Elevated Prostaglandin E2 Levels Research Articles

Pathogenesis of chronic enteropathy associated with the SLCO2A1 gene: Hypotheses and conundrums.

Chronic enteropathy associated with the SLCO2A1 gene (CEAS) is a complex gastroenterological condition characterized by multiple ulcers in the small intestine with chronic bleeding and protein loss. This review explores the potential mechanisms underlying the pathogenesis of CEAS, focusing on the role of SLCO2A1-encoded prostaglandin transporter OATP2A1 and its impact on prostaglandin E2 (PGE2) levels. Studies have suggested that elevated PGE2 levels contribute to mucosal damage, inflammation, and disruption of the intestinal barrier. The effects of PGE2 on macrophage activation and Maxi-Cl channel functionality, as well as its interaction with nonsteroidal anti-inflammatory drugs play crucial roles in the progression of CEAS. Understanding the balance between its protective and pro-inflammatory effects and the complex interactions within the gastrointestinal tract can shed light on potential therapeutic targets for CEAS and guide the development of novel, targeted therapies.

Pyrazoles have a multifaceted anti-inflammatory effect targeting prostaglandin E2, cyclooxygenases and leukocytes’ oxidative burst

Elevated levels of prostaglandin E2 have been implicated in the pathophysiology of various diseases. Anti-inflammatory drugs that act through the inhibition of cyclooxygenase enzymatic activity, thereby leading to the suppression of prostaglandin E2, are often associated with several side effects due to their non-specific inhibition of cyclooxygenase enzymes. Consequently, the targeted suppression of prostaglandin E2 production with innovative molecules and/or mechanisms emerges as a compelling therapeutic strategy for the treatment of inflammatory-related diseases. Therefore, in this study, a systematic analysis of 28 pyrazole derivatives was conducted to explore their potential mechanisms for reducing prostaglandin E2 levels. In this context, the evaluation of these derivatives extended to examining their capacity to reduce prostaglandin E2in vitro in human whole blood, inhibit cyclooxygenase-1 and cyclooxygenase-2 enzymes, modulate cyclooxygenase-2 expression, and suppress oxidative burst in human leukocytes. The results enabled the establishment of significant structure-activity relationships, elucidating key determinants for their activities. In particular, the 4-styryl group on the pyrazole moiety and the presence of chloro substitutions were identified as key determinants. Pyrazole 8 demonstrated the capacity to reduce prostaglandin E2 levels by downregulating cyclooxygenase-2 expression, and pyrazole-1,2,3-triazole 18 emerged as a dual-acting agent, inhibiting human leukocytes' oxidative burst and cyclooxygenase-2 activity. Furthermore, pyrazole 26 demonstrated effective reduction of prostaglandin E2 levels through selective cyclooxygenase-1 inhibition. These results underscore the multifaceted anti-inflammatory potential of pyrazoles, providing new insights into the substitutions and structural frameworks that are beneficial for the studied activity.

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.

Airway and Systemic Prostaglandin E2 Association with COPD Symptoms and Macrophage Phenotype.

Polymorphisms and products of the cyclooxygenase (COX) pathway have been associated with the development of chronic obstructive pulmonary disease (COPD) and adverse outcomes. COX-produced prostaglandin E2 (PGE-2) may play a role in the inflammation observed in COPD, potentially through deleterious airway macrophage polarization. A better understanding of the role of PGE-2 in COPD morbidity may inform trials for therapeutics targeting the COX pathway or PGE-2. Urine and induced sputum were collected from former smokers with moderate-severe COPD. The major urinary metabolite of PGE-2 (PGE-M) was measured, and ELISA was performed on sputum supernatant for PGE-2 airway measurement. Airway macrophages underwent flow cytometry phenotyping (surface CD64, CD80, CD163, CD206, and intracellular IL-1β, TGF-β1). Health information was obtained the same day as the biologic sample collection. Exacerbations were collected at baseline and then monthly telephone calls. Among 30 former smokers with COPD (mean±SD age 66.4±8.88 years and forced expiratory volume in 1 second [FEV1] 62.4±8.37 percent predicted), a 1 pg/mL increase in sputum PGE-2 was associated with higher odds of experiencing at least one exacerbation in the prior 12 months (odds ratio 3.3; 95% confidence interval: 1.3 to15.0), worse respiratory symptoms and health status. PGE-M was not associated with exacerbations or symptoms. Neither airway PGE-2 nor urinary PGE-M was uniformly associated with an M1 or M2 polarization. Elevated levels of sputum PGE-2, rather than systemic PGE-2, is associated with increased respiratory symptoms and history of exacerbation among individuals with COPD. Additional studies focused on mechanism of action are warranted.

