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Objective To investigate the effects of estrogen ( E2) on the resistance to anoikis and a possible role of extracellular signal-regulated kinse ( ERK)-focal adhesion kinse ( FAK) signaling in the effect of estrogen to under-stand its underlying mechanism .Methods Poly-Hema-coated culture of human breast cancer cell line MCF-7 was used to induce anoikis .Cells were treated with E2 and/or pretreated with MEK or FAK inhibitors .Western blot was used to assess the phosphorylation of ERK and FAK , trypan blue staining and cell counting were employed to evaluate cell viability , and Hoechst staining was used to check apoptosis .Results Suspension culture greatly re-duced cell survival (P<0.01), and exposure of MCF-7 cells to E2 (10 nmol/L) led to a significantly increased resistance to anoikis and survival ( P<0.05 ) as compared to DMSO .Meanwhile , E2 induced increased phospho-rylation of both ERK and FAK .Pharmacological inhibition of MEK with U 0126 ( 10 μmol/L ) reduced E2-in-creased cell survival by 57.48%(P<0.01) and E2-decreased anoikis;Treatment with FAK inhibitor (10μmol/L) attenuated E2-enhanced cell survival by 53.59% ( P<0.01 ) and E2-reduced apoptosis .Conclusions E2 con-tributes to the enhanced cell viability and increased resistance to anoikis in MCF-7 breast cancer cells , and ERK-FAK signaling may be involved in the E 2-stimulated survival during suspension culture of MCF-7 cells.
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Aim To investigate the effect of transduct-ed-hemeoxygenase-1 ( HO-1 ) protein on brain ischemi-a-reperfusion ( I/R ) rat hippocampal neurons injury. Methods 11 R ( arginine residues )-fused HO-1 pro-tein was established and 50 male Mongolian gerbils were randomly divided into 5 groups ( n=10 ):I/R ( control group ) , I/R + 5 mg · kg-1 saline group ( group S ) , I/R + 5 mg · kg-1 11 R group ( group R), I/R + 5mg·kg-1 11R-HO-1 group (group H1) and I/R + 25 mg · kg-1 11 R-HO-1 group ( group H2). For I/R experiments, ischemia was induced for 5 min by occluding the common carotid arteries bilater-ally with aneurysm clips under Ketamine anesthesia. The experiment was conducted after the neurons were intraperitoneally injected with 5mg·kg-1 saline,11R , 11R-HO-1,or 25mg · kg-1 11R-HO-1 for 3 h. The rats were killed after 24h of reperfusion. Hippocampus was removed immediately for determination of cAMP level, neuronal apoptotic rate, and expression of HO-1 and Caspase-3 protein, mitochondria was observed un-der electron microscope. Results Among group C, group S and group R,there were no differences in the expressions of HO-1, Caspase-3 protein, cAMP level , neuronal apoptotic rate and mitochondria damage ( P>0. 05). Compared with group C, group S and group R, the expression of HO-1 protein was up-regulated, the expression of Caspase-3 protein was down-regula-ted, cAMP level increased, the apoptotic rate was sig-nificantly decreased and mitochondria damage de-creased in group H1 ( P < 0. 01 ) . Compared with group H1 , the expression of HO-1 protein was up-regu-lated, the expression of Caspase-3 protein was down-regulated, cAMP level increased, the apoptotic rate was significantly decreased and mitochondria damage decreased in group H2 ( P <0. 01 ) . Conclusion Transducted-HO-1 protein can attenuate brain ischemi-a-reperfusion rat hippocampal neurons injury.
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Objective To investigate the role of quorum sensing Escherichia coli regulator C (qseC) in intestinal bacterial translocation in rats subjected to hemorrhagic shock.Methods Thirty Sprague-Dawley rats,weighing 250-300 g,were randomly divided into 5 groups (n =6 each):control group (group C),MC1000-sham shock group (group M-SS),MC1000qseC-sham shock group (group △-SS),MC1000-hemorrhagic shock group (group M-HS),and MC1000△ qseC-hemorrhagic shock group (group △-HS).The rats drank 150 μg/ml of disinfect water containing streptomycin in 3 consecutive days to inhibit the autochthonous flora in the intestinal tract.From 4th day,the rats were fed with Escherichia Coli MC1000 or MC1000△ qseC 1 ml/100 g by gastric perfusion once a day for another 3 consecutive days in the other 4 groups,while the rats were fed with normal saline instead in group C.Hemorrhagic shock was induced by blood-letting.The mesenteric lymph node (MLN),spleen and liver specimens were obtained at 24 h after operation for bacterial culture and the bacteria were identified.Bacterial translocation from gut to MLN,spleen and liver was observed and the number of bacteria in MLN,spleen and liver tissues were counted.Results The rate of bacterial translocation was significantly higher,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly larger in groups M-HS and △-HS than in group C,and in group M-HS than in groups M-SS and △-SS (P ＜ 0.05).The rate of bacterial translocation was significantly lower,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly smaller in group △-HS than in group MHS.Conclusion QseC is involved in the intestinal bacterial translocation following hemorrhagic shock in rats.
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Objective To study the effect of epinephrine on biofilm formation of the qseC-deleted mutant of Escherichia coli on biomaterial.Methods The strains used in this study are Escherichia coli MC1000 and MC1000AqseC.LB was used for all the experiments.To determine the effect of epinephrine on motility,halos were measured in LB medium at 37℃ in the presence of epinephrine(50 μmol/L).LB with epinephrine and without epinephrine were used,and then the experiment of bacterial biofilm formation on PVC material was taken.The relative amount of biofilm was estimated.The thickness of bacterial community and bacterial community quantity in the unit area on PVC materials were measured by confocal laser scanning microscope( CLSM),and the surface structure of biofilm formation was observed by scanning electron microscope(SEM).Results The mutant strain formed less biofilm than the wild-type strain in LB.The increment in motility of wild-type strain due to epinephrine addition was shown,but mutant strain is unaffected.Similarly,biofilm formation of the wild-type strain was increased by epinephrine,but epinephrine did not affect the biofilm formation of the qseC mutant.The CLSM and SEM showed that epinephrine stimulated biofilm formation of wild-type strain on PVC materials,but had no effect on qseC-deleted mutant strain.Conclusion Epinephrine increases Escherichia coli biofilms on biomaterials through qseC.