Transcriptomic Changes in Response to Form of Selenium on the Interferon-Tau Signaling Mechanism in the Caruncular Tissue of Beef Heifers at Maternal Recognition of Pregnancy

We have reported that selenium (Se) provided to grazing beef cattle in an inorganic (ISe) form versus a 1:1 mixture (MIX) of inorganic and organic (OSe) forms affects cholesterol biosynthesis in the corpus luteum (CL), the abundance of interferon tau (IFNτ) and progesterone (P4)-induced mRNAs in the caruncular (CAR) tissue of the endometrium, and conceptus length at maternal recognition of pregnancy (MRP). In this study, beef heifers were supplemented with a vitamin-mineral mix containing 35 ppm Se as ISe or MIX to achieve a Se-adequate status. Inseminated heifers were killed at MRP (d 17, n = 6 per treatment) for tissue collection. In CAR samples from MIX versus ISe heifers, qPCR revealed that mRNA encoding the thyroid regulating DIO2 and DIO3 was decreased (p < 0.05) and a complete transcriptomic analysis revealed effects on the interferon JAK-STAT1/2 pathway, including decreased expression of mRNAs encoding the classical interferon stimulated genes IFIT1, IFIT2, IFIT3, IRF1, IRF9, ISG15, OAS2, and RSAD2 (p < 0.05). Treatment also affected the abundance of mRNAs contributing to the immunotolerant environment (p < 0.05). In combination, these findings suggest more advanced preparation of the CAR and developing conceptus for implantation and to evade immune rejection by the maternal system in MIX- vs. ISe-treated heifers.

Indoleamine 2, 3-dioxygenase 1 mediated alterations in the functionality of immune cells, deciphers the pregnancy outcomes in crossbred dairy cows

Pregnancy establishment in bovines requires maternal immune cell modulation. Present study investigated possible role of immunosuppressive indolamine-2, 3-dioxygenase 1 (IDO1) enzyme in the alteration of neutrophil (NEUT) and peripheral blood mononuclear cells (PBMCs) functionality of crossbred cows. Blood was collected from non-pregnant (NP) and pregnant (P) cows, followed by isolation of NEUT and PBMCs. Plasma pro-inflammatory (IFNγ and TNFα) and anti-inflammatory cytokines (IL-4 and IL-10) were estimated by ELISA and analysis of IDO1 gene in NEUT and PBMCs by RT-qPCR. Neutrophil functionality was assessed by chemotaxis, measuring activity of myeloperoxidase and β-D glucuronidase enzyme and evaluating nitric oxide production. Changes in PBMCs functionality was determined by transcriptional expression of pro-inflammatory (IFNγ, TNFα) and anti-inflammatory cytokine (IL-4, IL-10, TGFβ1) genes. Significantly elevated (P < 0.05) anti-inflammatory cytokines, increased IDO1 expression, reduced NEUT velocity, MPO activity and NO production observed only in P cows. Significantly higher (P < 0.05) expression of anti-inflammatory cytokines and TNFα genes were observed in PBMCs. Study highlights possible role of IDO1 in modulating the immune cell and cytokine activity during early pregnancy and may be targeted as early pregnancy biomarkers.

Reconstitution of Caruncle Placenta through the 20α-HSD/Casp-3 Apoptotic Pathway during Early Pregnancy in Bovines

Trophoblast cells of endometrium during bovine pregnancy with different characteristics undergo dynamic changes during uterine remodeling, which can be observed as continuous changes, as P4 secreted by the mother is replaced by placental hormones. In this context, the present study analyzed tissues' morphological changes through uterine apoptosis during early pregnancy. In addition, the expression pattern associated with apoptosis genes and 20α-HSD was determined in the endometrium and caruncle tissues. The localization of 20α-HSD, VEGF, Casp3, and mTOR protein was also determined in endometrium and caruncle during early pregnancy. From around 30 days, caruncle trophoblast cells with very high invasiveness expanded the villus section as the gestation period progressed. The surrounding cells detached and reorganized into new cells. In addition, an analysis of the effect of apoptosis on cell reorganization in the caruncle revealed that the expression of 20α-HSD/Casp-3 signals in the villus section gradually increased from 30 to 90 days. However, on the 30th day, glandular epithelial cells occurred sporadically in the trophoblast cell section. Moreover, the apoptosis of trophoblast cells increased at 90 days. Taken together, the results of the present study show that changes in the uterus during early pregnancy promote changes during later pregnancy by inducing the reorganization through the stimulation of 20α-HSD and Casp-3, promoting uterine and caruncle tissues, unlike cell development mediated by hormone signaling.

The Role of L-Arginine-NO System in Female Reproduction: A Narrative Review

Accumulating evidence are available on the involvement of l-arginine-nitric oxide (NO) system in complex biological processes and numerous clinical conditions. Particular attention was made to reveal the association of l-arginine and methylarginines to outcome measures of women undergoing in vitro fertilization (IVF). This review attempts to summarize the expression and function of the essential elements of this system with particular reference to the different stages of female reproduction. A literature search was performed on the PubMed and Google Scholar systems. Publications were selected for evaluation according to the results presented in the Abstract. The regulatory role of NO during the period of folliculogenesis, oocyte maturation, fertilization, embryogenesis, implantation, placentation, pregnancy, and delivery was surveyed. The major aspects of cellular l-arginine uptake via cationic amino acid transporters (CATs), arginine catabolism by nitric oxide synthases (NOSs) to NO and l-citrulline and by arginase to ornithine, and polyamines are presented. The importance of NOS inhibition by methylated arginines and the redox-sensitive elements of the process of NO generation are also shown. The l-arginine-NO system plays a crucial role in all stages of female reproduction. Insufficiently low or excessively high rates of NO generation may have adverse influences on IVF outcome.

