p38 MAP Kinase Inhibition Reduces Propionibacterium acnes-Induced Inflammation in Vitro.

Introduction: Propionibacterium acnes, a ubiquitous skin bacterium, stimulates keratinocytes to produce a number of proinflammatory cytokines and may contribute to inflammatory acne. The aim of the study was to investigate whether P. acnes-induced proinflammatory cytokine release is mediated by P.

IL-11, IL-1α, IL-6, and TNF-α are induced by solar radiation in vitro and may be involved in facial subcutaneous fat loss in vivo.

Background: The loss of subcutaneous (sc) fat is associated with aging. Inflammatory cytokines, such as interleukin-1 α (IL-1α), interleukin-11 (IL-11) and tumor necrosis factor-α (TNF-α), are known to inhibit the differentiation of preadipocytes.

Objective: This study investigated the potential role of inflammatory cytokines in solar-radiation-induced facial fat loss.

Melanocortin-5 receptor and sebogenesis.

The melanocortins (α-MSH, β-MSH, γ-MSH, and ACTH) bind to the melanocortin receptors and signal through increases in cyclic adenosine monophosphate to induce biological effects. The melanocortin MC(5) and MC(1) receptors are expressed in human sebaceous glands, which produce sebum, a lipid mixture of squalene, wax esters, triglycerides, cholesterol esters, and free fatty acids that is secreted onto the skin. Excessive sebum production is one of the major factors in the pathogenesis of acne.

Role of Janus kinase-2 in IgE receptor-mediated leukotriene C4 production by mast cells.

We have previously shown that Janus kinase 3, a member of the family of non-receptor protein tyrosine kinases, plays a critical role in the regulation of FcepsilonRI-mediated mast cell responses. In the current study, we investigated the role of another JAK family member, JAK2, in these responses. Our results show that the treatment of IgE-sensitized mouse mast cells with an inhibitor of JAK2 (AG490) blocked the release of leukotriene C(4) in a dose-dependent fashion after antigen challenge.

A kinase-dead knock-in mutation in mTOR leads to early embryonic lethality and is dispensable for the immune system in heterozygous mice.

Background: The mammalian target of rapamycin protein (mTOR) is an evolutionarily conserved kinase that regulates protein synthesis, cell cycle progression and proliferation in response to various environmental cues. As a critical downstream mediator of PI3K signaling, mTOR is important for lymphocyte development and function of mature T and B-cells. Most studies of mTOR in immune responses have relied on the use of pharmacological inhibitors, such as rapamycin.

Synthetic staurosporines via a ring closing metathesis strategy as potent JAK3 inhibitors and modulators of allergic responses.

The synthesis and biological evaluation of JAK3 based staurosporine compounds is described. The compounds are constructed completely de novo, and a ring closing metathesis strategy is used to assemble the sugar mimetic portion. These analogs show potent JAK3 activity against isolated enzyme and in T-cells.

Synthesis and structure-activity relationship of 7-azaindole piperidine derivatives as CCR2 antagonists.

The synthesis and structure-activity relationship of a series of 7-azaindole piperidine derivatives are described. SAR studies led to the discovery of the potent CCR2 antagonists displaying IC(50) values in the nanomolar range. The representative compound 15 showed reasonable P450 and pharmacokinetics profile.

Substituted dipiperidine alcohols as potent CCR2 antagonists.

The synthesis and biological evaluation of a series of substituted dipiperidine alcohols are described. Structure-activity relationship studies led to the discovery of potent CCR2 antagonists displaying IC(50) values in the nanomolar or subnanomolar range. The cinnamoyl compounds had higher binding affinities than the corresponding urea analogs.

Synthesis, structure-activity relationship and in vivo antiinflammatory efficacy of substituted dipiperidines as CCR2 antagonists.

A series of substituted dipiperidine compounds have been synthesized and identified as selective CCR2 antagonists. Combining the most favorable substituents led to the discovery of remarkably potent CCR2 antagonists displaying IC50 values in the nanomolar range. Compound 7a had outstanding selectivity over CCR1, CCR3, CCR4, CCR5, CCR6, CCR7, and CCR8 and showed excellent efficacy in adjuvant-induced arthritis model, collagen-induced arthritis model, and allergic asthma model.

Synthesis and biological evaluation of phenyl piperidine derivatives as CCR2 antagonists.

A series of phenyl piperidine derivatives possessing potent and selective CCR2 antagonist activity is reported. Structure-activity relationship (SAR) studies have established that incorporation of a second ring system adjacent to the aryl piperidine plays an important role in determining the CCR2 potency. Both a second piperidine ring and a 1,3-substituted cyclopentylamine have been probed as linkers.

Potent and selective CC-chemokine receptor-2 (CCR2) antagonists as a potential treatment for asthma.

A number of compounds bearing a quaternary ammonium moiety were found to be antagonists with nanomolar binding affinity for the chemokine receptor-2. The structure-activity relationships in the series are described herein along with some detailed characterization of the interesting compounds.

Different approaches to study mast cell functions.

Mast cells have long been known to play a detrimental role in the pathogenesis of IgE-associated allergic disorders by their ability to release a wide variety of pro-inflammatory mediators. A number of studies, however, have demonstrated that mast cells play a beneficial role in innate host defense against bacterial infections. Since mast cells clearly play both physiological and pathophysiological functions in the body, it is important to learn about the components of mast cells that drive these responses.

Simplified staurosporine analogs as potent JAK3 inhibitors.

Simplification of bottom ring and regioselective functionalization of the indolocarbazole unit of staurosporine (2) are described. The modification led to a new series of simplified staurosporine analogs, which exhibited significant inhibitory activity against Janus kinase 3 (JAK3). The structure-activity relationships (SAR) are discussed and a proposed binding model is also highlighted.

