Physiological and muscle tissue responses in Litopenaeus vannamei under hypoxic stress via iTRAQ.

White L. vannamei have become the most widely cultivated shrimp species worldwide. Cultivation of L. vannamei is one of the predominant sectors in China's aquaculture industry. This study focused on the physiological and biochemical responses, differential protein expression, and expression characteristics of the related crucial functional protein genes under low oxygen conditions among different strains of L. vannamei. It was found that 6 h of hypoxic stress caused a significant reduction in the total hemocyte number in both strains, while the hypoxia-sensitive strain showed a stronger reduction. In contrast, the hemocyanin concentration showed only an overall upward trend. Proteomic analysis of L. vannamei muscle tissue revealed 3,417 differential proteins after 12 h of hypoxic stress. Among them, 29 differentially expressed proteins were downregulated and 244 were upregulated in the hypoxia-sensitive strain. In contrast, there were only 10 differentially expressed proteins with a downregulation pattern and 25 with an upregulation pattern in the hypoxia-tolerant strain. Five protein genes that responded significantly to hypoxic stress were selected for quantitative real-time PCR analysis, namely, hemocyanin, chitinase, heat shock protein 90 (HSP 90), programmed death protein, and glycogen phosphorylase. The results showed that the gene expression patterns were consistent with proteomic experimental data except for death protein and glycogen phosphorylase. These results can enrich the general knowledge of hypoxic stress in L. vannamei and the information provided differentially expressed proteins which may be used to assist breeding programs of L. vannamei of new strains with tolerance to hypoxia.

Coral and it's symbionts responses to the typical global marine pollutant BaP by 4D-Proteomics approach.

The symbiosis of corals, zooxanthellae, and microbes is the foundation of the coral reef ecosystem. In addition to global warming, marine pollutants are another important factor causing the breakdown of coral symbiosis. Benzo(a)pyrene (BaP) is a globally widespread marine environmental pollutant that poses a severe threat to marine ecosystems. However, responses of coral symbionts to global marine pollutant stress remain unclear. In this study, we selected Acropora formosa as the target coral to explore its response to 50 µg L-1 BaP stress using diaPASEF proteomics and 16s rRNA microbiome analysis. The results showed that: 1) the coral symbionts were sensitive to BaP stress; 2) the photosynthetic system of zooxanthellae was crucial for the balance of symbiotic relationships; 3) the destruction of the photosynthetic system induced a zooxanthellae hypoxic stress response; 4) corals adapted to BaP stress by promoting non-essential protein degradation and changing energy metabolism strategies; 5) symbiotic bacteria showed strong adaptability to BaP. This study not only fills the gap in understanding the response mechanism of coral symbionts under BaP stress, but also provides fundamental data for coral reef protection strategies.

The potential effects of microplastic pollution on human digestive tract cells.

The level of environmental microplastics in the biosphere is constantly increasing. These environmental microplastics can enter the human body with food, be absorbed through the gut, and have negative effects on the organism health after its digestion. Four sizes (0.1, 0.5, 1, 5 µm) polystyrene microspheres (PS-MPs) and nanospheres (PS-NPs) were selected for this study. The effects of different sizes of polystyrene particles on human colonic epithelial cell CCD841CoN and small intestinal epithelial cell HIEC-6 within 24 h were explored. The uptake of PS-NPs was found to has more potential to enter cells than micro-sized polystyrene PS-MPs that was confirmed by fluorescence microscope, and the intake amount was proportional to the exposure time. PS-MPs had no significant effect on cell viability and apoptosis, but the group treated with high concentration showed low toxicity to oxidative stress level and mitochondrial membrane potential. In addition, the membrane damage caused by PS-MPs was significantly higher than that of PS-NPs. This may be due to the large amount of polystyrene adhering to interstitial, which have a significant negative effect on the cell membrane functions. For the first time human intestinal normal cell lines were used to study the effect of microplastic pollution, which can provide some references for the influence of microplastics on human health in the future.