Modulation of C2 and C3 gene expression of human peripheral blood monocytes by interleukin 1β, interferon γ, tumor necrosis factor α and lipopolysaccharide

The effect of interleukin 1β (IL-1β), interferon γ (IFN-γ), tumor necrosis factor α (TNFα) and lipopolysaccharide (LPS) on the expression of the C2 and C3 genes in human adherent monocytes was studied. Stimulation of monocytes with IFN-γ increased both C2 and C3 mRNA. IL-1β also increased C2 mRNA level, whereas C3 gene expression was not enhanced. TNFα failed to increase either C2 or C3 mRNA. LPS increased C2 mRNA, but suppressed C3 gene expression. These results suggest that C2 and C3 production by monocytes is regulated by IL-1β and IFN-β in the local tissues.     

Inhibition of interleukin-1 beta release from cultured human peripheral blood mononuclear cells by prednisolone

Prednisolone, a water-soluble glucocorticoid hormone, suppressed the secretion of interleukin-1 beta from human peripheral blood mononuclear cells in culture. The prednisolone-induced suppression of the monokine release was dose-related and the half maximal response was observed at 0.1 nM.     

Activation of protease-activated receptor (PAR) 1 by frog trefoil factor (TFF) 2 and PAR4 by human TFF2

Trefoil factors (TFFs) promote epithelial cell migration to reseal superficial wounds after mucosal injury, but their receptors and the molecular mechanisms underlying this process are poorly understood. In this study, we showed that frog TFF2 activates protease-activated receptor (PAR) 1 to induce human platelet aggregation. Based on this result, we further tested the involvement of PARs in human TFF2 (hTFF2)-promoted mucosal healing. hTFF2-stimulated migration of epithelial HT-29 cells was largely inhibited by PAR4 depletion with small interfering RNAs but not by PAR1 or PAR2 depletion. The PAR4-negative epithelial cell lines AGS and LoVo were highly responsive to hTFF2 as assessed by phosphorylation of ERK1/2 and cell migration upon PAR4 expression. Our findings suggest that hTFF2 promotes cell migration via PAR4. These findings will be helpful in further investigations into the functions and molecular mechanisms of TFFs and PARs in physiology and disease.     

Differential distribution of TASK-1, TASK-2 and TASK-3 immunoreactivities in the rat and human cerebellum

In this work, the distributions of some acid-sensitive two-pore-domain K⁺ channels (TASK-1, TASK-2 and TASK-3) were investigated in the rat and human cerebellum. Astrocytes situated in rat cerebellar tissue sections were positive for TASK-2 channels. Purkinje cells were strongly stained and granule cells and astrocytes were moderately positive for TASK-3. Astrocytes isolated from the hippocampus, cerebellum and cochlear nucleus expressed TASK channels in a primary tissue culture. Our results suggest that TASK channel expression may be significant in the endoplasmic reticulum of the astrocytes. The human cerebellum showed weak TASK-2 immunolabelling. The pia mater, astrocytes, Purkinje and granule cells demonstrated strong TASK-1 and TASK-3 positivities. The TASK-3 labelling was stronger in general, but it was particularly intense in the Purkinje cells and pia mater.Received 25 February 2004; received after revision 19 April 2004; accepted 28 April 2004     

Differential expression of genes for uncoupling proteins 1, 2 and 3 in brown and white adipose tissue depots during rat development

