Comparative effect of FGF2, synthetic peptides 1-28 N-POMC and ACTH on proliferation in rat adrenal cell primary cultures

There is evidence that pro-opiomelanocortin (POMC)-derived peptides other than adrenocorticotropic hormone (ACTH) have a role in adrenal cell proliferation. We compared the activity of synthetic rat N-terminal POMC fragment 1-28 with disulfide bridges (N-POMC(w)) and without disulfide bridges (N-POMC(w/o)), with the activity of fibroblast growth factor (FGF2), a widely studied adrenal growth factor, and ACTH, in well-characterized pure cultures of both isolated adrenal Glomerulosa (G) and Fasciculata/Reticularis (F/R) cells. Three days of FGF2-treatment had a proliferative effect similar to serum, and synthetic peptide N-POMC(w) induced proliferation more efficiently than N-POMC(w/o). Moreover, both induced proliferation via the ERK1/2 pathway. In contrast, sustained ACTH treatment decreased proliferation and viability through apoptosis induction, but not necrosis, and independently of PKA and PKC pathways. Further elucidation of 1-28 POMC signal transduction is of interest, and primary cultures of adrenal cells were found to be useful for examining the trophic activity of this peptide.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Foundation for the Support of Research in the State of Sao Paulo)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, The National Council for Scientific and Technological Development)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pro-Reitoria de Pesquisa da Universidade de Sao Paulo (USP University of Sao Paulo Dean`s Office for Research Projects)

Pró-Reitoria de Pesquisa da USP (PRP-USP)