Regular swimming exercise prevented the acute and persistent mechanical muscle hyperalgesia by modulation of macrophages phenotypes and inflammatory cytokines via PPARγ receptors.

Physically active individuals are less likely to develop chronic pain, and physical exercise is an established strategy to control inflammatory diseases. Here, we hypothesized that 1) peripheral pro-inflammatory macrophages phenotype contribute to predisposition of the musculoskeletal to chronic pain, and that 2) activation of PPARγ receptors, modulation of macrophage phenotypes and cytokines through physical exercise would prevent persistent muscle pain. We tested these hypotheses using swimming exercise, pharmacological and immunochemical techniques in a rodent model of persistent muscle hyperalgesia. Swimming prevented the persistent mechanical muscle hyperalgesia most likely through activation of PPARγ receptors, as well as activation of PPARγ receptors by 15d-PGJ2 and depletion of muscle macrophages in sedentary animals. Acute and persistent muscle hyperalgesia were characterized by an increase in pro-inflammatory macrophages phenotype, and swimming and the 15d-PGJ2 prevented this increase and increased anti-inflammatory macrophages phenotype. Finally, IL-1ß concentration in muscle increased in the acute phase, which was also prevented by PPARγ receptors activation through swimming. Besides, swimming increased muscle concentration of IL-10 in both acute and chronic phases, but only in the persistent phase through PPARγ receptors. Our findings suggest physical exercise activates PPARγ receptors and increases anti-inflammatory responses in the muscle tissue by modulating macrophages phenotypes and cytokines, thereby preventing the establishment of persistent muscle hyperalgesia. These results further highlight the potential of physical exercise to prevent chronic muscle pain.

Prostaglandin 15d-PGJ2 targets PPARγ and opioid receptors to prevent muscle hyperalgesia in rats.

Pharmacological agents directed to either opioid receptors or peroxisome proliferator-activated receptor gamma (PPARγ) at peripheral tissues reduce behavioral signs of persistent pain. Both receptors are expressed in muscle tissue, but the contribution of PPARγ activation to muscle pain and its modulation by opioid receptors remains unknown. To address this question, we first tested whether the endogenous PPARγ ligand 15d-PGJ2 would decrease mechanical hyperalgesia induced by carrageenan administration into the gastrocnemius muscle of rats. Next, we used receptor antagonists to determine whether the antihyperalgesic effect of 15-deoxyΔ-12,14-prostaglandin J2 (15d-PGJ2) was PPARγ- or opioid receptor-dependent. Three hours after carrageenan, muscle hyperalgesia was quantified with the Randall-Selitto test. 15d-PGJ2 prevented carrageenan-induced muscle hyperalgesia in a dose-dependent manner. The antihyperalgesic effect of 15d-PGJ2 was dose-dependently inhibited by either the PPARγ antagonist, 2-chloro-5-nitro-N-phenylbenzamide, or by the opioid receptor antagonist, naloxone. We conclude that 15d-PGJ2 targets PPARγ and opioid receptors to prevent muscle hyperalgesia. We suggest that local PPARγ receptors are important pharmacological targets for inflammatory muscle pain.

Acellular Human Amniotic Membrane Scaffold with 15d-PGJ2 Nanoparticles in Postinfarct Rat Model.

