Drivers of Human Insulin Resistance and Sex-specific Alterations

Project Summary/Abstract Insulin resistance is a major risk factor in the development of type 2 diabetes (T2D) and is also present in one- quarter of the general population in a sex-dependent manner, which predisposes these individuals to the development of T2D. The molecular determinants underlying insulin resistance and sex-specific impact remain elusive. MS-based global phosphoproteomics using myoblasts derived from induced pluripotent stem cells (iMyos) taken from insulin sensitive (I-Sen) and insulin resistant (I-Res) individuals showed a large network of dysregulated phosphorylations linked to differences in insulin sensitivity. In addition, transcriptomic and proteomic analyses of these cells revealed many genes differentially regulated by insulin resistance. While many alterations were observed in cells of both sexes, I also identified many changes at the phosphoproteome, proteome, and gene expression level that were modified by the sex of the patient. Preliminary analysis suggests that DNA methylation may contribute to the sex-specific gene expression differences, but its role in insulin resistance changes remains unclear. Based on these findings and the importance of insulin resistance in the development of T2D, the overall goal of the grant is to identify the primary drivers of altered insulin signaling and impaired glucose uptake ability in insulin resistance. To achieve this goal, the research aims are to identify the upstream regulators of insulin resistance including Identifying the kinases driving the altered phosphorylation in insulin resistance and identifying the drivers of defective glucose uptake using an unbiased CRISPR screening approach. Phosphoproteome based Kinome analysis will be performed to determine how the kinase based signaling alterations are related to changes in insulin resistance and cellular metabolism. A loss-of-function genome-wide unbiased CRISPR screen will be performed to identify which genes/proteins and/or potential kinases contribute to impaired glucose uptake characteristic of insulin resistance. This research proposal will identify primary drivers of insulin resistance and provide mechanistic insights into different risks of developing metabolic diseases between men and women. In addition to research work, training and career development objectives will also be accomplished during the K01 career development award, including expanding knowledge in metabolism and diabetes research, developing proficiency in computational analysis of sequencing data, and developing leadership and professional skills. The training environment at Joslin Diabetes Center is phenomenal, given that Joslin has been a preeminent center for diabetes research for over 110 years and the mentor, Dr. C. Ronald Kahn, is an internationally recognized investigator in the field of diabetes research. I have an integrative and multidisciplinary training opportunity to receive intellectual and career development advice.