The human homolog of the JE gene encodes a monocyte secretory protein

Heterotypic signaling of cancer-associated fibroblasts in shaping the cancer cell drug resistance

The context-dependent reciprocal interaction between the cancer cells and surrounding fibroblasts is imperative for regulating malignant potential, metabolic reprogramming, immunosuppression, and ECM deposition. However, recent evidence also suggests that cancer-associated fibroblasts induce chemoresistance in cancer cells to various anticancer regimens. Because of the protumorigenic function of cancer-associated fibroblasts, these stromal cell types have emerged as fascinating therapeutic targets for cancer. However, this notion was recently challenged by studies that targeted cancer-associated fibroblasts and highlighted the underlying heterogeneity by identifying a subset of these cells with tumor-restricting functions. Hence, it is imperative to understand the heterogeneity and heterotypic signaling of cancer-associated fibroblasts to target tumor-promoting signaling processes by sparing tumor-restricting ones. In this review, we discuss the heterogeneity and heterotypic signaling of cancer-associated fibroblasts in shaping drug resistance and also list the cancer-associated fibroblast-targeting therapeutics.

Characterisation of urinary monocyte chemoattractant protein 1: Potential biomarker for patients with overactive bladder

Objective: To investigate urinary monocyte chemoattractant protein 1 (MCP-1) as a potential marker for idiopathic overactive bladder (OAB). This is a quantitative measurement of urinary MCP-1 to establish baseline normal values that could help in future index studies. Normalised urinary MCP-1 levels are measured in female patients with OAB and aged-matched controls. Severity of OAB symptoms is correlated to normalised urinary MCP-1 levels.

Patients and methods: Urinary MCP-1 levels were measured in 29 female patients with OAB and 10 normal female controls. The patients with OAB were either newly diagnosed or off any OAB oral therapy for at least 2 weeks. OAB symptoms were assessed using validated OAB questionnaires. Urinary MCP-1 levels were measured using enzyme-linked immunosorbent assay and normalised by urinary creatinine (Cr) levels.

Results: The baseline urinary MCP-1 levels in female patients with OAB were significantly higher than those of the controls, at a mean of 210.25 vs 48.02 pg/mg Cr (P < 0.001). Patients who had severe OAB bother symptoms had higher levels of urinary MCP-1 (r = 0.03), also patients with OAB-wet had higher levels of urinary MCP-1, at a mean (SEM) of 209.25 (30.5) vs OAB-dry 185.25 (10) pg/mg Cr (P < 0.001).

Conclusion: Urinary MCP-1 levels were higher in female patients with idiopathic OAB. The close association of urinary MCP-1 and OAB bother severity symptoms and OAB-wet suggest that inflammation plays a major role in the pathophysiological mechanisms underlying the sensitisation of bladder afferent nerves. Establishing urinary MCP-1 levels in patients with OAB hopefully will help future studies to confirm the correlation as a baseline and changes with treatments.

Abbreviations: BMI: body mass index; Cr: creatinine; MCP-1: monocyte chemoattractant protein 1; OAB: overactive bladder; OAB-q: Overactive Bladder Questionnaire; PPBC: Patient Perception of Bladder Condition; UI: urinary incontinence

Stromal cells in breast cancer as a potential therapeutic target

Breast cancer in the United States is the second most commonly diagnosed cancer in women. About 1 in 8 women will develop invasive breast cancer over the course of her lifetime and breast cancer remains the second leading cause of cancer-related death. In pursuit of novel therapeutic strategies, researchers have examined the tumor microenvironment as a potential anti-cancer target. In addition to neoplastic cells, the tumor microenvironment is composed of several critical normal cell types, including fibroblasts, vascular and lymph endothelial cells, osteoclasts, adipocytes, and immune cells. These cells have important roles in healthy tissue stasis, which frequently are altered in tumors. Indeed, tumor-associated stromal cells often contribute to tumorigenesis, tumor progression, and metastasis. Consequently, these host cells may serve as a possible target in anti-tumor and anti-metastatic therapeutic strategies. Targeting the tumor associated host cells offers the benefit that such cells do not mutate and develop resistance in response to treatment, a major cause of failure in cancer therapeutics targeting neoplastic cells. This review discusses the role of host cells in the tumor microenvironment during tumorigenesis, progression, and metastasis, and provides an overview of recent developments in targeting these cell populations to enhance cancer therapy efficacy.

Chemokine isoforms and processing in inflammation and immunity

The first dimension of chemokine heterogeneity is reflected by their discovery and purification as natural proteins. Each of those chemokines attracted a specific inflammatory leukocyte type. With the introduction of genomic technologies, a second wave of chemokine heterogeneity was established by the discovery of putative chemokine-like sequences and by demonstrating chemotactic activity of the gene products in physiological leukocyte homing. In the postgenomic era, the third dimension of chemokine heterogeneity is the description of posttranslational modifications on most chemokines. Proteolysis of chemokines, for instance by dipeptidyl peptidase IV (DPP IV/CD26) and by matrix metalloproteinases (MMPs) is already well established as a biological control mechanism to activate, potentiate, dampen or abrogate chemokine activities. Other posttranslational modifications are less known. Theoretical N-linked and O-linked attachment sites for chemokine glycosylation were searched with bio-informatic tools and it was found that most chemokines are not glycosylated. These findings are corroborated with a low number of experimental studies demonstrating N- or O-glycosylation of natural chemokine ligands. Because attached oligosaccharides protect proteins against proteolytic degradation, their absence may explain the fast turnover of chemokines in the protease-rich environments of infection and inflammation. All chemokines interact with G protein-coupled receptors (GPCRs) and glycosaminoglycans (GAGs). Whether lectin-like GAG-binding induces cellular signaling is not clear, but these interactions are important for leukocyte migration and have already been exploited to reduce inflammation. In addition to selective proteolysis, citrullination and nitration/nitrosylation are being added as biologically relevant modifications contributing to functional chemokine heterogeneity. Resulting chemokine isoforms with reduced affinity for GPCRs reduce leukocyte migration in various models of inflammation. Here, these third dimension modifications are compared, with reflections on the biological and pathological contexts in which these posttranslational modifications take place and contribute to the repertoire of chemokine functions and with an emphasis on autoimmune diseases.

Live fibroblast harvest reveals surface marker shift in vitro

Current methods for the isolation of fibroblasts require extended ex vivo manipulation in cell culture. As a consequence, prior studies investigating fibroblast biology may fail to adequately represent cellular phenotypes in vivo. To overcome this problem, we describe a detailed protocol for the isolation of fibroblasts from the dorsal dermis of adult mice that bypasses the need for cell culture, thereby preserving the physiological, transcriptional, and proteomic profiles of each cell. Using the described protocol we characterized the transcriptional programs and the surface expression of 176 CD markers in cultured versus uncultured fibroblasts. The differential expression patterns we observed highlight the importance of a live harvest for investigations of fibroblast biology.

Vimentin is a target of PKCβ phosphorylation in MCP-1-activated primary human monocytes

OBJECTIVE AND DESIGN

We designed a study to detect downstream phosphorylation targets of PKCβ in MCP-1-induced human monocytes.

METHODS

Two-dimensional gel electrophoresis was performed for monocytes treated with MCP-1 in the presence or absence of PKCβ antisense oligodeoxyribonucleotides (AS-ODN) or a PKCβ inhibitor peptide, followed by phospho- and total protein staining. Proteins that stained less intensely with the phospho-stain, when normalized to the total protein stain, in the presence of PKCβ AS-ODN or the PKCβ inhibitor peptide, were sequenced.

