Alterations of gene expression indicating effects on estrogen signaling and lipid homeostasis in seabream hepatocytes exposed to extracts of seawater sampled from a coastal area of the central Adriatic Sea (Italy)

Effects of dietary crude oil exposure on molecular and physiological parameters related to lipid homeostasis in polar cod ( Boreogadus saida )

“…Although PAHs are identified as ligands for PPAR-α in human cells (Kim et al, 2005), this interaction is not known for fish. However, several studies have shown that petroleum compounds affect transcription levels of genes related to lipid metabolism (Bilbao et al, 2010;Adeogun et al, 2016;Xu et al, 2016;Cocci et al, 2017). Furthermore, PAH exposure altered lipid plasma parameters in Chinook salmon (Oncorhynchus tshawytscha) in a similar pattern of that found in starving fish (Meador et al, 2006).…”

“…An excess in bile acid levels activates, in turn, the FXR, which indirectly inhibits the expression of cyp7α1 and thereby the metabolic breakdown of cholesterol (Desvergne et al, 2006). Petroleum compounds have been suggested to affect cholesterol homeostasis at transcriptional level in fish species such as mahi-mahi (Coryphaena hippurus) (Xu et al, 2016), brown trout (Salmo trutta) (Meland et al, 2011) and Gilthead seabream (Sparus aurata) (Cocci et al, 2017). The treatment effects found on cyp7α1 transcription and plasma chemistry were, however, limited to the later time points of the present experiment (days 24 and 32).…”

“…The crude oil treatment did not affect transcription levels of ppar-α and -γ in exposed polar cod, which is in contrast to recent experimental studies on freshwater and marine fish. Waterborne exposure to relatively high levels of PAHs caused a significant activation of PPAR isotypes at transcription level next to induced CYP1A activity in exposed fish (Adeogun et al, 2016;Cocci et al, 2017). Furthermore, the study by Bilbao et al (2010) showed that fuel oil exposure induced the transcriptional up-regulation of ppar-α, rxr and aox1 in thicklip grey mullets (Chelon labrosus), as well as typical effects associated to peroxisome proliferation in marine organisms.…”

“…However, as discussed before polar cod were exposed to relatively low crude oil doses that may not have been high enough to induce significant effects in endpoints related to lipid metabolism. Furthermore, it is important to highlight that polar cod were exposed through the food, which is in contrast to the waterborne exposure in the studies on thicklip grey mullets (Bilbao et al, 2010), seabream (Cocci et al, 2017) and tilapia species (Adeogun et al, 2016). If thermodynamic equilibrium occurs between diet and water, whole-body uptake of PAHs may be similar from these two exposure routes (Meador et al, 1995), however, additional factors such as differential tissue metabolism and enterohepatic circulation may result in disparate internal PAH concentration in fish.…”

An In Silico and In Vitro Study for Investigating Estrogenic Endocrine Effects of Emerging Persistent Pollutants Using Primary Hepatocytes from Grey Mullet (Mugil cephalus)

“…In this regard, the ER-induced hepatic vitellogenin (Vtg) production is typically used to confirm exposure to estrogenic compounds in male fish [24,25]. Of the different fish organ cells, liver cells are widely used in in vitro primary culture models due to their ability to retain native liver properties including estrogen responsiveness [26][27][28]. For that reason, in vitro methods using primary cultures of fish hepatocytes represent a fundamental and recommendable alternative to in vivo studies for investigating several toxicologically relevant mechanisms [29,30].…”