Two calcium-binding proteins in infiltrate macrophages of rheumatoid arthritis

Molecular cloning and expression of a novel keratinocyte protein (psoriasis-associated fatty acid-binding protein [PA-FABP]) that is highly up-regulated in psoriatic skin and that shares similarity to fatty acid-binding proteins

Analysis by means of two-dimensional (2D) gel electrophoresis of the protein patterns of normal and psoriatic unfractionated non-cultured keratinocytes has revealed a few low-molecular-weight proteins that are highly up-regulated in psoriatic skin. These include psoriasin; calgranulin B, also known as MRP 14, L1, or calprotectin; calgranulin A or MRP 8; and cystatin A or stefin A. Here, we have cloned and sequenced the cDNA (clone 1592) encoding a new member of this group of low-molecular-weight proteins [isoelectric focusing (IEF) SSP 3007 in the keratinocyte 2D gel protein database] that we have termed PA-FABP (psoriasis-associated fatty acid-binding protein). The deduced sequence predicted a protein with molecular weight of 15,164 daltons and a calculated pI of 6.96, values that are close to those recorded in the keratinocyte 2D gel protein database. The protein comigrated with PA-FABP as determined by 2D gel analysis of [35S]-methionine-labeled proteins expressed by transformed human amnion (AMA) cells transfected with clone 1592 using the vaccinia virus expression system and reacted with a rabbit polyclonal antibody raised against 2D gel purified PA-FABP. Structural analysis of the amino acid sequence revealed 48%, 52%, and 56% identity to known low-molecular-weight fatty acid-binding proteins belonging to the FABP family. Northern blot analysis showed that PA-FABP mRNA is indeed highly up-regulated in psoriatic keratinocytes. The transcript is present in human cell lines of epithelial and lymphoid (Molt 4) origin but cannot be detected in normal or SV40 transformed MRC-5 fibroblasts. 2D gel protein analysis of normal primary keratinocytes cultured for at least 8 d under conditions that promoted incomplete terminal differentiation [serum-free keratinocyte (SFK) medium supplemented with epidermal growth factor (EGF), pituitary extract, and 10% fetal calf serum] revealed a strong up-regulation of PA-FABP, psoriasin, calgranulins A and B, and a few other proteins that are highly expressed in psoriatic skin. The levels of these proteins exceeded by far those observed in non-cultured normal keratinocytes implying that the cultured cells have followed an altered pattern of differentiation that resembles--at least in part--that of non-cultured psoriatic keratinocytes. The implications of these results for the study of psoriasis are discussed.

S100P, a novel Ca(2+)-binding protein from human placenta. cDNA cloning, recombinant protein expression and Ca2+ binding properties

A novel member of the S100 protein family, present in human placenta, has been characterized by protein sequencing, cDNA cloning, and analysis of Ca(2+)-binding properties. Since the placenta protein of 95 amino acid residues shares about 50% sequence identity with the brain S100 proteins alpha and beta, we proposed the name S100P. The cDNA was expressed in Escherichia coli and recombinant S100P was purified in high yield. S100P is a homodimer and has two functional EF hands/polypeptide chain. The low-affinity site (Kd = 800 microM), which, in analogy to S100 beta, seems to involve the N-terminal EF hand, can be followed by the Ca(2+)-dependent decrease in tyrosine fluorescence. The high-affinity site, provided by the C-terminal EF hand, influences the reactivity of the sole cysteine which is located in the C-terminal extension (Cys85). Binding to the high-affinity site (Kd = 1.6 microM) can be monitored by fluorescence spectroscopy of S100P labelled at Cys85 with 6-proprionyl-2-dimethylaminonaphthalene (Prodan). The Prodan fluorescence shows a Ca(2+)-dependent red shift of the maximum emission wavelength from 485 nm to 502 nm, which is accompanied by an approximately twofold loss in integrated fluorescence intensity. This indicates that Cys85 becomes more exposed to the solvent in Ca(2+)-bound S100P, making this region of the molecule, the so-called C-terminal extension, an ideal candidate for a putative Ca(2+)-dependent interaction with a cellular target. In p11, a different member of the S100 family, the C-terminal extension which contains a corresponding cysteine (Cys82 in p11), is involved in a Ca(2+)-independent complex formation with the protein ligand annexin II. The combined results support the hypothesis that S100 proteins interact in general with their targets after a Ca(2+)-dependent conformational change which involves hydrophobic residues of the C-terminal extension.

The calcium-binding proteins MRP8 and MRP14 form a membrane-associated heterodimer in a subset of monocytes/macrophages present in acute but absent in chronic inflammatory lesions

Monocytes/macrophages expressing an epitope recognized by a monoclonal antibody 27E10 are present in acute but are absent in chronic inflammatory disorders. This report shows that the 27E10 antigen is formed by noncovalent association of the two Ca(2+)-binding proteins MRP8 and MRP14 which belong to the S100 protein family. Identification has been confirmed immunochemically, by matrix-assisted UV-laser desorption/ionization spectrometry and by partial amino acid sequencing. Surface expression of the MRP8/MRP14 complex on a subset of monocytes is reported for the first time and shown to be up-regulated in a Ca(2+)-dependent manner. The 27E10 surface-positive monocytes isolated by cell separation techniques release high amounts of tumor necrosis factor-alpha and interleukin-1 beta in contrast to their 27E10 surface-negative counterparts thus emphasizing their role in inflammation.

