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Salah-Dine Chibout

Publications and source records attributed to Salah-Dine Chibout.

8 recordsLinked to original sources
PubMed2006

Discovery of proteins related to coronary artery disease using industrial-scale proteomics analysis of pooled plasma.

BACKGROUND: Relating a disease state to an entire population of proteins provides an opportunity to gain new insights into a disease. METHODS: Male populations of 53 patients with angiographic coronary artery disease and 53 control subjects without coronary disease from the Duke Databank for Cardiovascular Disease were established and matched for age and race as well as extremes of risk factors. Major plasma protein abnormalities were excluded. Plasma samples of each group were pooled to make large volumes (6 L each) to identify low-abundance proteins. After removal of albumin as well as immunoglobulins and enrichment of smaller proteins (<20-40 kDa), samples were separated into 12,960 fractions by cation exchange and 2 reversed-phase chromatography steps. Proteins were analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry. RESULTS: There were 731 plasma proteins or fragments identified. Of these proteins, 95 were differentially displayed in the case versus control populations. These represent broad categories of proteins involved with natural defenses, inflammation, growth, and coagulation. CONCLUSION: We identified a large number of proteins that differ in abundance in populations with and those without angiographic coronary disease. These proteins now comprise candidates for validation studies in individual patients and in larger clinical data sets to better define disease pathways and establish novel markers for disease.

Adult↗
PubMed2005

VeloceGenomics: an accelerated in vivo drug discovery approach to rapidly predict the biologic, drug-like activity of compounds, proteins, or genes.

PURPOSE: The aim of this study is to test the predictive power of in vivo multiorgan RNA expression profiling in identifying the biologic activity of molecules. METHODS: Animals were treated with compound A or B. At the end of the treatment period, in vivo multiorgan microarray-based gene expression data were collected. Investigators masked to the identity of the compounds analyzed the transcriptome signatures to define the molecular pathways affected by treatment and to hypothesize the biologic activity and potential therapeutic indications of the blinded compounds. RESULTS: For compound A, G-protein-coupled receptors and factors associated with cell growth were affected-growth hormone/insulin-like growth factor-1, glucagon/insulin axes, and general somatomedin-like activity. Deblinding showed the compound to be a somatostatin analog, SOM230, confirming the accuracy of the predicted biologic activity. For compound B, components of the inflammatory cascade potentially mediated by lipopolysaccharide, tumor necrosis factor, or proinflammatory cytokines were affected. The gene expression signatures were most consistent with an interleukin-6 family activity. Deblinding revealed that compound B was leukemia inhibitory factor. CONCLUSIONS: VeloceGenomics is a strategy of coupling in vivo compound testing with genomic technologies. The process enables prediction of the mechanism of action and, coupled with other relevant data, prediction of the suitability of compounds for advancement in the drug development process.

Animals↗
PubMed2004

Functional genomics and prognosis in sarcoidosis--the critical role of antigen presentation.

BACKGROUND: Sarcoidosis is a systemic disorder of unknown cause, highly variable phenotype and unpredictable outcome. Antigen processing, inflammatory response and immunomodulation appear critical to development and prognosis of the disease. METHODS: We performed a comprehensive genomic analysis, applying high-density human GeneChip probe arrays (HUG95A, Affymetrix Inc.) for gene expression profiling from peripheral blood of patients with acute pulmonary sarcoidosis (n = 12) and matched healthy controls (n = 12), mean age 36 +/- 12 and 33 +/- 10 years respectively. RESULTS: At follow-up (18 [15-24] months), 7 patients had self-limited disease and 5 had persistent disease. Significantly different expression comparing patients and controls was identified for 1,860 (14.9%) and 729 (5.8%) gene products at p = 0.05 and p = 0.01 levels respectively. Genes closely associated with persistent disease included HLA-DRB1*1501 DQB1*0602, TNFA, NFKB, cyclic AMP-responsive element modulator (CREM) and T-cell activation marker CD69. IL1B, IL8, growth related (GRO)-beta/-gamma and CCR 2,5,6 were closely associated with self-limited disease. CONCLUSION: We hypothesize that, in self-limited disease, greater effector cell activation leads to successful antigen elimination/tolerance, whereas HLA-DRB1*1501 DQBI*0602-mediated, probably defective/partial T-lymphocyte activation results in an inefficient primary immune response, antigen intolerance and persistent disease.

