Novel Synthesized Benzophenone Thiazole Hybrids Exhibited Ex Vivo and In Silico Anti-Inflammatory Activity.

Novel benzophenone-thiazole hybrids with different substituents were synthesized and evaluated for anti-inflammatory activity using an ex vivo human whole-blood assay. All hybrids (3c and 5a-h) showed significant anti-inflammatory activity via prostaglandin E2 (PGE2) release inhibition. Moreover, 5c (82.8% of PGE2 inhibition), 5e (83.1% of PGE2 inhibition), and 5h (82.1% of PGE2 inhibition) were comparable to the reference drugs. Molecular docking revealed potential preferable binding to the active sites of cyclooxygenase 2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) enzymes. This study provides the first evidence that benzophenone-thiazole hybrids may also dock in mPGES-1, a new attractive anti-inflammatory drug target, besides providing promising ex vivo anti-inflammatory activity. Thus, the novel hybrids are promising anti-inflammatory lead compounds and highlight the significance of optimal substituent selection in the design of potent PGE2 inhibitors.

Attenuation of adjuvant-induced arthritis with carnosic acid by inhibiting mPGES-1, COX-2, and bone loss in male SD rats.

OBJECTIVE: Rheumatoid arthritis (RA), a chronic inflammatory disease, is characterized by joint swelling, cartilage erosion, and bone destruction. This study investigated the therapeutic efficacy of Carnosic acid (CA), a natural compound with anti-inflammatory and antioxidant properties, in an adjuvant-induced arthritis model. METHODS: Paw swelling and arthritis index were measured. Oxidative stress markers, including lipid peroxidation and antioxidant enzyme levels, were assessed. Synovial tissue was analyzed for pro-inflammatory markers using real-time Q-PCR and Western blotting. The expression of mPGES-1 was determined by Western blotting. Peripheral neuropathic pain was assessed using cold and mechanical allodynia tests. Bone loss was quantitatively assessed through microcomputed tomography (µCT) scanning of femurs and X-ray radiography. Indomethacin-induced gastric ulcers were evaluated. Molecular docking studies were conducted to analyze the binding affinity of CA to mPGES-1. RESULTS: The CA treatment not only demonstrated a significant reduction in joint inflammation and paw swelling but also mitigated oxidative stress and improved the antioxidant defence system. CA inhibited microsomal prostaglandin E synthase-1 (mPGES-1) expression and the expression of pro-inflammatory molecules such as inducible nitric oxide synthase (iNOS) and cyclooxygenases-2 (COX-2), thus attenuating the arthritis symptoms without severe gastrointestinal side effects. Additionally, it inhibited the expression of pro-inflammatory molecules such as iNOS and COX-2, contributing to the reduction of arthritis symptoms. Notably, CA treatment prevented the common side effects of traditional RA treatments like corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs), including weight loss, bone degradation, and gastric ulcers. CONCLUSIONS: These findings suggest that CA, through specific enzyme inhibition, offers a compelling alternative therapeutic approach for RA. Further research is warranted to explore the potential of CA in other arthritis models and its suitability for human RA treatment.

CA significantly reduces inflammation in FCA induced arthritis model.CA treatment inhibits key pro-inflammatory molecules, including mPGES-1 and COX-2In silico docking studies confirm the affinity of CA to mPGES-1.CA prevents bone loss and avoids side effects seen with standard treatments.Antioxidant properties of CA counteract oxidative stress related to chronic inflammation.

Activation of the PGE2-EP2 pathway as a potential drug target for treating eosinophilic rhinosinusitis.