RESULTS

Of the proteins identified, vimentin was consistently identified using both experimental approaches. Upon (32)P-labeling and vimentin immunoprecipitation, increased phosphorylation of vimentin was observed in MCP-1 treated monocytes as compared to the untreated monocytes. Both PKCβ AS-ODN and the PKCβ inhibitor reduced MCP-1-induced vimentin phosphorylation. The IP of monocytes with anti-vimentin antibody and immunoblotting with a PKCβ antibody revealed that increased PKCβ becomes associated with vimentin upon MCP-1 activation. Upon MCP-1 treatment, monocytes were shown to secrete vimentin and secretion depended on PKCβ expression and activity.

CONCLUSIONS

We conclude that vimentin, a major intermediate filament protein, is a phosphorylation target of PKCβ in MCP-1-treated monocytes and that PKCβ phosphorylation is essential for vimentin secretion. Our recently published studies have implicated vimentin as a potent stimulator of the innate immune receptor Dectin-1 as reported by Thiagarajan et al. (Cardiovasc Res 99:494-504, 2013). Taken together our findings suggest that inhibition of PKCβ regulates vimentin secretion and, thereby, its interaction with Dectin-1 and downstream stimulation of superoxide anion production. Thus, PKCβ phosphorylation of vimentin likely plays an important role in propagating inflammatory responses.

Utilizing pharmacokinetics/pharmacodynamics modeling to simultaneously examine free CCL2, total CCL2 and carlumab (CNTO 888) concentration time data

The chemokine ligand 2 (CCL2) promotes angiogenesis, tumor proliferation, migration, and metastasis. Carlumab is a human IgG1κ monoclonal antibody with high CCL2 binding affinity. Pharmacokinetic/pharmacodynamic data from 21 cancer patients with refractory tumors were analyzed. The PK/PD model characterized the temporal relationships between serum concentrations of carlumab, free CCL2, and the carlumab-CCL2 complex. Dose-dependent increases in total CCL2 concentrations were observed and were consistent with shifting free CCL2. Free CCL2 declined rapidly after the initial carlumab infusion, returned to baseline within 7 days, and increased to levels greater than baseline following subsequent doses. Mean predicted half-lives of carlumab and carlumab-CCL2 complex were approximately 2.4 days and approximately 1 hour for free CCL2. The mean dissociation constant (KD ), 2.4 nM, was substantially higher than predicted by in vitro experiments, and model-based simulation revealed this was the major factor hindering the suppression of free CCL2 at clinically viable doses.

Microenvironment and tumor cell plasticity: an easy way out

Cancer cells undergo genetic changes allowing their adaptation to environmental changes, thereby obtaining an advantage during the long metastatic route, disseminated of several changes in the surrounding environment. In particular, plasticity in cell motility, mainly due to epigenetic regulation of cancer cells by environmental insults, engage adaptive strategies aimed essentially to survive in hostile milieu, thereby escaping adverse sites. This review is focused on tumor microenvironment as a collection of structural and cellular elements promoting plasticity and adaptive programs. We analyze the role of extracellular matrix stiffness, hypoxia, nutrient deprivation, acidity, as well as different cell populations of tumor microenvironment.

Structural basis for high selectivity of anti-CCL2 neutralizing antibody CNTO 888

Human CC chemokine ligand 2 (CCL2), also known as monocyte chemoattractant protein-1 (MCP-1), is a member of the β chemokine family whose actions are mediated through the G-protein-coupled receptor CCR2. Binding of CCL2 to its receptor CCR2 triggers calcium mobilization and chemotaxis. CCL2 is implicated in the pathogenesis of certain inflammatory diseases and cancer. CNTO 888, a neutralizing human anti-CCL2 antibody, was derived by antibody phage display. The antibody binds human CCL2 with high affinity (K(D)=22 pM) and inhibits CCL2 binding to its receptor. The crystal structure of the CNTO 888 Fab alone and in complex with the monomeric form of CCL2 (P8A variant) was determined at 2.6 Å and 2.8 Å resolution, respectively. CNTO 888 recognizes a conformational epitope encompassing residues 18-24 and 45-51 that overlaps the mapped receptor binding site. The epitope of CNTO 888 does not overlap with the dimerization site of CCL2, and thus its inhibitory activity is not expected to result from interference with the oligomeric state of CCL2. Comparison of the X-ray-determined epitopes of CNTO 888 and another CCL2-neutralizing antibody, 11K2, provides insight into the molecular basis of antibody selectivity and functional inhibition.

Regulation of MCP-1 chemokine transcription by p53

BACKGROUND

Our previous studies showed that the expression of the monocyte-chemoattractant protein (MCP)-1, a chemokine, which triggers the infiltration and activation of cells of the monocyte-macrophage lineage, is abrogated in human papillomavirus (HPV)-positive premalignant and malignant cells. In silico analysis of the MCP-1 upstream region proposed a putative p53 binding side about 2.5 kb upstream of the transcriptional start. The aim of this study is to monitor a physiological role of p53 in this process.

RESULTS

The proposed p53 binding side could be confirmed in vitro by electrophoretic-mobility-shift assays and in vivo by chromatin immunoprecipitation. Moreover, the availability of p53 is apparently important for chemokine regulation, since TNF-alpha can induce MCP-1 only in human keratinocytes expressing the viral oncoprotein E7, but not in HPV16 E6 positive cells, where p53 becomes degraded. A general physiological role of p53 in MCP-1 regulation was further substantiated in HPV-negative cells harboring a temperature-sensitive mutant of p53 and in Li-Fraumeni cells, carrying a germ-line mutation of p53. In both cases, non-functional p53 leads to diminished MCP-1 transcription upon TNF-alpha treatment. In addition, siRNA directed against p53 decreased MCP-1 transcription after TNF-alpha addition, directly confirming a crosstalk between p53 and MCP-1.

CONCLUSION

These data support the concept that p53 inactivation during carcinogenesis also affects immune surveillance by interfering with chemokine expression and in turn communication with cells of the immunological compartment.

Effects of synthetic monocyte chemotactic protein-1 fragment 65-76 on neointima formation after carotid artery balloon injury in rats

The effects of the synthetic monocyte chemotactic protein-1 (MCP-1) peptide fragment 65-76 (peptide X) on the development of neointima after balloon injury to the carotid artery were studied. The agent was given i.m. at a dose of 33 microg/kg once daily for 28 days after balloon injury. Animals given peptide showed significant suppression of neointima growth 4 and 7 days after lesioning, as indicated by morphometric analysis of sections of lesioned arteries. On days 14 and 28, there were no significant differences in neointima formation in rats given and not given peptide. Peptide administration was not accompanied by any changes in C-reactive peptide concentrations, leukocyte counts, or the population composition of peripheral blood lymphocytes. Use of synthetic peptide X as an inhibitor of leukocyte migration during angioplasty may, along with traditional treatments, decrease the risk of restenosis.

Monocyte chemoattractant protein-1 and atherosclerosis: is there room for an additional biomarker?

Atherosclerosis is an inflammatory disease in which several chemokines are implicated. The roles of these molecules extend from the recruitment of circulating inflammatory cells to the activation of inflammatory and pro-thrombotic cascades, which ultimately leads to an atherosclerosis-related event. One of the most studied chemokines is monocyte chemoattractant protein-1 (CCL2), which has been strongly linked to atherosclerosis in both animal and human studies. The higher the expression of either the CCL2 gene or its receptor CCR-2, the higher the likelihood of developing atherosclerosis in genetically-modified animals. Conversely, the deletion of either CCL2 or its receptor is followed by a significant reduction in the development of atherosclerotic plaques. Studies in humans yield controversial results. Most of these studies linked the plasma CCL2 concentration to the occurrence of atherosclerosis or related events; however, this relationship does not seem to be independent of the classical, known risk factors. Currently, there are no suitable analytical tools to reach strong conclusions with respect to the value of plasma CCL2 concentration as a biomarker of atherosclerosis, but experimental evidence suggests that the CCL2/CCR2 pathway should be further explored as a diagnostic, prognostic and therapeutic target.

