Telomerase is essential for cardiac differentiation and sustained metabolism of human cardiomyocytes II
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE260618 | GEO | 2024/04/25
REPOSITORIES: GEO
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Project description:The scRNA seq was performed on day 12 of hiPSC-cardiomyocyte differentiation protocol with 3 different conditions of telomere length at the hiPSC stage, namely- long telomeres, intermediate telomeres and short telomeres. The analysis showed expected clusters of the mesodermal lineage but a shift of clusters was observed depending upon the telomere legth status of the parent CRISPRi TERT hiPSCs used for differentiation
2024-04-25 | GSE239887 | GEO
Project description:Coronary heart disease is a main cause of death in the developed world and treatment success remains modest with high mortality rates within one year after myocardial infarction (MI). Thus, new therapeutic targets and effective treatments are necessary. Short telomeres are risk factors for age-associated diseases including heart disease. Here, we address the potential of telomerase (Tert) activation in prevention of heart failure after MI in adult mice. We use adeno-associated viruses for cardiac-specific Tert expression in a mouse model of MI. We find that upon MI, hearts expressing Tert show attenuated cardiac dilation, improved ventricular function and smaller infarct scars concomitant with increased mouse survival by 17% compared to controls. Furthermore, Tert treatment results in elongated telomeres, increased numbers of Ki67 and pH3-positive cardiomyocytes and a gene expression switch towards a regeneration signature of neonatal mice. Our work highlights telomerase activation as a novel therapeutic strategy to prevent heart failure after MI.
2014-12-15 | GSE62973 | GEO
Project description:Coronary heart disease is a main cause of death in the developed world and treatment success remains modest with high mortality rates within one year after myocardial infarction (MI). Thus, new therapeutic targets and effective treatments are necessary. Short telomeres are risk factors for age-associated diseases including heart disease. Here, we address the potential of telomerase (Tert) activation in prevention of heart failure after MI in adult mice. We use adeno-associated viruses for cardiac-specific Tert expression in a mouse model of MI. We find that upon MI, hearts expressing Tert show attenuated cardiac dilation, improved ventricular function and smaller infarct scars concomitant with increased mouse survival by 17% compared to controls. Furthermore, Tert treatment results in elongated telomeres, increased numbers of Ki67 and pH3-positive cardiomyocytes and a gene expression switch towards a regeneration signature of neonatal mice. Our work highlights telomerase activation as a novel therapeutic strategy to prevent heart failure after MI. Mice of one year of age were left untreated (control) or injected with 5*10^11 adeno associated viruses particles of serotype 9 (AAV9) that carry either en empty expression cassette or express telomerase under control of the CMV promoter. Virus injected mice then underwent myocardial infarction induced through permenant left anterior descending artery (LAD) ligation. Mice that survived for six weeks after LAD ligation were sacrificed and 4 hearts per group (AAV9-empty or AAV9-Tert) and 3 control hearts (no virus treatment, no ligation) were subjected to total RNA isolation for micro array analysis.
2014-12-15 | E-GEOD-62973 | biostudies-arrayexpress
Project description:Telomerase reverse transcriptase (TERT) plays a crucial role in maintaining telomere length, which are specialised protective caps at the end of chromosomes. The lack of in vitro aging models, particularly for the central nervous system (CNS), has impeded progress in understanding aging and age-associated neurodegenerative diseases. In this study, we aimed to explore the possibility of accelerating aging in vitro using hiPSC (human induced pluripotent stem cell) technology. To achieve this, we utilised CRISPR/Cas9 to generate TERT loss-of-function hiPSCs, resulting in a loss of telomerase function and shortened telomeres. Through directed differentiation, we generated motor neurons and astrocytes to investigate whether telomere shortening could lead to age-associated phenotypes in CNS cell types.
2023-12-09 | GSE240447 | GEO
Project description:In our previous study, mice with pulmonary fibrosis induced by a bleomycin insult in the context of short telomeres develop pulmonary fibrosis. By using AAV9 vectors carrying the telomerase Tert gene to treat those mice, we explore the possibility of telomerase gene therapy as a possible treatment for IPF patients carrying short telomeres. To further understand gene expression changes undergoing in ATII cells upon telomerase activation, we isolated ATII cells from pulmonary fibrosis Tert-treated and empty vector-treated lungs at 1 week after AAV9 inoculation by FACS.
2018-01-22 | GSE93869 | GEO
Project description:Telomerase reverse transcriptase (TERT) and the noncoding telomerase RNA (TR) subunit constitute the core of telomerase. We now report that the putative F-box protein Pof8 is also a constitutive component of active telomerase in fission yeast. Pof8 functions in a hierarchical assembly pathway by promoting the binding of the Lsm2-8 complex to telomerase RNA, which in turn promotes binding of the catalytic subunit. Loss of Pof8 reduces TER1 stability, causes a severe assembly defect and results in critically short telomeres. Structure profile searches identified similarities between Pof8 and telomerase subunits from ciliated protozoa, making Pof8 next to TERT the most widely conserved telomerase subunits identified to date.
