Over the last years, genetic studies have greatly improved our knowledge on the receptor subtypes mediating various pharmacological effects of positive allosteric modulators at GABA A receptors. This stimulated the development of new benzodiazepine (BZ)-like ligands, especially those inactive/low-active at GABA A receptors containing the α 1 subunit, with the aim of generating more selective drugs. Hereby, the affinity and efficacy of four recently-synthesized BZ site ligands: SH-053-2'N, SH-053-S-CH3-2'F, SH-053-R-CH3-2'F and JY-XHe-053 were assessed. They were also studied in behavioral tests of spontaneous locomotor activity, elevated plus maze, and water maze in rats, which are considered predictive of, respectively, the sedative, anxiolytic, and amnesic influence of BZs. The novel ligands had moderately low to low affinity and mild to partial agonistic efficacy at GABA A receptors containing the α 1 subunit, with variable, but more pronounced efficacy at other BZ-sensitive binding sites. While presumably α 1 receptor-mediated sedative effects of GABA A modulation were not fully eliminated with any of the ligands tested, only SH-053-2'N and SH-053-S-CH3-2'F, both dosed at 30 mg/kg, exerted anxiolytic effects. The lack of clear anxiolytic-like activity of JY-XHe-053, despite its efficacy at α 2 -and α 3 -GABA A receptors, may have been partly connected with its preferential affinity at α 5 -GABA A receptors © 2010 Elsevier Inc. All rights reserved. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. coupled with weak agonist activity at α 1 -containing subtypes. The memory impairment in watermaze experiments, generally reported with BZ site agonists, was completely circumvented with all four ligands. The results suggest that a substantial amount of activity at α 1 GABA A receptors is needed for effecting spatial learning and memory impairments, while much weaker activity at α 1 -and α 5 -GABA A receptors is sufficient for eliciting sedation. NIH Public Access
The clinical use of benzodiazepines (BZs) is hampered by sedation and cognitive deterioration. Although genetic and pharmacological studies suggest that α1- and α5-containing GABAA receptors mediate and/or modulate these effects, their molecular substrate is not fully elucidated. By the use of two selective ligands : the α1-subunit affinity-selective antagonist β-CCt, and the α5-subunit affinity- and efficacy-selective antagonist XLi093, we examined the mechanisms of behavioural effects of diazepam in the tests of spontaneous locomotor activity and water-maze acquisition and recall, the two paradigms indicative of sedative- and cognition-impairing effects of BZs, respectively. The locomotor-activity decreasing propensity of diazepam (significant at 1.5 and 5 mg/kg) was antagonized by β-CCt (5 and 15 mg/kg), while it tended to be potentiated by XLi093 in doses of 10 mg/kg, and especially 20 mg/kg. Diazepam decreased acquisition and recall in the water maze, with a minimum effective dose of 1.5 mg/kg. Both antagonists reversed the thigmotaxis induced by 2 mg/kg diazepam throughout the test, suggesting that both GABAA receptor subtypes participate in BZ effects on the procedural component of the task. Diazepam-induced impairment in the declarative component of the task, as assessed by path efficiency, the latency and distance before finding the platform across acquisition trials, and also by the spatial parameters in the probe trial, was partially prevented by both, 15 mg/kg β-CCt and 10 mg/kg XLi093. Combining a BZ with β-CCt results in the near to control level of performance of a cognitive task, without sedation, and may be worth testing on human subjects.
