62 research outputs found
Prolastin, a pharmaceutical preparation of purified human Ξ±1-antitrypsin, blocks endotoxin-mediated cytokine release
BACKGROUND: Ξ±1-antitrypsin (AAT) serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects. METHODS: Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS) or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFΞ±, IL-1Ξ² and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 ΞΌg) and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge. RESULTS: In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml) inhibition of endotoxin-stimulated TNFΞ± and IL-1Ξ² release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p < 0.001 compared to zymosan treated cells) and monocyte TNFΞ± and IL-1Ξ² release (10.7- and 7.3-fold, p < 0.001, respectively, compared to LPS treated cells). Furthermore, Prolastin (2.5 mg per nostril) significantly inhibited nasal IL-8 release in response to pure LPS challenge. CONCLUSION: Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions
Cardiac rehabilitation adapted to transient ischaemic attack and stroke (CRAFTS): a randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Coronary Heart Disease and Cerebrovascular Disease share many predisposing, modifiable risk factors (hypertension, abnormal blood lipids and lipoproteins, cigarette smoking, physical inactivity, obesity and diabetes mellitus). Lifestyle interventions and pharmacological therapy are recognised as the cornerstones of secondary prevention. Cochrane review has proven the benefits of programmes incorporating exercise and lifestyle counselling in the cardiac disease population. A Cochrane review highlighted as priority, the need to establish feasibility and efficacy of exercise based interventions for Cerebrovascular Disease.</p> <p>Methods</p> <p>A single blind randomised controlled trial is proposed to examine a primary care cardiac rehabilitation programme for adults post transient ischemic attack (TIA) and stroke in effecting a positive change in the primary outcome measures of cardiac risk scores derived from Blood Pressure, lipid profile, smoking and diabetic status and lifestyle factors of habitual smoking, exercise and healthy eating participation. Secondary outcomes of interest include health related quality of life as measured by the Hospital Anxiety and Depression Scale, the Stroke Specific Quality of Life scale and WONCA COOP Functional Health Status charts and cardiovascular fitness as measured by a sub-maximal fitness test.</p> <p>A total of 144 patients, over 18 years of age with confirmed diagnosis of ischaemic stroke or TIA, will be recruited from Dublin community stroke services and two tertiary T.I.A clinics. Exclusion criteria will include oxygen dependence, unstable cardiac conditions, uncontrolled diabetes, major medical conditions, claudication, febrile illness, pregnancy or cognitive impairment. Participants will be block-statified, randomly allocated to one of two groups using a pre-prepared computer generated randomisation schedule. Both groups will receive a two hour education class on risk reduction post stroke. The intervention group will receive a 10 week programme of supervised aerobic exercises (twice weekly) and individually tailored brief intervention lifestyle counselling. Both groups will be tested on week one and week ten of the programme. Follow-up at 1 year will assess longer term benefits. Analysis will test for significant changes in the key variables indicated.</p> <p>Discussion</p> <p>Application of the Cardiac Rehabilitation paradigm to patients with ischaemic stroke or TIA has not been explored despite the obvious overlap in aetiology. It is hoped the anticipated improvement in vascular risk factors and fitness resulting from such a programme will enhance health and social gain in this population.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISCTRN90272638.</p
Human Cysteine Cathepsins Are Not Reliable Markers of Infection by Pseudomonas aeruginosa in Cystic Fibrosis
Cysteine cathepsins have emerged as new players in inflammatory lung disorders. Their activities are dramatically increased in the sputum of cystic fibrosis (CF) patients, suggesting that they are involved in the pathophysiology of CF. We have characterized the cathepsins in CF expectorations and evaluated their use as markers of colonization by Pseudomonas aeruginosa. The concentrations of active cathepsins B, H, K, L and S were the same in P. aeruginosa-positive (19 Ps+) and P. aeruginosa-negative (6 Psβ) samples, unlike those of human neutrophil elastase. Also the cathepsin inhibitory potential and the cathepsins/cathepsin inhibitors imbalance remained unchanged and similar (βΌ2-fold) in the Ps+ and Psβ groups (p<0.001), which correlated with the breakdown of their circulating cystatin-like inhibitors (kininogens). Procathepsins, which may be activated autocatalytically, are a potential proteolytic reservoir. Immunoblotting and active-site labeling identified the double-chain cathepsin B, the major cathepsin in CF sputum, as the main molecular form in both Ps+ and Psβ samples, despite the possible release of the βΌ31 kDa single-chain form from procathepsin B by sputum elastase. Thus, the hydrolytic activity of cysteine cathepsins was not correlated with bacterial colonization, indicating that cathepsins, unlike human neutrophil elastase, are not suitable markers of P. aeruginosa infection
