Biology subjects

Pope, Z. S.

Publications and source records attributed to Pope, Z. S..

2 recordsLinked to original sources

bioRxiv2026

Clonal hematopoiesis-associated DNMT3A mutations derepress bivalent Polycomb target genes and enhance macrophage migration

Somatic mutations in the de novo DNA methyltransferase DNMT3A are frequent in clonal hematopoiesis, but how they alter the function of differentiated myeloid cells remains unclear. Here, we used isogenic human embryonic stem cell-derived macrophage models to define the consequences of DNMT3A dysfunction during myeloid differentiation. DNMT3A-mutant macrophages selectively upregulated bivalent Polycomb target genes, accompanied by DNA hypomethylation, reduced H3K27me3 and increased promoter accessibility. Despite broad epigenetic changes across bivalent promoters, transcriptional derepression occurred at a subset of loci characterized by lower baseline DNA methylation and higher H3K27me3, identifying pre-existing chromatin state as a determinant of transcriptional response. This Polycomb-associated program was conserved in murine macrophages and enriched for genes involved in cell migration and wound repair. DNMT3A-mutant macrophages exhibited enhanced migration and preferential early recruitment to injured tissue. These findings link clonal hematopoiesis-associated epigenetic alterations to selective transcriptional reprogramming and altered function of differentiated myeloid cells.

cell biology↗

bioRxiv2025

Convergent DNA Methylation Abnormalities at Bivalent Chromatin in Human Growth Disorders

Loss-of-function mutations in DNMT3A, a DNA methyltransferase, or NSD1, a histone methyltransferase, cause overgrowth syndromes. Conversely, disruption of the DNMT3A domain that binds NSD1-deposited H3K36 dimethylation (H3K36me2) results in growth restriction. To investigate the molecular basis of these opposing growth outcomes, we generated isogenic human embryonic stem cells carrying growth syndrome-associated mutations in DNMT3A and NSD1. Unexpectedly, both overgrowth- and growth restriction- associated DNMT3A mutations led to DNA hypomethylation in a shared subset of active enhancers, implicating H3K36me2 in directing enhancer methylation maintenance. In contrast, bivalent chromatin--marked by both active and repressive chromatin modifications--showed divergent DNA methylation changes: hypermethylation in growth restriction-associated DNMT3A mutants and hypomethylation in overgrowth-associated DNMT3A or NSD1 loss-of-function mutants. These findings identify locus-specific DNA methylation defects as a common molecular feature and nominate dysregulated DNA methylation at bivalent chromatin as a potential driver of abnormal growth phenotypes.

genomics↗