scholarly journals DNA damage dependent hypomethylation regulates the pro-angiogenic LncRNA MEG9

2018 ◽  
Author(s):  
Cristina Espinosa-Diez ◽  
RaeAnna Wilson ◽  
Rishima Mukherjee ◽  
Marlee Feltham ◽  
Clayton Hudson ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Dna Damage ◽  
Cell Fate ◽  
Genotoxic Stress ◽  
Loss Of Function ◽  
Fibrin Gel ◽  
Cell Fate Decisions ◽  
Angiogenesis Assay ◽  
Non Coding Rna ◽  
Long Non Coding Rna

AbstractChanges in gene expression are key for the cells to adapt and response to intrinsic and extrinsic stimulus. It has been shown that genotoxic stress induces global hypomethylation as a result of decreased expression of DNA methyl transferases (DNMT). We hypothesized that DNA damage suppresses long non-coding RNA expression in the vasculature via DNA methylation leading to more robust DNA repair/survival or cellular senescence/death cell fate decisions. We show here that ionizing radiation reduces the expression of DNMTs in the vascular endothelium and this leads to increased expression of the anti-apoptotic lncRNA MEG9. MEG9 is a lncRNA from the DLK1-DIO3 ncRNA cluster. Loss-of-function studies using RNA gapmers indicate that MEG9 protects endothelial cells from DNA damage induced cell death. Consistent with this phenotype, knockdown of MEG9 decreases growth factor dependent angiogenesis in a 3D fibrin gel angiogenesis assay. Mechanistically, we observed that MEG9 knockdown decreased the expression of cell survival genes including survivin and induced the expression of pro-apoptotic genes such as Bad/Bax. Taken together, our findings illustrate how DNA methylation at selective lncRNA loci can regulate their expression and drive endothelial cell fate decisions.

scholarly journals p53 pro-apoptotic activity is regulated by the G2/M promoting factor Cdk1 in response to DNA damage

2021 ◽  
Author(s):  
Mireya Ruiz-Losada ◽  
Raul González ◽  
Ana Peropadre ◽  
Antonio Baonza ◽  
Carlos Estella
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Fate ◽  
Cell Cycle Progression ◽  
P53 Protein ◽  
Genotoxic Stress ◽  
Suppressor Gene ◽  
Cell Fate Decisions ◽  
Apoptotic Activity ◽  
Induced Apoptosis

SummaryExposure to genotoxic stress promotes cell-cycle arrest and DNA repair or apoptosis. These “life” or “death” cell fate decisions often rely on the activity of the tumor suppressor gene p53. Therefore, how p53 activity is precisely regulated is essential to maintain tissue homeostasis and to prevent cancer development. Here we demonstrate that Drosophila p53 pro-apoptotic activity is regulated by the G2/M kinase Cdk1. We find that cell cycle arrested or endocycle-induced cells are refractory to ionizing radiation induced apoptosis. We show that the p53 protein is not able to bind to and to activate the expression of the pro-apoptotic genes in experimentally arrested cells. Our results indicate that p53 genetically and physically interacts with Cdk1 and that p53 pro-apoptotic role is regulated by the cell cycle status of the cell. We propose a model in which cell cycle progression and p53 pro-apoptotic activity are molecularly connected to coordinate the appropriate response after DNA damage.

scholarly journals An Evolving Role for the Long Non-Coding RNA H19 in Aging and Senescence

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 563-563
Author(s):  
Christian Sell ◽  
Manali Potnis
Keyword(s):  
Cell Cycle ◽  
Somatic Cell ◽  
Cell Fate ◽  
Cell Cycle Progression ◽  
Adult Stem Cells ◽  
Somatic Cells ◽  
Gene Transcript ◽  
Cell Fate Decisions ◽  
Non Coding Rna ◽  
Long Non Coding Rna

Abstract The long non-coding RNA (lncRNA) H19 is a maternally imprinted gene transcript that, in conjunction with the neighboring Igf2 gene, is critical in controlling embryonic growth. Loss of H19 results in fetal overgrowth associated with Beckwith Weidemann syndrome, while elevated H19 occurs in human cancers. In the adult, H19 functions in cancer cells where it promotes migration and is correlated with poor prognosis, and in adult stem cells where it is a key regulator of cell fate decisions during differentiation. While the function of H19 in primary somatic cells has not been defined, a reduction in the abundance of H19 has been reported during senescence in endothelial cells. Given the critical importance of H19 in cell fate decisions, it is likely that understanding the precise function of H19 in somatic cells in general and why reduced levels occur with cellular senescence will provide novel insights into both somatic cell maintenance and the senescence program. Towards this end, we examined the role of H19 in somatic cell growth using cardiac interstitial fibroblasts. Our results indicate that H19 is not only vital for somatic cell proliferation and survival, but that depletion of H19 leads to cell cycle arrest and the formation of abnormal nuclei resulting in senescent cells. We are defining both the upstream regulators of H19 and the downstream mediators of senescence following H19 depletion. Overall, these results indicate an essential role for H19 in cell cycle progression, chromatin structure, and possibly proper mitotic division.

