The mitochondrial phosphatase PGAM5 functions at the convergence point of multiple necrotic death pathways.

The programmed necrosis induced by TNF-α requires the activities of the receptor-interacting serine-threonine kinases RIP1 and RIP3 and their interaction with the mixed lineage kinase domain-like protein MLKL. We report the identification of RIP1- and RIP3-containing protein complexes that form specifically in response to necrosis induction. One component of these complexes is the mitochondrial protein phosphatase PGAM5, which presents as two splice variants, PGAM5L (long form) and PGAM5S (short form). Knockdown of either form attenuated necrosis induced by TNF-α as well as reactive oxygen species (ROS) and calcium ionophore, whereas knockdown of RIP3 and MLKL blocked only TNF-α-mediated necrosis. Upon necrosis induction, PGAM5S recruited the mitochondrial fission factor Drp1 and activated its GTPase activity by dephosphorylating the serine 637 site of Drp1. Drp1 activation caused mitochondrial fragmentation, an early and obligatory step for necrosis execution. These data defined PGAM5 as the convergent point for multiple necrosis pathways.

Mixed lineage kinase domain-like protein mediates necrosis signaling downstream of RIP3 kinase.

The receptor-interacting serine-threonine kinase 3 (RIP3) is a key signaling molecule in the programmed necrosis (necroptosis) pathway. This pathway plays important roles in a variety of physiological and pathological conditions, including development, tissue damage response, and antiviral immunity. Here, we report the identification of a small molecule called (E)-N-(4-(N-(3-methoxypyrazin-2-yl)sulfamoyl)phenyl)-3-(5-nitrothiophene-2-yl)acrylamide--hereafter referred to as necrosulfonamide--that specifically blocks necrosis downstream of RIP3 activation. An affinity probe derived from necrosulfonamide and coimmunoprecipitation using anti-RIP3 antibodies both identified the mixed lineage kinase domain-like protein (MLKL) as the interacting target. MLKL was phosphorylated by RIP3 at the threonine 357 and serine 358 residues, and these phosphorylation events were critical for necrosis. Treating cells with necrosulfonamide or knocking down MLKL expression arrested necrosis at a specific step at which RIP3 formed discrete punctae in cells. These findings implicate MLKL as a key mediator of necrosis signaling downstream of the kinase RIP3.

Stella safeguards the oocyte methylome by preventing de novo methylation mediated by DNMT1.

Postnatal growth of mammalian oocytes is accompanied by a progressive gain of DNA methylation, which is predominantly mediated by DNMT3A, a de novo DNA methyltransferase1,2. Unlike the genome of sperm and most somatic cells, the oocyte genome is hypomethylated in transcriptionally inert regions2-4. However, how such a unique feature of the oocyte methylome is determined and its contribution to the developmental competence of the early embryo remains largely unknown. Here we demonstrate the importance of Stella, a factor essential for female fertility5-7, in shaping the oocyte methylome in mice. Oocytes that lack Stella acquire excessive DNA methylation at the genome-wide level, including in the promoters of inactive genes. Such aberrant hypermethylation is partially inherited by two-cell-stage embryos and impairs zygotic genome activation. Mechanistically, the loss of Stella leads to ectopic nuclear accumulation of the DNA methylation regulator UHRF18,9, which results in the mislocalization of maintenance DNA methyltransferase DNMT1 in the nucleus. Genetic analysis confirmed the primary role of UHRF1 and DNMT1 in generating the aberrant DNA methylome in Stella-deficient oocytes. Stella therefore safeguards the unique oocyte epigenome by preventing aberrant de novo DNA methylation mediated by DNMT1 and UHRF1.

CK1α, CK1δ, and CK1ε are necrosome components which phosphorylate serine 227 of human RIPK3 to activate necroptosis.

