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Several 4-nitro- and 4-amino-5-acyl-6-aryl-3(2 H )pyridazinones were prepared and their in vitro and ex vivo antiaggregatory properties were evaluated. 4-Nitro derivatives 3 generally showed good activity in vitro towards arachidonic acid (AA)-induced human blood platelet aggregation. The 4-amino compound 4a , which has weak in vitro activity, exhibited antiplatelet activity, particularly on adenosine dephosphate (ADP)-induced aggregation ex vivo in rabbit. Moreover, the same compound was shown to be active in platelet-activating factors (PAF)- induced rat paw hyperalgesia and to be endowed with low acute oral toxicity. The 4-amino derivatives 4a – m and the other pyridazinones 5–9 administered orally to rats were also found to be more potent antiinflammatory agents than acetyl salicylic acid (ASA). Compounds 3a and 4a , tested in vitro on lipopolysaccharide (LPS)-stimulated rat peritoneal macrophages, were seen to be active in the inhibition of prostaglandin E 2 (PGE 2 ) production and interleukin-1 activity. Structure–activity relationship studies in the series of antiaggregating pyridazinones 3 have shown the primary importance of the nitro and acetyl substituents at positions 4 and 5, respectively. Hydrophobic substituents at position 2 were also required for better activity.

PUBLISHED, A recent focus meeting on Controlling Acute Inflammation was held in London, April 27-28, 2006, organized by D.W. Gilroy and S.D. Brain for the British Pharmacology Society. We concluded at the meeting that a consensus report was needed that addresses the rapid progress in this emerging field and details how the specific study of resolution of acute inflammation provides leads for novel anti-inflammatory therapeutics, as well as defines the terms and key components of interest in the resolution process within tissues as appreciated today. The inflammatory response protects the body against infection and injury but can itself become dysregulated with deleterious consequences to the host. It is now evident that endogenous biochemical pathways activated during defense reactions can counter-regulate inflammation and promote resolution. Hence, resolution is an active rather than a passive process, as once believed, which now promises novel approaches for the treatment of inflammation-associated diseases based on endogenous agonists of resolution., The authors acknowledge grant support for their respective research efforts from the National Institutes of Health (NIH) (U.S.A.) and Medical Research Councils (U.K., Ireland, Canada).

Rat CINC induced a dose- and time-dependent accumulation of neurophils into murine air-pouches, a response which was inhibited by two selective H1-antagonists, mepyramine and triprolidine (approximately 60%). As pretreatment with fucoidin abolished CINC effect, the relative time-related contribution of selectins on this process was then investigated by using specific monoclonal antibodies (mAb). Anti-CD62L mAb gave a similar degree of inhibition of CINC-induced cell accumulation both at the 2h and 4h time-point (approximately 75%). Anti-CD62P mAb, but not the anti-CD62E mAb, inhibited PMN accumulation at 2h (65%), but only co-administration of these two mAbs inhibited the cell response to CINC at the 4h time-point (90%). Thus endogenous histamine, CD62L, CD62P, and CD62E, though to a different degree, are required for PMN extravasation observed in response to CINC administration.

SDF-1 (CXCL12), a CXC chemokine, has a primary role in signalling the recruitment of haematopoietic stem-cell precursors to the bone marrow during embryonic development. In post-natal life, SDF-1 is widely expressed and is induced in chronically inflamed tissues such as psoriatic skin and the rheumatoid synovium, but has also been implicated in the migration of lymphocytes to lymphoid organs. To investigate the role of SDF-1 in recirculation and homing in vivo we have developed a model in which human peripheral lymph nodes (huPLN) are transplanted into SCID mice. We have shown that huPLN transplants are viable and are vascularised by the murine circulation, forming functional anastomoses with transplant vessels. In addition grafts retain some of the histological features of the pretransplantation tissue, such as follicular dendritic cell-associated B-cell aggregates, lymphatic and HEV markers. We also show that SDF-1 is capable of inducing the migration of an SDF-1 responsive cell-line (U-937) and human PBL's from the murine circulation into the grafts in a dose dependant manner which is inhibitable by CXCR4 blockade. The mechanism of action of SDF-1 in this model is independent from that of TNF-α and does not rely on the upregulation of adhesion molecules (such as ICAM-1) on the graft vascular endothelium. This is the first description of huPLN transplantation into SCID mice, and of the functional effects of SDF-1 regarding the migration of human cells into huPLN in vivo. This model provides a powerful tool to investigate the pathways involved in cell-migration into lymphoid organs and potentially to target them for therapeutic purposes.

