The formulae and biologically active ingredients of Chinese herbal medicines for the treatment of atopic dermatitis.

Atopic dermatitis (AD) is a common relapsing inflammatory skin disease characterized by severe pruritus that seriously affects the quality of patients' life. There is an increasingly large amount of research demonstrating that traditional Chinese medicine (TCM) including herbal formulae and bioactive ingredients exerts pharmacological effects on atopic dermatitis. It has been a long history of TCM being used to treat atopic dermatitis, especially in preventing disease recurrence, maintaining long-term remission, and reducing disease burden. Nowadays, both of TCM monomer preparations and traditional formulae are still widely used. This review focuses on TCM as well as its bioactive ingredients for the treatment of AD, from the perspectives of animal model construction, pharmacodynamic mechanisms and clinical studies of formulae. To be more specific, the regulation and molecular mechanisms of the herbal formulae and bioactive ingredients of TCM are investigated, and the latest clinical research on TCM formulae is discussed. Furthermore, it provides a summary of the strengths and utilities of TCM, and will be useful for doctors who use Chinese medicine for treatment or researchers who select candidates for clinical treatments or further high-quality clinical studies.

A neuroendocrine role for chemerin in hypothalamic remodelling and photoperiodic control of energy balance.

Long-term and reversible changes in body weight are typical of seasonal animals. Thyroid hormone (TH) and retinoic acid (RA) within the tanycytes and ependymal cells of the hypothalamus have been implicated in the photoperiodic response. We investigated signalling downstream of RA and how this links to the control of body weight and food intake in photoperiodic F344 rats. Chemerin, an inflammatory chemokine, with a known role in energy metabolism, was identified as a target of RA. Gene expression of chemerin (Rarres2) and its receptors were localised within the tanycytes and ependymal cells, with higher expression under long (LD) versus short (SD) photoperiod, pointing to a physiological role. The SD to LD transition (increased food intake) was mimicked by 2 weeks of ICV infusion of chemerin into rats. Chemerin also increased expression of the cytoskeletal protein vimentin, implicating hypothalamic remodelling in this response. By contrast, acute ICV bolus injection of chemerin on a 12 h:12 h photoperiod inhibited food intake and decreased body weight with associated changes in hypothalamic neuropeptides involved in growth and feeding after 24 hr. We describe the hypothalamic ventricular zone as a key site of neuroendocrine regulation, where the inflammatory signal, chemerin, links TH and RA signaling to hypothalamic remodeling.

[Hypothalamic inflammation and energy balance deregulations: focus on chemokines.] / Inflammation hypothalamique et dérégulations de la balance énergétique : focus sur les chimiokines.

