Role of dihydroartemisinin in regulating prostaglandin E2 synthesis cascade and inflammation in endothelial cells.

Endothelial cells (ECs) are crucial in maintaining vascular homeostasis. Endothelial dysfunction was involved in many cardiovascular diseases (CVDs). Recently, antimalarial medicine artemisinin and its derivatives including dihydroartemisinin (DHA) were found to be beneficial in some diseases including CVDs. Prostaglandin (PG) E2 is a known inflammatory mediator and plays important roles in cardiovascular system. This study was to investigate the role of DHA in regulating cyclooxygenase (COX)/PGE synthase (PGES)/PGE2 cascade and inflammation in ECs. After DHA treatment, the mRNA and protein levels of COX-2 were strikingly upregulated in time- and dose-dependent manners. In contrast, COX-1 was significantly downregulated. As expected, inhibition of COX-1 or COX-2 further reduced PGE2 production after DHA treatment. Moreover, DHA enhanced microsomal PGE2 synthase (mPGES)-2 and moderately modulated cytosolic PGE2 synthase (cPGES) with no effect on mPGES-1 expression. Importantly, DHA significantly reduced PGE2 levels in line with the upregulation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH, a key enzyme for prostaglandin degradation). Lastly, we observed that DHA not only reduced the PGE2 levels in tumor necrosis factor-α (TNF-α)-treated ECs but also blunted the upregulation of inflammatory cytokines of interleukin (IL)-6 and IL-1ß induced by TNF-α or PGE2. These findings demonstrated an important role of DHA in regulating PGE2 synthesis cascade and inflammation in ECs, suggesting a potential of DHA for the treatment of inflammatory vascular diseases.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii.

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.

Renal medullary cyclooxygenase-2 and (pro)renin receptor expression during angiotensin II-dependent hypertension.

The (pro)renin receptor [(P)RR] upregulates cyclooxygenase-2 (COX-2) in inner medullary collecting duct (IMCD) cells through ERK1/2. Intrarenal COX-2 and (P)RR are upregulated during chronic ANG II infusion. However, the duration of COX-2 and (P)RR upregulation has not been determined. We hypothesized that during the early phase of ANG II-dependent hypertension, membrane-bound (P)RR and COX-2 are augmented in the renal medulla, serving to buffer the hypertensinogenic and vasoconstricting effects of ANG II. In Sprague-Dawley rats infused with ANG II (0.4 µg·min(-1)·kg(-1)), systolic blood pressure (BP) increased by day 7 (162 ± 5 vs. 114 ± 10 mmHg) and continued to increase by day 14 (198 ± 15 vs. 115 ± 13 mmHg). Membrane-bound (P)RR was augmented at day 3 coincident with phospho-ERK1/2 levels, COX-2 expression, and PGE2 in the renal medulla. In contrast, membrane-bound (P)RR was reduced and COX-2 protein levels were not different from controls by day 14. In cultured IMCD cells, ANG II increased secretion of the soluble (P)RR. In anesthetized rats, COX-2 inhibition decreased the glomerular filtration rate (GFR) and renal blood flow (RBF) during the early phase of ANG II infusion without altering BP. However, at 14 days of ANG II infusions, COX-2 inhibition decreased mean arterial BP (MABP), RBF, and GFR. Thus, during the early phase of ANG II-dependent hypertension, the increased (P)RR and COX-2 expression in the renal medulla may contribute to attenuate the vasoconstrictor effects of ANG II on renal hemodynamics. In contrast, at 14 days the reductions in RBF and GFR caused by COX-2 inhibition paralleled the reduced MABP, suggesting that vasoconstrictor COX-2 metabolites contribute to ANG II hypertension.

Mathematical modeling of the Phoenix Rising pathway.

