Relationship of cyclic stretching of human patellar tendon fibroblasts with abnormal increase of prostaglandins E2 and leukotriene B4

To investigate the relationship between tendinopathy and higher production of prostaglandins E2 (PGE2) and leukotriene B4(LTB4) induced by cyclic stretching of human patellar tendon fibroblasts.Methods We used a novel in vitro model system to mimic in vivo conditions,where human patellar tendon fibroblasts (HPTFs) were uniaxially stretched with different magnitudes of stretching (4%,8% and 12%).Non-stretched fibroblasts were used as control.The productions of PGE2 and LTB4 as well as the expression of cycloxygenase (COX) and 5-lipoxygenase (5-LO) were then measured every four hours of cyclic stretching.In addition,we treated the cells with inhibitors of COX or 5-LO.Results It was found that cyclic stretching of fibroblasts at 8% and 12% of stretching increased PGE2 and LTB4 levels.Blocking the COX enzyme with indomethacin (25 mol/L) decreased PGE2 levels but increased LTB4 production and vice versa.Whereas decreasing LTB4 production with MK-886 (10 μmol/L) could increase PGE2 levels compared to cells tretched without inhibitors.Conclusion Cyclic stretching of HPTFs produces high levels of PGE2 and LTB4,where a balance exists:blocking PGE2 production increases the production of LTB4,and vice versa.Therefore,this study raises the possibility that the routine use of COX inhibitors in clinical treatment of tendinopathy may exacerbate the condition by causing neutrophil-mediated inflammatory and degenerative changes in the tendon due to increased levels of LTB4,which is a potent chemoattractant for neutrophils.17 refs,3 figs.

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.

Mating behaviors in ovoviviparous black rockfish(Sebastes schlegelii):molecular function of prostaglandin E2 as both a hormone and pheromone

Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors.However,the molecular mechanism by which PGs trigger mating behavior in ovoviviparous teleosts is still unclear.In the present study,we employed the ovoviviparous black rockfish(Sebastes schlegelii),an economically important marine species whose reproductive production is limited by incomplete fertilization,as a model species.The results showed that when the dose of PGE2 was higher than 10 nmol/L,a significant(P<0.05)increase in mating behaviors was observed.Dual-fluorescence in situ hybridization indicated that PGE2 could fire specific neurons in different brain regions and receptor cells in the olfactory sac.After combining with specific neurons in the central nervous system(CNS),a series of genes related to reproduction are activated.The intracerebroventricular administration of PGE_(2) significantly increased lhb levels(P<0.05)in both sexes.Moreover,steroidogenesis in gonads was also affected,inducing an increase(P<0.05)in E_(2) levels in males and T levels in females.PGE_(2) levels were also increased significantly(P<0.05)in both sexes.The present study revealed that PGE2 can activate mating behavior in black rockfish in both hormone and pheromone pathways,leading to variations in sex steroid levels and activation of reproductive behaviors.Our results provide not only novel insight into the onset of mating behaviors in ovoviviparous teleosts but also solutions for the incomplete fertilization caused by natural mating in cage aquaculture.

西黄丸联合紫杉醇抑制人乳腺癌细胞MDA-MB-231的作用机制研究

目的研究西黄丸(Xihuang wan,XHW)联合紫杉醇(paclitaxel,PTX)对人乳腺癌细胞MDA-MB-231增殖、凋亡的影响及其分子机制。方法首先,通过低温浸提法获得西黄丸浸液,用不同浓度的西黄丸浸液单独或联合紫杉醇处理MDA-MB-231细胞系,通过CCK8实验检测细胞增殖,流式细胞术检测其凋亡的变化,ELISA检测细胞上清中前列腺素E2(prostaglandin E2,PGE2)含量。结果单独使用西黄丸即可抑制MDA-MB-231增殖,联用紫杉醇抑制细胞增殖效果更明显;单用西黄丸可诱导MDA-MB-231凋亡,联用紫杉醇诱导凋亡效果也可获得提高;紫杉醇会诱导细胞外液中PGE2含量升高,联用西黄丸可降低升高的PGE2。结论西黄丸联合紫杉醇可更好地诱导人乳腺癌细胞系MDA-MB-231发生凋亡并抑制其增殖,同时还可以抑制受紫杉醇诱导而升高的PGE2,这可能是西黄丸联用化疗药防止肿瘤复发、转移的重要分子机制之一。

