Triclosan exposure induces immunotoxic impacts by disrupting the immunometabolism, detoxification, and cellular homeostasis in blood clam (Tegillarca granosa)

Abstract

Omnipresent presence of triclosan (TCS) in aqueous environment puts a potential threat to organisms. However, it's poorly understood about its immunometabolic impacts of marine invertebrates. In present study, we use a representative bivalve blood clam (Tegillarca granosa) as a model, investigating the effects of TCS exposure at 20 and 200 μg/L for 28 days on immunometabolism, detoxification, and cellular homeostasis to explore feasible toxicity mechanisms. Results demonstrated that the clams exposed to TCS resulting in evident immunotoxic impacts on both cellular and humoral immune responses, through shifting metabolic pathways and substances, as well as suppressing the expressions of genes from the immune- and metabolism-related pathways. In addition, significant alterations in contents (or activity) of detoxification enzymes and the expression of key detoxification genes were detected in TCS-exposed clams. Moreover, exposure to TCS also disrupted cellular homeostasis of clams through increasing MDA contents and caspase activities, and promoting activation of the apoptosis-related genes. These findings suggested that TCS might induce immunotoxic impacts by disrupting the immunometabolism, detoxification, and cellular homeostasis.

Keywords: Bivalves; Cellular homeostasis; Detoxification; Immunometabolism; Triclosan.