Skeletal muscle is composed of both slow-twich oxidative myofibers and fast-twitch glycolytic myofibers that differentially impact muscle metabolism, function, and eventually whole-body physiology. In the present study, we find that the mesodermal transcription factor T-box 15 (Tbx15) is highly and specifically expressed in glycolytic myofibers. Ablation of Tbx15 in vivo leads to a decrease in muscle size due to a decrease in the number of glycolytic fibers, associated with a small increase in the number of oxidative fibers. This shift in fiber composition results in muscles with slower myofiber contraction and relaxation, and also results in decreased whole-body oxygen consumption, decreased spontaneous activity, increased adiposity, and glucose intolerance. In order to identify genes regulated by Tbx15, we utilized C2C12 myoblasts with either a stable retroviral over-expression or stable lentiviral knockdown of Tbx15.
Tbx15 controls skeletal muscle fibre-type determination and muscle metabolism.
Specimen part, Cell line, Treatment
View SamplesThe T-box transcription factor TBX18 is essential to mesenchymal cell differentiation in several tissues and Tbx18 loss-of-function results in dramatic organ malformations and perinatal lethality. Here we demonstrate for the first time that Tbx18 is required for the normal development of periductal smooth muscle stromal cells in prostate, particularly in the anterior lobe, with a clear impact on prostate health in adult mice. Prostate abnormalities are only subtly apparent in Tbx18 mutants at birth; to examine postnatal prostate development we utilized a relatively long-lived hypomorphic mutant and a novel conditional Tbx18 allele. Similar to the ureter, cells that fail to express Tbx18 do not condense normally into smooth muscle cells of the periductal prostatic stroma. However, in contrast to ureter, the periductal stromal cells in mutant prostate assume a hypertrophic, myofibroblastic state and the adjacent epithelium becomes grossly disorganized. To identify molecular events preceding the onset of this pathology, we compared gene expression in the urogenital sinus (UGS), from which the prostate develops, in Tbx18-null and wild type littermates at two embryonic stages. Genes that regulate cell proliferation, smooth muscle differentiation, prostate epithelium development, and inflammatory response were significantly dysregulated in the mutant urogenital sinus around the time that Tbx18 is first expressed in the wild type UGS, suggesting a direct role in regulating those genes. Together, these results argue that Tbx18 is essential to the differentiation and maintenance of the prostate periurethral mesenchyme and that it indirectly regulates epithelial differentiation through control of stromal-epithelial signaling. Overall design: Embryos were collected from timed matings of Tbx18Gfp/+ knock-in mutants at E16.5 and E18.5, and genotyped to identify Tbx18Gfp/Gfp null mutants and wild-type (WT) littermates. The urogenital sinus (UGS) was dissected and used to extract RNA from each of three animals of each genotype. The RNA samples were pooled to generate libraries for sequencing.
Tbx18 Regulates the Differentiation of Periductal Smooth Muscle Stroma and the Maintenance of Epithelial Integrity in the Prostate.
Specimen part, Subject
View SamplesAcquisition and maintenance of vascular smooth muscle fate is essential for the morphogenesis and function of the circulatory system. Loss of contractile properties or changes in the identity of vascular smooth muscle cells (vSMC) can result in structural alterations associated with aneurysms and vascular wall calcifications. Here we report that maturation of sclerotome-derived vSMC is dependent on a transcriptional switch between mouse embryonic days 13 and 14.5. At this time point, Jag1-mediated repression of sclerotome transcription factors Pax1, scleraxis and Sox9 is necessary to fully enable vSMC maturation. Specifically, Notch signaling in vSMC antagonizes sclerotome and cartilage transcription factors, and promotes upregulation of contractile genes. In the absence of Jag1, vSMC acquire a chondrocytic transcriptional repertoire that can lead to ossification of the vascular wall. Importantly, our findings suggest that sustained Notch signaling is essential throughout vSMC life to maintain contractile function, prevent vSMC reprogramming and promote vascular wall integrity. Overall design: mRNA profile of vSMC from the descending aorta of 14.5 embryos Wild type (WT), SMC Jag1-heterozygous (HTZ) and SMC Jag1-null (KO) was generated by deep sequencing, in duplicate.
Repression of Sox9 by Jag1 is continuously required to suppress the default chondrogenic fate of vascular smooth muscle cells.
No sample metadata fields
View SamplesAcquisition and maintenance of vascular smooth muscle fate is essential for the morphogenesis and function of the circulatory system. Loss of contractile properties or changes in the identity of vascular smooth muscle cells (vSMC) can result in structural alterations associated with aneurysms and vascular wall calcifications. Here we report that maturation of sclerotome-derived vSMC is dependent on a transcriptional switch between mouse embryonic days 13 and 14.5. At this time point, Jag1-mediated repression of sclerotome transcription factors Pax1, scleraxis and Sox9 is necessary to fully enable vSMC maturation. Specifically, Notch signaling in vSMC antagonizes sclerotome and cartilage transcription factors, and promotes upregulation of contractile genes. In the absence of Jag1, vSMC acquire a chondrocytic transcriptional repertoire that can lead to ossification of the vascular wall. Importantly, our findings suggest that sustained Notch signaling is essential throughout vSMC life to maintain contractile function, prevent vSMC reprogramming and promote vascular wall integrity. Overall design: mRNA profile of vascular Smooth Muscle Cells, isolated from the descending aorta of Immorto mouse, treated or not with gamma-secretase inhibitor was generated by deep sequencing, in triplicate.
