The immune status of the bovine uterus during the peripartum period

The effect of puerperal uterine disease on histopathologic findings and mRNA expression of proinflammatory cytokines of the endometrium in dairy cows

The aim of this study was to investigate the effect of puerperal uterine disease on histopathologic findings and gene expression of proinflammatory cytokines in the endometrium of postpuerperal dairy cows; 49 lactating Holstein-Friesian cows were divided into two groups, one without (UD-; n = 29) and one with uterine disease (UD+; n = 21), defined as retained fetal membranes and/or clinical metritis. General clinical examination, vaginoscopy, transrectal palpation, and transrectal B-mode sonography were conducted on days 8, 11, 18, and 25 and then every 10 days until Day 65 (Day 0 = day of calving). The first endometrial sampling (ES1; swab and biopsy) was done during estrus around Day 42 and the second endometrial sampling (ES2) during the estrus after synchronization (cloprostenol between days 55 and 60 and GnRH 2 days later). The prevalence of histopathologic evidence of endometritis, according to the categories used here, and positive bacteriologic cultures was not affected by group (P > 0.05), but cows with uterine disease had a higher prevalence of chronic purulent endometritis (ES1; P = 0.07) and angiosclerosis (ES2; P ≤ 0.05) than healthy cows. Endometrial gene expression of IL1α (ES2), IL1β (ES2), and TNFα (ES1 and ES2) was higher (P ≤ 0.05) in the UD+ group than in the UD- group. In conclusion, puerperal uterine disease had an effect on histopathologic parameters and on gene expression of proinflammatory cytokines in the endometrium of postpuerperal cows, indicating impaired clearance of uterine inflammation in cows with puerperal uterine disease.

Vaginal Microbiome Characterization of Nellore Cattle Using Metagenomic Analysis

Understanding of microbial communities inhabiting cattle vaginal tract may lead to a better comprehension of bovine physiology and reproductive health being of great economic interest. Up to date, studies involving cattle microbiota are focused on the gastrointestinal tract, and little is known about the vaginal microbiota. This study aimed to investigate the vaginal microbiome in Nellore cattle, heifers and cows, pregnant and non-pregnant, using a culture independent approach. The main bacterial phyla found were Firmicutes (~40–50%), Bacteroidetes (~15–25%) and Proteobacteria (~5–25%), in addition to ~10–20% of non-classified bacteria. 45–55% of the samples were represented by only ten OTUs: Aeribacillus, Bacteroides, Clostridium, Ruminococcus, Rikenella, Alistipes, Bacillus, Eubacterium, Prevotella and non-classified bacteria. Interestingly, microbiota from all 20 animals could be grouped according to the respiratory metabolism of the main OTUs found, creating three groups of vaginal microbiota in cattle. Archaeal samples were dominated by the Methanobrevibacter genus (Euryarchaeota, ~55–70%). Ascomycota was the main fungal phylum (~80–95%) and Mycosphaerella the most abundant genus (~70–85%). Hormonal influence was not clear, but a tendency for the reduction of bacterial and increase of archaeal populations in pregnant animals was observed. Eukaryotes did not vary significantly between pregnant and non-pregnant animals, but tended to be more abundant on cows than on heifers. The present work describes a great microbial variability in the vaginal community among the evaluated animals and groups (heifers and cows, pregnant and non-pregnant), which is significantly different from the findings previously reported using culture dependent methods, pointing out the need for further studies on this issue. The microbiome found also indicates that the vaginal colonization appears to be influenced by the gastrointestinal community.

Oxidant/Antioxidant Balance in Animal Nutrition and Health: The Role of Protein Oxidation

This review examines the role that oxidative stress (OS), and protein oxidation in particular, plays in nutrition, metabolism, and health of farm animals. The route by which redox homeostasis is involved in some important physiological functions and the implications of the impairment of oxidative status on animal health and diseases is also examined. Proteins have various and, at the same time, unique biological functions and their oxidation can result in structural changes and various functional modifications. Protein oxidation seems to be involved in pathological conditions, such as respiratory diseases and parasitic infection; however, some studies also suggest that protein oxidation plays a crucial role in the regulation of important physiological functions, such as reproduction, nutrition, metabolism, lactation, gut health, and neonatal physiology. As the characterization of the mechanisms by which OS may influence metabolism and health is attracting considerable scientific interest, the aim of this review is to present veterinary scientists and clinicians with various aspects of oxidative damage to proteins.

Integrated analysis of the local and systemic changes preceding the development of post-partum cytological endometritis

BACKGROUND

The regulation of endometrial inflammation has important consequences for the resumption of bovine fertility postpartum. All cows experience bacterial influx into the uterus after calving; however a significant proportion fail to clear infection leading to the development of cytological endometritis (CE) and compromised fertility. We hypothesised that early immunological changes could not only act as potential prognostic biomarkers for the subsequent development of disease but also shed light on the pathogenesis of endometritis in the postpartum dairy cow.

METHODS

Endometrial biopsy RNA was extracted from 15 cows at 7 and 21 days postpartum (DPP), using the Qiagen RNeasy(®) Plus Mini kit and quality determined using an Agilent 2100 bioanalyser. Disease status was determined by histpathology based on inflammatory cell infiltrate. RNA-seq of both mRNA and miRNA libraries were performed on an Illumina® HiSeq(™) 2000. Paired reads were aligned to the bovine genome with Bowtie2 and differentially expressed genes were identified using EdgeR. Significantly over-represented Gene Ontology terms were identified using GO-seq, and pathway analysis was performed using KEGG. Quanititative real-time PCR was also performed for validation (ABI 7500 fast). Haematology was assessed using an automated ADVIA 2120 analyser. Serum proteins were evaluated by ELISA and metabolite analysis was performed using a Beckman Coulter AU 400 clinical analyser. Terminal-restriction fragment length polymorphism (T-RFLP) was used to obtain fingerprints of the microbial communities present.

RESULTS

Next-generation sequencing from endometrial biopsies taken at 7 DPP identified significant induction of inflammatory gene expression in all cows. Despite the common inflammatory profile and enrichment of the Toll-like receptor and NFκB pathways, 73 genes and 31 miRNAs were significantly differentially expressed between healthy cows (HC, n = 9) and cows which subsequently developed CE at 7 DPP (n = 6, FDR < 0.1). While significant differential expression of 4197 genes in the transcriptome of healthy cows between 7 and 21 DPP showed the transition from a proinflammatory to tissue profliferation and repair, only 31 genes were differentially expressed in cows with CE (FDR < 0.1), indicating the arrest of such a transition. A link betwene the dysregulated inflammatory response and the composition of the uterine microbial communities was suggested by the presence of significant differences in uterine bacterial tRFLP profiles between HC and CE groups. Furthermore, inflammatory activity was not confined to the uterus; decreased circulating granulocytes and increased Acute Phase Protein (SAA and HP) expression levels were detected in plasma at 7 DPP in cows that developed CE.

