A comparison of the uterine proteome of mares in oestrus and dioestrus

Metagenomic and proteomic analyses reveal similar reproductive microbial profiles and shared functional pathways in uterine immune regulation in mares and jennies

This study aims to unveil potential differences in the vaginal and uterine microbiomes in mares and jennies, and to identify possible mechanisms involved in uterine immune homeostasis. The microbiota was characterized using 16S rRNA sequencing, and the uterine proteome was analyzed using UHPLC/MS/MS in 18 samples from healthy mares and 14 from jennies. While taxonomic analysis revealed high interspecies similarities, β-diversity analysis showed distinct clustering, with only two vaginal taxa and five uterine taxa differing between species. Despite compositional differences, PICRUSt analysis suggested minimal variations in predicted functional pathways across species. Comparing vaginal and uterine microbiota within the same species revealed overlapping bacterial taxa, but significant differences in α- and β-diversity and functional pathways. The uterine microbiota of both species was dominated by Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, with abundant taxa like Streptococcus, Pseudomonas, Bacillus, Corynebacterium, and Staphylococcus, many of which are frequently associated with endometritis. The presence of Lactobacillus in the equine reproductive tract was minimal or non-existent. KEGG functional pathway analysis predicted that uterine microbiota of both species utilize metabolic pathways with potential immunomodulatory effects. Proteomic enrichment analysis showed that numerous overexpressed uterine proteins in both species are linked to adaptive and innate immune regulation and defense mechanisms against symbionts. Gene enrichment analysis identified several enriched Gene Ontology terms, including response to bacterial stimuli, humoral immune regulation, and TGF-beta receptor signaling, underscoring microbial-host interactions. The uterine microbiota may play a vital role in maintaining immune balance. Further research is required to confirm its interaction with the uterine immune system and clarify the mechanisms involved.

The Impact of the Competition on miRNA, Proteins, and Metabolites in the Blood Exosomes of the Yili Horse

PURPOSE

Horse racing may cause stress-induced physiological changes and tissue damage in horses, but the changes in miRNA expression, protein expression, and metabolic substances in the plasma exosomes of the Yili horse after racing are still unclear. This study detected miRNA, protein expression, and metabolic substances in the plasma exosomes of Yili horses before and after competition, providing new insights for post-race recovery and care of Yili horses.

METHOD

Eight three-year-old Yili horses that had undergone training were selected as the research subjects, with four horses that had not competed as the control group and four horses that had participated in the competition for half an hour as the training group. Extract whole blood and separate plasma from two groups of horses, and then extract plasma exosomes; MiRNAs, proteins, and metabolites in extracellular vesicles were detected and analyzed using miRNAomics, proteomics, and metabolomics. P Result: After the competition, the levels of miRNAs related to the cytoplasm and nucleus in Yili horse plasma exosomes increased, and miRNAs related to the transcription and transcriptional regulation of biological processes significantly increased. The levels of proteins related to the cytoplasm and nucleus also increased, and the levels of proteins related to cell signaling function increased, carbohydrates and their metabolites were significantly reduced.

CONCLUSIONS

The competition process causes significant changes in the miRNA, proteomics, and metabolomics of plasma exosomes in the Yili horses, which are mainly related to metabolic regulation.

Unraveling the uterine fluid proteome of mares diagnosed with post-breeding and infectious endometritis

Endometritis is the leading cause of subfertility in mares and a significant challenge to equine reproduction. Unraveling uterine fluid proteome may promote advancements in the knowledge of endometritis etiopathogeneses and its diagnosis and therapeutic practices. Therefore, we aimed to characterize and compare the protein profile of the uterine fluid from healthy mares and animals diagnosed with endometritis. Mangalarga Marchador breed mares from Muriaé - Brazil were divided into control, infectious endometritis, and post-breeding endometritis groups (n = 8/ group). Uterine fluid was collected via low-volume lavage and subjected to protein identification and relative abundance counting. From the 549 proteins detected, 279 were in the uterine fluid of mares from the three experimental groups. Thirteen proteins expressed mostly in healthy mares were associated with endometrial remodeling and early embryonic development. Albumin and uteroglobin presented higher relative abundance in healthy mares and animals with infectious endometritis. Infectious endometritis exhibited proteins related to innate immune and inflammatory responses, including annexin and glutathione S-transferase, and the highest abundance of lipocalins. Fifty-five proteins detected in mares with post-breeding endometritis showed signaling pathways and biological processes related to the innate immune response. These animals also presented the highest abundance of PIGR proteins, which promote IgA transport from plasma into the endometrial mucosa. In conclusion, our results revealed distinct protein profiles from the uterine fluid of mares with infections and post-breeding endometritis. These findings provided valuable insights into the molecular alterations during the establishment and progression of endometritis, contributing to further identification of potential biomarkers.

