TY - JOUR
T1 - Effect of tetracyclines on the dynamics of formation and destructuration of β2-microglobulin amyloid fibrils
AU - Giorgetti, Sofia
AU - Raimondi, Sara
AU - Pagano, Katiuscia
AU - Relini, Annalisa
AU - Bucciantini, Monica
AU - Corazza, Alessandra
AU - Fogolari, Federico
AU - Codutti, Luca
AU - Salmona, Mario
AU - Mangione, Palma
AU - Colombo, Lino
AU - De Luigi, Ada
AU - Porcari, Riccardo
AU - Gliozzi, Alessandra
AU - Stefani, Massimo
AU - Esposito, Gennaro
AU - Bellotti, Vittorio
AU - Stoppini, Monica
PY - 2011/1/21
Y1 - 2011/1/21
N2 - The discovery of methods suitable for the conversion in vitro of native proteins into amyloid fibrils has shed light on the molecular basis of amyloidosis and has provided fundamental tools for drug discovery. We have studied the capacity of a small library of tetracycline analogues to modulate the formation or destructuration of β2-microglobulin fibrils. The inhibition of fibrillogenesis of the wild type protein was first established in the presence of 20% trifluoroethanol and confirmed under a more physiologic environment including heparin and collagen. The latter conditions were also used to study the highly amyloidogenic variant, P32G. The NMR analysis showed that doxycycline inhibits β2-microglobulin self-association and stabilizes the native-like species through fast exchange interactions involving specific regions of the protein. Cell viability assays demonstrated that the drug abolishes the natural cytotoxic activity of soluble β2-microglobulin, further strengthening a possible in vivo therapeutic exploitation of this drug. Doxycycline can disassemble preformed fibrils, but the IC50 is 5-fold higher than that necessary for the inhibition of fibrillogenesis. Fibril destructuration is a dynamic and timedependent process characterized by the early formation of cytotoxic protein aggregates that, in a few hours, convert into non-toxic insoluble material. The efficacy of doxycycline as a drug against dialysis-related amyloidosis would benefit from the ability of the drug to accumulate just in the skeletal system where amyloid is formed. In these tissues, the doxycycline concentration reaches values several folds higher than those resulting in inhibition of amyloidogenesis and amyloid destructuration in vitro.
AB - The discovery of methods suitable for the conversion in vitro of native proteins into amyloid fibrils has shed light on the molecular basis of amyloidosis and has provided fundamental tools for drug discovery. We have studied the capacity of a small library of tetracycline analogues to modulate the formation or destructuration of β2-microglobulin fibrils. The inhibition of fibrillogenesis of the wild type protein was first established in the presence of 20% trifluoroethanol and confirmed under a more physiologic environment including heparin and collagen. The latter conditions were also used to study the highly amyloidogenic variant, P32G. The NMR analysis showed that doxycycline inhibits β2-microglobulin self-association and stabilizes the native-like species through fast exchange interactions involving specific regions of the protein. Cell viability assays demonstrated that the drug abolishes the natural cytotoxic activity of soluble β2-microglobulin, further strengthening a possible in vivo therapeutic exploitation of this drug. Doxycycline can disassemble preformed fibrils, but the IC50 is 5-fold higher than that necessary for the inhibition of fibrillogenesis. Fibril destructuration is a dynamic and timedependent process characterized by the early formation of cytotoxic protein aggregates that, in a few hours, convert into non-toxic insoluble material. The efficacy of doxycycline as a drug against dialysis-related amyloidosis would benefit from the ability of the drug to accumulate just in the skeletal system where amyloid is formed. In these tissues, the doxycycline concentration reaches values several folds higher than those resulting in inhibition of amyloidogenesis and amyloid destructuration in vitro.
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U2 - 10.1074/jbc.M110.178376
DO - 10.1074/jbc.M110.178376
M3 - Article
C2 - 21068391
AN - SCOPUS:78751560834
VL - 286
SP - 2121
EP - 2131
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 3
ER -