PG Pathway Research Articles

Unraveling the anti-primary dysmenorrhea mechanism of Ainsliaea fragrans Champ. extract by the integrative approach of network pharmacology and experimental verification

BackgroundThe plant Ainsliaea fragrans Champ. (A. fragrans) named "Xingxiang Tuerfeng", is a traditional herb with a long history of therapeutic practice in southern China in the treatment of gynecological diseases. PurposeThe anti-inflammatory extract of Ainsliaea fragrans Champ. (AF-ext) exhibited anti-primary dysmenorrhea (PD) activity in oxytocin-induced mice. This study aimed to unravel the underlying mechanisms of AF-ext on PD by the integrative approach of network pharmacology and experimental verification. MethodsFirst, the therapeutic targets of AF-ext are predicted using network pharmacology and molecular docking methods. Second, activity screening and immunoblotting methods were used for target validation. Then, the therapeutic effect of AF-ext on PD was evaluated using oxytocin-induced mice and uterine strips model. ResultsAF-p1, and AF-p2, the active ingredients of AF-ext, showed inhibitory effects on COX1/2 and EGFR, and all five active components showed antagonistic activity on TRPV1. AF-ext (25, 50, 100 mg/kg) could significantly reduce the number of writhing times and prolong writhing latencies in a dose-dependent manner. AF-ext inhibited spasmolytic activity in uterine strips induced by oxytocin and Ca2+ stimulation. AF-ext inhibited NF-κB/COX-2/PG pathway and activation of the NLRP3 inflammasome in PD mice. It significantly downregulated the PD-induced overexpression of p-p65/p65, p-IκBα, and COX-2 by inhibiting the NF-κB pathway. Moreover, the overexpression of NLRP3, p20/pro-Caspase 1, and p17/pro-IL-1β was greatly downregulated. ConclusionsAF-ext demonstrated anti-inflammatory, analgesic, and spasmolytic activity in the treatment of PD. It inhibited the NF-κB/COX-2/PG pathway and NLRP3 inflammasome activation in PD mice with a multi-target approach.

Antioxidative and Anti-Inflammatory Activities of Rosebud Extracts of Newly Crossbred Roses.

Oxidative stress and inflammation are basic pathogenic factors involved in tissue injury and pain, as well as acute and chronic diseases. Since long-term uses of synthetic steroids and non-steroidal anti-inflammatory drugs (NSAIDs) cause severe adverse effects, novel effective materials with minimal side effects are required. In this study, polyphenol content and antioxidative activity of rosebud extracts from 24 newly crossbred Korean roses were analyzed. Among them, Pretty Velvet rosebud extract (PVRE) was found to contain high polyphenols and to show in vitro antioxidative and anti-inflammatory activities. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), PVRE down-regulated mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and thereby decreased nitric oxide (NO) and prostaglandin E2 (PGE2) production. In a subcutaneous air-pouch inflammation model, treatment with PVRE decreased λ-carrageenan-induced tissue exudation, infiltration of inflammatory cells, and inflammatory cytokines such as tumor necrosis factor-α and interleukin-1β concentrations, as achieved with dexamethasone (a representative steroid). Notably, PVRE also inhibited PGE2, similar to dexamethasone and indomethacin (a representative NSAID). The anti-inflammatory effects of PVRE were confirmed by microscopic findings, attenuating tissue erythema, edema, and inflammatory cell infiltration. These results indicate that PVRE exhibits dual (steroid- and NSAID-like) anti-inflammatory activities by blocking both the iNOS-NO and COX-2-PG pathways, and that PVRE could be a potential candidate as an anti-inflammatory material for diverse tissue injuries.

Sperm-Guiding Unconventional Prostaglandins in C. elegans: Synthesis and Signaling.

Prostaglandins comprise a family of lipid signaling molecules derived from polyunsaturated fatty acids and are involved in a wide array of biological processes, including fertilization. Prostaglandin-endoperoxide synthase (a.k.a. cyclooxygenase or Cox) initiates prostaglandin synthesis from 20-carbon polyunsaturated fatty acids, such as arachidonic acid. Oocytes of Caenorhabditis elegans (C. elegans) have been shown to secrete sperm-guidance cues prostaglandins, independent of Cox enzymes. Both prostaglandin synthesis and signal transduction in C. elegans are environmentally modulated pathways that regulate sperm guidance to the fertilization site. Environmental factors such as food triggers insulin and TGF-β secretion and their levels regulate tissue-specific prostaglandin synthesis in C. elegans. This novel PG pathway is abundant in mouse and human ovarian follicular fluid, where their functions, mechanism of synthesis and pathways remain to be established. Given the importance of prostaglandins in reproductive processes, a better understanding of how diets and other environmental factors influence their synthesis and function may lead to new strategies towards improving fertility in mammals.