Current treatments of eosinophilic chronic rhinosinusitis (ECRS) involve corticosteroids with various adverse effects and costly therapies such as dupilumab, highlighting the need for improved treatments. However, because of the lack of a proper mouse ECRS model that recapitulates human ECRS, molecular mechanisms underlying this disease are incompletely understood. ECRS is often associated with aspirin-induced asthma, suggesting that dysregulation of lipid mediators in the nasal mucosa may underlie ECRS pathology. We herein found that the expression of microsomal PGE synthase-1 (encoded by PTGES) was significantly lower in the nasal mucosa of ECRS patients than that of non-ECRS subjects. Histological, transcriptional, and lipidomics analyses of Ptges-deficient mice revealed that defective PGE2 biosynthesis facilitated eosinophil recruitment into the nasal mucosa, elevated expression of type-2 cytokines and chemokines, and increased pro-allergic and decreased anti-allergic lipid mediators following challenges with Aspergillus protease and ovalbumin. A nasal spray containing agonists for the PGE2 receptor EP2 or EP4, including omidenepag isopropyl that has been clinically used for treatment of glaucoma, markedly reduced intranasal eosinophil infiltration in Ptges-deficient mice. These results suggest that the present model using Ptges-deficient mice is more relevant to human ECRS than are previously reported models and that eosinophilic inflammation in the nasal mucosa can be efficiently blocked by activation of the PGE2-EP2 pathway. Furthermore, our findings suggest that drug repositioning of omidenepag isopropyl may be useful for treatment of patients with ECRS.

The components of the AhR-molecular chaperone complex differ depending on whether the ligands are toxic or non-toxic.

The aryl hydrocarbon receptor (AhR) forms a complex with the HSP90-XAP2-p23 molecular chaperone when the cells are exposed to toxic compounds. Recently, 1,4-dihydroxy-2-naphthoic acid (DHNA) was reported to be an AhR ligand. Here, we investigated the components of the molecular chaperone complex when DHNA binds to AhR. Proteins eluted from the 3-Methylcolanthrene-affinity column were AhR-HSP90-XAP2-p23 complex. The AhR-molecular chaperone complex did not contain p23 in the eluents from the DHNA-affinity column. In 3-MC-treated cells, AhR formed a complex with HSP90-XAP2-p23 and nuclear translocation occurred within 30 min, while in DHNA-treated cells, AhR formed a complex with AhR-HSP90-XAP2, and translocation was slow from 60 min. Thus, the AhR activation mechanism may differ when DHNA is the ligand compared to toxic ligands.

Novel 1,3,4-oxadiazole derivatives as highly potent microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitors.

Selective inhibition of microsomal prostaglandin E2 synthase-1 (mPGES-1) is implicated as a new therapeutic modality for the development of new-generation anti-inflammatory drugs. Here, we present the discovery of new and potent inhibitors of human mPGES-1, i.e., compounds 13, 15-25, 29-30 with IC50 values in the range of 5.6-82.3 nM in a cell-free assay of prostaglandin (PG)E2 formation. We also demonstrate that 20 (TG554, IC50 = 5.6 nM) suppresses leukotriene (LT) biosynthesis at low µM concentrations, providing a benchmark compound that dually intervenes with inflammatory PGE2 and LT biosynthesis. Comprehensive lipid mediator (LM) metabololipidomics with activated human monocyte-derived macrophages showed that TG554 selectively inhibits inflammatory PGE2 formation over all cyclooxygenase (COX)-derived prostanoids, does not cause substrate shunting towards 5-lipoxygenase (5-LOX) pathway, and does not interfere with the biosynthesis of the specialized pro-resolving mediators as observed with COX inhibitors, providing a new chemotype for effective and safer anti-inflammatory drug development.

Genetic or pharmacologic blockade of mPGES-2 attenuates renal lipotoxicity and diabetic kidney disease by targeting Rev-Erbα/FABP5 signaling.

Diabetic kidney disease (DKD) is one of the most common complications of diabetes, and no specific drugs are clinically available. We have previously demonstrated that inhibiting microsomal prostaglandin E synthase-2 (mPGES-2) alleviated type 2 diabetes by enhancing ß cell function and promoting insulin production. However, the involvement of mPGES-2 in DKD remains unclear. Here, we aimed to analyze the association of enhanced mPGES-2 expression with impaired metabolic homeostasis of renal lipids and subsequent renal damage. Notably, global knockout or pharmacological blockage of mPGES-2 attenuated diabetic podocyte injury and tubulointerstitial fibrosis, thereby ameliorating lipid accumulation and lipotoxicity. These findings were further confirmed in podocyte- or tubule-specific mPGES-2-deficient mice. Mechanistically, mPGES-2 and Rev-Erbα competed for heme binding to regulate fatty acid binding protein 5 expression and lipid metabolism in the diabetic kidney. Our findings suggest a potential strategy for treating DKD via mPGES-2 inhibition.

