Glucocorticoids inhibit placental cytokines from cultured normal and preeclamptic placental explants

Effects of prenatal opioid and alcohol exposures on immune and serotonin factors in human placenta

PURPOSE

Opioids and alcohol impact critical serotonin (5-HT) function in the developing placenta and fetus through the actions of immune proinflammatory factors. Yet, possible convergent effects of opioids and alcohol on human placental toll-like receptor 4 (TLR4) activation and subsequent 5-HT homeostasis remain entirely unknown. The purpose of this study was to examine the effect of prenatal exposure to opioids with or without prenatal alcohol exposure (PAE) on the expression of key placental immune and serotonin signaling factors in human placental tissue obtained from a well-characterized prospective cohort.

METHODS

Data were collected from a subset of participants enrolled in the prospective pre-birth Ethanol, Neurodevelopment, Infant, and Child Health (ENRICH-1) cohort. Women were recruited and classified into four study groups: 1) PAE (n = 20); 2) those taking medications for opioid use disorder (MOUD; n = 28), 3) concurrent PAE and MOUD (n = 20); and 4) controls (HC; n = 20) based on prospective, repeated self-report, and biomarker analysis. Placenta samples underwent tissue processing to identify mRNA for TLR4, nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), serotonin transporter (SERT), tryptophan hydroxylase (TPH1), indoleamine 2,3-Dioxygenase 1 (IDO) as well as protein concentrations of TLR4, IL-1β, TNF-α, SERT. To consider the association between study group and mRNA/protein expression of our targets, multivariable regression models were developed with inclusion of a priori selected covariates.

RESULTS

There was a significant negative association between PAE and SERT mRNA (β = -0.01; p < 0.01) and a positive association with TPH1 mRNA expression (β = 0.78; p < 0.05). In addition, there was a negative association between MOUD and TNF-α protein expression (β = -0.12; p < 0.05).

CONCLUSIONS

This study provides the first evidence that PAE may inhibit SERT expression while simultaneously promoting increased TPH1 protein expression in human placenta. This may result in increased 5-HT in fetal circulation known to affect neurodevelopment. Our data suggest that opioids and alcohol may disturb the bidirectional, dynamic interaction between the placental immune and serotonin system. Given the implication for brain development and health across the life-span further investigation of these critical mechanisms in well-defined cohorts is required.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.

Adhering maternal platelets can contribute to the cytokine and chemokine cocktail released by human first trimester villous placenta

Placental villous explant culture has been increasingly recognized as suitable model to study secretion of inflammatory and immune modulating factors by human placenta. Most of these factors likely derive from the syncytiotrophoblast, whereas extraplacental sources such as maternal peripheral blood cells are rarely considered. Due to their small size and absence of a nucleus, platelets adhering to perivillous fibrinoid of normal placenta are frequently ignored in routine immunohistochemistry. Here we demonstrate adhering maternal platelets on first trimester placental villi after explant culture and point out that platelet-derived factors must be considered when analyzing the inflammatory secretion profile of human placenta.

Peri-intraventricular hemorrhage and oxidative and inflammatory stress markers in very-low birth weight newborns

OBJECTIVES

To evaluate the association between oxidative and inflammatory stress markers with peri-intraventricular hemorrhage (PIVH) in very-low birth weight newborns.

METHODS

This was a prospective study conducted in a level III neonatal unit. Basal and stimulated reactive oxygen intermediates (ROIs), reduced glutathione (GSH), and interleukin-6 (IL-6) levels were measured in umbilical cord blood. Newborns underwent serial ultrasound at the bedside, at 6, 12, 24, and 72hours of life and at seven days for the diagnosis of PIVH, classified as grades I to IV. Two groups were assessed, those with and without PIVH; maternal and neonatal control variables were used for comparison. Univariate and multiple regression analyses were applied.

