Catabolism of 2-keto-3-deoxy-galactonate and the production of its enantiomers.

2-Keto-3-deoxy-galactonate (KDGal) serves as a pivotal metabolic intermediate within both the fungal D-galacturonate pathway, which is integral to pectin catabolism, and the bacterial DeLey-Doudoroff pathway for D-galactose catabolism. The presence of KDGal enantiomers, L-KDGal and D-KDGal, varies across these pathways. Fungal pathways generate L-KDGal through the reduction and dehydration of D-galacturonate, whereas bacterial pathways produce D-KDGal through the oxidation and dehydration of D-galactose. Two distinct catabolic routes further metabolize KDGal: a nonphosphorolytic pathway that employs aldolase and a phosphorolytic pathway involving kinase and aldolase. Recent findings have revealed that L-KDGal, identified in the bacterial catabolism of 3,6-anhydro-L-galactose, a major component of red seaweeds, is also catabolized by Escherichia coli, which is traditionally known to be catabolized by specific fungal species, such as Trichoderma reesei. Furthermore, the potential industrial applications of KDGal and its derivatives, such as pyruvate and D- and L-glyceraldehyde, are underscored by their significant biological functions. This review comprehensively outlines the catabolism of L-KDGal and D-KDGal across different biological systems, highlights stereospecific methods for discriminating between enantiomers, and explores industrial application prospects for producing KDGal enantiomers. KEY POINTS: • KDGal is a metabolic intermediate in fungal and bacterial pathways • Stereospecific enzymes can be used to identify the enantiomeric nature of KDGal • KDGal can be used to induce pectin catabolism or produce functional materials.

New insights into the dominance of mixed fermentation of Staphylococcus cohnii and Staphylococcus saprophyticus in Chinese bacon: Complete genomic and comparative genomic perspectives.

Previous studies have demonstrated that Staphylococcus cohnii WX_M8 and S. saprophyticus MY_A10 significantly enhanced the flavor of Chinese bacon in a mixed fermentation. However, due to the complexity of the processing, the contribution of the bacteria is deceptive when investigating only the phenotypic changes at the time of fermentation. In order to clarify the metabolic mechanisms of mixed fermentation, a technological characterization, whole genome and comparative genomics analysis, and metabolites were approached in this study. Results showed that differences in tolerance characteristics existed between WX_M8 and MY_A10. And the genomes of both the two strains consisted of one chromosome and four circular plasmids. Their genome sizes were 2.74 Mp and 2.62 Mp, the GC contents were 32.45% and 33.18%, and the predicted coding genes (CDS) were 2564 and 2541, respectively. Based on the annotation of gene functions and assessment of metabolic pathways in the KEGG database, WX_M8 and MY_A10 strains were found to harbor complete protein degradation and amino acid metabolic pathways, pyruvate and butanol metabolic pathways, and isoleucine metabolic pathways, and their diverse enzyme-encoding genes superimposed the metabolic functions, whereas the alcohol dehydrogenase genes, adh and frmA, achieved complementary functions in the production of esters. Comparative genomics analysis revealed a diversity of encoding genes of aminotransferases and a greater metabolism for sulfur-containing amino acids, aromatic amino acids, and branched-chain amino acids in the mixed fermentation of strains WX_M8 and MY_A10. Metabolites analysis showed that MY_A10 focused on the production of soluble peptides and free amino acids (FAAs), while WX_M8 focused on volatile organic compounds (VOCs), resulting in a significant enhancement of the flavor of Chinese bacon when the two were mixed fermented. This result may provide direction for strains WX_M8 and MY_A10 to be used as starter cultures and targeted to regulate flavor.

Novel aspects of ethylene glycol catabolism.

