The effect of ethanol and nicotine on ER stress in human placental villous explants

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Nicotine increased the GRP78/BiP protein in first trimester and term placental villous explants.

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Nicotine can cause endoplasmic reticulum stress in human placenta.

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Placental villous explants can be isolated from first trimester and term placenta to compare responses to toxic compounds.

Pregnant mothers continue smoking and drinking during pregnancy. To clarify the mechanisms of nicotine and ethanol toxicity during development, we have examined their effects on endoplasmic reticulum (ER) stress in human first trimester and term placental explants. First trimester and term human placental explants were treated with ethanol (2 ‰) or nicotine (15 µM), or their combination. The ER stress markers glucose regulated protein 78 (GRP78/BiP) and inositol requiring enzyme 1 α (IRE1α) were analyzed by immunoblotting. A statistically significant increase (p < 0.05) of GRP78/BiP by nicotine was noted in first trimester placental explants at 48 h, and in term placental explants at 24 h. Ethanol did not change protein expression of GRP78/BiP in either first trimester or term placental explants. IRE1α increased, although not statistically significantly, by all treatments in both first trimester and term placental explants. Thus, regardless of the known structural and functional differences in early and late placenta, both responded very similarly to the toxic compounds studied. These data support our earlier results in BeWo cells (Repo et al., 2014) implicating that nicotine induces ER stress in human placenta and may interfere with placental functions potentially disrupting fetal growth and development.

Impact of bisphenol A (BPA) on cells and tissues at the human materno-fetal interface

Bisphenol A (BPA) is an endocrine disruptor extensively used in the production of polycarbonate plastics and epoxy resins and a component of liquid and food containers. It is a hazard in the prenatal period because of its presence in the placenta, fetal membranes, amniotic fluid, maternal and fetal blood and its ability to cross the placenta and reach the fetus. Estimation of the risk of BPA exposure during in utero life is extremely important in order to prevent complications of pregnancy and fetal growth. This review describes in vitro models of the human materno-fetal interface. It also outlines the effects of BPA at doses indicated as "physiological", namely at the concentrations found in the general population, and at "supraphysiological" and "subphysiological" doses, i.e. above and below the physiological range. This work will help clarify the discrepancies observed in studies on the effects of BPA on human reproduction and pregnancy, and it will be useful for the choice of appropriate in vitro models for future studies aimed at identifying the potential impact of BPA on specific functional processes.

The xenoestrogens, bisphenol A and para-nonylphenol, decrease the expression of the ABCG2 transporter protein in human term placental explant cultures

Many endogenous and xenobiotic compounds are substrates and regulators of human placental ABC transporters. ABCG2 is protecting fetus against foreign chemicals. Environmental xenoestrogens, like bisphenol A (BPA) and p-nonylphenol (p-NP), mimic natural estrogens and can affect hormonal systems. Effects of BPA, p-NP, DES (diethylstilbestrol) and estradiol (E2), on ABCG2 expression were studied using human first trimester and term placental explants. Role of estrogen receptors (ER) in the effects of chemicals was studied by ER antagonist. Term placenta expressed less ABCG2 protein. In term placentas BPA (p < 0.05), p-NP (p < 0.01) and E2 (p < 0.05) decreased the ABCG2 protein expression after 48 h exposure while after 24 h exposure, only E2 decreased the expression (p < 0.05). The chemicals did not affect ABCG2 in first trimester placentas. The ER antagonist affected differently the responses of chemicals. In conclusion, environmental xenoestrogens downregulate placental ABCG2 protein expression depending on gestational age.

First Evidence of Cardiac Stem Cells From the Left Ventricular Apical Tip in Patients With Left Ventricular Assist Device Implantation

BACKGROUND

Recent studies have challenged the dogma that the adult heart is a postmitotic organ and raise the possibility of the existence of resident cardiac stem cells (CSCs). Our study aimed to explore if these CSCs are present in the "ventricular tip" obtained during left ventricular assist device (LVAD) implantation from patients with end-stage heart failure (HF) and the relationship with LV dysfunctional area extent.

METHODS

Four consecutive patients with ischemic cardiomyopathy and end-stage HF submitted to LVAD implantation were studied. The explanted "ventricular tip" was used as a sample of apical myocardial tissue for the pathological examination. Patients underwent clinical and echocardiographic examination, both standard transthoracic echocardiography (TTE) and speckle tracking echocardiography (STE), before LVAD implantation.

RESULTS

All patients presented severe apical dysfunction, with apical akinesis/diskinesis and very low levels of apical longitudinal strain (-3.5 ± 2.9%). Despite this, the presence of CSCs was demonstrated in pathological myocardial samples of "ventricular tip" in all 4 of the patients. It was found to be a mean of 6 c-kit cells in 10 fields magnification 40×.

CONCLUSIONS

Cardiac stem cells can be identified in the LV apical segment of patients who have undergone LVAD implantation despite LV apical fibrosis.

Review: putative roles for the macrophage migratory inhibitory factor at the maternal fetal interface

Complex and dynamic networks of molecules participate in the essential interactions between maternal organism, placenta and fetus in a healthy and successful pregnancy. Macrophage migratory inhibitory factor (MIF) is one of several molecules produced at implantation sites; MIF is mostly expressed by trophoblast cells. This has led to expectations of MIF's relevance as a partner in the maternal/fetal dialog. MIF is known by its biological interactions and functional roles as an activator of innate immunity, regulating subsequent adaptive responses, which include inhibition of migration of mononuclear cells in vitro, antagonism of glucocorticoids, and regulation of expression of Toll-like receptor 4. Beyond roles in the inflammatory response, MIF can interfere with proliferative activities in different cell types, as well as with cell death pathways. This intriguing factor found at the human, porcine, ovine, bovine and rodent maternal-fetal interfaces is present in a time- and spatially-dependent manner, indicating regulatory roles in the process of embryo implantation, placental development, maintenance of pregnancy and birth. Here, we will review MIF participation in placental physiology, including new evidence for a dialog with uterine cells, and a potential role in protection of uterine decidual cells.