Influence of estradiol on bovine trophectoderm and uterine gene transcripts around maternal recognition of pregnancy†

Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time-artificial insemination, but there are no differences in conceptus survival to d16. The objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm (TE) transcripts, and uterine luminal fluid proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-time polymerase chain reaction (RT-PCR) was performed on TE (n = 21) RNA to measure relative abundance of IFNT, PTGS2, TM4SF1, C3, FGFR2, and GAPDH. Uterine fluid was analyzed using 2D Liquid Chromatography with tandem mass spectrometry-based Isobaric tags for relative and absolute quantitation (iTRAQ) method. RT-PCR data were analyzed using the MIXED procedure in SAS. There were no differences in messenger RNA (mRNA) abundances in TE, but there were 432 differentially expressed genes (253 downregulated, 179 upregulated) in highE2/conceptus versus lowE2/conceptus groups. There were also 48 differentially expressed proteins (19 upregulated, 29 downregulated); 6 of these were differentially expressed (FDR < 0.10) at the mRNA level. Similar pathways for mRNA and proteins included: calcium signaling, protein kinase A signaling, and corticotropin-releasing hormone signaling. These differences in uterine function may be preparing the conceptus for improved likelihood of survival after d16 among highE2 animals.

Recent Advances in Camel Immunology

Camels are domesticated animals that are highly adapted to the extreme desert ecosystem with relatively higher resistance to a wide range of pathogens compared to many other species from the same geographical region. Recently, there has been increased interest in the field of camel immunology. As the progress in the analysis of camel immunoglobulins has previously been covered in many recent reviews, this review intends to summarize published findings related to camel cellular immunology with a focus on the phenotype and functionality of camel leukocyte subpopulations. The review also describes the impact of different physiological (age and pregnancy) and pathological (e.g. infection) conditions on camel immune cells. Despite the progress achieved in the field of camel immunology, there are gaps in our complete understanding of the camel immune system. Questions remain regarding innate recognition mechanisms, the functional characterization of antigen-presenting cells, and the characterization of camel NK and cytotoxic T cells.

Interaction of preimplantation factor with the global bovine endometrial transcriptome

Preimplantation factor (PIF) is an embryo derived peptide which exerts an immune modulatory effect on human endometrium, promoting immune tolerance to the embryo whilst maintaining the immune response to invading pathogens. While bovine embryos secrete PIF, the effect on the bovine endometrium is unknown. Maternal recognition of pregnancy is driven by an embryo-maternal cross talk, however the process differs between humans and cattle. As many embryos are lost during the early part of pregnancy in cattle, a greater knowledge of factors affecting the embryo-maternal crosstalk, such as PIF, is needed to improve fertility. Therefore, for the first time, we demonstrate the effect of synthetic PIF (sPIF) on the bovine transcriptome in an ex vivo bovine endometrial tissue culture model. Explants were cultured for 30h with sPIF (100nM) or in control media. Total RNA was analysed via RNA-sequencing. As a result of sPIF treatment, 102 genes were differentially expressed compared to the control (Padj<0.1), although none by more than 2-fold. The majority of genes (78) were downregulated. Pathway analysis revealed targeting of several immune based pathways. Genes for the TNF, NF-κB, IL-17, MAPK and TLR signalling pathways were down-regulated by sPIF. However, some immune genes were demonstrated to be upregulated following sPIF treatment, including C3. Steroid biosynthesis was the only over-represented pathway with all genes upregulated. We demonstrate that sPIF can modulate the bovine endometrial transcriptome in an immune modulatory manner, like that in the human endometrium, however, the regulation of genes was much weaker than in previous human work.

Effects of Pre-Calving Body Condition and Different post partum Concentrate Feed Proportions on Immune-Associated and Hematological Parameters in Pluriparous Dairy Cows

Simple Summary

Dairy cows have to cope with physiological, metabolic and endocrine challenges during the transition from late gestation to lactation. This period is characterized by a negative energy balance. Concentrate feed proportion of the rations is often increased to compensate the energy deficit. This can lead to acidotic conditions in the rumen, which might trigger the release of lipopolysaccharides from bacteria and result in inflammatory responses. An unfavorable pre-calving body condition is known to cause health problems after calving. Cows with a higher body condition (expressed as score, BCS, at a five-point scale) prior to calving might respond differently to either low or high concentrate feed proportions after calving with regard to hematological traits as indicators for possible interactions between nutritional status and immune system. For testing this hypothesis, cows were split into two classes (higher and adequate BCS) six weeks prior to calving according to their actual BCS and fed either a low- or high-energy-dense diet after calving. Neither BCS class nor dietary energy concentration influenced markedly hematological traits, including immune cell phenotypes, and inflammatory markers, such as haptoglobin. The overall covered individual BCS range and the post partum concentrate feed challenge did not overstress physiological adaptability.

Abstract

The present study aimed at evaluating the influences of different concentrate feed proportions in the ration offered to dairy cows post partum with different body condition scores (BCS) before calving. Therefore, 60 pluriparous cows were divided 42 days before expected calving into two groups with a higher or an adequate BCS. After calving, both groups were further subdivided into a group fed a ration with either a low concentrate feed proportion (C, 35% at dry matter basis) or a high (60% at dry matter basis) one. It was hypothesized that different BCS would lead to different reactions concerning varying concentrate feed proportions. Isolated BCS effects were detected in the white blood profile only before calving. Neither low nor high concentrate feed proportions affected hematological, blood immune cell phenotypes and inflammatory markers consistently irrespective of BCS group. It was concluded, that the assessed BCS span covered a range in which the capability of cows to cope with different dietary post partum energy supply remained unchanged.

Implantation associated changes in expression profile of indoleamine-2, 3-dioxygenase 1, Th1-Th2 cytokines and interferon-stimulated genes on neutrophils and peripheral blood mononuclear cells of crossbred cows