Inhibitors of unactivated p38 MAP kinase.

Inhibition of the p38 map kinase pathway has been shown to be beneficial in the treatment of inflammatory diseases. The first class of potent p38 kinase inhibitors was the pyridinylimidazole compounds from SKB. Since then several pyridinylimidazole-based compounds have been shown to inhibit activated p38 kinase in vitro and in vivo.

Targeting cytosolic phospholipase A2 by arachidonyl trifluoromethyl ketone prevents chronic inflammation in mice.

Cytosolic phospholipase A(2) (cPLA(2)) plays a pivotal role in inflammation by catalyzing the release of arachidonic acid, a substrate for lipoxygenase and cyclooxygenase enzymes, from membrane phospholipids. In the present study we examined the role of cPLA(2) in inflammatory responses through the use of a specific inhibitor of the enzyme, cPLA(2), arachidonyl trifluoromethyl ketone (AACOCF3). Interestingly, we observed that AACOCF3 is an inhibitor of chronic but not acute inflammatory responses.

Development of a sensitive and HTS-compatible reporter gene assay for functional analysis of human adenosine A2a receptors in CHO-K1 cells.

Adenosine A2a receptor, a member of the G protein-coupled receptor superfamily, has been demonstrated to be an important pharmacological target. It couples to stimulatory G protein and activates adenylate cyclase upon agonist stimulation. Here we attempted to stably transfect Chinese hamster ovary (CHO-K1) cells, which lack any known subtypes of adenosine receptors, with recombinant human adenosine A2a receptors (hA2aR).

In vivo activity of a phospholipase C inhibitor, 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), in acute and chronic inflammatory reactions.

To investigate the role of phospholipase C (PLC) in inflammatory processes, we tested 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), a widely used PLC inhibitor, in several in vitro and in vivo assays. We first examined the effects of U73122 on human phospholipase C-beta (PLC-beta) isozymes and found that U73122 significantly inhibited recombinant human PLC-beta2, with an IC(50) of approximately 6 microM. U73122 had little effect on PLC-beta1, PLC-beta3, or PLC-beta4.

Imidazopyrimidines, potent inhibitors of p38 MAP kinase.

The MAP kinase p38 is implicated in the release of the pro-inflammatory cytokines TNF-alpha and IL-1 beta. Inhibition of cytokine release may be a useful treatment for inflammatory conditions such as rheumatoid arthritis and Crohn's disease. A novel series of imidazopyrimidines have been discovered that potently inhibit p38 and suppress the production of TNF-alpha in vivo.

Immunomodulation and adenoviral gene transfer to the lungs of nonhuman primates.

Previous data from our laboratory and others have demonstrated a critical role for the CD4+ T lymphocyte in in vivo immune responses to recombinant adenoviral vectors. In rodent models, this subset of T cells is required for T cell proliferation, subsequent cytotoxic T cell generation, and production of anti-adenoviral antibodies by B cells. Both depleting and nondepleting anti-CD4 antibodies can attenuate these immune responses to recombinant adenovirus.

Investigation of capillary electrochromatography with brush-type chiral stationary phases.

Fused-silica capillaries (100 microm ID) were packed with the (3R, 4S)-Whelk-O chiral stationary phase (CSP) bonded on 3.0 microm silica particles. The enantiomers of 41 neutral analytes containing stereogenic centers, axes or planes were examined by packed capillary electrochromatography.

RWJ 67657, a potent, orally active inhibitor of p38 mitogen-activated protein kinase.

Tumor necrosis factor-alpha (TNF-alpha), a cytokine secreted by activated monocytes/macrophages and T lymphocytes, has been implicated in several disease states, including rheumatoid arthritis, inflammatory bowel disease, septic shock, and osteoporosis. Monocyte/macrophage production of TNF-alpha is dependent on the mitogen-activated protein kinase p38. RWJ 67657 (4-[4-(4-fluorophenyl)-1-(3-phenylpropyl)-5-(4-pyridinyl)-1H-imidazol -2-yl]-3-butyn-1-ol) inhibited the release of TNF-alpha by lipopolysaccharide (a monocyte stimulus)-treated human peripheral blood mononuclear cells with an IC(50) of 3 nM, as well as the release of TNF-alpha from peripheral blood mononuclear cells treated with the superantigen staphylococcal enterotoxin B (a T cell stimulus), with an IC(50) value of 13 nM.

Anti-inflammatory doses of ibuprofen: effect on neutrophils and exercise-induced muscle injury.

The purpose of the study was to determine the effect of anti-inflammatory doses of ibuprofen on neutrophils, neutrophil O2* production, and markers of muscle injury. Males (n=10) performed 2 bouts of one-arm eccentric exercise on opposite arms separated by three weeks. Subjects received 2400 mg x d(-1) of ibuprofen or a placebo 5 d before exercise and during 10 d of recovery.

Potent inhibitors of the MAP kinase p38.

The MAP kinase p38 plays a key role in the biosynthesis of the inflammatory cytokines TNF-alpha and IL-1. We have developed a novel series of potent p38 inhibitors that could lead to new methods of treatment for inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease.

Interleukin (IL)-1 receptor-associated kinase (IRAK) requirement for optimal induction of multiple IL-1 signaling pathways and IL-6 production.

Interleukin (IL)-1 is a proinflammatory cytokine with pleiotropic effects in inflammation. IL-1 binding to its receptor triggers a cascade of signaling events, including activation of the stress-activated mitogen-activated protein (MAP) kinases, c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase, as well as transcription factor nuclear factor kappaB (NF-kappaB). IL-1 signaling results in cellular responses through induction of inflammatory gene products such as IL-6.