4-Hydroxymelatonin alleviates nickel stress, improves physiochemical traits of Solanum melongena: Regulation of polyamine metabolism and antioxidative enzyme

AbstractEnzymatic browning is one of the crucial problems compromising the flavor and texture of fresh-cut fruit and vegetables. In this study, an untargeted metabolomics approach based on liquid chromatography-mass spectrometry (LC–MS) was used to explore the browning mechanism in fresh-cut eggplant. Metabolomics studies showed that with the increase of fresh-cut time, the contents of 946 metabolites changed dynamically. The metabolites having the same trend share common metabolic pathways. As an important browning substrate, the content of chlorogenic acid increased significantly, suggesting that may be more important to fresh-cut eggplant browning; all 119 common differential metabolites in 5 min/CK and 3 min/CK contrastive groups were mapped onto 31 KEGG pathways including phenylpropanol metabolism, glutathione metabolism pathway, et al. In physiological experiments, results showed that the Phenylpropanoid-Metabolism-Related enzymes (PAL, C4H, 4CL) were changed after fresh-cut treatment, the activities of three enzymes increased first and then decreased, and reached the maximum value at 5 min, indicating the accumulation of phenolic substances. At the same time, ROS were accumulated when plant tissue damaged by cutting, the activities of related antioxidant enzymes (SOD, APX and CAT) changed dynamically after oxidative damage. SOD and APX content increased significantly and reached the maximum value at 10 min after cutting, and then showed a downward trend. However, CAT activity increased sharply and reached the maximum value within 3 min after cutting, then maintained the same activity, and showed a downward trend after 30 min. These data fully demonstrated that the activities of browning related enzymes and gene expression increased with the prolonging of fresh cutting time. We explained the browning mechanism of fresh-cut eggplant by combining metabolomics and physiology, which may lay the foundation for better understanding the mechanism of browning during the fruits and vegetables during processing.

Download Full-text

Effect of Methionine Restriction on Aging: Its Relationship to Oxidative Stress

Biomedicines ◽

10.3390/biomedicines9020130 ◽

2021 ◽

Vol 9 (2) ◽

pp. 130

Author(s):

Munehiro Kitada ◽

Yoshio Ogura ◽

Itaru Monno ◽

Jing Xu ◽

Daisuke Koya

Keyword(s):

Oxidative Stress ◽

Metabolic Health ◽

Polyamine Metabolism ◽

Lifespan Extension ◽

Methionine Metabolism ◽

Glutathione Synthesis ◽

Methyl Donors ◽

Methionine Restriction ◽

Adenosyl Methionine ◽

Species Production

Enhanced oxidative stress is closely related to aging and impaired metabolic health and is influenced by diet-derived nutrients and energy. Recent studies have shown that methionine restriction (MetR) is related to longevity and metabolic health in organisms from yeast to rodents. The effect of MetR on lifespan extension and metabolic health is mediated partially through a reduction in oxidative stress. Methionine metabolism is involved in the supply of methyl donors such as S-adenosyl-methionine (SAM), glutathione synthesis and polyamine metabolism. SAM, a methionine metabolite, activates mechanistic target of rapamycin complex 1 and suppresses autophagy; therefore, MetR can induce autophagy. In the process of glutathione synthesis in methionine metabolism, hydrogen sulfide (H2S) is produced through cystathionine-β-synthase and cystathionine-γ-lyase; however, MetR can induce increased H2S production through this pathway. Similarly, MetR can increase the production of polyamines such as spermidine, which are involved in autophagy. In addition, MetR decreases oxidative stress by inhibiting reactive oxygen species production in mitochondria. Thus, MetR can attenuate oxidative stress through multiple mechanisms, consequently associating with lifespan extension and metabolic health. In this review, we summarize the current understanding of the effects of MetR on lifespan extension and metabolic health, focusing on the reduction in oxidative stress.

Download Full-text

A MYC-Driven Plasma Polyamine Signature for Early Detection of Ovarian Cancer

Cancers ◽

10.3390/cancers13040913 ◽

2021 ◽

Vol 13 (4) ◽

pp. 913

Author(s):

Johannes Fahrmann ◽

Ehsan Irajizad ◽

Makoto Kobayashi ◽

Jody Vykoukal ◽

Jennifer Dennison ◽

...

