Transcription profiling of rat heart at several time points after either a myocardial infraction or sham operation
ABSTRACT: Myocardial Infarction Model: Sixty nine animals (252 ± 2 g) were randomized to either myocardial infraction (MI) or sham operation. MI were produced by partial ligation of the left coronary artery as described in detail by Loennechen et al. (Loennechen JP, Stoylen A, Beisvag V, Wisloff U, Ellingsen O: Regional expression of endothelin-1, ANP, IGF-1, and LV wall stress in the infarcted rat heart. Am J Physiol Heart Circ Physiol 2001, 280: H2902-H2910.). Animals with large infarctions (45 ± 2% of LV) were euthanized on one of the following days: day 1 (n = 6), 3(n = 5), 7 (n = 6), 14 (n = 6), 42 (n =6) and 91 (n = 4); and sham-operated animals were euthanized on one of the following days: 1 (n = 6), 3(n = 6), 7 (n = 6), 14 (n = 6), 42 (n =6) and 91 (n = 6). After sacrifice, heart tissue was removed, weighted and scored for size of the healed infarction. Infarct size was measured and the left ventricular myocardium stored on -80°C for preparation of RNA.
Project description:Myocardial infarction (MI) often results in left ventricular (LV) remodeling followed by heart failure (HF). It is of great clinical importance to understand the molecular mechanisms that trigger transition from compensated LV injury to HF and to identify relevant diagnostic biomarkers. In this study, we performed transcriptional profiling of LVs in rats with a wide range of experimentally induced infarct sizes and of peripheral blood mononuclear cells (PBMCs) in animals that developed HF. We used microarrays to investigate gene expression in the left ventricle (LV) accompanying myocardial infarction and concomitant heart failure (HF) in a well validated model of post-infarcted heart failure and to evaluate their reflection in peripheral blood mononuclear cells (PBMCs) Myocardial infarction (MI) was induced in male Wistar rats by ligation of the proximal left coronary artery. The sham-operated group (control group) was subjected to the same protocol, except that the suture was not tied around the proximal left coronary artery. Sham-operated rats (n=6) and rats with small (n=6), moderate (n=6), and large (n=5) MI size were included into the experiment two months after the operation. Then, left ventricules and blood samples were obtained for RNA extraction and hybridization on Affymetrix microarrays. Microarrays were used to compare the LV and PBMCs transcriptomes of control and experimental animals. The development of heart failure was estimated by echocardiography and catheterization.
Project description:Myocardial infarction (MI) triggers a reparative response involving fibroblast proliferation and differentiation driving extracellular matrix modulation necessary to form a stabilizing scar. Recently, it was shown that a genetic variant of the base excision repair enzyme endonuclease VIII-like 3 (NEIL3) was associated with increased risk of MI in humans. Here, we report elevated myocardial NEIL3 expression in heart failure patients and marked myocardial upregulation of Neil3 following MI in mice, especially in a fibroblast-enriched cell fraction. Neil3-/- mice showed increased mortality after MI compared to WT, caused by myocardial rupture. Neil3-/- hearts displayed enrichment of mutations in genes involved in mitogenesis of fibroblasts and transcriptome analysis revealed dysregulated fibrosis. Correspondingly, proliferation of vimentin+ and aSMA+ (myo)fibroblasts was increased in Neil3-/- hearts following MI. We propose that NEIL3 operates in genomic regions crucial for regulation of cardiac fibroblast proliferation and thereby controls extracellular matrix modulation after MI. Overall design: RNA from infarcted and non-infarcted LV of WT and Neil3-/- C57BL/6 mice obtained three days after induced myocardial infarction were subjected to RNA sequencing using Illumina Hiseq 2000
Project description:Myocardial infarction (MI) triggers a reparative response involving fibroblast proliferation and differentiation driving extracellular matrix modulation necessary to form a stabilizing scar. Recently, it was shown that a genetic variant of the base excision repair enzyme endonuclease VIII-like 3 (NEIL3) was associated with increased risk of MI in humans. Here, we report elevated myocardial NEIL3 expression in heart failure patients and marked myocardial upregulation of Neil3 following MI in mice, especially in a fibroblast-enriched cell fraction. Neil3-/-mice showed increased mortality after MI compared to WT, caused by myocardial rupture. Epigenomic analysis suggested dysregulated myofibroblast proliferation and differentiation in Neil3-/-hearts and several differentially expressed genes were downstream targets of differentially methylated/hydroxymethylated transcriptional regulators. Furthermore, proliferation of Vimentin+ and SMA+ (myo)fibroblasts was increased in Neil3 -/-hearts following MI. We propose that NEIL3-dependent modulation of epigenetic DNA methylation regulates cardiac fibroblast proliferation and thereby controls extracellular matrix modulation after MI. Overall design: Genomic DNA from infarcted and non-infarcted LV of WT and Neil3-/- C57BL/6 mice obtained three days after induced myocardial infarction were subjected to 5mC and 5hmC sequencing using Illumina Hiseq 2000