The difficulty in the regeneration of cardiomyocytes after myocardial infarction is a major cause of heart failure. Together, the amniotic membrane and 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) can help in the recovery of cardiomyocyte, as they present many growth factors and anti-inflammatory effect, respectively. The objective of this study is to compare the efficacy of Human Decellularized Amniotic Membrane Scaffold (AHAS) loaded with 15d-PGJ2 in improving ventricular function in a rat model of postinfarct ventricular dysfunction. Myocardial infarction was induced in 24 rats by left coronary occlusion. After a week, the animals were subjected to echocardiography for evaluation of left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV), and left ventricle end systolic volume (LVESV). Animals with ejection fraction <40% were included in the study and were randomized into three groups: control (n = 8), AHAS (n = 8) and AHAS +15d-PGJ2 (n = 8). In the AHAS group only the membrane was implanted, whereas in the AHAS +15d-PGJ2 the membrane +15d-PGJ2 was implanted on myocardial infarction. Echocardiographic evaluation was performed after 1 month. For histological analysis, heart tissue was stained with Gomori trichome, Sirius Red, the antibody against CD31 and connexin 43 (Cx43). There were no significant differences in the baseline LVEF, LVEDV, and LVESV in all groups. After 1 month, ejection fraction decreased in the control group but increased in the AHAS group and in the AHAS +15d-PGJ2 group in comparison with the control group. The LVEDV and LVESV in the AHAS and AHAS +15d-PGJ2 groups decreased compared with the control group, featuring a ventricular antiremodeling effect. Histopathology of the infarcted area identified the reduction of infarct size and collagen type 1 in the AHAS and AHAS +15d-PGJ2 groups. New blood vessels and cardiomyocytes have been identified in an infarcted area by CD31 and Cx43. AHAS +15d-PGJ2 provided an increase in the ejection fraction and prevented ventricular dilation in this postinfarction ventricular dysfunction model. Impact Statement Our study demonstrated reduction of myocardial fibrosis, proliferation of cardiomyocytes and increase in ejection fraction in rats after experimental acellular amniotic membrane scaffold (AHAS) carrying nanoparticles of 15d-PGJ2 scaffold engraftment in infarcted myocardium. AHAS grafts facilitated colonization of fibrotic myocardium regions with new contractile cells, in addition to preventing reduction of left ventricle wall thickness. This contribution is theoretically and practically relevant as current literature describes experimental studies performed on cardiac ischemic models which present conflicting results concerning cell types used in a research model.

Activation of PPAR-γ induces macrophage polarization and reduces neutrophil migration mediated by heme oxygenase 1.

Natural or synthetic ligands for peroxisome proliferator-activated receptor gamma (PPAR-γ) represent an interesting tool for pharmacological interventions to treat inflammatory conditions. In particular, PPAR-γ activation prevents pain and inflammation in the temporomandibular joint (TMJ) by decreasing cytokine release and stimulating the synthesis of endogenous opioids. The goal of this study was to clarify whether PPAR-γ activation induces macrophage polarization, inhibiting inflammatory cytokine release and leukocyte recruitment. In addition, we investigated the involvement of heme oxygenase 1 (HO-1) in downstream events after PPAR-γ activation. Our results demonstrate that PPAR-γ activation ablates cytokine release by Bone Marrow-Derived Macrophages (BMDM) in vitro. 15d-PGJ2 induces the PPAR-γ heterodimer activation from rat macrophages, with macrophage polarization from M1-like cells toward M2-like cells. This response is mediated through HO-1. PPAR-γ activation diminished neutrophil migration induced by carrageenan, which was also HO-1 dependent. Ca2+/calmodulin expression did not change after PPAR-γ activation indicating that is not required for the activation of the intracellular L-arginine/NO/cGMP/K+ATP channel pathway. In summary, the anti-inflammatory actions induced by PPAR-γ activation involve macrophage polarization. HO-1 expression is increased and HO-1 activity is required for the suppression of neutrophil migration.

Poloxamer micellar system for intra-articular injection of 15-deoxy-Δ12,14-prostaglandin J2 with improved bioavailability and anti-inflammatory properties in the temporomandibular joint of rats.

Painful conditions of the temporomandibular joint (TMJ) are challenging to manage and most attempts often result in unsatisfactory outcomes. In such context, nanocarrier systems, such as polymeric micelles, have been showing encouraging results in solving therapeutic limitations. Poloxamers are widely used, especially PL 407, because of their high biocompatibility and approval by the Food and Drug Administration (FDA) for clinical use. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has shown important antinociceptive and anti-inflammatory activity. The present study evaluated the efficacy and viability of the micellar system of PL-15dPGJ2 in a formalin-induced acute pain model in the temporomandibular joint of rats. The PL-15dPGJ2 was prepared and characterized. The animals were pretreated with an intra-articular injection of PL-15dPGJ2 followed by the formalin challenge. The nociceptive response was evaluated at different time-periods and the periarticular tissue and articular wash were collected for analysis. We found that intra-articular injection of PL-15d-PGJ2 produced pain relief at lower concentrations and in a sustained manner compared with free 15d-PGJ2. Moreover, a strong anti-inflammatory effect was observed with decreased levels of key pro-inflammatory cytokines and modulation of the leukocyte migration process. Our findings suggest that 15d-PGJ2 combined with a poloxamer micellar system provided clinical relevance in terms of bioavailability, long-lasting effect, and safe dosage. The formulation investigated herein is a promising micellar carrier system for managing pain conditions of the TMJ.