The hypothalamus is a key brain region in the regulation of energy balance. It especially controls food intake and both energy storage and expenditure through integration of humoral, neural and nutrient-related signals and cues. Hypothalamic neurons and glial cells act jointly to orchestrate, both spatially and temporally, regulated metabolic functions of the hypothalamus. Thus, the existence of a causal link between hypothalamic inflammation and deregulations of feeding behavior, such as involuntary weight-loss or obesity, has been suggested. Among the inflammatory mediators that could induce deregulations of hypothalamic control of the energy balance, chemokines represent interesting candidates. Indeed, chemokines, primarily known for their chemoattractant role of immune cells to the inflamed site, have also been suggested capable of neuromodulation. Thus, chemokines could disrupt cellular activity together with synthesis and/or secretion of multiple neurotransmitters/mediators that are involved in the maintenance of energy balance. Here, we relate, on one hand, recent results showing the primary role of the central chemokinergic signaling CCL2/CCR2 for metabolic and behavioral adaptation to high-grade inflammation, especially loss of appetite and weight, through its activity on hypothalamic neurons producing the orexigenic peptide Melanin-Concentrating Hormone (MCH) and, on the other hand, results that suggest that chemokines could also deregulate hypothalamic neuropeptidergic circuits to induce an opposite phenotype and eventually participate in the onset/development of obesity. In more details, we will emphasize a study recently showing, in a model of high-grade acute inflammation of LPS injection in mice, that central CCL2/CCR2 signaling is of primary importance for several aspects explaining weight loss associated with inflammation: after LPS injection, animals lose weight, reduce their food intake, increase their fat oxidation (thus energy consumption from fat storage)...These inflammation-induced metabolic and behavioral changes are reduced when central CCR2 signaling is disrupted either pharmacologically (by a specific inhibitor of CCR2) or genetically (in mice deficient for CCR2). This underlines the importance of this signaling in inflammation-related weight loss. We further determined that the LPS-induced and CCR2-mediated weight loss depends on the direct effect of CCR2 activation on MCH neurons activity. Indeed, the MCH neurons express CCR2, and the application of CCL2 on brain slices revealed that activation of CCR2 actually depolarizes MCH neurons and induces delays and/or failures of action potential emission. Furthermore, CCL2 is able to reduce KCl-evoked MCH secretion from hypothalamic explants. Taken together, these results demonstrate the role of the central CCL2/CCR2 signaling in metabolic and behavioral adaptation to inflammation. On the other hand, this first description of how the chemokinergic system can actually modulate the activity of the hypothalamic regulation of energy balance, but also some less advanced studies and some unpublished data, suggest that some other chemokines, such as CCL5, could participate in the development of the opposite phenotype, that is to say obesity.

Adhesion molecules and chemokines; relation to anthropometric, body composition, biochemical and dietary variables.

INTRODUCTION: Among the inflammatory mediators involved in the pathogenesis of obesity, the cell adhesion molecules P-selectin, E-selectin, VCAM-1, ICAM-1 and the chemokine MCP-1 stand out. They play a crucial role in adherence of cells to endothelial surfaces, in the integrity of the vascular wall and can be modulated by body composition and dietary pattern. OBJETIVES: To describe and discuss the relation of these cell adhesion molecules and chemokines to anthropometric, body composition, dietary and biochemical markers. METHODS: Papers were located using scientific databases by topic searches with no restriction on year of publication. RESULTS: All molecules were associated positively with anthropometric markers, but controversial results were found for ICAM-1 and VCAM-1. Not only obesity, but visceral fat is more strongly correlated with E-selectin and MCP-1 levels. Weight loss influences the reduction in the levels of these molecules, except VCAM-1. The distribution of macronutrients, excessive consumption of saturated and trans fat and a Western dietary pattern are associated with increased levels. The opposite could be observed with supplementation of w-3 fatty acid, healthy dietary pattern, high calcium diet and high dairy intake. Regarding the biochemical parameters, they have inverse relation to HDLC and positive relation to total cholesterol, triglycerides, blood glucose, fasting insulin and insulin resistance. CONCLUSION: Normal anthropometric indicators, body composition, biochemical parameters and eating pattern positively modulate the subclinical inflammation that results from obesity by reducing the cell adhesion molecules and chemokines.

INTRODUCCIÓN: Entre los mediadores inflamatorios involucrados en la fisiopatogenia de la obesidad, se destacan las moléculas de adhesión P-selectina, E-selectina, VCAM-1, ICAM-1 y la quimiocina MCP-1. Estas desempeñan un papel crucial en la adherencia de células en las superficies endoteliales y en la integridad de la pared vascular y pueden ser moduladas por la composición corporal y patrón alimentario. OBJETIVOS: Describir y discutir la relación de esas moléculas de adhesión y quimiocina con marcadores antropométricos, composición corporal, bioquímicas y dietéticas. MÉTODOS: Se utilizaron bases científicas electrónicas para selección de artículos, sin límite de año de publicación. RESULTADOS: Todas las moléculas se asociaron de forma positiva con marcadores antropométricos; sin embargo, se encontraron resultados controvertidos para ICAM-1 y VCAM-1. No solamente la obesidad per si, sino también la grasa visceral está más fuertemente relacionadas con las concentraciones de E-selectina y MCP-1. La pérdida de peso influencia en la reducción de las concentraciones de esas moléculas, con excepción de la VCAM-1. La distribución de macronutrientes, el consumo excesivo de grasa saturada y trans y un patrón alimentario occidental están asociados con aumento de sus concentraciones. El inverso se pudo observar con la suplementación de ácido graso w-3 en la dieta, el patrón alimentario sano y dieta rica en calcio y productos lácteos. Ya en cuanto a los parámetros bioquímicos, las mismas poseen relación inversa con HDL-c y positiva con colesterol total, triacilgliceroles, glicemia e insulinemia de ayuno y resistencia a insulina. CONCLUSIÓN:: Conclusión: Marcadores antropométricos, composición corporal, parámetros bioquímicos y patrón alimentario adecuados modulan positivamente la inflamación subclínica derivada de la obesidad por medio de la reducción de las moléculas de adhesión y quimiocinas.

