The C5a receptor antagonist PMX205 ameliorates experimentally induced colitis associated with increased IL-4 and IL-10

Background and Purpose

Anti-complement therapies have not been advanced for treating the inflammatory bowel diseases (IBDs) despite a growing body of evidence that blocking C5a protects against induced colitis in rodents. The purpose of this study was to further build on this evidence by examining the efficacy, mechanism and specificity of a potent, non-competitive and orally active C5a receptor (CD88) antagonist, PMX205, in the dextran sulphate sodium (DSS) model of murine innate colitis.

Experimental Approach

Mice with DSS added to their drinking water were orally administered 100 or 200 μg day⁻¹ PMX205 in prophylactic and therapeutic regimens. Clinical illness, colon histology and local generation of inflammatory mediators were measured to evaluate the impact of PMX205 on disease.

Key Results

PMX205 significantly prevented DSS-induced colon inflammation in both regimens, associated with lower pro-inflammatory cytokine production and nitrotyrosine staining in colon sections. Additionally, the levels of anti-inflammatory cytokines IL-4 and IL-10 were increased. PMX205 had no significant effect on C5a levels. The beneficial effect of PMX205 was seen in two strains of mice of differing sensitivities to DSS inflammation, but was inactive in mice lacking CD88.

Conclusions and Implications

Pharmacological inhibition of C5a activity by PMX205 is efficacious in preventing DSS-induced colitis, providing further evidence that targeting CD88 in IBD patients could be a valuable therapeutic option.     

Pulsus alternans induced by inferior vena caval occlusion in man

To assess the effect of rapid preload reduction on left ventricular performance in nonischemic cardiomyopathy, 11 patients were studied during inferior vena caval (IVC) balloon occlusion. Five developed sustained pulsus alternans. During pulsus alternans, the strong beats demonstrated systolic performance characteristics similar to baseline values, despite a drop in both left ventricular (LV) end-diastolic diameter (66 +/- 13 to 61 +/- 13 mm; p less than 0.05) and LV end-diastolic pressure (21 +/- 8 to 9 +/- 6 mmHg; p less than 0.05). In contrast, the weak beats demonstrated a reduction in peak systolic pressure (130 +/- 36 to 109 +/- 33 mmHg; p less than 0.02), fractional shortening (20% +/- 4% to 17% +/- 9%; p less than 0.05) and peak positive dP/dt (1,006 +/- 224 to 921 +/- 287 mmHg; p less than 0.05). Measures of diastolic performance (peak negative dP/dt, the time constant of LV relaxation, the length of diastasis, and LV end-diastolic stress) were not different between baseline beats and the strong beats; and only LV end-diastolic stress differed when baseline beats were compared to the weak beats. When the strong beats were compared to the weak beats during induced pulsus alternans, significant differences were observed in peak systolic pressure, peak positive dP/dt, and fractional shortening, but no differences in any measured diastolic parameter was observed. A slight difference was noted in the left ventricular end-diastolic diameters, with the weak beat consistently beginning at a slightly smaller diameter (61 +/- 13; mm vs 59 +/- 13; p less than 0.05). In summary, these data are consistent with an augmentation and deletion of intrinsic contractile forces in association with an alternation in preload on a beat-to-beat basis as best describing left ventricular performance during pulsus alternans.     

Trisomy 3 in low-grade B-cell lymphomas of mucosa-associated lymphoid tissue

Characteristic chromosomal aberrations have been associated with subtypes of non-Hodgkin's lymphoma with distinct clinicopathologic features. Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) form such a group and might be expected to be characterized by a specific cytogenetic abnormality. Metaphase analyses of MALT lymphoma are rare due to problems with fresh tissue collection and poor in vitro proliferation. However, the small number of published series suggests that chromosome trisomies, particularly trisomy 3, might be characteristic of these tumors. The application of interphase cytogenetic techniques to routinely processed material allows the examination of a large series of archival cases and is particularly useful for the demonstration of chromosome trisomies. We have used this technique to analyze 70 cases of low-grade MALT lymphoma from various sites and found trisomy 3 in 60%. This finding compares with 16% in low- grade nodal B-cell lymphoma and 27% in primary splenic lymphoma of marginal zone type (splenic lymphoma with villous lymphocytes). These results provide further evidence that low-grade MALT lymphomas from all sites form a single pathologic entity distinct from nodal B-cell lymphomas. Although MALT lymphoma and primary splenic lymphoma may arise from marginal zone B cells, they are genetically distinct.     

