Study the Role of Surfactant Protein C in Innate Lung Defense.
Persistence of LPS-induced lung inflammation in surfactant protein-C-deficient mice.
Specimen part, Disease
View SamplesPulmonary fibrosis is often triggered by an epithelial injury resulting in the formation of fibrotic lesions in the lung, which progress to impair gas exchange and ultimately cause death. Recent clinical trials using drugs that target either inflammation or a specific molecule have failed, suggesting that multiple pathways and cellular processes need to be attenuated for effective reversal of established and progressive fibrosis. Although activation of MAPK and PI3K pathways have been detected in human fibrotic lung samples, the therapeutic benefits of in vivo modulation of the MAPK and PI3K pathways in combination are unknown. Overexpression of TGFa in the lung epithelium of transgenic mice results in the formation of fibrotic lesions similar to those found in human pulmonary fibrosis, and previous work from our group shows that inhibitors of either the MAPK or PI3K pathway can alter the progression of fibrosis. In this study, we sought to determine whether simultaneous inhibition of the MAPK and PI3K signaling pathways is a more effective therapeutic strategy for established and progressive pulmonary fibrosis. Our results showed that inhibiting both pathways had additive effects compared to inhibiting either pathway alone in reducing fibrotic burden, including reducing lung weight, pleural thickness, and total collagen in the lungs of TGFa mice. This study demonstrates that inhibiting MEK and PI3K in combination abolishes proliferative gene changes associated with fibrosis and myfibroblast accumulation and thus may serve as a therapeutic option in the treatment of human fibrotic lung disease where these pathways play a role. Overall design: mRNA profiles of CCSP/TGFalpha mice treated with vehicle, ARRY, PX-866, ARRY/PX-866
Dual targeting of MEK and PI3K pathways attenuates established and progressive pulmonary fibrosis.
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View SamplesIdentifying the genes underlying quantitative trait loci (QTL) for disease has proven difficult, mainly due to the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals and test candidate genes. In addition to identifying the causative genes, defining the pathways that are affected by these QTL is of major importance as it can give us insight into the disease process and provide evidence to support candidate genes. In this study we mapped three significant and one suggestive QTL on Chromosomes (Chrs) 1, 4, 15, and 17, respectively, for increased albumin excretion (measured as albumin-to-creatinine ratio) in a cross between the MRL/MpJ and SM/J mouse inbred strains. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL. Among these were the glycan degradation, leukocyte migration, and antigen presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL, but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.
Uncovering genes and regulatory pathways related to urinary albumin excretion.
Sex, Age
View SamplesDevelopment of spider veins is caused by the remodeling of veins located in the upper dermis and promoted by risk factors such as obesity or pregnancy that chronically increase venous pressure. We have repeatedly shown that the pressure-induced increase in biomechanical wall stress is sufficient to evoke the formation of enlarged corkscrew-like superficial veins in mice. Subsequent experimental approaches revealed that interference with endothelial- and/or smooth muscle cell activation counteracts this remodeling process. Here, we investigate whether the herbal agent glycyrrhetinic acid (GA) is a suitable candidate for that purpose given its anti-proliferative as well as anti-oxidative properties.
Glycyrrhetinic Acid Antagonizes Pressure-Induced Venous Remodeling in Mice.
Specimen part, Subject
View SamplesChronic biomechanical stress elicits remodeling of the arterial wall and causes detrimental arterial stenosis and stiffening. In this context, molecular determinants controlling proliferation and stress responses of vascular smooth muscle cells (VSMCs) have been insufficiently studied. We identified the transcription factor nuclear factor of activated T-cells 5 (NFAT5) as crucial regulatory element of mechanical stress responses of VSMCs. The relevance of this observation for biomechanically induced arterial remodeling was investigated in mice upon SMC-specific knockdown of NFAT5. While blood pressure levels, vascular architecture and flow-induced collateral growth were not affected in these mice, both hypertension-mediated arterial thickening and muscularization of pulmonary arteries during pulmonary artery hypertension (PAH) were impaired. In all models, a decrease in VSMC proliferation was observed indicating that NFAT5 controls activation of VSMCs in the remodeling arterial wall. Mechanistically, mechanoactivation of VSMCs promotes nuclear translocation NFTA5c upon its phosphorylation at Y143 and dephosphorylation at S1197. As evidenced by transcriptome studies, loss of NFAT5 in mechanoactivated VSMCs impairs expression of gene products controlling cell cycle and transcription/translation. These findings identify NFAT5 as molecular determinant of VSMC responses to biomechanical stress and arterial thickening.
