Increased Prostaglandin E2 Levels Research Articles

Role of lipid droplets and prostaglandinE2 in Coxiella burnetii intracellular growth.

Abstract The obligate intracellular bacterium, Coxiella burnetii, causes human Q fever. Infection with Coxiella via inhalation presents as atypical pneumonia which may relapse years later, leading to potentially fatal endocarditis. Our goal is to determine the mechanisms Coxiella employs for long-term survival in the host. While the bacterium initially infects alveolar macrophages, in endocarditis patients Coxiella is found in foamy macrophages rich in neutral lipid storage organelles, lipid droplets (LDs). Our studies show that blocking LD breakdown inhibits bacterial growth suggesting that LD-derived lipids are crucial for Coxiella’s survival. LD breakdown releases arachidonic acids, precursors for the lipid immune mediator prostaglandinE2 (PGE2) which promotes immunosuppression in alveolar macrophages. We hypothesize that Coxiella manipulates host cell LD metabolism to promote a PGE2-mediated immunosuppressive environment and survive long-term in the host. To test this, we quantified PGE2 production in Coxiella-infected cells with and without LD breakdown inhibitor, atglistatin. ELISA showed a LD breakdown-dependent increase in PGE2 levels. Fluorescence microscopy revealed PGE2 production blockade with COX-2 inhibitors significantly decreased bacterial growth which was rescued by exogenous PGE2 suggesting that PGE2 promotes Coxiella survival. Ongoing studies are identifying the correlation between LDs and PGE2 production and the role of LDs in immunosuppression.

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

A monocentric, randomized, double-blind, controlled crossover trial of nasturtium (Tropaeolum majus) on the lipid regulator prostaglandin E2.

As prostaglandin E2 (PGE2) has important roles in physiological and inflammatory functions, a double-blind randomized controlled crossover study to investigate the potential of nasturtium (Tropaeolum majus) for modulating PGE2 was conducted, aiming at clarifying the role of benzyl isothiocyanate (BITC). As secondary parameters leukotriene 4 (LTB4), and cytokine release (tumor necrosis factor alpha, TNF-α; interleukins IL-1β, IL-10, and IL-12) were quantified. Thirty-four healthy female participants consumed 1.5 g nasturtium containing BITC, (verum) or no BITC (control) twice a day for 2 weeks each. Nasturtium intervention resulted in an increase in mean PGE2 levels in serum samples (verum: 1.76-fold, p ≤ 0.05; control: 1.78-fold, p ≤ 0.01), and ex vivo stimulated peripheral blood mononuclear cells (PBMC) (verum: 1.71-fold, p ≤ 0.01; control: 1.43-fold). Using a pre-to-post responder analysis approach, 18 of 34 subjects showed a > 25% PGE2 increase in serum, while it was >25% decreased for 9 subjects (stimulated PBMC: 14 and 8 of 28, respectively). Under the selected conditions, the BITC content of nasturtium did not affect the observed changes in PGE2. Verum intervention also increased mean LTB4 serum level (1.24-fold, p ≤ 0.01), but not in LPS stimulated PBMC, and significantly increased TNF-α release in stimulated PBMC after 3 h (verum: 1.65-fold, p = 0.0032; control: 1.22-fold, p = 0.7818). No change was seen in the anti-inflammatory cytokine IL-10, or the pro-inflammatory cytokines IL-1β, and IL-12. In contrast to the previously reported in vitro results, on average, LPS activated PBMC and serum from both groups showed increased PGE2 levels. Further analyses suggest that PGE2 release after intervention could possibly depend on the baseline PGE2 level. Identification of phenotypes that respond differently to the nasturtium intervention could be useful to establish personalized approaches for dosing phytopharmaceuticals medicines.

Tailored PGE2 Immunomodulation of moDCs by Nano-Encapsulated EP2/EP4 Antagonists.

