Skeletal muscle possesses a remarkable capacity to regenerate when injured, but when confronted with major traumatic injury resulting in volumetric muscle loss (VML), the regenerative process consistently fails. The loss of muscle tissue and function from VML injury has prompted development of a suite of therapeutic approaches but these strategies have proceeded without a comprehensive understanding of the molecular landscape that drives the injury response. Herein, we administered a VML injury in an established rodent model and monitored the evolution of the healing phenomenology over multiple time points using muscle function testing, histology, and expression profiling by RNA sequencing. The injury response was then compared to a regenerative medicine treatment using orthotopic transplantation of autologous minced muscle grafts (~1?mm3 tissue fragments). A chronic inflammatory and fibrotic response was observed at all time points following VML. These results suggest that the pathological response to VML injury during the acute stage of the healing response overwhelms endogenous and therapeutic regenerative processes. Overall, the data presented delineate key molecular characteristics of the pathobiological response to VML injury that are critical effectors of effective regenerative treatment paradigms. Overall design: RNA-Seq time couse of muscle volumetric muscle loss injury healing with controls
Multiscale analysis of a regenerative therapy for treatment of volumetric muscle loss injury.
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View SamplesObesity is linked to the development of metabolic disorders. Expansion of white adipose tissue (WAT) from hypertrophy of pre-existing adipocytes and/or differentiation of precursors into new mature adipocytes contributes to obesity. We found that Nck2 expression is largely restricted to WAT, raising the hypothesis that it may play a unique function in that tissue. Using mice lacking Nck2, we found that Nck2 regulates adipocyte hypertrophy thus contributing to increased adiposity and progressive glucose intolerance, insulin resistance and hepatic steatosis. These findings were recapitulated in humans such that Nck2 expression in omental WAT was inversely correlated with the degree of obesity. Mechanistically, Nck2 deficiency promoted the induction of an adipocyte differentiation program and signaling by the PERK-eIF2a-ATF4 pathway in agreement with a role for the unfolded protein response in adipogenesis. These findings uncover Nck2 as a novel regulator of adipogenesis and that perturbation in its functionality contributes to adiposity-related metabolic disorders. Overall design: Differential gene expression profile between epididymal white adipose tissue of Nck2-/- and Nck2+/+ mice by RNA sequencing (Illumina HiSEq 2000)
Nck2 Deficiency in Mice Results in Increased Adiposity Associated With Adipocyte Hypertrophy and Enhanced Adipogenesis.
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View SamplesThe white adipose tissue (WAT) rapidly loses mass when mice are fed a diet containing trans-10, cis-12 conjugated linoleic acid (t10c12 CLA). A microarray analysis of WAT due to CLA feeding was performed to better define the processes and genes involved. WAT weight decreased by ca. 80% over 17 days of feeding a 0.5% t10c12 CLA diet. The lipid volume decreased by 90% and the number of adipocytes and total cells were reduced by15% and 47%, respectively. Microarray profiling of replicated pools of control and treated mice (n=140) at seven time points over the 17day feeding indicated between 2798 to 4318 genes showed mRNA changes of 2-fold or more. Transcript levels for genes of glucose and fatty acid import or biosynthesis were significantly reduced. A prolific inflammation response was indicated by the 2 to100-fold induction of many cytokine transcripts, including those for IL-6, IL1?, TNF ligands, and CXC family members
Trans-10, cis-12 conjugated linoleic acid causes inflammation and delipidation of white adipose tissue in mice: a microarray and histological analysis.
Age
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse 3T3-L1 adipocyte tissue culture. The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT). The early transcriptome changes in WAT were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Sex, Specimen part
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT) and 3T3-L1 adipocyte tissue culture; however in preadipocyte tissue (this series) the UPS/ISR and fat loss is not detected. The early transcriptome changes in 3T3-L1 preadipocyte tissue culture were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 12 hr after treatment do not show a set of genes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesTrans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse 3T3-L1 adipocyte tissue culture; however cis-9, trans-11 CLA does not (this series). The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to c9t11 CLA. Their gene expression responses between 8 to 12 hr after treatment showed no gene expression changes indicative of an integrated stress response (ISR).
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesTunycamcin induces UPR/ISR and Inflammation in mouse 3T3-L1 adipocyte tissue culture. The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to tunicamycin, to be compared with similar experiments with CLA as the treatment. Their gene expression responses between 4 to 12 hr after treatment showed a common set of early gene expression changes indicative of a UPR/Inflammation stress response.
Trans-10, cis-12 conjugated linoleic acid activates the integrated stress response pathway in adipocytes.
Cell line
View SamplesHeterochromatin protein 1a (HP1a) is a chromatin associated protein that has been well studied in many model organisms, such as Drosophila, where it is a determining factor for classical heterochromatin. HP1a is associated with the two histone methyltransferases SETDB1 and Su(var)3-9, which mediate H3K9 methylation marks and participate in the establishment and spreading of HP1a enriched chromatin. While HP1a is generally regarded as a factor that represses gene transcription, several reports have linked HP1a binding to active genes, and in some cases, it has been shown to stimulate transcriptional activity. To clarify the function of HP1a in transcription regulation and its association with Su(var)3-9, SETDB1 and the chromosome 4 specific protein POF, we conducted genome-wide expression studies and combined the results with available binding data in Drosophila melanogaster. The results suggested that HP1a has a repressing function on chromosome 4, where it preferentially targets non-ubiquitously expressed genes (NUEGs), and a stimulating function in pericentromeric regions. Further, we showed that the effects of SETDB1 and Su(var)3-9 are similar to HP1a, and on chromosome 4, Su(var)3-9, SETDB1 and HP1a target the same genes. In contrast, transposons are repressed by HP1a and Su(var)3-9 but are un-affected by SETDB1 and POF. In addition, we found that the binding level and expression effects of HP1a are affected by gene length. Our results indicate that genes have adapted to be properly expressed in their local chromatin environment.
HP1a, Su(var)3-9, SETDB1 and POF stimulate or repress gene expression depending on genomic position, gene length and expression pattern in Drosophila melanogaster.
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View SamplesStudy of single and double mutants of the two roX RNAs in D. melanogaster Overall design: Study of single and double mutants of the two roX RNAs in D. melanogaster
RNA-on-X 1 and 2 in Drosophila melanogaster fulfill separate functions in dosage compensation.
Specimen part, Cell line, Subject
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