Necroptosis is a regulated necrotic cell death pathway, mediated by a supermolecular complex called the necrosome, which contains receptor-interacting protein kinase 1 and 3 (RIPK1, RIPK3) and mixed-lineage kinase domain-like protein (MLKL). Phosphorylation of human RIPK3 at serine 227 (S227) has been shown to be required for downstream MLKL binding and necroptosis progression. Tandem immunoprecipitation of RIPK3 reveals that casein kinase 1 (CK1) family proteins associate with the necrosome upon necroptosis induction, and this interaction depends on the kinase activity of RIPK3. In addition, CK1 proteins colocalize with RIPK3 puncta during necroptosis. Importantly, CK1 proteins directly phosphorylate RIPK3 at S227 in vitro and in vivo. Loss of CK1 proteins abolishes S227 phosphorylation and blocks necroptosis. Furthermore, a RIPK3 mutant with mutations in the CK1 recognition motif fails to be phosphorylated at S227, does not bind or phosphorylate MLKL, and is unable to activate necroptosis. These results strongly suggest that CK1 proteins are necrosome components which are responsible for RIPK3-S227 phosphorylation.

Necroptosis-blocking compound NBC1 targets heat shock protein 70 to inhibit MLKL polymerization and necroptosis.

Necroptosis is a regulated necrotic cell death pathway involved in development and disease. Its signaling cascade results in the formation of disulfide bond-dependent amyloid-like polymers of mixed lineage kinase domain-like protein (MLKL), which mediate proinflammatory cell membrane disruption. We screened compound libraries provided by the National Cancer Institute and identified a small-molecule inhibitor of necroptosis named necroptosis-blocking compound 1 (NBC1). Biotin-labeled NBC1 specifically conjugates to heat shock protein Hsp70. NBC1 and PES-Cl, a known Hsp70 substrate-binding inhibitor, block the formation of MLKL polymers, but not MLKL tetramers in necroptosis-induced cells. In vitro, recombinant Hsp70 interacts with the N-terminal domain (NTD) of MLKL and promotes NTD polymerization, which has been shown to mediate the cell killing activity. Furthermore, the substrate-binding domain (SBD) of Hsp70 is sufficient to promote MLKL polymerization. NBC1 covalently conjugates cysteine 574 and cysteine 603 of the SBD to block its function. In addition, an SBD mutant with both cysteines mutated to serines loses its ability to promote MLKL polymerization. Interestingly, knockdown of Hsp70 in cells leads to MLKL destabilization, suggesting that MLKL might also be a client protein of Hsp70. In summary, using NBC1, an inhibitor of necroptosis, we identified Hsp70 as a molecular chaperone performing dual functions in necroptosis. It stabilizes MLKL protein under normal condition and promotes MLKL polymerization through its substrate-binding domain during necroptosis.

In-Depth Analysis of the Mechanism of Astaxanthin Succinate Diester in Reducing Ulcerative Colitis in C57BL/6J Mice Based on Microbiota Informatics.

This paper aims to explore the effect and mechanism of water-soluble astaxanthin succinate diester (Asta-SD) on ulcerative colitis (UC) induced by dextran sodium sulfate in zebrafish and C57BL/6J mice. Asta-SD was synthesized with hydrophilic fatty acid succinic anhydride and the hydroxyl groups at the ends of F-Asta were synthesized by esterifying. Through the construction of a zebrafish intestinal inflammation model, it was found that Asta-SD could effectively reduce the levels of ROS and increase the number of healthy intestinal lysosomes in zebrafish. After continuous gavage of Asta-SD for seven days, the body weight, disease activity index, colonic length, colonic histopathology, expression of inflammatory factors, and intestinal flora of the mice were measured. The results showed that Asta-SD could significantly alleviate weight loss and colonic shrinkage, as well as reducing pro-inflammatory cytokines and recess injury in UC mice. The 16S rRNA gene sequencing showed that Asta-SD significantly increased the beneficial bacteria (Lactobacillus, Anaerotruncus) and decreased the relative abundance of pathogenic bacteria, effectively maintaining intestinal microbiota homeostasis in mice. Based on Pearson analysis, Bacteroides, Parabacteroides, and Butyrimionas were expected to be associated with the significant difference in the expression of inflammatory factors between the UC and the corresponding host. Thus, Asta-SD significantly improves UC and maintains intestinal microbiota homeostasis.

Rapeseed peptide inhibits HepG2 cell proliferation by regulating the mitochondrial and P53 signaling pathways.