Effect of ScLL and 15d-PGJ2 on viability and cytokine release in LPS-stimulated fibroblasts: an in vitro study.

This study evaluated the effect of a cyclopentenone-type PG, 15-Deoxy-Δ12,14-PG J2 (15d-PGJ2), and lectin (ScLL) on the viability of human gingival fibroblasts (HGFs), and on IL-6 and TGFß-1 release by these fibroblasts, stimulated with lipopolysaccharide (LPS). HGFs were stimulated with LPS 10 µg/ml and treated with 15d-PGJ2 1 and 2 µg/ml, and ScLL 2 and 5 µg/ml, for 1 and 3h, and then evaluated for viability by MTT assay. Supernatant was collected to detect IL-6 and TGFß-1 release, by ELISA. Positive control was cells kept in Dulbecco's Modified Eagle's Medium, and negative control was those kept in LPS. Data were analyzed by ANOVA and Dunnett's test (α = 0.05). No significant difference was found in viability among experimental groups at 1h (p > 0.05). Percentage of ScLL 5 µg/ml viable cells was similar to that of positive control at evaluated periods (p > 0.05), whereas the other groups had lower levels than the positive control (p < 0.05). IL-6 release was statistically higher for ScLL 5 µg/ml and 15d-PGJ2 2 µg/ml at 1h, compared with the other treated groups and positive control (p < 0.05). No significant differences were found among the groups at 3h (p > 0.05), except for ScLL 2 µg/ml and 15d-PGJ2 1 µg/ml, which showed lower IL-6 release compared with that of negative control (p < 0.05). No significant difference was found among the groups for TGFß-1 release (p > 0.05). Results indicated that ScLL 5 µg/ml did not interfere in viability, and ScLL 2 µg/ml and 15d-PGJ2 1 µg/ml demonstrated reduced IL-6 release. Tested substances had no effect on TGFß-1 release.

Effect of ScLL and 15d-PGJ2 on viability and cytokine release in LPS-stimulated fibroblasts: an in vitro study

Abstract This study evaluated the effect of a cyclopentenone-type PG, 15-Deoxy-Δ12,14-PG J2 (15d-PGJ2), and lectin (ScLL) on the viability of human gingival fibroblasts (HGFs), and on IL-6 and TGFβ-1 release by these fibroblasts, stimulated with lipopolysaccharide (LPS). HGFs were stimulated with LPS 10 μg/ml and treated with 15d-PGJ2 1 and 2 μg/ml, and ScLL 2 and 5 μg/ml, for 1 and 3h, and then evaluated for viability by MTT assay. Supernatant was collected to detect IL-6 and TGFβ-1 release, by ELISA. Positive control was cells kept in Dulbecco's Modified Eagle's Medium, and negative control was those kept in LPS. Data were analyzed by ANOVA and Dunnett's test (α = 0.05). No significant difference was found in viability among experimental groups at 1h (p > 0.05). Percentage of ScLL 5 µg/ml viable cells was similar to that of positive control at evaluated periods (p > 0.05), whereas the other groups had lower levels than the positive control (p < 0.05). IL-6 release was statistically higher for ScLL 5 μg/ml and 15d-PGJ2 2 µg/ml at 1h, compared with the other treated groups and positive control (p < 0.05). No significant differences were found among the groups at 3h (p > 0.05), except for ScLL 2 µg/ml and 15d-PGJ2 1 µg/ml, which showed lower IL-6 release compared with that of negative control (p < 0.05). No significant difference was found among the groups for TGFβ-1 release (p > 0.05). Results indicated that ScLL 5 μg/ml did not interfere in viability, and ScLL 2 µg/ml and 15d-PGJ2 1 µg/ml demonstrated reduced IL-6 release. Tested substances had no effect on TGFβ-1 release.

