Project description:We examined differential expression of genes within 10MBs of telomeres in myoblasts with long or short telomeres We offer telomere looping with telomere length as a partial mechanistic explanation for the changes gene expression that is observed. Compare expression of genes within 10MB of the telomere in normal myoblasts with long (15 kb) and short (6 kb) telomeres.
Project description:We examined differential expression of genes within 10MBs of telomeres in myoblasts with long or short telomeres We offer telomere looping with telomere length as a partial mechanistic explanation for the changes gene expression that is observed.
Project description:Summary Many epidemiologic studies have identified important relationships between leukocyte telomere length (LTL) with genetics and health. Most of these studies have been significantly limited in scope by focusing predominantly on individual diseases or restricted to GWAS analysis. Using two large patient populations derived from Vanderbilt University and Marshfield Clinic biobanks linked to genomic and phenomic data from medical records, we investigated the inter-relationship between LTL, genomics, and human health. Our GWAS confirmed 11 genetic loci previously associated with LTL and two novel loci in SCNN1D and PITPNM1. PheWAS of LTL identified 67 distinct clinical phenotypes associated with both short and long LTL. We demonstrated that several diseases associated with LTL were related to one another but were largely independent from LTL genetics. Age of death was correlated with LTL independent of age. Those with very short LTL (<−1.5 standard deviation [SD]) died 10.4 years (p < 0.0001) younger than those with average LTL (±0.5 SD; mean age of death = 74.2 years). Likewise, those with very long LTL (>1.5 SD) died 1.9 years (p = 0.0175) younger than those with average LTL. This is consistent with the PheWAS results showing diseases associating with both short and long LTL. Finally, we estimated that the genome (12.8%) and age (8.5%) explain the largest proportion of LTL variance, whereas the phenome (1.5%) and sex (0.9%) explained a smaller fraction. In total, 23.7% of LTL variance was explained. These observations provide the rationale for expanded research to understand the multifaceted correlations between TL biology and human health over time, leading to effective LTL usage in medical applications. Most studies studying telomere length are limited in scope by focusing on an individual disease or genomic analysis. Using two large patient populations derived from Vanderbilt University and Marshfield Clinic biobanks we provide one of the first comprehensive studies that examine the inter-relationship between telomere length, genomics, and human health.
Project description:Telomere length heterogeneity in various cell types including stem cells and cancer cells has been recognized. Cell heterogeneity also is found in pluripotent stem cells such as embryonic stem cells (ESCs). The implication and mechanisms underlying the heterogeneity remain to be defined. We have optimized a robust method that can simultaneously measure telomere length coupled with RNA-sequencing analysis (scT&R-seq) in the same human ES cell. Using this method, we show that telomere length varies with pluripotency state. Long telomere hESCs highly express TERF1/TRF1 as well as ZFP42/REX1, PRDM14 and NANOG for naïve pluripotency, in contrast to short telomere hESCs. hESCs express high telomerase activity as expected, and ubiquitously express NOP10 and DKC1, stabilizing components of telomerase complexes, regardless of telomere lengths. Moreover, new candidate genes such as MELK, MSH6 and UBQLN1 cluster with long telomeres and pluripotency network. Notably, short telomere hESCs exhibit higher oxidative phosphorylation primed for lineage differentiation, whereas long telomere hESCs show elevated glycolysis, another key feature for naïve pluripotency. Our data further suggest that telomere length is implicated in metabolism activity and pluripotency state of hESCs. Single cell analysis of telomere and RNA-sequencing can be exploited to further understand the molecular mechanisms of telomere heterogeneity.
Project description:Reporter genes inserted immediately adjacent to telomeres are frequently repressed in cells of model organisms as well as human cells, a phenomena referred to as telomere position effect (TPE). TPE has been proposed to be involved in regulation of cellular senescence, cancer and aging. However, the identification of endogenous genes in human cells regulated by natural telomeres has not been reported. Here we show that the expression of interferon simulated gene 15 (ISG15, located on 1p36.33, G1P2) varies with telomere length. ISG15 expression (RNA and protein) increases in human cells with short telomeres, and decreases with the elongation of telomeres by human telomerase reverse transcriptase (hTERT). The up-regulation of ISG15 is independent of p53 and type I interferon, and is not due to replicative senescence and DNA damage. In human skin specimens obtained from various aged individuals, ISG15 was up-regulated in a subset of cells in older individuals. Our results demonstrate that endogenous human genes can be regulated by the length of telomeres prior to the onset of DNA damage signals, and it suggests that telomeres may be involved in the regulation of human physiology that contributes to the process of aging. Keywords: cell type comparison
Project description:This pilot research trial studies telomere length in predicting toxicity in older patients with stage III-IV colorectal cancer undergoing chemotherapy. Studying samples of blood from patients with cancer in the laboratory may help doctors learn more about changes that occur in deoxyribonucleic acid (DNA) and predict how well patients will respond to treatment.