Toxicity assessment on trophoblast cells for some environment polluting chemicals and 17β-estradiol

The identification of reproductive toxicants is a major scientific challenge for human health. We investigated the effects of a selected group of environmental polluting chemicals mostly provided with estrogenic activity on the human trophoblast cell lines BeWo and HTR-8/SVneo. Cells were exposed for 24h to various concentrations (from 0.1 pM to 1 mM) of atrazine (ATR), diethylstilbestrol (DES), para-nonylphenol (p-NP), resveratrol (RES) and 17 β-estradiol (E2) and assayed for cell viability and human beta-Chorionic Gonadotropin (β-hCG) secretion. Decrease of cell viability as respect to control, vehicle-treated, cultures was obtained for all chemicals in the concentration range of 1 μM-1 mM in both cell types. A parallel decrease of β-hCG secretion was observed in BeWo cells, at 1 μM-1 mM concentrations, with the only exception of ATR which caused an increase at concentrations up to 1mM. β-hCG release was also unexpectedly inhibited by ATR, DES, p-NP and RES at non-toxic (pM-nM) concentrations. These findings raise concern about the negative, potential effects of various environmental polluting chemicals on pregnancy success and fetal health.

Fine structure of the female reproductive system in a viviparous insect, Glossina morsitans morsitans (Diptera, Glossinidae)

The female reproductive system of the tsetse fly Glossina morsitans morsitans is analysed by scanning electron microscopy (SEM). The study focuses in particular on the choriothete, a peculiar uterine structure involved in the viviparous mode of reproduction of Glossina morsitans morsitans. Under light microscopy, the choriothete appears formed by numerous tongue-like folds projecting towards the uterine lumen and lined by a thin cuticle. SEM analysis highlights for the first time a distinctive new feature that is not visible by traditional histological methods. That is a cuticular covering of the choriothete, which shows numerous thorns in the form of crest-like structures arranged in nearly parallel lines. The role of the choriothete in pregnancy and in larval nourishment is discussed.

Expression and localization of ATP binding cassette transporter A1 (ABCA1) in first trimester and term human placenta

ATP binding cassette transporter A1 (ABCA1) is a membrane transporter which performs cellular efflux of cholesterol and phospholipid. ABCA1's cholesterol transporting role in human placenta appears to be crucial for normal fetal development. Despite the critical importance of cholesterol in fetal development, expression of ABCA1 in the human placenta throughout gestation and its specific cellular localization have not been known yet. We therefore investigated ABCA1 expression in human placenta at first trimester and term by western blot and quantitative real-time PCR (qRT-PCR) analysis. Furthermore, its localization was investigated by immunohistochemistry and confocal microscopy. Expression of ABCA1 did not differ significantly between first trimester and term placenta at both protein and mRNA levels. Immunohistochemical data demonstrated that ABCA1 was widely localized in the villous and extravillous cytotrophoblast as well as in some stromal and endothelial cells. Confocal microscopy imaging data showed that ABCA1 was localized largely at the basolateral and to some extent at the apical side of first trimester villous cytotrophoblast cell membranes. Placental expression of ABCA1 throughout the gestation and its specific cellular localization indicate that this transporter may play an important role in materno-fetal cholesterol transfer.

Evidence for a role of TGF-beta1 in the expression and regulation of alpha-SMA in fetal growth restricted placentae

There is evidence that alpha-smooth muscle actin (alpha-SMA) is a protein that plays a pivotal role in the production of contractile forces and it is induced by transforming growth factor-beta1 (TGF-beta1). We have analysed the expression of alpha-SMA, TGF-beta1, its receptor RI and the activator phospho-Smad2 in (a) fetal growth restriction pre-eclamptic placentae characterised by early onset and absence of end diastolic velocities in the umbilical arteries (FGR-AED) and (b) control placentae accurately matched for gestational age. The study was performed by immunohistochemical, quantitative Western blotting, ELISA, RT-PCR and in vitro analyses. We found that TGF-beta1 stimulates alpha-SMA production in chorionic villi cultured in vitro. In addition, we observed that in vivo TGF-beta1 concentration is significantly higher in FGR-AED placental samples than in control placentae and that this growth factor could have a paracrine action on villous stroma myofibroblasts expressing TGF-beta1 receptors and phospho-Smad2. Indeed, we report that alpha-SMA undergoes a redistribution in FGR-AED placental villous tree, i.e. we show that alpha-SMA is enhanced in medium and small stem villi and significantly decreased in the peripheral villi. Our data allow us to consider TGF-beta1 and alpha-SMA as key molecules related to FGR-AED placental villous tree phenotypic changes responsible for increased impedance to blood flow observable in this pathology.

Expression of macrophage migration inhibitory factor in diffuse systemic sclerosis

OBJECTIVE

To evaluate whether, in patients with the diffuse form of systemic sclerosis (dSSc), macrophage migration inhibitory factor (MIF) production is dysregulated.

METHODS

10 patients with dSSc and 10 healthy controls, matched for age and sex, were studied. MIF expression was evaluated by immunohistochemistry on formalin fixed skin biopsies of patients with dSSc and controls. MIF levels were assayed in the sera and in the supernatants of skin cultured fibroblasts by a colorimetric sandwich enzyme linked immunosorbent assay (ELISA). MIF concentrations in culture medium samples and in serum samples were compared by Student's two tailed t test for unpaired data.