Expression of mPGES1 and p16 in feline and human oral squamous cell carcinoma: A comparative oncology approach.

Comparative cancer studies help us determine if discoveries in one species apply to another. Feline and human oral squamous cell carcinoma (FOSCC and HOSCC) are invasive tumours in which inflammation and abnormal p16 expression are reported. Immunohistochemistry was used to determine the expression of p16 and microsomal prostaglandin E2 synthase 1 (mPGES1) in 42 HOSCC and 45 FOSCC samples with known expression of cyclooxygenase 2 (COX2) and cluster of differentiation 147 (CD147). High p16 expression was more common in HOSCC tumour cells compared to adjacent stroma and oral epithelium (p < .05), with a similar but statistically nonsignificant pattern in FOSCC. Interestingly, high mPGES1 expression in FOSCC was more common in the adjacent epithelium compared to the other compartments (p < .05). In HOSCC, mPGES1 was more similar between compartments but was numerically more common in the tumour compartment (p > .05). There were nominal (p > 0.05) differences in marker expression between high and low mPGES1 expressing tumours in both species, including high p16 observed more commonly in high mPGES1 tumours, and COX-2 positive tumours being more common in low mPGES1 tumours. High CD147 HOSCC tumours were more common in the high mPGES1 HOSCC group (p < .05). In the FOSCC cohort, where there was no statistical difference in CD147 expression between high and low mPGES1 tumours, there were numerically higher CD147 cases in the high mPGES1group. Different expression patterns in FOSCC and HOSCC could be related to different risk factors. For example, p16 is a marker of papillomavirus-driven HOSCC, but a causal relationship between papillomaviruses and FOSCC has yet to be definitively demonstrated. The significance of high P16 expression in the absence of papillomavirus infection deserves further study, and the relative contributions of COX2 and mPGES1 to tumour inflammation and progression should be explored. The findings reveal potential similarities in FOSCC and HOSCC biology, while also demonstrating differences that may relate to risk factors and pathogenesis that are unique to each species.

Progesterone-independent endometrial mRNA expression in dairy cows with clinical or subclinical endometritis.

Up to 50 % of dairy cows fail to resolve uterine involution and develop chronic clinical (CE) or subclinical endometritis (SE) 21 days after calving. Clinical endometritis is associated with purulent discharge, while SE is not associated with overt clinical signs. Along with numerous knowledge gaps related to its pathogenesis, SE does not allow for a straightforward and effective therapy. Therefore, it is crucial to unravel differences in the expression of genes among healthy, CE, and SE cows. This might contribute to the discovery of new drug candidates and, in consequence, a potentially effective treatment. In the present study, cows between 21 and 28 days postpartum (PP) were examined using vaginoscopy for the presence of vaginal discharge and endometrial cytology for the determination of the endometrial polymorphonuclear cell (PMN) percentage. Next, an endometrial biopsy sample was taken to investigate the expression of 13 selected candidate genes by qPCR. Uterine health status was assigned to healthy (absence of abnormal vaginal discharge and ≤5 % PMN, n = 13), SE (absence of abnormal vaginal discharge and >5 % PMN, n = 30), and CE (mucopurulent or purulent vaginal discharge and >5 % PMN, n = 9). At the same time, a blood sample was collected to assess serum progesterone concentration and to categorize cows as low (≤1 ng/mL) or high (>1 ng/mL) in progesterone. High expression of IL1B, IL6, IL17A, CXCL8, PTGES, PTGS1, PTGS2, and INHBA genes and low expression of FST was noted in the endometrium of CE compared to healthy cows. Increased endometrial INHBA expression was observed in both SE and CE compared to healthy cows. Interestingly, greater expression of PTGES and PRXL2B genes and lower expression of PTGS2 were characteristic of SE versus CE or healthy. Among cows with no overt clinical symptoms of uterine disease (healthy and SE), the endometrial expression of IL1 B, CXCL8, and PTGES was greater in cows with high versus low serum progesterone. Several genes were differentially expressed among healthy, SE, and CE cows indicating different pathways for the development of different uterine diseases. In conclusion, we found progesterone-independent SE markers, which suggests that low endometrial PTGS2 expression may be indicative of an inadequate immune response and thus contribute to the pathogenesis of SE.