Subunit structure of calgranulins A and B obtained from sputum, plasma, granulocytes and cultured epithelial cells

The calcium-binding proteins calgranulins A and B co-purified with an elastase-specific inhibitor after the affinity and cation-exchange chromatography of the perchloric acid-soluble fraction of pooled sputum collected from patients with chronic obstructive pulmonary disease (Sallenave, J.-M. and Ryle, A.P. (1991) Biol. Chem. Hoppe-Seyler 372, 13-21). The calgranulins were separated from the inhibitor by reverse-phase FPLC. Protein blot analysis of the calgranulin fraction in the absence of reducing agent revealed a band of 25 kDa corresponding to the disulphide-bonded heterodimerization of the two monomer components. Similar results were obtained from the immunoprecipitation and protein blot analysis of plasma, granulocytes and cultured epithelial cells. This implies that the calgranulins exist in the heterodimeric form in secretions in vivo. Their association with pancreatic elastase during the affinity chromatography stage of purification implicates them in the tissue destruction elicited by the inflammatory response in chronic obstructive pulmonary diseases.

Purification and characterization of a new member of the S-100 protein family from human placenta

A novel Ca(2+)-binding protein which is termed S-100P was purified from human placenta with a hydrophobic column followed by an anion exchange column and reverse phase high performance liquid chromatography (HPLC). Molecular mass of the protein was 10 kDa according to sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Using immunoblotting technique, anti-human calcyclin antibodies did not bind to the S-100P. Isoelectric point of S-100P was pI = 4.6. S-100P did not formed disulfide-linked dimer. Calcium binding ability was proved by UV difference spectrometry, urea/alkaline gel electrophoresis, and 45Ca overlay technique. A ninety amino acid sequence of S-100P was determined. It is 49% identical with human S-100 beta, 38% with human calcyclin, and 37% with human cystic fibrosis antigen.

Unique histological changes in lung metastases of osteosarcoma patients following therapy with liposomal muramyl tripeptide (CGP 19835A lipid)

We have recently begun a phase II trial in patients with osteosarcoma who developed pulmonary metastases during adjuvant chemotherapy or who presented with pulmonary metastases that persisted despite chemotherapy. Eligible patients were rendered free of visible disease by surgery. Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (MTP-PE, CGP 19835A lipid) (2 mg/m2) was infused twice weekly for 3 months. In five patients, a single tumor nodule recurred within 6 weeks after completion of therapy. These lesions were resected and submitted for pathological examination. Tissue specimens obtained after therapy were compared to those obtained before therapy. All the patients showed a histological change in the characteristics of the pulmonary tumors. In three patients, peripheral fibrosis surrounded the tumor and inflammatory cell infiltration and neovascularization were present. This is in contrast to central necrosis, with viable peripheral tumor cells and no inflammatory response observed in lesions resected following chemotherapy. In a fourth case, evidence of early fibrotic changes was found. This and the fifth case showed a change in malignant characteristics, from high grade before liposomal therapy to low grade after therapy. The present study provides evidence for a biological effect of liposomal MTP-PE.

1 alpha,25-(OH)2 vitamin D3 enhances expression of the genes encoding Ca(2+)-binding proteins MRP-8 and MRP-14

Two closely related Ca(2+)-binding proteins, migration inhibitory factor-related protein (MRP)-8 and MRP-14, are synthesized under specific conditions of myeloid cell differentiation. Because 1 alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3] induces myeloid cell differentiation and expression of other S-100 class calcium-binding proteins, we examined the effects of 1,25-(OH)2D3 on MRP mRNA levels in human U-937 histiocytic lymphoma cells. 1,25-(OH)2D3 increased MRP-8 and MRP-14 mRNA levels in a time- and dose-dependent manner. MRP mRNA levels were maximal at 24 h and remained elevated for at least 96 h after exposure of the cells to 1,25-(OH)2D3. MRP-8 mRNA accumulation required 100- to 1,000-fold higher concentrations of 25-(OH)D3, which binds to the 1,25-(OH)2D3 intracellular receptor with 100- to 1,000-fold lower affinity. Other differentiating agents, dimethyl sulfoxide, retinoic acid, and dexamethasone, also increased levels of MRP-8 and MRP-14 mRNA. Phorbol myristate acetate enhanced MRP-14 mRNA levels to a greater extent than MRP-8 mRNA levels, suggesting differential regulation of MRP gene expression by protein kinase C. The 1,25-(OH)2D3-induced relative increase in MRP mRNA levels was not changed by a 1,000-fold reduction in extracellular [Ca2+]. Thus 1,25-(OH)2D3 is potentially a physiological modulator of MRP gene expression. Expression of the MRP-8 and MRP-14 genes may be important for differentiation of myeloid cells.

