Extracellular matrix markers for disease progression and follow-up of therapies in familial amyloid polyneuropathy V30M TTR-related

摘要

Abstract. Familial Amyloidotic Polyneuropathy (FAP) is a disorder characterized by the extracellular deposition of fibrillarnTransthyretin (TTR) amyloid, with a special involvement of the peripheral nerve. Several extracellular matrix proteins have beennfound elevated in tissues from FAP patients, namely metalloproteinase-9 (MMP-9), neutrophil gelatinase associated lipocalinn(NGAL) and biglycan. In this work we assessed the levels of MMP-9, tissue inhibitor of metalloproteinase 1 (TIMP-1), NGAL,nbiglycan and chondroitin sulphate (CSPG) in an FAP V30M TTR-related transgenic mouse model at different stages of TTRndeposition and after two different treatment approaches to remove fibrillar deposits. Immunohistochemistry or RT-PCR analysisnshowed that biglycan was already increased in animals presenting TTR deposited in a non-fibrillar state, whereas MMP-9,nTIMP-1, NGAL and CSPG were elevated only in mice with TTR amyloid deposits. Mice treated with doxycycline, a TTR fibrilndisrupter, presented lower levels of MMP-9, TIMP-1 and NGAL, suggestive of matrix recovery. Mice immunized with TTRnY78F to remove TTR deposition showed significantly lower levels of all the five tested markers, suggesting removal of fibrillarnand non-fibrillar deposits. Cellular studies using oligomeric TTR showed induction of MMP-9 when compared to soluble TTR,nlarge aggregates or fibrils. Furthermore, this induction was neutralized by an anti-receptor for advanced glycation end productsn(RAGE) antibody, indicating RAGE engagement in this process. Further studies in a larger number of tissue samples will indicatenthe application of these ECM markers in parallel with Congo Red staining in tissue characterization of pre-clinical and clinicalnstages in FAP and other amyloidoses.