Overexpression of the human 72 kDa heat shock protein in renal tubular cells confers resistance against oxidative injury and cisplatin toxicity.
BACKGROUND
Recent studies have shown that the 72-kDa heat shock protein (HSP72) can be induced in renal tubular cells by a variety of stress conditions, and suggested its cytoprotective function. We have tested this hypothesis directly by transfection studies.


METHODS
LLC-PK1 cells (porcine renal tubular epithelial cells) were stably transfected with pBK-CMV or pBK-CMV containing the human HSP72 gene (pBK-CMV-HSP72). These cells were then treated with various concentrations of hydrogen peroxide or cisplatin. The cell viability and lytic cell damage were determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and lactate dehydrogenase release assay.


RESULTS
Immunoblot and immunocytochemical analyses showed the high level expression of HSP72 in LLC-PK1 cells transfected with pBK-CMV-HSP72. In addition, the expression of other major HSPs (HSP90, HSP73, HSP60 and HSP27) was not affected by transfection. LLC-PK1 cells overexpressing HSP72 were significantly more resistant to hydrogen peroxide and cisplatin treatments than control cells.


CONCLUSIONS
These results indicate that overexpressed HSP72 plays a direct role in protecting renal tubular cells against oxidative injury and cisplatin toxicity.
Komatsuda
A
A
Third Department of Internal Medicine, Akita University School of Medicine, Japan.
Wakui
H
H
Oyama
Y
Y
Imai
H
H
Miura
A B
AB
Itoh
H
H
Tashima
Y
Y
D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D002478:Cells, Cultured; D002945:Cisplatin / Q000633:toxicity*; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D007684:Kidney Tubules / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress; D013552:Swine
D000970:Antineoplastic Agents; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D006861:Hydrogen Peroxide; D002945:Cisplatin