Epigenetics and epigenomics in diabetic kidney disease and metabolic memory

Abstract

The development and progression of diabetic kidney disease (DKD), a highly prevalent complication of diabetes mellitus, are influenced by both genetic and environmental factors. DKD is an important contributor to the morbidity of patients with diabetes mellitus, indicating a clear need for an improved understanding of disease aetiology to inform the development of more efficacious treatments. DKD is characterized by an accumulation of extracellular matrix, hypertrophy and fibrosis in kidney glomerular and tubular cells. Increasing evidence shows that genes associated with these features of DKD are regulated not only by classical signalling pathways but also by epigenetic mechanisms involving chromatin histone modifications, DNA methylation and non-coding RNAs. These mechanisms can respond to changes in the environment and, importantly, might mediate the persistent long-term expression of DKD-related genes and phenotypes induced by prior glycaemic exposure despite subsequent glycaemic control, a phenomenon called metabolic memory. Detection of epigenetic events during the early stages of DKD could be valuable for timely diagnosis and prompt treatment to prevent progression to end-stage renal disease. Identification of epigenetic signatures of DKD via epigenome-wide association studies might also inform precision medicine approaches. Here, we highlight the emerging role of epigenetics and epigenomics in DKD and the translational potential of candidate epigenetic factors and non-coding RNAs as biomarkers and drug targets for DKD.This Review describes the current understanding of the role of epigenetics and epigenomics in diabetic kidney disease (DKD) and how epigenetic mechanisms might contribute to metabolic memory. The authors also discuss how epigenetic factors and non-coding RNAs could be used as biomarkers and drug targets for DKD diagnosis, prognosis and treatment.Key pointsDiabetic kidney disease (DKD), involving the accumulation of extracellular matrix, hypertrophy and fibrosis in kidney glomerular and tubular cells, can lead to end-stage renal disease.Genes associated with DKD are regulated not only by classical signalling pathways and transcription factors but also by epigenetic mechanisms, including chromatin histone modifications, DNA methylation and non-coding RNAs.Metabolic memory is a phenomenon characterized by the persistent expression of DKD-related genes and phenotypes induced by glycaemic exposure despite subsequent glycaemic control.Persistent epigenetic changes (DNA methylation and histone modifications) and signalling circuitry mediated by non-coding RNAs may be involved in metabolic memory.Targeting epigenetic factors (using small molecules or locus-specific epigenetic editing via the CRISPR–Cas9 system) or non-coding RNAs (using chemically modified antisense oligonucleotides) are potential approaches to prevent or treat DKD and erase metabolic memory.Epigenetic profiling through epigenome-wide association studies and RNA (transcriptome) profiling of patient samples (blood, urine and biopsy samples) might facilitate a precision (personalized) medicine approach for the treatment of DKD.