Apoptosis of cardiomyocytes limits the contractile efficiency of the heart during sepsis. Prosurvival autophagy has been proposed as a novel mechanism to maintain normal heart function. Here, we demonstrated that autophagy was activated in lipopolysaccharide (LPS)-treated HL-1 cells, and it counteracted the LPS-induced apoptosis. We investigated further the mechanism by which LPS triggered autophagy in HL-1 cells. We discovered that endoplasmic reticulum (ER) stress played an important role in LPS-triggered autophagy. The ER activated a survival pathway through the ER-localized transmembrane protein PERK, which was essential for LPS-induced autophagy. Lipopolysaccharide increased expression of GRP78, phosphorylated PERK and phosphorylated eukaryotic initiation factor 2 alpha. Similar results were observed after administration of tunicamycin, a well-known ER stressor. Most importantly, we found that 4-phenylbutyrate, an inhibitor of ER stress, suppressed LPS-activated autophagy in the presence of LPS in HL-1 cells. The same results were observed after small interfering RNA-mediated silencing of PERK protein. We also noticed that LPS-induced apoptosis appeared early, at 4 h. Our findings revealed that PERK, one arm of ER stress, facilitated survival of LPS-treated HL-1 cells by promoting autophagy, and could serve as a potential therapeutic strategy to alleviate septic myocardial dysfunction.
基金:
National Science Foundation of China [30901405, 81102691]
第一作者单位:[1]Huazhong Univ Sci & Technol, Tongji Med Coll, Union Hosp, Dept Anesthesiol,Lab Anesthesiol & Crit Care Med, Wuhan 430030, Hubei, Peoples R China
通讯作者:
通讯机构:[3]Huazhong Univ Sci & Technol, Tongji Med Coll, Tongji Hosp, Dept Emergency Med, Wuhan 430030, Hubei, Peoples R China[*1]Huazhong Univ Sci & Technol, Tongji Med Coll, Tongji Hosp, Dept Emergency Med, 1095 Jiefang Ave, Wuhan 430030, Hubei, Peoples R China
推荐引用方式(GB/T 7714):
Zou Xiaojing,Xu Jianjun,Yao Shanglong,et al.Endoplasmic reticulum stress-mediated autophagy protects against lipopolysaccharide-induced apoptosis in HL-1 cardiomyocytes[J].EXPERIMENTAL PHYSIOLOGY.2014,99(10):1348-1358.doi:10.1113/expphysiol.2014.079012.
APA:
Zou, Xiaojing,Xu, Jianjun,Yao, Shanglong,Li, Jian,Yang, Yan&Yang, Le.(2014).Endoplasmic reticulum stress-mediated autophagy protects against lipopolysaccharide-induced apoptosis in HL-1 cardiomyocytes.EXPERIMENTAL PHYSIOLOGY,99,(10)
MLA:
Zou, Xiaojing,et al."Endoplasmic reticulum stress-mediated autophagy protects against lipopolysaccharide-induced apoptosis in HL-1 cardiomyocytes".EXPERIMENTAL PHYSIOLOGY 99..10(2014):1348-1358