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Redundant roles of AKT1 and AKT2 in fertility, estrous cyclicity and endometrial gland development

Pascal Adam, Laurence Tardif, François Fabi, Dadou Likonza Lokengo, Léa-Isabelle Renaud, Sophie Parent, Monique Cadrin, Derek Boerboom, and Eric Asselin

In brief

The regulation of AKT in the endometrium during many cellular processes such as apoptosis and cell survival is crucial during the estrous cycle to ensure fertility. This research shows the specific function of AKT isoforms in the mouse endometrium for litter size, estrous cyclicity and endometrial gland development.

Abstract

Apoptosis and cell survival regulation are crucial processes during the estrous cycle to prepare a receptive uterus during implantation for successful recognition of pregnancy. PI3K/AKT signaling has a crucial role during gestation, and AKT isoforms (1, 2 or 3) are regulated differently in the endometrium during the estrous cycle and embryo implantation. However, the specific roles of these isoforms are still unclear. We have previously shown that AKT isoforms expression during the rat estrous cycle and gestation is differently regulated. The present study aimed to establish the specific role of AKT isoforms in the mouse uterus. The hypothesis is that dysregulation of AKT isoforms expression could cause fertility-related issues in an isoform-specific manner. With four different mouse models and in-house crossbreeding, all isoforms KO combinations (single, double and triple) were obtained in progesterone receptor-expressing tissues. The results demonstrated that in absence of one or more AKT isoforms, female fertility was decreased. Mainly, we have observed smaller litter size, specifically in Akt1-2 KO mice. Additionally, we have found Akt1-2-3 KO mice to be fully infertile. Estrous cyclicity was also disrupted in Akt1-2 KO mice with longer diestrus stage. Moreover, the number of endometrial glands was decreased throughout the estrous cycle suggesting an important role in gland development for AKT1 and AKT2. Our results suggest not only specific roles between each isoform but also a partially redundant function of AKT1 and AKT2 in litter size, estrous cyclicity and endometrial gland development. This highlights the importance of AKT in the physiological regulation of mouse fertility.

DOI:
https://doi.org/10.1530/REP-22-0353
Volume 165: Issue 6,
Pages:
605–616 (12 total)
Open access

Temporal trends in equine sperm progressive motility: a systematic review and meta-regression

I T Harris, C Maddock, M Farnworth, K Nankervis, J Perrett, A Z Pyatt, and R N Blanchard

In brief

Adverse trends in reproductive function are a concern in humans, companion, livestock, and wildlife species. This study indicates that equine populations are at risk of a comparable decline in sperm progressive motility.

Abstract

There is increasing evidence reporting geographically sensitive adverse trends in human semen quality, with parallel trends observed in the dog sentinel. Despite significant economic and welfare complications associated with poor testicular function, trends in current equine populations are undetermined. Given the predictive value of sperm progressive motility (PMOT) in male factor infertility and fertilisation potential, research determining trends in this parameter is warranted. This research analysed trends in stallion sperm PMOT through systematic review and meta-regression. Using a comprehensive search strategy, Scopus, Embase (Ovid), Medline (Ovid), and VetMed (CAB direct) were scoped for eligible data. Using best practices, 230 meta-data points from 229 articles published from 1991 to 2021 were collated for meta-regression analysis. Sperm PMOT declined significantly between 1984 and 2019 (simple linear regression: b −0.340, P = 0.017; meta-regression: b −0.610, P ≤ 0.001). Overall and yearly PMOT declines were predicted at 33.51 and 0.96%, respectively (1984: 63.69 ± 5.07%; 2019: 42.35 ± 3.69%). Trends remained consistent irrespective of sensitivity analyses. Yearly and overall declines were stronger in western (yearly: 0.75%, overall: 26.29%) compared to non-western (yearly: 0.46%, overall: 10.65%) populations. Adverse trends contribute vital data to the debate surrounding declining semen quality, supporting the use of equines as novel comparative models for human reproduction. Results could have significant economic, health, and welfare consequences for equine breeding sectors. A comparable decline in human, dog, and horse sperm quality is indicative of a common environmental aetiology, indicating the need for a holistic One Health approach in determining causes and developing preventative strategies.