A novel role for the glucocorticoid receptor in the regulation of monocyte chemoattractant protein-1 mRNA stability

Monocyte chemoattractant protein-1 (MCP-1) plays an important role in attracting monocytes to sites of inflammation and is the dominant mediator of macrophage accumulation in atherosclerotic plaques. We have previously shown that glucocorticoids inhibit the secretion of MCP-1 in arterial smooth muscle cells (SMC) by markedly decreasing MCP-1 mRNA stability. We now report that the destabilization of MCP-1 mRNA is mediated by the glucocorticoid receptor (GR). The GR antagonist, RU486, blocked the effect of the glucocorticoid dexamethasone (Dex) on MCP-1 mRNA stability in SMC culture. Using a previously reported in vitro mRNA gel shift and stability assay, antibodies to the GR blocked the ability of cytoplasmic extracts from Dex-treated SMC to decay MCP-1 mRNA. Recombinant human GR (rhGR) bound in a concentration-dependent manner to in vitro transcribed MCP-1 mRNA, whereas other members of the steroid hormone receptor family did not. Binding of GR to MCP-1 mRNA was specific as it was not found to bind other mRNAs. Immunoprecipitation of GR in extracts from Dex-treated SMC followed by real-time reverse transcription-PCR demonstrated that endogenous GR was bound specifically to MCP-1 mRNA. The addition of exogenous rhGR blocked the ability of extracts from Dex-treated SMC to degrade MCP-1 mRNA, suggesting that exogenous rhGR can compete with an endogenous GR-containing degradative complex. These data suggest a novel role for the GR in binding to and facilitating mRNA degradation. These results provide novel insights into GR function and may provide a new approach to attenuate the inflammatory response mediated by MCP-1.

Fibroblasts in cancer

Tumours are known as wounds that do not heal - this implies that cells that are involved in angiogenesis and the response to injury, such as endothelial cells and fibroblasts, have a prominent role in the progression, growth and spread of cancers. Fibroblasts are associated with cancer cells at all stages of cancer progression, and their structural and functional contributions to this process are beginning to emerge. Their production of growth factors, chemokines and extracellular matrix facilitates the angiogenic recruitment of endothelial cells and pericytes. Fibroblasts are therefore a key determinant in the malignant progression of cancer and represent an important target for cancer therapies.

Prostaglandin E2 promotes degranulation-independent release of MCP-1 from mast cells

Mast cells (MCs) are common components of inflammatory infiltrates and a source of proangiogenic factors. Inflammation is often accompanied by vascular changes. However, little is known about modulation of MC-derived proangiogenic factors during inflammation. In this study, we evaluated the effects of the proinflammatory mediator prostaglandin E2 (PGE2) on MC expression and release of proangiogenic factors. We report that PGE2 dose-dependently induces primary MCs to release the proangiogenic chemokine monocyte chemoattractant protein-1 (MCP-1). This release of MCP-1 is complete by 2 h after PGE2 exposure, reaches levels of MCP-1 at least 15-fold higher than background, and is not accompanied by degranulation or increased MCP-1 gene expression. By immunoelectron microscopy, MCP-1 is detected within MCs at a cytoplasmic location distinct from the secretory granules. Dexamethasone and cyclosporine A inhibit PGE2-induced MCP-1 secretion by approximately 60%. Agonists of PGE2 receptor subtypes revealed that the EP1 and EP3 receptors can independently mediate MCP-1 release from MCs. These observations identify PGE2-induced MCP-1 release from MCs as a pathway underlying inflammation-associated angiogenesis and extend current understanding of the activities of PGE2.

Antibody-bound β-amyloid precursor protein stimulates the production of tumor necrosis factor-α and monocyte chemoattractant protein-1 by cortical neurons

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the accumulation of extracellular depositions of fibrillar beta-amyloid (A beta), which is derived from the alternative processing of beta-amyloid precursor protein (APP). Although APP is thought to function as a cell surface receptor, its mode of action still remains elusive. In this study, we found that the culture medium derived from cortical neurons treated with an anti-APP antibody triggers the death of naive neurons. Biochemical and immunocytochemical analyses revealed the presence, both in the conditioned medium and in neurons, of increased levels of tumor necrosis factor-alpha and monocyte chemoattractant protein-1. Furthermore, the expression of these proinflammatory mediators occurred through a c-Jun N-terminal protein kinase/c-Jun-dependent mechanism. Taken together, our findings provide evidence for a novel mechanism whereby neuronal APP in its full-length configuration induces neuronal death. Such a mechanism might be relevant to neuroinflammatory processes as those observed in AD.

Pioglitazone, a peroxisome proliferator-activated receptor-gamma agonist, attenuates myocardial ischemia/reperfusion injury in a rat model

Thiazolidinediones are insulin-sensitizing drugs, ligands for peroxisome proliferator-activated receptor-gamma (PPAR-gamma), which play an important role in the modulation of inflammatory responses. Myocardial ischemia/reperfusion (MI/R) injury is associated with inflammation, in which various cells, particularly monocytes and macrophages, are involved. This study examined the effects of the thiazolidinedione peroxisome proliferator-activated receptor-gamma ligand, pioglitazone, in a rat model of MI/R injury. Pioglitazone at 3 mg/kg/day or the vehicle was administered for 7 days before rats were subjected to 30 minutes of coronary ligation followed by 24 hours of reperfusion. The mRNA expression [monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1] in the ischemic region, the number of infiltrating macrophages in the ischemic region, and the myocardial infarct size were examined. The inhibitory effects of pioglitazone on activated macrophages were studied in vitro. Phorbol 12-myristate 13-acetate-induced MCP-1 production, in the absence or presence of pioglitazone, were assayed in cultured macrophages. Compared with the control group, (1). mRNA levels of MCP-1 and intercellular adhesion molecule-1 and the number of infiltrating macrophages in the ischemic region were significantly lower in the pioglitazone-treated group; and (2). myocardial infarct size was significantly smaller in the pioglitazone-treated group. Phorbol 12-myristate 13-acetate-stimulated cultured macrophages in the presence of pioglitazone produced significantly lower levels of MCP-1 than the stimulated control in the absence of pioglitazone. These observations demonstrate that pioglitazone has anti-inflammatory effects in MI/R injury that are independent of its insulin-sensitizing effect.

Phenotypic change regulates monocyte chemoattractant protein-1 (MCP-1) gene expression in human retinal pigment epithelial cells

We investigated the expression profile of monocyte chemoattractant protein-1 (MCP-1) in human retinal pigment epithelial (RPE) cells under different culture conditions and evaluated the molecular mechanism responsible for MCP-1 gene expression in RPE cells. After cellular confluence, total RNA was extracted and used for RT-PCR. Medium conditioned by RPE was used for ELISA and Western blotting. The result showed that RPE cells cultured on plastic expressed MCP-1 constitutively in the absence of any stimuli. On the other hand, growing human RPE on laminin-coated flasks instead of plastic reduced the production of MCP-1. In the RPE cells cultured on plastic, IkappaB was degraded and A20 protein increased concomitantly. MCP-1 upregulation in RPE cells on plastic was attenuated by the addition of MG-132, a proteasome inhibitor. Also, the addition of pyrolidine dithiocarbonate (PDTC) and hypoxic conditions (0.5% O2) decreased MCP-1 production in these cells. These findings suggested that the expression profile of MCP-1 is regulated by phenotypic alterations of the RPE cells. And the increased MCP-1 expression in RPE cells cultured on plastic is caused via spontaneous activation of NFkappaB induced by susceptibility to oxidative stress.

