Resolution of inflammation: a new therapeutic frontier

Dysregulated inflammation is a central pathological process in diverse disease states. Traditionally, therapeutic approaches have sought to modulate the pro- or anti-inflammatory limbs of inflammation, with mixed success. However, insight into the pathways by which inflammation is resolved has highlighted novel opportunities to pharmacologically manipulate these processes — a strategy that might represent a complementary (and perhaps even superior) therapeutic approach. This Review discusses the state of the art in the biology of resolution of inflammation, highlighting the opportunities and challenges for translational research in this field

Infliximab as long-term maintenance in steroid-resistant and recurrent sarcoidosis in a renal transplant with central nervous system involvement.

Sarcoidosis is a multisystemic, granulomatous disease of unknown aetiology, which commonly involves the lungs, skin and the eyes. Renal sarcoidosis is rare. Recurrent renal sarcoidosis leading to transplant graft failure in adults has not been reported. We report a single case of steroid-resistant sarcoid with recurrence in a renal transplant and the central nervous system that was managed with infliximab. We describe successful resolution of granulomas in the transplant kidney and stabilization of renal function with catastrophic central nervous system recurrence upon withdrawal of infliximab

Cyclooxygenase-2 and prostaglandin E<inf>2</inf> signaling through prostaglandin receptor EP- 2 favor the development of myocarditis during acute trypanosoma cruzi infection

Inflammation plays an important role in the pathophysiology of Chagas disease, caused by Trypanosoma cruzi. Prostanoids are regulators of homeostasis and inflammation and are produced mainly by myeloid cells, being cyclooxygenases, COX-1 and COX-2, the key enzymes in their biosynthesis from arachidonic acid (AA). Here, we have investigated the expression of enzymes involved in AA metabolism during T. cruzi infection. Our results show an increase in the expression of several of these enzymes in acute T. cruzi infected heart. Interestingly, COX-2 was expressed by CD68+ myeloid heart-infiltrating cells. In addition, infiltrating myeloid CD11b+Ly6G- cells purified from infected heart tissue express COX-2 and produce prostaglandin E2 (PGE2) ex vivo. T. cruzi infections in COX-2 or PGE2- dependent prostaglandin receptor EP-2 deficient mice indicate that both, COX-2 and EP-2 signaling contribute significantly to the heart leukocyte infiltration and to the release of chemokines and inflammatory cytokines in the heart of T. cruzi infected mice. In conclusion, COX-2 plays a detrimental role in acute Chagas disease myocarditis and points to COX-2 as a potential target for immune intervention.This work was supported by (NG) grants from “Fondo de Investigaciones Sanitarias” (PS09/00538 and PI12/00289); “Universidad Autónoma de Madrid” and “Comunidad de Madrid” (CC08-UAM/SAL-4440/08); by (MF) grants from “Ministerio de Ciencia e Innovación” (SAF2010-17833); “Red de Investigación de Centros de Enfermedades Tropicales” (RICET RD12/0018/0004); European Union (HEALTH-FE-2008-22303, ChagasEpiNet); AECID Cooperation with Argentine (A/025417/09 and A/031735/10), Comunidad de Madrid (S-2010/BMD- 2332) and “Fundación Ramón Areces”. NAG was recipient of a ISCIII Ph.D. fellowship financed by the Spanish “Ministerio de Sanidad”. CCM and HC were recipients of contracts from SAF2010-17833 and PI060388, respectively.Peer Reviewe

LipocalinPred: a SVM-based method for prediction of lipocalins

<p>Abstract</p> <p>Background</p> <p>Functional annotation of rapidly amassing nucleotide and protein sequences presents a challenging task for modern bioinformatics. This is particularly true for protein families sharing extremely low sequence identity, as for lipocalins, a family of proteins with varied functions and great diversity at the sequence level, yet conserved structures.</p> <p>Results</p> <p>In the present study we propose a SVM based method for identification of lipocalin protein sequences. The SVM models were trained with the input features generated using amino acid, dipeptide and secondary structure compositions as well as PSSM profiles. The model derived using both PSSM and secondary structure emerged as the best model in the study. Apart from achieving a high prediction accuracy (>90% in leave-one-out), lipocalinpred correctly differentiates closely related fatty acid-binding proteins and triabins as non-lipocalins.</p> <p>Conclusion</p> <p>The method offers a promising approach as a lipocalin prediction tool, complementing PROSITE, Pfam and homology modelling methods.</p