DOI:
https://doi.org/10.1530/REP-22-0490
Volume 165: Issue 6,
Pages:
M1–M10
Restricted access

The CASR antagonist NPS2143 induces loss of acrosomal integrity and proteolysis of SPACA1 in boar spermatozoa

Beatriz Macías-García and Lauro González-Fernández

In brief

The mechanism by which p32 protein increases during capacitation in boar spermatozoa is unknown. This manuscript shows a new mechanism of induction of p32 in boar spermatozoa: the proteolysis of the phosphorylated and glycosylated form of SPACA1.

Abstract

Protein tyrosine phosphorylation (PY) induction is associated with sperm capacitation. We previously showed that calcium-sensing receptor (CASR) inhibition by NPS2143 induces the 32 kDa tyrosine-phosphorylated protein (p32) in boar spermatozoa. We showed that NPS2143 induced an increase in p32 and loss of acrosomal integrity in live and dead spermatozoa in capacitating conditions (Tyrode's complete medium); the p32 rise occurred in dead spermatozoa, as shown by flow cytometry sorting. EGTA addition blunted the increase in p32, the loss of acrosomal integrity, and the increase in dead spermatozoa induced by NPS2143, indicating that the effects of NPS2143 are calcium-dependent. Mass spectrometry was used to identify which tyrosine-phosphorylated proteins were induced by NPS2143, but only serine/threonine-phosphorylated proteins were found; among these, SPACA1 was identified with different molecular weights (18, 32, and 35–45 kDa). We confirmed tyrosine phosphorylation of SPACA1 at 32 and 35–45 kDa by immunoprecipitation and co-localization of PY and SPACA1 in the presence of NPS2143 by immunofluorescence. The molecular weight of SPACA1 (35–45 kDa) decreased after treatment with peptide-N-glycosidase F, indicating that this protein is N-glycosylated. The soybean trypsin inhibitor (STI), a serine protease inhibitor, suppressed the appearance of p32 and SPACA1 (30 and 32 kDa) induced by NPS2143. Also, 8-Br-cAMP and A23187 treatments induced an increase in p32 and SPACA1 (30–32 kDa) and a parallel induction of the acrosome reaction. These findings suggest that CASR inhibition induces loss of acrosomal integrity and proteolysis of the glycosylated and phosphorylated SPACA1 (35–45 kDa) resulting in a SPACA1 rise at 32 kDa (p32).

DOI:
https://doi.org/10.1530/REP-22-0299
Volume 165: Issue 5,
Pages:
475–489 (15 total)
Restricted access

Conserved H3K27me3-associated chromatin remodelling allows STRA8 but not MEIOSIN expression in mammalian germ cells

Teruhito Ishihara, Jane C Fenelon, Oliver W Griffith, Kei-ichiro Ishiguro, and Marilyn B Renfree

In brief

Apart from mice, meiosis initiation factors and their transcriptional regulation mechanisms are largely unknown in mammals. This study suggests that STRA8 and MEIOSIN are both meiosis initiation factors in mammals, but their transcription is epigenetically regulated differently from each other.

Abstract

In the mouse, the timing of meiosis onset differs between sexes due to the sex-specific regulation of the meiosis initiation factors, STRA8 and MEIOSIN. Before the initiation of meiotic prophase I, the Stra8 promoter loses suppressive histone-3-lysine-27 trimethylation (H3K27me3) in both sexes, suggesting that H3K27me3-associated chromatin remodelling may be responsible for activating STRA8 and its co-factor MEIOSIN. Here we examined MEIOSIN and STRA8 expression in a eutherian (the mouse), two marsupials (the grey short-tailed opossum and the tammar wallaby) and two monotremes (the platypus and the short-beaked echidna) to ask whether this pathway is conserved between all mammals. The conserved expression of both genes in all three mammalian groups and of MEIOSIN and STRA8 protein in therian mammals suggests that they are the meiosis initiation factors in all mammals. Analyses of published DNase-seq and chromatin-immunoprecipitation sequencing (ChIP-seq) data sets confirmed that H3K27me3-associated chromatin remodelling occurred at the STRA8, but not the MEIOSIN, promoter in therian mammals. Furthermore, culturing tammar ovaries with an inhibitor of H3K27me3 demethylation before meiotic prophase I affected STRA8 but not MEIOSIN transcriptional levels. Our data suggest that H3K27me3-associated chromatin remodelling is an ancestral mechanism that allows STRA8 expression in mammalian pre-meiotic germ cells.

