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Leke Wiering and Frank Tacke

progresses, Kupffer cells are replaced by monocyte-derived macrophages. Also, other immune cells as neutrophils and Type 1 T helper cells contribute to the inflammatory environment in NASH. However, also anti-inflammatory effects of immune cells in NASH are

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Ronald J van der Sluis, Tim van den Aardweg, Anne Q Reuwer, Marcel T Twickler, Florence Boutillon, Miranda Van Eck, Vincent Goffin, and Menno Hoekstra

for visualization of HRP. Hematological analysis Total leukocyte numbers as well as the absolute number of neutrophils, monocytes, and lymphocytes in whole blood samples with EDTA anticoagulant obtained at the time of killing were routinely measured

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Linda Vignozzi, Annamaria Morelli, Erica Sarchielli, Paolo Comeglio, Sandra Filippi, Ilaria Cellai, Elena Maneschi, Sergio Serni, Mauro Gacci, Marco Carini, Marie-Pierre Piccinni, Farid Saad, Luciano Adorini, Gabriella B Vannelli, and Mario Maggi

) showed no alterations. INT-747 did not prevent these HFD-induced abnormalities ( Fig. 2 e). To better study inflammatory prostate infiltrates, we immunostained for the neutrophil marker lactoferrin and the macrophage marker RAM11 ( Fig. 3 ). CA stained

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1. An investigation of the diurnal variations of circulating leucocytes has been carried out at Spitsbergen under constant conditions of diet, activity and lighting.

2. The effect of reversal of the activity-sleep pattern on the diurnal variations was studied, and the reversal of lymphocyte, eosinophil and basophil periodicity occurred in less than 3 days. The neutrophil periodicity was reversed in from 3 to 6 days.

3. The periodicity is ultimately dependent upon habit and activity.

4. The neutrophil variations appear to be controlled by a mechanism different from that of the other leucocytes.

5. The diurnal variation in adrenocortical activity is assumed to have reversed in response to the activity-sleep reversal.

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SJ Heasman, KM Giles, C Ward, AG Rossi, C Haslett, and I Dransfield

Glucocorticoids represent one of the most effective clinical treatments for a range of inflammatory conditions, including severe acute inflammation. Although glucocorticoids are known to affect processes involved in the initiation of inflammation, the influence of glucocorticoids on the mechanisms by which acute inflammation normally resolves have received less attention. Apoptosis of granulocytes present at inflamed sites leads to their rapid recognition and internalisation by macrophages, a process which may be important for resolution of inflammation. However, if clearance of either eosinophils or neutrophils is impaired, these cells rapidly undergo secondary necrosis leading to release of pro-inflammatory mediators from the phagocyte, potentially prolonging inflammatory responses. Physiologically relevant concentrations of glucocorticoids accelerate eosinophil apoptosis whilst delaying neutrophil apoptosis during in vitro culture. Here we discuss key pathways regulating the granulocyte apoptotic programme and summarise the effects of glucocorticoids on monocyte differentiation and the consequent changes to apoptotic cell clearance capacity. Definition of the mechanisms underlying resolution of inflammatory responses following glucocorticoid treatment may unveil new targets for modulation of inflammatory disease, allowing co-ordinated augmentation of granulocyte apoptosis together with increased macrophage capacity for clearance of apoptotic cells.

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G Aust, M Steinert, C Boltze, S Kiessling, and C Simchen

Thyroid glands affected by Graves' disease (GD) show striking leukocytic infiltration, mainly by T-cells. The mechanisms by which the various leukocytes are maintained in the thyroid are unknown. Growth-regulated oncogene-alpha (GRO-alpha) in interaction with its receptor CXCR2 is a chemoattractant for both T-cells and neutrophils and may be one of the chemokines involved in the cell maintenance. GRO-alpha and CD18 mRNA as a marker of leukocytic infiltration were quantified in thyroid tissue using competitive RT-PCR. We found very high GRO-alpha mRNA levels in all thyroid tissues. In GD patients (n=16), the GRO-alpha mRNA did not correlate with the CD18 mRNA level or thyroid peroxidase and TSH-receptor antibodies in patients' sera. In thyroid autonomy (n=10), the GRO-alpha mRNA levels were significantly lower in autonomous single adenomas compared with the corresponding normal tissue. In order to define the cellular source of GRO-alpha mRNA and protein, we examined various thyroid-derived cells. Thyrocytes, thyroid-derived leukocytes and fibroblasts showed basal GRO-alpha mRNA and protein expression, which was remarkably upregulated by different stimuli in vitro. The expression of GRO-alpha by thyroid carcinoma cell lines confirms that thyrocytes may actually produce GRO-alpha. As shown by flow cytometry and immunohistology, CD68+ monocytes/macrophages are the only cell population strongly expressing CXCR2 in the thyroid.

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FC Denison, RW Kelly, AA Calder, and SC Riley

Secretory leukocyte protease inhibitor is a potent inhibitor of neutrophil function, a mediator of mucosal immunity and an inhibitor of NF|gkB regulated inflammatory responses. However, its source, function and regulation within the uterus during pregnancy and at parturition are not well defined. In amniotic fluid, the concentration of secretory leukocyte protease inhibitor increased significantly from 2nd trimester (24+/-3 ng/ml; mean+/-s.e.m.; n=20) to term (751+/-53 ng/ml; P<0.05; n=15) with a further profound increase (P<0.005) with the onset of labour (3929+/-1076 ng/ml; n=15). To establish the intra-uterine sites of secretion, explants (n=6 different patients per tissue) were collected at term after elective caesarean section. High levels of secretory leukocyte protease inhibitor were released by decidua (135.2+/-12.4 pg/mg; mean+/-s.e.m.) and chorio-decidua (325.1+/-26.4 pg/mg) with less by amnion (55.6+/-6.0 pg/mg) and placenta (9.2+/-1.9 pg/mg). Intense immunoreactivity for secretory leukocyte protease inhibitor was detected predominantly in decidua parietalis cells adherent to the chorion laeve and myometrium, and also in decidua basalis. We propose that, within the pregnant uterus, secretory leukocyte protease inhibitor is released by decidua, fetal membranes and potentially the fetal lung. The increase in secretory leukocyte protease inhibitor may act to modulate pro-inflammatory paracrine interactions for the maintenance of pregnancy and limit those occurring at parturition within the uterus.