RESULTS

A total of 125 newborns were assessed. PIVH incidence rate was 12.0%. In the univariate analysis, basal ROI, the use of two or more doses of corticosteroids, birth weight<1,000g, ventilatory support use, and SNAPPE II value ≥ 22 were significantly associated with PIVH. However, in the multivariate analysis, only antenatal steroid use was independently associated with the disease (OR 0,194; 95% CI: 0,048 to 0,773; p=0,02).

CONCLUSION

ROI, GSH, and IL-6 levels were not associated with the occurrence of PIVH in very-low birth weight infants.

The presence of maternal asthma during pregnancy suppresses the placental pro-inflammatory response to an immune challenge in vitro

The mechanisms that contribute to adverse outcomes for the neonate in pregnancies complicated by asthma may be mediated via changes in placental immune function. This study was designed to determine whether the presence of maternal asthma during pregnancy alters the placental pro-inflammatory immune response in vitro. A prospective cohort study of women with asthma (n = 22) and control (n = 11) subjects had placentae collected immediately after delivery. Placental explants were exposed to an immune challenge, lipopolysaccharide, in the presence and absence of cortisol in vitro. Cytokines, glucocorticoid receptor α (GR α) and p38 MAPK protein were measured. Placentae of control pregnancies had an increase in pro-inflammatory cytokine production over a 24 h period. Placentae from pregnancies complicated by maternal asthma had a reduced pro-inflammatory cytokine response to an immune challenge relative to the controls especially in relation to the production of interleukin (IL)-1β and TNFα regardless of fetal sex. Cortisol inhibition of placental cytokine production was dependent on timing of exposure, fetal sex and presence and absence of asthma. GRα and p38 MAPK protein expression did not appear to contribute to differences in response to endotoxin or cortisol. Maternal asthma during pregnancy induces a hyposensitive inflammatory state in the placenta which is regulated by cortisol in a sexually dimorphic manner.

Alpha7 nicotinic receptors as novel therapeutic targets for inflammation-based diseases

In recent years the etiopathology of a number of debilitating diseases such as type 2 diabetes, arthritis, atherosclerosis, psoriasis, asthma, cystic fibrosis, sepsis, and ulcerative colitis has increasingly been linked to runaway cytokine-mediated inflammation. Cytokine-based therapeutic agents play a major role in the treatment of these diseases. However, the temporospatial changes in various cytokines are still poorly understood and attempts to date have focused on the inhibition of specific cytokines such as TNF-α. As an alternative approach, a number of preclinical studies have confirmed the therapeutic potential of targeting alpha7 nicotinic acetylcholine receptor-mediated anti-inflammatory effects through modulation of proinflammatory cytokines. This "cholinergic anti-inflammatory pathway" modulates the immune system through cholinergic mechanisms that act on alpha7 receptors expressed on macrophages and immune cells. If the preclinical findings translate into human efficacy this approach could potentially provide new therapies for treating a broad array of intractable diseases and conditions with inflammatory components.

Antiglaucoma drug GLC756 and its effect on cellular cAMP and tumor necrosis factor alpha release in vitro of activated human monocytic leukemia cells

PURPOSE

GLC756, a putative antiglaucoma drug with dopamine D(2) agonist and D(1) antagonist properties, significantly decreases tumor necrosis factor alpha (TNF-alpha) levels in lipopolysaccharide (LPS)-induced rats. The present study describes the effects of GLC756 on cellular adenosine 3', 5'-cyclic monophosphate (cAMP) in relation to TNF-alpha production on LPS-stimulated human acute monocytic leukemia cells.

METHODS

A human peripheral blood acute monocytic leukemia cell line (THP-1) was activated via LPS. THP-1 cells were incubated with GLC756 or betamethasone (positive control) at concentrations of 1, 10, and 30 microM. The TNF-alpha concentration in supernatant and cAMP levels in cellular extract were measured by enzyme-linked immunosorbent assay 0,1, 2.5, 4.5, 7, and 24 h post-activation.