Ethylene glycol (EG) is an industrially important two-carbon diol used as a solvent, antifreeze agent, and building block of polymers such as poly(ethylene terephthalate) (PET). Recently, the use of EG as a starting material for the production of bio-fuels or bio-chemicals is gaining attention as a sustainable process since EG can be derived from materials not competing with human food stocks including CO2, syngas, lignocellulolytic biomass, and PET waste. In order to design and construct microbial process for the conversion of EG to value-added chemicals, microbes capable of catabolizing EG such as Escherichia coli, Pseudomonas putida, Rhodococcus jostii, Ideonella sakaiensis, Paracoccus denitrificans, and Acetobacterium woodii are candidates of chassis for the construction of synthetic pathways. In this mini-review, we describe EG catabolic pathways and catabolic enzymes in these microbes, and further review recent advances in microbial conversion of EG to value-added chemicals by means of metabolic engineering. KEY POINTS: • Ethylene glycol is a potential next-generation feedstock for sustainable industry. • Microbial conversion of ethylene glycol to value-added chemicals is gaining attention. • Ethylene glycol-utilizing microbes are useful as chassis for synthetic pathways.

Heat-stress-responsive HvHSFA2e gene regulates the heat and drought tolerance in barley through modulation of phytohormone and secondary metabolic pathways.

KEY MESSAGE: The heat stress transcription factor HSFA2e regulates both temperature and drought response via hormonal and secondary metabolism alterations. High temperature and drought are the primary yield-limiting environmental constraints for staple food crops. Heat shock transcription factors (HSF) terminally regulate the plant abiotic stress responses to maintain growth and development under extreme environmental conditions. HSF genes of subclass A2 predominantly express under heat stress (HS) and activate the transcriptional cascade of defense-related genes. In this study, a highly heat-inducible HSF, HvHSFA2e was constitutively expressed in barley (Hordeum vulgare L.) to investigate its role in abiotic stress response and plant development. Transgenic barley plants displayed enhanced heat and drought tolerance in terms of increased chlorophyll content, improved membrane stability, reduced lipid peroxidation, and less accumulation of ROS in comparison to wild-type (WT) plants. Transcriptome analysis revealed that HvHSFA2e positively regulates the expression of abiotic stress-related genes encoding HSFs, HSPs, and enzymatic antioxidants, contributing to improved stress tolerance in transgenic plants. The major genes of ABA biosynthesis pathway, flavonoid, and terpene metabolism were also upregulated in transgenics. Our findings show that HvHSFA2e-mediated upregulation of heat-responsive genes, modulation in ABA and flavonoid biosynthesis pathways enhance drought and heat stress tolerance.

Targeted suppression of MEP pathway genes DXS, IspD and IspF to explore the mycobacterial metabolism and survival.

Due to the uniqueness and essentiality of MEP pathway for the synthesis of crucial metabolites- isoprenoids, hopanoids, menaquinone etc. in mycobacterium, enzymes of this pathway are considered promising anti-tubercular drug targets. In the present study we seek to understand the consequences of downregulation of three of the essential genes- DXS, IspD, and IspF of MEP pathway using CRISPRi approach combined with transcriptomics in Mycobacterium smegmatis. Conditional knock down of either DXS or IspD or IspF gene showed strong bactericidal effect and a profound change in colony morphology. Impaired MEP pathway due to downregulation of these genes increased the susceptibility to frontline anti-tubercular drugs. Further, reduced EtBr accumulation in all the knock down strains in the presence and absence of efflux inhibitor indicated altered cell wall topology. Subsequently, transcriptional analysis validated by qRT-PCR of +154DXS, +128IspD, +104IspF strains showed that modifying the expression of these MEP pathway enzymes affects the regulation of mycobacterial core components. Among the DEGs, expression of small and large ribosomal binding proteins (rpsL, rpsJ, rplN, rplX, rplM, rplS, etc), essential protein translocases (secE, secY and infA, infC), transcriptional regulator (CarD and SigB) and metabolic enzymes (acpP, hydA, ald and fabD) were significantly depleted causing the bactericidal effect. However, mycobacteria survived under these damaging conditions by upregulating mostly the genes needed for the repair of DNA damage (DNA polymerase IV, dinB), synthesis of essential metabolites (serB, LeuA, atpD) and those strengthening the cell wall integrity (otsA, murA, D-alanyl-D-alanine dipeptidase etc.).

