Interleukin-6 increases the expression of key proteins associated with steroidogenesis in human NCI-H295R adrenocortical cells

• Published in: Steroids Vol. 119; pp. 1 - 17
• Main Authors: Strickland, Janae, McIlmoil, Stephen, Williams, Brice J., Seager, Dennis C., Porter, James P., Judd, Allan M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2017
• Subjects: Adrenal Cortex - drug effects; Adrenal Cortex - metabolism; Blotting, Western; Cell Line; DAX-1; Humans; Hydrocortisone - metabolism; Interleukin-6; Interleukin-6 - pharmacology; JAK/STAT pathway; Janus Kinases - metabolism; NCI-H295R adrenocortical cells; Phosphorylation - drug effects; RNA, Messenger - metabolism; STAT Transcription Factors - metabolism; Steroidogenesis; Steroidogenic Factor 1 - metabolism; Steroidogenic factor-1; Steroids - metabolism; Transcription Factors - metabolism; Steroidogenic factor-1; DAX-1; Steroidogenesis; NCI-H295R adrenocortical cells; JAK/STAT pathway; Interleukin-6
• ISSN: 0039-128X; 1878-5867
• DOI: 10.1016/j.steroids.2016.12.014

•Interleukin 6 (IL-6) increased H295R adrenocortical cell cortisol release.•IL-6 increased expression of H295R StAR and five steroidogenic enzymes (SE).•IL-6 increased H295R SF-1, a nuclear factor that increases SE and StAR expression.•IL-6 decreased expression of H295R DAX-1, a nuclear factor that inhibits SE and StAR.•JAK/STAT phosphorylation increased by IL-6; JAK/STAT inhibition decreased StAR. Mechanisms of interleukin-6 (IL-6)-induced cortisol release (CR) were investigated by exposing H295R cells to IL-6 and determining mRNA/protein expression (PCR/western blots) for steroidogenic enzymes (SE), steroidogenic acute regulatory protein (StAR), steroidogenic factor-1 (SF-1) (enhances SE/StAR expression), activator protein 1 (AP-1) (regulates SE/StAR expression) and adrenal hypoplasia congenita-like protein (DAX-1) (inhibits SE/StAR expression). Promoter activity of StAR (SPA) was measured by a luciferase-coupled promoter. Cortisol release was increased by 10ng/mL IL-6 (24h P<0.01). Proteins/mRNAs (StAR, cholesterol side chain cleavage enzyme, SF-1, AP-1) and SPA were increased by IL-6 (60min 1–50ng/mL IL-6; 5ng/mL IL-6 30–120min P<0.05). Four other SE proteins/mRNAs were also increased by 10ng/mL IL-6 (60min P<0.01). Protein/mRNA for DAX-1 was decreased by IL-6 (60min 1–50ng/mL IL-6; 5ng/mL IL-6 30–120min P<0.01). Phosphorylation of Janus kinase (JAK) and signal transducer and activator of transcription (STAT) was increased by IL-6 (JAK2 60min 1–50ng/mL IL-6; 10ng/mL IL-6 5–60min P<0.05; STAT1 and STAT3 60min 10ng/mL IL-6 P<0.01). Inhibition of JAK/STAT with AG490 (10μM) or piceatannol (50μM) blocked (P<0.01 10ng/mL IL-6vs. IL-6 plus AG490 or piceatannol) IL-6-induced increases in SPA and StAR mRNA. In summary, IL-6-induced CR may be facilitated by increased StAR and SE mediated by increased SF-1 and AP-1, decreased DAX-1, and increased phosphorylation of JAK/STAT.