Protein kinase C beta is required for human monocyte chemotaxis to MCP-1

Monocyte chemoattractant protein 1 (MCP-1) is important in attracting monocytes to sites of inflammation. Using predominantly pharmacological approaches, prior studies have indicated that serine/threonine kinases are involved in the MCP-1-induced signaling pathways. We report here that there is substantial inhibition of MCP-1-stimulated chemotaxis of human monocytes treated with inhibitors selective for the subset of serine/threonine kinases, protein kinase C (PKC). Selective inhibitors of PKC such as GF109203X and Calphostin C both caused approximately 80% inhibition of chemotaxis. Because these pharmacological inhibitors do not specifically inhibit individual PKC isoforms, we chose to use antisense oligodeoxyribonucleotides (ODN) to specifically reduce PKC isoform expression, first by inhibiting expression of the conventional PKC family, and next by using specific antisense ODN for PKCalpha and PKCbeta. Conventional PKC-antisense ODN treatment completely and significantly inhibited monocyte chemotaxis to MCP-1, whereas sense-control ODN caused no significant inhibition. PKCbeta-antisense ODN caused 89.2% inhibition of chemotaxis at its highest dose. In contrast, PKCbeta-sense ODN and PKCalpha-antisense and -sense ODN were without effect. Further studies evaluating the calcium response that is triggered upon MCP-1 interaction with its receptor, CCR2, indicate that this response is not altered by antisense or sense ODN treatment, thus supporting our hypothesis that PKCbeta is critical for post-receptor signal transduction downstream of the immediate calcium signal. These data contribute to our developing understanding of the signal transduction pathways involved in the chemotactic response of human monocytes to MCP-1 and uniquely identify the requirement for the PKCbeta isoform in this important process.

Distinct gene expression of osteopontin in patients with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a multifactorial disorder of unknown etiology. Few studies have applied genome-wide gene expression analysis in colon tissue samples of UC. We report the analysis of mucosal gene expression in UC and noninflamed control specimens.

MATERIALS AND METHODS

This study included 7 UC patients who received a total colectomy because of severe total colitis. Normal control colon tissues were obtained at least 10 cm from the area of pathology in 3 colon cancer patients. Ten colonic tissue samples (7 UC and 3 normal control samples) were subjected to high-density oligonucleotide array analysis. To compare differences in the level of gene expression between UC and control samples, Mann-Whitney U-test was used, with significance set at P < 0.05.

RESULTS

Twenty-five genes had a 3.0 approximately 23.4-fold higher mRNA expression in UC samples compared with normal samples, whereas three genes had a 3.0 approximately 3.4-fold lower expression in UC samples compared with normal samples. Two genes showing more than a 10-fold increase expression in UC samples were a macrophage metalloelastase (L23808) and a osteopontin (AF052124). It has been said that macrophage metalloelastase is related to ulcer formation of the intestine, whereas osteopontin plays an important role in the pathogenesis of systemic lupus erythematosus and rheumatoid arthritis.

CONCLUSION

Our present study supports the previous report that macrophage metalloelastase is related to ulcer formation of UC, and it also indicates the possibility that osteopontin plays an important role in the pathogenesis of UC via increased immune activity.

Serine protease inhibitors modulate chemotactic cytokine production by human lung fibroblasts in vitro

Chemotactic chemokines can be released from lung fibroblasts in response to interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. An imbalance between proteases and antiproteases has been observed at inflammatory sites, and, therefore, protease inhibitors might modulate fibroblast release of chemotactic cytokines. To test this hypothesis, serine protease inhibitors (FK-706, alpha(1)-antitrypsin, or N(alpha)-p-tosyl-L-lysine chloromethyl ketone) were evaluated for their capacity to attenuate the release of neutrophil chemotactic activity (NCA) or monocyte chemotactic activity (MCA) from human fetal lung fibroblasts (HFL-1). Similarly, the release of the chemoattractants IL-8, granulocyte colony-stimulating factor, monocyte chemoattractant protein-1, macrophage colony-stimulating factor, and granulocyte/macrophage colony-stimulating factor, from HFL-1, were evaluated in response to IL-1beta and TNF-alpha. NCA, MCA, and chemotactic cytokines were attenuated by FK-706. However, matrix metalloproteinase inhibitors were without effect, and cysteine protease inhibitors only slightly attenuated chemotactic or cytokine release. These data suggest that IL-1beta and TNF-alpha may stimulate lung fibroblasts to release NCA and MCA by a protease-dependent mechanism and that serine protease inhibitors may attenuate the release.

The role of MCP-1 (CCL2) and CCR2 in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE)

Multiple sclerosis (MS) is the commonest inflammatory demyelinating disease of the human central nervous system (CNS). In MS, CNS inflammation is associated with demyelination and axonal degeneration, which leads to clinical presentation. Expression and cellular localization of CCL2/MCP-1 and CCR2 in MS have been described in the three compartments: brain, cerebrospinal fluid (CSF) and blood. Evidence from descriptive, transgenic, knockout and neutralizing studies of experimental autoimmune encephalomyelitis (EAE) points towards a nonredundant role of CCL2 and CCR2 in the recruitment of inflammatory infiltrate into the CNS. Hence, CCL2 and CCR2 may be targets for specific and effective treatment in MS.

Dual response to Fas ligation in human endothelial cells: apoptosis and induction of chemokines, interleukin-8 and monocyte chemoattractant protein-1

BACKGROUND

To maintain the integrity of tissues, endothelial cells play critical roles. Fas ligand (FasL) is well known to deliver a death signal through its receptor, Fas. The Fas/FasL system may concomitantly induce expressions of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) besides triggering apoptosis in endothelial cells. We also investigated whether an inhibitor of caspase-8 (Z-IETD-FMK) does modulate IL-8 and MCP-1 secretion.

METHODS AND RESULTS

After treatment with interferon-gamma (IFN-gamma), human recombinant FasL (hr FasL) or Fas agonistic antibody (CH-11) was added to cultured human endothelial cells. IFN-gamma up-regulated Fas mRNA levels. Fas ligation promoted apoptosis assessed by fluorescent-activated cell sorter (FACS) analysis in a dose-dependent manner and induced prominent DNA fragmentation. Simultaneously, IL-8 and MCP-1 were secreted from the endothelial cells in response to hr FasL or CH-11 in a dose-dependent manner (P < 0.01). Fas-neutralizing agent (Fas-Fc) suppressed the Fas-mediated secretions of IL-8 and MCP-1 (P < 0.01) both as well as the Fas-mediated apoptosis. On the other hand, whereas Z-IETD-FMK suppressed apoptosis, the inhibitor enhanced the Fas-mediated secretions of both IL-8 and MCP-1 beyond the value of the Fas stimulation alone (P < 0.01), suggesting an enhanced signalling for the chemokine expression.

CONCLUSION

In human endothelial cells, the Fas/FasL system induces both IL-8 and MCP-1 secretions probably via a caspase-8 independent pathway. The Fas/FasL system may amplify the inflammatory cascade in the vascular injury and atherogenesis by recruiting leukocytes at the region of apoptotic endothelial damage.

