Migration Of White Blood Cells Research Articles

An experimental evaluation of Albuca setosa aqueous extract on membrane stabilization, protein denaturation and white blood cell migration during acute inflammation

Albuca setosa is widely distributed in the Eastern Cape region of South Africa where its traditional usage is very extensive. This study was aimed to experimentally evaluate the effect of A. setosa water extract (ASWE) on inflammation events such as membrane stabilization, protein denaturation and white blood cell migration during acute inflammation. This study was undertaken using hypotonicity and heat induced erythrocytes haemolysis, heat induced albumin denaturation, carrageenan and dextran induced peritonis and rat paw edema. The results showed that ASWE at a concentration range of 125 - 500 μg/ml significantly (p < 0.01) protects the erythrocyte membrane against lysis induced by heat and hypotonic medium solution. At the dose of 500 and 125 μg/ml, ASWE showed significant (p < 0.01) inhibition of 59 and 65% of protein denaturation of egg albumin. Oral administration of 150 and 300 mg/kg of ASWE significantly (p < 0.05) reduced the total WBC count in rat paw fluid after inflammation induced by carrageenin and in the peritoneal wash after acute inflammation induced by dextran and carrageenan, respectively. The present work contributes to the validation of the anti-inflammatory activity of the plant and may provide some evidence for its folk use and further exploitation. Key words: Albuca setosa, membrane stabilization, protein denaturation, white blood cell migration, anti-inflammatory activity.

Critical Role for Leukocyte Hypoxia Inducible Factor-1α Expression in Post-Myocardial Infarction Left Ventricular Remodeling

Hypoxia inducible factor (HIF)-1alpha is a transcription factor stabilized by hypoxia. It regulates cytokines involved in the inflammatory response after ischemia and affects white blood cell (WBCs) function. The effect of HIF-1alpha on WBC function and inflammation following myocardial infarction (MI) is unknown. We assessed peritoneal and myocardial inflammation in the setting of low WBC HIF-1alpha expression through bone marrow transplantation of hematopoietic stem cells transfected with scramble or HIF-1alpha small interfering (si)RNA. Rosa hematopoietic stem cells (lin(-), cKit(+)) were transfected with a green fluorescent protein (GFP) reporter lentivirus encoding a siRNA to HIF-1alpha or scramble. Irradiated 6- to 8-week-old C57/BL6J mice received 50 000 GFP(+) HIF-1alpha or scramble siRNA-transfected hematopoietic stem cells. Peritonitis or myocardial infarction via left anterior descending coronary artery ligation was induced 6 weeks after bone marrow transplantation. In the peritonitis model, HIF-1alpha siRNA group exhibited a significant decrease in neutrophil and monocyte entry to the peritoneum compared to scramble mice. Similarly neutrophil infiltration into the infarct zone was decreased in the HIF-1alpha siRNA group. No difference of myocardial infarct size was observed between groups. Interestingly, the ejection fraction were similar in both groups at baseline and 3 days post-MI but increased significantly in the HIF-1alpha siRNA group compared to control beginning 7 days after MI. Gene array studies demonstrated that downregulation of WBC HIF-1alpha was associated with decreased WBC CCR1, -2, and -4 expression. Chemotaxis assay results confirmed that decreased monocyte migration induced by downregulation of HIF-1alpha was partially reversed by overexpression of CCR2. Downregulation of leukocyte HIF-1alpha expression resulted in decreased recruitment of WBC to the sites of inflammation and improvement in cardiac function following MI. Downregulation of HIF-1alpha suppressed WBC cytokine receptors CCR1, -2, and -4, which are necessary for WBC mobilization and recruitment to inflammatory cytokines following MI. The effects of downregulation of leukocyte HIF-1alpha on WBC migration are attributable, at least in part, to the decreased CCR2 expression. These results demonstrate that WBC infiltration into the newly injured myocardium plays a significant role in left ventricular remodeling, but not infarct size.

