The role of the Dnmt3aR882H mutation in the evolution of clonal haematopoiesis.
type: CreativeWork
description: DNMT3A mutations are very frequent events in clonal haematopoiesis of indeter- minate potential (CHIP), and considered one of the earliest genetic events during the development of haematopoietic malignancies. Individuals with CHIP, in spite of having a normal full blood count are at increased risk of cardiovascular and pulmonary diseases as well as haematological neoplasms. Somatic mutations in DNMT3A are drivers of CHIP, but decades may elapse between the acquisition of a mutation and CHIP. Besides, only a minority of these individuals will go onto developing a haematological cancer, this wide interindividual heterogeneity suggests that environmental factors influence clonal expansion. It is in particular emerging, that individuals with CHIP have a proinflamma- tory phenotype, additionally, chronic inflammation is typically considered deleterious to normal haematopoiesis, as it leads to haematopoietic stem cells (HSCs) exhaustion. R882H Using a conditional knock-in mouse model heterozygous for Dnmt3a mon DNMT3A mutation, we have assessed the responses of Long-Term Haematopoietic Stem Cells (LT-HSCs) to inflammatory "stress" in vitro and in vivo. We have also em- ployed bulk LT-HSCs genomics studies to interrogate differences in the transcriptional landscape in response to inflammation. We have demonstrated that Dnmt3a-mutant LT- HSCs have a globally abnormal response to inflammation, characterised by faster exit from quiescence and subsequent hyper-proliferation. Interestingly, as well as a larger differentiated output, Dnmt3aR882H HSCs were also better preserving their progenitor compartment and their self-renewal ability compared to wild-type HSCs exposed to the same stimulus, giving some insight into potential mechanisms that lead to clonal expan- sion within an inflammatory microenvironment. We linked this phenotype to the reduced expression of two TP53 target genes: Niam/Tbrg1, involved in the TP53-mediated activation of the p21 pathway that leads to G1 growth…
abstract: DNMT3A mutations are very frequent events in clonal haematopoiesis of indeter- minate potential (CHIP), and considered one of the earliest genetic events during the development of haematopoietic malignancies. Individuals with CHIP, in spite of having a normal full blood count are at increased risk of cardiovascular and pulmonary diseases as well as haematological neoplasms. Somatic mutations in DNMT3A are drivers of CHIP, but decades may elapse between the acquisition of a mutation and CHIP. Besides, only a minority of these individuals will go onto developing a haematological cancer, this wide interindividual heterogeneity suggests that environmental factors influence clonal expansion. It is in particular emerging, that individuals with CHIP have a proinflamma- tory phenotype, additionally, chronic inflammation is typically considered deleterious to normal haematopoiesis, as it leads to haematopoietic stem cells (HSCs) exhaustion. R882H Using a conditional knock-in mouse model heterozygous for Dnmt3a mon DNMT3A mutation, we have assessed the responses of Long-Term Haematopoietic Stem Cells (LT-HSCs) to inflammatory "stress" in vitro and in vivo. We have also em- ployed bulk LT-HSCs genomics studies to interrogate differences in the transcriptional landscape in response to inflammation. We have demonstrated that Dnmt3a-mutant LT- HSCs have a globally abnormal response to inflammation, characterised by faster exit from quiescence and subsequent hyper-proliferation. Interestingly, as well as a larger differentiated output, Dnmt3aR882H HSCs were also better preserving their progenitor compartment and their self-renewal ability compared to wild-type HSCs exposed to the same stimulus, giving some insight into potential mechanisms that lead to clonal expan- sion within an inflammatory microenvironment. We linked this phenotype to the reduced expression of two TP53 target genes: Niam/Tbrg1, involved in the TP53-mediated activation of the p21 pathway that leads to G1 growth…
author: Marando, Ludovica
language: eng
keywords: Clonal Haematopoiesis, Haematopoietic stem cells, Leukaemia
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9452a089-d392-435d-b16b-f873141f4ec4/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2021-10-14
date modified: 2026-07-22T22:24:24Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.78599