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ObjectiveTo investigate the effects of 5(S),6(R),7-trihydroxyheptanoic acid methyl ester (BML-111) on pregnant mice with fetal growth restriction(FGR) induced by antenatal dexamethasone and its probable mechanism. MethodsThe mice were mated overnight,with day 1 of pregnancy designated as the day on which spermatozoa were presented in a vaginal smear.The pregnant mice were then randomly divided into control group,dexamethasone group and BML-111 group.From 9 to 14 days of pregnancy,pregnant ICR mice of control,dexamethasone and BML-111 group were treated separately with saline,dexamethasone(5 mg/kg) and dexamethasone at 8:00 am,and two hours later they were treated separately again with 1 mg/kg saline,saline and BML-111.On the day 18 of gestation,they were sacrificed after blood were collected from their eyeballs.The serum lipoxin A4 was measured with enzyme-linked immunosorbent assay. Fetuses were delivered by cesarean section; the placenta and uterus were immediately removed and frozen.Gene expressions of 11β-hydroxysteroid dehydrogenase 2 ( 11β-HSD2 ),interleukin-1β (IL-1β) in placenta and lipoxin A4 receptor-formyl peptide receptor 3 (FPR3)in uterine were detected by reverse transcriptionpolymerase chain reaction and compared with analysis of variance.The 11β-HSD2 protein in mice placenta was detected by immunohistochemistry. ResultsThe mean fetal weight of dexamethasone group was (0.823±0.054) g,lower than that of the control group and BML-111 group [(1.103±0.218) g and (0.992 ± 0.207) g] (t =- 4.108 and - 2.890,P ＜ 0.05 respectively).Protein expression of 11β-HSD2 in dexamethasone group (0.030±0.019) was weaker than that in control group (0.058±0.015,t=-3.107,P＜0.05) or in BML-111 group (0.049±0.026,t=-2.211,P＜0.05).The expression of 11β-HSD2 mRNA in dexamethasone group (0.457±0.062) was lower than that in control group (0.943±0.057,t=-9.418,P＜0.05) or in BML-111 group (0.698±0.071,t=-4.617,P＜0.05).Expression of IL-1β mRNA in dexamethasone group (0.543±0.103)was less than that in control group (0.710± 0.085,t=-3.736,P＜0.05) but more than that in BML-111 group (0.229 ±0.031,t=7.025,P＜0.05). The expression of FPR3 mRNA in dexamethasone group (0.323 ± 0.019) was less than that in control group (0.857 ± 0.057,t =-14.630,P＜0.05) or in BML-111 group (0.499 ±0.050,t=-4.822,P＜0.05).The serum concentration of lipoxin A4 in dexamethasone group was lower than that in control group [(64.463±22.144) pg/ml vs (101.610±24.916) pg/ml,t=3.152,P＜0.05].ConclusionsBML-111 regulate the expression of 11β-HSD2 and then protect against FGR resulted from too much prenatal application of dexamethasone.
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Objective To explore whether lipoxin A4 (LXA4)could prevent lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVEC) monolayer hyperpermeability and its possible mechanism. Methods Human umbilical cords were obtained from women with normal pregnancy immediately after delivery from Tongji Hospital Affiliated of Tongji Medical College. Primary HUVEC were isolated from umbilical veins and subcultured, then, HUVEC were divided into four groups:control group;LPS group (10 mg/L of LPS); LPS + LXA4 group(10 mg/L of LPS and 100 nmol/L of LXA4); LPS +LXA4 + BOC-2 group [10 μmol/L of BOC-2, an effective antagonist of formyl peptide receptor like 1 (FPRL-1)]. All expriments were performed after cells were treated for 24 hours. Endothelial permeability was measured by fluorescein isothiocyan-ate labelled bovine serum albumin (FITC-BSA) clearance across the monolayer; tumor necrosis factor α(TNF-o) mRNA and secretion were detected by reverse transcriplase (RT) -PCR and ELISA assay respectively, and nuclear factor κB(NF-κB) protein change was determined by western blot. Results (1) LPS induced a significant increase in the permeability [Pa value of LPS group was (183.1 ±1.7)%], while co-administrating with LXA4 obviously attenuated this LPS-induced hyperpermeability, Pa value of LPS + LXA4 group was (103.1 ±2.2)%, LPS + LXA4 + BOC-2 group was (162.2 ± 2.8)%, control group was 100%, the permeability of HUVEC monolayer was significantly increased by LPS which was (83.1 ± 1.7)% of control (P <0.01), however, it was notably inhibited by LXA4 (P<0.05); the blockade of FPRL-1 could attenuate the effect of LXA4, that is, there was no difference between the LPS + LXA4 + BOC-2 group and the LPS group. (2) After treatment with different concentration of LPS(0,0.1, 1,10 mg/L), the mRNA expressions of TNF-α were increased (1.11 ±0.11,1.27 ± 0.03, 1.60 ± 0.06, 1.82 ± 0. 04, respectively), compared with the control group, at the concentration of 1,10 mg/L LPS, the difference was statistically significant (P<0. 05). (3) The increased levels of NF-κB and inflammatory mediator TNF-α in the LPS group were both inhibited by LXA4. Levels of NF-κB protein and TNF-o mRNA secretion in LPS treated group (0.53 ±0.06 and 0.81 ±0.09 ,respectively)were both inhibited by LXA4 (0.19 ± 0.05 and 0.41 ± 0.07, respectively, and both had significant difference, P<0.05). (4) Levels of TNF-α in HUVEC culture medium of LPS group [(31.94 ±0.01)ng/L] was significantly higher than the control group [(18.17 ± 0.03) ng/L, P<0.05], LPS + LXA4 group [(15.72 ± 0.07) ng/L] was significantly lower than the LPS group (P<0.05). Conclusion Our findings demonstrated that LXA4 could prevent the endothelial cell hyperpermeability induced by LPS in HUVEC under which the possible mechanism was through inhibiting the expression of NF-κB and its related cytokines through receptor-dependent.
