Cholinergic Receptor and Cyclic Stretch-Mediated Inflammatory Gene Expression in Intact Airway Smooth Muscle
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ABSTRACT: 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).
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:We tested the hypothesis that cholinergic stimulation and cyclic stretch regulate inflammatory gene expression in intact airway smooth muscle by measuring mRNA expression in bovine tracheal smooth muscle using limited microarray analysis and RT-PCR. Carbachol (1 microM) induced significant increases in the expression of cyclooxygenase (COX)-1, COX-2, IL-8, and plasminogen activator, urokinase type (PLAU) to levels ranging from 1.3- to 3.1-fold of control. Sinusoidal length oscillation at an amplitude of 10% muscle length and a frequency of 1 Hz induced significant increases in the expression of CCL-2, COX-2, IL-1 beta, and IL-6 to levels ranging from 12- to 206-fold of control. Decreasing the oscillatory amplitude by 50% did not significantly change inflammatory gene expression. In contrast, decreasing the oscillatory frequency by 50% significantly attenuated inflammatory gene expression by 76-93%. Nifedipine (1 microM) had an insignificant effect on carbachol-induced gene expression, but significantly inhibited sinusoidal length oscillation-induced inflammatory gene expression by 40-78%. Correlation analysis revealed two groups of genes with differential responses to sinusoidal length oscillation. The highly responsive group included COX-2, IL-6, and IL-8, which exhibited 45- to 364-fold increases in gene expression in response to sinusoidal length oscillation. The moderately responsive group included CCL2 and PLAU, which exhibited 13- to 19-fold increases in gene expression in response to sinusoidal oscillation. These findings suggest that cyclic stretch regulates inflammatory gene expression in intact airway smooth muscle in an amplitude- and frequency-dependent manner by modulating the activity of L-type voltage-gated calcium channels.
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.
Project description:Mechanical stress is a potent regulator of cell growth, contractility and gene regulation. Abnormal uterine distension during pregnancy increases the risk of preterm birth and likely activates crosstalk between multiple signaling networks with protein phosphorylation playing a critical role. Telomerized human uterine smooth muscle cells were exposed to 18% biaxial stretch for 5 min and the phosphoproteome was probed by mass spectrometry. We observed specific phospho-activation of mitogen activated protein kinase at threonine 183 and tyrosine 185, myosin regulatory light chain 9 at threonine 19, and heat shock protein 27 at serine 82. Our analysis revealed protein phosphorylation changes in signaling pathways related to actin cytoskeleton remodeling, activation of the focal adhesion kinase pathway, smooth muscle contraction and mechanistic target of rapamycin activation. These data point to potential mechanistic links between stretch-induced phosphorylation and development of the contractile phenotype in myometrial cells.
Project description:Context: Increased uterine stretch appears to increase the risk of preterm labour, but the mechanism is unknown. Objectives: To identify a targetable mechanism mediating the effect of stretch on human myometrium. Design: Myometrial explants, prepared from biopsies obtained at elective caesarean delivery, were either studied acutely, or were maintained in prolonged culture (up to 65 h) under tension with either a 0.6 g or 2.4 g mass, and compared using in vitro contractility, whole genome array, and qRT-PCR. Results: Increased stretch for 24 or 65 h increased potassium-induced and oxytocin-induced contractility. Gene array identified 62 differentially expressed transcripts after 65 h exposure to increased stretch. Two probes for gastrin-releasing peptide (GRP), a known stimulatory agonist of smooth muscle, were among the top five up-regulated by stretch (3.4-fold and 2.0-fold). Up-regulation of GRP by stretch was confirmed in a separate series of 10 samples using qRT-PCR (2.8-fold, P = 0.01). GRP stimulated contractions acutely when added to freshly obtained myometrial strips in 3 out of 9 cases, but Western blot demonstrated expression of the GRP receptor in 9 out of 9 cases. Prolonged incubation of stretched explants in the GRP antagonists PD-176252 or RC-3095 (65 and 24 h respectively) significantly reduced potassium chloride and oxytocin-induced contractility. Conclusion: Stretch of human myometrium increases contractility and stimulates the expression of a known smooth muscle stimulatory agonist, GRP. Incubation of myometrium in GRP receptor antagonists ameliorates the effect of stretch. GRP may be a target for novel therapies to reduce the risk of preterm birth in multiple pregnancy. 9 paired samples of human myometrium cultured under low (0.6g) or high (2.4g) tension
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:With gene expression profiling it was aimed to identify the differentially expressed genes associated with the regulation of the cytoskeleton to investigate the stretch-induced cell alignment mechanism. A whole genome microarray based analysis of the stretch-induced gene expression changes was done. Gene expression was measured at the beginning of the alignment process showing first reoriented cells after 5 h stretching and at the end after 24 h, where nearly all cells are aligned. Cyclic mechanical stretching of cells results in cellular alignment perpendicular to the stretch direction regulating cellular response. This stress response is assumed to be an adaptation mechanism to reduce extensive stretching but also acts as architectural restructuring changing performance and biomechanics of the tissue. Gene expression profiling of control vs. stretched primary human dermal fibroblasts after 5 h and 24 h demonstrated the regulation of differentially expressed genes associated with metabolism, differentiation and morphology.
Project description:Lung cancer is one of the leading causes of death. However, most of the researches were based on the traditional cell-culturing method. Whereas cells of lung are subjected to the mechanical forces periodically while breathing. In the present study, we applied cyclic stretch to stimulate the continuously contracting physical condition. We uncovered the stretching force-induced phosphoproteome in lung cancer cell A549 and fibroblast IMR-90. 2048 and 2604 phosphosites corresponding to 837 and 1008 phosphoproteins were identified in A549 and IMR-90, respectively. Interestingly, cytoskeleton reorganization and mitochondrial localization were enriched in the significantly expressed phosphoproteins in response to cyclic stretch. Indeed, we found this physical stress changed cell alignment thus disrupted mitochondrial dynamics. We proved that mitochondrial fusion is induced by uniaxial stretch in 2 cell lines. This study reveals the molecular mechanism of cyclic stretch and supports that stretching force enhanced cellular rearrangement and mitochondrial fusion in lung cells.
Project description:With gene expression profiling it was aimed to identify the differentially expressed genes associated with the regulation of the cytoskeleton to investigate the stretch-induced cell alignment mechanism. A whole genome microarray based analysis of the stretch-induced gene expression changes was done. Gene expression was measured at the beginning of the alignment process showing first reoriented cells after 5 h stretching and at the end after 24 h, where nearly all cells are aligned. Cyclic mechanical stretching of cells results in cellular alignment perpendicular to the stretch direction regulating cellular response. This stress response is assumed to be an adaptation mechanism to reduce extensive stretching but also acts as architectural restructuring changing performance and biomechanics of the tissue. Gene expression profiling of control vs. stretched primary human dermal fibroblasts after 5 h and 24 h demonstrated the regulation of differentially expressed genes associated with metabolism, differentiation and morphology. Primary human dermal fibroblasts from ten donors were cultured on Bioflex culture plates and stretched for 5h and 24 h or left untreated to avoid changes according to cell culturing. Each of the subject provided 4 samples (control/treated and 5hrs/24hrs) resulting in 40 samples total.