Fig. 6: Stem cell niches in neonatal piglets.

Localization in situ of stem cell niches in 1-day-old piglet livers, pancreas, and duodenum. Immunohistochemistry was processed on the sections of the Large-sized FFPE blocks of 1-day-old piglets using the set of stem cell markers (SOX2, SOX17, and PDX1) to identify the location of the stem cells niches in neonatal pig liver, pancreas, and duodenum. The left panel for every marker staining is the scaled image from the scanning of the entire section and is presented to give the landscape of the stem cell niches for endodermal stem cells. Scale bar for the enblock = 3 mm; for the enlargement images are 50 μm in all panels. a SOX2. Notice that the liver shows uniform dark staining in the section stained for SOX2. The SOX2⁺, SOX17⁺, PDX1⁺ stem cell niches can be observed primarily at the duodenum papilla where the hepatic common duct joins to the duodenum. For the pancreas, the zones are mostly in the glands in the pancreatic duct located at the pancreas head and partially in the next region of the pancreas, but not in the tail lobe. Cells doubly positive for Sox17 and PDX1 at the stem cell niches at the major papilla site at the duodenum. b Compared to the stem cell markers and EpCAM, Ki67 was found in the parenchyma of the liver, pancreas, and duodenum, and interestingly in distinct patterns in the three organs. c SOX17. Peribiliary glands at the large intrahepatic bile duct, the accessory pancreatic duct as well as the Brunner’s glands in the submucosa at the duodenum indicated SOX17⁺ signals. d PDX1. The large extrahepatic bile duct was found to be PDX1⁻, while the peribiliary glands in the accessory pancreatic duct, as well as the Brunner’s Glands in duodenum, were PDX1⁺. e Positive areas (percentages) of stem cell markers expressed by the hepatocytes and biliary epithelium in the liver; islet, pancreatic ducts, and acinar cells in the pancreas; Brunner’s Glands and surface epithelium in the duodenum. The error bars indicate the standard deviation of triplicate values from three experimental replicates.