Impact of exposure time, particle size and uptake pathway on silver nanoparticle effects on circulating immune cells in mytilus galloprovincialis

Abstract

Nanomaterials have increasingly emerged as potential pollutants to aquatic organisms. Nanomaterials are known to be taken up by hemocytes of marine invertebrates including Mytilus galloprovincialis. Indeed, assessments of hemocyte-related parameters are a valuable tool in the determination of potentials for nanoparticle (NP) toxicity. The present study assessed the effects from two size types of silver nanoparticles (AgNP: <50 nm and <100 nm) on the frequency of hemocytes subpopulations as immunomodulation biomarkers exposed in a mollusk host. Studies were performed using exposures prior to and after inhibition of potential NP uptake pathways (i.e. clathrin- and caveolae-mediated endocytosis) and over different durations of exposure (3, 6 and 12 h). Differential hemocyte counts (DHC) revealed significant variations in frequency of different immune cells in mussels exposed for 3 hr to either AgNP size. However, as exposure duration progressed cell levels were subsequently differentially altered depending on particle size (i.e. no significant effects after 3 h with larger AgNP). AgNP effects were also delayed/varied after blockade of either clathrin- or caveolae-mediated endocytosis. The results also noted significant negative correlations between changes in levels hyalinocytes and acidophils or in levels basophils and acidophils as a result of AgNP exposure. From these results, we concluded AgNP effects on mussels were size and duration of exposure dependent. This study highlighted how not only was NP size important, but that differing internalization mechanisms could be key factors impacting on the potential for NP in the environment to induce immunomodulation in a model/test sentinel host like M. galloprovincialis.

Evaluation of the effect of silver nanoparticles onOLN-93 oligodendroglial cells

“…Since Ag-NPs presents remarkable broad-spectrum bactericidal properties and biocompatibility (i.e. as drug delivery agent), it makes Ag-NPs a really wide-range useful material (Bouallegui et al, 2017). In contrast, some studies reported the toxic effects of Ag-NPs such as neurovascular toxicity, astrocytes metabolic and biosynthesis suppression (Xu et al, 2015), voltage-gated sodium channels toxicity (Liu et al, 2009), as well as de structive effects on cortical cell survival through cytoskeletal and synaptic protein degradation, and mitochondrial degeneration in rats (Xu et al, 2013).…”

“…In this regard, it is also important to know that neurotoxicity might be influenced by some characteristics of the Ag-NPs such as size, shape, surface coatings, rates of silver ions release and interactions with specific cells and proteins (Teleanu et al, 2018). Incidentally, a study on circulating immune cells in mytilus galloprovincialis, a marine invertebrate, notifies that nanotoxicity of Ag-NPs is size-dependent and indirectly dependent to duration of exposure (Bouallegui et al, 2017). Another case about the size-dependent effects of Ag-NPs indicates that Ag-NPs (20nm) have high cytotoxic properties with respect to permeating and damaging cerebral microvascular structures, as compared with larger particles (40nm and 80nm) (Xu et al, 2013).…”

Redox proteomic insights into involvement of clathrin-mediated endocytosis in silver nanoparticles toxicity to Mytilus galloprovincialis

“…As previously described by [ 31 ], mussels were separately exposed to AgNP (<50nm) for 12 h—with/without having also been exposed to inhibitor of endocytosis. For the inhibitor-treated groups, mussels (n = 10) were incubated at 100 μM amantadine (Sigma).…”

Nanomaterials and Annelid Immunity: A Comparative Survey to Reveal the Common Stress and Defense Responses of Two Sentinel Species to Nanomaterials in the Environment

“…Recent research on Mytilus galloprovincialis mussel hemocytes discusses the connection between different endocytic pathways, AgNP cytotoxicity, and immunocyte counts [ 76 , 77 ]. Upon the blocking of CME by amantadine, small AgNPs (<50 nm) caused slight toxicity to hemocytes.…”