CONCLUSION

Our data suggests that the IL1 and IL17 inflammatory cascade activated early postpartum is resolved thereby restoring homeostasis in healthy cows by 21 DPP, but this transition fails to occur in cows which develop CE. Despite a common early inflammatory profile, elevated and differential expression of specific immune genes may identify cows at risk of prolonged inflammation and the development of CE postpartum.

Global transcriptomic profiling of bovine endometrial immune response in vitro. I. Effect of lipopolysaccharide on innate immunity

The dysregulation of endometrial immune response to bacterial lipopolysaccharide (LPS) has been implicated in uterine disease and infertility in the postpartum dairy cow, although the mechanisms are not clear. Here, we investigated whole-transcriptomic gene expression in primary cultures of mixed bovine epithelial and stromal endometrial cells. Cultures were exposed to LPS for 6 h, and cellular response was measured by bovine microarray. Approximately 30% of the 1006 genes altered by LPS were classified as being involved in immune response. Cytokines and chemokines (IL1A, CX3CL1, CXCL2, and CCL5), interferon (IFN)-stimulated genes (RSAD2, MX2, OAS1, ISG15, and BST2), and the acute phase molecule SAA3 were the most up-regulated genes. Ingenuity Pathway Analysis identified up-regulation of many inflammatory cytokines and chemokines, which function to attract immune cells to the endometrium, together with vascular adhesion molecules and matrix metalloproteinases, which can facilitate immune cell migration from the tissue toward the uterine lumen. Increased expression of many IFN-signaling genes, immunoproteasomes, guanylate-binding proteins, and genes involved in the intracellular recognition of pathogens suggests important roles for these molecules in the innate defense against bacterial infections. Our findings confirmed the important role of endometrial cells in uterine innate immunity, whereas the global approach used identified several novel immune response pathways triggered by LPS in the endometrium. Additionally, many genes involved in endometrial response to the conceptus in early pregnancy were also altered by LPS, suggesting one mechanism whereby an ongoing response to infection may interfere with the establishment of pregnancy.

Dietary polyunsaturated fatty acids from flaxseed affect immune responses of dairy sheep around parturition

The objective of the study was to characterize the immune profile of dairy ewes fed flaxseed, rich in polyunsaturated fatty acids (PUFA), around parturition. The hypothesis to be verified was that a physiological stressor, such as parturition, could be overcome with a nutritional manipulation in the diet of the animal in order to guarantee welfare of animals and to sustain their immune responses. Twenty Comisana ewes were divided in two groups (10 ewes/group), and fed a supplementation of whole flaxseed in the diet (FS group) or no supplementation (CON group). Blood samples were collected at parturition and then 7, 14, 21, 28, and 42 day post partum. Plasma samples were used to assess the humoral immune response after ovalbumin (OVA) immunization. At parturition, at 14 day, and 42 day post partum the level of plasma cytokines was assessed. The sheep showed a reduced responsiveness to OVA immunization. In FS ewes the IL-6 level remained unchanged until 14 day post partum and then significantly decreased from 14 day to 42 day post partum. IL-10 level was significantly higher in FS ewes than in CON ewes at 14 day. At parturition IL-1β level was significantly lower in FS ewes than in CON ewes and significantly decreased in both groups from parturition to 42 day. In conclusion, PUFA from flaxseed, as supplement in the diet of ewes around parturition can modulate sheep immune reactivity by influencing cytokine production.

Relationships between Circulating Urea Concentrations and Endometrial Function in Postpartum Dairy Cows

Simple Summary

Dairy cows fed high levels of protein to increase milk yield tend to have reduced fertility but the reasons behind this are unclear. Differing dietary protein levels are reflected in altered urea concentrations in both blood and other tissues including the uterus. We showed that the circulating urea concentration was highly correlated to changed expression levels of many genes in the endometrium shortly after calving. These were predominantly associated with tissue repair, innate immunity and lipid metabolism. A subsequent study found no effect of altered urea concentration on endometrial gene expression in vitro implying that the dietary influence is indirect.

Abstract

Both high and low circulating urea concentrations, a product of protein metabolism, are associated with decreased fertility in dairy cows through poorly defined mechanisms. The rate of involution and the endometrial ability to mount an adequate innate immune response after calving are both critical for subsequent fertility. Study 1 used microarray analysis to identify genes whose endometrial expression 2 weeks postpartum correlated significantly with the mean plasma urea per cow, ranging from 3.2 to 6.6 mmol/L. The biological functions of 781 mapped genes were analysed using Ingenuity Pathway Analysis. These were predominantly associated with tissue turnover (e.g., BRINP1, FOXG1), immune function (e.g., IL17RB, CRISPLD2), inflammation (e.g., C3, SERPINF1, SERPINF2) and lipid metabolism (e.g., SCAP, ACBD5, SLC10A). Study 2 investigated the relationship between urea concentration and expression of 6 candidate genes (S100A8, HSP5A, IGF1R, IL17RB, BRINP1, CRISPLD2) in bovine endometrial cell culture. These were treated with 0, 2.5, 5.0 or 7.5 mmol/L urea, equivalent to low, medium and high circulating values with or without challenge by bacterial lipopolysaccharide (LPS). LPS increased S100A8 expression as expected but urea treatment had no effect on expression of any tested gene. Examination of the genes/pathways involved suggests that plasma urea levels may reflect variations in lipid metabolism. Our results suggest that it is the effects of lipid metabolism rather than the urea concentration which probably alter the rate of involution and innate immune response, in turn influencing subsequent fertility.

