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L Paulesu

Publications and source records attributed to L Paulesu.

At least 19 recordsLinked to original sources
PubMed2003

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.

Adult↗
PubMed2002

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.

Adult↗
PubMed2002

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.

Adult↗
PubMed2001

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.

Blotting, Western↗
PubMed2000

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.

11-beta-Hydroxysteroid Dehydrogenase Type 1↗
PubMed1999

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.

Blotting, Western↗
PubMed1998

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.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1998

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.

Animals↗
PubMed1998

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.

Alanine↗
PubMed1997

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.

Aged↗
PubMed1997

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.

Antibodies, Monoclonal↗
PubMed1996

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.

Animals↗
PubMed1995

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.

Animals↗
PubMed1995

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.

Animals↗
PubMed1995

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.

Animals↗
PubMed1994

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.

Embryonic and Fetal Development↗
PubMed1994

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.

Adult↗