Fatty Acid Synthesis Research Articles

Metabolome-Wide Mendelian Randomization Assessing the Causal Relationship Between Blood Metabolites and Primary Ovarian Insufficiency

Background & aimsPrimary ovarian insufficiency (POI) is a significant clinical syndrome that leads to female infertility, and its incidence continues to increase. We used metabolome-specific Mendelian randomization (MR) to identify causally associated metabolites and explore the relationship between candidate metabolites and upstream genetic variations. MethodsThe primary MR analysis utilized the inverse variance weighted (IVW) method as the primary approach to assess the causal relationship between exposure and POI. Multiple sensitivity analyses included MR-Egger, weighted median, and weighted mode methods. ResultsAfter using genetic variants as probes, we identified 27 metabolites of 278 that are associated with the risk of POI, including dodecanedioate (OR 0.052, 95% CI 0.010 – 0.265; P < 0.001), adrenate (OR 0.113, 95% CI 0.016 – 0.822; P = 0.031), indolepropionate (OR 0.174, 95% CI 0.051 – 0.593; P = 0.005), homocitrulline (OR 0.194, 95% CI 0.051 – 0.741; P = 0.016), and 3-methylhistidine (OR 0.404, 95% CI 0.193 – 0.848; P = 0.017). Our study indicated the presence of heterogeneity; therefore, we employed the IVW random-effects model as the primary approach. KEGG pathway enrichment analysis identified six significant metabolic pathways, primarily including biosynthesis of unsaturated fatty acids, phenylalanine, tyrosine and tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, linoleic acid metabolism, valine, leucine and isoleucine biosynthesis, ubiquinone and other terpenoid-quinone biosynthesis. ConclusionsBy integrating genomics and metabolomics, this study provides novel insights into the causal relationship linking circulating metabolites and the onset of POI.

Distinct interspecies thermal resistance strategies exhibited by euplanktonic, tychoplanktonic and benthic diatoms under marine heatwaves

Extreme climate events, such as marine heatwaves (MHWs), are expected to occur more frequently and intensely in the future, resulting in a substantial impact on marine life. The way that diatoms respond to MHWs may have crucial effects on global primary production and biogeochemical cycles. Euplanktonic diatoms appear to benefit from MHWs directly, but this phenomenon needs an explanation. As concerns tychoplanktonic and benthic diatoms, no studies have been addressed on their thermal response strategies. To address this, we investigated the responses and underlying mechanisms of three typical growth forms of diatoms, Pseudo-nitzschia multiseries (euplanktonic), Paralia guyana (tychoplanktonic) and Navicula avium (benthic), under heat stress by combining a growth experiment with transcriptomic analysis. Our results showed that the physiological responses of diatoms to MHWs and underlying molecular mechanisms are largely related to their growth forms. The euplanktonic diatom was first depressed, but then had a distinct increase in the growth rate accompanied by inducing zeatin and unsaturated fatty acid biosynthesis and repressing substance assimilation and energy metabolism. Contrarily, the benthic diatom showed elevated substance and energy demands for macromolecules accumulation by reducing cell division and increasing photosynthesis and nitrogen assimilation. The tychoplanktonic diatom exhibited higher physiological plasticity to maintain growth and cellular homeostasis. Our results indicate the increased rate of cell division in euplanktonic diatoms under heat stress is likely an emergency response strategy promoting diatom dispersal for survival, but at the cost of disturbances of metabolic balance.

Molecular Binding of Cycloxydim to Acetyl-CoA Carboxylase in Cultivated Soybeans and Weed Plants

Acetyl-CoA carboxylase (ACC) is one of the main enzymes that play a regulatory role in the biosynthesis of fatty acids in plants. Cyclodime is one of the herbicides that is an inhibitor of this enzyme. Some weedy cereal plants, such as common hedgehog (Echinochloa crus-galli L.) and annual bluegrass (Poa annua L.), are resistant to cycloxyme. Other types of grass weeds – blood-red dewdrop (Digitaria sanguinalis (L.) Scop.) and green bristle (Setaria viridis (L.) P. Beauv.), on the contrary, are susceptible to the herbicide. The molecular mechanisms underlying ACC resistance are poorly understood. The explanation of the mechanism of resistance probably lies in the structure of ACC in different species. The use of bioinformatics methods will help to understand the mechanisms of adaptation based on the molecular properties of the enzyme, which will contribute to the creation of new herbicides. The purpose of this work was to study the specifics of the binding of cycloxydime to the ACC enzyme for each of these weed species, including soy (Glycine max (L.) Merr.). For weeds E. crus-galli and P. annua revealed from 6 to 7 possible complexes with different ligand positions relative to the receptor, which could potentially explain the mechanism of resistance. At the same time, a low binding energy was determined for the cycloxydime complex with G. max (up to –7.31 kcal/mol), which demonstrates the presence of other resistance mechanisms in the culture.

