ABSTRACT
Ezetimibe was reported to pharmacologically defend against oxidative stress.This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprotein (oxLDL) in vitro and the underlying mechanism.Human umbilical vein endothelial cells (HUVECs) were pretreated with ezetimibe and then exposed to oxLDL for 24 h.TUNEL assay and detection for the protein levels of cleaved caspase-3,Bcl-xl and Bcl-2 were employed to assess the oxLDL-induced endothelial apoptosis.Intracellular reactive oxygen species (ROS) generation was evaluated by measuring dichlorofluorescein (DCF) fluorescence.The activities of endothelial antioxidant enzymes [superoxide dismutase (SOD) and catalase] were tested via an enzymatic assay.The mitochondrial membrane potential (MMP) was monitored by flow cytometry using JC-1 staining.Phosphorylation levels of glycogen synthase kinase-3β (p-GSK-3β) and Akt (p-Akt),as well as total GSK-3β and Akt were determined by Western blotting.The results showed that ezetimibe treatment inhibited HUVECs apoptosis,intracellular ROS production,and enhanced antioxidant enzyme activities elicited by oxLDL.HUVECs exposed to oxLDL alone had reduced mitochondrial function,while ezetimibe pre-intervention could significantly rescue the MMP.Furthermore,the protein levels of p-GSK-3β and p-Akt in ezetimibe-pretreated HUVECs were markedly increased as compared with those in oxLDL-induced HUVECs.However,no significant effect on total GSK-3β and Akt was found in ezetimibe-pretreated HUVECs.Taken together,it was concluded that ezetimibe protects against oxLDL-induced oxidative stress through restoring the MMP,which may be mediated by Akt-dependent GSK-3β phosphorylation.
ABSTRACT
Ezetimibe was reported to pharmacologically defend against oxidative stress.This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprotein (oxLDL) in vitro and the underlying mechanism.Human umbilical vein endothelial cells (HUVECs) were pretreated with ezetimibe and then exposed to oxLDL for 24 h.TUNEL assay and detection for the protein levels of cleaved caspase-3,Bcl-xl and Bcl-2 were employed to assess the oxLDL-induced endothelial apoptosis.Intracellular reactive oxygen species (ROS) generation was evaluated by measuring dichlorofluorescein (DCF) fluorescence.The activities of endothelial antioxidant enzymes [superoxide dismutase (SOD) and catalase] were tested via an enzymatic assay.The mitochondrial membrane potential (MMP) was monitored by flow cytometry using JC-1 staining.Phosphorylation levels of glycogen synthase kinase-3β (p-GSK-3β) and Akt (p-Akt),as well as total GSK-3β and Akt were determined by Western blotting.The results showed that ezetimibe treatment inhibited HUVECs apoptosis,intracellular ROS production,and enhanced antioxidant enzyme activities elicited by oxLDL.HUVECs exposed to oxLDL alone had reduced mitochondrial function,while ezetimibe pre-intervention could significantly rescue the MMP.Furthermore,the protein levels of p-GSK-3β and p-Akt in ezetimibe-pretreated HUVECs were markedly increased as compared with those in oxLDL-induced HUVECs.However,no significant effect on total GSK-3β and Akt was found in ezetimibe-pretreated HUVECs.Taken together,it was concluded that ezetimibe protects against oxLDL-induced oxidative stress through restoring the MMP,which may be mediated by Akt-dependent GSK-3β phosphorylation.
ABSTRACT
Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality in part due to its high resistance to chemotherapeutic drugs. The anti-apoptotic Mcl-1 expression has been reported as a resistance factor in various types of tumors. Here, we investigated the expression of Mcl-1 in hepatoma cells and HCC tissues and its relationship with p53, and analyzed the possibility of the gene as a molecular target for HCC therapy. HCC specimens of 30 patients were examined by immunohistochemistry for Mcl-1 and p53 expression. Mcl-1 expression in hepatoma cell lines was measured by RT-PCR and Western blotting. The suppression of Mcl-1 by RNA interference or specific phosphatidylinositol-3 kinase (PI3K) inhibitor, LY294002, was evaluated as monotherapy, and it was combined with mitomycin C (MMC) in treating hepatoma cell line HepG2. Cell viability and apoptosis were assessed by MTT and FACS analysis. Finally, changes of Mcl-1 or p53 expression in various hepatoma cell lines were examined after transfection with Mcl-1 siRNA, the Mcl-1 expression plasmid, or the wide-type p53 expression plasmid, respectively. Mcl-1 protein was remarkably enhanced in HCC tissues as compared with adjacent non-tumor liver tissues. In addition, Mcl-1 was prominently expressed in HepG2 and Hep3B cells, weakly in SMMC7721 cells, and not in L02 cells. P53 protein was also overexpressed in HCC tissues and there was a significant correlation between the expression of p53 and Mcl-1. Silencing Mcl-1 by RNAi or LY294002 downregulated Mcl-1 expression and led to decreased cell viability and increased apoptosis. Combination of MMC and Mcl-1 RNAi or LY294002 exhibited a significant chemosensitizing effect. The expression of p53 was not influenced by Mcl-1 siRNA in HepG2 cells or transfection with the Mcl-1 expression plasmid in L02 cells. Furthermore, the expression of Mcl-1 in Hep3B cells was also not significantly changed after transfection with the wild-type p53 expression plasmid. It is concluded that Mcl-1 is overexpressed in HCC tissues. The mechanisms by which silencing Mcl-1 sensitizes hepatoma cells towards chemotherapy may be not attributed to the upregulated expression of p53 but the dysfunction of p53 through Mcl-1/p53 interaction. Mcl-1 may be a potential target of gene therapy for HCC.
