β(2)-microglobulin amyloidosis

Subcell Biochem. 2012:65:517-40. doi: 10.1007/978-94-007-5416-4_19.

Abstract

Dialysis-related amyloidosis (DRA) is a clinical syndrome of pain, loss of function and other symptoms due to the deposition of amyloid consisting of β(2)-microglobulin (β(2)m) in the musculoskeletal system. The condition is seen in patients who suffer from chronic kidney disease and are treated with hemodialysis for a long time. Even though β(2)m easily can be manipulated to form amyloid in laboratory experiments under non-physiological conditions the precise mechanisms involved in the formation of β(2)m-amyloid in patients with DRA have been difficult to unravel. The current knowledge which is reviewed here indicates that conformational fluctuations centered around the D-strand, the DE-loop, and around the cis-configured Pro32 peptide bond are involved in β(2)m amyloidosis. Also required are highly increased concentrations of circulating β(2)m and possibly various post-translational modifications mediated by the pro-inflammatory environment in uremic blood, together with the influence of divalent metal ions (specifically Cu(2 +)), uremic toxins, and dialysis-enhanced redox-processes. It seems plausible that domain-swapped β(2)m dimers act as building blocks of β-spine cross-β -sheet fibrils consisting of otherwise globular, roughly natively folded protein. An activated complement system and cellular activation perpetuate these reactions which due to the affinity of β(2)m-amyloid for the collagen of synovial surfaces result in the DRA syndrome.

Publication types

  • Review

MeSH terms

  • Amyloid* / chemistry
  • Amyloid* / metabolism
  • Amyloidosis* / blood
  • Amyloidosis* / etiology
  • Animals
  • Complement Activation
  • Complement System Proteins / chemistry
  • Complement System Proteins / metabolism
  • Copper* / chemistry
  • Copper* / metabolism
  • Humans
  • Protein Folding
  • Protein Multimerization*
  • Protein Structure, Quaternary
  • Protein Structure, Secondary
  • Renal Dialysis / adverse effects*
  • Renal Insufficiency, Chronic / blood*
  • Renal Insufficiency, Chronic / therapy
  • Uremia / blood
  • Uremia / therapy
  • beta 2-Microglobulin

Substances

  • Amyloid
  • beta 2-Microglobulin
  • Copper
  • Complement System Proteins