| 1. |
- Huang, Ranyang, et al.
(author)
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Expression of a Mast Cell Tryptase in the Human Monocytic Cell Lines U-937 and Mono Mac 6
- 1993
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In: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 38:4, s. 359-367
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Journal article (peer-reviewed)abstract
- Expression of a mast cell tryptase mRNA was detected in two human monocytic cell lines, the U-937 and the Mono Mac 6, and in normal human peripheral blood(PB) monocytes. In the U-937 cell line but not in normal PB monocytes, the tryptase expression was upregulated 3-50 fold following phorbol ester (PMA)-induced differentiation, but no such induction was seen after retinoic acid, interferon-gamma or vitamin D3 exposure. The tryptases expressed in PMA-induced and non-induced U-937 and in Mono Mac 6 were characterized by PCR amplification and nucleotide sequence analysis. The U-937 cell line was found to express a tryptase identical to one of the previously cloned mast-cell beta tryptases (Tryptase I), and the tryptase expressed in Mono Mac 6 was found to be nearly identical to the previously cloned alpha tryptase. By northern blot analysis with oligonucleotide probes specific for the alpha and beta tryptases both cell lines were found to express only one type of tryptase. Densitometric quantifications of tryptase mRNA levels, in the two cell lines, showed approximately 80 times higher mRNA levels in Mono Mac 6 compared to non-induced U-937. Immunohistochemical staining for tryptase showed a marked heterogeneity in the Mono Mac 6 cell line. Only one out of 10 cells were positive for the protein but the levels in these cells were very high, equivalent, or even higher than the levels seen in the human mast cell line HMC-1. This shows that the expression of a single tryptase, in this case the alpha tryptase, is sufficient for the production of a stable protein and probably also a stable proteolytically active tetramer. The family of human mast-cell tryptases has been considered to represent a class of proteases specifically expressed in mast cells and basophilic leucocytes. The expression of tryptases in two monocytic cell lines and in normal PB monocytes indicate that in humans, the lineage specificity of these serine proteases is less restricted than earlier expected. The cloning of a full length cDNA for the murine counterpart to the human mast cell tryptases, the MMCP-6, is presented. No expression of the MMCP-6 was detected in a panel of mouse monocyte or macrophage cell lines indicating a species difference in the lineage specificity of the 'mast cell tryptases'.
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| 2. |
- Blom, Thomas, et al.
(author)
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Phenotypic characterization of KU812, a cell line identified as an immature human basophilic leukocyte
- 1992
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In: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 22:8, s. 2025-2032
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Journal article (peer-reviewed)abstract
- The knowledge about the differentiation of basophilic leukocytes is fragmentary. This report discusses a detailed phenotypic characterization of molecular markers for hematopoietic differentiation in a basophilic leukemia cell line, KU812. The expression of markers for lymphoid, erythroid, neutrophil, eosinophil, monocytic, megakaryocytic, mast cell and basophil differentiation was analyzed at the mRNA level by Northern blots in the KU812 cells, and for reference, in a panel of human cell lines representative of the different hematopoietic differentiation lineages. KU812 was found to express a number of mast cell and basophil-related proteins, i.e. mast cell tryptase, mast cell carboxypeptidase A, high-affinity immunoglobulin (IgE) receptor α and γ chains and the core protein for heparin and chondroitin sulphate synthesis. We found no expression of a number of monocyte/-macrophage or neutrophil leukocyte markers except for lysozyme. From earlier studies, it has been shown that lysozyme is not expressed in murine mucosal mast cell lines. This finding, together with the expression of the mast cell carboxypeptidase in KU812 might distinguish the phenotype of this cell line from that typical of mucosal mast cell lines in rodents. We found a low level of expression of the eosinophil and basophil marker, major basic protein, which might indicate a relationship between basophils and eosinophils. No expression is, however, detected with the eosinophil-specific markers, eosinophil cationic protein, eosinophil-derived neurotoxin or eosinophil peroxidase. We also report an extensive screening for inducers of basophilic differentiation of the KU812 cells. The most efficient protocol of induction included serum starvation which led to a dramatic increase in a number of markers specific for mast cells and basophils such as tryptase, carboxypeptidase A and the heparin core protein. Finally, diisopropylfluorophosphate analysis of total protein extracts from KU812 show four labeled protein bands with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that this cell line expresses at least three previously undescribed serine proteases of which one or more could be a potential basophil-specific marker(s).
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| 3. |
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| 4. |
- Lindvall-Axelsson, Maria, et al.
(author)
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Inhibition of cerebrospinal fluid formation by omeprazole
- 1992
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In: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 115:3, s. 394-399
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Journal article (peer-reviewed)abstract
- Omeprazole, a specific inhibitor of H(+)-K(+)-activated ATPase, gave a dose-dependent inhibition of CSF production as determined by cerebroventriculocisternal perfusions in the rabbit. The reduction was 35% when the perfusate concentration of omeprazole was 10(-6) M and 25% after an intravenous dose of 0.2 mg/kg of omeprazole, respectively. A similarly substituted benzimidazol (H178/42) without H(+)-K(+)-ATPase-inhibiting properties did not affect CSF production at a perfusate concentration of 10(-5) M. Omeprazole in a concentration of 2 x 10(-4) M and more caused a significant but variable reduction in total and Na(+)-K(+)-ATPase activity in choroid plexus homogenates. However, in concentrations of 2 x 10(-5) M and less, no effect on total or Na(+)-K(+)-ATPase activity was obtained. Nor did omeprazole (2 x 10(-4) M) influence HCO3-ATPase. Choline uptake in isolated choroid plexus was significantly reduced by 86% in the presence of acid-pretreated omeprazole 2 x 10(-3) M, but was not affected by 2 x 10(-5) M omeprazole (intact or acid-pretreated). Thus, the mechanism for the marked inhibitory influence of omeprazole on CSF production is not yet evident. In doses causing even a 50% reduction of CSF production, no side effects were observed in contrast to Na(+)-K(+)-ATPase inhibitors such as ouabain.
