The emerging role of HSP20 as a multifunctional protective agent.

The small heat shock proteins (sHSPs) are a highly conserved family of molecular chaperones that are ubiquitously expressed throughout nature. They are transiently upregulated in many tissue types following stressful stimuli. Recently, one member of the sHSP family, HSP20 (HspB6), has been shown to be highly effective as a protective mediator against a number of debilitating pathological conditions, including cardiac hypertrophy and Alzheimer's disease. Hsp20 is also an important modulator of vital physiological processes, such as smooth muscle relaxation and cardiac contractility. This review focuses on the molecular mechanisms employed by HSP20 that allow it to act as an innate protector in the context of cardiovascular and neurological diseases. Emerging evidence for a possible role as an anti-cancer agent is also presented.