Project description:We performed deep targeted somatic mutation analysis to identify cases of clonal hematopoiesis (CH) associated with pre-leukemic mutations. For the healthy cohort, we used our CH panel V3, containing 705 probes, covering leukemia-related Single Nucleotide Variants (SNVs) and Indels in 47 genes, complemented by two amplicon sequencing reactions to cover GC-rich regions in SRSF2 and ASXL1. For the cytopenic cohort, we used our CH panel V4 (described in detail in Biezuner, T. et al., NAR Genom Bioinform, 2022). Both panels were designed to ensure capture uniformity and specificity. Each DNA sample was sequenced twice with a minimum depth of 1,000,000 paired-end reads on an Illumina Novaseq 6000 machine.
Project description:The role of the cotyledonary haustorium (CH) in the mobilization of nutrient reserves in the endosperm of species of the palm family Arecaceae is a moot question. To shed light on this matter, we present here an analysis of the quantitative proteome changes associated with four developmental stages of CH and three of endosperm during germination. Together, a total of 1965 proteins were identified, being 1538 in the CH and 960 in the endosperm. Both in the CH and endosperm proteomes, we observed an increase in the diversity of hydrolases as the CH and endosperm develops. Qualitative proteomics analysis of four CH developmental stages indicated that each stage is populated by a unique set of proteins and the quantitative analysis data showed an increase in the relative abundance of hydrolases, particularly mannan degrading enzymes, as development progresses. These results add weight to the hypothesis that the CH in the seeds of E. oleracea acts both as a conduit of carbon and nitrogen sources generated by the hydrolysis of the reserves in the endosperm and as a source of hydrolases that will contribute to the mobilization of these reserves.
Project description:Identifying the differentially expressed proteins of Riemerella anatipestifer CH-1 and CH-1_zntR under TSB condition through proteomic analysis
Project description:Congenital hydrocephalus (CH), occurring in approximately 1/1000 live births, represents an important clinical challenge due to the limited knowledge of underlying molecular mechanisms. The discovery of novel CH-genes is thus essential to shed light on the intricate processes responsible for ventricular dilatation in CH Here we identify FLVCR1 (Feline Leukemia Virus Subgroup C Receptor 1) as a novel gene responsible for a severe form of CH in humans and mice. Mechanistically, our data reveal that the heme exporter FLVCR1a interacts with IP3R3-VDAC, a complex located on mitochondrial-associated membranes (MAMs) that controls mitochondrial calcium handling. Loss of Flvcr1 in mouse neural stem cells (NSCs) affects mitochondrial calcium levels and energy metabolism, leading to defective cortical neurogenesis and brain ventricle enlargement. These data point to defective NSC calcium handling and metabolic activity as one of the pathogenetic mechanisms driving CH.
Project description:The aim of this experiment was to investigate the dysregulation of gene expression in whole E12.5 embryos containing a gene trap (CH) or point mutation (H275R) within the Klf3 gene Affymetrix microarrays were performed on RNA from wildtype, Klf3 H275R/H275R, Klf3 H275R/+, Klf3 CH homozygous and Klf3 CH heterozygous E12.5 embryos Four wildtype replicates, three Klf3 H275R/H275R replicates, four Klf3 H275R/+ replicates, four Klf3 CH homozygous replicates and two Klf3 CH heterozygous replicates of whole E12.5 embryos, litter-matched where possible.
Project description:Clonal hematopoiesis (CH) in inherited bone marrow failure (BMF) is disease-specific but has been poorly characterized in telomere biology disorders (TBD).We studied the architecture, trajectories, and impact of CH in a cohort of 207 TBD patients and assessed the clinical relevance of molecular signatures linked to telomere dysfunction. Most patients (92%) had known germline mutations in TBD genes. CH was rare in asymptomatic but present in 46% of symptomatic patients, recurrently in PPM1D, POT1, TERT promoter (TERTp), and U2AF1. CH frequency increased with age and was significantly higher than in age- matched controls. CH in PPM1D/TERTp was enriched in TERT patients while CH in POT1 was enriched in TINF2 patients. CH in myelodysplastic syndromes (MDS)-related genes, most commonly splicing factors, was enriched in TERT/TERC patients. CH in TERTp, TP53 ̧ and MDS- related genes associated with poorer survival. Chromosome 1q (Chr1q) gain, and splicing factor gene (dominated by U2AF1S34/Q157R) or TP53 mutations increased the risk of MDS/acute myeloid leukemia (AML) development, regardless of allele burden. Trajectories with successive acquisition of MDS-related CH driven by U2AF1S34/Q157R were maladaptive, while adaptive CH involved branched POT1/PPM1D/TERTp trajectories. U2AF1S34/Q157R compensated aberrant TP53 and interferon-γ pathway activation that contribute to hematopoietic stem cell exhaustion in TBD.
