Protective effect of adrenomedullin on hyperoxia-induced lung injury / 中国当代儿科杂志

OBJECTIVES@#To study the role of adrenomedullin (ADM) in hyperoxia-induced lung injury by examining the effect of ADM on the expression of calcitonin receptor-like receptor (CRLR), receptor activity-modifying protein 2 (RAMP2), extracellular signal-regulated kinase (ERK), and protein kinase B (PKB) in human pulmonary microvascular endothelial cells (HPMECs) under different experimental conditions.@*METHODS@#HPMECs were randomly divided into an air group and a hyperoxia group (@*RESULTS@#Compared with the air group, the hyperoxia group had significant increases in the mRNA and protein expression levels of ADM, CRLR, RAMP2, ERK1/2, and PKB (@*CONCLUSIONS@#ERK1/2 and PKB may be the downstream targets of the ADM signaling pathway. ADM mediates the ERK/PKB signaling pathway by regulating CRLR/RAMP2 and participates in the protection of hyperoxia-induced lung injury.

RhoA/mDia1 pathway involved in the expression of p-ERM in the pulmonary micro-vascular endothelial cell induced by lipopolysaccharide / 中华急诊医学杂志

Objective To investigate the possibility of the involvement of RhoA/mDia1 pathway to cause the expression of phosphorylate ezrin-radixin-moesin (p-ERM) in rat pulmonary micro-vascular endothelial cell (PMVEC) after the stimulation of lipopolysaccharide (LPS).Methods The specimens of lung tissue were taken from healthy male SPF grade SD rat with 100-120 g body weight which was purchased from the laboratory animal center of Anhui province.After culture,the PMVECs were randomly divided into dose-dependent groups (0,0.1,1,10 μg/mL LPS added in PMVECs and cultured for30 min,n =8 in each),time-dependent groups (10 μg/mL LPS added to PMVECs cultured for 0,15,30,60,120 min,n =8 in each) and intervention group (n =8).In the intervention group,PMVECs were cultured with 1 μg/mL C3 transferase in serum free media for 240 min,followed by treatment with 10 μg/mL LPS for 30 min.Meanwhile,two control groups in serum-free DMEM medium were made by adding 10.μg/mL LPS to PMVECs and 1 μg/mL C3 transferase to PMVECs respectively cultured for 30 min (n =8 in each).Western blot was used to detect the level of p-ERM,ERM and mDia1.Data were analyzed with SPSS 16.0 software,while one way analysis of variance (ANOVA) was used to compare multiple sets of variables,the intergroup comparisons were analyzed by the least-significant-difference (LSD) tests,with P ＜0.05 for the statistically significant difference.Results ERM,p-ERM and mDia1 were presented in rat PMVEC.Stimulation with LPS up-regulated p-ERM,mDia1 in a dose-dependent manner:LPS [0 μg/mL LPS group:(0.520±0.101),0.1 μg/mL LPS group:(0.657 ±0.092),1 μg/mL LPS group:(0.891 ±0.167),10 μg/mL LPS group:(1.227 ±0.106);0 μg/mL group vs.0.1 μg/mL group,P ＞0.05;the rest P ＜0.01];and mDia1 [0 μg/mL LPS group:(0.200 ±0.102),0.1 μg/mL LPS group:(0.430 ±0.121),1 μg/mL LPS group:(0.603 ±0.154),10 μg/mL LPS group:(0.887 ±0.204);0.1 μg/mL group vs.1 μg/mL group,P ＞ 0.05;the rest P ＜ 0.05].In time-dependent group,the level of p-ERM protein increased at 15 min (0.670 ±0.149),peaked at 30 min (1.175 ±0.103),then decreased,at 60 min (0.959 ±0.189),90 min (0.842 ±0.129),but kept at higher level at 120 min (0.767 ±0.097) than that in control group (0.471 ±0.157,15 min group vs.120 min group,60 min group vs.90 min group and 90 min group vs.120 min group,P ＞ 0.05;the rest P ＜ 0.05);and the level of mDia1 increased at 15 min (0.779 ±0.035),peaked at 30 min (0.889 ±0.036) then decreased at 60 min (0.648 ±0.019),90 min (0.582 ±0.068),but kept at higher level at 120 min (0.526 ±0.059) than that in control group (0.284±0.118,all P ＜ 0.01).C3 transferase caused a marked attenuation of LPS induced p-ERM expression [control group:(0.339 ± 0.069);C3 + LPS group:(0.438 ± 0.07);C3 control group:(0.352 ± 0.071);LPS control group:(0.634 ± 0.191),C3 + LPS group vs.LPS control group,P =0.01],as the same in mDia1 [control group:(0.449 ±0.122);C3 + LPS group:(0.380 ±0.148);C3 control group:(0.404 ±0.164);LPS control group:(0.622 ±0.174),C3 + LPS group vs.LPS control group,P ＜ 0.01].Conclusions LPS could up-regulated the expression of p-ERM protein,and inhibition of RhoA/mDia1 signal pathway by C3 transferase could down-regulated the p-ERM levels.