RESULTS

Anti-MIF antibody immunostained the basal and mainly suprabasal keratinocytes. Small perivascular clusters of infiltrating mononuclear cells were positive; scattered spindle fibroblast-like cells were immunostained in superficial and deep dermal layers. The serum concentrations of MIF in patients with dSSc (mean (SD) 10705.6 (9311) pg/ml) were significantly higher than in controls (2157.5 (1288.6) pg/ml; p=0.011); MIF levels from dSSc fibroblast cultures (mean (SD) 1.74 (0.16) ng/2 x 10(5) cells) were also significantly higher than in controls (0.6 (0.2) ng/2 x 10(5) cells; p=0.008).

CONCLUSION

These results suggest that MIF may be involved in the amplifying proinflammatory loop leading to scleroderma tissue remodelling.

Interferons and their receptors in human papillomavirus lesions of the uterine cervix

PURPOSE OF INVESTIGATION

In this study we analyzed the immunohistochemical expression of specific types of interferon (IFN) in human papillomavirus (HPV) associated cervical lesions.

METHODS

Reactivity to anti-IFN-alpha,-beta and -gamma and to anti-IFN-alpha/beta- and gamma-receptors was tested in 33 cervical punch biopsies from 24 HPV-infected women and nine healthy controls. The HPV-infected cases were subdivided into low-risk and high-risk groups, according to the known "oncogenic" potential of the HPV-types detected by PCR.

RESULTS

Cervical epithelium and stroma in HPV-negative as well as low-risk HPV-positive samples were diffusely stained by anti IFN-alpha, beta and gamma antibodies. In contrast, a significantly lower percentage of high-risk HPV-infected tissues was immunoreactive to IFN-beta in the stroma and IFN-gamma in the epithelium. There were no relevant differences between control and HPV cases in the expression of IFN-receptors.

CONCLUSION

We show that a decreased production of some specific classes of IFN is associated with high-risk-type HPV lesions suggesting an important role of IFN distribution patterns in the pathogenesis of HPV lesions.

Macrophage migration inhibitory factor in human pregnancy and labor

PROBLEM

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in reproduction. Presently there is no information on the possible involvement of MIF in the onset of labor.

METHODS

Macrophage migration inhibitory factor was assayed, by enzyme-linked immunosorbent assay (ELISA), in maternal serum (MS) and amniotic fluid (AF) both, at midtrimester and at term, as well as in cord serum (CS) at birth. Extraembryonic membranes were analyzed by immunohistochemistry.

RESULTS

Amniotic fluid MIF concentrations were significantly higher at term (median 62.10 ng/mL) than at midtrimester (median 20.07 ng/mL) and reached a peak in term labor (median 258.80 ng/mL). The AF/MS ratio varied from a median of 4.34 at midtrimester and 33.7 at term labor. The MS/CS ratio was 0.4. Migration inhibitory factor immunoreactivity was found in different cell layers of the extraembryonic membranes.

CONCLUSIONS

The increased secretion of MIF in AF at term, particularly at term labor, suggests that MIF contributes to the inflammatory events leading to labor.

Evidence of H beta 58, a gene involved in mammalian placental development, in the three-toed skink, Chalcides chalcides (Squamata: Scincidae), a viviparous placentotrophic reptile

The H beta 58 gene, whose disruption in mice causes reabsorption of the embryo at 9.5 days post-conception, is believed to be essential for development of the placenta. Although the H beta 58 gene is well conserved in some Amniota, nothing is known about its presence in reptiles, some species of which have developed a chorioallantoic placenta. In this work, we investigated the expression of H beta 58 mRNA and protein in the three-toed skink, Chalcides chalcides. H beta 58 protein expression was found in the uterine epithelium beginning from the peri-ovulatory stage. However, it increased strongly at the moment of placental formation, when a high level of expression of mRNA and protein was also observed in the extra-embryonic membranes. The expression of H beta 58 mRNA and protein was maintained, although to a lesser degree, in the placenta during late pregnancy. It was also present in the early embryo. Finally, cloning and sequencing of a gene fragment revealed strong homology of the reptile gene with that of mammals. The high degree of conservation of the gene in amniote vertebrates and its presence in a viviparous squamate reptile (as in mammals) indicates an important role of this gene in the chorioallantoic placenta formation and development.

Macrophage migration inhibitory factor in the human endometrium: expression and localization during the menstrual cycle and early pregnancy

Macrophage migration inhibitory factor (MIF) was discovered as an activated T-lymphocyte-derived protein that inhibits the random migration of macrophages in vitro. Subsequently, knowledge of the physiological actions of MIF was extended to include its role as a proinflammatory cytokine that affects several functions of macrophages and lymphocytes. Previous reports have suggested an involvement of MIF in reproduction. However, no data are currently available on the presence of this cytokine in the human endometrium. In this study, the expression and tissue localization of MIF was evaluated in specimens of cycling endometrium, first trimester placenta bed biopsy, and isolated endometrial glands by Western blot analysis, immunohistochemistry, ELISA, and reverse transcription-polymerase chain reaction. The results demonstrated that MIF is expressed in human endometrium across the menstrual cycle and in early pregnancy. Immunohistochemical localization identified the protein in glandular epithelium, in stromal and predecidualized stromal cells of cycling endometrium, as well as in the decidua of first-trimester placenta. The proinflammatory features and specific actions of MIF on lymphoid cells suggest its potential involvement in several aspects of endometrial physiology.

