Deep Tissue Clearing for Three-dimensional Imaging Analysis of Murine Pancreas

Abstract

Optical imaging of the vascular system is necessary for structural, functional, developmental, and pathological biology. Recent developments in optical tissue-clearing methods have significantly advanced largescale tissue researches by integrating a three-dimensional (3D) visualization of topographical vasculature, so we aimed to enhance the vascular structure of the murine pancreas which are highly vascularized structure. In this study, the adult C57/BL6 murine pancreatic tissue was cleared after lectin staining, resulting in the reconstructed structures for 3D imaging within a short period without damaging. Enhancing the visualization processes using light-sheet fluorescence microscopy (LSFM) together with 3D reconstruction imaging tool, we studied in depth of the entire vascular system, which further enabled to reconstruct 3D structure of the vasculature in pancreas and islets. We successfully implemented the normal murine pancreatic tissues including exocrine and endocrine cells and vascular structures, reflecting pancreatic β-cell function. The size of islets of each pancreatic lobe were not different but the number of islets in each lobe was variable in our quantification. In conclusion, this deep tissue clearing technique for 3D imaging could be applied in future studies to further understand the topological interactions of various cells and blood vessels within intact organs and tissues.