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Background/objectives: The porcine intestinal epithelium plays a fundamental role as a defence interface against pathogens. Its alteration can cause severe inflammatory conditions and diseases. Hyperosmotic stress under physiological conditions and upon pathogen challenge can cause malabsorption. Different cell types counteract the osmolarity increase by accumulating organic osmolytes such as betaine, taurine, and myo-inositol through specific transporters. Betaine is known for protecting cells from hyperosmotic stress and has positive effects when fed to pigs. The aim of this study is to demonstrate the modulation of osmolyte transporters gene expression in IPEC-J2 during osmolarity changes and assess the effects of betaine. Methods: IPEC-J2 were seeded in transwells, where differentiate as a polarized monolayer. Epithelial cell integrity (TEER), oxidative stress (NO) and gene expression of osmolyte transporters, tight junction proteins (TJp) and pro-inflammatory cytokines were evaluated. Results: Cells treated with NaCl hyperosmolar medium (500 mOsm/L) showed a TEER decrease at 3 h and detachment within 24 h, associated with an osmolyte transporters reduction. IPEC-J2 treated with mannitol hyperosmolar medium (500 mOsm/L) upregulated taurine (TauT), myo-inositol (SMIT) and betaine (BGT1) transporters expression. A decrease in TJp expression was associated with a TEER decrease and an increase in TNFα, IL6, and IL8. Betaine could attenuate the hyperosmolarity-induced reduction in TEER and TJp expression, the NO increase and cytokines upregulation. Conclusions: This study demonstrates the expression of osmolyte transporters in IPEC-J2, which was upregulated upon hyperosmotic treatment. Betaine counteracts changes in intracellular osmolarity by contributing to maintaining the epithelial barrier function and reducing the inflammatory condition. Compatible osmolytes may provide beneficial effects in therapies for diseases characterized by inflammation and TJp-related dysfunctions. [ABSTRACT FROM AUTHOR]

Upon glucose starvation, S. cerevisiae shows a dramatic alteration in transcription, resulting in wide-scale repression of most genes and activation of some others. This coincides with an arrest of cellular proliferation. A subset of such cells enters quiescence, a reversible non-dividing state. Here, we demonstrate that the conserved transcriptional corepressor Tup1 is critical for transcriptional repression after glucose depletion. We show that Tup1-Ssn6 binds new targets upon glucose depletion, where it remains as the cells enter the G0 phase of the cell cycle. In addition, we show that Tup1 represses a variety of glucose metabolism and transport genes. We explored how Tup1 mediated repression is accomplished and demonstrated that Tup1 coordinates with the Rpd3L complex to deacetylate H3K23. We found that Tup1 coordinates with Isw2 to affect nucleosome positions at glucose transporter HXT family genes during G0. Finally, microscopy revealed that a quarter of cells with a Tup1 deletion contain multiple DAPI puncta. Taken together, these findings demonstrate the role of Tup1 in transcriptional reprogramming in response to environmental cues leading to the quiescent state. Author summary: Quiescence is a very common and important state for the cells of many organisms, where cell functions 'pause' but can resume when the right conditions are met. Most microbes exist in a quiescent state and will start growing and dividing again in the presence of nutrients or other cues. In mammals, a quiescent state is used to maintain stem cell populations and cancer cells often evade treatment by entering quiescence. The budding yeast Saccharomyces cerevisiae is an excellent model for studying quiescence because we can easily isolate populations of quiescent cells. Since budding yeast share many proteins and cellular pathways with higher organisms, our findings are applicable to more complex systems, which may be relevant to maintenance of healthy cells or provide insight to treating disease states. We know that a hallmark of quiescence is reduced transcription, and we are interested in how this change occurs. We have examined how the protein Tup1 causes changes in gene expression in cellular quiescence. We also looked at how Tup1-dependent changes depend on other chromatin interacting factors, such as the histone deacetylase Rpd3, the transcription factor Xbp1, or the chromatin remodeling protein Isw2. [ABSTRACT FROM AUTHOR]

Bovine mastitis is among the most serious disease in the dairy industry and brings huge economic losses due to the decrease in milk quality and quantity. Betaine, a naturally occurring compound, possesses several pharmacological activities including anti-inflammatory and anti-oxidant ability, but whether betaine has protective effects on bovine mastitis is unknown. The aim of this study is to investigate the effect of betaine on mastitis and further discover its feasible molecular mechanism in lipopolysaccharide (LPS)-stimulated bovine mammary epithelial cells (BMECs). BMECs were pre-treated with or without betaine or LPS. Cell viability was measured with CCK-8 to examine the cytotoxicity. The levels of pro-inflammatory cytokines were measured by ELISA kits. Western blotting was used to explore the regulation of genes associated with inflammatory and oxidative stress genes. The results showed that LPS treatment significantly increased the production of pro-inflammation (IL-1β, IL-6 and TNFα), enhanced malondialdehyde (MDA) content, reduced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, and markedly up-regulated the protein expression of COX2 and iNOS (p < 0.05). However, betaine pre-treatment remarkably restored the above phenomenon compared with the LPS group. Additionally, we also observed that betaine exposure significantly restricted LPS-induced the phosphorylation of IκB and NF-κB p65 (p < 0.05). Moreover, pre-treatment of BMECs with betaine abolished LPS-induced the increase of Nrf2 and HO-1 protein levels (p < 0.05). These results confirm that betaine can alleviate LPS-induced inflammatory response and oxidative damage by modulating NF-κB and Nrf2 signalling pathways. Betaine alleviated the production of pro-inflammation cytokines (IL-1β, IL-6 and TNFα) in BMECs after LPS stimulation. Betaine restored LPS-elicited nuclear factor kappa-B (NF-κB) signalling pathway activity. Betaine recovered LPS-induced the activity of SOD and GSH-Px and MDA content. Betaine inhibited the increase of protein expression of Nrf2 and HO-1 challenged with LPS. [ABSTRACT FROM AUTHOR]

The identification of traces of life beyond Earth (e.g., Mars, icy moons) is a challenging task because terrestrial chemical-based molecules may be destroyed by the harsh conditions experienced on extraterrestrial planetary surfaces. For this reason, studying the effects on biomolecules of extremophilic microorganisms through astrobiological ground-based space simulation experiments is significant to support the interpretation of the data that will be gained and collected during the ongoing and future space exploration missions. Here, the stability of the biomolecules of the cryptoendolithic black fungus Cryomyces antarcticus , grown on two Martian regolith analogues and on Antarctic sandstone, were analysed through a metabolomic approach, after its exposure to Science Verification Tests (SVTs) performed in the frame of the European Space Agency (ESA) Biology and Mars Experiment (BIOMEX) project. These tests are building a set of ground-based experiments performed before the space exposure aboard the International Space Station (ISS). The analysis aimed to investigate the effects of different mineral mixtures on fungal colonies and the stability of the biomolecules synthetised by the fungus under simulated Martian and space conditions. The identification of a specific group of molecules showing good stability after the treatments allow the creation of a molecular database that should support the analysis of future data sets that will be collected in the ongoing and next space exploration missions. [ABSTRACT FROM AUTHOR]