A Bayesian view of murine seminal cytokine networks.

It has long been established that active agents in seminal fluid are key to initiating and coordinating mating-induced immunomodulation. This is in part governed by the actions of a network of cytokine interactions which, to date, remain largely undefined, and whose interspecific evolutionary conservation is unknown. This study applied Bayesian methods to illustrate the interrelationships between seminal profiles of interleukin (IL)-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12 (p70), IL-13, IL-17, eotaxin, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon (IFN)-gamma, keratinocyte-derived chemokine (KC), monocyte chemoattractant protein (MCP-1), macrophage inflammatory protein (MIP-1) alpha, MIP-1beta, regulated on activation normal T cell expressed and secreted (RANTES), tumour necrosis factor (TNF)-alpha, leptin, inducible protein (IP)-10 and vascular endothelial growth factor (VEGF) in a rat model. IL-2, IL-9, IL-12 (p70), IL-13, IL-18, eotaxin, IFN-gamma, IP-10, KC, leptin, MCP-1, MIP-1alpha and TNF-alpha were significantly higher in serum, whilst IL-1beta, IL-5, IL-6, IL-10, IL-17, G-CSF and GM-CSF were significantly higher in seminal fluid. When compared to mouse profiles, only G-CSF was present at significantly higher levels in the seminal fluid in both species. Bayesian modelling highlighted key shared features across mouse and rat networks, namely TNF-alpha as the terminal node in both serum and seminal plasma, and MCP-1 as a central coordinator of seminal cytokine networks through the intermediary of KC and RANTES. These findings reveal a marked interspecific conservation of seminal cytokine networks.

Gestational effects on host inflammatory response in normal and pre-eclamptic pregnancies.

OBJECTIVE: Pre-eclampsia (PET) remains a leading cause of maternal and neonatal morbidity and mortality. Although its pathophysiology involves an underlying inflammatory dysfunction, it is unclear how this may be affected by increasing gestational age, particularly in relation to the time of onset of disease. Murine studies have indicated that a progressive increase in serum inflammatory profile is a physiological feature of normal gestation. The present study aimed to investigate this phenomenon in women in relation to normal and pre-eclamptic pregnancies. STUDY DESIGN: Control and PET groups (each n=20) were divided into early and late pregnancy (before and after 34 weeks gestation, respectively). Whole blood was diluted 1:1 with RPMI 1640 medium with/without 1 microg/ml lipopolysaccharide at 37 degrees C for 24 h under a humidified 5% CO(2) atmosphere. Samples were collected at 0, 2, 6 and 24 h and analysed for interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p70), IL-13, IL-17, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon (IFN)-gamma, monocyte chemotactic protein (MCP-1), macrophage inflammatory protein (MIP)-1beta and tumour necrosis factor (TNF)-alpha by fluid-phase multiplex immunoassay. RESULTS: This study confirms that pregnancy features an increasing inflammatory response with advancing gestational age, which was seen in both control and PET pregnancies (P<0.01). CONCLUSIONS: This increase in inflammatory responsiveness with advancing gestation may provide an explanation for the incidence of late onset PET in the absence of placental pathology, as well as serving as a potential physiological priming mechanism geared towards increasing maternal sensitivity to the fetal triggers of labour.

Matrix metalloproteinases and their tissue inhibitors in preterm perinatal complications.

The objective of this article is to review the role of matrix metalloproteinases (MMPs) in fetomaternal/neonatal complications of preterm birth. The function of MMPs as proteolytic enzymes involved in tissue remodeling/destruction is reviewed in preterm labor, preeclampsia, premature rupture of membranes, intrauterine growth restriction, chronic lung disease, necrotizing enterocolitis, intraventricular hemorrhage, cystic periventricular leukomalacia, and retinopathy of prematurity. Cytokines, steroid hormones, and reactive oxygen species all regulate MMP labor and expression/activity. In labor, activation follows an inflammatory response, which results in fetal membrane rupture and cervical dilation/ripening, particularly when premature. Expression/activation is elevated during parturition, particularly when premature. While fetal membrane rupture is preceded by increases in tissue-specific MMPs, neonatal complications also ensue from an imbalance between MMPs and their tissue inhibitors. These e fects implicate environmental triggers and a genetic predisposition. MMPs are involved in the perinatal complications of prematurity and are potential targets for therapeutic intervention. Functional MMP genetic polymorphisms may assist in identifying patients at risk of complications.

Genetics of preterm labour.

The identification of women at risk of preterm labour remains an important challenge. While current prevention programmes rely on overt clinical and environmental parameters, the clustering of preterm labour within families and recurrence in susceptible women presents the case for a complex underlying genetic predisposition. Genetic polymorphisms are useful markers to identify high risk groups, although they provide little information either to their underlying functionality or the pathophysiological mechanisms involved; these must be validated through complementary analytical approaches. Data interpretation and inter-study comparisons must be made with caution, taking into account population size, study power, racial differences, inclusion/exclusion criteria and any underlying gene-environment and feto-maternal interactions. Large-scale, multicentre genetic studies coupled with high-throughput screening techniques are the most viable approaches to identify multilocus preterm labour susceptibility screening panels. Preventive strategies may then be applied to those women most likely to benefit from intervention.