Prostaglandin E2 (PGE2) is an important maturation mediator for dendritic cells (DCs). However, increased PGE2 levels in the tumor exert immunosuppressive effects on DCs by signaling through two E-Prostanoid (EP) receptors: EP2 and EP4. Blocking EP-receptor signaling of PGE2 with antagonists is currently being investigated for clinical applications to enhance anti-tumor immunity. In this study, we investigated a new delivery approach by encapsulating EP2/EP4 antagonists in polymeric nanoparticles. The nanoparticles were characterized for size, antagonist loading, and release. The efficacy of the encapsulated antagonists to block PGE2 signaling was analyzed using monocyte-derived DCs (moDCs). The obtained nanoparticles were sized between 210 and 260 nm. The encapsulation efficacy of the EP2/EP4 antagonists was 20% and 17%, respectively, and was further increased with the co-encapsulation of both antagonists. The treatment of moDCs with co-encapsulation EP2/EP4 antagonists prevented PGE2-induced co-stimulatory marker expression. Even though both antagonists showed a burst release within 15 min at 37 °C, the nanoparticles executed the immunomodulatory effects on moDCs. In summary, we demonstrate the functionality of EP2/EP4 antagonist-loaded nanoparticles to overcome PGE2 modulation of moDCs.

PGE2 pathway mediates oxidative stress-induced ferroptosis in renal tubular epithelial cells.

Prostaglandin E2 (PGE2) is one of the most abundant prostaglandins and has been implicated in various diseases. Here, we aimed to explore the role of the PGE2 pathway in mediating ferroptosis during acute kidney injury. When renal tubular epithelial cells stimulated by H2 O2 , the contents of glutathione (GSH) and glutathione peroxidase 4 (GPX4) decreased, whereas the level of lipid peroxide increased. Ferrostatin-1 can effectively attenuate these changes. In this process, the expression levels of cyclooxygenase (COX)-1 and COX-2 were up-regulated. Meanwhile, the expression of microsomal prostaglandin E synthase-2 was elevated, whereas the expression of microsomal prostaglandin E synthase-1 and cytosolic prostaglandin E synthase were down-regulated. Furthermore, the expression of 15-hydroxyprostaglandin dehydrogenase decreased. An excessive accumulation of PGE2 promoted ferroptosis, whereas the PGE2 inhibitor pranoprofen minimized the changes for COX-2, GSH, GPX4 and lipid peroxides. A decrease in the levels of the PGE2 receptor E-series of prostaglandin 1/3 partially restored the decline of GSH and GPX4 levels and inhibited the aggravation of lipid peroxide. Consistent with the in vitro results, increased PGE2 levels led to increased levels of 3,4-methylenedioxyamphetamine, Fe2+ accumulation and decreased GSH and GPX4 levels during renal ischaemia/reperfusion injury injury in mice. Our results indicate that the PGE2 pathway mediated oxidative stress-induced ferroptosis in renal tubular epithelial cells.

Gastroprotective Effect of Capparis spinosa on Indomethacin-induced Gastric Ulcer in Rats.

Peptic ulcer is an acid-induced lesion that is usually found in the stomach and duodenum. It is usually a case of imbalance between the acid (and other injurious factors) and the mucosal defense mechanisms. Indomethacin is one of the most ulcerogenic drugs that is prescribed over-the-counter for the management of musculoskeletal problems. Capparis spinosa is one of the most important species in the Capparidaceae family, which has a wide range of diversity. Caper (Capparis spinosa L.) is a common member of the genus Capparis (Capparidaceae family). The present study was designed to compare the effect of C. spinosa extract as a gastroprotective agent with indomethacin as an induction agent and ranitidine as a standard drug. To this aim, 40 adult male Wistar rats were randomly divided into 4 groups (n=10 each), including Control +: indomethacin-treated group, Control -: receiving physiological saline solution, C.S: C. spinosa-treated group; and ranitidine-treated group (50 mg/kg) as a standard agent for the treatment of the gastric ulcer. After the experimental period, all the animals were sacrificed by anesthesia overdose and their stomachs were removed. The gastroprotective effect of C. spinosa was investigated by studying prostaglandin E2 (PGE2), Gastrin, anti-tumor necrosis factor alpha (TNF-α), and Interleukin 1 beta (IL1-β), along with histopathological examination. The results showed a significant increase in PGE2 levels in the ranitidine-treated group with a significant reduction in Gastrin, TNF-α, and IL1-β. The recorded data obtained from the histopathological study showed a significant improvement in the treated group with the extract of C. spinosa. The study concluded that C. spinosa had gastroprotective properties possibly through enhancing PGE2 which was acting as anti-inflammatory inhibiting neutrophil infiltration.

