Expression and Contribution of NLRP3 Inflammasome During the Follicular Development Induced by PMSG.

Zhenghong Zhang,Fan Wang,Yan Zhang

doi:10.3389/fcell.2019.00256

Zhenghong Zhang, Fan Wang + Show 1 more

Open Access

https://doi.org/10.3389/fcell.2019.00256

Copy DOI

Abstract

Follicular development and following ovulation induced by luteinizing hormone (LH) surge are critical for ovarian functions, but the molecular mechanism regulating ovarian ovulation attracts more attention and remains mainly unknown. Recent researches on the nucleotide leukin rich polypeptide 3 (NLRP3) inflammasome shred light on it. Given pregnant mare serum gonadotropin (PMSG) can not only trigger the follicular development, but also induce the following ovulation, the present study therefore examined that expression and localization of NLRP3 inflammasome through immunohistochemistry and Western blotting during the follicular development induced by PMSG. The results showed expressions of NLRP3 and the adaptor protein apoptosis-associated speck-like protein (ASC) significantly increased in the outside of intrafollicular fluid, further analysis found that caspase-1 was activated and IL-1β production was also upregulated after 52 h-treatment of PMSG. Furthermore, a significant increase of ovulation-related genes, hypoxia inducible factor (HIF)-1α and endothelin (ET)-1, was found after 52 h-treatment of PMSG. To our knowledge, it is the first time to clearly indicated the activation of NLRP3 inflammasome may contribute to the ovulation of PMSG-treated ovaries, which will help to further clarify the ovulatory mechanism in mammals.

Highlights

In mammals, the ovary is the reproductive organs of females, and its main function is to produce oocytes and steroids
The results showed nucleotide leukin rich polypeptide 3 (NLRP3) mainly expressed in the outside of intrafollicular fluid in the ovaries with Pregnant mare serum gonadotropin (PMSG)-52 h treatment (Figure 1), which was similar with the pattern of associated speck-like protein (ASC) expressions (Figure 2)
For confirming the above findings, the expressions of NLRP3 and ASC were further examined by Western blotting (Figure 3) and the results suggested NLRP3 and ASC mainly expressed in the ovaries after PMSG-52 h treatment, indicating the activation of NLRP3 inflammasomes this time

Summary

Introduction

The ovary is the reproductive organs of females, and its main function is to produce oocytes and steroids. It’s believed that follicular development is triggered by folliclestimulating hormone (FSH) and the following ovulation is induced by luteinizing hormone (LH) surge (Komatsu and Masubuchi, 2016; Jiang et al, 2018; Qi et al, 2018; Wei et al, 2018). Pregnant mare serum gonadotropin (PMSG) can trigger the follicular development mainly similar to FSH, and induce the following ovulation like LH, which was widely used in the field of reproductive investigation (Ma et al, 1997; Tarín et al, 2002; Nie et al, 2018; Kim et al, 2019). The researches on the nucleotide leukin rich polypeptide 3 (NLRP3) inflammasome shred light on it (Ahechu et al, 2018; Groslambert and Py, 2018; de Alba, 2019; Komada and Muruve, 2019; Takahashi, 2019; Yang et al, 2019).

Methods

Results

Conclusion