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SRP057984
Mus musculus
24 Downloadable Samples
Illumina HiSeq 2500
Description
Conversion of fibroblasts to functional cardiomyocytes represents a potential approach for restoring cardiac function following myocardial injury, but the technique thus far has been slow and inefficient. To improve the efficiency of reprogramming fibroblasts to cardiac-like myocytes (iCMs) by cardiac transcription factors (Gata4, Hand2, Mef2c, and Tbx5=GHMT), we screened 192 protein kinases and discovered that Akt/protein kinase B dramatically accelerates and amplifies this process. Approximately 50% of reprogrammed fibroblasts displayed spontaneous beating after three weeks of induction by Akt plus GHMT. Furthermore, addition of Akt1 to GHMT evoked a more mature cardiac phenotype for iCMs, as seen by enhanced polynucleation, cellular hypertrophy, gene expression, and metabolic reprogramming. Igf1 and Pi3 kinase acted upstream of Akt, whereas mTORC1 and Foxo3a acted downstream of Akt to influence fibroblast-to-cardiomyocyte reprogramming. These findings provide new insights into the molecular basis of cardiac reprogramming and represent an important step toward further application of this technique. Overall design: We performed RNA-Seq using either isolated adult mouse ventricular cardiomyocytes (CMs) or MEFs treated for three weeks with empty vector, GHMT (iCMs cell sorted using aMHC-GFP before RNA-Seq), or AGHMT (iCMs cell sorted using aMHC-GFP before RNA-Seq).
Publication Title
Akt1/protein kinase B enhances transcriptional reprogramming of fibroblasts to functional cardiomyocytes.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
Myocardin-related transcription factors (MRTFs) play a central role in the regulation of actin expression and cytoskeletal dynamics. Stimuli that promote actin polymerization allow for shuttling of MRTFs to the nucleus where they activate serum response factor (SRF), a regulator of actin and other cytoskeletal protein genes. SRF is an essential regulator of skeletal muscle differentiation and numerous components of the muscle sarcomere, but the potential involvement of MRTFs in skeletal muscle development has not been examined. We explored the role of MRTFs in muscle development in vivo by generating mutant mice harboring a skeletal muscle-specific deletion of MRTF-B and a global deletion of MRTF-A. These double knockout (dKO) mice were able to form sarcomeres during embryogenesis. However, the sarcomeres were abnormally small and disorganized, causing skeletal muscle hypoplasia and perinatal lethality. Transcriptome analysis demonstrated dramatic dysregulation of actin genes in MRTF dKO mice, highlighting the importance of MRTFs in actin cycling and myofibrillogenesis. MRTFs were also necessary for the survival of skeletal myoblasts and for the efficient formation of intact myotubes. Our findings reveal a central role for MRTFs in sarcomere formation during skeletal muscle development and point to the potential involvement of these transcriptional coactivators in skeletal myopathies. Overall design: Gene expression profile was generated comparing wild type (WT) and HSA-Cre, MRTF-A/B double knockout mice, by deep seqencing, with three biological replicates, using Illumina HiSeq 2500.
Publication Title
Myocardin-related transcription factors are required for skeletal muscle development.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
The Mediator complex regulates gene transcription by linking basal transcriptional machinery with DNA-bound transcription factors. The activity of the Mediator complex is mainly controlled by a kinase submodule that is comprised of four proteins, including MED12. Although ubiquitously expressed, Mediator subunits can differentially regulate gene expression in a tissue-specific manner. Here, we report that MED12 is required for normal cardiac function such that mice with conditional cardiac-specific deletion of MED12 display progressive dilated cardiomyopathy. Loss of MED12 perturbs expression of calcium handling genes in the heart, consequently altering calcium cycling in cardiomyocytes and disrupting cardiac electrical activity. We identified transcription factors that regulate expression of calcium-handling genes that are downregulated in the heart in the absence of MED12, and found that MED12 localizes to transcription factor consensus sequences within calcium handling genes. We showed that MED12 interacts with one such transcription factor, MEF2, in cardiomyocytes, and that MED12 and MEF2 co-occupy promoters of calcium handling genes. Furthermore, we demonstrated that MED12 enhances MEF2 transcriptional activity and overexpression of both increases expression of calcium handling genes in cardiomyocytes. Our data support a role for MED12 as a coordinator of transcription through MEF2 and other transcription factors. We conclude that MED12 is a regulator of a network of calcium handling genes, consequently “mediating” contractility in the mammalian heart. Overall design: Ventricle mRNA profiles of 1-day old control (CTL, CreNEG) and cardiac-specific Med12 knockout mice (Med12cKO, CrePOS) were generated by deep sequencing, in triplicate, using Illumina.