Repression of Sox9 by Jag1 is continuously required to suppress the default chondrogenic fate of vascular smooth muscle cells.
No sample metadata fields
View SamplesHuntingtons disease (HD) is an incurable hereditary neurodegenerative disorder, which manifests itself as a loss of GABAergic medium spiny (GABA MS) neurons in the striatum and caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. There is no cure for HD, existing pharmaceutical can only relieve its symptoms. Here, induced pluripotent stem cells were established from patients with low CAG repeat expansion in the huntingtin gene, and were then efficiently differentiated into GABA MS-like neurons under defined culture conditions. Analysis of differentially expressed genes between Huntingtons disease and wild type iPSCs derived GABA MS-like neurons has been performed.
Manifestation of Huntington's disease pathology in human induced pluripotent stem cell-derived neurons.
Age, Specimen part
View SamplesNeural precursor cells (NPCs) in the mammalian neocortex generate various neuronal and glial cell types in a developmental stage-dependent manner. Most neocortical NPCs lose their neurogenic potential after birth. We have previously shown that high mobility group A (HMGA) proteins confer the neurogenic potential on early-stage NPCs during the midgestation period, although the underlying mechanisms are not fully understood. Here we performed microarray analysis and compared expression profiles between control and HMGA2-overexpressed NPCs.
IMP2 regulates differentiation potentials of mouse neocortical neural precursor cells.
Specimen part
View SamplesRed light can affect a variety of responses in Arabidopsis. We characterize the early gene expression patterns of seedlings exposed to 1 hour of red light using a small sized sample of 5, 7-day-old seedlings and also performed dark controls.
Extraction and labeling methods for microarrays using small amounts of plant tissue.
No sample metadata fields
View SamplesPurpose: The ability of adult zebrafish tissues to undergo dedifferentiation provides an opportunity to probe the molecular underpinnings of cell identity and reprogramming. Zebafish muscle regeneration utilizes dedifferentiation to reprogram mature multinucleated myocytes into dedifferentiated myoblast that re-enter the cell cycle. A unique advantage of this system is that the regenerating cell mass is large and fairly homogenous, facilitating genomics approaches to uncovering the underlying biology. Methods: To better understand cellular reprogramming of mature myocytes, we temporally analyzed the changing transcriptome leading up to the proliferative switch. RNA was obtained after Laser Micro-dissection (LMD) of Control, 9 hour post-injury (HPI) or 18 HPI using Trizol and micro column purification. Illumina''s TruSeq Stranded mRNA Library Prep Kit and 0.1 - 4 µg total mRNA from pooled purified RNA samples were used for performing ribosomal-depletion (Ribo-Zero Gold rRNA Removal Kit, Illumina) and library preparation. Sequencing was performed by the UM DNA Sequencing Core, using an Illumina Hi-Seq 2000 (50-cycle, single end read) platform. Results: Clustering and functional annotation of differentially expressed genes highlighted the importance of catabolic and phagocytic processes upregulation at 9 and 18 hours post injury (hpi). Furthermore, genes encoding principle regulators of chromatin states were actively re-regulated during the reprogramming process. Utilizing the accessibility of these tissues in the zebrafish model, kKnockdown experiments enabled in vivo validation and phenotypic analysis of candidate genes and pathways for their roles in genomic and cellular reprogramming. Additionally, we found that despite of their low expression levels, lncRNAs were highly represented in gene clusters with dynamic, “switch-like” expression profiles, and that miRNA processing was also found important for reprogramming Conclusions: We conclude that reprogramming of a “post-mitotic” myocyte into a dedifferentiated myoblast requires both heritable yet nuanced epigenetic alterations and molecular switches that involve transcription factors, miRNA and lncRNA, while maintaining the lineage restriction of the cell of origin. Overall design: Early time points post injury (9 & 18 hours) mRNA and lncRNA profiles of Zebrafish lateral eye muscle (EOM) were generated by deep sequencing, in quadruplicate, using Illumina Hi-seq.
Temporally distinct transcriptional regulation of myocyte dedifferentiation and Myofiber growth during muscle regeneration.
No sample metadata fields
View SamplesMutations of the transcriptional regulator Mecp2 cause the X-linked autism spectrum disorder Rett syndrome (RTT), and Mecp2 has been implicated in several other neurodevelopmental disorders. To identify potential target genes regulated directly or indirectly by MeCP2, we performed comparative gene expression analysis via oligonucleotide microarrays on Mecp2-/y (Mecp2-null) and wild-type CPN purified via fluorescence-activated cell sorting (FACS).
Reduction of aberrant NF-κB signalling ameliorates Rett syndrome phenotypes in Mecp2-null mice.
Specimen part
View SamplesThese investigations studied the fundamentals of how plants perceive gravity and develop in microgravity. It informs how gene regulation is altered by spaceflight conditions.
Comparative transcriptomics indicate changes in cell wall organization and stress response in seedlings during spaceflight.
Specimen part
View Samples