The adrenal gland secretes several cytokines, and cytokines modulate steroid secretion by this gland. In this study, a survey of cytokine production by H295R human adrenocortical cells demonstrated that these cells secreted IL-2, IL-4, IL-8, IL-10, IL-13, and TNFα but not IL-5, IL-12, or interferon-γ. IL-8 was the IL secreted at higher concentration. IL-8 secretion, its regulation, and role in steroidogenesis were further studied. Secreted ILs and steroids were measured by ELISA in cell culture supernatant. IL-8 mRNA was quantified by real-time RT-PCR. H295R cells and human adrenal gland expressed IL-8 mRNA. Angiotensin II, potassium, endothelin-1, IL-1α, IL-1β, TNFα, and Escherichia coli lipopolysaccharide dose-dependently increase IL-8 secretion by H295R cells after 24 h incubation. IL-6 had no effect on IL-8 secretion. Angiotensin II time-dependently increased IL-8 secretion by H295R cells up to 48 h. Angiotensin II caused a biphasic increase in IL-8 mRNA expression with a peak 6 h after stimulation. TNFα synergized angiotensin II, potassium, and IL-1α-mediated IL-8 secretion. IL-8 did not modify aldosterone or cortisol secretion by H295R cells under basal or stimulated (angiotensin II or potassium) conditions. In conclusion, it is demonstrated for the first time that human adrenal cells expressed and secreted IL-8 under the regulation of angiotensin II, potassium, endothelin-1, and immune peptides. Adrenal-secreted IL-8 is one point of convergence between the adrenal gland and the immune system and may have relevance in physiological and pathophysiological conditions associated with increased levels of aldosterone secretagogues and the immune system.
Stimulus-selective induction of the orphan nuclear receptor NGFIB underlies different influences of angiotensin II and potassium on the human adrenal gland zona glomerulosa-specific 3β-HSD isoform gene expression in adrenocortical H295R cells