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T Okada, N Matsuzaki, K Sawai, T Nobunaga, K Shimoya, K Suzuki, N Taniguchi, F Saji, and Y Murata

Chorioamnionitis has been shown to be one of the most important factors in inducing preterm delivery. The present study was undertaken to examine the effects of chorioamnionitis on placental endocrine functions. Preterm placentas with histologic chorioamnionitis produced smaller amounts of human chorionic gonadotropin (hCG) and human placental lactogen (hPL) than those without chorioamnionitis (P < 0.001). To examine the mechanism involved in the suppression of placental endocrine functions induced by chorioamnionitis, we initially confirmed the expression of lipopolysaccharide (LPS) receptor, i.e. the CD14 molecule, on trophoblasts by Northern blot analysis and immunohistochemistry. We then stimulated purified trophoblasts with LPS, which is the major agent which induces inflammatory responses in the host via the LPS receptor. The trophoblasts stimulated with LPS produced reduced amounts of hCG, hPL, and progesterone in a time- and dose-dependent fashion in spite of the induced manganese-superoxide dismutase (SOD) synthesis. Stimulation of trophoblasts with hypoxanthine and xanthine oxidase resulted in suppressed hCG production, while the simultaneous addition of SOD into the culture medium reversed the suppression of hCG production. LPS in the placenta with chorioamnionitis might directly stimulate trophoblasts through the LPS receptor (CD14), thus reducing placental endocrine functions. Superoxide anions which exogenously act on trophoblasts might be generated by simultaneous stimulation of neutrophils and monocytes at the feto-maternal interface by LPS, and additively reduce placental endocrine functions.

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A Bateman and HP Bennett

The granulin/epithelin motif defines a family of structurally unique proteins, of great evolutionary antiquity, which have been implicated as regulators of cell growth. Recurrent in granulin research are the surprising parallels between the granulin and EGF systems. Both are cysteinerich peptides of approximately 6 kDa that can modify cell growth. They show similar, but not identical, biological activities, although granulin/epithelin peptides do not bind EGF receptors; the three-dimensional folds of granulin and EGF are partially superimposible; and the precursors for mammalian granulin/epithelins and EGF are both organized as multiple repeats of conserved cysteine modules. Given the dissimilarity between amino acid sequences of members of the granulin/epithelin family and EGF-related peptides, the parallelism between the two systems probably represents convergent evolution towards related solutions to common biological problems. The granulin/epithelin precursor gene is expressed throughout the body, but its expression is predominantly in epithelial and haematopoietic cells. There is a great deal of versatility in the means by which cells process and handle the granulin/epithelin precursor. In some instances, the precursor is secreted intact (Zhou et al. 1993), and in others it is stored in a vesicular organelle, such as the sperm acrosome (Baba et al. 1993a). It may be processed into small 6-kDa peptides, which, in the neutrophil, can also be stored in vesicles (Bateman et al. 1990, Couto et al. 1992). The 6-kDa peptide forms, the intact precursor, and related proteins such as TGFe, regulate the growth of epithelial and mesenchymal cells. Epithelial cells express putative receptors for granulin/epithelin peptides and TGFe (Culouscou et al. 1993, Parnell et al. 1995). Thus, although much remains to be clarified, granulin/epithelin polypeptides and related proteins are emerging as widely distributed potential autocrine and paracrine growth modulating factors for epithelial and mesenchymal cells.

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CE Berger, BR Horrocks, and HK Datta

Calciotropic hormones such as parathyroid hormone (PTH) and calcitonin have been shown to have stimulatory and inhibitory effects respectively on superoxide anion (O2-) generation by osteoclasts, but the exact intracellular signalling mediating these pathways has not been investigated. In order to elucidate the intracellular pathways controlling O2- generation, we have carried out a systematic study of the effect of different agents on O2- production in osteoclasts cultured on bovine cortical bone. Dibutyryl cAMP and cholera toxin, while having no effect on the basal level of O2- production in bone-resorbing osteoclasts, were, however, found to completely block the stimulation of free radical production by PTH, pertussis toxin and ionomycin. The stimulation of O2- production was found to be independent of protein kinase C-dependent pathways since the presence of bisindolylmaleimide (GF109203X) (1 microM) did not block stimulation by PTH and pertussis toxin. Interestingly, while exposure to bisindolylmaleimide at this concentration did not have any effect on the basal level of O2- production, exposure to a higher concentration (10 microM), which is known to inhibit both protein kinase C and A, produced significant stimulation. These in vitro findings suggest that in the bone-resorbing cells, cAMP-dependent protein kinases prevent further stimulation of NADPH oxidase by agents such as PTH and pertussis toxin. The increase in cAMP has also been recently demonstrated to be associated with down-regulation of the oxidative burst in adherent neutrophils; and the findings reported here suggest a similar role for cAMP in O2- generation in osteoclasts cultured on bone.