IRE1α–XBP1 signaling in leukocytes controls prostaglandin biosynthesis and pain

Science ◽  
2019 ◽  
Vol 365 (6450) ◽  
pp. eaau6499 ◽  
Author(s):  
Sahil Chopra ◽  
Paolo Giovanelli ◽  
Perla Abigail Alvarado-Vazquez ◽  
Sara Alonso ◽  
Minkyung Song ◽  
...  

Inositol-requiring enzyme 1[α] (IRE1[α])–X-box binding protein spliced (XBP1) signaling maintains endoplasmic reticulum (ER) homeostasis while controlling immunometabolic processes. Yet, the physiological consequences of IRE1α–XBP1 activation in leukocytes remain unexplored. We found that induction of prostaglandin-endoperoxide synthase 2 (Ptgs2/Cox-2) and prostaglandin E synthase (Ptges/mPGES-1) was compromised in IRE1α-deficient myeloid cells undergoing ER stress or stimulated through pattern recognition receptors. Inducible biosynthesis of prostaglandins, including the pro-algesic mediator prostaglandin E2 (PGE2), was decreased in myeloid cells that lack IRE1α or XBP1 but not other ER stress sensors. Functional XBP1 transactivated the human PTGS2 and PTGES genes to enable optimal PGE2 production. Mice that lack IRE1α–XBP1 in leukocytes, or that were treated with IRE1α inhibitors, demonstrated reduced pain behaviors in PGE2-dependent models of pain. Thus, IRE1α–XBP1 is a mediator of prostaglandin biosynthesis and a potential target to control pain.

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1103.2-1103
Author(s):  
C. Edenius ◽  
G. Ekström ◽  
J. Kolmert ◽  
R. Morgenstern ◽  
P. Stenberg ◽  
...  

Background:Microsomal prostaglandin E synthase-1 (mPGES-1) catalyzes the formation prostaglandin (PG) E2from cyclooxygenase derived PGH2(1, 2). Inhibition of mPGES-1 leads to reduction of pro-inflammatory PGE2, while in vessels there is a concomitant increase of vasoprotective prostacyclin (PGI2) via shunting of PGH2(3,4). Apart from relieving symptoms in experimental animal models of inflammation, inhibitors of mPGES-1 cause relaxation of human medium sized arteries(4)and resistance arteries(5). The prostaglandin profile following mPGES-1 inhibition, explains the anti-inflammatory effects and also opens for the possibility of treating inflammatory diseases with concomitant vasculopathies. GS-248 is a potent and selective inhibitor of mPGES-1 exhibiting sub-nanomolar IC50in human whole bloodex vivo.Objectives:To evaluate safety, tolerability, pharmacokinetics and pharmacodynamics of GS-248.Methods:Healthy males and females (age 18–73 years) were included in the study. Six cohorts were administrated single oral doses of 1-300mg GS-248 (n=36) or placebo (n=12), three cohorts were administered once daily doses of 20-180mg GS-248 (n=18) or placebo (n=12) over ten days. In addition, 8 subjects were treated in a separate cohort with 200mg celecoxib bid for ten days. Blood samples were drawn for measurement of GS-248 exposure and production of PGE2after LPS incubationex vivo. The content of PGE2and PGI2metabolites was measured in urine. All analyses were performed by LC-MS/MS.Results:GS-248 was safe and well tolerated at all tested dose levels. Maximum plasma concentration was achieved 1 - 2.5 hours after dosing, and half-life was about 10 hours. Induced PGE2formationex vivo,catalyzed by mPGES-1, was completely inhibited for 24 hours after a single low dose (40mg) of GS-248. In urine, GS-248 dose-dependently reduced the excretion of PGE2metabolite by more than 50% whereas the excretion of PGI2metabolite increased more than twice the baseline levels. In the celecoxib cohort urinary metabolites of both PGE2and PGI2were reduced with approx 50%.Conclusion:GS-248 at investigated oral doses was safe and well tolerated. There was a sustained inhibition of LPS induced PGE2formation in whole blood. In urine, there was a metabolite shift showing reduced PGE2and increased PGI2, while celecoxib reduced both PGE2and PGI2metabolites. This suggests that selective inhibition of mPGES-1 results in systemic shunting of PGH2to PGI2formation, leading to anti-inflammatory and vasodilatory effects, while preventing platelet activation. The results warrant further evaluation of GS-248 in inflammatory conditions with vasculopathies such as Digital Ulcers and Raynaud’s Phenomenon in Systemic Sclerosis.References:[1]Korotkova M, Jakobsson PJ. Persisting eicosanoid pathways in rheumatic diseases. Nat Rev Rheumatol. 2014;10:229-41[2]Bergqvist F, Morgenstern R, Jakobsson PJ. A review on mPGES-1 inhibitors: From preclinical studies to clinical applications. Prostaglandins Other Lipid Mediat. 2019;147:106383[3]Kirkby NS, et al. Mechanistic definition of the cardiovascular mPGES-1/COX-2/ADMA axis. Cardiovasc Res. 2020[4]Ozen G, et al. Inhibition of microsomal PGE synthase-1 reduces human vascular tone by increasing PGI2: a safer alternative to COX-2 inhibition. Br J Pharmacol. 2017;174:4087-98[5]Larsson K, et al. Biological characterization of new inhibitors of microsomal PGE synthase-1 in preclinical models of inflammation and vascular tone. Br J Pharmacol. 2019;176:4625-38Disclosure of Interests:Charlotte Edenius Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Gunilla Ekström Shareholder of: Gesynta Pharma, Consultant of: Gesynta Pharma,, Johan Kolmert Consultant of: Gesynta Pharma,, Ralf Morgenstern Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Patric Stenberg Shareholder of: Gesynta Pharma, Employee of: Gesynta Pharma, Per-Johan Jakobsson Shareholder of: Gesynta Pharma, Grant/research support from: Gesynta Pharma, AstraZeneca,, Göran Tornling Shareholder of: Gesynta Pharma, Vicore Pharma,, Consultant of: Gesynta Pharma, Vicore Pharma, AnaMar