Differential regulation of the phenylpropanoid pathway highly contributes to the susceptibility of chilling-induced necrotic peel disorders in cold-stored hardy kiwifruit

Fruit of hardy kiwifruit cultivars respond differently to chilling stress during cold storage. Therefore, this study aimed to evaluate the differential responses of fruit quality attributes, physiological disorders, and untargeted and targeted metabolites of two contrasting hardy kiwifruit cultivars, ‘Greenheart’ and ‘Daebo’ during cold storage. During cold storage, the ‘Daebo’ cultivar exhibited more severe symptoms of chilling injury, such as peel browning and peel pitting, compared to the ‘Greenheart’ cultivar. Untargeted and targeted metabolic analyses indicated that syringic acid, total phenolic compounds, total flavonoids, catechin, rutin, ferulic acid, quinic acid, citramalic acid, and isoquercitrin levels were higher in ‘Greenheart’ compared to ‘Daebo’ during cold storage. However, citric, isocitric, and threonic acids, gamma-aminobutyric acid, cysteine, β-alanine, titratable acidity, epicatechin, and proline were high in the ‘Daebo’ cultivar. Peel browning and pitting were positively correlated with soluble carbohydrates, organic acids, and amino acids but negatively correlated with individual phenolic compounds in ‘Daebo’ cultivar. The tricarboxylic acid cycle, glyoxylate and dicarboxylate metabolism, arginine and proline metabolism, biosynthesis of unsaturated fatty acids, arginine biosynthesis, and alanine, aspartate, and glutamate metabolism were upregulated in the ‘Daebo’ cultivar, whereas the phenylpropanoid pathway was upregulated in the ‘Greenheart’ cultivar. Our study showed that differentially upregulated pathways could lead to the contrasting development of necrotic peel disorders in these two hardy kiwifruit cultivars during cold storage. Our results suggest that the distinctive responses of metabolic analyses to chilling stress can contribute to susceptibility in chilling-induced necrotic peel disorders in cold-stored fruit of the ‘Daebo’ hardy kiwifruit cultivar.

Jingfang Granules alleviates the lipid peroxidation induced ferroptosis in rheumatoid arthritis rats by regulating gut microbiota and metabolism of short chain fatty acids

BackgroundRheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation, bone and cartilage damage, musculoskeletal pain, swelling, and stiffness. Inflammation is one of the key factors that induce RA. Jingfang Granule (JFG) is a traditional Chinese medicine (TCM) with significant anti-inflammatory effects. Clinical studies have confirmed that JFG can be used to treat RA, but the mechanism is still vague. PurposeThis study was designed to evaluate the protective function and the mechanism of JFG on rats with RA. Study design and methodsComplete Freud's Adjuvant (CFA) was used to establish a rat RA model, and JFG or Diclofenac Sodium (Dic) was orally administered. Foot swelling and hematoxylin eosin (H&E) staining were used to test the therapeutic effect of JFG on RA treatment, while ELISA kits were used to detect serum cytokines. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), and reactive oxygen species (ROS) were used to evaluate oxidative stress levels. The integration of label-free proteomics, fecal short chain fatty acid (SCFA) targeted metabolomics, peripheral blood SCFA, medium and long chain fatty acid targeted metabolomics, and 16S rDNA sequencing of gut microbiota were used to screen the mechanism. Western blot technology was used to validate the results of multiple omics studies. Serum D-Lactic acid, lipopolysaccharide specific IgA antibody (LPS IgA), diamine oxidase (DAO), and colon Claudin 5 and ZO-1 were used to evaluate the intestinal barrier. ResultsThe results confirmed that JFG effectively protected rats from RA injury, which was confirmed by improved foot swelling and synovial pathology. At the same time, JFG reduced the levels of TNF-α, IL-1β, and IL-6 in serum by inhibiting the NLRP3 inflammasome signaling pathway and TLR4/NF-κB signaling pathway in synovial tissue. Multiple omics studies indicated that JFG increased the abundance of gut microbiota and regulated the number of gut bacteria, thereby increased the levels of Acetic acid, Propionic acid, and Butyric acid in the gut and serum of RA rats, which activated AMPK to regulate fatty acid metabolism and fatty acid biosynthesis, thereby inhibited lipid oxidative stress induced ferroptosis to improve tissue damage caused by RA. Meanwhile, JFG improved the intestinal barrier by upregulating the expresses of Claudin 5 and ZO-1, which was confirmed by low concentrations of D-Lactic acid, LPS-SIgA and DAO in serum. ConclusionsThis study confirmed that JFG improved the disturbance of fatty acid metabolism by modulating gut microbiota and the production of fecal SCFAs to activate AMPK, and then inhibited ferroptosis caused by lipid oxidative stress in synovium tissue and prevented AR injury. This study proposes for the first time to investigate the mechanism of JFG treatment for RA from the perspective of the "Gut-joint" axis, and provides a promising approach for the treatment of RA.