Progestin regulation of 11beta-hydroxysteroid dehydrogenase expression in T-47D human breast cancer cells

This study examined the enzymatic characteristics and steroid regulation of the glucocorticoid-metabolizing enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) in the human breast cancer cell line T-47D. In cell homogenates, exogenous NAD significantly increased the conversion of corticosterone to 11-dehydrocorticosterone, while NADP was ineffective. There was no conversion of 11-dehydrocorticosterone to corticosterone either with NADH or NADPH demonstrating the lack of reductase activity. In keeping with these results, RT-PCR analysis indicated a mRNA for 11beta-HSD2 in T-47D cells, while 11beta-HSD1 mRNA levels were undetectable. In T-47D cells treated for 24 h with medroxyprogesterone acetate (MPA), 11beta-HSD catalytic activity was elevated 11-fold, while estrone (E(1)), estradiol (E(2)) and the synthetic glucocorticoid dexamethasone (DEX) were ineffective. The antiprogestin mifepristone (RU486) acted as a pure antagonist of the progestin-enhanced 11beta-HSD activity, but did not exert any agonistic effects of its own. In addition, RT-PCR analysis demonstrated that MPA was a potent inducer of 11beta-HSD2 gene expression, increasing the steady-state levels of 11beta-HSD2 mRNA. Taken together, these results demonstrate that 11beta-HSD2 is the 11beta-HSD isoform expressed by T-47D cells under steady-state conditions and suggest the existence of a previously undocumented mechanism of action of progestins in breast cancer cells.

Expression of macrophage migration inhibitory factor transcript and protein by first-trimester human trophoblasts

Macrophage migration inhibitory factor (MIF) was originally identified for its capacity to inhibit the random migration of macrophages in vitro. To date, the role of MIF as a pro-inflammatory cytokine, pituitary hormone, and counter-regulator of glucocorticoid action on the immune response is commonly recognized. Although recent studies suggest an involvement of MIF in reproduction, no data exist on the expression of this cytokine in early human pregnancy. In this study, we evaluated the presence of MIF protein and mRNA in specimens of chorionic villi from first-trimester human placenta. Tissues were obtained at 6-10 wk of gestation and analyzed by Western blotting, reverse transcription-polymerase chain reaction, and immunohistochemistry. Our results demonstrate that human villous tissue is a novel site of MIF synthesis. In addition, immunohistochemical analysis identified MIF protein in the cytotrophoblasts of both the inner layer of villi and in the trophoblastic cell islands. We speculate that in view of its proinflammatory features, MIF might play a critical role in human implantation and in early embryonic development.

Endocrine activity of the corpus luteum and placenta during pregnancy in Chalcides chalcides (Reptilia, Squamata)

The structure of the corpus luteum and the steroidogenic activity of the corpus luteum and placenta in the viviparous reptile Chalcides chalcides have been investigated. The corpus luteum has a compact structure, almost without internal vascularized connective septa. It begins to degenerate after the middle of pregnancy, when plasma progesterone (P) remains high. The sections of the corpora lutea taken during early pregnancy showed an intense 3beta-HSDH reaction, whereas the sections taken in late pregnancy gave weak reactions localized exclusively in the peripheral luteal cells. In contrast, sections of placentae taken at the beginning and in the middle of pregnancy always gave negative 3beta-HSDH reactions, whereas those of late pregnancy were always strongly positive, localized in the maternal component of the placenta. In vitro, the corpora lutea from early pregnancy secreted significant amounts of P, whereas appreciable amounts of P were not detected in incubates of early pregnancy placentae. Near the time of delivery, P levels decreased in the culture medium of the corpora lutea, but increased in that of the placentae. The addition of pregnenolone (a precursor of P biosynthesis) to the culture medium caused an increase in the luteal and placental P levels, whereas the addition of trilostane (an inhibitor of 3beta-HSDH) reduced them. The placenta of C. chalcides is suggested to have an endocrine function and to replace the corpus luteum in the production of P when the gland degenerates in late pregnancy.

Identification of critical residues of staphylococcal enterotoxin B for lymphomonocyte proliferation and cytokine production

Superantigens bind to major histocompatibility complex class II molecules and stimulate large numbers of T cells expressing particular Vbeta elements of the T-cell receptor. Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that causes food poisoning and toxic-shock syndrome. The toxicity of SEB is thought to be mediated by T-cell stimulation and cytokine production. Different regions of the SEB molecule are important for mitogenic activity. To identify critical residues of SEB in the region 124-1 54, which competitively inhibits the mitogenic activity of the toxin, we used the synthetic peptide approach and alanine scanning mutagenesis as a probe. We synthesized eight peptides with alanine replacement of all residues in the SEB sequence 131-138 and tested them for the capacity to inhibit both SEB-induced proliferation of human lymphomonocytes and the production of tumor necrosis factor alpha and interferon gamma. Mutation to alanine of the residue Thr 133 improved the inhibition of SEB-induced proliferation and cytokine production, whereas the substitution of Ser 131 also increased the inhibition, albeit to a lesser degree. The peptide obtained by substitution of Val 136 with alanine was unable to inhibit SEB-induced proliferation and cytokine production, suggesting that Val 136 is essential for mitogenic activity. Thus hydrophobic interactions apparently are very important for mitogenic activity. The identification of critical residues in this active site in the SEB and the computer modeling based on crystal X-ray data contribute to a better understanding of the molecular mechanism of the superantigen and may be useful for therapeutical applications.

