ABSTRACT: A unique herpesviral transcriptional program in KSHV-infected lymphatic endothelial cells leads to mTORC1 activation and rapamycin sensitivity
Project description:This SuperSeries is composed of the following subset Series: GSE16353: The profile of cellular and KSHV microRNAs in AIDS_KS biopsies (and normal skin control biopsies) GSE16354: Infection of Lymphatic and Blood Vessel Endothelial Cells (LEC and BEC) with KSHV GSE16355: Lymphatic endothelial cells (LEC) transfected with the KSHV microRNA cluster GSE16356: Lymphatic endothelial cells (LEC) treated with a MAF-targeted siRNA Refer to individual Series
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions.The disease is caused by the KSHV virus (HHV8) and is recognisable by its distinctive red skin lesions. The lesions are KSHV infected spindle cells expressing markers of the lymphatic endothelial and blood vessel endothelial cells as well as other cell types. The effects of KSHV infection of lymphatic endothelial cells (LEC) cultured in 3D matrix for three days were assayed using Affymetrix hgu133plus2 chips. There are n=3 of 1. control LEC spheroids (LEC), 2. KSHV infected LEC spheroids (K-LEC)
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions. The disease is caused by the KSHV virus (HHV8) and is recognizable by its distinctive red skin lesions. The lesions are KSHV infected spindle cells, most commonly the lymphatic endothelial and blood vessel endothelial cells (LEC and BEC), plus surrounding stroma. The effects of KSHV infection of LECs were assayed using Affymetrix hgu133plus2 chips at 6 and 72 hours post infection. There were n=4 each of lymphatic endothelial cells (LEC) following 6 hours of culture, LEC following 6 hours post KSHV infection, LEC following 72 hours of culture, and LEC following 72 hours post KSHV infection.
Project description:Here, we show that CR enhances regenerative capacity of the intestinal epithelium as a result of increased number of reserve ISCs. We observe that precise regulation of mechanistic target of Rapamycin complex 1 (mTORC1) signaling plays a significant role in regulation of sensitivity of reserve intestinal stem cells to injury and that premature activation of mTORC1 signaling through nutrient modulation, at the time of damage, leads to poor regeneration outcome. These data delineate a critical role for mTORC1 signaling in epithelial regeneration and inform clinical strategies based on nutrient modulation of mTORC1 activity.
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions.The disease is caused by the KSHV virus (HHV8) and is recognisable by its distinctive red skin lesions. The lesions are KSHV infected spindle cells expressing markers of the lymphatic endothelial and blood vessel endothelial cells as well as other cell types. The effects of KSHV infection of lymphatic endothelial cells (LEC) cultured in 3D matrix for three days were assayed using Affymetrix hgu133plus2 chips.
Project description:The mechanistic target of rapamycin complex 1 (mTORC1) integrates cellular nutrient signaling and hormonal cues to control metabolism. We have previously shown that constitutive nutrient signaling to mTORC1 by means of genetic activation of RagA (RagAGTP) in mice resulted in a fatal energetic crisis at birth. Herein, we have rescued neonatal lethality in RagAGTP mice and found morphometric and metabolic alterations that span glucose, lipid, ketone, bile acid and amino acid homeostasis in adults, and a median lifespan of nine months. Proteomic and metabolomic analyses of livers from RagAGTP mice revealed a failed metabolic adaptation to fasting due to a global impairment in PPARα transcriptional program. These metabolic defects were partially recapitulated by restricting activation of RagA to hepatocytes, and reverted by pharmacological inhibition of mTORC1. Constitutive hepatic nutrient signaling did not cause hepatocellular damage and carcinomas, unlike genetic activation of growth factor signaling upstream of mTORC1. In summary, RagA signaling dictates dynamic responses to feeding-fasting cycles to tune metabolism so as to match the nutritional state.