Targeting mPGES-2 to protect against acute kidney injury via inhibition of ferroptosis dependent on p53.

Acute kidney injury (AKI) is a clinical syndrome with high morbidity and mortality but no specific therapy. Microsomal prostaglandin E synthase-2 (mPGES-2) is a PGE2 synthase but can metabolize PGH2 to malondialdehyde by forming a complex with heme. However, the role and mechanism of action of mPGES-2 in AKI remain unclear. To examine the role of mPGES-2, both global and tubule-specific mPGES-2-deficient mice were treated with cisplatin to induce AKI. mPGES-2 knockdown or overexpressing HK-2 cells were exposed to cisplatin to cause acute renal tubular cell injury. The mPGES-2 inhibitor SZ0232 was used to test the translational potential of targeting mPGES-2 in treating AKI. Additionally, mice were subjected to unilateral renal ischemia/reperfusion to further validate the effect of mPGES-2 on AKI. Interestingly, both genetic and pharmacological blockage of mPGES-2 led to decreased renal dysfunction and morphological damage induced by cisplatin and unilateral renal ischemia/reperfusion. Mechanistic exploration indicated that mPGES-2 deficiency inhibited ferroptosis via the heme-dependent regulation of the p53/SLC7A11/GPX4 axis. The present study indicates that mPGES-2 blockage may be a promising therapeutic strategy for AKI.

The anti-inflammatory and vasoprotective properties of mPGES-1 inhibition offer promising therapeutic potential.

INTRODUCTION: Prostaglandin E2 (PGE2) is produced by cyclooxygenases (COX-1/2) and the microsomal prostaglandin E synthase 1 (mPGES-1). PGE2 is pro-inflammatory in diseases such as rheumatoid arthritis, cardiovascular disorders, and cancer. While Nonsteroidal anti-inflammatory drugs (NSAIDs) targeting COX can effectively reduce inflammation, their use is limited by gastrointestinal and cardiovascular side effects resulting from the blockade of all prostanoids. To overcome this limitation, selective inhibition of mPGES-1 is being explored as an alternative therapeutic strategy to inhibit PGE2 production while sparing or even upregulating other prostaglandins. However, the exact timing and location of PGH2 conversion to PGD2, PGI2, TXB2 or PGF2α, and whether it hinders or supports the therapeutic effect of mPGES-1 inhibition, is not fully understood. AREAS COVERED: The article briefly describes prostanoid history and metabolism with a strong focus on the vascular effects of prostanoids. Recent advances in mPGES-1 inhibitor development and results from pre-clinical and clinical studies are presented. Prostanoid shunting after mPGES-1 inhibition is highlighted and particularly discussed in the context of cardiovascular diseases. EXPERT OPINION: The newest research demonstrates that inhibition of mPGES-1 is a potent anti-inflammatory treatment strategy and beneficial and safer regarding cardiovascular side effects compared to NSAIDs. Inhibitors of mPGES-1 hold great potential to advance to the clinic and there are ongoing phase-II trials in endometriosis.

Alpinia katsumadai Hayata Volatile Oil Is Effective in Treating 5-Fluorouracil-Induced Mucositis by Regulating Gut Microbiota and Modulating the GC/GR Pathway and the mPGES-1/PGE2/EP4 Pathways.

