1,721,032 research outputs found
Bone marrow as a source of stem cells and germ cells? Perspectives for transplantation
Full text linkRecent publications have suggested the existence of germ stem cells in the mouse at postnatal stages. The mechanism of de novo oocyte formation is proposed to involve a contribution from the bone marrow to the germ cell pool, via the bloodstream. Critical examination of the data underpinning these contentious claims is under way from a reproductive biology perspective but little has been said about the nature of this elusive bone marrow population with germ cell potential. Furthermore, whereas the prospect of marrow-derived germ cells may appear propitious for fertility applications, its wider impact on transplantation medicine remains to be considered. This paper examines the evidence leading to the current debate and considers the implications of such findings for the field of bone marrow transplantation. © 2007 Springer-Verlag
The chick embryo: Hatching a model for contemporary biomedical research
Full text linkAnimal models play a crucial role in fundamental and medical research. Progress in the fields of drug discovery, regenerative medicine and cancer research among others are heavily dependent on in vivo models to validate in vitro observations, and develop new therapeutic approaches. However, conventional rodent and large animal experiments face ethical, practical and technical issues that limit their usage. The chick embryo represents an accessible and economical in vivo model, which has long been used in developmental biology, gene expression analysis and loss/ gain of function experiments. It is also an established model for tissue/ cell transplantation, and because of its lack of immune system in early development, the chick embryo is increasingly recognised as a model of choice for mammalian biology with new applications for stem cell and cancer research. Here, we review novel applications of the chick embryo model, and discuss future developments of this in vivo model for biomedical research. © 2009 Wiley Periodicals, Inc
A high-capacity screen for adipogenic differentiation
Full text linkGlycerol-3-phosphate dehydrogenase (GPDH) is highly expressed in mature adipocytes. Activity of this enzyme is therefore routinely measured to assess adipogenic differentiation in cell cultures. Existing protocols for GPDH assays require relatively large amounts of cells, and throughput is limited due to multiple steps needed for cell harvest and enzyme extraction. We present here a new protocol allowing GPDH determinations to be performed in a 96-well-plate format. From the start of cell culture to the final readout all steps are carried out using the same multiwell plate, with a minimum of handling required. Our method is suitable for setting up high-throughput assays of adipogenic differentiation. © 2001 Academic Press
Exposure to the ROCK inhibitor fasudil promotes gliogenesis of neural stem cells in vitro
Full text linkFasudil is a clinically approved Rho-associated protein kinase (ROCK) inhibitor that has been used widely to treat cerebral consequences of subarachnoid hemorrhage. It is known to have a positive effect on animal models of neurological disorders including Parkinson's disease and stroke. However, its cellular effect on progenitor populations and differentiation is not clearly understood. While recent studies suggest that fasudil promotes the mobilization of neural stem cells (NSCs) from the subventricular zone in vivo and promotes the differentiation of the C17.2 cerebellar neuroprogenitor line in vitro, it is unclear whether fasudil is involved in the differentiation of primary NSCs. Here, we tested the effect of fasudil on mouse NSCs in vitro, and observed increased gliogenesis in NSCs derived from lateral ventricles. Upon treatment, fasudil promoted characteristics of neurogenesis including phenotypic changes in neural outgrowth and interkinetic nuclear-like movements as an immediate response, while Sox2 expression was maintained and GFAP expression increased. Moreover, the gliogenic response to fasudil medium was observed in both early postnatal and adult NSC cultures. Taken together, our results show that fasudil promotes the differentiation of NSCs into astroglial lineage, suggesting that it could be used to develop novel vitro gliogenesis models and regulate differentiation for neural repair
In vitro osteogenic differentiation of human ES cells
Full text linkSince their isolation in 1998, human embryonic stem (hES) cells have been shown to be capable of adopting various cell fates in vitro. Here, we present in vitro data demonstrating the directed commitment of human embryonic stem cells to the osteogenic lineage. Human ES cells are shown to respond to factors that promote osteogenesis, leading to activation of the osteogenic markers osteocalcin, parathyroid hormone receptor, bone sialoprotein, osteopontin, cbfa1, and collagen 1. Moreover, the mineralized nodules obtained are composed of hydroxyapatite, further establishing the similarity of osteoblasts in culture to bone. These results show that osteoblasts can be derived from human ES cultures in vitro and provide the basis for comparison of adult and embryonic-derived osteogenesis, and for an investigation of potential applications for hES cells in orthopaedic tissue repair
Bergmann glia as putative stem cells of the mature cerebellum
No full textThe adult brain is known to retain a population of stem cells with self-renewing and differentiation ability, which have been identified in two main regions. Recent reports now suggest the presence of such cells in the cerebellum, a part of the CNS which was not formerly thought to harbour stem cells. The precise nature and localisation of these potential new stem cells within the tissue remains unclear, as they have primarily been described at early postnatal stages, before completion of the extensive cell migration accompanying cerebellum maturation. We have shown that a discrete cell population of the cerebellar cortex, the Bergmann glia, shares the expression of key molecular markers with neural stem cells. We examine the hypothesis that the Bergmann glia may represent a novel and abundant stem cell population in the mature cerebellum. © 2007
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