Apoptosis is a tightly controlled process in mammalian cells. It is important for embryogenesis, tissue homoeostasis, and cancer treatment. Apoptosis not only induces cell death, but also leads to the release of signals that promote rapid proliferation of surrounding cells through the Phoenix Rising (PR) pathway. To quantitatively understand the kinetics of interactions of different molecules in this pathway, we developed a mathematical model to simulate the effects of various changes in the PR pathway on the secretion of prostaglandin E2 (PGE2), a key factor for promoting cell proliferation. These changes include activation of caspase 3 (C3), caspase 7 (C7), and nuclear factor κB (NFκB). In addition, we simulated the effects of cyclooxygenase-2 (COX2) inhibition and C3 knockout on the level of secreted PGE2. The model predictions on PGE2 in MEF and 4T1 cells at 48 hours after 10-Gray radiation were quantitatively consistent with the experimental data in the literature. Compared to C7, the model predicted that C3 activation was more critical for PGE2 production. The model also predicted that PGE2 production could be significantly reduced when COX2 expression was blocked via either NFκB inactivation or treatment of cells with exogenous COX2 inhibitors, which led to a decrease in the rate of conversion from arachidonic acid to prostaglandin H2 in the PR pathway. In conclusion, the mathematical model developed in this study yielded new insights into the process of tissue regrowth stimulated by signals from apoptotic cells. In future studies, the model can be used for experimental data analysis and assisting development of novel strategies/drugs for improving cancer treatment or normal tissue regeneration.

Ultraviolet radiation-induced inflammation activates ß-catenin signaling in mouse skin and skin tumors.

UVB-induced inflammation, in particular the overexpression of cyclooxygenase-2 (COX-2) and prostaglandin (PG) E2, has been implicated in photocarcinogenesis. UVB-induced COX-2 has been associated with ß-catenin signaling in keratinocytes. However, a definitive role for COX-2 in the activation of ß-catenin signaling as well as its role in UVB-induced skin tumors has not been established. We report that exposure of the skin to UVB resulted in a time- and dose-dependent activation of ß-catenin in C3H/HeN mice. This response was COX-2-dependent as UVB-exposed COX-2-deficient mice exhibited significantly lower levels of UVB-induced activation of ß-catenin. Moreover, treatment of mice with indomethacin, a COX-2 inhibitor, and an EP2 antagonist inhibited UVB-induced ß-catenin signaling. Exposure of SKH-1 hairless mice to UVB radiation (180 mJ/cm2) 3 times a week for 24 weeks resulted in activation of ß-catenin signaling in UVB-irradiated skin as well as UVB-induced skin tumors. Concomitantly, the levels of CK1α and GSK-3ß, which are responsible for ß-catenin signaling, were reduced while the levels of c-Myc and cyclin D1, which are downstream targets of ß-catenin, were increased. To further verify the role of UVB-induced inflammation in activation of ß-catenin signaling, a high-fat-diet model was used. Administration of high-fat diet exacerbated UVB-induced inflammation. Administration of the high-fat diet enhanced ß-catenin signaling and the levels of its downstream targets (c-Myc, cyclin D1, cyclin D2, MMP-2 and MMP-9) in UVB-exposed skin and skin tumors in SKH-1 mice. These data suggest that UV-induced COX-2/PGE2 stimulates ß-catenin signaling, and that ß-catenin activation may contribute to skin carcinogenesis.

Synthesis and biological evaluation of new benzo-thieno[3,2-d]pyrimidin-4-one sulphonamide thio-derivatives as potential selective cyclooxygenase-2 inhibitors.

The aim of this work was to evaluate the potential anti-inflammatory activity of eleven (5-15) new synthesized derivatives of benzo-thieno[3,2-d]pyrimidine on two cell models, namely human keratinocytes NCTC 2544 and mouse monocyte-macrophages J774. For the synthesis of test compounds an efficient approach was developed: the key isothiocyanate was prepared through a simple and ecological method using di-2-pyridyl thionocarbonate (DPT) in substitution of thiophosgene, a highly toxic agent, and the cyclization reaction of benzo-thiosemicarbazide derivates was performed through Wamhoff methods. This procedure can be a new alternative method economically and environmentally advantageous by the simplicity of procedure, reduction of isolation and purification steps, time, costs, and waste production. The potential anti-inflammatory activity of 5-15 was evaluated by determining the expression of cyclooxygenase (COX)-2, inducible NO synthase (iNOS), and intercellular adhesion molecule-1 (ICAM-1), and the release of prostaglandins (PG)E[Formula: see text] and interleukin-8 (IL-8). Our results demonstrate that the compounds 7, 10, 12, 13, 14, and 15 act as a potent inhibitor of COX-2, iNOS, ICAM-1 expression while also suppressing the production of PGE[Formula: see text] and IL-8 in human keratinocytes NCTC 2544 exposed to interferon-gamma (IFN-[Formula: see text]) and histamine and monocyte-macrophages J774 cells treated with lipopolysaccharides (LPS). In conclusion, some derivatives of benzo-thieno[3,2-d]pyrimidine could be developed as a novel class of anti-inflammatory agents.

