Project description:Myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic disorders characterized by ineffective blood cell production and a high risk of progression to acute myeloid leukemia (AML). CD34+ hematopoietic stem and progenitor cells (HSPCs) play a critical role in the pathophysiology of MDS, yet the proteomic changes underlying the disease remain poorly characterized. This project focuses on performing comprehensive quantitative proteomic profiling of CD34+ cells isolated from the bone marrow of MDS patients and healthy controls. By leveraging advanced mass spectrometry and quantitative proteomics techniques, we aim to identify unbiased differences in protein expression and pathways between diseased and healthy cells. These findings will contribute to a deeper understanding of the molecular mechanisms driving MDS and may reveal potential biomarkers or therapeutic targets.
Project description:We investigated the spectra of circulating miRNAs in plasma of myelodysplastic syndromes (MDS) patients. Peripheral blood plasma from MDS patients with different risk scores was used for Agilent miRNA expression microarray analysis to define miRNA profile and to find miRNAs with discriminatory levels for lower risk and higher risk MDS. Results were further validated using droplet digital PCR on a larger cohort, enabling absolute quantification of plasma miRNAs and defining miRNAs with prognostic value for the disease. We analyzed expression profile of circulating miRNAs in plasma from 21 individuals: 7 controls and 14 MDS patients.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Identification of relevant subgroups in childhood MDS patients by gene expression analysis and gene involve in progression into AML Class comparison between different subgroups of pediatric MDS (class risk, classification subtype)