Project description:Regulatory Mechanisms of Atrial Remodeling of Mitral Regurgitation Pigs This study enrolled 6 pigs (age: 18 months) and divided into three groups: mitral regurgitation pigs (MR) (n = 2; 2 males sacrificed 12 months after surgery), MR pigs treated with valsartan (MRV) (n = 2; 2 males age-matched to MR sacrificed 12 months after surgery), and normal control pigs (NC) (n = 2; 2 males age-matched to MR pigs). Valsartan (3.43 mg/kg/day), a type I angiotensin II receptor blocker, was administered from one week before surgery and then daily after surgery in the MRV group. We sought to systemically elucidate critical differences in the alteration of RNA expression pattern between the atrial myocardium of pigs with and without MR, and between the atrial myocardium of MR pigs with and without valsartan using high-density oligonucleotide microarrays and functional network enrichment analysis.
Project description:Introduction: Cardiac ischemic reperfusion injury (IRI) is paradoxically instigated by re-establishing blood-flow to ischemic myocardium typically from a myocardial infarction (MI). Although revascularization following MI remains the standard of care, effective strategies remain limited to prevent or attenuate IRI. We hypothesized that epicardial placement of human placental amnion/chorion (HPAC) grafts will protect against IRI. Methods: Using a clinically relevant model of IRI, swine were subjected to 45 minutes percutaneous ischemia followed with (MI+HPAC, n=3) or without (MI only, n=3) HPAC. Cardiac function was assessed by echocardiography, and regional punch biopsies were collected 14 days post-operatively. A deep phenotyping approach was implemented by using histological interrogation and incorporating global proteomics and transcriptomics in non-ischemic, ischemic, and border zone biopsies. Results: Our results established HPAC limited the extent of cardiac injury by 50% (11.02.0% vs 22.03.0%, p=0.039) and preserved ejection fraction in HPAC-treated swine (46.8±2.7% vs 35.8±4.5%, p=0.014). We present comprehensive transcriptome and proteome profiles of infarct (IZ), border (BZ), and remote (RZ) zone punch biopsies from swine myocardium during the proliferative cardiac repair phase 14 days post-MI. Both HPAC-treated and untreated tissues showed regional dynamic responses, whereas only HPAC-treated IZ revealed active immune and extracellular matrix remodeling. Decreased endoplasmic reticulum (ER)-dependent protein secretion and increased anti-apoptotic and anti-inflammatory responses were measured in HPAC-treated biopsies. Discussion: We provide quantitative evidence HPAC reduced cardiac injury from MI in a preclinical swine model, establishing a potential new therapeutic strategy for IRI.
Project description:We analyzed the lactylomes and proteomes of infarcted myocardium in mice subjected to sham treatment, myocardial infarction (MI) for 30 min or MI followed by I/R for 6 h using liquid chromatography-tandem mass spectrometry (LC–MS/MS) system.
Project description:The use of cDNA microarrays has made it possible to analyze expression of thousands of genes simultaneously. We employed microarray gene expression profiling of porcine cDNA to compare myocardial gene expression in infarct core and remote myocardium at 1 week (n=3), 4 weeks (n=3), and 6 weeks (n=3) after surgically induced myocardial infarction (MI) and in sham-operated controls (n=3). More than 8,000 cDNA sequences were identified in myocardium that showed differential expression in response to MI. Different temporal and spatial patterns of gene expression were recognized in the infarct core tissue within this large set of data. Microarray gene profiling revealed candidate genes, some of them described for the first time, which elucidate changes in biological processes at different stages after MI. We evaluated temporal gene expression in a porcine model of myocardial infarction by microarray technology. Nine female pigs (Sus scrofa crossbreed Landrace x Large White) weighing 30-40 kg were subjected to experimental MI by a double-ligation of the first marginal branch of the circumflex artery. Animals were randomly sacrificed at 1 week (n=3), 4 weeks (n=3), or 6 weeks (n=3) after MI. Three paired myocardial samples from the infarct core and remote myocardium were analyzed at each time point. Myocardial samples from sham-operated animals (open-chest cardiac exposure without coronary artery ligation; n=3) were included as physiological controls.
