Effect of the immunosuppressants on a weanling animal model of liver regeneration: an immunohistochemical study using tissue microarrays

• Grant number: 07/01333-2
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2007
• End date: May 31, 2009
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Uenis Tannuri
• Grantee: Uenis Tannuri
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Liver regeneration is a phenomenon that results as a physiological response to ther loss of liver parenchyma and after partial liver transplantation. It depends on hepatocytes and hepatic stem cells proliferation, on the starting mechanisms (cell growth factors and cytokines) and on apoptosis (a programmed cell death) of hepatocytes. Among the experimental models utilized for liver regeneration studies there are no reported models with newborn or weanling animals. In addition, there are few studies about the molecular mechanisms of cell proliferation and apoptosis in the regenerating liver as well as the effects of immunosuppressive drugs utilized in the postoperative period of liver transplanted patients. The current paper is a sequence of experimental researches that have been performed in the Pediatric Surgery Laboratory of University of São Paulo Medical School (LIM-30). Objective: to study the effects of immunosuppressive drugs on the liver regeneration utilizing immunohistochemical methods and the technique of tissue microarray. Material and methods: paraffin blocks containing the livers collected from 36 weanling rats from a previous experience will be utilized. These remaining livers were harvested 24 hours after a partial hepatectomy performed the animals that were dived into groups according to the procedures: 1. control; 2. sham (only laparotomy and suture of abdominal wall); 3. hepatectomy; 4. hepatectomy plus solumedrol; 5. hepatectomy plus cyclosporine A (CsA) and 6. hepatectomy plus tacrolimus (Tac). The remnant livers will be studied utilizing tissue microarray technique. Cylindrical minute tissues (1.0 X 1.0 X 4.0mm) will be punched from morphologically representative sites of the original paraffin blocks and arrayed in the bottom of a custom-made embedding box, and again embedded in paraffin. A paraffin block containing several minute tissue representative samples of the livers will be cut into 3 µm-thick sections to generate tissue microarray slides. Liver cell proliferation will be evaluated by immunohistochemical stainings for proliferating cell nuclear antigen (PCNA) and hepatic cells apoptosis will be detected by the terminal deoxynucleotidyl transferase- mediated dUTP-FITC nick-end labeling (TUNEL) method. The stained nuclei will be counted and the results will be submitted to statistical analyses by utilizing ANOVA method. If the results demonstrate non-parametric data, the Kruskall Wallys will be utilized. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS‚ M.M.; TANNURI‚ U.; COELHO‚ M.C.M.. Study of acetylcholinesterase activity in rectal suction biopsy for diagnosis of intestinal dysganglionoses: 17-year experience of a single center. PEDIATRIC SURGERY INTERNATIONAL, v. 24, n. 6, p. 715-719, 2008. (07/01333-2)

TANNURI‚ A.C.A.; TANNURI‚ U.; WAKAMATSU‚ A.; MELLO‚ E.S.; COELHO‚ M.C.M.; DOS SANTOS‚ N.A.S.R.. Effect of the immunosuppressants on hepatocyte proliferation and apoptosis in a young animal model of liver regeneration: An immunohistochemical study using tissue microarrays. PEDIATRIC TRANSPLANTATION, v. 12, n. 1, p. 40-46, 2008. (07/01333-2)

ANA CRISTINA AOUN TANNURI; UENIS TANNURI; MARIA CECÍLIA COELHO; NEIDE APARECIDA DOS SANTOS; EVANDRO SOBROZA DE MELLO. Modelos experimentais de hepatectomia e regeneração hepática em ratos recém-nascidos e recém-desmamados. Clinics, v. 62, n. 6, p. 757-762, 2007-00-00. (07/01333-2)

COELHO, MARIA CECILIA M.; TANNURI, UENIS; BENDITT, ISRAEL; SANTOS, MARIA MERCES. Studies of RET gene expression and acetylcholinesterase activity in a series of sporadic Hirschsprung's disease. PEDIATRIC SURGERY INTERNATIONAL, v. 24, n. 9, p. 1017-1021, SEP 2008. (07/01333-2)

MENDES GIBELLI, NELSON ELIAS; TANNURI, UENIS; DE MELLO, EVANDRO SOBROZA; RODRIGUES, CONSUELO JUNQUEIRA. Bile duct ligation in neonatal rats: Is it a valid experimental model for biliary atresia studies?. PEDIATRIC TRANSPLANTATION, v. 13, n. 1, p. 81-87, FEB 2009. (07/01333-2)