Therapeutic effects of telomerase in mice with pulmonary fibrosis induced by damage to the lungs and short telomeres
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE93869 | GEO | 2018/01/22
REPOSITORIES: GEO
Similar Datasets
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: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: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.
2015-04-23 | GSE60175 | GEO
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.
2015-04-23 | GSE60223 | 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:In this study, we employed an inducible CRISPRi human induced pluripotent stem cell (hiPSC) line to silence TERT expression enabling the generation of hiPSCs and hiPSC-derived cardiomyocytes with long and short telomeres. Reduced telomerase activity and shorter telomere lengths of hiPSCs strongly hampered their differentiation potential towards cardiomyocytes
2024-04-25 | GSE260618 | 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:Genetic lesions that reduce telomerase cause a range of incurable diseases including dyskeratosis congenita (DC) and pulmonary fibrosis (PF), and restoring telomere length in these patients would be curative. Ectopic expression of telomerase reverse transcriptase (TERT) risks cellular immortalization, and how to target telomerase in stem cells throughout the body remains unclear. Here we describe a successful screen for small molecules that augment TERC, the non-coding telomerase RNA component, and thereby specifically elongate telomeres in stem cells. PAPD5 is a non-canonical polymerase that oligo-adenylates and destabilizes TERC. Using a high-throughput screen we identify BCH001, a specific PAPD5 inhibitor that decreases TERC 3′- oligo(A) tailing and increases telomerase activity and telomere length by thousands of nucleotides in DC patient induced pluripotent stem cells (iPSCs). BCH001 does not result in immortalization or telomere elongation in somatic cells which lack TERT, establishing a favorable safety profile. When human hematopoietic stem and progenitor cells (HSPCs) engineered by CRISPR-Cas9 to carry PARN mutations that cause DC and PF are xenotransplanted into immunodeficient mice, oral treatment with PAPD5 inhibitors rescues TERC 3′-end maturation and telomere length. Our data demonstrate telomere restoration in human stem cells in vivo using small molecules.
2020-04-21 | GSE144986 | GEO
Project description:Telomere is a highly refined system for maintaining the stability of linear chromosomes. Most telomeres rely on simple repetitive sequences and telomerase enzymes, but in some species or telomerase-defective situations, alternative telomere lengthening (ALT) mechanism is utilized to protect chromosomal ends. Telomere loss can induce telomere recombination by which specific sequences can be recruited into telomeres. However, canonical telomeric repeat-based telomeres have been found in mammals. Here, we show that mammalian telomeres can also be completely reconstituted using a non-telomeric unique sequence. We found that a specific subtelomeric element, named as mouse template for ALT (mTALT), is utilized for repairing telomeric DNA damage and composing new telomeric sequences in mouse embryonic stem cells. We found a high-level of non-coding mTALT transcript despite the heterochromatic nature of mTALT-based telomere. After ALT activation, the increased HMGN1, a non-histone chromosomal protein, contributed to maintaining telomere stability by regulating telomeric transcriptions. Our findings reveal novel molecular features of potential telomeric sequences which can reconstitute telomeres during cancer formation and evolution.
2020-07-17 | MSV000085772 | MassIVE