Effectiveness of aromatherapies with lavender and cinnamon essential oils on prostaglandin E2 levels in adolescent girls with primary dysmenorrhea

Background: Dysmenorrhea is a gynecologic complaint characterized by the presence of painful cramps before and during menstruation due to elevated levels of prostaglandin E2 and F2α, resulting in hypercontraction in the endometrium. Objective: This study aims at analyzing the effectiveness of aromatherapies with lavender and cinnamon essential oils on prostaglandin E2 levels in adolescent girls with primary dysmenorrhea. Methods: This research applied the pretest-posttest randomized experimental design and was conducted at Hidayatullah Islamic boarding school Makassar. The number of samples is 36 respondents that are obtained by purposive sampling. These respondents are divided into three groups: aromatherapy with lavender, aromatherapy with cinnamon, and control, each consisting of 12 respondents. The intervention is conducted three times on the first and second days of the menstruation cycle. This research also uses ELISA Kit at Hasanuddin University Laboratory to measure the levels of prostaglandin E2. Findings: There is a significant decrease in prostaglandin E2 levels in both aromatherapies with lavender and cinnamon groups (p<0.05), whereas there is only an increase in prostaglandin E2 levels of 5.46 pg/ml in the control group (p>0.05). Conclusion: Aromatherapies with Lavender and Cinnamon Essential Oils effectively reduce prostaglandin E2 levels.

Increased Endogenous Production of Pro‐inflammatory Adipokines by 3T3‐L1 Adipocytes Differentiated with Arachidonic Acid

Inflammatory factors derived from adipose tissue (AT) can set the stage for chronic, low‐grade inflammation. This meta‐inflammation can predispose the individual to further inflammatory‐based disorders and diseases. Polyunsaturated fatty acids (PUFAs) are known to have immune modulating effects, with omega‐6 (n‐6) PUFAs typically being associated with increased production of inflammatory molecules, and n‐3 PUFAs having been shown to be anti‐inflammatory, in both in vivo and in vitro studies. The 3T3‐L1 cell line is an embryonic mouse fibroblast line that can be differentiated into an adipocyte phenotype making it a suitable line for studies on the effects of PUFAs on inflammatory molecule production by AT. The aim of this research was to determine the effects of n‐6 and n‐3 PUFAs on the release of inflammatory adipokines in lipopolysaccharide (LPS)‐challenged and LPS‐unchallenged adipocytes. Fibroblasts were differentiated into adipocytes with the addition of 100 μM of linoleic acid (LA; n‐6), arachidonic acid (ARA; n‐6) or eicosapentaenoic acid (EPA; n‐3) throughout the differentiation period, followed by a 6 h, 1 μg/ml LPS challenge. Cell‐conditioned media was collected before and after the LPS challenge for interleukin (IL)‐6 and prostaglandin E2 (PGE2) quantification via enzyme‐linked immunosorbent assays. Differentiation of adipocytes with n‐6 ARA caused a significant increase in PGE2 levels compared to control cells, or cells differentiated with LA or EPA, both after LPS challenge (two‐way ANOVA; p<0.0001) and before LPS challenge (two‐way ANOVA; p<0.0001). We did not observe differences in PGE2 levels between LPS‐challenged and non‐challenged cells differentiated with ARA (matched pairs t‐test; p=0.42) and EPA (p=0.57), while control (p=0.0005) and LA‐treated cells (p=0.0003) produced higher amounts of PGE2 after LPS stimulation. Interestingly, quantified levels of IL‐6 across treatments did not differ before and after LPS stimulation (matched pairs t‐test; p=0.75), although, as observed with PGE2, there was a significant increase in IL‐6 production by ARA‐differentiated cells compared to control, LPS, LA, and EPA‐treated cells (two‐way ANOVA; p=0.004). In conclusion, use of ARA in the differentiation process of 3T3‐L1 fibroblasts into a final adipocyte phenotype increases their endogenous (non‐LPS stimulated) production of IL‐6 and PGE2.