Bacterial endometritis-induced changes in the endometrial proteome in mares: Potential uterine biomarker for bacterial endometritis

Equine endometritis is one of the main causes of subfertility in the mare. Unraveling the molecular mechanisms involved in this condition and pinpointing proteins with biomarker potential could be crucial in both diagnosing and treating this condition. This study aimed to identify the endometritis-induced changes in the endometrial proteome in mares and to elucidate potential biological processes in which these proteins may be involved. Secondly, biomarkers related to bacterial endometritis (BE) in mares were identified. Uterine lavage fluid samples were collected from 28 mares (14 healthy: negative cytology and culture, and no clinical signs and 14 mares with endometritis: positive cytology and culture, in addition to clinical signs). Proteomic analysis was performed with a UHPLC-MS/MS system and bioinformatic analysis was carried out using Qlucore Omics Explorer. Gene Ontology enrichment and pathway analysis (PANTHER and KEGG) of the uterine proteome were performed to identify active biological pathways in enriched proteins from each group. Quantitative analysis revealed 38 proteins differentially abundant in endometritis mares when compared to healthy mares (fold changes >4.25, and q-value = 0.002). The proteins upregulated in the secretome of mares with BE were involved in biological processes related to the generation of energy and REDOX regulation and to the defense response to bacterium. A total of 24 biomarkers for BE were identified using the biomarker workbench algorithm. Some of the proteins identified were related to the innate immune system such as isoforms of histones H2A and H2B involvement in neutrophil extracellular trap (NET) formation, complement C3a, or gelsolin and profilin, two actin-binding proteins which are essential for dynamic remodeling of the actin cytoskeleton during cell migration. The other group of biomarkers were three known antimicrobial peptides (lysosome, equine cathelicidin 2 and myeloperoxidase (MPO)) and two uncharacterized proteins with a high homology with cathelicidin families. Findings in this study provide the first evidence that innate immune cells in the equine endometrium undergo reprogramming of metabolic pathways similar to the Warburg effect during activation. In addition, biomarkers of BE in uterine fluid of mares including the new proteins identified, as well as other antimicrobial peptides already known, offer future lines of research for alternative treatments to antibiotics.

Metagenomic analysis unravels novel taxonomic differences in the uterine microbiome between healthy mares and mares with endometritis

BACKGROUND

The application of high throughput technologies has enabled unravelling of unique differences between healthy mares and mares with endometritis at transcriptomic and proteomic levels. However, differences in the uterine microbiome are yet to be investigated.

OBJECTIVES

The present study was aimed at evaluating the differences in uterine microbiome between healthy mares and mares with endometritis.

METHODS

Low-volume lavage (LVL) samples were collected from the uterus of 30 mares classified into healthy (n = 15) and endometritis (n = 15) based on their reproductive history, intrauterine fluid accumulation, gross appearance of LVL samples, endometrial cytology and bacterial culture. The samples were subjected to 16S rRNA sequencing.

RESULTS

Notable differences in the uterine microbiome were observed between healthy mares and mares with endometritis at various taxonomic levels. In healthy mares, the most abundant phylum, class, order and family were Firmicutes, Bacilli, Bacillales and Paenibacillaceae, respectively. In contrast, the most abundant corresponding taxonomic levels in mares with endometritis were Proteobacteria, Gammaproteobacteria, Enterobacterales and Enterobacteriaceae, respectively. At the genus level, Brevibacillus and Paenibacillus were more abundant in healthy mares, whereas Escherichia, Salmonella and Klebsiella were more abundant in mares with endometritis. In healthy mares, Brevibacillus brevis was the most abundant species, followed by Brevibacillus choshinensis and Paenibacillus sp JDR-2. However, in mares with endometritis, Escherichia coli was the most abundant species, followed by Salmonella enterica and Klebsiella pneumoniae.