Phosphatidylserine inhibits inflammatory responses in interleukin-1ß-stimulated fibroblast-like synoviocytes and alleviates carrageenan-induced arthritis in rat.

Recently, phosphatidylserine (PS) has received attention for its anti-inflammatory effect; however, the molecular mechanisms of its action have not been fully understood. Thus, we hypothesized that PS might have antiarthritic and anti-inflammatory effects. To test this hypothesis, the in vitro anti-inflammatory effect of soybean-derived PS was tested on interleukin (IL)-1ß-stimulated fibroblast-like synoviocytes from rheumatoid arthritis patients (RA-FLS) by measuring the levels of IL-6, IL-8, prostaglandin E(2), and vascular endothelial growth factor by enzyme-linked immunosorbent assay. The analgesic and antiarthritic activities of PS were investigated in rat models of carrageenan-induced acute paw pain and arthritis. The former was evaluated with a paw pressure test; the latter, by measuring paw volume and weight distribution ratio. In addition, the participation of mitogen-activated protein kinase signaling in the anti-inflammatory and antiarthritic effects of PS was investigated in RA-FLS. Phosphatidylserine inhibited the production of inflammatory mediators IL-6; IL-8; vascular endothelial growth factor; and, in particular, prostaglandin E(2) in IL-1ß-stimulated RA-FLS. These effects were associated with abrogation of inhibitor of nuclear factor-κBα phosphorylation and suppression of p38 and c-jun amino terminal kinase but not extracellular signal-regulated kinase 1/2 phosphorylation. In rats, PS also showed a significant inhibitory effect on arthritic and nociceptive symptoms induced by carrageenan. These findings suggest that PS has anti-inflammatory and antiarthritic effects in vitro and in in vivo animal models; thus, PS should be further studied to determine its potential use as either a pharmaceutical or dietary supplement for alleviating arthritic symptoms.

Toll-like receptor 2 heterodimers, TLR2/6 and TLR2/1 induce prostaglandin E production by osteoblasts, osteoclast formation and inflammatory periodontitis.

TLR2 forms heterodimers with TLR1 and TLR6, and regulates host defense mechanisms against pathogens. We examined the role of TLR2 heterodimer signaling in osteoclast formation and inflammatory periodontitis. In co-cultures of mouse bone marrow cells and osteoblasts, a TLR2/6 ligand (diacylated lipopeptide designed from Gram-positive bacteria) markedly induced osteoclast formation. A TLR2/1 ligand (triacylated lipopeptide designed from Gram-negative bacteria) also induced osteoclast formation. The osteoclast formation induced by TLR2/6 and TLR2/1 ligands was completely suppressed by indomethacin. Osteoblasts expressed TLR1, 2, 4, and 6 mRNAs, and both TLR2/6 and TLR2/1 ligands induced the expression of COX-2, mPGES-1, and RANKL mRNA, as well as PGE production in osteoblasts. Both TLR2/6 and TLR2/1 ligands induced the resorption of mandibular alveolar bone in organ cultures, and elicited inflammatory periodontitis in vivo. Therefore, TLR2 heterodimer signaling may play a key role in PGE-mediated inflammatory bone loss in periodontal disease.

Inhibitory effects of panduratin A on allergy-related mediator production in rat basophilic leukemia mast cells.

Immediate-type hypersensitivity is characterized by elevated levels of immunoglobulin E (IgE) and activated mast cell plays a crucial role by releasing granule contents, lipid-derived mediators, cytokines, and chemokines. To evaluate the antiallergic effects of panduratin A isolated from Boesenbergia pandurata Roxb., we determined its effects on calcium (Ca(2+)) influx, degranulation, and inflammatory mediators in calcium ionophore A23187 and phorbol 12-myristate 13-acetate (PMA)-stimulated rat basophilic leukemia (RBL-2H3) cells. Panduratin A (20 µM) inhibited secretion of ß-hexosaminidase (46.69 ± 9.6 %), histamine (34.32 ± 2.1 %), and Ca(2+) influx (43.84 %). Panduratin A reduced the production of prostaglandin E(2) (PGE(2), 47.58 ± 3.4 %), leukotriene B(4) (LTB(4), 98.15 ± 1.6 %), and the mRNA expression of cyclooxygenase-2, 5-lipoxygenase, interleukin (IL)-4, IL-13, and tumor necrosis factor-α. Furthermore, panduarin A attenuated phosphorylation of Akt, the mitogen-activated protein kinases (MAPK) extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) expression. These results indicate that panduratin A might be useful as an agent against immediate-type hypersensitivity.