Inflammatory reactions in primary osteoarthritis of the hip and total hip prosthesis loosening

In 14 patients [9 with loosened total hip arthroplasty (THA), 5 with primary osteoarthritis], the inflammatory cell infiltrate was characterized in cryostat tissue sections using antibodies against subsets of macrophages and lymphocytes. In all patients the abundance of a mature type macrophage (25F9+) was observed, whereas 27E10+ macrophages, characteristic of acute inflammatory reactions, were not seen in primary osteoarthritis but were found in 4 out of 9 patients with THA loosening. The RM3/1 + macrophage phenotype was seen in some of both sets of patients (osteoarthritis 4/5; THA loosening 4/9). The markers MRP8 and MRP14 typical of immature macrophages, were found in all patients with osteoarthritis and in some (4/9 and 8/9 respectively) of those with THA loosening. IOT4+ T-helper cells were only present in 1/5 5 patients with osteoarthritis and in 2/9 patients with THA loosening. IOT8+ T-suppressor lymphocytes were more frequently present (in 4/5 and 5/9 respectively). The data reveal remarkable differences between the two groups of patients. While the inflammatory infiltrate in patients with osteoarthritis lacks the characteristics of acute inflammation, in patients THA loosening the inflammatory process seems to be determined by periods of acute reactions. The occasional presence particularly of T-helper cells suggests that the inflammatory process is less T-cell but rather macrophage-driven.

Perspectives in S-100 protein biology. Review article

The S-100 protein family constitutes a subgroup of Ca(2+)-binding proteins of the EF-hand type comprising three dimeric isoforms, S-100a0, S-100a and S-100b, plus a number of structurally related proteins displaying 28-55% homology with S-100 subunits. S-100 protein was discovered in 1965; yet, its biological functions have not been fully elucidated. The present report will review the putative biological roles of S-100 protein. Both intracellular and extracellular roles have been proposed for S-100 protein. Within cells, S-100 protein has been reported to regulate protein phosphorylation, ATPase, adenylate cyclase, and aldolase activities and Ca(2+)-induced Ca2+ release. Also, cytoskeletal systems, namely microtubules and microfilaments have been reported to be regulated by the protein in the presence of Ca2+. Some molecular targets of S-100 protein within cells, have been identified. This is the case with microtubule proteins, caldesmon, and a brain aldolase. S-100 protein has been reported to be secreted; extracellular S-100 protein can stimulate neuronal differentiation, glial proliferation, and prolactin secretion. However, the mechanisms by which S-100 is secreted and stimulates the above processes are largely unknown. Future research should characterize these latter aspects of S-100 biology and find out the linkage between its intracellular effects and its extracellular activities.

Calprotectin (the L1 protein) during surgery in patients with rheumatoid arthritis

Calprotectin (L1) is a major leukocyte protein which is released during activation or death of neutrophil granulocytes and monocytes. Previous studies have shown that L1 may be a useful marker of disease activity in patients with adult or juvenile rheumatoid arthritis (RA). In the present study, the plasma concentrations of L1 were analysed during shoulder-joint surgery in 16 patients with adult or juvenile RA. Decreased L1 concentrations were found 48 h postoperatively. Thereafter, the L1 concentrations were increased at 72 h, with a following decrease until day 14 postoperatively. In contrast, increased serum concentrations of both C-reactive protein (CRP) and orosomucoid (i.e. alpha 1-acid glycoprotein) were found at 48 h after surgery. Plasma samples obtained before and after surgery were analysed by gel filtration. Approximately 3/4 of the plasma L1 was found in fractions corresponding to the native molecule, while the rest was detected in higher molecular mass fractions. The distribution of L1 antigen in low and high molecular mass regions did not differ between the pre- and postoperative plasma samples. The L1 protein consists of light and heavy chains. Increased serum levels of the cystic fibrosis antigen, which is identical to L1 light chain, have been described in patients with cystic fibrosis. The existence of circulating free L1 chains was presently investigated in plasma obtained before and after surgery. After gel filtration of plasma samples, no free L1 chains were detected by use of enzyme immunoassay and dot blot.

Microsequencing of proteins recorded in human two-dimensional gel protein databases

Sixty-six human proteins recorded in the master transformed human epithelial amnion cells (AMA) (55) and keratinocyte (11) two-dimensional gel protein databases have been microsequenced since the last publication of the AMA database (Electrophoresis 1990, 12, 989-1071). Coomassie Brilliant Blue stained protein spots cut from several (up to 40) dry gels were concentrated by elution-concentration gel electrophoresis, electroblotted onto polyvinylidene difluoride membranes and in situ digested with trypsin. The eluting peptides were separated by reversed-phase high performance liquid chromatography (HPLC), collected individually and sequenced. Computer searches using the FASTA and TFASTA programs from the Genetics Computer Group indicated that 29 of the analyzed polypeptides correspond to hitherto unknown proteins.

Molecular cloning, occurrence, and expression of a novel partially secreted protein "psoriasin" that is highly up-regulated in psoriatic skin

Analysis of the protein patterns of normal and psoriatic noncultured unfractionated keratinocytes has revealed several low-molecular-weight proteins that are highly up-regulated in psoriatic epidermis. Here, we have cloned and sequenced the cDNA (clone 1085) for one of these proteins that we have termed psoriasin. The deduced sequence predicted a protein of molecular weight of 11,457 daltons and a pI of 6.77. The protein co-migrated with psoriasin as determined by two-dimensional (2D) gel analysis of [35S]-methionine-labeled proteins expressed by RK13 cells transfected with clone 1085 using the vaccinia virus expression system. Analysis of the predicted sequence revealed a potential calcium-binding sequence of the EF-hand type, as well as the absence of a signal sequence at its amino terminal. Psoriasin is not related to other proteins that migrate closely in 2D gels (MRP 14, also known as calgranulin B, L1 and calprotectin; MRP 8, or calgranulin A and cystatin A or stefin A), and bears no significant sequence homology with any other protein of known primary structure. Increased expression of psoriasin mRNA in psoriatic keratinocytes was confirmed by Northern blotting and in situ hybridization. Psoriasin showed a restricted occurrence in fetal human tissues as determined by 2D gel electrophoresis. Of 21 tissues analyzed, only ear, skin, and tongue showed significant levels of this protein. Psoriasin was not detected in normal human fibroblasts, lymphocytes, endothelial cells and transformed epithelial cells of keratinocyte origin. Granulocyte extracts contained this protein suggesting that its overexpression by psoriatic keratinocytes may be linked to the inflammatory stimuli.