Eicosapentaenoic acid mitigates palmitic acid-induced heat shock response, inflammation and repair processes in fish intestine

Understanding the metabolic effects of fatty acids on fish intestine is critical to the substitution of fish oil with vegetable oils in aquaculture. In this study, the effects of eicosapentaenoic acid (EPA) and palmitic acid (PA) on fish intestine were evaluated in vitro and in vivo. As the first step for in vitro study, an intestinal cell line (SPIF) was established from silver pomfret (Pampus argenteus). Thereafter, the effects of EPA and PA on cell viability, prostaglandin E2 (PGE2) production, and the expression of genes related to heat shock response, inflammation, extracellular matrix (ECM) formation and degradation were examined in SPIF cells. Finally, these metabolic effects of EPA and PA on the intestine were examined in zebrafish (Danio rerio) larvae. Results showed that all tested fatty acids (PA, oleic acid, linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid) except EPA reduced SPIF viability to distinct degrees at the same concentrations. PA decreased SPIF viability accompanied by an increase in PGE2 level. Meanwhile, PA increased the expression of genes related to heat shock response (grp78, grp94, hsp70, and hsp90) and inflammation (nf-κb, il-1β, and cox2). Furthermore, PA reduced the expression of collagen type I (col1a1a and col1a1b) and extracellular matrix (ECM) degradation-related gene mmp2, while up-regulating timp2 mRNA expression. In vivo, PA also increased hsp70, il-1β, and cox2 mRNA levels and limited the expression of collagen type I in the larval zebrafish intestine. Interestingly, the combination of EPA and PA partially recovered the PA-induced changes in cell viability, PGE2 production, and mRNA expression in vitro and in vivo. These results suggest that PA may result in heat shock and inflammatory responses, as well as alter ECM formation and degradation in fish intestine, while EPA could at least partially mitigate these negative effects caused by PA.

NSAIDs and Cancer Resolution: New Paradigms beyond Cyclooxygenase.

Acute inflammation or resolved inflammation is an adaptive host defense mechanism and is self-limiting, which returns the body to a state of homeostasis. However, unresolved, uncontrolled, or chronic inflammation may lead to various maladies, including cancer. Important evidence that links inflammation and cancer is that nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, reduce the risk and mortality from many cancers. The fact that NSAIDs inhibit the eicosanoid pathway prompted mechanistic drug developmental work focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E2 levels and the overexpression of COX-2 in the colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. However, NSAIDs do not require the presence of COX-2 to prevent cancer. In this review, we highlight the effects of NSAIDs and selective COX-2 inhibitors (COXIBs) on targets beyond COX-2 that have shown to be important against many cancers. Finally, we hone in on specialized pro-resolving mediators (SPMs) that are biosynthesized locally and, in a time, -dependent manner to promote the resolution of inflammation and subsequent tissue healing. Different classes of SPMs are reviewed, highlighting aspirin’s potential in triggering the production of these resolution-promoting mediators (resolvins, lipoxins, protectins, and maresins), which show promise in inhibiting cancer growth and metastasis.

Streptococcus suis Induces Expression of Cyclooxygenase-2 in Porcine Lung Tissue.

Streptococcus suis is a common pathogen colonising the respiratory tract of pigs. It can cause meningitis, sepsis and pneumonia leading to economic losses in the pig industry worldwide. Cyclooxygenase-2 (COX-2) and its metabolites play an important regulatory role in different biological processes like inflammation modulation and immune activation. In this report we analysed the induction of COX-2 and the production of its metabolite prostaglandin E2 (PGE2) in a porcine precision-cut lung slice (PCLS) model. Using Western blot analysis, we found a time-dependent induction of COX-2 in the infected tissue resulting in increased PGE2 levels. Immunohistological analysis revealed a strong COX-2 expression in the proximity of the bronchioles between the ciliated epithelial cells and the adjacent alveolar tissue. The morphology, location and vimentin staining suggested that these cells are subepithelial bronchial fibroblasts. Furthermore, we showed that COX-2 expression as well as PGE2 production was detected following infection with two prevalent S. suis serotypes and that the pore-forming toxin suilysin played an important role in this process. Therefore, this study provides new insights in the response of porcine lung cells to S. suis infections and serves as a basis for further studies to define the role of COX-2 and its metabolites in the inflammatory response in porcine lung tissue during infections with S. suis.

Adipose-derived stem cells inhibit dermal fibroblast growth and induce apoptosis in keloids through the arachidonic acid-derived cyclooxygenase-2/prostaglandin E2 cascade by paracrine.