CONCLUSIONS

These results confirmed the previously reported presence of a uterine microbiome in healthy mares and helped unravel some alterations that occur in mares with endometritis. The findings can potentially help formulate new approaches to prevent or treat equine endometritis.

Proteomic analysis of uterine lavage fluid of dairy cows at different time after delivery by mass spectrometry

Endometritis is a common disease in the reproductive system, which is the infection and inflammation of the endometrium. In severe cases, it can affect the myometrium and adversely affect the subsequent fertility of dairy cows. We used a mass spectrometry-based technique to compare proteomics of uterine lavage fluid between healthy cows and cows with cytological endometritis classified according to 100-day postpartum pregnancy results and diagnosis result. The uterine lavage fluid of dairy cows collected at 15 and 30 days after delivery was analyzed. 15 days postpartum, we identified a total of 1129 proteins in the control and cytological endometritis (CEM) groups. Among them, 160 proteins were accurately screened out. 30 days postpartum, we identified a total of 846 proteins in the control and cytological endometritis (CEM) groups. Among them, 186 proteins were accurately cytological endometritis (CEM). Endometritis is a costly reproductive disease in lactating cows, which needs to be diagnosed in time. Using proteomics method based on gel mass spectrometry, we compared the proteome of uterine lavage fluid of dairy cows with and without cytological endometritis to characterize the changes of proteomic characteristics associated with postpartum uterine disease. To provide reference for clinical application and basic research.

The bovine uterine fluid proteome is more impacted by the stage of the estrous cycle than the proximity of the ovulating ovary in the periconception period

Uterine secretions provide a suitable environment for sperm selective migration during a couple of days preceding ovulation and for early embryo development before implantation. Our goal was to identify and quantify proteins in the bovine uterine fluid during the periovulatory period of the estrous cycle. Genital tracts with normal morphology were collected from adult cyclic Bos taurus females in a local slaughterhouse and classified into pre-ovulatory or post-ovulatory stages of cycle (around days 19-21 and 0-5 of cycle, respectively; n = 8 cows per stage) based on ovarian morphology. Proteins from uterine fluid collected from the utero-tubal junction to the base of each horn (four pools of two cows per condition) were analyzed by nanoLiquid Chromatography coupled with tandem Mass Spectrometry (nanoLC-MS/MS). A total of 1214 proteins were identified, of which 91% were shared between all conditions. Overall, 57% of proteins were predicted to be secreted and 17% were previously reported in uterine extracellular vesicles. Paired comparisons between uterine horns ipsilateral and contralateral to ovulation evidenced 12 differentially abundant proteins, including five at pre-ovulatory stage. Furthermore, 35 proteins differed in abundance between pre- and post-ovulatory stages, including 21 in the ipsilateral side of ovulation. Functional analysis of identified proteins demonstrated roles in binding, metabolism, cellular detoxification and the immune response. This study provides a valuable database of uterine proteins for functional studies on sperm physiology and early embryo development.

Comparative Proteome Analysis of Serum Uncovers Differential Expression of Proteins in Donkeys (Equus Asinus) With Endometritis Caused by Escherichia Coli

Endometritis is a common disease in donkeys that causes economic losses to donkey farms and the common cause is bacterial infection. Uterine flush fluid proteomics has been used to study protein biomarkers associated with endometritis in mares. As a convenient diagnostic tool, serum proteomics has not been studied yet in equine species with endometritis. This study is aiming to evaluate the serum proteomics in jennies with and without endometritis and identify potential proteins as biomarker for endometritis diagnosis. Nine donkeys recruited into this study were diagnosed of bacterial (Escherichia coli) endometritis and nine healthy jennies were selected as control. Blood samples of each donkey was collected, and serum was separated from each sample. Peptides samples extracted from the serum were analyzed using nano-ultrahigh-performance liquid chromatography-tandem mass spectrometry in data-independent acquisition mode. Protein identification and quantification were performed followed by differential and functional analysis. Of 579 proteins identified in all jennies, 12 proteins were exclusively identified in jennies with endometritis (group E) including myeloperoxidase and Ras-related protein Rab-1B, which might be associated with bacterial infection. There were 11 differentially expressed proteins detected between the two groups of jennies with 4 downregulated proteins and 7 upregulated proteins in jennies with endometritis. Some upregulated proteins along with the GO and KEGG annotation indicated inflammatory response against uterine infection. Characteristic serum proteins identified in jennies with endometritis were associated with inflammation or bacterial infection. These proteins might be potential biomarkers for endometritis diagnosis in jennies.