Multi-omics reveals new links between Fructosamine-3-Kinase (FN3K) and core metabolic pathways.

Fructosamine-3-kinases (FN3Ks) are a conserved family of repair enzymes that phosphorylate reactive sugars attached to lysine residues in peptides and proteins. Although FN3Ks are present across the Tree of Life and share detectable sequence similarity to eukaryotic protein kinases, the biological processes regulated by these kinases are largely unknown. To address this knowledge gap, we leveraged the FN3K CRISPR Knock-Out (KO) HepG2 cell line alongside an integrative multi-omics study combining transcriptomics, metabolomics, and interactomics to place these enzymes in a pathway context. The integrative analyses revealed the enrichment of pathways related to oxidative stress response, lipid biosynthesis (cholesterol and fatty acids), and carbon and co-factor metabolism. Moreover, enrichment of nicotinamide adenine dinucleotide (NAD) binding proteins and localization of human FN3K (HsFN3K) to mitochondria suggests potential links between FN3K and NAD-mediated energy metabolism and redox balance. We report specific binding of HsFN3K to NAD compounds in a metal and concentration-dependent manner and provide insight into their binding mode using modeling and experimental site-directed mutagenesis. Our studies provide a framework for targeting these understudied kinases in diabetic complications and metabolic disorders where redox balance and NAD-dependent metabolic processes are altered.

Model-driven characterization of functional diversity of Pseudomonas aeruginosa clinical isolates with broadly representative phenotypes.

Pseudomonas aeruginosa is a leading cause of infections in immunocompromised individuals and in healthcare settings. This study aims to understand the relationships between phenotypic diversity and the functional metabolic landscape of P. aeruginosa clinical isolates. To better understand the metabolic repertoire of P. aeruginosa in infection, we deeply profiled a representative set from a library of 971 clinical P. aeruginosa isolates with corresponding patient metadata and bacterial phenotypes. The genotypic clustering based on whole-genome sequencing of the isolates, multilocus sequence types, and the phenotypic clustering generated from a multi-parametric analysis were compared to each other to assess the genotype-phenotype correlation. Genome-scale metabolic network reconstructions were developed for each isolate through amendments to an existing PA14 network reconstruction. These network reconstructions show diverse metabolic functionalities and enhance the collective P. aeruginosa pangenome metabolic repertoire. Characterizing this rich set of clinical P. aeruginosa isolates allows for a deeper understanding of the genotypic and metabolic diversity of the pathogen in a clinical setting and lays a foundation for further investigation of the metabolic landscape of this pathogen and host-associated metabolic differences during infection.

A complex metabolic network and its biomarkers regulate laccase production in white-rot fungus Cerrena unicolor 87613.

BACKGROUND: White-rot fungi are known to naturally produce high quantities of laccase, which exhibit commendable stability and catalytic efficiency. However, their laccase production does not meet the demands for industrial-scale applications. To address this limitation, it is crucial to optimize the conditions for laccase production. However, the regulatory mechanisms underlying different conditions remain unclear. This knowledge gap hinders the cost-effective application of laccases. RESULTS: In this study, we utilized transcriptomic and metabolomic data to investigate a promising laccase producer, Cerrena unicolor 87613, cultivated with fructose as the carbon source. Our comprehensive analysis of differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) aimed to identify changes in cellular processes that could affect laccase production. As a result, we discovered a complex metabolic network primarily involving carbon metabolism and amino acid metabolism, which exhibited contrasting changes between transcription and metabolic patterns. Within this network, we identified five biomarkers, including succinate, serine, methionine, glutamate and reduced glutathione, that played crucial roles in co-determining laccase production levels. CONCLUSIONS: Our study proposed a complex metabolic network and identified key biomarkers that determine the production level of laccase in the commercially promising Cerrena unicolor 87613. These findings not only shed light on the regulatory mechanisms of carbon sources in laccase production, but also provide a theoretical foundation for enhancing laccase production through strategic reprogramming of metabolic pathways, especially related to the citrate cycle and specific amino acid metabolism.

