Exosomes from patients with septic shock convey miRNAs related to inflammation and cell cycle regulation: new signaling pathways in sepsis?

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.

Age­dependent increase in the expression of antioxidant­like protein­1 in the gerbil hippocampus.

Antioxidant-like protein-1 (AOP-1) reduces the intracellular level of reactive oxygen species. In the present study, the age­related change in AOP­1 expression in the hippocampus among young, adult and aged gerbils was compared using western blot analysis and immunohistochemistry. The results demonstrated that the protein expression of AOP­1 was gradually and significantly increased in the hippocampus during the normal aging process. In addition, the age­dependent increase in AOP­1 immunoreactivity was also observed in pyramidal neurons of the hippocampus proper; however, in the dentate gyrus, AOP­1 immunoreactivity was not altered during the normal aging process. These results indicated that the expression of AOP­1 is significantly increased in the hippocampus proper, but not in the dentate gyrus, during the normal aging process.

Identification of cholesterol gallstone with two-dimensional gel electrophoresis and mass spectrometry.

BACKGROUND AND RATIONALE: We aimed to provide novel information to better understand the molecular mechanisms underlying gallstones formation and explore the potential protein markers for gallstones progression. The gallbladder tissues were collected from 20 patients with cholesterol gallstone and 10 liver transplant donors from November 2010 to April 2011. The proteomics were compared between gallstone patients and controls by two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins were identified and validated by western blotting and real-time PCR. RESULTS: Total 19 protein spots were found to be different between two groups and 11 proteins were identified, among which 4 ones (such as Peroxiredoxin 3/Prdx3) were down-regulated and 7 (such as Tropomyosin 4/TPM4, Transgelin/SM22, Transthyretin/ TTR) were up-regulated in gallstone group. Results of western blotting and RT-PCR were consistent with the 2-DE results. CONCLUSION: The differentially expressed proteins of TTR, TPM4, SM22 and Prdx3 may play key roles in gallstone formation and may be markers for gallstone progression.

Detection and identification of peroxiredoxin 3 as a biomarker in hepatocellular carcinoma by a proteomic approach.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with poor prognosis due to resistance to conventional chemotherapy and limited efficacy of radiotherapy. Thus, alternative therapeutic strategies need to be established. In order to search for a useful biomarker to improve its efficacy, we conducted a two-dimensional gel electrophoresis and MALDI-TOF MS-based comparative proteomic analysis to profile the differentially expressed proteins between HCC tumor tissues with histological evidence and the adjacent non-tumor tissues. Twenty-two out of 43 dysregulated proteins were identified, including 15 upregulated proteins, and 7 downregulated proteins (over 2-fold, P<0.01). The expression of peroxiredoxin 3 (PRDX3) at the mRNA and protein levels was confirmed by RT-PCR and western blotting in HCC cell lines, and HCC samples, and further analysed by immunohistochemistry in HCC samples of different clinical pathological stages. The results indicated that overexpression of PRDX3 was associated with 94.9% HCC, and correlated with poor differentiation (P<0.05), which suggest that PRDX3 has substantial clinical impact on the progression of hepatocarcinoma, and may be a potential therapeutic target for HCC.