Type 2 diabetes is characterized by excessive lipid storage in skeletal muscle. Excessive intramyocellular lipid storage exceeds intracellular needs and induces lipotoxic events ultimately contributing to the development of insulin resistance. Lipid droplet (LD)-coating proteins may control proper lipid storage in skeletal muscle. Perilipin 2 (PLIN2/ADRP) is one of the most abundantly expressed LD-coating proteins in skeletal muscle. Here we examined the role of PLIN2 in myocellular lipid handling and insulin sensitivity by investigating the effects of in vitro PLIN2 knockdown and in vitro and in vivo overexpression. PLIN2 knockdown decreased LD formation and triacylglycerol storage, marginally increased FA oxidation, and increased incorporation of palmitate into diacylglycerols and phospholipids. PLIN2 overexpression in vitro increased intramyocellular TAG storage paralleled with improved insulin sensitivity. In vivo muscle-specific PLIN2 overexpression resulted in increased LD accumulation and blunted the high-fat diet-induced increase of OXPHOS protein content. Diacylglycerol levels were unchanged, while ceramide levels were increased. Despite the increased intramyocellular lipid accumulation, PLIN2 overexpression improved skeletal muscle insulin sensitivity. We conclude that PLIN2 is essential for lipid storage in skeletal muscle by enhancing the partitioning of excess FAs towards triacylglycerol storage in LDs thereby blunting lipotoxicity-associated insulin resistance.
Perilipin 2 improves insulin sensitivity in skeletal muscle despite elevated intramuscular lipid levels.
Cell line
View SamplesFOG-1/CPEB and FOG-3/Tob are the terminal regulators of the sex determination in C. elegans germ cells. CPEB and Tob proteins are both translational regulators. To investigate how FOG-1 and FOG-3 regulate germ cell sex determination we sought to identify the target mRNAs. We used transgenic epitope tagged animals (3xMyc::FOG-1 and FOG-3::3xFLAG). To identify the mRNA targets of FOG-1/CPEB and FOG-3/Tob on a genome wide scale we used RNA immunoprecipitation followed by microarray analysis. We found 81 putative mRNA targets of FOG-1 and 722 putative targets of FOG-3. 76 target mRNAs were common to both FOG-1 and FOG-3.
Genomic Analyses of Sperm Fate Regulator Targets Reveal a Common Set of Oogenic mRNAs in Caenorhabditis elegans.
Specimen part
View SamplesTranscriptome analysis by RNA-seq of lungs from control and Rfwd2 epithelial-specific conditional knockout mice at embryonic 13.5 day age. RFWD2, is an E3 ubiquitin ligase that modifies specific target proteins, priming their degradation via the ubiquitin proteasome system. Rfwd2 deficiency led to a striking halt in branching morphogenesis shortly after secondary branch formation. In the mutant lung, two ETS transcript factors essential for normal lung branching, ETV4 and ETV5, were upregulated at the protein, but not transcript level. Introduction of Etv loss-of-function alleles into the Rfwd2 mutant background attenuated the branching phenotype, suggesting that RFWD2 functions at least in part through degrading ETV proteins. As a number of E3 ligases are known to target factors important for lung development, our findings provides a preview of a protein-level regulatory network essential for lung branching morphogenesis. Overall design: Total mRNA obtained from three samples per group (control and Rfwd2 conditional knockout)
E3 ubiquitin ligase RFWD2 controls lung branching through protein-level regulation of ETV transcription factors.
Specimen part, Subject
View SamplesWe generated chimeric mice with livers that were predominantly repopulated with human hepatocytes. Hepatocytes were isolated from the chimeric mouse livers and their gene expressions were compared with hepatocytes isolated from normal human livers . Cluster and principal components analyses showed that gene expression profiles of hepatocytes from the chimeric mice and those from normal human livers were extremely closed.
Morphological and microarray analyses of human hepatocytes from xenogeneic host livers.
