Abacavir, nevirapine, and ritonavir modulate intracellular calcium levels without affecting GHRH-mediated growth hormone secretion in somatotropic cells in vitro

Publication date: Available online 11 December 2018Source: Molecular and Cellular EndocrinologyAuthor(s): Giulia Brigante, Laura Riccetti, Clara Lazzaretti, Laura Rofrano, Samantha Sperduti, Francesco Potì, Chiara Diazzi, Flavia Prodam, Giovanni Guaraldi, Andrea G. Lania, Vincenzo Rochira, Livio CasariniAbstractGrowth Hormone (GH) deficiency is frequent in HIV-infected patients treated with antiretroviral therapy. We treated GH3 cells with antiretrovirals (nevirapine, ritonavir or abacavir sulfate; 100 pM-1 mM range), after transfection with human growth hormone releasing hormone (GHRH) receptor cDNA. Cells viability, intracellular cAMP, phosphorylation of CREB and calcium increase, GH production and secretion were evaluated both in basal condition and after GHRH, using MTT, bioluminescence resonance energy transfer, western blotting and ELISA.Antiretroviral treatment did not affect GHRH 50% effective dose (EC50) calculated for 30-min intracellular cAMP increase (Mann-Whitney's U-test; p ≥ 0.05; n = 4) nor 15-min CREB phosphorylation. The kinetics of GHRH-mediated, rapid intracellular calcium increase was perturbed by pre-incubation with drugs, while GHRH failed to induce the ion increase in ritonavir pre-treated cells (ANOVA; p < 0.05; n = 3). Antiretrovirals did not impact 24-h intracellular and extracellular GH levels (ANOVA; p ≥ 0.05; n = 3).We demonstrated the association between antiretrovirals and intracellular calcium increase, witho...
Source: Molecular and Cellular Endocrinology - Category: Endocrinology Source Type: research