scholarly journals Coordination between cell proliferation and apoptosis after DNA damage in Drosophila

2021 ◽  
Author(s):  
Mireya Ruiz-Losada ◽  
Raul González ◽  
Ana Peropadre ◽  
Alejandro Gil-Gálvez ◽  
Juan J. Tena ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Fate ◽  
Cell Cycle Progression ◽  
Genotoxic Stress ◽  
Regulatory Elements ◽  
Suppressor Gene ◽  
Cycle Progression ◽  
Cell Fate Decisions ◽  
Induced Apoptosis

AbstractExposure to genotoxic stress promotes cell cycle arrest and DNA repair or apoptosis. These “life” or “death” cell fate decisions often rely on the activity of the tumor suppressor gene p53. Therefore, the precise regulation of p53 is essential to maintain tissue homeostasis and to prevent cancer development. However, how cell cycle progression has an impact on p53 cell fate decision-making is mostly unknown. In this work, we demonstrate that Drosophila p53 proapoptotic activity can be impacted by the G2/M kinase Cdk1. We find that cell cycle arrested or endocycle-induced cells are refractory to ionizing radiation-induced apoptosis. We show that p53 binding to the regulatory elements of the proapoptotic genes and its ability to activate their expression is compromised in experimentally arrested cells. Our results indicate that p53 genetically and physically interacts with Cdk1 and that p53 proapoptotic role is regulated by the cell cycle status of the cell. We propose a model in which cell cycle progression and p53 proapoptotic activity are molecularly connected to coordinate the appropriate response after DNA damage.

scholarly journals LncRNA GUARDIN suppresses cellular senescence through a LRP130-PGC1α-FOXO4-p21-dependent signaling axis

2019 ◽  
Author(s):  
Xuedan Sun ◽  
Rick FrancisThorne ◽  
Xu Dong Zhang ◽  
Miao He ◽  
Shanshan Feng ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cellular Senescence ◽  
Genome Stability ◽  
Transcriptional Repressor ◽  
Cell Fate Decisions ◽  
Non Coding Rna ◽  
Repressor Complex ◽  
Signaling Axis ◽  
Molecular Signals ◽  
Long Non Coding Rna

AbstractThe long non-coding RNA GUARDIN functions to protect genome stability. Inhibiting GUARDIN expression can alter cell fate decisions towards senescence or apoptosis, but the underlying molecular signals are unknown. Here we show that GUARDIN is an essential component of a transcriptional repressor complex involving LRP130 and PGC1α which suppresses FOXO4 expression. GUARDIN acts as a scaffold to stabilize LRP130/PGC1α heterodimers and their occupancy at the FOXO4 promotor. Destabilizing this complex by silencing of GUARDIN, LRP130 or PGC1α leads to FOXO4-dependent upregulation of p21, thereby driving cells into senescence. We also found that GUARDIN expression was induced by rapamycin, a senolytic agent that suppresses cell senescence. FOS-Like Antigen 2 (FOSL2) acts as a transcriptional repressor of GUARDIN with increased levels in the presence of rapamycin resulting from downregulation of FOSL2. Together, these results demonstrate that GUARDIN inhibits p21-dependent senescence through a LRP130-PGC1α-FOXO4 signaling axis and moreover, GUARDIN contributes to the anti-senolytic activities of rapamycin.

Abstract TMP25: Long Non-Coding RNA Mediates Stroke-Induced Neurogenesis

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Baoyan Fan ◽  
Wanlong Pan ◽  
Xinli Wang ◽  
Michael Chopp ◽  
Zheng Gang Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Regulation Of Gene Expression ◽  
Artery Occlusion ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Guide Rna ◽  
Non Coding Rna ◽  
Cerebral Artery Occlusion ◽  
Long Non Coding Rna