BACKGROUND: Rapeseed peptide, extracted from rapeseed protein, is known to have a variety of biological activities. In this study, the anti-proliferation effect and molecular mechanism of rapeseed peptide on HepG2 cells were investigated. RESULTS: In vitro anticancer experiments showed that the rapeseed peptide NDGNQPL could inhibit HepG2 cell proliferation in a concentration-dependent manner [half maximal inhibitory concentration (IC50 ), 1.56 mmol L-1 ). HepG2 cells were induced by NDGNQPL at a 0.5 mmol L-1 concentration and exhibited a 28.39 ± 0.80% apoptosis rate and a cell cycle arrest in the G0/G1 phase. Meanwhile, rapeseed peptide induced a decrease in mitochondrial membrane potential, an increase in reactive oxygen species (ROS) release, and changes in the nuclear morphology of HepG2 cells, indicating that rapeseed peptide could induce cell apoptosis through the mitochondrial pathway. In addition, rapeseed peptide activated the proliferation-related P53 signaling pathway, in which the expression levels of P53, P21, and cleaved-caspase3 were up-regulated, while the expression levels of murine double minute 2 (MDM2) were down-regulated. In molecular docking simulations, NDGNQPL exhibited a good affinity for the MDM2 molecule, which supported the notion that the rapeseed peptide is able to inhibit MDM2, a negative regulator of P53. CONCLUSION: The current results indicate that the rapeseed-derived NDGNQPL peptide has the potential to inhibit the proliferation of HepG2 cells and promote human health. © 2022 Society of Chemical Industry.

Docosahexaenoic acid-acylated astaxanthin monoester ameliorates chronic high-fat diet-induced autophagy dysfunction via ULK1 pathway in the hypothalamus of mice.

BACKGROUND: Dietary astaxanthin (AST) exhibits the ability to resist lipid accumulation and stimulate hepatic autophagy. Natural AST predominantly exists in stable esterified forms. More importantly, in our previous study, docosahexaenoic acid-acylated AST monoester (AST-DHA) possessed better stability, bioavailability, and neuroprotective ability than AST in free and diester form. However, the AST-DHA mechanisms of action in regulating the obese phenotype and autophagy of the central nervous system remain unclear. RESULTS: High-fat diet (HFD)-fed C57BL/6J mice were orally administered AST-DHA (50 mg/kg body weight/d) for 3 days or 8 weeks. AST-DHA supplementation alleviated HFD-induced abnormal body weight gain, significantly enhanced autophagy with an increased microtubule-associated protein light chain 3 II/I (LC3II/I) ratio, and reduced the accumulation of p62/sequestosome 1 (SQSTM1) in the hypothalamus rather than in the hippocampus. Mechanistically, AST-DHA effectively promoted autophagy and autophagosome formation, and most notably rescued the HFD-impaired autophagosome-lysosome fusion (indicated by the colocalization of LC3 and LAMP1) by regulating mTOR- and AMPK-induced phosphorylation of ULK1. Consequently, AST-DHA enhanced hypothalamic autophagy, leading to pro-opiomelanocortin (POMC) cleavage to produce alpha-melanocyte-stimulating hormone (α-MSH). CONCLUSIONS: This study identified AST-DHA as an enhancer of autophagy that plays a beneficial role in restoring hypothalamic autophagy, and as a new potential therapeutic agent against HFD-induced obesity. © 2023 Society of Chemical Industry.

Neutrophil-lymphocyte count ratio as a diagnostic marker for acute kidney injury: a systematic review and meta-analysis.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is calculated from the white cell differential blood count. Recently, NLR was identified as a potential biomarker for the prediction of acute kidney injury (AKI). We conducted this systematic review and meta-analysis to evaluate the diagnostic value of NLCR for AKI in adult patients. METHODS: Studies in the PubMed, EMBASE, Web of Science and Cochrane Library databases were systematically searched from the date of database inception to February 28, 2019. The predictive value of NLR for AKI was evaluated by the pooled sensitivity, specificity, and summary receiver operating characteristic curve (SROC) analyses. Review Manager and Stata were used for all statistical analyses. The sources of potential heterogeneity were explored by a sensitivity analysis and subgroup analysis. RESULTS: This meta-analysis returned 89 reports, of which 9 fulfilled the inclusion criteria, accounting for 9766 patients. Bivariate analysis yielded a mean sensitivity of 0.736 (95% CI 0.675-0.790) and specificity of 0.686 (95% CI 0.601-0.759). The SROC was 0.77 (95% CI 0.74-0.81). The studies had no significant heterogeneity (Q = 0.675, p = 0.357, I2 = 0). CONCLUSIONS: Our findings indicate that the NLR may be a reliable biomarker for the early detection of AKI. Our findings also provide important information and assistance for clinicians in the prediction of AKI.