Subject(s)
Humans , Adenoma, Liver Cell , Drug Therapy , Genetics , Pathology , Apoptosis , Biomarkers, Tumor , Genetics , Chromones , Gene Expression Regulation, Neoplastic , Hep G2 Cells , Liver Neoplasms , Drug Therapy , Genetics , Pathology , Morpholines , Myeloid Cell Leukemia Sequence 1 Protein , Genetics , RNA, Small Interfering , Genetics , Transfection , Tumor Suppressor Protein p53 , GeneticsABSTRACT
CD151 is a member of the tetraspanin family that is implicated as a promoter of pathological or physiological angiogenesis. C-Met is expressed on a variety of cells including vascular endothelial cells (VECs) and up-regulated during angiogenesis. In this study, we investigated whether CD151 regulated migration, proliferation, tube formation and angiogenesis of human umbilical VECs (HUVECs) with activation of C-Met. Moreover, we studied whether CD151 could affect the angiogenic molecules such as nitric oxide (NO), vascular cell adhesion molecule-1 (VCAM-1) and vascular endothelial growth factor (VEGF). The expression of CD151 was determined by Western blotting. The cell proliferation assay was performed using the cell counting kit-8 (CCK-8) method and cell migration was assessed in microchemotaxis chambers by using fetal bovine serum (FBS) as the chemotactic stimulus. The angiogenic molecules were evaluated using ELISA. The NO level was detected using NO detection kit. The potential involvement of various signaling pathways was explored using relevant antibodies. We found that proliferation, migration and tube formation of HUVECs were promoted by CD151 with activation of C-Met, FAK and CDC42, while they were suppressed with CD151 knockdown by RNAi. Similarly, the levels of NO, VCAM-1 and VEGF in HUVECs were increased by CD151, but they were inhibited with CD151 knockdown by RNAi. These data suggested that CD151 could promote migration, proliferation, tube formation and angiogenesis of HUVECs, which was possibly related to the C-Met signaling pathways.
Subject(s)
Humans , Base Sequence , Human Umbilical Vein Endothelial Cells , Neovascularization, Physiologic , RNA, Small Interfering , Genetics , Receptor Protein-Tyrosine Kinases , Metabolism , Signal Transduction , Tetraspanin 24 , Genetics , MetabolismABSTRACT
CD151 is a member of the tetraspanin family that is implicated as a promoter of pathological or physiological angiogenesis. C-Met is expressed on a variety of cells including vascular endothelial cells (VECs) and up-regulated during angiogenesis. In this study, we investigated whether CD151 regulated migration, proliferation, tube formation and angiogenesis of human umbilical VECs (HUVECs) with activation of C-Met. Moreover, we studied whether CD151 could affect the angiogenic molecules such as nitric oxide (NO), vascular cell adhesion molecule-1 (VCAM-1) and vascular endothelial growth factor (VEGF). The expression of CD151 was determined by Western blotting. The cell proliferation assay was performed using the cell counting kit-8 (CCK-8) method and cell migration was assessed in microchemotaxis chambers by using fetal bovine serum (FBS) as the chemotactic stimulus. The angiogenic molecules were evaluated using ELISA. The NO level was detected using NO detection kit. The potential involvement of various signaling pathways was explored using relevant antibodies. We found that proliferation, migration and tube formation of HUVECs were promoted by CD151 with activation of C-Met, FAK and CDC42, while they were suppressed with CD151 knockdown by RNAi. Similarly, the levels of NO, VCAM-1 and VEGF in HUVECs were increased by CD151, but they were inhibited with CD151 knockdown by RNAi. These data suggested that CD151 could promote migration, proliferation, tube formation and angiogenesis of HUVECs, which was possibly related to the C-Met signaling pathways.