The Pathogenic Potential of Campylobacter concisus Strains Associated with Chronic Intestinal Diseases
Campylobacter concisus has garnered increasing attention due to its association with intestinal disease, thus, the pathogenic potential of strains isolated from different intestinal diseases was investigated. A method to isolate C. concisus was developed and the ability of eight strains from chronic and acute intestinal diseases to adhere to and invade intestinal epithelial cells was determined. Features associated with bacterial invasion were investigated using comparative genomic analyses and the effect of C. concisus on host protein expression was examined using proteomics. Our isolation method from intestinal biopsies resulted in the isolation of three C. concisus strains from children with Crohn's disease or chronic gastroenteritis. Four C. concisus strains from patients with chronic intestinal diseases can attach to and invade host cells using mechanisms such as chemoattraction to mucin, aggregation, flagellum-mediated attachment, βmembrane rufflingβ, cell penetration and damage. C. concisus strains isolated from patients with chronic intestinal diseases have significantly higher invasive potential than those from acute intestinal diseases. Investigation of the cause of this increased pathogenic potential revealed a plasmid to be responsible. 78 and 47 proteins were upregulated and downregulated in cells infected with C. concisus, respectively. Functional analysis of these proteins showed that C. concisus infection regulated processes related to interleukin-12 production, proteasome activation and NF-ΞΊB activation. Infection with all eight C. concisus strains resulted in host cells producing high levels of interleukin-12, however, only strains capable of invading host cells resulted in interferon-Ξ³ production as confirmed by ELISA. These findings considerably support the emergence of C. concisus as an intestinal pathogen, but more significantly, provide novel insights into the host immune response and an explanation for the heterogeneity observed in the outcome of C. concisus infection. Moreover, response to infection with invasive strains has substantial similarities to that observed in the inflamed mucosa of Crohn's disease patients
SpeB of Streptococcus pyogenes Differentially Modulates Antibacterial and Receptor Activating Properties of Human Chemokines
BACKGROUND: CXC chemokines are induced by inflammatory stimuli in epithelial cells and some, like MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11, are antibacterial for Streptococcus pyogenes. METHODOLOGY/PRINCIPAL FINDINGS: SpeB from S. pyogenes degrades a wide range of chemokines (i.e. IP10/CXCL10, I-TAC/CXCL11, PF4/CXCL4, GROalpha/CXCL1, GRObeta/CXCL2, GROgamma/CXCL3, ENA78/CXCL5, GCP-2/CXCL6, NAP-2/CXCL7, SDF-1/CXCL12, BCA-1/CXCL13, BRAK/CXCL14, SRPSOX/CXCL16, MIP-3alpha/CCL20, Lymphotactin/XCL1, and Fractalkine/CX3CL1), has no activity on IL-8/CXCL8 and RANTES/CCL5, partly degrades SRPSOX/CXCL16 and MIP-3alpha/CCL20, and releases a 6 kDa CXCL9 fragment. CXCL10 and CXCL11 loose receptor activating and antibacterial activities, while the CXCL9 fragment does not activate the receptor CXCR3 but retains its antibacterial activity. CONCLUSIONS/SIGNIFICANCE: SpeB destroys most of the signaling and antibacterial properties of chemokines expressed by an inflamed epithelium. The exception is CXCL9 that preserves its antibacterial activity after hydrolysis, emphasizing its role as a major antimicrobial on inflamed epithelium
Quantitative differential proteomics of yeast extracellular matrix: there is more to it than meets the eye
Background: Saccharomyces cerevisiae multicellular communities are sustained by a scaffolding extracellular matrix, which provides spatial organization, and nutrient and water availability, and ensures group survival. According to this tissue-like biology, the yeast extracellular matrix (yECM) is analogous to the higher Eukaryotes counterpart for its polysaccharide and proteinaceous nature. Few works focused on yeast biofilms, identifying the flocculin Flo11 and several members of the HSP70 in the extracellular space. Molecular composition of the yECM, is therefore mostly unknown. The homologue of yeast Gup1 protein in high Eukaryotes (HHATL) acts as a regulator of Hedgehog signal secretion, therefore interfering in morphogenesis and cell-cell communication through the ECM, which mediates but is also regulated by this signalling pathway. In yeast, the deletion of GUP1 was associated with a vast number of diverse phenotypes including the cellular differentiation that accompanies biofilm formation.
Methods: S. cerevisiae W303-1A wt strain and gup1Ξ mutant were used as previously described to generate biofilmlike mats in YPDa from which the yECM proteome was extracted. The proteome from extracellular medium from batch liquid growing cultures was used as control for yECM-only secreted proteins. Proteins were separated by SDS-PAGE and 2DE. Identification was performed by HPLC, LC-MS/MS and MALDI-TOF/TOF. The protein expression comparison between the two strains was done by DIGE, and analysed by DeCyder Extended Data Analysis that included Principal Component Analysis and Hierarchical Cluster Analysis.