MLKL forms disulfide bond-dependent amyloid-like polymers to induce necroptosis.

Mixed-lineage kinase domain-like protein (MLKL) is essential for TNF-α-induced necroptosis. How MLKL promotes cell death is still under debate. Here we report that MLKL forms SDS-resistant, disulfide bond-dependent polymers during necroptosis in both human and mouse cells. MLKL polymers are independent of receptor-interacting protein kinase 1 and 3 (RIPK1/RIPK3) fibers. Large MLKL polymers are more than 2 million Da and are resistant to proteinase K digestion. MLKL polymers are fibers 5 nm in diameter under electron microscopy. Furthermore, the recombinant N-terminal domain of MLKL forms amyloid-like fibers and binds Congo red dye. MLKL mutants that cannot form polymers also fail to induce necroptosis efficiently. Finally, the compound necrosulfonamide conjugates cysteine 86 of human MLKL and blocks MLKL polymer formation and subsequent cell death. These results demonstrate that disulfide bond-dependent, amyloid-like MLKL polymers are necessary and sufficient to induce necroptosis.

Enzyme-catalyzed acylation improves gel properties of rapeseed protein isolate.

BACKGROUND: Although rapeseed protein isolate (RPI) possessed some good functional properties, the use of RPI as an ingredient in the food industry is restricted mainly due to its inferior gelation. The purpose of this study was to improve the heat-induced gel properties of RPI using double processes of acylation and additional transglutaminase catalysis. RESULTS: Scanning electron microscopy showed that the gel formed by native RPI exhibited randomly aggregated particulate network structures whereas transglutaminase (TG)-assisted RPI gels significantly improved gelation properties. More importantly, the combined modifications of RPI using TG-assisted acylation can form a gel with unique percolating and small porous structure. Furthermore, TG-catalyzed 5% acylated RPI gel (100 U g-1 , protein basis) exhibited excellent gel properties in terms of gel strength, thermal stability, surface roughness and apparent viscosity compared to non-treated or single modification of RPI gel as determined by texture analyzer, atomic force microscopy and rheometer. Mechanistically, Fourier-transform infrared spectra and gel dissociation test revealed that TG-catalyzed acylation extensively unfolded the hydrophobic and sulfhydryl residues of RPI, in turn, reinforced re-assembly of protein molecules via hydrophobic interactions and disulfide bonds during gel formation. CONCLUSION: Combined processes of acylation and additional TG catalysis improved the thermal gelation properties by altering inter- and intra-protein structures. Such sequential processes will provide a promising approach to improve the protein gelation that could be potentially applied in the food industry. © 2020 Society of Chemical Industry.

Effect of static-state fermentation on volatile composition in rapeseed meal.

BACKGROUND: Fermented rapeseed meal has been used as an alternative protein source for animal feed, but the volatile compounds and how their contents change during fermentation have not been reported. To clarify the effect of static-state fermentation on its aroma, the volatile compounds of rapeseed meal during different stages of fermentation were analyzed using an electronic nose system and headspace solid-phase microextraction-gas chromatography-mass spectrometry. RESULTS: The results suggested that the volatile compounds in the raw rapeseed meal, mostly hydrocarbons and some aldehydes, were lost. The levels of the volatile compounds resulting from microbial metabolism, especially pyrazines, greatly increased during fermentation. Nonanal was the dominant volatile measured in the headspace of raw rapeseed meal. However, the volatile compounds found at high concentrations in rapeseed meal after 5 days of fermentation were tetramethylpyrazine, followed by butanoic acid, benzenepropanenitrile, 2-methylbutanoic acid, trimethylamine, 2,3,5-trimethyl-6-ethylpyrazine, and 2,3,5-trimethylpyrazine. CONCLUSION: The fermentation process could significantly change the composition and content of volatile compounds in rapeseed meal. The results may provide reference data for studies on the choice of fermentation period and formation mechanism of flavor substances in fermented rapeseed meal. © 2020 Society of Chemical Industry.

