Project description:The aim of the present study was to compare, on a statistical basis, the performance of different microarray platforms to detect differences in gene expression in a realistic and challenging biological setting. Gene expression profiles in the hippocampus of five wild-type and five transgenic δC-doublecortin-like kinase mice were evaluated with five microarray platforms: Applied Biosystems, Affymetrix, Agilent, Illumina and home-spotted oligonucleotide arrays. We observed considerable overlap between the different platforms, the overlap being better detectable with significance level-based ranking than with a p-value based cut-off. Confirming the qualitative agreement between platforms, Pathway analysis consistently demonstrated aberrances in GABA-ergic signalling in the transgenic mice, even though pathways were represented by only partially overlapping genes on the different platforms. Keywords: microarray platform comparison
Project description:Expression of VP16-CREB, a constitutively active form of CREB, in hippocampal neurons of the CA1 region lowers the threshold for eliciting the late, persistent phase of long-term potentiation (L-LTP) in the Schaffer collateral pathway. This VP16-CREB-mediated L-LTP differs from the conventional late phase of LTP in not being dependent on new transcription. This finding suggests that in the transgenic mice the mRNA transcript(s) encoding the protein(s) necessary for this form of L-LTP might already be present in CA1 neurons in the basal condition. We used high-density oligonucleotide arrays to identify the mRNAs differentially expressed in the hippocampus of transgenic and wild-type mice. Experiment Overall Design: To identify the specific gene whose induction in hippocampal neurons correlated with the facilitated L-LTP phenotype, we harvested hippocampal mRNA at time points assessed in our physiological study and carried out a gene expression analysis using oligonucleotide microarrays. To obtain a sufficient quantity of poly(A)-RNA and reduce the effect of the biological variability of the sample, hippocampi from 6 to 10 mice matched for genotype and time of induction were pooled together in each sample. The final data set included genechips for animals on dox (gene Off) and for animals that were one, two, and five weeks after removal of dox (gene On). We also included samples from wild-type mice maintained under identical conditions and from transgenic mice that expressed VP16-CREB for three weeks before turning the transgene off again for two weeks with dox (Rev, gene Off). Since the isolation of mRNA from the whole hippocampus favors genes that are more broadly over-expressed in the hippocampus of transgenic mice and, therefore, may lead to an underestimation of the total complement of genes showing an altered expression in specific hippocampal subregions, we extended our comparison between transgenic and wild-type expression profiles using microdissected CA1 regions. We obtained two samples corresponding to VP16-CREB mice three weeks after induction and one sample corresponding to wild-type mice kept in the same conditions. Experiment Overall Design: These twelve mRNA samples were analyzed using Affymetrix genechips MG-U74v2 setA.
Project description:Transcriptome analysis of hippocampal RNA samples from wild-type, 5xFAD, 5xFAD;eIF2α+/S51A and eIF2α+/S51A mice Our transcriptome analyses showed clear transcriptional alterations in hippocampi of 5xFAD compared to wild type mice that were not corrected by the eIF2αS51A allele. Hemizygous 5xFAD mice, which were on a genetic background of B6/SJL, were crossed with eIF2α+/S51A mice (C57BL/6J background), to generate the offspring that was analyzed in the microarray. Hippocampal samples of 12 mice (4 groups: wild-type, 5xFAD, 5xFAD;eIF2α+/S51A and eIF2α+/S51A) were processed using Affymetrix Mouse Exon 1.0 ST platform. Array data was processed by Affymetrix Exon Array Computational Tool. No technical replicates were performed.
Project description:To explore effect of variants (G82R and L85P ) in SLC1A2 (encoding GLT-1), we profiled hippocampal tissues from wild-type and transgenic (TG) mice possessing G82R/L85P variant mice by RNA sequencing (RNA-seq).
Project description:We have previously found that overexpression of CHF1/Hey2 in the myocardium prevents the development of phenylephrine-induced hypertrophy. To determine the role of CHF1/Hey2 in pressure overload hypertrophy, we performed ascending aortic banding on wild type and transgenic mice overexpressing CHF1/Hey2 in the myocardium. We found that both wild type and transgenic mice developed increased ventricular weight to body weight ratios one week after aortic banding. Wild type mice also developed decreased fractional shortening after one week when compared to preoperative echocardiograms and sham operated controls. Transgenic mice, in comparison, demonstrated preserved fractional shortening. Histological examination of explanted heart tissue demonstrated extensive fibrosis in wild type hearts, but minimal fibrosis in transgenic hearts. TUNEL staining demonstrated increased apoptosis in the wild type hearts but not in the transgenic hearts. Exposure of cultured neonatal myocytes from wild type and transgenic animals to hydrogen peroxide, a potent inducer of apoptosis, demonstrated increased apoptosis in the wild type cells. Gene Set Analysis of microarray data from wild type and transgenic hearts one week after banding revealed suppression and activation of multiple pathways involving apoptosis, cell signaling and biosynthesis. These findings demonstrate that CHF1/Hey2 promotes physiological over pathological hypertrophy in pressure overload through suppression of apoptosis and global regulation of multiple transcriptional pathways.
Project description:We aim to investigate the role of renal Sirt1 on albuminuria. To further development of our gene expression approach to biodosimetry, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish between wild type(C57BL/6J) mice treated with streptozotocin (WT+STZ) and Sirt1-overexpressing transgenic mice treated with streptozotocin (TG+STZ) mice. To elucidate the molecular mechanisms underlying the amelioration of albuminuria by our TG (Sirt1-overexpressing transgenic) mice, we performed DNA microarray analysis using micro-dissected glomerular regions to examine the differences in gene expression between WT+STZ and TG+STZ mice.
Project description:Atherosclerosis is a chronic inflammatory disease with high morbidity and mortality rates worldwide. Doublecortin-like kinase 1 (DCLK1), a microtubule-associated protein kinase, is involved in neurogenesis and human cancers. However, the role of DCLK1 in atherosclerosis remains undefined. In this study, we identified up-regulated DCLK1 in macrophages in atherosclerotic lesions of ApoE-/- mice fed an HFD and determined that macrophage-specific DCLK1 deletion attenuates atherosclerosis by reducing inflammation in mice. Mechanistically, RNA sequencing analysis indicated that DCLK1 mediates oxLDL-induced inflammation via NF-κB signaling pathway in primary macrophages. Co-immunoprecipitation followed by LC-MS/MS analysis identified IKKβ as a binding protein of DCLK1. We confirmed that DCLK1 directly interacts with IKKβ and phosphorylates IKKβ at S177/181, thereby facilitating subsequent NF-κB activation and inflammatory gene expression in macrophages. Finally, a pharmacological inhibitor of DCLK1 prevents atherosclerotic progression and inflammation both in vitro and in vivo. Our findings demonstrated that macrophage DCLK1 promotes inflammatory atherosclerosis by binding to IKKβ and activating IKKβ/NF-κB. This study reports DCLK1 as a new IKKβ regulator in inflammation and a potential therapeutic target for inflammatory atherosclerosis.