Localization and level of proapoptotic protein regulators in a rat lung tissue during development of acute experimental bronchopneumonia

Abstract

Apoptosis plays an important role in the development of acute inflammatory lung injury (AILI) and its consequences, which can be realized in different cells with distinct intensity and rate. The aim of this study was to determine the distribution and expression intensity of apoptosis markers in the lungs of rats in the AILI model with endotracheal introduction of capron thread and LPS. Immunoblotting and immunohistochemical studies were performed using monoclonal antibodies against Bax and caspase-3 proteins. It was shown that Bax level increased significantly with the peak on the 7th day. The second peak of Bax 40 dimeric form was noted on the 21st day. The level of both pro-caspase-3 and active caspase-3 was also dramatically increased with a maximum on the 5th day and the second peak of active caspase-3 content was observed on the 21st day. These changes reflected the activation of apoptosis in key trigger periods of AILI during the development of exudative hemorrhagic pneumonia and subsequent fibrotic remodeling of the lungs. Keywords: AILI, apoptosis, Bax, caspase-3, lipopolysaccharide