Identification of Novel Low-Dose Bisphenol A Targets in Human Foreskin Fibroblast Cells Derived from Hypospadias Patients

Xian-Yang Qin,Jun Yoshinaga,Hideko Sone,Kenjiro Kohri,Hiromi Akanuma,Mami Miyado,Hiroko Zaha,Yutaro Hayashi,Tsutomu Ogata,Junzo Yonemoto,Tomokazu Fukuda,Qin Zeng,Katsuhiko Ueoka,Maki Fukami,Yoshiyuki Kojima,Kentaro Mizuno,Koji Muroya,Bin He

doi:10.1371/journal.pone.0036711

Abstract

Background/PurposeThe effect of low-dose bisphenol A (BPA) exposure on human reproductive health is still controversial. To better understand the molecular basis of the effect of BPA on human reproductive health, a genome-wide screen was performed using human foreskin fibroblast cells (hFFCs) derived from child hypospadias (HS) patients to identify novel targets of low-dose BPA exposure.Methodology/Principal FindingsGene expression profiles of hFFCs were measured after exposure to 10 nM BPA, 0.01 nM 17β-estradiol (E2) or 1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 24 h. Differentially expressed genes were identified using an unpaired Student's t test with P value cut off at 0.05 and fold change of more than 1.2. These genes were selected for network generation and pathway analysis using Ingenuity Pathways Analysis, Pathway Express and KegArray. Seventy-one genes (42 downregulated and 29 upregulated) were identified as significantly differentially expressed in response to BPA, among which 43 genes were found to be affected exclusively by BPA compared with E2 and TCDD. Of particular interest, real-time PCR analysis revealed that the expression of matrix metallopeptidase 11 (MMP11), a well-known effector of development and normal physiology, was found to be inhibited by BPA (0.47-fold and 0.37-fold at 10 nM and 100 nM, respectively). Furthermore, study of hFFCs derived from HS and cryptorchidism (CO) patients (n = 23 and 11, respectively) indicated that MMP11 expression was significantly lower in the HS group than in the CO group (0.25-fold, P = 0.0027).Conclusions/SignificanceThis present study suggests that an involvement of BPA in the etiology of HS might be associated with the downregulation of MMP11. Further study to elucidate the function of the novel target genes identified in this study during genital tubercle development might increase our knowledge of the effects of low-dose BPA exposure on human reproductive health.

Highlights

Hypospadias (HS) is one of the most common congenital abnormalities with a global prevalence of approximately 0.2–1% at birth in male infants [1]
The gene expression profiles in human foreskin fibroblast cells (hFFCs) treated with Dimethyl sulfoxide (DMSO) control or 10 nM Bisphenol A (BPA), 0.01 nM E2 or 1 nM TCDD were determined by Agilent microarray analysis using three biological replicates
No nuclear receptor was found to be significantly differentially expressed in response to BPA, while estrogen-related receptor-a (ESRRA), retinoic acid receptor-a (RARA) and RAR-related orphan receptor-a (RORA) and RARA were found to be significantly differentially expressed in response to E2 and TCDD, respectively

Summary

Introduction

Hypospadias (HS) is one of the most common congenital abnormalities with a global prevalence of approximately 0.2–1% at birth in male infants [1]. It has been hypothesized that testicular cancer, cryptorchidism (CO) and some cases of HS and impaired spermatogenesis are symptoms of a single underlying entity that has been named as the testicular dysgenesis syndrome (TDS) [2,3]. This concept proposes the existence of a common underlying cause for the occurrence of these reproductive and developmental diseases, and suggests that adverse environmental factors, such as environmental endocrine disruptors (EEDs) might exert their etiological effects on a susceptible genetic background. In recent decades, there has been a heated controversy over the safety of BPA among scientists and risk assessors

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