The effect of lysophosphatidic acid on myometrial contractility and the mRNA transcription of its receptors in the myometrium at different stages of endometrosis in mares.

Background: Endometrosis (chronic degenerative endometritis) results in morphological changes in the equine endometrium and impairs its secretory function. However, the effect of this condition on the myometrium remains unclear. Lysophosphatidic acid (LPA) may affect female reproductive function and embryo transport by influencing uterine contractility through its receptors (LPARs).

Intrauterine devices influence prostaglandin secretion by equine uterus: in vitro and in vivo studies.

Background: Intrauterine devices (IUD) are used in the veterinary practice as the non-pharmacological method of oestrus suppression in mares. When placed in the uterus, IUD create a physical contact with the endometrium that mimics the presence of an equine embryo. However, the mechanism of their action has not been fully elucidated.

Apoptosis, autophagic cell death, and necroptosis: different types of programmed cell death in bovine corpus luteum regression.

In mammals, the corpus luteum (CL) is a transient organ that secretes progesterone (P4). In the absence of pregnancy, the CL undergoes regression (luteolysis), which is a crucial preparation step for the next estrous cycle. Luteolysis, initiated by uterine prostaglandin F (PGF) in cattle, is usually divided into two phases, namely functional luteolysis characterized by a decline in P4 concentration and structural luteolysis characterized by the elimination of luteal tissues from the ovary.

Effects of cortisol on prostaglandin F2α secretion and expression of genes involved in the arachidonic acid metabolic pathway in equine endometrium - In vitro study.

Glucocorticoids (GCs) are known to play an important role in maintaining basal and stress-related homeostasis by interacting with endocrine mediators and prostaglandins (PGs). Although a growing body of evidence shows that GCs exert their regulatory action at a multitude of sites in the reproductive axis through corticosteroid receptors, little is known about the direct role of cortisol, an active form of GCs, in the equine endometrium. Thus, the study aimed to determine the effect of cortisol on PGF synthesis in the endometrial tissue and cells in vitro.

Vaginal temperature before calving assessed with wireless vaginal temperature sensor in dairy and beef cattle.

We evaluated the daily and hourly vaginal temperature changes and the relationships between the dams' breed and parity by using a commercially available vaginal temperature sensor in 72 Holstein (Hol) calvings and 101 Japanese Black (JB) calvings. Vaginal temperature sensors inserted 7-10 days before the expected calving day sounded two alerts: when the temperature fell below the threshold (Alert 1), and when the sensor reached the ambient temperature after falling out of the dam's vagina with the rupture of the allantoic sac (Alert 2). The durations from Alert 1 to Alert 2 (Time 1) and from Alert 2 to delivery (Time 2) were calculated.

Receptor interacting protein kinases-dependent necroptosis as a new, potent mechanism for elimination of the endothelial cells during luteolysis in cow.

Necroptosis is an alternative form of programmed cell death regulated by receptor-interacting protein kinase (RIPK) 1 and 3-dependent. In the present study, to clarify if necroptosis in luteal endothelial cells (LECs) participates and contributes for bovine luteolysis, we investigated RIPK1 and RIPK3 localization in luteal tissue and their expression in cultured LECs after treatment with selected immune factors - mediators of luteolytic action of prostaglandin F2α (PGF). In addition, effects of tumor necrosis factor α (TNF; 2.

Efficiency of a pedometer device for detecting estrus in standing heat and silent heat in Japanese Black cattle.

The usefulness of a radiotelemetric pedometer for estrus detection in standing (ST) heat, or in silent heat without ST events, but in which ovulation is observed, in Japanese Black cattle was investigated. The duration of an increase in steps in ST heat was 11.8 ± 1.

Live births from artificial insemination of microfluidic-sorted bovine spermatozoa characterized by trajectories correlated with fertility.

Selection of functional spermatozoa plays a crucial role in assisted reproduction. Passage of spermatozoa through the female reproductive tract requires progressive motility to locate the oocyte. This preferential ability to reach the fertilization site confers fertility advantage to spermatozoa.

Vaginal temperature measurement by a wireless sensor for predicting the onset of calving in Japanese Black cows.