ABSTRACT
The clinical characteristics of painless aortic dissection were investigated in order to improve the awareness of diagnosis and treatment of atypical aortic dissection. The 482 cases of aortic dissection were divided into painless group and pain group, and the data of the two groups were retrospectively analyzed. The major clinical symptom was pain in 447 cases (92.74%), while 35 patients (7.26%) had no typical pain. The gender, age, hypertension, hyperlipidemia, diabetes, smoking and drinking history had no statistically significant differences between the two groups (P>0.05). The proportion of Stanford type A in painless group was significantly higher than that in pain group (48.57% vs. 21.03%, P=0.006). The incidence of unconsciousness in the painless group was significantly higher than that in the pain group (14.29% vs. 3.58%, P=0.011). The incidence of hypotension in painless group was significantly higher than that in pain group for 4.26 folds (P=0.01). Computed tomography angiography (CTA) examination revealed that the incidence of aortic arch involved in the painless group was significantly higher than that in the pain group (19.23% vs. 5.52%, P=0.019). It was concluded that the incidence of painless aortic dissection was higher in Stanford A type patients, commonly seen in the patients complicated with hypotension and unconsciousness. CTA examination revealed higher incidence of aortic arch involvement.
ABSTRACT
The clinical characteristics of painless aortic dissection were investigated in order to improve the awareness of diagnosis and treatment of atypical aortic dissection. The 482 cases of aortic dissection were divided into painless group and pain group, and the data of the two groups were retrospectively analyzed. The major clinical symptom was pain in 447 cases (92.74%), while 35 patients (7.26%) had no typical pain. The gender, age, hypertension, hyperlipidemia, diabetes, smoking and drinking history had no statistically significant differences between the two groups (P>0.05). The proportion of Stanford type A in painless group was significantly higher than that in pain group (48.57% vs. 21.03%, P=0.006). The incidence of unconsciousness in the painless group was significantly higher than that in the pain group (14.29% vs. 3.58%, P=0.011). The incidence of hypotension in painless group was significantly higher than that in pain group for 4.26 folds (P=0.01). Computed tomography angiography (CTA) examination revealed that the incidence of aortic arch involved in the painless group was significantly higher than that in the pain group (19.23% vs. 5.52%, P=0.019). It was concluded that the incidence of painless aortic dissection was higher in Stanford A type patients, commonly seen in the patients complicated with hypotension and unconsciousness. CTA examination revealed higher incidence of aortic arch involvement.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Angiography , Aortic Rupture , Diagnostic Imaging , Epidemiology , Hypotension , Diagnostic Imaging , Epidemiology , Incidence , Pain , Diagnostic Imaging , Epidemiology , Retrospective Studies , Tomography, X-Ray Computed , Unconsciousness , Diagnostic Imaging , EpidemiologyABSTRACT
<p><b>BACKGROUND</b>Morphologic imaging after radiofrequency ablation (RFA) of liver metastases is hampered by an inflammatory response in the ablation margin, making the identification of local tumor progression (LTP) difficult. The aim of this study was to evaluate the efficacy of early (18)F-FDG PET/CT scanning to monitor the effectiveness of RFA in colorectal liver metastases.</p><p><b>METHODS</b>Twelve patients with 20 metastases were treated with RFA for colorectal liver metastases. They underwent PET/CT within 2 weeks before RFA and within 24 hours after RFA (so termed "early PET/CT"). PET/CT was repeated at 1, 3, and 6 months, and then every 6 months after ablation. The standard of reference was based on available clinical and radiological follow-up data.</p><p><b>RESULTS</b>Early PET/CT revealed total photopenia in 16 RFA-treated metastases, which were found to be without residual tumor on the final PET/CT scan. Three RFA-treated metastases with focal uptake were identified as local tumor progression, which necessitated further treatment. One RFA-treated metastasis with rim-shaped uptake was regarded as inflammation. The results of the early PET/CT scanning were consistent with the findings of the final follow-up.</p><p><b>CONCLUSIONS</b>PET/CT performed within 24 hours after RFA can effectively detect whether residual tumor exists for colorectal cancer liver metastases. The results can guide further treatment, and may improve the efficacy of RFA.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Catheter Ablation , Colorectal Neoplasms , Diagnostic Imaging , Therapeutics , Fluorodeoxyglucose F18 , Therapeutic Uses , Liver Neoplasms , Diagnostic Imaging , Therapeutics , Positron-Emission Tomography , Methods , Tomography, X-Ray Computed , MethodsABSTRACT
Objective To evaluate the clinical efficacy of multiple stents placement in the management of hilar cholangiocarcinoma,especially in the complex cases of which the hepatic ducts are invaded.Methods Forty-five consecutive patients with hilar cholangiocarcinoma were treated with percutaneous transhepatic placement of two or three self-expandable metallic endoprostheses.The cause of hilar obstructions in these patients were all cholangiocarcinoma,including Bismuth classification type Ⅱ(n 12 ),Ⅲa(n 17),Ⅲb(n 10),and Ⅳ(n 6).Two or 3 stents were placed in the configuration of T,Y or X over the strictures.Results Stent placement with 2 or 3 endoprostheses was successful in all patients.All patients showed significant decrease in serum bilirubin level.The mortality rate within 30 days of stent placement was 2.2%(1/45).The mean survival and stent patency times were 215.3 d(26— 516 d)and 181.5 d(26—473 d),respectively.Conclusion Deploying of multiple metallic stents is an effective method to treat complex hilar cholangiocarcinoma,especially for the cases of which hepatic ducts are invaded:the henatic ducts should be drained as much as nossible.