Background and Purpose: Adult neurogenesis contributes to functional recovery after stroke. Long non-coding RNAs (lncRNAs) regulate stem cell self-renewal and differentiation. However, the role of lncRNAs in stroke-induced neurogenesis remains unknown. Methods and Results: Using lncRNA array and in situ hybridization, we analyzed lncRNA profiles of adult neural stem cells (NSCs) isolated from the subventricular zone neurogenic region in rats subjected to middle cerebral artery occlusion. We found that H19 was the most highly upregulated lncRNA (19 fold) in ischemic NSCs compared with non-ischemic NSCs. Reduction of endogenous H19 in NSCs by CRISPR-Cas9 genome editing significantly decreased the proliferation and increased the apoptosis of ischemic NSCs, as assayed by the number of BrdU + cells (56±5% vs 22±3%, p<0.01, n=3) and Caspase-3/7 activity compared to NSCs transfected with scrambled small guide RNA (sgRNA). Knockdown of H19 significantly decreased the number of Tuj1 + neuroblasts (8±2% vs 5±0.4%, p<0.01, n=3) and NG 2 + oliogodendrocyte progenitor cells (10±1% vs 5±0.3%, p<0.01, n=3), suggesting that deletion of H19 suppresses the proliferation and survival and blocks the differentiation of NSCs into neurons and oligodendrocytes. Additional RNA-sequencing and bioinformatics analyses revealed that genes deregulated by H19 knockdown were involved in transcription, apoptosis, proliferation, cell cycle and response to hypoxia. Western blot analysis validated that loss-of-function and gain-of-function of H19 significantly increased and reduced, respectively, the transcription of cell cycle-related genes including p27. Using ChIRP assay, we found that upregulated H19 in NSCs was physically associated with EZH2 which catalyzes the repressive H3K27me3 histone marker. Knockdown of H19 significantly reduced the enrichment of H3K27me3 at the promoter of p27, leading to the upregulation of p27 expression and consequently inhibition of NSC proliferation. Conclusions: H19 mediates stroke-induced neurogenesis by regulating genes involved in cell cycle and survival through the interaction with chromatin remodeling proteins. Our data provide novel insights into epigenetic regulation of gene expression by lncRNA in neurogenesis.

Nano-Coated si-SNHG14 Regulated PD-L1 Expression and Decreased Epithelial-Mesenchymal Transition in Nasopharyngeal Carcinoma Cells

2021 ◽  
Vol 17 (10) ◽  
pp. 1993-2002
Author(s):  
Haoran Yu ◽  
Chen Zhang ◽  
Wanpeng Li ◽  
Xicai Sun ◽  
Quan Liu ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epithelial Mesenchymal Transition ◽  
Animal Experiments ◽  
Loss Of Function ◽  
Mesenchymal Transition ◽  
Non Coding Rna ◽  
Long Non Coding Rna ◽  
Tumor Agent

To investigate the expression characteristics of long non-coding RNA SNHG14 in nasopharyngeal carcinoma (NPC) and its effects on epithelial-mesenchymal transition and development of nano-coated si-SNHG14 as an anti-tumor agent. The SNHG14 expression in cancerous and adjacent non-cancerous tissues was monitored using reverse transcriptionpolymerase chain reaction (RT-PCR). Gain- and loss-of-function experiments tested the regulation of SNHG14, miR- 5590-3p, and ZEB1 on PD-L1. The binding association between the above three factors was verified using bioinformatics analysis. EMT-related E-cadherin, N-cadherin, and Vimentin were tested using Western blot. Animal experiments in nude mice verified the function of SNHG14 in the EMT of NPC in vivo. The nano-coated si-SNHG14 was developed as an anti-tumor agent and was verified NPC cell in vitro. SNHG14 was upregulated in NPC tissues. Knocking down SNHG14 markedly inhibited the EMT of NPC. Additionally, the expression of ZEB1 was positively related to that of the SNHG14, while it was inversely correlated with that of miR-5590-3p. Moreover, ZEB1 transcription upregulated PD-L1 and promoted the EMT, while SNHG14 could accelerate the EMT of NPC in vivo by regulating the PD-1 and PD-L1. SNHG14-miR-5590- 3p-ZEB1 positively regulated PD-L1 and facilitate the EMT of NPC. Nano-coated si-SNHG14 significantly downregulated PD-L1 expression and decreased EMT.

ADAMTS9-AS2: A functional long non-coding RNA in tumorigenesis

2021 ◽  
Vol 27 ◽  
Author(s):  
Wen Xu ◽  
Bei Wang ◽  
Yuxuan Cai ◽  
Jinlan Chen ◽  
Xing Lv ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Signaling Pathways ◽  
Therapeutic Target ◽  
Molecular Mechanisms ◽  
Human Cancer ◽  
Migration Inhibition ◽  
Cancer Proliferation ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
Long Non Coding Rna

Background: Long non-coding RNAs (lncRNA) have been identified as novel molecular regulators in cancers. LncRNA ADAMTS9-AS2 can mediate the occurrence and development of cancer through various ways such as regulating miRNAs, activating the classical signaling pathways in cancer, and so on, which have been studied by many scholars. In this review, we summarize the molecular mechanisms of ADAMTS9-AS2 in different human cancers. Methods: Through a systematic search of PubMed, lncRNA ADAMTS9-AS2 mediated molecular mechanisms in cancer are summarized inductively. Results: ADAMTS9-AS2 aberrantly expression in different cancers is closely related to cancer proliferation, invasion, migration, inhibition of apoptosis. The involvement of ADAMTS9-AS2 in DNA methylation, mediating PI3K / Akt / mTOR signaling pathways, regulating miRNAs and proteins, and such shows its significant potential as a therapeutic cancer target. Conclusion: LncRNA ADAMTS9-AS2 can become a promising biomolecular marker and a therapeutic target for human cancer.

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