Effective bidirectional communication between the embryo and dam improves the reproductive efficiency of dairy cows. Possible role of immunosuppressive indolamine-2, 3-dioxygenase 1 (IDO1) enzyme in the regulation of maternal systemic cytokine balance/shift during early pregnancy establishment along with various interferon-stimulated genes (ISGs) expression in neutrophils and peripheral blood mononuclear cell (PBMCs) were investigated in crossbred cows. Blood was collected on days 0 i.e. day of Artificial Insemination (AI), 10, 18 and 36 post-AI followed by isolation of neutrophils and PBMCs for gene expression study of IDO1, anti-inflammatory cytokines (IL-4, IL-10 and TGFβ1), pro-inflammatory cytokines (IFNγ and TNFα) and ISGs (ISG15, MX1, MX2, OAS1) in pregnant and non-pregnant cows. Cows were grouped as pregnant and non-pregnant after pregnancy confirmation by non-return to heat, ultrasonography, per rectal examination along with progesterone and IFNτ assay. Significantly (P < 0.05) higher relative mRNA expression of IDO1 and anti-inflammatory cytokines on days 10 and 18 post-AI were observed in both neutrophils and PBMCs of pregnant cows. Pregnant cows showed significantly (P < 0.05) higher mRNA transcripts of IFNγ and TNFα genes on days 18 post-AI in both neutrophils and PBMCs. Expression of ISGs was higher (P < 0.05) on day 10^th and 18^th post AI in both the neutrophils and PBMCs of pregnant cows. The study indicates that systemic immune regulation by IDO1 (through cytokine shift) and ISGs in peripheral immune cells are essential for the establishment of pregnancy and may be targeted in future as biomarkers for pregnancy diagnosis.

Peptidoglycan disrupts early embryo-maternal crosstalk via suppression of ISGs expression induced by interferon-tau in the bovine endometrium

Uterine infection with bacteria and the release of peptidoglycan (PGN), antigenic cell wall components of both Gram-negative and Gram-positive bacteria, can cause early pregnancy losses in ruminants, but the associated mechanisms remain unsolved. Day 7 blastocyst starts to secrete a minute amount of interferon-tau (IFNT) in the uterine horn which is required for early stage of maternal recognition of pregnancy (MRP) in ruminants, and it induces interferon stimulated genes (ISGs) for driving uterine receptivity in cows. This study investigated if PGN disrupts IFNT response through modulation of endometrial ISGs expressions. Cultured bovine endometrial epithelial cells (BEECs) were treated with embryo culture medium (ECM) or IFNT (1 ng/ml) in the presence or absence of a low level of PGN (10 pg/ml) for 24 h. A real-time PCR analyses revealed that the presence of PGN suppressed IFNT-induced ISGs (OAS1 and ISG15) and STAT1 expressions in BEECs. To visualize the impact of PGN in an ex-vivo model that resembles the in vivo status, endometrial explants were treated by IFNT (1 ng/ml) with or without PGN (10 pg/ml) for 12 h. PGN suppressed IFNT-induced gene expressions of the above factors, but not for IFNA receptor type1 (IFNAR1) or type2 (IFNAR2) in explants. Immunofluorescence analysis illustrated that PGN completely suppressed the IFNT-triggered OAS1 protein expression in the luminal epithelium of explants. Of note, PGN did not stimulate pro-inflammatory cytokines (TNFA and IL1B) or TLR2 mRNA expression in both models. These findings indicate that the presence of low levels of PGN suppresses ISGs expression induced by IFNT secreted from early embryo, at the luminal epithelium of the bovine endometrium. This could severely interfere with early stage of MRP processes in cows, leading to pregnancy failure.

Interferon tau-dependent and independent effects of the bovine conceptus on the endometrial transcriptome†

This study investigated bovine conceptus-induced modifications to the endometrial transcriptome related to effects of interferon tau (IFNT), conceptus origin (in vivo vs. in vitro), and conceptus sex. In vitro (IVF) or in vivo (superovulation and artificial insemination, AI) produced blastocysts were transferred into recipient heifers on day 7 of the estrous cycle. On day 15, IVF- or AI-derived conceptuses were obtained by uterine flushing and individually placed on endometrial explants in media for 6 h. Explants were also cultured with media alone as a control or media containing 100 ng/mL IFNT. Total explant RNA was analyzed by RNA-Seq. Incubation of endometrium with IFNT or IVF- or AI-derived conceptuses changed (P ≤ 0.001) expression of 491, 498, and 576 transcripts, respectively, compared to the control. Further, 369 differentially expressed genes (DEGs) were common between explants exposed to IFNT or a conceptus. A total of 240 DEGs were uniquely altered by conceptuses (IVF- and AI-derived) but not IFNT. Of these transcripts, 46 were shared between the IVF and AI groups, while 61 and 133 were specific to IVF and AI conceptuses, respectively. Five genes [melanophilin (MLPH), prominin-2 (PROM2), myeloid associated differentiation marker (MYADM), vomeronasal 1 receptor 4 like (VN1R4L) and 5-hydroxytryptamine receptor 1A (HTR1A)] were more abundant in endometrium exposed to female compared to male conceptuses (P < 0.001). A single gene [ADP-ribosylation factor like GTPase 4C (ARL4C)] was more abundant in response to male conceptuses (P < 0.001) than female conceptuses. These data support the hypothesis that conceptus regulation of gene expression in the endometrium is complex and involves factors other than IFNT that may have a biological role in pregnancy establishment.

Effect of repeated intravenous lipopolysaccharide infusions on systemic inflammatory response and endometrium gene expression in Holstein heifers