Trans triacylglycerols from dairy products and industrial hydrogenated oil exhibit different effects on the function of human umbilical vein endothelial cells via modulating phospholipase A2/arachidonic acid metabolism pathways

Dairy fat intake has been considered as a risk factor for cardiovascular disease. Rodent models show that trans fatty acids in industrial hydrogenated oil and ruminant milk have different effects on cardiovascular diseases. One of the main reasons is that the distributions of trans fatty acids in triacylglycerols from dairy products and from industrial hydrogenated oil are different, which affects lipid absorption and metabolism. This study investigated the effects of 1,3-olein-2-elaidin (OEO, representing industrial hydrogenated oil triacylglycerols) and 1-vaccenic-2,3-olein (OOV, representing ruminant triacylglycerols in dairy products) on the function of human umbilical vein endothelial cells (HUVEC), including cell viability, lactate dehydrogenase (LDH) exudation rate, and nitric oxide secretory and nitric oxide synthase relative activity. We found that the detrimental effect of OEO on HUVEC was significantly greater than that of OOV. The results also showed that the absorption rate of OEO in HUVEC (78.25%) was significantly greater than that of OOV (63.32%). Mechanistically, based on phospholipidomics analysis, we found that calcium-independent phospholipase A2 (iPLA2) played a key role with regard to the OOV-mediated arachidonic acid (ARA)/COX-2/PG pathway, whereas secretory phospholipase A2 (sPLA2) and cytoplasmic phospholipase A2 (cPLA2) are responsible for the OEO-mediated ARA/COX-2/PG pathway. Moreover, OEO had a greater effect on the protein expression of COX-2 and PG secretion than OOV. In addition, iPLA2, sPLA2, and cPLA2 could mediate the ARA/CYP4A11 pathway in OOV-treated HUVEC, but only iPLA2 could mediate this pathway in HUVEC treated with OEO. We also found that sPLA2 could mediate the ARA/5-LOX pathway in HUVEC treated with OOV, but none of these 3 forms of PLA2 could mediate this pathway in HUVEC treated with OEO. On the other hand, after OOV treatment, trans-11 C18:1 was converted to beneficial forms of fatty acids in HUVEC, including conjugated linoleic acid (CLA) and trans-9 C16:1. In conclusion, we elucidated the potential mechanisms that might account for the diverse effects of triacylglycerols from industrial hydrogenated oil and ruminant milk on the function of HUVEC.

NLRP3 inflammasome inhibitor MCC950 attenuates primary dysmenorrhea in mice via the NF-\u03baB/COX-2/PG pathway

BackgroundPrimary dysmenorrhea (PD) constitutes a common gynecological disease among young women. The NLRP3 inflammasome may be activated and expressed in PD, but the mechanistic link between NLRP3 inflammasome activation and PD is still unclear.MethodsTo investigate the potential role of NLRP3 inflammasome activation in the pathogenesis of PD, 30 female Kunming mice without pregnancy were used for experiments. The PD mouse model was constructed by 11 days of successive co-treatment with estradiol and oxytocin. MCC950, a potent and specific small-molecule inhibitor of the NLRP3 inflammasome, was used to treat PD mice. The disease level was assessed by the writhing response and hot water tail-flick test. The levels of prostaglandin E2 (PGE2) and prostaglandin F2 alpha (PGF2α) in the uterine tissues of mice were detected by ELISA. The expression levels of protein and cytokines, including NLRP3, cysteine aspartic acid-specific protease 1 (caspase-1), interleukin (IL)-1β, IL-18, nuclear factor kappa B (NF-κB) p65, phospho-NF-κB p65, and cyclooxygenase-2 (COX-2) were revealed by western blot analysis.ResultsMCC950 greatly ameliorated the writhing response induced by the combination of oxytocin and estradiol, with an increasing length of tail-flick latency. MCC950 also significantly decreased the levels of PGF2α and PGE2, and the expressions of NLRP3, caspase-1, IL-1β, IL-18, phospho-NF-κB p65, NF-κB p65, and COX-2 in the uterus.ConclusionsMCC950 markedly alleviated the pain and pathological damage in PD mice by inhibiting NLRP3 activation. The underlying mechanism may be related to hypoactive uterine inflammation via suppression of NLRP3 activation and the NF-κB/COX-2/PG pathway in uteruses of PD mice.