Immunophenotypic analysis of histiocytes involved in AIDS-associated Mycobacterium scrofulaceum infection: similarities with lepromatous lepra

The present study reports a rare case of systemic M. scrofulaceum infection in an AIDS patient and analyses the inflammatory infiltrate in a lymph node by immunohistochemistry. Special emphasis is put on the histiocytes. The diffuse infiltrate consists mainly of large histiocytes that contain numerous bacilli. These cells display the phenotype of mature histiocytes and in addition coexpress the antigens recognized by RFD7 and RFD9, both markers of different subsets of histiocytes which have been reported to be co-expressed by the infected histiocytes in the infiltrate of lepromatous lepra. Interdigitating reticulum cells are rare as well as T cells which are mainly of the suppressor/cytotoxic type. These findings are similar to those reported for lepromatous lepra and might indicate common deficiencies in T cell-macrophage interactions in both conditions. Superimposed on the diffuse infiltrate of large histiocytes we observed 'monocytic granulomas', the presence of which might be related to a reactional state comparable to erythema nodosum leprosum, a reactional state of lepromatous lepra.

Differential regulation of S100 beta and mRNAs coding for S100-like proteins (42A and 42C) during development and after lesion of rat sciatic nerve

The changes in the levels of S100 beta (a protein that stimulates neurite extension and neuronal survival) and 42A and 42C (S100-like proteins whose mRNAs are induced in PC12 cells by nerve growth factor) during development and after rat sciatic nerve lesions were analyzed. S100 beta, 42A, and 42C mRNAs showed differential regulation during development. S100 beta mRNA was present both in sciatic nerve and brain, and increased more than 11-fold during the first 3 wk of nerve postnatal development. 42A and 42C mRNAs were essentially restricted to sciatic nerve, with little found in either embryonic or adult brain. The levels of 42C and 42A mRNAs in sciatic nerve increased 4- and 14-fold, respectively, by postnatal day 23 compared to postnatal day 2. 42A, 42C, and S100 beta mRNAs also showed a differential regulation during sciatic nerve degeneration and regeneration. Axotomized and control sciatic nerves were examined by Northern blots at various times after a crush or cut injury. 42A and 42C mRNA levels increased rapidly in the distal segment of axotomized nerve, remained two- to five-fold higher than controls at day 14 after injury but returned to control levels by 40 days. In contrast, S100 beta mRNA showed a three-fold decrease in the axotomized nerve between days 1 and 3 after injury, and slowly returned towards control levels over the next few weeks. The decrease in S100 beta mRNA was reflected by a corresponding decrease in S100 beta protein levels. The induction of 42A and 42C mRNAs and repression of S100 beta mRNA remained if nerve regeneration was prevented.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurotrophic protein S100 beta stimulates glial cell proliferation

Nervous system development involves a coordinated series of events, including regulation of cell proliferation and differentiation by specific extracellular factors. S100 beta is a neurotrophic protein that has been implicated in regulation of cellular proliferation, but direct evidence was lacking. In this report, nanomolar concentrations of S100 beta are shown to stimulate proliferation of rat C6 glioma cells and primary astrocytes. An S100 mutant with a single amino acid change was inactive. S100 beta also stimulated increases in the steady-state levels of c-myc and c-fos protooncogene mRNAs and complemented the effects of platelet-derived growth factor. Two neuroblastoma cell lines did not proliferate in response to S100 beta, suggesting that the mitogenic activity of S100 beta is selective for astroglial cells. These results suggest that S100 beta may be involved in the coordinate development and maintenance of the central nervous system by synchronously stimulating the differentiation of neurons and the proliferation of astroglia.

Histiocytes in Sweet's syndrome

The histological features of biopsies from 18 previously unreported cases of Sweet's syndrome are reported. The dermal infiltrate in the majority of the cases contained numerous histiocytes that at first sight appeared to mimic neutrophils. The immunophenotype of these histiocytes was consistent with monocytes that have freshly infiltrated into the lesions. Only two of the cases in this series, associated with leukaemia, displayed the histological features of Sweet's syndrome with a predominant neutrophilic infiltration. We suggest that the initiating mechanisms in Sweet's syndrome are that monocyte/histiocyte-derived cytokines such as the interleukins IL-1 and IL-8, secreted either by infiltrating histiocytes in the non-leukaemia-associated cases of Sweet's syndrome or by tumoural myelomonocytic cells in those associated with leukaemia, are responsible for the systemic manifestations and the infiltration with neutrophils in the skin lesions.

