Chronic stress boosts systemic inflammation and compromises antiviral innate immunity in Carassius gibel

Abstract

It is generally considered that stress causes decreased immune function and render fish vulnerable to infection and diseases. However, the molecular mechanisms between stress responses and susceptibility to infections, especially viral diseases, in fish remain unknown. Understanding and monitoring the biological consequences and mechanisms underlying stress responses in fish may contribute to the improvement of animal welfare and production efficiency. In this study, long-term exposure to a variety of stressors, including chasing, overcrowding, restraint stress, and air exposure mimicking chronic stresses, in aquaculture practices was conducted in Carassius gibel to investigate the consequences of chronic stress on inflammation and antiviral capability. With the continuation of stimulation, experimental fish gradually became insensitive to the stress of net chasing and feeding with the accompaniment of upregulated gene expressed in the HPI axis and elevated levels of stress hormones. As expected, stress-induced hyperglycaemia with a decrease in the insulin signaling pathway and altered gene expression in glycolysis and gluconeogenesis, suggesting the disturbance of glycometabolism. Importantly, a link between intestinal homoeostasis and systemic low-grade inflammation in stressed C. gibel was observed, implying crosstalk among the brain, intestine, and other organs. Furthermore, the compromised antiviral capability with impaired antiviral innate immunity in stressed fish was confirmed by RNA sequencing and infection with Cyprinid herpesvirus 2 (CyHV-2), promoting the understanding of enhanced susceptibility to viral infection in stressed fish.

Conversion of Retinoids along the Marine Food Chain Contributes to Adverse Impacts on the Spine, Liver, and Intestinal Health of the Marine Medaka (Oryzias melastigma)

“…The increased abundance of Rhodobacteraceae may have triggered intestinal diseases. Decreased carbohydrate metabolism and digestive system functions (Figure ) may reduce intestinal nutrient absorption and metabolism, and decreased immune system function may further aggravate the occurrence of intestinal diseases . The structure and dysfunction of the intestinal microbial community have adverse effects on the structure and function of the intestines in marine medaka.…”

Unleashing lactoferrin's antidepressant potential through the PI3K/Akt/mTOR pathway in chronic restraint stress rats

“…46–48 Similarly, it has been noted that reduced norepinephrine production is caused by elevated corticosterone levels. 49,50…”

“…[46][47][48] Similarly, it has been noted that reduced norepinephrine production is caused by elevated corticosterone levels. 49,50 Previous studies have shown that CRS triggers an increased oxidative stress response in various rat brain regions. [51][52][53] In accordance with this approach, the current data showed that rats exposed to CRS developed higher levels of reactive oxygen species (ROS) (TBARS) and lower levels of antioxidants in the brain (GSH).…”

Fish Responses to Alternative Feeding Ingredients under Abiotic Chronic Stress

“…Midgut samples manifested morphological changes, including damage in obliterated villi, decreased number of goblet cells, and loosened submucous layer. Microbiota also changed, reducing Bifidobacterium , Lactobacillus , Faecalibacterium , and Flavobacterium [ 62 ]. These results showed the detrimental effects of chronic stress in fish, the importance of microbiota, and that any damage in the gut might directly affect fish’s immune status [ 63 ].…”