Microbial community changes and metabolic pathways analysis during waste activated sludge and meat processing waste anaerobic co-digestion.

Waste activated sludge (WAS) and meat processing waste (MPW) were acted as co-substrates in anaerobic co-digestion (AcD), and biochemical methane potential (BMP) test was carried out to investigate the methane production performances. Microbial community structure and metabolic pathways analyses were conducted by 16S rRNA high-throughput sequencing and functional prediction analysis. BMP test results indicated that AcD of 70% WAS+30% MPW and 50% WAS+50% MPW (VS/VS) could significantly improve methane yield to 371.05 mL/g VS and 599.61 mL/g VS, respectively, compared with WAS acting as sole substrate (191.87 mL/g VS). The results of microbial community analysis showed that Syntrophomonas and Petrimonas became the dominant bacteria genera, and Methanomassiliicoccus and Methanobacterium became the dominant archaea genera after MPW addition. 16S functional prediction analysis results indicated that genes expression of key enzymes involved in syntrophic acetate oxidation (SAO), hydrogenotrophic and methylotrophic methanogenesis were up-regulated, and acetoclastic methanogenesis was inhibited after MPW addition. Based on these analyses, it could be inferred that SAO combined with hydrogenotrophic and methylotrophic methanogenesis was the dominant pathway for organics degradation and methane production during AcD. These findings provided systematic insights into the microbial community changes and metabolic pathways during AcD of WAS and MPW.

Identification of Anticancer Enzymes and Biomarkers for Hepatocellular Carcinoma through Constraint-Based Modeling.

Hepatocellular carcinoma (HCC) results in the abnormal regulation of cellular metabolic pathways. Constraint-based modeling approaches can be utilized to dissect metabolic reprogramming, enabling the identification of biomarkers and anticancer targets for diagnosis and treatment. In this study, two genome-scale metabolic models (GSMMs) were reconstructed by employing RNA sequencing expression patterns of hepatocellular carcinoma (HCC) and their healthy counterparts. An anticancer target discovery (ACTD) framework was integrated with the two models to identify HCC targets for anticancer treatment. The ACTD framework encompassed four fuzzy objectives to assess both the suppression of cancer cell growth and the minimization of side effects during treatment. The composition of a nutrient may significantly affect target identification. Within the ACTD framework, ten distinct nutrient media were utilized to assess nutrient uptake for identifying potential anticancer enzymes. The findings revealed the successful identification of target enzymes within the cholesterol biosynthetic pathway using a cholesterol-free cell culture medium. Conversely, target enzymes in the cholesterol biosynthetic pathway were not identified when the nutrient uptake included a cholesterol component. Moreover, the enzymes PGS1 and CRL1 were detected in all ten nutrient media. Additionally, the ACTD framework comprises dual-group representations of target combinations, pairing a single-target enzyme with an additional nutrient uptake reaction. Additionally, the enzymes PGS1 and CRL1 were identified across the ten-nutrient media. Furthermore, the ACTD framework encompasses two-group representations of target combinations involving the pairing of a single-target enzyme with an additional nutrient uptake reaction. Computational analysis unveiled that cell viability for all dual-target combinations exceeded that of their respective single-target enzymes. Consequently, integrating a target enzyme while adjusting an additional exchange reaction could efficiently mitigate cell proliferation rates and ATP production in the treated cancer cells. Nevertheless, most dual-target combinations led to lower side effects in contrast to their single-target counterparts. Additionally, differential expression of metabolites between cancer cells and their healthy counterparts were assessed via parsimonious flux variability analysis employing the GSMMs to pinpoint potential biomarkers. The variabilities of the fluxes and metabolite flow rates in cancer and healthy cells were classified into seven categories. Accordingly, two secretions and thirteen uptakes (including eight essential amino acids and two conditionally essential amino acids) were identified as potential biomarkers. The findings of this study indicated that cancer cells exhibit a higher uptake of amino acids compared with their healthy counterparts.

