Heparan sulfates facilitate harmless amyloidogenic fibril formation interacting with elastin-like peptides

Federica Boraldi,Brigida Bochicchio,Daniela Quaglino,Antonietta Pepe,Anna M Salvi,Pasquale Moscarelli

doi:10.1038/s41598-018-21472-0

Federica Boraldi, Brigida Bochicchio + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-21472-0

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Abstract

Heparan sulfates (HSs) modulate tissue elasticity in physiopathological conditions by interacting with various matrix constituents as tropoelastin and elastin-derived peptides. HSs bind also to protein moieties accelerating amyloid formation and influencing cytotoxic properties of insoluble fibrils. Interestingly, amyloidogenic polypeptides, despite their supposed pathogenic role, have been recently explored as promising bio-nanomaterials due to their unique and interesting properties. Therefore, we investigated the interactions of HSs, obtained from different sources and exhibiting various degree of sulfation, with synthetic amyloidogenic elastin-like peptides (ELPs), also looking at the effects of these interactions on cell viability and cell behavior using in vitro cultured fibroblasts, as a prototype of mesenchymal cells known to modulate the soft connective tissue environment. Results demonstrate, for the first time, that HSs, with differences depending on their sulfation pattern and chain length, interact with ELPs accelerating aggregation kinetics and amyloid-like fibril formation as well as self-association. Furthermore, these fibrils do not negatively affect fibroblasts’ cell growth and parameters of redox balance, and influence cellular adhesion properties. Data provide information for a better understanding of the interactions altering the elastic component in aging and in pathologic conditions and may pave the way for the development of composite matrix-based biomaterials.

Highlights

Heparan sulfates (HSs) are anionic polysaccharides made up of repeating amino sugar-uronic acid disaccharide units that undergo a various degree of sulfation[1]
Despite the significant progress made in the last years in understanding amyloidogenic protein interactions with a variety of extracellular matrix-associated biomolecules[36,37], no data are available on the ability of HSs to bind to elastin-like peptides (ELPs) and if these interactions may influence cell behaviour and/or may induce a cytotoxic effect
By contrast, when HSs were added to the other peptides (Fig. 1b,c and d and Table 1), the time course of Thioflavin T (ThT) fluorescence was characterized by two phases (Fig. 1): an exponential growth phase corresponding to kinetics of aggregation and a final levelling off, when the process reaches an equilibrium

Summary

Introduction

Heparan sulfates (HSs) are anionic polysaccharides made up of repeating amino sugar-uronic acid disaccharide units that undergo a various degree of sulfation[1]. Loss of tissue elasticity is the hallmark of increasing age or of a number of pathological conditions, being the consequence of the almost absent elastin turnover, of damages to elastic fibers, as degradation and fragmentation, which release biologically active EDPs10–13, or favour the deposition of protein aggregates called elastotic material[14,15]. These aggregates have not been fully characterized, it appears that they consist predominantly of fibronectin, microfibrillar proteins, elastin and amyloid-like proteins[16,17,18]. Despite the significant progress made in the last years in understanding amyloidogenic protein interactions with a variety of extracellular matrix-associated biomolecules[36,37], no data are available on the ability of HSs to bind to ELPs and if these interactions may influence cell behaviour and/or may induce a cytotoxic effect

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