This study was aimed to investigate the therapeutic effect and mechanism of AKHO on 5-fluorouracil (5-FU)-induced intestinal mucositis in mice. Mouse body weight, diarrhea score, and H&E staining were applied to judge the therapeutic effect of AKHO. 16S rDNA and nontargeted metabolomics have been used to study the mechanism. WB, ELISA, and immunohistochemistry were adopted to validate possible mechanisms. The results demonstrated that AKHO significantly reduced diarrhea scores and intestinal damage induced by 5-FU in mice. AKHO lowered the serum levels of LD and DAO, and upregulated the expressions of ZO-1 and occludin in the ileum. Also, AKHO upregulated the abundance of Lactobacillus in the gut and suppressed KEGG pathways such as cortisol synthesis and secretion and arachidonic acid metabolism. Further validation studies indicated that AKHO downregulated the expressions of prostaglandin E2 (PGE2), microsomal prostaglandin E synthase-1 (mPGES-1), and PGE2 receptor EP4, as well as upregulated the expression of glucocorticoid (GC) receptor (GR), leading to improved intestinal epithelial barrier function. Taken together, AKHO elicited protective effects against 5-FU-induced mucositis by regulating the expressions of tight junction proteins via modulation of GC/GR and mPGES-1/PGE2/EP4 pathway, providing novel insights into the utilization and development of this pharmaceutical/food resource.

The inducible prostaglandin E synthase (mPGES-1) in neuroinflammatory disorders.

The cyclooxygenase (COX)/prostaglandin E2 (PGE2) signaling pathway has emerged as a critical target for anti-inflammatory therapeutic development in neurological diseases. However, medical use of COX inhibitors in the treatment of various neurological disorders has been limited due to well-documented cardiovascular and cerebrovascular complications. It has been widely proposed that modulation of downstream microsomal prostaglandin E synthase-1 (mPGES-1) enzyme may provide more specificity for inhibiting PGE2-elicited neuroinflammation. Heightened levels of mPGES-1 have been detected in a variety of brain diseases such as epilepsy, stroke, glioma, and neurodegenerative diseases. Subsequently, elevated levels of PGE2, the enzymatic product of mPGES-1, have been demonstrated to modulate a multitude of deleterious effects. In epilepsy, PGE2 participates in retrograde signaling to augment glutamate release at the synapse leading to neuronal death. The excitotoxic demise of neurons incites the activation of microglia, which can become overactive upon further stimulation by PGE2. A selective mPGES-1 inhibitor was able to reduce gliosis and the expression of proinflammatory cytokines in the hippocampus following status epilepticus. A similar mechanism has also been observed in stroke, where the overactivation of microglia by PGE2 upregulated the expression and secretion of proinflammatory cytokines. This intense activation of neuroinflammatory processes triggered the secondary injury commonly observed in stroke, and blockade of mPGES-1 reduced infarction size and edema, suppressed induction of proinflammatory cytokines, and improved post-stroke well-being and cognition. Furthermore, elevated levels of PGE2 have been shown to intensify the proliferation of glioma cells, mediate P-glycoprotein expression at the blood-brain barrier (BBB) and facilitate breakdown of the BBB. For these reasons, targeting mPGES-1, the central and inducible enzyme of the COX cascade, may provide a more specific therapeutic strategy for treating neuroinflammatory diseases.

Generation of a novel three-dimensional scaffold-based model of the bovine endometrium.

Bovine in vitro endometrial models that resemble tissue function in vivo are needed to study infertility, long-term uterine alterations induced by pathogens and impact of endocrine disruptor chemicals on reproductive function and other reproductive system complications that cause high economic losses in livestock species. The present study aimed to generate an innovative, reproducible, and functional 3D scaffold-based model of the bovine endometrium structurally robust for long term-culture. We developed a multicellular model containing both endometrial epithelial and stromal cells. Epithelial cells organized to form a luminal-like epithelial layer on the surface of the scaffold. Stromal cells produced their own extracellular matrix forming a stable subepithelial compartment that physiologically resembles the normal endometrium. Both cell types released prostaglandin E2 and prostaglandin F2α following a treatment with oxytocin and arachidonic acid. Additionally signal pathways mediating oxytocin and arachidonic acid stimulation of prostaglandin synthesis were analyzed by real time PCR (RT-PCR). Oxytocin receptor (OXTR), prostaglandin E2 receptor 2 (EP2), prostaglandin E2 receptor 4 (EP4), prostaglandin F receptor (PTGFR), prostaglandin E synthase (PTGES), PGF-synthase (PGFS) and prostaglandin-endoperoxide synthase 2 (COX-2) expression was detected in both control and treatment groups, however, only significant changes in abundance of OXTR mRNA transcripts were found. The results obtained by this study are a step forward in bovine in vitro culture technology. This 3D scaffold-based model provides a platform to study regulatory mechanisms involved in endometrial physiology and can set the basis for a broader tool for designing and testing novel therapeutic strategies for recurrent uterine pathologies.

