Age-dependent increase in thiol conjugated forms of transthyretin (TTR) in the elderly: quantitative analyses by the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) protein chip system.

摘要

Senile systemic amyloidosis (SSA) caused by wild-type (WT) transthyretin (TTR) is a prevalent disorder in the elderly. However, mechanisms of WT TTR amyloid formation and risk factors for SSA remain to be elucidated. In this study, to determine age-related changes in serum TTR, we investigated TTR concentrations and modifications ratios in sera of the elderly. Neither significant age-related changes nor gender-related distinctions in serum TTR concentrations were observed from the age of 60's to 90's. In addition, serum TTR concentrations of SSA patients did not significantly change compared to those in coeval elderly. However, all kinds of thiol conjugated-TTR ratios significantly increased as the age by means of surface-enhanced laser desorption/ ionization time-of-flight mass spectrometry, while those of SSA patients did not significantly differ from those of the coeval elderly. We speculate that those thiol conjugations of TTR are one of the required trigger for SSA in the elderly.