Transcriptomics and Metabolite Analysis Reveals the Molecular Mechanism of Anthocyanin Biosynthesis Branch Pathway in Different Senecio cruentus Cultivars

The cyanidin (Cy), pelargonidin (Pg), and delphinidin (Dp) pathways are the three major branching anthocyanin biosynthesis pathways that regulate flavonoid metabolic flux and are responsible for red, orange, and blue flower colors, respectively. Different species have evolved to develop multiple regulation mechanisms that form the branched pathways. In the current study, five Senecio cruentus cultivars with different colors were investigated. We found that the white and yellow cultivars do not accumulate anthocyanin and that the blue, pink, and carmine cultivars mainly accumulate Dp, Pg, and Cy in differing densities. Subsequent transcriptome analysis determined that there were 43 unigenes encoding anthocyanin biosynthesis genes in the blue cultivar. We also combined chemical and transcriptomic analyses to investigate the major metabolic pathways that are related to the observed differences in flower pigmentation in the series of S. cruentus. The results showed that mutations of the ScbHLH17 and ScCHI1/2 coding regions abolish anthocyanin formation in the white and the yellow cultivars; the competition of the ScF3′H1, ScF3′5′H, and ScDFR1/2 genes for naringenin determines the differences in branching metabolic flux of the Cy, Dp, and Pg pathways. Our findings provide new insights into the regulation of anthocyanin branching and also supplement gene resources (including ScF3′5 ′H, ScF3′H, and ScDFRs) for flower color modification of ornamentals.

Flaxseed reduces the pro-carcinogenic micro-environment in the ovaries of normal hens by altering the PG and oestrogen pathways in a dose-dependent manner.

The objective of the present study was to find the optimum dose of flaxseed that would decrease PG and alter oestrogen pathway endpoints implicated in ovarian cancer. In the study, four groups of fifty 1.5-year-old chickens were fed different amounts of flaxseed (0, 5, 10 or 15% of their total diet) for 4 months and were then killed to collect blood and tissues. Levels of flaxseed lignan metabolites, Enterolactone (EL) and Enterodiol (ED) were measured in the serum, liver and ovaries by liquid chromatography-MS/MS, and n-3 and n-6 fatty acid (FA) levels were measured by GC. The effects of the varied flaxseed doses were assessed by measuring levels of PGE2 and oestrogen metabolites (16-hydroxyestrone (16-OHE1) and 2-hydroxyestrone (2-OHE1)) as well as by analysing the expression of the oestradiol metabolising enzymes CYP3A4 (cytochrome p450, family 3, subfamily A, polypeptide 4), CYP1B1 (cytochrome p450, family 1, subfamily B, polypeptide 1) and CYP1A1 (cytochrome p450, family 1, subfamily A, polypeptide 1) and that of oestrogen receptor α (ERα) in the ovaries. The ratio of n-3:n-FA increased with an increase in flaxseed supplementation and corresponded to a dose-dependent decrease in cyclo-oxygenase-2 protein and PGE2 levels. EL and ED increased in the serum, liver and ovaries with increased concentrations of flaxseed. Flaxseed decreased the expression of ERα in the ovaries. The ratio of 2-OHE1:16-OHE1 in the serum increased significantly in the 15% flaxseed diet, and there was a corresponding increase in CYP1A1 in the liver and decrease in CYP3A4 in the ovaries. CYP1B1 mRNA also decreased with flaxseed diet in the ovaries. The 15% flaxseed-supplemented diet significantly decreased inflammatory PGE2, ERα, CYP3A4, CYP1B1 and 16-OHE1, but it increased CYP1A1 and 2-OHE1, which thus reduced the inflammatory and pro-carcinogenic micro-environment of the ovaries.