RESULTS

Compared with LPS controls, both GLC756 at 30 muM and betamethasone at > or =1 microM had a significant inhibitory effect on TNF-alpha release from THP-1 cells 2.5 to 24 h post-activation. Parallel to the TNF-alpha decrease, GLC756 induced significant increases of cellular cAMP 2.5 and 7 h post-activation. Betamethasone had no effect on the cellular cAMP level.

CONCLUSION

Intracellular signaling pathway leading to inhibition of the production of the proinflammatory cytokine TNF-alpha after GLC756 treatment might be mediated through the second messenger cAMP.

Placental cytokine expression covaries with maternal asthma severity and fetal sex

In the presence of maternal asthma, we have previously reported reduced placental blood flow, decreased cortisol metabolism, and reductions in fetal growth in response to maternal asthma and asthma exacerbations. We have proposed that these changes in placental function and fetal development may be related to activation of proinflammatory pathways in the placenta in response to maternal asthma. In the present study, we examined the influence of maternal asthma severity, inhaled glucocorticoid treatment, maternal cigarette use, placental macrophage numbers, and fetal sex on placental cytokine mRNA expression from a prospective cohort study of pregnant women with and without asthma. Placental expression of TNF-alpha, IL-1beta, IL-6, IL-8, and IL-5 mRNA were all increased significantly in placentae of female fetuses whose mothers had mild asthma, but no changes were observed in placentae of male fetuses. The proinflammatory cytokines TNF-alpha, IL-1beta, and IL-6 were negatively correlated with female cord blood cortisol, but there were no such correlations in placentae from males. Multivariate analysis indicated the strongest predictor of both cytokine mRNA expression in the placenta and birth weight was fetal cortisol but only in females. Placental cytokine mRNA levels were not significantly altered by inhaled glucocorticoid use, placental macrophage numbers, cigarette use, moderate-severe asthma, or male sex. These data suggest that placental basal cytokine mRNA expression is sex specifically regulated in pregnancies complicated by asthma, and interestingly these changes are more prevalent in mild rather than severe asthma.

Prednisolone suppresses NK cell cytotoxicity in vitro in women with a history of infertility and elevated NK cell cytotoxicity

PROBLEM

To evaluate the effect of prednisolone on NK cell cytotoxicity in vitro environment and also to compare the effect of prednisolone versus immunoglobulin-G (IVIG) on NK cell cytotoxicity using in vitro co-culture with K562 cells.

METHOD OF STUDY

The following is a prospective observational study, between August 2006 and February 2007, was carried out on blood samples from 110 patients with a history of recurrent miscarriage or recurrent failed implantation. Peripheral blood mononuclear cells containing NK cells were isolated and co-cultured with target cell K562 in three different effector-to-target (E:T) ratios of 50:1, 25:1 and 12.5:1. Prednisolone or IVIG was then added to the tube with E:T ratio of 50:1 to assess suppressive effect. The percentage killing was recorded and statistical analysis performed using Student's t-test.

RESULTS

In the experiments with an E:T ratio of 50:1 without prednisolone or IVIG in the co-culture, the mean target cell killing percentage was 26.4%. In cultures using the same E:T ratio, this killing percentage was significantly reduced in the presence of IVIG (9.9%) or prednisolone (13.6%), (P<0.001 in both analyses). On comparing the reduction in killing percentage of target cells by prednisolone versus IVIG, a slightly lower reduction in the prednisolone co-culture was noted but this was not statistically significant (P>0.05).

CONCLUSION

The results of this study show that prednisolone is able to suppress the cytolytic activity of the NK cell. Prednisolone and IVIG are almost equally effective in suppressing in vitro NK cell cytolytic activity.

