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The immunomodulatory potential of mesenchymal stromal cells (MSCs) and regulatory T cells (T‐reg) is well recognized by translational scientists in the field of regenerative medicine and cellular therapies. A wide range of preclinical studies as well as a limited number of human clinical trials of MSC therapies have not only shown promising safety and efficacy profiles but have also revealed changes in T‐reg frequency and function. However, the mechanisms underlying this potentially important observation are not well understood and, consequently, the optimal strategies for harnessing MSC/T‐reg cross‐talk remain elusive. Cell‐to‐cell contact, production of soluble factors, reprogramming of antigen presenting cells to tolerogenic phenotypes, and induction of extracellular vesicles (“exosomes”) have emerged as possible mechanisms by which MSCs produce an immune‐modulatory milieu for T‐reg expansion. Additionally, these two cell types have the potential to complement each other's immunoregulatory functions, and a combinatorial approach may exert synergistic effects for the treatment of immunological diseases. In this review, we critically assess recent translational research related to the outcomes and mechanistic basis of MSC effects on T‐reg and provide a perspective on the potential for this knowledge base to be further exploited for the treatment of autoimmune disorders and transplants., Mesenchymal stromal cells (MSCs) promote regulatory T cell numbers and immune suppressive functions through mechanisms involving cell‐cell contact, production of soluble mediators, reprogramming of antigen presenting cells, and release of extracellular vesicles that likely represent important components of MSC therapeutic effects in immune/inflammatory diseases.

Amplification of MYCN is the most well-known prognostic marker of neuroblastoma risk classification, but still is only observed in 25% of cases. Recent evidence points to the cyclic adenosine monophosphate (cAMP) elevating ligand prostaglandin E2 (PGE2 ) and β-catenin as two novel players in neuroblastoma. Here, we aimed to define the potential role of PGE2 and cAMP and its potential interplay with β-catenin, both of which may converge on neuroblastoma cell behaviour. Gain and loss of β-catenin function, PGE2 , the adenylyl cyclase activator forskolin and pharmacological inhibition of cyclooxygenase-2 (COX-2) were studied in two human neuroblastoma cell lines without MYCN amplification. Our findings show that PGE2 enhanced cell viability through the EP4 receptor and cAMP elevation, whereas COX-2 inhibitors attenuated cell viability. Interestingly, PGE2 and forskolin promoted glycogen synthase kinase 3β inhibition, β-catenin phosphorylation at the protein kinase A target residue ser675, β-catenin nuclear translocation and TCF-dependent gene transcription. Ectopic expression of a degradation-resistant β-catenin mutant enhances neuroblastoma cell viability and inhibition of β-catenin with XAV939 prevented PGE2 -induced cell viability. Finally, we show increased β-catenin expression in human high-risk neuroblastoma tissue without MYCN amplification. Our data indicate that PGE2 enhances neuroblastoma cell viability, a process which may involve cAMP-mediated β-catenin stabilization, and suggest that this pathway is of relevance to high-risk neuroblastoma without MYCN amplification.

Bovine mycoplasmosis caused by Mycoplasma bovis results in pneumonia and mastitis in cattle. We previously demonstrated that the programmed death 1 (PD-1)/PD-ligand 1 (PD-L1) pathway is involved in immune dysfunction during M. bovis infection and that prostaglandin E-2 (PGE(2)) suppressed immune responses and upregulated PD-L1 expression in Johne's disease, a bacterial infection in cattle. In this study, we investigated the role of PGE(2) in immune dysfunction and the relationship between PGE(2) and the PD-1/PD-L1 pathway in M. bovis infection. In vitro stimulation with M. bovis upregulated the expressions of PGE(2) and PD-L1 presumably via Toll-like receptor 2 in bovine peripheral blood mononuclear cells (PBMCs). PGE(2) levels of peripheral blood in infected cattle were significantly increased compared with those in uninfected cattle. Remarkably, plasma PGE(2) levels were positively correlated with the proportions of PD-L1(+) monocytes in M. bovis-infected cattle. Additionally, plasma PGE(2) production in infected cattle was negatively correlated with M. bovis-specific interferon (IFN)-gamma production from PBMCs. These results suggest that PGE(2) could be one of the inducers of PD-L1 expression and could be involved in immunosuppression during M. bovis infection. In vitro blockade assays using anti-bovine PD-L1 antibody and a cyclooxygenase 2 inhibitor significantly upregulated the M. bovis-specific IFN-gamma response. Our study findings might contribute to the development of novel therapeutic strategies for bovine mycoplasmosis that target PGE(2) and the PD-1/PD-L1 pathway.

