Project Summary/Abstract
Title: Insulin regulates aging-associated genes through chromatin topology
Insulin signaling plays an important role in controlling metabolic homeostasis, with its dysregulation
linked to various metabolic diseases associated with aging, including type 2 diabetes (T2D) and obesity.
Inhibiting insulin signaling has been shown to prolong lifespan and postpone aging-associated diseases across
various animal species. However, the mechanism by which insulin activity controls aging and related metabolic
syndromes remain unclear. In mouse liver, a significant portion of insulin-regulated genes are associated with
aging. Among them, the expression level of Tmtc2 (transmembrane and tetratricopeptide repeat containing
protein 2), a novel Ca2+ regulator, significantly declines with aging, insulin treatment and insulin-associated
metabolic conditions. This project has three objectives.
1) Aim 1.1 (F99): This project determines how Tmtc2 controls cell response to stress and senescence
through Ca2+ homeostasis. Tmtc2 will be knocked down followed by the identification of cell response to
metabolic stress. Mechanistically, Ca2+ channels and pumps interacting with Tmtc2 will be defined.
2) Aim 1.2 (F99): This project defines how insulin regulates chromatin topology through transcription
factor (TF)-mediated alterations in CTCF binding, subsequently regulating the expression of novel aging-
associated genes. Chromatin topology will be defined upon insulin treatment followed by the identification of
how TFs mediates this process.
3) Aim 2 (K00): This project further identifies how altered DNA methylation remodels the genomic
template in aging cells to alter CTCF binding and chromatin loops, shifting the transcriptional impact of insulin
and permitting aging-associated metabolic dysfunction. Differential DNA methylation landscape in hepatocytes
from young and old mice will be defined, and its functional implications in the alterations of CTCF occupancy
and chromatin topology in aging will be identified.
This proposal has the potential to provide new genes or DNA elements as targets to achieve liver
rejuvenation and the reversal of insulin resistance, which is associated with aging. This project also has the
potential to shed light on the fundamental mechanism by which aging shifts cell response to insulin.