The 15d­PGJ2 hydrogel ameliorates atopic dermatitis through suppression of the immune response.

The present study examined the efficacy of the topical 15d­PGJ2­poloxamer 407 hydrogel in an atopic dermatitis (AD) animal model. The 15d­PGJ2 hydrogel was prepared and characterized. The examined rats possessed AD­Like cutaneous lesions, which were induced using 2,4­dinitrochlorobenzene, the rats were then treated with a hydrogel vehicle, 15d­PGJ2 hydrogel or tacrolimus for 14 days. The rats were sacrificed and blood samples were collected to quantify the IgE levels. Subsequently, skin biopsies were stained with toluidine blue to identify mast cells and immunohistochemistry was performed for ROR­Î³t and TNF­α. Histological analyses demonstrated that 15d­PGJ2 hydrogel significantly decreased mast cell infiltration (P<0.05) when compared with the AD­group. Tacrolimus at 0.1% exhibited decreased mast cell infiltration; however, this difference was not statistically significant from the AD­group. Topical 15d­PGJ2 hydrogel and Tacrolimus 0.1% significantly reduced the serum levels of IgE (P<0.05) compared with the AD­group. Immunohistochemistry revealed a significant decrease in ROR­Î³t and TNF­α positive cell expression (P<0.05) in the 15d­PGJ2 hydrogel group compared with the AD­group. In summary, topical administration of 15d­PGJ2 hydrogel had a beneficial effect on AD symptoms, suggesting that this formulation may be a useful strategy for the treatment of AD.

15d-PGJ2-loaded nanocapsules ameliorate experimental gout arthritis by reducing pain and inflammation in a PPAR-gamma-sensitive manner in mice.

Gout arthritis (GA) is a painful inflammatory disease in response to monosodium urate (MSU) crystals in the joints. 15deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is a natural activator of PPAR-γ with analgesic, anti-inflammatory, and pro-resolution properties. Thus, we aimed to evaluate the effect and mechanisms of action of 15d-PGJ2 nanocapsules (NC) in the model of GA in mice, since a reduction of 33-fold in the dose of 15d-PGJ2 has been reported. Mice were treated with 15d-PGJ2-loaded NC, inert NC, free 15d-PGJ2 (without NC), or 15d-PGJ2-loaded NC+ GW9662, a PPAR-γ inhibitor. We show that 15d-PGJ2-loaded NC provided analgesic effect in a dose that the free 15d-PGJ2 failed to inhibiting pain and inflammation. Hence, 15d-PGJ2-loaded NC reduced MSU-induced IL-1ß, TNF-α, IL-6, IL-17, and IL-33 release and oxidative stress. Also, 15d-PGJ2-loaded NC decreased the maturation of IL-1ß in LPS-primed BMDM triggered by MSU. Further, 15d-PGJ2-loaded NC decreased the expression of the components of the inflammasome Nlrp3, Asc, and Pro-caspase-1, as consequence of inhibiting NF-κB activation. All effects were PPAR-γ-sensitive. Therefore, we demonstrated that 15d-PGJ2-loaded NC present analgesic and anti-inflammatory properties in a PPAR-γ-dependent manner inhibiting IL-1ß release and NF-κB activation in GA. Concluding, 15d-PGJ2-loaded NC ameliorates MSU-induced GA in a PPAR-γ-sensitive manner.

A Snake Venom-Secreted Phospholipase A2 Induces Foam Cell Formation Depending on the Activation of Factors Involved in Lipid Homeostasis.

