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.

Asiatic acid prevents renal fibrosis in UUO rats via promoting the production of 15d-PGJ2, an endogenous ligand of PPAR-γ.

Renal fibrosis is an inevitable outcome of all kinds of progressive chronic kidney disease (CKD). Recently, asiatic acid (AA), a triterpenoid compound from Chinese medicine Centella asiatica, has been found to attenuate renal fibrosis. In the current study, we explored the mechanisms underlying antifibrotic effect of AA on UUO model. SD rats and ICR mice were subjected to unilateral ureteral occlusion (UUO) surgery. Prior the surgery, rats were administered AA (10 mg·kg-1 per day, ig) for 7 days, whereas the mice received AA (15 mg·kg-1 per day, ig) for 3 days. UUO group displayed significant degree of renal dysfunction, interstitial fibrosis, oxidative stress, and activation of the TGF-ß/Smad and Wnt/ß-catenin signaling pathway in the kidney, these pathological changes were greatly ameliorated by pretreatment with AA. In addition, we found that co-treatment with GW9662, a selective PPAR-γ antagonist (1 mg·kg-1 per day, ip) for 7 days, abolished the protective effects of AA. We further revealed that AA pretreatment did not significantly change the expression levels of PPAR-γ in the kidney, but markedly increase the plasma levels of 15d-PGJ2, an endogenous ligand of PPAR-γ. In UUO mice, pretreatment with 15d-PGJ2 (24 µg·kg-1 per day, ip, for 7 days) produced similar protective effect as AA. Moreover, AA pretreatment upregulated the expression levels of active, nuclear-localized SREBP-1 (nSREBP-1), whereas fatostatin, a specific inhibitor of SREBP-1, decreased the expression of nSREBP-1, as well as the level of 15d-PGJ2. These results provide new insight into the antifibrotic mechanism of AA and endogenous metabolites might become a new clue for investigation of drug mechanism.

15-Deoxy-Δ12,14-prostaglandin J2 ameliorates dextran sulfate sodium-induced colitis in mice through heme oxygenase-1 induction.

The prostaglandin D2 metabolite, 15-deoxy-Δ12,14-Prostaglandin J2 (15d-PGJ2), exerts an anti-inflammatory effect through peroxisome proliferator-activated receptor γ (PPARγ)-dependent and -independent anti-inflammatory actions. In the present study, we focused on heme oxygenase-1 (HO-1) induced by 15d-PGJ2, and evaluated the effects of enema treatment with 15d-PGJ2 in the development of intestinal inflammation using a murine colitis model. Acute colitis was induced with dextran sulfate sodium (DSS) in male C57BL/6 mice (8 weeks old) and NF-E2-related factor-2 (Nrf2) deficient mice. Mice were rectally administered 15d-PGJ2 (1 µM, 0.2 mL: 66.9 ng) daily during DSS administration. Intestinal expression of HO-1 mRNA and protein after rectal administration of 15d-PGJ2 was evaluated by real-time PCR and western blotting, respectively. A disease activity index (DAI) was determined on a daily basis for each animal, and consisted of a calculated score based on changes in body weight, stool consistency, and intestinal bleeding. Tissue-associated myeloperoxidase (MPO) activity as an index of neutrophil infiltration and mRNA expression levels of TNF-α, IFN-γ, and IL-17A were measured in the colonic mucosa. In addition, we evaluated the effects of co-treatment with a HO-1 inhibitor, zinc protoporphyrin IX (ZnPP), or a specific PPARγ antagonist, GW9662. As a result, rectal administration of 15d-PGJ2 markedly induced HO-1 protein and mRNA expression in the colonic mucosa. Treatment with 15d-PGJ2 ameliorated the increase in DAI score and MPO activity and the mRNA expression levels of TNF-α, IFN-γ, and IL-17A after DSS administration. These effects of 15d-PGJ2 against intestinal inflammation were negated by co-treatment with ZnPP, but not with GW9662. In Nrf2 deficient mice, the rectal administration of 15d-PGJ2 did not affect colonic HO-1 expression and activity of DSS-induced colitis. These results demonstrate that 15d-PGJ2 inhibits development of intestinal inflammation in mice via PPAR-independent and Nrf2-HO-1-dependent mechanisms.