BackgroundThe clinical features of keloids consist of aberrant proliferation, secretion, differentiation and apoptosis of keloid dermis-derived fibroblasts (KFBs). Notably, the apoptosis rate of KFBs is lower than the proliferation rate. Though the anti-fibrotic effect of adipose-derived stem cells (ADSCs) on keloids has become a hot topic of research, the exact anti-fibrotic mechanism of the paracrine effect remains unclear. This study aimed to find out how the conditioned medium of ADSCs (ADSC-CM) exerts an anti-fibrotic effect in KFBs.MethodsKFBs and ADSCs were extracted and cultured. Then, ADSC-CM was prepared. Whether ADSC-CM could inhibit KFB growth and induce apoptosis was verified by the use of a cell counting kit-8, an 5-Ethynyl-2-deoxyuridine (Edu) kit and flow cytometry. The expressions of cyclooxygenase-1 (COX-1), COX-2, caspase 3 and B-cell lymphoma-2 (Bcl-2) in ADSC-CM-cultured KFBs were tested by real-time PCR and western blotting. To clarify the role of COX-2 in ADSC-CM-induced KFB apoptosis, a specific COX-2 inhibitor, celecoxib, was applied to KFBs cultured in ADSC-CM. Moreover, we tested the production of arachidonic acid (AA) and prostaglandin E2 (PGE2) by ELISA. Then, we established a keloid transplantation model in a nude mouse to validate the therapeutic effect in vivo.ResultsThe proliferation ability of KFBs cultured in ADSC-CM was found to be weakened and apoptosis was significantly increased. Caspase 3 expression was significantly upregulated and Bcl-2 was downregulated in ADSC-CM-cultured KFBs. Furthermore, ADSC-CM strikingly elevated COX-2 mRNA and protein expressions, but COX-1 expression was unaltered. COX-2 inhibitors reduced ADSC-CM-induced apoptosis. Additionally, COX-2 inhibition blocked the elevation of caspase 3 and reversed the decrease in Bcl-2 expression. ADSC-CM increased PGE2 levels by 1.5-fold and this effect was restrained by COX-2 inhibition. In the nude mouse model, expressions of AA, COX-2 and PGE2 were higher in the translated keloid tissues after ADSC-CM injection than in the controls.ConclusionsWe showed activation of the COX-2/PGE2 cascade in KFBs in response to ADSC-CM. By employing a specific COX-2 inhibitor, COX-2/PGE2 cascade activation played a crucial role in mediating the ADSC-CM-induced KFB apoptosis and anti-proliferation effects.

Feline adipose tissue-derived mesenchymal stem cells pretreated with IFN-γ enhance immunomodulatory effects through the PGE₂ pathway.

BackgroundPreconditioning with inflammatory stimuli is used to improve the secretion of anti-inflammatory agents in stem cells from variant species such as mouse, human, and dog. However, there are only few studies on feline stem cells.ObjectivesThis study aimed to evaluate the immune regulatory capacity of feline adipose tissue-derived (fAT) mesenchymal stem cells (MSCs) pretreated with interferon-gamma (IFN-γ).MethodsTo assess the interaction of lymphocytes and macrophages with IFN-γ-pretreated fAT-MSCs, mouse splenocytes and RAW 264.7 cells were cultured with the conditioned media from IFN-γ-pretreated MSCs.ResultsPretreatment with IFN-γ increased the gene expression levels of cyclooxygenase-2, indoleamine 2,3-dioxygenase, hepatocyte growth factor, and transforming growth factor-beta 1 in the MSCs. The conditioned media from IFN-γ-pretreated MSCs increased the expression levels of M2 macrophage markers and regulatory T-cell markers compared to those in the conditioned media from naive MSCs. Further, prostaglandin E2 (PGE2) inhibitor NS-398 attenuated the immunoregulatory potential of MSCs, suggesting that the increased PGE2 levels induced by IFN-γ stimulation is a crucial factor in the immune regulatory capacity of MSCs pretreated with IFN-γ.ConclusionsIFN-γ pretreatment improves the immune regulatory profile of fAT-MSCs mainly via the secretion of PGE2, which induces macrophage polarization and increases regulatory T-cell numbers.

Suppressive effects of an apoptotic mimicry prepared from jumbo-flying squid-skin phospholipids on the osteoclastogenesis in receptor activator of nuclear factor kappa B ligand/macrophage colony-stimulating factor-induced RAW 264.7 cells.

