Lymph vessels in the mouse pancreas in normal and diabetic conditions: Immunohistochemical Identification by Podoplanin.

Abstract

This study explores lymphatic vascularization in the mouse pancreas under normal and diabetic conditions, focusing on histological and metabolic changes in normal mice and in db/db, db/lean, and lean/lean mice. Histological analysis using hematoxylin and eosin staining revealed significant structural disruptions in the diabetic pancreas, such as smaller, poorly defined pancreatic islets with marked destruction and distortion of endocrine cells. Metabolic assessments indicated higher blood glucose levels in db/db mice compared to db/lean (p<0.05) but more significant compared to lean/lean mice (P<0.001). All groups exhibited weight gain over three weeks, with db/db mice showing the most pronounced increase, indicative of obesity. Immunohistochemical (IHC) analysis, with a focus on podoplanin and other antibodies against VEGFR3, LYVE-1, insulin, and CD31, provided a baseline for normal pancreatic architecture. Podoplanin successfully marked lymphatic vessels at the islet periphery and in the exocrine pancreas, and unexpectedly also labeled the luminal side of ductal cells. Insulin staining highlighted well-defined islets and individual insulin-producing β-cells, and VEGFR3 staining highlighted various lymphatic vessels and fenestrated capillaries within the islets. In diabetic mice, Immunohistochemical staining with insulin revealed diminished and heterogeneous insulin staining within the islets, signifying impaired insulin production and reduced β-cell mass. The islets in diabetic strains appeared disorganized, reflecting significant functional impairment. These findings align with previous research and emphasize the progressive nature of diabetes, highlighting the critical need for early intervention. This study enhances our understanding of both normal and pathological pancreatic islet and lymphatic vessel structures, offering valuable insights into the relationship between the pancreas and diabetes. Further research is recommended to deepen our knowledge on the complex interactions between pancreatic structure, lymphatic function, and diabetes, ultimately leading to improved therapeutic strategies.

Date of Award	31 Jul 2024
Original language	English
Supervisor	Victor Nacher Garcia (Director)