Project description:Stem cell-derived products could replace damaged heart muscle in regenerative cardiology. Here, human embryonic stem cells (hESCs) were differentiated on laminin 521+221 to cardiovascular progenitors (CVPs). The CVPs were transplanted into the infarcted region of 10 pigs and maintained for 4- and 12- weeks. Immunohistology analyses revealed in vivo engraftment and maturation of the CVPs into cardiomyocytes (CMs). Furthermore, heart function was analyzed by magnetic resonance imaging (MRI). We observed significant improvement in the left ventricular ejection fraction (DLVEF: 21.9 ± 1.6 %, at 12-weeks), ventricular wall thickness and wall motion, as well as a reduction in infarction size after CVP transplantation as compared to control pigs (p-value < 0.05). There are temporary episodes of ventricular tachyarrhythmia (VT) in four pigs and one pig had persistent VT. On the other hand, the remaining 5 pigs remained in normal sinus rhythm. Importantly, all pigs survived without any VT-related death, suggesting the potential for developing CVPs towards applications in regenerative cardiology.
Project description:We used transverse aortic constraction pressure overload hypertrophy mouse hearts as a model of cardiovascular disease to study the genetic changes between TAC and SHAM (normal) mouse hearts and over 1 circadian cycle (24h). This is one approach to identify diurnal genetic biomarkers of cardiovascular disease. The micorarray approach allowed to see the gene expression in all genes in cardiovascular disease and sham hearts. There are 36 samples of cardiovascular disease (TAC) and normal SHAM hearts. For TAC: There were 3 mice sacrificed at each time point as biological replicates, for 6 timepoints over 24 hrs. For SHAM: There were 3 mice sacrificed at each time point as biological replicates, for 6 timepoints over 24 hrs.
Project description:We used transverse aortic constraction pressure overload hypertrophy mouse hearts as a model of cardiovascular disease to study the genetic changes between TAC and SHAM (normal) mouse hearts and over 1 circadian cycle (24h). This is one approach to identify diurnal genetic biomarkers of cardiovascular disease. The micorarray approach allowed to see the gene expression in all genes in cardiovascular disease and sham hearts.
Project description:Myocardial infarction (MI) is the leading cause for hear failure (HF). Following MI, the non-infarcted region of left ventricle (LV) is critical for maintaining heart function, and disruption of the LV contributes greatly to post-MI HF. Transcriptomic profiling by high-throughput sequencing was performed in a chronic HF pig model, to explore the molecular changes in the post-MI LV related to cardiovascular deterioration. Samples were taken from heart tissue of MI-induced pigs and from control pigs not subjected to MI. Regions of the heart where samples were taken included the site of ischemia (LV ischemia), area bordering ischemia (LV border), area remote to ischemia (LV remote) and the right ventricle (RV).
Project description:IntroductionThe adult heart lacks the regenerative capacity to self-repair. Serum response factor (SRF) is essential for heart organogenesis, sarcomerogenesis, and contractility. SRF interacts with co-factors, such as NKX2.5 and GATA4, required for cardiac specified gene activity. ETS factors such as ELK1 interact with SRF and drive cell replication. To weaken SRF interactions with NKX2.5 and GATA4, one mutant, SRF153(A3) named STEMIN, did not bind CArG boxes, yet induced stem cell factors such as NANOG and OCT4, cardiomyocyte dedifferentiation, and cell cycle reentry. The mutant YAP5SA of the Hippo pathway also promotes cardiomyocyte proliferation and growth.AimInfarcted adult mouse hearts were injected with translatable STEMIN and YAP5SA mmRNA to evaluate their clinical potential.Methods and resultsMice were pulsed one day later with alpha-EDU and then heart sections were DAPI stained. Replicating cells were identified by immuno-staining against members of the DNA replisome pathway that mark entry to S phase of the cell cycle. Echocardiography was used to determine cardiac function following infarcts and mRNA treatment. To monitor cardiac wall repair, microscopic analysis was performed, and the extent of myocardial fibrosis was analyzed for immune cell infiltration. Injections of STEMIN and YAP5SA mmRNA into the left ventricles of infarcted adult mice promoted a greater than 17-fold increase in the DAPI stained and alpha-EDU marked cardiomyocyte nuclei, within a day. We observed de novo expression of phospho-histone H3, ORC2, MCM2, and CLASPIN. Cardiac function was significantly improved by four weeks post-infarct, and fibrosis and immune cell infiltration were diminished in hearts treated with STEMIN and YAP5SA mmRNA than each alone.ConclusionSTEMIN and YAP5SA mmRNA improved cardiac function and myocardial fibrosis in left ventricles of infarcted adult mice. The combinatorial use of mmRNA encoding STEMIN and YAP5SA has the potential to become a powerful clinical strategy to treat human heart disease.
Project description:We have observed that DBA/2J and C57Bl6/N mice exhibit different responses to permanent coronary artery ligation, with mice in a C57 background having about a 14-fold increase in cardiomyocyte S-phase activity as compared to DBA mice. We mapped the responsible gene to the distal arm of Chromosome 3 in the C57 background. We then RNA-Seq analyses on hearts from normal and infarcted DBA and C57 mice, with the hope of identifying candidate genes within the region of interest on the distal arm of Chromosome 3 which are differentially expressed. These genes identified Tnni3k as a potential candidate contributing to the elevated S-phase phenotype.
Project description:This dataset is a time series (1 hour [h], 4 hours, 24 hours, 48 hours, 1 week [w], and 8 weeks) intended to compare normal functioning left ventricles [lv + lv2] with infarcted [ilv] and non-infarcted left ventricles [nilv]. ilv samples are taken from the region between the LAD artery and the apex on a mouse with myocardial infarction. Lv2 samples are from the same region in a sham operated mouse. Nilv samples are taken from the region above the infartion and the left ventricle [lv] samples mimic that region in a sham mouse. The lv and lv2 samples can be compared as both are from normal functioning hearts. For more information visit http://cardiogenomics.med.harvard.edu/groups/proj1/pages/mi_home.html