Rationale: While modulation of the serotonin transporter (5HTT) has shown to be a risk factor for pulmonary arterial hypertension for almost 40 years, there is a lack of in vivo data about the broad molecular effects of pulmonary inhibition of 5HTT. Previous studies have suggested effects on inflammation, proliferation, and vasoconstriction. The goal of this study was to determine which of these were supported by alterations in gene expression in serotonin transporter knockout mice. Methods: Eight week old normoxic mice with a 5-HTT knock-out (5HTT-/-) and their heterozygote(5HTT+/-) or wild-type(5HTT+/+) littermates had right ventricular systolic pressure(RVSP) assessed, lungs collected for RNA, pooled, and used in duplicate in Affymetrix array analysis. Representative genes were confirmed by quantitative RT-PCR and western blot. Results: RVSP was normal in all groups. Only 124 genes were reliably changed between 5HTT-/- and 5HTT+/+ mice. More than half of these were either involved in inflammatory response or muscle function and organization; in addition, some matrix, heme oxygenase, developmental, and energy metabolism genes showed altered expression. Quantitative RT-PCR for examples from each major group confirmed changes seen by array, with an intermediate level in 5HTT+/- mice. Conclusions: These results for the first time show the in vivo effects of 5HTT knockout in lungs, and show that many of the downstream mechanisms suggested by cell culture and ex vivo experiments are also operational in vivo. This suggests that the effect of 5HTT on pulmonary vascular function arises from its impact on several systems, including vasoreactivity, proliferation, and immune function.
Gene expression in lungs of mice lacking the 5-hydroxytryptamine transporter gene.
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View SamplesLysine methylation of histones is associated with both transcriptionally active chromatin and with silent chromatin, depending on what residue is modified. Histone methyltransferases and demethylases ensure that histone methylations are dynamic and can vary depending on cell cycle- or developmental stage. KDM4A demethylates H3K36me3, a modification enriched in the 3end of active genes. The genomic targets and the role of KDM4 proteins in development remain largely unknown.
Gene regulation by the lysine demethylase KDM4A in Drosophila.
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View SamplesMice expressing a doxycycline-inducible dominant negative BMPR2 transgene expressed only in smooth muscle are activated for one or eight weeks, and compared to transactivator-only mice also fed doxycycline. All mice are 12 weeks of old at sacrifice.
Molecular effects of loss of BMPR2 signaling in smooth muscle in a transgenic mouse model of PAH.
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View SamplesThe Brakeless protein performs many important functions during Drosophila development, but how it controls gene expression is not understood. We previously showed that Brakeless can function as a transcriptional co-repressor. Here, we report transcriptional profiling of brakeless mutant embryos to identify additional target genes.
The Brakeless co-regulator can directly activate and repress transcription in early Drosophila embryos.
Specimen part
View SamplesFamilial 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 SamplesCilia are ubiquitous cell surface projections that modulate various sensory- and motility based processes and are implicated in a growing number of multi-organ genetic disorders termed ciliopathies. As new components required for cilium biogenesis and function remain unidentified, we sought to further define and validate the transcriptional targets of the ciliogenic C. elegans RFX transcription factor DAF-19. To this end, transcriptional profiling of daf-19 mutants (which do not form cilia) and wild-type animals was performed using selectively staged embryos where ciliogenesis occurs in most ciliated sensory neurons
Transcriptional profiling of C. elegans DAF-19 uncovers a ciliary base-associated protein and a CDK/CCRK/LF2p-related kinase required for intraflagellar transport.
Specimen part
View SamplesPulmonary arterial hypertension (PAH) is thought to be driven by dysfunction of pulmonary vascular microendothelial cells (PMVEC). Most hereditary PAH is associated with BMPR2 mutations.
Physiologic and molecular consequences of endothelial Bmpr2 mutation.
Specimen part
View SamplesNeuregulin (NRG) signaling through the receptor tyrosine kinase, ERBB3, is required for embryonic development, and dysregulated signaling has been associated with cancer progression. Here, we show that NRG1/ERBB3 signaling inhibits melanocyte (MC) maturation and promotes undifferentiated, migratory and proliferative cellular characteristics. Embryonic analyses demonstrated that initial MC specification and distribution were not dependent on ERBB3 signaling. However NRG1/ERBB3 signaling was both necessary and sufficient to inhibit differentiation of later stages of MC development in culture. Analysis of tissue arrays of human melanoma samples suggests that ERBB3 signaling may also contribute to metastatic progression of melanoma as ERBB3 was phosphorylated in primary tumors compared with nevi or metastatic lesions. Neuregulin 1-treated MCs demonstrated increased proliferation and invasion and altered morphology concomitant with decreased levels of differentiation genes, increased levels of proliferation genes and altered levels of melanoma progression and metastases genes. ERBB3 activation in primary melanomas suggests that NRG1/ERBB3 signaling may contribute to the progression of melanoma from benign nevi to malignancies. We propose that targeting ERBB3 activation and downstream genes identified in this study may provide novel therapeutic interventions for malignant melanoma.
NRG1 / ERBB3 signaling in melanocyte development and melanoma: inhibition of differentiation and promotion of proliferation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
WNT5A inhibits metastasis and alters splicing of Cd44 in breast cancer cells.
Cell line
View SamplesA highly metastatic breast cancer cell line, 4T1, was used to generate stable Wnt5a expressing and vector only control cells. Cells were generated using lentivirus infection and selection with blasticidin. Expression of Wnt5a was confirmed using western blot. Cell behaviour was characterized. Wnt5a expressing cells exhibited reduced migration in a transwell assay and reduced metastasis in a tail vein injection assay. Growth was not significantly affected.
WNT5A inhibits metastasis and alters splicing of Cd44 in breast cancer cells.
Cell line
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