复方柴芩退热颗粒对发热大鼠模型退热作用的研究

目的:研究复方柴芩退热颗粒对2,4二硝基苯酚及细菌内毒素所致大鼠发热模型的退热作用,进一步明确该颗粒的退热效果,初步探讨其退热机制。方法:将SPF级SD大鼠随机分为正常对照组、模型组、酚麻美敏片组[给药剂量0.148 g/(kg·d)]、小柴胡冲剂组[给药剂量2.160 g/(kg·d)]、复方柴芩退热颗粒高、中、低剂量组[给药剂量分别为6.480、3.240、1.620 g/(kg·d)]。各给药组按相应剂量灌胃给药,正常对照组、模型组同法给予等体积的蒸馏水,每天1次,连续给药5天,第4天各组动物均开始禁食不禁水24 h,末次给药前开始造模。造模实验一:除正常对照组外,余各组大鼠均皮下注射2,4-二硝基苯酚17 mg/kg,正常对照组皮下注射同体积生理盐水;造模实验二:除正常对照组外,余各组大鼠均腹腔注射细菌内毒素80μg/kg。测大鼠各时间点的体温和血清中白细胞介素-1β(IL-1β)、前列腺素E2(PGE2)、肿瘤坏死因子-α(TNF-α)的含量。结果:实验一:与正常对照组比较,模型组大鼠造模后1 h、2 h、3 h体温上升值均显著升高,大鼠血清IL-1β、PGE2含量均显著升高(P<0.01)。与模型组比较,酚麻美敏片组、小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组大鼠血清IL-1β、PGE2含量均明显降低(P<0.05,P<0.01);酚麻美敏片组大鼠在造模后1 h、2 h、3 h体温上升值均显著降低(P<0.05,P<0.01);小柴胡冲剂组大鼠在造模后2 h、3 h体温上升值均显著降低(P<0.05,P<0.01);复方柴芩退热颗粒高、低剂量组在造模后1 h、2 h、3 h体温上升值均明显降低(P<0.05,P<0.01);复方柴芩退热颗粒中剂量组在造模后2 h、3 h体温上升值均明显降低(P<0.05)。实验二:与正常对照组比较,模型组大鼠造模后2 h、4 h、6 h、8 h体温上升值均显著升高,大鼠血清PGE2、TNF-α含量均显著升高(P<0.01)。与模型组比较,酚麻美敏片组、小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组大鼠血清PGE2、TNF-α含量均明显降低(P<0.05,P<0.01);酚麻美敏片组大鼠在造模后2 h、4 h、6 h体温上升值均显著降低(P<0.05,P<0.01);小柴胡冲剂组、复方柴芩退热颗粒高、中、低剂量组在造模后2 h、4 h体温上升值均明显降低(P<0.05,P<0.01)。结论:复方柴芩退热颗粒对2,4二硝基苯酚及细菌内毒素所致大鼠发热均有降温作用,能有效降低大鼠血清PGE2、IL-1β和血清TNF-α含量,对大鼠实验性高热模型有较好的解热作用。

Genetic variant of cyclooxygenase-2 in gastric cancer:More inflammation and susceptibility