The long subclinical phase of Mycobacterium avium ssp. paratuberculosis infections explained without adaptive immunity

Mycobacterium avium ssp. paratuberculosis (MAP) is an infection of the ruminant intestine. In cows, a long subclinical phase with no or low intermittent shedding precedes the clinical phase with high shedding. It is generally considered that an adaptive cell-mediated immune response controls the infection during the subclinical phase, followed by unprotective antibodies later in life. Based on recent observations, we challenge the importance of adaptive immunity and instead suggest a role of the structural organization of infected macrophages in localized granulomatous lesions. We investigated this hypothesis by mathematical modelling. Our first model describes infection in a villus, assuming a constant lesion volume. This model shows the existence of two threshold parameters, the MAP reproduction ratio R_MAP determining if a lesion can develop, and the macrophage replacement ratio R_MF determining if recruitment of macrophages is sufficient for unlimited growth. We show that changes in R_MF during a cow’s life – i.e. changes in the innate immune response – can cause intermittent shedding. Our second model describes infection in a granuloma, assuming a growing lesion volume. This model confirms the results of the villus model, and can explain early slow granuloma development: small granulomas grow slower because bacteria leave the granuloma quickly through the relatively large surface area. In conclusion, our models show that the long subclinical period of MAP infection can result from the structural organization of the infection in granulomatous lesions with an important role for innate rather than adaptive immunity. It thus provides a reasonable hypothesis that needs further investigation.

Inflammatory cytokine and acute phase protein concentrations in the peripheral blood and uterine washings of cows with subclinical endometritis in the late postpartum period

The aim of the study was to evaluate the concentrations of proinflammatory cytokines: tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), anti-inflammatory cytokine interleukin-10 (IL-10), and acute phase proteins (APPs)—haptoglobin (Hp) and serum amyloid A (SAA) in serum and uterine washings of cows with subclinical endometritis, and compare them to healthy animals. The study was performed on 24 cows on day 60 after delivery. The cows were divided into two groups based on the results of cytological tests: 12 cows with subclinical endometritis and 12 healthy cows. Experimental material consisted of blood serum and uterine washings. The levels of the following cytokines in the study material were determined with ELISA: TNF-α, IL-6, IL-10 and APPs - Hp and SAA. The results show that the levels of TNF-α (p < 0.01), IL-6, IL-10 as well as SAA and Hp were significantly higher in the serum of cows with subclinical endometritis compared to the controls (p < 0.001). Uterine washings had significantly higher levels of IL-6, IL-10, and Hp in the experimental cows compared to the controls (p < 0.001). The demonstrated differences in the concentration of cytokines and APP between cows with subclinical endometritis and healthy cows, in both the serum and uterine washings, may suggest the usefulness of these parameters in the diagnosis of subclinical endometritis in cows in the late postpartum period.

The concentrations of inflammatory cytokines and acute-phase proteins in the peripheral blood and uterine washings in cows with pyometra

The development of pyometra in cows depends largely on the state of local immunity of the uterus. The objective of the study was to evaluate the concentration of the following proinflammatory cytokines: tumour necrosis factor (TNF-α) and interleukin-6 (IL-6); anti-inflammatory cytokine: interleukin-10 (IL-10); and acute-phase proteins (APPs): haptoglobin (Hp) and serum amyloid A (SAA), in serum and uterine washings in cows with pyometra and healthy animals. The study was performed on 20 cows divided into two groups based on the results of cytological and ultrasonographic tests: a pyometra and a healthy group (10 cows per group). Experimental material consisted of blood serum and uterine washings. The levels of the following cytokines, TNF-α, IL-6, IL-10 and APPs - Hp and SAA, in the study material were determined by ELISA. The results showed that the values of TNF-α, IL-6, IL-10 as well as SAA and Hp were significantly higher in serum of cows with pyometra compared to controls (p < 0.001). The uterine washings had significantly higher levels of IL-6, IL-10, and Hp in pyometra cows compared to the control (p < 0.001). Our results indicate that it is possible to monitor the course of pyometra in cows based on the evaluation of the concentration of cytokines and Hp in the serum and uterine washings. Simultaneous evaluation of selected indicators of antagonistic interaction can be helpful in determining the current status of local immunity of the uterus. On this basis, it could be possible to properly select an adjunctive therapy in the form of immunomodulating preparations.

Inflammatory cytokines and acute-phase proteins concentrations in the peripheral blood and uterus of cows that developed endometritis during early postpartum

The aim of the study was to evaluate the level of proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6]), anti-inflammatory cytokine (interleukin-10 [IL-10]), and acute-phase proteins (haptoglobin [Hp] and serum amyloid A [SAA]) in serum and uterine washings in cows that developed endometritis during the early postpartum period. The study was carried out on 40 cows. The experimental group consisted of 20 cows with subclinical endometritis and the control group of 20 cows without endometritis. Analyses in both groups of cows were carried out at 5, 22, and 40 days postpartum (DPP). Experimental material consisted of the blood serum and uterine washings. The levels of the following cytokines: TNF-α, IL-6, IL-10 and acute-phase proteins: Hp and SAA were determined using ELISA. Our study reported that the levels of TNF-α, IL-6, IL-10, Hp, and SAA at 22 DPP were higher in cows with subclinical endometritis (P < 0.001). The levels of TNF-α (P = 0.01), IL-6 and IL-10 (P = 0.001), and Hp (P < 0.001) at 40 DPP were higher in cows with subclinical endometritis compared to healthy cows. The level of IL-10 in uterine washings at 5 DPP was higher (P = 0.001), whereas of SAA was lower (P = 0.01) in cows with subclinical endometritis. At 22 DPP, the levels of IL-6, IL-10, and Hp were higher (P < 0.001) in cows with endometritis. At 40 DPP, the level of TNF-α was lower, whereas these of IL-10 and Hp were elevated (P < 0.001) in cows with endometritis compared to healthy cows. The results indicate that the evaluation of the levels of cytokines and Hp in serum, but primarily in uterine washings, can be an important diagnostic indicator in cows that developed subclinical endometritis. High levels of IL-10 in cows with subclinical endometritis may contribute to the weakening of local resistance mechanisms of the uterus and lead to the persistence of the inflammation in the postpartum period. The present study also shows that the simultaneous examination of selected parameters of antagonistic interactions allows for better assessment of the current state of local immunity in the uterus.

