes. This finding validates the importance of H9C2 cells as a model for in vitro studies of cardiac hypertrophy and supports current work with human cardiomyocyte cell lines for prospective molecular studies in heart development and disease.

The H9C2 cell line and primary neonatal cardiomyocyte cells show similar hypertrophic responses in vitro

The primary culture of neonatal mice cardiomyocyte model enables researchers to study and understand the morphological, biochemical, and electrophysiological characteristics of the heart, besides being a valuable tool for pharmacological and toxicological studies. Because cardiomyocytes do not proliferate after birth, primary myocardial culture is recalcitrant. The present study describes an improved method for rapid isolation of cardiomyocytes from neonatal mice, as well as the maintenance and propagation of such cultures for the long term. Immunocytochemical and gene expression data also confirmed the presence of several cardiac markers in the beating cells during the long-term culture condition used in this protocol. The whole culture process can be effectively shortened by reducing the enzyme digestion period and the cardiomyocyte enrichment step.

An improved protocol for primary culture of cardiomyocyte from neonatal mice

Cellular therapy using stem cells for cardiac diseases has recently gained much interest in the scientific community due to its potential in regenerating damaged and even dead tissue and thereby restoring the organ function. Stem cells from various sources and origin are being currently used for regeneration studies directly or along with differentiation inducing agents. Long term survival and minimal side effects can be attained by using autologous cells and reduced use of inducing agents. Cardiomyogenic differentiation of adult derived stem cells has been previously reported using various inducing agents but the use of a potentially harmful DNA demethylating agent 5-azacytidine (5-azaC) has been found to be critical in almost all studies. Alternate inducing factors and conditions/stimulant like physical condition including electrical stimulation, chemical inducers and biological agents have been attempted by numerous groups to induce cardiac differentiation. Biomaterials were initially used as artificial scaffold in in vitro studies and later as a delivery vehicle. Natural ECM is the ideal biological scaffold since it contains all the components of the tissue from which it was derived except for the living cells. Constructive remodeling can be performed using such natural ECM scaffolds and stem cells since, the cells can be delivered to the site of infraction and once delivered the cells adhere and are not "lost". Due to the niche like conditions of ECM, stem cells tend to differentiate into tissue specific cells and attain several characteristics similar to that of functional cells even in absence of any directed differentiation using external inducers. The development of niche mimicking biomaterials and hybrid biomaterial can further advance directed differentiation without specific induction. The mechanical and electrical integration of these materials to the functional tissue is a problem to be addressed. The search for the perfect extracellular matrix for therapeutic applications including engineering cardiac tissue structures for post ischemic cardiac tissue regeneration continues.

Natural ECM as Biomaterial for Scaffold Based Cardiac Regeneration Using Adult Bone Marrow Derived Stem Cells

Mesenchymal stem cells (MSC), because of their multipotency and ease of purification and amplification, are an ideal stem cell source for cell therapies. Bone-marrow-derived stem cells (BMSC) can be used to develop MSC-like immortalized cell lines with large proliferation and differentiation potentialities. Their immortalized status prevents the maintenance of MSC function and characters; this can be negated by modifying the isolation and maintenance protocol. Adult murine BMSC were isolated and maintained in media without additional growth factors together with passage-dependent reseeding following trypsinization. Cells maintained over 25 passages were considered as putative cell lines and characterized. The phenotypic and genotypic characteristics and multilineage differentiation potential of the cells were assessed by morphological, phenotypic, and molecular assays at various passages. The putative BMSC cell lines showed the characteristics of MSC and were able to maintain these characteristics, even after immortalization. The phenotypic data demonstrated difference among two cell lines; this was further validated by the difference in their multilineage differentiation potential following specific induction. More importantly, no changes were observed in the genotypic level in comparison with control cells, even after more than 50 passages. Our protocol thus advances the isolation and maintenance of BMSC and the development of putative BMSC cell lines that maintain characteristics of MSC, including multilineage differentiation potential, after more than 40 passages.

Generation of mesenchymal stem cell lines from murine bone marrow

Cultured murine bone marrow derived mesenchymal stem cells (BMSC) when grown along with cardiogel derived from mouse cardiac fibroblast, exhibited increased cell proliferation and differentiation and enhanced survival under oxidative stress induced by the exposure of H2O2 in vitro (similar to in vivo ischemia like condition) Adhesion of BMSC to the cardiogel occurred at a faster rate when compared to the cells grown on normal surface BMSC attached to cardiogel showed an increased resistance to proteolytic (enzymatic) disassociation This is the first report on an attempt to use an in house biomaterial for the growth of BMSC that led to their heightened resistance towards oxidative stress These studies support that cardiogel is an efficient biodegradable three-dimensional extracellular matrix which supports better growth of BMSC and can be used as a scaffold for stem cell delivery, with potential therapeutic applications in cardiac tissue regeneration

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Cardiogel supports adhesion, proliferation and differentiation of stem cells with increased oxidative stress protection.

The extracellular matrix (ECM) and its components are known to promote growth and cellular differentiation in vitro. Cardiogel, a three-dimensional extracellular matrix derived from cardiac fibroblasts, is evaluated for its cardiomyogenic-differentiation-inducing potential on bone-marrow-derived stem cells (BMSC). BMSC from adult mice were grown on cardiogel and induced to differentiate into specific lineages that were validated by morphological, phenotypic and molecular assays. The data revealed that the cardiogel enhanced cardiomyogenic and adipogenic differentiation and relegated osteogenic differentiation following specific induction. More importantly, increased cardiomyogenic differentiation was also observed following BMSC growth on cardiogel without specific chemical (5-azacytidine) induction. This is the first report of an attempt to use cardiogel as a biomaterial on which to achieve cardiomyogenic differentiation of BMSC without chemical induction. Our study suggests that cardiogel is an efficient extracellular matrix that enhances the cardiomyogenic differentiation of BMSC and that it can therefore be used as a scaffold for cardiac tissue regeneration.

P. Sreejit

Papers

An improved protocol for primary culture of cardiomyocyte from neonatal mice

Natural ECM as Biomaterial for Scaffold Based Cardiac Regeneration Using Adult Bone Marrow Derived Stem Cells

Generation of mesenchymal stem cell lines from murine bone marrow

Cardiogel supports adhesion, proliferation and differentiation of stem cells with increased oxidative stress protection.

Enhanced cardiomyogenic lineage differentiation of adult bone-marrow-derived stem cells grown on cardiogel