Discovery of Pathways and Molecular Mediators of Early T1D Pathogenesis using Spatial Multi-Omics

About This Grant

PROJECT SUMMARY/ABSTRACT Type 1 diabetes (T1D) is a complex, devastating autoimmune disease with a slow progression of pancreatic beta-cell dysfunction (e.g., a decline of first phase insulin release occurs over several years) before the clinical onset of T1D. Unfortunately, we still have a lack of knowledge on the molecular mechanisms of early T1D pathogenesis. The long-term goal of this project is to gain a detailed understanding of in situ molecular mechanisms of early human T1D development through advanced spatial omics profiling of human islet microenvironments within clinical tissue specimens and functional studies of novel mediators. Our research plan centers on the critical role of human islet microenvironments in disease progression and the observations of substantial intra-donor heterogeneity of islet microenvironments (in both pre-diabetic and recent-onset subjects) for unraveling progression information. Our hypothesis is that pathways or molecular mediators of disease progression (otherwise unattainable without longitudinal samples) can be uncovered through advanced spatial multi-omics profiling of individual islet microenvironments in the context of intra-donor heterogeneity for each pre-T1D or new-onset T1D donor. Spatial omics data on individual islet microenvironments will unravel “pseudo- time” progression of islet dysfunction within each donor. Common pathways and molecular mediators across multiple donors will be identified for functional studies. Our plan is to pursue spatial multi-omics profiling of islet microenvironments at two different resolutions. Aim 1 will focus on characterizing intra-donor heterogeneity across individual islet microenvironments at the ROI (region of interest) level with each islet microenvironment as a ROI. Pseudo-time progression and its underlying pathways will be uncovered through correlation analysis with pathology scores for each ROI. One example of the pathology scores is the immune signature (a 20-protein panel discovered from our preliminary studies) whose expression levels can serve as a pathology score for each islet microenvironment. Aim 2 will characterize islet microenvironments at the single cell resolution with the goal to reveal cellular niches of specific type of islet dysfunction (e.g., insulitis or β-cell loss). Aim 3 will explore the functional significance of identified molecular mediators through assessing their roles in cellular communication and beta cell survival using human islet/β-cells and acinar cell co-cultures. Our approach is enabled by mass spectrometry-based spatial proteomics, spatial transcriptomics, and mass spectrometry imaging (MSI) for lipidomics and extracellular matrix (ECM)-omics. Statement of Impact: We anticipate this project will establish first-of-its-kind spatial molecular resources on human islet microenvironments in early stages of T1D development, provide evidence of novel in situ molecular mediators and biological processes from human patient samples, and contribute towards the development of novel therapeutic intervention strategies. These innovative approaches and data resources will also likely enhance the overall impact of the current resources from the Human Islet Research Network (HIRN) and enable further collaborations with other investigators within the T1D community.