Physiological response to central and peripheral injection of prostaglandin D2 in chicks.

Prostaglandin D2 (PGD2) is associated with a diverse array of functions in mammals including regulation of appetite, body temperature, sleep, and immune responses. Although much is known about the effects of PGD2 in mammals, there is a lack of information about its effects in birds. Therefore, the purpose of the present study was to determine if intracerebroventricular (ICV) and intraperitoneal (IP) injections of PGD2 affect feeding, voluntary movement, crop-emptying rate, corticosterone release, and cloacal temperature in chicks (Gallus gallus). ICV injection of PGD2 was associated with a reduction in food intake, a reduction in voluntary movement, an increase in the time spent sitting, a decline in crop emptying rate, and also short-term hypothermia. Central injection of PGD2 also decreased the plasma glucose concentration in chicks while it tended to increase the plasma corticosterone concentration. On the other hand, except for crop emptying, such physiological changes are not observed after IP injection of PGD2. In sum, the present study suggests that PGD2 induces anorexia, change in behavior, decline in crop empting rate, hypoglycemia and hypothermia, but most of these effects are exerted via central nervous system in chicks.

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.

15-Deoxy-Δ12,14-Prostaglandin J2 Exerts Proresolving Effects Through Nuclear Factor E2-Related Factor 2-Induced Expression of CD36 and Heme Oxygenase-1.

AIMS: 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has been shown to rescue cells from inflammatory insults and to participate in the resolution of acute inflammation. In this study, we investigated molecular mechanisms underlying proresolving effects of 15d-PGJ2. RESULTS: 15d-PGJ2 injected into the peritoneum of mice facilitated the resolution of zymosan A-induced peritonitis. 15d-PGJ2 administration reduced the number of total leukocytes and attenuated polymorphonuclear leukocyte infiltration. Furthermore, 15d-PGJ2 increased the proportion of macrophages engulfing apoptotic neutrophils, a process called efferocytosis. In addition, when the thioglycollate-elicited mouse peritoneal macrophages were stimulated with 15d-PGJ2, their efferocytic activity was amplified. In another experiment, RAW264.7 murine macrophages exposed to 15d-PGJ2 conducted phagocytic clearance of apoptotic cells to a greater extent than the control cells. Under these conditions, expression of CD36 and heme oxygenase-1 (HO-1) was enhanced along with increased accumulation of the nuclear factor E2-related factor 2 (Nrf2) in the nucleus. Knockdown of Nrf2 abolished 15d-PGJ2-induced expression of CD36 and HO-1, and silencing of CD36 and HO-1 attenuated 15d-PGJ2-induced efferocytosis. Moreover, peritoneal macrophages isolated from Nrf2-null mice failed to upregulate 15d-PGJ2-induced expression of CD36 and HO-1 and to mediate efferocytosis. Unlike 15d-PGJ2, its nonelectrophilic analog 9,10-dihydro-15d-PGJ2 lacking the α,ß-unsaturated carbonyl group could not induce CD36 expression and efferocytosis. INNOVATION: 15d-PGJ2, as one of the terminal products of cyclooxygenase-2, exerts proresolving effects through induction of efferocytosis. The results of this study suggest that 15d-PGJ2 possesses a therapeutic value in the management of inflammatory disorders. CONCLUSION: 15d-PGJ2 facilitates resolution of inflammation by inducing Nrf2-induced expression of CD36 and HO-1 in macrophages. Antioxid. Redox Signal. 27, 1412-1431.

Synthesis and Evaluation of the Novel Prostamide, 15-Deoxy, Δ12,14-Prostamide J2, as a Selective Antitumor Therapeutic.