BAMBI Is a Prognostic Biomarker Associated with Macrophage Polarization, Glycolysis, and Lipid Metabolism in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. Affected patients have poor prognoses due to high rates of post-surgical recurrence and metastasis. Bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) reportedly contributes to the development and progression of various human cancers. Thus far, there have been no comprehensive studies regarding the expression of BAMBI in HCC; similarly, no studies have investigated the prognostic significance of BAMBI and its associated mechanisms in HCC. In this study, we analyzed the expression profiles of BAMBI, along with its contributions to pathological findings, metastasis characteristics, and prognosis, in multiple human cancers. We found that upregulation of BAMBI was associated with poor prognosis in HCC. Next, we explored the associations of BAMBI with multiple cell signaling pathways, immune cells, and immune checkpoints in HCC. The results showed that BAMBI was associated with tumor proliferation, epithelial–mesenchymal transition (EMT) markers, glycolysis, fatty acid biosynthesis and degradation pathways, and immune checkpoint regulation in HCC. In vitro and in vivo experiments showed that BAMBI promoted polarization of M1 macrophages and is linked to the expression of key genes involved in glycolipid metabolism. Furthermore, protein–protein interaction analysis suggested that BAMBI plays multiple roles in HCC by regulating genes in the transforming growth factor (TGF)-β and Wnt signaling pathways. Our findings elucidated that BAMBI is a prognostic biomarker and is associated with macrophage polarization, glycolysis, and lipid metabolism in HCC.

Molecular profiling and biochemical characterization of Brassica napus advanced lines for enhanced polyunsaturated fatty acid production

BackgroundBrassica napus (rapeseed) is a globally significant oilseed crop known for its rich polyunsaturated fatty acid (PUFA) content, which is essential for human health and industrial applications. This study provides a comprehensive molecular and biochemical characterization of 45 advanced B. napus lines, using 11 simple sequence repeat (SSR) markers to explore genetic diversity and gas chromatography–mass spectrometry (GC–MS) to analyze fatty acid profiles.Methods and resultsThe seeds, derived from F6 generation crossbreeding of local and Canadian varieties with low erucic acid content, were grown under controlled conditions. Genomic DNA was extracted using a standard CTAB method and analyzed with SSR primers to detect polymorphisms associated with fatty acid synthesis. This study identified BRMS-287 as a novel, highly prevalent marker, detected in 97% of the lines, and highlighted its potential linkage to desirable oil quality traits. Conversely, BRMS-056 showed the lowest average frequency (75%). Fatty acid profiling revealed significant variation in oleic, linoleic, and linolenic acid content, with 74% of lines meeting industry standards for low saturated fatty acids (< 7%) and desirable erucic acid levels (< 5%).ConclusionsThis research provides new insights into the genetic basis of fatty acid composition in B. napus, highlighting the potential of BRMS-287 marker for breeding programs aimed at enhancing oil quality. The findings suggest a path forward for developing B. napus lines with improved PUFA content and reduced undesirable fatty acids, which could have significant implications for health and industry.