Storage characteristics of infrared radiation stabilized rice bran and its shelf-life evaluation by prediction modeling.

BACKGROUND: Rice bran is a nutrient-dense and resource-rich byproduct produced from the rice milling. The limitation of rice bran utilization is mainly caused by oxidative deterioration. Improvement of stability to prolong rice bran shelf-life has thus become an urgent requirement. RESULTS: The present study aimed to determine the characteristics of infrared radiation heat treatment of rice bran (IRRB) and raw rice bran stored under different temperatures. The effects of heating and storage time on physicochemical, microbial, storage stability and structural properties were investigated. Additionally, the prediction model for the shelf-life of rice bran was established based on free fatty acids and the peroxide value by fitting the curve of bran lipid oxidation. The results obtained demonstrated that infrared radiation heating at 300 °C for 210 s resulted in decreased lipase activity and peroxidase activity of 73.05% and 81.50%, respectively. The free fatty acids and peroxide value of IRRB stored at 4 and 25 °C for 8 weeks were only reached at 2.35% and 3.17% and 2.53 and 3.64 meq kg-1 , respectively. The shelf-life prediction model showed the the shelf-life of infrared radiation-treated samples increased to 71.6 and 25.8 weeks under storage at 4 and 25 °C, respectively. CONCLUSION: The stabilizing process could effectively suppress microbial growth and had no prominent effect on the physicochemical and microstructure properties of rice bran and, simultaneously, storage life was greatly extended. © 2020 Society of Chemical Industry.

Anti-Inflammatory Activity of a Peptide from Skipjack (Katsuwonus pelamis).

In this paper, the effect of skipjack (Katsuwonus pelamis) enzymatic peptide (SEP), which was prepared and purified from a byproduct of skipjack, on inflammation, ulcerative colitis and the regulation of intestinal flora was studied in a mouse ulcerative colitis model and a transgenic zebrafish inflammation model. The aggregation of transgenic granulocyte neutrophils in zebrafish from a normal environment and from a sterile environment was calculated, and the anti-inflammatory activity of SEP was evaluated. To evaluate the anti-ulcerative colitis activity of SEP, DSS-induced colitis mice were given SEP, salicylazosulfapyridine (SASP), or SASP + SEP. Then, the concentrations of IL-6, IL-10 and TNF-α in the serum were detected, the HE-stained colon tissue was examined by microscopy the species composition and abundance distribution of the intestinal flora was analyzed. The results showed that 500 µg/mL SEP treatment significantly alleviated neutrophil granulocyte aggregation in the zebrafish inflammation model; Diarrhea, hematochezia and body weight loss were alleviated to a certain extent in mice gavaged with SEP and SASP, and the combination of SASP with SEP was the most effective in mice. The damage to villi in the intestine was completely repaired, and the levels of IL-6, IL-10 and TNF-α, which are associated with inflammation, were all reduced. In addition, the proportion of intestinal probiotics or harmless bacteria increased, while that of pathogenic bacteria decreased, and the effect of the combined treatment was the most pronounced. These results show that SEP could relieve inflammation, cure ulcerative colitis, regulate intestinal flora and enhance the therapeutic effect of the clinical drug SASP. This study provides a theoretical basis for the development of SEP as an anti-inflammatory adjuvant therapy and intestinal flora regulator.

Thioredoxin-1 actively maintains the pseudokinase MLKL in a reduced state to suppress disulfide bond-dependent MLKL polymer formation and necroptosis.

