High mobility group box 1 and kidney diseases (Review).

High mobility group box 1 (HMGB1), a non-histone DNA-binding protein, regulates nucleosome function and transcription in the nuclei of all metazoans and plants. However, extracellular HMGB1, which is actively or passively released under different conditions, can act as a key inflammatory mediator through MyD88/mitogen-activated protein kinase signaling by binding to its receptors including the receptor for advanced glycation end products or Toll-like receptors. A growing body of evidence indicates that HMGB1 plays an important role in kidney diseases, such as glomerulonephritis, lupus nephritis, antineutrophilic cytoplasmatic antibody-associated vaculitis, diabetic nephropathy, renal allograft rejection and acute kidney injury. In this review, we focus on the biology of HMGB1 and the association of HMGB1 with kidney diseases.