Microsomal prostaglandin E synthase-1 inhibition promotes shunting in arachidonic acid metabolism during inflammatory responses in vitro.

Microsomal Prostaglandin E Synthase 1 (mPGES-1) is the key enzyme for the generation of the pro-inflammatory lipid mediator prostaglandin E2 (PGE2), which contributes to several pathological features of many diseases. Inhibition of mPGES-1 has been shown to be a safe and effective therapeutic strategy in various pre-clinical studies. In addition to reduced PGE2 formation, it is also suggested that the potential shunting into other protective and pro-resolving prostanoids may play an important role in resolution of inflammation. In the present study, we analysed the eicosanoid profiles in four in vitro inflammation models and compared the effects of mPGES-1 inhibition with those of cyclooxygenase-2 (Cox-2) inhibition. Our results showed a marked shift to the PGD2 pathway under mPGES-1 inhibition in A549 cells, RAW264.7 cells and mouse bone marrow-derived macrophages (BMDMs), whereas enhanced prostacyclin production was observed in rheumatoid arthritis synovial fibroblasts (RASFs) treated with an mPGES-1 inhibitor. As expected, Cox-2 inhibition completely suppressed all prostanoids. This study suggests that the therapeutic effects of mPGES-1 inhibition may be mediated by modulation of other prostanoids in addition to PGE2 reduction.

PLPP/CIN-mediated NF2 S10 dephosphorylation distinctly regulates kainate-induced seizure susceptibility and neuronal death through PAK1-NF-κB-COX-2-PTGES2 signaling pathway.

BACKGROUND: Pyridoxal-5'-phosphate phosphatase/chronophin (PLPP/CIN) selectively dephosphorylates serine (S) 10 site on neurofibromin 2 (NF2, also known as merlin (moesin-ezrin-radixin-like protein) or schwannomin). p21-activated kinase 1 (PAK1) is a serine/threonine protein kinase, which is involved in synaptic activity and plasticity in neurons. NF2 and PAK1 reciprocally regulate each other in a positive feedback manner. Thus, the aim of the present study is to investigate the effects of PLPP/CIN-mediated NF2 S10 dephosphorylation on PAK1-related signaling pathways under physiological and neuroinflammatory conditions, which are largely unknown. METHODS: After kainate (KA) injection in wild-type, PLPP/CIN-/- and PLPP/CINTg mice, seizure susceptibility, PAK1 S204 autophosphorylation, nuclear factor-κB (NF-κB) p65 S276 phosphorylation, cyclooxygenase-2 (COX-2) upregulation, prostaglandin E synthase 2 (PTGES2) induction and neuronal damage were measured. The effects of 1,1'-dithiodi-2-naphthtol (IPA-3, a selective inhibitor of PAK1) pretreatment on these responses to KA were also validated. RESULTS: PLPP/CIN overexpression increased PAK1 S204 autophosphorylation concomitant with the enhanced NF2 S10 dephosphorylation in hippocampal neurons under physiological condition. Following KA treatment, PLPP/CIN overexpression delayed the seizure on-set and accelerated PAK1 S204 phosphorylation, NF-κB p65 S276 phosphorylation, COX-2 upregulation and PTGES2 induction, which were ameliorated by PLPP/CIN deletion or IPA-3. Furthermore, IPA-3 pretreatment shortened the latency of seizure on-set without affecting seizure severity (intensity) and ameliorated CA3 neuronal death induced by KA. CONCLUSIONS: These findings indicate that PLPP/CIN may regulate seizure susceptibility (the latency of seizure on-set) and CA3 neuronal death in response to KA through NF2-PAK1-NF-κB-COX-2-PTGES2 signaling pathway.

Microsomal prostaglandin E synthase-1 inhibition prevents adverse cardiac remodelling after myocardial infarction in mice.

