Procyanidins, from Castanea mollissima Bl. shell, induces autophagy following apoptosis associated with PI3K/AKT/mTOR inhibition in HepG2 cells.
Procyanidins from Castanea mollissima Bl. shell (CSPCs) induced autophagy and apoptosis in HepG2 cells and its mechanism remains to be examined. In this paper, autophagy was measured by the lipid modification of light chain-3 (LC3) and the formation of autophagosomes. Hoechst 33258 staining and flow cytometer analysis were used to measure apoptosis. The western blot analysis was used to examine the effects of CSPCs on the expression of LC3, PI3K, phosphorylation of AKT, mTOR, Bcl-2, Bad, Bax, BID and cleaved caspase 3 in HepG2 cells. The results showed that 3-methyladenine (3-MA) and apoptosis inhibitor (Z-VAD) could inhibited the death of HepG2 induced by CSPCs for 48h (150μg/mL). CSPCs induced the accumulation of autophagosomes and microtubule-associated proteins light chain 3-II (LC3-II, a marker of autophagy). P-AKT, PI3K and mTOR were significantly decreased on CSPCs exposure. However, these phenomena were not observed in the group pretreated with the autophagy inhibitor 3-MA and Z-VAD. CSPCs also induced the expression of Bad, Bax and Beclin-1 proteins and decreased the expression of Bcl-2, which was inhibited by 3-MA and Z-VAD. Moreover the apoptotic cell death could be inhibited by 3-MA. In addition, inhibition of LC3-II by siRNA-dependent knockdown attenuated the cleavage of caspase 3. These results suggested CSPCs could trigger autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway, enhanced apoptosis in HepG2 cells which may be associated with the mitochondria-dependent signaling way.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China. Electronic address: zhanghh@mail.ujs.edu.cn.
Haihui
H
Zhang
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Xiaoping
X
Luo
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Jiajia
J
Ke
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China. Electronic address: dyq101@mail.ujs.edu.cn.
Yuqing
Y
Duan
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Yuanqing
Y
He
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Di
D
Zhang
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Meihong
M
Cai
Institute of Medicinal Plants, Chinese Academy of Medical Sciences, Beijing 100193, China.
Guibo
G
Sun
Institute of Medicinal Plants, Chinese Academy of Medical Sciences, Beijing 100193, China.
Xiaobo
X
Sun
D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D044946:Biflavonoids / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D056945:Hep G2 Cells; D031318:Hippocastanaceae / Q000737:chemistry*; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D044945:Proanthocyanidins / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
D000225:Adenine; D044946:Biflavonoids; D002392:Catechin; D049452:Green Fluorescent Proteins; D009363:Neoplasm Proteins; D009842:Oligopeptides; D019869:Phosphatidylinositol 3-Kinases; D044945:Proanthocyanidins; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2; D058570:TOR Serine-Threonine Kinases; C517629:benzyloxycarbonyl-valyl-alanyl-aspartic acid; C017674:procyanidin; C025946:3-methyladenine
Apoptosis; Autophagy; Castanea mollissima Bl. shell; HepG2 cells; Mitochondria; Procyanidins