15-deoxy, Δ12,14-prostaglandin J2-ethanolamide, also known as 15-deoxy, Δ12,14-prostamide J2 (15d-PMJ2) is a novel product of the metabolism of arachidonoyl ethanolamide (AEA) by COX-2. 15d-PMJ2 preferentially induced cell death and apoptosis in tumorigenic A431 keratinocytes and B16F10 melanoma cells compared with nontumorigenic HaCaT keratinocytes and Melan-A melanocytes. Activation of the ER stress execution proteins, PERK and CHOP10, was evaluated to determine whether this process was involved in 15d-PMJ2 cell death. 15d-PMJ2 increased the phosphorylation of PERK and expression of CHOP10 in tumorigenic but not nontumorigenic cells. The known ER stress inhibitors, salubrinal and 4-phenylbutaric acid, significantly inhibited 15d-PMJ2-mediated apoptosis, suggesting ER stress as a primary apoptotic mediator. Furthermore, the reactive double bond present within the cyclopentenone structure of 15d-PMJ2 was identified as a required moiety for the induction of ER stress apoptosis. The effect of 15d-PMJ2 on B16F10 melanoma growth was also evaluated by dosing C57BL/6 mice with 0.5 mg/kg 15d-PMJ2 Tumors of animals treated with 15d-PMJ2 exhibited significantly reduced growth and mean weights compared with vehicle and untreated animals. TUNEL and IHC analysis of tumor tissues showed significant cell death and ER stress in tumors of 15d-PMJ2-treated compared with control group animals. Taken together, these findings suggest that the novel prostamide, 15d-PMJ2, possesses potent antitumor activity in vitro and in vivoMol Cancer Ther; 16(5); 838-49. ©2017 AACR.

15-Deoxy-Δ12,14-prostaglandin J2 alleviates hepatic ischemia-reperfusion injury in mice via inducing antioxidant response and inhibiting apoptosis and autophagy.

Hepatic ischemia-reperfusion (I/R) injury is a common clinical impairment that occurs in many circumstances and leads to poor prognosis. Both apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is one of the best-studied anti-inflammatory prostaglandins, which has been verified to exert anti-inflammatory and cell-protective functions in various types of cells and animal models. In this study we explored the effects of 15d-PGJ2 on both apoptosis and autophagy in mouse hepatic I/R injury and its possible mechanisms. A model of segmental (70%) hepatic warm ischemia was established in Balb/c mice, and the pathological changes in serum and liver tissues were detected at 6, 12, and 24 h post-surgery, while 15d-PGJ2 (2.5, 7.5, 15 µg, iv) was administered 30 min prior the surgery. Pretreatment with 15d-PGJ2 (7.5, 15 µg) significantly ameliorated I/R-induced hepatic injury evidenced by dose-dependent reduction of serum ALT and AST levels as well as alleviated tissue damages. 15d-PGJ2 pretreatment significantly decreased the serum TNF-α and IL-1ß levels and the hepatic expression of F4/80, a major biomarker of macrophages. 15d-PGJ2 pretreatment upregulated the Bcl-2/Bax ratio, thus reducing the number of apoptotic cells in the livers. 15d-PGJ2 pretreatment considerably suppressed the expression of Beclin-1 and LC3, thus decreasing the number of autophagosomes in the livers. Furthermore, 15d-PGJ2 pretreatment activated Nrf2 and inhibited a ROS/HIF1α/BNIP3 pathway in the livers. Pretreatment with the PPARγ receptor blocker GW9662 (2 µg, ip) partly reversed the protective effects of 15d-PGJ2 on hepatic I/R injury. In conclusion, our results confirm the protective effect of 15d-PGJ2 on hepatic I/R injury, an effect that may rely on a reduction in the activation of Kupffer cells and on activation of the Nrf2 pathway, which lead to inhibition of ROS generation, apoptosis, and autophagy.

Adenosine A2A receptor deficiency attenuates the somnogenic effect of prostaglandin D2 in mice.

