Brown adipose tissue dissipates energy through heat and functions as a defense against cold and obesity. PPAR ligands have been shown to induce the browning of white adipocytes; however, the underlying mechanisms remain unclear. Here we show that PPAR ligands require full agonism to induce a brown fat gene program preferentially in subcutaneous white adipose. These effects require expression of PRDM16, a factor that controls the development of classical brown fat. Depletion of PRDM16 blunts the effects of the PPAR agonist rosiglitazone on the induced brown fat gene program. Conversely, PRDM16 and rosiglitazone synergistically activate the brown fat gene program in vivo. This synergy is tightly associated with an increased accumulation of PRDM16 protein, due in large measure to an increase in the half-life of the protein in agonist treated cells. Identifying compounds that stabilize PRDM16 protein may represent a novel therapeutic pathway for the treatment of obesity and diabetes.
PPARγ agonists induce a white-to-brown fat conversion through stabilization of PRDM16 protein.
Sex
View SamplesMedium conditioned by LLC cells stimulates thermogenic gene expression when added onto primary adipocytes. We generated single cell colonies from parental LLC cells. Media conditioned by the subclones stimulated thermogenic gene expression in primary adipocytes at varying degrees.
Tumour-derived PTH-related protein triggers adipose tissue browning and cancer cachexia.
Specimen part
View SamplesPPAR is a member of the nuclear receptor family for which agonist ligands have anti-growth effects. However, clinical studies using PPAR ligands as a monotherapy failed to show a beneficial effect. Here we have studied the effects of PPAR activation with chemotherapeutic agents in current use for specific cancers. We observed a striking synergy between rosiglitazone and platinum-based drugs in several different cancers both in vitro and using transplantable and chemically induced spontaneous tumor models. The effect appears to be due in part to PPAR-mediated downregulation of metallothioneins, proteins that have been shown to be involved in resistance to platinum-based therapy. These data strongly suggest combining PPAR agonists and platinum-based drugs for the treatment of certain human cancers
Synergy between PPARgamma ligands and platinum-based drugs in cancer.
No sample metadata fields
View SamplesPRDM16 is a 140 kDa transcriptional coregulatory protein. PRDM16 has been shown to function as a bi-directional switch in brown fat cell fate by stimulating the development of brown fat cells from myf-5 positive myoblastic precursors.
Initiation of myoblast to brown fat switch by a PRDM16-C/EBP-beta transcriptional complex.
Cell line
View SamplesSkeletal muscle must perform a wide range of kinds of work, and different fiber types have evolved to accommodate these different tasks. The attributes of fibers are determined in large part by the coordinated regulation of oxidative capacity, as reflected by mitochondrial content, and the specific makeup of myofibrillar proteins. Adult muscle fibers contain four myosin heavy chain isotypes: I, IIa, IIx and IIb. Type I and IIa fibers have slower twitches and are rich in mitochondria, while type IIb fibers are fast-twitch and predominantly glycolytic. The intermediate IIx fibers are less well understood. Previous work had shown that the transcriptional coactivator PGC-1 alpha could drive the formation of type I and IIa muscle fibers. We show here that mice with transgenic expression of PGC-1 beta in skeletal muscle results in marked induction of IIx fibers. The fibers in transgenic mice are rich in mitochondria and are highly oxidative. As a result, PGC-1 beta transgenic animals can perform oxidative activity for longer and at higher work loads than wild type animals. In cell culture, PGC-1 beta coactivates the MEF2 family of transcription factors to stimulate the MHC IIx promoter. Together, these data indicate that PGC-1 beta is sufficient to drive the formation in vivo of highly oxidative fibers with type IIx characteristics.
The transcriptional coactivator PGC-1beta drives the formation of oxidative type IIX fibers in skeletal muscle.