This study aimed to evaluate the effect of repeated intravenous lipopolysaccharide (LPS) infusions in nonlactating heifers on (1) the systemic proinflammatory state as measured by biomarkers in blood and plasma, and (2) endometrial gene expression of candidate transcripts on d 15 of gestation. Our hypothesis was that target transcripts related to a major functional group would be negatively modified in the preimplantation endometrium by the LPS treatments. In the first experiment (n = 13), a systemic proinflammatory state [defined as increased plasma concentrations of tumor necrosis factor (TNF)-α and haptoglobin for 2 wk] was established using 2 different sequential LPS infusion protocols. In the second experiment, heifers (n = 22; 11 mo of age) had their time of ovulation synchronized by a modified Ovsynch protocol and were enrolled in 1 of 2 treatments: control (CON; n = 11), which received sterile saline solution i.v., and LPS treatment (LPS; n = 11), submitted to repeated i.v. LPS injections (0.10, 0.25, 0.50, 0.75, 1.00, and 1.25 µg/kg) starting 2 d after artificial insemination (AI; d 0) and then every other day until d 15 after AI. At each LPS injection, rectal temperatures were measured hourly for 6 h. Blood samples were collected from d -1 to d 13 for analyses of progesterone, TNF-α, and haptoglobin in plasma, along with white blood cell (WBC) count and differential analysis. On d 15, endometrium tissue biopsies were taken and kept at -80°C until quantitative real-time PCR analysis of 30 target transcripts related to the immune system, adhesion molecules, and endometrium receptivity. Data were checked for normality and analyzed by repeated-measures ANOVA using PROC UNIVARIATE and PROC MIXED of SAS (SAS Institute Inc., Cary, NC). After each LPS injection, temperature was greater in the first 4 h in the LPS group compared with CON. Both TNF-α and haptoglobin increased in the LPS treatment with a significant treatment by day interaction. Total leukocyte count did not differ between treatments, but the differential count increased for neutrophils, band cells, and monocytes, and decreased for lymphocytes and eosinophils in LPS compared with CON. Progesterone concentrations in plasma did not differ between treatments during the experimental period. Out of 30 target genes analyzed, 3 transcripts were differentially expressed: indoleamine 2,3-dioxygenase (IDO; fold-change = 0.48) and pentraxin-3 (PTX3; fold-change = 0.38) were downregulated, whereas myxovirus-resistance protein (MX1; fold-change = 2.85) was upregulated in the LPS group. Sequential LPS injections were able to induce a prolonged systemic proinflammatory state, but effects on gene expression were limited to transcripts associated with the immune system. These results suggest that a mechanism for subfertility is linked to a proinflammatory state in dairy heifers.

Symposium review: Immunological detection of the bovine conceptus during early pregnancy

Infertility and subfertility reduce the economic viability of dairy production. Inflammation reduces conception rates in dairy cattle, but surprisingly little information exists about the populations and the functions of immune cells at the conceptus-maternal interface during the periattachment period in dairy cattle. Early pregnancy is accompanied by immune stimulation at insemination and conceptus secretion of IFN-τ, pregnancy-associated glycoproteins, prostaglandins, and other molecules whose effects on immune function during early pregnancy have not been determined. Our working hypothesis is that pregnancy induces changes in immune cell populations and functions that are biased toward immunological tolerance, tissue remodeling, and angiogenesis. This review summarizes current knowledge, starting with insemination and proceeding through early pregnancy, as this is the period of maximal embryo loss. Results indicated that early pregnancy is accompanied by a marked increase in the proportion of endometrial immune cells expressing markers for natural killer (CD335) cells and cytotoxic T cells (CD8) along with an increase in cells expressing major histocompatibility class II antigens (macrophages and dendritic cells). This is accompanied by increased abundance of mRNA for IL-15, a natural killer growth factor, and IL-10 in the endometrium during early pregnancy. Furthermore, expression of indoleamine 2,3 dioxygenase was 15-fold greater in pregnant compared with cyclic heifers at d 17, but then declined by d 20. This enzyme converts tryptophan to kynurenine, which alters immune function by creating a localized tryptophan deficiency and by activation of the aryl hydrocarbon receptor and induction of downstream tolerogenic mediators. Expression of the aryl hydrocarbon receptor is abundant in the bovine uterus, but its temporal and spatial regulation during early pregnancy have not been characterized. Pregnancy is also associated with increased expression of proteins known to inhibit immune activation, including programed cell death ligand-1 (CD274), lymphocyte activation gene-3 (CD223), and cytotoxic T-lymphocyte associated protein-4 (CD152). These molecules interact with receptors on antigen-presenting cells and induce lymphocyte tolerance. Current results support the hypothesis that early pregnancy signaling in dairy heifers involves changes in the proportions of immune cells in the endometrium as well as induction of molecules known to mediate tolerance. These changes are likely essential for uterine wall remodeling, placentation, and successful pregnancy.

Nutrient pattern analysis in critically ill patients using Omics technology (NAChO) - Study protocol for a prospective observational study

INTRODUCTION

Intensive care unit-acquired weakness (ICU-AW) is often observed in critically ill patients with prolonged intensive care unit (ICU) stay. We hypothesized that evolving metabolic abnormalities during prolonged ICU stay are reflected by changing nutrient patterns in blood, urine and skeletal muscle, and that these patterns differ in patients with/without ICU-AW and between patients with/without sepsis.

METHODS

In a prospective single-center observational trial, we aim to recruit 100 critically ill patients (ICU length of stay ≥ 5 days) with severe sepsis/septic shock ("sepsis group", n = 50) or severe head trauma/intracerebral hemorrhage ("CNS group", n = 50). Patients will be sub-grouped for presence or absence of ICU-AW as determined by the Medical Research Council sum score. Blood and urine samples will be collected and subjected to comprehensive nutrient analysis at different time points by targeted quantitative mass spectrometric methods. In addition, changes in muscular tissue (biopsy, when available), muscular architecture (ultrasound), electrophysiology, body composition analyses (bioimpedance, cerebral magnetic resonance imaging), along with clinical status will be assessed. Patients will be followed-up for 180 and 360 days including assessment of quality of life.

DISCUSSION

Key objective of this trial is to assess changes in nutrient pattern in blood and urine over time in critically ill patients with/without ICU-AW by using quantitative nutrient analysis techniques. Peer-reviewed published NAChO data will allow for a better understanding of metabolic changes in critically ill patients on standard liquid enteral nutrition and will likely open up new avenues for future therapeutic and nutritional interventions.

Regulation of inflammatory mediator expression in bovine endometrial cells: effects of lipopolysaccharide, interleukin 1 beta, and tumor necrosis factor alpha

An abnormal uterine environment can influence maternal-fetal communication, conception rate and disrupt normal embryo development, thereby affecting fertility and the reproductive performance of dairy cows. Animal variability means that development of endometrial cell lines with appropriate characteristic are required. We evaluated the effect of an infectious agent (i.e., bacterial lipopolysaccharide; LPS) and proinflammatory mediators (i.e., Interleukin 1 beta; IL-1β, and tumor necrosis factor alpha; TNFα) on inflammatory mediator gene expression and production by bovine endometrial epithelial (bEEL) and stromal (bCSC) cell lines. Expression of CXCL8/IL8, IL1A, IL1B, and IL6 cytokine genes was significantly upregulated in both epithelial and stromal cells when treated with LPS and IL-1β. LPS treatment of epithelial cells (compared with treatment by IL-1β and TNFα) exhibited greater CXCL8/IL8, IL1A, IL1B, and IL6 cytokine gene expression. Whereas, in stromal cells, IL-1β treatment (compared with LPS and TNFα) exhibited greater CXCL8/IL8, IL1A, IL1B, and IL6 cytokine gene expression. Interestingly, bEEL and bCSC cells treated with IL-1β increased IL1B gene expression, suggesting that IL-1β may act unusually in an autocrine-positive feedback loop. Cytokine production was stimulated by these agents in both cell types. We suggest that the characteristics of these two cell lines make them excellent tools for the study of intrauterine environment.

