Interleukin-1 beta modulates prostaglandin and progesterone production by primate luteal cells in vitro

A critical role of interleukin-1 in preterm labor

Preterm birth (PTB) is a leading cause of neonatal mortality and morbidity worldwide, and represents a heavy economic and social burden. Despite its broad etiology, PTB has been firmly linked to inflammatory processes. Pro-inflammatory cytokines are produced in gestational tissues in response to stressors and can prematurely induce uterine activation, which precedes the onset of preterm labor. Of all cytokines implicated, interleukin (IL)-1 has been largely studied, revealing a central role in preterm labor. However, currently approved IL-1-targeting therapies have failed to show expected efficacy in pre-clinical studies of preterm labor. Herein, we (a) summarize animal and human studies in which IL-1 or IL-1-targeting therapeutics are implicated with preterm labor, (b) focus on novel IL-1-targeting therapies and diagnostic tests, and (c) develop the case for commercialization and translation means to hasten their development.

Menstrual cycle and detectable human papillomavirus in reproductive-age women: a time series study

BACKGROUND

Current evidence on the relationship between human papillomavirus (HPV) DNA detection and menstrual cycle has been inconsistent.

METHODS

We included 21 nonoral contraceptive pill (non-OCP) users who self-collected vaginal samples twice per week for 16 weeks. We explored whether variable detection of HPV DNA exhibited cyclic or other structured temporal patterns. We also evaluated relationships between serial HPV prevalence, sexual behavior, and suspected bacterial vaginosis (BV) as defined by Nugent Gram stain score ≥7.

RESULTS

During follow-up, any-type HPV prevalence varied between 61.1% and 85.0%. Although not statistically significant, we observed a maximum autocorrelation in serial HPV prevalence lagging 14 days (correlation coefficient [ρ], -0.24). Any-type HPV detection had a periodic behavior, generally repeating every 28.0 days (bootstrapped interquartile range, 22.4-28.0) and peaking around the ovulation time (adjusted odds ratio, 1.96; 95% confidence interval [CI], 1.06-3.62) as compared to menstruation. We also showed that an increase in any-type HPV prevalence preceded the beginning of a menstrual cycle by 9-12 days. There was no evidence of relationships between HPV prevalence and sexual activity or Nugent score.

CONCLUSIONS

Serially detected any-type HPV DNA showed a periodic behavior and was likely to peak in the periovulatory phase among non-OCP users.

The a2 isoform of vacuolar ATPase is a modulator of implantation and feto-maternal immune tolerance in early pregnancy

In mammalian reproduction, two immunologically disparate entities, the mother and her fetus, co-exist in close proximity and mutually tolerate each other. The maternal immune system plays a major contributing role in the reproductive outcome. A coordinated set of immunological events takes place between the maternal and fetal cells to ensure fetal survival. Among these, cytokines secreted by proximal maternal immune cells as well as fetal trophoblast cells play a major role in feto-maternal tolerance. In this review, we describe the role of the vacuolar ATPase (and more specifically the a2 isoform, a2V-ATPase) in controlling the expression of these vital cytokines. a2V-ATPase is a key enzyme that controls the acidification of intracellular vesicles and the extracellular environment, processes that play a major role in cellular function. The localization of a2V-ATPase in tissues and immune cells of the reproductive tract which are essential for pregnancy will be described. Information will be provided on the role of a2V-ATPase on aspects of cell development in pregnancy, from fertilization to implantation and fetal growth. Particular emphasis will be placed on the role of a2V-ATPase in (a) regulating parts of the cytokine network at the implantation site and (b) attenuating the potentially harmful maternal immune response against trophoblast cells.