Communicating with the dead:lipids, lipid mediators and extracellular vesicle

Apoptosis is a key event in the control of inflammation. However, for this to be successful, dying cells must efficiently and effectively communicate their presence to phagocytes to ensure timely removal of dying cells. Here we consider apoptotic cell-derived extracellular vesicles (ACdEV) and the role of contained lipids and lipid mediators in ensuring effective control of inflammation. We discuss key outstanding issues in the study of cell death and cell communication, and introduce the concept of the ‘active extracellular vesicle’ as a metabolically-active and potentially changing intercellular communicator

Mast cell tryptase stimulates myoblast proliferation; a mechanism relying on protease-activated receptor-2 and cyclooxygenase-2

<p>Abstract</p> <p>Background</p> <p>Mast cells contribute to tissue repair in fibrous tissues by stimulating proliferation of fibroblasts through the release of tryptase which activates protease-activated receptor-2 (PAR-2). The possibility that a tryptase/PAR-2 signaling pathway exists in skeletal muscle cell has never been investigated. The aim of this study was to evaluate whether tryptase can stimulate myoblast proliferation and determine the downstream cascade.</p> <p>Methods</p> <p>Proliferation of L6 rat skeletal myoblasts stimulated with PAR-2 agonists (tryptase, trypsin and SLIGKV) was assessed. The specificity of the tryptase effect was evaluated with a specific inhibitor, APC-366. Western blot analyses were used to evaluate the expression and functionality of PAR-2 receptor and to assess the expression of COX-2. COX-2 activity was evaluated with a commercial activity assay kit and by measurement of PGF₂α production. Proliferation assays were also performed in presence of different prostaglandins (PGs).</p> <p>Results</p> <p>Tryptase increased L6 myoblast proliferation by 35% above control group and this effect was completely inhibited by APC-366. We confirmed the expression of PAR-2 receptor <it>in vivo </it>in skeletal muscle cells and in satellite cells and <it>in vitro </it>in L6 cells, where PAR-2 was found to be functional. Trypsin and SLIGKV increased L6 cells proliferation by 76% and 26% above control, respectively. COX-2 activity was increased following stimulation with PAR-2 agonist but its expression remained unchanged. Inhibition of COX-2 activity by NS-398 abolished the stimulation of cell proliferation induced by tryptase and trypsin. Finally, 15-deoxy-Δ-^12,14-prostaglandin J₂(15Δ-PGJ₂), a product of COX-2-derived prostaglandin D₂, stimulated myoblast proliferation, but not PGE₂and PGF₂α.</p> <p>Conclusions</p> <p>Taken together, our data show that tryptase can stimulate myoblast proliferation and this effect is part of a signaling cascade dependent on PAR-2 activation and on the downstream activation of COX-2.</p

Hypoxia-inducible factor-1 alpha, in association with inflammation, angiogenesis and MYC, is a critical prognostic factor in patients with HCC after surgery