Increased urinary excretion of kynurenic acid is associated with non-recovery from acute kidney injury in critically ill patients

Background

Acute kidney injury (AKI) is often observed in critically ill patients and is associated with high morbidity and mortality. Non-recovery from AKI has a negative impact on the prognosis of affected patients and early risk stratification seems key to improve clinical outcomes. We analyzed metabolites of a conserved key inflammatory pathway (i.e. tryptophan degradation pathway) in serial urine samples of patients with AKI.

Methods

One hundred twelve ICU patients with AKI were included in a prospective observational analysis. After exclusion criteria, 92 patients were eligible for analysis. Serial urine samples were collected and tryptophan levels including key tryptophan metabolites were measured using tandem mass spectrometry.

Results

Sixty-seven patients recovered in the first 7 days of AKI (early recovery, ER) whereas n = 25 had late−/non-recovery (LNR). Urinary concentrations of tryptophan, kynurenine, 3-OH anthranillic acid, serotonine, and kynurenine/tryptophan were significantly lower in LNR patients. In contrast, creatinine normalized excretion of kynurenic acid (KynA) was substantially increased in LNR patients (7.59 ± 6.81 vs. 3.19 ± 3.44 (ER) μmol/mmol, p <  0.005). High urinary KynA excretion was associated with higher RIFLE class, longer AKI duration, increased need for RRT, and 30-day mortality. Logistic regression revealed KynA as the single most important predictor of renal recovery on days 1 and 2 of AKI.

Conclusions

Increased urinary levels of kynurenic acid, a key inflammatory metabolite of the tryprophan degradation pathway, are associated with adverse renal and clinical outcomes in critically ill patients with AKI. Urinary KynA may serve as an early risk stratificator in respective patients with AKI.

Assessment of immune organ dysfunction in critical illness: utility of innate immune response markers

In critically ill patients, organ dysfunctions are routinely assessed, monitored, and treated. Mounting data show that substantial critical illness-induced changes in the immune system can be observed in most ICU patients and that not only "hyper-inflammation" but also persistence of an anti-inflammatory phenotype (as in sepsis-associated immunosuppression) is associated with increased morbidity and mortality. Despite common perception, changes in functional immunity cannot be adequately assessed by routine inflammatory biomarkers such as C-reactive protein, procalcitonin, or numerical analysis of leukocyte (sub)-counts. Cytokines appear also not suited due to their short half-life and pleiotropy, their unexclusive origin from immune cells, and their potential to undergo antagonization by circulating inactivating molecules. Thus, beyond leukocyte quantification and use of routine biomarkers, direct assessment of immune cell function seems required to characterize the immune systems' status. This may include determination of, e.g., ex vivo cellular cytokine release, phagocytosis activity, and/or antigen-presenting capacity. In this regard, standardized flow-cytometric assessment of the major histocompatibility-II complex human leukocyte antigen (-D related) (HLA-DR) has gained particular interest. Monocytic HLA-DR (mHLA-DR) controls the interplay between innate and adaptive immunity and may serve as a "global" biomarker of injury-associated immunosuppression, and its decreased expression is associated with adverse clinical outcomes (e.g., secondary infection risk, mortality). Importantly, recent data demonstrate that injury-associated immunosuppression can be reversed-opening up new therapeutic avenues in affected patients. Here we discuss the potential scientific and clinical value of assessment of functional immunity with a focus on monocytes/macrophages and review the current state of knowledge and potential perspectives for affected critically ill patients.

Increased Activity of the Immunoregulatory Enzyme Indoleamine-2,3-Dioxygenase with Consecutive Tryptophan Depletion Predicts Death in Patients with Neuroendocrine Neoplasia

BACKGROUND/AIMS

Data from a considerable number of malignancies demonstrate that depletion of the essential amino acid tryptophan via induction of the immunoregulatory enzyme indoleamine-2,3-dioxygenase (IDO) serves as an important tumour escape strategy and is of prognostic importance. Here we investigate the predictive value of the activity of IDO as well as levels of tryptophan and respective downstream catabolites in a large cohort of patients with neuroendocrine neoplasms (NEN).

METHODS

142 consecutive Caucasian patients (62 male, aged 60.3 ± 11.9 years) with histologically confirmed NEN were systematically analysed in a retrospective blinded end point analysis. Patients were followed up for a mean period of about 3.9 ± 1.9 years. Clinical outcome, levels of established biomarkers, and tryptophan degradation markers (assessed using tandem mass spectrometry) including estimated IDO activity were recorded. Cox proportional hazards regression models were performed for the assessment of prognostic power.

RESULTS

We found that baseline tryptophan levels were significantly lower and IDO activity was significantly increased in non-survivors. The risk for death inclined stepwise and was highest in patients in the upper tertile of IDO activity. Cox proportional regression models identified IDO activity as an independent predictor of death.

CONCLUSIONS

In this retrospective analysis, we observed that baseline activity of the immunoregulatory enzyme IDO was significantly increased in non-survivors. IDO activity was identified as an independent predictor of death in this cohort of NEN patients. Whether IDO activity or tryptophan depletion serves to guide future therapeutic interventions in NEN remains to be established.

Influence of core body temperature on Tryptophan metabolism, kynurenines, and estimated IDO activity in critically ill patients receiving target temperature management following cardiac arrest

BACKGROUND/AIMS

Temperature control improves neurological prognosis in comatose cardiac arrest (CA) survivors. Previous reports demonstrate that most affected patients show signs of significant systemic inflammation. In an effort to better characterize potential temperature-related effects on key inflammatory pathways, we investigate the course of Tryptophan (Trp) levels, Tryptophan catabolites (including kynurenines) and indoleamine-2,3-dioxygenase (IDO)-activity in post CA patients.

