Familial pulmonary arterial hypertension (fPAH) is associated with mutations in BMPR2. Many of these mutations occur in the BMPR2 tail domain, leaving the SMAD functions intact. In order to determine the in vivo consequences of BMPR2 tail domain mutation, we created a smooth-muscle specific doxycycline inducible BMPR2 mutation with an arginine to termination mutation at amino acid 899. When these SM22-rtTA x TetO7-BMPR2R899X mice had transgene induced for 9 weeks, starting at 4 weeks of age, they universally developed pulmonary vascular pruning as assessed by fluorescent microangiography. Approximately half the time the induced animals developed elevated right ventricular systolic pressures (RVSP), associated with extensive pruning, muscularization of small pulmonary vessels, and development of large structural pulmonary vascular changes. These lesions included large numbers of macrophages and T-cells in their adventitial compartment, as well as CD133 positive cells in the lumen. Small vessels filled with CD45 positive and sometimes CD3 positive cells were a common feature in all SM22-rtTA x TetO7-BMPR2R899X mice. Gene array experiments show changes in stress response, muscle organization and function, proliferation and apoptosis, and developmental pathways before RVSP increases. Our results show that the primary phenotypic result of BMPR2 tail domain mutation in smooth muscle is pulmonary vascular pruning leading to elevated RVSP, associated with early dysregulation in multiple pathways with clear relevance to PAH. This model should be useful to the research community in examining early molecular and physical events in the development of PAH, and as a platform to validate potential treatments.
Mice expressing BMPR2R899X transgene in smooth muscle develop pulmonary vascular lesions.
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View SamplesTo gain insight into the changes in gene expression pattern upon Ebola infection, CD45+/+ (100% protein level) and CD45+/- (62% protein level) mice were challenged with mouse adapted Ebola virus. At time-points day 0, 1, 3, 5, 7, 9, 11 and 13, spleen tissue was harvested and splenocytes isolated. Total RNA was isolated for mRNA expression analysis. The mouse genome 430 2.0 array (Affymetrix, Inc.), which consists of over 39,000 genes in a single array, was used. Based on gene expression patterns, the variable genes were grouped into sixteen clusters. Each cluster contained genes associated with cellular immune processes, signaling, cell-cycle, complement coagulation cascade, biosynthesis/metabolism, ubiquitous genes involved in several cascades, and genes of unknown function. Interestingly, gene expression in clusters 2 and 3 were significantly downregulated by day 1 following EBOV challenge in CD45100% mice. In contrast, at day 1 following EBOV infection, the CD45 62% mice maintained gene expression patterns similar to day 0. The differences in gene expression patterns between the CD45 100% and CD45 62% splenocytes were less apparent at day 3 following infection and by days 5 and 7 they became very similar. At day 9, when wild-type mice had succumbed to the disease, the pattern in CD45 62% mice remained similar to the day 7 patterns of CD45 100% and CD45 62% mice. The pattern at days 11 and 13 in the CD45 62% mice had returned to that of day 0 CD45 100% or CD45 62% mice. These results suggested that in CD45 100% mice, subversion of the cell transcriptional machinery during the early stages of EBOV infection (day 1) might represent a major factor leading to death of the mice. In CD45 62% mice, early control of gene regulation likely provided the appropriate antiviral responses leading to regulated inflammation, immune co-stimulation, and survival.
Reduced levels of protein tyrosine phosphatase CD45 protect mice from the lethal effects of Ebola virus infection.
Specimen part
View SamplesBMPR2 mutation causes pulmonary arterial hypertension (PAH); ACE2 treatment can resolve established BMPR2-mediated PAH. The purpose of this study was to uncover the molecular mechanism behind this.
Cytoskeletal defects in Bmpr2-associated pulmonary arterial hypertension.
Sex, Specimen part, Treatment
View SamplesWe investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion.
mTOR complex 1 plays critical roles in hematopoiesis and Pten-loss-evoked leukemogenesis.