Keyword(s):

Ovarian Cancer ◽

Early Stage ◽

Area Under The Curve ◽

Polyamine Metabolism ◽

Healthy Controls ◽

Test Set ◽

Exact Test ◽

Oncogenic Driver ◽

Characteristic Area ◽

Validation Set

MYC is an oncogenic driver in the pathogenesis of ovarian cancer. We previously demonstrated that MYC regulates polyamine metabolism in triple-negative breast cancer (TNBC) and that a plasma polyamine signature is associated with TNBC development and progression. We hypothesized that a similar plasma polyamine signature may associate with ovarian cancer (OvCa) development. Using mass spectrometry, four polyamines were quantified in plasma from 116 OvCa cases and 143 controls (71 healthy controls + 72 subjects with benign pelvic masses) (Test Set). Findings were validated in an independent plasma set from 61 early-stage OvCa cases and 71 healthy controls (Validation Set). Complementarity of polyamines with CA125 was also evaluated. Receiver operating characteristic area under the curve (AUC) of individual polyamines for distinguishing cases from healthy controls ranged from 0.74–0.88. A polyamine signature consisting of diacetylspermine + N-(3-acetamidopropyl)pyrrolidin-2-one in combination with CA125 developed in the Test Set yielded improvement in sensitivity at >99% specificity relative to CA125 alone (73.7% vs 62.2%; McNemar exact test 2-sided P: 0.019) in the validation set and captured 30.4% of cases that were missed with CA125 alone. Our findings reveal a MYC-driven plasma polyamine signature associated with OvCa that complemented CA125 in detecting early-stage ovarian cancer.

Download Full-text

Tannery sludge and urban waste compost in the production of Solanum melongena L. through regression and multivariate analysis

Journal of Plant Nutrition ◽

10.1080/01904167.2021.1918714 ◽

2021 ◽

pp. 1-13

Author(s):

Sávio da Silva Berilli ◽

Rebyson Bissaco Guidinelle ◽

Jaqueline Rodrigues Cindra de Lima Souza ◽

Ramon Amaro de Sales ◽

Marcus Vinícius Souza Silva ◽

...

Keyword(s):

Multivariate Analysis ◽

Solanum Melongena ◽

Tannery Sludge ◽

Urban Waste

Download Full-text

Polyamine Metabolism in Scots Pine Embryogenic Cells under Potassium Deficiency

Cells ◽

10.3390/cells10051244 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1244

Author(s):

Riina Muilu-Mäkelä ◽

Jaana Vuosku ◽

Hely Häggman ◽

Tytti Sarjala

Keyword(s):

Scots Pine ◽

Culture Medium ◽

Developmental Regulation ◽

Cell Mass ◽

Arginine Decarboxylase ◽

Protective Role ◽

Potassium Deficiency ◽

Polyamine Metabolism ◽

Embryogenic Cells ◽

Embryogenic Cell

Polyamines (PA) have a protective role in maintaining growth and development in Scots pine during abiotic stresses. In the present study, a controlled liquid Scots pine embryogenic cell culture was used for studying the responses of PA metabolism related to potassium deficiency. The transcription level regulation of PA metabolism led to the accumulation of putrescine (Put). Arginine decarboxylase (ADC) had an increased expression trend under potassium deficiency, whereas spermidine synthase (SPDS) expression decreased. Generally, free spermidine (Spd) and spermine (Spm)/ thermospermine (t-Spm) contents were kept relatively stable, mostly by the downregulation of polyamine oxidase (PAO) expression. The low potassium contents in the culture medium decreased the potassium content of the cells, which inhibited cell mass growth, but did not affect cell viability. The reduced growth was probably caused by repressed metabolic activity and cell division, whereas there were no signs of H2O2-induced oxidative stress or increased cell death. The low intracellular content of K+ decreased the content of Na+. The decrease in the pH of the culture medium indicated that H+ ions were pumped out of the cells. Altogether, our findings emphasize the specific role(s) of Put under potassium deficiency and strict developmental regulation of PA metabolism in Scots pine.

Download Full-text