[Roles of lipid mediators in controlling vascular inflammation and the progression of atherosclerosis].

Atherosclerosis is recognized as an inflammatory condition of the vessel wall, characterized by accumulation of inflammatory cells such as macrophages and T cells. There are accumulating evidences that chemokines, cytokines, and lipid mediators coordinately modulate platelet- or leukocyte-endothelial cell interactions, and contribute to the maintenance of vascular homeostasis. This review focuses on the role of lipid mediators, especially those derived from polyunsaturated fatty acids, in controlling vascular inflammation and the progression of atherosclerosis.

Targeting inflammatory pathways by flavonoids for prevention and treatment of cancer.

Observational studies have suggested that lifestyle risk factors such as tobacco, alcohol, high-fat diet, radiation, and infections can cause cancer and that a diet consisting of fruits and vegetables can prevent cancer. Evidence from our laboratory and others suggests that agents either causing or preventing cancer are linked through the regulation of inflammatory pathways. Genes regulated by the transcription factor NF- kappaB have been shown to mediate inflammation, cellular transformation, tumor cell survival, proliferation, invasion, angiogenesis, and metastasis. Whereas various lifestyle risk factors have been found to activate NF- kappaB and NF- kappaB-regulated gene products, flavonoids derived from fruits and vegetables have been found to suppress this pathway. The present review describes various flavones, flavanones, flavonols, isoflavones, anthocyanins, and chalcones derived from fruits, vegetables, legumes, spices, and nuts that can suppress the proinflammatory cell signaling pathways and thus can prevent and even treat the cancer.

Modified adenine (9-benzyl-2-butoxy-8-hydroxyadenine) redirects Th2-mediated murine lung inflammation by triggering TLR7.

Substitute adenine (SA)-2, a synthetic heterocycle chemically related to adenine with substitutions in positions 9-, 2-, and 8- (i.e., 9-benzyl-2-butoxy-8-hydroxyadenine), induces in vitro immunodeviation of Th2 cells to a Th0/Th1 phenotype. In this article, we evaluate the in vivo ability of SA-2 to affect Th2-mediated lung inflammation and its safety. TLR triggering and NF-kappaB activation by SA-2 were analyzed on TLR-transfected HEK293 cells and on purified bone marrow dendritic cells. The in vivo effect of SA-2 on experimental airway inflammation was evaluated in both prepriming and prechallenge protocols by analyzing lung inflammation, including tissue eosinophilia and goblet cell hyperplasia, bronchoalveolar lavage fluid cell types, and the functional profile of Ag-specific T cells from draining lymph nodes and spleens. SA-2 induced mRNA expression and production of proinflammatory (IL-6, IL-12, and IL-27) and regulatory (IL-10) cytokines and chemokines (CXCL10) in dendritic cells but down-regulated TGF-beta. Prepriming administration of SA-2 inhibited OVA-specific Abs and Th2-driven lung inflammation, including tissue eosinophilia and goblet cells, with a prevalent Foxp3-independent regulatory mechanism. Prechallenge treatment with SA-2 reduced the lung inflammation through the induction of a prevalent Th1-related mechanism. In this model the activity of SA-2 was route-independent, but adjuvant- and Ag dose-dependent. SA-2-treated mice did not develop any increase of serum antinuclear autoantibodies. In conclusion, critical substitutions in the adenine backbone creates a novel synthetic TLR7 ligand that shows the ability to ameliorate Th2-mediated airway inflammation by a complex mechanism, involving Th1 redirection and cytokine-mediated regulation, which prevents autoreactivity.

