Selected Genetic Factors Associated with Primary Ovarian Insufficiency

Oncofertility as an Essential Part of Comprehensive Cancer Treatment in Patients of Reproductive Age, Adolescents and Children

The number of children, adolescents and young adults diagnosed with cancer has been rising recently. Various oncological treatments have a detrimental effect on female fertility, and childbearing becomes a major issue during surveillance after recovery. This review discusses the impact of oncological treatments on the ovarian reserve with a thorough explanation of oncologic treatments' effects and modes of oncofertility procedures. The aim of this review is to help clinicians in making an informed decision about post-treatment fertility in their patients. Ultimately, it may lead to improved overall long-term outcomes among young populations suffering from cancer.

TP63 truncating mutation causes increased cell apoptosis and premature ovarian insufficiency by enhanced transcriptional activation of CLCA2

BACKGROUND

Premature ovarian insufficiency (POI) is a severe disorder leading to female infertility. Genetic mutations are important factors causing POI. TP63-truncating mutation has been reported to cause POI by increasing germ cell apoptosis, however what factors mediate this apoptosis remains unclear.

METHODS

Ninety-three patients with POI were recruited from Beijing Obstetrics and Gynecology Hospital, Capital Medical University. Whole-exome sequencing (WES) was performed for each patient. Sanger sequencing was used to confirm potential causative genetic variants. A minigene assay was performed to determine splicing effects of TP63 variants. A TP63-truncating plasmid was constructed. Real-time quantitative PCR, western blot analyses, dual luciferase reporter assays, immunofluorescence staining, and cell apoptosis assays were used to study the underlying mechanism of a TP63-truncating mutation causing POI.

RESULTS

By WES of 93 sporadic patients with POI, we found a 14-bp deletion covering the splice site in the TP63 gene. A minigene assay demonstrated that the 14-bp deletion variant led to exon 13 skipping during TP63 mRNA splicing, resulting in the generation of a truncated TP63 protein (TP63-mut). Overexpression of TP63-mut accelerated cell apoptosis. Mechanistically, the TP63-mut protein could bind to the promoter region of CLCA2 and activate the transcription of CLCA2 several times compared to that of the TP63 wild-type protein. Silencing CLCA2 using a specific small interfering RNA (siRNA) or inhibiting the Ataxia Telangiectasia Mutated (ATM) pathway using the KU55933 inhibitor attenuated cell apoptosis caused by TP63-mut protein expression.

CONCLUSION

Our findings revealed a crucial role for CLCA2 in mediating apoptosis in POI pathogenesis, and suggested that CLCA2 is a potential therapeutic target for POI.

A Human Homozygous HELQ Missense Variant Does Not Cause Premature Ovarian Insufficiency in a Mouse Model

Disruption of meiosis and DNA repair genes is associated with female fertility disorders like premature ovarian insufficiency (POI). In this study, we identified a homozygous missense variant in the HELQ gene (c.596 A>C; p.Gln199Pro) through whole exome sequencing in a POI patient, a condition associated with disrupted ovarian function and female infertility. HELQ, an enzyme involved in DNA repair, plays a crucial role in repairing DNA cross-links and has been linked to germ cell maintenance, fertility, and tumour suppression in mice. To explore the potential association of the HELQ variant with POI, we used CRISPR/Cas9 to create a knock-in mouse model harbouring the equivalent of the human HELQ variant identified in the POI patient. Surprisingly, Helq knock-in mice showed no discernible phenotype, with fertility levels, histological features, and follicle development similar to wild-type mice. Despite the lack of observable effects in mice, the potential role of HELQ in human fertility, especially in the context of POI, should not be dismissed. Larger studies encompassing diverse ethnic populations and alternative functional approaches will be necessary to further examine the role of HELQ in POI. Our results underscore the potential uncertainties associated with genomic variants and the limitations of in vivo animal modelling.

The effects of prenatal azithromycin exposure on offspring ovarian development at different stages, doses, and courses

Azithromycin, a commonly used macrolide antibiotic for treating chlamydial infections during pregnancy, has sparked investigations into its potential effects on offspring development. Despite these inquiries, there remains uncertainty about the specific impact of prenatal azithromycin exposure (PAzE) on offspring ovarian development and the precise "effect window". Pregnant mice, following clinical guidelines for azithromycin dosing, were orally administered azithromycin at different gestational stages [(gestational day, GD) 10-12 or GD 15-17], doses (50, 100, or 200 mg/kg·d), and courses (single or multiple). On GD 18, we collected offspring blood and ovaries to examine changes in fetal serum estradiol (E2) levels, fetal ovarian morphology, pre-granulosa cell function, and oocyte development. Multiple courses of PAzE resulted in abnormal fetal ovarian morphological development, disorganized germ cell nests, enhanced ovarian cell proliferation, and reduced apoptosis. Simultaneously, multiple courses of PAzE significantly increased fetal serum E2 levels, elevated ovarian steroidogenic function (indicated by Star, 3β-hsd, and Cyp19 expression), disrupted oocyte development (indicated by Figlα and Nobox expression), and led to alterations in the MAPK signal pathway in fetal ovaries, particularly in the high-dose treatment group. In contrast, a single course of PAzE reduced fetal ovarian cell proliferation, decreased steroidogenic function, and inhibited oocyte development, particularly through the downregulation of Mek2 expression in the MAPK signal pathway. These findings suggest that PAzE can influence various aspects of fetal mouse ovarian cell development. Multiple courses enhance pre-granulosa cell estrogen synthesis function and advance germ cell development, while a single terminal gestation dose inhibits germ cell development. These differential effects may be associated with changes in the MAPK signal pathway.