11Beta-hydroxysteroid dehydrogenase expression in first trimester human trophoblasts

This study evaluated the levels and the enzymatic characteristics of 11beta-hydroxysteroid dehydrogenase activity (11beta-HSD) of chorionic villi isolated from first trimester human placenta. The results demonstrated a predominant expression of the NAD-dependent dehydrogenase isoform (11beta-HSD2) over the NADP-dependent oxoreductase (11beta-HSD1). Thus, in tissue homogenates exogenous NAD increased the conversion of corticosterone to 11-dehydrocorticosterone of about 14-fold while NADP was ineffective. There was no conversion of 11-dehydrocorticosterone to corticosterone either with NADH or NADPH demonstrating the lack of reductase activity. In keeping with these results, RT-PCR analysis indicated a mRNA for 11beta-HSD2 in villous tissue while 11beta-HSD1 mRNA levels were undetectable. In addition, immunohistochemical staining localized the 11beta-HSD2 protein to syncytiotrophoblasts and cell columns of the chorionic villi. These results suggest roles for the trophoblast-associated 11beta-HSD2 oxidative activity in modulating the exposure of the embryo to active glucocorticoids in the early gestation and in regulating trophoblasts invasion of the uterine wall.

Extracorporeal photochemotherapy restores Th1/Th2 imbalance in patients with early stage cutaneous T-cell lymphoma

Extracorporeal photochemotherapy (ECP) has been shown to be a potent activator of peripheral blood macrophages because it causes a marked release of macrophage-dependent proinflammatory cytokines, and it is therefore currently considered to be a safe and non-toxic immunomodulatory treatment. On this basis we studied the function of peripheral blood mononuclear cells (PBMC) in eight patients with early stage (Ib) cutaneous T-cell lymphoma (CTCL), before and 1 year after ECP, together with their clinical and histological responses. In particular we evaluated in vitro phytohaemagglutinin (PHA)-stimulated proliferation and production of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) as well as lipopolysaccharide (LPS)-induced production of IL-12. Before treatment we observed that PBMC of patients produced significantly higher levels of IL-4 and lower levels of IFN-gamma and IL-12 than those of healthy control subjects. After 1 year of ECP, IL-4, IFN-gamma and IL-12 production no longer differed from that of control subjects. Moreover, we observed a good clinical result matched by histological response. Our data confirm that early-stage CTCL patients show a predominantly type-2 immune response that might be responsible for several immunological abnormalities found in this disease. We have demonstrated that ECP reverses the T-helper type 1/T-helper type 2 (Th1/Th2) imbalance and may therefore be considered an efficient biological response modifier.

Cytokines in mammalian reproduction and speculation about their possible involvement in nonmammalian viviparity

In recent years, the secretion of immunoregulatory factors (cytokines) at the maternofetal interface in mammals has been widely documented. Although cytokine production seems to be a specific phenomenon in mammalian reproduction, the specific roles of these substances in different species are still not clear. However, a balance of different cytokine activities appears to be crucial for regulation of the establishment and survival of the semiallogeneic embryo in maternal tissues. The apparent immunological role of placental cytokines in the mechanisms of implantation and embryonic development in mammals has raised the question of whether cytokines are also involved in the reproduction of nonmammalian vertebrates. Our studies have shown that the production of cytokines by the maternofetal unit is not limited to mammalian species, but that interleukin-1 (IL-1)alpha, IL-1beta, and transforming growth factor-beta (TGF-beta) are secreted by the placenta of a viviparous squamate reptile, Chalcides chalcides. Our finding of this parallelism between reptilian and mammalian reproduction suggests that immunological mechanisms, possibly mediated by the secretion of cytokines, played an important role in the evolution of viviparity.

Distribution of type-I interferon-receptors in human first trimester and term placental tissues and on isolated trophoblast cells

PROBLEM

Type-I interferon (IFN) is the protein recognizing pregnancy in ruminants. Although IFN is secreted in early pregnancy, its role is not still clear in other species. Like other cytokines, IFN exerts its biological functions through specific membrane receptors. We have investigated the potential action of IFN in human pregnancy by studying the distribution of the receptors in the human placenta.

METHOD

Reactivity to monoclonal antibodies (mAbs) to the type-I IFN-receptor (R) was analyzed by immunohistochemistry in human placental tissues and in cytospins of first trimester trophoblast cells.

RESULTS

Type-I IFN-R immunoreactivity was observed mostly in first trimester villous cytotrophoblasts and in the cytotrophoblast cell columns. Trophoblast in the decidua, the epithelium of the uterine glands, and most of the isolated trophoblast cells were also immunoreactive.

CONCLUSION

The expression of type-I IFN-R in the highly proliferating and migrating trophoblast suggests that this cytokine has a role in trophoblast growth and invasion.

Pulmonary catabolism of interleukin 6 evaluated by lung perfusion of normal and smoker rats

Cytokines such as interleukin 6 are involved in the pulmonary inflammation arising as a result of smoking. By use of isolated and perfused lung preparations we have evaluated the role of the lungs in the catabolism of human recombinant interleukin 6 both in normal rats and in rats subjected to an acute cigarette smoking episode. When interleukin 6 was incorporated into the lung perfusion medium, neither control nor smoke-exposed rat lungs cleared the cytokine and only 0.1 +/- 0.2% of the total dose was recovered in the bronchoalveolar lavage fluid. When, on the other hand, the same amount of interleukin 6 was instilled into the bronchoalveolar tree, concentrations of the cytokine in the perfusate increased progressively so that after 3 h up to 70.1 +/- 9.8% and 40.9 +/- 22.5% of the administered dose, as measured by immunoenzymatic test, had been transferred from the bronchial lumen to the perfusion medium of either control or smoker rat lungs, respectively, indicating significantly (P < or = 0.05) different behaviour of the cytokine in the two experimental groups. Total recoveries of the administered interleukin 6 evaluated in smoke-exposed rat lungs were 55.3 +/- 23.2%, significantly lower than those for control rat lungs (83.9 +/- 11%). Determination of biological activity gave values always lower than those measured by immunoenzymatic test, indicating loss of biological activity during the transalveolar transit. It appears that the transfer of interleukin 6, especially in smokers, is almost exclusively unidirectional, from the alveolar space to the plasmatic pool with degradation during the transalveolar passage.

