Multimodal 3-D/2-D human islet and duct imaging in exocrine and endocrine lesion environment: associated pancreas tissue remodeling

Abstract

Background: Pancreatic intraepithelial neoplasia (PanIN) and islet cell microadenoma are exocrine and endocrine neoplasms of human pancreas which have been linked to pancreatic ductal adenocarcinoma (PDAC) and neuroendocrine tumor, respectively. However, in health and at the surgical margin of pancreatic cancer, it remains unresolved how to simultaneously characterize duct and islet remodeling to investigate the exocrine-endocrine association in the lesion microenvironment. Here, we develop a new vibratome-based approach to detect, confirm, and analyze the two types of pancreas remodeling via stereo/3-D and classic/2-D histology. Methods: Surgical margins of PDAC (n=10, distal) and cadaveric donor pancreases (n=10, consecutive cases) were fixed, sectioned by vibratome (350 µm), and surveyed for PanIN and microadenoma via stereomicroscopy. After lesion detection, PanIN and microadenoma were analyzed with 3-D fluorescence imaging and clinical microtome-based histology for confirmation and assessment of microenvironment. Results: Multimodal imaging of PDAC surgical margins and cadaveric donor pancreases detected the peri-PanIN islet aggregation with duct-islet cell clusters. Organ-wide survey of cadaveric donor pancreases shows a marked 2.3-fold increase in the lesion size with the PanIN-islet association vs. without the association. In the survey, we unexpectedly detected the islet cell microadenoma adjacent to (<2 mm) PanIN. Overall, among the 53 early lesions in the cadaveric donor pancreases (PanINs and microadenomas), 81% are featured with the associated exocrine-endocrine tissue remodeling. Conclusion/interpretation: Multimodal 3-D/2-D tissue imaging reveals local and simultaneous duct and islet remodeling in the cancer surgical margin and cadaveric donor pancreas. In the cadaveric donor pancreas, the peri-PanIN islet aggregation and PanIN-microadenoma association are two major features of pancreas remodeling in the early lesion microenvironment.

Transparent tissue in solid state for solvent-free and antifade 3D imaging

“…This phenomenon is highlighted by the detection of duct-islet cell clusters (Fig. 5k–o and Supplementary Movie 7 ) 33 , 41 . In the A-ha copolymer, the cluster is well preserved and can be identified with glucagon (α-cell), insulin (β-cell), and cytokeratin 7 (CK7, duct cell) staining.…”

“…Perfused pancreases from two donors (male, no history of diabetes or pancreatic diseases, aged 40-55, with BMI 20.4-23.6) with normal HbA 1c , amylase, and lipase levels were used to characterize the pancreatic lobular environment in health and pancreatic intraepithelial neoplasia (PanIN). The two donor pancreases were grossly normal, but low-grade PanIN lesions were detected by organ-wide examination of vibratome sections via stereomicroscopy; the PanIN lesions were subsequently confirmed by H&E histology 41 .…”

“…Afterward, the organs were harvested and post-fixed in 4% paraformaldehyde solution for 30 minutes at 15 °C. The human donor pancreas was first cut to separate the head, body, and tail of the organ and then into strips (~1.5 cm in width) 41 . Afterward, the tissue was fixed in formaldehyde 10% (w/v; Macron Fine Chemicals, Centre Valley, PA, USA, H121-08) for two days and then washed in PBS for four days at 4 °C.…”

“…Vibratome sections of human pancreas (350 µm in thickness; Fig. 5a, b ) were examined with stereomicroscopy to detect the potential duct lesion 41 . Afterward, the area of interest was examined by clinical 2D histology (H&E stain of microtome section, gold standard) to confirm the PanIN lesion (Fig.…”