Identification of differentially expressed genes and polymorphisms related to intramuscular oleic-to-stearic fatty acid ratio in pigs.

The intramuscular oleic-to-stearic fatty acid ratio (C18:1n-9/C18:0) is an important indicator of the biosynthesis and desaturation of fatty acids in muscle. By using an RNA-Seq approach in muscle samples from 32 BC1_DU (25% Iberian and 75% Duroc) pigs with divergent values (high: H and low: L) of C18:1n-9/C18:0 fatty acids ratio, a total of 81 differentially expressed genes (DEGs) were identified. Functional analyses of DEGs indicate that mainly peroxisome proliferator-activated receptor signaling pathway (associated genes: PPARG, SCD, PLIN1, and FABP3) was overrepresented. Notably, SCD is directly involved in the conversion of C18:0 to C18:1n-9, and PPARG is a transcription factor regulating lipid metabolism genes, including SCD. However, other DEGs (e.g., ACADVL, FADS3, EPHB2, HGFAC, NGFR, NR0B2, MDH1, MMAA, PPP1R1B, SFRP5, RAB30, and TRARG1) are plausible candidate genes to explain the phenotypic differences of the C18:1n-9/C18:0 ratio. Interestingly, seven genetic variants within the SCD (including the well-known AY487830:g.2228T>C SNP and other novel genotyped polymorphisms) are associated with two haplotypes. Although the haplotypes are segregating at different frequencies in the H and L groups, they do not fully explain the desaturation ratios or the SCD expression levels. A more complex model, including polyunsaturated fatty acids such as C18:2n-6, C20:4n-6, and C18:3n-3, is suggested to explain the regulation of the C18:1n-9/C18:0 desaturation ratio in porcine muscle.

Phytohormone augmented biomass and lipid production in Dunaliella salina under two-stage cultivation strategy: A comprehensive characterization of biomass and lipid using DLS, FTIR, CHNS and NMR for bioenergy prospects

Increasing population, climatic shifts, and decreasing fossil-fuels worldwide led scientists to explore microalgae as a renewable energy resource. The present study unravels the impact of gibberellic acid (GA3) on biomass production, enzymatic activities, macromolecular synthesis, and metabolome analysis of Dunaliella salina using two-stage cultivation strategy. The results indicated a marked increase in biomass (1.44-fold), photosynthetic yield (Fv/Fm 0.68), along with RuBisCO activity (1.66-fold), with an increased in absolute value of zeta potential(ζ) in cultures treated with 10 µM GA3 compared to controls (Stage I). Interestingly, 15 µM GA3-treated cells significantly enhanced lipid content (42.36 %), and carbohydrates (16.56 %) with elevated antioxidative enzymes (SOD, CAT, and APX) activities (Stage II). Enhanced lipid content was further confirmed through FTIR spectra (2928 cm-1, and 1740 cm-1) and 1H NMR signals (1.0– 2, 3.5–4.5 ppm), indicating an increase in both saturated (SFA) and polyunsaturated fatty acids (PUFAs). Elemental analysis demonstrated higher carbon and hydrogen percentages, reflected in higher heating value (HHV) and H/C ratio at 15 µM GA3. The increased lipid content was found to be significantly correlated with ACCase and GPAT activities, suggesting the allocation of carbon flux toward lipid biosynthesis pathways. To substantiate the carbon flux, HR-MS-based metabolomic analysis was performed, indicating a reduction in TCA and Calvin cycle intermediates with a significant rise in carotenoid biosynthesis, as well as metabolic shift towards fatty acid biosynthesis reflecting in the enhanced SFA and PUFAs. Thus, these findings highlighted GA3 significant role in the carbon flux allocation towards the neutral lipid biosynthesis for bioenergy prospects.

S-metolachlor in pre-emergence reduces the leaf cuticular wax and increases the efficiency of glyphosate.

