Naproxen ((S)-6-methoxy-␣-methyl-2-naphthaleneacetic acid)is a powerful non-selective non-steroidal anti-inflammatory drug that is extensively used as a prescription and over-thecounter medication. Naproxen exhibits gastrointestinal toxicity, but its cardiovascular toxicity may be reduced compared with other drugs in its class. Despite the fact that naproxen has been marketed for many years, the molecular basis of its interaction with cyclooxygenase (COX) enzymes is unknown. We performed a detailed study of naproxen-COX-2 interactions using site-directed mutagenesis, structure-activity analysis, and x-ray crystallography. The results indicate that each of the pendant groups of the naphthyl scaffold are essential for COX inhibition, and only minimal substitutions are tolerated. Mutation of Trp-387 to Phe significantly reduced inhibition by naproxen, a result that appears unique to this inhibitor. Substitution of S or CH 2 for the O atom of the p-methoxy group yielded analogs that were not affected by the W387F substitution and that exhibited increased COX-2 selectivity relative to naproxen. Crystallization and x-ray analysis yielded structures of COX-2 complexed to naproxen and its methylthio analog at 1.7 and 2.3 Å resolution, respectively. The combination of mutagenesis, structure analysis, and x-ray crystallography provided comprehensive information on the unique interactions responsible for naproxen binding to COX-2. Cyclooxygenase (COX)4 enzymes are the targets for inhibition by a diverse array of non-steroidal anti-inflammatory drugs (NSAIDs), which contain functional groups, such as arylacetic acids, arylpropionic acids, -ketoenols, and diarylheterocycles. Investigation of the molecular determinants of inhibition by different classes of compounds reveals that the protein residues in the active site maintain similar orientations and that each chemical class forms distinct sets of interactions within the active site (1). Compounds with nanomolar binding affinity (and, in many cases, COX-2 selectivity) have been successfully designed for multiple chemical series, despite their diverse binding modes.Naproxen is one of the oldest and largest selling NSAIDs (Fig. 1). It was introduced in prescription form as Naprosyn in 1976 and as the over-the-counter drug Aleve in 1994. It exhibits analgesic, anti-pyretic, and anti-inflammatory activity and was recently reported to be effective in the prevention of bladder cancer progression even when administered several weeks after the tumor-initiating agent (2). Naproxen is a non-selective NSAID that inhibits both COX-1 and COX-2 with comparable IC 50 values (3). It exhibits significant gastrointestinal side effects, but recent mounting evidence suggests that it does not exert cardiovascular side effects when administered in the higher doses that provide sustained inhibition of platelet COX-1 throughout the dosing interval (e.g. Ն500 mg twice daily) (4 -6). This latter property has taken on increasing importance because evolving data suggest that the cardiovascular toxicit...
The chemokine system represents a diverse group of G proteincoupled receptors responsible for orchestrating cell recruitment under both homeostatic and inflammatory conditions. Chemokine receptor 9 (CCR9) is a chemokine receptor known to be central for migration of immune cells into the intestine. Its only ligand, CCL25, is expressed at the mucosal surface of the intestine and is known to be elevated in intestinal inflammation. To date, there are no reports of small-molecule antagonists targeting CCR9. We report, for the first time, the discovery of a small molecule, CCX282-B, which is an orally bioavailable, selective, and potent antagonist of human CCR9. CCX282-B inhibited CCR9-mediated Ca 2ϩ mobilization and chemotaxis on Molt-4 cells with IC 50 values of 5.4 and 3.4 nM, respectively. In the presence of 100% human serum, CCX282-B inhibited CCR9-mediated chemotaxis with an IC 50 of 33 nM, and the addition of ␣1-acid glycoprotein did not affect its potency. CCX282-B inhibited chemotaxis of primary CCR9-expressing cells to CCL25 with an IC 50 of 6.8 nM. CCX282-B was an equipotent inhibitor of CCL25-directed chemotaxis of both splice forms of CCR9 (CCR9A and CCR9B) with IC 50 values of 2.8 and 2.6 nM, respectively. CCX282-B also inhibited mouse and rat CCR9-mediated chemotaxis. Inhibition of CCR9 with CCX282-B results in normalization of Crohn's disease such as histopathology associated with the TNF ⌬ARE mice. Analysis of the plasma level of drug associated with this improvement provides an understanding of the pharmacokinetic/ pharmacodynamic relationship for CCR9 antagonists in the treatment of intestinal inflammation.