Purpose: There is a growing interest in markers for cartilage degradation in synovial joints because of their potential diagnostic and prognostic value. Therefore, the aim of this study was to identify valuable degradation markers for temporomandibular joint (TMJ) osteoarthritis (OA) by comparing the relative concentrations of carboxyterminal telopeptides type I and II (CTX-I and II), cartilage oligomeric matrix protein (COMP), and prostaglandin E-2 (PGE(2)) in the synovial fluid (SF) of TMJs with OA with those of healthy symptom-free TMJs.Materials and Methods: In this cross-sectional case-control study, participants were recruited from the University Medical Center Groningen (Groningen, the Netherlands). Cases were defined as patients with TMJ OA, and control patients had symptom-free TMJs. The outcome variables were the relative concentrations of CTX-I, CTX-II, COMP, and PGE(2) in osteoarthritic TMJ SF compared with symptom-free joints. An independent-samples Mann-Whitney U test was used to compare the relative concentrations.Results: Thirty cases (9 male, 21 female; mean age, 40.1 yr; standard deviation, 15.3 yr) and 10 controls (5 male, 5 female; mean age, 30.3 yr; standard deviation, 10.8 yr) were studied. No significant differences in relative concentrations of CTX-I (P = .548), CTX-II (P = .842), COMP (P = .140), and PGE(2) (P = .450) were found between the groups. Unexpected low relative concentrations of CTX-I and high relative concentrations of CTX-II were observed.Conclusions: Assumed changes in the SF concentration of CTX-I, CTX-II, COMP, and PGE(2) in TMJ OA seem to occur proportionally. Furthermore, the unexpected large contribution of CTX-II suggests that this marker may be useful to quantify cartilage degradation in TMJ OA. (C) 2013 American Association of Oral and Maxillofacial Surgeons

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising therapy for autoimmune diseases, including multiple sclerosis (MS). Administration of MSCs to MS patients has proven safe with signs of immunomodulation but their therapeutic efficacy remains low. The aim of the current study has been to further characterize the immunomodulatory mechanisms of adipose tissue-derived MSCs (ASCs) in vitro and in vivo using the EAE model of chronic brain inflammation in mice. We found that murine ASCs (mASCs) suppress T cell proliferation in vitro via inducible nitric oxide synthase (iNOS) and cyclooxygenase- (COX-) 1/2 activities. mASCs also prevented the lipopolysaccharide- (LPS-) induced maturation of dendritic cells (DCs) in vitro. The addition of the COX-1/2 inhibitor indomethacin, but not the iNOS inhibitor L-NAME, reversed the block in DC maturation implicating prostaglandin (PG) E2 in this process. In vivo, early administration of murine and human ASCs (hASCs) ameliorated myelin oligodendrocyte protein- (MOG35-55-) induced EAE in C57Bl/6 mice. Mechanistic studies showed that mASCs suppressed the function of autoantigen-specific T cells and also decreased the frequency of activated (CD11c+CD40 and CD11c+TNF-α+) DCs in draining lymph nodes (DLNs). In summary, these data suggest that mASCs reduce EAE severity, in part, through the impairment of DC and T cell function., This work has been financed by the Instituto de Salud Carlos III, Spain (http://www.isciii.es) and Fondo Europeo de Desarrollo Regional (FEDER, http://ec.europa.eu/regional_policy/es/funding/erdf/) from the European Union, through the Research Grants PI15/00794, CP09/00228, and CPII15/00032 (Per Anderson); PI12/01097, PI15/02015, and ISCIII Red de Terapia Celular (RD12/0019/0006, http://www.red-tercel.com/) (Francisco Martin); and PS09-00928 (Mario Delgado). Mario Delgado was supported by a grant (PSE-010000-2009-3) from the Ministerio de Ciencia e Innovación, Spain (http://www.idi.mineco.gob.es/), and P09-CTS-4723 from the Junta de Andalucia (Proyecto de Excelencia). Francisco Martin is funded by the Fundación Progreso y Salud (Consejería de Salud, Junta de Andalucía, http://www.juntadeandalucia.es/fundacionprogresoysalud/).

Human mesenchymal stem/stromal cells (hMSC) are increasingly used in advanced cellular therapies. The clinical use of hMSCs demands sequential cell expansions. As it is well established that membrane glycerophospholipids (GPL) provide precursors for signaling lipids that modulate cellular functions, we studied the effect of the donor's age and cell doublings on the GPL profile of human bone marrow MSC (hBMSC). The hBMSCs, which were harvested from five young and five old adults, showed clear compositional changes during expansion seen at the level of lipid classes, lipid species, and acyl chains. The ratio of phosphatidylinositol to phosphatidylserine increased toward the late-passage samples. Furthermore, 20:4n-6-containing species of phosphatidylcholine and phosphatidylethanolamine accumulated while the species containing monounsaturated fatty acids (FA) decreased during passaging. Additionally, in the total FA pool of the cells, 20:4n-6 increased, which happened at the expense of n-3 polyunsaturated FAs, especially 22:6n-3. The GPL and FA correlated with the decreased immunosuppressive capacity of hBMSCs during expansion. Our observations were further supported by alterations in the gene expression levels of several enzymes involved in lipid metabolism and immunomodulation. The results show that extensive expansion of hBMSCs harmfully modulates membrane GPLs, affecting lipid signaling and eventually impairing functionality.

Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibroblasts, substantially contribute to disease features by the release of inflammatory mediators, smooth musde contraction, extracellular matrix deposition and structural changes in the airways. Current pharmacological treatment of both diseases intends to target the dynamic features of the endogenous intracellular suppressor cyclic AMP (cAMP). This review will summarize our current knowledge on cAMP and will emphasize on key discoveries and paradigm shifts reflecting the complex spatio-temporal nature of compartmentalized cAMP signalling networks in health and disease. As airway fibroblasts and airway smooth muscle cells are recognized as central players in the development and progression of asthma and COPD, we will focus on the role of cAMP signalling in their function in relation to airway function and plasticity. We will recapture on the recent identification of cAMP-sensing multi-protein complexes maintained by cAMP effectors, including A-kinase anchoring proteins (AKAPs), proteins kinase A (PICA), exchange protein directly activated by cAMP (Epac), CAMP-elevating seven-transmembrane (7TM) receptors and phospho-diesterases (PDEs) and we will report on findings indicating that the pertubation of compartmentalized cAMP signalling correlates with the pathopysiology of obstructive lung diseases. Future challenges include studies on CAMP dynamics and compartmentalization in the lung and the development of novel drugs targeting these systems for therapeutic interventions in chronic obstructive inflammatory diseases. (C) 2012 Elsevier Inc. All rights reserved.

Signal transduction by the cAMP/cAMP-dependent protein kinase A (PKA) pathway is triggered through multiple receptors and is important for many processes in a variety of cells. In T cells, the engagement of the TCR-CD3 complex induces CAMP, a second messenger that controls immune response. IL-10, produced by a variety of lymphocyte subpopulations, is an important regulator of this response exerting a wide range of immunomodulatory actions. Elevation of cAMP has been shown to increase IL-10 production by monocytes. However, the mechanism of cAMP mediated regulation of IL-10 production by T lymphocytes remains unclear. In this study using normal peripheral T lymphocytes stimulated either through the TCR-CD3 complex or the TCR-CD3 and the CD28 molecule, we show that IL-10 is produced mainly by memory T lymphocytes after either way of stimulation and is drastically inhibited (70-90%) by CAMP elevating agents. cAMP mediated inhibition was reversed by the use of the specific PKA inhibitor Rp-8-Br-cAMP but not by the addition of exogenous rhIL-2, indicating that the inhibitory effect depends on PKA activation and is not secondary to IL-2 inhibition, Inhibition is taking place at both transcriptional and posttranscriptional level. Transfection of a luciferase reporter plasmid carrying the IL-10 promoter in T cells, revealed that TCR/CD28-induced activation was inhibited by 60% by cAMP elevation. The most sensitive part to cAMP mediated inhibition was a fragment of 135 bp Upstream of TATA box, which contains multiple binding sites for MEF-2. Overexpression of MEF-2 in the same cells increased IL-10 promoter activity by 2.5-fold. Stimulation through TCR/CD28 increased MEF-2 binding in its Corresponding binding sites which was inhibited by 80% in the presence of cAMP elevating agents. These results suggest that the inhibitory effect of cAMP on IL-10 production by normal peripheral T lymphocytes is cell type and stimulus specific, exerted on multiple levels and involves MEF2 transcription factor. (C) 2008 Elsevier Ltd. All rights reserved. Mol Immunol

Secreted phospholipase A2 group X (sPLA(2)-X) is one of the most potent enzymes of the phospholipase A(2) lipolytic enzyme superfamily. Its high catalytic activity toward phosphatidylcholine (PC), the major phospholipid of cell membranes and low-density lipoproteins (LDL), has implicated sPLA(2)-X in chronic inflammatory conditions such as atherogenesis. We studied the role of sPLA(2)-X enzyme activity in vitro and in vivo, by generating sPLA(2)-X-overexpressing macrophages and transgenic macrophage-specific sPLA(2)-X mice. Our results show that sPLA(2)-X expression inhibits macrophage activation and inflammatory responses upon stimulation, characterized by reduced cell adhesion and nitric oxide production, a decrease in tumor necrosis factor (TNF), and an increase in interleukin (IL)-10. These effects were mediated by an increase in IL-6, and enhanced production of prostaglandin E-2 (PGE(2)) and 15-deoxy-Delta 12,14-prostaglandin J(2) (PGJ(2)). Moreover, we found that overexpression of active sPLA(2)-X in macrophages strongly increases foam cell formation upon incubation with native LDL but also oxidized LDL (oxLDL), which is mediated by enhanced expression of scavenger receptor CD36. Transgenic sPLA(2)-X mice died neonatally because of severe lung pathology characterized by interstitial pneumonia with massive granulocyte and surfactant-laden macrophage infiltration. We conclude that overexpression of the active sPLA(2)-X enzyme results in enhanced foam cell formation but reduced activation and inflammatory responses in macrophages in vitro. Interestingly, enhanced sPLA(2)-X activity in macrophages in vivo leads to fatal pulmonary defects, suggesting a crucial role for sPLA(2)-X in inflammatory lung disease.

The innate immune response to bacterial infections requires the interaction of neutrophils and platelets. Here, we show that a multistep reciprocal crosstalk exists between these two cell types, ultimately facilitating neutrophil influx into the lung to eliminate infections. Activated platelets adhere to intravascular neutrophils through P-selectin/P-selectin glycoprotein ligand-1 (PSGL-1)-mediated binding, a primary interaction that allows platelets glycoprotein Ibα (GPIbα)-induced generation of neutrophil-derived extracellular vesicles (EV). EV production is directed by exocytosis and allows shuttling of arachidonic acid into platelets. EVs are then specifically internalized into platelets in a Mac1-dependent fashion, and relocated into intracellular compartments enriched in cyclooxygenase1 (Cox1), an enzyme processing arachidonic acid to synthesize thromboxane A2 (TxA2). Finally, platelet-derived-TxA2 elicits a full neutrophil response by inducing the endothelial expression of ICAM-1, intravascular crawling, and extravasation. We conclude that critical substrate–enzyme pairs are compartmentalized in neutrophils and platelets during steady state limiting non-specific inflammation, but bacterial infection triggers regulated EV shuttling resulting in robust inflammation and pathogen clearance., Interaction between platelets and neutrophils promotes neutrophil activation. Here the authors show that neutrophils initiate the cross-talk with platelets by shuttling arachidonic acid via extracellular vesicles, which platelets convert to thromboxane A2 that then elicits neutrophil activation.