Project description:Sexual dimorphisms are well recognized in various cardiac diseases, including myocardial infarction (MI). MI develops later in women, but once established, it contributes more persistent symptoms and higher mortality than in men. Although mRNA-level sexual dimorphism of MI have been reported, whether miRNA transcriptome also confers such dimorphism remains unknown. Comprehensive understanding of the mRNA- and miRNA-level genetic programs underlying the heart sexual dimorphisms will expectedly improve clinical outcome by facilitating the development of gender specific treatment strategies. Here, by conducting miRNA microarray analysis of human MI samples, we set out to characterize the heart sexual dimorphisms at the level of miRNA transcriptome Human tissue samples, acquired during post-mortem examination and frozen in liquid nitrogen, were provided by the department of pathology, Tokyo Metropolitan Geriatric Hospital after the approval from the ethical committee. Age- and sex-matched cohorts were selected to compare healthy hearts to those with post-MI LV remodeling. Border zone for myocardial infarction was sampled. Total RNA was extracted using Sepasol solution (Sepasol-RNA I super G, nakalai tesque, Japan), and microarray analysis was performed using Affymetrix GeneChip® miRNA 3.0 Arrays
Project description:In this study, we used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted cardiomyocyte proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing cardiomyocyte apoptosis. Rather, we found that AAV9:hYAP stimulated adult cardiomyocyte proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated cell cycle gene expression, enhanced TGFβ-signaling, and activated of components of the inflammatory response.Cardiac specific YAP activation after MI mitigated myocardial injury after MI, improved cardiac function and mouse survival. These findings suggest that therapeutic activation of hYAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI. Three groups were involved in this study: sham group, AAV9:Luci+MI group and AAV9-YAP+MI group. Each group contained three biological replicates. The sham group had neither myocardial infarction nor AAV injection. The AAV9:Luci +MI(L for brief) group had myocardial infarction and injected with AAV9:Luic. The AAV9:hYAP+MI(YAP for brief) group had myocardial infarction and injected with AAV9:hYAP. 5 days after MI and AAV injection, the heart apexes were collected and the total RNA were isolated for microarray analysis.
Project description:Characterisation of M2-like macrophage in terms of gene expression level. The hypothesis tested in the present study was that M2-like macrophages in myocardial infarction (MI) heart have upregulation of genes relevant to cardiac repair. The results obtained showed tha various tanti-inflammatory and reparative genes were upregulated in M2-like macrophage from MI heart compared to those from intact hearts. M2-like macrophages from the heart (either MI or intact) were distinct from those in the peritoneal cavity. Overall design: Total RNA obtained from M2-like macrophages from peritoneal cavity, intact heart and myocardial infarction heart.
Project description:Myocardial infarction (MI) is a highly prevalent cardiac emergency, which results in adverse left ventricular remodeling exacerbating progressive heart failure. Inflammation in post-MI is necessary for myocyte repair and wound healing. However, it is also a key component of subsequent heart failure pathology. Myoblasts transplantation after MI have been fulfilled a good effect on cardiac repair, but the occasion, complications of transplantation, and the underlying mechanisms have not been fully elucidated. Here, we found that myoblast transplantation decreased the expression of many pro-inflammatory genes and the activation of inflammation-related signal pathway in heart tissue of pig post MI, which mainly contributed to the improved heart function and attenuated damage of myocardial cells. Overall design: We constructed a minipig surgical model of myocardial infarction. Myoblasts were intramyocardially injected into the infarct and border zone of heart. The infarct and border zone heart tissues from minipigs treated with myoblast transplantation or untreated control (one sample for every group) were submitted for gene expression array analysis.
Project description:We have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to influence the pathogenesis after myocardial infarction. Male mice (8 weeks old) were anesthetized and subjected to permanent occlusion of the left coronary artery [Myocardial infarction (MI) model]. Overall design: Gene expression in wild-type mouse heart was measured at 3 days after the MI-surgery.
Project description:In order to examine the mechanism of TPO on cardiac protection against myocardial infarction damage (MI), we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to delineate the TPO cardioprotective mechanism against infarction. MI and TPO induced gene expressions in rat heart were measured at week 4. Two biological replicates were performed for each treatment group.
Project description:Heart failure (HF) is the most common cause of morbidity and mortality in the developed countries, especially considering the present demographic tendencies in those populations. We identified biologically relevant transcripts that are significantly altered in the early phase of myocardial infarction (MI) and are associated with the development of post-myocardial infarction HF. We collected peripheral blood samples from patients (n=111) with ST-segment elevation myocardial infarction (STEMI) at four time points (admission, discharge, 1 month after MI, and 6 months after MI). Control group comprised patients (n=46) with a stable coronary artery disease and without a history of myocardial infarction. Affymetrix HuGene 1.0 ST arrays were used to analyze mRNA levels in periperal blood mononuclear cells (PBMCs) isolated from the study and control groups. Samples from the first three time points were compared with the samples from the same patients collected 6 months after MI (stable phase) and with the control group. Additionaly, based on plasma NT-proBNP level and left ventricular ejection fraction parameters the STEMI patients were divided into HF and non-HF groups.We attempted to identify transcripts whose differential expression on the 1st day of myocardial infarction predicted which patients would develop symptoms of HF during the 6 months of follow-up. For this purpose, we compared the microarray results for samples collected on admission for the HF group versus the non-HF group.