The different expression patterns of genes for uncoupling proteins (UCPs) 1, 2 and 3 (ucp1, ucp2 and ucp3) were studied in interscapular brown adipose tissue (BAT) and in four white adipose tissue (WAT) depots (epididymal, inguinal, mesenteric and retroperitoneal) in male rats of different ages (18 days-12 months). UCP mRNA expression levels were determined by Northern blotting. In BAT, there were high levels of expression of UCP1 and UCP3 mRNA, but no detectable levels of UCP2 mRNA. Both ucp1 and ucp3 followed a similar expression pattern with age, with high levels in suckling rats which decreased to 50% or less in rats just under 2 months old, declining thereafter until 5 months and then recovering with age. However, an additional peak of expression was observed for ucp3 at the age of 3 months. In WAT, ucp1 expression was rare: occasional expression was found for UCP1 mRNA in the retroperitoneal depot in suckling rats and in the epididymal and inguinal depots in suckling and mature adult rats. ucp2 and ucp3 had different developmental expression patterns, but these were similar for each gene in the different depots studied. UCP3 mRNA was highly expressed in rats soon after birth, it decreased until 3 months, and increased thereafter, except for the mesenteric WAT where ucp3 expression decreased until 7 months before recovering. The fact that changes with age of both ucp1 and ucp3 expression have a similar profile in BAT, which is also similar to the ucp3 and also ucp1 profiles in some WAT depots, might reflect a common regulatory pattern for the expression of these genes, and also a common function. In contrast to ucp1 and ucp3, ucp2 had a peak of expression at about 2 months, and lower expression at 3 months, suggesting different regulation and probably a different role for this UCP.     

Possible involvement of protein kinase C in the stimulation of amino acid transport by phorbol ester,platelet-derived growth factor and A23187 in Swiss 3T3 cells

Summary Stimulation of amino acid transport induced by phorbol-12, 13-dibutyrate, platelet-derived growth factor or A23187 was not observed in cells lacking protein kinase C. On the other hand, stimulation of transport by epidermal growth factor or insulin was not affected. These results suggested that the stimulation of amino acid transport is mediated by at least two separate pathways.This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, and the Ministry of Health and Welfare of Japan.     

Possible involvement of protein kinase C in the stimulation of amino acid transport by phorbol ester, platelet-derived growth factor and A23187 in Swiss 3T3 cells

Stimulation of amino acid transport induced by phorbol-12,13-dibutyrate, platelet-derived growth factor or A23187 was not observed in cells lacking protein kinase C. On the other hand, stimulation of transport by epidermal growth factor or insulin was not affected. These results suggested that the stimulation of amino acid transport is mediated by at least two separate pathways.     

The distribution of α2β1, α3β1 and α6β4 integrins identifies distinct subpopulations of basal keratinocytes in the outer root sheath of the human anagen hair follicle

The human hair follicle is composed of different concentric compartments, which reflect different programmes of differentiation. Using monoclonal antibodies against α2β1 and α3β1 integrins we demonstrated a shift in their expression, from a basolateral distribution in the basal cells of the lower outer root sheath, to an apicolateral expression in the upper outer root sheath, as in epidermis. This shift takes place in a transition zone, localized to the midpart of the follicle. The distinct basolateral distribution of α2β1 and α3β1 integrins in the lower portion of the outer root sheath coincides with the presence of basal cell protrusions and is probably linked to the presence of the vitreous membrane which surrounds the bottom part of the anagen human hair follicle. Moreover, we showed that the expression of α6β4 integrin is discontinuous along the hair follicle and coincides with that of laminin 5. Together these results establish that within a given compartment – namely the outer root sheath – several domains can be clearly identified, which probably reflect the onset of successive differentiation pathways along the hair follicle. Received 17 January 1997; received after revision 18 February 1997; accepted 24 February 1997     

Effects of [N-(2-oxo-3,5,7-cycloheptatrien-1-yl)] aminooxoacetic acid ethyl ester (AY-25,674) on cyclic 3',5'-nucleotide formation and phosphodiesterase activity.

The orally-effective antiallergic compound [N-(2-oxo-3,5,7-cycloheptatrien-1-yl)] aminooxoacetic acid ethyl ester (AY-25,674) exhibited a potency equivalent to or 3 times less than theophylline in inhibiting guinea-pig lung and beef heart PDE, respectively, AY-25,674 did not affect the basal activity of guinea-pig lung adenyl cyclase. Although part of the antiallergic activity of AY-25,674 may be due to the ability to elevate cyclic AMP levels by PDE inhibition, other modes of action appear to be of greater relevance.