Liposomes containing docosahexaenoic acid (DHA) and phosphatidylserine were claimed to inhibit osteoclast formation and bone resorption in the inflammatory status. Herein, we proposed that an apoptotic mimicry (SQ liposome) prepared from squid-skin phospholipids can explore the suppressive osteoclastogenesis. The intermolecular fatty-acid composition in the phospholipid of squid-skin extract was analyzed by GC-FID. The SQ liposome structure was characterized by size distribution and zeta potential (ζ). RAW 264.7 cell is used to study the effect of SQ liposomes on osteoclast differentiation. Secretion of prostaglandin E2 (PGE2) and transforming growth factor-β (TGF-β) from RAW 264.7 cells were assayed. Antiosteoclastogenesis effects were performed via the tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) counting, bone resorption pit assay, and TRAP activity analysis. The specific gene expressions related to antiosteoclastogenesis were also detected. An apoptotic mimicry through the use of a single-layer liposome (SQ liposome) with phosphatidylserine exposure contains DHA (28.7%) and eicosapentaenoic acid (EPA, 11.8%). Co-treatment with receptor activator of nuclear factor kappa B ligand (RANKL)/macrophage colony-stimulating factor induced RAW 264.7-cell differentiation into mature osteoclasts, thus enhancing PGE2 and TGF-β secretion. However, cotreatment with 1 mg/mL of SQ liposome restored (p < 0.05) the cell viabilities under the RANKL stress. Increased PGE2 levels was downregulated (p < 0.05) in cotreatments with 0.11 and 0.33 mg/mL of SQ liposome, but on the TGF-β levels were not (p > 0.05) influenced in SQ liposome cotreatments. Cotreatments with 0.33-1 mg/mL of SQ liposome suppressed (p < 0.05) the osteoclast maturation (such as decreased MNCs and bone pit formation), inhibited TRAP activities, and downregulated the osteoclastogenesis-related gene expressions. In summary, current data support that a possible prevention of our prepared SQ liposomes which are rich in DHA and EPA on bone loss is through the suppression of osteoclastogenesis. Moreover, based on the results from this study an in vivo study warrants a further investigation.

A Representative GIIA Phospholipase A2 Activates Preadipocytes to Produce Inflammatory Mediators Implicated in Obesity Development.

Adipose tissue secretes proinflammatory mediators which promote systemic and adipose tissue inflammation seen in obesity. Group IIA (GIIA)-secreted phospholipase A2 (sPLA2) enzymes are found to be elevated in plasma and adipose tissue from obese patients and are active during inflammation, generating proinflammatory mediators, including prostaglandin E2 (PGE2). PGE2 exerts anti-lipolytic actions and increases triacylglycerol levels in adipose tissue. However, the inflammatory actions of GIIA sPLA2s in adipose tissue cells and mechanisms leading to increased PGE2 levels in these cells are unclear. This study investigates the ability of a representative GIIA sPLA2, MT-III, to activate proinflammatory responses in preadipocytes, focusing on the biosynthesis of prostaglandins, adipocytokines and mechanisms involved in these effects. Our results showed that MT-III induced biosynthesis of PGE2, PGI2, MCP-1, IL-6 and gene expression of leptin and adiponectin in preadipocytes. The MT-III-induced PGE2 biosynthesis was dependent on cytosolic PLA2 (cPLA2)-α, cyclooxygenases (COX)-1 and COX-2 pathways and regulated by a positive loop via the EP4 receptor. Moreover, MT-III upregulated COX-2 and microsomal prostaglandin synthase (mPGES)-1 protein expression. MCP-1 biosynthesis induced by MT-III was dependent on the EP4 receptor, while IL-6 biosynthesis was dependent on EP3 receptor engagement by PGE2. These data highlight preadipocytes as targets for GIIA sPLA2s and provide insight into the roles played by this group of sPLA2s in obesity.

