Project description:We have evaluated the microRNA expression profile of SUM159 cells stably infected with a control shRNA or a dicer-targeting shRNA treated with vehicle or metformin for 24 hrs at non cytotoxic doses. microRNA expression was evaluated from total RNA extracted from logaritmically growing SUM159 cells stably expressing a control shRNA or a dicer-targeting shRNA and treated with vehicle (PBS) or metformin (0.5mM) for 24 hrs.
Project description:We stably infected IMR90 fibroblasts with lentiviral vectors expressing doxycycline-inducible TRF2dBdM or vector control. Cells were treated with 1mg/ml of doxycycline for 7 days to induce senescence in the cells expressing TRF2dBdM before collecting RNA. IMR90 cells, either young (passage 10, population doubling ~20) or old (passage 24, population doubling ~40-48) were also used as a model of replicative senescence. The transcriptomes were analyzed using RNA microarrays.
Project description:This experiment includes treatment of human pulmonary fibroblasts obtained from IPF patients with metformin. Since, we would like to investigate the transcriptome profile of these samples following metformin treatment. There will be two groups consist of four samples each. First group treated with metformin for 72 hours, while the second group treated with vehicle.
Project description:We have evaluated the microRNA expression profile of SUM159 cells stably infected with a control shRNA or a dicer-targeting shRNA treated with vehicle or metformin for 24 hrs at non cytotoxic doses.
Project description:Purpose: The purpose of this experiment was to determine the time point following activation at which greatest transcriptional differences in metabolic genes were observed between primary human CD4+ T cells treated with metformin + 2-deoxyglucose combination regimen and cells treated with vehicle. Methods: Targeted RNA-Seq data was generated from primary human CD4+ T cell mRNA using a Qiagen custom designed panel of metabolic genes and the Illumina TruSeq stranded mRNA prep. Results: We obtained differential gene expression between metformin + 2-deoxyglucose and vehicle-treated cells using the DESeq2 app in Illumina Basespace for a set of metabolic genes during different time points following activation, and found the greatest changes at 24hr.
Project description:Metformin reduces the incidence of cancer in diabetics or in animal models. At the cellular level, the effects of metformin include the inhibition of complex I of the mitochondrial electron transport chain, a reduction in ATP levels and the activation of the energy sensor AMP kinase. Metformin also prevents the production of reactive oxygen species in primary human cells expressing oncogenic ras and the DNA damage associated to the process. We used microarrays to characterize the gene expression changes induced by metformin in primary human fibroblasts expressing oncogenic ras.
Project description:The expansion of repressive epigenetic marks has been implicated in heterochromatin formation during embryonic development, but the general applicability of this mechanism is unclear. Here we show that nuclear rearrangement of repressive histone marks H3K9me3 and H3K27me3 into non-overlapping structural layers characterizes senescence-associated heterochromatic foci (SAHF) formation in human fibroblasts. However, the global landscape of these repressive marks remains unchanged upon SAHF formation, suggesting that in somatic cells heterochromatin can be formed through the spatial repositioning of pre-existing repressively marked histones. This model is reinforced by the correlation of pre-senescent replication timing with both the subsequent layered structure of SAHFs and the global landscape of the repressive marks, allowing us to integrate microscopic and genomic information. Furthermore, modulation of SAHF structure does not affect the occupancy of these repressive marks nor vice versa. These experiments reveal that high-order heterochromatin formation and epigenetic remodeling of the genome can be discrete events. ChIP-seq for different histone marks in both growing and Ras-induced senescent fibroblasts, in the presence or absence of certain sh-RNAs K9me3Grow2.bed (growing) Chip Seq Analysis of H3K9me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K9me3Sen2.bed (senescent) Chip Seq Analysis of H3K9me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K9me2Grow3.bed (growing) Chip Seq Analysis of H3K9me2 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K9me2Sen3.bed (senescent) Chip Seq Analysis of H3K9me2 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K27me3Sen3.bed (senescent) Chip Seq Analysis of H3K27me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K27me3Grow2.bed (growing) Chip Seq Analysis of H3K27me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K36me3Grow2.bed (growing) Chip Seq Analysis of H3K36me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K36me3Sen2.bed (senescent) Chip Seq Analysis of H3K36me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT K4me3Grow2.bed (growing) Chip Seq Analysis of H3K4me3 in ER:Ras expressing IMR90 human diploid fibroblasts with no treatment K4me3Sen3.bed (senescent) Chip Seq Analysis of H3K4me3 in ER:Ras expressing IMR90 human diploid fibroblasts d6 4OHT
Project description:In this study, we have uncovered novel proteolytic processing of the histone H3 tail in senescence models in primary fibroblasts and melanocytes. Cleavage of H3 tail occurs at two distinct residues and is mediated by Cathepsin L. We show that variant H3.3 is preferentially cleaved, and that cleaved histones are associated with chromatin and incorporated into nucleosomes. We also found that the histone chaperone ASF1a is required for chromatin incorporation of the cleaved histone species. Further, we show that overexpression of cleaved H3.3 induces a senescence program in fibroblasts in the absensence of oncogenic signaling. For the RNA-seq studies, growing IMR90 fibroblasts were compared to cells induced to senesce via oncogene activation or cleaved H3.3 overexpression. Growing controls consist of IMR90 cells infected with empty retroviral construct pBabe and grown under normal conditions for 13 days prior to RNA isolation. For oncogene-induced senescence samples, IMR90s carrying a tamoxifen-inducible H-RasV12 retroviral construct were induced to senesce by addition of 10nM tamoxifen to the media for 8 days. Finally, IMR90s were infected with a retroviral construct expressing the cleaved form of H3.3 with a C-terminal Flag tag. RNA samples form this group were isolated at days 3 (early) and 13 (late) post-infection. In all cases, total RNA samples were isolated using RNeasy kit (Qiagen) and prepared at the Icahn School of Medicine at Mount Sinai Genomics Core Facility for poly A library construction and sequencing on IlluminaHiSeq 2500.