DOI:
https://doi.org/10.1530/REP-22-0286
Volume 165: Issue 5,
Pages:
507–520 (14 total)
Open access

The effect of sperm DNA fragmentation on the incidence and origin of whole and segmental chromosomal aneuploidies in human embryos

Jiangman Gao, Zhiqiang Yan, Liying Yan, Xiaohui Zhu, Hui Jiang, and Jie Qiao

We aimed to investigate the correlation of sperm DNA fragmentation (SDF) with the incidence and paternal origin of whole and segmental chromosomal aneuploidies of embryos at the blastocyst stage. A retrospective cohort study was conducted with a total of 174 couples (women aged 35 years or younger) who underwent 238 cycles (including 748 blastocysts) of preimplantation genetic testing for monogenic diseases (PGT-M). All subjects were divided into two groups based on the sperm DNA fragmentation index (DFI) level: low DFI (<27%) and high DFI (≥27%). The rates of euploidy, whole chromosomal aneuploidy, segmental chromosomal aneuploidy, mosaicism, parental origin of aneuploidy, fertilization, cleavage, and blastocyst formation were compared between low and high DFI groups. We found no significant differences in fertilization, cleavage, or blastocyst formation between the two groups. Compared to that in the low DFI group, segmental chromosomal aneuploidy rate was significantly higher in the high DFI group (11.57 vs. 5.83%, P=0.021; OR 2.32, 95% CI 1.10-4.89, P=0.028). The whole chromosomal embryonic aneuploidy of paternal origin was significantly higher in cycles with high DFI than in cycles with low DFI (46.43% vs. 23.33%, P=0.018; OR 4.32, 95% CI 1.06-17.66, P=0.041). However, the segmental chromosomal aneuploidy of paternal origin was not significantly different between the two groups (71.43% vs. 78.05%, P=0.615; OR 1.01, 95% CI 0.16-6.40, P=0.995). In conclusion, our results suggested that high sperm DNA fragmentation was associated with the incidence of segmental chromosomal aneuploidy and increased paternal whole chromosomal aneuploidies in embryos.

DOI:
https://doi.org/10.1530/REP-23-0011
Accepted Manuscripts
Restricted access

Hypoxia-mediated chemotaxis and residence of macrophage in decidua by secreting VEGFA and CCL2 during normal pregnancy

Xue-Yun Qin, Hui-Hui Shen, Xin-Yan Zhang, Xing Zhang, Feng Xie, Wen-Jun Wang, Yu Xiong, Jie Mei, and Ming-Qing Li

In brief

Hypoxia is vital for the establishment of the maternal–fetal interface during early pregnancy. This study shows that decidual macrophages (dMφ) could be recruited and reside in decidua under the regulation of hypoxia/VEGFA-CCL2 axis.