Syntaxin interacts with arachidonic acid to prevent diabetes mellitus

Syntaxin regulates pancreatic β cell mass and participates in insulin secretion by regulating insulin exocytosis. In addition, syntaxin 4 reduces IFNγ and TNF-α signaling via NF-ĸB in islet β-cells that facilitates plasma glucose sensing and appropriate insulin secretion. Arachidonic acid (AA) has potent anti-inflammatory actions and prevents the cytotoxic actions of alloxan and streptozotocin (STZ) against pancreatic β cells and thus, prevents the development of type 1 diabetes mellitus (induced by alloxan and STZ) and by virtue of its anti-inflammatory actions protects against the development of type 2 diabetes mellitus (DM) induced by STZ in experimental animals that are models of type 1 and type 2 DM in humans. AA has been shown to interact with syntaxin and thus, potentiate exocytosis. AA enhances cell membrane fluidity, increases the expression of GLUT and insulin receptors, and brings about its anti-inflammatory actions at least in part by enhancing the formation of its metabolite lipoxin A4 (LXA4). Prostaglandin E2 (PGE2), the pro-inflammatory metabolite of AA, activates ventromedial hypothalamus (VMH) neurons of the hypothalamus and inhibits insulin secretion leading to reduced glucose tolerance and decreases insulin sensitivity in the skeletal muscle and liver. This adverse action of PGE2 on insulin release and action can be attributed to its (PGE2) pro-inflammatory action and inhibitory action on vagal tone (vagus nerve and its principal neurotransmitter acetylcholine has potent anti-inflammatory actions). High fat diet fed animals have hypothalamic inflammation due to chronic elevation of PGE2. Patients with type 2 DM show low plasma concentrations of AA and LXA4 and elevated levels of PGE2. Administration of AA enhances LXA4 formation without altering or reducing PGE2 levels and thus, tilts the balance more towards anti-inflammatory events. These results suggest that administration of AA is useful in the prevention and management of DM by enhancing the action of syntaxin, increasing cell membrane fluidity, and reducing VMH inflammation. Docosahexaenoic acid (DHA) has actions like AA: it increases cell membrane fluidity; has anti-inflammatory actions by enhancing the formation of its anti-inflammatory metabolites resolvins, protectins and maresins; interacts with syntaxin and enhance exocytosis in general and of insulin. But the DHA content of cell membrane is lower compared to AA and its content in brain is significant. Hence, it is likely DHA is important in neurotransmitters secretion and regulating hypothalamic inflammation. It is likely that a combination of AA and DHA can prevent DM.

Anti-inflammatory and antioxidant effect of methanol extract of latex of Calotropis procera in rat model of colorectal cancer

Ethnopharmacological relevancePreparations derived from the plant Calotropis procera, have been used for medicinal purpose though the plant is known for its toxic effects. The aerial parts of the plant contain latex in plenty and have been found effective in treating disorders of gastrointestinal system and cancer. Aim of the studyThis study evaluated the efficacy of C. procera dried latex extract prepared in methanol (MeDL) against inflammation and oxidative stress in experimental model of colorectal carcinoma (CRC). Materials and methodsTwo subcutaneous injections of chemical carcinogen, 1,2-dimethylhydrazine (DMH; 150 mg/kg) were given at an interval of one week to induce CRC in rats. The MeDL (50 and 150 mg/kg) and aspirin (60 mg/kg) were given daily and their effect was evaluated on markers of oxidative stress and inflammation after completion of 8 weeks following second injection of carcinogen. A comparison was made with normal and experimental control groups. The colon tissue levels of glutathione (GSH), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), nitrite and myeloperoxidase (MPO) were determined. Enzyme-linked immunosorbent assay was performed to determine the levels of prostaglandin E2 (PGE2) and tumor necrosis factor-alpha (TNF-α) and immunohistochemical analysis was performed for IL-1β. ResultsInduction of cancerous changes in the colon resulted in altered oxidative homeostasis as evident from a reduction in GSH level and SOD activity and rise in TBARS level when compared with normal rats. Elevated levels of nitrite, MPO, TNF-α, PGE2 and immunoreactivity of IL-1β were also observed in these rats. The levels of these markers were normalized when the rats were treated with MeDL or anti-inflammatory drug, aspirin. ConclusionThis study demonstrates that suppression of oxidative stress and inflammation contributes to the beneficial effect of MeDL in rat model of colon carcinogenesis.