<p>Abstract</p> <p>Background</p> <p>Despite well-studied tumor hypoxia in laboratory, little is known about the association with other pathophysiological events in the clinical view. We investigated the prognostic value of hypoxia-inducible factor-1 alpha (HIF-1alpha) in hepatocellular carcinoma (HCC), and its correlations with inflammation, angiogenesis and MYC oncogene.</p> <p>Methods</p> <p>In a random series of 110 HCC patients, the mRNA of HIF-1alpha, inflammation related factors (COX-2, MMP7 and MMP9), angiogenesis related factors (VEGF and PDGFRA) and MYC in tumor tissue were detected by real-time RT-PCR and HIF-1alpha protein was assessed by immunohistochemistry. The correlations between HIF-1alpha mRNA and the factors mentioned previously, the relationship between HIF-1alpha and clinicopathologic features, and the prognostic value were analyzed.</p> <p>Results</p> <p>The expression of both HIF-1alpha mRNA and protein in HCC were independent prognostic factors for overall survival (OS) (<it>P </it>= 0.012 and <it>P </it>= 0.021, respectively) and disease-free survival (DFS) (<it>P </it>= 0.004 and <it>P </it>= 0.007, respectively) as well. Besides, the high expression of HIF-1alpha mRNA and protein proposed an advanced BCLC stage and more incidence of vascular invasion. The mRNA of HIF-1alpha had significantly positive correlations to that of COX-2, PDGFRA, MMP7, MMP9, MYC, except VEGF. In addition to HIF-1alpha, COX-2 and PDGFRA were also independent prognosticators for OS (<it>P </it>= 0.004 and <it>P </it>= 0.010, respectively) and DFS (<it>P </it>= 0.010 and <it>P </it>= 0.038, respectively).</p> <p>Conclusion</p> <p>HIF-1alpha in HCC plays an important role in predicting patient outcome. It may influence HCC biological behaviors and affect the tumor inflammation, angiogenesis and act in concert with the oncogene MYC. Attaching importance to HIF-1alpha in HCC may improve the prognostic and therapeutic technique.</p

Triterpenoid modulation of IL-17 and Nrf-2 expression ameliorates neuroinflammation and promotes remyelination in autoimmune encephalomyelitis

Inflammatory cytokines and endogenous anti-oxidants are variables affecting disease progression in multiple sclerosis (MS). Here we demonstrate the dual capacity of triterpenoids to simultaneously repress production of IL-17 and other pro-inflammatory mediators while exerting neuroprotective effects directly through Nrf2-dependent induction of anti-oxidant genes. Derivatives of the natural triterpene oleanolic acid, namely CDDO-trifluoroethyl-amide (CDDO-TFEA), completely suppressed disease in a murine model of MS, experimental autoimmune encephalomyelitis (EAE), by inhibiting Th1 and Th17 mRNA and cytokine production. Encephalitogenic T cells recovered from treated mice were hypo-responsive to myelin antigen and failed to adoptively transfer the disease. Microarray analyses showed significant suppression of pro-inflammatory transcripts with concomitant induction of anti-inflammatory genes including Ptgds and Hsd11b1. Finally, triterpenoids induced oligodendrocyte maturation in vitro and enhanced myelin repair in an LPC-induced non-inflammatory model of demyelination in vivo. These results demonstrate the unique potential of triterpenoid derivatives for the treatment of neuroinflammatory disorders such as MS

Alkylation of the Tumor Suppressor PTEN Activates Akt and β-Catenin Signaling: A Mechanism Linking Inflammation and Oxidative Stress with Cancer

PTEN, a phosphoinositide-3-phosphatase, serves dual roles as a tumor suppressor and regulator of cellular anabolic/catabolic metabolism. Adaptation of a redox-sensitive cysteinyl thiol in PTEN for signal transduction by hydrogen peroxide may have superimposed a vulnerability to other mediators of oxidative stress and inflammation, especially reactive carbonyl species, which are commonly occurring by-products of arachidonic acid peroxidation. Using MCF7 and HEK-293 cells, we report that several reactive aldehydes and ketones, e.g. electrophilic α,β-enals (acrolein, 4-hydroxy-2-nonenal) and α,β-enones (prostaglandin A2, Δ12-prostaglandin J2 and 15-deoxy-Δ-12,14-prostaglandin J2) covalently modify and inactivate cellular PTEN, with ensuing activation of PKB/Akt kinase; phosphorylation of Akt substrates; increased cell proliferation; and increased nuclear β-catenin signaling. Alkylation of PTEN by α,β-enals/enones and interference with its restraint of cellular PKB/Akt signaling may accentuate hyperplastic and neoplastic disorders associated with chronic inflammation, oxidative stress, or aging