Prostaglandin (F and E, 2- and 3-series) production and cyclooxygenase (COX-2) gene expression of wild and cultured broodstock of Senegalese sole (Solea senegalensis).

Prostaglandin levels in different tissues and cyclooxygenase (COX-2) gene expression were compared between wild and cultured Senegalese sole (Solea senegalensis) broodstock in which a significantly different fatty acid profile, particularly lower tissue levels of arachidonic acid (ARA, 20:4n-6) and higher levels of eicosapentaenoic acid (EPA, 20:5n-3) in the cultured fish compared to wild had already been described. This is the first report of the COX-2 mRNA expression in Senegalese sole. Cyclooxygenase (COX-2) mRNA expression and prostaglandin (2- and 3-series) levels were determined in tissues from 32 broodstock fish, 16 (8 males and 8 females) from each origin wild and cultured (G1). Transcripts of COX-2 were highly expressed in gills, sperm-duct (s-duct), testis, oviduct and spleen compared to liver, kidney and muscle. Differences in COX-2 transcripts expression were found in response to the origin of the fish and expression was significantly higher in s-duct and gills from wild fish compared to cultured. Wild fish showed significantly higher levels of total 2-series PGs and lower levels of 3-series compared to cultured fish. The significance of the lower COX-2 expression and lower PG 2-series production in some of the tissues of cultured fish was discussed in relation to the previously described differences in fatty acid profile (lower tissue levels of ARA and higher levels of EPA and EPA/ARA ratio in cultured fish) and the reproductive failure to spawn viable eggs from G1 cultured Senegalese sole compared to successful spawning from captive wild broodstock.

Nobiletin, a polymethoxy flavonoid, suppresses bone resorption by inhibiting NFκB-dependent prostaglandin E synthesis in osteoblasts and prevents bone loss due to estrogen deficiency.

Nobiletin, a polymethoxy flavonoid, prevents cancer and inflammation, but the roles of nobiletin in bone are unclear. We examined the effects of nobiletin on bone resorption in vitro and on bone mass in ovariectomized (OVX) mice in vivo. In vitro, nobiletin suppressed osteoclast formation and bone resorption induced by interleukin (IL)-1. Nobiletin suppressed the expression of cyclooxygenase-2, NFκB-dependent transcription, and prostaglandin E (PGE) production induced by IL-1 in osteoblasts. OVX mice showed severe bone loss in the femur by increased bone resorption due to estrogen deficiency, and nobiletin significantly restored the bone mass. Nobiletin could be beneficial to bone health in postmenopausal women.

Effect of eicosapentaenoic acid on E-type prostaglandin synthesis and EP4 receptor signaling in human colorectal cancer cells.

The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA), in the free fatty acid (FFA) form, has been demonstrated to reduce adenoma number and size in patients with familial adenomatous polyposis. However, the mechanistic basis of the antineoplastic activity of EPA in the colorectum remains unclear. We tested the hypothesis that EPA-FFA negatively modulates synthesis of and signaling by prostaglandin (PG) E(2) in human colorectal cancer (CRC) cells. EPA-FFA induced apoptosis of cyclooxygenase (COX)-2-positive human HCA-7 CRC cells in vitro. EPA-FFA in cell culture medium was incorporated rapidly into phospholipid membranes of HCA-7 human CRC cells and acted as a substrate for COX-2, leading to reduced synthesis of PGE(2) and generation of PGE(3). Alone, PGE(3) bound and activated the PGE(2) EP4 receptor but with reduced affinity and efficacy compared with its "natural" ligand PGE(2). However, in the presence of PGE(2), PGE(3) acted as an antagonist of EP4 receptor-dependent 3',5' cyclic adenosine monophosphate induction in naturally EP4 receptor-positive LoVo human CRC cells and of resistance to apoptosis in HT-29-EP4 human CRC cells overexpressing the EP4 receptor. We conclude that EPA-FFA drives a COX-2-dependent "PGE(2)-to-PGE(3) switch" in human CRC cells and that PGE(3) acts as a partial agonist at the PGE(2) EP4 receptor.

ATP-induced relaxation of porcine retinal arterioles in vitro depends on prostaglandin E synthesized in the perivascular retinal tissue.