Reproductive aging is associated with altered gene expression in human luteinized granulosa cells

Declining reproductive success with aging is attributable to qualitative and quantitative deterioration in oocytes, which are nurtured by granulosa cells (GCs). This prospective study assesses whether reproductive aging is accompanied by differential gene expression in luteinized GCs from in vitro fertilization (IVF) patients. Women with nonovarian infertility etiologies were categorized as younger (< or =30, n = 3) or older (> or =40, n = 3). During oocyte retrieval, mural GCs were isolated; messenger RNA (mRNA) was extracted and transcribed for complementary DNA (cDNA) microarray analysis. Differential gene expression was confirmed by real-time polymerase chain reaction (PCR). Analysis revealed 120 genes were differentially expressed. Three genes were upregulated and 117 were downregulated (including interleukin [IL]-1beta, IL-1R2, and IL-6R) in GCs of older versus younger patients. Our data provide evidence of downregulation in IL-1 and IL-6 gene families in luteinized GCs with advancing age. Given previously recognized roles for the IL gene family in folliculogenesis and ovulation, our findings may partly explain ovulatory and luteal dysfunctions associated with reproductive aging.

Cytokines and chemokines in postovulatory follicle regression of domestic chicken (Gallus gallus domesticus)

The mechanism of postovulatory follicle (POF) regression in birds is still poorly understood. In the current study, expression of IL-1beta, IL-6, GM-CSF, IFN-gamma, IL-2, IL-4, IL-13, chCXCLi2, chCCLi2, chCCLi4, chCCLi7, IL-10 and TGF-beta2 mRNAs was estimated in regressing POF by semi-quantitative RT-PCR. In addition, the changes in immune cell population, histological and apoptotic changes were also studied in regressing POF. The expression of cytokines (IL-1beta, IL-6, IL-10 and TGF-beta2) and chemokines (chCXCLi2, chCCLi2, chCCLi4 and chCCLi7) was upregulated in POFs, suggesting a role for these molecules in tissue regression. The histological findings suggested a significant infiltration of immune cells, especially heterophils, lymphocytes and macrophages, into the regressing POF. The flow cytometry analysis of lymphocyte subpopulations revealed that CD3(+), CD4(+), CD8(+) and Bu-1(+) lymphocytes were significantly increased during this regression. The significant up-regulation of chemokines might have attracted the immune cells during POF regression. The percentage of apoptotic cells was significantly increased during the regression of POF. The up-regulation of IL-1beta, IL-6, IL-10 and TGF-beta2 and down-regulation of GM-CSF might have induced apoptosis during the POF regression. However, expression of IFN-gamma, IL-2, IL-4 and IL-13 was not significantly altered during POF regression. In conclusion, cytokines appear to play an important role in the regression of POF in chicken. Furthermore, the regression of chicken POF seems to be an inflammatory event similar to luteolysis of the mammalian corpus luteum.

The class II major histocompatibility complex molecule BoLA-DR is expressed by endothelial cells of the bovine corpus luteum

Cells expressing class II major histocompatibility complex (MHC) molecules are found within the corpus luteum (CL) of several species. Expression and localization of class II MHC molecules in the bovine CL were examined in the present study. Immunohistochemical evaluation revealed class II MHC molecules on single cells in early CL (days 4 and 5 post-estrus). Two class II MHC-expressing cell types were observed in midcycle CL (days 10–12 post-estrus), single cells similar to those observed in the early CL, and endothelial cells. Not all endothelial cells expressed class II MHC, and further investigation revealed expression of only one type of class II MHC molecule, DR, on endothelial cells. Class II MHC was also localized to endothelial cells in late CL (day 18 post-estrus). Steroidogenic luteal cells were negative for class II MHC throughout the estrous cycle. Quantitative RT-PCR revealed higher (P< 0.05) concentrations of mRNA encoding the α-subunit of DR (DRA) in late CL when compared with those in the early CL.DRAmRNA abundance was also measured in cultures of mixed luteal and luteal endothelial (CLENDO) cells, in the presence or absence of tumor necrosis factor-α (TNF). No differences were found in theDRAmRNA concentration between mixed luteal and CLENDO cell cultures, and TNF had no effect onDRAmRNA concentration in both cell types. Expression of DR by endothelial cells of the midcycle CL may induce anergy of T lymphocytes, or stimulate them to secrete products that enhance normal luteal function.

