Project description:Fanconi anemia (FA) is a rare inherited disease complicated by aplastic anemia. There is evidence that hematopoietic stem cells have lost self replicative capacity and undergo apoptosis when exposed to inhibitory cytokines including interferon gamma and tumor necrosis factor-alpha. We used gene expression microarrays to identify transcriptomal differences between bone marrow cells from normal volunteers and from children and adults with Fanconi anemia
Project description:Fanconi anemia (FA) is a rare inherited disease complicated by aplastic anemia. There is evidence that hematopoietic stem cells have lost self replicative capacity and undergo apoptosis when exposed to inhibitory cytokines including interferon gamma and tumor necrosis factor-alpha. We used gene expression microarrays to identify transcriptomal differences between bone marrow cells from normal volunteers and from children and adults with Fanconi anemia Experiment Overall Design: Fanconi anemia patients were identified using mitomycin C and/or diepoxybutane chromosomal breakage analysis. Eleven normal volunteers and 21 FA patients were studied. All FA patients with cytogenetic evidence of clonal evolution were excluded. All FA patients with acute leukemia were excluded. RNA was prepared from freshly obtained low density mononuclear cell fractions.
Project description:Fanconi anemia (FA) is a rare genetic disorder characterized by genomic instability, developmental defects and bone marrow failure. Homeostasis of hematopoietic stem cells (HSCs) in the bone marrow partly relies on their direct or indirect interactions with the mesenchymal stem/stromal cells (MSCs). miRNAs can play a critical role during these interactions. There is no study available so far addressing the miRNA profile of bone marrow (BM-) MSCs in the FA disease state. Non-coding RNA expression profiling was performed in BM-MSCs obtained from Donors, as well as FA patients before bone marrow transplantation (preBMT) using GeneChip miRNA 2.0 array. Quality Control (QC) was performed via Normalized Unscaled Standard Errors (NUSE) and Relative Log Expression (RLE) before further analysis.
Project description:Fanconi anemia (FA) is a rare genetic disorder characterized by genomic instability, developmental defects and bone marrow failure. Homeostasis of hematopoietic stem cells (HSCs) in the bone marrow partly relies on their direct or indirect interactions with the mesenchymal stem/stromal cells (MSCs). miRNAs can play a critical role during these interactions. There is no study available so far addressing the miRNA profile of bone marrow (BM-) MSCs in the FA disease state. Non-coding RNA expression profiling was performed in BM-MSCs obtained from Donors (siblings of FA patients), as well as FA patients before bone marrow transplantation (preBMT) using GeneChip miRNA 2.0 Array. Quality Control (QC) was performed via Normalized Unscaled Standard Errors (NUSE) and Relative Log Expression (RLE) before further analysis.
Project description:IntroductionFanconi anemia (FA) is an inherited disorder characterized by bone marrow failure, congenital malformations, and predisposition to malignancies. Alterations in hematopoietic stem cells (HSC) have been reported, but little is known regarding the bone marrow (BM) stroma. Thus, the characterization of Mesenchymal Stromal Cells (MSC) would help to elucidate their involvement in the BM failure.MethodsWe characterized MSCs of 28 FA patients (FA-MSC) before and after treatment (hematopoietic stem cell transplantation, HSCT; or gene therapy, GT). Phenotypic and functional properties were analyzed and compared with MSCs expanded from 26 healthy donors (HD-MSCs). FA-MSCs were genetically characterized through, mitomycin C-test and chimerism analysis. Furthermore, RNA-seq profiling was used to identify dysregulated metabolic pathways.ResultsOverall, FA-MSC had the same phenotypic and functional characteristics as HD-MSC. Of note, MSC-GT had a lower clonogenic efficiency. These findings were not confirmed in the whole FA patients' cohort. Transcriptomic profiling identified dysregulation in HSC self-maintenance pathways in FA-MSC (HOX), and was confirmed by real-time quantitative polymerase chain reaction (RT-qPCR).DiscussionOur study provides a comprehensive characterization of FA-MSCs, including for the first time MSC-GT and constitutes the largest series published to date. Interestingly, transcript profiling revealed dysregulation of metabolic pathways related to HSC self-maintenance. Taken together, our results or findings provide new insights into the pathophysiology of the disease, although whether these niche defects are involved in the hematopoietic defects seen of FA deserves further investigation.
Project description:Fanconi anemia (FA) is a rare genetic disorder characterized by genomic instability, developmental defects and bone marrow failure. Homeostasis of hematopoietic stem cells (HSCs) in the bone marrow partly relies on their direct or indirect interactions with the mesenchymal stem/stromal cells (MSCs). miRNAs can play a critical role during these interactions. There is no study available so far addressing the miRNA profile of bone marrow (BM-) MSCs in FA disease state. Non-coding RNA expression profiling was performed in BM-MSCs obtained from Donors (siblings of FA patients) as well as FA patients before (preBMT) and after bone marrow transplant (postBMT) using GeneChip miRNA 2.0 Array. Quality Control (QC) was performed via Normalized Unscaled Standard Errors (NUSE) and Relative Log Expression (RLE) before further analysis.
Project description:We profiled primary HSPCs from Fanconi anemia (FA) patients for single cell transcriptome (scRNA-seq) to identify additional determinants of HSPC impairment leading to the bone marrow failure,. Trajectory analysis revealed that early hematopoietic differentiation potential is preserved in FA HSPCs. As expected, p53 and TGFβ pathway genes were overexpressed in HSPCs from FA patients. The oncogene MYC was also identified as one of the top over-expressed genes in FA HSPCs. Interestingly, we observed co-existence of “High-TP53” expressing HSPCs and HighMYC expressing HSPCs in FA bone marrow. Inhibition of MYC expression by the BET bromodomain inhibitor (+)-JQ1 reduced the clonogenic potential of primary HSPCs from FA patients but rescued the physiological/genotoxic stress in HSPCs from FA mice. The “High-MYC” expressing HSPCs exhibited a significant downregulation of cell adhesion genes, such as CXCR4. Consistently, HSPCs in FA patients showed a defect in adhesion to their bone marrow niche resulting in egression from the bone marrow into peripheral blood. We speculate that MYC overexpression impairs HSPC function and contributes to exhaustion of HSPCs in FA bone marrow.