Leveraging genetic diversity to identify small molecules that reverse mouse skeletal muscle insulin resistance

Abstract

Systems genetics has begun to tackle the complexity of insulin resistance by capitalising on computational advances to study high-diversity populations. “Diversity Outbred in Australia (DOz)” is a population of genetically unique mice with profound metabolic heterogeneity. We leveraged this variance to explore skeletal muscle’s contribution to whole-body insulin action through metabolic phenotyping and skeletal muscle proteomics of 215 DOz mice. Linear modelling identified 553 proteins that associated with whole-body insulin sensitivity (Matsuda Index) including regulators of endocytosis and muscle proteostasis. To enrich for causality, we refined this network by focussing on negatively associated, genetically regulated proteins, resulting in a 76-protein fingerprint of insulin resistance. We sought to perturb this network and restore insulin action with small molecules by integrating the Broad Institute Connectivity Map platform andin vitroassays of insulin action using the Prestwick chemical library. These complimentary approaches identified the antibiotic thiostrepton as an insulin resistance reversal agent. Subsequent validation inex vivoinsulin resistant mouse muscle, and palmitate induced insulin resistant myotubes demonstrated potent insulin action restoration, potentially via up-regulation of glycolysis. This work demonstrates the value of a drug-centric framework to validate systems level analysis by identifying potential therapeutics for insulin resistance.

The genetic and dietary landscape of the muscle insulin signalling network

“…Phosphorylation of this site leads to increased production of F2,6BP, a potent glycolytic agonist, suggesting that activating glycolysis may play a key role in muscle insulin responsiveness. This is consistent with our previous findings that glycolytic enzyme abundance was strongly associated with ex vivo insulin-stimulated glucose uptake in muscle from inbred mice 18 , that the insulin resistancereversing small molecule thiostrepton enhances glycolytic capacity 56 , and that decreasing glycolytic flux caused insulin resistance in vitro 57 . To further establish glycolysis as a regulator of insulin responsiveness in skeletal muscle, we decided to investigate whether upregulating glycolysis through F2,6BP production can restore insulin-stimulated glucose uptake in insulin resistance.…”

Identification of SEC61B as a novel regulator of calcium flux and platelet hyperreactivity in diabetes mellitus

“…To understand if upregulation of SEC61B in hyperglycemia originates from megakaryocytes, we employed different mouse models of DM for analysis of megakaryocyte SEC61B content. The first was injection of STZ in Apoe-/- mice 40 ; and the second was an outbred mouse model fed on a high-fat diet 22 . The characteristics of the mice included in the study (Apoe-/- and outbred) are shown in Table 2 .…”

“…The characteristics and diet of these mice have been provided previously. 22,23 Experiments were performed in accordance with NHMRC (Australia) guidelines and under approval of the University of Sydney Animal Ethics Committee (protocol number #2017/1274 and #2021/1936).…”

The Molecular Architecture of Variable Lifespan in Diversity Outbred Mice

“…Without a reference of where individual molecules come from, nor where they go, it is difficult to anchor interpretation in physiology. With the emergence of high quality genome-scale datasets studying aging DO mice in many major tissues, this is beginning to change 6,[25][26][27] .…”