Unlocking the formate utilization of wild-type Yarrowia lipolytica through adaptive laboratory evolution.

Synthetic biology is contributing to the advancement of the global net-negative carbon economy, with emphasis on formate as a member of the one-carbon substrate garnering substantial attention. In this study, we employed base editing tools to facilitate adaptive evolution, achieving a formate tolerance of Yarrowia lipolytica to 1 M within 2 months. This effort resulted in two mutant strains, designated as M25-70 and M25-14, both exhibiting significantly enhanced formate utilization capabilities. Transcriptomic analysis revealed the upregulation of nine endogenous genes encoding formate dehydrogenases when cultivated utilizing formate as the sole carbon source. Furthermore, we uncovered the pivotal role of the glyoxylate and threonine-based serine pathway in enhancing glycine supply to promote formate assimilation. The full potential of Y. lipolytica to tolerate and utilize formate establishing the foundation for pyruvate carboxylase-based carbon sequestration pathways. Importantly, this study highlights the existence of a natural formate metabolic pathway in Y. lipolytica.

Historic obstacles and emerging opportunities in the field of developmental metabolism - lessons from Heidelberg.

The field of developmental metabolism is experiencing a technological revolution that is opening entirely new fields of inquiry. Advances in metabolomics, small-molecule sensors, single-cell RNA sequencing and computational modeling present new opportunities for exploring cell-specific and tissue-specific metabolic networks, interorgan metabolic communication, and gene-by-metabolite interactions in time and space. Together, these advances not only present a means by which developmental biologists can tackle questions that have challenged the field for centuries, but also present young scientists with opportunities to define new areas of inquiry. These emerging frontiers of developmental metabolism were at the center of a highly interactive 2023 EMBO workshop 'Developmental metabolism: flows of energy, matter, and information'. Here, we summarize key discussions from this forum, emphasizing modern developmental biology's challenges and opportunities.

[Advances in the biosynthesis and metabolic regulation of terpenoids in Saccharomyces cerevisiae].

Terpenoids are the one of most abundant natural products. With diverse varieties and biological activities, they are widely used in the food, medicine, chemical industry, and novel fuels. However, the conventional methods such as plant extraction and chemical synthesis cannot meet the current market demand for terpenoids. Efficient microbial cell factories, especially engineered Saccharomyces cerevisiae strains, have been constructed for the industrial production of terpenoids. In recent years, researchers have constructed multiple S. cerevisiae strains with increased yield and productivity via approaches of synthetic biology and metabolic engineering. This paper reviews the recent progress in the biosynthesis of terpenoids in S. cerevisiae cells and summarizes a variety of metabolic engineering strategies for the production of terpenoids in S. cerevisiae. These strategies include the construction and optimization of metabolic pathways, the mining and modification of key enzymes, the regeneration of cofactors, the engineering of cell localization and cell efflux, and the improvement of cell tolerance. Our review will provide information and strategies for the effective biosynthesis of terpenoids in S. cerevisiae.

[Comparative metabolomics analysis of metabolic pathways in the high-yielding mutant strain of avilamycin].