MATERIAL/METHODS

In an observational blinded endpoint analysis, a total of n=270 serial samples from 20 post CA patients (63.1±16.6 yrs., 45% shockable rhythm, mean time to return of spontaneous circulation (ROSC) 26.6±16.0min) treated with target temperature management (TTM) were analyzed. Core body temperatures, course of Trp, Trp catabolites (incl. kynurenines), and estimated IDO-activity were followed up for a maximum of 7 days after ROSC. Patients were followed up until hospital discharge or death and functional outcome was recorded.

RESULTS

Over the 7-day observational interval, marked changes in Trp serum levels and IDO-activity were noted. In general, Trp serum levels but not IDO-activity seemed to parallel with the course of core body temperature. In explorative analyses, a correlation of Trp (rho=0.271 (95%-CI: 0.16-0.38, p<0.0001) and IDO-activity (rho=-0.155, 95%-CI: -0.27 to -0.037, p=0.01) with core body temperature was observed. Linear mixed effect models revealed a positive significant association of core body temperature with Trp serum levels (Likelihood ratio test χ(2)=6.35, p=0.012). In patients with good (vs. unfavorable) outcome, a tendency toward higher Trp serum levels, lower IDO-activity, and lower Kynurenic acid levels was noted.

CONCLUSIONS

We observed significant changes in Trp catabolism and IDO-activity that appeared temperature associated in post CA patients. Under hypothermia, decreased serum levels of Trp and increased IDO-activity were noted. We speculate from our data that IDO-induction during hypothermia contributes to the previously described increased susceptibility to infection or sepsis under reduced temperatures.

Metabotypes with properly functioning mitochondria and anti-inflammation predict extended productive life span in dairy cows

The failure to adapt metabolism to the homeorhetic demands of lactation is considered as a main factor in reducing the productive life span of dairy cows. The so far defined markers of production performance and metabolic health in dairy cows do not predict the length of productive life span satisfyingly. This study aimed to identify novel pathways and biomarkers related to productive life in dairy cows by means of (targeted) metabolomics. In a longitudinal study from 42 days before up to 100 days after parturition, we identified metabolites such as long-chain acylcarnitines and biogenic amines associated with extended productive life spans. These metabolites are mainly secreted by the liver and depend on the functionality of hepatic mitochondria. The concentrations of biogenic amines and some acylcarnitines differed already before the onset of lactation thus indicating their predictive potential for continuation or early ending of productive life.

Expression of inflammation-associated genes in circulating leukocytes and activity of indoleamine-2,3-dioxygenase in dairy cattle with acute puerperal metritis and bacteremia

OBJECTIVE

To investigate whether expression of genes associated with inflammation and activity of indoleamine-2,3-dioxygenase (IDO) correlated with disease status and prevalence of bacteremia in post-partum dairy cattle with and without acute puerperal metritis (APM).

PROCEDURES

Blood was collected from cattle with APM and control cattle matched by parity and days in milk. Leukocytes were isolated and expression of 6 genes was quantified. Activity of IDO was measured in serum with higher performance liquid chromatography (HPLC).

RESULTS

The relative expression of IL-1β in cattle with APM was significantly lower than that in controls. IDO activity was not significantly different between bacteremic and non-bacteremic cattle

CONCLUSIONS AND CLINICAL RELEVANCE

The expression of IL-1β was lower in cattle with APM. The lower levels of IL-1β expression in PBMCs of cattle with APM suggest impaired inflammatory responses and may contribute to the development of the disease in this population of animals.

Multiple-embryo transfer for studying very early maternal-embryo interactions in cattle

In the present paper, we highlight the need to study very early maternal-embryo interactions and discuss how these interactions can be addressed. Bovine species normally carry one or, less frequently, two embryos to term; there are very rare cases of triplets or higher-order multiple pregnancies in which all the offspring are born alive. Multiple-embryo transfer (MET) in cattle allows for the detection of endometrial responses in scenarios where single-embryo transfer would not. Although MET is non-physiological, the present study shows that at the very early embryonic stages, a uterus carrying zona-enclosed embryos does not exhibit non-physiological reactions. On the contrary, MET should be considered the sum of multiple individual effects triggered by developing embryos. We provide arguments to support our hypothesis that describe a rationale for current work with MET, and we discuss alternative hypotheses. Using cattle as a model, we describe how technical approaches to analyzing zona-enclosed early embryo-maternal interactions (i.e., transcriptomics, proteomics, and endometrial cell culture) can help identify molecular changes that may be difficult to observe when only a single embryo is present. We conclude that MET can be used for studying very early maternal-embryo interactions in vivo in monotocous species. Free Spanish abstract: A Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/150/2/R35/suppl/DC1.

Preimplantation embryo metabolism and culture systems: experience from domestic animals and clinical implications

Despite advantages of in vitro embryo production in many species, widespread use of this technology is limited by generally lower developmental competence of in vitro derived embryos compared to in vivo counterparts. Regardless, in vivo or in vitro gametes and embryos face and must adjust to multiple microenvironments especially at preimplantation stages. Moreover, the embryo has to be able to further adapt to environmental cues in utero to result in the birth of live and healthy offspring. Enormous strides have been made in understanding and meeting stage-specific requirements of preimplantation embryos, but interpretation of the data is made difficult due to the complexity of the wide array of culture systems and the remarkable plasticity of developing embryos that seem able to develop under a variety of conditions. Nevertheless, a primary objective remains meeting, as closely as possible, the preimplantation embryo requirements as provided in vivo. In general, oocytes and embryos develop more satisfactorily when cultured in groups. However, optimization of individual culture of oocytes and embryos is an important goal and area of intensive current research for both animal and human clinical application. Successful culture of individual embryos is of primary importance in order to avoid ovarian superstimulation and the associated physiological and psychological disadvantages for patients. This review emphasizes stage specific shifts in embryo metabolism and requirements and research to optimize in vitro embryo culture conditions and supplementation, with a view to optimizing embryo culture in general, and culture of single embryos in particular.