Project description:Transcriptional profiling of rat liver comparing male rats with congenital hypothyrodism (CH) vs intact at adulhood. Here we studied how CH influences liver gene expression program in adulthood. Thyroid hormones are required for normal growth and development in mammals. Congenital-neonatal hypothyroidism (CH) has a profound impact on physiology but its specific influence in liver is less understood. Here we studied how CH influences liver gene expression program in adulthood. Pregnant rats were given anti-thyroid drug methimazole (MMI) from GD12 until PND30 to induce CH in male offspring. Growth defects due to CH were evident as a reduction in body weight and tail length from the second week of life. Once the MMI treatment was discontinued, feed efficiency increased in CH and this was accompanied by significant catch-up growth. On PND80, significant reduction in body mass, tail length, and circulating IGF-I remained in CH rats. On the other hand, mRNA levels of known GH targeted genes were significantly up-regulated. Serum levels of thyroid hormones, cholesterol, and triglycerides showed no significant differences. In contrast, CH rats showed significant changes in expression for hepatic genes involved in lipid metabolism with an increased transcription of PPAR and reduced expression of genes involved in fatty acids and cholesterol uptake, cellular sterol efflux, triglycerides assembly, bile acid synthesis, and lipogenesis. These changes were associated with a decrease of intrahepatic lipids. Finally, CH rats responded to hypothyroidism onset in adulthood with a reduction of serum fatty acids and hepatic cholesteryl esters, and to T3 replacement with enhanced activation of lipogenic transcriptional program. In summary, we provided in vivo evidence that neonatal hypothyroidism causes long-lasting effects on hepatic transcriptional program and tissue sensitivity to hormone treatment. This highlights the critical role that a euthyroid state during development plays on normal liver physiology in adulthood. Two conditions CH vs INTACT male rats. Biological replicates: Four independent hybridizations: 4 controls (age-matched intact rats) vs 4 CH (male rats with congenital hypothyroidism) on postnatal day 80 for a total of four arrays. One replicate per array.
Project description:Chronic hypoxia (CH) produces changes not fully understood in morphology and function of the carotid body (CB). To characterize the effect of CH, primary rat CB cells were exposed to 7 days of CH, total RNA was extracted, cDNA-32P synthesized and hybridized with 1185 genes printed on a nylon membrane. Out of 324 differentially expressed genes, 184 were up-regulated and 140 were down-regulated. Since data analyses showed that nitric oxide synthases (NOS) and endothelin-1 (ET-1) pathways were enriched, we studied the effect of CH at protein levels of NOS isoforms and ET-1 receptors. CH induced an increase in all NOS and in ET-1 receptor B (ETB). Combining CH and SNAP, iNOS and ETB were significantly up-regulated, whereas the ET-1 receptor A (ETA) was down-regulated, while Tezosentan up-regulated iNOS and ETA and L-NAME induced up-regulation of all NOS. These results described the changes of CH on the CB gene expression profile, affecting a possible interaction in between NOS and ET-1 receptors, as part of the adaptive CB response to CH.
Project description:Somatic mutations acquired by hematopoietic stem cells (HSCs) are commonly found over the course of a lifespan. Some of these clones will outgrow through a process known as clonal hematopoiesis (CH) and produce mutated immune cell progeny, which will shape host immunity. Individuals with CH are asymptomatic but have increased risk of developing leukemia, cardiovascular and pulmonary inflammatory diseases, and severe infections. Despite the key role that neutrophils play in the development of such diseases, little is known about how these prevalent somatic mutations affect neutrophil functionality. In this work, we describe how mutations in TET2, one of the most common mutated genes in individuals with CH, affect human neutrophil biology.
Project description:Clonal hematopoiesis (CH) is a common premalignant state in the blood and confers an increased risk of blood cancers and all-cause mortality. Identification of therapeutic targets in CH has been hindered by the lack of an ex vivo platform amenable for studying primary hematopoietic stem and progenitor cells (HSPCs) with and without CH-associated mutations. Here, we utilize an ex vivo co-culture system of primary murine HSPCs with bone marrow endothelial cells to perform CRISPR/Cas9 screens and identify vulnerabilities specific to mutant versus wild-type HSPCs. Our data reveal that loss of the histone demethylase family members KDM3B and JMJD1C specifically reduces the fitness of IDH2- and TET2- mutant HSPCs, but not wild-type HSPCs, including in TET2-mutant human HSPCs and Tet2-mutant murine leukemia cells with cooperating disease alleles. KDM3B loss in mutant cells leads to decreased expression of critical cytokine receptors including MPL, rendering mutant HSPCs preferentially susceptible to inhibition of downstream JAK2 signaling. Our study provides a scalable platform to identify genetic dependencies in mutant HSPCs and reveals an atlas of dependencies in normal and CH-mutant HSPCs. This study nominates an epigenetic regulator and an epigenetically regulated receptor signaling pathway as genotype-specific therapeutic targets in a subset of CH and myeloid malignancies.