Prostaglandin D2 (PGD2) is one of the most potent endogenous sleep promoting substances. PGD2 activates the PGD2 receptor (DPR) and increases the extracellular level of adenosine in wild-type (WT) mice but not DPR knockout (KO) mice, suggesting that PGD2-induced sleep is DPR-dependent, and adenosine may be the signaling molecule that mediates the somnogenic effect of PGD2. The aim of this study was to determine the involvement of the adenosine A2A receptor (A2AR) in PGD2-induced sleep. We infused PGD2 into the lateral ventricle of WT and A2AR KO mice between 20:00 and 2:00 for 6 h, and electroencephalograms and electromyograms were simultaneously recorded. In WT mice, PGD2 infusion dose-dependently increased non-rapid eye movement (non-REM, NREM) sleep, which was 139.1%, 145.0% and 202.7% as large as that of vehicle-treated mice at doses of 10, 20 and 50 pmol/min, respectively. PGD2 infusion at doses of 20 and 50 pmol/min also increased REM sleep during the 6-h PGD2 infusion and 4-h post-dosing periods in WT mice to 148.9% and 166.7%, respectively. In A2AR KO mice, however, PGD2 infusion at 10 pmol/min did not change the sleep profile, whereas higher doses at 20 and 50 pmol/min increased the NREM sleep during the 6-h PGD2 infusion to 117.5% and 155.6%, respectively, but did not change the sleep in the post-dosing period. Moreover, PGD2 infusion at 50 pmol/min significantly increased the episode number in both genotypes but only enhanced the episode duration in WT mice. The results demonstrate that PGD2-induced sleep in mice is mediated by both adenosine A2AR-dependent and -independent systems.

15-Deoxy-Δ12,14-prostaglandin J2 induced neurotoxicity via suppressing phosphoinositide 3-kinase.

15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) induces neuronal cell death via apoptosis independently of its receptors. 15d-PGJ2 inhibits growth factor-induced cell proliferation of primary astrocytes via down-regulating phosphoinositide 3-kinase (PI3K)-Akt pathway. Although 15d-PGJ2-reduced cell viability is accompanied with attenuation of the PI3K signaling in neuroblastoma, it has not been sufficiently clarified how 15d-PGJ2 induces cell death in primary neurons. Here, we found that 15d-PGJ2 exhibited neurotoxicity via inhibiting the PI3K signaling in the primary culture of rat cortical neurons. A PI3K inhibitor induced neuronal cell death regardless serum throughout maturation, confirming that PI3K is required for neuronal cell survival. The inhibitor disrupted neuronal cell bodies, shortened neurites thinly, damaged plasma membranes and activated caspase-3 similarly to 15d-PGJ2. Little additive or synergistic neurotoxicity was detected between 15d-PGJ2 and the PI3K inhibitor. A PI3K activator prevented neurons from undergoing the 15d-PGJ2-induced cell death in vitro. In vivo, the PI3K signaling is required for contextual memory retrieval, which was impaired by bilateral injection of 15d-PGJ2 into hippocampus. The activator suppressed the 15d-PGJ2-impaired memory retrieval significantly. In neurons as well as primary astrocytes and neuroblastomas, 15d-PGJ2 exhibited cytotoxicity via suppressing the PI3K-Akt pathway in vivo and in vitro.

Targeting arachidonic acid pathway to prevent programmed hypertension in maternal fructose-fed male adult rat offspring.

Hypertension can be programmed in response to nutritional insults in early life. Maternal high-fructose (HF) intake induced programmed hypertension in adult male offspring, which is associated with renal programming and arachidonic acid metabolism pathway. We examined whether early treatment with a soluble epoxide hydrolase (SEH) inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) or 15-Deoxy-Δ12,14-prostagandin J2 (15dPGJ2) can prevent HF-induced programmed hypertension. Pregnant Sprague Dawley rats received regular chow or chow supplemented with fructose (60% diet by weight) during the whole period of pregnancy and lactation. Four groups of male offspring were studied: control, HF, HF+AUDA and HF+15dPGJ2. In HF+AUDA group, mother rats received AUDA 25 mg/L in drinking water during lactation. In the HF+15dPGJ2 group, male offspring received 15dPGJ2 1.5 mg/kg body weight by subcutaneous injection once daily for 1 week after birth. Rats were sacrificed at 12 weeks of age. Maternal HF-induced programmed hypertension is associated with increased renal protein level of SEH and oxidative stress, which early AUDA therapy prevents. Comparison of AUDA and 15dPGJ2 treatments demonstrated that AUDA was more effective in preventing HF-induced programmed hypertension. AUDA therapy increases angiotensin converting enzyme-2 (ACE2) protein levels and PGE2 levels in adult offspring kidney exposed to maternal HF. 15dPGJ2 therapy increases plasma asymmetric dimethylarginine (ADMA) levels and decreases L-arginine-to-ADMA ratio. Better understanding of the impact of arachidonic acid pathway, especially inhibition of SEH, on renal programming may aid in developing reprogramming strategy to prevent programmed hypertension in children exposed to antenatal HF intake.