Immunomodulation by n-3- versus n-6-rich lipid emulsions in murine acute lung injury--role of platelet-activating factor receptor.

OBJECTIVE: Cytokines, platelet-activating factor (PAF), and eicosanoids control local and systemic inflammation. Conventional soybean oil-based lipid emulsions used for parenteral nutrition may aggravate the leukocyte inflammatory response or adhesion to the vessel wall. Fish oil-based lipid emulsions, in contrast, may exert an anti-inflammatory effect. DESIGN: We investigated the impact of lipid emulsions on leukocyte invasion, protein leakage, and cytokines in two murine models of acute inflammation. SETTING: Research laboratory of a university hospital. SUBJECTS: Wild-type mice and PAF-receptor knockout mice. INTERVENTIONS: Mice received an infusion of normal saline, fish oil- or soybean oil-based lipid emulsions before lipopolysaccharide challenge. MEASUREMENTS AND MAIN RESULTS: Preinfusion with soybean oil resulted in increased leukocyte invasion, myeloperoxidase activity, and protein leakage and exaggerated release of tumor necrosis factor (TNF)-alpha as well as macrophage inflammatory protein (MIP)-2 into the alveolar space after intratracheal lipopolysaccharide challenge. In contrast, preinfusion with fish oil reduced leukocyte invasion, myeloperoxidase activity, protein leakage, and TNF-alpha as well as MIP-2 generation. Corresponding profiles were found in plasma following intraperitoneal lipopolysaccharide application: Soybean oil increased but fish oil decreased the TNF-alpha and MIP-2 formation. When PAF-receptor-deficient mice were challenged with lipopolysaccharide, leukocyte invasion, lung tissue myeloperoxidase, cytokine generation, and alveolar protein leakage corresponded to those observed in wild-type animals. Fish oil and soybean oil lost their diverging effects on leukocyte transmigration, myeloperoxidase activity, leakage response, and cytokine generation in these knockout mice. Similarly, the differential impact of both lipid emulsions on these lipopolysaccharide-provoked changes was suppressed after pretreating animals with a PAF-receptor antagonist. CONCLUSIONS: Fish oil- vs. soybean oil-based lipid infusions exert anti- vs. proinflammatory effects in murine models of acute inflammation. The PAF/PAF-receptor-linked signaling appears to be a prerequisite for this differential profile.

Are there any realistic chances to develop new drugs for asthma?

Asthma bronchiale, an inflammatory airway disease, imposes a significant health care problem worldwide. It is characterized by three critical phenotypic traits: intermittent and reversible bronchoconstriction, bronchial hyperresponsiveness and airway inflammation. Conventional therapy basically consists of beta(2)-adrenoceptor agonists in combination with glucocorticoids. Nevertheless, there is an urgent need for novel therapies, both for patients with uncontrollable disease symptoms and for those suffering from glucocorticoid-insensitive asthma. Monotherapy seems to be relatively ineffective against this complex and multifaceted disease, which is evident by the variety of disappointing treatment strategies. Thus, we should instead concentrate on multiple target strategies, such as novel and more potent glucocorticoids or phosphodiesterase type 4 (PDE4) inhibitors with isozyme selectivity. In addition, an examination of the application method should not be neglected, with emphasis on inhalative approaches. To summarize, research into asthma's pathophysiology is of critical importance, concentrating on human-relevant targets and conducting preliminary studies. With these imperatives in mind, we can hope to better manage this multifactor disease in the near future.

The attraction of chemokines as a target for specific anti-inflammatory therapy.