Strategies for chemokine antagonists as therapeutics

Chemokines are responsible for specific recruitment of leukocytes that are involved both in homing as well as in inflammation. Dysregulation of the system results in excessive recruitment to inflammatory sites and thus prevention of this recruitment is an effective anti-inflammatory strategy. Chemokine receptors are not limited only to cellular recruitment but are also the essential co-factor along with CD4 that enable HIV-1 viruses to infect cells. In this review we discuss the various points of intervention that can be addressed to provide anti-inflammatory and anti-HIV infectivity therapeutics. These include prevention of the receptor-ligand interaction, prevention of the chemokine-glycosaminoglycan interaction, interfering with the signaling pathways that are induced upon receptor activation, and modification of receptor trafficking pathways. We summarize the status of the approaches that have been undertaken to produce therapeutics that block chemokine action.

Gene expression profiling of 12633 genes in Alzheimer hippocampal CA1: transcription and neurotrophic factor down-regulation and up-regulation of apoptotic and pro-inflammatory signaling

Alterations in transcription, RNA editing, translation, protein processing, and clearance are a consistent feature of Alzheimer's disease (AD) brain. To extend our initial study (Alzheimer Reports [2000] 3:161-167), RNA samples isolated from control and AD hippocampal cornu ammonis 1 (CA1) were analyzed for 12633 gene and expressed sequence tag (EST) expression levels using DNA microarrays (HG-U95Av2 Genechips; Affymetrix, Santa Clara, CA). Hippocampal CA1 tissues were carefully selected from several hundred potential specimens obtained from domestic and international brain banks. To minimize the effects of individual differences in gene expression, RNA of high spectral quality (A(260/280) > or= 1.9) was pooled from CA1 of six control or six AD subjects. Results were compared as a group; individual gene expression patterns for the most-changed RNA message levels were also profiled. There were no significant differences in age, postmortem interval (mean < or = 2.1 hr) nor tissue pH (range 6.6-6.9) between the two brain groups. AD tissues were derived from subjects clinically classified as CDR 2-3 (CERAD/NIA). Expression data were analyzed using GeneSpring (Silicon Genetics, Redwood City, CA) and Microarray Data Mining Tool (Affymetrix) software. Compared to controls and 354 background/alignment markers, AD brain showed a generalized depression in brain gene transcription, including decreases in RNA encoding transcription factors (TFs), neurotrophic factors, signaling elements involved in synaptic plasticity such as synaptophysin, metallothionein III, and metal regulatory factor-1. Three- or morefold increases in RNAs encoding DAXX, cPLA(2), CDP5, NF-kappaBp52/p100, FAS, betaAPP, DPP1, NFIL6, IL precursor, B94, HB15, COX-2, and CEX-1 signals were strikingly apparent. These data support the hypothesis of widespread transcriptional alterations, misregulation of RNAs involved in metal ion homeostasis, TF signaling deficits, decreases in neurotrophic support and activated apoptotic and neuroinflammatory signaling in moderately affected AD hippocampal CA1.

Antibody binding to fas ligand attenuates inflammatory cell infiltration and cytokine secretion, leading to reduction of myocardial infarct areas and reperfusion injury

Fas ligand (FasL) induces apoptotic cell death when bound to Fas antigen. The engagement of FasL has anti-inflammatory effects through the prevention of cell proliferation and cytokine secretion. However, the role of FasL in myocardial ischemia/reperfusion (MI/R) injury is unclear. We examined the expression of FasL mRNA in the myocardium of MI/R rats by ligating the left coronary artery for 30 minutes and allowing reperfusion to occur for 0, 1, 3, and 24 hours. The expression of FasL mRNA was enhanced 1 hour after reperfusion, and enhanced levels were consistently seen after 24 hours of reperfusion. FasL immunostaining was observed on neutrophils, macrophages, T cells, and vascular endothelial cells. We then assessed the potential role of FasL in the cell proliferation and cytokine production seen in MI/R injury after 24 hours of reperfusion. Rats were divided into three groups; Group A, without treatment; Group B, treated with nonspecific rabbit IgG; and Group C, treated with anti-FasL antibody. Anti-FasL antibody or rabbit IgG were administered intravenously before coronary artery occlusion. In Group C, interleukin-1beta and interleukin-2 mRNA levels were decreased, and neutrophil and T cell accumulation was attenuated. The infarct area determined by triphenyltetrazolium chloride staining was significantly smaller in Group C (18 +/- 4%) than in Group A (34 +/- 2%) or Group B (33 +/- 4%) (p< 0.0001). However, there was no significant difference in the prevalence of terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling-positive cardiomyocytes among the three groups. These findings suggest that the cardioprotective effect of anti-FasL antibody is due to its anti-inflammatory action, rather than antiapoptotic action. The Fas/FasL system may be involved in the development of MI/R injury.

Analysis of inflammatory gene induction by oxidized phospholipids in vivo by quantitative real-time RT-PCR in comparison with effects of LPS

Oxidized phospholipids are thought to play a role in the development of atherosclerosis and other chronic inflammatory processes. In this study, we analyzed the expression of inflammatory genes induced by oxidized L-alpha-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholin (OxPAPC) in vitro and in vivo using quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Cultured human umbilical vein endothelial cells (HUVEC) and monocyte-like U937 cells were treated with OxPAPC or lipopolysaccharide (LPS) for 3 h. For in vivo studies, OxPAPC or LPS was injected intravenously into female C57Bl/6J mice and different tissues were isolated after 3 h. We found that both OxPAPC and LPS induced expression of early growth response factor 1 (EGR-1) and monocyte chemoattractant protein 1 (MCP-1) in HUVEC and of JE, the mouse homologue of MCP-1, in liver and heart. Interestingly, OxPAPC but not LPS increased expression of heme oxygenase 1 (HO-1) in U937 cells, HUVEC, aorta, heart, liver, and isolated blood cells. In contrast, E-selectin was selectively induced by LPS, but not by OxPAPC. Finally, OxPAPC-induced expression of HO-1 was blocked by a platelet-activating factor (PAF) receptor antagonist. We conclude that oxidized phospholipids are biologically active in vivo and exert a specific response inducing a pattern of genes that is different from that induced by LPS. In addition, we demonstrate that the quantitative real-time RT-PCR technology is a proper tool to investigate differential inflammatory gene induction in vivo.

Unexpected transcriptional induction of monocyte chemoattractant protein 1 by proteasome inhibition: involvement of the c-Jun N-terminal kinase-activator protein 1 pathway

Proteasome inhibitors, the well-known inhibitors of NF-kappaB, are recently considered therapeutic agents for inflammation. However, the anti-inflammatory properties of these agents have not been fully evaluated. In this report we describe a novel effect of proteasome inhibitors on the expression of monocyte chemoattractant protein 1 (MCP-1) in mesangial cells. We found that proteasome inhibitor MG132 dose-dependently induced expression of MCP-1 at the transcriptional level. The stimulatory effect was similarly observed with other proteasome inhibitors (proteasome inhibitor 1 and lactacystin) and in other cell types (NRK fibroblasts). The 5'-flanking region of the MCP-1 gene contains multiple AP-1 sites. To explore the mechanisms involved, we examined the effects of proteasome inhibition on the AP-1 pathway. Northern blot analysis showed that MG132 rapidly induced the expression of c-jun, but not c-fos. Immunoblot analysis showed that MG132 prevented degradation of c-Jun protein. Kinase assay revealed that c-Jun N-terminal kinase (JNK) was rapidly activated by MG132. Consistent with these results, a reporter assay showed that AP-1 activity was up-regulated after treatment with MG132. Curcumin, a pharmacological inhibitor of the JNK-AP-1 pathway, abrogated the induction of MCP-1 by MG132. Similarly, stable transfection with a dominant-negative mutant of c-Jun attenuated both MG132-induced activation of AP-1 and expression of MCP-1. The transcriptional activation by proteasome inhibitors was observed not only in MCP-1, but also in other AP-1-dependent genes, including stromelysin and mitogen-activated protein kinase phosphatase 1. These data revealed that proteasome inhibition triggered the expression of MCP-1 and other genes via the multistep induction of the JNK-c-Jun/AP-1 pathway.