Publication Title
MED12 regulates a transcriptional network of calcium-handling genes in the heart.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
The purpose of this experiment is to anlyze the transcriptomic changes associated with Notch inhibition, by DAPT treatment, during cardiac reprogramming mediated by GHMT (Gata4, Hand2, Mef2c anf Tbx5). Overall design: RNA-seq was performed on MEFs infected with GHMT (Gata4, Hand2, Mef2c anf Tbx5) and treated for 15 days with DMSO (vehicle) or DAPT.
Publication Title
Notch Inhibition Enhances Cardiac Reprogramming by Increasing MEF2C Transcriptional Activity.
Sample Metadata Fields
Specimen part, Cell line, Treatment, Subject
View Samples- Mus musculus
- 4 Downloadable Samples
- Illumina HiSeq 2500
Description
Myocardin-Related Transcription Factors A and B (MRTF-A and MRTF-B) are highly homologous proteins that function as powerful coactivators of serum response factor (SRF), a ubiquitously expressed transcription factor essential for cardiac development. The SRF/MRTF complex binds to CArG boxes found in the control regions of genes that regulate cytoskeletal dynamics and muscle contraction, among other processes. While SRF is required for heart development and function, the role of MRTFs in the developing or adult heart has not been explored. Through cardiac-specific deletion of MRTF alleles in mice, we show that either MRTF-A or MRTF-B is dispensable for cardiac development and function, whereas deletion of both MRTF-A and MRTF-B causes a spectrum of structural and functional cardiac abnormalities. Defects observed in MRTF-A/B null mice ranged from reduced cardiac contractility and adult onset heart failure to neonatal lethality accompanied by sarcomere disarray. RNA-seq analysis on neonatal hearts identified the most altered pathways in MRTF double knockout hearts as being involved in cytoskeletal organization. Together, these findings demonstrate redundant but essential roles of the MRTFs in maintenance of cardiac structure and function and as indispensible links in cardiac cytoskeletal gene regulatory networks. Overall design: P0 Heart mRNA profiles of wild-type (WT) and MRTFA/B double knockout animals were generated in duplicate using DeepSeq using Illumina HiSeq 2500
Publication Title
Myocardin-related transcription factors are required for cardiac development and function.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
- Illumina HiSeq 2500
Description
We profiled the gene expression/splicing program of normal and hnRNP U-deficient mouse hearts by RNA-seq. Overall design: RNA-seq profiles of control and Hnrnpu mutant hearts at postnatal day 14. Hnrnpu mutant hearts were generated by breeding the Hnrnpu conditional knockout mice with Ckmm-Cre transgenic mice.