Gastric cancer accounts for the majority cancer-related deaths worldwide.Although various methods have considerably improved the screening,diagnosis,and treatment of gastric cancer,its incidence is still high in Asia,and the 5-year survival rate of advanced gastric cancer patients is only 10%-20%.Therefore,more effective drugs and better screening strategies are needed for reducing the incidence and mortality of gastric cancer.Cyclooxygenase-2(COX-2)is considered to be the key inducible enzyme in prostaglandins(PGs)synthesis,which is involved in multiple pathways in the inflammatory response.For example,inflammatory cytokines stimulate innate immune responses via Toll-like receptors and nuclear factor-kappa B to induce COX-2/PGE2 pathway.In these processes,the production of an inflammatory microenvironment promotes the occurrence of gastric cancer.Epidemiological studies have also indicated that non-steroidal antiinflammatory drugs can reduce the risk of malignant tumors of the digestive system by blocking the effect of COX-2.However,clinical use of COX-2 inhibitors to prevent or treat gastric cancer may be limited because of potential side effects,especially in the cardiovascular system.Given these side effects and low treatment efficacy,new therapeutic approaches and early screening strategies are urgently needed.Some studies have shown that genetic variation in COX-2 also play an important role in carcinogenesis.However,the genetic variation analysis in these studies is incomplete and isolated,pointing out only a few single nucleotide polymorphisms(SNPs)and the risk of gastric cancer,and no comprehensive study covering the whole gene region has been carried out.In addition,copy number variation(CNV)is not mentioned.In this review,we summarize the SNPs in the whole COX-2 gene sequence,including exons,introns,and both the 5’and 3’untranslated regions.Results suggest that COX-2 does not increase its expression through the CNV and the SNPs in COX-2 may serve as the potential marker to establish risk stratification in the general population.This review synthesizes emerging insights of COX-2 as a biomarker in multiple studies,summarizes the association between whole COX-2 sequence variation and susceptibility to gastric cancer,and discusses the future prospect of therapeutic intervention,which will be helpful for early screening and further research to find new approaches to gastric cancer treatment.

Celecoxib Inhibits Proliferation and Induces Apoptosis via Cyclooxygenase-2 Pathway in Human Pancreatic Carcinoma Cells

In order to evaluate the effects and mechanisms of celecoxib in inhibiting proliferation and inducing apoptosis on human pancreatic carcinoma cells, the anti-proliferative effect was measured by using methabenzthiazuron (MTT) assay. Cell cycle and apoptosis were analyzed by using flow cytometry (FCM), and the PGE 2 levels in the supernatant of cultured pancreatic carcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA). Our results showed that celecoxib suppressed the production of PGE 2 and inhibited the growth of JF-305 cells, and the anti-proliferative effect of celecoxib could be abolished by addition of PGE 2. FCM revealed that celecoxib could inhibit proliferation and induce apoptosis by G 1-S cell cycle arrest. It was concluded that cyclooxygenase-2 specific inhibitor celecoxib could inhibit proliferation and induced apoptosis of human pancreatic carcinoma cells via suppression of PGE 2 production in vitro.

The oral commensal Streptococcus mitis activates the aryl hydrocarbon receptor in human oral epithelial cells

Streptococcus mitis （S. mitis） is a pioneer commensal bacterial species colonizing many of the surfaces of the oral cavity in healthy individuals. Yet, not much information is available regarding its interaction with the host. We used examination of its transcriptional regulation in oral keratinocytes to elucidate some of its potential roles in the oral cavity. Transcription factor analysis of oral keratinocytes predicted S. mitis.mediated activation of aryl hydrocarbon receptor （AhR）, Activation and functionality of AhR was confirmed through nuclear translocation determined by immunofluorescence microscopy and real-time polymerase chain reaction with reverse transcription analysis of CYPIA1, the hallmark gene for AhR activation. Addition of Streptococcus mutans or Streptococcus gordonfi did not induce CYPIA1 transcription in the keratinocyte cultures. Introduction of an AhR-specific inhibitor revealed that S. mitis-mediated transcription of CXCL2 and CXCL8 was regulated by AhR. Elevated levels of pmstaglandin E2 （enzyme-linked immunosorbent assay） in supernatants from S. mitis-treated oral epithelial cells were also attenuated by inhibition of AhR activity. The observed AhR-regulated activities point to a contribution of S. mitis in the regulation of inflammatory responses and thereby to wound healing in the oral cavity. The concept that the oral commensal microbiota can induce AhR activation is important, also in view of the role that AhR has in modulation of T-cell differentiation and as an anti-inflammatory factor in macrophaees.