MT-III, a snake venom GIIA sPLA2, which shares structural and functional features with mammalian GIIA sPLA2s, activates macrophage defense functions including lipid droplet (LDs) formation, organelle involved in both lipid metabolism and inflammatory processes. Macrophages (MΦs) loaded with LDs, termed foam cells, characterize early blood vessel fatty-streak lesions during atherosclerosis. However, the factors involved in foam cell formation induced by a GIIA sPLA2 are still unknown. Here, we investigated the participation of lipid homeostasis-related factors in LD formation induced by MT-III in macrophages. We found that MT-III activated PPAR-γ and PPAR-ß/δ and increased the protein levels of both transcription factors and CD36 in macrophages. Pharmacological interventions evidenced that PPAR-γ, PPAR-ß/δ, and CD36 as well as the endoplasmic reticulum enzymes ACAT and DGAT are essential for LD formation. Moreover, PPAR-ß/δ, but not PPAR-γ, is involved in MT-III-induced PLIN2 protein expression, and both PPAR-ß/δ and PPAR-γ upregulated CD36 protein expression, which contributes to MT-III-induced COX-2 expression. Furthermore, production of 15-d-PGJ2, an activator of PPARs, induced by MT-III, was dependent on COX-1 being LDs an important platform for generation of this mediator.

Microneedles enhance topical delivery of 15-deoxy-Δ12,14-prostaglandin J2 and reduce nociception in temporomandibular joint of rats.

The pain arising from temporomandibular disorders is often treated with opioids and agents that inhibit the immune response and are associated with substantial adverse effects and long-term risks. Thus, the development of new therapies that are safer and more effective is of great interest to patients and clinicians. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is naturally produced in the human body and has anti-inflammatory properties. We have previously shown in a rat temporomandibular joint (TMJ) model that injection of 15d-PGJ2 into the rat TMJ can provide antinociceptive relief against a subsequent noxious challenge from formalin injection into the same TMJ. However, intra-TMJ injections are painful. Thus, to make the treatment patient friendly, this study aimed to evaluate whether the antinociceptive property of 15d-PGJ2 cream can be enhanced with microneedles (MNs). We found that topical application of 15d-PGJ2 cream for 15min directly on the rat TMJ skin did not induce any significant antinociceptive effect. However, if MNs were inserted in the skin for 5min, removed, and then 15d-PGJ2 cream was applied, a significant reduction in formalin-induced nociceptive behavior was observed. This reduction in nociception was comparable to an intra-TMJ injection of 15d-PGJ2. A concentration-dependent effect of 15d-PGJ2 was observed, with higher concentrations of 15d-PGJ2 in the cream showing a more durable effect up to 8h. 15d-PGJ2 cream associated with MNs also significantly reduced the release of tumor necrosis factor-α and interleukin-1 beta, which are pro-inflammatory cytokines. Our findings suggest that 15d-PGJ2 cream associated with MNs provides antinociceptive and anti-inflammatory effect, and can offer a potential patient-friendly therapeutic option for pain control related to inflammatory disorders of the TMJ.

A snake venom group IIA PLA2 with immunomodulatory activity induces formation of lipid droplets containing 15-d-PGJ2 in macrophages.

Crotoxin B (CB) is a catalytically active group IIA sPLA2 from Crotalus durissus terrificus snake venom. In contrast to most GIIA sPLA2s, CB exhibits anti-inflammatory effects, including the ability to inhibit leukocyte functions. Lipid droplets (LDs) are lipid-rich organelles associated with inflammation and recognized as a site for the synthesis of inflammatory lipid mediators. Here, the ability of CB to induce formation of LDs and the mechanisms involved in this effect were investigated in isolated macrophages. The profile of CB-induced 15-d-PGJ2 (15-Deoxy-Delta-12,14-prostaglandin J2) production and involvement of LDs in 15-d-PGJ2 biosynthesis were also investigated. Stimulation of murine macrophages with CB induced increased number of LDs and release of 15-d-PGJ2. LDs induced by CB were associated to PLIN2 recruitment and expression and required activation of PKC, PI3K, MEK1/2, JNK, iPLA2 and PLD. Both 15-d-PGJ2 and COX-1 were found in CB-induced LDs indicating that LDs contribute to the inhibitory effects of CB by acting as platform for synthesis of 15-d-PGJ2, a pro-resolving lipid mediator. Together, our data indicate that an immunomodulatory GIIA sPLA2 can directly induce LD formation and production of a pro-resolving mediator in an inflammatory cell and afford new insights into the roles of LDs in resolution of inflammatory processes.

