Perfluorooctanoic Acid‐Induced Progesterone Synthesis Inhibition is Associated with Decreased Expression of Steroidogenic Acute Regulatory Protein (StAR) mRNA but Not p450 Side‐Chain Cleavage mRNA in hCG‐Stimulated mLTC‐1 Cells

Abstract

Perfluorooctanoic acid (PFOA) is an environmentally persistent synthetic fluoropolymer that has been identified as an endocrine disruptor. Although its mechanism of action remains largely unknown, it has been suggested to decrease steroidogenesis. The aims of this study were to determine if PFOA decreases progesterone (P4) synthesis in stimulated Mouse Leydig Tumor (mLTC‐1) cells and which steroidogenic enzymes are involved. Cells were treated with PFOA (100nm ‐ 100μM) for 24h before stimulation for 4h with human chorionic gonadotropin (hCG) or forskolin. Cell viability was measured using the CellTiter‐Blue® Cell Viability Assay. The effects of PFOA on P4 production were assessed by ELISA. The expression of steroidogenic acute regulatory protein (StAR), p450 side‐chain cleavage (p450scc), and the luteinizing hormone receptor (LHR) were determined by real‐time PCR. Cells treated with 100μM PFOA for 24h showed an 86% reduction in hCG‐induced P4 synthesis compared to untreated cells. To ensure that this decline was not due to diminished LHR expression (mRNA levels were decreased in PFOA‐treated cells), cells were also stimulated with forskolin. Similar results were obtained. There was no significant decrease in cell viability. There was no significant difference in levels of p450scc mRNA between PFOA‐stimulated and unstimulated cells. However, the levels of StAR mRNA levels were markedly declined in cells treated with 100μM PFOA. These data show inhibition of steroidogenesis in PFOA‐treated mLTC‐1 cells and an associated decrease in the expression of LHR and StAR mRNA. 
 Funding: Center for Undergraduate Research and Dept of Biological Sciences, GRU