ABSTRACT
PURPOSE: Exercise has cardiovascular benefits which might be related to endothelial progenitor cells (EPC). Meanwhile, there is evidence suggesting that EPC-derived exosomes (EPC-EX) promote vascular repair and angiogenesis through their carried microRNA (miR)-126. In this study, we investigated whether exercise could increase the levels of circulating EPC-EX and their miR-126 cargo, and by which promote the protective function of EPC-EX on endothelial cells (EC). METHODS: Plasma EPC-EX from sedentary, low, or moderate exercise mice, respectively, denoted as EPC-EX, EPC-EX, and EPC-EX, were isolated using microbead-based sorting techniques and characterized by nanoparticle tracking analysis, Western blot, and quantitative real-time polymerase chain reaction assessments of biomarkers and miR-126. High glucose (25 mM) with hypoxia (1% O2) was used for inducing an EC injury model. The injured EC were treated by coculturing with vehicle, EPC-EX, EPC-EX, EPC-EX, or EPC-EX + anti-miR-126. After that, EC were used for flow cytometry analysis of apoptosis, assessments of tube formation and migration, and measurements of miR-126 level and its downstream sprouty-related protein-1 (SPRED1) and vascular endothelial growth factor (VEGF). RESULTS: 1) Isolated EPC-EX positively expressed exosomal markers (CD63 and Tsg101) and EPC markers (CD34 and VEGFR2). 2) Exercise intensity dependently elevated plasma level of EPC, EPC-EX/EPC ratio, and miR-126 expression in EPC and EPC-EX. 3) Injured EC displayed apoptosis increment, angiogenic dysfunction and miR-126 reduction. 4) EPC-EX had better effects than EPC-EX and EPC-EX on alleviating those changes of injured EC, accompanied with SPRED1 downregulation and VEGF upregulation. 5) The effects of EPC-EX were abolished by miR-126 knockdown. CONCLUSIONS: Our data demonstrate that exercise can increase EPC-EX release and miR-126 level and enhance the effects of EPC-EX on protecting EC against injury through the SPRED1/VEGF pathway.
Subject(s)
Endothelial Progenitor Cells/metabolism , Exosomes/metabolism , MicroRNAs/metabolism , Physical Conditioning, Animal , Adaptor Proteins, Signal Transducing , Animals , Apoptosis , Cell Hypoxia , Cell Movement , Cells, Cultured , Culture Media , Glucose , Mice , Mice, Inbred C57BL , Random Allocation , Repressor Proteins/metabolism , Vascular Endothelial Growth Factor A/metabolismABSTRACT
We previously demonstrated that mice which overexpress human renin and angiotensinogen (R+A+) show enhanced cerebral damage in both in vivo and in vitro experimental ischemia models. Angiotensin-converting enzyme 2 (ACE2) counteracts the effects of angiotensin (Ang-II) by transforming it into Ang-(1-7), thus reducing the ligand for the AT1 receptor and increasing stimulation of the Mas receptor. Triple transgenic mice, SARA, which specifically overexpress ACE2 in neurons of R+A+ mice were used to study the role of ACE2 in ischemic stroke using oxygen and glucose deprivation (OGD) of brain slices as an in vitro model. We examined tissue swelling, the production of reactive oxygen species (ROS), and cell death in the cerebral cortex (CX) and the hippocampal CA1 region during OGD. Expression levels of NADPH oxidase (Nox) isoforms, Nox2 and Nox4 were measured using western blots. Results show that SARA mice and R+A+ mice treated with the Mas receptor agonist Ang-(1-7) had less swelling, cell death, and ROS production in CX and CA1 areas compared to those in R+A+ animals. Treatment of slices from SARA mice with the Mas antagonist A779 eliminated this protection. Finally, western blots revealed less Nox2 and Nox4 expression in SARA mice compared with R+A+ mice both before and after OGD. We suggest that reduced brain swelling and cell death observed in SARA animals exposed to OGD result from diminished ROS production coupled with lower expression of Nox isoforms. Thus, the ACE2/Ang-(1-7)/Mas receptor pathway plays a protective role in brain ischemic damage by counteracting the detrimental effects of Ang-II-induced ROS production.