Publication Title
hnRNP U protein is required for normal pre-mRNA splicing and postnatal heart development and function.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
Skeletal muscle possesses remarkable regenerative potential due to satellite cells, a stem cell population located beneath the muscle basal lamina. By lineage tracing of progenitor cells expressing the Twist2 (Tw2) transcription factor in mice, we discovered a unique myogenic lineage that resides outside the basal lamina of adult muscle and contributes specifically to type IIb/x myofibers during adulthood and muscle regeneration. Tw2+ progenitors are molecularly and anatomically distinct from satellite cells, are highly myogenic in vitro and can fuse with satellite cells. Transplantation of Tw2+ progenitors into adult mice is sufficient to reconstitute new myofibers, and genetic ablation of endogenous Tw2+ progenitors causes wasting of type IIb myofibers. We show that Tw2 expression maintains progenitor cells in an undifferentiated state that is poised to initiate myogenesis in response to appropriate cues that suppress Tw2 expression. Tw2-expressing progenitors represent a previously unrecognized, fiber-type specific progenitor cell involved in muscle growth and regeneration. Overall design: Gene expression profile was generated by comparing freshly sorted Twist2+ and Pax7+ cells from skeletal muscle
Publication Title
A Twist2-dependent progenitor cell contributes to adult skeletal muscle.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 8 Downloadable Samples
- Illumina HiSeq 2500
Description
Skeletal muscle possesses remarkable regenerative potential due to satellite cells, a stem cell population located beneath the muscle basal lamina. By lineage tracing of progenitor cells expressing the Twist2 (Tw2) transcription factor in mice, we discovered a unique myogenic lineage that resides outside the basal lamina of adult muscle and contributes specifically to type IIb/x myofibers during adulthood and muscle regeneration. Tw2+ progenitors are molecularly and anatomically distinct from satellite cells, are highly myogenic in vitro and can fuse with satellite cells. Transplantation of Tw2+ progenitors into adult mice is sufficient to reconstitute new myofibers, and genetic ablation of endogenous Tw2+ progenitors causes wasting of type IIb myofibers. We show that Tw2 expression maintains progenitor cells in an undifferentiated state that is poised to initiate myogenesis in response to appropriate cues that suppress Tw2 expression. Tw2-expressing progenitors represent a previously unrecognized, fiber-type specific progenitor cell involved in muscle growth and regeneration. Overall design: Gene expression profile was generated by comparing Twist2- or GFP-overexpressing Tw2 myoblasts before and after differentiation.
Publication Title
A Twist2-dependent progenitor cell contributes to adult skeletal muscle.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
The heart requires a continuous supply of energy but has little capacity for energy storage and thus relies on exogenous metabolic sources. We previously showed that cardiac MED13 modulates systemic energy homeostasis in mice. Here we sought to define the extra-cardiac tissue(s) that respond to cardiac MED13 signaling. We show that cardiac over-expression of MED13 in transgenic (MED13cTg) mice confers a lean phenotype that is associated with increased lipid uptake, beta-oxidation and mitochondrial content in white adipose tissue (WAT) and liver. Cardiac expression of MED13 decreases metabolic gene expression and metabolite levels in heart and liver but enhances them in WAT. Although exhibiting increased energy expenditure in the fed state, MED13cTg mice metabolically adapt to fasting. Furthermore, MED13cTg hearts oxidize fuel that is readily available, rendering them more efficient in the fed state. Parabiosis experiments in which circulations of wild-type and MED13cTg mice are joined, reveal that circulating factor(s) in MED13cTg mice promote enhanced metabolism and leanness. These findings demonstrate that MED13 acts within the heart to promote systemic energy expenditure in extra-cardiac energy depots and point to an unexplored metabolic communication system between the heart and other tissues. Overall design: n=3 for each genotype and organ
Publication Title
MED13-dependent signaling from the heart confers leanness by enhancing metabolism in adipose tissue and liver.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 3 Downloadable Samples
Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Reprogramming of mouse fibroblasts toward a myocardial cell fate by forced expression of cardiac transcription factors or microRNAs has recently been demonstrated. The potential clinical applicability of these findings is based on the minimal regenerative potential of the adult human heart and the limited availability of human heart tissue. An initial, but mandatory step toward clinical application of this approach is to establish conditions for conversion of adult human fibroblasts to a cardiac phenotype. Toward this goal, we sought to determine the optimal combination of factors necessary and sufficient for direct myocardial reprogramming of human fibroblasts. Here we show that four human cardiac transcription factors, including Gata4, Hand2, Tbx5, and myocardin, and two microRNAs, miR-1 and miR-133, activated cardiac marker expression in neonatal and adult human fibroblasts. After maintenance in culture for 4-11 weeks, human fibroblasts reprogrammed with these proteins and microRNAs displayed sarcomere-like structures and calcium transients, and a small subset of such cells exhibited spontaneous contractility. These phenotypic changes were accompanied by expression of a broad range of cardiac genes and suppression of non-myocyte genes. These findings indicate that human fibroblasts can be reprogrammed to cardiac-like myocytes by forced expression of cardiac transcription factors with muscle-specific microRNAs and represent a step toward possible therapeutic application of this reprogramming approach.
Publication Title
Reprogramming of human fibroblasts toward a cardiac fate.
Sample Metadata Fields
Specimen part
View Samples