Evidence for Increased Content of PGF2α, PGE2, and 6-keto-PGF1α in Endometrial Tissue Cultures From Heavy Draft Mares in Anestrus With Endometritis

Effects of Wharton's jelly mesenchymal stromal/stem cells-derived conditioned medium and platelet-rich plasma on in vitro induced equine endometrial inflammation

Over the years, regenerative therapies have emerged as promising alternatives for persistent breeding-induced endometritis. In vitro studies testing the effects of these therapies on equine endometrial cells are still scarce. This study aimed to evaluate in vitro the effect of Wharton's jelly (WJ) mesenchymal stromal/stem cell (MSCs)-derived conditioned medium (WJ-CM) and platelet-rich plasma (PRP) on equine endometrial cells, with or without lipopolysaccharide (LPS)-induced inflammation. The WJ-CM was obtained after 24 h of starvation in Ringer's lactate of WJ-MSCs and PRP was prepared using the double centrifugation. Endometrial epithelial cells obtained from 3 diestrus mare uteri at slaughterhouse were treated for 24 h according to six experimental groups: DMEM standard complete medium (CTRL); 10 ng/mL LPS (LPS); 10 % WJ-CM (CM); 5 % PRP (PRP); 10 ng/mL LPS and 10 % WJ-CM (LPS + CM); 10 ng/mL LPS and 5 % PRP (LPS + PRP). After 6, 12, and 24 h, endometrial cells were evaluated for viability (apoptosis and necrosis), mitochondrial activity and reactive oxygen species (ROS) generation. PGE-2 and IL-10 concentrations in spent medium were measured. The WJ-CM alone did not affect endometrial cell viability and prevented the detrimental effect of LPS on endometrial cells; it suppressed the production of PGE-2. PRP had a deleterious effect on endometrial cell viability, induced the secretion of PGE-2, as well as increased mitochondrial activity and ROS production. Endometrial benefits of the WJ-CM treatment are evident even after an LPS challenge, while unexpectedly PRP showed a deleterious effect.

The early pregnancy in mares - What do we still not know?

Equine conceptus development is a critical study area due to its significant implications for the equine breeding industry. Following a high fertilization success rate of 71-96 % (Ball, 1988), it is concerning that 30-40 % of developing embryos may not survive beyond the crucial initial two weeks of gestation, coinciding with the onset of gastrulation (Ball, 1988). The pregnancy in mares lasts 330-345 days. The underlying molecular mechanisms of the embryonic period are not fully explained in mares. During early pregnancy in mares, the following takes place: the descent of the blastocyst from the oviduct to the uterus around 5-6 days post-fertilization; migration of the spherical conceptus, surrounded by a glycoprotein capsule in the uterine lumen; fixation of the vesicle near the base of the uterine horn around 16-17 days post-fertilization; implantation; development of endometrial cups that produce chorionic gonadotropin, as well as an additional corpus luteum that produces progesterone. In mares, there is no clear determination of what constitutes the early signal of pregnancy recognition. The results of previous research indicate that mechanical stimuli, i.e. the movement of the conceptus in the uterine lumen, trigger a cascade of molecular events in the endometrium responsible for the luteostasis and the maintenance of early pregnancy in mares. This study aims to provide a synthetic summary of the knowledge we have gained so far about early pregnancy and to attempt to answer the question of what molecular mechanisms underlie maternal recognition of pregnancy in mares.

Effects of Ammonia Stress on Liver Tissue Structure, Enzyme Activities, and Metabolome of Juvenile Largemouth Bass Micropterus salmoides

Background: Ammonia, a ubiquitous contaminant in aquatic ecosystems, poses multifaceted threats to fish species at elevated concentrations. Methods: In order to investigate the toxic effects of chronic ammonia stress on the liver of juvenile Micropterus salmoides, the present experiment was conducted to investigate the differences in changes in liver tissue structure, enzyme activities, and metabolomes after 28 days of ammonia exposure (0, 4, 8, and 16 mg/L). Results: The findings revealed that ammonia exposure induced significant oxidative stress in the liver, manifesting in decreased activities of antioxidant enzymes SOD and GSH-Px, elevated levels of GSH, GST, and MDA, and heightened activities of immune enzymes LZM, ALP, and ACP. An increase in ammonia concentration exacerbated liver tissue damage. Metabolome analysis further unveiled perturbations in liver metabolites of Micropterus salmoides exposed to ammonia, with Ala-His emerging as a potentially pivotal functional substance under chronic stress. Specifically, the 4 mg/L group responded to ammonia toxicity by augmenting GSH and L-Carnosine levels, the 8 mg/L group detoxified via upregulation of L-Glutamine, and the 16 mg/L group mitigated toxicity through the urea synthesis pathway. Conclusions: This research offers preliminary insights into the toxicological responses of Micropterus salmoides under chronic ammonia stress. It is suggested that the duration of ammonia concentration exceeding 4 mg/L in high-density aquaculture should not exceed 7 days.