Regulation of maternal serum and amniotic fluid cytokine profiles in the mouse: possible roles in the onset of labour.

Murine pregnancy is characterised by marked increases in serum cytokine profiles with advancing gestation, but whether these changes reflect concentrations in amniotic fluid is unknown. This study therefore profiled 23 cytokines by fluid-phase multiplex immunoassay of amniotic fluid and serum collected from naturally mated mice during mid- and late pregnancy (days 11 and 18, respectively). The marked increase in serum profile of many cytokines from days 11 to 18 was not reflected in amniotic fluid, wherein most cytokine concentrations were lower on day 18. Serum and amniotic fluid cytokine concentrations were largely inversely related, indicating separate, localised regulatory mechanisms geared towards the maintenance of pregnancy, modulation of immune effector cell function and optimisation of fetal development. We suggest that, while maternal systemic inflammatory priming prepares the mother for birth, the amniotic compartment exhibits a tightly regulated inflammatory quiescence. These findings are discussed in relation to the onset of labour, which ultimately results in the elevated cytokine amniotic levels traditionally associated with the final stages of pregnancy.

Uterine and serum cytokine arrays in the mouse during estrus.

Cytokines govern uterine immunology and embryo receptivity and are increasingly recognized for their embryotrophic roles. While supplementing culture media with cytokines may improve embryo development/viability in vitro, little is known about their physiological profiles in vivo, and hence which are likely to be uterine immunoregulators and embryotrophins. Therefore, this study profiled 23 cytokines in uterine fluid and serum from individual naturally cycling estrous mice. Samples were analyzed by fluid-phase multiplex immunoassays for interleukin (IL)-1alpha, IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-17, eotaxin, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon (IFN)-gamma, keratinocyte-derived chemokine (KC), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha MIP)-1beta regulated upon activation, normal T-cell expressed and secreted (RANTES) and tumor necrosis factor (TNF)-alpha. There was a marked divergence in cytokine concentrations between uterine fluid and serum. The former was dominated by G-CSF, eotaxin, KC and IL-1alpha, and had significantly higher levels of IL-1beta, IL-2, IL-3, IL-4, IL-6, IL-9, GM-CSF, MIP-1alpha, MIP-1beta and RANTES. Serum had significantly higher IL-12 (p40), IL-12 (p70), IL-17 and IFN-gamma concentrations. No significant differences in IL-5, IL-10, IL-13, MCP-1 or TNF-alpha profiles were noted. These data indicated a strict compartmentalization of uterine cytokines, with G-CSF as a major cytokine at estrous. Results are discussed with respect to immune cell function, post-coital paternal antigen processing, estrous cyclicity, and endometrial angiogenesis, cell turnover and differentiation.

Multiplex determination of murine seminal fluid cytokine profiles.

Seminal fluid is known to be responsible for orchestrating mating-induced immunomodulation. Central to this process are numerous cytokines that modulate uterine leukocyte recruitment and trafficking. Despite this, a comprehensive analysis of the cytokine profile of murine seminal fluid is lacking. This study addressed this issue by using multiplex immunoassays to characterise the profile of interleukin (IL)-1alpha , IL-1beta , IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-17, eotaxin, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon (IFN)-gamma, keratinocyte-derived chemokine (KC), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha , MIP-1beta , regulated upon activation normal T-cell expressed and secreted (RANTES), and tumour necrosis factor (TNF)-alpha in fluid drawn from the seminal vesicles of single mice (n = 18). Their levels and ratios were compared with those found in serum. IL-1alpha , IL-1beta , IL-2, IL-5, IL-9, IL-12 (p40), IL-12 (p70), IL-13, IL-17, GM-CSF, IFN-gamma, MCP-1 and TNF-alpha levels were significantly higher in serum; IL-4, G-CSF, eotaxin, KC and RANTES exhibited the opposite trend. Based on these findings, we propose a model of mating-induced immunomodulation that implicates seminal eotaxin, RANTES and MIP-1alpha in the relocation and concentration of extravasated migrating endometrial eosinophils to the luminal epithelium. Furthermore, KC may participate in uterine neutrophil chemotaxis and activation. Eotaxin and MIP-alpha , together with IL-1beta and IL-9, may also enhance further cytokine synthesis for endometrial antigen-presenting cell recruitment for processing paternal ejaculate antigens. IL-4 and G-CSF could also minimise deleterious cell-mediated immunity and modulate IFN-gamma production, thereby supporting the establishment of pregnancy.

The effect of paracrine/autocrine interactions on the in vitro culture of bovine preimplantation embryos.

