A Novel Xenogeneic Co-Culture System to Examine Neuronal Differentiation Capability of Various Adult Human Stem Cells

Background: Targeted differentiation of stem cells is mainly achieved by the sequential administration of defined growth factors and cytokines, although these approaches are quite artificial, cost-intensive and time-consuming. We now present a simple xenogeneic rat brain co-culture system which supports neuronal differentiation of adult human stem cells under more in vivo-like conditions. Methods and Findings: This system was applied to well-characterized stem cell populations isolated from human skin, parotid gland and pancreas. In addition to general multi-lineage differentiation potential, these cells tend to differentiate spontaneously into neuronal cell types in vitro and are thus ideal candidates for the introduced co-culture system. Consequently, after two days of co-culture up to 12% of the cells showed neuronal morphology and expressed corresponding markers on the mRNA and protein level. Additionally, growth factors with the ability to induce neuronal different iation in stem cells could be found in the media supernatants of the co-cultures. Conclusions: The co-culture system described here is suitable for testing neuronal differentiation capability of numerous types of stem cells. Especially in the case of human cells, it may be of clinical relevance for future cell-based therapeutic applications

Veranschaulicht am Beispiel des Erstspracherwerbs

Die Pädagogik ist in Bewegung, in Praxis wie in Theorie. Fragen nach Kompetenzorientierung, Individualisierung, länderübergreifenden Austauschmöglichkeiten und Standards bewegen die Gemüter; Schule, Universität und Lehrerbildung verändern sich. Im Zuge dieser Entwicklung regen insbesondere die kognitionswissenschaftlichen Erkenntnisse unserer Zeit dazu an, den Status Quo unserer Bildungslandschaft, die daran hängenden Vorstellungen und Institutionen neu, mit umfassenderem, empirisch gestütztem Blick auf den Menschen, auf seine Biologie sowie seine sozio-kulturelle Einbettung, zu reflektieren. Die Bildungswissenschaften1, hält Gudjons (2008: 47) fest, sind ohne Bezug zu Nachbardisziplinen heute nicht mehr denkbar, sie werden mehr und mehr „Integrationswissenschaft“. Die vorliegende Arbeit beschäftigt sich mit der Frage, in welche Richtung diese Entwicklung weist. Sie untersucht, inwieweit eine moderne Pädagogik von den derzeit so stark im Aufschwung begriffenen kognitiv-empirischen Untersuchungen ihrer zunehmend diversen Bezugsdisziplinen profitieren, welcher Art sie fachübergreifend Anregung erfahren und weitergedacht werden kann

Controlling alpha-SMA expression in adult human pancreatic stem cells by soluble factors

In the application of adult stem cells in regenerative medicine, it is indispensable to control stem cell behaviour in vitro. Since stem cells spontaneously differentiate into several cell types, it is mandatory to identify methods to enrich the desired cell types and concurrently block other differentiation pathways. More precisely, generation of a defined cell population is a key prerequisite for a therapeutic application of stem cells. Here we have demonstrated that it is possible to influence the differentiation of human pancreatic stem cells (hPSCs). During activation of mesodermal differentiation, the cytoskeletal protein alpha-smooth muscle actin (alpha-SMA) seems to play an important role in different cell systems and can usually be detected in hPSCs during in vitro cultivation. We cultured stem cells under different conditions and analyzed the impact on alpha-SMA expression. On the one hand, supplements like retinoic acid (RA) and dimethyl sulfoxide (DMSO) were added to the cultivation medium; on the other hand, different media with or without the addition of fetal calf serum (FCS) were used. Expression of alpha-SMA was determined by immunocytochemistry, Western blot analysis and quantitative RT-PCR. After the treatment of hPSCs with RA, a strong induction of alpha-SMA protein expression was observed when 2mM RA was added to the medium. DMSO in turn induced a marked reduction in alpha-SMA-positive cells. This could also be observed using a keratinocyte serum-free medium (KSFM). Furthermore, the general. addition of FCS to the medium had a blocking effect on alpha-SMA expression and decreased the number of alpha-SMA-positive cells to a minimum. The controlled modulation of hPSCs by soluble factors is a first success on the way to a promising application for transplantation medicine and cell therapy of degenerative diseases

Towards the development of a pragmatic technique for isolating and differentiating nestin-positive cells from human scalp skin into neuronal and glial cell populations: Generating neurons from human skin?

Nestin+ hair follicle-associated cells of murine skin can be isolated and differentiated in vitro into neuronal and glial cells. Therefore, we have asked whether human skin also contains nestin+ cells, and whether these can be differentiated in vitro into neuronal and/or glial cell populations. In this methodological pilot study, we show that both are indeed the case - employing purposely only very simple techniques for isolating, propagating, and differentiating nestin+ cells from normal human scalp skin and its appendages that do not require selective microdissection and tissue compartment isolation prior to cell culture. We show that, it is in principle, possible to maintain and propagate human skin nestin+ cells for extended passage numbers and to differentiate them into both neuronal (i.e. neurofilament+ and/or PGP9.5+) and glial (i.e. GFAP+, MBP+ and/or O4+) cell populations. Therefore, human scalp skin can serve as a highly accessible, abundant, and convenient source for autologous adult stem cell-like cells that offer themselves to be exploited for neuroregenerative medicine purposes

Phenotypic indications that human sweat glands are a rich source of nestin-positive stem cell populations

Background We have recently shown that the expression of nestin, a progenitor/stem cell marker protein, is localized in different mesenchymal compartments in human skin including the sweat gland stroma. Objectives As other exocrine glands are recognized sources of multipotent stem cell populations with potential for multilineage differentiation, it was our aim to isolate, expand and characterize glandular stem cells from human sweat glands. Methods Isolation of human sweat glands was based on mechanical and enzymatic digestion of axillary skin. Cultivation was performed on collagen-coated cell culture dishes and the resulting cell population was investigated at the protein and mRNA level. Results Outgrowing cells of isolated sweat glands showed a high-proliferation activity and were characterized by nestin expression in more than 80% of the cells. These sweat gland stem cells could be maintained in culture for long periods of time and showed spontaneous differentiation into cells representative of the different germ layers. Conclusions This pilot study provides the first, simple protocol for the isolation of adult human nestin-positive stem cells from the sweat gland mesenchyme, which promises to provide an easily accessible and abundantly available, autologous source of multipotent stem cells for cell-based regenerative medicine applications