Articles by Agapios Sachinidis in JoVE
Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation Vaibhav Shinde*1, Stefanie Klima*2, Perumal Srinivasan Sureshkumar1, Kesavan Meganathan1, Smita Jagtap1, Eugen Rempel3, Jörg Rahnenführer3, Jan Georg Hengstler4, Tanja Waldmann2, Jürgen Hescheler1, Marcel Leist*2, Agapios Sachinidis*1 1Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, 2Department of Biology, University of Konstanz, 3Department of Statistics, Technical University of Dortmund, 4Leibniz Research Centre for Working Environment and Human Factors, Technical University of Dortmund The protocols describe two in vitro developmental toxicity test systems (UKK and UKN1) based on human embryonic stem cells and transcriptome studies. The test systems predict human developmental toxicity hazard, and may contribute to reduce animal studies, costs and the time required for chemical safety testing.
Other articles by Agapios Sachinidis on PubMed
Evidence for Self-maintaining Pluripotent Murine Stem Cells in Embryoid Bodies Stem Cell Reviews. Feb, 2014 | Pubmed ID: 24022811 Pluripotent stem cells have great potential for regenerative medicine; however, their clinical use is associated with a risk of tumor formation. We utilized pluripotent cells expressing green fluorescent protein and puromycin resistance under control of the Oct4 promoter to study the persistence of potential pluripotent cells under embryoid body (EB) culture conditions, which are commonly used to obtain organotypic cells. We found that i.) OCT4-expressing cells dramatically decrease during the first week of differentiation, ii.) the number of OCT4-expressing cells recovers from day 7 on, iii.) the OCT4-expressing cells are similar to embryonic stem cells grown in the presence of leukemia inhibitory factor LIF but express several markers associated with germ cell formation, such as DAZL and STRA-8 and iv.) the persistence of potentially pluripotent cells is independent of supportive cells in EBs. Finally, OCT4-expressing cells, isolated from EBs after 2-month of culture, were further maintained under feeder-free conditions in absence of LIF and continued to express OCT4 in 95 % of the population for at least 36 days. These findings point to an alternative state of stable OCT4 expression. In the frame of the landscape model of differentiation two attractors of pluripotency might be defined based on their different characteristics.