Since the identification of the first chemotactic cytokines 20 years ago, the field has mushroomed, with the discovery of approximately 40 ligands, which interact with 20 different cell surface receptors. At the time of writing this review, a PubMed trawl using the word 'chemokine' will recover over 28,000 manuscripts. In this article, we will give a short history of the discovery of chemokines and provide examples of the potential for therapeutic targeting of the chemokine network in inflammatory disease.

Causal links between brain cytokines and experimental febrile convulsions in the rat.

PURPOSE: Despite the prevalence of febrile convulsions (FCs), their pathophysiology has remained elusive. We tested the hypothesis that components of the immune response, particularly the proinflammatory cytokine interleukin-1beta (IL-1beta) and its naturally occurring antagonist interleukin-1 receptor antagonist (IL-1ra) may play a role in the genesis of FC. METHODS: Postnatal day 14 rats were treated with lipopolysaccharide (LPS; 200 microg/kg, i.p.) followed by a subconvulsant dose of kainic acid (1.75 mg/kg, i.p.). Brains were harvested at and 2 h after onset of FCs to measure brain levels of IL-1beta and IL-1ra. Separate groups of animals were given intracerebroventricular (ICV) injections of IL-1beta, or IL-1ra in an attempt to establish a causal relation between the IL-1beta/IL-1ra system and FCs. RESULTS: Animals with FCs showed increased IL-1beta in the hypothalamus and hippocampus but not in the cortex compared with noFC animals that also received LPS and kainic acid. This increase was first detected in the hippocampus at onset of FCs. No detectable difference in IL-1ra was found in brain regions examined in either group. When animals were treated with IL-1beta ICV, a dose-dependant increase was noted in the proportion of animals that experienced FCs, whereas increasing doses of IL-1ra, given to separate groups of animals, were anticonvulsant. CONCLUSIONS: Our results suggest that excessive amounts of IL-1beta may influence the genesis of FCs. This may occur by overproduction of IL-1beta, or by alteration in the IL-1beta/IL-1ra ratio in the brain after an immune challenge.

Chemokine receptors are expressed widely by embryonic and adult neural progenitor cells.

We investigated the expression and functions of chemokine receptors in neural progenitor cells isolated from embryonic and adult mice. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated mRNA expression for most known chemokine receptors in neural progenitor cells grown as neurospheres from embryonic (E17) and adult (4-week-old) mice. The expression of CXCR4 receptors was demonstrated further in E17 neurospheres using immunohistochemistry, in situ hybridization, Northern blot analysis and fura-2-based Ca(2+) imaging. Most neurospheres grown from E17 mice responded to stromal cell-derived factor-1 (SDF-1/CXCL12) in Ca(2+) imaging studies. In addition, immunohistochemical studies demonstrated that these neurospheres consisted of dividing cells that uniformly colocalized nestin and CXCR4 receptors. Differentiation of E17 neurospheres yielded astrocytes and neurons exhibiting several different phenotypes, including expression of calbindin, calretinin, gamma-aminobutyric acid (GABA), and glutamate, and many also coexpressed CXCR4 receptors. In addition, neurospheres grown from the subventricular zone (SVZ) of 4-week-old mice exhibited large increases in Ca(2+) in response to CXCL12 and several other chemokines. In comparison, neurospheres prepared from olfactory bulb of adult mice exhibited only small Ca(2+) responses to CXCL12, whereas neurospheres prepared from hippocampus were insensitive to CXCL12, although they did respond to other chemokines. Investigations designed to investigate whether CXCL12 can act as a chemoattractant demonstrated that cells dissociated from E17 or adult SVZ neurospheres migrated toward an CXCL12 gradient and this was blocked by the CXCR4 antagonist AMD3100. These results illustrate widespread chemokine sensitivity of embryonic and adult neural progenitor cells and support the view that chemokines may be of general importance in control of progenitor cell migration in embryonic and adult brain.

Rho GTPases as therapeutic targets for the treatment of inflammatory diseases.