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.

Obesity Inhibits Innate Immune Functions During Pseudomonas aeruginosa Pneumonia

Abstract Obesity is a major global public health concern. Worldwide, 39% of the population is overweight and 13% of the population is obese. Obesity contributes to many diseases, such as heart disease, stroke, some cancers, and notably, type 2 diabetes (T2D). Although T2D itself is a non-communicable disease, many patients with diabetes are more susceptible to microbial infections and exhibit a higher burden of disease. Although obese animals have an increased production of myeloid cells, previous work from our labs has shown that a failure to heal diabetic wounds corresponds to elevated levels of prostaglandin E2 (PGE2) in the inflammatory macrophages that are recruited to the wound. Furthermore, past studies from our lab have demonstrated that PGE2 signaling can impair the innate immune functions of macrophages. Therefore, we hypothesized that diabetic obese mice would be more susceptible to a respiratory Pseudomonas aeruginosa strain PA01 infection due to impaired function of lung resident and recruited macrophages. Preliminary studies demonstrate that obese diabetic mice do have an increased P. aeruginosa burden in the lung 24 hours after infection. Additionally, we have determined that naïve obese diabetic mice have an increase in lung neutrophils compared to lean mice, however, after infection with P. aeruginosa, these mice have a trend of decreased neutrophil recruitment. Additionally, functional assays show that macrophages and neutrophils from obese diabetic mice have a defect in killing P. aeruginosa. These observations suggest that obese diabetic mice have not only a defect in innate immune cell recruitment, but also a defect in innate immune cell function during bacterial pneumonia. Supported by grants from NIH (T32 AI007528-21)

Assessment of hepatic prostaglandin E2 level in carbamazepine induced liver injury.

Objective. Carbamazepine (CBZ), a widely used antiepileptic drug, is one major cause of the idiosyncratic liver injury along with immune reactions. Conversely, prostaglandin E2 (PGE2) demonstrates a hepatoprotective effect by regulating immune reactions and promoting liver repair in various types of liver injury. However, the amount of hepatic PGE2 during CBZ-induced liver injury remains elusive. In this study, we aimed to evaluate the hepatic PGE2 levels during CBZ-induced liver injury using a mouse model. Methods. Mice were orally administered with CBZ at a dose of 400 mg/kg for 4 days, and 800 mg/kg on the 5th day. Results. Plasma alanine transaminase (ALT) level increased in some of mice 24 h after the last CBZ administration. Although median value of hepatic PGE2 amount in the CBZ-treated mice showed same extent as vehicle-treated control mice, it exhibited significant elevated level in mice with severe liver injury presented by a plasma ALT level >1000 IU/L. According to these results, mice had a plasma ALT level >1000 IU/L were defined as responders and the others as non-responders in this study. Even though, the hepatic PGE2 levels increased in responders, the hepatic expression and enzyme activity related to PGE2 production were not upregulated when compared with vehicle-treated control mice. However, the hepatic 15-hydroxyprostaglandin dehydrogenase (15-PGDH) expression and activity decreased significantly in responders when compared with control mice. Conclusions. These results indicate that elevated hepatic PGE2 levels can be attributed to the downregulation of 15-PGDH expression under CBZ-induced liver injury.

Evaluation of Therapeutic Efficacy of Stigma and Petal Extracts of Crocus sativus L. on Acetic Acid-Induced Gastric Ulcer in Rats

