Can Helicobacter pylori infection influence human reproduction?

Helicobacter pylori (H. pylori) infection could be associated with extra-digestive diseases. Here, we report the evidences concerning the decrease in reproductive potential occurring in individuals infected by H. pylori, especially by strains expressing CagA. This infection is more prevalent in individuals with fertility disorders. Infected women have anti-H. pylori antibodies in cervical mucus and follicular fluid that may decrease sperm motility and cross react immunologically with spermatozoa, conceivably hampering the oocyte/sperm fusion. Infection by CagA positive organisms enhances the risk of preeclampsia, which is a main cause of foetus death. These findings are supported by the results of experimental infections of pregnant mice, which may cause reabsorption of a high number of foetuses and alter the balance between Th1 and Th2 cell response. Infected men have decreased sperm motility, viability and numbers of normally shaped sperm and augmented systemic levels of inflammatory cytokines, such as tumor necrosis factor-α, which may damage spermatozoa. In countries where parasitic infestation is endemic, detrimental effects of infection upon spermatozoa may not occur, because the immune response to parasites could determine a switch from a predominant Th1 type to Th2 type lymphocytes, with production of anti-inflammatory cytokines. In conclusion, the evidences gathered until now should be taken into consideration for future studies aiming to explore the possible role of H. pylori infection on human reproduction.

Similar causes of various reproductive disorders in early life

During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals （EDCs）, due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of EDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

Genetic factors of reproductive disorders in female

Successful reproduction in mammals requires gamete development,fertilization,and early embryonic development.Defects in any of these processes can lead to infertility,recurrent miscarriages,and congenital defects.The clinical recognition of the genetic causes of female reproductive insufficiency using increasingly advanced genetic technologies poses a serious challenge for reproductive medicine in the 21st century.Herein,the current literature on genetic factors involved in reproductive losses was summarized.A literature search was conducted using Web of Science,MEDLINE,and PubMed databases for articles written in English on the genetic causes of women’s reproductive health disorders.Future implementation of whole-exome and wholegenome sequencing is expected to identify numerous genetic factors responsible for oocyte quality.Which will aid in increasing the likelihood of successful female reproductive function,improve the outcomes of assisted reproductive technologies,optimize treatment,and facilitate genetic diagnosis of patients.

NLRP3 inflammasome:a new therapeutic target for high-risk reproductive disorders?

The NOD-like receptor protein 3(NLRP3)inflammasome is a key regulator of the host’s immune response,and many immune and metabolic disorders are linked to its activation.This review aimed to investigate and clarify the relationship between this inflammasome and high-risk reproductive disorders.Papers cited here were retrieved from PubMed up to August 2020 using the keywords"NLRP3"or"NALP3","caspase-1","endometriosis","gestational diabetes","interleukin(IL)-18","IL-1β","pre-eclampsia(PE)","preterm birth","polycystic ovarian syndrome(PCOS)","recurrent spontaneous abortion(RSA)",and combinations of these terms.The results show that NLRP3 inflammasome is associated with various high-risk reproductive disorders and many inflammatory factors are secreted during its activation,such as IL-1βinduced during the development of endometriosis.PCOS is also associated with activation of the NLRP3 inflammasome,especially in overweight patients.It also participates in the pathogenesis of RSA and is activated in fetal membranes before preterm birth.The placentas of pregnant women with PE show higher expression of the NLRP3 inflammasome,and gestational diabetes mellitus occurs simultaneously with its activation.Current evidence suggest that the NLRP3 inflammasome plays an important role in female reproductive disorders.New treatment and management methods targeting it might help reduce the incidence of such disorders and improve neonatal outcomes.