P47 Exogenous and endogenous hydrogen sulfide (H2S) in gastroprotection against ischemia/reperfusion lesions progressing into chronic ulcers. Role of endogenous prostaglandins, sensory neuropeptides and vanilloid receptors

H 2 S is an endogenous gasotransmitter which exerts vasodilatatory, neuromodulatory and anti-inflammatory activities but little is known whether this gaseous mediator affects ischemia–reperfusion (I/R)-induced gastric erosions. We studied the effect of H 2 S precursor, l -cysteine and H 2 S-donor, NaHS on I/R lesions induced by 30 min of I followed by 3 h of R and their progression into chronic gastric ulcers at 12–72 h after the end of I. Rats exposed to I/R received once daily (1) l -cysteine (2–40 mg/kg) and (2) NaHS (0.1–10 mg/kg i.g.) combined or not with the inhibitor of CSE, d , l -propargylglycine (PAG 30 mg/kg i.g.); (3) the non-selective (indomethacin; 5 mg/kg i.p.) or selective COX-1 (SC-560, 5 mg/kg i.p.) and COX-2 inhibitors (celecoxib 30 mg/kg i.g.); (4) blockade of sensory nerves by capsaicin (125 mg/kg s.c.) and the inhibition of vanilloid receptor (VR-1) by capsazepine (10 mg/kg i.g.). The number of gastric lesions was measured by planimetry, the gastric blood flow (GBF) determined by H 2 -gas clearance technique, the mucosal concentration of H 2 S was determined spectrophotometrically, the plasma IL-1beta and TNF-alpha were determined by ELISA and mRNA expressions for CSE, COX-1-, COX-2-, CGRP, IL-1beta-, and TNF-alpha were assessed by RT-PCR. I/R-induced gastric mucosal lesions progressed into gastric ulcers at 72 h following the end of I. The significant fall in the H 2 S concentration and GBF were observed in gastric mucosa of I/R and these effects persisted up to 72 h upon standard I/R. NaHS (5 mg/kg i.g.) and l -cysteine (20 mg/kg i.g.) which significantly increased H 2 S content in the gastric mucosa and GBF, significantly reduced I/R-induced gastric lesions area at 24 h and 72 h following end of I. Capsaicin denervation, capsazepine and treatment with COXs inhibitors exacerbated I/R injury and significantly reduced the GBF and these effects were reversed by co-treatment with CGRP (10 μg/kg s.c.) or dimethyl PGE 2 (5 μg/kg i.g.) in the presence of NaHS and cysteine in capsaicin-denervated or COX-1- and COX-2-inhibited animals. The mRNA expression for CSE and CBS was increased in I/R gastric mucosa and this was inhibited by NaHS and cysteine. We conclude that (1) pathogenesis of I/R injury involves the fall in the generation of H 2 S and (2) NaHS and cysteine protect the gastric mucosa against I/R lesions and accelerate the healing of these lesions progressing into gastric ulcers via an increase in GBF mediated by endogenous H 2 S, PG pathway and CGRP.

Genetic polymorphisms of SLC28A3, SLC29A1 and RRM1 predict clinical outcome in patients with metastatic breast cancer receiving gemcitabine plus paclitaxel chemotherapy

BackgroundPaclitaxel and gemcitabine (PG) combination chemotherapy is effective as a maintenance chemotherapeutic regimen in metastatic breast cancer (MBC) patients because it increases progression-free survival (PFS), which increases overall survival (OS). The primary purpose of our study was to investigate the association between genetic polymorphisms in the genes involved in PG pathways and clinical outcomes in MBC patients treated with PG chemotherapy. MethodsA total of 324 MBC patients were enrolled in this prospective multicenter trial of PG as the first-line chemotherapy. Eighty-five of the 324 patients from two institutes were available for analysis of single nucleotide polymorphisms (SNPs). Germline DNA was extracted from peripheral blood mononuclear cells. Thirty-eight SNPs in 15 candidate genes selected from pathways that may influence the metabolism and transport of, or sensitivity, to PG were analysed. ResultsThe median PFS and OS of all 324 patients were 8.7months (95% confidence interval [CI]: 7.5–9.6months) and 26.9months (95% CI: 23.6–30.1months), respectively. An SNP in SLC28A3 (rs7867504, C/T) was associated with OS (CC or CT versus TT: 37 versus 21months, p=0.027, hazard ratio [HR] 2.6, 95% CI: 1.1–6.3). SLC29A1 GA haplotype had a significantly shorter OS (p=0.030, HR 3.391, 95% CI: 1.13–10.19). RRM1 (ribonucleotide reductase large subunit M1) SNP (rs9937), and haplotypes ATAA and ATGA were significantly associated with neurotoxicity. ConclusionGenetic polymorphisms in SLC28A3, SLC29A1 and RRM1 can influence the clinical outcome of MBC patients treated with PG chemotherapy. Further studies on the functional mechanisms relating to these germline polymorphisms in these genes are warranted.

