Project description:We tested the hypothesis that cholinergic stimulation (via treatment with carbachol) and cyclic stretch regulate inflammatory gene expression in intact airway smooth muscle by measuring mRNA expression in bovine tracheal smooth muscle. Keywords: response to stress and drug
Project description:The aim of the experiment was to determine the effect of cyclic stretch-relaxation ("stretch") on gene expression patterns in normal diploid human bladder smooth muscle cells. Cells plated on silicone elastomer bottomed 6-well culture dishes were grown to ~80% confluence, serum-depleted for 48h and subjected to cyclic stretch-relaxation at 20% elongation for 4h. Cells seeded in stretch plates but not subjected to stretch served as controls. Total RNA was extracted from both groups of cells, reverse-transcribed, biotin-labeled, fragmented and hybridized to HG-U133A. Four biological replicates were generated for each treatment group (non-stretched or stretched). Keywords = bladder Keywords = smooth muscle cells Keywords = cyclic stretch-relaxation Keywords: other
Project description:The aim of the experiment was to determine the effect of cyclic stretch-relaxation ("stretch") on gene expression patterns in normal diploid human bladder smooth muscle cells. Cells plated on silicone elastomer bottomed 6-well culture dishes were grown to ~80% confluence, serum-depleted for 48h and subjected to cyclic stretch-relaxation at 20% elongation for 4h. Cells seeded in stretch plates but not subjected to stretch served as controls. Total RNA was extracted from both groups of cells, reverse-transcribed, biotin-labeled, fragmented and hybridized to HG-U133A. Four biological replicates were generated for each treatment group (non-stretched or stretched).
Project description:Vascular smooth muscle cells (VSMCs) respond to biomechanical stretch with specific changes in gene expression which govern the phenotype of these cells. The mechanotransducer zyxin is a potential candidate for regulating the expression of such genes. Using microarrays, we compared stretch-induced gene expression in wild type and zyxin-null VSMCs to define such changes in detail. Wild type (WT) and zyxin-null VSMCs were stretched at 10% cyclic elongation for 6 hours and the changes in gene expression were compared under static and stretched conditions. Up to 3 biological replicates were used for each of the 4 sample types.
Project description:Persistent severe asthma is associated with hyper-contractile airways and structural changes in the airway wall, including an increased airway smooth muscle (ASM) mass. This study used gene expression profiles from asthmatic and healthy airway smooth muscle cells grown in culture to identify novel receptors and pathways that potentially contributed to asthma pathogenesis. We used microarrays to compare the gene expression between asthmatic and healthy airway smooth muscle cells to understand the underlying pathway contributing the differences in cellular phenotypes Asthmatic airway smooth muscle cells (ASMC) are intrinsically different and have a differential transcriptional response to pro-fibrotic, pro-proliferation and pro-inflammatory stimuli than ASMC from healthy patients. We sought to identify genes that are differentially expressed between asthmatic and healthy ASMC under various stimulations which mimic the asthmatic airways. To this end, we obtained human ASMC from bronchial biopsies and explanted lungs from doctor diagnosed asthmatic patients (n=3) and healthy controls (n=3). The ASMC were then grown in culture and treated with pro-fibrotic (Transforming growth factor beta (TGFβ)), pro-proliferation (Fetal Bovine Serum (FBS)) and pro-inflammatory stimuli (Interleukin-1 beta (IL-1β)) for 8 hours. Gene expression was then evaluated using Affymetrix Human Gene 1.0ST arrays.
Project description:The Toll-like receptor (TLR) and peptidoglycan recognition protein 1 (PGLYRP1) genes play key roles in the innate immune systems of mammals. While the TLRs recognize a variety of invading pathogens and induce innate immune responses, PGLYRP1 is directly microbicidal. We used custom allele-specific assays to genotype and validate 220 diallelic variants, including 54 nonsynonymous SNPs in 11 bovine innate immune genes (TLR1-TLR10, PGLYRP1) for 37 cattle breeds. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and we were unable to differentiate between the specialized B. t. taurus beef and dairy breeds, despite an average polymorphism density of one locus per 219 bp. Ninety-nine tagSNPs and one tag insertion-deletion polymorphism were sufficient to predict 100% of the variation at all 11 innate immune loci in both subspecies and their hybrids, whereas 58 tagSNPs captured 100% of the variation at 172 loci in B. t. taurus. PolyPhen and SIFT analyses of nonsynonymous SNPs encoding amino acid replacements indicated that the majority of these substitutions were benign, but up to 31% were expected to potentially impact protein function. Several diversity-based tests provided support for strong purifying selection acting on TLR10 in B. t. taurus cattle. These results will broadly impact efforts related to bovine translational genomics.
