IL-6 secretion in keratinocyte cell line HaCaT by dopaminergic agen

A.C. PARRADO, M.T. GENTILE AND E.B. REY-ROLDÁN

Buenos Aires

Congreso; III Iberoamerican Congress of Neuroimmunomodulation; 2009

It has been demonstrated that both dopaminergic agonists and ©¬-adrenergic antagonists promote wound healing. Epidermal keratinocytes synthetize and express catecholamine receptors besides the production of IL-6, a cytokine with proliferative properties.   We evaluated in a non-tumoral human keratinocyte cell line (HaCaT) the action of dopaminergic agonists on IL-6 secretion (ELISA) and cell proliferation (colorimetric assay WST-1 based). The study was done in relation to the presence/absence of ¥á, ©¬-adrenergic, dopaminergic receptors antagonists and ascorbic acid (antioxidant).   Dopamine (DA) significantly stimulate IL-6 secretion after 24 h incubation (10-5M: 417.8¡¾30.1% and 10-4 M: 532.1¡¾55.0 %, p< 0.001). This effect was enhanced in the absence of ascorbic acid  (10-5M: 667.7¡¾47.0 % and 10-4 M: 1300¡¾ 300.4 %, p< 0.01) without altering cell proliferation. DA-induced IL-6 secretion was blocked by propranolol (©¬-adrenergic antagonist), partially reduced by sulpiride (dopaminergic antagonist) but not by phentolamine (¥á-adrenergic antagonist).    IL-6 release by cabergoline (dopaminergic agonist) was detected. However this effect was not modified by adrenergic antagonists, while slightly blocking action by sulpiride was observed. Dopaminergic antagonists haloperidol and chlorpromazine (10-4 M) reduced HaCaT proliferation.   Our results suggest that dopaminergic agents increase IL-6 secretion in keratinocytes mainly through ©¬-adrenoreceptors, and probably other receptor independent mechanisms are involved.