Plasticizer DEHP exposure in early pregnancy affects the endometrial decidualization in mice through reducing lncRNA RP24 - 315D19.10 expression.

Objectives: To explore the effect of exposure to di (2-ethyl) hexyl phthalate (DEHP) in early pregnancy on endometrial decidualization in mice and its relation with lncRNA RP24 - 315D19.10 .
Methods: Early pregnancy mice were exposed to DEHP (1000 mg·kg ^－1 ·d ^－1 ) to construct the model. The uterus was collected on day 6 of pregnancy to detect its effect on decidualization by HE staining and immunofluorescence. A decidualization induction model of mouse endometrial stromal cells exposed to DEHP (0.1, 0.5, 2.5, 12.5, 62.5 μmol/L) was constructed. The changes of cell morphology were observed by light microscopy and phalloidin staining, and the expression of decidual reaction related molecular markers were detected by immunofluorescence, realtime RT-PCR and Western blotting. The expression of RP24 - 315D19.10 in decidua tissue and cells was detected by realtime RT-PCR. Cellular localization of RP24 - 315D19.10 was determined by lncLocator database and RNA FISH. AnnoLnc2 database was used to predict miRNAs bound to RP24 - 315D19.10 .
Results: The number of embryo implantation sites, uterine weight and uterine area were significantly lower in the DEHP exposed group than those in the control group, and the expression of the decidual reaction related molecular markers matrix metalloprotein 9 and homeobox A10 in the DEHP exposure group were also significantly lower than those in the control group (all P <0.05). With the increase of DEHP concentration, the expression of dtprp in decidua cells was gradually decreased. 2.5 μmol/L DEHP exposed stromal cells failed to be fully decidualized in vitro, andphalloidin staining showed abnormal cytoskeleton morphology. The expression levels of homeobox A10, bone morphogenetic protein 2 and proliferating cell nuclear antigen in the DEHP exposure group were significantly lower than those in the control group (all P <0.05). The expression of RP24 - 315D19.10 in DEHP exposed decidua tissue and cells was significantly reduced (both P <0.05). RP24 - 315D19.10 is mainly localized in the cytoplasm and RP24 - 315D19.10 might bind to 45 miRNAs, among them, miR-138-5p, miR-155-5p, miR-183-5p and miR-223-3p were associated with endometrial decidualization.
Conclusions: DEHP exposure in early pregnancy may impair endometrial decidualization, and the damage may be associated with the down-regulation of RP24 - 315D19.10 .