Avilamycin (AVI) is an oligosaccharide antibiotic that has strong inhibitory effect on Gram-positive bacteria. It is widely used in livestock and poultry farming. However, the use of traditional breeding techniques and immature fermentation process have become the key factors limiting its commercialization. In this study, we used comparative metabolomics techniques to examine the difference in intracellular metabolism between a high-yield AVI mutant strain modified by ribosome engineering technology and the parental strain. GC-MS analysis was conducted on mycelia samples taken on days 4, 6, and 8 of fermentation, resulting in the detection of a total of 112 compounds. After comparison with the NIST library, 29 intracellular metabolites were accurately identified. Two-dimensional principal component analysis (PCA) revealed significant differences in metabolites between the mutant strain and the parental strain at different time points. Orthogonal partial least squares-discriminant analysis (OPLS-DA) identified 11 intracellular metabolites that were closely related to AVI biosynthesis. KEGG metabolic pathway enrichment analysis showed that avilamycin synthesis was closely related to carbohydrate metabolism and amino acid metabolism. Six key differential metabolites were selected: L-valine, L-serine, L-alanine, D-galactose, D-cellobiose, and D-glucose. Upregulation of these metabolites in the mutant strain enhanced its metabolic flow for AVI synthesis. After 8 days of fermentation, the mutant strain produced 76.86% more AVI than the parental strain. The findings of this study serve as reference for the future rational optimization of avilamycin fermentation.

Multistationarity questions in reduced versus extended biochemical networks.

We address several questions in reduced versus extended networks via the elimination or addition of intermediate complexes in the framework of chemical reaction networks with mass-action kinetics. We clarify and extend advances in the literature concerning multistationarity in this context, mainly from Feliu and Wiuf (J R Soc Interface 10:20130484, 2013), Sadeghimanesh and Feliu (Bull Math Biol 81:2428-2462, 2019), Pérez Millán and Dickenstein (SIAM J Appl Dyn Syst 17(2):1650-1682, 2018), Dickenstein et al. (Bull Math Biol 81:1527-1581, 2019). We establish general results about MESSI systems, which we use to compute the circuits of multistationarity for significant biochemical networks.

Potential Metabolic Pathways Involved in Osteoporosis and Evaluation of Fracture Risk in Individuals with Diabetes.

Diabetes has a significant global prevalence. Chronic hyperglycemia affects multiple organs and tissues, including bones. A large number of diabetic patients develop osteoporosis; however, the precise relationship between diabetes and osteoporosis remains incompletely elucidated. The activation of the AGE-RAGE signaling pathway hinders the differentiation of osteoblasts and weakens the process of bone formation due to the presence of advanced glycation end products. High glucose environment can induce ferroptosis of osteoblasts and then develop osteoporosis. Hyperglycemia also suppresses the secretion of sex hormones, and the reduction of testosterone is difficult to effectively maintain bone mineral density. As diabetes therapy, thiazolidinediones control blood glucose by activating PPAR-γ. Activated PPAR-γ can promote osteoclast differentiation and regulate osteoblast function, triggering osteoporosis. The effects of metformin and insulin on bone are currently controversial. Currently, there are no appropriate tools available for assessing the risk of fractures in diabetic patients, despite the fact that the occurrence of osteoporotic fractures is considerably greater in diabetic individuals compared to those without diabetes. Further improving the inclusion criteria of FRAX risk factors and clarifying the early occurrence of osteoporosis sites unique to diabetic patients may be an effective way to diagnose and treat diabetic osteoporosis and reduce the risk of fracture occurrence.

Emerging roles of long noncoding RNAs in enzymes related intracellular metabolic pathways in cancer biology.

Metabolic reprogramming plays critical roles in the development and progression of tumor by providing cancer cells with a sufficient supply of nutrients and other factors needed for fast-proliferating. Emerging evidence indicates that long noncoding RNAs (lncRNAs) are involved in the initiation of metastasis via regulating the metabolic reprogramming in various cancers. In this paper, we aim to summarize that lncRNAs could participate in intracellular nutrient metabolism including glucose, amino acid, lipid, and nucleotide, regardless of whether lncRNAs have tumor-promoting or tumor-suppressor function. Meanwhile, modulation of lncRNAs in glucose metabolic enzymes in glycolysis, pentose phosphate pathway and tricarboxylic acid cycle (TCA) in cancer is reviewed. We also discuss therapeutic strategies targeted at interfering with enzyme activity to decrease the utilization of glucoses, amino acid, nucleotide acid and lipid in tumor cells. This review focuses on our current understanding of lncRNAs participating in cancer cell metabolic reprogramming, paving the way for further investigation into the combination of such approaches with existing anti-cancer therapies.