Project description:BackgroundWe present here the assembly of the bovine genome. The assembly method combines the BAC plus WGS local assembly used for the rat and sea urchin with the whole genome shotgun (WGS) only assembly used for many other animal genomes including the rhesus macaque.ResultsThe assembly process consisted of multiple phases: First, BACs were assembled with BAC generated sequence, then subsequently in combination with the individual overlapping WGS reads. Different assembly parameters were tested to separately optimize the performance for each BAC assembly of the BAC and WGS reads. In parallel, a second assembly was produced using only the WGS sequences and a global whole genome assembly method. The two assemblies were combined to create a more complete genome representation that retained the high quality BAC-based local assembly information, but with gaps between BACs filled in with the WGS-only assembly. Finally, the entire assembly was placed on chromosomes using the available map information.Over 90% of the assembly is now placed on chromosomes. The estimated genome size is 2.87 Gb which represents a high degree of completeness, with 95% of the available EST sequences found in assembled contigs. The quality of the assembly was evaluated by comparison to 73 finished BACs, where the draft assembly covers between 92.5 and 100% (average 98.5%) of the finished BACs. The assembly contigs and scaffolds align linearly to the finished BACs, suggesting that misassemblies are rare. Genotyping and genetic mapping of 17,482 SNPs revealed that more than 99.2% were correctly positioned within the Btau_4.0 assembly, confirming the accuracy of the assembly.ConclusionThe biological analysis of this bovine genome assembly is being published, and the sequence data is available to support future bovine research.
Project description:Several different mechanical signals have been proposed to control the extent and pattern of myocardial growth and remodeling, though this has largely been studied using in vitro model systems that are not representative of intact myocardium or in vivo models in which isolating the effects of individual candidate stimuli is exceedigly difficult. We used a unique tissue culture system that allows the simultaneous control of multiple mechanical inputs and other potentially confounding stimuli (e.g., hormonal). Following a 12 hour culture period under prescribed mechanics, we used microarrays to identify genes that are up- or down-regulated in response to different amounts of mean stretch and cyclic shortening. Muscles were dissected (one from each of 12 different male LBN-F1 rats) and cultured for 12 hours in a pseudo-sterile muscle culture system under one of four mechanical input schemes (i.e., three biological replicates per mechanical input group). We prescribed low or high values of both time averaged stretch and cyclic shortening. Specifically, we targeted 4% or 16% mean stretch (from slack length) and 4% of 16% cylic shortening (% of slack length) over the 12 hour culture period to give the following four groups: high mean stretch x high shortening (group A); high mean stretch x low shortening (group B); low mean stretch x low shortening (group C); low mean stretch x high shortening (group D). This 2 x 2 factorial design allowed us to identify individual genes and/or molecular pathways that might be regulated by one or both of these mechanical inputs indpendent from other candidate mechanical or hormonal stimuli.
Project description:Smooth muscle differentiation has been proposed to sculpt airway epithelial branches in mammalian lungs. Serum response factor (SRF) acts with its cofactor myocardin to promote the expression of contractile smooth muscle markers. However, smooth muscle cells exhibit a variety of phenotypes beyond contractile that are independent of SRF-myocardin-induced transcription. To determine whether airway smooth muscle exhibits phenotypic plasticity during embryonic development, we deleted Srf from the pulmonary mesenchyme. Srf-mutant lungs branch normally, and the mesenchyme exhibits normal cytoskeletal features and patterning. scRNA-seq revealed an Srf-null smooth muscle cluster wrapping the airways of mutant lungs that lacks contractile smooth muscle markers but retains many features of control smooth muscle. Srf-null airway smooth muscle exhibits a synthetic phenotype, compared to the contractile phenotype of wildtype airway smooth muscle. Our findings reveal plasticity in mesenchymal differentiation during lung development and demonstrate that a synthetic smooth muscle layer is sufficient for airway branching morphogenesis.