Influence of Reproductive Status on Equine Serum Proteome: Preliminary Results

The reproductive cycle and early pregnancy represent dynamic physiological states in mammals, but mechanisms involved in early pregnancy in the domestic horse remain poorly understood. Proteins in uterine secretions have been studied, but the proteome of peripheral serum during various reproductive states has not been investigated. This study characterized and compared the serum proteome in the domestic horse during various reproductive states. Serum was collected from three mares during: (1) estrus (day [d] -1; d 0 = ovulation), (2) diestrus (d 12.5, non-mated), (3) early pregnancy (d 12.5, pregnant), and (4) nonpregnant (d 12.5, unsuccessfully mated) states. Serum proteins in each sample were analyzed by Nano LC-MS/MS, and 308 proteins were identified. Differentially-expressed proteins (DEP; > 1.5-fold or < - 0.5-fold) were identified by comparison of protein relative abundance between reproductive states: (1) diestrus compared to estrus (DEP = 71), (2) pregnant compared to diestrus (DEP = 72), and (3) non-pregnant compared to pregnant (DEP = 81). DEPs were analyzed for biological function using PANTHER (pantherdb.org). Several pregnancy-specific proteins previously identified in equine pregnant histotroph, including Apolipoprotein A-I, Complement C3, and Histone H4, were detectable in the serum. The ability to detect these biomarkers in serum provides a more readily available option for investigating and understanding early equine pregnancy.

Expression and characterization of the serum proteome from yak induced into estrus by improved nutrition

Regulation of estrus plays a crucial role in the livestock industry. It is reported that providing better nutrition can induce early estrus in animals. However, little is known about the major endocrine and physiological mechanisms that could enhance estrus in anestrus animals. Hence in the current research two different groups of yaks, non-breeding season (February-June, NBS) estrus yaks as the experiment group and breeding season (July-September, BS) estrus animals as the control group were compared using the isobaric tags for relative and absolute quantitation (iTRAQ) technique. Study displayed that cold season supplementation significantly improved growth performance, serum biochemical indicators and reproductive hormone concentrations in yaks. We also identified 25 differentially expressed proteins in yak serum using iTRAQ proteomics. Go and KEGG analysis indicated that calcium signaling pathway and beta-alanine metabolism may be candidate pathways for seasonal estrus induced by nutrition. Differential protein expression was validated using parallel reaction monitoring (PRM). The results of this study initially identified A2M, IGF2, A1BG and APOA1 as candidate proteins for seasonal estrus induced by nutrition. Altogether, In conclusion, our results show that providing additional nutrients in the cold season can improve yak productivity and reproductive efficiency, and provide a new reference.

Chronic stress increases the tyrosine phosphorylation in female reproductive organs: An experimental study

BACKGROUND

Changes in tyrosine-phosphorylated (TyrPho) protein expressions have demonstrated stress in males. In females, chronic stress (CS) is a major cause of infertility, especially anovulation. However, the tyrosine phosphorylation in the female reproductive system under stress conditions has never been reported.

OBJECTIVE

To investigate the alteration of TyrPho protein expression in ovary, oviduct, and uterus of CS rats.

MATERIALS AND METHODS

In this experimental study, 16 female Sprague-Dawley rats (5 wk: 220-250 gr) were divided into control and CS groups (n = 8/group). Every day, the CS animals were immobilized within a restraint cage and individually forced to swim in cold water for 60 consecutive days. Following the stress induction, the ovary, oviduct, and uterus of all rats were observed for their morphologies. The total protein profiles of all tissues were revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) before detecting TyrPho proteins using western blot. Intensity analysis was used to compare the expression of proteins between groups.