Cytometric analysis of surface molecules of leucocytes and phagocytic activity of granulocytes and monocytes/macrophages in cows with pyometra

Pyometra is a serious problem in dairy cow herds, causing large economic losses due to infertility. The development of pyometra depends mainly on the immunological status of the cow. The aim of the study was a comparative evaluation of selected indicators involving non-specific and specific immunity in cows with pyometra and in cows without inflammation of the uterus. The study was performed in 20 cows, which were divided into two groups: pyometra group and healthy group, each comprising 10 cows, based on the results of cytological and ultrasonographic tests. A flow cytometric analysis was performed for the surface molecules CD4, CD8, CD14, CD21, CD25 and CD4(+) CD25(+) on leucocytes, and the phagocytic activity was determined from granulocytes and monocytes/macrophages in the peripheral blood and uterine washings, respectively. It was demonstrated that the percentage of phagocytic granulocytes and monocytes/macrophages in both the peripheral blood and uterine washings was significantly lower in cows with pyometra compared with the healthy group (p < 0.001). Significantly (p ≤ 0.001) lower percentage of CD4(+) , CD14(+) , CD25(+) and CD4(+) CD25(+) phenotype leucocytes was also observed in the peripheral blood of cows from the pyometra group, along with a significantly higher (p < 0.001) percentage of CD8(+) and CD21(+) lymphocytes as compared to the healthy group. The results of work indicate that disfunction of cell immunity coexisting with pyometra may be caused by a bacterial infection and the presence of blocking agents (IL-10), released by the increasing number of CD8(+) lymphocytes what leads to the advanced inflammation of uterus.

Determination of selected parameters for non-specific and specific immunity in cows with subclinical endometritis

Endometritis in dairy cow herds is a serious economic problem all over the world due to the large economic losses. The aim of the study was a comparative evaluation of selected indicators of non-specific and specific immunity in cows with subclinical endometritis and in cows without inflammation of the uterus. The study was performed on 40 cows on day 65 after delivery. Based on the results of cytological tests, the cows were divided into two groups: experimental (subclinical endometritis) and control (20 cows in each group). A flow cytometric analysis was performed for the leukocyte surface molecules CD4, CD8, CD14, CD21, CD25. Moreover the phagocytic activity of granulocytes and monocytes/macrophages in peripheral blood and uterine washings was determined. It has been demonstrated that the percentage of phagocytic granulocytes and monocytes/macrophages in both the peripheral blood and uterine washings was significantly lower for cows with subclinical endometritis when compared to cows undergoing a normal puerperal period (p<0.001). A significant (p≤0.001) decrease in the percentage of CD4+, CD14+, CD25+ and CD4+CD25+ leukocytes was also observed in peripheral blood of the cows from the experimental group. In uterine washings a significant decrease (p<0.001) in CD21+ and increase in CD8+ lymphocytes was detected. The results indicate that dysfunction of cell immunity coexisting with subclinical endometritis may be the main factor causing advanced inflammation of the uterus. Knowledge of immunological mechanisms observed in cows with subclinical endometritis could aid in choosing the right adjuvant therapy using immunomodulating agents.

Phenotyping of leukocytes and granulocyte and monocyte phagocytic activity in the peripheral blood and uterus of cows with endometritis

This study was a comparative evaluation of selected immunological parameters in peripheral blood and uterine wash samples from cows with a normal postpartum period compared with cows with endometritis. We aimed to determine the usefulness of these parameters in monitoring the puerperium. In total, 40 cows were included in the study: 20 had endometritis (experimental group), and 20 did not have uterine inflammation (control group). Animals were chosen on the basis of cytological and bacteriological test results. The tests were conducted 5, 22, and 40 days postpartum. In both groups, flow cytometric analysis of the surface molecules CD4, CD8, CD21, CD25, and CD14 in the peripheral blood and uterine washings was performed. Granulocyte and monocyte phagocytic activity was determined using a commercial Phagotest kit that was adapted for flow cytometry. The percentage of phagocytic granulocytes and monocytes in both the peripheral blood and the uterine washings was significantly lower for cows in the experimental group compared with the control group (P < 0.01). A significant decrease (P < 0.01) in the percentage of CD4+, CD25+, CD14+, and CD4 + CD25(high) leukocyte subpopulations was also observed in the peripheral blood of cows with endometritis. A significant decrease (P < 0.01) in CD21+ lymphocytes and an increase in CD8+ lymphocytes was detected in uterine washings. The results of this work indicate that cell immunity dysfunction may be the main factor causing advanced inflammation of the uterus in endometritis. Knowledge of the immunological mechanisms observed in cows with endometritis might aid in choosing the correct immunomodulating agent-based adjuvant therapy.

Subcutaneous immunization with inactivated bacterial components and purified protein of Escherichia coli, Fusobacterium necrophorum and Trueperella pyogenes prevents puerperal metritis in Holstein dairy cows

In this study we evaluate the efficacy of five vaccine formulations containing different combinations of proteins (FimH; leukotoxin, LKT; and pyolysin, PLO) and/or inactivated whole cells (Escherichia coli, Fusobacterium necrophorum, and Trueperella pyogenes) in preventing postpartum uterine diseases. Inactivated whole cells were produced using two genetically distinct strains of each bacterial species (E. coli, F. necrophorum, and T. pyogenes). FimH and PLO subunits were produced using recombinant protein expression, and LKT was recovered from culturing a wild F. necrophorum strain. Three subcutaneous vaccines were formulated: Vaccine 1 was composed of inactivated bacterial whole cells and proteins; Vaccine 2 was composed of proteins only; and Vaccine 3 was composed of inactivated bacterial whole cells only. Two intravaginal vaccines were formulated: Vaccine 4 was composed of inactivated bacterial whole cells and proteins; and Vaccine 5 was composed of PLO and LKT. To evaluate vaccine efficacy, a randomized clinical trial was conducted at a commercial dairy farm; 371 spring heifers were allocated randomly into one of six different treatments groups: control, Vaccine 1, Vaccine 2, Vaccine 3, Vaccine 4 and Vaccine 5. Late pregnant heifers assigned to one of the vaccine groups were each vaccinated twice: at 230 and 260 days of pregnancy. When vaccines were evaluated grouped as subcutaneous and intravaginal, the subcutaneous ones were found to significantly reduce the incidence of puerperal metritis. Additionally, subcutaneous vaccination significantly reduced rectal temperature at 6±1 days in milk. Reproduction was improved for cows that received subcutaneous vaccines. In general, vaccination induced a significant increase in serum IgG titers against all antigens, with subcutaneous vaccination again being more effective. In conclusion, subcutaneous vaccination with inactivated bacterial components and/or protein subunits of E. coli, F. necrophorum and T. pyogenes can prevent puerperal metritis during the first lactation of dairy cows, leading to improved reproduction.

