bims-polyam 2022-05-08 papers

Issue of 2022‒05‒08
four papers selected by
Sebastian J. Hofer
University of Graz

Front Plant Sci. 2022 ;13 846280

Foliar Application of Spermidine Reduced the Negative Effects of Salt Stress on Oat Seedlings.

Xia Hai, Junzhen Mi, Baoping Zhao, Biru Zhang, Zhou Zhao, Jinghui Liu.

The effects of foliar application of spermidine (Spd) on the physiological aspects of salt-stressed oat seedlings were studied under greenhouse conditions. At the seedling stage, the salt-sensitive variety, namely, Caoyou 1 and the salt-tolerant variety, namely, Baiyan 2 were treated with 70 and 100 mM of salt, followed by the foliar application of 0.75 mM Spd or distilled water. Results showed that Spd application increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and reduced the rate of O2 ⋅- production and the accumulation of H2O2 and malondialdehyde (MDA). In addition, it increased the level of zeatin riboside (ZR) and the content of endogenous polyamines. The application of Spd increased the contents of soluble sugar, soluble protein, and free proline and helped maintain the osmotic balance of oat leaves. At the same time, foliar Spd treatment helped in maintaining the ion nutrition balance. Specifically, it reduced the content of Na+ and thereby stabilized the ratio of Na+/K+, Na+/Ca2+, and Na+/Mg2+. The effects of Spd application were more obvious for the salt-sensitive cultivar Caoyou 1 and under the lighter 70 mM salt stress.

Keywords: antioxidant defense; endogenous hormone; ion accumulation; oat; osmotic adjustment; salt stress; spermidine

DOI: https://doi.org/10.3389/fpls.2022.846280

RSC Adv. 2020 Jul 15. 10(45): 26709-26716

Effects of spermine on ileal physical barrier, antioxidant capacity, metabolic profile and large intestinal bacteria in piglets.

Guangmang Liu, Weiwei Mo, Wei Cao, Xianjian Wu, Gang Jia, Hua Zhao, Xiaoling Chen, Caimei Wu, Jing Wang.

Spermine, a polyamine, exerts important roles in alleviating oxidative damage, improving immunity, increasing antioxidant status and digestive enzyme activities, and promoting the development of small intestine. However, information is not available regarding the effects of spermine supplementation on gut barrier function, intestinal microbiota and metabolic profile in piglets. Therefore, this study was designed to explore the effect of spermine administration on these parameters. The experiment was conducted on twenty 12 day-old suckling piglets, which were allocated either to the group fed basal formula milk (control group) or to that fed a basal formula milk that contained spermine (0.4 mmol kg-1 BW per day) for 3 days. Caecal and colonic digesta and ileal tissues were collected at the end of the three-day feeding experiment. The results were as follows: (1) supplementation with spermine increased glutathione S-transferase (GST) capacity by 27.84% and glutathione content by 18.68% in the ileum (P < 0.05). (2) Glutathione peroxidase 1 (GPx1), catalase (CAT), GST, nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein1 (Keap1) mRNA levels in ileum were increased in the spermine-supplemented group in contrast to those in the control group (P < 0.05). (3) The spermine-supplemented group increased zonula occludens-1 (ZO-1) (by 42.0%), ZO-2 (by 101.0%), occludin (by 84.0%), claudin 2 (by 98.0%), claudin 3 (by 121.0%), claudin 12 (by 47.0%), claudin 14 (by 68.0%) and claudin 16 (by 73.0%) mRNA levels in ileum relative to the control group (P < 0.05). (4) Supplementation with spermine increased ZO-2 and occludin mRNA levels in ileum by reducing myosin light chain kinase (MLCK) (by 23.0%) mRNA level. (5) Spermine supplementation increased choline, glycerolphosphocholine, creatine and serine levels, and decrease alanine, glutamate, lysine, phenylalanine, threonine, lactate, tyrosine levels in ileum (P < 0.05). (6) The population of Lactobacilli, Bifidobacteria and total bacteria increased, but the number of Escherichia coli decreased in the caecal and colonic digesta after spermine supplementation (P < 0.05). In summary, dietary spermine supplementation promotes ileal health by enhancing antioxidant properties, improving ileal barrier function, modulating metabolic profiles, and maintaining large intestinal microbial homeostasis.

DOI: https://doi.org/10.1039/c9ra10406b

Front Vet Sci. 2022 ;9 861137

Proteomic Investigation Reveals Eukaryotic Translation Initiation Factor 5A Involvement in Porcine Reproductive and Respiratory Syndrome Virus Infection in vitro.

Huawei Li, Bo Wan, Dawei Jiang, Pengchao Ji, Mengmeng Zhao, Xinfeng Li, Rui Li, Songlin Qiao.

Porcine reproductive and respiratory syndrome virus (PRRSV), one of the most serious animal pathogens in the world, has caused enormous global swine industry losses. An in-depth investigation of the PRRSV-host interaction would be beneficial for preventing and controlling PRRSV infections and transmission. In this study, we performed label-free quantitative proteomic assays to investigate proteome dynamics of porcine alveolar macrophages (PAMs) during infection with highly pathogenic PRRSV (HP-PRRSV) strain HN07-1. Analysis of the results led to identification of 269 significantly differentially expressed host cellular proteins, of which levels of proteins belonging to the eukaryotic translation initiation factor (eIF) family were found to be decreased in abundance in HP-PRRSV-infected PAMs. Furthermore, knockdown of eIF5A expression was demonstrated to markedly suppress HP-PRRSV propagation, as reflected by reduced progeny virus titers in vitro. These results highlight the importance of eIF5A in PRRSV infection, while also demonstrating that PAMs down-regulate eIF5A expression as a host cell antiviral strategy. Results of the current study deepen our understanding of PRRSV pathogenesis and provide novel insights to guide development of effective strategies to combat the virus.

Keywords: PAMs; PRRSV; eIF5A; infection; proteome

DOI: https://doi.org/10.3389/fvets.2022.861137

FEBS Lett. 2022 May 01.

The activator/repressor Hap1 binds to the yeast eIF5A-encoding gene TIF51A to adapt its expression to the mitochondrial functional status.

Marina Barba-Aliaga, Paula Alepuz.

Mitochondrial activity adapts to cellular energetic and metabolic demands; its dysfunction is a hallmark of aging and many human diseases. The evolutionarily conserved translation elongation factor eIF5A is involved in maintaining mitochondrial function. In humans, eIF5A is encoded by two highly homologous but differentially expressed genes; in yeast, these are TIF51A and TIF51B. We show that yeast transcription factor Hap1 constitutively binds to the TIF51A promoter to activate its expression under respiration, but represses its expression under non-respiration conditions by recruiting the co-repressor Tup1. Hap1 indirectly regulates TIF51B expression by binding to and activating the TIF51B-repressor genes ROX1 and MOT3 under respiration and repressing them under non-respiration. Thus, the levels of eIF5A isoforms are adapted to the mitochondrial functional status.

Keywords: TIF51A ; TIF51B ; Hap1; Tup1; eIF5A; mitochondrial respiration; translation; yeast

DOI: https://doi.org/10.1002/1873-3468.14366