RESULTS

The results showed that the morphology and weights of ovary and oviduct in the CS group were not different from control. In contrast, the CS significantly increased the uterine weight as compared to control. Moreover, the expressions of TyrPho proteins in the ovary (72, 43, and 28 kDas), oviduct (170, 55, and 43 kDas), and uterus (55, 54, and 43 kDas) were increased in CS group as compared to those of control.

CONCLUSION

The increased expressions of TyrPho proteins in ovary, oviduct, and uterus could be potential markers used to explain some machanisms of female infertility caused from chronic stress.

Uterine infusion of conceptus fragments changes the protein profile from cyclic mares

This experiment aimed to compare at day seven after ovulation, the protein profile of uterine fluid in cyclic mares with mares infused two days before with Day 13 conceptus fragments. Experimental animals were ten healthy cyclic mares, examined daily to detect ovulation (Day 0) as soon as estrus was confirmed. On day seven, after ovulation, uterine fluid was collected, constituting the Cyclic group (n = 10). The same mares were examined in the second cycle until ovulation was detected. On day five, after ovulation, fragments from a previously collected concepti were infused into each mare's uterus. Two days after infusion, uterine fluid was collected, constituting the Fragment group (n = 10). Two-dimensional electrophoresis technique processed uterine fluid samples. A total of 373 spots were detected. MALDI-TOF/TOF and NanoUHPLC-QTOF mass spectrometry identified twenty spots with differences in abundance between the Cyclic and Fragment group. Thirteen proteins were identified, with different abundance between groups. Identified proteins may be related to embryo-maternal communication, which involves adhesion, nutrition, endothelial cell proliferation, transport, and immunological tolerance. In conclusion, conceptus fragments signalized changes in the protein profile of uterine fluid seven days after ovulation in comparison to the observed at Day 7 in the same cyclic mares.

Sperm interactions with the female reproductive tract: A key for successful fertilization in mammals

Sperm migration through the female genital tract is not a quiet journey. Uterine contractions quickly operate a drastic selection, leading to a very restrictive number of sperm reaching the top of uterine horns and finally, provided the presence of key molecules on sperm, the oviduct, where fertilization takes place. During hours and sometimes days before fertilization, subpopulations of spermatozoa interact with dynamic and region-specific maternal components, including soluble proteins, extracellular vesicles and epithelial cells lining the lumen of the female tract. Interactions with uterine and oviductal cells play important roles for sperm survival as they modulate the maternal immune response and allow a transient storage before ovulation. The body of work reported here highlights the importance of sperm interactions with proteins originated from both the uterine and oviductal fluids, as well as hormonal signals around the time of ovulation for sperm acquisition of fertilizing competence.

Qualitative analysis and functional classification of the uterine proteome of mares in oestrus and dioestrus

Quantitative analysis of the uterine flush fluid proteome of mares in oestrus and dioestrus has been previously reported. The objectives of this study were to: a) evaluate qualitative differences in the uterine flush fluid proteome between mares in oestrus and mares in dioestrus and b) perform a functional classification of proteins either unique to each stage or common between the two stages. Uterine flush fluid samples were collected from 8 light breed mares in either oestrus (n = 5) or dioestrus (n = 3). Proteomic analysis of the samples was conducted using liquid chromatography-tandem mass spectrometry. Proteins exclusively detected in oestrus or dioestrus and those common to both stages were identified using the Scaffold software (version 4.4.8, Proteome Software Inc., Portland, OR). The identified proteins were classified into gene ontology (GO) categories (cellular component [CC], molecular function [MF] and biological process [BP]) using the PANTHER (www.pantherdb.org) classification system version 14.0. Of 172 proteins identified, 51 and 28 were exclusively detected in mares in oestrus and dioestrus, respectively, and 93 proteins were common to both stages. The most represented terms in various GO categories were similar among the three subsets of proteins. The most represented CC terms were extracellular region and cell, the most represented MF terms were catalytic activity and binding, and the most represented BP terms were metabolic process and cellular process. In conclusion, proteomic analysis of the uterine flush fluid enabled the identification of subsets of proteins unique to oestrus or dioestrus, or common to both stages. The results of this study can serve as a baseline for future research focused on finding stage-specific protein markers or evaluating differences in the uterine flush fluid proteome between normal mares and those with uterine disease.

