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Elucidation of ATP‐stimulated stress protein expression of RBA‐2 type‐2 astrocytes: ATP potentiate HSP60 and Cu/Zn SOD expression and stimulates pI shift of peroxiredoxin II
Author(s) -
Chen Hammer B.,
Chan YaTing,
Hung Amos C.,
Tsai YouCheng,
Sun Synthia H.
Publication year - 2005
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20547
Subject(s) - peroxiredoxin , hsp60 , superoxide dismutase , chemistry , protein kinase c , biochemistry , microbiology and biotechnology , biology , oxidative stress , heat shock protein , signal transduction , hsp70 , enzyme , peroxidase , gene
ATP has been shown to mediate stress responses in the brain. The present study examined the ATP‐stimulated stress protein expression of RBA‐2 type‐2 astrocytes. Our results revealed that ATP stimulated HSP60 expression in a dose‐ and time‐dependent manner. The stimulation requires a minimal ATP concentration of 500 µM and high concentration of extracellular ATP (1 mM) stimulated a significant increase of HSP60 expression from 2 to 24 h. In addition, the ATP‐stimulated HSP60 expressions were inhibited by inhibitors for protein kinase C (PKC) and phospholipase D (PLD), and by antioxidants, resveratrol, and catalase. Furthermore, ATP stimulated the expression of Cu/Zn superoxide dismutase (SOD). In addition, ATP and P2X 7 receptor selective agonist BzATP also decreased mitochondria membrane potential measured by flow cytometry. To further examine the proteins involving in ATP‐mediated stress responses, we conducted proteomic analysis. We found that RBA‐2 astrocytes possess abundant peroxiredoxin II (Prx II), an antioxidant enzyme. ATP and exogenous H 2 O 2 stimulated Prx II shifting from oxidized form to reduced form. Thus, we concluded that ATP potentiated the expression of HSP60 and Cu/Zn SOD, and decreased mitochondria membrane potential. In addition, RBA‐2 astrocytes expressed Prx II that might also serve as a protective mechanism to control the concentration of reactive oxygen species. © 2005 Wiley‐Liss, Inc.