Amentoflavone protects hippocampal neurons: anti-inflammatory, antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.

B-1 cells modulate the murine macrophage response to Leishmania major infection

AIM To investigate the modulatory effect of B-1 cells on murine peritoneal macrophages infected with Leishmania major(L. major) in vitro.METHODS Peritoneal macrophages obtained from BALB/c andBALB/c XID mice were infected with L. major and cultured in the presence or absence of B-1 cells obtained from wild-type BALB/c mice. Intracellular amastigotes were counted, and interleukin-10(IL-10) production was quantified in the cellular supernatants using an enzymelinked immunosorbent assay. The levels of the lipid mediator prostaglandin E2(PGE2) were determined using a PGE2 enzyme immunoassay kit(Cayman Chemical, Ann Arbor, MI), and the number of lipid bodies was quantified in the cytoplasm of infected macrophages in the presence and absence of B-1 cells. Culturing the cells with selective PGE2-neutralizing drugs inhibited PGE2 production and confirmed the role of this lipid mediator in IL-10 production. In contrast, we demonstrated that B-1 cells derived from IL-10 KO mice did not favor the intracellular growth of L. major.RESULTS We report that B-1 cells promote the growth of L. major amastigotes inside peritoneal murine macrophages. We demonstrated that the modulatory effect was independent of physical contact between the cells, suggesting that soluble factor(s) were released into the cultures. We demonstrated in our co-culture system that B-1 cells trigger IL-10 production by L. major-infected macrophages. Furthermore, the increased secretion of IL-10 was attributed to the presence of the lipid mediator PGE2 in supernatants of L. major-infected macrophages. The presence of B-1 cells also favors the production of lipid bodies by infected macrophages. In contrast, we failed to obtain the same effect on parasite replication inside L. major-infected macrophages when the B-1 cells were isolated from IL-10 knockout mice. CONCLUSION Our results show that elevated levels of PGE2 and IL-10 produced by B-1 cells increase L. major growth, as indicated by the number of parasites in cell cultures.

Anti-inflammatory effect of Heliotropium indicum Linn on lipopolysaccharide-induced uveitis in New Zealand white rabbits

AIM： To investigate the anti-inflammatory effect of an aqueous whole plant extract of Heliotropium indicum（HIE） on endotoxin-induced uveitis in New Zealand white rabbits.·METHODS： Clinical signs of uveitis including flares,iris hyperemia and miosis, were sought for and scored in1.0 mg/kg lipopolysaccharide（LPS）-induced uveitic rabbits treated orally with HIE（30-300 mg/kg）,prednisolone（30 mg/kg）, or normal saline（10 m L/kg）. The number of polymorphonuclear neutrophils infiltrating, the protein concentration, as well as levels of tumor necrosis factor-α（TNF-α）, prostaglandin E2（PGE2）, and monocyte chemmoattrant protein-1（MCP-1） in the aqueous humor after the various treatments were also determined. A histopathological study of the anterior uveal was performed.· RESULTS： The extract and prednisolone-treatment significantly reduced（P ≤0.001） both the clinical scores of inflammation（1.0-1.8 compared to 4.40 ±0.40 in the normal saline-treated rabbits） and inflammatory cells infiltration. The level of protein, and the concentrationsof TNF-α, PGE2 and MCP-1 in the aqueous humor were also significantly reduced（P ≤0.001）. Histopathological studies showed normal uveal morphology in the HIE and prednisolone-treated rabbits while normal saline-treated rabbits showed marked infiltration of inflammatory cells.· CONCLUSION： The HIE exhibits anti-inflammatory effect on LPS-induced uveitis possibly by reducing the production of pro-inflammatory mediators.

