ABSTRACT
BACKGROUND: Exosomes isolated from plasma of patients with sepsis may induce vascular apoptosis and myocardial dysfunction by mechanisms related to inflammation and oxidative stress. Despite previous studies demonstrating that these vesicles contain genetic material related to cellular communication, their molecular cargo during sepsis is relatively unknown. In this study, we evaluated the presence of microRNAs (miRNAs) and messenger RNAs (mRNAs) related to inflammatory response and redox metabolism in exosomes of patients with septic shock. METHODS: Blood samples were collected from 24 patients with septic shock at ICU admission and after 7 days of treatment. Twelve healthy volunteers were used as control subjects. Exosomes were isolated by ultracentrifugation, and their miRNA and mRNA content was evaluated by qRT-PCR array. RESULTS: As compared with healthy volunteers, exosomes from patients with sepsis had significant changes in 65 exosomal miRNAs. Twenty-eight miRNAs were differentially expressed, both at enrollment and after 7 days, with similar kinetics (18 miRNAs upregulated and 10 downregulated). At enrollment, 35 differentially expressed miRNAs clustered patients with sepsis according to survival. The pathways enriched by the miRNAs of patients with sepsis compared with control subjects were related mostly to inflammatory response. The comparison of miRNAs from patients with sepsis according to hospital survival demonstrated pathways related mostly to cell cycle regulation. At enrollment, sepsis was associated with significant increases in the expression of mRNAs related to redox metabolism (myeloperoxidase, 64-fold; PRDX3, 2.6-fold; SOD2, 2.2-fold) and redox-responsive genes (FOXM1, 21-fold; SELS, 16-fold; GLRX2, 3.4-fold). The expression of myeloperoxidase mRNA remained elevated after 7 days (65-fold). CONCLUSIONS: Exosomes from patients with septic shock convey miRNAs and mRNAs related to pathogenic pathways, including inflammatory response, oxidative stress, and cell cycle regulation. Exosomes may represent a novel mechanism for intercellular communication during sepsis.
Subject(s)
Exosomes/chemistry , MicroRNAs/analysis , Shock, Septic/physiopathology , Adult , Aged , Brazil , Exosomes/metabolism , Exosomes/pathology , Female , Forkhead Box Protein M1/analysis , Forkhead Box Protein M1/blood , Glutaredoxins/analysis , Glutaredoxins/blood , Humans , Inflammation/complications , Inflammation/diagnosis , Inflammation/metabolism , Intensive Care Units/organization & administration , Male , Membrane Proteins/analysis , Membrane Proteins/blood , MicroRNAs/blood , MicroRNAs/metabolism , Middle Aged , Oxidative Stress , Patient Outcome Assessment , Peroxidase/analysis , Peroxidase/blood , Peroxiredoxin III/analysis , Peroxiredoxin III/blood , Prospective Studies , RNA, Messenger/analysis , RNA, Messenger/blood , RNA, Messenger/metabolism , Selenoproteins/analysis , Selenoproteins/blood , Shock, Septic/metabolism , Superoxide Dismutase/analysis , Superoxide Dismutase/bloodABSTRACT
Glutaredoxin 1 (Grx1) has been found to be an important endogenous antioxidant enzyme closely related to the pathogenesis of diabetes and cardiovascular diseases caused by oxidative stress. In this study, the functional changes of the Grx1 redox system in blood of hyperglycemic patients were examined. Furthermore, using a rat model of streptozotocin (STZ)- and high-fat-diet-induced type 2 diabetes, we explored the correlation between functional changes of the Grx1 redox system in the left ventricular tissue and blood of the diabetic rats. Moreover, we studied the protective effect of Grx1 against cardiac toxicity caused by the high-glucose-induced expression of cardiac matrix metalloproteinases (MMPs) in primary cultured cardiac fibroblasts. Finally, we investigated the protective effects and signaling regulatory mechanism of Grx1 against diabetic cardiomyopathy (DCM) in terms of oxidative stress and NF-kB-mediated fibrosis-associated signaling pathways. In the serum of hyperglycemic patients, Grx1 levels were elevated, total/protein thiol or sulfhydryl (Total-SH/P-SH) levels were decreased, glutathione was downregulated, and oxidized glutathione was upregulated. In addition, in the left ventricular myocardium and blood of the diabetic rats, Grx1 levels were significantly increased and glutathione reductase and P-SH levels were decreased. Moreover, endogenous Grx1 was highly expressed in cardiac fibroblasts during high-glucose treatment, and exogenous Grx1 can prevent DCM by controlling oxidative damage and MMP expression. These findings are suggestive of changes in the Grx1 redox system, and Grx1-regulated protein oxidative modifications may serve as molecular markers for diabetes caused by high-glucose-induced oxidative stress.