Saffron (Crocus sativus L.) has long been considered a medicinal plant in Traditional Persian Medicine (TPM) due to its therapeutic properties. Despite this interest, its effects on gastrointestinal disorders have not been completely taken into consideration. Hence, this study aimed to evaluate the pharmacological activity of ethanolic extracts of saffron stigma (SS) and saffron petal (SP) in acetic acid-induced gastric ulcer in rats. The gastric ulcer model was imitated by the serosal application of acetic acid in male Wistar rats. Then, the animals were orally fed with 100 mg/kg and 200 mg/kg of ethanolic extracts of SS or SP, omeprazole (40 mg/kg), or saline for 12 days. The macroscopic and microscopic appearances of gastric ulcers and the levels of malondialdehyde (MDA), vascular endothelial growth factor (VEGF), and prostaglandin E2 (PGE2) in gastric tissues were assessed. The highest anti-ulcer activity was observed in the omeprazole-treated animals with the lowest ulcer size (4.29 ± 1.78 mm2). SS could not reduce gastric ulcer size in rats. Compared to the untreated rats, SP treatment significantly decreased ulcer indices in a dose-dependent manner. The gastric levels of PGE2, VEGF, and MDA were significantly elevated in the untreated animals with gastric ulcers compared to rats in the control group. The SS extract suppressed the elevated PGE2 and VEGF levels at both doses, while SP did not have a significant influence. Both SS and SP treatments significantly ameliorated MDA levels in rats with gastric ulcers. Omeprazole treatment enhanced the PGE2 level and suppressed MDA contents, but it did not influence the VEGF level. In conclusion, our findings demonstrated that the saffron stigma has no significant effects on the gastric ulcer healing process, while its petals accelerate the process. This discrepancy can be attributed to the difference in the main secondary metabolites between saffron stigma and petals.

MO431LIPIDOMIC ANALYSIS IN A NON-DIABETIC RAT MODEL WITH HYPERFILTRATION AND ALBUMINURIA REVEALS DYNAMIC CHANGES IN THE PROSTAGLANDIN E2 PATHWAY DURING ONSET OF ALBUMINURIA AS A POTENTIAL CAUSATIVE MECHANISM

Abstract Background and Aims We recently identified prostaglandin reductase 2 (Ptgr2) and the prostaglandin E2 (PGE2) pathway as potential causative mechanism in the Munich Wistar Frömter (MWF) non-diabetic rat model of chronic kidney disease. MWF is characterized by early onset of spontaneous albuminuria during a critical time window between 4 and 8 weeks of age, that associates with hyperfiltration, due to low nephron number, and podocyte injury. Ptgr2 plays an important role in the prostaglandin metabolism, in which PGE2 is metabolized by 15-prostaglandin dehydrogenase (15-PGDH) to 15-keto-PGE2. The latter is terminally degraded by prostaglandin reductases (PTGRs) 1, 2, and 3 to 13,14-dihydro-15-keto-PGE2. Recently, we detected elevated glomerular levels of PGE2 and 15-keto-PGE2 in MWF compared to spontaneously hypertensive rats (SHR) with no albuminuria. The aim of the present study was to characterize in detail the renal PGE2 metabolic pathway in MWF by lipidomic analysis during the time window of albuminuria onset. Method Male MWF and SHR rats were studied at week 4 and 8, respectively; 24 h-urine was collected in metabolic cages. In addition, plasma and kidney tissues including kidney cortex and isolated glomeruli were obtained from anesthetized rats. Lipidomic analysis was done by liquid chromatography electrospray ionization tandem mass spectrometry. Statistical analysis was performed by unpaired, two-tailed Student’s t-test, or otherwise the Mann-Whitney test. Results Urinary PGE2 was significantly lower (p<0.01), while urinary 15-keto-PGE2 and 13,14-dihydro-15-keto PGE2 levels were significantly increased in MWF compared to SHR at week 4 (p<0.01, respectively). All three analytes were significantly decreased in urine of MWF with increased albuminuria at week 8 (p<0.05 vs. SHR). The urinary metabolic ratio of 15-keto-PGE2/13,14-dihydro-15-keto-PGE2 as a surrogate for PTGRs activities was significantly increased at week 4 (p<0.01), whereas it was significantly decreased in MWF vs. SHR at week 8 (p<0.05). Plasma levels of PGE2 and 13,14-dihydro-15-keto-PGE2 did not differ between strains at both time points, while 15-keto-PGE2 was below the detection limit. Glomerular levels of PGE2 and 15-keto-PGE2 were increased in MWF at week 4 and 8 (p<0.01, respectively). In contrast, 13,14-dihydro-15-keto-PGE2 was only significantly higher at week 4 compared to SHR (p<0.01). In isolated glomeruli, the metabolic ratios of PTGRs were similar between the strains at week 4, but significantly increased in MWF compared to SHR at week 8 (p<0.01, respectively). In kidney cortex, 15-keto-PGE2 and 13,14-dihydro-15-keto-PGE2 were increased in MWF at week 4 (p<0.05 and p<0.01, respectively), whereas PGE2 levels were comparable to SHR. No difference for cortical levels of PGE2 and its metabolites was observed at week 8. Conclusion This study provides the first insights into age-dependent dynamic changes in the PGE2 pathway that support potential causality for the onset of albuminuria in the setting of non-diabetic hyperfiltration due to low nephron number. Notably, the increased glomerular levels of PGE2 and its downstream metabolites in 4-week-old MWF point towards an early activation of this pathway, i.e. before albuminuria occurs. This finding corroborates the hypothesis that glomerular PGE2 signaling is relevant in the early stages of hyperfiltration and suggests this pathway as a target for future therapeutics to modify the manifestation and progression of renal disease.