Necroptosis is an immunogenic cell death program that is associated with a host of human diseases, including inflammation, infections, and cancer. Receptor-interacting protein kinase 3 (RIPK3) and its substrate mixed lineage kinase domain-like protein (MLKL) are required for necroptosis activation. Specifically, RIPK3-dependent MLKL phosphorylation promotes the assembly of disulfide bond-dependent MLKL polymers that drive the execution of necroptosis. However, how MLKL disulfide bond formation is regulated is not clear. In this study we discovered that the MLKL-modifying compound necrosulfonamide cross-links cysteine 86 of human MLKL to cysteine 32 of the thiol oxidoreductase thioredoxin-1 (Trx1). Recombinant Trx1 preferentially binds to monomeric MLKL and blocks MLKL disulfide bond formation and polymerization in vitro Inhibition of MLKL polymer formation requires the reducing activity of Trx1. Importantly, shRNA-mediated knockdown of Trx1 promotes MLKL polymerization and sensitizes cells to necroptosis. Furthermore, pharmacological inhibition of Trx1 with compound PX-12 induces necroptosis in multiple cancer cell lines. Altogether, these findings demonstrate that Trx1 is a critical regulator of necroptosis that suppresses cell death by maintaining MLKL in a reduced inactive state. Our results further suggest new directions for targeted cancer therapy in which thioredoxin inhibitors like PX-12 could potentially be used to specifically target cancers expressing high levels of MLKL or MLKL short isoforms.

A Correlational Study on Cerebral Microbleeds and Carotid Atherosclerosis in Patients with Ischemic Stroke.

PURPOSE: This study aimed to investigate the correlation between cerebral microbleeds and carotid atherosclerosis in patients with ischemic stroke. SUBJECTS AND METHODS: Patients with ischemic stroke treated in a hospital in China from 2016 to 2017 were enrolled in the study. Based on the results from susceptibility-weighted imaging, the patients were divided into cerebral microbleed and noncerebral microbleed groups. The degree of carotid atherosclerosis was assessed with carotid intima-media thickness (CIMB) and Crouse score of carotid plaque. The details of patients' demographic information, cerebrovascular disease-related risk factors, carotid atherosclerosis indices, cerebral microbleed distribution, and grading were recorded, compared, and analyzed. RESULTS: Logistic regression analysis of the 198 patients showed that CIMB and Crouse score were significantly correlated with the occurrence of cerebral microbleeds. The CIMB thickening group (P = .03) and the plaque group (P = .01) were more susceptible to cerebral microbleeds. In the distribution of cerebral microbleed sites, Crouse scores were the highest in the mixed group and showed a statistically significant difference (P < .01). As the degree of carotid atherosclerosis increased, the average number of cerebral microbleeds also increased (P < .01). The receiver operating characteristic curve analysis of the carotid atherosclerosis indices showed a statistically significant difference. The CIMB value combined with the Crouse score was the best indicator (P < .01). CONCLUSION: In patients with ischemic stroke, cerebral microbleeds are closely related to carotid atherosclerosis. Active control of carotid atherosclerosis is important to prevent cerebral microbleeds in patients with ischemic stroke.

Dissipative particle dynamics simulation on paclitaxel loaded PEO-PPO-PEO block copolymer micelles.

Self-assembly behavior of the polymer drug loading micelle PEO-PPO-PEO was studied using dissipative particle dynamics (DPD) simulation method with various simulation steps. The distributions of drugs in polymer carriers were also investigated with different drug feed ratios. Polymer carriers distributed on the surface of the spherical micelle, and drugs were almost encapsulated in the inner of the micelle. Our simulation work demonstrates that the DPD simulation is effective to study the drug loaded systems and can give useful guidance on the design and preparation of new drug carriers with tailored properties.

Alpha and beta diversity of functional traits in subtropical evergreen broad-leaved secondary forest communities.

