Di (2-ethylhexyl) Phthalate Exposure Impairs the microRNAs Expression Profile During Primordial Follicle Assembly

Abstract

This research was performed to estimate the potential effects of Di (2-ethylhexyl) phthalate (DEHP) on changes of ovarian miRNA expression profile during mouse primordial follicle assembly using miRNAs-seq analysis. The ovaries of newborn mice were collected and in vitro cultured with different concentration of DEHP for 72 h. Then they were prepared for miRNAs-seq analysis. The results indicated that DEHP exposure altered ovarian miRNA expression profile of newborn mice. Eighteen differentially expressed miRNAs were screened after 100 µM DEHP exposure. The target mRNAs of differentially expressed miRNAs were predicted and further analyzed through gene ontology (GO) enrichment analysis and pathway enrichment analysis. Our results showed that the differentially expressed miRNAs from DEHP exposure can regulate ovarian development by targeting mRNAs involved in MAPK, mTOR, FoxO signaling pathways. Three miRNAs of miR-32-5p, miR-19a-3p, and miR-141-3p were randomly selected from the differentially expressed miRNAs to quantify their expression level by miRNA qRT-PCR. The results of qRT-PCR and miRNA-seq were consistent. Considering one of its target gene PTEN of miR-19a-3p and the decreased level of pAKT and increased Bax/Bcl-2 under DEHP exposure, we speculated that the altered expression of miR-19a-3p by DEHP exposure affected mouse primordial follicle assembly via PI3K/AKT1/mTOR signaling pathway. Epigenetic changes are one of the most important targets of toxicant exposure. The effects of DEHP exposure on microRNA (one of the epigenetic regulators) expression profile were uncovered to enrich the research on relationship of epigenetics and toxicant exposure.

Daily exposure to phthalates and alkylphenols alters miR biogenesis and expression in mice ovaries

“…In women, urinary concentrations of phthalate metabolites are associated with the expression of extracellular vesicle miRs in follicular fluid (Martinez et al 2019). The exposure to DEHP altered the ovarian miR expression profile of newborn mice (Zhang et al 2019). In a previous work, we found that female mice chronically exposed to a mixture of phthalates and alkylphenols show a decrease in the expression of ovarian steroidogenesis genes, including CYP19A1, along with a significant decrease in E 2 plasmatic levels (Patino-Garcia et al 2018).…”

“…New research has proposed a link between these changes in mRNA expression and the loss of the post-transcriptional regulation by miRs or other sncRNAs (Sandhu et al 2012) affecting female fertility (Ahmed et al 2017, Lite et al 2019. Studying the miRome (miR expression) profile, Zhang et al showed that only some miRs were deregulated and the progesterone-mediated oocyte maturation signaling pathway was one of the most altered in newborn mice ovaries after exposure to DBP (Zhang et al 2019). Interestingly, mmu-miR-200a-5p was reported to be upregulated.…”

Linking emerging contaminants exposure to adverse health effects: Crosstalk between epigenome and environment

“…to the reduced Bax/Bcl2 ratio, which may initiate testicular apoptosis in Wistar rats (Helmy et al, 2020). In terms of female reproductive toxicities, ovarian development and primordial follicular assembly can be stressed by DEHP-induced miRNA expression, for instance, miR-19a-3p (Zhang et al, 2019). Similar effects were also recorded under the mice study by Liu et al (2018) By crossing blood-brain barrier and entering into the nervous system, DEHP can also affect neuronal growth (Smith, MacDonald, & Holahan, 2011;Tanida et al, 2009;Testa et al, 2012).…”

“…DEHP‐induced aberrant expression of oxidative stress responsive miRNAs (miR‐126 and miR‐181a) has also been implicated to the reduced Bax / Bcl2 ratio, which may initiate testicular apoptosis in Wistar rats (Helmy et al, 2020). In terms of female reproductive toxicities, ovarian development and primordial follicular assembly can be stressed by DEHP‐induced miRNA expression, for instance, miR‐19a‐3p (Zhang et al, 2019). Similar effects were also recorded under the mice study by Liu et al (2018) that DEHP down‐regulated the expression of follicle development‐related factors, c‐Kit , Kitl , Gdf9 , and Atm with the upregulation of ovarian miRNAs (let‐7b, miR‐17‐5p, miR‐181a, and miR‐151), which suppress follicular granulosa cell proliferation.…”

Impact of Plasticizer on the Intestinal Epithelial Integrity and Tissue-Repairing Ability within Cells in the Proximity of the Human Gut Microbiome

“…It is best known as an endocrine disruptor that disrupts the regulation and action of thyroid hormones [3]. In addition, DEHP and its metabolites have the potential to induce testicular, ovarian, renal, neuro, and cardiovascular toxicity [4][5][6]. Both occupational and environmental routes of exposure to DEHP are of concern for human health [7].…”