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
To evaluate the effect of acute high-altitude exposure on sensory and short-term memory using interactive software, we transported 30 volunteers in a sport utility vehicle to a 4280 m plateau within 3 h. We measured their memory performance on the plain (initial arrival) and 3 h after arrival on the plateau using six measures. Memory performance was significantly poorer on the plateau by four of the six measures. Furthermore, memory performance was significantly poorer in the acute mountain sickness (AMS) group than in the non-AMS group by five of the six measures. These findings indicate that rapid ascent to 4280 m and remaining at this altitude for 3 h resulted in decreased sensory and short-term memory, particularly among participants who developed AMS.
Subject(s)
Adult , Humans , Male , Young Adult , Acute Disease , Altitude , Altitude Sickness , Epidemiology , China , Epidemiology , Memory Disorders , Epidemiology , Memory, Short-Term , Time FactorsABSTRACT
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
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
Low pressure, low oxygen concentration, and intense ultraviolet (UV) radiation in high-altitude environments, can cause oxidative stress which can trigger mountain sickness. A recent study demonstrated that hydrogen gas with a good permeability in biological membranes can treat various disorders by exerting its selective anti-oxidation and anti-inflammatory effects, indicating that hydrogen therapy plays a role in scavenging free radicals and in balancing oxidation and anti-oxidation systems of cells. Therefore, we hypothesize that inhaling low-dose hydrogen or drinking hydrogen-saturated water is a novel and simple method to prevent and treat oxidative stress injury caused by low pressure, low oxygen concentration and intense UV radiation in plateaus, thus reducing the risk of mountain sickness.
Subject(s)
Humans , Altitude , Environmental Exposure , Free Radical Scavengers , Therapeutic Uses , Hydrogen , Therapeutic Uses , Oxidative Stress , Oxygen , Ultraviolet RaysABSTRACT
<p><b>OBJECTIVE</b>To investigate the efficacy of CD151 gene delivery in promoting blood perfusion in swines after myocardial infarction.</p><p><b>METHODS</b>Swines received coronary artery ligation and intramyocardial injection with rAAV-CD151, rAAV-anti-CD151 or rAAV-GFP. Eight weeks after vector injection, Western blot, immunostaining and 13N-labeled NH3 PET were performed to detect gene expression and biological effects of various treatments.</p><p><b>RESULTS</b>High level of CD151 protein expression was detected in the rAAV-CD151 group. The capillary density in the rAAV-CD151 group [(83.8 +/- 6.7) n/mm2] was significantly higher than that in the control group [(33.2 +/- 4.5) n/mm2] and rAAV-GFP group [(41.6 +/- 5.6) n/mm2] (all P<0.05); the arteriole density in the rAAV-CD151 group [(16.4 +/- 2.5) n/mm2] was also higher than that in the control group [(6.6 +/- 2.3) n/mm2] and the rAAV-GFP group [(8.4 +/- 1.6) n/mm2] (all P<0.05). However, the lowest capillary density and arteriole density were evidenced in rAAV-anti-CD151 group. Myocardial blood perfusion was significantly increased in rAAV-CD151 group and significantly reduced in rAAV-anti-CD151 group (all P<0.05 vs. control).</p><p><b>CONCLUSION</b>Intramyocardial injection of rAAV-CD151 could enhance the myocardial express of CD151 protein, increase capillary and arteriole densities and improve blood perfusion in swine with myocardial infarction.</p>
Subject(s)
Animals , Female , Humans , Male , Antigens, CD , Genetics , Coronary Occlusion , Therapeutics , Dependovirus , Genetics , Gene Transfer Techniques , Genetic Therapy , Genetic Vectors , Myocardial Infarction , Therapeutics , Neovascularization, Physiologic , Swine , Swine, Miniature , Tetraspanin 24 , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To establish an effective method for purification of Helicobacter pylori UreB fragment and conduct functional analysis of the purified protein.</p><p><b>METHODS</b>The protein fragment expression was induced by IPTG and the expressed protein was purified through affinity chromatography and ion-exchange chromatography. The purity of the fragment was determined by high-performance liquid chromatography (HPLC), and the specific biological activity of the purified fragment was assayed by urease activity inhibition test.</p><p><b>RESULTS</b>The protein fragment was highly expressed in E. coli with a purity over 91%. The protein fragment showed highly specific biological activity and the specific antibody induced by this fragment in rabbits could inhibit the activity of urease in a dose-dependent manner.</p><p><b>CONCLUSION</b>The UreB fragment with high purity and biological activity can be applied for further studies.</p>
Subject(s)
Animals , Rabbits , Amino Acid Sequence , Antibody Specificity , Bacterial Proteins , Chemistry , Bacterial Vaccines , Chemistry , Allergy and Immunology , Chromatography, High Pressure Liquid , Electrophoresis , Escherichia coli , Genetics , Helicobacter pylori , Genetics , Allergy and Immunology , Molecular Sequence Data , Peptide Fragments , Chemistry , Allergy and Immunology , UreaseABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of in vivo CD151 gene transfer on angiogenesis and heart function in rats with myocardial infarction.</p><p><b>METHODS</b>Acute myocardial infarction (AMI) was induced in male Sprague-Dawley (SD) rats by left anterior descending coronary artery ligation. The surviving rats randomly received myocardial injection of saline (MI control), pAAV-CD151 and pAAV-GFP (n = 12/group). Sham-operated rats without myocardial injection (n = 12) were taken as normal control. Four weeks later, heart function and the expression of CD151 were measured. Micro vessels density (MVD) in infarct myocardium was observed by factor VIII related antigen immunochemical staining.</p><p><b>RESULTS</b>The expression of CD151 (1.98 +/- 0.23 vs. 0.91 +/- 0.09, P < 0.01) and MVD counting [(385.4 +/- 79.9) vs. (252.5 +/- 43.0) n/mm(2), P < 0.01] in pAAV-CD151 treated MI rats were significantly higher than that in MI control group, similarly, EF (64.0 +/- 8.7)% vs. (41.5 +/- 5.0)%, P < 0.01] and dp/dt(max) (6620.2 +/- 884.6 vs. 5545.5 +/- 693.0, P < 0.01) were also significantly increased post pAAV-CD151 treatment. These parameters were not affected by pAAV-GFP treatment.</p><p><b>CONCLUSION</b>CD151 in vivo gene transfer for rats with acute myocardial infarction enhanced myocardial angiogenesis and improved left ventricular function.</p>