Project description:The goal of this study was to identify microRNAs that are modulated by cyclic stretch. miRNA-Seq was performed comparing samples from cultured E16.5 mouse cardiomyocytes exposed to either cyclic stretch of 16% at 1Hz for 24h or static conditions.
Project description:The present study focuses on the identification of the gene expression profile of neonatal rat cardiomyocytes (NRVCMs) after dynamic mechanical stretch through microarrays of RNA isolated from cells stretched for 2, 6 or 24 h.
Project description:miRNA-Sequencing was performed on human aortic valve interestitial cells (AVICs) exposed to 14% stretch at 1 hz or static conditions for 24h. Six static control and six samples exposed to cyclic stretch 14% for 24h
Project description:Neonatal rat ventricular cardiomyocytes (NRVCMs) were stretched biaxially (112%/24h) or stimulated with phenylephrine (PE, 50 uM), both resulting in a similar degree of hypertrophy. Unstretched NRVCMs served as negative control. Affymetrix microarray analysis revealed 164 genes more than 2.0-fold up- and 21 genes less than 0.5-fold downregulated (p<0.01). Differential expression was confirmed by real-time PCR. Several genes of the “fetal gene program”, i.e. BNP (4.2-fold, all p<0.05) were induced by stretch as well as PE. We also verified the upregulation of known stretch-responsive genes, including HSP70 (20.9x) and c-myc (3.0x). Moreover, we identified genes exclusively induced by stretch, such as the cardioprotective and antihypertrophic cytokine GDF15 (24.8x) and the antihypertrophic factor heme oxygenase 1 (Hmox1, 10.8x; both confirmed on protein level). Of note, neither PE nor endothelin-1 were able to upregulate GDF15 and Hmox1, while angiotensin II significantly induced both genes. Conversely, addition of the AT1 receptor blocker irbesartan markedly blunted stretch-mediated GDF15 and Hmox1 induction, suggesting that the angiotensin II receptor mediates stretch-dependent signals. In conclusion, we report a comprehensive gene expression profile of cardiomyocytes subjected to biomechanical stress in comparison to pharmacologically induced hypertrophy. Our data imply that a stretch-specific gene program exists, that is mediated, at least in part, by angiotensin-II-dependent signalling. Keywords: stress response
Project description:Neonatal rat ventricular cardiomyocytes (NRVCMs) were stretched biaxially (112%/24h) or stimulated with phenylephrine (PE, 50 uM), both resulting in a similar degree of hypertrophy. Unstretched NRVCMs served as negative control. Affymetrix microarray analysis revealed 164 genes more than 2.0-fold up- and 21 genes less than 0.5-fold downregulated (p<0.01). Differential expression was confirmed by real-time PCR. Several genes of the âfetal gene programâ, i.e. BNP (4.2-fold, all p<0.05) were induced by stretch as well as PE. We also verified the upregulation of known stretch-responsive genes, including HSP70 (20.9x) and c-myc (3.0x). Moreover, we identified genes exclusively induced by stretch, such as the cardioprotective and antihypertrophic cytokine GDF15 (24.8x) and the antihypertrophic factor heme oxygenase 1 (Hmox1, 10.8x; both confirmed on protein level). Of note, neither PE nor endothelin-1 were able to upregulate GDF15 and Hmox1, while angiotensin II significantly induced both genes. Conversely, addition of the AT1 receptor blocker irbesartan markedly blunted stretch-mediated GDF15 and Hmox1 induction, suggesting that the angiotensin II receptor mediates stretch-dependent signals. In conclusion, we report a comprehensive gene expression profile of cardiomyocytes subjected to biomechanical stress in comparison to pharmacologically induced hypertrophy. Our data imply that a stretch-specific gene program exists, that is mediated, at least in part, by angiotensin-II-dependent signalling. Experiment Overall Design: Three conditions were compared with two replicates each. These are: Experiment Overall Design: (1) control, i.e. no treatment; (2) induction by phenylephrine (50 uM); (3) induction by biomechanical stretch (112%/24h)
Project description:miRNA-Sequencing was performed on human aortic valve interestitial cells (AVICs) exposed to 14% stretch at 1 hz or static conditions for 24h.
