Signal molecule 3-oxo-C12-HSL of Pseudomonas aeruginosa promotes autophagy of mouse alveolar macrophages MH-S cells / 基础医学与临床

ABSTRACT

Objective To investigate the effect of 3-oxo-C12-HSL on autophagy in mouse alveolar macrophages MH-S cells. Methods MH-S cells were treated with culture supernatants of the mutant and wild type Pseudomonas aeruginosa(PA) strains of LasI gene(3-oxo-C12-HSL synthetic gene) and chemically synthesized 3-oxo-C12-HSL signaling molecules. GFP puncta was observed by laser confocal fluorescence microscopy and the ratio of LC3Ⅱ/LC3Ⅰ was detected by Western blot to detect the formation of autophagic.Autophagic flux was also detected by mo-nitoring the degradation of p62 and the change of chloroquine to LC3Ⅱ/LC3Ⅰratio. Results The supernatant of the culture medium of the wild type PA strain increased the GFP puncta of the MH-S cells(P<0.05) and the ra-tio of LC3Ⅱ/LC3Ⅰ(P<0.01),The mutant PA strain of LasI gene could not cause the above changes related to autophagy. The chemically synthesized 3-oxo-C12-HSL signal molecules could increase the number of autophagic bodies and the expression of LC3Ⅱ (P<0.01). Autophagic substrate p62 was degraded by 3-oxo-C12-HSL. Chloroquine, a lysosomal inhibitor, enhanced LC3Ⅱaccumulation caused by 3-oxo-C12-HSL (P<0.05,P<0.01).Conclusions 3-oxo-C12-HSL increases the level of autophagy in MH-S cells.