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.

Elimination of the biphasic pharmacodynamics of 15d-PGJ2 by controlling its release from a nanoemulsion.

15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has a dual action of stimulating anti-inflammation and anti-proliferation when exogenously administered at high doses. However, at lower doses, it can be toxic inducing opposite actions, ie, stimulation of both inflammation and cell proliferation. This biphasic phenomenon of 15d-PGJ2 is believed to be due to its multitarget behavior. In this study, we provide a strategy for controlling such biphasic pharmacodynamics by separating its dual actions while retaining the beneficial one by using a nanoemulsion (NE). The 15d-PGJ2 was encapsulated in the NE composed of triolein/distearoyl phosphatidylcholine/Tween 80 at a high encapsulation ratio (>83%). Furthermore, NE enhanced drug retention by slowing down its release rate, which was, unconventionally, inversely dependent on the total surface area of the NE system. Next, focusing on the biphasic effect on cell proliferation, we found that the 15d-PGJ2-loaded slow-release NE showed only a dose-dependent inhibition of the viability of a mouse macrophage cell line, RAW264.7, although a fast-release NE as well as free 15d-PGJ2 exerted a biphasic effect. The observed slow-release kinetics are believed to be responsible for elimination of the biphasic pharmacodynamics of 15d-PGJ2 mainly for two reasons: 1) a high proportion of 15d-PGJ2 that is retained in the NE was delivered to the cytosol, where proapoptotic targets are located and 2) 15d-PGJ2 was able to bypass cell membrane-associated targets that lead to the induction of cellular proliferation. Collectively, our strategy of eliminating the 15d-PGJ2-induced biphasic pharmacodynamics was based on the delivery of 15d-PGJ2 to its desired site of action, excluding undesired sites, on a subcellular level.

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.

Early postnatal treatment with soluble epoxide hydrolase inhibitor or 15-deoxy-Δ(12,14)-prostagandin J2 prevents prenatal dexamethasone and postnatal high saturated fat diet induced programmed hypertension in adult rat offspring.

Prenatal dexamethasone (DEX) exposure, postnatal high-fat (HF) intake, and arachidonic acid pathway are closely related to hypertension. We tested whether a soluble epoxide hydrolase (SEH) inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) or 15-deoxy-Δ(12,14)-prostagandin J2 (15dPGJ2) therapy can rescue programmed hypertension in the DEX+HF two-hit model. Four groups of Sprague Dawley rats were studied: control, DEX+HF, AUDA, and 15dPGJ2. Dexamethasone (0.1mg/kg body weight) was intraperitoneally administered to pregnant rats from gestational day 16-22. Male offspring received high-fat diet (D12331, Research Diets) from weaning to 4 months of age. In AUDA group, mother rats received 25mg/L in drinking water during lactation. In the 15dPGJ2 group, male offspring received 15dPGJ2 1.5mg/kg BW by subcutaneous injection once daily for 1 week after birth. We found postnatal HF diet aggravated prenatal DEX-induced programmed hypertension, which was similarly prevented by early treatment with AUDA or 15dPGJ2. The beneficial effects of AUDA and 15d-PGJ2 therapy include inhibition of SEH, increases of renal angiotensin converting enzyme-2 (ACE2) and angiotensin II type 2 receptor (AT2R) protein levels, and restoration of nitric oxide bioavailability. Better understanding of the impact of arachidonic acid pathway in the two-hit model will help prevent programmed hypertension in children exposed to corticosteroids and postnatal HF intake.

Bone-marrow-derived mesenchymal stem cells inhibit gastric aspiration lung injury and inflammation in rats.

