Premium
Neuronal differentiation requires a biphasic modulation of gap junctional intercellular communication caused by dynamic changes of connexin43 expression
Author(s) -
Lemcke Heiko,
Nittel MarieLouise,
Weiss Dieter G.,
Kuznetsov Sergei A.
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12219
Subject(s) - microbiology and biotechnology , cellular differentiation , biology , gap junction , connexin , fluorescence recovery after photobleaching , progenitor cell , embryonic stem cell , neural stem cell , cell fate determination , intracellular , cell growth , neurogenesis , stem cell , transcription factor , biochemistry , membrane , gene
It was suggested that gap junctional intercellular communication ( GJIC ) and connexin ( C x) proteins play a crucial role in cell proliferation and differentiation. However, the mechanisms of cell coupling in regulating cell fate during embryonic development are poorly understood. To study the role of GJIC in proliferation and differentiation, we used a human neural progenitor cell line derived from the ventral mesencephalon. Fluorescence recovery after photobleaching ( FRAP ) showed that dye coupling was extensive in proliferating cells but diminished after the induction of differentiation, as indicated by a 2.5‐fold increase of the half‐time of fluorescence recovery. Notably, recovery half‐time decreased strongly (five‐fold) in the later stage of differentiation. Western blot analysis revealed a similar time‐dependent expression profile of C x43, acting as the main gap junction‐forming protein. Interestingly, large amounts of cytoplasmic C x43 were retained mainly in the Golgi network during proliferation but decreased when differentiation was induced. Furthermore, down‐regulation of C x43 by small interfering RNA reduced functional cell coupling, which in turn resulted in a 50% decrease of both the proliferation rate and neuronal differentiation. Our findings suggest a dual function of C x43 and GJIC in the neural development of R e N cell VM 197 human progenitor cells. GJIC accompanied by high C x43 expression is necessary (1) to maintain cells in a proliferative state and (2) to complete neuronal differentiation, including the establishment of a neural network. However, uncoupling of cells is crucial in the early stage of differentiation during cell fate commitment.