Metabolomic and transcriptomic analyses highlight metabolic regulatory networks of Salvia miltiorrhiza in response to replant disease.

BACKGROUND: Salvia miltiorrhiza, a well-known traditional Chinese medicine, frequently suffers from replant diseases that adversely affect its quality and yield. To elucidate S. miltiorrhiza's metabolic adaptations to replant disease, we analyzed its metabolome and transcriptome, comparing normal and replant diseased plants for the first time. RESULTS: We identified 1,269 metabolites, 257 of which were differentially accumulated metabolites, and identified 217 differentially expressed genes. Integrated transcriptomic and metabolomic analyses revealed a significant up-regulation and co-expression of metabolites and genes associated with plant hormone signal transduction and flavonoid biosynthesis pathways in replant diseases. Within plant hormone signal transduction pathway, plants afflicted with replant disease markedly accumulated indole-3-acetic acid and abscisic acid, correlating with high expression of their biosynthesis-related genes (SmAmidase, SmALDH, SmNCED, and SmAAOX3). Simultaneously, changes in hormone concentrations activated plant hormone signal transduction pathways. Moreover, under replant disease, metabolites in the local flavonoid metabolite biosynthetic pathway were significantly accumulated, consistent with the up-regulated gene (SmHTC1 and SmHTC2). The qRT-PCR analysis largely aligned with the transcriptomic results, confirming the trends in gene expression. Moreover, we identified 10 transcription factors co-expressed with differentially accumulated metabolites. CONCLUSIONS: Overall, we revealed the key genes and metabolites of S. miltiorrhiza under replant disease, establishing a robust foundation for future inquiries into the molecular responses to combat replant stress.

Metabolic Regulation of Endothelial Cells: A New Era for Treating Wet Age-Related Macular Degeneration.

Wet age-related macular degeneration (wet AMD) is a primary contributor to visual impairment and severe vision loss globally, but the prevailing treatments are often unsatisfactory. The development of conventional treatment strategies has largely been based on the understanding that the angiogenic switch of endothelial cells (ECs) is mainly dictated by angiogenic growth factors. Even though treatments targeting vascular endothelial growth factor (VEGF), like ranibizumab, are widely administered, more than half of patients still exhibit inadequate or null responses, suggesting the involvement of other pathogenic mechanisms. With advances in research in recent years, it has become well recognized that EC metabolic regulation plays an active rather than merely passive responsive role in angiogenesis. Disturbances of these metabolic pathways may lead to excessive neovascularization in angiogenic diseases such as wet AMD, therefore targeted modulation of EC metabolism represents a promising therapeutic strategy for wet AMD. In this review, we comprehensively discuss the potential applications of EC metabolic regulation in wet AMD treatment from multiple perspectives, including the involvement of ECs in wet AMD pathogenesis, the major endothelial metabolic pathways, and novel therapeutic approaches targeting metabolism for wet AMD.

Untargeted Metabolome Analyses Revealed Potential Metabolic Mechanisms of Leymus chinensis in Response to Simulated Animal Feeding.

Leymus chinensis (Trin.) Tzvel., also known as the "Alkali Grass", is a major forage grass in the eastern and northeastern steppe vegetation in the Songnen Prairie. It is of great practical significance for grassland management to understand the influence of animal saliva on L. chinensis during animal feeding. In this study, we used clipping and daubing animal saliva to simulate responses to grazing by L. chinensis, and analyzed the physiological and metabolomic changes in response to simulated animal feeding. Results showed that the effects of animal saliva on physiological and metabolic processes of the treated plants produced a recovery phenomenon. Moreover, the effects of animal saliva produced a large number of differential metabolites related to several known metabolic pathways, among which the flavonoid biosynthesis pathway has undergone significant and persistent changes. We posit that the potential metabolic mechanisms of L. chinensis in response to simulated animal feeding are closely related to flavonoid biosynthesis.