Morphoquantitative and cyclooxygenase-2 immunohistochemical investigation in bone and cartilage tissue of an experimental model for Duchenne Muscular Dystrophy

• Grant number: 16/05618-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2016
• End date: June 30, 2017
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Flávia de Oliveira
• Grantee: Ana Carolina Camacho Cabral
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

The Duchenne muscular dystrophy is a recessive genetic disorder linked to the X chromosome, affecting 1: 3500 born males, which is a mutation in the dystrophin gene, leading to a progressive and irreversible muscle degeneration. It is known that bone health is also involved in this dystrophy, showing a decrease in bone mineral density and high incidence of fractures associated to weakness of this tissue. However, as a muscle disease character, there is a need of further research about how the chronic inflammation occasioned by the disease, affects the bone tissue on DMD carrier. The mouse model for Duchenne muscular dystrophy (mdx), is widely used to study the pathological mechanisms of this disease, particularly the molecular point of view. The purpose of the present study is to evaluate, in the distal epiphysis of the mdx femur, the possible morphological changes and relation the same with the COX-2 inflammatory marker. For this, C57BL/10 (n = 05) and C57BL10/Dmdmdx (n = 05) male mice with eight weeks old will be used. Animal will be distributed in control group (C) and Duchenne muscular dystrophy (DMD) group. After euthanasia, the distal femoral epiphysis of these animals will be separated for histopathological, morphometric and immunohistochemical evaluations. For histological analysis longitudinal cuts of the tissue will be obtained and will be stained with hematoxylin and eosin, and evaluate for the presence of inflammation. These sections will be evaluate morphometrically, wherein the thickness of the epiphyseal plate will be measured by a microscope coupled to an image analysis system. Finally, the longitudinal sections of the distal femoral epiphysis will be subjected to COX-2 immunohistochemical analysis. The hypothesis of this study is that the DMD can change the histopathological, morphometric and inflammatory parameters of the investigated bone. Such data may provide important information to understand bone changes in DMD and its relation to inflammatory process. (AU)