Expressions of MK2, HuR, and ICAM-1 in the pulmonary microvascular endothelial cells of the mouse with acute respiratory distress syndrome / 医学研究生学报

Objective Intercellular adhesion molecule-1 (ICAM-1) plays an important role in mediating pulmonary infiltration of neutrophils .The aim of the study was to observe the expression of ICAM-1 and its potential regulators MK 2/HuR in pulmonary micro-vascular endothelial cells ( PMVEC ) in mice with acute respiratory distress syndrome ( ARDS) induced by lipopolysaccharide ( LPS) . Methods Ten 6-8 weeks old healthy C57BL/6 mice were randomly divided into an LPS and a control group of equal number , the former injected intraperitoneally with LPS diluted in 100 μL PBS while the latter with PBS only , both at 5 mg per kg of the body weight .At 24 hours after injection , all the mice were sacrificed .Real-time PCR was used to determine the mRNA expressions of HuR and ICAM-1 in the PMVECs, Western bolt employed to detect the protein expressions of MK2, HuR and ICAM-1, and flow cytometry adopted to measure the ICAM-1 expression on the surface of the PMVECs and pulmonary infiltration of neutrophils . Results The W/D ratio in the lung tissue of the mice was significantly lower in the LPS than in the control group (3.61 ±0.28 vs 6.16 ±0.40, P<0.05), while the rate of neutrophil infiltration markedly higher in the former than in the latter ([13.92 ±3.23]%vs [3.24 ±1.24]%, P<0.05).The mRNA and protein expressions of ICAM-1 in the PMVECs were significantly elevated in the LPS group as compared with that in the control (P<0.05), and so was the mRNA expression of HuR (P<0.05).No remarkable changes were observed in the expressions of total MK 2 and HuR proteins, but phosphorylated MK2 (p-MK2) and cytoplasmic HuR were increased in the LPS-stimulated mice. Conclusion Specific blockage or reduction of the HuR expression in PMVECs may lower the expression of ICAM-1, reduce neutrophil infiltration , and lessen pathophysiological changes in mice with ARDS .

Study of the level of ERM proteins in pulmonary microvascular endothelial cells induced by tumor necrosis factor-α / 中华急诊医学杂志