Pharmacokinetics and catabolism of tumor necrosis factor-alpha in rat lungs

The role of the lungs in the catabolism of tumor necrosis factor alpha (TNF-alpha) either in normal rats, or in rats subjected to an acute cigarette smoking episode has been evaluated by using isolated and perfused lung preparations. After administration of TNF-alpha into the lung perfusion medium, there was no clearance of the cytokine in both control and smoker rat lungs and only 0.2 +/- 0.1% of the administered dose was recovered in the bronchoalveolar lavage fluid. When TNF-alpha was instilled into the bronchoalveolar tree, concentrations of the cytokine in the perfusate increased progressively so that after 3 h up to 68.8 +/- 8% and 52.7 +/- 11.4% of the administered dose had been transferred from the bronchial lumen to the perfusion medium of either control or smoker rat lungs, respectively, the latter values being significantly lower (p < or = 0.05) than those obtained in control lungs. Moreover, total recoveries of TNF-alpha evaluated in smoker rat lungs (65.5 +/- 10.2%) were also significantly lower than those observed in control rat lungs (82.8 +/- 7.1%). In conclusion, it appears that transfer of TNF-alpha is almost exclusively unidirectional, from the alveolar space to the plasma pool with partial degradation during the transalveolar passage. These results may be useful when attempting to deliver TNF-alpha by aerosol.

Cytokines in the viviparous reproduction of squamate reptiles: interleukin-1 alpha (IL-1 alpha) and IL-1 beta in placental structures of a skink

Placental viviparity is known in many species of squamate reptiles. Among these, some scincids have developed an epithelio-chorial chorio-allantoic placenta which in the structure of its central ridged zone is similar to those of certain therian mammalian species. A broad range of immunoregulatory peptides, cytokines, has been identified at the maternofetal interface of several species of mammals, either with invasive or non-invasive types of placenta. Thus we began to study whether interleukin-1, which is considered to play a crucial role in mammalian pregnancy, might also be involved in the viviparity of reptilian species. Placentae of Chalcides chalcides L. were processed by immunohistochemistry and incubated in a culture medium for different times. A very strong immunoreactivity for interleukin-1 alpha (IL-1 alpha) and for interleukin-1 beta (IL-1 beta) was present in the chorial epiblast and in uterine epithelial cells, with varying degree and localization in different periods of pregnancy. IL-1 beta was also released into the medium at different amounts during incubation. In light of the mammalian data, our results suggest that the role of cytokines in pregnancy may represent a significant event in the evolution of placental viviparity.

Pulmonary catabolism of interferon-gamma evaluated by lung perfusion of both normal and smoke-exposed rats

The role of the lungs in the catabolism of rat recombinant interferon-gamma, either in normal rats or in rats subjected to an acute cigarette smoking episode, was evaluated using an isolated and perfused lung preparation. After administration of interferon-gamma into the lung perfusion medium, there was no clearance of the cytokine in either control or smoke-exposed rat lungs, and only 0.1 +/- 0.2% of the total dose was recovered in the bronchoalveolar lavage fluid. When the same amount of interferon-gamma was instilled into the bronchial alveolar tree, concentrations of the cytokine in the perfusate increased progressively so that after 3 h up to 71.2 +/- 4.3 and 62 +/- 5.7% of the administered dose, as measured by ELISA test, had been transferred from the bronchial lumen to the perfusion medium of either control or smoke-exposed rat lungs, respectively, the latter values being significantly lower (p < or = 0.05) than those obtained in control lungs. Moreover, total recoveries of interferon-gamma evaluated in smoke-exposed rat lungs (78.4 +/- 8.6%) were also significantly lower than those observed in control rat lungs (91.4 +/- 11.8%). Biologic activity evaluations on the same samples gave values significantly lower than those obtained using ELISA, indicating a partial loss of biologic activity during transalveolar transit. In conclusion, it appears that the transfer of interferon-gamma is almost exclusively unidirectional from the alveolar space to the plasmatic pool, with partial degradation during transalveolar passage.

Inhibitory effect of melatonin on production of IFN gamma or TNF alpha in peripheral blood mononuclear cells of some blood donors

Melatonin, the main pineal hormone, has been shown to influence many biological functions, including the immune response and cancer growth. The purpose of this study was to examine the effect of melatonin on the production of interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha) by peripheral blood mononuclear cells (PBMC) in culture. Melatonin at physiological concentrations fails to induce production of IFN or TNF by PBMC in culture but causes a dose-related inhibition of production of both cytokines if the PBMC are stimulated with phytohaemagglutinin. This inhibitory effect occurs in only 22% of cases (melatonin-sensitive) but disappears when the cells are stored at 4 degrees C for 4 days. The effect of melatonin appears not to be mediated by opiates nor to be correlated with the age, sex, or blood group of donors, but seems to be influenced by the seasonal time of blood collection. These results provide further evidence for an interaction between melatonin and the immune system and suggest that the effect of melatonin on production of IFN and TNF may be mediated by various factors not yet fully understood.

First trimester human trophoblast expresses both interferon-gamma and interferon-gamma-receptor

Interferon-gamma (IFN-gamma) is a lymphokine, produced by activated T lymphocytes, which plays a key regulatory role in the host immunological responses. In addition, IFN-gamma is expressed by human and porcine trophoblast. As IFN-gamma exerts its biological functions through specific cell surface receptors and a great number of IFN-gamma receptors (IFN-gamma R) have been purified from human placenta, we have examined the relative distribution of IFN-gamma and IFN-gamma R in human placental tissues at different stages of pregnancy. By using immunohistochemical analysis and monoclonal antibodies, it was found that IFN-gamma expression is intense in the first trimester but almost imperceptible at term, whereas the expression of IFN-gamma R is present at both stages of pregnancy. For both lymphokine and receptor, the most intense expression was observed in villous syncytiotrophoblast and in extravillous interstitial trophoblast. From these results it appears that the expression of IFN-gamma R in trophoblast is related to the presence of the lymphokine in the early phase of gestation but not later. On this basis, it can be argued that IFN-gamma exerts its functional role via an autocrine and/or a paracrine loop mainly during the first trimester.