2018 ◽  
Vol 206 (1-2) ◽  
pp. 46-53 ◽  
Author(s):  
Maryam Sadat Tafakh ◽  
Massoud Saidijam ◽  
Tayebeh Ranjbarnejad ◽  
Sara Malih ◽  
Solmaz Mirzamohammadi ◽  
...  

Background: A high expression of prostaglandin E2 (PGE2) is found in colorectal cancer. Therefore, blocking of PGE2 generation has been identified as a promising approach for anticancer therapy. Sulforaphane (SFN), an isothiocyanate derived from glucosinolate, is used as the antioxidant and anticancer agents. Methods: HT-29 cells were treated with various concentrations of SFN and compared to untreated cells for the expression of microsomal prostaglandin E synthase-1 (mPGES-1), cyclooxygenase 2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-2 and MMP-9 at the mRNA level. The PGE2 level was measured by ELISA assay. Apoptosis was evaluated by the proportion of sub-G1 cells. The activity of caspase-3 was determined using an enzymatic assay. HT-29 cell migration was assessed using a scratch test. Results: SFN preconditioning decreased the expression of COX-2, mPGES-1, HIF-1, VEGF, CXCR4, MMP-2, and MMP-9. An apoptotic effect of SFN was preceded by the activation of caspase-3 as well as accumulation of cells in the sub-G1 phase of the cell cycle. SFN decreased PGE2 generation and inhibited the in vitro motility/wound-healing activity of HT-29 cells. Conclusions: SFN anticancer effects are associated with antiproliferative, antiangiogenic, and antimetastatic activities arising from the downregulation of the COX-2/ mPGES-1 axis.


2005 ◽  
Vol 53 (11) ◽  
pp. 1391-1401 ◽  
Author(s):  
William E. Ackerman IV ◽  
John M. Robinson ◽  
Douglas A. Kniss

Cytokine-induced prostaglandin (PG)E2 synthesis requires increased expression of cyclooxygenase-2 (COX-2) in human WISH epithelial cells. Recently, an inducible downstream PGE synthase (microsomal PGE synthase-1, mPGES-1) has been implicated in this inflammatory pathway. We evaluated cooperation between COX-2 and mPGES-1 as a potential mechanism for induced PGE2 production in WISH cells. Cytokine stimulation led to increased expression of both enzymes. Selective pharmacological inhibition of these enzymes demonstrated that induced PGE2 release occurred through a dominant COX-2/mPGES-1 pathway. Unexpectedly, immunofluorescent microscopy revealed that the expression of these enzymes was not tightly coordinated among cells after cytokine challenge. Within cells expressing high levels of both mPGES-1 and COX-2, immunolabeling of high-resolution semithin cryosections revealed that COX-2 and mPGES-1 were largely segregated to distinct regions within continuous intracellular membranes. Using biochemical means, it was further revealed that the majority of mPGES-1 resided within detergent-insoluble membrane fractions, whereas COX-2 was found only in detergent-soluble fractions. We conclude that although mPGES-1 and COX-2 show transcriptional and functional coordination in cytokine-induced PGE2 synthesis, complementary morphological and biochemical data suggest that a majority of intracellular mPGES-1 and COX-2 are segregated to discrete lipid microdomains in WISH epithelial cells.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4880-4880
Author(s):  
Eugene McPherson