Elevated levels of prostaglandin E2 in the tears of patients with severe allergic conjunctivitis and primary cultured conjunctival cells are suppressed by ketotifen and dexamethasone

ObjectiveWe examined the production of prostaglandin E2 (PGE2), which is the key prostaglandin involved in inflammatory disorders of the ocular surface. Tears and conjunctival fibroblasts were evaluated in order to...

Protective Role of Loranthus regularis against Liver Dysfunction, Inflammation, and Oxidative Stress in Streptozotocin Diabetic Rat Model.

Earlier studies revealed the potential therapeutic values of Loranthus regularis (L. regularis). This study evaluated Loranthus regularis (L. regularis) extract systemic antidiabetic effects and benefits against diabetic hepatocellular injuries through antioxidant and anti-inflammatory pathways using the streptozotocin (STZ) model in Wistar albino rats. After diabetes induction, animals were orally treated with L. regularis extract for 4 weeks. Serum levels of glucose, insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were estimated. Furthermore, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), caspase-3, nitric oxide (NO), and prostaglandin E-2 (PGE-2) were estimated in serum. In liver, thiobarbituric acid reactive substances (TBARSs) and reduced glutathione (GSH) as well as the proinflammatory cytokines and enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reeducates (GR), and glutathione-S-transferase (GST) were assayed. Finally, the degree of hepatic tissue damage was evaluated histologically. Treatment of the diabetic rats with L. regularis extract markedly reduced the elevated serum levels of glucose, ALT, AST, TC, TG, LDL, TNF-α, IL-1β, IL-6, caspase-3, NO, and PGE-2. L. regularis extract also improved serum levels of insulin and HDL. The elevated TBARS, TNF-α, IL-1β, and IL-6 levels in hepatic tissue of diabetic animals were reduced by L. regularis. Moreover, L. regularis extract significantly restored the diminished hepatic GSH level and enzymatic activities of SOD, CAT, GPx, GR, and GST in diabetic animals. The biochemical protective effects of L. regularis were associated with improved histological hepatocellular integrity and architecture. Taken together, L. regularis has therapeutic effects against diabetic-induced hepatic complications. The restored liver functions and cellular damage might be mediated through free radicals scavenging and proinflammatory cytokine inhibition.

Famotidine with Celecoxib Adjuvant Therapy on Hospitalized COVID-19 Patients: A Case Series

