Differential proteomics of the plasma of individuals with sepsis caused by Acinetobacter baumannii.

This study examines alterations in the plasma proteome in ten adults affected by sepsis caused by Acinetobacter baumannii as compared to paired healthy controls. 2-DE profiles of plasma from patients and paired healthy donors, depleted of the six most abundant proteins, were analysed by the DIGE technique. Protein spot detection and quantification were performed with the Differential In-gel Analysis and Biological Variation Analysis modules of the DeCyder() software. Differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) after colloidal Coomassie blue staining. Almost 900 spots were detected on a unique 2-D gel by the DIGE technique. A total of 269 protein spots of differential abundance were shown to be statistically significant (2.5-fold) with p values of p< or =0.01 (135 spots) and p< or =0.05 (134 spots) as determined by the t test. Seventy-one spots were submitted to mass spectrometry and about 30% could be successfully identified. This multiplex approach significantly reduced experimental variability, allowing for the confident detection of small differences in protein levels. Results include differentially expressed lipoproteins as well as proteins belonging to inflammatory/coagulation pathways and the kallikrein-kinin system. These data improves the knowledge for future developments in sepsis diagnosis, staging and therapy.

Bothrops insularis venomics: a proteomic analysis supported by transcriptomic-generated sequence data

A joint transcriptomic and proteomic approach employing two-dimensional electrophoresis, liquid chromatography and mass spectrometry was carried out to identify peptides and proteins expressed by the venom gland of the snake Bothrops insularis, an endemic species of Queimada Grande Island, Brazil. Four protein families were mainly represented in processed spots, namely metalloproteinase, serine proteinase, phospholipase A2 and lectin. Other represented families were growth factors, the developmental protein G10, a disintegrin and putative novel bradykinin-potentiating peptides. The enzymes were present in several isoforms. Most of the experimental data agreed with predicted values for isoelectric point and Mr of proteins found in the transcriptome of the venom gland. The results also support the existence of posttranslational modifications and of proteolytic processing of precursor molecules which could lead to diverse multifunctional proteins. This study provides a preliminary reference map for proteins and peptides present in Bothrops insularis whole venom establishing the basis for comparative studies of other venom proteomes which could help the search for new drugs and the improvement of venom therapeutics. Altogether, our data point to the influence of transcriptional and post-translational events on the final venom composition and stress the need for a multivariate approach to snake venomics studies.

Chronic dynamic exercise increases apolipoprotein A-I expression in rabbit renal cortex as determined by proteomic technology.

OBJECTIVE: We have shown previously that exercise training enhances endothelium-dependent and endothelium-independent vascular relaxation in rabbit kidney. This study aimed to investigate protein expression changes in the rabbit renal cortex induced by chronic dynamic exercise. DESIGN: Kidneys were obtained from New Zealand rabbits either confined to pens (n = 8) or trained on a treadmill (0% grade) for 5 days/week at a speed of 18 m/min for 60-min periods over 12 weeks (n = 8). Expression of proteins in the renal cortex was determined by colloidal Coomassie blue staining after two-dimensional polyacrylamide gel electrophoresis. Differential protein spots were excised and digested with trypsin, and peptides were sequenced by electrospray ionization-ion trap mass spectrometry. RESULTS: Two pairs of matching differentially stained spots displayed an approximate threefold increase in trained compared with sedentary animals. These four spots presented a molecular mass of 23 kDa but different pI values. Mass spectrometric analyses revealed the pairs of matching spots as being rabbit apolipoprotein A-I. CONCLUSION: Chronic dynamic exercise increases apolipoprotein A-I expression in the rabbit renal cortex. This fact could be involved in the alterations observed in the renal circulation after exercise training.