Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress. To address this gap, we conducted a study to investigate the effects of high temperature stress (24 °C) on the gut tissue structure, antioxidant capacity, gut microorganisms, and metabolome reactions of tsinling lenok trout. Our analysis using 16 S rDNA gene sequencing revealed significant changes in the gut microbial composition and metabolic profile. Specifically, the abundance of Firmicutes and Gemmatimonadetes decreased significantly with increasing temperature, while the abundance of Bacteroidetes increased significantly. Metabolic analysis revealed a significant decrease in the abundance of glutathione, which is synthesized from glutamate and glycine, under high temperature stress. Additionally, there was a notable reduction in the levels of adenosine, inosine, xanthine, guanosine, and deoxyguanosine, which are essential for DNA/RNA synthesis. Conversely, there was a significant increase in the abundance of D-glucose 6 P. Furthermore, high temperature stress adversely affects intestinal structure and barrier function. Our findings provide valuable insights into the mechanism of high temperature stress in cold-water fish and serve as a foundation for future research aimed at mitigating the decline in production performance caused by such stress.

Heat shock proteins (Hsps) play an important role in many biological processes. However, as a typical cold water fish, the systematic identification of Hsp70/110 gene family of rainbow trout (Oncorhynchus mykiss) has not been reported, and the role of Hsp70/110 gene in the evolution of rainbow trout has not been described systematically. In this study, bioinformatics methods were used to analyze the Hsp70/110 gene family of rainbow trout. A total of 16 hsp70/110 genes were identified and classified into ten subgroups. The 16 Hsp70/110 genes were all distributed on chromosomes 2, 4, 8 and 13. The molecular weight is ranged from 78.93 to 91.39 kD. Gene structure and motif composition are relatively conserved in each subgroup. According to RNA-seq analysis of rainbow trout liver and head kidney, a total of four out of 16 genes were significantly upregulated in liver under heat stress, and a total of seven out of 16 genes were significantly upregulated in head kidney. RT-qPCR was carried out on these gene, and the result were consistent with those of RNA-seq. The significantly regulated expressions of Hsp70/110 genes under heat stress indicats that Hsp70/110 genes are involved in heat stress response in rainbow trout. This systematic analysis provided valuable information about the diverse roles of Hsp70/110 in the evolution of teleost, which will contribute to the functional characterization of Hsp70/110 genes in further research.

Eukaryotic translation initiation factor 3 (eIF3) plays an important role in the regulation of mRNA translation, cell growth and cancer development. eIF3b is the main scaffolding subunit in the eIF3 complex and has been demonstrated to contribute to the development of several cancers. First, our study found that the downregulation of eIF3b could inhibit the proliferation and metastasis of gastric cancer cells by regulating the expression of cancer-related genes. In addition, the expression of eIF3b correlated with the stage and progression of gastric cancer and was shown to be upregulated in human chronic gastritis and in gastric cancer tissues compared with the expression of eIF3b in normal gastric tissues. Moreover, Helicobacter pylori (H. pylori) infection could upregulate the expression of eIF3b in gastric cancer cells, suggesting that eIF3b might be involved in the carcinogenic process of H. pylori. The above findings identified the oncogenic role of eIF3b in gastric cancer development, and this may contribute to the exploration and discovery of novel therapeutic targets for gastric cancer treatment.

Aim The metabolic markers and differentially expressed genes (DEGs) related to fructo-oligosaccharide (FOS) were screened, and the response of FOS to the ileum metabolic pathway of Taiping chickens was analyzed. Methods and Results Prebiotic are widely used in agricultural breeding for care and maintenance of animal health, especially FOS. Metabonomics evaluation of ileum of Taiping chicken ultra-performance liquid chromatography-quadruple time of-flight high-sensitivity mass spectrometry showed that 93 differentially altered metabolites were identified and divided into 8 categories, of which organic acids and derivatives was the most important one. Transcriptomic analysis showed that DEGs were mainly enriched in drug metabolism-cytochrome p450, metabolism of xenobiotics by cytochrome p450, retinol metabolism and fat digestion and absorption. Integrated analysis of metabolite profiles and gene expression revealed that the significantly up-regulated GSTT1 was significantly correlated with most of the different lipid metabolites, suggesting that GSTT1 may play an important role in FOS regulation of lipid metabolism. Conclusions The results of this study suggest that supplementation of FOS can have a positive effect on gut metabolites, which may contribute to the overall health with indigenous chickens. Significance and Impact of the Study Insight into the responses of intestinal prebiotics of Taiping chicken is helpful to understand the role of prebiotics in maintaining intestinal microflora balance and improving immune response and productivity of poultry from the molecular and metabolic levels.