Project description:Adult and fetal megakaryocytes are morphologically different. These differences contribute to neonatal thrombocytopenia in premature neonates and in neonates after infection and also contribute to poor megakaryocytes engraftment after umbilical cord blood transplant. We found that Dyrk1a kinase inhibition shift the fetal megakaryocytes phenotype toward adult phenotype. This effect is mediated by MKL1 the master regulator of megakaryocytes morphogenesis. To identify differences between adult and fetal megakaryocytes we performed RNA seq of adult derived megakaryocytes and fetal derived megakaryocytes treated and untreated with Dyrk inhibitors. Through this approach we identified cohorts of genes co-regulated in adult megakaryocytes and fetal megakaryocytes treated with the dyrk inhibitors. More importantly, we found that the dyrk inhibition in fetal megakaryocytes leads to upregulation of a significant number of MKL1 target genes.
Project description:Adult and fetal megakaryocytes are morphologically different. These differences contribute to neonatal thrombocytopenia in premature neonates and in neonates after infection and also contribute to poor megakaryocytes engrafment after umbilical cord blood transplant. We found that Dyrk1a kinase inhibition shift the fetal megakaryocytes phenotype toward adult phenotype. This effect is mediated by MKL1 the master regulator of megakaryocytes morphogenesis. To identify deferences between adult and fetal megakaryocytes we performed RNA seq of adult derived megakaryocytes and fetal derived megakaryocytes treated and untreated with Dyrk inhibitors. Through this approach we identified cohorts of genes co-regulated in adult megakaryocytes and fetal megakaryoctes treated with the dyrk inhibitors. More importantly, we found that the dyrk inhibition in fetal megakaryocytes leads to upregulation of a significant number of MKL1 target genes.
Project description:Angiogenesis is a highly regulated process essential for organ development and maintenance, and its deregulation contributes to inflammation, cardiac disorders and cancer. The Ca2+/Nuclear Factor of Activated T-cells (NFAT) signaling pathway is central to endothelial cell angiogenic responses, and it is activated by stimuli like the vascular endothelial growth factor A (VEGF). NFAT phosphorylation by dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs) is thought to be an inactivating event. Contrary to expectations, we show that the DYRK family member DYRK1A positively regulates VEGF-dependent NFAT transcriptional responses in primary endothelial cells. DYRK1A silencing reduces intracellular Ca2+ influx in response to VEGF, which dampens NFAT activation. The effect is exerted at the level of VEGFR2 accumulation leading to impairment in PLCg1 activation. Notably, Dyrk1a heterozygous mice show defects in developmental retinal vascularization. Our data establish a regulatory circuit, DYRK1A/ Ca2+/NFAT, to fine-tune endothelial cell proliferation and angiogenesis.
Project description:We used expression profiling, SNP arrays, and mutational profiling to investigate a well-characterized cohort of MPN patients. MPN patients with homozygous JAK2V617F mutations were characterized by a distinctive transcriptional profile. Notably, a transcriptional signature consistent with activated JAK2 signaling is seen in all MPN patients regardless of clinical phenotype or mutational status. In addition, the activated JAK2 signature was present in patients with somatic CALR mutations. Conversely, we identified a gene expression signature of CALR mutations; this signature was significantly enriched in JAK2-mutant MPN patients consistent with a shared mechanism of transformation by JAK2 and CALR mutations. We also identified a transcriptional signature of TET2 mutations in MPN patent samples. Our data indicate that MPN patients, regardless of diagnosis or JAK mutational status are characterized by a distinct gene expression signature with upregulation of JAK-STAT target genes, demonstrating the central importance of the JAK-STAT pathway in MPN pathogenesis. [MPN patients] We have performed microarray gene expression analysis in 93 patients with MPNs (28 PV, 47 ET, 18 MF) and 11 age-matched normal donors.
Project description:DYRK1A is a protein kinase with several roles in brain development. This kinase is involved in two intellectual disability syndromes: Down syndrome and DYRK1A haploinsufficiency syndrome. The Dyrk1a+/- mouse is a model for DYRK1A haploinsufficiency syndrome. We used microarray to evaluate the impact of DYRK1A haploinsufficiency in the development of the cerebral cortex.
Project description:Transcription profiling of transgenic down syndrome mouse model to show the role of DYRK1A gene. The molecular mechanisms that lead to the cognitive defects characteristic of Down syndrome (DS), the most frequent cause of mental retardation, have remained elusive. Here we use a transgenic DS mouse model to show that DYRK1A gene dosage imbalance deregulates chromosomal clusters of genes located near neuron-restrictive silencer factor (REST/NRSF) binding sites. We found that DYRK1A binds the SWI/SNF-complex known to interact with REST/NRSF. Mutation of a REST/NRSF binding site in the promoter of the REST/NRSF target gene L1cam modifies the transcriptional effect of Dyrk1Adosage imbalance on L1cam. DyrkA dosage imbalance perturbs Rest/Nrsf levels with decreased Rest/Nrsf expression in embryonic neurons and increased expression in adult neurons. We identified a coordinated deregulation of multiple genes that are responsible for the cellular phenotypic traits present in DS such as dendritic growth impairment and microcephaly during prenatal cortex development. Dyrk1a overexpression in primary mouse cortical neurons reduced the neuritic complexity. In the postnatal hippocampus, DYRK1A overexpression suppresses a form of synaptic plasticity that may be sufficient to cause DS cognitive defects. We propose that DYRK1A overexpression-related neuronal gene deregulation generates the brain phenotypic changes that characterize DS, with an accessory role for the gene dosage imbalance of other chromosome 21 genes. Transgenic embrionic brain regions versus wild type mice were analysed. The log2 values represent Cy5/Cy3 ratio (transgenic Cy5/wild type Cy3). Each array was scanned under a green laser (543 nm for Cy3 labeling) or a red laser (633 nm for Cy5 labeling) using a ScanArray Lite scanning confocal fuorescent scanner with 10 u resolution (laser power: 85% for Cy5 and 90% for Cy3, gain: 75% for Cy5 and 70% for Cy3). Scanned output files were analyzed using the GenePix Pro 3.0 software. Each spot was defined by automatic positioning of a grid of circles over the image. The average and median pixel intensity ratios calculated from both channels and the local background of each spot were determined. Local background corrected intensity ratios was determined for each spot. The background-corrected expression data were filtered for flagged spots and weak signal. Normalization was performed by the global Lowess method. Studentâs t-test was applied to determine the p value.