Movements and home range of a common species of tree–shrew,Tupaia glis,surrounding houses of otoacariasis cases in Kuantan,Pahang, Malaysia

ObjectiveTo document movement patterns, home range, nesting behaviour and social organization of 5 individuals (3 males and 2 females) of a common species of tree-shrew, Tupaia glis (T. glis) surrounding houses of otoacariasis cases.MethodsEach shrew was fitted with a transmitter chip radio-collar which operates between the frequencies of 154.13 MHz to 154.21 MHz. Each transmitter was then tracked with a Portable Telemetry Receiver (Sirtrack, New Zealand) fitted with a 3-element Yagi antenna. Collared shrews were located using standard methods of ground-based triangulation. Each location was taken from at least 2 directional fixes and a minimum of 3 compass bearings. Fixes were taken hourly for each collared individual from the time of emergence from nest (beginning of activity) till time of entry into the nest (end of activity) every day for 5 to 7 continuous days. Three series of radio telemetry observations were carried out. The bearings, time and positions of an observer were recorded and later plotted on a graph paper in order to derive coordinates of the collared animal. [These coordinates then analyzed using Ecological Software Solutions (Biotas Version 1.03)].ResultsNests were found in a jack fruit tree, long bushes, and 2 houses. Daily telemetry detections demonstrated 2 individuals of different sex having nests (or a nest) in the same house. All shrews emerged from and returned to their nests between 0601 to 0659 hours and 1901 to 1959 hours, respectively. Both the time of exit from and entry into nest were the same between sexes (P>0.05). Their average total active period was 4.90 to 7.00 hours with a total daily travel distant of 270 m to 382 m. A male and a female shrew can move as far as 3 285 m and 4 591 m, respectively. Active movements of T. glis were during daytime. They regularly entered some houses in the area during day and night except for one individual which visited during daytime only. The sizes of home range and core area for the shrews were 2.00–3.40 ha and 0.05–0.42 ha, respectively. Generally, the mean home range size of females was 20.8% larger than that of males. Females covered a 15.4% slightly higher daily movement range compared to males.ConclusionsThis is the first radio telemetry study in Malaysia to monitor movements and home range of shrews carrying ticks on their body. It demonstrates that shrews are potential carriers of ticks from wild into the houses and their compounds based on their total active periods spent moving around from fruit orchards, secondary forest, plantations and other vegetations to trees in compound of 4 to 7 houses and vice versa. There are also evidences showing shrews have close contact with humans.     

Characterization of ZK 245186, a novel,selective glucocorticoid receptor agonist for the topical treatment of inflammatory skin diseases

Background and purpose:

Glucocorticoids are highly effective in the therapy of inflammatory diseases. Their value, however, is limited by side effects. The discovery of the molecular mechanisms of the glucocorticoid receptor and the recognition that activation and repression of gene expression could be addressed separately opened the possibility of achieving improved safety profiles by the identification of ligands that predominantly induce repression. Here we report on ZK 245186, a novel, non-steroidal, low-molecular-weight, glucocorticoid receptor-selective agonist for the topical treatment of inflammatory dermatoses.

Experimental approach:

Pharmacological properties of ZK 245186 and reference compounds were studied in terms of their potential anti-inflammatory and side effects in functional bioassays in vitro and in rodent models in vivo.

Key results:

Anti-inflammatory activity of ZK 245186 was demonstrated in in vitro assays for inhibition of cytokine secretion and T cell proliferation. In vivo, using irritant contact dermatitis and T cell-mediated contact allergy models in mice and rats, ZK 245186 showed anti-inflammatory efficacy after topical application similar to the classical glucocorticoids, mometasone furoate and methylprednisolone aceponate. ZK 245186, however, exhibits a better safety profile with regard to growth inhibition and induction of skin atrophy after long-term topical application, thymocyte apoptosis, hyperglycaemia and hepatic tyrosine aminotransferase activity.