Effect of HDL and apo AI on PGE_2 Production by Monocyte-Derived Macrophages

Effect of antiatherogenic high density lipoprotein (HDL) and apolipoprotein AI (apo AI) on production of prostaglandin E2 (PGE2 ) by human m onocyte- derived macrophages was investigated.Macrophages were loaded with acetylated low density lipoprotein followed by incuba- tion with HDL3or apo AI.PGE2 produced and secreted in culture supernatant was quantified by en- zyme im munoassay.HDL3induced production of PGE2 by m acrophages in a time- dependent m an- ner.2 4 h after incubation,PGE2 production by HDL3- treated macrophages increased 3.7- fold of that by control cells.Apo AI also induced PGE2 secretion to 2 .1- fold,which was significantly less than HDL3.The data indicate that both HDL3and lipid- free apo AI enhance PGE2 synthesis and se- cretion by hum an m acrophages and this may further contribute to the protection from atheroscle- rosis.

Expression of prostaglandin E_2 receptors in rat hippocampus

BACKGROUND: Prostaglandin E2 (PGE2) can directly regulate toxic injury of hippocampal neurons through participation by its receptor. Increase of excitability of hippocampal membrane and long-term synaptic elasticity are closely related to PGE2, PGD2 and PGF2A. This suggests that PGE2 may be a key molecule of neuronal signal passage and regulate the existence of neurons through its receptor. However, which isoforms of PGE2 receptor expressing in hippocampal neurons is still unclear. OBJECTIVE: To research the subtype expression of PGE2 receptor in hippocampus of rats through mRNA transcription and protein interpretation. DESIGN: Animal studies with random, control and operator and designer double-blind methods. SETTING: University of South Carolina, Animal Center. MATERIALS: Sprague-Dawley rats, aged 12 weeks, weighing 200 g, females 48 and males 48, were selected from Animal Center in South Carolina University. Tri ReagentTM kit was provided by Molecular Research Center, USA. METHODS: The experiment was carried out in Animal Center in South Carolina University from January to December 2005. The expression of the PGE2 receptors was profiled and compared in rat hippocampus using real-time RT-PCR and Western-blot techniques. MAIN OUTCOME MEASURES: Expression of PGE2 receptors in various isoforms of hippocampal neurons of rats. RESULTS: mRNAs of all four EP1-4 subtypes were detected in the hippocampus. Western-blot data showed consistently detectable bands at approximately Mr 50 000 of EP1, Mr 40 000 and Mr 52 000 of EP2, Mr 45 000, Mr 57 000 and Mr 105 000 of EP3, and Mr 46 000 of EP4. CONCLUSION: Identifying four subtypes of EPs heterogeneously expresses in the hippocampus.

Combination of Paracetamol and the Glutathione Depleting Agent Buthionine Sulfoximine Show Differential Effect on Liver Cancer Cells and Normal Hepatocytes

Background: Paracetamol exerts toxic effects on liver cells through its metabolism into N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by conjugation with cellular glutathione (GSH). Once GSH is depleted, NAPQI stimulates a range of oxidative reactions that result in cell necrosis. The aim of the present investigation is to find a new strategy that would selectively protect normal hepatic tissues and sensitize liver cancer cells to the toxic effects of paracetamol or its metabolite. This may lead to the development of a targeted therapy for liver cancer. Methods: The anti-proliferative effects of paracetamol and buthionine sulfoximine BSO (a glutathione depleting agent) alone and in combination on the liver cancer cells HepG2 and normal rat hepatocytes were investigated by sulphorhodamine-B assay. Effects on cell cycle regulation and induction of apoptosis were tested by flow cytometry. The level of prostaglandin expression was measured by ELISA. Results: The present study showed that both agents alone or in combination have anti-proliferative effects on both cell types. Surprisingly, BSO showed a cytoprotective effects on normal hepatocytes treated with high concentrations (1.75 and 2 mM) of paracetamol. This was confirmed by cell cycle analysis that recorded decreased fraction of sub-G1 cells indicating reduction of apoptosis in normal hepatocytes. Analysis of prostaglandin E2 revealed differential effects of paracetamol on normal and liver cancer cells. A significant increase in PGE2 level over the control was observed in normal hepatocytes whereas a significant decrease was seen in HepG2 cells after treatment with paracetamol. Conclusion: These results indicate that combination of paracetamol/BSO has differential effects on liver cancer cells and normal hepatocytes, which opens the avenue for a new effective and selective combination for management of liver cancer.

