Correlation Between Parabens Exposure And Ovarian Function Deficiency And Its Mechanisms

Background: Parabens(PBs),a class of endocrine disruptors,are known to disrupt hormonal activities and affect reproductive development in males during early life exposure.There are few epidemiological studies on the relationship between PBs exposure and female reproductive health are scarce.Here,we aim to examine whether urinary PBs concentrations are associated with ovarian reserve among women from a reproductive center.Methods: One hundred thirty-nine women from our reproductive center were enrolled to participate a cross-sectional study.Single-point urine samples were collected to detect the four kinds of PBs concentrations in urine.Using self-reported personal care products(PCPs)use as a surrogate of exposure to PBs to determine whether PCPs use was associated with higher urinary PBs exposure.Data on measures of ovarian reserve,as indicated by serum anti-Mullerian hormone(AMH)levels,serum Inhibin B(INHB)levels and antral follicle count(AFC)were examined at the initial visit of the clinic.Multivariable linear models were performed to explore the associations of urinary PBs concentrations and the parameters of interest adjusted for potential confounders.Results:(1)A high urinary propyl-paraben(PrPB)concentration was negatively associated with the serum AMH level,serum INHB level and AFC numbers in women after adjustment(Ptrend= 0.020,Ptrend= 0.020,Ptrend= 0.040,respectively).Compared to the women with the lowest Pr PB concentrations in urine,the serum AMH level,serum INHB level and AFC numbers in the women with the highest Pr PB concentrations group were significantly decrease at-0.146(95% CI,-0.281,-0.012),-1.238(95% CI,-2.156,-0.320)and-0.149(95% CI,-0.286,-0.012),respectively.(2)No other urinary PBs were associated with ovarian reserve.(3)The use of facial cleansers and eye makeup products were associated with the greatest increases in urinary PBs concentrations.Conclusions: Our results support the hypothesis that PBs exposure is highly likely to have a detrimental effect on female ovarian function.Objective: To explore the effect of propylparaben(Pr PB)exposure on ovarian function and its mechanisms.Methods: Long-term PrPB-induced mice model was to simulate human daily PrPB exposure pattern.Sixty 5-week-old C57BL/6j female mice were randomly divided into 2groups.One group received nothing as control,and the other one was treated with Pr PB(7.5 mg/kg bw/d)according to human exposure to Pr PB mode.Long-term Pr PB exposure was performed by feeding method until the mice reached 36-week-old.The ovarian fucntion of mice was evaluated by estrous cycle monitoring,serum sex hormones expression levels examing and follicle numbers counting.The mating test was performed to evaluate the reproductive ability of mice,and the ovarian function of the offspring female pups was continuously monitored until their sexual maturity.Transmisssion electron microscopy,Sirius red staining,Masson staining,Immunofluorescence,transcriptome sequencing analysis and western-blot were used to explore the mechanisms of Pr PB exposure in vivo.Furthermore,the cellular models of mouse primary granulosa cells and human luteinized granulosa cells were used to explore the effects and the mechanisms of Pr PB exposure in vitro.Results:(1)PrPB-treated mice showed higher pecent of irregular estrous cycle accompanied by lower serum estrogen and progesterone levels.(2)The primordial follicles number of the ovaries in the Pr PB-treated group was significantly decreased.(3)In Pr PB-treated group,the survival rate of the litters was decreased and the proportion of female litters was increased.The birth weight of female pups decreased significantly until reached sexual maturity.The percent of irregular estrous cycle was increased,the serum progesterone levels and the antral follicle counts were decreased significantly.(4)The lipid droplets of the ovaries in Pr PB-treated group were increased and cell synapses decreased.(5)Ovarian fibrosis and DNA damage were markedly increased in the Pr PB-treated mice.(6)WGCNA analysis of transcriptome sequencing data indicated that histone deacetylase Hdac4 may be involved in the ovarian function deficiency in mice after Pr PB exposure.(7)The protein expression levels of CYP19A1,CYP11A1 and STAR were decreased,while HDAC4,P-ERK and P-JNK were increased in the Pr PB-treated mice.(8)Mouse primary granulosa cells were treated with Pr PB in vitro.The levels of estrogen and progesterone expression of the culture medium were significantly decreased.The m RNA expression levels of Cyp19a1 and Star were significantly decreased,while Nrf2,Ho1 and Hdac4 were significantly increased.The protein expression levels of CYP19A1 and STAR were decreased,while NRF2,HO1,HDAC4,P-ERK and P-JNK were increased.(9)The progesterone expression levels of the human luteinizing granulosa cells which treated with Pr PB were significantly decreased in vitro.The m RNA expression level of Hsd3? was significantly decreased.The protein expression levels of CYP19A1 and STAR were decreased,while NRF2,HO1,P-ERK and P-JNK were increased.Conclusions: Long-term PrPB exposure impaired ovarian function in mice and offspring female litters,the potential mechanism of which could be the destruction of ovarian ultrastructure,increase of DNA damage and ovarian fibrosis.MAPK signaling pathway and histone deacetylation may play key roles in this process.