BACKGROUND AND PURPOSE: Heart failure with reduced ejection fraction (HFrEF) is a major consequence of myocardial infarction (MI). The microsomal prostaglandin E synthase-1 (mPGES-1)/PGE2 pathway has been shown to constrain reperfusion injury after acute myocardial ischaemia. However, it is unknown whether pharmacological inhibition of mPGES-1, a target with lower risk of thrombosis compared with selective inhibition of cyclooxygenase-2, affects chronic cardiac remodelling after MI. EXPERIMENTAL APPROACH: Mice were subjected to left anterior descending coronary artery ligation, followed by intraperitoneal treatment with the mPGES-1 inhibitor compound III (CIII) or 118, celecoxib (cyclooxygenase-2 inhibitor) or vehicle, once daily for 28 days. Urinary prostanoid metabolites were measured by liquid chromatography-tandem mass spectrometry. KEY RESULTS: Chronic administration of CIII improved cardiac function in mice after MI compared with vehicle or celecoxib. CIII did not affect thrombogenesis or blood pressure. In addition, CIII reduced infarct area, augmented scar thickness, decreased collagen I/III ratio, decreased the expression of fibrosis-related genes and increased capillary density in the ischaemic area. Shunting to urinary metabolites of PGI2 , not thromboxane B2 or PGD2 , after inhibition of mPGES-1 was positively correlated with cardiac function after MI. CIII administration significantly increased urinary PGI2 /PGE2 metabolite ratio compared to vehicle or celecoxib. The PGI2 /PGE2 metabolite ratio correlated positively with ejection fraction, fractional shortening and scar thickness. Treatment with 118 also improved cardiac function. CONCLUSION AND IMPLICATIONS: Inhibition of mPGES-1 prevented chronic adverse cardiac remodelling via an augmented PGI2 /PGE2 metabolite ratio and therefore represents a potential therapeutic strategy for development of HFrEF after MI.

Microsomal Prostaglandin E Synthase-1 and -2: Emerging Targets in Non-Alcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) affects a substantial proportion of the general population and is even more prevalent in obese and diabetic patients. NAFLD, and particularly the more advanced manifestation of the disease, nonalcoholic steatohepatitis (NASH), increases the risk for both liver-related and cardiovascular morbidity. The pathogenesis of NAFLD is complex and multifactorial, with many molecular pathways implicated. Emerging data suggest that microsomal prostaglandin E synthase-1 and -2 might participate in the development and progression of NAFLD. It also appears that targeting these enzymes might represent a novel therapeutic approach for NAFLD. In the present review, we discuss the association between microsomal prostaglandin E synthase-1 and -2 and NAFLD.

Virtual screening, molecular simulations and bioassays: Discovering novel microsomal prostaglandin E Synthase-1 (mPGES-1) inhibitors.

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible prostaglandin E synthase expressed following exposure to pro-inflammatory stimuli. The mPGES-1 enzyme represents a new target for the therapeutic treatment of acute and chronic inflammatory disorders and cancer. In the present study, compounds from the ZINC15 database with an indole scaffold were docked at the mPGES-1 binding site using Glide (high-throughput virtual screening [HTVS], standard precision [SP] and extra precision [XP]), and the stabilities of the complexes were determined by molecular simulation studies. Following HTVS, the top 10% compounds were retained and further screened by SP. Again, the top 10% of these compounds were retained. Finally, the Glide XP scores of the compounds were determined, 20% were analyzed, and the Prime MM-GBSA total free binding energies of the compounds were calculated. The molecular simulations (100 ns) of the reference ligand, LVJ, and the two best-scoring compounds were performed with the Desmond program to analyze the dynamics of the target protein-ligand complexes. In human lung cells treated with the hit compounds, cell viability by colorimetric method and PGE2 levels by immunoassay method were determined. These in vitro experiments demonstrated that the two indole-containing hit compounds are potential novel inhibitors of mPGES-1 and are, therefore, potential therapeutic agents for cancer/inflammation therapies. Moreover, the compounds are promising lead mPGES-1 inhibitors for novel molecule design.

LDL-Dependent Regulation of TNFα/PGE2 Induced COX-2/mPGES-1 Expression in Human Macrophage Cell Lines.