We evaluated the utility of the continuous measurement of vaginal temperature by a wireless sensor and wireless connection for predicting the onset of calving and for clarifying the relationships among dystocia, calf conditions, and temperature changes at a commercial beef cattle farm in Japan. A total of 625 effective delivery data was collected. The temperature sensor inserted to the vagina on 7 days before the expected due date and collected the vaginal temperature every 5 min.

Evaluating the electrical impedance and mucus-related gene expression of uterine endometrial tissues in mares.

We investigated the electrical impedance of the reproductive tracts (vagina and uterine endometrial tissues) and the expression of mucus-related genes to identify the stage of the estrous cycle in mares. We first examined vaginal impedance in native Hokkaido mares during their estrous cycle and found no significant differences. However, impedance levels tended to decrease towards ovulation.

Programmed necrosis - a new mechanism of steroidogenic luteal cell death and elimination during luteolysis in cows.

Programmed necrosis (necroptosis) is an alternative form of programmed cell death that is regulated by receptor-interacting protein kinase (RIPK) 1 and 3-dependent, but is a caspase (CASP)-independent pathway. In the present study, to determine if necroptosis participates in bovine structural luteolysis, we investigated RIPK1 and RIPK3 expression throughout the estrous cycle, during prostaglandin F2α (PGF)-induced luteolysis in the bovine corpus luteum (CL), and in cultured luteal steroidogenic cells (LSCs) after treatment with selected luteolytic factors. In addition, effects of a RIPK1 inhibitor (necrostatin-1, Nec-1; 50 μM) on cell viability, progesterone secretion, apoptosis related factors and RIPKs expression, were evaluated.

Potential role of hCG in apoptosis of human luteinized granulosa cells.

The corpus luteum (CL) forms after ovulation and acts as a temporary endocrine gland that produces progesterone (P4), a hormone that is essential for implantation and maintenance of pregnancy in mammals. In pregnant women, human chorionic gonadotropin (hCG) secreted by the conceptus prevents luteolysis. hCG also increases the survival of cultured human luteinized granulosa cells (hLGCs).

Galectin-3 contributes to luteolysis by binding to Beta 1 integrin in the bovine corpus luteum.

Luteolysis is characterized by a reduction in progesterone (P4) production and tissue degeneration in the corpus luteum (CL). One of major events during luteolysis is luteal cell death. Galectin-3, a ubiquitously expressed protein involved in many cellular processes, serves as an antiapoptotic and/or proapoptotic factor in various cell types.

Interleukins affect equine endometrial cell function: modulatory action of ovarian steroids.

The aim of the present study was to investigate the interaction between ovarian steroids, interleukins and prostaglandins (PG) in equine epithelial and stromal cells in vitro. In Experiment 1, cells were exposed to IL-1α (10 ng/mL), IL-1β (10 ng/mL) or IL-6 (10 ng/mL) for 24 h and cell proliferation was determined using MTT. In Experiment 2, cells were exposed to progesterone (P4; 10(-7) M); 17-β estradiol (E2; 10(-9) M) or P4+E2 for 24 h and later medium was replaced with a fresh one treated with IL-1α, IL-1β or IL-6 (10 ng/mL, each) for 24 h.

The effect of single nucleotide polymorphisms in the tumor necrosis factor-α gene on reproductive performance and immune function in dairy cattle.

The present study aimed to assess the effect of polymorphisms in the tumor necrosis factor α (TNF-α) promoter (A/A, A/G and G/G) and exons (T/T, T/C and C/C) on immune function and reproductive performance in dairy cows. The occurrence of the first postpartum ovulation within 3 weeks in the cows with the TNF-α promoter A/G and G/G genotypes was higher than in the A/A group. Among the different TNF-α exon genotypes, the occurrence of early first postpartum ovulation was higher in the T/C and C/C genotype groups than in the T/T group.

Expression of aldo-keto reductase 1C23 in the equine corpus luteum in different luteal phases.

Regression of the corpus luteum (CL) is characterized by a decay in progesterone (P4) production (functional luteolysis) and disappearance of luteal tissues (structural luteolysis). In mares, structural luteolysis is thought to be caused by apoptosis of luteal cells, but functional luteolysis is poorly understood. 20α-hydroxysteroid dehydrogenase (20α-HSD) catabolizes P4 into its biologically inactive form, 20α-hydroxyprogesterone (20α-OHP).