Diseases related to inflammation are a major cause of morbidity and mortality throughout the world and affect the functions of several tissues. The pathophysiology of these diseases involves release of many pro-inflammatory cytokines, such as TNF and IL-1, in addition to anti-inflammatory molecules. Recent studies have demonstrated that neuroimmune interactions are important in the initiation and progress of inflammatory processes. TNF, IL-1 and neuropeptides such as substance P and neurotensin stimulate the release of chemokines, in particular IL-8, a potent neutrophil chemoattractant. Expression of IL-8 is regulated mainly by the transcription factors NF-kappaB, activating protein-1 and CCAAT/enhancer-binding proteins. Recent exciting results indicate that the Rho family of small GTP-binding proteins plays an important role in the expression of NF-kappaB-dependent genes and migration of leukocytes. These results suggest that these proteins may represent a potential therapeutic target to treat several inflammatory states.

Factors modifying the migration of lymphocytes across the blood-brain barrier.

Characterising the factors that control the entry of leucocytes into tissue in response to inflammatory or microbial insult continues to generate considerable interest. Of all the tissues studied it is probably that of the CNS which is the most fascinating because of the specialised properties of its blood vessel walls, which constitute the blood-brain barrier (BBB). In health, very few leucocytes penetrate the BBB but in disorders such as MS the barrier becomes compromised with the result that there is an intense infiltration of the CNS by T lymphocytes whose subsequent activity appears to underlie the onset and progression of disease. The purpose of this article is to summarise and assess recent literature pertaining to how lymphocytes bind to cerebral endothelial cells, migrate across the blood vessel walls and enter the CNS parenchyma. Particular emphasis is devoted to the cellular and molecular aspects of these events and addressing the questions of whether certain subsets of circulating T lymphocytes are more favourably disposed than others to CNS infiltration and whether entry is dependent upon the initial expression of distinct groups of adhesion molecules and upon the generation of chemotactic factors. This article also focuses upon identifying the key stages of lymphocyte migration across the BBB and their susceptibility to antagonism by therapeutic agents. It is intended that the review will provide a useful source of information and offer additional insights into the mechanisms controlling lymphocyte passage across the BBB during pathological disturbance.

Modulation of apoptotic and inflammatory genes by bioflavonoids and angiotensin II inhibition in ureteral obstruction.

OBJECTIVES: Ureteral obstruction results in an injury response that can progress to irreversible renal fibrosis and tubular atrophy by apoptosis. The molecular events leading to apoptosis from obstruction are not well understood. We investigated the effect of bioflavonoids and angiotensin II inhibition on apoptotic and inflammatory gene expression in a model of unilateral ureteral obstruction (UUO). METHODS: Complete UUO was produced in rats by ureteral ligation. The rats were treated with dimethyl sulfoxide (control), enalapril, losartan, curcumin, or quercetin. The animals were killed on day 7 and both obstructed and contralateral unobstructed kidneys were harvested. Expression of the inflammatory chemokine monocyte chemotactic protein-1, apoptosis effector genes Fas and Fas ligand, and oxidative stress gene HO-1 was evaluated by reverse transcriptase-polymerase chain reaction. RESULTS: Ureteral obstruction was associated with a 6.3-fold increase in monocyte chemotactic protein-1 expression compared with sham-operated rats (P = 0.01). Monocyte chemotactic protein-1 expression was severely attenuated in all other treatment groups (P <0.05). Similarly, Fas and Fas ligand expression were increased in control UUO kidneys compared with sham-operated ones (P <0.05). Fas gene expression was significantly inhibited by quercetin but not enalapril, losartan, or curcumin compared with the control. The induction of Fas ligand was attenuated in all treatment groups (P <0.05). HO-1 was expressed at low levels in both unobstructed and obstructed kidneys. Treatment with curcumin increased HO-1 expression fourfold (P <0.05). CONCLUSIONS: The expression of apoptotic and chemokine genes is significantly upregulated in UUO. Bioflavonoids and angiotensin inhibitors are able to attenuate the expression of these genes and thus may be beneficial in renal protection.

