bims-polyam 2022-03-06 papers

Issue of 2022‒03‒06
five papers selected by
Sebastian J. Hofer
University of Graz

Front Plant Sci. 2021 ;12 812396

Grafting Watermelon Onto Pumpkin Increases Chilling Tolerance by Up Regulating Arginine Decarboxylase to Increase Putrescine Biosynthesis.

Junyang Lu, Fei Cheng, Yuan Huang, Zhilong Bie.

Low temperature is a major environmental factor that severely impairs plant growth and productivity. Watermelon (Citrullus lanatus) is a chilling-sensitive crop. Grafting of watermelon onto pumpkin rootstock is an effective technique to increase the chilling tolerance of watermelon when exposure to short-time chilling stress. However, the mechanism by which pumpkin rootstock increases chilling tolerance remains poorly understood. Under 10°C/5°C (day/night) chilling stress treatment, pumpkin-grafted watermelon seedlings showed higher chilling tolerance than self-grafted watermelon plants with significantly reduced lipid peroxidation and chilling injury (CI) index. Physiological analysis revealed that pumpkin rootstock grafting led to the notable accumulation of putrescine in watermelon seedlings under chilling conditions. Pre-treat foliar with 1 mM D-arginine (inhibitor of arginine decarboxylase, ADC) increased the electrolyte leakage (EL) of pumpkin-grafted watermelon leaves under chilling stress. This result can be ascribed to the decrease in transcript levels of ADC, ornithine decarboxylase, spermidine synthase, and polyamine oxidase genes involved in the synthesis and metabolism of polyamines. Transcriptome analysis showed that pumpkin rootstock improved chilling tolerance in watermelon seedlings by regulating differential gene expression under chilling stress. Pumpkin-grafted seedling reduced the number and expression level of differential genes in watermelon scion under chilling stress. It specifically increased the up-regulated expression of ADC (Cla97C11G210580), a key gene in the polyamine metabolism pathway, and ultimately promoted the accumulation of putrescine. In conclusion, pumpkin rootstock grafting increased the chilling tolerance of watermelon through transcription adjustments, up regulating the expression level of ADC, and promoting the synthesis of putrescine, which ultimately improved the chilling tolerance of pumpkin-grafted watermelon plants.

Keywords: chilling tolerance; grafting; pumpkin rootstock; putrescine; transcriptome; watermelon

DOI: https://doi.org/10.3389/fpls.2021.812396

J Anim Sci. 2022 Mar 05. pii: skac069. [Epub ahead of print]

Polyamines Protect Boar Sperm from Oxidative Stress in vitro.

Rongnan Li, Xiaodong Wu, Zhendong Zhu, Yinghua Lv, Yi Zheng, Hongzhao Lu, Kaifeng Zhou, De Wu, Wenxian Zeng, Wuzi Dong, Tao Zhang.

Sperm are susceptible to excessive reactive oxygen species (ROS). Spermine and spermidine are secreted in large amounts by the prostate and potent natural free radical scavengers and protect cells against redox disorder. Thus, we used boar sperm as a model to study the polyamines uptake and elucidate whether polyamines protected sperm from ROS stress. Seven mature and fertile Duroc boars (aged 15-30 months) were used in this study. In Exp.1, spermine and spermidine (3.6 ± 0.3 mmol/L and 3.3 ± 0.2 mmol/L, respectively) were abundant in seminal plasma, and the content of polyamine decreased (P < 0.05) after preservation at 17 °C for 7 d or incubation at 37 °C for 6 h. In Exp.2, using labeling of spermine or spermidine by conjugation with fluorescein isothiocyanate (FITC) and Ultra-High-Performance Liquid Chromatography (UHPLC), we found that the accumulation of spermine or spermidine in sperm was inhibited by quinidine and DL-Tetrahydropalmatine (THP, organic cation transporters(OCT) inhibitors, P < 0.05), but not mildronate and L-carnitine (organic cation/carnitine transporter (OCTN) inhibitors, P > 0.05). In Exp.3, the addition of spermine or spermidine (0.5 mmol/L) in extender resulted in higher motility, plasma membrane and acrosome integrity and lower ROS level after preservation in vitro at 17 °C for 7 d (P < 0.05). In Exp.4, in the condition of oxidative stress (treatment with H2O2 at 37 °C for 2 h), addition of spermine (1 mmol/L) or spermidine (0.5 mmol/L) in extender increased activities of glutathione peroxidase, glutathione reductase, and glutathione S-transferase, and reduced glutathione/oxidized glutathione ratio (P < 0.05), and alleviate oxidative stress-induced lipid peroxidation (LPO), DNA damage, mitochondrial membrane potential (ΔΨm) decline, adenosine triphosphate (ATP) depletion, and intracellular calcium concentration ([Ca 2+]i) overload (P < 0.05), thereby improving boar sperm motility, the integrity of plasma membrane and acrosome (P < 0.05) in vitro. These data suggest that spermine and spermidine alleviate oxidative stress via the antioxidant capacity, thereby improving the efficacy of boar semen preservation.

