Evaluation of waterborne exposure to heavy metals in innate immune defences present on skin mucus of gilthead seabream (Sparus aurata)

Abstract

Abstracts:Aquatic animals are continuously exposed to chemical pollutants but the effects evoked in mucins and the carbohydrate nature of the glycoproteins in the unicellular glands in fish epidermis skin surfaces, which receive the most direct contact with them, has not been fully studied and characterized. Moreover, microorganisms use lectins to recognize and bind to host terminal carbohydrates to facilitate the infection whilst host lectins bind to pathogen carbohydrates to exert protective effector functions, such as agglutination, immobilization, and complement-mediated opsonization and killing of potential pathogens. Thus, terminal carbohydrate composition and the presence of a fucose binding lectin (FBL) were determined by lectin ELISA and western blot, respectively, in skin mucus of gilthead seabream (Sparus aurata L.) specimens exposed to waterborne sublethal dosages of heavy metals [arsenic (As2O3), cadmium (CdCl2) and mercury (CH3HgCl) at 5, 5 and 0.04 μM, respectively] after 2, 10 and 30 days. Results showed little effects of heavy metals in the presence of several terminal carbohydrates with few increments or decrements depending on the sugars, exposure time and heavy metal studied. Moreover, the FBL was undetected in any of the control fish skin mucus but was evident in all the heavy metal exposed fish. Further studies are needed to understand the relation of terminal carbohydrates and lectins in skin mucus fish defense and the implications during contamination exposure.Acknowledgements.

Differential proteome profile of skin mucus of gilthead seabream (Sparus aurata) after probiotic intake and/or overcrowding stress

“…For example, KTRs of fish mucus have shown some antibacterial activity due to their pore-formation ability [37], and this points to the increase of this immune activity in seabream specimens. In fact, seabream exposed to heavy metal stressors showed significant increments in the bactericidal activity of the skin mucus and altered protein profiles [38]. These data together suggest that the altered structural proteins in the skin mucus might have some unknown biological role at present, which merits further evaluation.…”

“…The fact of finding the maximum upregulation in Pdp11 probiotic diet groups could suggest the improvement of skin mucosal immunity by Pdp11 probiotic effect and no negative impact of the tested stress. In this regard, skin mucus of seabream specimens under stress caused by exposure to heavy metals showed increased levels of F-lectin as detected by western blotting [38].…”

Evaluation of immune response and performance of silver catfish fed functional linseed fibres in response to hypoxia stress

“…The effects of stress on mucosal surfaces of the fish are little known. Research is mostly restricted to studies that evaluate stress caused by water quality, transportation, heavy metal contamination, density, anaesthetic agent and air exposure (Guardiola et al, , ; Tacchi et al, ; Vatsos, Kotzamanis, Henry, Angelidis, & Alexis, ). Furthermore, the majority of studies focused on evaluating only the increased release of mucus but not the differences in mucus composition (Guardiola et al, ; Shephard, ; Vatsos et al, ).…”

Toxic Effects and Depuration on the Antioxidant and Neurotransmitter Responses after Dietary Lead Exposure in Starry Flounder

“…Guardiola et al. () reported increased lysozyme activity in the Gilthead Seabream Sparus aurata after exposure to Cd, Hg, and As. Our results showed that dietary Pb exposure stimulated the nonspecific immune system of Starry Flounder.…”