Cutting edge: identification of the orphan receptor G-protein-coupled receptor 2 as CCR10, a specific receptor for the chemokine ESkine.

A number of orphan G-protein coupled receptors (GPR) have been reported as putative chemokine receptors. One previously reported orphan receptor is an incomplete PCR clone, called GPR2. Here we report the cloning of full-length human (h)GPR2 and mouse (m)GPR2 cDNAs, and the identification of GPR2 as a receptor for a novel CC chemokine called ESkine. hGPR2 is expressed at high levels in testis and small intestine, and at lower levels in other tissues. mGPR2 was expressed at high levels in small intestine, colon, lymph nodes, and Peyer's patches and at lower levels in thymus and spleen. Stimulation of L1.2/hGPR2 transfectants with hESkine induced their migration and resulted in intracellular calcium mobilization. These results provide evidence that GPR2 is a specific receptor for ESkine. We propose that GPR2 be renamed as CCR10. The expression pattern of mGPR2/CCR10 suggests that it may play a role in the homing/trafficking of leukocytes within intestinal and lymphoid environments.

Cloning and functional characterization of a novel human CC chemokine that binds to the CCR3 receptor and activates human eosinophils.

Eotaxin has been found to bind exclusively to a single chemokine receptor, CCR3. Using expression sequence tag screening of an activated monocyte library, a second chemokine has been identified; it was expressed and purified from a Drosophila cell culture system and appears to only activate CCR3. Eotaxin-2, MPIF-2, or CKbeta-6, is a human CC chemokine with low amino acid sequence identity to other chemokines. Eotaxin-2 promotes chemotaxis and Ca2+ mobilization in human eosinophils but not in neutrophils or monocytes. Cross-desensitization calcium mobilization experiments using purified eosinophils indicate that eotaxin and MCP-4, but not RANTES, MIP-1alpha, or MCP-3, can completely cross-desensitize the calcium response to eotaxin-2 on these cells, indicating that eotaxin-2 shares the same receptor used by eotaxin and MCP-4. Eotaxin-2 was the most potent eosinophil chemoattractant of all the chemokines tested. Eotaxin-2 also displaced 125I-eotaxin bound to the cloned CCR3 stably expressed in CHO cells (CHO-CCR3) and to freshly isolated human eosinophils with affinities similar to eotaxin and MCP-4. 125I-Eotaxin-2 binds with high affinity to eosinophils and both eotaxin and cold eotaxin-2 displace the ligand with equal affinity. Eotaxin and eotaxin-2 promote a Ca2+ transient in RBL-2H3 cells stably transfected with CCR3 (RBL-2H3-CCR3) and both ligands cross-desensitized the response of the other but not the response to LTD4. The data indicate that eotaxin-2 is a potent eosinophil chemotactic chemokine exerting its activity solely through the CCR3 receptor.

Neurotactin, a membrane-anchored chemokine upregulated in brain inflammation.

Chemokines are small secreted proteins that stimulate the directional migration of leukocytes and mediate inflammation. During screening of a murine choroid plexus complementary DNA library, we identified a new chemokine, designated neurotactin. Unlike other chemokines, neurotactin has a unique cysteine pattern, Cys-X-X-X-Cys, and is predicted to be a type 1 membrane protein. Full-length recombinant neurotactin is localized on the surface of transfected 293 cells. Recombinant neurotactin containing the chemokine domain is chemotactic for neutrophils both in vitro and in vivo. Neurotactin messenger RNA is predominantly expressed in normal murine brain and its protein expression in activated brain microglia is upregulated in mice with experimental autoimmune encephalomyelitis, as well as in mice treated with lipopolysaccharide. Distinct from all other chemokine genes, the neurotactin gene is localized to human chromosome 16q. Consequently we propose that neurotactin represents a new delta-chemokine family and that it may play a role in brain inflammation processes.