Project description:Valve interstial cells(VICs) are the major cellular compents in the aortic valve. Under pathological circumstances, normal VICs differentiate into myofibroblasts or osteoblast-like phentotypes, which play important roles in the pathogenesis of calcified aortic valve disease. We used micrroarrary analysis to compare the global programme of gene expression in normal and calcified human aortic valve intersitial cells (VICs), in order to find out some key factors that mediate the phenotype change of VICs. Overall design: Calcified aortic valve leaflets (n=5) were obtained intraoperatively from patients undergoing aortic valve replacement due to severe aortic stenosis at University of Colorado Hospital. Patients with a history of infective endocarditis, rheumatic heart disease, or a genetic syndrome were excluded. The normal aortic valve leaflets (n=5) were collected from the explanted hearts of patients with cardiomyopathy and undergoing heart trans¬plantation. Valve leaflets were digested by collagenase 1 to procure P0 VICs. Then P0 VICs were sub-cultured to get P1 VICs.A fraction of P1 VICs subject to RNA extraction and microarray analysis.
Project description:Background—Diagnosis and pronostic assessment are challenging in infective endocarditis (IE). To investigate the host response during IE and identify potential biomarkers, we determined the circulating gene expression profile through a whole genome microarray analysis. Methods and Results—A transcriptomic case-control study was performed on blood samples from patients with native valve IE (n=39), excluded IE after an initial suspicion (n=10) at patient’s admission, and age-matched healthy controls (n=10). The whole genome microarray analysis showed that patients with IE exhibited a specific transcriptional program with a predominance of gene categories associated with cell activation, innate immune and inflammatory responses. These categories were organized in a dense network from which arose numerous subnetworks including major histocompatibily complex and natural killer cell network, type 1 interferon pathway and intracellular traffic. Quantitative real-time RT-PCR performed on a selection of highly modulated genes showed that the expression of the gene encoding S100 calcium binding protein A11 (S100A11) was significantly increased in patients with IE in comparison with controls (P<0.001) and patients with excluded IE (P<0.05). Interestingly, the upregulated expression of S100A11 gene was more pronounced in staphylococcal IE than in streptococcal IE (P<0.01). These results were confirmed by serum concentrations of the S100A11 protein. Finally, we showed that, in patients with IE, the upregulation of aquaporin-9 gene (AQP9) was significantly related to the occurrence of acute heart failure (P=0.02). Conclusions— Using transcriptional signatures of blood samples, we identified S100A11 as a potential diagnostic marker of IE. In addition, the determination of AQP9 may improve the prognostic assessment of IE. The transcriptomic case-control study was performed in 39 consecutive patients with native valve IE (IE group) diagnosed by a multidisciplinary team who applied the modified Duke criteria,12 10 patients admitted for a suspicion of IE but with a final excluded IE diagnosis. Ten IE patients and five controls were arbitrary selected and investigated with microarrays.
Project description:Q fever is due to Coxiella burnetii, an obligate intracellular bacterium. We investigated the mechanism of establishment of chronic form of the Q fever that mainlym anifested by endocarditis. We showed that patients with acute Q fever and valvulopathy, who have the higher risk to develop an endocarditis, exhibited high levels of circulating apoptotic cells. We further investigated the effect of the uptake of dead cells on the intracellular fate of the bacterium and the immune response of monocytes and macrophages.
Project description:Seven streptococcal isolates from the Mitis group were analysed for the presence of pneumococcal gene homologues using comparative genomic hybridization studies with microarrays based on open reading frames from the genomes of Streptococcus pneumoniae TIGR4 and R6. The diversity of pneumolysin (ply) and neuramindase A (nanA) gene sequences was explored in more detail in a collection of 14 S. pseudopneumoniae and 29 Mitis group isolates respectively. The Mitis group isolates used in the microarray experiments included a type strain (NCTC 12261), 2 S. mitis isolates from the nasopharynx of children, one S.mitis from infective endocarditis, one S. mitis isolate from a dental abscess, plus one S. oralis isolate and one S. pseudopneumoniae isolate from the nasopharynx of children. The results of the microarray study showed that the 5 S. mitis isolates had homologues to between 67-82% of pneumococcal virulence genes, S. oralis hybridised to 83% and S. pseudopneumoniae to 92% of identified pneumococcal virulence genes. Comparison of the pneumolysin, mitilysin (mly) and newly identified pseudopneumolysin (pply) gene sequences revealed that mly and pply genes are more closely related to each other than either is to ply. In contrast, the nanA gene sequences in the pneumococcus and streptococci from the Mitis group are closely clustered together sharing 99.4-99.7% sequence identity with pneumococcal nanA alleles. Data is also available from http://bugs.sgul.ac.uk/E-BUGS-82
Project description:We are interested in the role of NOTCH1 and Shear Stress in Aortic Valve Endothelium. Overall design: Primary aortic valve endothelial cells were infected with NOTCH1 intracellular domain fused with a myc tag in order to perform ChIP-seq.
Project description:Transcriptional profiles of cardiac valves from patients with bacterial infectious endocarditis (3 infected with Streptococcus sp. and 2 infected with Staphylococcus aureus) were compared with uninfected cardiac valves (7 patients) from patients with hemodynamic disturbing events
Project description:Comparative analysis of gene expression profiles provided novel insights into the genes that are transcriptionally active in infective and developing larvae of two closely related species. Species differences may indicate different metabolic adaptations that could affect host specificity, tissue tropism, and pathogenicity Two biological replicates of infective (L3) or developing larval RNA used for hybridization, in duplicate, to examine the gene expression changes in Brugia larvae Brugia malayi vector derived third stage larvae (Bm VL3); Brugia pahangi vector derived third stage larvae (Bp VL3); Brugia pahangi L3 cultured in vitro (Bp cL3); Brugia pahangi L3 derived from peritoneal cavity of infected gerbils (Bp ipL3); Brugia pahangi migrating L3 (Bp mL3) from infected gerbils