Photosensibilité du lupus érythémateux

Photosensitivity is one of the ARA diagnostic criteria of systemic lupus erythematosus. Sun exposure can also induce extracutaneous manifestations of the disease. Photosensitivity may be difficult to prove by history taking in lupus patients, as the delay between sun exposure and the onset of specific skin lesions is rather long. Photo-induction of lupus can occur by ultraviolet A (UVA) radiation in the shadow or behind window glass, so that the relationship between radiation exposure and exacerbation of the disease may not seem obvious to the patient. Phototesting procedures for lupus erythematosus have been described, but they are not used in routine practice. Both UVB and UVA play a role in the pathogenesis of lupus erythematosus: in the epidermis they induce DNA damage, they expose nuclear antigens and photo-induced neo-antigens at the cell surface, they lead to an accumulation of apoptotic material, and they induce several pro-inflammatory cytokines. In the dermis, UV radiation triggers skin infiltration by inflammatory cells by modulation of microvascular flow rates and by upregulation of white blood cell migration from dermal capillaries to the skin. Photodistribution of skin lesions and a delay of their onset of more than 48 hours after sun exposure are clinical hallmarks of cutaneous lupus erythematosus that are usually completed by histological confirmation. Photoprotection is essential in the treatment of lupus patients: it comprises sun avoidance suitable for both UVB and UVA radiation, protective clothing, and topical broad-spectrum filters.

Crude aqueous extract of the root bark of zanthoxylum xanthoxyloides inhibits white blood cells migration in acute inflammation.

Crude aqueous extract of Zanthoxylum xanthozyloides is used locally to treat inflammatory conditions. Previous study confirmed that the extract has anti-inflammatory activity and also reduced vascular response in inflammation. To identify the effect of the extract on migration of white blood cells to the site of inflammation. The extract was obtained by Soxhlet extraction and rotatory evaporation, followed by freeze-drying. Cohorts of Wistar rats (150g - 200g) were randomly assigned to 6 treatment cells, and were given, per os, three different treatments: indomethacin (20mg/kg and 40mg/kg), the extract (2000mg/kg and 4000mg/kg), and 0.9% saline (two groups of control). Inflammation was induced with carrageenin in the hind paw of the treated groups of rats and one group of the control (positive control), one hour after treatment. Inflammatory exudates from the inflamed paws were collected and the white blood cells (WBCs) counted. Carrageenin increased the total WBC count (in the paw fluid) which was reduced by the extract and indomethacin (p<0.05). Neither the extract nor indomethacin had any effect on total WBC count in the non-carrageenin treated control rats. The extract did not affect the pre-existing WBC population at the site of inflammation but rather inhibited migration of the cells to the site.

The chemokine CCL20 and its receptor CCR6 in human malignancy with focus on colorectal cancer

Chemokines are a superfamily of small chemotactic cytokines, which interact with their G-protein-coupled receptors. These interactions regulate multiple physiological functions, particularly tissue architecture and compartment-specific migration of white blood cells. It has been found that the chemokine/chemokine receptor system has been utilized by cancer cells for migration and metastasis. The chemokine receptor CCR6 is expressed in colorectal cancer and several other cancer types, and stimulation by its physiological chemokine ligand CCL20 has been reported to promote cancer cell proliferation and migration in vitro. Moreover, CCR6/CCL20 interactions apparently play a role in organ selective liver metastasis of colorectal cancer. Here, we review the literature on expression patterns of CCL20 and CCR6 and their physiological interactions as well as the currently presumed role of CCR6 and CCL20 in the formation of colorectal cancer liver metastasis, providing a potential basis for novel treatment strategies.

Blood Genomics in Human Stroke

Advances in microarray technology and the sequencing of the human genome are opening up new possibilities for applying genomic information in clinical medicine, using information about structural polymorphisms in DNA and changes in gene expression as measured by mRNA. Gene expression profiling studies in cancer samples have led to the identification of clinical signatures that are already being applied in some centers. In stroke, it may be possible to use peripheral blood as a source of mRNA to study gene expression. After stroke, there is a selective recruitment and migration of white blood cells to the ischemic focus in the brain. This appears to involve all white cell types and is believed to impact significantly on tissue and clinical outcome through the exacerbation of ischemic injury, particularly after reperfusion, on the one hand, and conversely contributing to tissue remodeling and repair days to weeks after stroke. The first results from clinical studies in ischemic stroke suggest that a gene expression signature can be demonstrated from peripheral white blood cells and that this represents at least a partial adaptation to the altered cerebral microenvironment. Further studies are indicated to see whether these methods may lead to new management approaches for stroke.