Project description:We performed high throughput RNA-sequencing on KSHV-infected blood and lymphatic Endothelial Colony-Forming Cells at 48hpi to identify differences in gene expression induced by KSHV in these two cell types.
Project description:Alternative RNA splicing greatly increases proteome diversity, and the possibility of studying genome-wide alternative splicing (AS) events becomes available with the advent of high-throughput genomics tools devoted to this issue. Kaposi’s sarcoma associated herpesvirus (KSHV) is the etiological agent of KS, a tumor of lymphatic endothelial cell (LEC) lineage, but little is known about the AS variations induced by KSHV. We analyzed KSHV-controlled AS using high-density microarrays capable of detecting all exons in the human genome. Splicing variants and altered exon-intron usage in infected LEC were found, and these correlated with protein domain modification. The different 3’ UTR used in new transcripts also help isoforms to escape microRNA-mediated surveillance. Exome-level analysis further revealed information that cannot be disclosed using classical gene-level profiling: a significant exon usage difference existed between LEC and CD34+ precursor cells, and KSHV infection resulted in LEC-to-precursor, dedifferentiation-like exon level reprogramming. Our results demonstrate the application of exon arrays in systems biology research, and suggest the regulatory effects of AS in endothelial cells are far more complex than previously observed. This extra layer of molecular diversity helps to account for various aspects of endothelial biology, KSHV life cycle and disease pathogenesis that until now have been unexplored. 5 samples were analyzed. 3 were KSHV infected lymphatic endothelial cells (LECs), and 2 were non-infected control samples.
Project description:Kaposi sarcoma is the most common cancer in AIDS patients and is typified by red skin lesions. The disease is caused by the KSHV virus (HHV8) and is recognisable by its distinctive red skin lesions. The lesions are KSHV-infected spindle cells, most commonly the lymphatic endothelial and blood vessel endothelial cells (LEC and BEC), plus surrounding stroma. The KSHV virus expresses multiple microRNA in a single cluster. Here we test the effects of this KSHV microRNA cluster in LEC cells using Affymetrix hgu133plus2 chips. Experiment Overall Design: There are n=3 of: 1. LEC control with empty vector pSIN-MCS (LEC), 2. LEC transfected with the same vector containing the KSHV microRNA cluster.
Project description:Aberrant activation of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) is a common molecular event in a large variety of pathological settings, including genetic tumor syndromes, cancer, and obesity. However, the cell intrinsic consequences of mTORC1 activation remain poorly defined. Here, we identify global trancriptional changes in TSC1 and TSC2 null MEFs, which exhibit constitutive activation of mTORC1, compared to wild-type littermate control lines. A rapamycin time course is included to determine those changes that are dependent on mTORC1 signaling, revealing mTORC1 induced and repressed transcripts. In order to identify mTORC1-dependent transcriptional changes, we compared wild-type MEFs to both Tsc1-/- and Tsc2-/- MEFs following serum starvation, where mTORC1 signaling is off in wild-type cells and fully active in TSC-deficient cells. All cell lines were serum-starved for 24 h, and the Tsc1-/- and Tsc2-/- cells were treated with a time course of rapamycin prior to the isolation of mRNA for microarray analysis. Immortalized wild-type (Tsc2+/+ p53-/-), Tsc1-/- (p53+/+, 3T3-immortalized), and Tsc2-/- (p53-/-, derived from a littermate of the wild-type cell line) MEFs are the three cell lines used in this study and were derived in the laboratory of David J. Kwiatkowski (Brigham and Women's Hospital, Harvard Medical School, Boston, MA). Wild-type and null MEFs were grown to 70% confluence in 10 cm plates and were serum starved for 24 h in the presence of vehicle (DMSO) for 24 h or rapamycin (20 nM) for 2, 6, 12, or 24 h. All vehicle-treated samples (0 h time points) were plated in triplicate and all rapamycin time course samples were plated in duplicate. For each replicate, expression analysis was performed by hybridization to an Affymetrix Mouse 430_2 oligonucleotide microarray chip.