Nicotine inhibits cytokine production by placenta cells via NFkappaB: potential role in pregnancy-induced hypertension

Pregnancy-induced hypertension (PIH), also known as preeclampsia, is one of the major causes of maternal and fetal death. While the precise cause of PIH is not known, aberrant cytokine production and placenta participation are considered to be important factors. Gestational cigarette smoking, which is widely accepted to be harmful to both the mother and fetus, is protective against PIH. Based on the antiinflammatory activity of nicotine, the major component of cigarettes, we examined the effect of nicotine and other cholinergic agonists on placental inflammatory responses ex vivo. We observed that nicotine and other cholinergic agonists significantly suppress placenta cytokine production following stimulation. Placenta cells express the alpha7 nicotinic acetylcholine receptor (alpha7nAChR), and using cholinergic antagonists, we demonstrated that the antiinflammatory effect of nicotine and other cholinergic agonists is, in part, mediated through the nAChR pathway. By contrast, cholinergic stimulation had no effect on the expression of soluble fms-like tyrosine kinase (sFlt), an antiangiogenic substance implicated in maternal vascular dysfunction during PIH. Mechanistic studies reveal that cholinergic agonists exert their antiinflammatory effects through the NFkappaB pathway. Taken together, our results suggest that cholinergic agonists, including nicotine, may reduce cytokine production by placenta cells via NFkappaB to protect against PIH.

Control of human trophoblast function

The trophoblast, i.e. the peripheral part of the human conceptus, exerts a crucial role in implantation and placentation. Both processes properly occur as a consequence of an intimate dialogue between fetal and maternal tissues, fulfilled by membrane ligands and receptors, as well as by hormone and local factor release. During blastocyst implantation, generation of distinct trophoblast cell types begins, namely the villous and the extravillous trophoblast, the former of which is devoted to fetal-maternal exchanges and the latter binds the placental body to the uterine wall. Physiological placentation is characterized by the invasion of the uterine spiral arteries by extravillous trophoblast cells arising from anchoring villi. Due to this invasion, the arterial structure is replaced by amorphous fibrinoid material and endovascular trophoblastic cells. This transformation establishes a low-resistance, high-capacity perfusion system from the radial arteries to the intervillous space, in which the villous tree is embedded. The physiology of pregnancy depends upon the orderly progress of structural and functional changes of villous and extravillous trophoblast, whereas a derangement of such processes can lead to different types of complications of varying degrees of gravity, including possible pregnancy loss and maternal life-threatening diseases. In this review we describe the mechanisms which regulate trophoblast differentiation, proliferation, migration and invasiveness, and the alterations in these mechanisms which lead to pathological conditions. Furthermore, based on the growing evidence that proper inflammatory changes and oxidative balance are needed for successful gestation, we explain the mechanisms by which agents able to influence such processes may be useful in the prevention and treatment of pregnancy disorders.

Effect of GLC756, a novel mixed dopamine D1 receptor antagonist and dopamine D2 receptor agonist, on TNF-alpha release in vitro from activated rat mast cells

Tumor necrosis factor-alpha (TNF-alpha) is released from activated mast cells via an IgE-dependent mechanisms, and plays a crucial role in ocular allergic inflammation. This study examined the influence of three antiglaucoma drugs differing in their chemical structure and pharmacological profile (i.e. latanoprost, timolol, GLC756) on TNF-alpha release from activated rat mast cells. A rat basophilic leukemia mast cell line (RBL-2H3) was activated via IgE/anti-IgE. Rat mast cells were incubated with latanoprost, timolol, GLC756 or betamethasone (positive control) at concentrations of 0.1, 1, 10 and 30 microM. TNF-alpha concentration in supernatant was measured by ELISA 5 h post-activation. Compared to controls, the prostaglandin derivative latanoprost and the beta-blocker timolol in the concentration range 0.1-30 microM, had no significant effect on TNF-alpha release from rat mast cells measured 5h after activation. By contrast, the dopaminergic drug GLC756 compared to controls in the concentration range 1-30 microM significantly inhibited TNF-alpha release from activated rat mast cells in a concentration-dependent manner. The positive control betamethasone inhibited TNF-alpha release almost completely at all concentrations tested. In conclusion, the results of this study suggest that latanoprost and timolol do not reduce inflammation triggered by activated mast cells. By contrast, the dopaminergic drug GLC756 inhibited TNF-alpha release from activated mast cells, suggesting an palliative potential of dopaminergic compounds on allergic conjunctivitis in topical glaucoma medication.