脂氧素对脂多糖诱导的脐静脉内皮细胞通透性的影响

目的 研究脂氧素对脂多糖诱导的脐静脉内皮细胞通透性的影响,并进一步探讨其机制.方法 取华中科技大学同济医学院附属同济医院产科因社会因素行剖宫产术的健康产妇分娩的新生儿脐带,分离原代脐静脉内皮细胞后进行传代培养并分组:(1)对照组.(2)脂多糖组:加入10 mg/L脂多糖培养24 h.(3)脂多糖+脂氧素A4组:加入100 nmol/L脂氧素A4和10 mg/L脂多糖共同培养24 h.(4)脂多糖+脂氧素A4+BOC-2组:BOC-2为脂氧素受体拮抗剂,共同培养24 h.计算各组内皮细胞通透系数;逆转录(RT)PCR技术检测内皮细胞中肿瘤坏死因子α(TNF-α)mRNA表达水平;观察不同浓度脂多糖(0、0.1、1、10 mg/L)对对照组内皮细胞功能的影响(以TNF-α mRNA水平表示);蛋白印迹法检测内皮细胞中核因子κB蛋白表达水平;ELISA法检测内皮细胞培养液中TNF-α水平.结果 (1)内皮细胞通透系数:脂多糖组内皮细胞通透系数为(183.1±1.7)%,脂多糖+脂氧素A4组为(103.1±2.2)%,脂多糖+脂氧素A4+BOC-2组为(162.2±2.8)%,对照组为100%,脂多糖+脂氧素A4组通透系数较脂多糖组减小了(80.0±2.2)%,两组比较,差异有统计学意义(P<0.05).脂多糖+脂氧素A4+BOC-2组通透系数与脂多糖+脂氧素A4组相比增加了(59.1±2.8)%,两组比较,差异有统计学意义(P<0.01).脂多糖+脂氧素A4+BOC-2组与脂多糖组比较,差异无统计学意义(P>0.05).(2)TNF-α mRNA表达水平:脂多糖浓度为0、0.1、1、10 mg/L时,对照组脐静脉内皮细胞中的TNF-α mRNA表达水平分别为1.11±0.11、1.27±0.03、1.60±0.06、1.82±0.04,其中,脂多糖浓度为1、10 mg/L时,分别与0浓度比较,差异均有统计学意义(P<0.05).(3)核因子κB蛋白及TNF-αmRNA表达水平:核因子κB蛋白及TNF-αmRNA表达水平,对照组分别为0.24±0.06及0.25±0.05,脂多糖组分别为0.53±0.06及0.81±0.09,脂多糖+脂氧素A4组分别为0.19±0.05及0.41±0.07,脂多糖组核因子κB蛋白及TNF-α mRNA表达水平明显高于对照组,差异有统计学意义(P<0.05);脂多糖+脂氧素A4组核因子κB蛋白及TNF-αmRNA表达水平明显低于脂多糖组,差异有统计学意义(P<0.05).(4)细胞培养液中TNF-α水平:脂多糖组TNF-α水平(31.94±0.01)ng/L]明显高于对照组(18.17±0.03)ng/L],两组比较,差异有统计学意义(P<0.05);脂多糖+脂氧素A4组(15.72±0.07)ng/L]明显低于脂多糖组,两组比较,差异有统计学意义(P<0.05).结论 脂氧素A4可以抑制脂多糖诱导的脐静脉内皮细胞高通透性,其作用可能是首先与其受体结合然后通过抑制核因子κB及其下游细胞因子TNF-α的表达而实现的.

Abstract：

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.

Effect of lipoxin A(4) on lipopolysaccharide-induced endothelial hyperpermeability in human umbilical vein endothelial cell

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.