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Objective To explore lipoxinA4 (LXA4) expression in maternal serum of pregnant women and the protective effect and mechanism of LXA4 on trophoblastic cells from oxidative injury. Methods Trophoblastic cells were randomized into six groups: Control group; Lipopolysaccharides (LPS) group, cells were stimulated by 10 μg/ml LPS for 24 h; Intervention group, cells stimulated by LPS were treated with 100 nmol/L LXA4 for 24 h; LXA4 group, cells were treated with 100 nmol/L LXA4 for 24 h; Antagonistic group, cells stimulated by LPS were treated with 100 nmol/L LXA4 plus 100 μmol/L N-tert-butoxycarbonyl-2-pyrrolidine (BOC-2) for 24 h; BOC-2 group, trophoblastic cells stimulated by LPS were treated with 100 μmol/L BOC-2 for 24 h. The serum concentration of LXA4 in normal group and preeclampsia group was detected by ELISA. The intracellular formation of reactive oxygen species (ROS) was detected by 2,7-dichlorofluorescein diacetate (DCFH-DA) as a fluorescent probe. SOD mRNA was analyzed by RT-PCR. SOD and Nrf2 protein expressions were analyzed by Western blot. The levels of SOD in trophoblastic cells were detected by using detection kit. Results (1) The serum concentration of LXA4 was significantly lower in preeclampsia group (165.53±18.89) pg/L than in the control [(545.67±30.91) pg/L, P0.05). Conclusions LXA4 can significantly reduce the oxidative stress of placental trophoblastic cells stimulated by LPS. LXA4 can bind to lipoxin receptors and activate Nrf2-ARE signaling pathway playing a protective effect. So LXA4 in pregnant women can affect the oxidative stress of placenta.
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Objective To explore the effects of lipoxin A4 ( LXA4 ) on lipopolysaccharide ( LPS)-induced oxidative stress in human umbilical veins endothelial cells(HUVEC) and the possible mechanism.Methods Neonatal umbilical cords were obtained from normal term pregnant women with cesarean section within 4 hours and then were used to isolate HUVEC for subculture.HUVEC were divided into four groups:control group; LPS group ( 10 μg/ml of LPS); LPS + LXA4 group ( 10 μg/ml of LPS and 100 nmol/L of LXA4); LXA4 group (100 nmol/L of LXA4) All expriments were performed after cells treated for 12 and 24 hours respectively.Immunofluorescence was used to detect the expression of Ⅷ foctor and nuclear translocation of nuclear factor-erythroid-2-related factor 2 ( Nrf2 ); the mRNA expression of Nrf2, heme oxygenase 1 (HO-1) and reduced form of nicotinamide-adenine dinucleotide quinone oxidoreductase-1(NQO1) were evaluated by reverse transcription-PCR .Results (1)The flavovirens fluorescence was observed in the cytoplasm under fluorescence microscope, which confirmed the existence of Ⅷ factor which specifically expressed in endothelial cells, especially in HUVEC.(2)Immunofluorescent results showed that in control group, Nrf2 protein expressed in the cytosol rather than in the nucleus.In LPS group, the expression of Nrf2 protein obviously increased in the nucleus while decreased in the cytosol after 12 hours.However, after LPS treatment for 24 hours, Nrf2 expression reduced in the cytosol and nucleus.In cotreatment with LPS and LXA4 group,the expression of Nrf2 protein was much higher than that in LPS group after 12 hours or 24 hours.Furthermore, Nrf2 protein also mostly expressed in the cytosol in LXA4 group.(3) After stimulation for 12 hours, compared with control group, the gene expression of Nrf2 and HO-1 were significantly enhanced in LPS group (0.581 ± 0.019 and 0.081 ±0.009, P ＜ 0.05 ) and in LPS + LXA4group(0.692 ±0.048 and 0.136 ± 0.018, P ＜ 0.05 ), the level of NQO1 mRNA in LPS group and LPS +LXA4 group were 0.381 ± 0.009 ( P ＞ 0.05 ) and 0.574 ± 0.034 ( P ＜ 0.05 ).After treatment for 24 hours,compared with control goup, the gene expressions of Nrf2 and NQO1 were down-regulated in LPS group (0.180±0.017 and 0.472 ±0.064, P＜0.05).But in LPS + LXA4 group the expression of Nrf2 and NQOI were upregulated (0.532 ± 0.051 and 0.830 ± 0.068, P ＜ 0.05, compared with treatment for LPS group).The mRNA expressions of Nrf2, HO-1 and NQO1 were increased in LPS + LXA4 group compared with LPS group ( P ＜ 0.05 ).In addition, there was no markedly difference in the expressions of Nrf2, HO1 and NQO1 between control and LXA4 group after 12 hours and 24 hours ( P ＞ 0.05 ) .Conclusion Through activating nuclear translocation of Nrf2 protein from cytoplasm, LXA4 upregulates the Nrf2downstream enzymes, such as NQO1 and HO-1 to protect HUVEC against the oxidative stress induced by LPS.