Melatonin in male and female fertility

Melatonin, a hormone synthesized mainly by the pineal gland, has been found in extra-pineal organs as well. It’s known as an organizer of circadian rhythms and more recently as an anti-oxidant. In addition to its role in maintaining immunity, pathophysiology of cardiovascular and neurological diseases, and as an anti-cancer agent, evidence has demonstrated that melatonin exerts a positive impact on male and female fertility primarily through oxygen scavenging effects. In In Vitro Fertilization (IVF) programs, supplementation of melatonin may be associated with better outcomes in terms of sperm quality, oocyte quality, embryo quality and pregnancy rates. This review summarizes various actions of melatonin on the body focusing on male and female fecundity.

Phenolic Compounds and Oxidative Enzymes Involved in Female Fertility in Banana Plants of the Cavendish Subgroup

The present study investigated phenolic compounds and enzymes involved in female fertility in banana plants of the Cavendish subgroup. The wild diploid Calcutta 4 and commercial cultivar Grand Naine (Cavendish subgroup) were used. The following five stages of floral development were proposed: S1 (partial vertical emission), S2 (total vertical emission), S3 (total horizontal emission), S4 (pre-anthesis), and S5 (anthesis). Following collection, pistillate (female) flowers were freeze-dried for the subsequent removal of nectaries and the analysis of phenolic compounds (PCs), antioxidant activity (DPPH and ABTS), enzymatic activity [peroxidase (POD) and polyphenol oxidase (PPO)], and total proteins (TPs). The highest values were recorded at the S3 stage, with the values decreasing as the stages progressed (until S5). At the S3 stage, the following results were obtained for Calcutta 4 and Grand Naine, respectively: PCs (32.4 and 36.1 mg GAE·g−1); DPPH (735.2 and 454.4 µM TE·g−1); ABTS (647.8 and 555.5 µM TE·g−1); POD (0.8 and 0.7 µmol·min−1·g−1); PPO (3.7 and 2.7 µmol·min−1·g−1); and TP (3.2 and 2.4 µmol·min−1·g−1). These results indicate that PCs and enzymes regulate female fertility, suggesting that crossbreeding should be performed from the S3 stage in cultivars of the Cavendish subgroup to achieve fruits with seeds.

FATORES DE IMPACTO NA RESERVA OVARIANA E FERTILIDADE EM PACIENTES COM ENDOMETRIOSE

Introdução: Endometriose é uma afecção inflamatória na qual o conteúdo endometrial acomete sítios além da cavidade uterina como ovários e órgãos pélvicos. É uma doença comum, crônica, heterogênea e pode ter a infertilidade como um dos seus sintomas, tendo implicações importantes na reserva ovariana, diminuindo as taxas de fertilização, implantação e gravidez. Objetivos: Fazer uma revisão bibliográfica sobre os fatores que relacionam a endometriose com os impactos na reserva ovariana e fertilidade feminina em relação ao número e qualidade de oócitos e embriões, em taxas de sucesso em tratamentos de fertilização in vitro e nos fatores de risco modificáveis como tabagismo, uso de álcool, níveis de vitamina D e indicação cirúrgica para excisão da endometriose. Material e Métodos: Foram reunidos 100 trabalhos científicos inseridos nas bases de dados do PubMed, Scielo e Google Acadêmico. As palavras-chaves utilizadas foram “endometriosis”, “endometriosis management” “ovarian reserve”, “fertility preservation”, “fertility impact”, “female fertility”, “laparoscopy” em inglês e português, utilizando os termos de busca booleanos "AND" e "OR" para mesclar os assuntos. Apenas revisões de literatura e revisões sistemáticas publicadas entre os anos 2000 e 2021, nos idiomas inglês e português (PT/BR), foram consideradas. Resultados: A qualidade oocitária é impactada pela presença da endometriose, a reserva ovariana é menor em portadoras de endometriomas do que em endometriose peritoneal, as taxas de sucesso em fertilização in vitro e a qualidade dos embriões gerados são dependentes da idade materna e as taxas de implantação, gravidez e nascidos-vivos são similares a outros grupos em tratamentos assistidos por outras causas de infertilidade. A laparoscopia para a remoção da endometriose é danosa à reserva ovariana e deve ser indicada quando há outros sintomas além da infertilidade. Mulheres com indicação cirúrgica podem se beneficiar da vitrificação de oócitos previamente à excisão endometriótica. Níveis insuficientes de vitamina D estão relacionados a maiores taxas de infertilidade associada à endometriose, os dados sobre uso de álcool são inconclusivos. Tabagismo não tem ação comprovada sobre a manifestação da endometriose. Conclusão: A endometriose tem impacto sobre a fertilidade feminina e seu manejo deve ser individualizado de acordo com os sintomas apresentados e o desejo reprodutivo da mulher.

The impact of fine particulate matter (PM) on various beneficial functions of human endometrial stem cells through its key regulator SERPINB2

Fine particulate matter (PM) has a small diameter but a large surface area; thus, it may have broad toxic effects that subsequently damage many tissues of the human body. Interestingly, many studies have suggested that the recent decline in female fertility could be associated with increased PM exposure. However, the precise mechanisms underlying the negative effects of PM exposure on female fertility are still a matter of debate. A previous study demonstrated that resident stem cell deficiency limits the cyclic regenerative capacity of the endometrium and subsequently increases the pregnancy failure rate. Therefore, we hypothesized that PM exposure induces endometrial tissue damage and subsequently reduces the pregnancy rate by inhibiting various beneficial functions of local endometrial stem cells. Consistent with our hypothesis, we showed for the first time that PM exposure significantly inhibits various beneficial functions of endometrial stem cells, such as their self-renewal, transdifferentiation, and migratory capacities, in vitro and in vivo through the PM target gene SERPINB2, which has recently been shown to be involved in multiple stem cell functions. In addition, the PM-induced inhibitory effects on the beneficial functions of endometrial stem cells were significantly diminished by SERPINB2 depletion. Our findings may facilitate the development of promising therapeutic strategies for improving reproductive outcomes in infertile women.

Bitter Taste Receptors Expression in Human Granulosa and Cumulus Cells: New Perspectives in Female Fertility

Bitter taste receptors (TAS2RS) expression is not restricted to the oral cavity and the presence of these receptors in the male reproductive system and sperm provides insights into their possible role in human reproduction. To elucidate the potential role of TAS2Rs in the female reproductive system, we investigated the expression and localization of bitter taste receptors and the components of signal transduction cascade involved in the pathway of taste receptors in somatic follicular cells obtained from women undergoing assisted reproductive techniques. We found that TAS2R genes are expressed in both cumulus (CCs) and granulosa (GCs) cells, with TAS2R14 being the most highly expressed bitter receptor subtype. Interestingly, a slight increase in the expression of TAS2R14 and TAS2R43 was shown in both GCs and CCs in young women (p < 0.05), while a negative correlation may be established between the number of oocytes collected at the pickup and the expression of TAS2R43. Regarding α-gustducin and α-transducin, two Gα subunits expressed in the taste buds on the tongue, we provide evidence for their expression in CCs and GCs, with α-gustducin showing two additional isoforms in GCs. Finally, we shed light on the possible downstream transduction pathway initiated by taste receptor activation in the female reproductive system. Our study, showing for the first time the expression of taste receptors in the somatic ovarian follicle cells, significantly extends the current knowledge of the biological role of TAS2Rs for human female fertility.