Sperm Proteome after Interaction with Reproductive Fluids in Porcine: From the Ejaculation to the Fertilization Site

Ejaculated sperm are exposed to different environments before encountering the oocyte. However, how the sperm proteome changes during this transit remains unsolved. This study aimed to identify proteomic changes in boar sperm after incubation with male (seminal plasma, SP) and/or female (uterine fluid, UF; and oviductal fluid, OF) reproductive fluids. The following experimental groups were analyzed: (1) SP: sperm + 20% SP; (2) UF: sperm + 20% UF; (3) OF: sperm + 20% OF; (4) SP + UF: sperm + 20% SP + 20% UF; and (5) SP+OF: sperm + 20% SP + 20% OF. The proteome analysis, performed by HPLC-MS/MS, allowed the identification of 265 proteins. A total of 69 proteins were detected in the UF, SP, and SP + UF groups, and 102 proteins in the OF, SP, and SP + OF groups. Our results showed a higher number of proteins when sperm were incubated with only one fluid than when they were co-incubated with two fluids. Additionally, the number of sperm-interacting proteins from the UF group was lower than the OF group. In conclusion, the interaction of sperm with reproductive fluids alters its proteome. The description of sperm-interacting proteins in porcine species after co-incubation with male and/or female reproductive fluids may be useful to understand sperm transport, selection, capacitation, or fertilization phenomena.

Quantitative proteomic strategies to study reproduction in farm animals: Female reproductive fluids

Reproductive fluids from the female reproductive tract are gaining attention for their potential to support and optimize reproductive processes, including gamete maturation and embryo culture in vitro. Quantitative proteomics is a powerful way to decipher the proteome of reproductive tract fluids and to identify biologically relevant proteins. The present review describes proteomic strategies for analysing female reproductive fluid proteins. In addition, it considers the strategies for the preparation of oviductal, uterine and follicular fluid samples. Finally, it highlights the main results of quantitative proteomic studies, providing insights into the biological processes related to reproductive biology in farm animals. SIGNIFICANCE: Assisted reproductive technologies (ARTs) have become vitally important for farm animal breeding and much effort is going into the optimization and refinement of the techniques. There are also attempts to imitate physiological conditions by adding reproductive fluids or individual fluid proteins to improve in vitro procedures. A detailed knowledge of the reproductive fluid proteomes is indispensable. The present review summarizes the most widely used quantitative proteomic approaches for the analysis of fluids from the female reproductive tract and highlights the potential of quantitative proteomics to delineate reproductive processes and identify candidate proteins for ARTs in farm animals.

Influence of Metabolic Status and Diet on Early Pregnant Equine Histotroph Proteome: Preliminary Findings

Insulin resistance (IR) is characterized by an increase in biomarkers of systemic inflammation and susceptibility to laminitis in horses. Impacts on reproduction include a lengthened interovulatory period in horses. Dietary omega-3 (docosahexaenoic acid [DHA]) promotes anti-inflammatory processes, has been implicated in health benefits, and can reduce cytokine secretion. This preliminary study investigated the impact of IR as well as the influence of dietary supplementation (DHA) on the uterine fluid proteome in early pregnant horses. Mares were artificially inseminated; uterine fluid and embryos were collected on d 12.5 after ovulation. Uterine fluid was pooled for metabolic and diet categories (n = 8; n = 2 per metabolic and dietary status) and concentrated, and the proteome was analyzed using tandem mass spectrometry (iTRAQ). Five proteins met differential abundance criteria (±1.5-fold change, P < .05) in all comparisons (Control C, IS vs. C, IR; C, IS vs. DHA, IS; C, IR vs. DHA, IR). Serum amyloid A, afamin, and serotransferrin were upregulated in C, IR mares but downregulated in DHA, IR mares when compared to C, IS and C, IR, respectively. Quantitative PCR supported mass spectrometry results. The presence of serum amyloid A and serotransferrin in histotroph of IR mares potentially indicates an inflammatory response not seen in IS counterparts. These preliminary findings provide novel evidence on the potential impact of insulin resistance and DHA supplementation on the secreted equine uterine proteome during early pregnancy.