Studies on the biological effects of ozone: 4. Cytokine production and glutathione levels in human erythrocytes

We have investigated the effect of various concentrations of ozone on human blood aiming to correlate the production of cytokines with depletion of reduced glutathione and hemolysis. As erythrocytes constitute the bulk of blood cells and represent the main target of ozone they have been taken as a useful marker of its oxidative activity. It appears that a transient exposure (30 sec) of blood of up to 78 micrograms ozone per ml of blood does not depress the production of cytokines even though there is a slight increase of hemolysis and a small decrease of intracellular reduced glutathione. In contrast either a constant (up to 30 sec) exposure to an ozone flux or a high ozone concentration (108 micrograms/ml) markedly decreases reduced glutathione levels and depresses cytokine production.

Studies on the biological effects of ozone: 5. Evaluation of immunological parameters and tolerability in normal volunteers receiving ambulatory autohaemotherapy

Autohaemotherapy, after a bland treatment ex vivo of blood with ozone, is a fairly unknown medical procedure claimed to have therapeutic value in viral diseases and neoplasms. Having already shown that ozone acts as a mild inducer of cytokines, we have undertaken an investigation in normal rabbits and in normal volunteers aiming to evaluate eventual changes of some cytokine levels in plasma as well as of immunological parameters such as the Mx protein, neopterin, beta 2-microglobulin and of some acute-phase proteins after single or repeated autohaemotherapy. We have also evaluated the potential development of of side-effects. This study is the first one to show that autohaemotherapy can activate an immunological marker in normal subjects without procuring any toxic effects.

Studies on the biological effects of ozone: 3. An attempt to define conditions for optimal induction of cytokines

Ozonization of blood, normally carried out with citrated blood, may be fine for the autohemotherapy of ischemic diseases but it may be at a loss when employed in viral diseases or in immunodeficiencies. We have shown that heparin, used as an anticoagulant, with the addition of 5 mM CaCl2 favors production of cytokines by leukocytes with only a modest increase in hemolysis. High plasmatic levels of glucose, glutathione, and ascorbic acid decrease cytokine's yield because these compounds act as antioxidants and quench the inducing activity of ozone. Autohemotherapy with heparinized and Ca(2+)-supplemented blood has not revealed any side effects in volunteers.

Presence of interferon-gamma and interleukin-6 in colostrum of normal women

Colostrum and blood samples were obtained on postpartum day 2 and 3 from 17 lactating, healthy women. After delipidation and molecular sieving fractionation of colostrum, interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) could be readily measured by using a sensitive immunoassay. Antiviral activity could be also measured in some colostrum samples suggesting that interferon was biologically active. On the contrary, corresponding plasma samples showed negligible activity. These results expand previous data showing the presence of IL-1, tumor necrosis factor (TNF-alpha), and IL-6 in normal colostrum and are in line with the concept of a basal cytokine production in physiological conditions. All of these cytokines probably act on the oropharyngeal and gut-associated lymphoid tissue of the newborn and favor the development and maturation of the immune system.

Effect of tuftsin and its retro-inverso analogue on the release of interferon (IFN-gamma) and tumor necrosis factor (TNF-alpha) by human leucocytes

The aim of this work was to demonstrate whether natural tuftsin or a retro-inverso (r.i.) analogue may induce interferon (IFN) and tumor necrosis factor (TNF) in peripheral-blood-mononuclear-cells (PBMC). For this purpose tuftsin or its analogue were added at different molar concentrations to PBMC and the supernatants were tested for IFN and TNF activity. Both cytokines were released after 12 hours incubation with r.i. tuftsin at an optimum concentration of 10(-10) M. Under the same conditions no activity was observed in the presence of natural tuftsin. In comparison to natural tuftsin the stimulatory activity of this tuftsin analogue is likely to be due to its high stability.

Human beta-interferon incubated with muscle homogenate is protected by albumin but not by proteinase inhibitors

The scarce bioavailability of beta-interferon (IFN-beta) after intramuscular administration is probably due either to the binding of IFN-beta to interstitial matrix, or to lymphatic absorption and/or to local breakdown by lysosomal proteinases from muscle. In this work, we first showed that after intramuscular injection, the apparent bioavailability of natural human IFN-beta is about 10% of that of recombinant IFN-alpha 2 and then we evaluated the effects of proteinase inhibitors and albumin on IFN-beta incubated at 37 degrees C with muscle homogenate. IFN biological activity decreased spontaneously by about 20% after incubation for 6 hr at 37 degrees C in Hanks' solution, but it was almost completely lost after incubation with muscle homogenate. Proteinase inhibitors (alpha 1-antitrypsin, alpha 2-macroglobulin, aprotinin, soybean trypsin inhibitor, leupeptin, EP-459, and EP-475) failed to block the inactivation of IFN-beta by muscle proteinases, whereas albumin exerted a partial but consistent protection.

