Effect of secretin on the expression of cPLAand mPGEs-1 in mouse endometrial stromal cell during early pregnancy / 生理学报

Secretin, a gastrointestinal peptide, has been found to be expressed in mouse endometrial stromal cells (mESCs) during early pregnancy. In order to further investigate the function of secretin during embryo implantation, the expression levels of secretin, secretin receptor, cytosolic phospholipase A(cPLA) and membrane prostaglandin E synthase 1 (mPGEs-1) were detected in the mice uterus from day 4 to 8 of pregnancy by real-time PCR, ELISA and in situ hybridization. mESCs isolated and cultured from day 4 of pregnancy were transfected with secretin expression vectors or treated with H89, a PKA inhibitor. Then the expression levels of cPLA, mPGEs-1 and cAMP responsive element-binding protein (CREB) were detected by real-time PCR and Western blot. The concentration of prostaglandin E2 (PGE) in the supernatant was determined by ELISA. The result showed that secretin, cPLAand mPGEs-1 mRNA expression increased gradually in implantation sites from day 5 to day 7 of pregnancy with the same tendency. The secretin levels in serum were significantly higher on days 6, 7 and 8 of pregnancy than that on day 5 of pregnancy. The concentration of secretin was significantly higher in implantation sites on days 6, 7 than that in non-implantation site on day 5. Transfection of secretin expression vector promoted cPLA, p-cPLAand mPGEs-1 expressions in mESCs, but not PGElevel in the supernatant. H89 could effectively inhibit the expression of CREB, p-CREB, p-cPLAand cPLAinduced by secretin. The results showed that the increased secretin expression in mESCs during embryo implantation may promote p-cPLA, cPLAand mPGEs-1 expression, and the promotion may be through PKA signaling pathway.

Cinnamaldehyde decreases interleukin-1beta induced PGE2 production by down-regulation of mPGES-1 and COX-2 expression in mouse macrophage RAW264.7 cells / 中国中药杂志

Cinnamaldehyde was shown to have significant anti-inflammatory and anti-pyretic actions in studies from both others' and our lab. Prostaglandin E2 (PGE2) plays a key role in generation of these pathological states, while PGE, synthase-1 (mPGES-1) is one of crucial biological elements in the process of PGE2 production. And as a downstream inducible terminal prostaglandin synthase of COX-2, mPGES-1 is now regarded as a more promising novel drug target than COX-2 and is attracting more and more attention from both academia and pharmaceutical industry. The purpose of present study was to further investigate the anti-inflammatory and antipyretic molecular mechanisms of cinnamaldehyde based on the mouse macrophage cell line RAW264. 7 in vitro. The PGE2 was identified by using the method of enzyme-linked immunosorbent assay (ELISA) and the expression of COX-2 and mPGES-1 at mRNA and protein levels was detected by the Real-time PCR and Western blotting methods respectively. The experimental results suggested that cinnamaldehyde could evidently reverse the increased production of PGE2induced by IL-1beta. Moreover, the up-regulated expression levels of mPGES-1 and COX-2 were significatly decreased. Together, these results provide compelling evidence that the down-regulated actions to both the production of PGE2 as well as the expression of mPGES-I might account for, at least in part, the anti-inflammatory and anti-pyretic effects of cinnamaldehyde.

Effect of mPGES-1 inhibitor MK886 on cell cycle of leukemia HL-60 cells / 中国实验血液学杂志

To investigate the effect of a microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor MK886 on cell cycle of the human acute myeloid leukemia HL-60 cells. HL-60 cells were treated with different concentration of MK886 (10, 25, 50 µmol/L) for 24 h. Flow cytometry, Western blot and ELISA were used to measure cell cycle, cyclin D1, mPGES-1, PGE(2), Akt, P-Akt and C-MYC. The results indicated that after treated with MK886, the percentage of HL-60 cells decreased in G(0)/G(1) phase and increased in S phase, and expressions of mPGES-1, cyclin D1, P-Akt and C-MYC and synthesis of PGE(2) decreased significantly. It is concluded that MK886 can arrest HL-60 cells in G(0)/G(1) phase, the mechanism of which is possibly associated to inhibition of mPGES-1 expression, reduction of PGE(2) synthesis, suppression of Akt phosphorylation and C-MYC expression, down-regulation of cyclin D1 expression.

Role of mPGES-1 in the occurrence, progression, metastasis and invasion of hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the expression of mPGES-1 in hepatocellular carcinoma (HCC), observe the effect of MK886 on down-regulation of mPGES-1 gene expression on the biology of human hepatocarcinoma cell line HepG2 and to investigate its significance in the occurrence, progression, metastasis and invasion.</p><p><b>METHODS</b>HCC tissues, para-carcinoma tissues, far-carcinoma tissues and normal liver tissues were collected. The expressions of mPGES-1 were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The proliferation, adherence, migration and invasion abilities of HepG2 cells interfered by MK886 were assessed by MTT and transwell technique respectively.</p><p><b>RESULTS</b>The expression of mPGES-1 in HCCs was higher than that in normal liver tissues (P < 0.01), which increased following histological grade. Furthermore, mPGES-1 expression level was higher in the capsule invasion and metastasis tumor than in primary locus. A significant dose-dependent down-regulation of expressions of mPGES-1 gene mRNA and protein were observed in HepG2 cells when MK886 was given for 48 h (F = 140.402, P < 0.01; a'= 0.00714, P < 0.01). Compared with the control group, the growth inhibitory rate of HepG2 cell was observed significantly time and dose-dependent when MK886 was given. The rate of adhesion cells in experimental groups were 85.3% ± 1.3%, 70.5% ± 1.5% and 45.8% ± 2.4%, respectively, less than that in control group 100.0% ± 0 (F = 626.313, P < 0.01). The migration cells was 92.47 ± 1.90, 62.63 ± 1.96 and 37.33 ± 0.83 respectively in the experimental groups after 24 h, lower than that in the control group 128.93 ± 2.60 (F = 1253.805, P < 0.01). The invasion assay revealed that the invading cells were 41.67 ± 1.30, 25.47 ± 1.30 and 13.93 ± 1.66 in the experimental groups, in contrast to 55.67 ± 2.08 in control group after 24 h. The difference between these groups was significant (F = 372.615, P < 0.01). The numbers of adhesion, migration and invasion of HepG2 cells were dose-dependent in MK886 groups.</p><p><b>CONCLUSION</b>Over-expression of mPGES-1 was associated with the tumorigenesis and progression of HCC. The down-regulation of mPGES-1 gene expression might indicated the decrease of the invasion and metastasis of HCC.</p>

