fertility Archives | Misha Blagosklonny

In this new study, researchers investigated the relationship between paternal age, the BEGAIN gene and autism.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in communication and social interaction, as well as repetitive behaviors. It has been observed that children born to older fathers have an increased risk of developing ASD and other neurodevelopmental disorders. This phenomenon suggests that paternal age may have an impact on the risk of ASD in offspring.

Recent research has focused on understanding the potential mechanisms underlying the association between paternal age and ASD. One area of interest is the epigenome, specifically DNA methylation, which refers to the addition or removal of methyl groups to DNA molecules. DNA methylation can affect gene expression and play a role in various biological processes.

In a new study, researchers Ramya Potabattula, Andreas Prell, Marcus Dittrich, Caroline Nava, Christel Depienne, Yosra Bejaoui, Nady El Hajj, Thomas Hahn, Martin Schorsch, and Thomas Haaf from Julius Maximilians University, Groupe Hospitalier Pitié-Salpêtrière, University Hospital Essen, Hamad Bin Khalifa University, and Fertility Center in Wiesbaden, Germany, explored the relationship between paternal age, DNA methylation of the BEGAIN gene, and the risk of ASD. The BEGAIN gene encodes a protein involved in protein-protein interactions at synapses, which are crucial for proper brain function. On November 28, 2023, their research paper was published in Aging’s Volume 15, Issue 22, entitled, “Effects of paternal and chronological age on BEGAIN methylation and its possible role in autism.”

“So far, only 40 genes with sperm ageDMRs [age-associated differentially methylated regions] have been replicated in at least three independent genome-wide methylation screens [19], which makes them primary candidates for mediating paternal age effects on the next generation. Here, we focused on one of these top candidates, the BEGAIN promoter region.”

The Study

The study focused on examining the impact of paternal age on BEGAIN methylation. Various techniques were employed to investigate this relationship. Sperm samples from normozoospermic individuals attending a fertility center were analyzed. The researchers aimed to understand how paternal age influences BEGAIN methylation, specifically observing its trends in sperm.

To extend their exploration of transgenerational effects, fetal cord blood samples were also examined. The team aimed to discern whether paternal age influenced BEGAIN methylation differently in male and female offspring. The research team employed meticulous analyses to understand the sex-specific patterns associated with paternal age and BEGAIN methylation.

They also delved into the effects of chronological age on BEGAIN methylation. Peripheral blood samples from individuals of different ages were analyzed to investigate the relationship between chronological age and BEGAIN methylation. The study aimed to discern whether BEGAIN methylation undergoes changes with age in a sex-specific manner.

“It is tempting to speculate that transmission of paternal age-associated sperm methylation changes into the next generation modulates BEGAIN regulation and susceptibility to neurodevelopmental disorders.”

The Results

The research yielded significant findings. A negative correlation between paternal age and BEGAIN methylation was identified, suggesting a decrease in BEGAIN methylation in sperm as paternal age increases. The sex-specific impact of paternal age on BEGAIN methylation was observed, with a significant negative correlation in male offspring but not in female offspring.

Regarding chronological age, a significant negative correlation with BEGAIN methylation was found in males but not in females, indicating a potential sex-specific age-related change in BEGAIN methylation.

The study also explored the association between BEGAIN methylation and Autism Spectrum Disorder (ASD). Individuals with ASD were found to have significantly lower levels of BEGAIN methylation compared to age- and sex-matched controls, suggesting a potential involvement of BEGAIN methylation in the development of ASD.

Furthermore, the researchers identified a genetic variant, SNP rs7141087, associated with BEGAIN methylation. The CC genotype of this SNP was linked to lower levels of BEGAIN methylation compared to the TT genotype, potentially contributing to observed differences in BEGAIN methylation between individuals with ASD and controls.

“Individuals with CC genotype of SNP rs7141087 which show a 6% lower methylation than the TT genotype are significantly more frequent in our ASD group than in controls. This could be due to an association of the C allele with autism.”

Conclusions & Future Research

In conclusion, this research provides valuable insights into the effects of paternal and chronological age on BEGAIN methylation and its potential role in ASD. The findings suggest that paternal age and chronological age can influence BEGAIN methylation, and these changes may be associated with an increased risk of ASD. Further research is needed to fully understand the mechanisms underlying these associations and their implications for the development of ASD.

“The male-specific hypomethylation of the BEGAIN promoter in blood, and by extrapolation other somatic tissues is exaggerated in males suffering from autism. Moreover, our results also show a paternal age effect on BEGAIN methylation in sperm and the male offspring (FCB). […] However, the functional implications of small age-associated methylation changes in BEGAIN in a multifactorial disease model remain to be elucidated.”

Click here to read the full study published in Aging.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

In a new study, researchers aimed to reveal a link between telomere dysfunction, ovarian aging and infertility using a mouse model of accelerated-reproductive senescence.