15d-PGJ2 as an endoplasmic reticulum stress manipulator in multiple myeloma in vitro and in vivo.

Multiple myeloma (MM) is characterised by intense protein folding and, consequently endoplasmic reticulum (ER) stress. The prostaglandin 15d-PGJ2 is able to raise oxidative stress levels within the cell and potentially trigger cell death. The aim of this study was to evaluate the antineoplastic effect of 15d-PGJ2 on MM in vitro and in vivo via ER and oxidative stress pathways. MM.1R and MM.1S cell lines were treated with 15d-PGJ2 at 1-10µM and evaluated with regard to proliferation, mRNA expression of PRDX1, PRDX4, GRP78, GRP94, CHOP, BCL-2 and BAX. Stress data was validated via oxidized glutathione assays. MM.1R cells were inoculated into NOD/SCID mice, which were subsequently treated daily with 15d-PGJ2 at 4mg/kg or vehicle (control), with tumour volume being monitored for 14days. 15d-PGJ2 reduced cell proliferation, induced cell death and apoptosis at 5µM and 10µM and Stress-related genes were upregulated at the same doses. Oxidized glutathione levels were also increased. 15d-PGJ2 at 4mg/kg in vivo halted tumour growth. In conclusion, 15d-PGJ2 induced myeloma cell death via ER stress in vitro. 15d-PGJ2 in vivo also inhibited tumour growth.

Therapeutic Treatment of Arthritic Mice with 15-Deoxy Δ12,14-Prostaglandin J2 (15d-PGJ2) Ameliorates Disease through the Suppression of Th17 Cells and the Induction of CD4+CD25-FOXP3+ Cells.

The prostaglandin, 15-deoxy Δ12,14-prostaglandin J2 (15d-PGJ2), is a lipid mediator that plays an important role in the control of chronic inflammatory disease. However, the role of prostanoid in rheumatoid arthritis (RA) is not well determined. We demonstrated the therapeutic effect of 15d-PGJ2 in an experimental model of arthritis. Daily administration of 15d-PGJ2 attenuated the severity of CIA, reducing the clinical score, pain, and edema. 15d-PGJ2 treatment was associated with a marked reduction in joint levels of proinflammatory cytokines. Although the mRNA expression of ROR-γt was profoundly reduced, FOXP3 was enhanced in draining lymph node cells from 15d-PGJ2-treated arthritic mice. The specific and polyclonal CD4+ Th17 cell responses were limited during the addition of prostaglandin to cell culture. Moreover, in vitro 15d-PGJ2 increased the expression of FOXP3, GITR, and CTLA-4 in the CD4+CD25- population, suggesting the induction of Tregs on conventional T cells. Prostanoid addition to CD4+CD25- cells selectively suppressed Th17 differentiation and promoted the enhancement of FOXP3 under polarization conditions. Thus, 15d-PGJ2 ameliorated symptoms of collagen-induced arthritis by regulating Th17 differentiation, concomitant with the induction of Tregs, and, consequently, protected mice from diseases aggravation. Altogether, these results indicate that 15d-PGJ2 may represent a potential therapeutic strategy in RA.

Hepatic injury associated with Trypanosoma cruzi infection is attenuated by treatment with 15-deoxy-Δ12,14 prostaglandin J2.

Trypanosoma cruzi, the etiological agent of Chagas' disease, causes an intense inflammatory response in several tissues, including the liver. Since this organ is central to metabolism, its infection may be reflected in the outcome of the disease. 15-deoxy-Δ12,14 prostaglandin J2 (15dPGJ2), a natural agonist of peroxisome-proliferator activated receptor (PPAR) γ, has been shown to exert anti-inflammatory effects in the heart upon T. cruzi infection. However, its role in the restoration of liver function and reduction of liver inflammation has not been studied yet. BALB/c mice were infected with T. cruzi. The effects of in vivo treatment with 15dPGJ2 on liver inflammation and fibrosis, as well as on the GOT/GPT ratio were studied and the role of NF-κB pathway on 15dPGJ2-mediated effects was analysed. 15dPGJ2 reduced liver inflammatory infiltrates, proinflammatory enzymes and cytokines expression, restored the De Ritis ratio values to normal, reduced the deposits of interstitial and perisinusoidal collagen, reduced the expression of the pro-fibrotic cytokines and inhibited the translocation of the p65 NF-κB subunit to the nucleus. Thus, we showed that 15dPGJ2 is able to significantly reduce the inflammatory response and fibrosis and reduced enzyme markers of liver damage in mice infected with T. cruzi.

