Project description:RNA-seq profiling of gene expression of human telomerase reverse transcriptase (hTERT)-expressing human cardiac mesenchymal stem cells.
Project description:The 293T cells overexpressing human telomerase reverse transcriptase (hTERT) were lysed and co-immunoprecipitation was performed using hTERT antibody. Then protein mass spectrum was conducted in order to identify the hTERT-interacting proteins.
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.
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.
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.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
Project description:We identified a subset of hepatocytes with high Telomerase Reverse transcriptase (Tert) that functions as the repopulating stem cells in homeostasis and injury. We performed RNA-Seq to reveal the differences of these cells and the other hepatocytes.