Sex, Age, Specimen part, Race
View SamplesWe performed microarray experiments to examine gene expression in human tissues. This data was used for comparison with our humanized mouse study (GEO ID GSE33846) and threshold determination of our tiling array data (GEO ID GSE18490, public in the near future).
Morphological and microarray analyses of human hepatocytes from xenogeneic host livers.
Specimen part, Cell line, Race
View SamplesETV4 and ETV5 are FGF-activated transcription factor genes. Inactivation of Etv4 and Etv5 in the lung epithelium led to prolonged branch tip growth and delayed new branch formation.
FGF-Regulated ETV Transcription Factors Control FGF-SHH Feedback Loop in Lung Branching.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genetically Engineered iPSC-Derived FTDP-17 MAPT Neurons Display Mutation-Specific Neurodegenerative and Neurodevelopmental Phenotypes.
Specimen part, Treatment
View SamplesThe development of an effective therapy against tauopathies like Alzheimers disease (AD) and frontotemporal dementia (FTD) remains challenging, partly due to limited access to fresh brain tissue, the lack of translational in vitro disease models and the fact that underlying molecular pathways remain to be deciphered. Several genes play an important role in the pathogenesis of AD and FTD, one of them being the MAPT gene encoding the microtubule-associated protein tau. Over the past few years, it has been shown that induced pluripotent stem cells (iPSC) can be used to model various human disorders and can serve as translational in vitro tools. Therefore, we generated iPSC harboring the pathogenic FTDP-17 (frontotemporal dementia and parkinsonism linked to chromosome 17) associated mutations IVS10+16 with and without P301S in MAPT using Zinc Finger Nuclease technology. Whole transcriptome analysis of MAPT IVS10+16 neurons reveals neuronal subtype differences, reduced neural progenitor proliferation potential and aberrant WNT signaling. Notably, all phenotypes were recapitulated using patient-derived neurons. Finally, an additional P301S mutation causes an increased calcium bursting frequency, reduced lysosomal acidity and tau oligomerization.
Genetically Engineered iPSC-Derived FTDP-17 MAPT Neurons Display Mutation-Specific Neurodegenerative and Neurodevelopmental Phenotypes.
Treatment
View SamplesThe development of an effective therapy against tauopathies like Alzheimers disease (AD) and frontotemporal dementia (FTD) remains challenging, partly due to limited access to fresh brain tissue, the lack of translational in vitro disease models and the fact that underlying molecular pathways remain to be deciphered. Several genes play an important role in the pathogenesis of AD and FTD, one of them being the MAPT gene encoding the microtubule-associated protein tau. Over the past few years, it has been shown that induced pluripotent stem cells (iPSC) can be used to model various human disorders and can serve as translational in vitro tools. Therefore, we generated iPSC harboring the pathogenic FTDP-17 (frontotemporal dementia and parkinsonism linked to chromosome 17) associated mutations IVS10+16 with and without P301S in MAPT using Zinc Finger Nuclease technology. Whole transcriptome analysis of MAPT IVS10+16 neurons reveals neuronal subtype differences, reduced neural progenitor proliferation potential and aberrant WNT signaling. Notably, all phenotypes were recapitulated using patient-derived neurons. Finally, an additional P301S mutation causes an increased calcium bursting frequency, reduced lysosomal acidity and tau oligomerization.
Genetically Engineered iPSC-Derived FTDP-17 MAPT Neurons Display Mutation-Specific Neurodegenerative and Neurodevelopmental Phenotypes.
Specimen part, Treatment
View SamplesOzone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Wild type (WT), Notch3 (Notch3-/-) and Notch4 (Notch4-/-) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6-72 hours. Ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4-/- compared to WT and Notch3-/-. Significantly greater mean numbers of BALF neutrophils were found in Notch3-/- and Notch4-/- mice compared to WT mice after ozone. Expression of whole lung Tnf was significantly increased after ozone in all genotypes, and was significantly greater in Notch3-/- mice compared to WT. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation.
Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice.
Specimen part
View Samples