Fos expression was used to assess whether the proinflammatory cytokine interleukin-1beta (IL-1beta) activated specific, chemically coded neuronal populations in isolated preparations of guinea pig ileum and colon. Whether the effects of IL-1beta were mediated through a prostaglandin pathway and whether IL-1beta induced the expression of cyclooxygenase (COX)-2 was also examined. Single- and double-labeling immunohistochemistry was used after treatment of isolated tissues with IL-1beta (0.1-10 ng/ml). IL-1beta induced Fos expression in enteric neurons and also in enteric glia in the ileum and colon. For enteric neurons, activation was concentration-dependent and sensitive to indomethacin, in both the myenteric and submucosal plexuses in both regions of the gut. The maximum proportion of activated neurons differed between the ileal (approximately 15%) and colonic (approximately 42%) myenteric and ileal (approximately 60%) and colonic (approximately 75%) submucosal plexuses. The majority of neurons activated in the myenteric plexus of the ileum expressed nitric oxide synthase (NOS) or enkephalin immunoreactivity. In the colon, activated myenteric neurons expressed NOS. In the submucosal plexus of both regions of the gut, the majority of activated neurons were vasoactive intestinal polypeptide (VIP) immunoreactive. After treatment with IL-1beta, COX-2 immunoreactivity was detected in the wall of the gut in both neurons and nonneuronal cells. In conclusion, we have found that the proinflammatory cytokine IL-1beta specifically activates certain neurochemically defined neural pathways and that these changes may lead to disturbances in motility observed in the inflamed bowel.

It has become increasingly clear that caspases, far from being merely cell death effectors, have a much wider range of functions within the cell. These functions are as diverse as signal transduction and cytoskeletal remodelling, and caspases are now known to have an essential role in cell proliferation, migration and differentiation. There is also evidence that apoptotic cells themselves can direct the behaviour of nearby cells through the caspase-dependent secretion of paracrine signalling factors. In some processes, including the differentiation of skeletal muscle myoblasts, both caspase activation in differentiating cells as well as signalling from apoptotic cells has been reported. Here, we review the non-apoptotic outcomes of caspase activity in a range of different model systems and attempt to integrate this knowledge.

Purpose: Most of the current understanding of articular cartilage maintenance and degradation is derived from large load-bearing synovial joints, in particular the knee joint. The aim of this study was to identify valuable degradation markers for cartilage degradation in the temporomandibular joint (TMJ) by comparing the relative concentrations of carboxyterminal telopeptides of collagen types I and II (CTX-I and CTX-II), cartilage oligomeric matrix protein (COMP), and prostaglandin E-2 (PGE(2)) in synovial fluid (SF) of TMJ and knee joints with cartilage degradation.Materials and Methods: In this cross-sectional comparative study, participants were recruited from the University Medical Center Groningen, The Netherlands. Patients with TMJ osteoarthritis were compared with patients with knee osteoarthritis. The outcome variables were the relative SF concentrations of CTX-I, CTX-II, COMP, and PGE(2). An independent samples Mann-Whitney U test was used to compare the relative concentrations.Results: Thirty consecutive patients (9 male, 21 female; mean age, 40.1 yr; standard deviation, 15.3 yr) with TMJ osteoarthritis and 31 consecutive patients (20 male, 11 female; mean age, 37.4 yr; standard deviation, 13.7 yr) who were scheduled for arthroscopy of the knee joint participated in this study. Significant differences were found between relative concentrations of COMP (P = .000) and PGE(2) (P = .005), and no significant differences were found between relative concentrations of CTX-I (P = .720) and CTX-II (P = .242).Conclusions: Relative SF concentrations of COMP and PGE(2) showed significant differences between the TMJ and the knee joint, suggesting that there are differences in pathophysiology and that the inflammatory component may be more distinct in the TMJ. (C) 2014 American Association of Oral and Maxillofacial Surgeons

The present study was undertaken to evaluate the effects of the glucocorticoid hormones betamethasone and hydrocortisone, and of progesterone on the relative production of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) by explants of human fetal membranes at term gestation in the absence of labor. Tissues (n = 7) were incubated either in the presence or in the absence of the above mentioned hormones. PGE2 and LTB4 were measured in culture medium by radioimmunoassays. Glucocorticoids and progesterone did not affect PGE2 output by tissues; however, they greatly stimulated LTB4 production. Moreover, both betamethasone and hydrocortisone significantly increased the ratio of LTB4 to PGE2 formation by tissues. These results suggest that glucocorticoid hormones and progesterone might influence arachidonic acid metabolism in human fetal membranes by stimulating the production of lipoxygenase rather than cyclooxygenase substances before the onset of labor.

Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3′-untranslated region (3′-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E2 (PGE2) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 μM of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE2 levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE2, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.