In recent years, immune-based therapies have become an increasingly attractive treatment option for patients with cancer. Cancer immunotherapy is often used in combination with conventional chemotherapy for synergistic effects. The alkylating agent cyclophosphamide (CTX) has been included in various chemoimmunotherapy regimens due to its well-known immunostimulatory effects. Paradoxically, CTX can also induce suppressor cells that inhibit immune responses. However, the identity and biological relevance of these suppressor cells are poorly defined. Here we report that CTX treatment drives the expansion of inflammatory monocytic myeloid cells (CD11b+Ly6ChiCCR2hi) that possess immunosuppressive activities. In mice with advanced lymphoma, adoptive transfer (AT) of tumor-specific CD4+ T cells following CTX treatment (CTX+CD4 AT) provoked a robust initial antitumor immune response, but also resulted in enhanced expansion of monocytic myeloid cells. These therapy-induced monocytes inhibited long-term tumor control and allowed subsequent relapse by mediating functional tolerization of antitumor CD4+ effector cells through the PD-1/PD-L1 axis. PD-1/PD-L1 blockade after CTX+CD4 AT therapy led to persistence of CD4+ effector cells and durable antitumor effects. Depleting proliferative monocytes by administering low dose gemcitabine effectively prevented tumor recurrence after CTX+CD4 AT therapy. Likewise, targeting inflammatory monocytes by disrupting the CCR2 signaling pathway markedly potentiated the efficacy of CTX-based therapy. Besides CTX, we found that melphalan and doxorubicin can also induce monocytic myeloid suppressor cells. These findings reveal a counter-regulation mechanism elicited by certain chemotherapeutic agents, and highlight the importance of overcoming this barrier to prevent late tumor relapse after chemoimmunotherapy.
Smoking cigarettes is a major risk factor for the development of cardiovascular and respiratory disease. Moreover, smokinginduced pathophysiology is often resistant to the anti-inflammatory effects of glucocorticoids. The nature of cigarette smoke-induced inflammation is still not defined, although neutrophil recruitment and activation seem to be consistent features. In the current study, we have used a range of approaches to demonstrate that cigarette smoke activates human monocytes and macrophages to release the CXC chemokine CXCL8 ]. Furthermore, we show for the first time that cigarette smoke synergizes with proinflammatory cytokines IL-1 and tumor necrosis factor-␣, and it is this interaction that confers steroid resistance to smoke-induced CXCL8 release. We go on to show that smoke-induced activation of human cells is an oxidant-mediated phenomenon acting through activator protein-1, but not nuclear factor B, pathway. These observations add significantly to our understanding of smoke as an inflammatory stimulus that has implications for potential the development of treatments of smoking or related disease.
Nanofiltration technology has come a long way since first inception in the late 1980s. Research activity in this area covers a great many topics and the aim of this review is to quantify the level interest in each of these areas. The number of annual publications directly related to nanofiltration technology has been harvested from ScienceDirect since 2007. This quantification of research has shown that interest in nanofiltration technology has grown over the past decade, particularly over the past five years. The primary journals reporting articles on nanofiltration are the Journal of Membrane Science, Desalination and Separation and Purification Technology, although articles have been spread across a further 139 journals. Unsurprisingly, the major topics of interest have been water processing, membrane fabrication and membrane surface modification. There has been clear growth in the areas of organic solvent nanofiltration, pharmaceutical and biological applications, design and economics of nanofiltration processes and review articles. Nanofiltration modelling has received less support over the period reviewed and has experienced a steady decline. Clearly the overall growing trend in nanofiltration research indicates that the technology remains popular and this interest should materialise into further applications for a robust and sustainable future.
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