Pyroptosis in fish research: A promising target for disease management.

Pyroptosis is a newly discovered programmed cell death pathway that plays an essential role in the host's defense against pathogenic infections. This process is orchestrated by inflammasomes, which are intricate multiprotein complexes that orchestrate the activation of caspase and instigate the liberation of proinflammatory cytokines. Additionally, gasdermin family proteins execute their role by forming pores in the cell membrane, ultimately leading to cell lysis. In recent years, pyroptosis has emerged as a promising target for disease management in fish, particularly in the context of infectious diseases. In this review, we provide an overview of the current understanding regarding the role of pyroptosis in fish, focusing on its involvement in host-pathogen interactions and its potential as a therapeutic target. We also highlighted the latest advancements in the field development of pyroptosis inhibitors and their potential applications in fish disease management. Subsequently, we deliberate on the obstacles and future prospects for pyroptosis research in fish, emphasizing the necessity of conducting more comprehensive investigations to unravel the intricate regulatory mechanisms governing this process across diverse fish species and environmental contexts. Finally, this review will also highlight the current limitations and future perspectives of pyroptosis research in aquaculture.

Oxytetracycline-induced oxidative liver damage by disturbed mitochondrial dynamics and impaired enzyme antioxidants in largemouth bass (Micropterus salmoides).

Oxytetracycline (OTC), a commonly used tetracycline antibiotic in aquaculture, has been found to cause significant damage to the liver of largemouth bass (Micropterus salmoides). This study revealed that OTC can lead to severe histopathological damage, structural changes at the cellular level, and increased levels of reactive oxygen species (ROS) in M. salmoides. Meanwhile, OTC impairs the activities of antioxidant enzyme (such as T-SOD, CAT, GST, GR) by suppressing the activation of MAPK/Nrf2 pathway. OTC disrupts mitochondrial dynamics and mitophagy through via PINK1/Parkin pathway. The accumulation of damaged mitochondria, combined with the inhibition of the antioxidant enzyme system, contributes to elevated ROS levels and oxidative liver damage in M. salmoides. Further investigations demonstrated that an enzyme-treated soy protein (ETSP) dietary supplement can help maintain mitochondrial dynamic balance by inhibiting the PINK1/Parkin pathway and activate the MAPK/Nrf2 pathway to counteract oxidative damage. In summary, these findings highlight that exposure to OTC disrupts mitochondrial dynamics and inhibits the antioxidant enzyme system, ultimately exacerbating oxidative liver damage in M. salmoides. We propose the use of a dietary supplement as a preventive measure against OTC-related side effects, providing valuable insights into the mechanisms of antibiotic toxicity in aquatic environments.

Profiling miRNAs of Teleost Fish in Responses to Environmental Stress: A Review.

miRNAs are a class of endogenous and evolutionarily conserved noncoding short RNA molecules that post-transcriptionally regulate gene expression through sequence-specific interactions with mRNAs and are capable of controlling gene expression by binding to miRNA targets and interfering with the final protein output. The miRNAs of teleost were firstly reported in zebrafish development, but there are recent studies on the characteristics and functions of miRNAs in fish, especially when compared with mammals. Environmental factors including salinity, oxygen concentration, temperature, feed, pH, environmental chemicals and seawater metal elements may affect the transcriptional and posttranscriptional regulators of miRNAs, contributing to nearly all biological processes. The survival of aquatic fish is constantly challenged by the changes in these environmental factors. Environmental factors can influence miRNA expression, the functions of miRNAs and their target mRNAs. Progress of available information is reported on the environmental effects of the identified miRNAs, miRNA targets and the use of miRNAs in fish.