Search

Exercise can alter gene transcriptional and protein translational rates leading to changes in protein abundance toward adaptation to exercise. We investigated the alterations in protein abundance in skeletal muscle after one bout of an exhaustive exercise through proteomic analysis. Gastrocnemius muscles were sampled from non-exercised control rats and from rats exercised on a treadmill with incremental increases in speed until exhaustion (approximately 30 min). Rats were sacrificed 3 and 24 h after exercise cessation. Two-dimensional gel electrophoresis was performed and spots with a significant alteration in relative volume were identified by mass spectrometry. Six spots presented statistically significant altered abundances after exercise. The spots identified as the metabolic related proteins triosephosphate isomerase 1, glyceraldehyde-3-phosphate dehydrogenase, the β subunit of pyruvate dehydrogenase E1 and carnitine palmitoyltransferase 2 were all more abundant after exercise. One spot identified as heat shock cognate 70 was also more abundant after exercise. One spot demonstrated a decreased abundance after exercise and was identified as α-actin. These results suggest that a single session of exhaustive incremental exercise in untrained muscle can alter thin filaments synthesis/degradation rate and enhance cytosolic and mitochondrial proteins synthesis. The identified proteins may be important to a general preconditioning of skeletal muscle for subsequent exercise sessions. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis (OA) is the most common form of arthritis, affecting millions of people worldwide and characterised by joint pain and inflammation. It is a complex disease involving inflammatory factors and affecting the whole joint, including the synovial membrane. Since drug combination is widely used to treat chronic inflammatory diseases, a similar strategy of designing plant-derived natural products to reduce inflammation in OA joints may be of interest. In this study, we characterised the response of OA synovial cells to lipopolysaccharide (LPS) and investigated the biological action of the combination of curcumin, bromelain and harpagophytum in this original in vitro model of osteoarthritis. Methods: Firstly, human synovial cells from OA patients were stimulated with LPS and proteomic analysis was performed. Bioinformatics analyses were performed using Cytoscape App and SkeletalVis databases. Additionally, cells were treated with curcumin, bromelain and harpagophytum alone or with the three vegetal compounds together. The gene expression involved in inflammation, pain or catabolism was determined by RT-PCR. The release of the encoded proteins by these genes and of prostaglandin E2 (PGE2) were also assayed by ELISA. Results: Proteomic analysis demonstrated that LPS induces the expression of numerous proteins involved in the OA process in human OA synovial cells. In particular, it stimulates inflammation through the production of pro-inflammatory cytokines (Interleukin-6, IL-6), catabolism through an increase of metalloproteases (MMP-1, MMP-3, MMP-13), and the production of pain-mediating neurotrophins (Nerve Growth Factor, NGF). These increases were observed in terms of mRNA levels and protein release. LPS also increases the amount of PGE2, another inflammation and pain mediator. At the doses tested, vegetal extracts had little effect: only curcumin slightly counteracted the effects of LPS on NGF and MMP-13 mRNA, and PGE2, IL-6 and MMP-13 release. In contrast, the combination of curcumin with bromelain and harpagophytum reversed lots of effects of LPS in human OA synovial cells. It significantly reduced the gene expression and/or the release of proteins involved in catabolism (MMP-3 and -13), inflammation (IL-6) and pain (PGE2 and NGF). Conclusion: We have shown that the stimulation of human OA synovial cells with LPS can induce protein changes similar to inflamed OA synovial tissues. In addition, using this model, we demonstrated that the combination of three vegetal compounds, namely curcumin, bromelain and harpagophytum, have anti-inflammatory and anti-catabolic effects in synovial cells and may thus reduce OA progression and related pain. [ABSTRACT FROM AUTHOR]

Yokoyama T, Kobayashi T, Yamamoto K, Yamagata A, Oofusa K, Yoshie H. Proteomic profiling of human neutrophils in relation to immunoglobulin G Fc receptor IIIb polymorphism. J Periodont Res 2010; 45: 780-787. © 2010 John Wiley & Sons A/S Neutrophils are essential in host defense against periodontopathic bacteria. Immunoglobulin G Fc receptor IIIb (FcγRIIIb) is a neutrophil-specific receptor for immunoglobulin G and bears the functional NA1-NA2 polymorphism. Accumulating evidence suggests a significant association between FcγRIIIb gene polymorphism and periodontitis. In this study, we employed a proteomic approach to evaluate the relevance of FcγRIIIb polymorphism to protein expression profiles of neutrophils. Neutrophils were collected from ten healthy subjects whose FcγRIIIb genotypes were determined by allele-specific PCRs. Expressions of proteins induced by interaction via FcγRIIIb were examined between the FcγRIIIb genotypes with two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins that were significantly different in expression levels between the FcγRIIIb genotypes were determined with computer image analysis, and identified with mass spectrometry and protein databases. A total of 757 protein spots were observed in the two-dimensional electrophoretograms of neutrophils from five FcγRIIIb-NA1/NA1 and five FcγRIIIb-NA2/NA2 donors. A statistical analysis revealed that the expression levels of five proteins were significantly different between the FcγRIIIb genotypes ( p < 0.05). The FcγRIIIb-NA1/NA1 neutrophils exhibited two spots that were significantly underexpressed (protein-arginine deiminase type-4 and annexin VI) and three spots that were significantly overexpressed (Cdc42hs-Gdp complex, myosin light chain 12A and coactosin-like 1) when compared with FcγRIIIb-NA2/NA2 neutrophils. The same expression profiles of protein-arginine deiminase type-4 were obtained by ELISA. Differential protein expression profiles were observed in neutrophils between FcγRIIIb genotypes. [ABSTRACT FROM AUTHOR]