Cytokines in reproductive remodeling of molting White Leghorn hens

The role of cytokines in regression of the ovary and oviduct during induced molting in chickens was investigated by evaluating the expressions of IL-1beta, IL-6, IFN-gamma, IL-2, TGF-beta2, MIP-1beta and IL-8 in the regressing ovary and oviduct by semi-quantitative RT-PCR. In addition, serum hormonal profiles (estrogen, progesterone and corticosterone), along with the gross regression and histological changes of the ovary and oviduct, were investigated. The correlation between expression of cytokines and hormonal changes during the induced molting was also studied. The expression of IL-6, IL-8, MIP-1beta and IFN-gamma mRNAs in the ovary, and IL-1beta, IL-6, IL-8, MIP-1beta, IFN-gamma and TGF-beta2 mRNAs in the oviduct, were up-regulated significantly during induced molting, suggesting their role in tissue regression. However, histological findings suggested no significant increase in immune cells in the regressing oviduct and ovary. Significant up-regulation of TGF-beta2 in the regressing oviduct might have suppressed leukocyte recruitment thereby preventing the inflammatory response and tissue damage. The down-regulation of estrogen and progesterone and up-regulation of corticosterone is well correlated with increased expression of cytokines. It appears that cytokines released during the process of induced molting may have a role in decreasing ovarian steroids and increasing the corticosterone levels in chicken. From this study, it may be concluded that cytokines play a major role in regression of the ovary and oviduct during induced molting in chickens.

Expression of costimulatory molecules in the bovine corpus luteum

BACKGROUND

Bovine luteal parenchymal cells express class II major histocompatibility complex (MHC) molecules and stimulate class II MHC-dependent activation of T cells in vitro. The ability of a class II MHC-expressing cell type to elicit a response from T cells in vivo is also dependent on expression of costimulatory molecules by the antigen presenting cell and delivery of a costimulatory signal to the T cell. Whether bovine luteal parenchymal cells express costimulatory molecules and can deliver the costimulatory signal is currently unknown.

METHODS

Bovine luteal tissue was collected during the early (day 5; day of estrus = day 0), mid (day 11-12), or late (day 18) luteal phase of the estrous cycle, and at 0, 0.5, 1, 4, 12 or 24 hours following administration of PGF2alpha to cows on day 10 of the estrous cycle. Northern analysis was used to measure CD80 or CD86 mRNA concentrations in luteal tissue samples. Mixed luteal parenchymal cell cultures and purified luteal endothelial cell cultures were prepared, and real-time RT-PCR was used to examine the presence of CD80 and CD86 mRNA in each culture type. Monoclonal antibodies to CD80 and CD86 were added to a mixed luteal parenchymal cell-T cell co-culture in vitro T cell proliferation assay to assess the functional significance of costimulatory molecules on activation of T lymphocytes by luteal parenchymal cells.

RESULTS

Northern analysis revealed CD80 and CD86 mRNAs in luteal tissue, with greatest steady-state concentrations at midcycle. CD80 and CD86 mRNAs were detected in mixed luteal parenchymal cell cultures, but only slight amounts of CD80 (and not CD86) mRNA were detected in cultures of luteal endothelial cells. Luteinizing hormone, PGF2alpha and TNF-alpha were without effect on concentrations of CD80 or CD86 mRNA in mixed luteal parenchymal cells cultures. Anti-CD80 or anti-CD86 monoclonal antibodies inhibited T cell proliferation in the in vitro T cell proliferation assay.

CONCLUSION

It can be concluded from this study that parenchymal cells within the bovine CL express functional costimulatory molecules that facilitate interactions between with T cells, and these components of the antigen presentation pathway are expressed maximally in the midcycle CL.

Presence and regulation of messenger ribonucleic acids encoding components of the class II major histocompatibility complex-associated antigen processing pathway in the bovine corpus luteum

