Open AccessTemporal variations of Hsp60 and HSF-1 in primary rat myocardial cells in vitro under heat stress
Author(s) -
B Rehana,
Yingjun Lv,
Asimul Islam,
Shu Tang,
Z J Liu,
M Zhang,
Asha Adem,
J. Hartung,
Endong Bao
Publication year - 2013
Publication title -
genetics and molecular research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 48
ISSN - 1676-5680
DOI - 10.4238/2013.august.20.2
Subject(s) - hsp60 , heat shock protein , medicine , heat stress , immunocytochemistry , in vitro , endocrinology , biology , chemistry , hsp70 , biochemistry , gene , zoology
The mechanisms involved in sudden animal death due to acute heart failure during heat stress are not well understood. We examined the relationship between heat stress-induced variations of protective Hsp60 and expression of its regulatory factor, HSF-1, in heat-stressed primary myocardial cells of neonatal rats in vitro through cardiac enzyme detection, immunoblotting, immunocytochemistry, and qPCR. Increases in cardiac damage-related enzyme levels demonstrated injury to myocardial cells after heat exposure at 42°C. Hsp60 expression levels fluctuated during heat stress; they decreased significantly after 20 min, then increased at 120 min and decreased again at 360 min after initiation of heat stress. The highest levels of Hsp60 were observed at 240 min, while the lowest were at 60 min. Damage to myocardial cells was characterized by increases in cardiac enzyme levels and low levels of Hsp60 due to functional disorder of myocardial cells at early stages of heat stress. However, the significant induction of hsp60 mRNA levels from the beginning up to 240 min of heat stress was not consistent with the classic regulatory mechanisms that link transcription and translation, suggesting that Hsp60 expression is delayed due to loss of Hsp60 during the early stages of heat stress. hsf-1 mRNA levels were significantly increased from 10 min of heat stress; however, HSF-1 protein levels did not simultaneously increase, indicating that HSF-1 is not the sole regulator of Hsp60 expression.