Hypothermia-mediated oxidative stress induces immunosuppression, morphological impairment and cell fate disorder in the intestine of freshwater drum, Aplodinotus grunniens

Abstract

The mechanism of the intestine in freshwater drum response to hypothermia exposure has not been investigated, despite the fact that it is a key organ of metabolism and immunity. Here, we conducted an 8-day hypothermia experiment under 10 °C to uncover the underlying mechanism in the intestine of freshwater drum. Morphologically, hypothermia exposure caused intestinal microvilli shortening, mitochondrial structure disruption, and tight junction damage. Physiologically, immunosuppression and inflammatory response were involved in the intestinal hypothermia response. According to transcriptome analysis, we discovered that hypothermia exposure induced apoptosis and ferroptosis in the intestine. Combined with correlation analyses, oxidative stress was considered critical in modifying the intestinal hypothermia response. In conclusion, hypothermia-induced oxidative stress leads to intestinal structure damage, immunosuppression and cell fate alterations, ultimately affecting the well-being of freshwater drum. This may provide some insights into hypothermia prevention in aquaculture management.