Activation of PKC epsilon induces lactotroph proliferation through ERK1/2 in response to phorbol ester

PETITI J.P.; DE PAUL A.L.; GUTIÉRREZ S.; PALMERI C.; MUKDSI J. H.; TORRES A.I.

Elsevier

Año: 2008 vol. 289 p. 77 - 77

p class="abstract">The aim of this investigation was to contribute to current knowledge about intracellular mechanisms that are involved in lactotroph cell proliferation, by evaluating the role of PKCalpha, PKCepsilon and extracellular-signal regulated kinase (ERK) 1/2 in response to phorbol 12-myristate13-acetate (PMA). In primary pituitary cultures, the activation of protein kinase C (PKC) by PMA for 15min stimulated lactotroph proliferation; whereas a prolonged activation for 3-8h diminished this proliferative effect. The use of PMA for 15min-activated PKCepsilon and ERK1/2, whereas incubation with PMA for 3h induced PKCalpha activation and attenuated the PMA-triggered phosphorylation of ERK1/2. The following inhibitors: PKCs (bisindolylmaleimide I), PKCepsilon (epsilonV1 peptide) and ERK1/2 (PD98059) prevented the mitogenic activity induced by PMA for 15min. Lactotroph cells stimulated with PMA for 15min showed a translocation of PKCepsilon to membrane compartment and nucleus. The