The role of platelet‐derived lysophospholipids in the progression of head and neck cancer

Objectives. Platelets are known to have an important role in cancer progression but their function remains to be fully elucidated. In this study, we tested the hypothesis that platelet derived lysophospholipids are important in the spread and survival of head and neck cancer cells. Lysophospholipids are known to promote many of the hallmarks of cancer, including adhesion, proliferation, invasion and angiogenesis.Methods. In our study we utilised ‘paired’ primary and metastatic cell lines isolated from a primary tongue cancer lesion and a metastatic lymph node, respectively, from the same patient. This facilitates the study of the nature of head and neck cancer metastasis by comparing the local and metastatic neoplastic population from the same cancer. To investigate the role of lysophospholipids in squamous cell carcinoma of the tongue we compared the receptor profile of these cell lines at the RNA and protein level using PCR and flow cytometry. In addition, we analysed the functional significance of these findings using cell migration and chemoresistance assays.Results. We demonstrated for the first time that lysophospholipid receptors known to be critical in white blood cell migration are present in metastasising but not localised cancer cells. In addition, we proved that lysophospholipids are important in HNSCC migration and delineated many of the molecular pathways involved. Finally, we demonstrated that the presence of lysophospholipids protects cancer cells from chemotherapy‐induced apoptosis.Conclusions. Platelet derived lysophospholipids appear to be important in HNSCC metastasis. They may also explain why HNSCC nearly always metastasise to lymph nodes.

Niacin affects cell adhesion molecules and plasminogen activator inhibitor-1 in HepG2 cells

BackgroundBeyond lipid-modifying actions, niacin lowers the risk of atherothrombotic events by lowering prothrombotic factors like fibrinogen. Plasminogen activator inhibitor type 1 (PAI-1) is a potential factor for atherogenesis and thrombosis, increased in acute myocardial infarctions and restenosis after angioplasty. Cell adhesion molecules (CAM) mediate adhesion, recruitment and migration of white blood cells through vascular surfaces, an essential process in atherogenesis. ICAM-1 is a significant predictor of future coronary events. Whether niacin affects ICAM-1 expression is unknown. We studied the effects of niacin on PAI-1 and CAM using HepG2 cells. MethodsHepG2 cells were cultured in DMEM until 90% confluent. After serum starvation, cells were exposed to DME/F12 containing niacin. Transforming growth factor-beta (TGF-β) was added directly to cell media. Cell lysate and conditioned media were collected for measurement of PAI-1 by ELISA. For measurement of ICAM, cells were treated with tumor necrosis factor-alpha (TNF-α) instead. The effect of niacin on mRNA expression of ICAM-1 was studied using RT-PCR. ResultsNiacin reduced the TGF-β-induced rise by 30% to 55% (p=0.002). The differences in degree of PAI-1 reduction, between different niacin concentrations, were not statistically significant. Niacin reduced TNF-α-induced rise in ICAM-1 levels by 66% to 89% (p<0.0001), but did not significantly affect TNF-α-induced rise in PECAM-1. Semiquantitative RT-PCR analysis showed that reduced TNF-α-induced rise in ICAM-1 mRNA expression significantly by 17% (p=0.001). ConclusionsTreatment with niacin suppressed PAI-1 and ICAM-1 levels in HepG2 cells. Further studies to understand the mechanistic pathways of this suppression, could further explain benefits of niacin in prevention of atherosclerotic disease, and offer therapeutic avenues against the rising burden of atherothrombotic disease.

Identification of potent and novel alpha4beta1 antagonists using in silico screening.