PURPOSE: It has been shown that inhibition of prostaglandin synthesis in the perivascular retinal tissue can prevent the relaxation of retinal arterioles induced by N-methyl-d-aspartic acid (NMDA) and adenosine triphosphate (ATP). The purpose of the present study was to identify the prostaglandins involved in this retina-dependent relaxation. METHODS: Porcine retinal arterioles were mounted in a myograph for isometric tone measurements. The effect of the prostaglandins (PGs) PGE(2), PGF(2α), PGD(2), and PGI(2) and of thromboxane A(2) (TXA(2)) on vascular tone was recorded before and after removal of the perivascular retina, and the specificity of the responses were confirmed by blocking with specific antagonists. Finally, the coupling between prostaglandins found to have a specific vasoactive effect, dependent on the perivascular retina, and the individual vasorelaxing effects of NMDA, ATP, and adenosine were studied. RESULTS: All prostaglandins tested showed a significant relaxation of precontracted arterioles at the highest concentrations, whereas PGF(2α) induced a significant constriction of isolated noncontracted arterioles. In the presence of perivascular retinal tissue, the dilating effect of PGE(2) increased significantly, an effect that was blocked by a prostaglandin E prostanoid (EP(1)) receptor blocker, whereas PGD(2) induced a dual response, with a significant contraction at low concentrations and a significant dilation at high concentrations. Inhibition of the cyclo-oxygenase (COX) enzyme with ibuprofen, as well as the EP(1) receptor, blocked the vasodilating effect of ATP, but not that of NMDA and adenosine, in the presence of perivascular retinal tissue. CONCLUSIONS: ATP-induced vasodilation depends on the production of PGE in the perivascular retina. However, the regulation of retinal arteriolar tone involves COX products other than PGE.

Paracoccidioides brasiliensis uses endogenous and exogenous arachidonic acid for PGE x production.

Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis, the most prevalent deep mycosis in Latin America. Production of eicosanoids during fungal infections plays a critical role on fungal biology as well as on host immune response modulation. The purpose of our study was to assess whether P. brasiliensis strains with different degree of virulence (Pb18, Pb265, Bt79, Pb192) produce prostaglandin E(x) (PGE(x)). Moreover, we asked if P. brasiliensis could use exogenous sources of arachidonic acid (AA), as well as metabolic pathways dependent on cyclooxygenase (COX) enzyme, as reported for mammalian cells. A possible association between this prostanoid and fungus viability was also assessed. Our results showed that all strains, independently of their virulence, produce high PGE(x) levels on 4 h culture that were reduced after 8 h. However, in both culture times, higher prostanoid levels were detected after supplementation of medium with exogenous AA. Treatment with indomethacin, a COX inhibitor, induced a reduction on PGEx, as well as in fungus viability. The data provide evidence that P. brasiliensis produces prostaglandin-like molecules by metabolizing either endogenous or exogenous AA. Moreover, the results suggest the involvement of these mediators on fungal viability.

Anti-inflammatory activity of the constituents of the roots of Aralia continentalis.

To assess the anti-inflammatory activity of the constituents of the roots of Aralia continentalis, ent-pimara-8(14),15-diene-19-oic acid (continentalic acid, pimaradienoic acid, compound I), 7beta-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (compound II), 7-oxo-ent-pimara-8(14),15-diene-19-oic acid (compound III), 15alpha,16alpha-epoxy-17-hydroxy-ent-kauran-19-oic acid (compound IV) and ent-kaura-16-en-19-oic acid (kaurenoic acid, compound V), their inhibitory effects against cyclooxygenase-2 (COX-2)-catalyzed PGE(2) and inducible nitric oxide synthase (iNOS)-catalyzed NO production by lipopolysaccharide-treated RAW 264.7 cells were examined. Among the compounds tested, compound III and V moderately inhibited NO production. In addition, compound III weakly inhibited PGE2 production, while treatment with compounds II and IV at concentrations of up to 100 microM had no significant effects. Conversely, compound I only weakly inhibited PGE2 and NO production. To elucidate the mechanism by which these changes occurred, the iNOS down-regulating capacity of compound III was investigated. Western blot analysis and an electrophoretic mobility shift assay demonstrated that compound III weakly inhibited COX-2 and iNOS expression at 50-100 microM, and inhibited NF-kappaB activation. When in vivo anti-inflammatory activities of compounds I, III and V were examined, intraperitoneal injection of 4-100 mg/kg of compound I and V significantly inhibited carrageenan-induced paw edema in mice, whereas compound III did not. Taken together, the results of this study suggest that some constituents of A. continentalis, especially compounds I, III and V, exert significant anti-inflammatory activity, which suggests that these constituents contribute, at least in part, to the anti-inflammatory action of the roots of A. continentalis.