Adiponectin receptor 1 mediates the difference in adiponectininduced prostaglandin E2 production in rheumatoid arthritis and osteoarthritis synovial fibroblasts

The synovial fluid concentrations of adiponectin are significantly higher in patients with rheumatoid arthritis （RA） than in patients with osteoarthritis （OA）. Accumulating evidence suggests that adiponectin may be an inducer of inflammation in arthritis, but the mechanism remains unclear. The objectives of this study were to compare the expression levels of adiponectin receptors in rheumatoid arthritis synovial fibroblasts （RASF） and osteoarthritis synovial fibroblasts （OASF）, evaluate the roles of adiponectin receptors in adiponectin-induced prostaglandin E2 （PGE2） production, and then investigate the effects of a nonsteroidal anti-inflammatory drug （NSAID） and a cyclooxygenase （COX）-2-selective inhibitor on adiponectin-induced PGE2 release. Methods The expressions of adiponectin receptor 1 （AdipoR1） and AdipoR2 mRNA and protein in synovial fibroblasts from seven patients with RA and eight patients with OA undergoing total knee replacement were evaluated by real-time polymerase chain reaction, immunofluorescence microscopy and Western blotting analysis. Adiponectin-induced PGE2 production was detected by enzyme-linked immunosorbent assay. RNA interference against the AdipoR1 and AdipoR2 genes was performed to investigate the effects of the adiponectin receptors on adiponectin-induced PGE2 production in both RASF and OASE Results AdipoR1 and AdipoR2 mRNA and protein were expressed by both RASF and OASF. Compared with OASF, RASF exhibited higher levels of AdipoR1, but there was no significant difference for AdipoR2. Adiponectin induced the production of PGE2 by the synovial fibroblasts in a concentration-dependent manner, and this was more obvious in RASF. RNA interference showed that the difference may be mediated by the diverse distribution of AdipoRl. The adiponectin-induced PGE2 production was efficiently relieved by the NSAID and COX-2-selective inhibitor. Conclusion The present findings suggest that AdipoR1 may mediate the difference in adiponectin-induced PGE2 production in RASF and OASE

Follicular fluid levels of prostaglandin E2 and the effect of prostaglandin E2 on steroidogenesis in granulosa-lutein cells in women with moderate and severe endometriosis undergoing in vitro fertilization and embryo transfer

Background The mechanisms of endometriosis with infertility have not been fully studied. The present study aimed to assess the follicular fluid （FF） levels of prostaglandin E2 （PGE2）, which plays a critical role within the ovary, and to investigate the effect of PGE2 on steroidogenesis in granulosa-lutein cells （GLCs） from women with and without endometriosis. Methods Thirty-three women with laparoscopically documented endometriosis and 40 controls undergoing in vitro fertilization （IVF） were studied. We assayed the concentrations of PGE2 in FF, the production of E2 and progesterone in FF and in culture medium, and the expression of steroidogenic acute regulatory protein （STAR） and CYP19A1 in GLCs with the intervention of PGE2. Results PGE2 and progesterone concentrations were increased and displayed positive correlation in endometriotic FE PGE2 induced the expression of STAR and the production of progesterone in GLCs from women with endometriosis, and the expression of STAR and the production of progesterone were increased in GLCs from women with endometriosis. However, there were no significant effects of PGE2 on promoting the production of E2 or the expression of CYP19A1 in GLCs. Moreover, the production of E2 and the expression of CYP19A1 in GLCs from women with endometriosis were significantly decreased compared to the controls. Conclusions PGE2 concentrations are increased in endometriotic FF, along with concomitant increases in progesterone and STAR. In contrast, the E2 and CYP19A1 are decreased in GLCs, which may delay the development of the follicles and cause an imbalance in the follicular steroid hormone levels. These changes may have close relationship with endometriosis-associated infertility.