Prostaglandin-related genes are differentially expressed in equine endometrium with different biopsy grade, degrees of inflammation, and fibrosis

Prostaglandins have many roles in the equine reproductive tract, including but not limited to luteolysis, luteal support, ovulation, transport through the uterine tube, uterine contraction, embryonic mobility, inflammation, and fibrosis. Altered secretion of inflammatory proteins are likely to disrupt the balance of endometrial function and could impair fertility. Our overall goal was to measure the expression of several prostaglandin- and inflammation-related genes in mares with different degrees of endometrial histological changes. Our hypothesis was that mares with neutrophilic and lymphocytic plasmocytic inflammation, fibrosis, or different biopsy grades would have altered concentrations of prostaglandin E2 (PGE2) and F2α (PGF2α), as well as altered expression of inflammation- and prostaglandin-related genes, compared to mares with minimal to no histological changes on biopsy evaluation. Forty-five endometrial biopsies from estrous mares were assessed by a reproductive pathologist for the degree of neutrophilic inflammation, lymphocytic and plasmocytic inflammation, and fibrosis, and a biopsy grade was assigned based on the Kenney-Doig system. A low-volume uterine lavage was collected from a subset of twenty-six mares prior to biopsy collection and was used to measure PGE2 and PGF2α concentrations via ELISA. Total RNA was extracted from biopsies and mRNA expression was evaluated for twenty-five genes of interest. A restricted maximum likelihood linear model was used to compare differences of mRNA expression, with a statistical significance set at P < 0.05. There was no difference in the abundance of PGE2 or PGF2α between any of the variables tested. Mares with endometrial biopsy grade I had lower expression of NF-kB, PTGS1 and HPGD compared to grade IIA or IIB (P < 0.05). Mares with neutrophilic inflammation had decreased expression of NF-kB, PTGS1, PTGER4, CBR1, mPGES2 and PTGIS compared to mares without inflammation. Mares with mild or minimal endometrial fibrosis had increased expression of mPGES2 and PTGIS, compared to mares with moderate endometrial fibrosis. In conclusion, several genes were identified to be differentially expressed in mares with histological changes compared to mares with no to minimal histological changes. The presence of inflammation and fibrosis may alter the concentration of prostaglandins in endometrial tissue, which could impair many of the uterine reproductive and immune functions during estrus, affecting early embryo survival.

Leonurine Exerts Anti-Inflammatory Effects in Lipopolysaccharide (LPS)-Induced Endometritis by Modulating Mouse JAK-STAT/PI3K-Akt/PPAR Signaling Pathways

Endometritis is a common disease in postpartum cows, characterized by delayed uterine recovery due to endometrial inflammation. Although antibiotics and hormones are commonly used, they have certain limitations. One potential alternative is using motherwort extract, specifically leonurine, which exhibits anti-inflammatory properties. However, leonurine's exact molecular mechanism of action remains unclear. In this study, 40 mice were randomly divided into four groups: a control group, endometritis model group, LPS + leonurine group (30 mg/kg), and LPS + dexamethasone group (5 mg/kg). Transcriptomic analysis revealed that leonurine modulates multiple signaling pathways, including JAK-STAT/PI3K-Akt, and influences the expression of key genes, such as Prlr, Socs2, Col1a1, and Akt1. Furthermore, leonurine effectively reduces levels of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-1β (p < 0.01), which play a crucial role in regulating acute endometritis. Additionally, leonurine helps maintain cholesterol homeostasis and attenuates inflammation through the peroxisome proliferator-activated receptor (PPAR) signaling pathway by modulating genes such as Cyp27a1, Hmgcs1, and Scd2. These findings suggest that leonurine has a protective effect against LPS-induced endometritis and that its anti-inflammatory properties involve multiple pathways and targets, which are potentially mediated by regulating signaling pathways such as JAK-STAT/PI3K-Akt and PPAR.

Hemodynamic changes in cytokines, chemokines, acute phase proteins and prostaglandins in mares with subclinical endometritis

Apparently healthy mares with conception failure or embryonic loss may have subclinical endometritis (SE). Our objective was to document evidence of systemic immune responses against SE in mares. In apparently healthy (control) mares as well as those with chronic endometritis (ChE) or subacute suppurative endometritis (SSE), both considered classes of SE, serum concentrations of cytokines (IL-1β, IL-6, IL-10 and TNF_-α), chemokines (IL-8), acute phase protein (SAA), and plasma concentrations of prostaglandins (PGF_2α and PGE₂) were measured using validated enzyme linked immunoassays (EIA). Mixed-breed mares of known reproductive history, were used. Based on an endometrial cytological examination, mares were allocated into the following groups: healthy (control), ChE, and SSE (12, 26 and 11 mares, respectively). Serum concentrations of IL-6, IL-8 and IL-10 and plasma PGF_2α concentrations were increased (P < 0.01) in mares with SSE compared to healthy mares. Furthermore, serum concentrations of IL-6 (P < 0.05) and IL-10 (P < 0.05) were elevated in the ChE group compared to the healthy group whereas serum SAA (P < 0.01) and plasma PGE₂ (P < 0.05) were higher in healthy mares compared to ChE and SSE mares. However, serum concentrations of IL-1β and TNF_-α were not significantly different among groups. In conclusion, there were two novel findings: (1) development of serum testing for a set of biochemical markers has promise to explore the pathogenesis of inflammation in mares with SE; and (2) none of the individual biomarkers studied, excluding IL-8, was a significant predictor of SE. However, serum IL-6:IL-10 and IL-6:TNF_-α concentrations, as well as plasma PGE₂:PGF_2α ratios, may yield a novel diagnostic marker for chronic subclinical endometritis.