The low glyphosate uptake capacity, possibly due to the lipophilic character of epicuticular wax on leaves, may contribute to the natural tolerance of some weed species. The use of pre-emergence herbicides like S-metolachlor, which inhibits very-long-chain fatty acid synthesis, might enhance glyphosate's post-emergent efficacy against hard-to-control weeds, such as Euphorbia heterophylla L. (milkweed) and Ipomoea triloba L. (littlebell). This study aimed to determine whether S-metolachlor affects glyphosate's efficacy and its impact on epicuticular wax production in these species. In Experiment 1, milkweed was 2.27 times more tolerant to S-metolachlor than littlebell, with GR50 values of 1024.6 g ai ha-1 and 451.2 g ai ha-1, respectively. In Experiment 2, S-metolachlor enhanced glyphosate efficacy in both species. For littlebell, S-metolachlor increased glyphosate efficacy by 28% at 21 days after treatment (DAT), while milkweed boosted control to 61%, compared to 45% in untreated plants. The herbicide accelerated glyphosate's action, particularly at lower doses. In Experiment 3, S-metolachlor reduced epicuticular wax by up to 47% in littlebell and 45% in milkweed during early growth. Wax levels remained lower in treated plants, contributing to improved glyphosate efficacy. S-metolachlor in pre-emergence reduces the amount of wax deposited in the leaf surface, increasing glyphosate efficiency in both species, especially at the beginning of the phenological stage. © 2024 Society of Chemical Industry.

Soybean Oil and Protein: Biosynthesis, Regulation and Strategies for Genetic Improvement.

Soybean (Glycine max [L.] Merr.) is one of the world's most important sources of oil and vegetable protein. Much of the energy required for germination and early growth of soybean seeds is stored in fatty acids, mainly as triacylglycerols (TAGs), and the main seed storage proteins are β-conglycinin (7S) and glycinin (11S). Recent research advances have deepened our understanding of the biosynthetic pathways and transcriptional regulatory networks that control fatty acid and protein synthesis in organelles such as the plastid, ribosome and endoplasmic reticulum. Here, we review the composition and biosynthetic pathways of soybean oils and proteins, summarizing the key enzymes and transcription factors that have recently been shown to regulate oil and protein synthesis/metabolism. We then discuss the newest genomic strategies for manipulating these genes to increase the food value of soybeans, highlighting important priorities for future research and genetic improvement of this staple crop.

Characterization of pecan PEBP family genes and the potential regulation role of CiPEBP-like1 in fatty acid synthesis

Phosphatidyl ethanolamine-binding protein (PEBP) plays important roles in plant growth and development. However, few studies have investigated the PEBP gene family in pecan (Carya illinoinensis), particularly the function of the PEBP-like subfamily. In this study, we identified 12 PEBP genes from the pecan genome and classified them into four subfamilies: MFT-like, FT-like, TFL1-like and PEBP-like. Multiple sequence alignment, gene structure, and conserved motif analyses indicated that pecan PEBP subfamily genes were highly conserved. Cis-element analysis revealed that many light responsive elements and plant hormone-responsive elements are found in CiPEBPs promoters. Additionally, RNA-seq and RT-qPCR showed that CiPEBP-like1 was highly expressed during kernel filling stage. GO and KEGG enrichment analysis further indicated that CiPEBP-like1 was involved in fatty acid biosynthesis and metabolism progress. Overexpression of CiPEBP-like1 led to earlier flowering and altered fatty acid composition in Arabidopsis seeds. RT-qPCR confirmed that CiPEBP-like1 promoted fatty acid synthesis by regulating the expression of key genes. Overall, this study contributes to a comprehensive understanding of the potential functions of the PEBP family genes and lay a foundation to modifying fatty acid composition in pecan kernel.

Overlooked roles of improved substrates functions in remodeling microbial community and driving metabolic traits during sludge fermentation triggered by surfactants and antibiotics co-existence

Sludge anaerobic fermentation is a pivotal route to transit wastewater treatment plants towards energy-neutral and resource recovery-oriented plants, while the overall efficiency is commonly restrained by co-exist contaminants. This study unveiled the cooperative effect of sulfadiazine (SDZ) and linear alkylbenzene sulfonates (LAS) in driving volatile fatty acids (VFAs) biosynthesis during waste activated sludge (WAS) anaerobic fermentation. The VFAs remarkably elevated to 1189 mg COD/L in LAS/SDZ, which was approximately 1.3–3.2 folds of SDZ and LAS. SDZ and LAS synergistically disintegrated extracellular polymeric substances to provide fermentation substrates. These changes altered microbial population and enhanced microbial networks interconnection. Moreover, the proteins released from WAS might facilitate electron transfer among microorganisms. The functional anaerobic species, including hydrolytic-acidogenic bacteria (e.g., Veillonellaceae and Lactobacillus) and electroactive bacteria (e.g., Parabacteroides and Fonticella), were enriched. Also, the metabolic traits responsible for transmembrane transport, intracellular metabolism, VFAs biosynthesis and electron transfer-related process were strengthened with the upregulation of functional genes. Further analysis revealed that the functional anaerobic species activated quorum sensing and two-component systems to counteract unfavorable LAS/SDZ stress and maintain high metabolic activities. This work elucidated the overlooked roles of substrates in modulating anaerobic consortia and metabolic traits in sludge fermentation systems with mixed pollutants stressing.

