The release of lysosomal Pro⁃cathepsin L of BV⁃2 cells upon lipopolysaccharide stimulation and its toxicity to neurons

Abstract

Objective To investigate the secretion of lysosomal Pro ⁃ cathepsin L and its contribution to neuronal apoptosis upon lipopolysaccharide (LPS) stimulation. Methods The effect on the release of Pro ⁃ cathepsin L in BV ⁃ 2 cells upon LPS stimulation was determined by Western blotting. Dopaminergic cell line PC⁃12 cells were cultured with conditioned medium collected from BV⁃2 cells upon LPS stimulation, then the activated Caspase ⁃ 3 expression in PC ⁃ 12 cells was determined by Western blotting. After combination with Cathepsin L inhibitor (iCL) and LPS, the activated Caspase⁃3 expression in PC⁃12 cells was observed. Results The secretion of Pro⁃cathepsin L was increased significantly at 1 and 3 h upon LPS stimulation in BV⁃2 cells (P = 0.015, 0.021). Expression of activated Caspase⁃3 in PC⁃12 cells co⁃cultured with conditioned medium collected from BV⁃2 cells upon LPS stimulation at 1 and 3 h was increased (P = 0.000, for all). However, pretreatment with iCL in BV⁃2 cells could partially reverse Caspase⁃3 activation (P = 0.005, 0.001). Conclusion Inflammation increases secretion of Pro ⁃ cathepsin L in microglia, which can induce the Caspase⁃3 activation of neurons, which may participate in the pathogenesis of neurodegenerative diseases.

DOI：10.3969/j.issn.1672-6731.2011.01.015