Project description:To analyze expression of inflammatory cytokines in Exhaled Breath Condensates from pediatric patients with sickle cell disease, asthma, sickle cell disease and asthma, and controls
Project description:Polymorphonuclear neutrophils are key actors in the pathophysiology of sickle cell disease, but specific factors underlying their activation and sustained inflammation are not well documented. In the present study, we investigated the proteome of neutrophils by a label-free global comparative approach between 4 non-treated sickle patients (SS genotype) at steady state and 4 healthy donors. We identified 101 proteins differentially expressed in SS and normal neutrophils. We found overexpression of CD64 and under-expression of CD62L suggestive of an activated and aged neutrophil profile in SS patients. Comparison of the two proteomes revealed a strong involvement of the type 1 interferon (IFN) response pathway with a 3- to 84-fold increase of type 1 IFN-induced proteins in SS neutrophils, and overexpression of STAT1 and STAT2. Thus, we next determined the plasmatic concentration of type 1 IFNs (IFNα and IFNβ) using the digital-ELISA technology and found a significant higher concentration of IFNα in the plasma from half of our SS patients compared to controls. Overall, a dramatic high-level expression of IFNα signaling proteins in neutrophils from SS patients suggests auto-inflammatory-like phenotype in sickle cell disease at steady state. This finding could open the way to new anti-inflammatory therapies.
Project description:Circulating platelets from Sickle cell disease (SCD) patients express distinct gene expression patterns that regulate function. The objective of this study is to identify a role of post-transcriptional regulation of the platelet transcriptional signaling by microRNAs. Comparison of microRNA expression in platelets from SCD patients and control subjects, from 2 cohorts-University of Pittsburgh and National Institutes of Health.
Project description:Sickle cell disease (SCD) is caused by a pathogenic hemoglobin (Hb) mutation, yet patients can have dramatically variable clinical manifestations. Here we address the genetic basis of this clinical heterogeneity. Using a systems genetics approach, we performed whole blood gene expression analysis and eQTL analysis on different clinical phenotypes in SCD patients. We generated whole blood gene expression profiles for 311 West-African children recruited from the National Sickle Cell Disease Centre in Cotonou, Benin which included 250 patients with varying degrees of SCD severities and 61 age-matched controls. SCD is caused by a point-mutation in the beta-hemoglobin gene that changes the normal HbAA protein into, most often, an abnormal HbSS or HbSC protein. The SCD patients recruited in the study either had HbSS or HbSC phenotypes and were categorized into different 3 clinical states based on follow-up status (Rahimy, MC, et al. Effect of a comprehensive clinical care program on disease course in severely ill children with sickle cell anemia in sub-Saharan African setting. Bood 102, 834-838. 2002). When patients are refered to the clinic, they are enrolled when they are in steady-state condition, and are labeled as entry (E). Patients followed at the SCD clinic are labeled as FU. Control patients were recruited and are labeled as C. Patients were also assigned a severity score (Sebastiani, P. et al. A network model to predict the risk of death in sickle cell disease. Blood 110, 2727-2735, 2007). Hemoglobin protein status (Hb phenotype) was confirmed for each patient using standard electrophoretic techniques. We generated genotypes for 263 of these individuals and performed principal component analysis (PCA) which identified 2 signigicant genotypic principal components (gPC1 and gPC2). Using the gene expression and genotyping data, we performed an eSNP analysis. . Gene expression data presented in this study.
Project description:Circulating platelets from Sickle cell disease (SCD) patients express distinct gene expression patterns that regulate function. The objective of this study is to identify a role of post-transcriptional regulation of the platelet transcriptional signaling by microRNAs.