Positive selection of candidate tumor-suppressor genes by subtractive hybridization

A positive selection system designed to identify and recover candidate tumor-suppressor genes is described. The system compares mRNA expression of genes from normal and tumor-derived human mammary epithelial cells grown in a special medium that supports similar growth rates of the two cell types. mRNAs uniquely expressed in normal cells are recovered as cDNAs after subtraction with mRNA from tumor cells. Seven different clones, from 0.6 to 4.8 kilobases in transcript size and including both rare and abundunt transcripts, were recovered in the first 23 clones analyzed. Among the isolated clones were genes encoding the gap-junction protein connexin 26, two different keratins, and glutathione-S-transferase pi, as well as an unknown gene in the S100 family of small calcium-binding proteins. In principle, tumor-suppressor genes include two classes: class I, in which loss of function results from mutation or deletion of DNA and class II, in which loss of function is from a regulatory block to expression. A class II suppressor gene is assumed to be regulated by a different suppressor gene that lost its function by mutation or deletion. Both classes of tumor-suppressor genes may provide valuable proteins with clinical applications in cancer diagnosis or therapy. Class II suppressors may be especially useful because the normal genes are present and their reexpression may be inducible by drugs or other treatments.

Macrophage migration inhibitory factor (MIF) produced by a human T cell hybridoma clone

A human T cell hybridoma clone, F5, producing high levels of macrophage migration inhibitory factor (MIF) was established by the emetine-actinomycin D selection method. This clone produced two species of MIF which were separated on a Phenyl Sepharose column. We purified MIF-2 (the more hydrophobic species of the two) to homogeneity from the conditioned medium of stimulated F5 cells by a series of steps that included hydrophobic chromatography, ion-exchange chromatography. Ricinus communis lectin affinity chromatography, and high-performance liquid chromatography on anion exchange and reverse-phase columns. Purified MIF was digested with endoproteinase Lys-C and Asp-N. The amino acid sequences of the generated peptides were determined. No sequence similarity with any other protein was found. The molecular weight of MIF-2 was estimated to be 45 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of immunoprecipitates with anti-peptide antibodies. These results show that F5MIF-2 is a novel cytokine.

Identification of 'cystic fibrosis protein' as a complex of two calcium-binding proteins present in human cells of myeloid origin

Cystic fibrosis protein is a serum protein characterized by a pI close to 8.4 and present with a higher concentration in serum and plasma of cystic fibrosis carriers than in controls. This protein was found immunologically indistinguishable from the cystic fibrosis antigen isolated from granulocytes and presenting a sequence analogous to that of MRP-8, a calcium-binding protein expressed in the myeloid cell lineage. Using antibodies directed against MRP-8 and its closely associated calcium-binding protein, MRP-14, we demonstrate here that cystic fibrosis protein purified from serum is a complex of the two proteins MRP-8 and MRP-14.

Cultured epithelial cells from patients with cystic fibrosis have an increased expression of the 14 kDa Ca2(+)-binding protein CFA

The Cystic Fibrosis antigen (CFA) is a 14 kDa. Ca2(+)-binding protein known to be expressed in cells of myeloid origin during normal cell differentiation. CFA serum levels are elevated in Cystic Fibrosis (CF) patients and heterozygotes. We examined the expression of CFA in different cultured epithelial cells from controls and patients with CF. The steady state level of CFA was in general higher in epithelial cells from CF patients compared to control cells and was found to increase during cell aging. The latter difference could be attributed to an increased rate of CFA synthesis rather than to an impairment of CFA degradation or secretion, as shown by pulse chase experiments.

Macrophage-derived angiogenesis factors

A majority of angiogenic factors has been shown to be produced by macrophages. This review will give a concise description of their biochemical nature, their isolation from macrophages and their angiogenic activity. Among the factors with mitogenic effects on endothelial cells are basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha) and very probably insulin-like growth factor-1 (IGF-1). Other secretory products such as angiotropin and human angiogenic factor (HAF) are nonmitogenic but promote angiogenesis by inducing migration of endothelial cells. Prostaglandins, platelet-derived growth factor (PDGF), granulocyte-macrophage- and granulocyte-colony stimulating factor (GM-CSF, G-CSF), interleukin 6 (IL-6) and angiotensin converting enzyme (ACE) have also been shown to be angiogenic, but their mode of action is still to be clearly defined. As the extracellular matrix appears to be involved in the control of angiogenesis, macrophage-derived factors that can alter this structure via degradation or via the clotting system will also be discussed. Tumor necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1) and transforming growth factor-beta (TGF-beta) have complex actions on endothelial cells, and can partially inhibit angiogenesis. Among the factors which solely inhibit neovascularization are the interferons. As it is not known whether all of these factors play a role in angiogenesis in vivo attempts to detect them in situ during the course of neovascularization will be described. Finally macrophages will be discussed as cells that may not be mandatory for each phase of the angiogenic process but whose angiogenic capabilities are comprehensive and unsurpassed by any other cell.

The leukocyte protein L1 in plasma and synovial fluid from patients with rheumatoid arthritis and osteoarthritis

L1 is a major granulocyte and monocyte protein, released during activation and turnover of such cells. Blood and synovial fluid (SF) from 41 patients with rheumatoid arthritis (RA) and 6 patients with osteoarthritis (OA), were analyzed for L1 and the acute phase proteins C-reactive protein, orosomucoid, haptoglobin, alpha 1-antitrypsin and albumin as well as for differential leukocyte count. L1 levels in plasma and SF showed highly significant differences (p less than 0.0001), between the RA and OA patients. All the OA patients had normal plasma concentrations of L1 and low concentrations of L1 in SF. All the RA patients had elevated plasma levels of L1 and high L1 concentrations in SF. In the RA patients, the ratios between the protein concentrations in SF and blood were 3.29 for L1 and less than or equal to 0.64 for the acute phase proteins. In the SF, the L1 levels did not correlate with the monocyte count, while a low, positive correlation was found between L1 and the granulocyte count. The high L1 concentrations observed in SF from RA patients probably reflected an increased turnover of leukocytes in the inflamed joints. In SF from RA patients, high L1 concentrations were found in joints with a high amount of swelling. The present study suggests that L1 may represent a marker of both local and systemic inflammation.

