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Nishimori, M.

Publications and source records attributed to Nishimori, M..

2 recordsLinked to original sources

Stress-induced vascular remodeling: novel insight into the role of omega-3 fatty acid metabolite, 4-oxoDHA

BackgroundStress has garnered significant attention as a prominent risk factor for inflammation-related diseases, particularly cardiovascular diseases (CVDs). However, the precise mechanisms underlying stress-driven CVDs remain elusive, thereby impeding the development of effective preventive and therapeutic strategies. MethodsTo explore the correlation between plasma lipid metabolites and depressive states, we conducted a study involving healthy volunteers (n=408). Liquid chromatography (LC)/mass spectrometry (MS)/MS-based lipidomics and the self-rating depression (SDS) scale questionnaire were employed for data collection. In addition, we utilized a mouse model by subjecting mice to restraint stress and investigating the impact of stress on plasma lipid metabolites and vascular remodeling following carotid ligation. In vitro functional and mechanistic studies were performed using macrophages, endothelial cells, and neutrophil cells. ResultsOur findings revealed a significant association between depressive state and reduced plasma levels of 4-oxoDHA, a specific omega-3 fatty acid metabolite regulated by 5-lipoxygenase (LO) in neutrophils in healthy volunteers. In mice, restraint stress led to decreased plasma 4-oxoDHA levels and exacerbated vascular remodeling. Moreover, 4-oxoDHA demonstrated the ability to enhance Nrf2-HO-1 pathways, exerting anti-inflammatory effects on endothelial cells and macrophages. Mechanistically, stress-induced noradrenaline triggered the degradation of 5-LO in neutrophils through the proteasome system, facilitated by dopamine D2-like receptor activation. The reduction in circulating 4-oxoDHA resulted in the downregulation of the Nrf2-HO-1 anti-inflammatory axis and an increase in ICAM-1 expression, vascular permeability, and remodeling. ConclusionsOur study unveiled a novel stress-induced pathway of vascular inflammation, mediated through the regulation of omega-3 fatty acid metabolites. Reduced levels of circulating 4-oxoDHA under stress conditions may serve as a promising biomarker for stress. This understanding of the interplay between neurobiology and lipid metabolism provides a potential avenue for the development of treatments aimed at preventing stress-induced systemic neuroinflammation. Highlights- Our study reveals that stress-induced reduction in circulating levels of a specific omega-3 fatty acid metabolite, 4-oxoDHA, contributes to vascular inflammation. - We have identified a novel pathway that explains how stress promotes systemic vascular inflammation by regulating omega-3 fatty acid metabolites in the circulation. - Our findings provide new evidence for the role of 4-oxoDHA in maintaining Nrf2-ARE-related anti-inflammatory functions in endothelial cells and macrophages.

biochemistry↗

Effectiveness of heat tolerance rice cultivars in preserving grain appearance quality under high temperatures - A meta-analysis

BackgroundClimate change, particularly rising temperatures, negatively affects rice grain quality, increasing chalky grain percentage (CG) and hampering rice grade and price. Heat-tolerant cultivars have been bred and released since the 2000s, but the effectiveness of heat tolerance in reducing the occurrence of CG has yet to be quantified. ObjectivesThis study aimed to measure the effectiveness of breeding for better heat tolerance in reducing the negative impact of high temperatures on rice quality. MethodsThrough a systematic literature search, we developed a dataset including 1297 field observations covering 48 cultivars from five different heat tolerant ranks (HTRs) at 44 sites across Japan. A linear mixed-effect model (LME) and a random forest model (RF) were fitted to the data to analyze the effect of HTR and climatic factors such as the cumulative mean air temperature above 26 {degrees}C (TaHD), mean solar radiation, and mean relative humidity for 20 days after heading on CG. ResultsThe LME model explained 63 % of the variation with a 14% RMSE. The RF partial dependence plot revealed that the logit-transformed CG response to climate factors was linear, supporting the assumption of LME. The statistical analysis showed that CG increased as a function of TaHD (P < 0.001), with significant differences among HTRs (P < 0.001). The strongest effect of TaHD was obtained for the lowest HTR and was found to decrease with increasing HTR. CG also increased with higher relative humidity (P < 0.001) and solar radiation (P < 0.01). Based on our modeling, we estimated that as TaHD increased from 20 to 80 {degrees}Cd (equivalent to a mean temperature increase from 27 {degrees}C to 30 {degrees}C), CG increased by 66 % points (difference in CG) for cultivars with the lowest HTR, 45 % points for cultivars with an intermediate HTR, and 19 % points for cultivars with the highest HTR. Raising HTR by just one step (from intermediate to moderately tolerant) is projected to increase the proportion of first-grade rice at a grain-filling temperature of 27 {degrees}C, but tolerance levels need to be improved further in case of stronger warming. ConclusionsThe effect of high temperatures on CG was highly dependent on the cultivars HTR. Improvements in HTR effectively reduce the negative impacts of high temperatures on rice grain quality. SignificanceHeat-tolerant cultivars are projected to suppress the prevalence of CG more than threefold compared with heat-sensitive cultivars when grain-filling temperature increases from 27 to 30 {degrees}C.

plant biology↗