Small-Molecule PAPD5 Inhibitors Restore Telomerase Activity in Patient Stem Cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE144986 | GEO | 2020/04/21
REPOSITORIES: GEO
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Project description:The telomerase RNA component (TERC) is a critical determinant of cellular self renewal. Poly(A)-specific ribonuclease (PARN) is required for post-transcriptional maturation of TERC. PARN mutations lead to incomplete 3â² end processing and increased destruction of nascent TERC RNA transcripts, resulting in telomerase deficiency and telomere diseases. Here, we determined that overexpression of TERC increased telomere length in PARN-deficient cells and hypothesized that decreasing post-transcriptional 3â² oligo-adenylation of TERC would counteract the deleterious effects of PARN mutations. Inhibition of the noncanonical poly(A) polymerase PAP-associated domainâcontaining 5 (PAPD5) increased TERC levels in PARN-mutant patient cells. PAPD5 inhibition was also associated with increases in TERC stability, telomerase activity, and telomere elongation. Our results demonstrate that manipulating post-transcriptional regulatory pathways may be a potential strategy to reverse the molecular hallmarks of telomere disease. mRNA sequencing of induced pluripotent stem cells and 293 cell line.
2016-08-02 | E-GEOD-81507 | biostudies-arrayexpress
Project description:The telomerase RNA component (TERC) is a critical determinant of cellular self renewal. Poly(A)-specific ribonuclease (PARN) is required for post-transcriptional maturation of TERC. PARN mutations lead to incomplete 3′ end processing and increased destruction of nascent TERC RNA transcripts, resulting in telomerase deficiency and telomere diseases. Here, we determined that overexpression of TERC increased telomere length in PARN-deficient cells and hypothesized that decreasing post-transcriptional 3′ oligo-adenylation of TERC would counteract the deleterious effects of PARN mutations. Inhibition of the noncanonical poly(A) polymerase PAP-associated domain–containing 5 (PAPD5) increased TERC levels in PARN-mutant patient cells. PAPD5 inhibition was also associated with increases in TERC stability, telomerase activity, and telomere elongation. Our results demonstrate that manipulating post-transcriptional regulatory pathways may be a potential strategy to reverse the molecular hallmarks of telomere disease.
2016-08-02 | GSE81507 | GEO
Project description:Mammalian telomeres are formed by tandem repeats of the TTAGGG sequence, and shorten with each round of cell division in the absence of telomerase. Telomere shortening and dysfunction has been implicated in the pathology of several age-related diseases and premature ageing syndromes. Telomerase is important for telomere length maintenance. Telomerase RNA component, also known as TERC, is a component of telomerase. Terc knockout leads to telomerase deficiency and telomere shortening. Heterozygous telomerase-deficient (Terc+/-) mice were housed and bred for homozygous generation. ESC lines were generated with high efficiency from wild-type (WT, Terc+/+), heterozygous (Het, Terc+/-) and early- to late-generation (G1, G3 and G4) Terc-/- mouse blastocysts. Telomeres were shorter in Terc+/- ES cells than in WT ES cells, and further shortened from G1 to G4 Terc-/- ES cells. We took advantage of ES cell lines with various telomere lengths to investigate roles of telomere length on differentiation capacity of ES cells. We found that telomere length, but not telomerase activity, is required for differentiation of ES cells into epidermis. We performed microarray analysis to investigate differential gene expression profile at genome-wide levels between WT and G3/G4 Terc-/- (KO) mouse ES cells and during differentiation in vitro of WT and G4 Terc-/- mouse ES cells.
2016-01-29 | GSE77362 | GEO
Project description:Mutations in the poly(A) ribonuclease (PARN) gene cause telomere diseases including familial idiopathic pulmonary fibrosis (IPF) and dyskeratosis congenita (DC)1,2, but how PARN deficiency impacts telomere maintenance is unclear. Here, using somatic cells and induced pluripotent stem (iPS) cells from DC patients with PARN mutations, we show that PARN is required for the 3′ end maturation of the telomerase RNA component (TERC). Patient cells as well as immortalized cells in which PARN is disrupted show decreased levels of TERC. Deep sequencing of TERC RNA 3′ termini reveals that PARN is required for removal of posttranscriptionally acquired oligo(A) tails that target nuclear RNAs for degradation. Diminished TERC levels and the increased oligo(A) forms of TERC are normalized by restoring PARN, which is limiting for TERC maturation in cells. Our results reveal a novel role for PARN in the biogenesis of TERC, and provide a mechanism linking PARN mutations to telomere diseases. mRNA sequencing of fibroblasts, induced pluripotent stem cells, and 293 cell line.