L1, a major granulocyte protein; isolation of high quantities of its subunits

L1 is a major granulocyte and monocyte protein with a Mr of 36.5 kDa. It is found mainly in the cytosol of these cells. Purified L1 is shown, on two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), to contain three subunits. In this study, 6 mol/l concentration of urea was found to be sufficient for disassembly of the polypeptides, and urea-containing preparative isoelectric focusing gel was used for separation of high quantities of the subunits. The pI of the eluted subunits were 5.8, 6.1 and 7.1. When tested on 2D-PAGE, the isolated subunits were found at their typical locations. Polyclonal rabbit antibodies were produced against the subunits, and the antisera were, on dot-blot, found to react with the different subunits as well as the purified L1.

Changes in PC12 cell morphology induced by transfection with 42C cDNA, coding for a member of the S-100 protein family

The cloned DNA coding for 42C protein (light chain of calpactin I), whose mRNA is induced in PC12 cells by treatment with nerve growth factor (NGF), was reintroduced into these cells. A cell line was obtained in which the outgrowth of processes in the absence of added NGF, similar to that induced in the parental PC12 cells by the factor, was accompanied by high levels of 42C RNA. The apparent reason for this constitutive overexpression of 42C is the stable integration of multiple copies of the 42C DNA into the cell genome. These results further support the notion that S-100 protein family, of which 42C is a member, may play an important role in development.

Related calcium-binding proteins map to the same subregion of chromosome 1q and to an extended region of synteny on mouse chromosome 3

The serum protein cystic fibrosis-associated antigen (CFAG), present at elevated levels in CF homozygotes and heterozygotes, is now known to consist of two distinct but related subunits (calgranulins A (CAGA) and B (CAGB)). Both show similarity to the S100-related calcium-binding proteins. We have previously assigned CAGA to human chromosome 1q12-q21 and demonstrate here that the cDNA probe for CAGB cosegregates with it in our somatic cell hybrid panel. cDNA probes for the related genes calcyclin (CACY) and a mouse placental protein (18A2, suggested name Capl) enabled us to confirm and refine the in situ hybridization result assigning CACY to chromosome 1q21-25 and to demonstrate that both genes cosegregate with CAGA and CAGB. Capl was mapped to a region of chromosome 3 in the mouse using the BXD recombinant inbred strain mice where the p11 protein (calpactin light chain Cal1l), another S100 family member, has been localized. Cacy is shown to be within 8 kb of Capl in the mouse genome.

Antimicrobial actions of calcium binding leucocyte L1 protein, calprotectin

The calcium binding L1 protein was found to inhibit growth of blood culture isolates of Candida spp and cerebrospinal fluid isolates of Cryptococcus neoformans. Minimum inhibitory concentrations (MIC) were 4-128 mg/l, and concentrations 2-4 times the MIC were fungicidal. Blood culture isolates of Escherichia coli, Klebsiella spp, Staphylococcus aureus, and Staphylococcus epidermidis had MIC values of 64-256 mg/l. Antibacterial activity was strongly influenced by the nature of the culture medium. In view of the biological activity of L1, the name calprotectin is proposed to describe this antimicrobial protein with calcium binding properties.

Single chain-urokinase binds to oxidized fibrin(ogen) derivatives

Single chain- urokinase (scu-PA), in contrast to two chain urokinase, is a physiological plasminogen activator of fibrin selectivity. The mechanism of selective fibrinolysis of scu- PA has not been clarified up to now. This study has shown that fibrin selectivity might involve oxidative processes. Binding studies with immobilized oxidized fibrinogen degradation products (FDP) demonstrated higher affinity of scu-PA to oxidized than to unmodified FDP. The fibrin(ogen) domain responsible for this oxidant mediated increase of scu-PA affinity is localized in the D-subunit of fibrin(ogen). Thus, experimental data upon the interaction of scu-PA with fibrin(ogen) using oxidized and I- labelled fibrin(ogen) might be interpreted with caution: the oxidized product may behave in a distinct manner than the unoxidized, native, one. Activated leukocytes release large amounts of scu-PA and of oxidants of the chloramine type. The oxidants could contribute significantly to fibrinolysis and proteolysis in areas of inflammation, preparing fibrin for its specific degradation. The present data support the concept of an involvement of oxidative processes in the fibrinolytic pathway.

Differential expression of the calcium-binding proteins MRP8 and MRP14 in granulomatous conditions: an immunohistochemical study

MRP14 and MRP8 are well-characterized calcium-binding proteins present in myeloid cells and mononuclear phagocytes. These antigens can easily be visualized in paraffin-embedded tissue, making use of monospecific polyclonal antibodies. This study evaluates MRP14 and MRP8 expression in mononuclear phagocytes in various granulomatous conditions. MRP14 is strongly expressed in all granulomatous conditions. MRP8 is variably expressed. Mononuclear phagocytes in granulomas of foreign body type, cat-scratch disease and erythema nodosum strongly express MRP8. In contrast, MRP8 expression is weak or absent in mononuclear phagocytes of sarcoidosis and tuberculosis. These results show differences in immunophenotype between non-phagocytic mononuclear phagocytes in delayed hypersensitivity type granulomas and phagocytic mononuclear phagocytes in non-hypersensitivity and non-immunological granulomas.