Comparative studies on genital infections and antimicrobial susceptibility patterns of isolates from camels (Camelus dromedarius) and cows (Bos indicus) in Maiduguri, north-eastern Nigeria

A total of 160 genitalia of Camels and cows were investigated in Maiduguri, north-eastern Nigeria to compare bacterial isolates and the antibacterial susceptibilities of some of the isolates. Streptococcus (Str.) pyogenes (31%), Escherichia (E.) coli (24%) and Staphylococcus (S.) aureus (20%) were the most common vaginal bacterial isolates in camels; while E. coli (73%), Str. pyogenes (18%) and S. aureus (11%) were the most frequent isolates in the cows. Of the 78 uterine isolates recovered in this study, E. coli was the most prominent in camels (8%) and cows (54%). The overall weight of genital infection in all camels and cows examined was highest (P < 0.05) with E. coli (79%), but there was no difference (P > 0.05) between vaginal and uterine bacterial isolates from camels and cows in this study. The Relative Risk (RR) for an infection of the vagina with E coli (3.04, 95% Confidence Interval (CI): 2.104 to 4.398, P < 0.0001) is more in cows compared to the camel, but the RR for vaginal infection with S. aureus and Str. pyogenes were lower in cows compared to Camels. The E. coli and S. aureus isolates were highly susceptible to the antimicrobial agents tested. Therefore effective management of reproductive disorders associated with these pathogens can be achieved with proper use of these antimicrobial agents in these animal species

Associations among serum pro- and anti-inflammatory cytokines, metabolic mediators, body condition, and uterine disease in postpartum dairy cows

BACKGROUND

Adipose tissue is an active endocrine organ which secretes a wide range of hormones and protein factors, collectively termed adipokines. Adipokines affect appetite and satiety, glucose and lipid metabolism, inflammation and immune functions. The objectives were to evaluate serum concentrations of adipokines (adiponectin, leptin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6) in lactating dairy cows with postpartum uterine inflammatory conditions (metritis, clinical endometritis or subclinical endometritis) and in cows experiencing loss of body condition, and to assess the relationship of adipokines and body condition loss in the establishment of persistent uterine inflammatory conditions.

METHODS

Lactating multiparous Holstein cows (N = 40), with body condition scores (BCS) from 2 to 4 (eight cows for each 0.5 score increment) were enrolled. Body condition was monitored for all cows weekly for 7 weeks post calving; cows with uterine inflammatory conditions were also re-evaluated 2 weeks later. Blood samples were collected from 1 week prior to calving to 7 weeks after calving for determination of serum concentrations of adipokines, insulin and insulin like growth factor (IGF)-1.

RESULTS

Cows with metritis or clinical endometritis had higher serum concentrations of adiponectin, leptin, TNF-alpha, IL-1beta and IL-6 compared to normal cows (P < 0.05). Furthermore, serum leptin, TNF-alpha, IL-1beta and IL-6 were higher in cows with subclinical endometritis compared to normal cows (P < 0.05), and insulin and IGF-1 concentrations were lower in cows with metritis or clinical endometritis. Cows with low BCS (2 and 2.5) had significantly higher adiponectin, TNF-alpha, IL-1beta and IL-6 than those with high BCS (3 to 4). Cows with persistent uterine inflammatory conditions had higher adiponectin, leptin TNF-alpha, IL-1beta and IL-6 and insulin compared to normal and spontaneously recovered cows, except for IGF-1 (P < 0.05).

CONCLUSIONS

Serum concentrations of adipokines, insulin, and IGF-1 had significant associations with BCS categories (low vs. high) and postpartum uterine inflammatory conditions. Perhaps loss of body condition mediated increases in anti- and pro-inflammatory cytokines, whereas increased pro- and anti-inflammatory cytokines concentrations mediated body condition loss and thereby prolonged persistence of uterine inflammation in dairy cows.

Secretion of prostaglandins and leukotrienes by endometrial cells in cows with subclinical and clinical endometritis

The aims of this study were (1) to measure the secretion of prostaglandin F2α (PGF2α), prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and leukotriene C4 (LTC4) by endometrial cells collected by a cytobrush from healthy cows and cows with subclinical and clinical endometritis in the fourth week postpartum, and (2) to evaluate the relationship between the mediators' levels of secretion and the number of polymorphonuclear neutrophils (PMNs) in the uterine smears of cows with subclinical endometritis. The study included cows without any signs of clinical endometritis (n = 63) and cows with clinical endometritis as a positive control (ENDOM, n = 12). Two different threshold ratios (>5% and >18% of PMNs) were used to categorize the cows without clinical signs as with or without cytologic endometritis (CE). Considering the first or second threshold, the animals with CE were included in group CE POS I or CE POS II, whereas the healthy cows were assigned to group CE NEG I or CE NEG II, respectively. The prevalence of CE was 68.25% (42/63) and 57.14% (36/63) according to the first and second thresholds, respectively. The highest level of secretion of all of the measured mediators occurred in the ENDOM group and differed significantly (P < 0.05) from the CE POS and CE NEG groups, regardless of the threshold. PGF2α secretion in the CE POS II group (1629 pg/mL) was significantly lower (P < 0.05) when compared with the CE NEG II group (2797 pg/mL), whereas there was no significant difference between the CE POS I and CE NEG I groups. PGE2 secretion differed between both groups with CE; higher concentrations were measured in the CE POS II group (6.68 ng/mL) when compared with the CE POS I (2.4 ng/mL) and CE NEG II (2.37 ng/mL) groups (P < 0.05). No significant differences were observed in the LTB4 and LTC4 secretion between the CE POS and CE NEG groups, considering both thresholds. It seems that CE does not fully mimic the inflammatory cascade associated with clinical signs. The response in the subclinical cases was limited to enhanced production of PGE2, which was particularly well-pronounced in cows with high numbers of PMNs (>18%) in the endometrial scrapings.

The postpartum endometrial inflammatory response: a normal physiological event with potential implications for bovine fertility

After calving, the bovine endometrium undergoes marked morphological and functional changes that are necessary for subsequent re-breeding. Regulation and integration of these key events are largely uncharacterised. Here, endometrial swabs and biopsies were taken at 15, 30 and 60 days postpartum (DPP) from 13 healthy primiparous cows, 10 of which subsequently conceived, with a view to characterising innate and inflammatory gene expression profiles. Endometrial biopsies exhibited severe inflammation (>75 leukocytes per high-power field) at 15 DPP, which had begun to resolve by 30 DPP and had completely resolved by 60 DPP. The severe inflammation at 15 DPP coincided with uterine infection in all cows and a significant increase (P < 0.05) in the expression of all of 16 genes investigated, including CD45, IL8, IL6, IL1, TNF, TAP, SAA3 and HP at 15 DPP, relative to 60 DPP. All of these parameters had begun to return to normal physiological levels at 30 DPP. Systemically, serum protein concentrations of IL-8 were elevated at 15 DPP compared with 60 DPP (78 pgmL(-1)vs 48 pgmL(-1); P = 0.02). These results indicate that endometrial inflammation, leukocyte infiltration and increased expression of pro-inflammatory, antimicrobial and acute-phase protein genes are expected features of the postpartum period, critical to bacterial clearance and uterine involution.