The antigen alpha4beta1 (very late antigen-4, VLA-4) plays an important role in the migration of white blood cells to sites of inflammation. It has been implicated in the pathology of a variety of diseases including asthma, multiple sclerosis, and rheumatoid arthritis. We describe a series of potent inhibitors of alpha4beta1 that were discovered using computational screening for replacements of the peptide region of an existing tetrapeptide-based alpha4beta1 inhibitor (1; 4-[N'-(2-methylphenyl)ureido]phenylacetyl-Leu-Asp-Val) derived from fibronectin. The search query was constructed using a model of 1 that was based upon the X-ray conformation of the related integrin-binding region of vascular cell adhesion molecule-1 (VCAM-1). The 3D search query consisted of the N-terminal cap and the carboxyl side chain of 1 because, upon the basis of existing structure-activity data on this series, these were known to be critical for high-affinity binding to alpha4beta1. The computational screen identified 12 reagents from a virtual library of 8624 molecules as satisfying the model and our synthetic filters. All of the synthesized compounds tested inhibit alpha4beta1 association with VCAM-1, with the most potent compound having an IC(50) of 1 nM, comparable to the starting compound. Using CATALYST, a 3D QSAR was generated that rationalizes the variation in activities of these alpha4beta1 antagonists. The most potent compound was evaluated in a sheep model of asthma, and a 30 mg nebulized dose was able to inhibit early and late airway responses in allergic sheep following antigen challenge and prevented the development of nonspecific airway hyperresponsiveness to carbachol. Our results demonstrate that it is possible to rapidly identify nonpeptidic replacements of integrin peptide antagonists. This approach should be useful in identification of nonpeptidic alpha4beta1 inhibitors with improved pharmacokinetic properties relative to their peptidic counterparts.

3D QSAR (COMFA) of a series of potent and highly selective VLA-4 antagonists.

The integrin VLA-4 (alpha4,beta1) is involved in the migration of white blood cells to sites of inflammation, and is implicated in the pathology of a variety of diseases including asthma and multiple sclerosis. We report the structure-activity relationships of a series of VLA-4 antagonists that were based upon the integrin-binding sequence of the connecting segment peptide of fibronectin (Leu-Asp-Val), and of VCAM-1 (Ile-Asp-Ser), both natural ligands of VLA-4. We explore variation in the ligand derived peptide portion of these antagonists and also in the novel N-terminal cap, which have discovered through chemical optimization, and which confers high affinity and selectivity. Using the X-ray derived conformation of the Ile-Asp-Ser region of VCAM-1, we rationalize the structure-activity relationships of these antagonists using 3D QSAR (COMFA). The COMFA model was found to be highly predictive with a cross-validated R2CV of 0.7 and a PRESS of 0.49. The robustness of the model was confirmed by testing the influence of various parameters, including grid size, column filtering, as well as the role of orientation of the aligned molecules. Our results suggest that the VCAM-1 structure is useful in generating highly predictive models of our VLA-4 antagonists. The COMFA model coupled with the knowledge that the peptide amides are tolerant to methylation should prove useful in future peptidomimetic design studies.

Soluble adhesion molecule profile in normal pregnancy and pre-eclampsia

Objective: An exaggerated inflammatory response has been implicated as the cause of endothelial cell dysfunction and the maternal syndrome of pre-eclampsia. Adhesion molecules play a central rolein the adherence of leukocytes to endothelial cells and the subsequent migration of white blood cells into perivascular tissue. Cellular forms of adhesion molecules mediate specific steps of leukocyte-endothelialcell interaction, and have been implicated in the pathophysiology of pre-eclampsia. Soluble forms of these molecules can be detected in plasma, and their concentrations are thought to reflect the degreeof activation of a particular cell type. Elevations in soluble P-selectin (sP-selectin) reflect platelet activation; changes in soluble L-selectin (sL-selectin) suggest leukocyte activation; and an increasein soluble forms of E-selectin (sE-selectin), vascular cell adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1) and platelet endothelial cell adhesion molecule (sPECAM-1) indicateendothelial cell activation/dysfunction. The objective of this study was to determine whether normal pregnancy and pre-eclampsia were associated with changes in the concentrations of soluble selectins andmembers of the immunoglobulin superfamily of adhesion molecules.Study design: A cross-sectional study was conducted to determine the plasma concentrations of sL-selectin, sE-selectin, sP-selectin,sVCAM-1, sICAM-1 and sPECAM-1 in peripheral blood obtained from non-pregnant women (n = 20), normal pregnant women (n = 100) and patients with pre-eclampsia (n = 55). Concentrationsof soluble adhesion molecules were determined with enzyme-linked immunoassays. Parametric statistics were used for data analysis.Results: Normal pregnancy was associated with a significant increasein the maternal plasma concentration of sP-selectin, a decrease in sL-selectin, and no change in sE-selectin, sVCAM-1, sICAM-1 and sPECAM-1. In contrast, pre-eclampsia was associated with a significantincrease in sP-selectin, sE-selectin and sVCAM-1, a decrease in sL-selectin, but no change in sICAM-1 and sPECAM-1 concentrations.Conclusions: The increased concentration of sP-selectin anddecreased sL-selectin, as well as the lack of change in endothelial cell-associated soluble adhesion molecules suggest that pregnancy is associated with platelet and leukocyte activation, but not endothelialcell activation. In contrast, pre-eclampsia appears to be characterized by activation of platelets, leukocytes and endothelial cells.

