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Topic Review
Oxidative Stress on the Reproductive Tract of Males
The reduction of molecular oxygen (O2) yields superoxide (•O2−), which is the precursor of most other reactive oxygen species (ROS). ROS originate from the mitochondria along with other superoxides, and have a complex role in numerous cell signaling pathways that control cell proliferation rates and other cellular activities, such as molecular responses to hypoxia.
  • 945
  • 23 Apr 2023
Topic Review
Function of Melatonin Receptors in Animal Reproduction
Melatonin is an important hormone in animals that regulates various physiological activities such as neuroendocrine function, regulation of seasonal reproduction, sexual maturation, immunoregulation, thermoregulation, some aspects of aging, and antioxidation. The various functions of the melatonin receptors are mainly transmitted through the activation of various signaling pathways. Many studies focused on melatonin-modulated animal reproduction and attempted to understand the melatonin receptor-mediated mechanisms.
  • 944
  • 06 Jul 2022
Topic Review
Idiopathic Infertility and Genome Instability
Infertility (defined as the inability to conceive within a year of unprotected coitus) is a global health and social issue affecting close to 15% of couples. In half of the couples seeking medical treatment for infertility, male factor infertility is identified together with abnormal semen characteristics. The focus of current clinical practice is laid on the presence of sufficient sperm count in the ejaculated specimen with adequate motility and morphology of spermatozoa capable of giving fertilization a chance (conventional semen analysis).
  • 890
  • 20 Jul 2021
Topic Review
Endometrium Immunomodulation in Assisted Reproductive Technology
After more than four decades of assisted reproductive technology (ART) practice worldwide, more than 60% of women undergoing in vitro fertilization (IVF) treatments fail to become pregnant after the first embryo transfer and nearly 20% of patients are suffering from unexplained recurrent implantation failures (RIFs) and repeated pregnancy loss (RPL). The literature reported different causes of RIF–RPL, mainly multifactorial, endometrial and idiopathic. RIF remains a black box because of the complicated categorization and causes of this physio-pathological dysregulation of implantation and pregnancy process after ovarian stimulation. Many options were suggested as solutions to treat RIF–RPL with controversial results on their usefulness.
  • 880
  • 08 Nov 2022
Topic Review
Embryonic-Derived Extracellular Vesicles in Embryo–Endometrial Communication
Embryo–endometrial communication plays a critical role in embryo implantation and the establishment of a successful pregnancy. Successful pregnancy outcomes involve maternal immune modulation during embryo implantation. The endometrium is usually primed and immunomodulated by steroid hormones and embryo signals for subsequent embryo implantation and the maintenance of pregnancy. Evidence shows that endometrial EVs and trophectoderm-originated EV cargo, including microRNAs, proteins, and lipids in the physiological microenvironment, regulate maternal immunomodulation for embryo implantation and subsequent pregnancy. On the other hand, trophoblast-derived EVs also control the cross-communication between the trophoblasts and immune cells. The exploration of EV functions and mechanisms in the processes of embryo implantation and pregnancy will shed light on a practical tool for the diagnostic or therapeutic approaches to reproductive medicine and infertility.
  • 876
  • 16 Nov 2022
Topic Review
Protective Agents for Male Fertility
The male reproductive system is highly susceptible to noxious influences, that can induce germ cell damage, alterations in spermatogenesis and male fertility. For this reason, it is of major importance to investigate possible ways to protect the male reproductive system. For centuries, natural products have been used by humans in folk medicine as therapeutic agents, and because of their beneficial properties for human health, plenty of them have been introduced to the pharmaceutical market as supplementary therapies.
  • 874
  • 08 Nov 2021
Topic Review
Protect Mammalian Sperm from the Spontaneous Acrosome Reaction
To acquire the capacity to fertilize the oocyte, mammalian spermatozoa must undergo a series of biochemical reactions in the female reproductive tract, which are collectively called capacitation. The capacitated spermatozoa subsequently interact with the oocyte zona-pellucida and undergo the acrosome reaction, which enables the penetration of the oocyte and subsequent fertilization. However, the spontaneous acrosome reaction (sAR) can occur prematurely in the sperm before reaching the oocyte cumulus oophorus, thereby jeopardizing fertilization. One of the main processes in capacitation involves actin polymerization, and the resulting F-actin is subsequently dispersed prior to the acrosome reaction. Several biochemical reactions that occur during sperm capacitation, including actin polymerization, protect sperm from sAR.