Project description:Myocardial damage caused for example by cardiac ischemia leads to ventricular volume overload resulting in increased stretch of the remaining myocardium. In adult mammals, these changes trigger an adaptive cardiomyocyte hypertrophic response which, if the damage is extensive, will ultimately lead to pathological hypertrophy and heart failure. Conversely, in response to extensive myocardial damage, cardiomyocytes in the adult zebrafish heart and neonatal mice proliferate and completely regenerate the damaged myocardium. We therefore hypothesized that in adult zebrafish, changes in mechanical loading due to myocardial damage may act as a trigger to induce cardiac regeneration. Based, on this notion we sought to identify mechanosensors which could be involved in detecting changes in mechanical loading and triggering regeneration. Here we show using a combination of knockout animals, RNAseq and in vitro assays that the mechanosensitive ion channel Trpc6a is required by cardiomyocytes for successful cardiac regeneration in adult zebrafish. Furthermore, using a cyclic cell stretch assay, we have determined that Trpc6a induces the expression of components of the AP1 transcription complex in response to mechanical stretch. Our data highlights how changes in mechanical forces due to myocardial damage can be detected by mechanosensors which in turn can trigger cardiac regeneration.
Project description:Acute respiratory distress syndrome (ARDS) is a catastrophic form of acute lung injury (ALI). The necessity for mechanical ventilation (MV) renders patients at risk for ventilator induced lung injury (VILI). Exposure to repetitive cyclic stretch (CS) and/or over-inflation exacerbates injury. Reducing tidal volume (VT) is the only therapeutic strategy shown to mitigate morbidity and mortality. Cyclic stretch has been shown to differentially regulate gene expression in part through the activation of mammalian mitogen-activated protein kinase (MAPK). Although these studies have shown both molecular and cellular alterations, no unifying hypothesis to explain MV-induced lung injury has emerged. In the current study, we hypothesized that coordinated expression of cyclic stretch (CS)-responsive genes relies on the presence of common CS-sensitive regulatory elements. To identify CS-responsive genes, we undertook a comparative examination of the gene expression profile of human bronchial epithelial airway (Beas-2B) cells in response to various injurious stimuli involved in the pathogenesis of acute lung injury (ALI)/Ventilator induced lung injury (VILI): cyclic stretch, tumor necrosis factor alpha (TNF-a), and lipopolysaccharide (LPS). Experiment Overall Design: Human Bronchial Epithelial Cells (Beas-B2) cells grown on silicon elastic plates coated with Type I collagen (Flexercell International, McKeesport, PA) were exposed to six regiments for 4 h: 1) control (static, [control]); 2) mechanical stretch (25 PKa, 30 cycles per min, [stretch]); 3) LPS (1 mcg/ml [LPS]); 4) TNF-α (20 ng/ml; [TNF]); 5) mechanical stretch plus LPS [LPS+S], and 6) mechanical stretch plus TNF-α [TNF+S]. Total RNA (duplicate experiments) was extracted using TRIZOL reagent (as per manufactures specifications) and purified using Qiagen mRNA purification Kit (as per manufacturers specifications). mRNA was hybridized to Affymetrix Human U133plus2.0 chips. Probe based analysis, background reduction, and quantile data normalization was performed in MeV 4.0 of TM4 using Robust Multi-array Average (RMA).
Project description:The effect of cyclic mechanical stretch (0.5 Hz, 10-21% elongation) on gene expression of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) was studied using RNA sequencing.
Project description:Acute respiratory distress syndrome (ARDS) is a catastrophic form of acute lung injury (ALI). The necessity for mechanical ventilation (MV) renders patients at risk for ventilator induced lung injury (VILI). Exposure to repetitive cyclic stretch (CS) and/or over-inflation exacerbates injury. Reducing tidal volume (VT) is the only therapeutic strategy shown to mitigate morbidity and mortality. Cyclic stretch has been shown to differentially regulate gene expression in part through the activation of mammalian mitogen-activated protein kinase (MAPK). Although these studies have shown both molecular and cellular alterations, no unifying hypothesis to explain MV-induced lung injury has emerged. In the current study, we hypothesized that coordinated expression of cyclic stretch (CS)-responsive genes relies on the presence of common CS-sensitive regulatory elements. To identify CS-responsive genes, we undertook a comparative examination of the gene expression profile of human bronchial epithelial airway (Beas-2B) cells in response to various injurious stimuli involved in the pathogenesis of acute lung injury (ALI)/Ventilator induced lung injury (VILI): cyclic stretch, tumor necrosis factor alpha (TNF-a), and lipopolysaccharide (LPS).