Objective To investigate the effect of tumor necrosis factor-α (TNF-α) on the levels of ezrin-radixin-moesin (ERM) proteins and the phosphorylated ERM proteins (p-ERM) in rat pulmonary microvascular endothelial cells (PMVEC),and to explore Rho kinase (ROCK) influencing on modulation of the ERM proteins phosphorylation.Methods Cultured rat pulmonary microvascular endothelial cells were randomly divided into dose-dependent and time-dependent groups.In dose-dependent group,cells were cultured with different doses of TNF-α (0,0.1,1,10 μg/LTNF-α) for 60 min.In time-dependent group,cells were cultured with TNF-α (10 μg/L) for 0,15,30,60,90,120,180 min.In ROCK inhibitor (Y27632) intervention group,cells were cultured with TNF-α (10 μg/L) or Y27632 (30 μmol/L) + TNF-α (10 μg/L) for 60 min respectively.The levels of ERM proteins and p-ERM were determined by western blot.One way analysis of variance (ANOVA) was employed for statistical analysis by using SPSS version 16.0 software to compare values among all groups.A significant difference was presumed as a P value ＜ 0.05.Results Western blot revealed that ERM and p -ERM proteins were present in rat PMVEC.Stimulation withTNF-α gradually up-regulated the level of pERM proteins in a dose-dependent manner [0 μg/LTNF-α group:(0.648 ± 0.102),0.1 μg/LTNF-αgroup:(0.728-±0.082),1 μg/LTNF-α group:(0.926±0.121),10 μg/LTNF-α group:(1.245 ±0.134),all P =0.000].In time-dependent group,the level of p-ERM proteins rose at 15 min (0.777 ±0.151),peaked at 90 min (1.295 ±0.176),then decreased gradually at 120 min (0.802 ±0.139),but stayed higher level at 180 min (0.669 ±0.128) than that in un-stimulated 0 min group (0.631 ±0.123,P=0.004,0.000,0.001,0.016,respectively).When PMVEC pre-incubated with ROCK inhibitor and TNF-t,the level of p-ERM proteins caused a marked attenuation of TNF-αstimulation [(0.634 ± 0.112) vs.(0.875 ± 0.164),P =0.002],however,there are no significant differences compared to ROCK inhibitor alone group (0.661 ± 0.108) and no intervention group (0.654 ± 0.125),P =0.973,P =0.900,respectively).Conclusions TNF-α could induce up-regulation of the level of the phosphorylated ERM proteins in rat PMVEC,and ROCK signal molecules might involve in modulation of the ERM proteins phosphorylation.

Role of Ezrin in the injury of rat pulmonary microvascular endothelial cells induced by tumor necrosis factor-αand the impact of Rac 1 / 中华危重病急救医学

Objective To investigate the role of Ezrin and its phosphorylation(p-Ezrin)in the modulation of rat pulmonary microvascular endothelial cell(PMVEC)injury induced by tumor necrosis factor-α(TNF-α)and the impact of Rac 1. Methods Cultured PMVECs of Sprague-Dawley(SD)rats were randomly divided into time-dependent injury group induced by TNF-αand intervention group in which cells were pretreated with Rac 1 inhibitor (NSC 23766).①In the time-dependent injury group, Western Blot was used to detect the expression of Ezrin and p-Ezrin after 10μg/L TNF-αstimulation for 0,0.25,0.5,1,3,6,12,24 hours.②In the intervention group,after pre-treatment with 200μmol/L NSC 23766 for 0.5 h,PMVECs were treated with 10μg/L TNF-α,and the expression of p-Ezrin was detected by Western Blot after 3 hours. Besides these groups,there were control(1% fetal bovine serum simulation),single NSC 23766 or TNF-α simulation groups. Results ① Few Ezrin expression was found in PMVEC,and TNF-α could not affect Ezrin expression. p-Ezrin protein expression(p-Ezrin/Ezrin,gray scale) of PMVECs at 0 hour after TNF-αstimulation was 0.21±0.03,and elevated at 0.25 hour(0.53±0.19),peaked at 3 hours(1.68±0.30),then it was gradually lowered,but it remained at higher level at 24 hours(0.87±0.18)with significant difference(F=62.200,P=0.000). It demonstrated that TNF-αcould increase Ezrin phosphorylation in a time-dependent manner.②Compared with blank control group,in single NSC 23766 or TNF-αsimulation group, p-Ezrin expression was induced(TNF-αgroup:0.92±0.12 vs. 0.68±0.16,t=-2.864,P=0.020;NSC 23766 group:1.33±0.24 vs. 0.68±0.16,t=-5.429,P=0.000. When NSC 23766 was pre-treated with PMVECs,the expression of p-Ezrin was significantly increased compared with that in single TNF-αsimulation group(2.14±0.18 vs. 0.92±0.12,t=-14.670,P=0.000)with significant difference(F=73.810,P=0.000). Conclusion Ezrin proteins are phosphorylated by TNF-α. Rac 1 signaling pathway inhibition plays an important role in TNF-α-induced injury by up-regulation of p-Ezrin in PMVECs.