Keywords: antioxidant; oxidative stress; polyamine; preservation; sperm

DOI: https://doi.org/10.1093/jas/skac069

Front Cardiovasc Med. 2022 ;9 837780

Human Decidual Mesenchymal Stem Cells Obtained From Early Pregnancy Improve Cardiac Revascularization Postinfarction by Activating Ornithine Metabolism.

Kegong Chen, Long Bai, Jingtong Lu, Wei Chen, Chang Liu, Erliang Guo, Xionghai Qin, Xuan Jiao, Mingli Huang, Hai Tian.

Background: Compared with bone marrow mesenchymal stem cells (BMSCs), decidual mesenchymal stem cells (DMSCs) are easy to obtain and exhibit excellent angiogenic effects, but their role in cell transplantation after myocardial infarction (MI) remains unclear.Methods: BMSCs and DMSCs were harvested from healthy donors. The effects of both cell types on angiogenesis were observed in vitro. Metabonomics analysis was performed to compare different metabolites and screen critical metabolic pathways. A murine model of acute myocardial infarction (AMI) was established, which was randomized into five groups (control, BMSC, DMSC, DMSC + ODCshRNA and BMSC + ODC consisting of 50 animals, equally divided into each group). The therapeutic effect of DMSCs on MI in rats was assessed based on neovascularization and cardiac remodeling.
Results: DMSCs exhibited a better angiogenic effect on human umbilical vein endothelial cells (HUVECs) than BMSCs in vitro. In addition, ornithine metabolism, which is associated with vascularization, was significantly increased in DMSCs. The transplantation of DMSCs in the rat MI model significantly enhanced angiogenesis of the infarct border area and improved cardiac remodeling and dysfunction postinfarction compared with BMSCs. Furthermore, inhibition of ornithine metabolism by silencing ornithine decarboxylase (ODC) in DMSCs partly abolished the benefits of DMSC transplantation.
Conclusion: Compared with BMSCs, DMSCs exhibited better efficacy in improving revascularization and heart remodeling post-MI via the activation of ODC-associated ornithine metabolism.

Keywords: bone marrow mesenchymal stem cells; decidual mesenchymal stem cells; heart remodeling; ischemic heart disease; ornithine decarboxylase; revascularization

DOI: https://doi.org/10.3389/fcvm.2022.837780

ACS Omega. 2022 Feb 22. 7(7): 6393-6402

Computational Analysis of Histone Deacetylase 10 Mechanism by the ONIOM Method: A Complementary Approach to X-ray and Kinetics Studies.

Ibrahim Yildiz, Banu Sizirici Yildiz.

