Acute inflammatory response in the skin of gilthead seabream (Sparus aurata) caused by carrageenin

Implication of adipocytes from subcutaneous adipose tissue and fatty acids in skin inflammation caused by λ-carrageenin in gilthead seabream (Sparus aurata)

“…Interestingly, immune cell membranes are constituted by phospholipids with a high content of n-6 PUFAs and a low content of n-3 PUFAs [13]. These results could also support the recruitment of immune cells at the inflammation zone at this experimental time (6 h), previously evidenced by our research group by histology and gene expression analysis [36,40]. Besides this, the presence of n-3 PUFAs has been associated with the activation of PPAR-γ, the subsequent inhibition of NF-κB (the main molecular regulator of inflammation), and therefore, with the reduction of the inflammatory response [13].…”

“…According to our histological study, an increase in adipocyte area in SAT was detected in fish injected with λ-carrageenin at 3 h p.i. These results could be the morphological evidence of the response of adipocytes to the proinflammatory mediators that are released, in the area of inflammation, by immune cells recruited at this time point (3 h) [36,38,40]. This morphological change could be necessary to induce the polarization of adipocytes in the inflamed zone towards a proinflammatory phenotype.…”

“…In previous studies, the intramuscular injection of 1% carrageenin in PBS (50 μL per fish) in the left flank of gilthead seabream, below the lateral line at the level of the second dorsal fin, triggered acute skin inflammation with a peak at 3 h after administration, which then began to resolve after 6 h [36,37]. In this study, the expression of three proinflammatory cytokines and three molecules involved in the lipid metabolism of adipocytes has been studied.…”

“…In fish, carrageenin has been used to induce inflammation at different body sites in several fish species, such as plaice (Pleuronectes platessa) [29], carp (Cyprinus carpio) [23], Nile tilapia (Oreochromis niloticus) [30], pacu (Piaractus mesopotamicus) [31,32] and zebrafish (Danio rerio) [33][34][35]. More recently, the inflammatory response of gilthead seabream (Sparus aurata) has been studied by our team, providing diverse information on gene expression [36,37], humoral and cellular immune parameters [38] and the use of non-invasive techniques such as real-time ultrasound or micro-CT to study this complex process [39]. In addition, previous work has evidenced the local effect of mucus-secreting cells of the skin in the inflamed area at 3 h after carrageenin injection by immunohistochemical assay [40].…”

Bacterial Quorum-Sensing Signal DSF Inhibits LPS-Induced Inflammations by Suppressing Toll-like Receptor Signaling and Preventing Lysosome-Mediated Apoptosis in Zebrafish

“…TLR4 is the main LPS receptor, which activates and triggers MyD88 and TRIF-dependent signaling pathways under LPS stimulation, and promotes the expression of downstream inflammatory factors and type 1 interferon [41]. IKK (IκB kinase) is located downstream of the MyD88-dependent pathway and leads to the phosphorylation of the IκB (NF-κB inhibitor) protein, which is responsible for hiding the nuclear localization domain (NLD) of NFκB [42]. After the ubiquitination and degradation of IκB, transcription factor NF-κB is able to transfer from the cytoplasm into the nucleus, thus, participating in the inflammatory response process [40].…”