Immunohistochemical localization of IL-1 alpha and IL-1 beta in normal human placenta

Many reports show that interleukin 1 (IL-1) is produced by mouse and human placenta but the cell type that is responsible for this production has yet to be identified. For this reason we attempted to localize IL-1 alpha and IL-1 beta directly on formalin-fixed paraffin-embedded normal human placentae at different stages of pregnancy using immunohistochemical techniques and specific antibodies. The results obtained show that both IL-1 forms are localized to villous syncytiotrophoblast and to extravillous trophoblast, while villous cytotrophoblast and cytotrophoblast columns are unreactive. A gradual decrease of reactivity was observed with increasing gestation age for both IL-1 forms, but the staining for IL-1 beta was in all sections higher than for IL-1 alpha. Although the physiological role of IL-1 in pregnancy has yet to be established, the presence of this cytokine in the cells facing maternal blood and tissues suggests a possible involvement in the immunoregulation of fetal acceptance.

Studies on the biological effects of ozone: 2. Induction of tumor necrosis factor (TNF-alpha) on human leucocytes

The effect of ozone as a probable inducer of tumor necrosis factor (TNF-alpha) has been investigated on human blood and on Ficoll-purified blood mononuclear cells (PBMC). Samples were exposed at different ozone concentrations ranging from 2.2 to 108 micrograms/ml and incubated at 37 degrees C in an 95% air-5% CO2 atmosphere. At predetermined times, all cell supernatants were tested for TNF activity and some PBMC cultures were examined for DNA synthesis. We have shown that ozone concentration is critical in terms of TNF production and of cell mitogenesis and that, owing to the presence of erythrocytes, higher ozone concentrations are required to be effective in blood than in PBMC. Because ozonization of blood is a procedure followed in several European countries for the treatment of viral diseases and tumors, the release of factors with antiviral and immunomodulatory activities by leukocytes may explain the mechanism of action of ozone and of autohemotherapy.

What is the role of cytokines in human colostrum?

No one has ever doubted that maternal milk, in comparison to formula milk, has a far superior nutritional value. Colostrum has a well acknowledge crucial value for the survival of the animal species that cannot receive immunoglobulins through the placenta. Until recently the presence of cytokines in colostrum was unsuspected but it has been now clarified that normally there are at least four cytokines, namely interleukin 1 and 6, tumor necrosis factor and interferon gamma, that may exert an important immunostimulatory role particularly on the oropharyngeal-associated lymphoid tissue. As a corollary, physiological concentration of cytokines administered per os may exert a useful adjuvant activity in aged or immunodeficient people.

Immunocytochemical localization of interferons in human trophoblast populations

It is known that Interferon (IFN) is present in normal body fluids and tissues during pregnancy. Using an immunohistochemical technique and a panel of monoclonal antibodies we have localized IFN-alpha, -beta and -gamma directly on formalin-fixed paraffin-embedded normal human placentae at different stages of pregnancy and in the hydatidiform mole. The results show that IFNs is mostly localized in villous syncytiotrophoblast and in extravillous interstitial-trophoblast. No reactivity was observed in villous cytotrophoblast or in cytotrophoblast cell columns. The most intense staining was observed for IFN-alpha and -beta, while IFN-gamma was rather weak. There is then a gradual diminution in IFN reactivity with increasing gestation age being almost imperceptible at term. These results suggest that IFN may deploy antiviral, immunomodulator and differentiation activities during normal human pregnancy.

Interferon induction in rabbits after intraduodenal administration of a phosphorylated glucomannan-protein fraction of the cell wall of Candida albicans

The aim of this work was to demonstrate whether a glucomannan protein fraction (GMP) of Candida albicans cell wall could induce interferon after intraduodenal administration in normal rabbits and rabbits immunized against C. albicans. For this purpose we collected simultaneously plasma and abdominal lymph for 10 h after the administration of the inducer. We observed a peak of antiviral activity in the lymph 4 h after intraduodenal administration of 20 mg GMP dissolved in saline to 6 normal rabbits. Immunized rabbits (anti-GMP titres greater than 1024) responded earlier (peak after 2 h) and more intensely; analysis of the values of the areas under the curve indicated that the IFN response in the lymph of immunized rabbits was significantly higher (P less than 0.0025) than in normal rabbits. Antiviral activity was absent in plasma in all cases. Preliminary characterization of the IFN activity has shown it to be trypsin-sensitive, acid and heat stable, and species-specific.

Studies on the biological effects of ozone 1. Induction of interferon gamma on human leucocytes

In this study we have investigated the effects of ozone on human blood, as well as on resuspended buffy coats and Ficoll-purified mononuclear cells. Samples were exposed at different ozone concentrations (from 2.2 micrograms to 108 micrograms/ml) for 30 sec and then incubated for different times at 37 degrees C in a 95% air-5% CO2 humidified atmosphere. Supernatants were collected and frozen at-20 degrees C until tested for interferon (IFN) activity. We have determined that the ozone concentration is critical for lymphokine induction. In fact, while low concentrations (2.2 micrograms/ml) are effective in lymphocytes, they do not induce IFN in either whole or diluted (1:1) human blood, or resuspended buffy coats. In such cases levels as high as 42 micrograms/ml are required. On the other hand, a very high ozone concentration (108 micrograms/ml) is not effective and probably toxic. Maximal IFN production occurs 72-96 h after ozone exposure, and the kinetics of IFN release is similar to that after Staphylococcal Enterotoxin B addition. Because ozonization of blood is a medical procedure followed in several countries for treatment of viral diseases, this study can open a new field of investigation that may yield useful results both in biological and practical terms.

The lymphatic route. VII. Distribution of recombinant human interleukin-2 in rabbit plasma and lymph

Human recombinant (R) interleukin-2 (IL-2) has been administered through intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) routes and its distribution in lymph and plasma has been evaluated in rabbits. It has been shown that after i.m. administration of RIL-2 in saline, the lymphokine is preferentially absorbed via lymphatics. A similar result has been obtained after s.c. administration when RIL-2 was injected with a high concentration (12.5%) of human albumin, which acts as a retarder and a promoter of lymphatic absorption. These routes may be valid alternatives to i.v. administration.