Overexpression of the human 72 kDa heat shock protein in renal tubular cells confers resistance against oxidative injury and cisplatin toxicity.

HSP90 family, the HSP70 family, the HSP60 family, Background. Recent studies have shown that the 72- and low molecular weight HSPs, such as HSP27 (alias kDa heat shock protein (HSP72) can be induced in HSP28) [2]. Major members of these families are renal tubular cells by a variety of stress conditions, expressed in cells even under normal conditions. They and suggested its cytoprotective function. We have have been shown to act as molecular chaperones, tested this hypothesis directly by transfection studies. which regulate protein synthesis, translocation of proMethods. LLC-PK1 cells (porcine renal tubular epithe- teins into various intracellular organelles and protein lial cells) were stably transfected with pBK-CMV or degradation [3,4]. pBK-CMV containing the human HSP72 gene (pBK- Major HSPs are mainly localized in tubular epithelial CMV-HSP72). These cells were then treated with cells in the kidney [5]. Recent in vivo studies have various concentrations of hydrogen peroxide or cispla- shown that HSPs can be induced in injured cells in tin. The cell viability and lytic cell damage were animal model for acute renal failure due to ischaemia determined by the MTT (3-[4,5-dimethylthiazol-2-yl ]- and nephrotoxic drugs, and suggested their cytopro2,5-diphenyltetrazolium bromide) assay and lactate tective roles [5]. dehydrogenase release assay.