Inflammation is a hallmark in severe diseases such as atherosclerosis and non-alcohol-induced steatohepatitis (NASH). In the development of inflammation, prostaglandins, especially prostaglandin E2 (PGE2), are major players alongside with chemo- and cytokines, like tumor-necrosis-factor alpha (TNFα) and interleukin-1 beta (IL-1ß). During inflammation, PGE2 synthesis can be increased by the transcriptional induction of the two key enzymes: cyclooxygenase 2 (COX-2), which converts arachidonic acid to PGH2, and microsomal prostaglandin E2 synthase 1 (mPGES-1), which synthesizes PGE2 from PGH2. Both COX-2 and mPGES-2 were induced by a dietary intervention where mice were fed a fatty acid-rich and, more importantly, cholesterol-rich diet, leading to the development of NASH. Since macrophages are the main source of PGE2 synthesis and cholesterol is predominantly transported as LDL, the regulation of COX-2 and mPGES-1 expression by native LDL was analyzed in human macrophage cell lines. THP-1 and U937 monocytes were differentiated into macrophages, through which TNFα and PGE-2 induced COX-2 and mPGES-1 expression by LDL could be analyzed on both mRNA and protein levels. In addition, the interaction of LDL- and EP receptor signal chains in COX-2/mPGES-1 expression and PGE2-synthesis were analyzed in more detail using EP receptor specific agonists. Furthermore, the LDL-mediated signal transduction in THP-1 macrophages was analyzed by measuring ERK and Akt phosphorylation as well as transcriptional regulation of transcription factor Egr-1. COX-2 and mPGES-1 were induced in both THP-1 and U937 macrophages by the combination of TNFα and PGE2. Surprisingly, LDL dose-dependently increased the expression of mPGES-1 but repressed the expression of COX-2 on mRNA and protein levels in both cell lines. The interaction of LDL and PGE2 signal chains in mPGES-1 induction as well as PGE2-synthesis could be mimicked by through simultaneous stimulation with EP2 and EP4 agonists. In THP-1 macrophages, LDL induced Akt-phosphorylation, which could be blocked by a PI3 kinase inhibitor. Alongside blocking Akt-phosphorylation, the PI3K inhibitor inhibited LDL-mediated mPGES-1 induction; however, it did not attenuate the repression of COX-2 expression. LDL repressed basal ERK phosphorylation and expression of downstream transcription factor Egr-1, which might lead to inhibition of COX-2 expression. These findings suggest that simultaneous stimulation with a combination of TNFα, PGE2, and native LDL-activated signal chains in macrophage cell lines leads to maximal mPGES-1 activity, as well repression of COX-2 expression, by activating PI3K as well as repression of ERK/Egr-1 signal chains.

Inhibition of mPGES-2 ameliorates NASH by activating NR1D1 via heme.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD), a complex metabolic syndrome, has limited therapeutic options. Microsomal prostaglandin E synthase-2 (mPGES-2) was originally discovered as a prostaglandin E 2 (PGE 2 ) synthase; however, it does not produce PGE 2 in the liver. Moreover, the role of mPGES-2 in NAFLD remains undefined. Herein, we aimed to determine the function and mechanism of mPGES-2 in liver steatosis and steatohepatitis. APPROACH AND RESULTS: To evaluate the role of mPGES-2 in NAFLD, whole-body or hepatocyte-specific mPGES-2-deficient mice fed a high-fat or methionine-choline-deficient diet were used. Compared with control mice, mPGES-2-deficient mice showed reduced hepatic lipid accumulation, along with ameliorated liver injury, inflammation, and fibrosis. Furthermore, the protective effect of mPGES-2 deficiency against NAFLD was dependent on decreased cytochrome P450 4A14 and increased acyl-CoA thioesterase 4 levels regulated by the heme receptor nuclear receptor subfamily 1 group D member 1 (NR1D1), but not PGE 2 . Heme regulated the increased NR1D1 activity mediated by mPGES-2 deficiency. Further, we confirmed the protective role of the mPGES-2 inhibitor SZ0232 in NAFLD therapy. CONCLUSION: Our study indicates the pathogenic role of mPGES-2 and outlines the mechanism in mediating NAFLD, thereby highlighting the therapeutic potential of mPGES-2 inhibition in liver steatosis and steatohepatitis.