A 3D system to model human pancreas development and its reference single-cell transcriptome atlas identify signaling pathways required for progenitor expansion

Abstract

Human organogenesis remains relatively unexplored for ethical and practical reasons. Here, we report the establishment of a single-cell transcriptome atlas of the human fetal pancreas between 7 and 10 post-conceptional weeks of development. To interrogate cell–cell interactions, we describe InterCom, an R-Package we developed for identifying receptor–ligand pairs and their downstream effects. We further report the establishment of a human pancreas culture system starting from fetal tissue or human pluripotent stem cells, enabling the long-term maintenance of pancreas progenitors in a minimal, defined medium in three-dimensions. Benchmarking the cells produced in 2-dimensions and those expanded in 3-dimensions to fetal tissue identifies that progenitors expanded in 3-dimensions are transcriptionally closer to the fetal pancreas. We further demonstrate the potential of this system as a screening platform and identify the importance of the EGF and FGF pathways controlling human pancreas progenitor expansion.

Generation of human islet cell type-specific identity genesets

“…Similarly, we did not observe any identity modulation during pancreas development for cells progressing towards Neurog3 or Fev expression, which are features of islet endocrine precursors. With the recent appearance of datasets regarding human pancreas development 62 , generating carefully annotated genesets that describe these early stages may be a crucial addition for better profiling in iPS differentiation protocols.…”

Emerging diabetes therapies: Bringing back the β-cells

“…In fact, focusing on further improving the generation of PE cells, we reported the generation of glucose-responsive sBCs in only 3 weeks in 2015 [ 17 ]. Over the last few years, many studies have further enhanced the in vitro generation of functional sBCs by synchronizing cultures [ 18 ], changing signaling pathway modulation [ 19 , 20 ], altering available energy sources in culture media [ 21 ], facilitating coalescence of sBCs into islet-like structures [ 22 ], and recreating 3D culture systems that evoked pancreatic development [ 23 ]. Taken together, published data indicate that sBCs exhibit distinct degrees of functionality (often referred as maturity).…”

Single cell transcriptomic and spatial landscapes of the developing human pancreas

“…A clearer understanding of human pancreatic endocrinogenesis is therefore required, and some progress has recently been made in this through single cell RNA sequencing (scRNA-seq). Thus, different progenitor populations have been identified in the very early stages of pancreas development (7 and 10 post conception week; PCW) (Gonçalves et al, 2021) and significant differences in lineage differentiation between developing mouse and human pancreas have recently been identified (Yu et al, 2021). However, while scRNA-seq provides a snapshot of gene expression profiles at an unprecedented scale, gene information in relation to spatial cell context is lost since tissue dissociation is required.…”