2006 Volume No 11– pages 76-85
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Title: Nuclear Factor-kappaB controls the reaggregation
of 3D neurosphere cultures in vitro |
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Authors: D Widera, I Mikenberg, A Kaus, C Kaltschmidt,
B Kaltschmidt |
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Address: Institut für Neurobiochemie, Universität
Witten/Herdecke, Stockumer Str. 10, D-58448 Witten, Germany |
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E-mail: b.kaltschmidt at uni-wh.de |
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Key Words: Neural stem cell, neurosphere, TNF-alpha,
aggregation, cell motility, Nuclear Factor-kappaB, IkappaB,
neurosphere formation, somatic stem cell, reaggregation, tissue
culture, 3D |
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Publication date: May 23rd 2006 |
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Abstract: The approach of reaggregation involves
the regeneration and self-renewal of histotypical 3D spheres
from isolated tissue kept in suspension culture. Reaggregated
spheres can be used as tumour, genetic, biohybrid and neurosphere
models. In addition the functional superiority of 3D aggregates
over conventional 2D cultures developed the use of neurospheres
for brain engineering of CNS diseases. Thus 3D aggregate cultures
created enormous interest in mechanisms that regulate the
formation of multicellular aggregates in vitro. Here we analyzed
mechanisms guiding the development of 3D neurosphere cultures.
Adult neural stem cells can be cultured as self-adherent clusters,
called neurospheres. Neurospheres are characterised as heterogeneous
clusters containing unequal stem cell sub-types. Tumour necrosis
factor-alpha (TNF- alpha is one of the crucial inflammatory
cytokines with multiple actions on several cell types. TNF-
alpha strongly activates the canonical Nuclear Factor Kappa-B
(NF-kappaB) pathway. In order to investigate further functions
of TNF in neural stem cells (NSCs) we tested the hypothesis
that TNF is able to modulate the motility and/or migratory
behaviour of SVZ derived adult neural stem cells. We observed
a significantly faster sphere formation in TNF treated cultures
than in untreated controls. The very fast aggregation of isolated
NSCs (<2h) is a commonly observed phenomenon, though the
mechanisms of 3D neurosphere formation remain largely unclear.
Here we demonstrate for the first time, increased aggregation
and enhanced motility of isolated NSCs in response to the
TNF-stimulus. Moreover, this phenomenon is largely dependent
on activated transcription factor NF-kappaB. Both, the pharmacological
blockade of NF-kappaB pathway by pyrrolidine dithiocarbamate
(PDTC) or Bay11-7082 and genetic blockade by expression of
a transdominant-negative super-repressor IkappaB-AA1 led to
decreased aggregation.
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Article download: Pages
76-85 (PDF file) Download movies (see paper for details - Results section) |
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