Calcium-ion binding by the potential calcium-ion-binding protein, p9Ka

p9Ka is a polypeptide of apparent molecular mass 9 kDa, present in cultured rat mammary myoepithelial-like cells, but virtually absent in their parental epithelial cells. mRNA for p9Ka is present in normal rodent tissues. The amino acid sequence of a protein of molecular mass 12 KDa, derived from the nucleotide sequence of the p9Ka gene, is related to that of S-100 protein, a calcium-ion-binding protein. p9Ka, isolated from cultured rat mammary myoepithelial-like cells is now shown to bind calcium ions in vitro suggesting that the derived amino acid sequence is correct, and that an apparent discrepancy between the molecular masses of the predicted and isolated p9Ka does not affect this activity.

Evolution of EF-hand calcium-modulated proteins. I. Relationships based on amino acid sequences

The relationships among 153 EF-hand (calcium-modulated) proteins of known amino acid sequence were determined using the method of maximum parsimony. These proteins can be ordered into 12 distinct subfamilies--calmodulin, troponin C, essential light chain of myosin, regulatory light chain, sarcoplasmic calcium binding protein, calpain, aequorin, Stronglyocentrotus purpuratus ectodermal protein, calbindin 28 kd, parvalbumin, alpha-actinin, and S100/intestinal calcium-binding protein. Eight individual proteins--calcineurin B from Bos, troponin C from Astacus, calcium vector protein from Branchiostoma, caltractin from Chlamydomonas, cell-division-cycle 31 gene product from Saccharomyces, 10-kd calcium-binding protein from Tetrahymena, LPS1 eight-domain protein from Lytechinus, and calcium-binding protein from Streptomyces--are tentatively identified as unique; that is, each may be the sole representative of another subfamily. We present dendrograms showing the relationships among the subfamilies and uniques as well as dendrograms showing relationships within each subfamily. The EF-hand proteins have been characterized from a broad range of organismal sources, and they have an enormous range of function. This is reflected in the complexity of the dendrograms. At this time we urge caution in assigning a simple scheme of gene duplications to account for the evolution of the 600 EF-hand domains of known sequence.

Calbindin D-28k and parvalbumin in the rat nervous system

This paper describes the distribution of structures stained with mono- and polyclonal antibodies to the calcium-binding proteins calbindin D-28k and parvalbumin in the nervous system of adult rats. As a general characterization it can be stated that calbindin antibodies mainly label cells with thin, unmyelinated axons projecting in a diffuse manner. On the other hand, parvalbumin mostly occurs in cells with thick, myelinated axons and restricted, focused projection fields. The distinctive staining with antibodies against these two proteins can be observed throughout the nervous system. Calbindin D-28k is primarily associated with long-axon neurons (Golgi type I cells) exemplified by thalamic projection neurons, strionigral neurons, nucleus basalis Meynert neurons, cerebellar Purkinje cells, large spinal-, retinal-, cochlear- and vestibular ganglion cells. Calbindin D-28k occurs in all major pathways of the limbic system with the exception of the fornix. Calbindin D-28k is, however, also found in some short-axon cells (Golgi type II), represented by spinal cord interneurons in layer II and interneurons of the cerebral cortex. It is also detectable in some ependymal cells and abundantly occurs in vegetative centres of the hypothalamus. The "paracrine core" of the nervous system and its adjunct (1985, Nieuwenhuys, Chemoarchitecture of the Brain. Springer, Berlin) is very rich in calbindin D-28k. The distribution of calbindin D-28k-positive neurons is very similar to that of the dihydroperydine subtype of calcium channels. Most of the cells containing calbindin D-28k are vulnerable to neurodegenerative processes. Parvalbumin-immunoreactive neurons have a different, and mostly complementary distribution compared with those which react with calbindin D-28k antisera, but in a few cases (Purkinje cells of the cerebellum, spinal ganglion neurons), both calcium-binding proteins co-exist in the same neuron. Many parvalbumin-immunoreactive cells in the central nervous system are interneurons (Golgi type II) and, to a lesser extent, long-axon cells (Golgi type I), whereas conditions are vice versa in the peripheral nervous system. Intrinsic parvalbuminic neurons are prominent in the cerebral cortex, hippocampus, cerebellar cortex and spinal cord. Long-axon parvalbumin-immunoreactive neurons are, for example, the Purkinje cells, neurons of the thalamic reticular nucleus, globus pallidus, substantia nigra (pars reticulata) and a subpopulation among large spinal-, retinal-, cochlear- and vestibular ganglion cells. Parvalbumin is rich in cranial nerve nuclei related to eye movements. In addition to nervous elements, parvalbumin immunoreactivity occurs in a few ependymal cells and in some pillar cells of the organ of Corti.(ABSTRACT TRUNCATED AT 400 WORDS)

Neurite extension and neuronal survival activities of recombinant S100 beta proteins that differ in the content and position of cysteine residues