Comparison of metabolic, hematological, and peripheral blood leukocyte cytokine profiles of dairy cows and heifers during the periparturient period

The periparturient period presents major physiological challenges for the dairy cow. It is a period that is affected by metabolic stressors, major changes in endocrine status, and altered immune function, which together result in an increased risk of disease. Immunological, hematological, and metabolic profiles from the periparturient period of heifers (primipara) were compared with those of cows (pluripara) to test the hypothesis that at the time of calving they have qualitatively different peripheral blood profiles. Blood samples were collected from 22 Holstein-Friesian animals on 3 occasions: approximately 2 wk before calving, within 24h after calving, and approximately 2 wk after calving. Quantitative PCR was used to measure the expression of a selected set of cytokines and receptors by peripheral blood leukocytes. Additional analyses included hemoglobin concentration, red cell, platelet and white cell counts (total and differentiated), and clinical diagnostic biochemical profiles. Total leukocyte counts, neutrophils, and lymphocytes were higher in heifers than cows before calving and within 24h after calving. Alkaline phosphatase was consistently higher in heifers than cows and several significant differences were observed between the 2 groups with regards to cytokine and cytokine-receptor mRNA expression. The results warrant further investigation from the perspective of identifying risk factors for metabolic and parturient disease in dairy cattle.

Time course of defense mechanisms in bovine endometrium in response to lipopolysaccharide

Endometritis caused by uterine infection after calving reduces fertility and causes major economic losses to the dairy industry. This study investigated the time course of an inflammatory response in bovine endometrium triggered by exposure to bacterial endotoxin lipopolysaccharide (LPS). Mixed endometrial epithelial and stromal cells (9:1 ratio) were grown to confluence as a model system and treated with an optimized dose of 100 ng/ml LPS in vitro. Gene expression responses were measured using quantitative PCR, and gene products were investigated using assays of culture medium and Western blotting. Of 17 candidate genes tested initially, LPS treatment for 24 h up-regulated mRNA expression of TLR4 signaling (TLR4, CD14), cytokines (IL1B, TNF), chemokines (IL8, CXCL5), antimicrobial peptides (LAP, S100A8, S100A9, S100A12), and matrix metalloproteinases (MMP1, MMP13). A 48 h, LPS time course study showed that TNF increased first at 1 h, followed by peak expression of IL1B at 6 h, and those of S100A8, S100A12, and LAP at 12 h. The intracellular S100A8 protein content doubled at 12-24 h but with little excretion into the medium. Regarding prostaglandin biosynthesis, PTGES mRNA was slightly higher after LPS exposure, whereas expression of the PGF synthase AKR1B1 was inhibited. Despite this, LPS treatment stimulated the secretion of both PGE₂ and PGF₂(alpha) to a similar extent. These results suggest that the family of S100 Ca²⁺ binding proteins are released from damaged endometrial cells and may play a major antimicrobial role. Prostaglandin synthesis increased during the uterine infection, but we found no evidence that this was associated with a change in the PGE:PGF ratio.

Global endometrial transcriptomic profiling: transient immune activation precedes tissue proliferation and repair in healthy beef cows

BACKGROUND

All cows experience bacterial contamination and tissue injury in the uterus postpartum, instigating a local inflammatory immune response. However mechanisms that control inflammation and achieve a physiologically functioning endometrium, while avoiding disease in the postpartum cow are not succinctly defined. This study aimed to identify novel candidate genes indicative of inflammation resolution during involution in healthy beef cows. Previous histological analysis of the endometrium revealed elevated inflammation 15 days postpartum (DPP) which was significantly decreased by 30 DPP. The current study generated a genome-wide transcriptomic profile of endometrial biopsies from these cows at both time points using mRNA-Seq. The pathway analysis tool GoSeq identified KEGG pathways enriched by significantly differentially expressed genes at both time points. Novel candidate genes associated with inflammatory resolution were subsequently validated in additional postpartum animals using quantitative real-time PCR (qRT-PCR).

RESULTS

mRNA-Seq revealed 1,107 significantly differentially expressed genes, 73 of which were increased 15 DPP and 1,034 were increased 30 DPP. Early postpartum, enriched immune pathways (adjusted P < 0.1) included the T cell receptor signalling pathway, graft-versus-host disease and cytokine-cytokine receptor interaction pathways. However 30 DPP, where the majority of genes were differentially expressed, the enrichment (adjusted P < 0.1) of tissue repair and proliferative activity pathways was observed. Nineteen candidate genes selected from mRNA-Seq results, were independently assessed by qRT-PCR in additional postpartum cows (5 animals) at both time points. SAA1/2, GATA2, IGF1, SHC2, and SERPINA14 genes were significantly elevated 30 DPP and are functionally associated with tissue repair and the restoration of uterine homeostasis postpartum.

CONCLUSIONS

The results of this study reveal an early activation of the immune response which undergoes a temporal functional change toward tissue proliferation and regeneration during endometrial involution in healthy postpartum cows. These molecular changes mirror the activation and resolution of endometrial inflammation during involution previously classified by the degree of neutrophil infiltration. SAA1/2, GATA2, IGF1, SHC2, and SERPINA14 genes may become potential markers for resolution of endometrial inflammation in the postpartum cow.

Down-regulation of NOD1 in neutrophils of periparturient dairy cows

Increased susceptibility of periparturient dairy cows to infectious diseases has been linked to neutrophil dysfunction. Cytoplasmic nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) mediate numerous aspects of innate immunity in humans and experimental animals. The authors hypothesized that neutrophils in periparturient cows have reduced NLR expression, resulting in declined immune responses to NLR activation. In this study, blood neutrophils from periparturient and mid-lactating cows were isolated and assessed for mRNA and protein expression of NOD1 and NOD2. Neutrophil phagocytosis and oxidative burst activity following NLR agonist-induced activation were also investigated. Periparturient cows demonstrated weak-to-absent NOD1 mRNA expression along with a significant reduction in NOD1 protein in their neutrophils. However, no difference in NOD2 protein expression was observed between groups although NOD2 mRNA abundance in periparturient cows was significantly reduced. Phagocytosis and oxidative burst activity measured by production of reactive oxygen species (ROS) were diminished in periparturient cows. NOD1 activation enhanced phagocytosis and ROS production in both isolated cell populations, regardless of the lactation stage. Nevertheless, NOD1-activated neutrophils showed reduced phagocytosis and ROS generation in periparturient cows with respect to mid-lactating subjects. Collectively, our findings suggest that NOD1 down-regulation in neutrophils may be a mechanism involved in periparturient neutrophil dysregulation.

