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Topic Review
Female Fertility in Beef Cattle
Female fertility is the foundation of the cow–calf industry, impacting both efficiency and profitability. 
  • 691
  • 06 Nov 2023
Topic Review
Phosphoproteomics Technique in Male Fertility
Infertility affects approximately 15% of couples worldwide of childbearing age, and in many cases the etiology of male infertility is unknown. The current standard evaluation of semen is insufficient to establish an accurate diagnosis. Spermatozoa cellular development and maturation are tightly coordinated by sperm protein phosphorylation, among other protein post-translational modifications (PTM). Proteomics techniques, such as phosphoproteomics, applied in this field are a powerful tool to understand the mechanisms that regulate sperm functions such as motility, which is essential for successful fertilization.
  • 688
  • 20 May 2022
Topic Review
CatSper in Mammalian Sperm
After sperm enter the female reproductive tract, the physicochemical and biochemical microenvironment undergoes significant changes. In particular, the large changes in various ions encountered by sperm may alter the physiology of sperm, ultimately compromising capacitation and fertilization. Thus, the rapid response to environmental variations is vital for sperm functions. For example, Calcium, the most crucial ion for sperm functions, enters into sperm via Ca2+ permeable ion channels. The cation channel of sperm (CatSper) is a sperm-specific, pH-sensitive, and Ca2+-permeable ion channel. It is responsible for the predominant Ca2+ entry in mammalian sperm and is involved in nearly every event of sperm to acquire fertilizing capability. In addition, CatSper also serves as a pivotal polymodal chemosensor in mammalian sperm by responding to multiple chemical cues. Physiological chemicals (such as progesterone, prostaglandins, β-defensins, and odorants) provoke Ca2+ entry into sperm by activating CatSper and thus triggering sperm functions.
  • 679
  • 01 Sep 2023
Topic Review
The Pathogenic Mechanisms of Endometriosis
Endometriosis (EMS), characterized by the presence of endometrial stromal and glandular tissue outside the uterine cavity, is a relatively common gynecologic disease affecting about 10% of women of reproductive age. While the symptoms of EMS can vary, clinical manifestations such as pelvic pain, heavy or irregular menstrual bleeding, and gastrointestinal symptoms are frequently observed. Apart from the physical discomfort, EMS has been well noticed in infertility.
  • 672
  • 24 Nov 2023
Topic Review
Endometrial regulation by miRNA
The human endometrium is the only tissue that undergoes cyclic monthly structural modifications including proliferation, differentiation and shedding of the superficial layer during the so-called menstrual phase. During the proliferative phase, from day 1 of menses to ovulation day, the superficial layer regenerates from the basal layer under the action of estradiol. In the secretory phase, progesterone induces decidualization in the estradiol-primed endometrium, a crucial step for embryo implantation. These structural and functional modifications at the cellular and intercellular levels are finely orchestrated by numerous extrinsic and intrinsic factors. The molecular responses to hormonal stimuli are modulated at the transcriptional and post-transcriptional stages. Imbalance in cellular and molecular endometrial homeostasis may lead to gynecological disorders such as endometriosis, implantation failure, and endometrial cancer.
  • 671
  • 17 Aug 2021
Topic Review
The Duration of Menstrual Blood Loss
The duration of bleeding is not necessarily linked to the amount of loss but may be influenced by age, ethnicity, habitus, region and altitude of residence, dieting and stress. The onset of bleeding has been linked to declining steroid production by the corpus luteum. There remains considerable controversy around the extent of endometrial shedding at menstruation. This is likely to vary within and between women. The significance of a change from previous patterns, very short or prolonged bleeding, days of light loss or spotting before or after days of bleeding, or of bleed-free days that punctuate flow, remain poorly understood.