BACKGROUNDEmerging epidemiological evidence suggests independent associations between psoriasis and metabolic syndrome. Objectives: The aim of the study was to examine the prevalence of metabolic syndrome and its components in patients with psoriasis, and to assess which factors may predict metabolic syndrome in these patients.METHODSA hospital-based, cross-sectional study with 244 psoriatic patients and 163 control subjects with skin diseases other than psoriasis was conducted at the Clinic of Dermatovenerology, Clinical Center of Serbia, Belgrade, from October 2011 to October 2012. Metabolic syndrome was defined using the revised National Cholesterol Education Program Adult Treatment Panel III. Severity of psoriasis was measured by Psoriasis Area and Severity Index and Body Surface Area.RESULTSThe adjusted odds ratios (ORs) and 95% confidence intervals (CI) for psoriasis patients vs. non-psoriasis patients were 2.66 (95% CI, 1.58-4.42) for metabolic syndrome, 3.81 (95% CI, 2.30-6.31) for hypertension, 2.29 (95% CI, 1.39-3.78) for central obesity, 1.92 (95% CI, 1.08-3.41) for hyperglycemia, 1.87 (95% CI 1.18-2.96) for low high-density lipoprotein cholesterol level, and 1.42 (95% CI, 0.87-1.04) for hypertrigliceridemia. We failed to find any statistically significant association between the metabolic syndrome and clinical severity of psoriasis. Later onset and longer duration of psoriasis were predicting factors for metabolic syndrome in our patients. Study limitations: The cross-sectional design of the study does not allow us to draw directional causal inferences concerning the association between psoriasis and metabolic syndrome. Factors such as diet, alcohol consumption or mental health, which have not been evaluated in this study, may be confounders in this relation.CONCLUSIONA higher prevalence of metabolic syndrome and its components in patients with psoriasis than in controls, regardless of disease severity, emphasizes the need for early treatment and follow-up of all psoriatic patients with respect to metabolic diseases.
For circulating lymphocytes to migrate to inflammatory sites, they must first adhere to the target tissue endothelium with sufficient strength to overcome the shear forces of blood flow. We previously reported that dermal papillary vessels in acute graft-versus-host disease (aGVHD) support shear-resistant lymphocyte adherence. We now identify the relevant adhesion molecule(s) directing this binding, showing that interactions between lymphocyte CD44 and hyaluronic acid (HA) expressed on dermal vessels in aGVHD alone confer this shear-resistant attachment. Native HA deposits on vascular endothelium support lymphocyte adherence, whereas HA immobilized on plastic does not. HA expressed at dermal endothelium in aGVHD is thus specialized to support lymphocyte adherence under flow conditions, and CD44-HA interactions may contribute to lymphocytotropism to skin in aGVHD. IntroductionTo elucidate the molecular mediators of lymphocyte trafficking in acute graft-versus-host disease (aGVHD), we previously performed adhesion assays under blood flow shear stress conditions 1 to analyze lymphocyte binding to endothelia of skin eruptions after allogeneic and autologous hematopoietic stem cell transplantation (HSCT). 2 These studies showed that papillary dermal vessels in aGVHD reactions, but not in most other post-HSCT skin eruptions, support shear-resistant adherence of lymphocytes. 2 We show here that this binding interaction is mediated by endothelial deposits of hyaluronic acid (HA) specialized to support CD44-dependent lymphocyte adherence. These findings offer new perspectives on the molecular basis of cutaneous aGVHD reactions and highlight a role for HA in the pathobiology of this condition. Study design Lymphocyte-skin adherence assayAll specimens were obtained under institutional review board (IRB)-approved protocols. Biopsy samples of involved skin were obtained from 42 recipients of allogeneic HSCT with cutaneous aGVHD, and normal skin was from discarded tissue from cosmetic surgery. The lymphocyte-skin adherence assay was performed using lymphocytes (peripheral blood mononuclear cells [PBMCs]) from healthy donors. 2,3 Chemical, enzymatic, and anti-CD44 antibody treatments For all treatments, adherence assays were performed on alternating sequential sections (treated, or buffer/isotype-control). Lymphocytes were counted in comparable consecutive areas of the papillary dermis using an ocular grid. Protease digestions, EDTA (ethylenediaminetetraacetic acid), and neuraminidase treatments were performed as described. 4 Digestion of matrix elements and monoclonal antibody (mAb) (Hermes-1) 5 treatments were performed as described in Figure 1. ImmunohistochemistryImmunohistochemical staining of endothelial structures was performed using primary antibodies anti-CD34, anti-CD31, or mouse immunoglobulin G1 (IgG1) isotype (all at 10 g/mL in phosphate-buffered saline [PBS]/ 10% fetal bovine serum [FBS]), biotinylated secondary antibody, and streptavidin-horseradish peroxidase. Chromagen was NovaRed, and sections were counterst...
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