Immunohistochemical localization of beta defensins in the endometrium of rat uterus during the postpartum involution period

β-Defensins are small cationic molecules that have antimicrobial actions against bacteria, fungi and viruses and contribute to mucosal immune responses at epithelial sites. The female reproductive tract is an important site of defensin production. This study was conducted to determine the possible changes in proportions and localization of β-defensin 1-4 in the rat uterus at the 1st, 3th, 5th, 10th and 15th days of postpartum and at the period of diestrus using immunohistochemical techniques. In the present study, it was determined that β-defensin 1-4 were generally found in all structural components of the endometrium (luminal and glandular epithelium, stromal cells and blood vessels) in both the nucleus and the cytoplasm of cells during the involution period and diestrus. Suprisingly, immunoreaction of β-defensin 2 was also observed in the lateral membrane of the luminal and glandular epithelial cells on the 10th day of involution and immunostaining of β-defensin 4 was also localized in the apical membrane of the luminal and glandular epithelial cells. The current study demonstrated β-defensin 1-4 immunoreactivities in the endothelium of blood vessels were stronger throughout the involution period. Although β-defensins 2 and 3 were localized in both the nuclei and the cytoplasm of endothelial cells, β-defensins 1 and 4 were present in only cytoplasm. These results show that the most component of rat endometrium expresses human β-defensin 1-4 in a involution-dependent manner. Therefore it may be asserted that these molecules constitute a organised protection to prevent uterus from probable infections during the involution process.

The influence of genital tract status in postpartum period on the subsequent reproductive performance in high producing dairy cows

The aim of the present study was to characterize the early postpartum period in clinically healthy dairy cows by ultrasonography (US), endometrial cytology (EC), and white blood cell counts, and determine possible relationships between postpartum findings and subsequent reproductive performance. Fifty-three dairy cows were examined on Days 15 to 21 (Visit 1), 22 to 28 (Visit 2), and 29 to 35 (Visit 3) postpartum. The clinical examination included: examination of vaginal fluid, EC, transrectal palpation and ultrasonography of the genital tract (cervical diameter, endometrial thickness, presence of a corpus luteum [CL] or intrauterine fluid [IUF] and its echogenicity). Luteal activity (presence of a CL in a single visit), return to cyclicity (presence of a CL in 2 consecutive visits), and conception rate at 70 and 120 days postpartum were considered as the dependent variables in four consecutive binary logistic regression analyses. Factors affecting leukocyte counts were established by general linear model (GLM) repeated measures analysis of variance. Based on the odds ratio (OR), the likelihood of luteal activity was higher in multiparous than primiparous cows (OR = 3.75) and tended to diminish in cows showing increased endometrial thickness in Visit 1 (V1) (OR = 0.06). The likelihood of returning to cyclicity decreased for each centimeter increase in cervical diameter in V1 (OR = 0.14) and that of conception on Day 70 was lower in cows showing the presence of echogenic or anechogenic IUF in V1 (OR = 0.09 or OR = 0.13, respectively) compared with cows lacking IUF. Effects of parity and IUF were observed on neutrophil counts. Positive EC results were unrelated to the cumulative conception rate at 70 and 120 days in milk, whereas cows returning a positive EC result in V1 showed a greater likelihood of increased endometrial thickness. In conclusion, measuring cervical diameter, endometrial thickness, and detecting the echogenicity of IUF by ultrasonography from Days 15 to 21 postpartum in clinically normal cows is an appropriate tool to predict subsequent reproductive performance. Vaginal examination and transrectal palpation alone did not emerge as valuable predictors.

Relationship between late embryonic mortality and the increase in plasma advanced oxidised protein products (AOPP) in dairy cows

The involvement of protein oxidation in embryonic mortality (EM) has been poorly investigated in cows. Advanced oxidation protein products (AOPP) are markers of protein oxidation generated by activated neutrophils and involved in inflammation. The aim of this work was to study AOPP in cow plasma and their relationship with late EM. The outcomes of 158 artificial inseminations (AI) were examined in 72 cows, which were classified ex post on the basis of blood progesterone and pregnancy-associated glycoprotein concentrations and clinical confirmation of pregnancy into the following categories: (1) positive (AI+, resulted in pregnancy, n=58), (2) negative (AI-, did not result in pregnancy, n=86) and (3) embryonic mortality (EM, n=14). Plasma protein fractions, malondialdehyde (MDA), total glutathione and AOPP were measured at AI (Day 0) and on Days 15, 28, 35, 45 and 60. MDA was significantly higher in EM than AI+ and AI- animals on Day 45, and than AI+ animals on Day 60 (P<0.05). Mean plasma AOPP concentrations were significantly higher in the EM group (P<0.01) and the ratio of AOPP:albumin was significantly higher in the EM group on Days 15, 28, 45 and 60 (P<0.05). Based on the temporal pattern of the AOPP:albumin ratio, we propose that oxidative stress is implicated in and may possibly be a cause of EM.

Reproductive tract defense and disease in postpartum dairy cows

This paper briefly reviews recent data and concepts on the development and mitigation of infection and inflammation in the reproductive tract of dairy cows during the first 2 mo after calving. The incidence of metritis is typically between 10 and 20%, of clinical endometritis or purulent vaginal discharge (PVD) approximately 15%, and of subclinical or cytological endometritis a further 15%. Worse postpartum negative energy balance is associated with more severe or prolonged uterine inflammation. Changes in feed intake, expression of genes for pro-inflammatory cytokines, notably interleukin (IL) 1, IL6 and IL8, circulating concentrations of beta-hydroxybutyrate (BHBA) or nonesterified fatty acids (NEFA), and innate immune function precede both metritis and endometritis by several weeks. Infections with Escherichia coli and Arcanobacterium pyogenes are associated with both metritis and PVD. There are new data to suggest that specific virulence factors in E. coli associated with adherence may be important in metritis and PVD. Cytological endometritis and PVD are overlapping but largely distinct conditions, and there are emerging data that cervicitis exists both concurrent with and separate from endometritis. Much remains to be learned about what initiates and sustains harmful inflammation of the reproductive tract. Such information is necessary to develop effective treatments for the various forms of disease and, more importantly, to develop means to prevent endometritis and cervicitis. In particular, vaccination against specific uterine pathogens and interventions to modulate innate immune response appear to be important avenues for investigation. Presently, commonly recommended best management practices for cows in the transition period are likely to be helpful to mitigate the risk of reproductive disease.

