Hypertonicity affects heat shock protein 27 and F-actin localization in Madin-Darby canine kidney cells.

High concentrations of NaCl are known to perturb the cytoskeleton. In this study, expression and intracellular localization of actin, an important component of the cytoskeleton and of heat shock protein (HSP)27, which promotes the assembly of F-actin, were examined in Madin-Darby canine kidney (MDCK) cells grown chronically in hypertonic medium. HSP27 mRNA abundance was increased twofold compared with wild-type MDCK cells. Chronic hypertonic stress led to enrichment of HSP27 in the insoluble component of the cell lysate and colocalization with cortical F-actin. These results support the notion that HSP27 participates in the modulation of actin dynamics following hypertonic stress.