Abstract

Infiltration and residence of decidual macrophages (dMφ) are of great significance to pregnancy maintenance for their role in angiogenesis, placental development, and inducing immune tolerance. Besides, hypoxia has now been acknowledged as an important biological event at maternal–fetal interface in the first trimester. However, whether and how hypoxia regulates biofunctions of dMφ remain elusive. Herein, we observed increased expression of C–C motif chemokine ligand 2 (CCL2) and residence of macrophages in decidua compared to secretory-phase endometrium. Moreover, hypoxia treatment on stromal cells improved the migration and adhesion of dMφ. Mechanistically, these effects might be mediated by upregulated CCL2 and adhesion molecules (especially ICAM2 and ICAM5) on stromal cells in the presence of endogenous vascular endothelial growth factor-A (VEGFA) in hypoxia. These findings were also verified by recombinant VEGFA and indirect coculture, indicating that the interaction between stromal cells and dMφ in hypoxia condition may facilitate dMφ recruitment and residence. In conclusion, VEGFA derived from a hypoxic environment may manipulate CCL2/CCR2 and adhesion molecules to enhance the interactions between dMφ and stromal cells and thus contribute to the enrichment of macrophages in decidua early during normal pregnancy.

DOI:
https://doi.org/10.1530/REP-22-0473
Volume 165: Issue 5,
Pages:
543–555 (13 total)
Restricted access

Irisin modulates glucose metabolism and inhibits steroidogenesis in bovine granulosa cells

Mathilde Daudon, Christelle Ramé, Christopher Price, and Joëlle Dupont

In brief

Fertility in the dairy cow is low during the post-partum period of negative energy balance and high plasma irisin concentrations. This study shows irisin modulates granulosa cell glucose metabolism and impairs steroidogenesis.

Abstract

Fibronectin type III domain-containing 5 (FNDC5) is a transmembrane protein discovered in 2012 that is cleaved to release the adipokine-myokine, irisin. Originally described as an exercise hormone that browns white adipose tissue and increases glucose metabolism, irisin secretion also increases during periods of rapid adipose mobilization, such as the post-partum period in dairy cattle when ovarian activity is suppressed. The effect of irisin on follicle function is unclear and may be species-dependent. In this study, we hypothesized that irisin may compromise granulosa cell function in cattle using a well-established in vitro cell culture model. We detected FNDC5 mRNA and both FNDC5 and cleaved irisin proteins in follicle tissue and in follicular fluid. The abundance of FNDC5 mRNA was increased by the treatment of cells with the adipokine visfatin but not by other adipokines tested. The addition of recombinant irisin to granulosa cells decreased basal and insulin-like growth factor 1- and follicle-stimulating hormone-dependent estradiol and progesterone secretion and increased cell proliferation but had no effect on viability. Irisin decreased GLUT1, GLUT3, and GLUT4 mRNA levels in granulosa cells and increased lactate release in the culture medium. The mechanism of action is in part through MAPK3/1 but not Akt, MAPK14, or PRKAA. We conclude that irisin may regulate bovine folliculogenesis by modulating granulosa cell steroidogenesis and glucose metabolism.

DOI:
https://doi.org/10.1530/REP-22-0404
Volume 165: Issue 5,
Pages:
533–542 (10 total)
Free access

Negative effects of endocrine disruptor bisphenol A on ovarian granulosa cells and the protective role of folic acid

Dominika Celar Sturm and Irma Virant-Klun

In brief

Bisphenol A (BPA) is a widely produced chemical, mostly used in the production of polycarbonate plastics, and can act as an endocrine disruptor. This paper focuses on the different effects of BPA on ovarian granulosa cells.

Abstract

Bisphenol A (BPA) is an endocrine disruptor (ED), widely used as a comonomer or an additive in the plastics industry. It can be found in food and beverage plastic packaging, epoxy resins, thermal paper and other common products. To date, there have only been several experimental studies to have examined how BPA exposure affects human and mammalian follicular granulosa cells (GCs) in vitro and in vivo; the collected evidence data show that BPA negatively affects the GCs by altering steroidogenesis and gene expression, inducing autophagy, apoptosis and cellular oxidative stress through reactive oxygen species production. Exposure to BPA can also lead to abnormally constrained or elevated cellular proliferation and can even reduce cell viability. Therefore, research on EDs such as BPA is important as it provides some important insights into the causes and development of infertility, ovarian cancer and other conditions related to impaired ovarian and GC function. Folic acid, a biologic form of vitamin B9, is a methyl donor that can neutralize the toxic effects of the BPA exposure and is, as a common food supplement, an interesting option for researching its protective role against ubiquitous harmful EDs such as BPA.