2018-02-09 | GSE104672 | GEO
Project description:Telomeres are the nucleoprotein structures found at the ends of eukaryotic chromosomes. Conventional DNA polymerases are unable to fully replicate the telomeric end of the chromosome, which leads to a progressive loss of DNA after every cell division. This problem is solved by the ribonucleoprotein enzyme, telomerase. Proper maintenance of the telomeric end is critical for maintaining genome integrity in eukaryotes. The telomerase enzyme has two essential components: the telomerase RNA (TR), which provides the template required for telomeric DNA synthesis; and the catalytic protein telomerase reverse transcriptase (TERT) that catalyzes the extension of the telomeric DNA ends using the TR as a template. The action of telomerase prevents the progressive shortening of the telomeres after every cell division. The TR can form a large structural scaffold upon which many accessory proteins can bind to and form the complete telomerase holoenzyme in vivo. These accessory proteins are required for telomerase activity and regulation inside of cells. The interacting partners of the TERT protein have been extensively characterized in yeast, human, and Tetrahymena systems. These interactors have not been extensively studied in lower eukaryotes including clinically relevant human parasites, such as Trypanosoma brucei (T. brucei). To this end, we performed co-immunoprecipitation coupled to LC-MS/MS of TbTERT-FLAG-HA-HA from T. brucei cells using an anti-TbTERT antibody and protein G magnetic beads. An isotype matched IgG control was performed in tandem. Comparisons of enriched proteins in the IP vs. IgG control revealed previously known and novel interactors of TbTERT. These findings suggest potential mechanistic differences in telomere maintenance in T. brucei compared to higher eukaryotes.
2023-03-08 | PXD038235 | Pride
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumors . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis. P493 cells were stably infected with the following viruses: pLKO shControl and pLKO shTERT.
2015-04-23 | E-GEOD-60175 | biostudies-arrayexpress
Project description:Constitutively active MYC and reactivated telomerase often co-exist in cancers. While the reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with co-factors, confers several growth advantages to cancer cells. However, it is unclear which co-factors sustain elevated MYC activity in tumours . Here, we identify TERT, the catalytic subunit of telomerase, as a novel regulator of MYC stability in cancers. Binding of TERT to MYC stabilizes its levels on chromatin, contributing to either activation or repression of its target genes. Mechanistically, TERT regulates MYC ubiquitination and stability, and this effect of TERT is independent of its role on telomeres. Genetic inhibition and knocking out of TERT phenocopied the loss of MYC, resulting in reduced disease burden of early- and late-stage MYC-driven murine lymphomas. Conversly, the ectopic expression of TERT could substitute for reduced MYC in these functions. Finally we show that TERT null mice, unlike Terc null mice, show delayed onset of MYC induced lymphomagenesis. Accordingly, inhibiting TERT function in primary human leukemia cells blocked the expression of MYC targets, while Terc depletion had no effects . Based on our data, we conclude that the re-expression of TERT, a direct MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis. ChIP was performed using anti-MYC (sc-764) in primary lymphoma cells from Eµ-Myc;Tert -/- mice, Eµ-Myc;Tert +/+ mice, or in P493 cells treated with shTert, P493 shTerc and shControl.
2015-04-23 | E-GEOD-60223 | biostudies-arrayexpress
Project description:Critically short telomeres activate p53-mediated apoptosis, resulting in organ failure and causing malignant transformation. Mutations in genes responsible for telomere maintenance are linked to a number of specific human diseases. We derived induced pluripotent stem cells (iPSCs) from patients with mutations in the TERT and TERC telomerase genes. Telomerase-mutant iPSCs elongated telomeres, but at a lower rate than healthy iPSCs, and the magnitude of the elongation deficit correlated with the specific mutation’s impact on telomerase activity. However, elongation significantly varied among iPSC clones harboring the same mutation, and was affected by genetic and environmental factors. iPSCs cultured in hypoxia showed increased telomere length. Potential influence of residual expression of reprogramming factors on telomerase regulation and telomere length was ruled out by excising the transgenes after successful reprogramming. Evidence for telomerase-independent telomere elongation was not observed in these cells. We demonstrate that telomerase is required for telomere elongation in iPSCs and uncover heterogeneity in telomere maintenance even between clones derived from individual patients or siblings with the same mutation, indicating that telomere phenotype may be influenced by acquired and environmental agents. Our data underscore the necessity of studying multiple clones when using iPSCs to model disease. The exon array were done to validate the pluripotent phenotype of the derived normal and telomerase mutant iPSC and to potentially identify differentially expressed genes in mutant iPSC. Objective: confirming pluripotency by comparing telomerase mutated-, control-iPSC to human ESC and to their parental somatic cells (fibroblast used for iPSC derivation) 20 samples total, 5 different fibroblast cells, 13 iPSC lines, 1 ES line (H1) from different passages
2013-02-11 | E-GEOD-42869 | biostudies-arrayexpress