Bovine preimplantation embryos develop more successfully when cultured in groups, proibably because of the increased production of, and exposure to, embryotrophic autocrine and paracrine factors. Using a novel embryo culture technique, this study had two aims: 1. to determine the distance over which potential paracrine interactions affect bovine embryo development in terms of blastocyst and hatching rates, cell counts and carbohydrate metabolism; 2. to investigate the effect of platelet-activating factor (PAF) supplementation on bovine embryo development and metabolism. Groups of 16 presumptive zygotes were attached to the bottom of a culture dish by the cell adhesive Cell-Tak in a 4 x 4 equidistant array. The distance between individual embryos in each group was 0-689 microm. Optimal blastocyst formation rate occurred when embryos were cultured 165 microm apart compared with control non-attached zygotes (Kruskal-Wallis followed by Mann-Whitney U test post-hoc; P < 0.05). Increasing the distance between embryos resulted in a further decline in blastocyst rate, which reached zero at 540 microm apart. Blastocyst cell number, pyruvate/glucose uptake and lactate production decreased as the interembryo distance increased from 240 to 465 microm (P < 0.05). Supplementation with PAF during conventional group culture enhanced blastocyst cell number, hatching rates and the oxidative metabolism of pyruvate and glucose. The data indicate that the distance between individual bovine embryos in culture influences preimplantation development, in particular blastocyst formation, cell number and metabolism. It is suggested that diffusible paracrine/autocrine factors, such as PAF, are in part responsible for the regulation of early embryo development.

Nutrient concentrations in murine follicular fluid and the female reproductive tract.

The culture of murine oocytes and preimplantation embryos in vitro has been used successfully for many years. However, this practice can result in cellular stress and reduced viability. Since this phenomenon is partly attributable to differences in nutrient composition between culture media and maternal tract fluids, we determined the concentrations of glucose, pyruvate, lactate and 19 amino acids in murine preovulatory follicles and oestrous oviductal and uterine fluids. Follicular fluids were aspirated from hyperstimulated ovaries, whereas oviductal fluids (with/without oocyte-cumulus complexes) and uterine fluids were collected from naturally cycling animals. Glucose, pyruvate and lactate concentrations were analysed using ultramicrofluorometric methods, whilst amino acid profiles were determined by reverse-phase high performance liquid chromatography. Mean glucose concentrations in follicular, oviduct (with/without cumulus cells) and uterine fluids were 0.46, 1.09/1.65 and 0.61 mmol l(-1), respectively. Pyruvate concentrations were 0.38, 0.37/0.17 and 0.25 mmol l(-1), respectively, and lactate concentrations were 17.34, 10.92/11.68 and 9.41 mmol l(-1), respectively. Oviductal pyruvate concentration was significantly higher, and glucose significantly lower, in the presence of cumulus cells. Taurine, glycine, alanine, glutamine and glutamate were the major amino acids detected. Concentrations of amino acids differed among fluids, with highest levels being found in the oviduct. The follicular fluid and tract nutrient profiles differed from those of murine maturation, fertilisation and embryo culture media. These data extend our understanding of cellular metabolism and of nutritional environments of the oocyte and early embryo as they progress along the reproductive tract in vivo. These results may also contribute to the formulation of nutritionally more physiological media for mouse oocyte maturation and embryo culture.

Fluctuations in bovine ovarian follicular fluid composition throughout the oestrous cycle.

Bovine oocyte maturation in vitro frequently results in abnormal cytoplasmic maturation and failure to acquire developmental competence. This is, in part, likely to be due to the non-physiological nutritional milieu to which oocytes are exposed. Improvements in oocyte developmental potential may be achieved by modelling nutrient profiles on those of preovulatory follicular fluid (FF). However, little is known about fluctuations in FF nutrient levels according to follicle dominance and oestrous cyclicity. This study therefore characterised the carbohydrate and amino acid profile of FF according to these parameters, and compared preovulatory FF composition with that of maturation medium. Carbohydrate concentrations (n = 121) were determined enzymatically whilst amino acid profiles (n = 40) were determined by reverse-phase HPLC. Pyruvate and glucose concentrations were unaffected by follicle dominance, whereas Stage III-IV lactate profiles were higher in non-dominant FF (P < 0.01). While most dominant FF amino acid concentrations were affected by oestrous stage, only glutamate, alanine, leucine and lysine levels fluctuated in non-dominant FF. Glucose and lactate concentrations were significantly negatively correlated, whereas most amino acids were significantly positively correlated with each other. Maturation medium had higher pyruvate and lower lactate concentrations than preovulatory FF (P < 0.001), whereas glucose level was similar. All amino acid levels (except histidine, taurine, alanine and tryptophan) differed significantly between maturation medium and preovulatory FF. These data indicated that FF composition varies throughout the oestrous cycle. Preovulatory FF nutrient profile differed from that of maturation medium, perhaps accounting for the poor developmental competence of in vitro matured oocytes. These data may contribute to the formulation of a nutritionally more physiological maturation medium.