Time-dependent mRNA expression of selected pro-inflammatory factors in the endometrium of primiparous cows postpartum

BACKGROUND

Inflammatory processes and infections of the uterine wall must be accepted as a physiological event in dairy cows after calving. This might result in clinical or subclinical endometritis which is assumed to impair reproductive performance in the current lactation. Several cytokines and acute phase proteins have been discussed as local and systemic mediators of these inflammatory processes. The aim of the present study was to investigate the endometrial mRNA expression of the chemokine CXC ligand 5 (CXCL5), interleukin 1β (IL1B), IL6, IL8, tumour necrosis factor alpha (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2) and haptoglobin (HP) in the postpartum period.

METHODS

Endometrial samples were obtained from primiparous cows (n = 5) on days 10, 17, 24, 31, 38 and 45 postpartum (pp) using the cytobrush technique. Cytological smears were prepared from cytobrush samples to determine the proportion of polymorphonuclear neutrophils (PMN). Total RNA was extracted from endometrial samples, and real-time RT-PCR was performed.

RESULTS

A time-dependent mRNA expression of the investigated factors was found for the course of the postpartum period. In detail, a significantly higher expression of these factors was observed on day 17 pp compared to day 31 pp. Furthermore, the proportion of PMN peaked between days 10-24 pp and decreased thereafter to low percentages (< 5%) on day 31 pp and thereafter. In addition, CXCL5, IL1B, IL8 and HP mRNA expression correlated significantly with the proportion of PMN (P < 0.05). A significantly higher CXCL5, IL1B, IL6, IL8, PTGS2 and TNF mRNA content was observed in samples from cows with an inflamed endometrium compared with samples from cows with a healthy endometrium (P < 0.05).

CONCLUSIONS

These results show that inflammatory cytokines and acute phase proteins are expressed in the bovine endometrium in a time-related manner during the postpartum period, with a significant expression peak on day 17 pp as a possible mucosal immune response in the uterus. The evaluation of the expression patterns of such candidate genes may reveal more information than only determining the percentage of PMN to judge the severity of an inflammation.

Sensitivity to antibiotics of Arcanobacterium pyogenes and Escherichia coli from the uteri of cows with metritis/endometritis

The aim of the study was to determine the in vitro sensitivity of 161 Arcanobacterium pyogenes strains and 99 Escherichia coli strains isolated from the uteri of 312 cows with metritis/endometritis. Animals with pathological discharges were clinically diagnosed per rectum and per vaginum, and then swabs from the lumen of the uterus were aseptically collected. Bacteriological examination of swabs was according to commonly accepted procedures with the additional use of API tests. Sensitivity to antibiotics was tested by the disk diffusion method and performed in Mueller-Hinton agar. Arc. pyogenes strains were the most sensitive to amoxicillin/clavulanic acid (Amc) (97.3%), bacitracin (96.7%), ceftiofur (95.8%) and cephapirin (77.5%). E. coli strains were the most sensitive to norfloxacin (98.1%), marbofloxacin (95.8%), gentamycin (88%), Amc (80.7%) and ceftiofur (73.1%). Arc. pyogenes and E. coli were most resistant to oxytetracycline (63.7% and 31%, respectively).

Negative energy balance alters global gene expression and immune responses in the uterus of postpartum dairy cows

Most dairy cows suffer uterine microbial contamination postpartum. Persistent endometritis often develops, associated with reduced fertility. We used a model of differential feeding and milking regimes to produce cows in differing negative energy balance status in early lactation (mild or severe, MNEB or SNEB). Blood hematology was assessed preslaughter at 2 wk postpartum. RNA expression in endometrial samples was compared using bovine Affymetrix arrays. Data were mapped using Ingenuity Pathway Analysis. Circulating concentrations of IGF-I remained lower in the SNEB group, whereas blood nonesterified fatty acid and β-hydroxybutyrate concentrations were raised. White blood cell count and lymphocyte number were reduced in SNEB cows. Array analysis of endometrial samples identified 274 differentially expressed probes representing 197 recognized genes between the energy balance groups. The main canonical pathways affected related to immunological and inflammatory disease and connective tissue disorders. Inflammatory response genes with major upregulation in SNEB cows included matrix metalloproteinases, chemokines, cytokines, and calgranulins. Expression of several interferon-inducible genes including ISG20, IFIH1, MX1, and MX2 were also significantly increased in the SNEB cows. These results provide evidence that cows in SNEB were still undergoing an active uterine inflammatory response 2 wk postpartum, whereas MNEB cows had more fully recovered from their energy deficit, with their endometrium reaching a more advanced stage of repair. SNEB may therefore prevent cows from mounting an effective immune response to the microbial challenge experienced after calving, prolonging the time required for uterine recovery and compromising subsequent fertility.

Blood COX-2 and PGES gene transcription during the peripartum period of dairy cows with normal puerperium or with uterine infection

In the dairy cow, puerperal uterine intra-luminal concentrations of PGE(2) are related to the establishment and severity of uterine infections. Here we evaluated whether the blood concentrations of PGE(2) and the gene transcription profiles of enzymes involved in its synthesis (cyclooxygenase-2 and prostaglandin E synthase) could be used as markers of predisposition and/or presence of puerperal uterine infections. We also studied the relationship between the endocrine status and the leukocyte profiles around parturition and the transcription patterns of the genes. Finally, we have characterized the in vitro gene transcription and expression response to a challenge of LPS. Gene transcription profiles, quantified by real-time PCR, were similar in normal puerperium and metritis/endometritis cows, indicating that they are not suitable markers of predisposition to/presence of puerperal uterine infections. Transcription decreased from 2 weeks before parturition until parturition, when a minimum was attained, and then increased during the first week postpartum. The lowest gene transcription, at parturition, was coincidental with the highest total leukocytes, polymorphonuclear neutrophils and CD14 positive cell numbers. It is suggested that by this mechanism, a large number of PMN can be recruited into the uterus after parturition, avoiding an excessive acute inflammatory response. The lowest gene transcription was also coincidental with the surge in cortisol concentrations, indicating that this hormone plays a main immunomodulatory role around parturition. Gene transcription was significantly greater after stimulation with LPS than in non-stimulated blood. We suggest that this PGE(2) producing cells might arrive to the uterine lumen, contributing to the local PGE(2) concentrations and mediating the inflammatory response.