An acetylated polypeptide corresponding to residues 2-26 of human lipocortin 1 was synthesized and the anti-inflammatory activity assessed in three models of acute inflammation in rat and mouse. In the carrageenin rat paw oedema test, the peptide produced a maximal inhibition of approximately 41\% at the 3 h time point with a 10 micrograms dose. When rat paw oedema was induced by the injection of venom phospholipase A2, the peptide produced a significant inhibition (31\%) at the top dose of 20 micrograms per paw. In the mouse air-pouch model, systemic treatment with the peptide produced a dramatic reduction in cytokine-induced leukocyte migration with an ID50 of approximately 40 micrograms per mouse. The N-terminal peptide 2-26 shares the actions of lipocortin 1 in these acute models of inflammation.

Treatment with Aroclor 1254 produces a decrease of diamine oxidase (DAO) activity in quail liver microsomes evaluated on deamination of 14C-putrescine and of histamine. The inhibition observed with the 14C-putrescine assay has peculiar behavior; it increase with the increase of 14C-putrescine concentrations until it produces values of extracted radioactivity which are less than the blanks which do not contain proteins. This effect is reserved by dicyclohexylammonium, an inhibitor of spermidine synthase (SPDS). This paper shows that SPDS rapidly decreases the putrescine concentration during the assay of DAO in tissues, particularly when SPDS is increased by induction with Arocolor.

Lipoxins (LXs) are endogenously generated eicosanoids with potent bio-actions consistent with attenuation of inflammation. The costly synthesis and metabolic instability of LXs may limit their therapeutic potential. Here we report the synthesis and characterization of novel imidazole-/oxazole-containing synthetic-LX-mimetics (sLXms). The key steps of asymmetric synthesis of putative sLXms include a Suzuki reaction and an asymmetric ketone reduction. The effect of the novel compounds on inflammatory responses was assessed using a human monocyte cell line stably expressing a Nuclear Factor Kappa B (NFkB) reporter gene, by investigating downstream cytokine secretion. The potential interaction of the imidazoles/oxazoles with the molecular target of LXs, i.e. G-protein coupled receptor (GPCR) Formyl Peptide Receptor 2 (ALX/FPR2) was investigated using a cell system where ALX/FPR2 is coupled to the Gαq subunit and receptor interaction determined by mobilisation of intracellular calcium. In vivo anti-inflammatory effects were assessed using a murine zymosan-induced peritonitis model. Overall, structure-activity relationship (SAR) studies demonstrated that the (R)-epimer of 6C-dimethyl-imidazole (1R)-11 was the most potent and efficient anti-inflammatory agent, among the ten compounds tested. This molecule significantly attenuated LPS-induced NFkB activity, reduced the release of several pro-inflammatory cytokines and inhibited peritonitis-associated neutrophil infiltration in vivo. The underlying mechanism for those actions appeared to be through FPR2 activation. These data support the therapeutic potential of imidazole-containing sLXms in the context of novel inflammatory regulators.

The benefit of aspirin is well established in cardiovascular prevention, and involves the irreversible inhibition of platelet cyclooxygenase (COX)-1 and, as a consequence, decreased thromboxane levels [1]. In addition to inhibition of platelet aggregation, aspirin may also have anti-inflammatory properties, with potential additional benefit in atherosclerosis prevention. Acetylation of the COX-2 enzyme by aspirin directs the metabolism of polyunsaturated fatty acids (PUFAs) towards a biosynthetic pathway, which in addition involves lipoxygenase enzymes and leads to the formation of specific mediators, such as 15-epi-lipoxin A4, also referred to as aspirin-triggered lipoxin (ATL) [2]. ATL has been shown to promote the resolution of inflammation [3]. ATL shares its receptor with several other ligands, for example anti-bacterial peptides such as the cathelicidin LL-37, and this receptor has therefore been denoted as FPR2/ALX (formyl peptide receptor 2 and A type lipoxin receptor) [4]. It was recently shown that FPR2/ALX is expressed in human carotid atherosclerotic lesions, and that higher expression levels are inversely associated with clinical signs of cerebral ischemia, suggesting that this receptor may transduce increased atherosclerotic plaque stability [5]. In addition to macrophages, the latter study also identified vascular smooth muscle cells (vSMCs) in human atherosclerotic lesions expressing the FPR2/ALX receptor [5]. Furthermore, murine vSMCs that lack this receptor exhibit a decreased collagen production and cross-linking, whereas collagenases are increased, accompanied by decreased collagen content in atherosclerotic lesions in hyperlipidemic mice lacking FPR2/ALX [5]. Importantly, lipoxins are produced during percutaneous coronary interventions (PCI), and their levels increase after aspirin treatment [6]. However, the role of ATL signaling through the FPR2/ALX receptor in vSMC and vascular injury has remained unexplored. Therefore, the aim of the present study was to explore the ATL signaling through FPR2/ALX in vSMCs in vitro and in a mouse model of carotid artery ligation in vivo. Mice lacking the FPR2/ALX homologue (Fpr2−/−; FPR2/ALX knock-out [KO] mice) and wild type (Fpr2+/+; WT) mice were generated as previously described [7]. Aortic vSMCs were isolated from WT and KO mice, and used for evaluation of proliferation and migration according to established protocols [1,5,8]. Finally, FPR2/ALX WT and KO mice were subjected to ligation of the left common carotid artery. Furthermore, based on observations in the present and previous [3] studies that ATL acts as an inhibitor of vSMC responses in vitro, either ATL (10 μg/kg) or vehicle (15% ethanol in PBS) was administrated by means of osmotic pumps following carotid ligation. Experimental details are given in the Supplementary material. All animal experiments were performed according to procedures approved by the local ethics committee. Vascular SMC derived from FPR2/ALX KO mice exhibited 2.3 ± 0.2 fold higher proliferation compared with wild type vSMCs (P