Molecular Characterization, Expression Pattern, DNA Methylation and Gene Disruption of Figla in Blotched Snakehead (Channa maculata)

Figla is one of the earliest expressed genes in the oocyte during ovarian development. In this study, Figla was characterized in C. maculata, one of the main aquaculture species in China, and designated as CmFigla. The length of CmFigla cDNA was 1303 bp, encoding 197 amino acids that contained a conserved bHLH domain. CmFigla revealed a female-biased expression patterns in the gonads of adult fish, and CmFigla expression was far higher in ovaries than that in testes at all gonadal development stages, especially at 60~180 days post-fertilization (dpf). Furthermore, a noteworthy inverse relationship was observed between CmFigla expression and the methylation of its promoter in the adult gonads. Gonads at 90 dpf were used for in situ hybridization (ISH), and CmFigla transcripts were mainly concentrated in oogonia and the primary oocytes in ovaries, but undetectable in the testes. These results indicated that Figla would play vital roles in the ovarian development in C. maculata. Additionally, the frame-shift mutations of CmFigla were successfully constructed through the CRISPR/Cas9 system, which established a positive foundation for further investigation on the role of Figla in the ovarian development of C. maculata. Our study provides valuable clues for exploring the regulatory mechanism of Figla in the fish ovarian development and maintenance, which would be useful for the sex control and reproduction of fish in aquaculture.

Characteristics and clinical evaluation of X chromosome translocations

BACKGROUND

Individuals with X chromosomal translocations, variable phenotypes, and a high risk of live birth defects are of interest for scientific study. These characteristics are related to differential breakpoints and various types of chromosomal abnormalities. To investigate the effects of X chromosome translocation on clinical phenotype, a retrospective analysis of clinical data for patients with X chromosome translocation was conducted. Karyotype analysis plus endocrine evaluation was utilized for all the patients. Additional semen analysis and Y chromosome microdeletions were assessed in male patients.

RESULTS

X chromosome translocations were detected in ten cases, including seven females and three males. Infantile uterus and no ovaries were detected in case 1 (FSH: 114 IU/L, LH: 30.90 mIU/mL, E2: < 5.00 pg/ml), and the karyotype was confirmed as 46,X,t(X;22)(q25;q11.2) in case 1. Infantile uterus and small ovaries were both visible in two cases (FSH: 34.80 IU/L, LH: 17.06 mIU/mL, E2: 15.37 pg/ml in case 2; FISH: 6.60 IU/L, LH: 1.69 mIU/mL, E2: 23.70 pg/ml in case 3). The karyotype was detected as 46,X,t(X;8)(q13;q11.2) in case 2 and 46,X,der(X)t(X;5)(q21;q31) in case 3. Normal reproductive hormone levels and fertility abilities were found for cases 4, 6 and 7. The karyotype were detected as 46,X,t(X;5)(p22.3;q22) in case 4 and 46,X,der(X)t(X;Y)(p22.3;q11.2) in cases 6 and 7. These patients exhibited unremarkable clinical manifestations but experienced a history of abnormal chromosomal pregnancy. Normal phenotype and a complex reciprocal translocation as 46,X,t(X;14;4)(q24;q22;q33) were observed in case 5 with a history of spontaneous abortions. In the three male patients, multiple semen analyses confirmed the absence of sperm. Y chromosome microdeletion and hormonal analyses were normal. The karyotypes were detected as 46,Y,t(X;8)(q26;q22), 46,Y,t(X;1)(q26;q23), 46,Y,t(X;3)(q26;p24), respectively.

CONCLUSIONS

Our study provides insights into individuals with X chromosome translocations. The clinical phenotypes are variable and unpredictable due to differences in breakpoints and X chromosome inactivation (XCI) patterns. Our results suggest that physicians should focus on the characteristics of the X chromosome translocations and provide personalized clinical evaluations in genetic counselling.

Primary Ovarian Insufficiency and Ovarian Aging

Primary ovarian insufficiency (POI) is a complex condition of aberrant ovarian aging. POI etiologies are varied, and most cases have no identifiable underlying cause. Caring for women with POI requires an approach that understands the importance of ovarian function in a variety of target organs and tissues.

Nuclear Estrogen Receptors in Prostate Cancer: From Genes to Function

Estrogens are almost ubiquitous steroid hormones that are essential for development, metabolism, and reproduction. They exert both genomic and non-genomic action through two nuclear receptors (ERα and ERβ), which are transcription factors with disregulated functions and/or expression in pathological processes. In the 1990s, the discovery of an additional membrane estrogen G-protein-coupled receptor augmented the complexity of this picture. Increasing evidence elucidating the specific molecular mechanisms of action and opposing effects of ERα and Erβ was reported in the context of prostate cancer treatment, where these issues are increasingly investigated. Although new approaches improved the efficacy of clinical therapies thanks to the development of new molecules targeting specifically estrogen receptors and used in combination with immunotherapy, more efforts are needed to overcome the main drawbacks, and resistance events will be a challenge in the coming years. This review summarizes the state-of-the-art on ERα and ERβ mechanisms of action in prostate cancer and promising future therapies.

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.