Prostaglandin F2 alpha is a product of the decidualized human stromal cell

Literature suggest that PGE2 synthesis via the COX-2 pathway is important in implantation. We recently reported that COX-1, COX-2, and PGE2 are upregulated during in vitro decidualization of human endometrial stromal cells. Since COX-1 is upregulated, other prostaglandins may also be synthesized. The aim of the present study was to further characterize the PG pathway in stromal cells by determining whether PGF2αis synthesized upon decidualization.

Eicosanoid biosynthesis during mucociliary and mucous metaplastic differentiation of bronchial epithelial cells

The purpose of this study was to examine the profile of eicosanoids secreted by human bronchial epithelial cells (HBEC) during their in vitro differentiation toward mucociliary or mucous metaplastic phenotype. Eicosanoids were measured in supernatants by mass spectrometry, and corresponding gene expression by real-time PCR. Primary HBEC produced mainly prostaglandins (PGE2, PGD2) and epoxides (e.g. 14,15-EET), but during further mucociliary differentiation we observed a gradual increase in secretion of lipoxygenase derived HETEs. Treatment with IL-13 and IL-4 induced mucous metaplasia and resulted in downregulation of PG pathway, and potent induction of 15-lipoxygenase (marked release of 15-HETE). The deficiency in PG production sustained during long term culture of mucous metaplastic epithelia. In conclusions, Th2-type cytokines induce changes in eicosanoid metabolism of airway epithelial cells, resulting in an immense induction of 15-lipoxygenase pathway, and inhibition of PG pathways. Deficient production of immunomodulatory PGs may promote chronic inflammation and airway remodeling.

Effects of hecogenin and its possible mechanism of action on experimental models of gastric ulcer in mice

This study investigates the gastroprotective effects of hecogenin, a steroid saponin isolated from Agave sisalana, on experimental models of gastric ulcer. Male Swiss mice were used in the models of ethanol- and indometacin-induced gastric ulcer. To clarify the hecogenin mechanism of action, the roles of nitric oxide (NO), sulfhydryls (GSH), K+ATP channels and prostaglandins were also investigated, and measurements of lipid peroxidation (TBARS assay) and nitrite levels in the stomach of hecogenin-treated and untreated animals were performed. Furthermore, the effects of hecogenin on myeloperoxidase (MPO) release from human neutrophils were assessed in vitro. Our results showed that hecogenin (3.1, 7.5, 15, 30, 60 and 90mg/kg, p.o.) acutely administered, before ethanol or indomethacin, exhibited a potent gastroprotective effect. Although the pretreatments with L-NAME, an iNOS inhibitor, and capsazepine, a TRPV1 receptor agonist, were not able to reverse the hecogenin effect, this was reversed by glibenclamide, a K+ATP blocker, and indomethacin in the model of ethanol-induced gastric lesions. The hecogenin pretreatment normalized GSH levels and significantly reduced lipid peroxidation and nitrite levels in the stomach, as evaluated by the ethanol-induced gastric lesion model. The drug alone increased COX-2 expression and this effect was further enhanced in the presence of ethanol. It also decreased MPO release and significantly protected the gastric mucosa. In conclusion, we showed that hecogenin presents a significant gastroprotective effect that seems to be mediated by K+ATP channels opening and the COX-2/PG pathway. In addition, its antioxidant and anti-inflammatory properties may play a role in the gastroprotective drug effect.

Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis

BackgroundProstaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine-disrupting compounds (EDCs) share a high degree of structural similarity with mild analgesics.Objectives and MethodsUsing cell-based transfection and transduction experiments, mass spectrometry, and organotypic assays together with molecular modeling, we investigated whether inhibition of the PG pathway by known EDCs could be a novel point of endocrine disruption.ResultsWe found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis, and this reduction was correlated with a reduced testosterone production. The inhibition of PG synthesis occurred without involvement of canonical PG receptors or the peroxisome proliferator–activated receptors (PPARs), which have previously been described as targets of EDCs. Instead, our results suggest that the compounds may bind directly into the active site of the cyclooxygenase (COX) enzymes, thereby obstructing the conversion of arachidonic acid to PG precursors without interfering with the expression of the COX enzymes. A common feature of the PG inhibitory EDCs is the presence of aromatic groups that may stabilize binding in the hydrophobic active site of the COX enzymes.ConclusionOur findings suggest a hitherto unknown mode of action by EDCs through inhibition of the PG pathway and suggest new avenues to investigate effects of EDCs on reproductive and immunological disorders that have become increasingly common in recent decades.