BACKGROUND: Up to 80% of SARS-CoV-2 positive patients are asymptomatic and do not appear to progress to COVID-19. SARS-CoV-2 infection is not sufficient for development of COVID-19 disease; this may reflect differences in host inflammatory responses to infection. COX-2 expression is transcriptionally upregulated by SARS nucleocapsid N protein, and COVID-19 is associated with markedly elevated levels of prostaglandin E2 (PGE2). PGE2 modulates a wide variety of innate and adaptive inflammatory responses including mast cell activation. SARS-CoV-2 infection-associated mast cell degranulation may play a role in development of COVID-19. A randomized trial of hospitalized COVID-19 cases has demonstrated that COX-2 protein antagonist celecoxib dampened systemic PGE2 levels, prevented clinical deterioration, and was associated with rapid pulmonary CT-chest improvement. High doses of famotidine, a histamine H2 receptor antagonist/inverse agonist reduces severity of COVID-19 symptoms. We hypothesize that adjuvant therapy with a combination of celecoxib and high dose (HD) famotidine may improve COVID-19 outcomes.METHODS: We report a single institution, consecutive case series of 25 COVID-19 hospitalized patients treated with celecoxib and HD famotidine as adjuvant therapy. Outcome measurements include time to discharge, changes in supplemental oxygen requirements, pulmonary CT-chest findings, and laboratory changes in peripheral blood lactate dehydrogenase (LDH), C-reactive protein (CRP), ferritin, neutrophil counts, lymphocyte levels, neutrophil/lymphocyte ratio, creatinine, glomerular filtration rate, Interleukin 6 (IL6) and D-dimer concentrations. Nucleocapsid N protein sequence analysis was performed to compare COX-2 promoter activation domains of SARS, SARS-CoV-2, and related Sarbecovirus betacoronaviruses.RESULTS: All 25 patients in the series survived hospitalized COVID-19 without mechanical ventilation or renal replacement therapy (RRT) and were discharged on room air within a median of 3 days (range 1-16 days). Statistically significant improvements from admission to discharge were observed for all aggregated outcome measures. In general, progressive improvement was noted in supplemental oxygen requirements and ground-glass CT findings. Amino acid sequence analysis demonstrated high levels of conservation of N2 protein COX-2 promoter transactivation domains and nuclear localization sequences between SARS, SARS-CoV-2, and closely related Pangolin, Civet cat, and Horseshoe bat coronaviruses, but not MERS or other human or animal Betacoronaviruses.DISCUSSION: In this series, combined treatment with oral celecoxib and HD famotidine in an adjuvant setting was associated with 100% survival and improved radiographic outcomes, as well as statistically significant improvements in clinical, biomarker, and renal function measurements. The 9 patients with extremely high LDH (>365, Wuhan model prediction of 98% mortality) survived and were discharged on room air. Conservation of SARS and SARS-CoV-2 nucleocapsid N protein N2 sequences support that celecoxib treatment may mitigate the effects of direct viral transactivation of COX-2 expression in infected cells. HD famotidine acts to reduce cellular effects of local histamine via H2 receptor antagonism. Acute kidney injury was either prevented or mitigated by treatment; HD famotidine contributes to this effect. In contrast to these findings, previously published COVID-19 clinical intervention studies have not shown consistent laboratory or radiographic improvement. The data support performing randomized placebo-controlled trials to further examine the hypothesis that celecoxib with HD famotidine as adjuvant therapy to standard of care may reverse and prevent clinical deterioration in adult hospitalized COVID-19 patients.

Abstract A64: Commensal dysbiosis alters the tumor microenvironment in breast cancer and diminishes efficacy of PD-L1 blockade

Abstract Hormone receptor-positive (HR+) breast cancer is largely nonresponsive to checkpoint blockade therapy. Alterations in the composition of commensal microbes influence the systemic immune environment and can diminish responses to checkpoint blockade. Reduced diversity of commensal microbes, known as dysbiosis, has been demonstrated in women with advanced breast cancer and is associated with increases of systemic immunosuppressive mediators that are detrimental in the context of breast cancer, including prostaglandin E2 (PGE2). This bioactive lipid promotes the differentiation of myeloid cells that can exert immunosuppressive effects in the tumor microenvironment. In a novel, clinically relevant model of HR+ breast cancer, PD-L1 blockade was effective when combined with meloxicam, a drug that targets PGE2 synthesis through inhibition of COX-2. However, this combination therapy was ineffective in mice that were previously treated with antibiotics to induce dysbiosis, despite elevated levels of PGE2 in these animals. Commensal dysbiosis altered the cellular composition within the tumor microenvironment, promoting the recruitment of suppressive myeloid populations and driving significant and irreversible T-cell dysfunction. Importantly, COX-1 also regulates PGE2 synthesis, and mammary glands from dysbiotic mice showed significantly enhanced COX-1 activity, suggesting a previously unknown mechanism by which dysbiosis can affect breast tumor progression and resistance to therapy. Targeting COX-1-mediated PGE2 synthesis resulted in decreased tumor burden only in dysbiotic mice, suggesting that dysbiosis-induced COX-1-mediated tissue inflammation is sufficient to drive immune suppression in advanced breast cancer. This work provides important insights on the premalignant environment in the breast, enhances our understanding of the mechanisms driving failure of PD-1/PD-L1 blockade, and identifies novel targets that may provide clinical benefit for women with breast cancer. Citation Format: Claire Buchta Rosean, Raegan Bostic, Tzu Yu Feng, Melanie R. Rutkowski. Commensal dysbiosis alters the tumor microenvironment in breast cancer and diminishes efficacy of PD-L1 blockade [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A64.