Project description:[1] Microarray analysis in the rat myocardial tissue: 124I-HIB transplanted MI model Vs. phosphate buffered saline (PBS) injected myocardial infarction (MI) model Vs. Sham operated model [2] Microarray analysis in the rat adipose derived stem cells: 124I-HIB-labeled ADSCs Vs. Unlabeled ADSCs [1] We investigated the change of gene expression profile in sham operated-, PBS injected- and 124I-HIB-labeled ADSCs transplanted myocardium in rat myocaridial infarction (MI) model. [2] We compared gene expression profile with 124I-HIB labeled ADSCs and unlabeled ADSCs in vitro.
Project description:The molecular mechanism underlying cardiac remodeling following myocardial infarction have been incompletely understood. Until now, most studies have been performed in rodents. We studied cardiac remodeling in the physiologically more relevant animal model, the swine. Microarray analysis was performed on animals that underwent either sham surgery or permanent ligation of the left coronary artery (MI). RNA was isolated from the remote, non-ischemic, regions of the left ventricle. RNA was isolated from 8 sham and 8 MI animals three weeks after surgery. Each group contained 4 males and 4 females. Animals used for the study were 2-3 months old Yorkshire x Landrace swine. Only neutered males entered the study.
Project description:The use of cDNA microarrays has made it possible to analyze expression of thousands of genes simultaneously. We employed microarray gene expression profiling of porcine cDNA to compare myocardial gene expression in infarct core and remote myocardium at 1 week (n=3), 4 weeks (n=3), and 6 weeks (n=3) after surgically induced myocardial infarction (MI) and in sham-operated controls (n=3). More than 8,000 cDNA sequences were identified in myocardium that showed differential expression in response to MI. Different temporal and spatial patterns of gene expression were recognized in the infarct core tissue within this large set of data. Microarray gene profiling revealed candidate genes, some of them described for the first time, which elucidate changes in biological processes at different stages after MI.
Project description:RATIONALE: Myocardial infarction (MI) triggers a dynamic microRNA response with the potential of yielding therapeutic targets. OBJECTIVE: We aimed to identify novel aberrantly expressed cardiac microRNAs post-MI with potential roles in adverse remodeling in a rat model, and to provide post-ischemic therapeutic inhibition of a candidate pathological microRNA in vivo. METHODS AND RESULTS: Following microRNA array profiling in rat hearts 2 and 14days post-MI, we identified a time-dependent up-regulation of miR-31 compared to sham-operated rats. A progressive increase of miR-31 (up to 91.4±11.3 fold) was detected in the infarcted myocardium by quantitative real-time PCR. Following target prediction analysis, reporter gene assays confirmed that miR-31 targets the 3´UTR of cardiac troponin-T (Tnnt2), E2F transcription factor 6 (E2f6), mineralocorticoid receptor (Nr3c2) and metalloproteinase inhibitor 4 (Timp4) mRNAs. In vitro, hypoxia and oxidative stress up-regulated miR-31 and suppressed target genes in cardiac cell cultures, whereas LNA-based oligonucleotide inhibition of miR-31 (miR-31i) reversed its repressive effect on target mRNAs. Therapeutic post-ischemic administration of miR-31i in rats silenced cardiac miR-31 and enhanced expression of target genes, while preserving cardiac structure and function at 2 and 4weeks post-MI. Left ventricular ejection fraction (EF) improved by 10% (from day 2 to 30 post-MI) in miR-31i-treated rats, whereas controls receiving scrambled LNA inhibitor or placebo incurred a 17% deterioration in EF. miR-31i decreased end-diastolic pressure and infarct size; attenuated interstitial fibrosis in the remote myocardium and enhanced cardiac output. CONCLUSION: miR-31 induction after MI is deleterious to cardiac function while its therapeutic inhibition in vivo ameliorates cardiac dysfunction and prevents the development of post-ischemic adverse remodeling.