Cutting Edge: Bacterial Infection Induces Hematopoietic Stem and Progenitor Cell Expansion in the Absence of TLR Signaling

Bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs) can be activated by type I IFNs, TLR agonists, viruses, and bacteria to increase hematopoiesis. In this study, we report that endotoxin treatment in vivo induces TLR4, MyD88, and Toll/IL-1 resistance domain-containing adaptor-inducing IFN-beta (TRIF)-dependent expansion of BM HSPCs. Bacterial infection by Staphylococcus aureus or cecal ligation and puncture also induces HSPC expansion, but MyD88, TRIF, type I IFN, cytokine, PG, or oxidative stress pathways are not required for their expansion. S. aureus-induced HSPC expansion in MyD88(-/-)TRIF(-/-) mice is also normal, but is associated with BM remodeling as granulocyte stores are released peripherally. Importantly, reduction in BM cellularity alone can reproduce HSPC expansion. These data show in vivo HSPC responses to bacterial infection are complex and not absolutely dependent upon key inflammatory signaling pathways.

A phase II trial of calcitrol and naproxen in recurrent prostate cancer

16103 Background: Although commonly used as second-line treatment for patients with progressing prostate cancer, hormonal therapy is associated with unpleasant side effects, and has not unequivocally been shown to prolong survival. To this date, in vitro and in vivo studies, as well as early phase clinical trials, have shown a promising role for both calcitriol and nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of prostate cancer. Because calcitriol and NSAIDs interfere with PG pathways by different mechanisms, there is reason to believe that their combined effects to inhibit PG action may be synergistic and this was in fact demonstrated in cultured human prostate cancer cells. We combined calcitriol and naproxen (a non-selective NSAID) to delay the growth and progression of early recurrent prostate cancer. Methods: Patients with biochemical relapse after local therapy for prostate cancer were treated with a very large dose of calcitriol (DN101) (45 micrograms/once per week) and naproxen (400 mg bid) for one year. Patients were followed with serum PSA levels as well as imaging studies. Progressive disease was defined as a decrease in PSA doubling time (PSADT) from baseline, or initiation of hormonal therapy, and/or formation of new bone lesions on bone scan. Results: Twenty-one patients were enrolled in the trial from 4/05–10/07. Sixteen had radical prostatectomy as primary therapy and 12 of these had subsequent radiation for a rising serum PSA. Median Gleasons score was 7, and median number of cycles of therapy was 6. Eighteen patients were evaluable for response. Four patients met criteria for progression, with a PSADT that decreased while on therapy. Fourteen patients had a prolongation of PSADT compared to baseline. The prolongation was greater than a 2-fold increase in 50% of the patients. Three patients had a greater than 5-fold prolongation of the PSADT. One patient developed an asymptomatic kidney stone and was taken off study. Conclusions: Preliminary results show that weekly administration of calcitriol and naproxen is well tolerated in most patients with recurrent prostate cancer, with improvement in PSADT noted in 75% of patients. The combination therapy was successful in delaying the rate of progression in a majority of patients. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Novacea, Inc

Adenovirus Type 5 Exerts Multiple Effects on the Expression and Activity of Cytosolic Phospholipase A2, Cyclooxygenase-2, and Prostaglandin Synthesis

