Post-transcriptional manipulation of TERC reverses molecular hallmarks of telomere disease
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Patrick Cahan
PROVIDER: E-GEOD-81507 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
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: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: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: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:Here, we develop nascent RNAend-Seq, in which we isolate nascent RNA and sequence the 3' ends of RNA precursors. Using a pulse-chase experimental design, we follow extended precursors of the telomerase RNA component (hTR) and show that the mature telomerase RNA derives from these species with slow kinetics compared to other small non-coding RNAs. The human disease causing gene PARN further delays maturation of the hTR precursor in PARN- mutant cancer cell lines. Disruption of the poly(A)polymerase PAPD5 in PARN-mutant cells restores normal processing kinetics and levels of mature hTR. Unexpectedly, neither PARN nor PAPD5 is required for hTR processing. Instead, PAPD5 and PARN set the hTR maturation rate by controlling precursor adenylation.
2019-03-28 | GSE117054 | GEO
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: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:Telomere shortening due to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSC) in vitro. In order to study the role of telomere shortening in vivo, we studied the phenotype of telomerase deficient mice caused by absence of telomerase RNA component (TERC-/-). TERC-/- exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months follow up. Bone histomorphometry revealed decreased mineralized surface and bone formation rate as well as increased osteoclast number and size in TERC-/-. Also, serum total deoxy-pyridinoline (tDPD) was increased in TERC-/-. MSC isolated from TERC-/- exhibited intrinsic defects with reduced total number, lower proliferation rate, decreased expression of osteoblastic (OB) differentiation markers and formed less in vivo ectopic bone compared to WT cells. The TERC-/--MSC cultures accumulated a larger proportion of senescent Ã-galactosidase+ cells and cells exhibiting DNA damage positive for γ-H2AX. Micro-array analysis of bones of TERC-/- and WT revealed significant over-expression of a large number of pro-inflammatory genes and signaling pathways in TERC-/- known to control osteoclast (OC) differentiation. In accordance with that, serum from TERC-/- enhanced OC formation in control bone marrow cultures. Our data demonstrate two mechanisms for age-related bone loss caused by telomerase deficiency: intrinsic osteoblastic defects and creation of pro-inflammatory osteoclast-activating microenvironment. Approaches for re-telomerization of MSC may provide a novel approach for abolishing age-related bone loss. control (WT) and the test (G3 - mTERC-/-) samples
2010-05-27 | E-GEOD-21523 | biostudies-arrayexpress
Project description:Poly(A)-specific ribonuclease (PARN) and target of EGR1 protein 1 (TOE1) are nuclear granule-associated deadenylases, whose mutations are linked to multiple human diseases. Here, we applied mTAIL-seq and RNA sequencing (RNA-seq) to systematically identify the substrates of PARN and TOE1 and elucidate their molecular functions. We found that PARN and TOE1 do not modulate the length of mRNA poly(A) tails. Rather, they promote the maturation of nuclear small non-coding RNAs (ncRNAs). PARN and TOE1 act redundantly on some ncRNAs, most prominently small Cajal body-specific RNAs (scaRNAs). scaRNAs are strongly downregulated when PARN and TOE1 are compromised together, leading to defects in small nuclear RNA (snRNA) pseudouridylation. They also function redundantly in the biogenesis of telomerase RNA component (TERC), which shares sequence motifs found in H/ACA box scaRNAs. Our findings extend the knowledge of nuclear ncRNA biogenesis, and they provide insights into the pathology of PARN/TOE1-associated genetic disorders whose therapeutic treatments are currently unavailable.
2018-03-30 | GSE111511 | GEO
Project description:TERC is the core subunit of telomerase which is responsible for adding telomeric sequences to the telomere ends. Besides being the RNA temple of telomerase, TERC is a typical Lnc RNA and ubiquitously expressed in normal somatic cells without telomerase activity. It is very likely that TERC has other, yet to be discovered functions in normal somatic cells independent of telomerase activity. Identifying the genomic occupancy of TERC helps to understand its functional mechanism on chromosomal DNA. Then, we analyzed the genome occupancy of TERC in MRC5 fibroblast cells that is without telomerase activity by ChIRP-seq, and found that there was not apparent enrichment of TERC on telomere sequences in normal somatic cells, but showed a significant enrichment on gene promoters/transcription start sites. This study provides a mechanistic insight of TERC on transcriptional regulation in normal somatic cells.
2022-03-28 | GSE183642 | GEO