Interpretable Machine Learning Algorithms Identify Inetetamab-Mediated Metabolic Signatures and Biomarkers in Treating Breast Cancer.

HER2-positive breast cancer (BC), a highly aggressive malignancy, has been treated with the targeted therapy inetetamab for metastatic cases. Inetetamab (Cipterbin) is a recently approved targeted therapy for HER2-positive metastatic BC, significantly prolonging patients' survival. Currently, there is no established biomarker to reliably predict or assess the therapeutic efficacy of inetetamab in BC patients. This study harnesses the power of metabolomics and machine learning to uncover biomarkers for inetetamab in BC therapy. A total of 23 plasma samples from inetetamab-treated BC patients were collected and stratified into responders and nonresponders. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was utilized to analyze the metabolites in blood samples. A combination of univariate and multivariate statistical analyses was employed to identify these metabolites, and their biological functions were then ascertained by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Finally, machine learning algorithms were employed to screen responsive biomarkers from all differentially expressed metabolites. Our finding revealed 6889 unique metabolites that were detected. Pathways like retinol metabolism, fatty acid biosynthesis, and steroid hormone biosynthesis were enriched for differentially expressed metabolites. Notably, two key metabolites associated with inetetamab response in BC were identified: FAPy-adenine and 2-Pyrocatechuic acid. There was some negative correlation between progress-free survival (PFS) and their kurtosis content. In summary, the identification of these two significant differential metabolites holds promise as potential biomarkers for evaluating and predicting inetetamab treatment outcomes in BC, ultimately contributing to the diagnosis of the disease and the discovery of prognostic markers.

Relationship between metabolomics of T2DM patients and the anti-diabetic effects of Phellodendri Chinensis Cortex-Anemarrhenae Rhizoma herb pair in mice

Ethnopharmacological relevanceType 2 diabetes mellitus (T2DM) poses significant threats to public health. In Traditional Chinese Medicine (TCM), the Phellodendri Chinensis Cortex-Anemarrhenae Rhizoma (PCC/AR) herb pair has long been used for T2DM treatment, although its specific anti-diabetic mechanisms remain unclear. Aim of the studyThis study aimed to elucidate the relationship between metabolomics of T2DM patients and the anti-diabetic effects of PCC/AR herb pair in mice through clinical metabolomics and both in vitro and in vivo experiments. Materials and methodsIn this study, a T2DM mouse model was established via high-fat feeding (HFD) and streptozotocin (STZ) injection. The effects of PCC/AR on blood glucose, lipid metabolism, and inflammatory markers were evaluated. High-performance liquid chromatography-mass spectrometry (HPLC-MS) was performed for metabolomics analysis of T2DM patients. ResultsSerum metabolomics analysis identified significant alterations in metabolites linked to the biosynthesis of unsaturated fatty acids and purine metabolism in T2DM patients, with elevated 2-hydroxyvaleric acid (2HB) levels. In T2DM mice, PCC/AR intervention normalized FBG, GHbA1c, TC, TG, LDL-C, HDL-C, TNF-α and IL-1β levels, while improving insulin sensitivity and pancreatic β-cell function in T2DM mice. Notably, PCC/AR reduced key enzymes in gluconeogenesis and fatty acid synthesis, PEPCK and ACC1. ConclusionPCC/AR herb pair exerts an anti-diabetes effect in T2DM mice by regulating 2HB through ACC1 inhibition, thereby reducing FFA and TG synthesis. Additionally, PCC/AR may also exert its effects by modulating glucose and lipid metabolism and reducing inflammation. These results support further investigation into the PCC/AR herb pair as a complementary therapy for T2DM.