NFAT5 Isoform C Controls Biomechanical Stress Responses of Vascular Smooth Muscle Cells.
Treatment
View SamplesIn somatic cells elevated temperature induces activation of the heat shock transcription factor 1 (HSF1) what leads to heat shock proteins synthesis and cytoprotection. However, in the male germ cells (spermatocytes) upon HSF1 activation, caspase-3 dependent apoptosis is induced and spermatogenic cells are actively eliminated.
Impact of heat shock transcription factor 1 on global gene expression profiles in cells which induce either cytoprotective or pro-apoptotic response following hyperthermia.
Sex, Specimen part
View SamplesBulk RNA-seq to profile of c-kit+ cardiac interstitial cells, comparing the transcriptomes of Pim-1 enhanced cardiac progenitor cells and transfection control Overall design: Transcriptional profiling of Pim-1 enhanced human derived cardiac interstitial cells by bulk RNA-Seq
Safety profiling of genetically engineered Pim-1 kinase overexpression for oncogenicity risk in human c-kit+ cardiac interstitial cells.
Specimen part, Subject
View SamplesNearly all colorectal cancers have dysregulated Wnt signalling, predominantly through the mutation of the Apc (Adenomatous Polyposis Coli) gene. Therefore it is of vital importance to elucidate the key Wnt target genes in intestinal cells in vivo. We have used a novel inducible cre-lox based murine system (designated ApcFlox) to investigate the consequences of perturbation of Wnt signalling following inactivation of Apc in vivo within 100% of the intestinal epithelium. We have employed microarray analysis at 3 time points within our ApcFlox system (Day 3 prior to the onset of phenotype, day 4 the establishment of the phenotype and day 5 gross phenotype of altered proliferation, differentiation and migration) and from adenomas arising in the ApcMin/+ background allowing us characterise Wnt/beta-catenin target genes based on their expression profiles during different stages of intestinal tumourigenesis. Furthermore, we have employed microarray analysis using livers from our ApcFlox system and have demonstrated that there is very little overlap in the Wnt target genes induced by Apc loss in the liver and the intestine. More importantly, we have been able to determine a novel set of putative Wnt/beta-catenin target genes which are upregulated at both early and late stages of tumourigenesis in the intestine and may represent novel therapeutic targets in colon cancer.
Hunk/Mak-v is a negative regulator of intestinal cell proliferation.
Specimen part
View SamplesTo study the impact of the transcription factor NFAT5 on the vascular smooth muscle cell (VSMC) transcriptome, genetic ablation of floxed nfat5 in mouse aortic smooth muscle cells was achieved by transducing them with an adenoviral vector to express Cre-recombinase (Ad-Cre) under control of a CMV promoter.
Genetic ablation of NFAT5/TonEBP in smooth muscle cells impairs flow- and pressure-induced arterial remodeling in mice.
Specimen part
View SamplesThe intermediate filament protein Nestin serves as a biomarker for stem cells and has been used to identify subsets of cancer stem-like cells. However, the mechanistic contributions of Nestin to cancer pathogenesis are not understood. Here we report that Nestin binds the hedgehog pathway transcription factor Gli3 to mediate the development of medulloblastomas of the hedgehog subtype. In a mouse model system, Nestin levels increased progressively during medulloblastoma formation resulting in enhanced tumor growth. Conversely, loss of Nestin dramatically inhibited proliferation and promoted differentiation. Mechanistic investigations revealed that the tumor-promoting effects of Nestin were mediated by binding to Gli3, a zinc finger transcription factor that negatively regulates hedgehog signaling. Nestin binding to Gli3 blocked Gli3 phosphorylation and its subsequent proteolytic processing, thereby abrogating its ability to negatively regulate the hedgehog pathway. Our findings show how Nestin drives hedgehog pathway-driven cancers and uncover in Gli3 a therapeutic target to treat these malignancies.
Nestin Mediates Hedgehog Pathway Tumorigenesis.
Specimen part
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