In this study, we examine how infection of murine and human fibroblasts by adenovirus (Ad) serotype 5 (Ad5) affects the expression and activity of cytosolic phospholipase A2 (cPLA2), cyclooxygenase-2 (COX-2), and production of PGs. Our experiments showed that infection with Ad5 is accompanied by the rapid activation of cPLA2 and the cPLA2-dependent release of [3H]arachidonic acid ([3H]AA). Increased expression of COX-2 was also observed after Ad infection, as was production of PGE2 and PGI2. Later, however, as the infection progressed, release of [3H]AA and production of PGs stopped. Late-stage Ad5-infected cells also did not release [3H]AA or PGs following treatment with a panel of biologically diverse agents. Experiments with UV-inactivated virus confirmed that Ad infection is accompanied by the activation of a host-dependent response that is later inhibited by the virus. Investigations of the mechanism of suppression of the PG pathway by Ad5 did not reveal major effects on the expression or activity of cPLA2 or COX-2. We did note a change in the intracellular position of cPLA2 and found that cPLA2 did not translocate normally in infected cells, raising the possibility that Ad5 interferes with the PG pathway by interfering with the intracellular movement of cPLA2. Taken together, these data reveal dynamic interactions between Ad5 and the lipid mediator pathways of the host and highlight a novel mechanism by which Ad5 evades the host immune response. In addition, our results offer insight into the inflammatory response induced by many Ad vectors lacking early region gene products.

Microglial EP2 as a New Target to Increase Amyloid β Phagocytosis and Decrease Amyloid β-Induced Damage to Neurons

Epidemiologic and animal model data support a role for the prostaglandin pathway in AD pathogenesis. However, unexpected toxicity from protracted use of some nonsteroidal anti-inflammatory drugs (NSAIDs) compels investigation of therapeutic targets in this pathway other than COX inhibitors. Previously, we have shown that mice lacking one specific receptor for PGE2, EP2 (EP2-/-), are protected from the indirect neurotoxic effects of cerebral innate immune response mediated by CD14-dependent activation. Here we review data showing that EP2-/- microglia have a highly desirable combination of features: ablated indirect neurotoxicity following exposure to Abeta(1-42) coupled with enhanced phagocytosis of Abeta peptides, both synthetic and those deposited in human brain. These data point to microglial EP2 as a more focused target within the PG pathway for therapy in AD.

CD14-Dependent Innate Immunity-Mediated Neuronal Damage in Vivo is Suppressed by NSAIDs and Ablation of a Prostaglandin E2 Receptor, EP2

Activated innate immune response in brain has been extensively associated with several diseases, including Alzheimers disease, HIV-associated dementia, ischemia, head trauma, stroke, cerebral palsy, axonal degeneration in multiple sclerosis, and autism. Although initially investigated because of its role innate immune response to microorganisms, the CD14/Toll-like receptor pathway is now appreciated as a critical element in innate immune response to endogenous ligands, including fibrillar amyloid β peptides and neoantigens expressed by apoptotic cells. Here we review data on NSAID suppression of cerebral oxidative damage, as measured by F2-isoprostanes, and synaptodendritic degeneration in an in vivo model of CD14-dependent activation of glial innate immune response. Given recent concern over toxicity from protracted exposure to NSAIDs, we also review data from mice lacking specific receptors for PGE2, and show that mice lacking EP2, but not EP1, are completely protected from CD14-dependent paracrine neurotoxicity. These results suggest that EP2 may be a new and more focused target in the PG pathway to suppress innate immunity-mediated neuronal damage.

Cyclooxygenase-2 (COX-2) Is Frequently Expressed in Multiple Myeloma (MM) and Is Associated with Poor Outcome.