Adult↗
PubMed2003

Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

Aged↗
PubMed2003

Generation of transducers for fluorescence-based microarrays with enhanced sensitivity and their application for gene expression profiling.

The present paper describes a novel generation of microchips suitable for fluorescence-based assays, such as cDNA, oligonucleotide, or protein microarrays. The new transducers consist of a fully corrugated surface coated with a thin layer of Ta2O5 as a high refractive index material. Tuning of the incident excitation light beam to abnormal reflection geometry results in a confinement of the energy within the thin metal oxide layer. Consequently, strong evanescent fields are generated at the surface of these microchips and fluorophores located within the fields showed up to a 2 order of magnitude increase in fluorescence intensities relative to the epifluorescence signals. We have attributed this phenomenon as evanescent resonance (ER). Due to the surface architecture, propagation distances of the incident energy and fluorescence photons are in the micrometer range, thus preventing cross talk between adjacent regions. ER microchips offer a significant increase in fluorescence intensities in both "snapshot" fluorescence setups and commercial fluorescence scanners. The underlying principle of the novel chips is explained, and quantitative data on the fluorescence enhancement are provided. To demonstrate their potential, the novel chips are used to investigate the dependence of expression levels from metabolic genes in rat liver on drug treatment. In contrast to competitive hybridization, labeled samples were hybridized to individual ER microchips, and changes were observed by comparing with normalized data from different chips. Results obtained in gene expression profiling experiments with phenobarbital-treated rats are shown.

Animals↗
PubMed2002

Pimecrolimus identifies a common genomic anti-inflammatory profile, is clinically highly effective in psoriasis and is well tolerated.

The ascomycin macrolactam pimecrolimus is a novel inflammatory cytokine release inhibitor that so far has not been administered systemically to humans. In this phase I/II randomized double-blind, placebo-controlled, multiple rising dose proof of concept study psoriasis patients were treated with oral pimecrolimus or placebo. Gene profiling identified a common genomic profile with a downregulation of genes associated with inflammation but no changes in gene expression linked to drug-related side-effects. A steady state of pimecrolimus was reached after 5-10 d, Cmax, and area under the curve (0-24) was 54.5 ng per ml and 589.9 ng h per ml, respectively, at steady state at the highest dose. There was clear clinical efficacy in patients receiving 20 mg pimecrolimus twice daily and 30 mg twice daily with a reduction of Psoriasis Area and Severity Index by 60% and 75%, respectively. Histopatho logically and immunopathologically there was a reversion of the psoriatic phenotype towards normal. There were no notable clinical, laboratory, kidney function, or immunologic side-effects. We conclude that pimecrolimus taken orally is highly effective in a concentration-dependent manner in patients with psoriasis and on a short-term basis it is well tolerated and this is confirmed by its pharmacogenomic profile. The latter also indicates that pimecrolimus should be equally effective in other inflammatory skin diseases.

Adult↗
PubMedDate not supplied

Toxicogenomics in drug development.

Toxicogenomics represents the merging of toxicology with technologies that have been developed, together with bioinformatics, to identify and quantify global gene expression changes. It represents a new paradigm in drug development and risk assessment, which promises to generate a wealth of information towards an increased understanding of the molecular mechanisms that lead to drug toxicity and efficacy, and of DNA polymorphisms responsible for individual susceptibility to toxicity. Gene expression profiling, through the use of DNA microarray and proteomic technologies will aid in establishing links between expression profiles, mode of action and traditional toxic endpoints. Such patterns of gene expression, or 'molecular fingerprints' could be used as diagnostic or predictive markers of exposure, that is characteristic of a specific mechanism of induction of that toxic or efficacious effect. It is anticipated that toxicogenomics will be increasingly integrated into all phases of the drug development process particularly in mechanistic and predictive toxicology, and biomarker discovery. This review provides an overview of the expression profiling technologies applied in toxicogenomics. and discusses the promises as well as the future challenges of applying this discipline to the drug development process.

Animals↗