Lenti-siRNA Hsp60 promote bax in mitochondria and induces apoptosis during heat stress.
Hsp60 is a typical mitochondrial protein in eukaryotes, and is involved in facilitating the correction of misfolded protein back into the correct conformation. Previous, we identified aspirin-induced HSPs in response to heat stress [1]. To investigate whether Hsp60 can protect against death under heat stress, we used lenti-siRNA to knock down the expression of Hsp60. When exposed to heat stress, more apoptosis was observed with increasing exposure to heat stress, while necrosis was not affected. Furthermore, heat stress induced the loss of mitochondrial membrane potential (ΔΨm) and a significant increase of reactive oxygen species (ROS) produced in mitochondria as measured by TMRE and MitoSOXTM red. The loss of ΔΨm indicated a change in inner mitochondrial function. Real-time Quantitative PCR was used to investigate the mechanism by detecting mRNA expression profile of the inner mitochondrial membrane, including CypD, ANT, and PIC. Results showed no differences between lenti-siRNA Hsp60 and control. However, bax in the cytoplasm translocated to mitochondrial during heat stress and regulated the permeability of outer mitochondrial membrane. We hypothesize that Hsp60 can protect cardiac myocytes against apoptosis involving in outer mitochondrial membrane not the inner mitochondrial membrane under heat stress.
College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1 Road, Nanjing 210095, China.
Erbao
E
Song
College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1 Road, Nanjing 210095, China.
Shu
S
Tang
College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1 Road, Nanjing 210095, China.
Jiao
J
Xu
College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1 Road, Nanjing 210095, China.
Bin
B
Yin
College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1 Road, Nanjing 210095, China. Electronic address: b_endong@njau.edu.cn.
Endong
E
Bao
Institute for Animal Hygiene, Animal Welfare and Farm Animal Behaviour, University of Veterinary Medicine Hannover, Foundation, Hannover 30173, Germany.
Joerg
J
Hartung
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002460:Cell Line; D018834:Chaperonin 60 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D020868:Gene Silencing; D018869:Heat-Shock Response / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D032446:Myoblasts; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
C494828:Bax protein, rat; D018834:Chaperonin 60; C557067:Hspd1 protein, rat; D024101:Mitochondrial Proteins; D034741:RNA, Small Interfering; D051028:bcl-2-Associated X Protein
Apoptosis; Bax; Hsp60; Mitochondrial ROS; Mitochondrial permeability transition pore; Outer mitochondrial membrane