The next series of the Paris Postdoc Seminar Series at Institut Pasteur will take place Tuesday, 19th December 2023, at 11h30 in the Agnes Ullman Amphitheatre (Monod Building).
PhD students and Postdocs are welcome to have lunch with Dr Villalba at La Table. Please register here.
The exploration of human fetal pancreas development offers invaluable insights into the intricate mechanisms governing the proliferation and differentiation of pancreatic cells. In our study, we have employed an innovative approach that combines tissue clearing, comprehensive labeling, and light-sheet fluorescence microscopy to construct a three-dimensional atlas of the human embryonic and fetal pancreas during the first trimester of pregnancy. Our research reveals that the first appearance of INS+ cells occurs at approximately 5 weeks post-conception, significantly earlier than previously determined through conventional immunostaining methods. These INS+ cells are primarily localized within the inner part of the organ, alongside other endocrine subsets like GCG+ and SST+ cells. Conversely, proliferating pancreatic progenitors are situated in the periphery of the epithelium, suggesting the existence of two distinct pancreatic niches for differentiation and proliferation.
Moreover, our investigation demonstrates that acinar CPA1+ cells are predominantly situated in the peripheral regions of the embryonic and fetal pancreas, despite being fully differentiated and lacking proliferative capabilities. Furthermore, we have confirmed the presence of extra-pancreatic INS+ cells adjacent to the gut. In addition to this, we have developed an explant culture system that allows for in vitro proliferation of pancreatic progenitors. This system has revealed a mitogenic effect of PDGFAA on progenitors, which operates through the pancreatic mesenchyme.
In summary, our work provides the most comprehensive atlas of the human developing pancreas, encompassing both endocrine and proliferating cells throughout early development. These novel insights contribute significantly to our understanding of developmental biology and hold promise for advancing regenerative medicine and therapeutic interventions.
Room: Agnes Ullmann Amphitheatre
Address: Institut Pasteur, Rue du Docteur Roux, Paris, France