Histopathological changes in the swimbladder wall of the European eel Anguilla anguilla due to infections with Anguillicola crassus.

The histopathological changes in swimbladders of European eels naturally and experimentally infected with Anguillicola crassus were studied using transmission and scanning electron microscopy. During the course of probably several infections swimbladders undergo characteristic changes. In addition to the thickening of the entire swimbladder wall, and to the folded internal surface of this organ, inflammation, migration of white blood cells, fibrosis and changes in the epithelial cells are frequently seen. Epithelial cells tend to proliferate heavily and form hyperplastic tissues; these processes are accompanied by changes in the internal structure of the cells. The normally cubic cells become spherical or columnar and form folds facing the lumen of the swimbladder. As a consequence, most of these cells lose contact with the blood vessels and show no strict polarity. In heavily affected swimbladders the basal labyrinth of the epithelial cells is reduced, i.e. becomes shorter and less densely packed. The lamina propria shows severe fibrosis with infiltration of white blood cells. Larvae of A. crassus, inhabiting the wall of the swimbladder, were found to be surrounded by cell debris, but this local necrosis does not affect the entire swimbladder in its overall structure. These histological findings can partly explain changes in the gas composition in eels infected with A. crassus.

Elimination of blood-derived macrophages inhibits the release of interleukin-1 and the entry of leukocytes into the cerebrospinal fluid in experimental pneumococcal meningitis

Parameters of inflammation during pneumococcal meningitis were determined in rabbits after monocyte elimination by dichloromethylene diphosphonate (Cl 2MDP)-containing mannosylated liposomes in comparison with untreated controls. Monocyte depletion reduced the migration of white blood cells into the cerebrospinal fluid (CSF) (medians: 42 versus 2146/mm 3 at 18 h, 323 versus 7413/mm 3 at 24 h p.i., p<0.01). CSF IL-1 β concentrations were lower in depleted animals (379 versus 3282 pg/ml, 24 h p.i., p<0.01), whereas TNF- α concentrations were not different. Monocyte-depleted animals lost body temperature during the experiment carried out in anaesthesia ( p=0.01) indicating that macrophages are necessary for thermogenesis during meningitis.

Adhesion molecules in renal disease

Adhesion molecules are a heterogeneous class of ligands/receptors that mediate cell adhesion, either to other cells or to the extracellular matrix. Cell adhesion is of fundamental importance to an impressive number of physiological and pathological processes, including the differentiation of cells and their organization in tissues [1], the intercommunication and activation of immune cells [2], the recirculation and migration of white blood cells [3], the growth and metastatic diffusion of tumoral cells [4]. On the basis of molecular, structural and functional differences, adhesion molecules have been separated into three main groups: the integrins, the selectins and a group that belongs to the immunoglobulin superfamily. In addition to these classic families of adhesion molecules, a recently described family of chemoattractive cytokines, termed chemokines, behave as adhesion molecules after having been released at a site of inflammation. These ligands, in fact, bind to specific receptors in the endothelium or extracellular matrix [5] and here regulate immune cell migration by haptotaxis, a process driven by the gradient of adhesive ligands affixed to the surface of cells or to the extracellular matrix [6]. This article first summarizes the features that distinguish the families of adhesion molecules and gives a concise description of their most relevant members. Then, the expression of adhesion molecules in renal cells in culture and in normal renal tissue, and the pathophysiological role of adhesion molecules in renal disease, with an emphasis on nephritis, transplant rejection and the effects of hemodialysis on leukocytes will be reviewed.