Elevated plasma prostaglandins and acetylated histone in monocytes in Type 1 diabetes patients.

AIMS/HYPOTHESIS: Inflammation is implicated in diabetes and cyclooxygenase (COX) is involved in vascular inflammatory processes, participating in both atherosclerosis and thrombosis. The aims were to determine whether levels of monocyte COX and plasma COX metabolites are increased in Type 1 diabetic patients and to determine whether these could be linked to histone hyperacetylation. MATERIALS AND METHODS: Monocytes from 19 Type 1 diabetic and 39 non-diabetic control subjects were probed for COX and acetylated histone H4 proteins by immunoblotting. Plasma COX metabolite levels [thromboxane B(2) (TXB(2)) and prostaglandin E(2) (PGE(2))] were determined by enzyme immunoassay. RESULTS: Monocyte COX-2 expression was significantly up-regulated (1.3-fold) in diabetic relative to the non-diabetic control subjects and plasma PGE(2) was markedly elevated (2.7-fold). In diabetic subjects, monocyte acetylated histone H4 levels were significantly elevated; sub-group analysis indicated that the increased histone acetylation was found only in the complication-free group. CONCLUSIONS: Results support increased inflammatory activity in Type 1 diabetes that involves COX-2 and increased prostaglandin production, which may predispose patients to cardiovascular events. The observation of elevated histone acetylation only in complication-free diabetic subjects suggests that this may be a protective mechanism. This merits further investigation as histone hyperacetylation has been associated with reduced expression of factors involved in vascular injury and remodelling.

Regulation of functional and regressing stages of corpus luteum development in mice. Role of reactive oxygen species.

The endocrine and immune systems modulate ovarian function. The aim of the present work was to compare the status of various modulating factors in two well-defined stages of corpus luteum (CL) development (the functional stage and the regressing stage) by means of a gonadotropin-synchronised mouse model. At the regressing stage of CL development, we found that ovarian tissue showed increased prostaglandin (PG) F(2alpha) and diminished PGE levels concomitantly with enhanced protein abundance of ovarian cyclooxygenase 2, the inducible isoform of the limiting enzyme of PG synthesis. We also found both enhanced lipid peroxidation and enhanced total superoxide dismutase activity, as well as inhibited catalase activity and inhibited total hydroxyl radical scavenger capacity, when compared with ovaries at the functional stage. In addition, at the regressing stage we observed an increased percentage of CD8+ (cytotoxic/suppressor) T-cells and a decreased percentage of CD4+ (helper) T-cells from ovarian-draining lymph nodes. Also, the serum interleukin (IL)-2, IL-4 and IL-10 were diminished as compared with the functional stage. We conclude that a pro-oxidant status together with a pro-inflammatory response is responsible for the loss of luteal function.

[Marine fungus Stilbella aciculosa as a potential producer of prostaglandins].

The amount and composition of fatty acids in the fungus Stilbella aciculosa associated with the marine macroorganism Apostichopus japonica (trepang) were determined by gas-liquid chromatography and gas chromatography-mass spectrometry. In the culture liquid of S. aciculosa, prostaglandins (PG) of groups E and F were revealed by UV spectroscopy. This finding was confirmed by the presence of direct precursors of PG, polyunsaturated eicosapentaenoic and docosahexaenoic acids, in the culture liquid. The biomass of this fungus contained PG of group B.

Detrimental effects of hyperandrogenism on uterine functions.

The aim of the present work was to study some of the adverse effects produced by hyperandrogenism on the uterine function. Daily injection of dehydroepiandrosterone (DHEA: 6 mg/ 100 g body weight, sc) for 20 consecutive days induced polycystic ovaries in BALB/c mice. In this model, we found that DHEA produced alterations on uterine histology closely related to the development of tumour structures. In addition, hyperandrogenism induced a pro-inflammatory and a pro-oxidant condition represented by increased levels of prostaglandin F2 alpha production and uterine nitric oxide synthase (NOS) activity and by a decrease in both superoxide dismutase (SOD) and catalase (CAT) activities together with a decrease in the levels of the antioxidant metabolite glutathione (GSH). DHEA also induced an increase in CD4+ together with a decrease in the CD8+ T lymphocytes that infiltrate the uterine tissue. We conclude that this intricate network of regulators could be responsible for the low rate of implantation observed in women with polycystic ovary syndrome.