Cyclophosphamide stimulates lung fibroblasts to release neutrophil and monocyte chemoattractants

Cyclophosphamide is an alkylating antineoplastic agent used in several conditions. However, little is known about the mechanism of its pulmonary toxicity. In the present study, we determined that human lung fibroblasts release activity for neutrophils and monocytes in response to cyclophosphamide in a dose- and time-dependent manner. Checkerboard analysis revealed that both neutrophil and monocyte activities were chemotactic. The release of chemotactic activity was inhibited by lipoxygenase inhibitors and cycloheximide. Molecular-sieve column chromatography revealed that both neutrophil (NCA) and monocyte (MCA) chemotactic activities had multiple peaks. NCA was inhibited by a leukotriene B4receptor antagonist and anti-interleukin-8 and anti-granulocyte colony-stimulating factor antibodies. MCA was attenuated by a leukotriene B4receptor antagonist and anti-monocyte chemoattractant protein-1 and anti-granulocyte-macrophage colony-stimulating factor antibodies. The concentrations of interleukin-8, granulocyte colony-stimulating factor, monocyte chemoattractant protein-1, and granulocyte-macrophage colony-stimulating factor significantly increased in response to cyclophosphamide. These data suggest that lung fibroblasts may modulate inflammatory cell recruitment into the lung by releasing NCA and MCA in response to cyclophosphamide.

Suppression of constitutive but not Il-1beta-inducible expression of monocyte chemoattractant protein-1 in mesangial cells by retinoic acids: intervention in the activator protein-1 pathway

Retinoic acid regulates a wide range of biologic processes, including inflammation. This study investigated the effect of all-trans-retinoic acid (t-RA) on the constitutive and cytokine-inducible expression of monocyte chemoattractant protein 1 (MCP-1) in rat mesangial cells. Serum-deprived mesangial cells exhibited substantial levels of MCP-1 mRNA, and the expression was markedly upregulated by interleukin-1beta (IL-1beta). Pretreatment with t-RA abrogated the constitutive mRNA expression but did not inhibit the IL-1beta-inducible expression. The similar effects were observed by 9-cis-RA. The suppressive effect of t-RA required retinoic acid receptors. t-RA did not affect the stability of MCP-1 mRNA, indicating that its suppressive effect was at the transcriptional level. Experiments that used pharmacologic and genetic inhibitors showed that the IL-1beta-inducible MCP-1 expression was dependent on nuclear factor-kappaB (NF-kappaB) and independent of activator protein 1 (AP-1). In contrast, the constitutive expression of MCP-1 was dependent on both NF-kappaB and AP-1. t-RA substantially inhibited the constitutive activity of AP-1 but did not inhibit NF-kappaB activity in mesangial cells. These data suggested that (1) constitutive and IL-1beta-inducible expression of MCP-1 was differently regulated by AP-1 and NF-kappaB and (2) t-RA inhibited selectively the constitutive expression of MCP-1 via intervention in the AP-1 pathway.

Regulation of monocyte chemoattractant protein (MCP)-1 transcription by interferon-gamma (IFN-gamma) in human astrocytoma cells: postinduction refractory state of the gene, governed by its upstream elements

Monocyte chemoattractant protein (MCP)-1 is expressed by astrocytes in diverse inflammatory states and is a key regulator of monocyte recruitment to the central nervous system (CNS). In the current study, we addressed mechanisms by which transcription of the human MCP-1 gene (hMCP-1) was terminated, after induction by interferon (IFN)-gamma. Our results demonstrated that IFN-gamma-induced transcription of hMCP-1 was followed by a refractory state, during which hMCP-1 was resistant to restimulation by either IFN-gamma or heterologous activators such as TNF-alpha. This refractory state affected the hMCP-1 gene selectively, as other IFN-gamma-inducible genes remained responsive to restimulation. The IFN-gamma-induced hMCP-1 refractory state was governed at the transcriptional level and was sensitive to protein synthesis inhibitors, suggesting a requirement for newly expressed components. A minimal 213 base pair hMCP-1 regulatory element directed both IFN-gamma-mediated transcription and the subsequent refractory state. We previously demonstrated that IFN-gamma treatment resulted in coordinate protein occupancy in vivo of two hMCP-1 promoter elements, a gamma-activated site (GAS) and a GC-rich element. During the refractory state, IFN-gamma treatment failed to induce protection of either the hMCP-1 GAS element or the GC box. These results furnish insight into the expression of hMCP-1 during CNS inflammation and provide the first delineation of an IFN-gamma-induced transcriptional refractory state.

Differential transcriptional regulation of the monocyte-chemoattractant protein-1 (MCP-1) gene in tumorigenic and non-tumorigenic HPV 18 positive cells: the role of the chromatin structure and AP-1 composition

The expression of the monocyte-chemoattractant-protein-1 (MCP-1) is closely linked with a non-tumorigenic phenotype in somatic cell hybrids made between the human papillomavirus type 18 (HPV 18) positive cervical carcinoma cell line HeLa and normal human fibroblasts. In contrast, MCP-1 transcription is absent in tumorigenic segregants derived from the same hybrids or in parental HeLa cells. Selectivity of MCP-1 transcription, which is regulated at the level of initiation of transcription, is mainly based on differences in the location and extension of DNAse I-hypersensitive regions (DHSR) at both ends of the gene. While TNF-alpha only moderately increases the sensitivity of pre-existing 5'-DHSRs, a 3'-end DHSR became strongly induced exclusively in non-malignant hybrids. DNA sequencing showed that the 3'-DHSR coincides with an additional AP-1 site located approximately 600 bp downstream of the polyadenylation site. Analyses of AP-1 composition revealed that MCP-1 is only expressed in those cells where jun-family members were mainly heterodimerized with the fos-related protein fra-1. In contrast, in tumorigenic cells the 1: 1 ratio between jun and fra-1 is disturbed and the MCP-1 gene is no longer expressed. Hence, alterations in the heterodimerization pattern of AP-1 and its selective accessibility to opened chromatin may represent a novel regulatory pathway in the regulation of chemokines in malignant and non-malignant HPV-positive cells.

Renal expression of monocyte chemotactic protein-1 and epidermal growth factor in children with obstructive hydronephrosis

BACKGROUND/PURPOSE

The authors studied the potential role of ureteropelvic junction obstruction (UPJ-O) in causing progressive renal damage in children through the renal expression of epidermal growth factor (EGF) and monocyte chemotactic protein-1 (MCP-1) mRNA.

METHODS

Renal tissues were harvested from 11 children with UPJ-O and from 10 normal kidneys to study the renal expression of EGF and MCP-1 detected by means of in situ hybridization. Five of the patients were found to have a history of urinary tract infection (UTI).

RESULTS

Children with UPJ-O had marked reduction of EGF gene expression when compared with controls. Interstitial expression of MCP-1 mRNA was present in all UPJ-O cases. Both EGF and MCP-1 expression did not correlate with age, with differential renal function, and with renal thickness measured through MAG3 renal scan. Children with a history of UTI had a more severe reduction of the renal thickness of the affected kidney compared with those without UTI. MCP-1 expression was higher and EGF more reduced in children with a history of UTI.

CONCLUSIONS

Our results suggest a potential role of EGF and MCP-1 in the pathogenesis of renal damage and growth failure in UPJ-O, especially in children with UTI. These important functional changes begin early in life, possibly during fetal life.