Plasma Mono- and Diamine-Oxidase activities (MAO and DAO), two copper containing enzymes, were estimated in 5 patients with Wilson's disease, without treatment and during D-Penicillamine treatment. Ceruloplasmin and “free” copper plasma levels were simultaneously measured. MAO was elevated in all cases, while DAO was within normal limits. D-Penicillamine administration did not result in significant reductions of these enzyme activities. It is likely that alterations of copper metabolism induced by Wilson's disease and by D-Penicillamine administration do not affect the activity of MAO or DAO. The increase in MAO activity in Wilson's disease probably results from the hepatic fibrosis.

1 Peritoneal macrophages (M phi) collected from adrenalectomized (ADX) rats released more interleukin-1 (IL-1) activity and prostaglandin E2 (PGE2) than macrophages from sham-operated (SHO) rats. 2 The increase in IL-1 activity in the supernatants was confirmed by the increase of the cell-associated 33 kD IL-1 alpha precursor in ADX macrophages stimulated by lipopolysaccharide (LPS). 3 After the injection of Complete Freund's Adjuvant (CFA) to induce adjuvant arthritis, 60% of the ADX rats died, while no deaths occurred in the SHO group. 4 The in vivo administration of dexamethasone inhibited both IL-1 and PGE2 release by macrophages as well as protecting ADX animals from CFA-induced death. Indomethacin and BW 755C partially protected the animals from this lethal effect. 5 These results suggest that adrenalectomy induces an increased release of IL-1 both in vitro and in vivo, and are consistent with a feedback mechanism between IL-1 and glucocorticoid hormones.

In quail liver microsomes the metabolism of histamine is prevalently sustained by diaminoxidase (DAO). Treatment with phenobarbital (PB) and clofibrate (CF) does not modify DAO activity, while that with Aroclor 1254 (PCB) and beta-naphtoflavone (BNF) significantly decreases it. The decrease of DAO activity produced by these substances is not dependent on their direct inhibition of the enzyme. DAO decrease might represent a further possibility to discriminate among different inducers; moreover, it implies that histamine metabolism might be decreased, in quail liver, by some classes of inducers.

Male adult quails were treated with a single intraperitoneal dose of Aroclor 1254 mg/kg. The animals showed increases in hepatic weight and benzopyrene hydroxylase activity which were continuous up to 168 h after the treatment. At 96 h after treatment the activity of diamine oxidase (DAO) in the microsomal fraction was significantly decreased whereas that of spermidine synthase seemed to increase.

Interleukin-1 (IL-1) is a putative mediator of inflammation released by activated macrophages in vitro. The IL-1 release by rat macrophages collected either from exudates in pertussis-induced air pouches or from the peritoneum during adjuvant arthritis has been investigated. In air pouch inflammation LPS-stimulated macrophages collected from sensitized animals release more IL-1 than cells from control rats at day 6 after challenge. This enhanced IL-1 release parallels the extent of mononuclear cell migration in the inflammatory lesion. In adjuvant arthritis LPS-stimulated macrophages collected from sensitized animals release more IL-1 than cells from control rats at days 16 and 23 after adjuvant injection. The secondary inflammation in arthritic rats was statistically significant at days 16 to 28. These results indicate that during immunological inflammation macrophages either from the inflamed area or from a non-inflamed region release more IL-1 than control cells. This release parallels the extent of the inflammation and may be important in its pathogenesis.

