In Pelteobagrus fulvidraco, interleukin-22 reduces intestinal inflammation brought on by hypoxia by modifying pro- and anti-inflammatory factors

• PM Yohan

  English

  Author

• B Sasidhar

  English

  Author

Although the pathophysiology of intestinal
inflammation is still unknown, it is a frequent
problem in intensive aquaculture. In higher
vertebrates, interleukin 22 (IL-22) is known to be a
crucial regulator of cellular homeostasis during
inflammation; however, less is known about its
functions in fish. In order to examine the role of IL-
22 in preserving intestinal homeostasis, this study
created hypoxia-induced models in the intestinal
tissues and primary intestinal epithelial cells of
yellow catfish. The gill and gut had the highest
amounts of Pelteobagrus fulvidraco IL-22 (Pf_IL-
22), which was found to be widely expressed in
mucosal tissues. In addition to triggering hypoxia-
inducible factor (HIF) signaling and significantly
upregulating IL-22 production, hypoxia caused
severe intestine damage that was manifested by
loosening of the lamina propria and widespread
vacuolization. At 24 hours after hypoxia, IL-22
levels rose, indicating a potential role in early
immunological responses. Additionally, in primary
intestinal epithelial cells, recombinant Pf_IL-22
stimulated transcription of pro-inflammatory
mediators such as IL-1β and tumor necrosis factor
α (TNF-α), suggesting a dual regulatory role in
balancing inflammation and protection. HIF-1α
knockdown, dual-luciferase assays, and
electrophoretic mobility-shift tests all supported
the mechanistic findings that HIF-1α directly
interacts with a hypoxia response element in the IL-
22 promoter to drive transcription. Pf_IL-22's
significance in influencing downstream immune
responses was demonstrated by the considerable
suppression of Th17 cell development pathways
caused by its silencing. These results demonstrate
that the HIF-1α/IL-22 axis is a crucial regulatory
route influencing immune responses and reducing
intestinal inflammation, offering a foundation for
the creation of immunotherapies that target IL-22
and aquaculture breeding methods that are
selective.

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