None
Sex, Specimen part
View SamplesPurpose: The goal of this study is to identify host genes whose expression is perturbed in primary CD4+ T cells by histone deacetylase (HDAC) inhibitors (HDACi) SAHA and RMD, which have different potencies and specificities for various HDACs. The study aims to evaluate the effects of SAHA and RMD that may promote or inhibit reactivation of HIV provirus out of latency. Methods: Peripheral blood mononuclear cells were collected from 4 HIV-seronegative donors. CD4+ T cells were isolated and utilized to generate an in vitro model of latent HIV infection (model developed in the Spina laboratory and previously described in Spina et al., 2013). Mock-infected cells were cultured in parallel to evaluate effects of SAHA and RMD that may be dependent on the exposure of cells to virus. Following generation of the model, cells were treated with SAHA, RMD or their solvent dimethyl sulfoxide (DMSO) for 24 hours. Mock-infected cells were treated in parallel. The experiment had 4 biological replicates, 6 conditions for each, for a total of 24 samples. ERCC spikes (Thermo Fisher Scientific, Inc.) were added to cell lysates based on cell number in each sample (10 ul of 1:800 dilution per million cells). Mix 1 was used for DMSO- and mix 2 for SAHA- and RMD-treated cells. After all samples were collected, RNA was extracted and subjected to deep sequencing by Expression Analysis, Inc. Sequence reads that passed quality filters were mapped using Tophat (human genome) or Bowtie (ERCC spikes and HIV) and counted using HTSeq. ERCC spikes with the same concentration in mixes 1 and 2 were utilized to remove unwanted technical variation. Any human gene which did not achieve at least 1 count per million reads in at least 4 samples or any ERCC that did not achieve at least 5 reads in at least 4 samples was discarded. Differential gene expression analysis was performed using library EdgeR in Bioconductor R. National Center for Biotechnology Information (NCBI) HIV-1 Human Interaction Database was then searched for genes that have been implicated in controlling HIV latency. EdgeR output was used to extract expression information of the genes of interest from the NCBI database to identify genes implicated in HIV latency that were modulated by SAHA and RMD. The resulting lists were manually curated to verify relevance to HIV latency, using the Description column of the NCBI database, as well as available PubMed references. Results: Using a custom built data analysis pipeline, ~100 million reads per sample were mapped to the human genome (build hg38). After applying filtering criteria, 16058 human transcripts, 19 ERCC spikes transcripts, and HIV NL4-3 transcripts were identified with the Tophat/Bowtie and HTSeq workflow. Differential expression analysis was performed between SAHA or RMD-treated and DMSO-treated cells. In addition, differential modulation of gene expression by SAHA and RMD in the model of HIV latency and mock-infected cells was assessed using EdgeR. In mock-infected cells, SAHA upregulated 3,971 genes and downregulated 2,940 genes; RMD upregulated 5,068 genes and downregulated 4,050 genes. In the model of HIV latency, SAHA upregulated 3,498 genes and downregulated 2,904 genes; RMD upregulated 5,116 genes and downregulated 4,053 genes (FDR < 0.05). SAHA modulated 6, and RMD 11 genes differentially between mock-infected cells and the model of HIV latency. Following search of the NCBI HIV-1 Human Interaction Database, 27 genes upregulated and 29 downregulated in common between SAHA and RMD were found to be relevant to regulation of HIV latency; 31 were up- and 32 downregulated by RMD only; and 6 were up- and 2 were downregulated by SAHA only. Conclusions: This study demonstrates that SAHA and RMD, which have different potencies and specificities for HDACs, modulate a set of overlapping genes implicated in regulation of HIV latency. Some of these genes may be explored as additional host targets for improving the outcomes of “shock and kill” strategies. Overall design: Transcriptomic profiling of the in vitro model of HIV latency and mock-infected cells treated with SAHA, RMD or the solvent DMSO (N=4 donors) by deep sequencing at Expression Analysis, Inc.
Long non-coding RNAs and latent HIV - A search for novel targets for latency reversal.
Specimen part, Treatment, Subject
View SamplesTo identify the activity-induced gene expression programs in inhibitory and excitatory neurons, we analyzed RNA extracted from cultured E14 mouse MGE- and CTX-derived neurons (DIV 10) after these cultures were membrane-depolarized for 0, 1 and 6 hrs with 55mM extracellular KCl. To identify the gene programs regulated in these cells by the activity-induced early-response transcription factor Npas4, we repeated the same experiment in the MGE- and CTX-cultures lacking Npas4 (Npas4-KO).
Npas4 regulates excitatory-inhibitory balance within neural circuits through cell-type-specific gene programs.
Specimen part, Treatment, Time
View SamplesParathyroid hormone (PTH) and PTH-related protein (PTHrP) are involved in cachexia associated with chronic kidney disease and cancer respectively. Tumor-derived PTHrP triggers adipose tissue browning and thereby leads to wasting of fat tissue in tumor-bearing mice. Similarly, elevated in 5/6 nephrectomized mice, PTH stimulates adipose tissue browning and wasting. Mice lacking the PTH/PTHrP receptor in their fat tissue are resistant to wasting of both adipose tissue and skeletal muscle. Therefore, the PTH/PTHrP signaling in adipocytes should activate various pathways that contribute to hypermetabolism and muscle wasting.
PTH/PTHrP Receptor Mediates Cachexia in Models of Kidney Failure and Cancer.
Sex, Specimen part
View SamplesES cell-derived neurons of forebrain identity were isolated by magnetic sorting, cultured for 7 days and transduced with either Nurr1 or eGFP lentivirus. After an additional 12 h in culture, mRNA was isolated and subjected to microarray analysis.
NR4A orphan nuclear receptors as mediators of CREB-dependent neuroprotection.
Specimen part
View SamplesCommitted preadipocyte fibroblasts were genetically labelled in transgenic mice by expressing GFP under the control of the locus for Zfp423, a gene controlling preadipocyte determination. These mice are herein referred to as Zfp423-GFP mice. The overall goal was to identify genes differentially expressed between adipogenic GFP+ firboblasts and non-adipogenic GFP- fibroblasts from either inguinal or epididymal fat stromal vascular cultures obtained from Zfp423-GFP mice.
Zfp423 expression identifies committed preadipocytes and localizes to adipose endothelial and perivascular cells.
Sex, Specimen part
View Samples