2015-09-08 | E-GEOD-71709 | 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
Project description:Mutations in genes encoding components of the telomerase holoenzyme complex result in a spectrum of rare genetic disorders known as telomere diseases, including dyskeratosis congenita (DC). A consistent finding in DC due to pathogenic mutations in DKC1, which encodes dyskerin, is decreased steady-state levels of the non-coding RNA component of telomerase (TERC) and thus impaired telomere maintenance. Dyskerin binds hundreds of other small nucleolar RNAs (snoRNAs). However, the mechanisms by which DKC1 mutations cause variable impacts on these snoRNAs are poorly understood, which is a barrier to understanding disease mechanisms in DC beyond impaired telomere maintenance. Here, using somatic and induced pluripotent stem cells (iPSCs) from DC patients with DKC1 mutations and CRISPR-Cas9-engineered iPSCs, we show that mutations in the N-terminal extension domain (NTE) of dyskerin dysregulate the biogenesis of a subset of snoRNAs, with the most prominent effect on scaRNA13 (small Cajal body-specific RNA 13). In patient iPSCs carrying the del37L dyskerin NTE-domain mutation but not in those with C-terminal mutations, nascent scaRNA13 transcripts showed a discrete population of 3´-extended forms, as seen in the setting of DC-causing mutations in the PARN (polyA-specific ribonuclease) gene. By deep sequencing of RNA 3´ ends, we found that aberrant scaRNA13 transcripts were composed of genomically-encoded extensions and post-transcriptionally oligoadenylated species, mediated by the noncanonical polymerase PAPD5, which counters PARN. NTE domain mutations generated using CRISPR-Cas9 engineering of the endogenous DKC1 recapitulated the scaRNA13 3´-end processing defects seen in del37L patient cells. Conversely, repair of the DKC1 del37L mutation and genetic or pharmacological manipulation of PAPD5 rescued scaRNA13 end processing defects and steady-state levels. Analysis of the human telomerase cryo-EM structure showed that the dyskerin NTE interacts with 3´ end of bound RNA, suggesting that mutations in this domain impair 3´ end protection of nascent scaRNA13 in addition to canonical functions in snoRNA stabilization. Our results provide mechanistic insights into the interplay of dyskerin and the PARN/PAPD5 axis in the biogenesis and accumulation of snoRNAs beyond TERC, which has important implications for our broader understanding of ncRNA dysregulation in human diseases.
2022-08-01 | GSE190173 | GEO
Project description:Mutations in the poly(A) ribonuclease (PARN) gene cause telomere diseases including familial idiopathic pulmonary fibrosis (IPF) and dyskeratosis congenita (DC)1,2, but how PARN deficiency impacts telomere maintenance is unclear. Here, using somatic cells and induced pluripotent stem (iPS) cells from DC patients with PARN mutations, we show that PARN is required for the 3′ end maturation of the telomerase RNA component (TERC). Patient cells as well as immortalized cells in which PARN is disrupted show decreased levels of TERC. Deep sequencing of TERC RNA 3′ termini reveals that PARN is required for removal of posttranscriptionally acquired oligo(A) tails that target nuclear RNAs for degradation. Diminished TERC levels and the increased oligo(A) forms of TERC are normalized by restoring PARN, which is limiting for TERC maturation in cells. Our results reveal a novel role for PARN in the biogenesis of TERC, and provide a mechanism linking PARN mutations to telomere diseases.
2015-09-08 | GSE71709 | GEO
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)
2013-02-11 | GSE42869 | GEO
Project description:Telomerase holoenzyme plays a critical role in maintaining telomere length, and thus in regulating inflammation caused by telomeric DNA damage. However, beyond its role in telomere maintenance, the molecular function of telomerase in directly regulating inflammation remains unclear. Here, we show that the reverse transcriptase component of telomerase, TERT, has a cell-type-specific role in directly regulating inflammation via the cytoplasmic cGAS-STING nucleic acid-sensing pathway. Analyses of murine and zebrafish models of gut inflammation and human colitis/Crohn’s patients document that this function of TERT is evolutionarily conserved. Using our novel knock-in TERTVAA mouse model where reverse-transcriptase-inactive TERT is driven by its endogenous loci, and molecular, pharmacological and single-cell approaches we identify the myeloid subpopulation, termed T-MAC, wherein TERT enhances STING activation and initiates type-1 interferon responses independent of reverse transcriptase activity or telomere length. We highlight a hitherto unappreciated role of TERT in directly regulating inflammation and provide a therapeutic rationale for targeting TERT beyond cancers.
2024-07-22 | GSE241725 | GEO
Project description:Aging is the consequence of intra- and extracellular events that promote cellular senescence. Dyskeratosis congenita (DC) is an example of a premature aging disorder caused by underlying telomere/telomerase-related mutations. Cells from these patients offer an opportunity to study telomere-related aging and senescence. Our previous work has found that telomere shortening stimulates DNA damage responses (DDR) and increases reactive oxygen species (ROS), thereby promoting entry into senescence. This work also found that telomere elongation via TERT expression, the catalytic component of the telomere-elongating enzyme telomerase, or p53 shRNA could decrease ROS by disrupting this telomere-DDR-ROS pathway. To further characterize this pathway, we performed a CRISPR/Cas9 knockout screen to identify genes that extend lifespan in DC cells. Of the cellular clones isolated due to increased lifespan, 34% had a guide RNA (gRNA) targeting CEBPB while gRNAs targeting WSB1, MED28 and p73 were observed multiple times. CEBPB is a transcription factor associated with activation of proinflammatory response genes suggesting that inflammation may be present in DC cells. The inflammatory response was investigated using RNA-Seq to compare DC and control cells. Expression of inflammatory genes were found to be significantly elevated (p<0.0001) in addition to a key subset of these inflammation-related genes (IL1B, IL6, IL8, IL12A, CXCL1 (GROa), CXCL2 (GROb), and CXCL5) which are regulated by CEBPB. Exogenous TERT expression led to downregulation of RNA/protein CEBPB expression and the inflammatory response genes suggesting a telomere-length dependent mechanism to regulate CEBPB. Furthermore, unlike exogenous TERT and p53 shRNA, CEBPB shRNA did not significantly decrease ROS suggesting that CEBPB’s contribution in DC cells’ senescence is ROS-independent. Our findings demonstrate a key role for CEBPB in engaging senescence by mobilizing an inflammatory response within DC cells.
2023-08-30 | GSE224293 | GEO