Highlights • We report interactions of Toll-like receptors (TLRs) with COX enzymes in vivo. • COX-2 was broadly induced by LPS (TLR4) but more locally by poly(I:C) (TLR3). • COX-1/2 deletion modified the response to TLR activation in a TLR-specific manner. • COX-2 deletion enhanced interferon responses to viral-type TLR3/7/9 ligands. • COX-2 inhibition could provide a novel anti-viral therapeutic strategy., Cyclooxygenase 2 (COX)-2 is induced by bacterial and viral infections and has complex, poorly understood roles in anti-pathogen immunity. Here, we use a knock-in luciferase reporter model to image Cox2 expression across a range of tissues in mice following treatment with the either the prototypical bacterial pathogen-associated molecular pattern (PAMP), LPS, which activates Toll-like receptor (TLR)4, or with poly(I:C), a viral PAMP, which activates TLR3. LPS induced Cox2 expression in all tissues examined. In contrast, poly(I:C) elicited a milder response, limited to a subset of tissues. A panel of cytokines and interferons was measured in plasma of wild-type, Cox1−/− and Cox2−/− mice treated with LPS, poly(I:C), MALP2 (TLR2/6), Pam3CSK4 (TLR2/1), R-848 (TLR7/8) or CpG ODN (TLR9), to establish whether/how each COX isoform modulates specific PAMP/TLR responses. Only LPS induced notable loss of condition in mice (inactivity, hunching, piloerection). However, all TLR agonists produced cytokine responses, many of which were modulated in specific fashions by Cox1 or Cox2 gene deletion. Notably we observed opposing effects of Cox2 gene deletion on the responses to the bacterial PAMP, LPS, and the viral PAMP, poly(I:C), consistent with the differing abilities of the PAMPs to induce Cox2 expression. Cox2 gene deletion limited the plasma IL-1β and interferon-γ responses and hypothermia produced by LPS. In contrast, in response to poly(I:C), Cox2−/− mice exhibited enhanced plasma interferon (IFNα,β,γ,λ) and related cytokine responses (IP-10, IL-12). These observations suggest that a COX-2 selective inhibitor, given early in infection, may enhance and/or prolong endogenous interferon responses, and thereby increase anti-viral immunity.

BackgroundBacterial non-necrotizing erysipelas and cellulitis are often recurring, diffusely spreading infections of the skin and subcutaneous tissues caused most commonly by streptococci. Host genetic factors influence infection susceptibility but no extensive studies on the genetic determinants of human erysipelas exist.MethodsWe performed genome-wide linkage with the 10,000 variant Human Mapping Array (HMA10K) array on 52 Finnish families with multiple erysipelas cases followed by microsatellite fine mapping of suggestive linkage peaks. A scan with the HMA250K array was subsequently performed with a subset of cases and controls.ResultsSignificant linkage was found at 9q34 (nonparametric multipoint linkage score (NPL(all)) 3.84, p=0.026), which is syntenic to a quantitative trait locus for susceptibility to group A streptococci infections on chromosome 2 in mouse. Sequencing of candidate genes in the 9q34 region did not conclusively associate any to erysipelas/cellulitis susceptibility. Suggestive linkage (NPL(all)>3.0) was found at three loci: 3q22-24, 21q22, and 22q13. A subsequent denser genome scan with the HMA250K array supported the 3q22 locus, in which several SNPs in the promoter of AGTR1 (Angiotensin II receptor type I) suggestively associated with erysipelas/cellulitis susceptibility.ConclusionsSpecific host genetic factors may cause erysipelas/cellulitis susceptibility in humans.

Objective To explore the distribution of prostaglandin E receptor type 2 (EP2) in the bladder muscle layers and its spatial relationship to cyclo-oxygenase type 1 (COX I). Materials and methods Twelve male guinea pigs were killed by cervical dislocation, the bladders removed and fixed in 4% paraformaldehyde in PBS. Frozen sections of 10 μm were cut and stained with antibodies to EP2, COX I and vimentin. Results EP2 receptor immunoreactivity is located on the smooth muscle cells as well as on vimentin positive surface muscle and intramuscular interstitial cells. EP2 expression on interstitial cells is highly localized. Discrete regions of intense staining were observed on the interstitial cell processes. COX I is expressed in the muscle interstitial cells and was found to be located on discrete regions of the cell and cell processes. Double staining with EP2 and COX I suggests that the regions of a cell expressing EP2 are different from those expressing COX I. Conclusions The presence of COX I, prostaglandin E receptor type 2 (EP2) immune-reactivity in the network of interstitial cells suggests a role of this network in the propagation of signals. Due to a cAMP coupling of the EP2 receptor in many other tissues and a lower dissociation constant of EP2, it is suggested that a rise in PG levels may gradually push the balance from a relaxant EP2 effect towards a contractile effect. Hence, PG could have a modulatory role on the non-voiding bladder contractions by changing the threshold level for excitability of the interstitial cell network.