Influence of RhoA-Rock pathway inhibitor on the filamentous actin of hypoxia human pulmonary microvascular endothelial cells / 中国小儿急救医学

ObjectiveTo explore the control factor of pulmonary microvascular endothelial cells in pulmonary hemorrhage with the RhoA-Rock pathway inhibitors.MethodsHuman pulmonary rnicrovascular endothelial cells were conventionally cultured,and were divided into four groups:control group,inhibitor group,hypoxia group and hypoxia group with inhibitor.As different fluorescein lsothiocyanate-phalloidin and filamentous actin (F-actin) in cytoplasm combined,it issued red fluorescence.We observed the dynamic changes of F-actin by laser scanning confocal microscope in hypoxia human pulmonary microvascular endothelial cells and recorded the value of fluorescence.ResultsThe mean fluorescence intensity of F-actin of hypoxia group in 1 h,12h and 24 h was (64.3 ±5.5)％,(60.3±4.2)％,and (47.8 ±4.6)％ as compared with the control group;the ratio of hypoxia group with inhibitor was (66.2 ±3.2)％,(67.1 ±6.2)％,and (72.5 ± 6.1 ) ％ as compared with the control group.The mean fluorescence intensity of F-actin decreased obviously after 1 h hypoxia treated to cells,decreasing to (64.3 ± 5.5 ) ％ of the control group (P ＜0.05 ) ;to 24 h,decreasing to (47.8 ±4.6) ％ of the control group(P ＜0.05).The mean fluorescence intensity of F-actin decreased to (66.2 ± 3.2) ％ of the control group after 1 h hypoxia treated in inhibitor group,which was more than 1 h in the hypoxic group.F-actin decreased obviously to (72.5 ± 6.1 ) ％ of the control group after 24 h hypoxia treated in inhibitor group.There was significant difference comparing with the hypoxia group after 24 h hypoxia(P ＜0.05).The mean fluorescence intensity of F-actin of inhibitor group without anoxic was invariant comparing with the control group(P ＞0.05).Cortex-like structure disappeared and the stress fibers arranged disorderly after hypoxia.Actin depolymedzated and broke gradually with the extension of hypoxia time.If to be hypoxic after pretreated with RhoA-Rock pathway inhibitor,cortex-like structure by the composition of pednuclear F-actin reappeared,distribution and arrangement of stress fibers in the cytoplasm tended to rule.ConclusionThe RhoA-Rock pathway mediates the damage on F-actin of pulmonary microvascular endothelial cells after hypoxia.Interfering with the RhoA-Rock pathway inhibitors can provide a new direction for the treatment of neonatal pulmonary hemorrhage.

Effects of breviscapine on the injury of rat pulmonary microvascular endothelial cells induced by platelet-activating factor / 中国药理学通报

Aim To investigate the mechanism of platelet-activating factor(PAF) induced injury on the cultured rat pulmonary microvascular endothelial cells(RPMVEC),and the interfering action of breviscapine. Methods RPMVEC were isolated from Wistar rat and cultured in vitro, the effects of PAF on morphology,monolayer permeability and F-actin of RPMVEC were observed, F-actin expression was evaluated by flow cytometry. Results PAF in the concentration over 0.1 mg?L -1 induced detachment and rupture of RPMVEC within 48 h. 10 mg?L -1 of PAF increased permeability of RPMVEC monolayer and induced depolymerization of F-actin within 120 min.Breviscapine inhibited these effects of PAF. Conclusion ①The detachment and rupture of RPMVEC induced by PAF depends on the exposed concentration and time.②The increased permeability of RPMVEC monolayer induced by PAF is significantly correlated with the depolymerization of F-actin. ③The increased permeability of RPMVEC monolayer and depolymerization of F-actin induced by PAF can be markedly inhibited by breviscapine, which exerts protective action on RPMVEC injury induced by PAF.