POSSIBLE MECHANISMS INVOLVED IN THE ELONGATION/RETRACTION OF CAD CELLS NEURITES

MARÍA EUGENIA CHESTA; CARLOS GASTÓN BISIG; GUILLERMO GASTÓN ZAMPAR; AGUSTÍN CARBAJAL; CARLOS ÁNGEL ARCE

Huerta Grande

Congreso; XXVI Congreso anual de la sociedad argentina de investigación en neurociencia; 2011

CAD cells (derived from a mouse brain tumor) have a rounded shape and proliferate in standard culture medium. When deprived of serum, cells stop proliferation and emit long processes similar to normal neurons. Neurites rapidly retract when serum is re-added and cells resume growth. We found that microtubules (MTs) in these cells are highly dynamic, many of the major MAPs are absent, tubulin is mainly tyrosinated, and the acetylated isoform is not detected. We have determined that integrity and disassembly of MTs is required for neurite elongation and retraction, respectively. A transient increase of acetylated tubulin neither increased stability of MTs nor impeded retraction of neurites. Conditions that enhance the interaction of MTs with Na,K-ATPase do not alter elongation or retraction. Treatment of cells with lysophosphatidic acid or with adenosine deaminase, in the absence of serum, induced neurite retraction. Lack of ATP or the disassembly of microfilaments prevent retraction, suggesting that the actomyosin system is part of the retraction mechanism.