Evaluation of connexin expression and their subcellular localization in pancreatitis and endocrine and exocrine pancreatic neoplasias in dogs.

• Grant number: 25/07792-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2025
• End date: March 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Maria Lucia Zaidan Dagli
• Grantee: Raphael Assis Leandro de Morais
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Connexins are transmembrane proteins that form gap junctions or nexuses, responsible for the direct exchange of solutes between adjacent cells. Intercellular communication through gap junctions is important for preserving tissue homeostasis. Connexins are normally located in cell membranes and changes in their expression and subcellular localization may be associated with pathological processes, especially those in which there are changes in cell proliferation. The pancreas has both endocrine and exocrine functions and can be affected by several pathological processes such as pancreatitis and primary endocrine or exocrine neoplasias. The present study aims to evaluate the expression of connexins and their subcellular localization in pancreatitis and endocrine and exocrine neoplasias of the pancreas of dogs. A survey of the last 20 years of inflammatory and neoplastic lesions of the pancreas of dogs diagnosed at the Animal Pathology Service of the Pathology Department of FMVZ-USP will be conducted. Using histopathology, pancreatitis will be differentiated into acute and chronic, using data established in the literature. The diagnoses of pancreatic neoplasias will be reviewed and, if necessary, immunohistochemistry will be performed to confirm the histogenesis of endocrine neoplasias. For this purpose, antibodies for Insulin, Chromogranin A and Neurospecific Enolase (NSE) will be used. Meanwhile, for exocrine pancreatic tumors, antibodies for Cytokeratin 7, Cytokeratin 20 and Alpha-1-Antitrypsin will be used. Connexins will be detected in pancreatic tissue using immunofluorescence, and their subcellular location will be observed and recorded. Experimental studies report that connexins 26, 32, 36, 40, 43 and 45 act in intercellular communication in the exocrine and endocrine pancreas, and their expression and subcellular localization may be altered in pathological processes. The expression of Ki67 in benign and malignant neoplasms of the pancreas of dogs, originating from both the exocrine and endocrine portions, will also be analyzed. Thus, we seek to understand and characterize the expression of several connexins that act in the pancreas against the most common pancreatic diseases observed in canines.