DOI:
https://doi.org/10.1530/REP-22-0257
Volume 165: Issue 5,
Pages:
R117–R134
Restricted access

Pendimethalin exposure disrupts mitochondrial function and impairs processes related to implantation

Miji Kim, Junho Park, Garam An, Whasun Lim, and Gwonhwa Song

In brief

Pendimethalin as a dinitroaniline herbicide is used to eliminate weeds during the cultivation of various crops such as grains, fruits, and vegetables. This study reveals that pendimethalin exposure at various concentrations led to disruption in Ca2+ homeostasis and mitochondrial membrane potential, as well as dysregulation of the mitogen-activated protein kinase signaling pathway and implantation-related genes in porcine trophectoderm and uterine luminal epithelial cells.

Abstract

The use of herbicides is a major control method in agriculture. Pendimethalin (PDM) has been increasingly used as a herbicide for approximately 30 years. PDM has been reported to cause various reproductive problems, but its toxicity mechanism in the pre-implantation stage has not been investigated in detail. Herein, we studied the effects of PDM on porcine trophectoderm (pTr) and uterine luminal epithelial (pLE) cells and identified a PDM-mediated anti-proliferative effect in both cell types. PDM exposure generated intracellular reactive oxygen species, induced excessive Ca2+ influx into mitochondria, and activated mitogen-activated protein kinase signaling pathway. Ca2+ burden resulted in the dysfunction of mitochondria and eventual disruption of Ca2+ homeostasis. Further, PDM-exposed pTr and pLE cells showed cell cycle arrest and programmed cell death. In addition, a decrease in migration ability and dysregulated expression of genes related to the functioning of pTr and pLE cells was evaluated. This study provides insight into time-dependent transitions within the cell environment after PDM exposure and elucidates a detailed mechanism of induced adverse effects. These results imply that PDM exposure can potentially cause toxic effects on the implantation-related process in pigs. Moreover, to the best of our knowledge, this is the first study to describe the mechanism by which PDM induces these effects, enhancing our understanding of the toxicity of this herbicide.

DOI:
https://doi.org/10.1530/REP-22-0397
Volume 165: Issue 5,
Pages:
491–505 (15 total)
Open access

SHP2 participates in decidualization by activating ERK to maintain normal nuclear localization of progesterone receptor

Lin Chen, Weijie Zhao, Mengxiong Li, Yazhu Yang, Chengzi Tian, Dengyang Zhang, Zhiguang Chang, Yunzhe Zhang, Zhizhuang Joe Zhao, Yun Chen, and Lin Ma

Decidualization is the process of conversion of endometrial stromal cells (ESCs) into decidual stromal cells (DSCs), which is caused by progesterone production that begins during the luteal phase of the menstrual cycle and then increases throughout pregnancy dedicated to support embryonic development. Decidualization deficiency is closely associated with various pregnancy complications, such as recurrent miscarriage (RM). Here, we reported that Src-homology-2-containing phospho-tyrosine phosphatase (SHP2), a key regulator in the signal transduction process downstream of various receptors, plays an indispensable role in decidualization. SHP2 expression was upregulated during decidualization. SHP2 inhibitor RMC-4550 and shRNA mediated SHP2 reduction resulted in a decreased level of phosphorylation of ERK and aberrant cytoplasmic localization of progesterone receptor (PR), coinciding with reduced expression of IGFBP1 and various other target genes of decidualization. Solely inhibiting ERK activity recapitulated these observations. Administration of RMC-4550 led to decidualization deficiency and embryo absorption in mouse. Moreover, reduced expression of SHP2 was detected in decidua of RM patients. Our results revealed that SHP2 is key to PR's nuclear localization, thereby indispensable for decidualization and that reduced expression of SHP2 might be engaged in the pathogenesis of RM.

DOI:
https://doi.org/10.1530/REP-22-0367
Accepted Manuscripts