Purinergic signalling displays an anti‐inflammatory profile in the spleen of fish experimentally infected with Aeromonas caviae: Modulation of the immune response

Abstract

Extracellular adenosine triphosphate (ATP) and its metabolite adenosine (Ado) are recognized as key mediators of immune and inflammatory responses. Depending on its concentration, ATP may act as an immunostimulant or immunodepressant, while Ado levels display an anti-inflammatory profile. The aim of this study was to evaluate whether splenic purinergic signalling is capable of modulating immune and inflammatory responses in fish experimentally infected with Aeromonas caviae. Triphosphate diphosphohydrolase (NTPDase) and 5'-nucleotidase activities increased in the spleen of silver catfish (Rhamdia quelen) experimentally infected with A. caviae compared with the uninfected control group. Moreover, splenic Ado levels increased in the infected animals relative to the uninfected control group. Based on these lines of evidence, our findings revealed that adenine nucleotide hydrolysis is modified in the spleen of fish infected with A. caviae attempting to restrict the inflammatory process through the upregulation of NTPDase and 5'-nucleotidase activities, which occurs in an attempt to hydrolyse the excessive ATP in the extracellular environment and rapidly hydrolyse AMP to form Ado. In summary, purinergic signalling can modulate immune and inflammatory responses during A. caviae infection.

Intestinal metabolomics of juvenile lenok (Brachymystax lenok) in response to heat stress

“…Leukotoxin (9R, 10S-EpOME), an epoxide derivative of linoleic acid, is synthesized by cytochrome P450 monooxygenases (Vatanparast et al 2020). Increased 12-HETE and 9R, 10S-EpOME in HS-treated sh, consistent with previous ndings for sh under stress, reveals the activation of arachidonic acid released from membrane phospholipids and oxidative stress in HS-treated sh (Maha et al, 2019;Baldissera et al, 2018).…”

“…Energy limitation accounted for large-scale decreases in amino acids in sh when energy metabolism was inhibited, because these pools of oxidizable amino acids were used extensively in energy metabolism in severe conditions (Maha et al, 2019;Kullgren et al, 2013). Additionally, adenosine is a basic component of synthesis energy substances, such as adenosine triphosphate (ATP), coenzyme nicotinamide adenine dinucleotide (NAD), and avin adenine dinucleotide (FAD) (Duan et al, 2021;Baldissera et al, 2018). Cytidine, cytosine and uracil can be catalyzed by dihydropyrimidine dehydrogenase (DPD) to dihydrouracil, which could be used for synthesis of coenzyme A (CoA) and energy metabolism (Duan et al, 2021) (Figure 6).…”