Telomeres are the protective caps at the ends of chromosomes that prevent DNA damage and maintain genomic stability. However, telomeres shorten with each cell division and eventually reach a critical length that triggers cellular senescence or death. Telomere length (TL) and telomerase activity (TA), the enzyme that replenishes telomeric repeats, are influenced by genetic and environmental factors and vary among tissues and individuals.

“Telomere attrition has been identified as one of the molecular determinants of aging [7].”

Telomere dysfunction has been implicated in various age-related diseases, including infertility. Ovarian aging is the main cause of infertility in women, as it leads to a decline in both the quantity and quality of oocytes. Previous studies have shown that TL and TA are reduced in oocytes and granulosa cells of women with diminished ovarian reserve or poor response to ovarian stimulation. Moreover, TL and TA have been associated with ovarian reserve markers and pregnancy outcomes in assisted reproductive technologies.

To better understand the molecular mechanisms underlying ovarian aging and infertility, researchers Alba M. Polonio, Marta Medrano, Lucía Chico-Sordo, Isabel Córdova-Oriz, Mauro Cozzolino, José Montans, Sonia Herraiz, Emre Seli, Antonio Pellicer, Juan A. García-Velasco, and Elisa Varela from The Health Research Institute La Fe (IIS La Fe), IVIRMA Rome, New Jersey and Madrid, Centro Anatomopatológico, Yale School of Medicine, University of Valencia, and Rey Juan Carlos University conducted a new study using a mouse model of accelerated aging: the Senescence-Accelerated Mouse Prone 8 (SAMP8). On May 23, 2023, their research paper was published in Aging’s Volume 15, Issue 11, entitled, “Impaired telomere pathway and fertility in Senescence-Accelerated Mice Prone 8 females with reproductive senescence.”

The Study

The SAMP8 mouse model, which has previously been suggested as an Alzheimer’s disease model of aging, also exhibits a shortened estrous cycle, elevated follicle-stimulating hormone (FSH) levels, and reduced fertility in females at just seven months of age. SAMP8 mice have a shorter lifespan compared to senescence-accelerated mouse resistant 1 (SAMR1) mice. SAMR1 mice do not exhibit reproductive senescence. Thus, the researchers deemed the SAMR1 mouse model an appropriate control group to study the SAMP8 mouse model as a model of ovarian aging and infertility.

“In the current study, we sought to investigate whether the SAMP8 mice, which show accelerated-reproductive senescence, have alterations in their telomere pathway. This question has not yet been explored in relation to reproduction in this model.”

In this study, the team compared the TL and TA in blood and ovary samples from the SAMP8 female mice at seven months of age (when they show signs of reproductive senescence) with age-matched control SAMR1 mice. They also evaluated the ovarian follicle development, the expression of telomerase subunits (TERT and TERC), and the reproductive outcomes after ovarian stimulation in both groups of mice. In sum, the researchers measured survival rates (in male and female mice), alteration in the telomere pathway at seven months of age, TERT and TERC expression levels, TA on the TL of granulosa cells in developing follicles, and impairment/alterations in the telomere pathway in oogenesis and embryo development.

The results revealed that SAMP8 females had a reduced median lifespan compared to SAMP8 males and SAMR1 males and females. In blood, SAMP8 females had lower mean TL and higher accumulation of short telomeres than the other mice. In ovary, SAMP8 females had lower TA and TERT expression. Furthermore, SAMP8 females had fewer primordial, primary, secondary, and antral follicles than control females, indicating a diminished ovarian reserve. After ovarian stimulation, SAMP8 females had a lower number of oocytes than controls of the same age. Their results suggested that oogenesis and embryo development is impaired in SAMP8 mice at seven months compared to age-matched controls, and this coincides with alterations in the telomere pathway.

Conclusions

“Thus, SAMP8 females represent a bona fide model for the analysis of fertility, not only because it shows similar phenotype to middle-aged women as stated earlier [43], but also because the alterations in the telomere pathway are found in women with fertility disorders [37, 38, 40, 41] and this pathway links reproduction with longevity.”

The researchers concluded that SAMP8 females have impaired telomere pathway and fertility, reflecting signs of reproductive senescence described in middle-aged women. They suggested that the SAMP8 model could be useful in studying the role of telomere dysfunction in ovarian aging and infertility. In addition, this mouse model could be used to test potential therapeutic interventions to improve female reproductive health.

“Understanding the molecular pathways underlying aging and fertility, provides a basis for further studies focused on several topics. First, the analysis of embryo alterations, which can be better assessed in mice than in humans. Second, how reproductive lifespan improvement may ameliorate elderly health. And third, the mechanisms underlying follicle recruitment and development, which are not completely known.”

Click here to read the full research paper published by Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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