15d-PGJ2-Loaded Solid Lipid Nanoparticles: Physicochemical Characterization and Evaluation of Pharmacological Effects on Inflammation.

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, has physiological properties including pronounced anti-inflammatory activity, though it binds strongly to serum albumin. The use of solid lipid nanoparticles (SLN) can improve therapeutic properties increasing drug efficiency and availability. 15d-PGJ2-SLN was therefore developed and investigated in terms of its immunomodulatory potential. 15d-PGJ2-SLN and unloaded SLN were physicochemically characterized and experiments in vivo were performed. Animals were pretreated with 15d-PGJ2-SLN at concentrations of 3, 10 or 30 µg·kg-1 before inflammatory stimulus with carrageenan (Cg), lipopolysaccharide (LPS) or mBSA (immune response). Interleukins (IL-1ß, IL-10 and IL-17) levels were also evaluated in exudates. The 15d-PGJ2-SLN system showed good colloidal parameters and encapsulation efficiency of 96%. The results showed that the formulation was stable for up to 120 days with low hemolytic effects. The 15d-PGJ2-SLN formulation was able to reduce neutrophil migration in three inflammation models tested using low concentrations of 15d-PGJ2. Additionally, 15d-PGJ2-SLN increased IL-10 levels and reduced IL-1ß as well as IL-17 in peritoneal fluid. The new 15d-PGJ2-SLN formulation highlights perspectives of a potent anti-inflammatory system using low concentrations of 15d-PGJ2.

The role of endogenous opioid peptides in the antinociceptive effect of 15-deoxy(Δ12,14)-prostaglandin J2 in the temporomandibular joint.

We have previously demonstrated that peripheral administration of 15d-PGJ2 in the Temporomandibular joint (TMJ) of rats can prevent nociceptor sensitization, mediated by peroxisome proliferator activated receptor-γ (PPAR-γ), and κ- and δ- opioid receptors. However, the mechanism that underlies the signaling of PPAR-γ (upon activation by 15d-PGJ2) to induce antinociception, and how the opioid receptors are activated via 15d-PGJ2 are not fully understood. This study demonstrates that peripheral antinociceptive effect of 15d-PGJ2 is mediated by PPAR-γ expressed in the inflammatory cells of TMJ tissues. Once activated by 15d-PGJ2, PPAR-γ induces the release of ß-endorphin and dynorphin, which activates κ- and δ-opioid receptors in primary sensory neurons to induce the antinociceptive effect.

Selenoprotein Expression in Macrophages Is Critical for Optimal Clearance of Parasitic Helminth Nippostrongylus brasiliensis.