Effect of concanavalin A on expression of MAPEG mRNA in Balb/c mouse brain / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the gene expression of MAPEG in the cortex of concanavalin A (Con A)-induced mouse immune inflammatory model and the effect of cyclosporine A (Cs A).</p><p><b>METHODS</b>Male Balb/c mouse immune inflammation model was developed by intravenous injection of Con A (20 mg/kg). Cs A (150 mg/kg) was intravenously infected prior to Con A administration. The MAPEG expressions were determined by RT-PCR.</p><p><b>RESULT</b>mGST1, mGST3, LTC(4)S, FLAP and mPGES-1 were detected by RT-PCR but not mGST2. Eight hours after Con A treatment, mGST1 level was up-regulated to 1.2 approximately 1.5 folds of control with or without Cs A treatment. mGST3ìLTC(4)S, FLAP and mPGES-1 mRNA levels were not influenced by Con A administration.</p><p><b>CONCLUSION</b>Immune mechanism may be not involved in mGST1 up-regulation in this model and Con A does not alter arachidonic acid metabolism in cortex.</p>

Effect of lipopolysaccharide of Porphyromonas gingivalis on prostaglandin E2 biosynthetic pathway in human monocytic cell strain THP-1 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of lipopolysaccharide of Porphyromonas gingivalis (Pg-LPS) on the bio-thythetic pathway of prostaglandin E2 (PGE2) and its difference from lipopolysaccharide of Escherichia coli (Ec-LPS).</p><p><b>METHODS</b>Purified Pg-LPS and Ec-LPS were used to stimulate a human monocytic cell strain THP-1. PGE2 concentration was determined by an enzyme immunoassay kit. The release of tritium labeled arachidonic acid (AA) was detected by a liquid scintillation counter. Reverse transcription polymerase chain reaction and western blot were used to analyse the expression of cytosolic phospholipase A2 (cPLA2) enzyme, cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1).</p><p><b>RESULTS</b>The effect of Pg-LPS on induction of PGE2 and release of AA was significantly weaker than that of Ec-LPS (P < 0.05).Increased secretion of PGE2 was observed after stimulation with Pg-LPS for 6 h, which peak at 24 h at (221.40 +/- 29.46) ng/L; or with Ec-LPS for 1-48 h, at (161.80 +/- 17.31) approximately (379.80 +/- 37.35) ng/L. The highest levels of COX-2 and mPGES-1 were shown after 16 h treatment by Pg-LPS, or after 8 h and 16 h by Ec-LPS respectively.cPLA2 inhibitor AACOCF3 could lower the level of LPS-induced release of AA, while it did not influence the production of PGE2. COX-2 inhibitor NS-398 could remarkably reduce the concentration of PGE2.</p><p><b>CONCLUSIONS</b>Pg-LPS showed delayed and weaker effect on PGE2 biosynthetic pathway than Ec-LPS. Pg-LPS-induced PGE2 synthesis was mainly due to enhanced expression of COX-2 and mPGES-1, whereas cPLA2 played an insignificant role.</p>

COX-2 and mPGES-1 expression in carotid atherosclerotic plaques / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the changes in the expressions of inducible cyclooxygenase type 2 (COX-2) and membrane associated prostaglandin E-1(mPGES-1) in human carotid atherosclerotic plaques and to explore possible mechanisms of inflammatory process involved in plaque stability.</p><p><b>METHODS</b>The mRNA and protein levels of COX-2 and mPGES-1 were compared between minimally and grossly atherosclerotic arterial tissues. COX-2 and mPGES-1 gene expression were established by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) in 10 mesenchymal artery controls and 24 atherosclerotic specimens. Presence of COX-2 and mPGES-1 protein was assessed by Western blotting.</p><p><b>RESULTS</b>Immunohistochemical staining showed that the COX-2 and mPGES-1 immunoreactive substances were present in the cytoplasm of smooth muscle cell. Compared with the control group, immunostaining positive cells increased in carotid atherosclerotic plaque group. COX-2 and mPGES-1 gene expression was significantly elevated in atherosclerotic plaques (P< 0.05, respectively). The increased mRNA and protein levels of COX-2 and mPGES-1 were correlated in atherosclerotic tissue (P< 0.05). The mRNA and protein levels of COX-2 and mPGES-1 related to degree of pathological damage in atherosclerotic tissue (P< 0.05). COX-2 and mPGES-1 were not found in the control group (mesenteric vascular walls).</p><p><b>CONCLUSION</b>COX-2 and mPGES-1 expression in plaques is significantly higher than that in the control group. These findings suggests that COX-2 and mPGES-1 might play a role in pathogenesis of atheroscleros and modulation of inflammatory process involved in plaque stability, and COX-2 may have proinflammatory enzyme properties.</p>