Interleukin-1 receptor antagonist ameliorates the pain hypersensitivity, spinal inflammation and oxidative stress induced by systemic lipopolysaccharide in neonatal rats

Perinatal inflammation-induced reduction in pain threshold may alter pain sensitivity to hyperalgesia or allodynia which may persist into adulthood. In this study, we investigated the anti-inflammatory protective effect of interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory cytokine, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation and oxidative stress, thermal hyperalgesia, and mechanical allodynia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups, and IL-1ra (100 mg/kg) or saline was administered (i.p.) 5 min after LPS injection. Pain reflex behavior, spinal cord inflammation and oxidative stress were examined 24 h after LPS administration. Systemic LPS exposure led to a reduction of tactile threshold in the von Frey filament tests (mechanical allodynia) and pain response latency in the tail-flick test (thermal hyperalgesia) of P6 neonatal rats. Spinal cord inflammation was indicated by the increased numbers of activated glial cells including microglia (Iba1+) and astrocytes (GFAP+), and elevated levels of pro-inflammatory cytokine interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) 24 h after LPS treatment. LPS treatment induced spinal oxidative stress as evidenced by the increase in thiobarbituric acid reactive substances (TBARS) content in the spinal cord. LPS exposure also led to a significant increase in oligodendrocyte lineage population (Olig2+) and mature oligodendrocyte cells (APC+) in the neonatal rat spinal cord. IL-1ra treatment significantly reduced LPS-induced effects including hyperalgesia, allodynia, the increased number of activated microglia, astrocytes and oligodendrocytes, and elevated levels of IL-1β, COX-2, PGE2, and lipid peroxidation (TBARS) in the neonatal rat spinal cord. These data suggest that IL-1ra provides a protective effect against the development of pain hypersensitivity, spinal cord inflammation and oxidative stress in the neonatal rats following LPS exposure, which may be associated with the blockade of LPS-induced pro-inflammatory cytokine IL-1β.

Altered plasma prostaglandin E2 levels in epilepsy and in response to antiepileptic drug monotherapy

Prostaglandin E2 (PGE2), a physiologically active lipid compound, is increased in several diseases characterized by chronic inflammation. To determine its significance in epilepsy-associated inflammation and response to antiepileptic drug (AED), we evaluated the plasma PGE2 (median, pg/ml) levels in drug-free patients with epilepsy (N = 34) and patients receiving AED monotherapy (N = 55) in addition to that in healthy controls (N = 34). When compared to controls, plasma PGE2 levels were significantly elevated in all drug-free patients independent of the type of epilepsy (137.2 versus 475.7 pg/ml, p < 0.0001). Among the patients receiving AED monotherapy, only valproate responders showed a significant decrease compared to both drug-free patients (232.1 versus 475.7 pg/ml, p < 0.01) as well as valproate non-responders (232.1 versus 611.9 pg/ml, p < 0.0001). Both responders and non-responders on phenytoin or carbamazepine monotherapy had elevated PGE2 levels similar to drug-free patients. In addition, no difference was observed in plasma profiles of PGE2 precursor, arachidonic acid among the groups. Our work presents the clinical evidence of the association between plasma PGE2 levels and valproate efficacy in patients with epilepsy.

EP3 receptor antagonist L798,106 reduces proliferation and migration of SK-BR-3 breast cancer cells.

Purpose: COX-2 overexpression and elevated levels of prostaglandin E2 (PGE2) play an important role in breast cancer carcinogenesis. Recently, expression of the PGE2 receptor EP3 has been shown to be a positive prognostic factor in breast cancer. This study analyzes the functional aspects of targeting EP3 in breast cancer cell lines.Material and methods: EP3 and EP1 expressions were determined in five breast cancer cell lines on the mRNA- and the protein-level. The selected cell lines were subsequently stimulated for 24–72 hrs with 10–1,000 nM of PGE2, the EP1/EP3 agonist sulprostone and the EP3 antagonist L798,106. Cell proliferation was determined via BrdU-assay, migration via scratch assay, EP3, Gi-protein and p-ERK1/2 expressions via Western blot and cAMP concentrations via ELISA. The Mann–Whitney-U-test was used to test for statistical significance.Results: The cell lines T-47D (EP3 expression 77.7%) and SK-BR-3 (EP3 expression 48.7%) were chosen. EP3 antagonism reduced its expression on SK-BR-3 significantly, while no effect was observed on T-47D. The proliferation and migration of SK-BR-3 cells were significantly reduced due to treatment with the EP1/3 agonist, the EP3 antagonist or a combination of both. Neither agonism nor antagonism influenced cell proliferation or migration in T-47D. In SK-BR-3, EP3 antagonism showed a significant decrease in Gi-protein levels, an increase in cAMP levels, and no significant change in p-ERK1/2 expression.Conclusion: Antagonism of the EP3 receptor results in a reduced proliferation and migration of SK-BR-3 breast cancer cells, potentially mediated via a Gi-protein-cAMP pathway. The results suggest that EP3 plays a role in tumorigenesis. This is in accordance with the cell culture data of other gynecological tumors, but it is conflicting in so far, as positive EP3 expression is clinically a positive prognostic marker in breast cancer. Therefore, other factors may be important in explaining this contradiction.