The plasticity of macrophages is evident in helminthic parasite infections, providing protection from inflammation. Previously we demonstrated that the micronutrient selenium induces a phenotypic switch in macrophage activation from a classically activated (pro-inflammatory; M1/CAM) toward an alternatively activated (anti-inflammatory; M2/AAM) phenotype, where cyclooxygenase (COX)-dependent cyclopentenone prostaglandin J2 (15d-PGJ2) plays a key role. Here, we hypothesize that dietary selenium modulates macrophage polarization toward an AAM phenotype to assist in the increasing clearance of adult Nippostrongylus brasiliensis, a gastrointestinal nematode parasite. Mice on a selenium-adequate (0.08 ppm) diet significantly augmented intestinal AAM presence while decreasing adult worms and fecal egg production when compared with infection of mice on selenium-deficient (<0.01 ppm) diet. Further increase in dietary selenium to supraphysiological levels (0.4 ppm) had very little or no impact on worm expulsion. Normal adult worm clearance and enhanced AAM marker expression were observed in the selenium-supplemented Trsp(fl/fl)Cre(WT) mice that express selenoproteins driven by tRNA(Sec) (Trsp), whereas N. brasiliensis-infected Trsp(fl/fl)Cre(LysM) selenium-supplemented mice showed a decreased clearance, with lowered intestinal expression of several AAM markers. Inhibition of the COX pathway with indomethacin resulted in delayed worm expulsion in selenium-adequate mice. This was rescued with 15d-PGJ2, which partially recapitulated the effect of selenium supplementation on fecal egg output in addition to increasing markers of AAMs in the small intestine. Antagonism of PPARγ blocked the effect of selenium. These results suggest that optimal expression of selenoproteins and selenium-dependent production of COX-derived endogenous prostanoids, such as Δ(12)-PGJ2 and 15d-PGJ2, may regulate AAM activation to enhance anti-helminthic parasite responses.

15-Deoxy-prostaglandin J2 anti-inflammation in a rat model of chronic obstructive pulmonary disease and human bronchial epithelial cells via Nrf2 activation.

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates antioxidant and anti-inflammatory genes, and it plays a crucial role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Moreover, 15-deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) plays a protective role against oxidative stress and inflammation both in vivo and in vitro. In a previous study, we found that 15d-PGJ2 increased the expression of Nrf2 in a COPD rat model. This study aims to elucidate the role of 15d-PGJ2 in COPD pathogenesis and the relationship between Nrf2 and human bronchial epithelial (HBE) cells. Normal HBE (HBE) cells were cultured. Following cigarette smoke extract (CSE) stimulation, pre-incubation with or without small interfering RNA (siRNA) Nrf2, and stimulation with or without 15d-PGJ2, the expression levels of Nrf2, NF-κBp65, and IL-8 were detected by reverse transcription-polymerase chain reaction and western blot, respectively. The expression of NF-κBp65 and IL-8 in CSE-stimulated normal HBE cells was inhibited by 15d-PGJ2 at both the mRNA level and the protein level. Moreover, the expression of Nrf2 in normal HBE cells was improved by 15d-PGJ2 at both the mRNA level and the protein level. However, the inhibitory or improving effects of 15d-PGJ2 were disengaged by siRNA Nrf2 at both the mRNA level and the protein level. 15d-PGJ2 possesses anti-inflammatory properties in the pathogenesis of COPD, and HBE cells stimulated by CSE via Nrf2 activation.

Treatment in vitro with PPARα and PPARγ ligands drives M1-to-M2 polarization of macrophages from T. cruzi-infected mice.

Trypanosoma cruzi, the etiological agent of Chagas' disease, induces a persistent inflammatory response. Macrophages are a first line cell phenotype involved in the clearance of infection. Upon parasite uptake, these cells increase inflammatory mediators like NO, TNF-α, IL-1ß and IL-6, leading to parasite killing. Although desired, inflammatory response perpetuation and exacerbation may lead to tissue damage. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent nuclear transcription factors that, besides regulating lipid and carbohydrate metabolism, have a significant anti-inflammatory effect. This is mediated through the interaction of the receptors with their ligands. PPARγ, one of the PPAR isoforms, has been implicated in macrophage polarization from M1, the classically activated phenotype, to M2, the alternatively activated phenotype, in different models of metabolic disorders and infection. In this study, we show for the first time that, besides PPARγ, PPARα is also involved in the in vitro polarization of macrophages isolated from T. cruzi-infected mice. Polarization was evidenced by a decrease in the expression of NOS2 and proinflammatory cytokines and the increase in M2 markers like Arginase I, Ym1, mannose receptor and TGF-ß. Besides, macrophage phagocytic activity was significantly enhanced, leading to increased parasite load. We suggest that modulation of the inflammatory response by both PPARs might be due, at least in part, to a change in the profile of inflammatory macrophages. The potential use of PPAR agonists as modulators of overt inflammatory response during the course of Chagas' disease deserves further investigation.