Gastroprotective effect of tarantula cubensis extract in the indomethacin-induced peptic ulcer model in rats

Aim: Gastric ulcers are the most common gastrointestinal disease, due to several factors in the industrialized world. They may also occur after many pharmacological agents, combined with gastroprotective agents such as proton pump inhibitors (PPI) or anti-acids, are used as a preferred approach to maintaining gastrointestinal health. Unexpected adverse effects in these combinations make natural products an important alternative option. Methods: Therefore, the main aim of this study is to investigate one natural compound, the Tarantula cubensis extract (TCE), in the experimental peptic ulcer model which was created by a single administration of indomethacin (40 mg/kg, body weight) to fed state Wistar-albino rats. The animals were pre-treated with two-doses of the TCE (0.2 ml/kg) before the indomethacin administration. After six hours, they were euthanized and the stomach tissue was isolated for biochemical and immunohistochemical analysis. Total antioxidant status/total oxidant status (TAS/TOS), prostaglandin E2 (PGE2), and nuclear factor kappa-B (NF-κB) levels were determined with ELISA in tissue homogenates. Caspase-3, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α), were visualized with immunohistochemistry in intact tissues. Results: Pre-treatment with TCE increased PGE2 levels and decreased total oxidative status (TAS/TOS). Additionally, TCE alleviated the increase of (NF-κB) levels due to the indomethacin administration. Histopathological and immunostaining results showed that TCE mitigated elevated immunoreactivity of the caspase-3, COX-2, iNOS, and TNF-α which were the results of the indomethacin administration. Conclusion: Our study demonstrated that pre-TCE treatment ameliorated indomethacin-induced peptic ulcers via antioxidant and anti-inflammatory actions.

Cellular Microenvironment Stiffness Regulates Eicosanoid Production and Signaling Pathways.

Pathological changes in the biomechanical environment are implicated in the progression of idiopathic pulmonary fibrosis (IPF). Stiffened matrix augments fibroblast proliferation and differentiation and activates TGF-β1 (transforming growth factor-β1). Stiffened matrix impairs the synthesis of the antifibrogenic lipid mediator prostaglandin E2 (PGE2) and reduces the expression of the rate-limiting prostanoid biosynthetic enzyme cyclooxygenase-2 (COX-2). We now show that prostaglandin E synthase (PTGES), the final enzyme in the PGE2 biosynthetic pathway, is expressed at lower levels in the lungs of patients with IPF. We also show substantial induction of COX-2, PTGES, prostaglandin E receptor 4 (EP4), and cytosolic phospholipase A2 (cPLA2) expression in human lung fibroblasts cultured in soft collagen hydrogels or in spheroids compared with conventional culture on stiff plastic culture plates. Induction of COX-2, cPLA2, and PTGES expression in spheroid cultures was moderately inhibited by the p38 mitogen-activated protein kinase inhibitor SB203580. The induction of prostanoid biosynthetic enzyme expression was accompanied by an increase in PGE2 levels only in non-IPF-derived fibroblast spheroids. Our study reveals an extensive dysregulation of prostanoid biosynthesis and signaling pathways in IPF-derived fibroblasts, which are only partially abrogated by culture in soft microenvironments.

Cardiac injury modulates critical components of prostaglandin E2 signaling during zebrafish heart regeneration

The inability to effectively stimulate cardiomyocyte proliferation remains a principle barrier to regeneration in the adult human heart. A tightly regulated, acute inflammatory response mediated by a range of cell types is required to initiate regenerative processes. Prostaglandin E2 (PGE2), a potent lipid signaling molecule induced by inflammation, has been shown to promote regeneration and cell proliferation; however, the dynamics of PGE2 signaling in the context of heart regeneration remain underexplored. Here, we employ the regeneration-competent zebrafish to characterize components of the PGE2 signaling circuit following cardiac injury. In the regenerating adult heart, we documented an increase in PGE2 levels, concurrent with upregulation of cox2a and ptges, two genes critical for PGE2 synthesis. Furthermore, we identified the epicardium as the most prominent site for cox2a expression, thereby suggesting a role for this tissue as an inflammatory mediator. Injury also drove the opposing expression of PGE2 receptors, upregulating pro-restorative ptger2a and downregulating the opposing receptor ptger3. Importantly, treatment with pharmacological inhibitors of Cox2 activity suppressed both production of PGE2, and the proliferation of cardiomyocytes. These results suggest that injury-induced PGE2 signaling is key to stimulating cardiomyocyte proliferation during regeneration.

Annexin10 promotes extrahepatic cholangiocarcinoma metastasis by facilitating EMT via PLA2G4A/PGE2/STAT3 pathway.

