Perfluorooctyl Iodide Stimulates Steroidogenesis in H295R Cells via a Cyclic Adenosine Monophosphate Signaling Pathway

Abstract

Perfluorinated iodine alkanes (PFIs) are used widely in the organic fluorine industry. Increased production of PFIs has caused environmental health concerns. To evaluate the potential endocrine-disrupting effect of PFIs, we investigated the effects of perfluorooctyl iodide (PFOI) on steroidogenesis in human adrenocortical carcinoma cells (H295R). Levels of aldosterone, cortisol, 17β-estradiol, and testosterone were measured in H295R culture medium upon treatment with perfluorooctanoic acid (PFOA) and PFIs. Expression of 10 steroidogenic genes (StAR, HMGR, CYP11A1, 3βHSD2, 17βHSD, CYP17, CYP21, CYP11B1, CYP11B2, and CYP19) was measured by real-time polymerase chain reaction. Levels of cyclic adenosine monophosphate (cAMP) and adenylate cyclase (AC) activity were measured to understand the underlying mechanism of steroidogenic perturbations. Levels of production of aldosterone, cortisol, and 17β-estradiol were elevated significantly, and the level of testosterone generation decreased upon treatment with 100 μM PFOI. Similar to the effect induced by forskolin (AC activator), expression of all 10 genes involved in the synthesis of steroid hormones was upregulated significantly upon exposure to 100 μM PFOI. PFOA had no effect on steroid hormone production or steroidogenic gene expression even though it is highly structurally similar with PFOI. Therefore, the terminal -CF 2 I group in PFOI could be a critical factor for mediation of steroidogenesis. PFOI increased AC activity and cAMP levels in H295R cells, which implied an underlying mechanism for the disturbance of steroidogenesis. These data suggest that PFOI may act as an AC activator, thereby stimulating steroidogenesis by activating a cAMP signaling pathway.

Synthetic Phenolic Antioxidants Cause Perturbation in Steroidogenesis in Vitro and in Vivo

“…In steroidogenesis (SI Figure S7), cholesterol was first transferred to the inner mitochondrial membrane by StAR, converted to progesterone by CYP11A1, and subsequently metabolized through multistep process to aldosterone, cortisol, T and E 2 , respectively, under the regulation of diverse enzymes, including 3βHSD, CYP21, CYP11B1, CYP11B2, CYP17, 17βHSD, and CYP19 etc. 24 As demonstrated previously, 38 the significant up-regulation of target gene transcriptional levels induced by 10 μM forskolin (SI Figure S6), was consistent with increased steroid hormone secretion (SI Figure S5), showing the crucial correlation between the expression of key steroidogenic genes and hormone levels. To understand how SPAs disturbed steroidogenesis, BHA was selected as a representative compound for the study of its function on these target genes.…”

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and their effects on the ovary

“…PFAS are also known to have weak oestrogenic activity and, as with other weak oestrogens, exposure to a combination of E2, and these compounds produced anti-estrogenic effects ( Liu et al , 2007 ). Studies have reported contradictory results using in vitro screening systems to assay for hormone activity by ER- or AR-mediated transactivation in the human breast adenocarcinoma cell lines MCF-7 and MVLN ( Maras et al , 2006 ; Wang et al , 2012 ; Kjeldsen and Bonefeld-Jørgensen, 2013 ; Behr et al , 2018 ), human adrenal carcinoma cell H295R ( Du et al , 2013a ; 2013b ; Wang et al , 2015 ; Behr et al , 2018 ) and human placental choriocarcinoma cell JEG-3 ( Gorrochategui et al , 2014 ), as well as in in vivo testing ( Biegel et al , 1995 ; Du et al , 2013a ; Yao et al , 2014 ). It remains unclear whether PFAS affect oestrogen or androgen receptor signalling at concentrations relevant to human exposure.…”

Antioxidants (selenium and garlic) alleviated the adverse effects of tramadol on the reproductive system and oxidative stress markers in male rabbits

“…The steroidogenic acute regulatory protein (StAR) was responsible for transferring cholesterol from the outer mitochondrial membrane to the inner one, which hosts the cytochrome P450 side-chain cleavage (P450 SCC) enzyme 30 . P450scc converts cholesterol to pregnenolone, which is subsequently transported to the smooth endoplasmic reticulum, where it is converted to testosterone by CYP17, CYP21, 3-hydroxysteroid dehydrogenase (3-HSD), and 17-hydroxysteroid dehydrogenase (17-HSD) 31 – 35 . In the testes, the 17-HSD enzyme is almost expressed and is needed for testosterone biosynthesis 36 .…”