Abstract Abstract 4880 Invasive squamous cell carcinoma of the penis overexpress Cyclooxygenase-2 (cox-2), Microsomal Prostaglandin E Synthase-1 and Alpha V Beta Integrins. Trace minerals selenium (selenomethionine) is deficient in many neoplasia conditions especially SCC of the penis in HIV-1 patients. Selenium, an essential trace element, has been shown to inhibit tumorigenesis. Hence, selenium and arachidonic acid metabolism may be linked to SCC. Penile cancer (SCC histology) displays elevated COX-2 and PGE2 can be regulated by selenium supplementation. We present a 47 We present a 47 yo male with HIV-1, CD4-133/cumm, VL of 95,000 copies/ml with T4 advanced stage SCC of the penis post XRT, surgical skin graft with extensive lymphedema, pain and KPS score of 40–50%. CT scan of Abdomen/Pelvis was c/w extensive disease of his right inguinal region, bladder compressed and displaced into left pelvis and tissue massof the right and left groin with ill defined nodular densities within RLL and left hepatic lobe. Bone marrow was hypocellular, M:E ratio of 8:1 with foamy macrophages. When treated for selenium deficient level and pain with selenomethionine and COX-2 inhibitor, acute tumor lysis syndrome developed with hyperkalemia, hyperuricemia and hypocalcemia defervesing with aggressive therapy with hydration, alkalinization and allopurinol. Conclusion: Overexpression of COX-2, mPEGS-1, alpha V beta integrin leads to phenotypic changes in epithelial cells that could enhance tumorigenesis. Selenium supplementation and COX-2 inhibition may help regulate COX-2 alternating cellular adhesion and promote apoptosis in SCC of the penis and upon treatment of these HIV-1 patients, with heavy tumor burden, tumor lysis syndrome along with disease Invasive squamous cell carcinoma of the penis overexpress Cyclooxygenase-2 (cox-2), Microsomal Prostaglandin E Synthase-1 and Alpha V Beta Integrins. Trace minerals selenium (selenomethionine) is deficient in many neoplasia conditions and PGE2 can be regulated by selenium supplementation. especially SCC of the penis in HIV-1 patients. Selenium, an essential trace element, has been shown to inhibit tumorigenesis. Hence, selenium and arachidonic acid metabolism may be linked to SCC. Penile cancer (SCC histology) displays elevated COX-2. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Guangrui Yang ◽  
Lihong Chen

Nonsteroidal anti-inflammatory drugs (NSAIDs), especially cyclooxygenase-2 (COX-2) selective inhibitors, are among the most widely used drugs to treat pain and inflammation. However, clinical trials have revealed that these inhibitors predisposed patients to a significantly increased cardiovascular risk, consisting of thrombosis, hypertension, myocardial infarction, heart failure, and sudden cardiac death. Thus, microsomal prostaglandin E (PGE) synthase-1 (mPGES-1), the key terminal enzyme involved in the synthesis of inflammatory prostaglandin E2(PGE2), and the four PGE2receptors (EP1–4) have gained much attention as alternative targets for the development of novel analgesics. The cardiovascular consequences of targeting mPGES-1 and the PGE2receptors are substantially studied. Inhibition of mPGES-1 has displayed a relatively innocuous or preferable cardiovascular profile. The modulation of the four EP receptors in cardiovascular system is diversely reported as well. In this review, we highlight the most recent advances from our and other studies on the regulation of PGE2, particularly mPGES-1 and the four PGE2receptors, in cardiovascular function, with a particular emphasis on blood pressure regulation, atherosclerosis, thrombosis, and myocardial infarction. This might lead to new avenues to improve cardiovascular disease management strategies and to seek optimized anti-inflammatory therapeutic options.


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