Histone deacetylase 10 (HDAC 10) catalyzes deacetylation of N8-acetylspermidine into spermidine in the cytosolic region of eukaryotic cells. Inhibition of HDAC 10 has clinical importance in certain types of cancers. Recently, X-ray crystal structures corresponding to the substrate-bound, tetrahedral intermediate-bound, and product-bound enzymes have been resolved using variant forms of humanized HDAC 10. Based on these structures, it was proposed that Y307 residue polarizes the carbonyl of the acetyl group in N8-acetylspermidine together with a zinc atom, which is coordinated by D174, H176, D267, and an H2O molecule. The H2O molecule undergoes nucleophilic addition to the carbonyl carbon of N8-acetylspermidine to form the tetrahedral intermediate. During this process, it is suggested that H136 acts as a general base to deprotonate the H2O molecule. It is further proposed that the protonation of the amide N atom of the tetrahedral intermediate by H137 causes the deacetylation forming the final products, spermidine and acetate ion. In this study, computational models based on the ONIOM method were employed to study the proposed mechanism for the two steps of the deacetylation process based on the crystal structure of the substrate-bound enzyme. The energy profiles of each step as well as the roles of the active site residues were investigated for the catalysis. The calculated activation barrier is in good agreement with the reported kcat value.

DOI: https://doi.org/10.1021/acsomega.1c07055

Amino Acids. 2022 Mar 03.

Specific and sensitive GC-MS analysis of hypusine, Nε-(4-amino-2-hydroxybutyl)lysine, a biomarker of hypusinated eukaryotic initiation factor eIF5A, and its application to the bi-ethnic ASOS study.

Svetlana Baskal, Annette Kaiser, Catharina Mels, Ruan Kruger, Dimitrios Tsikas.

Hypusination is a unique two-step enzymatic post-translational modification of the Nε-amino group of lysine-50 of the eukaryotic initiation factor 5A (eIF5A). We developed a specific and sensitive gas chromatography-mass spectrometry (GC-MS) method for the measurement of biological hypusine (Hyp), i.e., Nε-(4-amino-2-hydroxybutyl)lysine. The method includes a two-step derivatization of Hyp: first esterification with 2 M HCl in CH3OH (60 min, 80 °C) to the methyl ester (Me) and then acylation with penta-fluoro-propionic (PFP) anhydride in ethyl acetate (30 min, 65 °C). Esterification with 2 M HCl in CD3OD was used to prepare the internal standard. The major derivatization product was identified as the un-labelled (d0Me) and the deuterium-labelled methyl esters (d3Me) derivatives: d0Me-Hyp-(PFP)5 and d3Me-Hyp-(PFP)5, respectively. Negative-ion chemical ionization generated the most intense ions with m/z 811 for d0Me-Hyp-(PFP)5 and m/z 814 for the internal standard d3Me-Hyp-(PFP)5. Selected-ion monitoring of m/z 811 and m/z 814 was used in quantitative analyses. Free Hyp was found in spot urine samples (10 µL) of two healthy subjects at 0.60 µM (0.29 µmol Hyp/mmol creatinine) in the female and 1.80 µM (0.19 µmol Hyp/mmol creatinine) in the male subject. The mean accuracy of the method in these urine samples spiked with 1-5 µM Hyp was 91-94%. The limit of detection (LOD) of the method is 1.4 fmol Hyp. The method was applied to measure the urinary excretion rates of Hyp in healthy black (n = 38, age 7.8 ± 0.7 years) and white (n = 41, age 7.7 ± 1.0 years) boys of the Arterial Stiffness in Offspring Study (ASOS). The Hyp concentrations were 3.55 [2.68-5.31] µM (range 0.54-9.84 µM) in the black boys and 3.87 [2.95-5.06] µM (range 1.0-11.7 µM) in the white boys (P = 0.64). The creatinine-corrected excretion rates were 0.25 [0.20-0.29] µmol/mmol (range 0.11-0.36 µmol/mmol) in the black boys and 0.26 [0.21-0.30] µmol/mmol (range 0.10-0.45 µmol/mmol) in the white boys (P = 0.82). These results suggest that there is no ethnic-related difference in the ASOS population in the eIF5A modification. Remarkable differences were found between black and white boys with respect to correlations of urinary Hyp with amino acids and advanced glycation end-products of Lys, Arg and Cys. Deoxyhypusine, formally the direct precursor of Hyp, seems not to be excreted in the urine by healthy subjects.

Keywords: AGEs; ASOS; Amino acids; Derivatization; Deuterium; GC–MS; Hypusine; Post-translational modification (PTM); Quantification; eIF5A

DOI: https://doi.org/10.1007/s00726-022-03142-8