The potential for dietary supplementation with n-3 polyunsaturated fatty acids (n-3 PUFA) to improve reproductive efficiency in cattle has received much interest. The mechanisms by which n-3 PUFA may affect physiological and biochemical processes in key reproductive tissues are likely to be mediated by significant alterations in gene expression. The objective of this study was to examine the effects of dietary n-3 PUFA supplementation on global uterine endometrial gene expression in cattle. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid (CON; palmitic acid) or high n-3 PUFA (n-3 PUFA; 275 g) diet per animal per day for 45 days and global gene expression was determined in uterine endometrial tissue using an Affymetrix oligonucleotide bovine array. A total of 1,807 (946 up- and 861 downregulated) genes were differentially expressed following n-3 PUFA supplementation. Dietary n-3 PUFA altered numerous cellular processes potentially important in the control of reproduction in cattle. These included prostaglandin biosynthesis, steroidogenesis and transcriptional regulation, while effects on genes involved in maternal immune response and tissue remodeling were also observed. This study provides new insights into the effects of n-3 PUFA supplementation on the regulation of gene expression in the bovine uterus.

Objectives To analyze the anti-inflammatory effects of Lactobacillus brevis extracts on periodontitis patients and to investigate the involved mechanisms in vitro on activated macrophages. Methods Eight healthy subjects and 21 patients with chronic periodontitis were enrolled to analyze the effect of L. brevis-containing lozenges on periodontitis-associated symptoms and signs. Before and after the treatment, the patients received a complete periodontal examination. Saliva samples, collected before and after treatment, were analyzed for metalloproteinase and nitric oxide synthase (NOS) activity, immunoglobulin-A (IgA), prostaglandin E(2) (PGE(2)) and gamma-interferon (IFN-gamma) levels. Arginine deiminase (AD) and NOS activities were determined through a radiometric assay. Metalloproteinases were assayed by zymogram and Western blotting, whereas IgA, PGE(2) and IFN-gamma were assayed by enzyme-linked imunosorbent assay tests. Results The treatment led to the total disappearance or amelioration of all analyzed clinical parameters in all patients. This was paralleled to a significant decrease of nitrite/nitrate, PGE(2), matrix metalloproteinase, and IFN-gamma levels in saliva samples. Conclusion Our results suggest that the anti-inflammatory effects of L. brevis could be attributed to the presence of AD which prevented nitric oxide generation. Our findings give further insights into the knowledge of the molecular basis of periodontitis and have a potential clinical significance, giving the experimental ground for a new innovative, simple and efficacious therapeutical approach of periodontal disease.

Dietary modulation of carcinogenesis-related pathwaysDietary item or component studied:tricin, apigenin, querceninPathways studied:COX-catalysed PGE-2 generationStudy type (in vitro, animals, humans): in vitroTissue/biological material/sample size:colorectal cell line HT-29, HCA-7Mode of exposure (if in vivo) (acute, chronic, root of exposure):different time points. KEYWORDS CLASSIFICATION: Animals;Anticarcinogenic Agents;Apigenin;biosynthesis;chemistry;Cell Line,Transformed;Cell Line,Tumor;Cell Proliferation;Cyclooxygenase 1;Cyclooxygenase 2;Cyclooxygenase Inhibitors;dietary modulation of carcinogenesis-related pathways;drug effects;Dinoprostone;Dose-Response Relationship,Drug;Flavonoids;HT29 Cells;Humans;Intramolecular Oxidoreductases;metabolism;Models,Biological;Molecular Structure;Oxidoreductases;pharmacology;Prostaglandin-Endoperoxide Synthases;Quercetin;Research;Sheep;Tetradecanoylphorbol Acetate. OBJECTIVES: Diet-derived flavonoids possess cancer chemopreventive properties in preclinical models. The knowledge of the pharmacology of most flavonoids is insufficient to warrant their advancement to clinical evaluation. METHODS: Here the three flavonoids tricin from rice bran, apigenin from leafy vegetables, and quercetin from onions and apples, were compared in terms of their ability to modulate cyclooxygenase- (COX-) catalyzed prostaglandin E-2 (PGE-2) generation. Specifically their effects on the following parameters were studied: (1) COX enzyme activity, (2) COX-2 expression in human-derived colon cancer cells HCA-7, which express COX-2 constitutively, (3) phorbol ester-mediated COX-2 induction in human colon epithelial cells (HCEC), and (4) PGE-2 levels in cellular incubations. RESULTS: Tricin and quercetin inhibited enzyme activity in purified COX-1 and -2 preparations with IC50 values of near 1 (tricin) and 5 microM (quercetin). Apigenin at up to 25 microM did not affect COX enzyme activity. Flavonoids were incubated with cells for 6 or 24 h and COX-2 protein expression and PGE-2 levels were assessed by Western blot and competitive immunoassay, respectively. None of the agents affected constitutive COX-2 expression in HCA-7 cells. Apigenin, but not tricin or quercetin, down-regulated inducible COX-2 expression in HCEC cells on 6 h incubation. All three flavonoids reduced cellular levels of PGE-2 in the supernatant of HCA-7 cells at both time points and of HCEC cells at 6 h. CONCLUSIONS: The results demonstrate that these structurally similar flavonoids regulate COX-mediated PGE-2 production in different fashions. Their ability to attenuate prostanoid levels may contribute to their cancer chemopreventive efficacy.