  • 855
  • 06 Dec 2023
Topic Review
Contemporary Use of Intracytoplasmic Sperm Injection
Intracytoplasmic sperm injection (ICSI) has been used for severe male factor infertility and non-male factors, such as unexplained infertility or advanced maternal age, without robust scientific evidence. However, applying ICSI blindly is not free of potential detrimental consequences since novel studies report possible health consequences to offspring. DNA methylation and epigenetic alterations in sperm cells of infertile men might help explain some of the adverse effects reported in ICSI studies on reproductive health in future generations. 
  • 841
  • 17 May 2022
Topic Review
Cryopreservation of Human Spermatozoa
Cryopreservation is an expanding strategy to allow not only fertility preservation for individuals who need such procedures because of gonadotoxic treatments, active duty in dangerous occupations or social reasons and gamete donation for couples where conception is denied, but also for animal breeding and preservation of endangered animal species. 
  • 840
  • 17 Mar 2023
Topic Review
Maternal Obesity and Gut Microbiota
Obesity in pregnancy induces metabolic syndrome, low-grade inflammation, altered endocrine factors, placental function, and the maternal gut microbiome. All these factors impact fetal growth and development, including brain development. The lipid metabolic transporters of the maternal-fetal-placental unit are dysregulated in obesity. Consequently, the transport of essential long-chain PUFAs for fetal brain development is disturbed. The mother’s gut microbiota is vital in maintaining postnatal energy homeostasis and maternal-fetal immune competence. Obesity during pregnancy changes the gut microbiota, affecting fetal brain development. Obesity in pregnancy can induce placental and intrauterine inflammation and thus influence the neurodevelopmental outcomes of the offspring.
  • 827
  • 03 Nov 2022
Topic Review
Melatonin in Physiological/Biological Ovarian Aging
Melatonin, a highly functionally diverse, low-molecular-weight antioxidant and anti-inflammatory agent has been sparingly studied relative to its ability to reduce patho-physiological processes common to the peripheral female reproductive system. Currently it is known that melatonin reduction is associated with multiple processes underlying changes in the ovary, especially late in the cessation of the reproductive life span. In this sense, it is essential deepen the knowledge about the physiological and molecular actions of melatonin in the maintenance of normal ovaries and in the aging ovaries, and integrate the acquired information for considering melatonin in the treatment of age-related infertility. Additional research is needed to fully understand the effects of melatonin supplementation on potentially enhancing fertility, however, studies published to date suggest it may be a promising option for those struggling with infertility.
  • 814
  • 21 Mar 2023
Topic Review
Sperm Proteins IZUMO1 and TMEM95 in Mammalian Fertilization
Gamete membrane fusion is a critical cellular event in sexual reproduction. In addition, the generation of knockout models has provided a powerful tool for testing the functional relevance of proteins thought to be involved in mammalian fertilization, suggesting IZUMO1 and TMEM95 (transmembrane protein 95) as essential proteins.
  • 809
  • 13 Apr 2022
Topic Review
Male Reproductive Toxicity of Polybrominated Diphenyl Ethers
Polybrominated diphenyl ethers (PBDE) are a group of flame retardants used in a variety of artificial materials. Despite being phased out in most industrial countries, they remain in the environment and human tissues due to their persistence, lipophilicity, and bioaccumulation. Populational and experimental studies demonstrate the male reproductive toxicity of PBDEs including increased incidence of genital malformations (hypospadias and cryptorchidism), altered weight of testes and other reproductive tissues, altered testes histology and transcriptome, decreased sperm production and sperm quality, altered epigenetic regulation of developmental genes in spermatozoa, and altered secretion of reproductive hormones. A broad range of mechanistic hypotheses of PBDE reproductive toxicity has been suggested. Among these hypotheses, oxidative stress, the disruption of estrogenic signaling, and mitochondria disruption are affected by PBDE concentrations much higher than concentrations found in human tissues, making them unlikely links between exposures and adverse reproductive outcomes in the general population. Robust evidence suggests that at environmentally relevant doses, PBDEs and their metabolites may affect male reproductive health via mechanisms including AR antagonism and the disruption of a complex network of metabolic signaling.