Prostaglandin E2-EP4 signaling persistently amplifies CD40-mediated induction of IL-23 p19 expression through canonical and non-canonical NF-κB pathways

While there is mounting evidence that interleukin （IL）-23-IL-17 axis plays a critical role in the pathogenesis of various autoimmune diseases, much remains to be elucidated on how IL-23 is induced in the pathological processes. IL-23 is a heterodimer composed of p19 and p40, the latter being shared with IL-12. We previously reported that prostaglandin （PG） E2 promotes CD40-mediated induction of 1123a （p19） expression through its E receptor subtype 4 （EP4） receptor in splenic dendritic cells （DCs）. Here, we have analyzed signaling pathways regulating 1123a induction in the cross talk between EP4 and CD40 in bone marrow-derived DCs. We found that PGE2 synergistically induced 1123a transcription with CD40 signaling. An EP4 agonist, but not agonists of EP1, EP2, or EP3, reproduced this action. Stimulation of CD40 with an agonist antibody evoked biphasic induction of 1123a expression, with the early phase peaking at 1 h and the late phase peaking at 12 h and lasting up to 36 h after stimulation, whereas induction by lipopolysaccharide or tumor necrosis factor-α was transient. The early phase induction by CD40 stimulation was absent in DCs derived from Nfkbl-deficient mice, and the late phase induction was eliminated by RNA interference of nuclear factor-kappa B （NF-κB） p100 subunit. Further, cAMP response element-binding protein （CREB） depletion completely eliminated the induction of 1123a by CD40 stimulation. The addition of the EP4 agonist amplified the induction in both phases through the cAMP-protein kinase A （PKA） pathway. These results suggest that 1123a expression in DCs is synergistically triggered by the PG E2-EP4-cAMP-PKA pathway and canonical/non-canonical NF-KB pathways and CREB activated by CD40 stimulation.

Prostaglandin E2 promotes hematopoietic development from human embryonic stem cells

Recent studies have suggested that prostaglan-din(PG)E2(PGE2)and the prostaglandin pathway are essential for hematopoietic stem cell growth and develop-ment.However,similar studies on hematopoietic commit-ment from human embryonic stem cells(hESCs)are still limited.Here we report that the addition of PGE2 promotes hematopoietic differentiation of hESCs.The induced cells from hESCs/OP9 co-culture and in the presence of PGE2 were characterized by reverse transcription-PCR(RT-PCR),flow cytometry,colony-forming assays and Wright-Giemsa staining.Our results demonstrated that PGE2 exposure could alter the gene expression pattern and morphology of co-cultured hESCs and resulted in a robust hematopoietic differentiation with higher frequencies of CD34+and CD45+cells.Furthermore,the Smad signaling pathway may be involved in PGE2 and OP9 induced hematopoietic differentiation of hESCs.This research may improve our knowledge of stem cell regulation and hopefully lead to better stem cell-based therapeutic options.

Damage control:Harnessing prostaglandin E2 as a potential healing factor of tissue injuries

Increasing prostaglandin E2 by knocking out its inhibitor 15-hydroxyprostaglandin dehydrogenase(15-PDGH)or administering a compound that inhibits 15-PDGH was recently found to improve healing in hematopoietic stem cell transplants,colitis recovery,and hepatogenesis after transection in mice.These results are suggestive of pharmacologic therapies or even genetic therapy that could improve patient outcomes,especially since the excess PGE2 and the 15-PDGH inhibitor have proven to be non-toxic.However,elevated levels of PGE2 are associated with increased risk of cancer and blood clotting problems.It would be unacceptable to treat a cancer patient with chemotherapy and replenish the hematopoietic stem cells with the help of PGE2,only to have increased expression of PGE2 and induce another cancer.Therefore,to assess the most therapeutic aspects of PGE2,it is important to consider effects that could induce disease.