Subject(s)
Angiotensin I/metabolism , Brain Ischemia/physiopathology , Brain/physiopathology , Peptide Fragments/metabolism , Peptidyl-Dipeptidase A/metabolism , Proto-Oncogene Proteins/metabolism , Receptors, G-Protein-Coupled/metabolism , Stroke/physiopathology , Angiotensin II/analogs & derivatives , Angiotensin II/metabolism , Angiotensin-Converting Enzyme 2 , Animals , Brain Edema/etiology , Brain Edema/physiopathology , Brain Ischemia/complications , CA1 Region, Hippocampal/physiopathology , Cell Death/physiology , Cerebral Cortex/physiopathology , Glucose/deficiency , Hypoxia/complications , Hypoxia/physiopathology , Membrane Glycoproteins/metabolism , Mice, Transgenic , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/metabolism , Neurons/physiology , Peptidyl-Dipeptidase A/genetics , Proto-Oncogene Mas , Proto-Oncogene Proteins/antagonists & inhibitors , Reactive Oxygen Species/metabolism , Receptor, Angiotensin, Type 1/metabolism , Receptors, G-Protein-Coupled/antagonists & inhibitors , Signal Transduction/physiology , Stroke/complications , Tissue Culture TechniquesABSTRACT
The activity of cefpimizole (formerly U-63196E) was compared with that of other broad-spectrum cephalosporins and penicillins. Overall, cefpimizole exhibited limited activity against gram-positive cocci and members of the family Enterobacteriaceae as compared with the other cephalosporins tested. The activity of cefpimizole against Pseudomonas aeruginosa was similar to that of cefoperazone and mezlocillin (90% MIC, 32 micrograms/ml) but poorer than that of ceftazidime (90% MIC, 8 micrograms/ml). Cefpimizole appears to have no in vitro advantage over the cephalosporins with which it was compared.
Subject(s)
Cephalosporins/pharmacology , Pseudomonas aeruginosa/drug effects , Enterobacteriaceae/drug effects , Microbial Sensitivity Tests , Penicillins/pharmacologyABSTRACT
The activity of ceftazidime was compared with those of aztreonam, newer cephalosporins and Sch 29482 against nonfermentative gram-negative bacilli. Ceftazidime was consistently more active (MIC less than or equal to 8 micrograms) against the nonfermenters. Only Flavobacterium odoratum, F. spp., Pseudomonas alcaligenes, P. maltophilia and P. stutzeri demonstrated substantial resistance (MIC90 greater than or equal to 64 micrograms) to ceftazidime. Sch 29482 and ceftriaxone also exhibited good activity (MIC90 less than or equal to 8 micrograms) against many of the nonfermenters. The broad activity of ceftazidime, however, makes it a potentially more useful therapeutic agent against these microorganisms.
Subject(s)
Anti-Bacterial Agents/pharmacology , Ceftazidime/pharmacology , Gram-Negative Bacteria/drug effects , Lactams , Aztreonam , Humans , Microbial Sensitivity TestsABSTRACT
The antimicrobial activities of BMY-28142, cefbuperazone (BMY-25182; formerly T-1982), and cefpiramide (WY-44635; formerly SM-1652) were compared with those of cefmenoxime, cefoperazone, cefotaxime, ceftizoxime, and moxalactam. BMY-28142 was the most active cephalosporin against the majority of aerobic and facultatively anaerobic microorganisms studied. Its spectrum of activity was very similar to that of cefotaxime. However, BMY-28142, cefbuperazone, cefmenoxime, cefotaxime, ceftizoxime, and moxalactam were equivalent in activity and rate of killing against members of the family Enterobacteriaceae. Cefpiramide was considerably less active than the other cephalosporins against the Enterobacteriaceae.
