Biochemical, Histopathological and Molecular Responses in Gills of Leuciscus cephalus Exposed to Metals

Abstract

Gills are major targets for acute metal toxicity in fish, due to their permanent contact with aquatic pollutants. To assess the effects of metals on gills of the Leuciscus cephalus (chub), fish individuals were collected from two sites in the Tur River, Romania, in upstream (site 1) and downstream (site 2) of a metal pollution source. Quantitative and hyperspectral analyses showed that Zn, Sr, and Fe concentrations were significantly higher in gills from site 2 compared with site 1. Malondialdehyde and advanced oxidation protein products levels increased 17 and 28%, respectively, whereas reduced glutathione level diminished significantly in the gills of fish collected from site 2 compared to site 1. The activities of superoxide dismutase, catalase, and glutathione-S-transferase increased significantly at 41, 21, and 28%, respectively. Proliferating cell nuclear antigen (PCNA) protein levels, as well as the amount of DNA damage, were significantly increased for site 2 compared with site 1. The induced oxidative stress generated hyperplasia, hypertrophy, and inflammation in the epithelial cells and apoptosis. Hence, this could suggest that gill cells have tried to counteract the oxidative stress-induced DNA fragmentation by PCNA up-regulation, but the PCNA expression decreased on longer time due to the low level of GSH, resulting in apoptosis.

Age and diet-specific trace element accumulation patterns in different tissues of chub (Squalius cephalus): Juveniles are useful bioindicators of recent pollution

“…arches and rakers) by Ca replacement, rather than in soft tissues (e.g. soluble gill fractions) (Hermenean et al, 2017).…”

Correlation between Heavy Metal-Induced Histopathological Changes and Trophic Interactions between Different Fish Species

“…Many epithelial cells appeared marked by hypertrophy and hyperplasia. Contamination of the freshwater with metals caused histopathological changes in fish gills in a metal concentration and exposure time-dependent manner, mainly because these are the primary target organs of aquatic pollutants [23,24]. The increased bioaccumulation of Cr and Zn in the gills of all analyzed species could be correlated with the observed histopathological changes.…”

“…The structural integrity of fish's gills, kidneys, and liver also depends on cell integrity [19] and can be correlated with the expression of PCNA (proliferating cell nuclear antigen) in fish organs exposed to metal contamination [24,38], taking into account that PCNA can act as a mediator between cell cycle control and DNA repair [39]. with TNF-α level determined in the same tissues of all three analyzed species.…”

Histopathological Research of the Therapeutic Effects of Grape (Vitis vinifera L.) Seeds Extracts on Cadmium-Exposed Carp (Cyprinus carpio L. 1758)

“…The primary target of aquatic pollutants is the gills, which are in direct contact with the environment. Therefore, it is stated that contamination of fresh water with metals causes histopathological changes in fish gills depending on metal concentration and exposure duration (Tchounwou et al, 2012;Hermenean et al, 2017). Heavy metals may have effects on filament epithelial proliferation, lamellar fusion and epithelial necrosis in the gills (Fonseca et al, 2017).…”