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Research Containing: Cell Differentiation/genetics/*physiology

Effects of Microgravity Modeled by Large Gradient High Magnetic Field on the Osteogenic Initiation of Human Mesenchymal Stem Cells

by on 9 June 2015in Biology & Biotechnology No comment

Microgravity (MG) leads to a decrease in osteogenic potential of human bone marrow-derived mesenchymal stem cells (hMSCs). In the present study, we used large gradient high magnetic field (LGHMF) produced by a superconducting magnet to model MG (LGHMF-MG) and analyzed the effects of LGHMF-MG on survival, cytoskeleton and osteogenic potential of hMSCs. Results showed that the LGHMF-MG treatment for 6 h disrupted the cytoskeleton of hMSCs, and the LGHMF-MG treatment for 24 h led to cell death. LGHMF-MG treatments for 6 h in early stages of osteogenic induction (the pre-treatment before osteogenic induction, the beginning-treatment in the beginning-stage of osteogenic induction and the middle-treatment in the middle-stage of osteogenic induction) resulted in suppression on osteogenesis of hMSCs. The suppression intensity was reduced gradually as the treatment stage of LGHMF-MG was postponed. The LGHMF-MG treatment for 6 h in the ending-stage of osteogenic induction (the ending-treatment) had no obvious effect on osteogenesis of hMSCs. These results indicated that LGHMF-MG should affect the initiation of osteogenesis. Finally, the possible mechanism for the inhibition effect of LGHMF-MG on osteogenesis of hMSCs is discussed.

Related URLs:
<Go to ISI>://WOS:000282424200009

Enhanced cardiac differentiation of mouse embryonic stem cells by use of the slow-turning, lateral vessel (STLV) bioreactor

by on 9 June 2015in Biology & Biotechnology No comment

Embryoid body (EB) formation is a common intermediate during in vitro differentiation of pluripotent stem cells into specialized cell types. We have optimized the slow-turning, lateral vessel (STLV) for large scale and homogenous EB production from mouse embryonic stem cells. The effects of inoculating different cell numbers, time of EB adherence to gelatin-coated dishes, and rotation speed for optimal EB formation and cardiac differentiation were investigated. Using 3 x 10(5) cells/ml, 10 rpm rotary speed and plating of EBs onto gelatin-coated surfaces three days after culture, were the best parameters for optimal size and EB quality on consequent cardiac differentiation. These optimized parameters enrich cardiac differentiation in ES cells when using the STLV method.

Related URLs:
<Go to ISI>://WOS:000293752000009

Microgravity promotes differentiation and meiotic entry of postnatal mouse male germ cells

by on 9 June 2015in Biology & Biotechnology No comment

A critical step of spermatogenesis is the entry of mitotic spermatogonia into meiosis. Progresses on these topics are hampered by the lack of an in vitro culture system allowing mouse spermatogonia differentiation and entry into meiosis. Previous studies have shown that mouse pachytene spermatocytes cultured in simulated microgravity (SM) undergo a spontaneous meiotic progression. Here we report that mouse mitotic spermatogonia cultured under SM with a rotary cell culture system (RCCS) enter into meiosis in the absence of any added exogenous factor or contact with somatic cells. We found that isolated Kit-positive spermatogonia under the RCCS condition enter into the prophase of the first meiotic division (leptotene stage), as monitored by chromosomal organization of the synaptonemal complex 3 protein (Scp3) and up-regulation of several pro-meiotic genes. SM was found to activate the phosphatidyl inositol 3 kinase (PI3K) pathway and to induce in Kit-positive spermatogonia the last round of DNA replication, typical of the preleptotene stage. A PI3K inhibitor abolished Scp3 induction and meiotic entry stimulated by RCCS conditions. A positive effect of SM on germ cell differentiation was also observed in undifferentiated (Kit-negative) spermatogonia, in which RCCS conditions stimulate the expression of Kit and Stra8. In conclusion, SM is an artificial environmental condition which promotes postnatal male germ cell differentiation and might provide a tool to study the molecular mechanisms underlying the switch from mitosis to meiosis in mammals.

Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed9&AN=2010168350
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:10.1371%2Fjournal.pone.0009064&issn=1932-6203&isbn=&volume=5&issue=2&spage=e9064&pages=&date=2010&title=PLoS+ONE&atitle=Microgravity+promotes+differentiation+and+meiotic+entry+of+postnatal+mouse+male+germ+cells&aulast=Pellegrini&pid=%3Cauthor%3EPellegrini+M.%3C%2Fauthor%3E&%3CAN%3E2010168350%3C%2FAN%3E