Exp Clin Endocrinol Diabetes 2006; 114 - P10_132
DOI: 10.1055/s-2006-933017

The influence of DHEA on NGF-induced differentiation of pheochromocytoma PC12 cells

CG Ziegler 1, AW Krug 1, F Sicard 1, S Sperber 1, M Ehrhart-Bornstein 2, S Bornstein 3
  • 1Technical University of Dresden, Department of Molecular Endocrinology, Dresden, Germany
  • 2Technical University of Dresden, Department of Diabetology, Dresden, Germany
  • 3Technical University of Dresden, Medical Clinic III, Dresden, Germany

Adrenocortical androgens, including dehydroepiandrosterone (DHEA), are produced in the inner zone of the adrenal cortex which is in direct contact to the neural crest-derived catecholamine-producing chromaffin cells. DHEA has recently been identified as a crucial regulator in neural stem cell proliferation. Thus, DHEA might play a hitherto unknown intra-adrenal role in adrenal tissue formation and/or tumorigenesis. The rat pheochromocytoma cell line PC12 is a well established model for proliferation- and mitotic competent chromaffin cells. In the present study we examined the influence of DHEA on nerve growth factor (NGF)-induced morphological changes, proliferation and signalling pathways in PC12 cells. NGF, in a dose dependent manner, promoted cell survival in serum deprived PC12 cells. This effect was lessened by DHEA (10–5–10–8 Mol). The influence of DHEA on NGF-induced differentiation was characterized by Western blotting and immunohistochemistry, using the neuroendocrine markers SNAP 25 and VAMP-2. Both are known to promote in PC12 cells morphological changes like, neurite elongation or neurite sprouting, respectively. NGF promoted the upregulation of SNAP 25 and VAMP-2, an effect reduced by DHEA in a dose dependent manner (10–5–10–8 Mol). In a next step, we explored the possible molecular mechanisms of DHEA and NGF interaction in more detail. It is well accepted that steroid hormones like DHEA can induce rapid (“non-genomic“) effects by interfering within e.g. intracellular second messenger generation, pH regulation or signalling cascades like the mitogen-activated protein kinases (MAPK) ERK 1/2. Differentiation as well as proliferation processes in PC12 cells are accompanied by ERK 1/2 activation. Phospho-specific ELISA and Western blotting showed that NGF-induced ERK 1/2 activation (2–10min) in PC12 cells was significantly inhibited by DHEA in a time- and dose dependent manner. In summary, the data shows that DHEA influences differentiation processes in pheochromocytoma cells.