Integrative analysis of multi-omic signatures and cellular function in human pancreas across developmental timeline at single-cell spatial resolution

Abstract
Studies of human pancreas development have begun to elucidate influences in the establishment of β cell
mass and formation of islets, but genetic and environmental influences that manifest during postnatal pancreas
development remain unknown. The first decade of life (termed the pediatric period for this proposal) is a
dynamic time in pancreas development when two critcal processes occur: (1) β cell mass is established and
(2) β cells and islets functionally mature. In addition, it is the time β cell-directed autoimmunity of type 1
diabetes (T1D) often begins. Thus, understanding the molecular and cellular processes that govern pediatric
pancreas development and function is key to improving the diagnosis of children and adolescents with T1D
and T2D and developing strategies to prevent, or treat the β cell dysfunction. While several ongoing initiatives
including the Human Islet Research Network (HIRN) have been generating datasets from adult nondiabetic,
T1D, and T2D donors, there is a major gap in deep molecular and tissue-level phenotyping of pancreata from
the pediatric period. Furthermore, the contributions of vascular, immune, and other stromal cell populations
and their β cell interactions, to human pediatric pancreas development are largely uncharacterized, despite
their known influence on adult β cell function. Our proposal is based on our exciting single-cell multi-omic
spatially-resolved pilot data that will allow us to map the context specificity of T1D and related trait GWAS
signals in pancreas across cell type, age, sex, and developmental stage. Moreover, using living slice
technology, we will be able to investigate cellular physiology and cell-cell communication in situ with high
temporal resolution to provide an insight into processes that govern β cell maturation and establishment of
healthy pancreatic architecture. The overlay of spatial, physiological, transcriptional, and chromatin data from
the same organs will provide unprecedented access to define changes in molecular signatures, tissue
architecture, and β cell maturation. This will not only complement phenotypic data collected from mostly adult
donors in the Human Pancreas Analysis Program (HPAP), but will also generate data useful to several HIRN
consortia and the broader research community. Our multidisciplinary research team with complementary
expertise in pancreas and islet biology, in situ physiology, single cell genomics and epigenomics, image data
analysis, statistical genetics, and machine learning devised tools and analyses to discover cell state dynamic
changes across the first decade of life and define how these changes influence downstream biology from
transcriptional regulation, to cellular spatial organization within the pancreas, and cellular function. If
successful, these studies will provide new mechanistic insights about the functional maturation of human β
cells during the critical pediatric life stages. This will likely influence the way we perceive T1D pathogenesis
and lead to new therapies for diabetes and other pancreas diseases.

Grant Number: 5U01DK135017-04
NIH Institute/Center: NIH
Principal Investigator: Marcela Brissova