Specimen part
View SamplesWe report a Jak2V617F knock-in mouse myeloproliferative neoplasm (MPN) model resembling human polycythemia vera (PV). The MPN is serially transplantable and we demonstrate that the hematopoietic stem cell (HSC) compartment has the unique capacity for disease initiation but does not have a selective competitive advantage over wild type HSCs. In contrast, myeloid progenitor populations are expanded and skewed towards the erythroid lineage, but cannot transplant the disease. Treatment with a JAK2 kinase inhibitor ameliorated the MPN phenotype, but did not eliminate the disease-initiating population. These findings provide insights into the consequences of JAK2 activation on HSC differentiation and function and have the potential to inform therapeutic approaches to JAK2V617F positive MPN.
Physiological Jak2V617F expression causes a lethal myeloproliferative neoplasm with differential effects on hematopoietic stem and progenitor cells.
Specimen part
View SamplesParticulate Matter Triggers Carotid Body Dysfunction, Respiratory Dysynchrony and Cardiac Arrhythmias in Mice with Cardiac Failure
Particulate matter induces cardiac arrhythmias via dysregulation of carotid body sensitivity and cardiac sodium channels.
Age, Specimen part
View SamplesThe goal of this study was to identify genes that are differentially expressed after genetic deletion of both alleles of the Cyp26a1 gene in murine embryonic stem cells. Cyp26a1 codes for the CYP26A1 enzyme which metabolizes RA to polar RA metabolites, such as 4-oxo-RA and 4-OH-RA. CYP26A1-/- ES cells do not metabolize RA within 48 hours of RA treatment while in Wt ES cells, polar RA metabolites are already detectable by 8 hr. In addition, the absence of CYP26A1 enzyme increases intracellular RA levels. By gene microarray analysis, we wanted to identify genes that would be affected by the lack of the Cyp26a1 gene.
CYP26A1 knockout embryonic stem cells exhibit reduced differentiation and growth arrest in response to retinoic acid.
No sample metadata fields
View SamplesAmong the multiple mechanisms that control the intensity and duration of macrophage activation, the development of a state of refractoriness to a second stimulation in cells treated with LPS has long been recognized. Release of inhibitory cytokines and alterations in intracellular signaling pathways may be involved in the development of LPS tolerance. Although a number of molecules have been implicated, a detailed picture of the molecular changes in LPS tolerance is still missing. We have used a genome-wide gene expression analysis approach to (i) define which fraction of LPS target genes are subject to tolerance induction and (ii) identify genes that are expressed at high levels in tolerant macrophages. Our data show that in LPS tolerant macrophages the vast majority of LPS-induced gene expression is abrogated. The extent of tolerance induction varies for individual genes, and a small subset appears to be excepted. Compared to other negative control mechanisms of macrophages, e.g. IL-10-induced deactivation, LPS-tolerance inhibits a much wider range of transcriptional targets. Some previously described negative regulators of TLR-signaling (e.g. IRAK-M) were confirmed as expressed at higher levels in LPS-tolerant macrophages. In addition, we discuss other potential players in LPS tolerance identified in this group of genes.
A genome-wide analysis of LPS tolerance in macrophages.
No sample metadata fields
View SamplesPU.1 is a key transcription factor for macrophage differentiation. Novel PU.1 target genes were identified by mRNA profiling of PU.1-deficient progenitor cells (PUER) before and after PU.1 activation. We used two different types of Affymetrix DNA-microarrays (430 2.0 arrays and ST 1.0 exon arrays) to characterize the global PU.1-regulated transcriptional program underlying the early processes of macrophage differentiation.
Transcriptomic profiling identifies a PU.1 regulatory network in macrophages.
No sample metadata fields
View SamplesSTEP (striatal-enriched tyrosine phosphatase) is a brain-specific phosphatase named for its robust expression in striatum. Brains from homozygous and heterozygous STEP knockout mice and wild-type littermates were harvested, and striatum microdissected. RNA was extracted and hybridized to Affymetrix 230_2 microarray chips.
Downstream effects of striatal-enriched protein tyrosine phosphatase reduction on RNA expression in vivo and in vitro.
Sex, Specimen part, Treatment
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