Investigation of the effectiveness and molecular mechanisms of thiamin priming to control early blight disease in potato.

In several plant species, thiamin foliar application primes plant immunity and can be effective in controlling various diseases. However, the effectiveness of thiamin against potato pathogens has seldom been investigated. Additionally, the transcriptomics and metabolomics of immune priming by thiamin have not previously been investigated. Here, we tested the effect of thiamin application against Alternaria solani, the causal agent of early blight in potato, and identified associated changes in gene expression and metabolite content. Thiamin applied on foliage at an optimal concentration of 10 mM reduced lesion size by ~33%. However, prevention of lesion growth was temporally limited, as a reduction of lesion size occurred when leaves were inoculated 4 h, but not 24 h, following thiamin treatment. Additionally, the effect of thiamin on lesion size was restricted to the application site and was not systemic. RNA-seq analysis showed that thiamin affected the expression of 308 genes involved in the synthesis of salicylic acid, secondary metabolites, fatty acid, chitin, and primary metabolism, and photosynthesis, which were also amongst the thousands of genes differentially regulated in the response to pathogen alone. Several of these genes and pathways were more differentially expressed and enriched when thiamin and the pathogen were combined. Thiamin also delayed the downregulation of photosynthesis-associated genes in plants inoculated with A. solani. Metabolite analyses revealed that thiamin treatment in the absence of pathogen decreased the amounts of several organic compounds involved in the citric acid cycle. We hypothesize that thiamin primes plant defenses through perturbation of primary metabolism.

Does periphyton turn less palatable under grazing pressure?

Abstract Periphyton acts as an important primary producer in stream food webs with bottom-up and also subject to top-down effects from grazing pressure. Yet the underlying mechanism remains unclear. Here we conducted a mesocosm experiment to explore response of food quality indicated by biomarkers polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA, 20: 5n3) and 22C fatty acids (FAs) docosahexaenoic acid (DHA, 22: 6n3), essential for cell growth and reproduction and most consumers cannot synthesize, of periphyton to Bellamya aeruginosa grazing pressure. Results indicated that grazing pressure led to a decrease in Bacillariophyta which contain high-quality PUFAs such as EPA and DHA and an increase in Cyanophyta and Chlorophyta which are rich in 18C PUFAs such as linoleic acid (LIN, 18: 2n6) and alpha-linolenic acid (ALA, 18: 3n3) in periphyton. We observed up-regulation of genes that participate in lipid metabolism promoting biosynthesis of unsaturated FAs, ALA metabolism and glycerophospholipid metabolism and those relate to carbohydrate and energy metabolism maintaining energy stability of periphyton. Therefore, food quality of periphyton decreased under grazing pressure, and the results also provide the compositional, chemical, and molecular perspectives of the interactive bottom-up and top-down effects on structuring stream food webs.

Engineering an Escherichia coli strain for enhanced production of flavonoids derived from pinocembrin.

Flavonoids are a structurally diverse group of secondary metabolites, predominantly produced by plants, which include a range of compounds with pharmacological importance. Pinocembrin is a key branch point intermediate in the biosynthesis of a wide range of flavonoid subclasses. However, replicating the biosynthesis of these structurally diverse molecules in heterologous microbial cell factories has encountered challenges, in particular the modest pinocembrin titres achieved to date. In this study, we combined genome engineering and enzyme candidate screening to significantly enhance the production of pinocembrin and its derivatives, including chrysin, pinostrobin, pinobanksin, and galangin, in Escherichia coli. By implementing a combination of established strain engineering strategies aimed at enhancing the supply of the building blocks phenylalanine and malonyl-CoA, we constructed an E. coli chassis capable of accumulating 353 ± 19mg/L pinocembrin from glycerol, without the need for precursor supplementation or the fatty acid biosynthesis inhibitor cerulenin. This chassis was subsequently employed for the production of chrysin, pinostrobin, pinobanksin, and galangin. Through an enzyme candidate screening process involving eight type-1 and five type-2 flavone synthases (FNS), we identified Petroselinum crispum FNSI as the top candidate, producing 82 ± 5mg/L chrysin. Similarly, from a panel of five flavonoid 7-O-methyltransferases (7-OMT), we found pinocembrin 7-OMT from Eucalyptus nitida to yield 153 ± 10mg/L pinostrobin. To produce pinobanksin, we screened seven enzyme candidates exhibiting flavanone 3-hydroxylase (F3H) or F3H/flavonol synthase (FLS) activity, with the bifunctional F3H/FLS enzyme from Glycine max being the top performer, achieving a pinobanksin titre of 12.6 ± 1.8mg/L. Lastly, by utilising a combinatorial library of plasmids encoding G. max F3H and Citrus unshiu FLS, we obtained a maximum galangin titre of 18.2 ± 5.3mg/L. Through the integration of microbial chassis engineering and screening of enzyme candidates, we considerably increased the production levels of microbially synthesised pinocembrin, chrysin, pinostrobin, pinobanksin, and galangin. With the introduction of additional chassis modifications geared towards improving cofactor supply and regeneration, as well as alleviating potential toxic effects of intermediates and end products, we anticipate further enhancements in the yields of these pinocembrin derivatives, potentially enabling greater diversification in microbial hosts.