Results: The proteome of S. cerevisiae yECM from biofilm-like mats was purified and analysed by Nano LC-MS/MS, 2D Difference Gel Electrophoresis (DIGE), and MALDI-TOF/TOF. Two strains were compared, wild type and the mutant defective in GUP1. As controls for the identification of the yECM-only proteins, the proteome from liquid batch cultures was also identified. Proteins were grouped into distinct functional classes, mostly Metabolism, Protein Fate/Remodelling and Cell Rescue and Defence mechanisms, standing out the presence of heat shock chaperones, metalloproteinases, broad signalling cross-talkers and other putative signalling proteins. The data has been deposited to the ProteomeXchange with identifier PXD001133.Conclusions: yECM, as the mammalian counterpart, emerges as highly proteinaceous. As in higher Eukaryotes ECM, numerous proteins that could allow dynamic remodelling, and signalling events to occur in/and via yECM were identified. Importantly, large sets of enzymes encompassing full antagonistic metabolic pathways, suggest that mats develop into two metabolically distinct populations, suggesting that either extensive moonlighting or actual metabolism occurs extracellularly. The gup1Ξ showed abnormally loose ECM texture. Accordingly, the correspondent differences in proteome unveiled acetic and citric acid producing enzymes as putative players in structural integrity maintenance.This work was funded by the Marie Curie Initial Training Network
GLYCOPHARM (PITN-GA-2012-317297), and by national funds from FCT I.P.
through the strategic funding UID/BIA/04050/2013. FΓ‘bio Faria-Oliveira was supported
by a PhD scholarship (SFRH/BD/45368/2008) from FCT (Fundação para a
CiΓͺncia e a Tecnologia). We thank David Caceres and Montserrat MartinezGomariz
from the Unidad de ProteΓ³mica, Universidad Complutense de Madrid
β Parque CientΓfico de Madrid, Spain for excellent technical assistance in the
successful implementation of all proteomics procedures including peptide
identification, and Joana Tulha from the CBMA, Universidade do Minho,
Portugal, for helping with the SDS-PAGE experiments, and the tedious and
laborious ECM extraction procedures. The mass spectrometry proteomics
data have been deposited to the ProteomeXchange Consortium, via the
PRIDE partner repository, with the dataset identifier PXD001133. We would
like to thank the PRIDE team for all the help and support during the submission
process.info:eu-repo/semantics/publishedVersio
Activated KrasG12D is associated with invasion and metastasis of pancreatic cancer cells through inhibition of E-cadherin
Structural and functional insights into oligopeptide acquisition by the RagAB transporter from Porphyromonas gingivalis
Porphyromonas gingivalis, an asaccharolytic member of the Bacteroidetes, is a keystone pathogen in human periodontitis that may also contribute to the development of other chronic inflammatory diseases. P. gingivalis utilizes protease-generated peptides derived from extracellular proteins for growth, but how these peptides enter the cell is not clear. Here, we identify RagAB as the outer-membrane importer for these peptides. X-ray crystal structures show that the transporter forms a dimeric RagA2B2 complex, with the RagB substrate-binding surface-anchored lipoprotein forming a closed lid on the RagA TonB-dependent transporter. Cryo-electron microscopy structures reveal the opening of the RagB lid and thus provide direct evidence for a βpedal binβ mechanism of nutrient uptake. Together with mutagenesis, peptide-binding studies and RagAB peptidomics, our work identifies RagAB as a dynamic, selective outer-membrane oligopeptide-acquisition machine that is essential for the efficient utilization of proteinaceous nutrients by P. gingivalis
Pathogen-Mediated Proteolysis of the Cell Death Regulator RIPK1 and the Host Defense Modulator RIPK2 in Human Aortic Endothelial Cells
Porphyromonas gingivalis is the primary etiologic agent of periodontal disease that is associated with other human chronic inflammatory diseases, including atherosclerosis. The ability of P. gingivalis to invade and persist within human aortic endothelial cells (HAEC) has been postulated to contribute to a low to moderate chronic state of inflammation, although how this is specifically achieved has not been well defined. In this study, we demonstrate that P. gingivalis infection of HAEC resulted in the rapid cleavage of receptor interacting protein 1 (RIPK1), a mediator of tumor necrosis factor (TNF) receptor-1 (TNF-R1)-induced cell activation or death, and RIPK2, a key mediator of both innate immune signaling and adaptive immunity. The cleavage of RIPK1 or RIPK2 was not observed in cells treated with apoptotic stimuli, or cells stimulated with agonists to TNF-R1, nucleotide oligomerization domain receptor 1(NOD1), NOD2, Toll-like receptor 2 (TLR2) or TLR4. P. gingivalis-induced cleavage of RIPK1 and RIPK2 was inhibited in the presence of a lysine-specific gingipain (Kgp) inhibitor. RIPK1 and RIPK2 cleavage was not observed in HAEC treated with an isogenic mutant deficient in the lysine-specific gingipain, confirming a role for Kgp in the cleavage of RIPK1 and RIPK2. Similar proteolysis of poly (ADP-ribose) polymerase (PARP) was observed. We also demonstrated direct proteolysis of RIPK2 by P. gingivalis in a cell-free system which was abrogated in the presence of a Kgp-specific protease inhibitor. Our studies thus reveal an important role for pathogen-mediated modification of cellular kinases as a potential strategy for bacterial persistence within target host cells, which is associated with low-grade chronic inflammation, a hallmark of pathogen-mediated chronic inflammatory disorders
Hippocampal CA1 region shows differential regulation of gene expression in mice displaying extremes in behavioral sensitization to amphetamine: relevance for psychosis susceptibility?
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