Endocrine Abstracts

Introduction: The highly active human fetal adrenal gland plays a critical role in long term health. Maternal cigarette smoking alters post-natal health of the fetus and the mechanisms involved may include the fetal adrenal. However, understanding of human fetal adrenal development is limited.

Aim: To examine the effects of nicotine, its metabolite cotinine, and cigarette smoke extract on H295R adrenocortical cell line steroidogenic capacity.

Methods: H295R cells were cultured for 5 days in the presence of cotinine, nicotine, or cigarette smoke extract, and stimulated with forskolin. Steroids and mRNA transcript levels were measured by ELISA, LC/MS and qPCR.

Results: Cell proliferation was not affected by cotinine or nicotine exposure but was reduced by cigarette smoke extract exposure in a dose dependent manner (P<0.01). Levels of CYP11A1, CYP17A1, CYP21A2, HSD3B, PGR and ESR2 transcripts were all significantly reduced in cigarette smoke extract exposed cells. The effects of cigarette smoke extract exposure on steroid production was variable. Dehydroepiandrosterone sulphate (DHEAS), 11-deoxycortisol and cortisol were all significantly reduced in cells exposed to cigarette smoke extract, whereas 17α-hydroxyprogesterone was significantly higher on day 3 and lower on day 5 of culture, compared to controls. Nicotine alone was not associated with any differences in steroid production or enzyme expression but its metabolite, cotinine, significantly increased levels of CYP11A1 (P<0.01), CYP17A1 (P<0.01), SULT2A1 (P<0.01), and ESR2 (P=0.03) at concentrations equivalent to those found in human breastmilk. Cortisol levels, in contrast, were significantly reduced in cells exposed to the same concentration of cotinine.

Conclusions: Cell proliferation, transcript expression, and steroid production are altered in a fetal adrenocortical cell model by exposure to cigarette smoke. Nicotine alone however has a lesser effect on these cells than its major, bioactive, metabolite cotinine. These results suggest that maternal cigarette smoking may directly affect human fetal adrenal development.