Project description:In this study we used microarrays to examine relative genes expression within the aorta of ApoE-/- infused with angiotensin II in relation to aneurysm formation. Infusion of angiotensin II induces aortic dilatation particularly of the suprarenal aorta in ApoE-/- mice. Based on studies carried out in our and other laboratories the response to angiotensin II is variable, with some mice developing large aneurysms but other animals appearing resistant to aneurysm formation with aortic diameters similar to that of saline controls. We compared RNA expression from whole aortas of 17 week old male ApoE-/- mice exposed to angiotensin II (1.44 µg/kg/min) for 4 weeks where there was clear evidence of aortic aneurysm formation (n=5) with that of mice failing to develop aneurysms (n=7) and those exposed to saline infusion (n=6). AAA was defined as diameter of suprarenal aorta greated than 1.5mm measured on photographs of aortas at necroscopy. Keywords: Disease state analysis 18 samples analysed, AAA (n=5), no AAA (n=7), saline (n=6). AAA - abdominal aortic aneurysm
Project description:In this study we used microarrays to examine relative genes expression within the aorta of ApoE-/- infused with angiotensin II in relation to aneurysm formation. Infusion of angiotensin II induces aortic dilatation particularly of the suprarenal aorta in ApoE-/- mice. Based on studies carried out in our and other laboratories the response to angiotensin II is variable, with some mice developing large aneurysms but other animals appearing resistant to aneurysm formation with aortic diameters similar to that of saline controls. We compared RNA expression from whole aortas of 17 week old male ApoE-/- mice exposed to angiotensin II (1.44 µg/kg/min) for 4 weeks where there was clear evidence of aortic aneurysm formation (n=5) with that of mice failing to develop aneurysms (n=7) and those exposed to saline infusion (n=6). AAA was defined as diameter of suprarenal aorta greated than 1.5mm measured on photographs of aortas at necroscopy. Keywords: Disease state analysis
Project description:Transcriptional profiling of suprarenal aorta from ApoE-/- mice (12-14 weeks old, C57BL/6J background) treated by subcutaneous pump with angiotensin II or saline for 7d, 14d and 28d. Includes Ang II-treated samples at 7d found to have dissected aneurysms. Goal was to examine gene expression in developing AAA in this model over time. Experiment Overall Design: Two condition experiment, one suprarenal aorta per array. Saline vs. angiotensin II at 3 time points, with inclusion of 3 Ang II-treated dissected. Total 35 arrays: 6 saline 7d, 6 saline 14d, 5 saline 28d, 4 Ang II 7d, 5 Ang II 14d, 6 Ang II 28d, 3 Ang II-dissected 7d.
Project description:Transcriptional profiling of suprarenal aorta from ApoE-/- mice (12-14 weeks old, C57BL/6J background) treated by subcutaneous pump with angiotensin II or saline for 7d, 14d and 28d. Includes Ang II-treated samples at 7d found to have dissected aneurysms. Goal was to examine gene expression in developing AAA in this model over time.
Project description:Aortic tissues of developing and established aneurysms produced by angiotensin II (AngII) infusion were examined in Apoe-/- and Ldlr-/- mice. Aortas were also acquired from wildtype C57BL/6J mice following intraluminal elastase incubation. Aortas were dissected free and separated into eight anatomical segments for proteomics in comparison to their appropriate controls. In addition, proteomics was performed on human infrarenal aortic aneurysm tissues as well as aortic tissue collected from age-matched controls.
Project description:Vascular smooth muscle cells (vSMC) exert a critical role in sensing and maintaining vascular integrity. These cells abundantly express the low-density lipoprotein receptor-related protein 1 (LRP1), a large endocytic and signaling receptor that recognizes numerous ligands including ApoE-rich lipoproteins, proteases, and protease-inhibitor complexes. We observed the spontaneous formation of aneurysms in the superior mesenteric artery (SMA) of both male and female mice in which LRP1 was genetically deleted in v SMC (smLRP1-/- mice). Quantitative proteomics revealed elevated abundance of several proteins in smLRP1-/- mice that are known to be induced by angiotensin II (AngII)-mediated signaling, suggesting that this pathway is dysregulated. Administration of losartan, an AngII type I receptor antagonist, or an angiotensinogen antisense oligonucleotide to reduce plasma angiotensinogen concentrations restored the normal SMA phenotype in smLRP1-/- mice and prevented aneurysm formation. Additionally, employing a vascular injury model, we noted excessive vascular remodeling and neointima formation in smLRP1-/- mice that was restored by losartan administration. Together, these findings reveal that LRP1 regulates vascular integrity and remodeling of the SMA by attenuating excessive AngII-mediated signaling.
Project description:Myocardin (Myocd) plays an important role in the maintenance and homeostasis of the vasculature. The loss of Myocd results in vascular smooth muscle cell (VSMC) phenotypic transition and thoracic aortic aneurysms and dissections (TAADs) by downregulating VSMC contractile genes. VSMC phenotypic transition plays a key role in the formation of abdominal aortic aneurysms and dissections (AAADs). However, little is known about the role of Myocd in AAAD. The effect of Myocd on AAA formation was proven in an angiotensin II (Ang II)-induced AAD model. Myocd overexpression or knockdown was achieved by the injection of the corresponding adeno-associated virus serotype 9 (AAV9) through the tail vein. The knockdown of Myocd in C57BL/6J mice treated with angiotensin II promoted the formation of AAAD, as demonstrated by increases in the maximal aortic diameter, vascular inflammation and elastin degradation relative to the control group, while Myocd-overexpressing ApoE-/- mice infused with Ang II were less likely to develop AAAD. Mechanistically, Myocd deficiency significantly repressed VSMC marker gene expression. In addition, qPCR results showed that Myocd knockdown promoted the expression of lncRNAs, which showed increased levels in human AAD tissues. Our results indicated the pivotal role of Myocd in protecting against AAAD formation.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.