Maternal exposure to fenarimol promotes reproductive performance in mouse offspring

Screening of potential oestrogen receptor α agonists in pesticides via in silico, in vitro and in vivo methods

In modern agricultural management, the use of pesticides is indispensable. Due to their massive use worldwide, pesticides represent a latent risk to both humans and the environment. In the present study, 1056 frequently used pesticides were screened for oestrogen receptor (ER) agonistic activity by using in silico methods. We found that 72 and 47 pesticides potentially have ER agonistic activity by the machine learning methods random forest (RF) and deep neural network (DNN), respectively. Among endocrine-disrupting chemicals (EDCs), 14 have been reported as EDCs or ER agonists by previous studies. We selected 3 reported and 7 previously unreported pesticides from 76 potential ER agonists to further assess ERα agonistic activity. All 10 selected pesticides exhibited ERα agonistic activity in human cells or zebrafish. In the dual-luciferase reporter gene assays, six pesticides exhibited ERα agonistic activity. Additionally, nine pesticides could induce mRNA expression of the pS2 and NRF1 genes in MCF-7 cells, and seven pesticides could induce mRNA expression of the vtg1 and vtg2 genes in zebrafish. Importantly, the remaining 48 out of 76 potential ER agonists, none of which have previously been reported to have endocrine-disrupting effects or oestrogenic activity, should be of great concern. Our screening results can inform environmental protection goals and play an important role in environmental protection and early warnings to human health.

FOXL2 posttranslational modifications mediated by GSK3β determine the growth of granulosa cell tumours

Approximately 97% of patients with ovarian granulosa cell tumours (GCTs) bear the C134W mutation in FOXL2; however, the pathophysiological mechanism of this mutation is unknown. Here we report how this mutation affects GCT development. Sequential posttranslational modifications of the C134W mutant occur where hyperphosphorylation at serine 33 (S33) by GSK3β induces MDM2-mediated ubiquitination and proteasomal degradation. In contrast, S33 of wild-type FOXL2 is underphosphorylated, leading to its SUMOylation and stabilization. This prominent hyperphosphorylation is also observed at S33 of FOXL2 in GCT patients bearing the C134W mutation. In xenograft mice, the S33 phosphorylation status correlates with the oncogenicity of FOXL2, and the inhibition of GSK3β efficiently represses GCT growth. These findings reveal a previously unidentified regulatory mechanism that determines the oncogenic attributes of the C134W mutation via differential posttranslational modifications of FOXL2 in GCT development.

Risk assessment's insensitive toxicity testing may cause it to fail

BACKGROUND

Risk assessment of chemicals and other agents must be accurate to protect health. We analyse the determinants of a sensitive chronic toxicity study, risk assessment's most important test. Manufacturers originally generate data on the properties of a molecule, and if government approval is needed to market it, laws globally require toxicity data to be generated using Test Guidelines (TG), i.e. test methods of the Organisation for Economic Cooperation and Development (OECD), or their equivalent. TGs have advantages, but they test close-to-poisonous doses for chronic exposures and have other insensitivities, such as not testing disease latency. This and the fact that academic investigators will not be constrained by such artificial methods, created a de facto total ban of academia's diverse and sensitive toxicity tests from most risk assessment.

OBJECTIVE

To start and sustain a dialogue between regulatory agencies and academic scientists (secondarily, industry and NGOs) whose goals would be to (1) agree on the determinants of accurate toxicity tests and (2) implement them (via the OECD).

DISCUSSION

We analyse the quality of the data produced by these incompatible paradigms: regulatory and academic toxicology; analyse the criteria used to designate data quality in risk assessment; and discuss accurate chronic toxicity test methods.

CONCLUSION

There are abundant modern experimental methods (and rigorous epidemiology), and an existing systematic review system, to at long last allow academia's toxicity studies to be used in most risk assessments.

Positive cross talk between FOXL2 and antimüllerian hormone regulates ovarian reserve

OBJECTIVE

To demonstrate interregulation between FOXL2 and antimüllerian hormone (AMH) in ovarian folliculogenesis.

DESIGN

Cell culture and animal study.

SETTING

University research laboratory.

ANIMAL(S)

Five-week-old B6C3F1 mice.

INTERVENTIONS(S)

Molecular analysis and in vivo mouse experiment were performed to demonstrate that AMH is a target gene of FOXL2 in the ovary.

MAIN OUTCOME MEASURE(S)

To determine whether FOXL2 transactivates AMH, luciferase reporter assay, electrophoretic mobility shift assay, and chromatin immuniprecipitation were conducted. Using an in vivo nucleic acid delivery system, the expression of AMH and/or FOXL2 was modulated in the mouse, and the ovaries were histologically analyzed.

RESULT(S)

AMH is an endogenous target gene of FOXL2. In contrast, mutated FOXL2s found in premature ovarian failure patients were defective in their ability to activate AMH transcription in human granulosa cells. In vivo mouse gene delivery experiments revealed that Amh-knockdown accelerated follicle growth; however, the acceleration was prevented by ectopic expression of FOXL2.

CONCLUSION(S)

AMH and FOXL2 collaboratively work to reserve ovarian follicles.