Coptisine inhibits lipid accumulation in high glucose- and palmitic acid-induced HK-2 cells by regulating the AMPK/ACC/CPT-1 signaling pathway.

AMPK (Adenosine 5'-Monophosphate activated Protein Kinase) functions as a fundamental regulator of glycolipid metabolism by regulating the rate-limiting enzyme activity of ACC (Acetyl-CoA Carboxylase, essential for fatty acid biosynthesis) and CPT-1 (Carnitine palmitoyltransferase-1, essential for mitochondrial fatty acid oxidation, FAO) in cells, which is crucial for maintaining energy homeostasis in the human body. Coptisine (COP) is a natural berberine and isoquinoline alkaloid in Coptis chinensis that has been used as a traditional Chinese herb to treat diabetes for thousands of years, but its mechanism of action is still unclear. In this study, we investigated the anti-lipid accumulation effect and mechanism of COP in high glucose and palmitic acid-induced HK-2 cells. Compared with the control HK-2 cells, the model HK-2 cells exhibited markedly greater lipid deposition, after treatment with high glucose (HG, 30 mM) and palmitic acid (PA, 250 µM) for 24h. However, COP significantly decreased the TC and TG levels in a dose dependent manner (2.5, 5, and 10 µM). Moreover, COP dramatically enhanced the effect of the positive control (AICAR, Acadesine, an AMPK activator) in alleviating lipid deposition, which was reversed by the negative control (Compound C, an AMPK inhibitor). Furthermore, COP also increased p-AMPK, p-ACC and CPT-1 protein expression. Our results indicate that COP can effectively protects HK-2 cells against HG- and PA-induced lipid accumulation by affecting the AMPK/ACC/CPT-1 signaling pathway, inhibiting de novo lipogenesis and enhancing the FAO processes, which offers novel insights for the application of COP in the clinic.

Enhanced immunity: the gut microbiota changes in high-altitude Tibetan pigs compared to Yorkshire pigs.

Long-term domestication in high-altitude environments has led to unique changes in the gut microbiota of Tibetan Pigs. This study aims to investigate specific alterations in the intestinal flora of Tibetan Pigs compared to Yorkshire pigs. We employed 16S rRNA and metagenomic sequencing technologies for comprehensive analysis of the gut microbiota. The data collected allowed us to assess microbial community structures and functional capabilities. Our analysis revealed that Tibetan Pigs raised under a "free-range + supplementary feeding" model exhibited increased abundance of microbial communities associated with short-chain fatty acid synthesis and the digestion of cellulose and hemicellulose. Notably, the characteristic bacterium Rhodococcus, commonly found in high-altitude environments, was enriched in the gut microbiota of Tibetan Pigs, facilitating the efficient utilization of natural compounds and degradation of toxic substances. Additionally, the increased abundance of probiotics in these pigs enhances their immunity, which may involve mechanisms such as disrupting the structure of pathogenic bacteria and detoxifying harmful metabolites. These findings underscore the advantages of Tibetan Pigs over common commercial breeds, highlighting their unique gut microbiota adaptations. Furthermore, they open new avenues for screening potential probiotics and developing genetic breeding strategies for improved livestock varieties. Understanding the distinct gut microbiota of Tibetan Pigs provides valuable insights into their health benefits and resilience, contributing to future research on breed improvement and microbiome applications in agriculture.