  • 660
  • 02 Aug 2023
Topic Review
Progesterone in the Nonhuman Primate Oviduct
Primates differ from most other mammals in that estrogen levels are >50 pg/mL during the entire menstrual cycle, except for a brief decline immediately preceding menstruation. Progesterone secreted in the luteal phase suppresses oviductal ciliation and secretion; at the end of the menstrual cycle, the drop in progesterone triggers renewed estrogen-driven tubal cell proliferation ciliation secretory activity. Thus, progesterone, not estrogen, drives fallopian tube cycles. Specific receptors mediate these actions of progesterone, and synthetic progesterone receptor modulators (PRMs) disrupt the normal cyclic regulation of the tube, significantly altering steroid receptor expression, cilia abundance, cilia beat frequency, and the tubal secretory milieu. Addressing the role of progesterone in the NHP oviduct is a critical step in advancing PRMs as pharmaceutical therapies. 
  • 634
  • 18 May 2022
Topic Review
The Establishment of Pregnancy and Placental Formation
The continuing progress in our understanding of the complexity of interactions between the maternal organism and the early embryo is changing the overall outlook on the initial steps in establishing a pregnancy through placental formation. The first two weeks after fertilization must today be viewed as the critical period during which a major embryo selection process takes place in which a proportion that may surpass 50% of them is physiologically eliminated because they are unfit to progress toward birth.
  • 634
  • 29 Jan 2024
Topic Review
PPARγ Functions in the Placenta and Trophoblasts
The increasing incidence of pregnancy complications, particularly gestational diabetes mellitus (GDM) and preeclampsia (PE), is a cause for concern, as they can result in serious health consequences for both mothers and infants. The pathogenesis of these complications is still not fully understood, although it is known that the pathologic placenta plays a crucial role. Studies have shown that PPARγ, a transcription factor involved in glucose and lipid metabolism, may have a critical role in the etiology of these complications.
  • 623
  • 08 Jun 2023
Topic Review
Animal Models in Biotechnologies for Male Fertility Preservation
To explore advanced reproductive technologies for male fertility preservation, underscoring the essential role that animal models have played in shaping these techniques through historical contexts and into modern applications. Rising infertility concerns have become more prevalent in human populations recently. The surge in male fertility issues has prompted advanced reproductive technologies, with animal models playing a pivotal role in their evolution.
  • 594
  • 28 Dec 2023
Topic Review
Opportunities and Limits of Conventional IVF
Conventional IVF (c-IVF) is one of the most practiced assisted reproductive technology (ART) approaches used worldwide. However, in the last years, the number of c-IVF procedures has dropped dramatically in favor of intracytoplasmic sperm injection (ICSI) in cases of non-male-related infertility. The advantages and disadvantages associated with c-IVF, highlighting the essential steps governing its success, its limitations, the methodology differences among laboratories and the technical progress were outlined. A framework for a better understanding of opportunities associated with human c-IVF and for best practice guidelines applicability in the reproductive medicine field was introduced.
  • 578
  • 11 Oct 2022
Topic Review
Phospholipase C Zeta in Human Spermatozoa
During fertilization, the fusion of the spermatozoa with the oocytes causes the release of calcium from the oocyte endoplasmatic reticulum. This, in turn, triggers a series of calcium ion (Ca2+) oscillations, a process known as oocyte activation. The sperm-specific factor responsible for oocyte activation is phospholipase C zeta (PLCζ). Men undergoing intracytoplasmic sperm injection (ICSI) with their spermatozoa lacking PLCζ are incapable of generating Ca2+ oscillation, leading to fertilization failure. The immunofluorescence assay is the most used technique to assess the expression and localization of PLCζ and to diagnose patients with reduced/absent ability to activate the oocytes.
  • 565
  • 11 Mar 2024
Topic Review
Oxidative Stress and Medicinal Plants for Leydig Cells
Leydig cells are essential for steroidogenesis and spermatogenesis. An imbalance in the production of reactive oxygen species (ROS) and the cellular antioxidant level brings about oxidative stress. Oxidative stress (OS) results in the dysfunction of Leydig cells, thereby impairing steroidogenesis, spermatogenesis, and ultimately, male infertility. To prevent Leydig cells from oxidative insults, there needs to be a balance between the ROS production and the cellular protective capacity of antioxidants. Evidence indicates that medicinal plants could improve Leydig cell function at specific concentrations under basal or OS conditions. The increased usage of medicinal plants has been considered a possible alternative treatment for male infertility. 