Gastric aspiration lung injury is one of the most common clinical events. This study investigated the effects of bone-marrow-derived mesenchymal stem cells (BMSCs) on combined acid plus small non-acidified particle (CASP)-induced aspiration lung injury. Enhanced green fluorescent protein (EGFP(+) ) or EGFP(-) BMSCs or 15d-PGJ2 were injected via the tail vein into rats immediately after CASP-induced aspiration lung injury. Pathological changes in lung tissues, blood gas analysis, the wet/dry weight ratio (W/D) of the lung, levels of total proteins and number of total cells and neutrophils in bronchoalveolar lavage fluid (BALF) were determined. The cytokine levels were measured using ELISA. Protein expression was determined by Western blot. Bone-marrow-derived mesenchymal stem cells treatment significantly reduced alveolar oedema, exudation and lung inflammation; increased the arterial partial pressure of oxygen; and decreased the W/D of the lung, the levels of total proteins and the number of total cells and neutrophils in BALF in the rats with CASP-induced lung injury. Bone-marrow-derived mesenchymal stem cells treatment decreased the levels of tumour necrosis factor-α and Cytokine-induced neutrophil chemoattractant (CINC)-1 and the expression of p-p65 and increased the levels of interleukin-10 and 15d-PGJ2 and the expression of peroxisome proliferator-activated receptor (PPAR)-γ in the lung tissue in CASP-induced rats. Tumour necrosis factor-α stimulated BMSCs to secrete 15d-PGJ2 . A tracking experiment showed that EGFP(+) BMSCs were able to migrate to local lung tissues. Treatment with 15d-PGJ2 also significantly inhibited CASP-induced lung inflammation and the production of pro-inflammatory cytokines. Our results show that BMSCs can protect lung tissues from gastric aspiration injury and inhibit lung inflammation in rats. A beneficial effect might be achieved through BMSC-derived 15d-PGJ2 activation of the PPAR-γ receptor, reducing the production of proinflammatory cytokines.

Prostaglandin D2 elicits the reversible neurite retraction in hypothalamic cell line.

Prostaglandins (PGs) play important roles in diverse physiological processes in the central nervous system. PGD2 is the most abundant PG in the brain and acts through specific receptors, DP1 and CRTH2. We investigated the effects of PGD2 on the morphology of the hypothalamic cell line mHypoE-N37 (N37). In N37 cells, serum starvation induced neurite outgrowth and PGD2 elicited neurite retraction, although we failed to detect transcripts for DP1 and CRTH2. Such an effect of PGD2 was efficiently mimicked by its metabolite, 15-deoxy-Δ(12,14)-prostaglandin J2. N-acetyl cysteine completely abolished the effect of PGD2, and reactive oxygen species (ROS) were considered to be important. Notably, neurite outgrowth was restored by PGD2 removal. These results suggest that PGD2 induces reversible neurite retraction in a ROS-mediated mechanism that does not involve any known receptor.

The responses of pulmonary and systemic circulation and airway to anaphylactic mediators in anesthetized BALB/c mice.

AIMS: Anaphylactic shock sometimes accompanies pulmonary vaso- and broncho-constriction. We previously reported the hemodynamic features of mouse anaphylaxis (Life Sci. 2014; 116: 98-105). However, the effects of anaphylactic chemical mediators on the hemodynamics of in vivo mice are not well known. Furthermore, it is uncertain whether the mediators exert the same directional actions. Therefore, we determined their effects systematically on total peripheral resistance (TPR), pulmonary vascular resistance (PVR), or airway pressure (AWP) in anesthetized mice. MAIN METHODS: We measured directly pulmonary arterial pressure, left atrial pressure, systemic arterial pressure, central venous pressure and aortic blood flow to determine PVR and TPR, as well as AWP, following injections of platelet-activating factor (PAF), histamine, serotonin, leukotriene (LT) C4, and prostaglandin (PG) D2 in anesthetized open-chest artificially ventilated BALB/c mice. KEY FINDINGS: Consecutive administration of any agents increased PVR dose-dependently with the maximal responsiveness being PAF>LTC4>serotonin>>histamine=PGD2. Histamine caused a biphasic PVR response, an initial decrease, which was abolished by L-NAME, followed by an increase at high doses. PAF, serotonin, and histamine decreased TPR dose-dependently, while LTC4 or PGD2 yielded an increase or no change in TPR, respectively. Serotonin, but not the other agents, increased AWP. SIGNIFICANCE: Anaphylactic mediators exert non-uniform actions on the pulmonary and systemic circulation and airway in anesthetized BALB/c mice: PAF, LTC4 and serotonin cause substantial pulmonary vasoconstriction, while histamine biphasic responses of the initial nitric oxide dependent vasodilation followed by vasoconstriction; PAF, serotonin, and histamine, but not LTC4 or PGD2, evoke systemic vasodilatation; only serotonin induces airway constriction.