The anti‐inflammatory activity of metal complexes and salts of amine carboxyboranes

AbstractThe metal complexes and salts of amine carboxyboranes were shown to be potent anti‐inflammatory agents in rodents at 8 mg kg−1. They were effective in blocking induced edema, pleurisy and endotoxic shock while blocking both local and central pain processes. The ability of the agents to function as anti‐inflammatory agents is multi‐fold. First, lysosomal enzymes of specific cells, e.g. macrophages, were inhibited with IC50 values in the range of 10−6 M. Collagenase I and II activities were inhibited with IC50 values approximately equal to 10−4 M. The anti‐inflammatory activity of these agents at the molecular levels appears to be due to inhibition of the release of TNFα and Il‐1 from macrophages which indirectly control chemotaxic migration of white blood cells as indicated by the suppression of PMN and macrophage invasion into sponges implanted subcutaneously (SC) in mice. Furthermore, in these invading cells, the agents' blockage of TNFα and Il‐1 or Il‐2 release down‐regulates prostaglandin and leukotriene enzymatic synthetic rates and, consequently, their release, resulting in a reduction of the inflammation process.

Anti-adhesive therapeutics: A new class of anti-inflammatory agents

Intercellular adhesion plays a discrete part in a co-ordinated sequence of events which lead to the pathology of inflammatory disease. The last decade has seen an explosion of information aimed at providing more detail on the mechanism of cell adhesion which essentially involves a number of signal transductions resulting in the migration of white blood cells to the site of infection. Over-recruitment of these cells can cause injury to the normal tissues as observed in the case of septic shock-reperfusion injury. Cell-cell interaction also takes place in metastasis - the migration and adherence of malignant tumour cells. Inhibition or control of these pathophysiological disorders is possible by introducing therapeutics that would block or modulate the adhesion process.

Intrauterine Devices

<h3>To the Editor.—</h3> I read with interest the article on intrauterine devices (IUDs) in the Questions and Answers section ofThe Journal.¹In general, the article is very well written and the conclusions are valid. The portion of the article that I disagree with is the paragraph dealing with the mechanism of action of the copper-containing IUDs, which states that the foreign-body reaction reduces implantability and therefore fertility.^1(p2128) There is a great body of evidence that indicates that the mechanism of action of IUDs in general, as well as the copper-bearing IUDs specifically, is to prevent fertilization by acting as a spermicide. Sagiroglu and Sagiroglu²showed that sperm were being phagocytized by white blood cells within the uterine cavity in women wearing IUDs. The IUDs exert a foreign-body reaction, inducing migration of white blood cells in large numbers to the endometrial cavity. These leukocytes phagocytize sperm, and

The quantification of blood cell motion by a method of automatic digital picture processing

In order to facilitate the study of cell movement, the paper introduces a new automatic picture processing method for tracking and quantifying the dynamics of blood cell motion. The input to the program is a 16 mm cine film of the cell culture viewed in a steady condition. Under the circumstances, the global directional movement tendencies of the group of cells under consideration can be characterized by a Markov chain model. By observing and quantifying the cell paths, it is possible, using this model, to determine the probability that the cell population is moving in a particular direction. This information might be of interest in the study of the effect of substances on cell movement, defects in white blood cell migration, and the general interaction among cells.

Metal allergy and the surgical patient

Allergy to metal implants is under study at the Dartmouth-Hitchcock Medical Center using in vitro examination of white blood cell migration. Retrospective data from 121 patients confirm that allergic responses do occur. Prospective data are being gathered to investigate the incidence, prevalence and relation to morbidity.