Nanosilver pathophysiology in earthworms: Transcriptional profiling of secretory proteins and the implication for the protein corona

Abstract

Previously we have identified lysenin as a key protein constituent of the secretome from Eisenia fetida coelomocytes and revealed its critical importance in priming interactions between the cells and the protein corona around nanosilver. As alterations of the protein environment can directly affect the corona composition, the extent to which nanoparticles influence the cells’ protein secretion profile is of remarkable interest that has rarely acquired attention. Here, we have probed transcriptional responses of E. fetida coelomocytes to the representative nanosilver NM-300K (15 nm) in a time-dependent manner (2, 4, 8 and 24 h at a low-cytotoxic concentration), and examined the implication of the temporal changes in transcriptional profiles of secretory proteins with a particular reference to that of lysenin. NM-300K was accumulated in/at the cells and lysenin was, after transient induction, gradually suppressed over time indicating a negative feedback cycle. This may limit further enrichment of lysenin in the corona and thereby decrease the lysenin-assisted uptake of the nanoparticles. Other differentially expressed genes were those involved in metal stress (likewise in AgNO₃-stressed cells) and in Toll-like receptor (TLR) signaling. This offers an intriguing perspective of the nanosilver pathophysiology in earthworms, in which the conserved pattern recognition receptor TLRs may play an effector role.

• Biomolecular corona
• coelomocytes
• gene expression
• NM-300K
• toll-like receptors

Declaration of interest

All authors declare not to have any conflicts of interest. We gratefully acknowledge the financial support of EU FP7-project MARINA (ref 263215), the Danish Strategic Research Council (SIDANA 09-067185), the Danish Research Council (FUU 1-5971-10000377), the Nordic Council of Ministers, the NKG environmental nanoproject, the Medical Faculty Research Foundation, University of Pécs (PTE ÁOK-KA 2013/09) and the János Bolyai Research Foundation of the Hungarian Academy of Sciences.

Supplementary material available online

Supplementary Figures S1-S4 and Tables S1-S2.