In Utero Exposure to Phthalate Downregulates Critical Genes in Leydig Cells of F₁ Male Progeny

Abstract

Phthalates are the largest group of environmental pollutants and are considered toxicant to the endocrine system. The present study was aimed to test the effect of in utero exposure of di(2-ethylhexyl)phthalate (DEHP) on Leydig cell steroidogenesis in F1 male offspring's. Pregnant dams were oral gavaged with different doses (1, 10, and 100 mg/kg/day) of DEHP or olive oil during gestational Day 9-21. Serum testosterone (T) and estradiol (E2) levels were significantly reduced in male offspring at 60 days of age. Our results also demonstrate a coordinate, dose-dependent disruption of genes involved in steroidogenesis. The gene expression of StAR, Cyp11a1, 3β-HSD, 17β-HSD, 5α-reductase and cytochrome P450 19a1 (or) aromatase (Cyp-19) were significantly decreased. The transcription factors like steroidogenic factor-1 (SF-1) and specific protein-1 (Sp-1) showed a significant decrease in 10 and 100 mg DEHP treatment group. DNA methylation analysis using bisulfite specific-methylation PCR shows hypermethylation in the SF-1 and Sp-1 promoter regions. Further to determine whether the DEHP-induced methylation changes were associated with increased DNA methyltransferase (Dnmt) levels, we measured the expression levels of Dnmt3a, Dnmt3b, Dnmt1, and Dnmt3l using real-time PCR and Western blot method. The mRNA and protein expressions of Dnmt3a, Dnmt3b, and Dnmt1 were stimulated in 10 and 100 mg DEHP treatment groups, whereas no significant change was seen in Dnmt3l expression, suggesting that increased Dnmt3a/b, Dnmt1 may cause DNA hypermethylation in testicular Leydig cells. Overall, these data suggest that gestational exposure to DEHP affects adult testicular function via altered methylation patterns.

Cytotoxic effects of ZnO nanoparticles on mouse testicular cells

“…Any agent that impairs the viability and functions of these two cell types will have profound effects on spermatogenesis. [23][24][25] Concerning the effect of ZnO NP on male reproduction, it has been reported that these NPs can act as a testicular toxicant. [26][27][28] Ji et al have reported that LCs exposed to 10/20 μM of cadmium (Cd) had reduced levels of steroid hormone due to inhibition of activation of cyclic adenosine monophosphate/protein kinase A, protein kinase C signaling pathway, and the steroidogenic enzymes StAR, CYP11A1, and 3β-HSD.…”

Effects of long-term endocrine disrupting compound exposure on Macaca mulatta embryonic stem cells

“…DEHP can act through multiple mechanisms, with effects as an anti-androgen and inhibitor of steroidogenesis, and may increase expression of DNA methyltransferase genes leading to DNA hypermethylation [58, 59]. DEHP treatment increased the expression of 12 genes (9 ≥ 1.5-fold, 5 ≥ 2-fold, and 2 ≥ 4-fold) and decreased the expression of 48 genes (15 ≥ 1.5-fold, 4 ≥ 2-fold and 1 ≥ 4-fold) (Table S3).…”

Molecular docking reveals the potential of phthalate esters to inhibit the enzymes of the glucocorticoid biosynthesis pathway

“…It converts cholesterol to pregnenolone in three successive monooxygenations (hydroxylation at C‐22, followed by C‐20, and finally cleavage of the C‐20, 22 bonds) (Hanukoglu, ). Sekaran and Jagadeesan () have reported decreased gene expression of StAR, CYP11A1, 3β‐HSD, 17β‐HSD, 5α‐reductase and CYP19A1 in Leydig cells of the progeny of in utero‐ exposed dams. Altered gene expression of StAR, CYP19A1 and CYP11A1 has also been found in testis on DEHP exposure (Lu et al , ) and rat fetal testis xenografts exposed to DBP significantly reduced CYP11A1 and StAR mRNA expression (Mitchell et al , ).…”