Endoplasmic reticulum stress in the kidney.

Endoplasmic reticulum (ER) stress is involved in a wide range of pathological circumstances including neurodegenerative disorders, diabetes mellitus, ischemic injury, cancers, atherosclerosis, inflammation, infection, toxicity of chemicals and metals, and psychotic diseases. ER stress is also involved in some physiological events including development of particular cell types. A number of pathophysiological triggers cause accumulation of unfolded proteins in the ER, i.e., ER stress. In response to accumulation of unfolded/misfolded proteins, cells adapt themselves to the stress conditions via a coordinated adaptive program, the unfolded protein response (UPR). UPR is a double-edged sword. It induces both prosurvival and proapoptotic signaling. It also triggers both proinflammatory and anti-inflammatory signals. In this review, I summarize current knowledge on putative, pathophysiological roles of ER stress in the kidney.