  • 785
  • 24 Nov 2022
Topic Review
Boechera Species
Plants from the Boechera genus are attractive models for research because both sexual and apomictic accessions are present within this genus. Moreover, plants from the Boechera genus are close relatives of Arabidopsis thaliana, which is very well studied in terms of molecular genetics and functional gene annotation. In apomictic Boechera species, the Taraxacum type diplospory with pseudogamous endosperm development that requires fertilization of the central cell and recently apospory is reported.
  • 769
  • 15 Mar 2022
Topic Review
SLO3
Sperm cells must undergo a complex maturation process after ejaculation to be able to fertilize an egg. One component of this maturation is hyperpolarization of the membrane potential to a more negative value. The ion channel responsible for this hyperpolarization, SLO3, was first cloned in 1998, and since then much progress has been made to determine how the channel is regulated and how its function intertwines with various signaling pathways involved in sperm maturation. 
  • 765
  • 17 Jul 2023
Topic Review
Chlorogenic Acid on Polycystic Ovarian Syndrome
Chlorogenic acid (CGA) is a powerful antioxidant polyphenol molecule found in many diets and liquid beverages, playing a preventive and therapeutic role in various diseases caused by oxidative stress and inflammation. Recent research has found that CGA can not only improve clinical symptoms in polycystic ovary syndrome (PCOS) patients but also improve follicular development, hormone status, and oxidative stress in PCOS rats, indicating the therapeutic effect of CGA on PCOS.
  • 764
  • 12 Jul 2023
Topic Review
Valproic Acid in Pregnancy Revisited
Valproic acid (VPA) is a very effective anticonvulsant and mood stabilizer with relatively few side effects. Being an epigenetic modulator, it undergoes clinical trials for the treatment of advanced prostatic and breast cancer. However, in pregnancy, it seems to be the most teratogenic antiepileptic drug. Among the proven effects are congenital malformations in about 10%. The more common congenital malformations are neural tube defects, cardiac anomalies, urogenital malformations including hypospadias, skeletal malformations and orofacial clefts. These effects are dose related; daily doses below 600 mg have a limited teratogenic potential. VPA, when added to other anti-seizure medications, increases the malformations rate. It induces malformations even when taken for indications other than epilepsy, adding to the data that epilepsy is not responsible for the teratogenic effects.
  • 744
  • 15 Apr 2024
Topic Review
Opposite-Sex Preference by Chemosensory Signals
The rodent nasal cavity has mainly two chemosensory sensory organs, the vomeronasal organ (VNO) and the olfactory epithelium (OE). However, recently, another chemosensory receptor in the end of the mouse nasal cavity, the Grueneberg ganglion, has been reported. It detects alarm pheromones and predator odors. The VNO hitherto had been thought to be a chemical detector specialized for pheromones, and the OE a detector of airborne chemicals, handling the role of general olfaction. Furthermore, these receptors’ ligands have almost no overlap; olfactory neurons in the OE express a single type of G-protein-coupled receptor (GPCR), that is, detecting a single ligand, whereas some vomeronasal neurons in the VNO express multiple GPCR types, detecting multiple ligands.
  • 737
  • 12 Aug 2021
Topic Review
Small Non-Coding RNAs in Extracellular Vesicles of Semen
Reproductive dysfunction and urogenital malignancies represent a serious health concern in men. This is in part as a result of the absence of reliable non-invasive tests of diagnosis/prognosis. Optimizing diagnosis and predicting the patient’s prognosis will affect the choice of the most appropriate treatment and therefore increase the chances of success and the result of therapy, that is, it will lead to a more personalized treatment of the patient. 
  • 722
  • 19 Jun 2023
Topic Review
In Vitro Growth of Human Follicles
Ovarian tissue cryopreservation is gaining importance as a successful method to restore fertility to girls and young women at high risk of sterility. However, there are concerns regarding the safety of transplantation after ovarian tissue cryopreservation due to the high risk of reintroducing cancer cells and causing disease recurrence. In these cases, the development of culture systems that support oocyte development from the primordial follicle stage is required.
  • 717
  • 19 Mar 2024
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