Estrogen is implicated in many autoimmune diseases and is a robust immunomodulator. For example, it regulates interferon (IFN)-gamma, a cytokine believed to up-regulate inducible nitric oxide synthase (iNOS). A notable gap in the literature is a lack of information on the regulation of nitric oxide in immune tissues by estrogen. We now show that activation of splenocytes with T cell stimulants [concanavalin-A (Con-A) or anti-CD3 antibodies] results in copious release of nitric oxide in splenocyte cultures from estrogen-treated but not placebo-treated mice. Moreover, even a low dose of T cell stimulants induced nitric oxide in splenocytes from estrogen-treated, but not placebo-treated, mice. Con-A-activated splenocytes from estrogen-treated mice also have up-regulated iNOS mRNA, iNOS protein, and cyclooxygenase-2 (a nitric oxide-regulated downstream proinflammatory protein) when compared with controls. Our studies suggest that the induction of nitric oxide by activated splenocytes from estrogen-treated mice is mediated in part by IFN gamma. First, blocking costimulatory signals mediated through interactions of CD28 and B7 molecules by CTLA-4Ig markedly decreased not only IFN gamma but also nitric oxide. Second, estrogen treatment of IFN gamma-knockout (IFN gamma(-)/(-)) mice did not induce iNOS protein or nitric oxide. Finally, in vitro addition of recombinant IFN gamma to Con-A-activated splenocytes from IFN gamma((-)/(-)) mice induced iNOS protein primarily in estrogen-treated mice. Overall, this is the first report to show that estrogen treatment up-regulates IFN gamma-inducible-iNOS gene expression, iNOS protein, nitric oxide, and cyclooxygenase-2 as an indirect consequence of activation of T cells. These findings may have wide implications to immunity and inflammatory disorders including female-predominant autoimmune diseases. National Institutes of Health (5RO1 AI51880-03) U.S. Department of Agriculture (USDA)-Hatch USDA-Animal Health and Disease programs

P388D1 cells release arachidonic acid (AA) and produce prostaglandin E2 (PGE2) upon long-term stimulation with lipopolysaccharide (LPS). The cytosolic Group IVA (GIVA) phospholipase A2 (PLA2) has been implicated in this pathway. LPS stimulation also results in increased expression and secretion of a secretory PLA2, specifically GV PLA2. To test whether GV PLA2 contributes to PGE2 production and whether GIVA PLA2 activation increases the expression of GV PLA2, we utilized the specific GIVA PLA2 inhibitor pyrrophenone and second generation antisense oligonucleotides (AS-ONs) designed to specifically inhibit expression and activity of GV PLA2. Treatment of P388D1 cells with antisense caused a marked decrease in basal GV PLA2 mRNA and prevented the LPS-induced increase in GV PLA2 mRNA. LPS-stimulated cells release active GV PLA2 into the medium, which is inhibited to background levels by antisense treatment. However, LPS-induced PGE2 release by antisense-treated cells and by control cells are not significantly different. Collectively, the results suggest that the upregulation of GV PLA2 during long-term LPS stimulation is not required for PGE2 production by P388D1 cells. Experiments employing pyrrophenone suggested that GIVA PLA2 is the dominant player involved in AA release, but it appears not to be involved in the regulation of LPS-induced expression of GV PLA2 or cyclooxygenase-2.

Complement activation products C1q and C3d, serum amyloid P component (SAP) and activated glial cells accumulate in amyloid deposits of conformationally changed prion protein (PrPSc) in Creutzfeldt-Jakob disease, Gerstmann-Straussier-Scheinker disease and scrapie-infected mouse brain. Biological properties, including the potential to activate microglia, relate to prion (PrP) peptide fibrillogenic abilities. We investigated if SAP and C1q influence the fibrillogenic properties of human and mouse PrP peptide and concomitantly their stimulatory effects on human microglia in vitro. PrP-peptide induced microglial IL-6 and TNF-alpha, release significantly increased in the presence of SAP and C1q. Also, SAP and C1q enhanced PrP-peptide fibril formation as revealed by electron microscopy and thioflavin S-based quantitative assays. This suggests that SAP and C1q contribute to fibrillar state-dependent cellular effects of PrP. Combined, ultrastructural and thioflavin assays, together with microglial cytokine release measurements, provide a test system to screen potential, fibrillarity impeding therapeutics for prion disease. (c) 2005 Elsevier Inc. All rights reserved

In the present study the accumulation of protease resistant prion protein (PrPres) in scrapie-infected neuroblastoma cells (ScN2a cells) was shown to be dependent on culture conditions. The highest levels of PrPres were found in slow growing cells. Further increases in PrPres accumulation were observed in ScN2a cells treated with retinoic acid, a compound that is associated with neuronal differentiation. The effects of retinoic acid were dose-dependent with a maximal effect at 200 ng/ml. A similar increase in PrPres was observed in another prion-infected cell line, scrapie-mouse brain (SMB) cells, treated with retinoic acid while retinoic acid increased the amount of PrPC in non-infected cells. Other drugs reported to cause neuronal differentiation, such as phorbol esters, did not increase the PrPres content of ScN2a cells. The survival of retinoic acid-treated ScN2a cells co-cultured with microglia was significantly reduced when compared to untreated ScN2a cells and an inverse correlation was demonstrated between the PrPres content of cells and their survival when co-cultured with microglia. The production of interleukin-6 by microglia cultured with retinoic acid-treated ScN2a cells was significantly higher than that of microglia cultured with untreated ScN2a cells.

