bims-polyam 2024-06-02 papers

Issue of 2024–06–02
two papers selected by
Sebastian J. Hofer, University of Graz

FEBS J. 2024 May 29.

Spermine and spermidine inhibit or induce programmed cell death in Arabidopsis thaliana in vitro and in vivo in a dose-dependent manner.

Rory Burke, Daniele Nicotra, Jim Phelan, Frances Downey, Paul F McCabe, Joanna Kacprzyk.

Polyamines are ubiquitous biomolecules with a number of established functions in eukaryotic cells. In plant cells, polyamines have previously been linked to abiotic and biotic stress tolerance, as well as to the modulation of programmed cell death (PCD), with contrasting reports on their pro-PCD and pro-survival effects. Here, we used two well-established platforms for the study of plant PCD, Arabidopsis thaliana suspension cultures cells and the root hair assay, to examine the roles of the polyamines spermine and spermidine in the regulation of PCD. Using these systems for precise quantification of cell death rates, we demonstrate that both polyamines can trigger PCD when applied exogenously at higher doses, whereas at lower concentrations they inhibit PCD induced by both biotic and abiotic stimuli. Furthermore, we show that concentrations of polyamines resulting in inhibition of PCD generated a transient ROS burst in our experimental system, and activated the expression of oxidative stress- and pathogen response-associated genes. Finally, we examined PCD responses in existing Arabidopsis polyamine synthesis mutants, and identified a subtle PCD phenotype in Arabidopsis seedlings deficient in thermo-spermine. The presented data show that polyamines can have a role in PCD regulation; however, that role is dose-dependent and consequently they may act as either inhibitors, or inducers, of PCD in Arabidopsis.

Keywords: Arabidopsis cell suspension culture; plant programmed cell death; polyamines; root hair assay; spermidine; spermine

DOI: https://doi.org/10.1111/febs.17165

Front Nutr. 2024 ;11 1393552

Non-linear associations of serum spermidine with type 2 diabetes mellitus and fasting plasma glucose: a cross-sectional study.

Xiaohong Zhang, Yao Zhang, Shaojie Li, Min Liu, Ying Lu, Mengyao He, Zhaoqing Sun, Mingfeng Ma, Liqiang Zheng.

Background: Previous animal experiments have demonstrated the potential of spermidine to mitigate glucose intolerance, insulin resistance, and hyperinsulinemia. However, there remains a scarcity of epidemiological evidence supporting these findings. Therefore, we aimed to elucidate the associations of serum spermidine with T2DM and FPG.
Materials and methods: The cross-sectional study was conducted from June to August 2019 in the rural areas of Fuxin County, Liaoning Province, China. A total of 4,437 participants were included in the study. The serum spermidine was detected using high-performance liquid chromatography with a fluorescence detector. FPG was measured using the hexokinase method. T2DM was defined as participants with a FPG level of 7.0 mmol/L or greater, or self-reported diagnosis of diabetes by a doctor. Restricted cubic spline model and piecewise linear regression model were used to explore the associations of serum spermidine with T2DM and FPG, respectively.
Results: The mean (SD) age of the participants was 59.3 (10.0) years, with 622 out of 4,437 participants being defined as T2DM. The serum spermidine in participants stratified by age and BMI categories was significantly different, with p values of 0.006 and 0.001, respectively. Among all the participants, the association of serum spermidine with T2DM was J-shaped. The log (spermidine) was negatively associated with T2DM (OR = 0.68, 95% CI: 0.52 to 0.92, p = 0.01) below the inflection point, while log (spermidine) was not significantly associated with T2DM (OR = 1.97, 95% CI: 0.93 to 4.15, p = 0.07) above the inflection point. Among the participants without T2DM, the association of serum spermidine with FPG was inverted J-shaped. The log (spermidine) was positively associated with FPG (β = 0.13, 95% CI: 0.05 to 0.21, p = 0.001) below the inflection point, while log (spermidine) was negatively associated with FPG (β = -0.29, 95% CI: -0.42 to -0.16, p < 0.001) above the inflection point.
Conclusion: In conclusion, non-linear associations of serum spermidine with T2DM and FPG were found in the cross-sectional study in Chinese rural adults. This provided insights into the use of spermidine for the prevention of T2DM, highlighting the potential role in public health prevention strategies of spermidine.

Keywords: FPG; T2DM; cross-sectional study; non-linear association; spermidine

DOI: https://doi.org/10.3389/fnut.2024.1393552