Expression of glucocorticoid receptor α and its regulation in the bovine endometrium: possible role in cyclic prostaglandin F2α production.

Cortisol (Cr), the most important glucocorticoid (GC), is well known to suppress uterine prostaglandin F2α (PGF) production. However, the details of the regulatory mechanisms controlling the cyclic changes in endometrial PGF production remain unclear. Here we investigated the expression of the GC receptor (GC-Rα), the actions of cortisol throughout the estrous cycle and the regulatory mechanism of GC-Rα in the bovine endometrium.

Possible role of insulin-like factor 3 in the bovine corpus luteum.

Insulin-like factor 3 (INSL3) is a local regulator in mammalian gonads, but little is known of its function in bovine corpus luteum (CL). Here, we show that RXFP2 protein, the receptor of INSL3, was expressed throughout the estrous cycle and significantly high at the early luteal stage compared to the regressed luteal stage. INSL3 stimulated progesterone secretion, but not prostaglandin F2α and viability in cultured luteal cells.

Seasonal changes in luteal progesterone concentration and mRNA expressions of progesterone synthesis-related proteins in the corpus luteum of mares.

Although circulating progesterone (P₄) levels tend to change with the season, little is known about the seasonal changes of P₄ synthesis-related proteins in the corpus luteum (CL) of mares. To examine these changes, seventy-four ovaries containing a CL were collected from Anglo-Norman mares at a local abattoir in Kumamoto, Japan (~N32°), five times during one year. The stages of the CLs were classified as early, mid and regressed by macroscopic observation of the CL and follicles.

Effects of tumor necrosis factor α and Interferon γ on the viability and mRNA expression of TNF receptor type I in endothelial cells from the bovine corpus luteum.

The corpus luteum (CL) is mainly composed of luteal steroidogenic cells (LSCs) and luteal endothelial cells (LECs). Cell death of LSCs and LECs is essential for structural luteolysis. Therefore, it is important to understand the mechanisms regulating cell death in both types of luteal cells.

Expression and localization of cFLIP, an anti-apoptotic factor, in the bovine corpus luteum.

The objective of the present study was to investigate the potential mechanisms regulating cellular FLICE-like inhibitory protein (cFLIP), an anti-apoptotic factor, in the bovine corpus luteum (CL). Expression of cFLIP mRNA was highest at the developing stage and then decreased significantly during the mid, late and regressed stages (P<0.05).

Changes in the vasculature of bovine corpus luteum during the estrous cycle and prostaglandin F2alpha-induced luteolysis.

To investigate the possible role of the vasculature in the local regulation of corpus luteum (CL) function, we determined the densities of capillaries and large blood vessels in the center of the bovine CL during the estrous cycle and following prostaglandin (PG) F2alpha-induced luteolysis. The CLs at the early (Days 2-3 post-ovulation), developing (Days 5-7), mid (Days 8-12), late (Days 15-17) and regressed (Days 19-21) stages were collected. In addition, the CLs were collected by transvaginal ovariectomy from 12 cows (Day 10 after ovulation), i.

Anti-apoptotic roles of prostaglandin E2 and F2alpha in bovine luteal steroidogenic cells.

Production of prostaglandins (PGs) and expression of their receptors have been demonstrated in bovine corpus luteum (CL). The aim of the present study was to determine whether PGE2 and PGF2alpha have roles in bovine luteal steroidogenic cell (LSC) apoptosis. Cultured bovine LSCs obtained at the midluteal stage (Days 8-12 of the cycle) were treated for 24 h with PGE2 (0.

Expressions of estrogen receptors in the bovine corpus luteum: cyclic changes and effects of prostaglandin F2alpha and cytokines.

Estrogen (E) exerts its function by binding to two intracellular estrogen receptors, ERalpha and ERbeta. Although ERs have been reported to be expressed in the bovine corpus luteum (CL), the mechanisms that control ER expression in the bovine CL are not fully understood. To determine the possible regulatory mechanisms of ERalpha and ERbeta that meditate distinct E functions, we examined 1) the changes in the protein expressions of ERs in the CL throughout the luteal phase and 2) the effects of prostaglandin (PG) F2alpha, tumor necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma) on the expressions of ERs in cultured bovine luteal cells.