Differential expression and regulation of Tdo2 during mouse decidualization

Tryptophan 2,3-dioxygenase (Tdo2) is a rate-limiting enzyme which directs the conversion of tryptophan to kynurenine. The aim of this study was to examine the expression and regulation of Tdo2 in mouse uterus during decidualization. Tdo2 mRNA was mainly expressed in the decidua on days 6-8 of pregnancy. By real-time PCR, a high level of Tdo2 expression was observed in the uteri from days 6 to 8 of pregnancy, although Tdo2 expression was observed on days 1-8. Simultaneously, Tdo2 mRNA was also detected under in vivo and in vitro artificial decidualization. Estrogen, progesterone, and 8-bromoadenosine-cAMP could induce the expression of Tdo2 in the ovariectomized mouse uterus and uterine stromal cells. Tdo2 could regulate cell proliferation and stimulate the expression of decidual marker Dtprp in the uterine stromal cells and decidual cells. Overexpression of Tdo2 could upregulate the expression of Ahr, Cox2, and Vegf genes in uterine stromal cells, while Tdo2 inhibitor 680C91 could downregulate the expression of Cox2 and Vegf genes in uterine decidual cells. These data indicate that Tdo2 may play an important role during mouse decidualization and be regulated by estrogen, progesterone, and cAMP.

Characterization of the Th profile of the bovine endometrium during the oestrous cycle and early pregnancy

Despite extensive research in the area of cow fertility, the extent to which the maternal immune system is modulated during pregnancy in cattle remains unclear. Therefore, the objective of the current study was to characterize the presence and response profile of B, T-helper (LTh), T- cytotoxic (LTc), gamma delta-T (γδT) and natural killer (NK) lymphocytes in terms of cell number, distribution and cytokine expression in bovine endometrial tissue to pregnancy. Endometrial tissue samples were collected from beef heifers on Days 5, 7, 13 and 16 of the estrous cycle or pregnancy. Samples were analysed by immunofluorescence to identify the presence and abundance of B-B7 (B-cells), CD4 (LTh), CD8 (LTc), γδT cell receptor (TCR) and CD335/NKp46 (NK cells) -positive immune cells. Quantitative real time PCR (QPCR) was carried out to analyse mRNA relative abundance of FOXP3 (a marker of regulatory T (Treg) cells) and a panel of immune factors, including MHC-I, LIF, Interleukins 1, 2, 6, 8, 10, 11,12A, IFNa and IFNG. Results indicate that B-B7+ cells are quite populous in bovine endometrial tissue, CD4+ and CD8+ -cells are present in moderate numbers and γδTCR+ and CD335+ cells are present in low numbers. Pregnancy affected the total number and distribution pattern of the NK cell population, with the most significant variation observed on Day 16 of pregnancy. Neither B lymphocytes nor T lymphocyte subsets were regulated temporally during the oestrous cycle or by pregnancy prior to implantation. mRNA transcript abundance of the immune factors LIF, IL1b, IL8 and IL12A, IFNa and IFNG, expression was regulated temporally during the estrous cycle and LIF, IL1b, IL-10, IL11, IL12A were also temporally regulated during pregnancy. In conclusion, the endometrial immune profile of the oestrous cycle favours a Th2 environment in anticipation of pregnancy and the presence of an embryo acts to fine tune this environment.

Physiology and Endocrinology Symposium: role of immune cells in the corpus luteum

The immune system is essential for optimal function of the reproductive system. The corpus luteum (CL) is an endocrine organ that secretes progesterone, which is responsible for regulating the length of the estrous cycle, and for the establishment and maintenance of pregnancy in mammals. This paper reviews literature that addresses 2 areas; i) how immune cells are recruited to the CL, and ii) how immune cells communicate with luteal cells to affect the formation, development, and regression of the CL. Immune cells, primarily recruited to the ovulatory follicle from lymphoid organs after the LH surge, facilitate ovulation and populate the developing CL. During the luteal phase, changes in the population of macrophages, eosinophils, neutrophils, and T lymphocytes occur at critical functional stages of the CL. In addition to their role in facilitating ovulation, immune cells may have an important role in luteal function. Evidence shows that cytokines secreted by immune cells modulate both luteotropic and luteolytic processes. However, the decision to pursue either function may depend on the environment provided by luteal cells. It is suggested that understanding the role immune cells play could lead to identification of new strategies to improve fertility in dairy cattle and other species.

Embryonic sex induces differential expression of proteins in bovine uterine fluid

The bovine endometrium recognizes early embryos and reacts differently depending on the developmental potential of the embryo. However, it is unknown whether the endometrium can distinguish embryonic sex. Our objective was to analyze sexual dimorphism in the uterus in response to male and female embryos. Differentially expressed (DE) proteins, different levels of hexoses, and other embryotrophic differences were analyzed in uterine fluid (UF). Proteomic analysis of day-8 UF recovered from heifers after the transfer of day-5 male or female embryos identified 23 DE proteins. Regulated proteasome/immunoproteasome protein subunits indicated differences in antigen processing between UF carrying male embryos (male-UF) or female embryos (female-UF). Several enzymes involved in glycolysis/gluconeogenesis and antioxidative/antistress responses were up-regulated in female-UF. Fructose concentration was increased in female-UF versus male-UF, while glucose levels were similar. In vitro cultures with molecules isolated from male-UF were found to improve male embryo development compared to female embryos cultured with molecules isolated from female-UF. We postulated that, in vivo, male embryos induce changes in the endometrium to help ensure their survival. In contrast, female embryos do not appear to induce these changes.