S100 beta produced in Escherichia coli from a synthetic gene (Van Eldik, L. J., J. L. Staecker, and F. Winningham-Major. 1988. J. Biol. Chem. 263:7830-7837) stimulates neurite outgrowth and enhances cell maintenance in cultures of embryonic chick cerebral cortex neurons. In control experiments, the neurite extension activity is reduced by preincubation with antibodies made against bovine brain S100 beta. When either of the two cysteines in S100 beta are altered by site-directed mutagenesis, the resultant proteins maintain the overall biochemical properties of S100 beta, but lose both the neurite extension and neuronal survival activities. However, another S100 beta mutant, in which the relative position of one of the two cysteines was changed, had neurotrophic activity similar to that of the unmodified protein. These and other results indicate that (a) specific neurite extension activity and neuronal survival activity are two related activities inherent to the S100 beta molecule; (b) a disulfide-linked form of S100 beta is required for full biological activity, and (c) the relative position of the cysteines can be modified. These data suggest potential in vivo roles for S100 beta in the development and maintenance of neuronal function in the central nervous system, and demonstrate the feasibility of the longer term development of selective pharmacological agents based on the S100 beta structure.

Ionomycin-regulated phosphorylation of the myeloid calcium-binding protein p14

Two associated calcium-binding proteins (CaBPs) have recently been identified specifically in cells of myeloid origin. These proteins have relative molecular masses (Mr) of 8,000 and 14,000 and are variously referred to as the cystic fibrosis antigen, the L1 light chain, MRP-8 or p8, and the L1 heavy chain, MRP14 or p14, respectively. The expression of p8 and p14 seems to be confined to a specific stage of myeloid cell differentiation, because both proteins are expressed in circulating neutrophils and monocytes but not in normal tissue macrophages. In chronic inflammatory conditions, however, such as rheumatoid arthritis, macrophages in affected tissues express both p8 and p14. These proteins are members of a family of CaBPs of low Mr, which include S-100 alpha and beta proteins, calcyclin (2A9), intestinal CaBP and p11. All the proteins have an Mr of approximately 10,000 with the exception of p14 which has a longer C-terminal sequence after the second calcium-binding domain. Little is known about their function, although by analogy with calmodulin they could be molecules involved in intracellular signalling that are activated by an increase in the intracellular Ca2+ concentration ([Ca2+]). Here we report that p14 is phosphorylated in both monocytes and neutrophils. The level of p14 phosphorylation can be increased by elevating the [Ca2+]i using the ionophore ionomycin, but is not affected by activation of protein kinase C using phorbol 12,13-dibutyrate. The phosphorylated residue is threonine at position 113, which is the penultimate amino acid in p14 and contained in the longer 'tail' sequence. Part of this sequence is identical to the neutrophil immobilizing factors NIF-1 and NIF-2, indicating that the phosphorylation event could have a role in the generation of NIF activity in the p14 protein.

Oxidized fibrin(ogen) derivatives enhance the activity of tissue type plasminogen activator

Oxidation of fibrinogen degradation products (FDP) with chloramines, results in a five- fold increase of their property to stimulate plasminogen activation by tissue type plasminogen activator (t-PA). Binding studies with immobilized stimulators demonstrated greater affinity of t-PA to oxidized than to unmodified FDP. The fibrin (ogen) domain responsible for this oxidant mediated increase in t-PA stimulation is localized in the D- subunit of fibrin(ogen). Thus, experimental data with (oxidized) I-labelled fibrin(ogen) should be interpreted with caution: the oxidized product might behave in a distinct manner than the unoxidized, native, one. As activated leukocytes release large amounts of oxidants of the chloramine type (Weiss et al., Science 222, 625-628, 1983), oxidation of fibrin might contribute significantly to fibrinolysis and proteolysis in areas of inflammation. The data give further evidence for an involvement of physiological components of haemostasis in non haemostasis but inflammation related processes.

Molecular cloning of a cDNA encoding a human macrophage migration inhibitory factor

A cDNA encoding a human macrophage migration inhibitory factor (MIF) was isolated, through functional expression cloning in COS-1 cells, from a cDNA library prepared from a lectin-stimulated T-cell hybridoma, T-CEMB. The 115-amino acid polypeptide encoded by the MIF cDNA (p7-1) was effectively released from the transfected COS-1 cells and yielded readily detectable MIF activity in the culture supernatant despite the apparent lack of a classical protein secretory sequence. Insertional mutational analysis and elution of MIF activity from polyacrylamide gel slices demonstrated that the Mr 12,000 protein with MIF activity released by the COS-1 cells is encoded by p7-1. The p7-1 cDNA hybridized with a 700-base mRNA expressed by Con-A-stimulated lymphocytes but not unstimulated lymphocytes. The availability of the MIF cDNA clone and recombinant MIF will facilitate the analysis of the role of this lymphokine in cell-mediated immunity, immunoregulation, and inflammation.

Calgranulin expression in inflammatory dermatoses

We have used monoclonal antibodies to study the expression of calgranulins by keratinocytes in inflammatory dermatoses. Calgranulins are intracellular calcium binding proteins which have inflammatory cytokine activity and are composed of at least two different chains, calgranulin A and B. Antibody CF 145 and CF 557 identify calgranulin A and B, respectively. MAC 387 recognizes a molecule probably containing both calgranulins. Keratinocytes in normal skin did not contain these molecules. The keratinocytes in 52 cases of different inflammatory dermatoses showed expression of both calgranulin chains in lesional but not in non-lesional skin. Keratinocytes in inflammatory dermatoses therefore express an intracellular calcium binding protein which has cytokine activity.