Introduction. A perturbed microenvironment with secretion of inflammatory cytokines is typical of MM. Prostaglandins (pg) are implicated in inflammation and angiogenesis and play a role in the pathogenesis of several solid malignancies. Expression of COX-2, the key enzyme of pg synthesis in inflamed tissues, is common in many of these cancers and plays a major role in their development. Moreover, it often acts as a poor prognostic indicator. Despite a large amount of data concerning COX-2 expression in solid tumors, few data are currently available in hematological malignancies. In MM there are several biological, epidemiological and clinical considerations suggesting a potential involvement of the pg pathway. Aim of this study is to verify the involvement of COX-2 in MM and to assess its prognostic role.Patients and methods. COX-2 expression has been assessed by western blotting (WB) as previously described (Du Bois RN, et al, Gastroenterology, 1996). Our positive control was the COX-2 positive cell line HT-29, while bone marrows (BM) from 15 healthy donors were our negative controls. We assessed a panel of 124 samples obtained by 113 patients with plasma cell dyscrasias. Sixteen samples belonged to subjects with MGUS, 80 to patients with MM at diagnosis, and 28 to patients with relapsed/refractory MM. In 11 patients, samples taken at different treatment phases were available. To confirm WB findings and to demonstrate that COX-2 expression occurs in malignant plasma cells immunohistochemistry (IC), and flow cytometry for COX-2 were also performed in 31 and four patients, respectively. Finally, COX-2 expression has been assessed in BM cells from four COX-2 positive patients following selection for the CD138 antigen using the Miltenyi cell separation system. COX-2 expression at the mRNA level has also been assessed by real time quantitative PCR.Results. A dilution test showed that our technique is sensitive enough to detect 2% HT-29 cells in a background of COX-2 negative cells. The 15 normal BM were COX-2 negative. In contrast, COX-2 expression was noticed in 12.5% of MGUS, 34.6% of MM at diagnosis and 56% of MM at relapse. COX-2 positivity at diagnosis and relapse was unrelated to disease stage, BM plasmacytosis, creatinine, Hb levels and ß2 microglobulin. COX-2 expression appeared to be of prognostic relevance: at diagnosis the median time to progression was 14 months in COX-2 positive and 40 months in COX-2 negative subjects (p<0.001). At relapse, of 14 patients showing COX-2 expression, 10 have already died of MM, and four are still alive. In contrast, of 11 COX-2 negative patients only one patient died while 10 are still alive (p<0.001). IC, cell separation and flow cytometry studies indicate that COX-2 expression is related to the malignant plasma cell population. COX-2 mRNA was overexpressed in patients showing increased COX-2 protein expression.Conclusions: a) COX-2 is frequently expressed in plasma cell dyscrasias; b) COX-2 expression is more frequent in advanced disease phases; c) COX-2 expression correlates to a worse outcome. Future studies are required to verify whether COX-2 might be clinically useful as a prognostic marker and/or therapeutic target.

Comparison of the antisecretory and antiulcer activity of epidermal growth factor, urogastrone and transforming growth factor alpha and its derivative in rodents in vivo.

This study investigates the effects of epidermal growth factor (EGF), urogastrone (UG) and transforming growth factor-alpha (TGFalpha) and its derivative on dimaprit- and pentagastrin-induced gastric acid secretion and on acidified ethanol (AE)-evoked ulcer formation in anaesthetized rats. EGF, TGFalpha and UG administered subcutaneously (s.c.) 30 min before dimaprit inhibited gastric acid secretion. Against pentagastrin-stimulated secretion, TGFalpha inhibited, while EGF and UG potentiated, acid secretion dose-dependently. Intraduodenal (i.d.) administration of TGFalpha and UG had no effect, while EGF potentiated, both secretagogue-induced acid secretion in the same dosage schedule. Administration of either EGF, UG or TGFalpha i.v. bolus, in response to continuous infusion of dimaprit resulted in a significant (p < 0.05-p < 0.001) inhibition of acid secretion which was transient and returned to normal within 30-45 min for UG while it slowly returned to normal for EGF and TGFalpha. The truncated form of TGFa (amino acids 34-43) did not show any antisecretory effect when administered parenterally. Acidified ethanol produced gastric haemorrhagic lesions in the rat 1 h after oral administration. The gastric mucosal protective effects of TGFalpha, EGF and UG administered either orally or s.c. 30 min before the administration of AE were dose-dependent against this model of ulcer induction. Indomethacin (Indo), administered 15 min before AE to inhibit prostanoids biosynthesis, significantly (p < 0.001) reduced the cytoprotective effects of TGFalpha, EGF and UG and aggravated the ulcer index when administered s.c. The results show that PGs may be involved in mediating the protective effects of the three growth factors. Administration of NG-nitro-L argininemethylester (L-NAME) 15 min prior to TGFa, EGF and UG s.c. or orally, significantly (p < 0.001) decreased the degree of ulcer indices and was able to reduce the protective effects of TGFalpha, EGF and UG, thus including the role of NO in mediating the protective effects of these growth factors. In conclusion, these results have demonstrated that EGF, UG and TGFalpha have a short and reversible inhibitory effect on dimaprit-stimulated gastric acid secretion and each is effective parenterally but not orally. UG and EGF potentiated, while, TGFa inhibited pentagastrin-stimulated acid secretion. In addition, TGFalpha seems to lose its activity when it is truncated from the C terminus. The present study also suggests that EGF, UG and TGFalpha are equally effective against AE-induced gastric ulcer and bring about their cytoprotective action through their reduction of acid secretion and through PG and NO pathways.