Conclusions and implications:

ZK 245186 is a potent anti-inflammatory compound with a lower potential for side effects, compared with classical glucocorticoids. It represents a promising drug candidate and is currently in clinical trials.This article is part of a themed issue on Mediators and Receptors in the Resolution of Inflammation. To view this issue visit http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009     

Phorbol ester stimulation increases sickle erythrocyte adherence to endothelium: a novel pathway involving alpha 4 beta 1 integrin receptors on sickle reticulocytes and fibronectin

Sickle-cell adherence to endothelium has been hypothesized to initiate or contribute to microvascular occlusion and pain episodes. Adherence involves plasma proteins, endothelial-cell adhesion molecules, and receptors on sickle erythrocytes. It has previously been reported that sickle reticulocytes express the alpha 4 beta 1 integrin receptor and bind to cytokine-activated endothelium via an alpha 4 beta 1/vascular- cell adhesion molecule-1 (VCAM-1) interaction. To elucidate other roles for alpha 4 beta 1 in sickle-cell adherence, the ability of activated alpha 4 beta 1 to promote adhesion to endothelium via a ligand different than VCAM-1 was explored. Adherence assays were performed under dynamic conditions at a shear stress of 1 dyne/cm2. Preincubation of sickle erythrocytes with phorbol 12,13-dibutyrate (PDBu) increased adherence of sickle cells eightfold as compared with untreated sickle cells. Normal erythrocytes, whether treated with PDBu or not, did not adhere to the endothelium. Activating anti-beta 1 antibodies 4B4 and 8A2 also increased the adhesion of sickle, but not normal, red blood cell (RBC) adhesion to endothelium. Anti-alpha 4 antibodies HP1/2 and HP2/1, inhibitory antibody 4B5, or an RGD peptide inhibited sickle-cell adherence induced by PDBu. Additional studies were undertaken to examine if fibronectin, a ligand for activated alpha 4 beta 1, was involved in PDBu-induced sickle erythrocyte adherence. Adherence of PDBu-treated sickle cells was completely inhibited by the CS-1 peptide of fibronectin. Fibronectin was detected on the surface of washed endothelium using an antifibronectin antibody in enzyme-linked immunosorbent assays. Antifibronectin antibody pretreatment of endothelial cells inhibited PDBu-induced adherence by 79% +/- 17%. Incubation of sickle RBCs with exogenous fibronectin after PDBu treatment inhibited adherence 86% +/- 8%. Taken together, these data suggest that endothelial-bound fibronectin mediates adherence of PDBu- treated sickle cells. Interleukin-8 (IL-8), a chemokine released in response to bacterial infection, viral infection, or other injurious agents, and known to activate integrins, also increased adherence of sickle erythrocytes to endothelial cells via fibronectin. This novel adherence pathway involving sickle-cell alpha 4 beta 1 activated by PDBu or IL-8 may therefore be relevant in vivo at vascular sites that produce IL-8 or similar agonists in response to vascular injury or immune activation. These observations describe ways in which inflammation and immune responses cause vasoocclusive complications in sickle-cell disease.     

mdx muscle pathology is independent of nNOS perturbation

In skeletal muscle, neuronal nitric oxide synthase (nNOS) is anchored to the sarcolemma via the dystrophin-glycoprotein complex. When dystrophin is absent, as in Duchenne muscular dystrophy patients and in mdx mice, nNOS is mislocalized to the interior of the muscle fiber where it continues to produce nitric oxide. This has led to the hypothesis that free radical toxicity from mislocalized nNOS may contribute to mdx muscle pathology. To test this hypothesis directly, we generated mice devoid of both nNOS and dystrophin. Overall, the nNOS- dystrophin null mice maintained the dystrophic characteristics of mdx mice. We evaluated the mice for several features of the dystrophic phenotype, including membrane damage and muscle morphology. Removal of nNOS did not alter the extent of sarcolemma damage, which is a hallmark of the dystrophic phenotype. Furthermore, muscle from nNOS-dystrophin null mice maintain the histological features of mdx pathology. Our results demonstrate that relocalization of nNOS to the cytosol does not contribute significantly to mdx pathogenesis.