Comparative transcriptomic evidence of physiological changes and potential relationships in vertebrates under different dormancy states.

Dormancy represents a fascinating adaptive strategy for organisms to survive in unforgiving environments. After a period of dormancy, organisms often exhibit exceptional resilience. This period is typically divided into hibernation and aestivation based on seasonal patterns. However, the mechanisms by which organisms adapt to their environments during dormancy, as well as the potential relationships between different states of dormancy, deserve further exploration. Here, we selected Perccottus glenii and Protopterus annectens as the primary subjects to study hibernation and aestivation, respectively. Based on histological and transcriptomic analysis of multiple organs, we discovered that dormancy involved a coordinated functional response across organs. Enrichment analyses revealed noteworthy disparities between the two dormant species in their responses to extreme temperatures. Notably, similarities in gene expression patterns pertaining to energy metabolism, neural activity, and biosynthesis were noted during hibernation, suggesting a potential correlation between hibernation and aestivation. To further explore the relationship between these two phenomena, we analyzed other dormancy-capable species using data from publicly available databases. This comparative analysis revealed that most orthologous genes involved in metabolism, cell proliferation, and neural function exhibited consistent expression patterns during dormancy, indicating that the observed similarity between hibernation and aestivation may be attributable to convergent evolution. In conclusion, this study enhances our comprehension of the dormancy phenomenon and offers new insights into the molecular mechanisms underpinning vertebrate dormancy.

Aestivation induces widespread transcriptional changes in the African lungfish.

Aestivation is a special ability possessed by some animals to cope with hot and dry environments utilizing dormancy. At a macroscopic level, dormant animals stop moving and eating. At the microscopic level, the expression of a large number of genes in these animals is strictly controlled. However, little is known about what changes occur during aestivation, especially in fish. In this study, we used transcriptome analysis to examine what changes occur in the gills and lungs of the African lungfish (Protopterus annectens) during the maintenance phase of aestivation and speculated on their causes. We found that aestivating transcriptomes were highly similar between gills and lungs. We also found that some genes showed differential expression or alternative splicing, which may be associated with different organs. In addition, differential expression analysis revealed that the lungs maintained significantly higher bioactivity during aestivation, which suggests that the main respiratory organ in aestivating lungfish can transform. Our study provides a reference point for studying the relationship between aestivation and hibernation and further increases understanding of aestivation.

Surface-layer protein from Lactobacillus acidophilus NCFM attenuates tumor necrosis factor-α-induced intestinal barrier dysfunction and inflammation.

Lactobacillus acidophilus NCFM, a probiotic generally regarded as safe, carries a proteinaceous surface (S) layer, composed of numerous identical subunits (surface layer protein, Slp). S-layer proteins have been confirmed to possess multiple biological properties, but their role in maintaining the intestinal epithelial barrier is not fully known. We investigated the effects of Slp on tumor necrosis factor (TNF)-α-elicited intestinal barrier dysfunction and explored the underlying molecular mechanism. TNF-α administration markedly induced intestinal epithelial injury and inflammation in Caco-2 cells. Preincubation of Caco-2 cells with Slp at concentrations ranging from 50 to 100 µg/mL for 6 h improved intestinal epithelial cell integrity and permeability, restored ZO-1 and Occludin protein expressions (P < 0.05) and reduced the secretion of interleukin 8 by a maximum of 47.8%. Furthermore, the addition of Slp to Caco-2 cell monolayers attenuated cell apoptosis and inhibited nuclear factor-κB (NF-κB) p65 nucleus translocation by suppressing the activation of NF-κB. Collectively, the ability of Slp to attenuate dysfunction of the intestinal epithelial barrier stimulated by TNF-α and to exert anti-inflammatory effects supports its potential use in the development of functional foods and in the prevention of inflammatory bowel diseases.

Contrasting impact of elevated atmospheric CO2 on nitrogen cycle in eutrophic water with or without Eichhornia crassipes (Mart.) Solms.

The elevation of atmospheric CO2 is an inevitable trend that would lead to significant impact on the interrelated carbon and nitrogen cycles through microbial activities in the aquatic ecosystem. Eutrophication has become a common trophic state of inland waters throughout the world, but how the elevated CO2 affects N cycles in such eutrophic water with algal bloom, and how vegetative restoration helps to mitigate N2O emission remains unknown. We conducted the experiments to investigate the effects of ambient and elevated atmospheric CO2 (a[CO2], e[CO2]; 400, 800 µmol﹒mol-1) with and without the floating aquatic plant, Eichhornia crassipes (Mart.) Solms, on N-transformation in eutrophic water using the 15N tracer method. The nitrification could be slightly inhibited by e[CO2], due mainly to the competition for dissolved inorganic carbon between algae and nitrifiers. The e[CO2] promoted denitrification and N2O emissions from eutrophic water without growth of plants, leading to aggravation of greenhouse effect and forming a vicious cycle. However, growth of the aquatic plant, Eichhornia crassipes, slightly promoted nitrification, but reduced N2O emissions from eutrophic water under e[CO2] conditions, thereby attenuating the negative effect of e[CO2] on N2O emissions. In the experiment, the N transformation was influenced by many factors such as pH, DO and algae density, except e[CO2] and plant presence. The pH could be regulated through diurnal photosynthesis and respiration of algae and mitigated the acidification of water caused by e[CO2], leading to an appropriate pH range for both nitrifying and denitrifying microbes. Algal respiration at night could consume DO and enhance abundance of denitrifying functional genes (nirK, nosZ) in water, which was also supposed to be a critical factor affecting denitrification and N2O emissions. This study clarifies how the greenhouse effect caused by e[CO2] mediates N biogeochemical cycle in the aquatic ecosystem, and how vegetative restoration mitigates greenhouse gas emission.