Modulation of maternal immune system during pregnancy in the cow

There is a molecular crosstalk between the trophoblast and maternal immune cells of bovine endometrium. The uterine cells are able to secrete cytokine/chemokines to either induce a suppressive environment for establishment of the pregnancy or to recruit immune cells to the endometrium to fight infections. Despite morphological differences between women and cows, mechanisms for immune tolerance during pregnancy seem to be conserved. Mechanisms for uterine immunesuppression in the cow include: reduced expression of major histocompatability proteins by the trophoblast; recruitment of macrophages to the pregnant endometrium; and modulation of immune-related genes in response to the presence of the conceptus. Recently, an eGFP transgenic cloned embryo model developed by our group showed that there is modulation of foetal proteins expressed at the site of syncytium formation, suggesting that foetal cell can regulate not only by the secretion of specific factors such as interferon-tau, but also by regulating their own protein expression to avoid excessive maternal recognition by the local immune system. Furthermore, foetal DNA can be detected in the maternal circulation; this may reflect the occurrence of an invasion of trophoblast cells and/or their fragment beyond the uterine basement membrane in the cow. In fact, the newly description of exosome release by the trophoblast cell suggests that could be a new fashion of maternal-foetal communication at the placental barrier. Additionally, recent global transcriptome studies on bovine endometrium suggested that the immune system is aware, from an immunological point of view, of the presence of the foetus in the cow during early pregnancy.

Hosting the preimplantation embryo: potentials and limitations of different approaches for analysing embryo - endometrium interactions in cattle

Ongoing detailed investigations into embryo–maternal communication before implantation reveal that during early embryonic development a plethora of events are taking place. During the sexual cycle, remodelling and differentiation processes in the endometrium are controlled by ovarian hormones, mainly progesterone, to provide a suitable environment for establishment of pregnancy. In addition, embryonic signalling molecules initiate further sequences of events; of these molecules, prostaglandins are discussed herein as specifically important. Inadequate receptivity may impede preimplantation development and implantation, leading to embryonic losses. Because there are multiple factors affecting fertility, receptivity is difficult to comprehend. This review addresses different models and methods that are currently used and discusses their respective potentials and limitations in distinguishing key messages out of molecular twitter. Transcriptome, proteome and metabolome analyses generate comprehensive information and provide starting points for hypotheses, which need to be substantiated using further confirmatory methods. Appropriate in vivo and in vitro models are needed to disentangle the effects of participating factors in the embryo–maternal dialogue and to help distinguish associations from causalities. One interesting model is the study of somatic cell nuclear transfer embryos in normal recipient heifers. A multidisciplinary approach is needed to properly assess the importance of the uterine milieu for embryonic development and to use the large number of new findings to solve long-standing issues regarding fertility.

Transcriptional profiling to address molecular determinants of endometrial receptivity--lessons from studies in livestock species

The development of a fertilized oocyte into a differentiated multi-cellular organism is a major challenge with regard to the orchestration of the expression of the mammalian genome. Highly complex networks of genes are temporally and spatially regulated during cellular differentiation to generate specific cell types. Embryonic development is critically influenced by external impacts in the female reproductive tract. A most critical phase of pregnancy in mammals is the pre- and peri-implantation period, during which the uterine environment plays a crucial role in supporting the development of the conceptus. The analytical description of the transcriptome, proteome and metabolome of the embryo-maternal interface is a prerequisite for the understanding of the complex regulatory processes taking place during this time. This review lines out potentials and limitations of different approaches to unravel the determinants of endometrial receptivity in cattle, the pig and the horse. Suitable in vivo and in vitro models, which have been used to elucidate factors participating in the embryo-maternal dialog are discussed. Taken together, transcriptome analyses and specified selective candidate gene driven approaches contribute to the understanding of endometrial function. The endometrium as sensor and driver of fertility may indicate the qualitative and quantitative nature of signaling molecules sent by the early embryo and in turn, accordingly impact on embryonic development.

Effects of lactation and pregnancy on gene expression of endometrium of Holstein cows at day 17 of the estrous cycle or pregnancy

Objectives were to determine effects of lactation and pregnancy on endometrial gene expression on d 17 of the estrous cycle and pregnancy. Heifers (n = 33) were assigned randomly after parturition to lactating (L, n = 17) or nonlactating (NL, n = 16) groups. Cows were subjected to an ovulation synchronization program for a timed artificial insemination (TAI); 10 cows in L and 12 in NL were inseminated. Slaughter occurred 17 d after the day equivalent to TAI, and intercaruncular endometrial tissues were collected. Gene expression was determined by DNA microarray analysis for pregnant (L, n = 8; NL, n = 6) and noninseminated cyclic (L, n = 7; NL, n = 4) cows. Differentially expressed genes were selected with a P-value <0.01 and absolute expression >40. In addition, a fold effect >1.5 was used as a criterion for genes affected by pregnancy. In total, 210 genes were differentially regulated by lactation (136 downregulated and 74 upregulated), and 702 genes were differentially regulated by pregnancy (407 downregulated and 295 upregulated). The interaction effect of pregnancy and lactation affected 61 genes. Genes up- and downregulated in pregnant cows were associated with several gene ontology terms, such as defense response and interferon regulatory factor, cell adhesion, and extracellular matrix. The gene ontology analyses of up- and downregulated genes of lactating cows revealed terms related to immunoglobulin-like fold, immune response, COMM domain, and non-membrane-bounded organelle. Several genes upregulated by lactation, such as IGHG1, IGLL1, IGK, and TRD, were related to immune function, particularly for B cells and γδ T cells. Developmental genes related to limb and neural development and glucose homeostasis (e.g., DKK1, RELN, PDK4) were downregulated by lactation, whereas an interaction was also detected for RELN. The stated genes associated with immune function and developmental genes expressed in the endometrium affected by lactational state are possible candidate genes for interventions to improve fertility of lactating dairy cows.

A cross-talk of decidual stromal cells, trophoblast, and immune cells: a prerequisite for the success of pregnancy

Embryo implantation and formation of a functional placenta are complex processes that require a plethora of regulatory mechanisms involving both mother and embryo cells. Recently, an important role in this complicated cells and factors network was assigned to the decidual stromal cells (DSC) and trophoblast cells. Decidualization includes biochemical changes that trigger DSC to produce a number of factors required for the implantation and induction of immunotolerance in maternal immune system. Immunotolerance is achieved by a cascade of strictly controlled events starting with selective homing of immune cells to the feto-maternal site, regulated proliferation, and predominant differentiation into a regulatory type of immune cells. Furthermore, cytotoxic effector functions are reduced owing to the influence of steroid hormones, factors, cytokines, and inhibitory receptors. Altogether the entire immune system of the mother is switched to tolerogenic functional state which is a prerequisite for the successful maintenance of pregnancy.