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| 5. |
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| 6. |
- Nilsson, Christer, et al.
(author)
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A Comparison of Species Richness and Traits of Riparian Plants between a Main River Channel and Its Tributaries
- 1994
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In: Journal of Ecology. - : JSTOR. - 0022-0477 .- 1365-2745. ; 82:2, s. 281-295
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Journal article (peer-reviewed)abstract
- Summary1 We examined differences in species richness and frequencies of vascular plants in the riverbank vegetation between the main channel of the Vindel River system and seven of its tributaries which spanned the same biogeographic range.2 Species richness per site was higher in the main channel than in the tributaries, both as a whole and for many species groups. The proportions of woody plants (phanerophytes and chamaephytes), geophytes, and natural species were higher in the tributaries, while the proportions of hemicryptophytes, ruderals, and short-floating species (i.e. species unable to float > 1 day) were higher in the main channel. Both types of river had species that were more than twice as frequent there than in the other category.3 The main channel had a high species richness at intermediate altitudes whereas the tributaries had least species at intermediate altitudes. Except for the highest altitudes, the tributaries also had a generally lower mean species richness than the main channel.4 Stepwise multiple regression analyses using 15 predictor variables explained stat- istically up to 85% of the floristic variation in the river system. Mean annual discharge and number of substrates explained most of the variation in five equations each, while peat cover explained most of the variation in four equations, and altitude and silt cover in one equation each. Mean annual discharge, peat cover and silt cover differed between the main channel and the tributaries and could therefore be responsible for the observed difference.
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| 7. |
- Nilsson, Christer, et al.
(author)
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Distribution of peptidergic nerves in the choroid plexus, focusing on coexistence of neuropeptide Y, vasoactive intestinal polypeptide and peptide histidine isoleucine
- 1990
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In: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 27:1, s. 11-26
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Journal article (peer-reviewed)abstract
- Choroid plexus from rat, guinea-pig, rabbit and pig was investigated by light-microscopic immunohistochemistry and by radioimmunoassay for the presence of neuropeptides. A moderately dense supply of nerve fibers containing neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), respectively, was found around blood vessels and in close relation to the secretory epithelium in both pig and rabbit, while lower densities of nerve fibers were found in rat and guinea-pig. Peptide concentrations ranged from 10-40 pmolequivalents/g (pmoleqv/g) for NPY and 0.5-6 pmoleqv/g for VIP in all four species. Peptide histidine isoleucine (PHI) immunoreactive nerve fibers were present in pig choroid plexus at a lower density than NPY and VIP but with a similar distribution. Low concentrations of substance P (0.3-3 pmoleqv/g) and calcitonin gene-related peptide (0.1-3 pmoleqv/g) were found to a varying degree in choroid plexus tissue from the different species, while immunohistochemical investigation was unable to detect any immunoreactive nerve fibers. NPY was often found to coexist with VIP and PHI in pig choroid plexus, while a lesser amount of nerve fibers showed coexistence of NPY and the noradrenaline synthetizing enzyme, dopamine-beta-hydroxylase. Surgical sympathetic denervation by excision of the superior cervical ganglion in the rabbit abolished NPY-containing nerve fibers, as revealed by immunohistochemistry, but only decreased NPY levels by one third, which may be due to different identity of the peptide being detected by the two techniques. It is concluded that NPY-containing nerve fibers have a dual origin in the choroid plexus and coexist with either noradrenaline or VIP/PHI.
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| 8. |
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| 9. |
- Nilsson, Christer, et al.
(author)
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Epithelial cells purified from choroid plexus have receptors for vasoactive intestinal polypeptide
- 1991
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In: Brain Research. - 1872-6240. ; 542:2, s. 241-247
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Journal article (peer-reviewed)abstract
- Using the choroid plexus from pig a method has been developed to purify the epithelial cells from the underlying vascularized connective tissue stroma. An epithelial cell fraction was obtained that showed a purity of at least 95%, as determined by light microscopic analysis. The epithelial cells were investigated for the presence of binding sites for the neurotransmitter peptide, vasoactive intestinal polypeptide (VIP). Suspensions of epithelial cells were found to have high affinity binding sites for 125I-labelled VIP, with maximum binding obtained after 30 min incubation at 20 degrees C with a concentration of 50 micrograms cell protein per sample. Competition experiments with displacement of [125I]VIP binding by increasing concentrations of unlabeled VIP indicated the presence of a single class of binding sites with a Kd of 3 nM and a binding capacity of 970 pmol/g cell protein. Cross-linking of [125I]VIP to epithelial cells with disuccinimido dithiobis (propionate) (DSP), followed by SDS-polyacrylamide gel electrophoresis, demonstrated binding to a single 55 kD protein. The receptor was highly specific for VIP as binding was only inhibited in the presence of high concentrations of the related peptides helodermin, growth hormone-releasing factor, secretin, and peptide histidine isoleucine. This is the first demonstration of VIP-binding to choroid plexus epithelial cells.
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| 10. |
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