The first case of primary hypertrophic osteoarthropathy with soft tissue giant tumors caused by HPGD loss-of-function mutation.

BackgroundPrimary hypertrophic osteoarthropathy (PHO) is a rare genetic multi-organic disease characterized by digital clubbing, periostosis and pachydermia. Two genes, HPGD and SLCO2A1, which encodes 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and prostaglandin transporter (PGT), respectively, have been reported to be related to PHO. Deficiency of aforementioned two genes leads to failure of prostaglandin E2 (PGE2) degradation and thereby elevated levels of PGE2. PGE2 plays an important role in tumorigenesis. Studies revealed a tumor suppressor activity of 15-PGDH in tumors, such as lung, bladder and breast cancers. However, to date, no HPGD-mutated PHO patients presenting concomitant tumor has been documented. In the present study, we reported the first case of HPGD-mutated PHO patient with soft tissue giant tumors at lower legs and evaluated the efficacy of selective COX-2 inhibitor (etoricoxib) treatment in the patient.MethodsIn this study, we summarized the clinical data, collected the serum and urine samples for biochemical test and analyzed the HPGD gene in our patient.ResultsA common HPGD mutation c.310_311delCT was identified in the patient. In addition to typical clinical features (digital clubbing, periostosis and pachydermia), the patient demonstrated a new clinical manifestation, a giant soft tissue tumor on the left lower leg which has not been reported in HPGD-mutated PHO patient before. After 6-month treatment with etoricoxib, the patient showed decreased PGE2 levels and improved PHO-related symptoms. Though the soft tissue tumor persisted, it seemed to be controlled under the etoricoxib treatment.ConclusionThis finding expanded the clinical spectrum of PHO and provided unique insights into the HPGD-mutated PHO.

Systemic Lipopolysaccharide-Induced Pain Sensitivity and Spinal Inflammation Were Reduced by Minocycline in Neonatal Rats.

In this study, we investigated the effects of minocycline, a putative suppressor of microglial activation, on systemic lipopolysaccharide (LPS)-induced spinal cord inflammation, allodynia, and hyperalgesia in neonatal rats. Intraperitoneal (i.p.) injection of LPS (2 mg/kg) or sterile saline was performed in postnatal day 5 (P5) rat pups and minocycline (45 mg/kg) or vehicle (phosphate buffer saline; PBS) was administered (i.p.) 5 min after LPS injection. The von Frey filament and tail-flick tests were performed to determine mechanical allodynia (a painful sensation caused by innocuous stimuli, e.g., light touch) and thermal hyperalgesia (a condition of altered perception of temperature), respectively, and spinal cord inflammation was examined 24 h after the administration of drugs. Systemic LPS administration resulted in a reduction of tactile threshold in the von Frey filament tests and pain response latency in the tail-flick test of neonatal rats. The levels of microglia and astrocyte activation, pro-inflammatory cytokine interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) in the spinal cord of neonatal rats were increased 24 h after the administration of LPS. Treatment with minocycline significantly attenuated LPS-induced allodynia, hyperalgesia, the increase in spinal cord microglia, and astrocyte activation, and elevated levels of IL-1β, COX-2, and PGE2 in neonatal rats. These results suggest that minocycline provides protection against neonatal systemic LPS exposure-induced enhanced pain sensitivity (allodynia and hyperalgesia), and that the protective effects may be associated with its ability to attenuate LPS-induced microglia activation, and the levels of IL-1β, COX-2, and PGE2 in the spinal cord of neonatal rats.