2-Ethylhexyl Diphenyl Phosphate Affects Steroidogenesis and Lipidome Profile in Human Adrenal (H295R) Cells

TL;DR

This study shows that EHDPP, an organophosphate flame retardant, disrupts hormone production and lipid balance in human adrenal cells, suggesting it may act as an endocrine disruptor.

Contribution

The study is the first to demonstrate EHDPP's effects on adrenal steroidogenesis and lipid metabolism in human cells.

Findings

EHDPP exposure increases estradiol, cortisol, and aldosterone secretion in H295R cells.

EHDPP alters lipid profiles, reducing cholesterol esters and sphingolipids while increasing phospholipids and triglycerides.

EHDPP exposure shifts mitochondrial dynamics and affects corticosteroidogenic gene expression.

Abstract

The ever-increasing use of chemicals and the rising incidence
of
adverse reproductive effects in the modern environment have become
an emerging concern. Several studies have shown that environmental
contaminants, such as organophosphate flame retardants (OPFRs), negatively
impact reproductive health. To evaluate the potential endocrine-related
adverse reproductive effects of widely used and priority-listed compound
2-Ethylhexyl diphenyl phosphate (EHDPP), we characterized its effects
on adrenal steroidogenesis in human adrenocortical (H295R) cells.
The cells were exposed to EHDPP (1 and 5 μM) for 48 h, and the
production of hormones, including progesterone, androstenedione, testosterone,
estradiol, cortisol, and aldosterone, was measured. In addition, LC-MS/MS-based
lipidomics analysis was done to quantify intracellular lipid profiles,
and transcriptional assays were performed to examine the expression
of genes related to corticosteroidogenesis, lipid metabolism, and
mitochondrial dynamics. Our findings indicate that EHDPP disrupts
hormone regulation in vitro, as evidenced by increased estradiol,
cortisol, and aldosterone secretion. The expression of key corticosteroidogenic
genes (CYP11B2, CYP21A1, 3β-HSD2, and 17β-HSD1) was upregulated
significantly upon EHDPP exposure. Intracellular lipidomics revealed
EHDPP-mediated disruption, including reduced total cholesterol ester,
sphingolipids, and increased phospholipids, triglyceride species,
and saturated-monounsaturated lipids subspecies. These alterations
were accompanied by decreased ACAT2 and SCD1 gene expression. Moreover,
a shift in mitochondrial dynamics was indicated by increased MF1 expression
and decreased FIS1 expression. These data suggest that EHDPP disrupts
adrenal steroidogenesis and lipid homeostasis, emphasizing its potential
endocrine-disrupting effects.

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