Microplastics accumulation in gastrointestinal tracts of Mullus barbatus and Merluccius merluccius is associated with increased cytokine production and signaling. (November 2022)

• Record Type: Journal Article
• Authors: Cocci, Paolo; Gabrielli, Serena; Pastore, Genny; Minicucci, Marco; Mosconi, Gilberto; Palermo, Francesco Alessandro
• Is Part Of: Chemosphere. Volume 307:Part 3(2022)
• Publication Date: 2022-11
• Subjects: Adriatic sea -- Microplastic -- Commercial fish -- Immunotoxicity -- Pro-inflammatory cytokines; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135813
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: There is clear evidence that different marine species can be impacted by microplastic (MP) ingestion accumulating such MPs mainly in the gastrointestinal tract. However, there is still limited knowledge on the consequences of MPs' accumulation in the gut. The present study aims to assess MPs and their potential immunotoxic effects in the digestive tract of two species showing different ecological traits: the red mullet ( Mullus barbatus ) and the European hake ( Merluccius merluccius ). Infrared spectroscopy (FTIR-ATR), micro-Raman and electron scanning microscope (SEM) were used to accurately identify the main plastic polymers detected in gut contents. In addition, we investigated the association between MP uptake and intestinal inflammation by evaluating expression and secretion of proinflammatory cytokines. MP abundance ranged from 1 to 20 items/individual in red mullet and from 2 to 15 items/individual in European hake. The majority of ingested MPs were fibers, while the dominant colors were black and blue in both species. Chemical characterization indicated polyethylene and polypropylene as the most common polymer types. Moreover, it was observed that MP abundance was highly positive correlated to cytokines ( i.e. interleukin-1β, 10, and interferon) and antioxidant enzyme ( i.e. catalase and superoxide dismutase) transcript levels suggesting ROS generation and an infiltration of immune cells in the gut. Our findings provide evidence that the induction of cytokine-dependent signaling pathways is one aspect of the complex mechanism by which MPs affect the gut system in fish. Graphical abstract: Image 1 Highlights: MP ingestion was assessed in two marine species: the red mullet and the European hake. The most of ingested MPs were black/blue fibers. FTIR-ATR, micro-Raman and SEM indicated PP and PE as the most common polymer types. MP abundance was highly positive correlated to mRNA levels of inflammatory cytokines. Cytokine production and signaling mediate MP-induced immunotoxicity in fish gut.