Calpain-mediated Cleavage of Atg5 Determine Autophagy or Apoptosis of PMN, and C5a's Role
- VernacularTitle:Calpain裂解Atg5决定中性粒细胞发生自噬还是凋亡,以及C5a在其中的可能作用
- Author:
Baoquan ZHANG
;
Zhenhui GUO
;
Wei FANG
;
Fenglin LU
- Publication Type:Journal Article
- Keywords:
polymorphonuclear neutrophil, apoptosis, autophagy, Atg5, calpain, C5a
- From:
Progress in Biochemistry and Biophysics
2006;0(12):-
- CountryChina
- Language:Chinese
-
Abstract:
Apoptosis of neutrophils controls the duration and the intensity of an inflammatory response and therefore the extent of neutrophil- mediated tissue damage, disturbance of neutrophil apoptosis has been associated with many diseases, underlying mechanism is not elucidated. C5a is a complement fragment that has multifunctional properties, which induces neutrophil chemoattraction, an oxidative burst, enhancement of phagocytosis, release of granule enzymes, and suppress neutrophil apoptosis. Several studies have reported calpain is involved in both neutrophil functions and apoptosis and it might play a more specific role in the regulation of neutrophil apoptosis. Diffenrent isoform of calpains is activted by diffenrent stimuli through different transduction pathway. It was reported previously that calpain is required for neutrophil migration and chemotaxis induced by C5a. In addition, autophagy is a ubiquitous physiological process that occurs in all eukaryotic cells and is considered to be a survival mechanism. Atg5 promotes autophagy and is indispensable to autophagosome formation. Upon calpain activation, Atg5 is cleaved and the resulting 24 ku Atg5 mediates apoptosis while losting the property of autophagy. Therefore, Atg5 represents a molecular switch between autophagy and apoptosis. The interaction among the C5a, calpain and Atg5 was introduced and new direction for further research was provided.