Luteal cells express class II major histocompatibility complex (MHC) molecules and can stimulate T lymphocyte proliferationin vitro. However, it is unknown whether luteal cells express the intracellular components necessary to process the peptides presented by class II MHC molecules. The objective of the present study was to examine the expression and regulation of three major class II-associated antigen processing components – class II MHC-associated invariant chain (Ii), DMα and DMβ – in luteal tissue. Corpora lutea were collected early in the estrous cycle, during midcycle and late in the estrous cycle, and at various times following administration of a luteolytic dose of prostaglandin F2α(PGF2α) to the cow. Northern analysis revealed the presence of mRNA encoding each of the class II MHC-associated antigen processing proteins in luteal tissue. Ii mRNA concentrations did not change during the estrous cycle, whereas DMα and DMβ mRNA concentrations were highest in midcycle luteal tissue compared with either early or late luteal tissue. Tumor necrosis factor-α (TNF-α) reduced DMα mRNA concentrations in cultured luteal cells in the presence of LH or PGF2α. DMα and DMβ mRNA were also present in highly enriched cultures of luteal endothelial (CLENDO) cells, and DMα mRNA concentrations were greater in CLENDO cultures compared with mixed luteal cell cultures. Expression of invariant chain, DMα and DMβ genes indicates that cells within the corpus luteum express the minimal requirements to act as functional antigen-presenting cells, and the observation that CLENDO cells are a source of DMα and DMβ mRNA indicates that non-immune cells within the corpus luteum may function as antigen-presenting cells.

Investigations on the expression of cytokines in the canine corpus luteum in relation to dioestrus

Control of luteal regression in the dog is still poorly understood. Unlike other domestic animal species, luteolysis is not prevented by hysterectomy. Indications that PGF(2alpha) may act as an endogenous luteolytic agent have been found only in pregnant animals during the prepartal decline of progesterone. Evidence from several species indicates that the immune system plays an important role in corpus luteum (Cl) function, possibly by the release of cytokines from immigrant immune cells. Hence, in the present experiment we attempted to examine the expression of cytokines in the canine Cl during the course of dioestrus (formation and regression of the Cl), using RT-PCR. Groups of 4-5 bitches were ovario-hysterectomised on days 5, 15, 25, 35, 45 and 60-80 after ovulation. Canine-specific primers for IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, TNFalpha, IFNgamma and TGFbeta1 were used. Positive and negative controls were included in all tests. Adequate expression was confirmed by sequencing selective samples of positive PCR products. The expression of mRNA for IL-8, IL-10, IL-12, TNF-alpha and TGF-beta1 was detected in all samples at each stage of dioestrus, without any obvious variations indicating a likely modulatory function of these cytokines in differentiation, maintenance or regression of the canine Cl. All tests for the expression of mRNA for IL-4, IL-1beta and IL-2 were negative. More negative than positive results were obtained when testing for the expression of mRNA for IL-6 and IFN-gamma, leading to the conclusion that expression of these two cytokines is at a low level, and no conclusion can be drawn as to their involvement in control of Cl function.

Regulation of Corpus Luteum-function in the Bitch

Functional lifespan of the corpus luteum (CL) in non-pregnant dogs exceeds that of pregnant animals and may last for more than 80 days. Prolactin and LH act luteotropic, however, luteolytic mechanisms are poorly understood. Other than in life stock there is no uterine luteolysine and it was postulated that local paracrine/autocrine mechanisms might play a major role. In following this hypothesis the present investigations have clearly demonstrated that up-regulation of prostaglandin synthesis in the CL as indicated by the expression of cyclo-oxygenase II occurs with its formation and not regression, pointing towards a luteotropic rather than luteolytic action. Throughout dioestrus luteal and other cells of the CL express the oestrogen (ERalpha) and progesterone receptor (PR). While ERalpha expression was not cycle-related, PR concentrations were high in the early and late-luteal phase and a regulatory role of both steroids on CL-function is assumed. As in other species also in the dog the immune system seems to participate in the mechanisms regulating CL-function as an increased presence of lymphocytes within the CL could be detected at the beginning [CD4- CD8-, major histocompatibility complex (MHC)II-antigen expressing cells] and during the latter half of dioestrus (CD8- and MHCII-antigen expressing cells). Thus, leucocyte-derived cytokines may be important and the expression of the mRNA for interleukin (IL)8, IL10, IL12, tumour necrosis factor (TNF)alpha and transforming growth factor (TGF) beta1 was observed throughout dioestrus. Electron microscopy confirmed the slow process of luteolysis; first distinct signs of degeneration were seen on day 60, accompanied by some apoptotic events. From these data it is concluded that luteal regression as monitored by the gradual decrease of systemic progesterone concentrations in the dog is not an actively regulated but rather a permissive process. Immune-mediated events may play a key role. Changes in the vascular supply, as indicated by the expression of endoglin, seem to be of lower importance.