  • 561
  • 11 Aug 2023
Topic Review
Molecular Dynamics of Early Pregnancy in Farm Animals
Infertility is a major problem in farm animals, which has a negative economic effect on farm industries. Infertility can be defined as the inability of animals to achieve a successful pregnancy. Early pregnancy is crucial to establish a successful pregnancy, and it is reported that 70–80% and 20–30% of total embryonic loss occur in cattle and pigs, respectively, during the first month of pregnancy.
  • 559
  • 05 Jan 2024
Topic Review
Establishment of the Sperm Epigenome
The sperm inherit the paternal half of the genetic material along with epigenetic instructions for the embryo development and inheritable traits. These epigenetic instructions include DNA methylation, histone/protamine marks and a plethora of RNA species. The production of male gametes is a tightly orchestrated cellular process, and the sperm epigenome and transcriptome are established at different phases of sperm production and maturation along the male reproductive tract. 
  • 555
  • 21 Dec 2022
Topic Review
Chromium Picolinate on Testicular Steroidogenesis and Antioxidant Balance
Reduced testosterone (T) levels significantly contribute to male infertility, as this hormone plays a vital role in various functions throughout the male reproductive system. T is produced in the Leydig cells (LC) via testicular steroidogenesis. Dysfunctional LC can impair steroid synthesis and therefore fertility. Endocrine-disrupting chemicals (EDCs) are noteworthy factors influencing steroidogenesis by interfering with hormonal signaling. The heavy metal chromium is classified as an EDC, existing as hexavalent (Cr(VI)) and trivalent chromium (Cr(III)). Despite the debate surrounding Cr(III), chromium picolinate (CrPic3), is used as a nutritional supplement due to its antioxidant and antidiabetic properties. Detrimental effects of CrPic3 on LC encompass enzyme inhibition in steroidogenesis and, while in other cell types, it was found to induce of mutagenesis and apoptosis. Notably, CrPic3 influences male fertility through modifications in reactive oxygen species, T levels, and sperm parameters (e.g., sperm motility and abnormal sperm count). Nonetheless, major gaps and inconsistencies exist in literature concerning its effects on male fertility. Thus, more research is essential to comprehend the mechanisms in which CrPic3 is involved that may be relevant to male fertility, ensuring the safety of this supplement for man.
  • 549
  • 11 Aug 2023
Topic Review
Immune Responses Potentially Involved in Brucella-Induced Pregnancy Complications
Infection by Brucella species in pregnant animals and humans is associated with an increased risk of abortion, preterm birth, and transmission of the infection to the offspring. The pathogen has a marked tropism for the placenta and the pregnant uterus and has the ability to invade and replicate within cells of the maternal–fetal unit, including trophoblasts and decidual cells. Placentitis is a common finding in infected pregnant animals. Several proinflammatory factors have been found to be increased in both the placenta of Brucella-infected animals and in trophoblasts or decidual cells infected in vitro. As normal pregnancies require an anti-inflammatory placental environment during most of the gestational period, Brucella-induced placentitis is thought to be associated with the obstetric complications of brucellosis.
  • 538
  • 22 Jan 2024
Topic Review
Fatty Acid-Binding Orotein-4 on Pregnancy Health
Fatty acid-binding protein-4 (FABP4), commonly known as adipocyte-fatty acid-binding protein (A-FABP), is a pleiotropic adipokine that broadly affects immunity and metabolism. Throughout pregnancy, FABP4 affects maternal–fetal interface homeostasis by affecting both glycolipid metabolism and immune tolerance, leading to adverse pregnancy outcomes, including miscarriage, gestational obesity, gestational diabetes, and preeclampsia. Moreover, maternal FABP4 levels exhibit a substantial linkage with the metabolic health of offspring. 
  • 522
  • 24 Aug 2023
Topic Review
Pharmaceuticals with Obesogen Action Impact Male Fertility
Obesogens have been identified as a significant factor associated with increasing obesity rates, particularly in developed countries. Substances with obesogenic traits are prevalent in consumer products, including certain pharmaceuticals. Specific classes of pharmaceuticals have been recognized for their ability to induce weight gain, often accompanied by hormonal alterations that can adversely impact male fertility. 
  • 480
  • 27 Feb 2024
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