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Objective To explore the effect of expression of protein kinase C receptor 1(RACK1) induced by lipopolysaccharide (LPS) on Sonic hedgehog(SHH) signaling pathway in rat puhnonary microvascular endothelial cells (RPMVEC).Methods The healthy male SPF grade SD rat with 100-120 g body weight were gotten from the laboratory animal center of Anhui province.Using immunocytochemistry method,the expression of RACK1 protein in RPMVECs was detected,cultured RPMVECs were randomly divided into different groups as LPS dose-dependent group,SAG(smoothened Agonist,a SHH signaling pathway specific agonist) dose-dependent group,LPS time-dependent group,SAG time-dependent group and LPS+SAG group.In LPS dose-dependent groups,RPMVECs were cultured with 0.1,1,10 mg/L LPS for 8 h.In LPS time-dependent groups,RPMVECs were cultured with 10 mg/L LPS for 0,2,4,8,12,24 h.In SAG dose-dependent groups,RPMVECs were cultured with 0.1,1,10 μ mol/L for 8 h.In SAG time-dependent groups,RPMVECs were cultured with 1 μ mol/L SAG for 0,2,4,8,12,24 h.In LPS+SAG group,RPMVECs were cultured with 1 μ mol/L SAG 8 h after 10 mg/L LPS treatment for 1 h.In addition,blank group,LPS group and SAG group were set for control.Western blot were used to detect the level of RACK1 and RT-PCR were used to detect the expression of GLI-1 mRNA after intervention.Results Immunocytochemistry revealed that RACK1 were present in RPMVEC.1.In LPS dose-dependent groups (0,0.1,1,10 mg/L),the level of RACK1 elevated as LPS dose increased correspondingly with inter-group difference (P＜0.05);the relative expression levels of GLI-1 mRNA were (1.109 + 0.063),(1.039 + 0.135),(0.813 ± 0.066),(0.770 + 0.105),(1 mg/L vs.10 mg/L,P＞0.05;the rest P＜0.05).In LPS time-dependent groups,the relative expression level of RACK1 at 2 h (0.370 + 0.010) was higher than that at 0 h (0.329 ± 0.008),peaked at 12 h (1.296 ± 0.048),and compared with 0 h,there was significant differences (F=1 272.204,P＜0.05).The relative expression level of GLI-1 mRNA was decreased at 2 h (0.929 ±-0.007),and compared with 0 h(1.089 ± 0.042),there was significant differences (F=306.609,P＜0.05).2.In SAG dose-dependent groups,there was no significant difference in level of RACK1 between groups(all P＞0.05).The relative expression levels ofGLI-1 mRNA were (1.109 ± 0.063),(1.169 ± 0.052),(3.468 ± 0.128),(3.434 ± 0.054),(0 μ mol/L vs.0.1 μ mol/L and 1 μ mol/L vs.10 μ mol/L,P＞0.05,the rest P＜0.05).Among SAG time-dependent groups,there was no significant difference in levels of RACK1 protein(P＞0.05).The relative expression level of GLI-1 mRNA increased at 2 h (3.027 ± 0.065),and compared with 0 h (2.651 + 0.123),there was significant differences (F=132.841,P＜0.05).3.In LPS+SAG intervention groups,the expression of RACKI was lower than that in LPS group (0.831 ±0.040 vs.1.189 ± 0.149,P＜0.05),and the expression of GLI-1 mRNA was higher than that in LPS group (2.720 + 0.130 vs.0.796-4-0.082,P＜0.05).Conclusions The LPS up-regulates the expression of RACK1 in RPMVECs,and the activated SHH signaling pathway can down-regulate the expression of RACK1 induced by LPS in RPMVECs.
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AIM:To investigate the potential role of Sonic hedgehog (Shh) signaling pathways in the radioresistance of esophageal cancer.METHODS:Radioresistant cell line Eca109R was established by repeating X-ray irradiation at dose of 60 Gy in total using Eca109 cells as parental cells.The radiosensitivity of the parental and radioresistant cells was confirmed by colony formation assay.The cell viability was detected by CCK-8 assay.The intracellular protein levels of Shh and Gli1 were determined by Western blot and immunofluorescence.RESULTS:The survival fractions at dose of 2 Gy for Eca109R cells and Eca109 cells were 0.937±0.013 and 0.499±0.042, respectively.The inhibitory rate of cell viability decreased gradually in the Eca109R cells (P<0.05), suggesting that the radioresistant cell line was successfully established.The results of Western blot indicated that the protein expression of Shh and Gli1 was much higher in the Eca109R cells than that in the Eca109 cells (P<0.05).Immunofluorescence staining showed that Gli1 was expressed in the cytoplasm and nucleus, and presented nuclear clustering in the Eca109R cells.The positive rate of Gil1 expression in Eca109 cells was 52.3%± 0.035%, while that in Eca109R cells was 87.6%±0.021% (P<0.05).CONCLUSION:The radioresistance of esophageal cancer may be related to the activation of Shh signaling pathways with over-expression of Gli1 and other related proteins.