Gene regulation in autophagy and apoptosis juncture
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE38643 | GEO | 2014/05/22
SECONDARY ACCESSION(S): PRJNA168484
REPOSITORIES: GEO
Similar Datasets
Project description:Autophagy to apoptosis switching event is an unexplored area. We were interested to explore the gene expression profile at this juncture. Our Microarray data emphasized that among all eNOS and p62 genes were markedly induced. In fuctional level eNOS expression activates mTORC1 followed by inhibition of autophagy. This ultimately allowed accumulation of p62 . Intraccellular accumulation of p62 sequestered unfolded toxic protein aggregates in mitochondria and ER resulting in to impaired redox regulation. Intraccelular ROS generation further sensitized cells for apoptosis and tilted autophagic response to apoptosis. Cells were treated with Tunicamycin as an inducer of both autophagy and apoptosis. At early stage of Tunicamycin treatment 24h , prostate cancer cell PC3 showed activation of autophagic process where apoptosis was not evident. Sustained ER stress with Tunicamycin induced late apoptoisis at 72h of treatment. Hence we isolated total RNA from Untreated cells, cells with Tunicamycin treatment after 24h and 72h. Further the RNA were used to perform whole genome microarray to analyze the gene expression profile at autophagy and apoptosis juncture. The selected genes were also validated by qPCR and western bot. Morover RNAi study were implemented to evaluate the signaling crosstalk at the juncture of autophagy and apoptosis.
2014-05-22 | E-GEOD-38643 | biostudies-arrayexpress
Project description:Gene regulation in autophagy and apoptosis juncture
| PRJNA168484 | ENA
Project description:Autophagy is a starvation response that facilitates cell survival under metabolic stress and yet defects in autophagy promote tumorigenesis. While the role of understarvation is relatively clearer, its mechanistic role in tumorigenesis is poorly understood. We show that defective autophagy promotes protein damage and accumulation of p62, a marker for protein damage accumulation that is cleared through autophagy pathway. The failure to eliminate p62 in autophagy-defective cells, leads to deregulation of cell signalling and gene expression and ultimately promotes tumorigenesis. Thus defective-autophagy is a mechanism for p62 accumulation commonly observed in human tumors. Keywords: Autophagy, p62, Signal transduction, NF-kB, tumorigenesis.
2009-03-12 | GSE15182 | GEO
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice. Eight week old Atg7F/F:Mx1-Cre mice and Atg7F/F:Mx1-Cre:Nrf2-/- together with control mice were injected with pIpC. At 4 weeks after pIpC injection, total RNAs were purified from each mouse liver.
2010-10-14 | E-GEOD-20415 | biostudies-arrayexpress
Project description:Age-related cell loss underpins many senescence-associated diseases. Senile cataract is a primary blindness-causing age-related ocular disease. Apoptosis of lens epithelial cells (LECs) is the common cellular basis of senile cataract resulted from prolonged exposure to oxidative stress, the mechanism of which remains elusive. Here we reported the concomitance of increased autophagy and apoptosis in the same LEC from senile cataract patients. Oxidative stress triggered autophagy preceded apoptosis, while blocking autophagy by ablation of Atg7 or Atg3 gene remarkably suppressed apoptosis in HLE-B3 cell line. We identified autophagy adaptor SQSTM1/p62 as the critical scaffold protein to sustain a pro-survival signaling PKCι-NF-κB cascades, which antagonized the pro-apoptotic signaling in LECs. Importantly, prolonged autophagy in human senescent LECs responding to oxidative stress induced extensive degradation of p62 protein and therefore facilitated apoptosis. Moreover, pharmacological inhibitor of autophagy, 3-MA, significantly rescued apoptosis of human senescent LECs challenged by oxidative stress. Collectively, our data demonstrated that hyperactivation of autophagy aggravates age-related apoptotic cell death via inhibiting the p62-PKCι-NF-κB pro-survival axis in human senescent LECs. This work expands the understanding of the etiology of senile cataract and provides insight for mechanisms of age-related cell death in senescence-associated diseases.
2022-01-19 | GSE161701 | GEO
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice.
2010-10-15 | GSE20415 | GEO
Project description:Epigenetic factors and related small molecules have emerged to be strongly involved in autophagy process. Here we report that two inhibitors of histone H3K4 demethylase KDM1A/LSD1, 2-PCPA and GSK-LSD1, are able to induce autophagy in multiple cell lines. The two small molecules induced accumulation of LC3II, formation of autophagosome, fusion of autophagosome with lysosome and SQSTM1/p62 degradation. 2-PCPA treatment inhibits cell proliferation through cell cycle arrest but not inducing cell death. Exogenous expression of KDM1A/LSD1 impaired the autophagic phenotypes triggered by 2-PCPA. The autophagy induced by 2-PCPA requires LC3-II processing machinery. But depletion of BECN1 and ULK1 with siRNA did not affect the LC3-II accumulation triggered by 2-PCPA. 2-PCPA treatment induces the change of global gene expression program, including a series of autophagy-related genes, such as SQSTM1/p62. Taken together, our data indicate that KDM1A/LSD1 inhibitors induce autophagy through affecting the expression of autophagy-related genes and in a BECN1-independent manner.
2017-11-07 | GSE89672 | GEO
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of pkb and pi3k were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0.
2012-07-21 | E-GEOD-35701 | biostudies-arrayexpress
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of foxo3 and foxo4 were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0 as reference.
2012-07-21 | E-GEOD-35703 | biostudies-arrayexpress
Project description:Huntington's disease (HD) is a dominantly inherited genetic disease caused by mutant huntingtin (htt) protein with expanded polyglutamine tracts. A neuropathological hallmark of HD is the presence of neuronal inclusions of mutant htt. p62 is an important regulatory protein in selective autophagy, a process by which aggregated proteins are degraded, and it is associated with several neurodegenerative disorders including HD. Here we investigated the effect of p62 depletion in three HD model mice: R6/2, HD190QG and HD120QG mice. We found that loss of p62 in these models led to longer lifespans and reduced nuclear inclusions, although cytoplasmic inclusions increased with polyglutamine length. In mouse embryonic fibroblasts (MEFs) with or without p62, mutant htt with a nuclear localization signal (NLS) showed no difference in nuclear inclusion between the two MEF types. In the case of mutant htt without NLS, however, p62 depletion increased cytoplasmic inclusions. Furthermore, to examine the effect of impaired autophagy in HD model mice, we crossed R6/2 mice with Atg5 conditional knockout mice. These mice also showed decreased nuclear inclusions and increased cytoplasmic inclusions, similar to HD mice lacking p62. These data suggest that the genetic ablation of p62 in HD model mice enhances cytoplasmic inclusion formation by interrupting autophagic clearance of polyQ inclusions. This reduces polyQ nuclear influx and paradoxically ameliorates disease phenotypes by decreasing toxic nuclear inclusions. Gene expression profiles were analyzed to examine the effects of p62 depletion in mouse with or without mutant huntingtin exon 1 To examine the effect of p62 depletion on the transcriptome of Huntington's disease model mice, we crossed p62 knockout mice with HD model mice. We extracted total RNA from the striatum of these mice at 8 weeks and used for a microaaray analysis. The samples are HD transgenic mice with p62 knockout (HD_p62KO), HD mice with normal p62 (HD_p62WT), non-HD-transgenic mice with p62 knockout (NT_p62KO), and non-HD-transgenic mice with normal p62 (NT_p62WT).
2014-10-10 | E-GEOD-62210 | biostudies-arrayexpress