This study was conducted to investigate the role of the enzyme cyclooxygenase (COX) and its prostaglandin product PGE2 in n-6 and n-3 polyunsaturated fatty acid (PUFA)-mediated effects on cellular proliferation of two human colorectal carcinoma cell lines. The long chain PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (AA; 20:4n-6) both inhibited cell proliferation of Caco-2 cells compared with the long chain fatty acids α-linolenic acid (ALA; 18:3n-3) and linoleic acid (LA; 18:2n-6). Neither incubation with PGE2 nor reduction in PGE2 synthesis by EPA compared with AA led to differential effects on cell proliferation in Caco-2 cells. This suggests that n-6 and n-3 PUFA-mediated cell proliferation in Caco-2 cells is not regulated via PGE2 levels. AA and EPA had no effect on growth of HT-29 colon cancer cells with a low COX activity. However, stimulation of COX-2 activity by IL-1β resulted in a decrease in cell proliferation and an induction of cytotoxicity by AA as well as by EPA. Both inhibition of the COX pathway by indomethacin as well as inhibition of direct lipid peroxidation by antioxidants such as vitamin E and C diminished the anti-proliferative effects of AA as well as EPA. Also, malondialdehyde, a product of lipid peroxidation and COX-activity was decreased by addition of vitamin E and partially decreased by indomethacin. These data support the hypothesis that growth inhibitory and cytotoxic effects of PUFAs with methylene-interrupted double bonds such as AA and EPA are due to peroxidation products that are generated during lipid peroxidation and COX activity. Chemicals/CAS: 5 (4 fluorophenyl) 1 [(4 methylsulfonyl)phenyl] 3 trifluoromethylpyrazole, 162054-19-5; 5,8,11,14,17 icosapentaenoic acid, 10417-94-4, 1553-41-9; acetylsalicylic acid, 493-53-8, 50-78-2, 53663-74-4, 53664-49-6, 63781-77-1; alpha tocopherol, 1406-18-4, 1406-70-8, 52225-20-4, 58-95-7, 59-02-9; arachidonic acid, 506-32-1, 6610-25-9, 7771-44-0; ascorbic acid, 134-03-2, 15421-15-5, 50-81-7; carbene, 2465-56-7; celecoxib, 169590-42-5; docosahexaenoic acid, 25167-62-8, 32839-18-2; indometacin, 53-86-1, 74252-25-8, 7681-54-1; linoleic acid, 1509-85-9, 2197-37-7, 60-33-3, 822-17-3; malonaldehyde, 542-78-9; prostaglandin E2, 363-24-6; prostaglandin synthase, 39391-18-9, 59763-19-8, 9055-65-6; Antioxidants; Cyclooxygenase Inhibitors; Dinoprostone, 363-24-6; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Prostaglandin-Endoperoxide Synthases, EC 1.14.99.1

Many reports indicate that nitric oxide (NO) could be involved in migraine without aura (MWA), an extremely diffuse clinical event. Since monocyte may be a relevant source of NO, we analysed monocyte activation in MWA patients, in a period in which they were free of symptoms. NO basal production by MWA peripheral monocytes was significantly higher than in healthy subjects (91.25 ± 8.6 μm/106cells vs. 22.6 ± 3.2 μm/106cells). Interestingly, even the release of prostaglandin E2(PGE2), was higher in MWA patients than in healthy subjects (3137 ± 320 pg/106cells vs. 1531 ± 220 pg/106cells). The incubation of monocytes from healthy subjects and MWA patients with N-nitro-l-arginine methyl ester caused a marked decrease of both NO and PGE2release. We hypothesise that NOS and cyclooxygenase pathways in monocytes are linked and are, in MWA patients, up-regulated, even in a symptoms-free period. NO and PGE2hyperproduction could therefore be involved in the neurovascular modifications leading to migraine attacks.

Background: Protein kinase A (PKA) activation is documented to be inhibitory for T helper cell (T-H1)-like cytokines (IL-2, IFN-gamma), whereas T-H2-like cytokines (IL-4, IL-5) are not affected or upregulated. We have recently shown that IL-4 gene expression can be inhibited by PKA activation but depends on the mode of T-cell activation. For IL-5 gene expression, we hypothesized that the mode of T-cell activation also determines the ultimate effect of simultaneous PKA activation. Objectives: The objective of this study was the examination of IL-5 gene expression in healthy T cells activated with various mitogenic stimuli after simultaneous activation of PKA by dibutyryl-cAMP or prostaglandin E-2 (PGE(2)). Methods: IL-5 mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction or Northern analysis. IL-5 protein was measured by ELISA. Transcriptional mechanisms involved in IL-5 gene expression were determined by nuclear run-on experiments and electrophoretic mobility shift assays. Posttranscriptional mechanisms were determined by actinomycin D chase studies. Results: Anti-CD2-, anti-CD3-, and anti-CD3 plus anti-CD28-induced IL-5 mRNA were completely inhibited by dibutyryl cyclic AMP (10(-3) mol/L) and PGE(2) (10(-5) mol/L), whereas concanavalin A-induced IL-5 mRNA was partially reduced. The effect of PGE(2) was accomplished at the transcriptional level, probably as the result of inhibition of DNA binding of nuclear factor-kappa B. Anti-CD3 plus anti-CD28-induced IL-5 protein (504 +/- 56 pg/ml) was significantly reduced by PGE(2) (122 +/- 42 pg/ml, p