RESUMEN
To date, it remains largely unclear to what extent chromatin machinery contributes to the susceptibility and progression of complex diseases. Here, we combine deep epigenome mapping with single-cell transcriptomics to mine for evidence of chromatin dysregulation in type 2 diabetes. We find two chromatin-state signatures that track ß cell dysfunction in mice and humans: ectopic activation of bivalent Polycomb-silenced domains and loss of expression at an epigenomically unique class of lineage-defining genes. ß cell-specific Polycomb (Eed/PRC2) loss of function in mice triggers diabetes-mimicking transcriptional signatures and highly penetrant, hyperglycemia-independent dedifferentiation, indicating that PRC2 dysregulation contributes to disease. The work provides novel resources for exploring ß cell transcriptional regulation and identifies PRC2 as necessary for long-term maintenance of ß cell identity. Importantly, the data suggest a two-hit (chromatin and hyperglycemia) model for loss of ß cell identity in diabetes.
Asunto(s)
Cromatina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa , Silenciador del Gen , Células Secretoras de Insulina/metabolismo , Complejo Represivo Polycomb 2/fisiología , Animales , Diferenciación Celular/genética , Células Cultivadas , Mapeo Cromosómico , Diabetes Mellitus Tipo 2/genética , Epigenómica , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Hiperglucemia/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Complejo Represivo Polycomb 2/genética , Análisis de la Célula IndividualRESUMEN
Natural killer (NK) cells contribute to the development of obesity-associated insulin resistance. We demonstrate that in mice obesity promotes expansion of a distinct, interleukin-6 receptor (IL6R)a-expressing NK subpopulation, which also expresses a number of other myeloid lineage genes such as the colony-stimulating factor 1 receptor (Csf1r). Selective ablation of this Csf1r-expressing NK cell population prevents obesity and insulin resistance. Moreover, conditional inactivation of IL6Ra or Stat3 in NK cells limits obesity-associated formation of these myeloid signature NK cells, protecting from obesity, insulin resistance, and obesity-associated inflammation. Also in humans IL6Ra+ NK cells increase in obesity and correlate with markers of systemic low-grade inflammation, and their gene expression profile overlaps with characteristic gene sets of NK cells in obese mice. Collectively, we demonstrate that obesity-associated inflammation and metabolic disturbances depend on interleukin-6/Stat3-dependent formation of a distinct NK population, which may provide a target for the treatment of obesity, metaflammation-associated pathologies, and diabetes.