Selective inhibition of monocyte chemoattractant protein-1 gene expression in human embryonal kidney cells by specific triple helix-forming oligonucleotides

Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that is expressed by a variety of tissue cells in response to inflammatory stimuli, such as IL-1beta, TNF-alpha, and IFN-gamma. A major function of MCP-1 is the recruitment and activation of monocytes and T lymphocytes. Overexpression of MCP-1 has been implicated in a number of diseases, including glomerulonephritis and rheumatoid arthritis, indicating that the modulation of MCP-1 activity and/or expression is a desired therapeutic strategy. In the present study, our aim was to test whether the MCP-1 expression could be inhibited at the transcriptional level using triple helix-forming oligonucleotides (TFOs). We designed a TFO targeted to the SP-1 binding site in the human MCP-1 gene promoter. Gel mobility shift assays demonstrated that the phosphodiester TFO formed a sequence-specific triplex with its dsDNA target with an EC50 of approximately 1.9 x 10(-7) M. The corresponding phosphorothioated oligonucleotide was also effective in this assay with an 8-fold higher EC50 value. Binding of the TFO to the target DNA prevented the binding of rSP-1 and of nuclear proteins in vitro. The TFO could also partially inhibit endogenous MCP-1 gene expression in cultured human embryonic kidney cells. Treatment of TNF-alpha-stimulated human embryonic kidney 293 cells with the TFO inhibited the secretion of MCP-1 in a dose-dependent manner (up to 45% at 5 microM oligonucleotide). The inhibition of MCP secretion was caused at the level of gene transcription, because MCP-1 mRNA levels in oligonucleotide-treated cells were also decreased by approximately 40%.

Retinoic acid-induced blr1 expression promotes ERK2 activation and cell differentiation in HL-60 cells

Retinoids are known to induce the differentiation and cell cycle arrest of human myeloid leukemia cells in vitro. Differential display was used to identify putative early regulatory genes that are differentially expressed in HL-60 human promyelocytic leukemia cells treated with retinoic acid. One of the cDNAs cloned encodes sequences identifying Burkitt's lymphoma receptor 1 (BLR1), a recently described chemokine receptor. Northern blot analysis demonstrates that blr1 mRNA expression increases within 9 h of retinoic acid treatment, well before functional differentiation or G(1)/G(0) growth arrest at 48 h or onset of morphological changes, suggesting a possible regulatory function. The expression of blr1 mRNA is transient, peaking at 72 h when cells are differentiated. blr1 mRNA also is induced by other differentiation-inducing agents, 1alpha,25-dihydroxyvitamin D(3) and DMSO. Induction of blr1 mRNA by retinoic acid is not blocked by the protein synthesis inhibitor cycloheximide. In HL-60 cells stably transfected with blr1 cDNA, ectopic expression of blr1 causes an increase in ERK2 MAPK activation and promotes retinoic acid-induced G(1)/G(0) growth arrest and cell differentiation. The early expression of blr1 mRNA during differentiation, its ability to increase ERK2 activation, and its enhancement of retinoic acid-induced differentiation suggest that blr1 expression may be involved in retinoic acid-induced HL-60 differentiation.

Bradykinin stimulates lung fibroblasts to release neutrophil and monocyte chemotactic activity

Activation of the kallikrein-kinin system in lung injury has long been recognized. However, the effects of bradykinin (BK) on human lung fibroblasts (HLF) remain to be elucidated. We determined whether BK stimulates HLF to release chemotactic activity for neutrophils and monocytes (NCA and MCA, respectively). We evaluated HLF supernatant fluids for chemotactic activity through a blind-well chamber technique. HLF released NCA and MCA in a dose- and time-dependent manner in response to BK. The release of chemotactic activity was inhibited by lipoxygenase inhibitors and cycloheximide. Molecular sieve column chromatography revealed that both NCA and MCA had multiple chemotactic peaks. NCA was inhibited by a leukotriene (LT) B(4) receptor antagonist and by antibodies to interleukin (IL)-8 and granulocyte colony-stimulating factor (G-CSF). MCA was attenuated by the LTB(4) receptor antagonist and by antibodies to monocyte chemoattractant protein-1 (MCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and transforming growth factor (TGF)-beta. Both the LTB(4) receptor antagonist and these antibodies inhibited chemotactic activity of the molecular weights corresponding to MCP-1, GM-CSF, and TGF-beta, separated by column chromatography. The concentrations of IL-8, G-CSF, MCP-1, GM-CSF, and TGF-beta in supernatant fluids increased significantly in a time-dependent manner in response to BK. The receptors responsible for the release of NCA, MCA, and individual chemokines included both BKB(1) and BKB(2) receptors. These data suggest that BK may stimulate lung fibroblasts to release inflammatory cytokines, which may modulate lung inflammation.

A synthetic selective inhibitor of factor Xa, DX-9065a, reduces monocyte chemoattractant protein-1 expression after ischemia-reperfusion injury in rat liver

Activated factor X (FXa) is a trypsinlike serine protease involved in the cascade of blood coagulation. The monocyte chemoattractant protein-1 (MCP-1) may be important in the pathophysiology of liver ischemia-reperfusion injury. We investigated the effects of a selective FXa inhibitor, DX-9065a, on MCP-1 expression after ischemia-reperfusion in the rat liver. Liver ischemia was induced in rats by occluding the portal vein for 30 min. DX-9065a was injected intravenously 5 min before vascular clamping. Serum concentrations of MCP-1 were measured by enzyme-linked immunosorbent assay. The levels of MCP-1 mRNA in the liver after reperfusion were determined by northern blot analysis. In vitro MCP-1 production by peritoneal macrophages in response to alpha-thrombin was examined. Serum concentrations of MCP-1 increased and peaked at 6 hr after reperfusion. However, pretreatment of animals with DX-9065a resulted in significantly smaller increases in the serum concentration of MCP-1 after reperfusion in a dose-dependent manner. Pretreatment with DX-9065a significantly reduced MCP-1 mRNA levels in the liver after ischemia-reperfusion. In vitro MCP-1 production by peritoneal macrophages was enhanced by alpha-thrombin. In addition, DX-9065a significantly reduced tissue factor mRNA levels in peripheral monocytes after ischemia-reperfusion, compared to untreated animals. In conclusion, a selective inhibitor of FXa, DX-9065a, limited MCP-1 production after ischemia-reperfusion of the rat liver.

Neutrophil elastase and oxygen radicals enhance monocyte chemoattractant protein- expression after ischemia/reperfusion in rat liver

BACKGROUND

The monocyte chemoattractant protein-1 (MCP-1) is produced during reperfusion injury and induces tissue factor that is the initiator of the clotting cascade. Neutrophil elastase is a crucial mediator of inflammatory tissue damage. Activation of the coagulation system stimulates cytokine production by activated leukocytes. We investigated the effects of neutrophil elastase and oxygen radicals generated by hypoxia associated with microthrombus formation on MCP-1 expression after ischemia/reperfusion in rat liver.

METHODS

In vitro MCP-1 production by macrophages after stimulation with human neutrophil elastase (HNE) or oxygen radicals generated by hypoxanthine and xanthine oxidase was examined. Liver ischemia was induced in rats by occluding the portal vein for 30 min. An inhibitor of human neutrophil elastase (ONO-5046*Na, 10 mg/kg) and antithrombin III (AT-III, 250 U/kg) were injected i.v. 5 min before vascular clamping. Serum concentrations of MCP-1 were measured by enzyme-linked immunosorbent assay.

