Zearalenone induces apoptosis of rat Sertoli cells through Fas‐Fas ligand and mitochondrial pathway

Abstract

Zearalenone (ZEA) is an estrogen-like toxin produced by Fusarium that is widely found in cereals worldwide. In recent years, ZEA has been found to cause reproductive dysfunction in male animals, but the underlying mechanism remains unclear. This study examined the apoptosis of rat Sertoli cells induced by different concentrations (0, 5, 10, and 20 μmol/L) of ZEA via Fas-Fas ligand and mitochondrial signaling pathway in vitro. Apoptosis rate was detected by flow cytometry. The mitochondrial membrane potential was detected by immunofluorescence assay and flow cytometry. Western Blot and qRT-PCR were used to identify the signaling pathway. The results revealed that ZEA induced apoptosis of rat Sertoli cells, significantly reduced the transcription and expression of the anti-apoptotic protein Bcl-2, increased the transcription and expression of pro-apoptotic proteins Bax and tBID, and Fas, FasL, FADD, and caspase-8. ZEA also increased the activation of caspase-8 and caspase-9, and promoted the release of cytochrome C from mitochondria to cytoplasm. Moreover, addition of caspase-8 inhibitor Z-IETD-FMK led to significant decrease in the mitochondrial membrane potential and apoptosis rate of the ZEA + Z-IETD-FMK group as compared to the ZEA treatment group. The release of cytochrome C from mitochondria to cytoplasm and the activation of caspase-9 and caspase-3 were significantly decreased in the ZEA + Z-IETD-FMK group. These results suggested that ZEA can induce apoptosis of rat Sertoli cells, activate the Fas-Fas ligand signaling pathway and participate in the regulation of mitochondrial apoptosis pathway. K E Y W O R D S apoptosis, Fas ligand, mitochondria, Sertoli cells, Zearalenone | INTRODUCTIONZearalenone (ZEA), also known as F-2 toxin, is a mycotoxin produced by fusarium spp, which is commonly found in feed and food. In nature, animals cannot avoid eating or touching feed or raw materials containing ZEA. 1 ZEA is structurally similar to estrogen, and can compete with estrogen to bind estrogen receptor, thus interfering with the effect of estrogen. 2 ZEA also has a similar structure to steroids. By competitive binding of 3α-HSD and 3β-HSD, the synthesis of reproductive hormones is affected, which leads to disorders of reproductive system function. 3 The estrogen receptor is the main target of zearalenone and its metabolites. 4 Early studies found that the degradation rate of porcine oocytes increased with the increase of α-ZEA and β-ZEA doses. 5 A study in which cows were fed with ZEA containing feeds showed that the pregnant cows had oestrus, while the pubertal cows were estrous but sterile. 6 ZEA can also affect the reproduction of male animals. High dose of ZEA and its metabolites could reduce the survival rate of sperms, increase the rate of deformity and mortality, decrease the concentration of sperms, and damage the reproductive function of male animals. 7,8 Cheraghi et al. showed that the interaction of cyclin D1 and E2F1 during mitosis resulted in an increase in apoptosis after subcutaneous injection of 1-...

Oxidative stress‐mediated apoptosis is involved in bisphenol S‐induced reproductive toxicity in male C57BL/6 mice

“…The results suggested that BPS exposure upregulated the protein expression of Fas and FasL in the testes. Furthermore, previous studies have demonstrated that caspase‐8 plays a very important role in the apoptotic cascade signal transduction in the apoptosis mediated by the Fas/FasL pathway (Cai et al, 2019). This result is consistent with our study in which BPS induced an increase in cleaved caspase‐8 protein expression in testes.…”

Zearalenone and the Immune Response

“…By contrast, Zheng et al [89], found that low doses of zearalenone (0.01, 0.02, 0.03, 0.04, and 0.05 µmol/L) stimulated cell viability of TM3 cells (Leydig cells) measured by using the xCELLigence real-time cell analysis. Also, under the action of ZEA (20µM), cell viability of Sertoli cells derived from Male Wistar, which are important for male reproductive system, increased over control [102].…”

Equol: A Microbiota Metabolite Able to Alleviate the Negative Effects of Zearalenone during In Vitro Culture of Ovine Preantral Follicles

“…In the present study, we demonstrated that even at low levels (1 µmol/L), ZEN can impair the in vitro development of preantral follicles, but this negative impact is minimised when these follicles are simultaneously exposed to ZEN and equol. Previous in vitro studies have showed that ZEN inhibits testosterone production by AM-10 Leydig cells (8 µmol/L) [29], increases the apoptosis rate in rat Sertoli cells (5 µmol/L) [30], affects gene expression in granulosa cells from mouse (30 µmol/L) and sows (10 µmol/L) [31], and impairs bovine oocyte maturation (1 mmol/L) [32] and porcine blastocyst rates (5 µmol/L) [33]. Although most of these concentrations are far higher than those tested in the present study, comparisons cannot be performed due to the differences of cell types and animal species.…”