BackgroundCholangiocarcinoma (CCA), consisting of intrahepatic (IHCCA), perihilar (PHCCA), and distal (DCCA) CCA, is a type of highly aggressive malignancy with a very dismal prognosis. Potential biomarkers and drug targets of CCA are urgently needed. As a new member of the Annexin (ANXA) family, the role of ANXA10 in the progression and prognosis of CCA is unknown.MethodsPotential PHCCA biomarkers were screened by transcriptome sequencing of 5 pairs of PHCCA and adjacent tissues. The clinical significance of ANXA10 was evaluated by analyzing its correlation with clinicopathological variables, and the prognostic value of ANXA10 was evaluated with univariate and multivariate analyses. The function of ANXA10 in the epithelial-mesenchymal transition (EMT), proliferation, invasion and metastasis was detected with in vitro and in vivo experiments. Moreover, we screened the key molecule in ANXA10-induced CCA progression by mRNA sequencing and evaluated the correlation between PLA2G4A and ANXA10. The effect of PLA2G4A downstream signaling, including Cyclooxygenase 2, Prostaglandin E2(PGE2) and Signal transducer and activator of transcription 3(STAT3), on EMT and metastasis was further detected with in vitro and in vivo experiments.FindingsANXA10 expression was upregulated in PHCCA and DCCA but not in IHCCA. High ANXA10 expression was significantly associated with poor tumor differentiation and prognosis. ANXA10 promoted the proliferation, migration and invasion of the PHCCA cells. PLA2G4A expression was regulated by ANXA10 and high PLA2G4A predicted poor prognosis in PHCCA and DCCA. ANXA10 facilitated EMT and promoted metastasis by upregulating PLA2G4A expression, thus increasing PGE2 levels and activating STAT3.InterpretationANXA10 was an independent prognostic biomarker of PHCCA and DCCA but not IHCCA. ANXA10 promoted the progression of PHCCA and facilitated metastasis by promoting the EMT process via the PLA2G4A/PGE2/STAT3 pathway. ANXA10, PLA2G4A and their downstream molecules, such as COX2 and PGE2, may be promising drug targets of PHCCA and DCCA.

Cadmium Induces Migration of Colon Cancer Cells: Roles of Reactive Oxygen Species, P38 and Cyclooxygenase-2.

Cadmium (Cd) is a heavy metal contaminant whose toxicity is associated with colorectal cancer (CRC). However, the underlying molecular mechanisms of Cd-induced CRC malignancy remain obscure. A monolayer scratch assay was employed to assess the migration of HT-29 human adenocarcinoma cells. Luciferasereporterassay was used to determine cyclooxygenase-2 (COX-2) transcriptional activity, and Western blotting was used to detect p38 Mitogen Activated Protein Kinase (MAPK) and Akt phosphorylation as well as COX-2 expression. Prostaglandin E2 (PGE2) levels were measured using Enzyme Linked Immunosorbent Assay (ELISA) and reactive oxygen species (ROS) formation was assessed using dihydroethidium (DHE) stain. Here, we show that Cd potentiates the migratory capacity of HT-29 CRC cells. Cd caused a time-dependent increase in COX-2 expression. Celecoxib, a COX-2 selective inhibitor, significantly reduced Cd-induced migration. Cd also increased levels of ROS and phosphorylated p38. Importantly, Cd-induced COX-2 expression and migration were significantly abolished by N-Acetyl-Cysteine (NAC), a ROS scavenger, or SB202190, a specific p38 inhibitor. Furthermore, Cd-induced p38 phosphorylation was inhibited by NAC. Cd (100 nM) also increased PGE2 levels, which was abrogated by NAC, SB202190, or celecoxib. Exogenous PGE2 significantly potentiated cell migration. Cd caused a significant increase in Akt phosphorylation in a ROS-mediated pathway. Moreover, Cd-induced migration was significantly attenuated by LY294 002, a phosphatidylinositol-3-kinase inhibitor. Taken together, our results suggest that exposure to low levels of Cd promotes a more migratory cancer phenotype in a ROS-p38-COX-2-PGE2 pathway as well as ROS-Akt pathway. Therefore, COX-2, PGE2 receptors or Akt represent potential targets in the treatment of CRC, particularly in patients exposed to Cd.