Dynamic changes of intracellular signals in ATTR Tyr114Cys amyloidosis

Hereditary transthyretin (TTR) amyloidosis (ATTRv amyloidosis) is an autosomal dominant disease caused by various TTR mutations. Despite the fact that ATTR Tyr114Cys (p.Tyr134Cys) amyloidosis (tyrosine to cysteine at codon 114) exhibits poorer prognosis than other ATTRv amyloidosis and leads to death due to severe clinical symptoms, the molecular pathogenesis of ATTR Tyr114Cys amyloidosis is still largely unknown. In this study, we took advantage of ATTR Tyr114Cys amyloidosis-specific induced pluripotent stem (iPS) cells to differentiate into hepatocyte-like cells (Y114C-HLCs), which are mainly TTR producing cells, and elucidated their pathogenesis. We performed proteomic analysis to comprehensively identify specific intracellular signaling pathways involved in Y114C-HLCs, and identified the specific proteins changed only in Y114C-HLCs, in comparison with disease control HLCs from ATTR Val30Met amyloidosis (V30M-HLCs). Moreover, we have succeeded in identifying several specific intracellular signals that are significantly activated in Y114C-HLCs, including cellular responses to stress and extracellular matrix organization. Our proteomic analysis is the first to report that the specific point mutations in ATTRv amyloidosis cause dynamic changes in cellular response, and reveal the specific intracellular signals may be involved in the specific pathogenesis of ATTR Tyr114Cys amyloidosis.