Prostaglandin D2-loaded microspheres effectively activate macrophage effector functions.

Biodegradable lactic-co-glycolic acid (PLGA) microspheres (MS) improve the stability of biomolecules stability and allow enable their sustained release. Lipid mediators represent a strategy for improving host defense; however, most of these mediators, such as prostaglandin D2 (PGD2), have low water solubility and are unstable. The present study aimed to develop and characterize MS loaded with PGD2 (PGD2-MS) to obtain an innovative tool to activate macrophages. PGD2-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process, and the size, zeta potential, surface morphology and encapsulation efficiency were determined. It was also evaluated in vitro the phagocytic index, NF-κB activation, as well as nitric oxide and cytokine production by alveolar macrophages (AMs) in response to PGD2-MS. PGD2-MS were spherical with a diameter of 5.0±3.3 µm and regular surface, zeta potential of -13.4±5.6 mV, and 36% of encapsulation efficiency, with 16-26% release of entrapped PGD2 at 4 and 48 h, respectively. PGD2-MS were more efficiently internalized by AMs than unloaded-MS, and activated NF-κB more than free PGD2. Moreover, PGD2-MS stimulated the production of nitric oxide, TNF-α, IL-1ß, and TGF-ß, more than free PGD2, indicating that microencapsulation increased the activating effect of PGD2 on cells. In LPS-pre-treated AMs, PGD2-MS decreased the release of IL-6 but increased the production of nitric oxide and IL-1ß. These results show that the morphological characteristics of PGD2-MS facilitated interaction with, and activation of phagocytic cells; moreover, PGD2-MS retained the biological activities of PGD2 to trigger effector mechanisms in AMs. It is suggested that PGD2-MS represent a strategy for therapeutic intervention in the lungs of immunocompromised subjects.

Dihomo-γ-linolenic acid prevents the development of atopic dermatitis through prostaglandin D1 production in NC/Tnd mice.

BACKGROUND: Atopic dermatitis (AD) is a chronic and relapsing skin disorder with pruritic skin symptoms. We previously reported that dihomo-γ-linolenic acid (DGLA) prevented the development of AD in NC/Tnd mice, though the mechanism remained unclear. OBJECTIVE: We attempted to investigate the mechanism of preventive effect of DGLA on AD development in NC/Tnd mice. METHODS: The clinical outcomes of NC/Tnd mice that were given diets containing DGLA, arachidonic acid, or eicosapentaenoic acid were compared. Lipid mediator contents in the skin in each group were also quantified. In addition, release of lipid mediators from RBL-2H3 mast cells treated with either DGLA or prostaglandin D1 (PGD1) was measured. Furthermore, effect of PGD1 on gene expression of thymic stromal lymphopoietin (TSLP) in PAM212 keratinocyte cells was determined. RESULTS: Only DGLA containing diet suppressed the development of dermatitis in vivo. By quantifying the 20-carbon fatty acid-derived eicosanoids in the skin, the application of DGLA was found to upregulate PGD1, which correlated with a better outcome in NC/Tnd mice. Moreover, we confirmed that mast cells produced PGD1 after DGLA exposure, thereby exerting a suppressive effect on immunoglobulin E-mediated degranulation. PGD1 also suppressed gene expression of TSLP in keratinocytes. CONCLUSION: These results suggest that oral administration of DGLA causes preventive effects on AD development in NC/Tnd mice by regulating the PGD1 supply.