Chronic, nonresolving inflammation is a critical factor in the clinical progression of advanced atherosclerotic lesions. In the normal inflammatory response, resolution is mediated by several agonists, among which is the glucocorticoid-regulated protein called annexin A1. The proresolving actions of annexin A1, which are mediated through its receptor N-formyl peptide receptor 2 (FPR2/ALX), can be mimicked by an amino-terminal peptide encompassing amino acids 2-26 (Ac2-26). Collagen IV (Col IV)-targeted nanoparticles (NPs) containing Ac2-26 were evaluated for their therapeutic effect on chronic, advanced atherosclerosis in fat-fed Ldlr(-/-) mice. When administered to mice with preexisting lesions, Col IV-Ac2-26 NPs were targeted to lesions and led to a marked improvement in key advanced plaque properties, including an increase in the protective collagen layer overlying lesions (which was associated with a decrease in lesional collagenase activity), suppression of oxidative stress, and a decrease in plaque necrosis. In mice lacking FPR2/ALX in myeloid cells, these improvements were not seen. Thus, administration of a resolution-mediating peptide in a targeted NP activates its receptor on myeloid cells to stabilize advanced atherosclerotic lesions. These findings support the concept that defective inflammation resolution plays a role in advanced atherosclerosis, and suggest a new form of therapy.

Acute inflammation is a protective reaction by the immune system in response to invading pathogens or tissue damage. Ideally, the response should be localized, self-limited, and returning to homeostasis. If not resolved, acute inflammation can result in organ pathologies leading to chronic inflammatory phenotypes. Acute inflammation and inflammation resolution are complex coordinated processes, involving a number of cell types, interacting in space and time. The biomolecular complexity and the fact that several biomedical fields are involved, make a multi and interdisciplinary approach necessary.This Atlas of Inflammation Resolution (AIR) is a web-based resource capturing the state-of-the-art in acute inflammation and inflammation resolution research. The AIR provides an interface for users to search thousands of interactions, arranged in inter-connected multi-layers of process diagrams, covering a wide range of clinically relevant phenotypes. The AIR serves as an open access knowledgebase, including a gateway to numerous public databases. It is furthermore possible for the user to map experimental data onto the molecular interaction maps of the AIR, providing the basis for bioinformatics analyses and systems biology approaches. By mapping experimental data onto the Atlas, it can be used to elucidate drug action as well as molecular mechanisms underlying different disease phenotypes. For the visualization and exploration of information, the AIR uses the Minerva platform, which is a well-established tool for the presentation of disease maps. The molecular details of the AIR are encoded using international standards.The Atlas of Inflammation Resolution was created as a freely accessible resource, supporting research and education in the fields of acute inflammation and inflammation resolution. The AIR connects research communities, facilitates clinical decision making, and supports research scientists in the formulation and validation of hypotheses.

The glucocorticoid hormones and their synthetic derivatives are potent suppressors of inflammatory and allergic pathologies. Their widespread efficacy is the result of multiple modes of action occurring predominantly at the level of the microcirculation. Indeed the glucocorticoids interfere with the function of all of the cellular components of the microcirculation associated with an inflammatory response. These agents inhibit vasodilatation of the arteriolar and capillary beds. therefore preventing the increase in blood flow that characterizes the initial stages of the inflammatory response. They also prevent increases in vascular permeability in the capillary and post-capillary venule, thereby reducing exudate formation. Finally, the glucocorticoids potently suppress leukocyte emigration across post-capillary venules. However, this promiscuity of the glucocorticoids to act at multiple sites also endows this class of (drugs with major side effects associated with chronic treatment. We propose that one way to progress forward is to understand better the effects of glucocorticoids within the microcirculation. This may aid identification of specific molecular sites of action and therefore the development of novel glucocorticoid molecules with fewer side effects.

Acute inflammation is a protective reaction by the immune system in response to invading pathogens or tissue damage. Ideally, the response should be localized, self-limited, and returning to homeostasis. If not resolved, acute inflammation can result in organ pathologies leading to chronic inflammatory phenotypes. Acute inflammation and inflammation resolution are complex coordinated processes, involving a number of cell types, interacting in space and time. The biomolecular complexity and the fact that several biomedical fields are involved, make a multi- and interdisciplinary approach necessary. The Atlas of Inflammation Resolution (AIR) is a web-based resource capturing an essential part of the state-of-the-art in acute inflammation and inflammation resolution research. The AIR provides an interface for users to search thousands of interactions, arranged in inter-connected multi-layers of process diagrams, covering a wide range of clinically relevant phenotypes. By mapping experimental data onto the AIR, it can be used to elucidate drug action as well as molecular mechanisms underlying different disease phenotypes. For the visualization and exploration of information, the AIR uses the Minerva platform, which is a well-established tool for the presentation of disease maps. The molecular details of the AIR are encoded using international standards. The AIR was created as a freely accessible resource, supporting research and education in the fields of acute inflammation and inflammation resolution. The AIR connects research communities, facilitates clinical decision making, and supports research scientists in the formulation and validation of hypotheses. The AIR is accessible through https://air.bio.informatik.uni-rostock.de.