Regulation of intraluteal production of prostaglandins

There is clear evidence for intraluteal production of prostaglandins (PGs) in numerous species and under a variety of experimental conditions. In general, secretion of PGs appears to be elevated in the early corpus luteum (CL) and during the period of luteolysis. Regulation of intraluteal PG production is regulated by a variety of factors. An autoamplification pathway in which PGF-2alpha stimulates intraluteal production of PGF-2alpha has been identified in a number of species. The mechanisms underlying this autoamplification pathway appear to differ by species with expression of Cyclooxygenase-2 (Cox-2) and activity of phospholipase A2 acting as important physiological control points. In addition, a number of other responses that are induced by PGF-2alpha (decreased luteal progesterone, increased endothelin-1, increased cytokines) also have been found to increase intraluteal PGF-2alpha production. Thus, regulation of intraluteal PG production may serve to initiate or amplify physiological signals to the CL and may be important in specific aspects of luteal physiology particularly during luteal regression.

Interleukin-1beta in the functional and structural luteolysis. Relationship with the nitric oxide system

The aim of the present report was to investigate the in vitro effect of interleukin-1beta(IL-1beta) on corpus luteum (CL) function and some aspects of this mechanism involved. Ovarian rat dispersates from mid-luteal phase were exposed to different doses of IL-1beta (1, 10, 20 ng/ml). Meanwhile 1, 10 and 20 ng/ml of IL-1beta decreased progesterone (P4) production, only the highest doses of IL-1beta increased prostaglandin F2alpha (PGF2alpha) levels. To investigate the possible relationship between PGs production and P4 synthesis, we incubated together IL-1beta (20 ng/ml) and indomethacin (0.1 mM) a potent inhibitor of cyclooxygenase pathway. We found that P4 inhibition induced by IL-1beta was completely prevented by addition of indomethacin. On the other hand, when ovarian rat tissue were exposed at 20 ng/ml of IL-1beta (doses that affected both PGF2alpha and P4 production) the nitric oxide synthase (NOS) activity was augmented. Moreover, IL-1beta effects on PGF2alpha and P4 levels were impaired when a NOS inhibitor N(W)-nitro- L -arginine methyl ester (L-NAME, 600 microM) was added to the incubation media. These data demonstrate that: (i) at the tested doses (1-20 ng/ml), IL-1beta is involved in CL function through the diminution of P4 production of whole ovarian dispersate culture; (ii) at the highest doses assayed (20 ng/ml) IL-1beta increased PGF2alpha production; (iii) at these doses, IL-1beta decreased P4 production by means of a cyclooxygenase pathway and (iv) the NO system would be a key intermediary second messenger in the IL-1beta actions.

Maternal depression and risk for postpartum complications: role of prenatal corticotropin-releasing hormone and interleukin-1 receptor antagonist

The pregnancies of 58 healthy adolescents (ages 13 to 19 years) were followed to examine links between symptoms of depression, corticotropin-releasing hormone (CRH), interleukin-1 beta, (IL-1 beta), and IL-1 receptor antagonist (IL-1ra) as possible predictors of maternal and infant outcomes. Maternal psychological adjustment and medical complications during gestation, labor, delivery, and the postpartum period were monitored. Plasma samples collected during gestation were assayed for CRH, IL-1 beta, and IL-1ra. During gestation, symptoms of maternal depression were found to be associated with lower levels of CRH; lower levels of CRH were associated with lower levels of IL-1ra. In addition, lower levels of IL-1ra predicted higher rates of maternal complications after childbirth. IL-1 beta, detected in only 4 mothers, was not associated with any predictor or outcome measures. During gestation, CRH may induce circulating cytokine inhibitors without significantly affecting cytokine production or synthesis. Maternal symptoms of depression during gestation may attenuate the association between CRH and IL-1ra.