RESULTS

Human neutrophil elastase or oxygen radicals significantly enhanced in vitro MCP-1 production by macrophage. Serum MCP-1 concentrations reached a peak at 6 hr after reperfusion and then gradually decreased. However, pretreatment of animals with AT-III or ONO-5046*Na alone resulted in significantly smaller increases in serum concentrations of MCP-1 after reperfusion. Pretreatment with both ONO-5046*Na and AT-III produced additive effects. The combined treatment with ONO-5046*Na and AT-III significantly reduced MCP-1 mRNA in liver after ischemia/reperfusion.

CONCLUSIONS

MCP-1 production by macrophages is stimulated by neutrophil elastase and oxygen radicals generated by hypoxia, probably due to microthrombus formation after ischemia/reperfusion of the rat liver.

Bioflavonoid quercetin inhibits interleukin-1-induced transcriptional expression of monocyte chemoattractant protein-1 in glomerular cells via suppression of nuclear factor-kappaB

Flavonoids are semiessential food components that possess anti-inflammatory properties. This report describes a novel potential of bioflavonoid quercetin as an inhibitor of monocyte chemoattractant protein-1 (MCP-1) in glomerular cells. Cultured mesangial cells as well as isolated glomeruli expressed MCP-1 mRNA in response to interleukin-1beta (IL-1beta). Quercetin dramatically inhibited the cytokine-triggered MCP-1 expression. To explore the mechanisms involved, effects of quercetin on the putative transcriptional activators of MCP-1, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1), were examined. Exposure of the cells to IL-1beta caused activation of NF-kappaB without significant upregulation of AP-1 activity. NF-kappaB inhibitor MG132 diminished the IL-1-induced expression of MCP-1 in mesangial cells and isolated glomeruli, whereas c-Jun/AP-1 inhibitor curcumin did not affect this process. Consistently, NF-kappaB-inactive mesangial cells expressing a super-repressor mutant of IkappaBalpha showed blunted expression of MCP-1 by IL-1beta. In contrast, AP-1-inactive mesangial cells expressing a dominant-negative mutant of c-Jun exhibited the same level of MCP-1 mRNA as that in control cells. These results suggest that: (1) quercetin has the ability to attenuate activation of NF-kappaB; and (2) it inhibits IL-1-triggered MCP-1 expression via suppression of NF-kappaB, but not AP-1, in glomerular cells.

Expression of monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 by human airway smooth-muscle cells. Modulation by corticosteroids and T-helper 2 cytokines

We have demonstrated that, in addition to their contractile function, human airway smooth-muscle cells (HASMC) are able to express and to secrete chemokines of the monocyte chemotactic protein (MCP)/ eotaxin subfamily. This group of chemokines is believed to play a fundamental role in the development of allergic airway diseases such as asthma. The expression levels of MCP (MCP-1, -2, and -3) messenger RNA (mRNA) were compared with those of regulated on activation, normal T cells expressed and secreted (RANTES) mRNA in HASMC in culture. HASMC express MCP and RANTES mRNA after stimulation with interleukin (IL)-1beta, tumor necrosis factor-alpha, and interferon-gamma. MCP mRNA was maximal at 8 h, whereas RANTES mRNA expression was delayed to 24 h after stimulation. Further, significant differences were observed in the induction patterns of MCP and RANTES mRNA expression after stimulation with the individual cytokines. Dexamethasone (DEX) significantly inhibited cytokine-induced accumulation of MCP and RANTES mRNA, in contrast to IL-4, IL-10, and IL-13, which had no inhibitory effect on cytokine-induced chemokine expression. The cytokine-induced MCP mRNA expression in HASMC was associated with MCP release, which was inhibited by DEX and post-translationally by IL-4. HASMC can actively participate in the pathogenesis of asthma by the expression and release of chemokines, which are likely to play a critical role in the generation and regulation of the inflammatory response characteristic of allergic airway diseases.

Constitutive protein expression of monocyte chemotactic protein-1 (MCP-1) by myelomonocytic cell lines and regulation of the secretion by anti- and proinflammatory stimuli

We have investigated the protein expression of the chemokine monocyte chemotactic/chemoattractant protein-1 (MCP-1) in various human myelomonocytic leukemia cell lines. Applying specific ELISA, we demonstrated that this chemokine is produced constitutively by the cell lines HL-60, ML-2, MONO-MAC-6 and MUTZ-3 ranging between 440 and 1400 pg/ml MCP-1 per million cells. In the culture medium of two other unstimulated cell lines, MONO-MAC-1 and THP-1, almost no MCP-1 was detected. Stimulation of HL-60 and MONO-MAC-6 with lipopolysaccharide (LPS), and stimulation of ML-2 and MUTZ-3 with 12-tetradecanoyl phorbol 13-acetate (TPA) dramatically increased the MCP-1 level in the culture medium. The highest amount of MCP-1 (> 80 ng/ml within 24 h) was achieved by TPA stimulation of MUTZ-3 cells. Out of 15 cytokines tested for induction or enhancement of MCP-1 secretion, interleukin-3 (IL-3), IL-6, interferon-gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF) and tumor necrosis factor (TNFalpha) were able to augment (twofold to 12-fold) the MCP-1 level in the culture medium of MONO-MAC-6 cells. While the antinflammatory cytokines IL-4, IL-10 and IL-13 failed to suppress MCP-1 secretion, the glucocorticoid dexamethasone strongly inhibited the MCP-1 production of unstimulated and stimulated MONO-MAC-6 cells. Thus, several regulatory elements are involved in MCP-1 secretion. Despite the quantitative differences of MCP-1 production among the cell lines analyzed, our results demonstrated a constitutive secretion in differentiation-arrested myelomonocytic leukemia cell lines and emphasize the usefulness of these malignant cell lines as models to study MCP-1 secretion and regulation.

Monocyte-chemo-attractant-protein-1 (MCP-1)-gene expression in cervical intra-epithelial neoplasias and cervical carcinomas

Chemokines play a central role in the chemotactic activation of immunological effector cells. One of the currently best characterized chemokines is the monocyte-chemo-attractant protein-1 (MCP-1), which is involved in the cross-talk with cells of the monocyte-macrophage lineage. Since macrophages and macrophage-derived cytokines appear to be important in the transcriptional regulation of "high-risk" types of human papillomaviruses (HPV), we monitored MCP-1 expression by in situ hybridization (ISH) in histologically distinct stages of cervical intra-epithelial neoplasms (CIN), cervical cancer and non-HPV-associated cases of erosive endocervicitis. Here, we demonstrate that high-grade dysplasia (CIN III, n = 9) completely lacks both MCP-1 expression and CD68+-macrophage infiltration, while MCP-1-specific signals were occasionally detectable in one out of 5 CIN-II and in one out of 3 CIN-I lesions. Inspection of hyperplastic squamous epithelium adjacent to cervical carcinomas reveals high MCP-1 expression and accumulation of infiltrating macrophages. In contrast, no macrophages could be detected in corresponding hyperplastic tissue areas surrounding CIN-II and CIN-III lesions, although MCP-1 was found to be highly expressed. Finally, in agreement with our earlier in vitro data, invasive carcinomas of the cervix uteri showed MCP-1-specific hybridization signals and macrophage infiltration only in the stroma surrounding the carcinoma cells and in endothelial cells of capillaries, especially at the invasion front of the tumor, while the inner mass of the carcinomas was completely negative. On the other hand, ISH and histochemical evaluation of inflammatory, non-HPV-associated cases of erosive endocervicitis indicate strong MCP-1 expression, which is regularly accompanied by chemotactic appearance of macrophages. These observations indicate that dysregulation of MCP-1-gene expression may represent an important step during HPV-linked carcinogenesis, allowing the escape of virus-positive cells from local immune response.