Induction of apoptosis in mouse type Ⅱ alveolar epithelial cells by LPS does not require TNF-? / 医学研究生学报

ABSTRACT

Objectives:To examine whether lipopolysaccharide (LPS) induced apoptosis correlates with TNF ? release by type Ⅱ alveolar epithelial cells (AEC Ⅱ), whether TNF ? knockout (TNF KO) abrogates the induction of apoptosis by LPS and whether TNF ? is sufficient to induce apoptosis in this cell type. Methods:AEC Ⅱ was isolated from wild type mice and TNF KO mice. Cells were stimulated with LPS or recombinant murine TNF ? for 24 h. TNF ? in culture supernatant was determined by ELISA following LPS stimulation. Apoptosis was determined by the TUNEL assay after treatment with either LPS or TNF ?. Results:LPS induced apoptosis in wild type AEC Ⅱ in a concentration dependent manner. LPS induced AEC Ⅱ apoptosis was accompanied by a 11 fold increase from (0.073?0.065) ng/ml in controls to( 0.94?0.14)ng/ml in 50 ?g/ml of LPS( P