Introduction: Intra-speciic variation is the main source of functional trait diversity and has similar ecological effects as inter-speciic variation. Methods: We studied 79 species and 3546 individuals from 50 ixed monitoring plots in subtropical evergreen broad - leaved secondary forests in Zhejiang Province, China. Using trait gradient analysis, we examined nine traits (speciic leaf area, leaf dry matter content, wood density, leaf area, chlorophyll content, leaf nitrogen content, leaf phosphorus content, leaf potassium content, and nitrogen-phosphorus ratio) by decomposing species functional traits into alpha (within-community) and beta (among-communities) measure the impact of environmental gradients and the presence of other species on the variation of traits. Result: All nine functional traits showed some degree of differentiation in the forest communities, with a greater range of variation in alpha values than in beta values . Correlations were signiicantly different between the trait differences in the communities. The alpha values of each trait showed a higher correlation with other components than the beta values. The factors affecting intra-speciic trait variation were relatively complex. The alpha component had a more signiicant and stronger effect on intra-speciic trait variation compared to the beta component. Abiotic factors, such as soil nutrient content, soil nitrogen-phosphorus content, directly affected the beta component. In contrast, biotic factors, such as tree height variation, had a direct and stronger effect on the alpha component. Discussion: Our results demonstrate that alpha and beta components, as independent differentiation axes among coexisting species, have different sensitivities to different environmental factors and traits in different ecological strategies and spatial scales. Trait gradient analysis can more clearly reveal the variation patterns of species traits in communities, which will help to understand the scale effects and potential mechanisms of trait relationships.

Enhanced emulsification performance and interfacial properties of Janus-like rapeseed cruciferin through asymmetric acylation modification.

Plant protein emulsifiers, particularly rapeseed protein isolate with its superior amino acid composition and predominantly globular protein, have captured significant interest in the food industry. Nonetheless, the application of these proteins has been stymied by their lackluster emulsification properties. Addressing this challenge, our study implements an innovative asymmetric acylation technique to modify the surface of rapeseed cruciferin (RC), morphing it into a structure resembling Janus nanoparticles. This alteration amplifies the emulsification prowess of RC by a remarkable 2.7 times compared to its natural form, and 1.43 times over its conventionally acylated counterpart. The asymmetrically acylated RC, marked by a distinctive three-phase contact angle of 90.4°, manifests an outstanding amphiphilic character. Moreover, it surpasses both the natural and conventionally acylated RC in terms of diffusion, penetration, and rearrangement rates, as well as protein concentration at the oil-water interface. Compared to commonly used emulsifiers in the food industry, such as lecithin and soy protein, the asymmetrically acylated RC stands out, stabilizing emulsions with the tiniest particle size and effectively staving off emulsion stratification over a longer duration. This study underscores that asymmetric acylation serves as a reliable methodology for producing efficient plant protein emulsifiers, considerably amplifying their utility in the food industry.

Docosahexaenoic Acid-Acylated Astaxanthin Monoester Ameliorates Amyloid-ß Pathology and Neuronal Damage by Restoring Autophagy in Alzheimer's Disease Models.

SCOPE: Astaxanthin (AST) is ubiquitous in aquatic foods and microorganisms. The study previously finds that docosahexaenoic acid-acylated AST monoester (AST-DHA) improves cognitive function in Alzheimer's disease (AD), although the underlying mechanism remains unclear. Moreover, autophagy is reportedly involved in amyloid-ß (Aß) clearance and AD pathogenesis. Therefore, this study aims to evaluate the preventive effect of AST-DHA and elucidates the mechanism of autophagy modulation in Aß pathology. METHODS AND RESULTS: In the cellular AD model, AST-DHA significantly reduces toxic Aß1-42 levels and alleviated the accumulation of autophagic markers (LC3II/I and p62) in Aß25-35 -induced SH-SY5Y cells. Notably, AST-DHA restores the autophagic flux in SH-SY5YmRFP-GFP-LC3 cells. In APP/PS1 mice, a 3-month dietary supplementation of AST-DHA exceeded free-astaxanthin (F-AST) capacity to increase hippocampal and cortical autophagy. Mechanistically, AST-DHA restores autophagy by activating the ULK1 signaling pathway and restoring autophagy-lysosome fusion. Moreover, AST-DHA relieves ROS production and mitochondrial stress affecting autophagy in AD. As a favorable outcome of restored autophagy, AST-DHA mitigates cerebral Aß and p-Tau deposition, ultimately improving neuronal function. CONCLUSION: The findings demonstrate that AST-DHA can rectify autophagic impairment in AD, and confer neuroprotection in Aß-related pathology, which supports the future application of AST as an autophagic inducer for maintaining brain health.