Search Results (857)

Succinate is a metabolite involved in chronic inflammatory diseases, regulating macrophages, dendritic cells, and lymphocytes via its receptor SUCNR1 and through intracellular pathways. Our aim was to analyze whether the succinate–SUCNR1 axis modulates the leukocyte–endothelium interactions (L/EI) that mediate the formation of inflammatory foci in response to a ubiquitous pro-inflammatory cytokine (TNFα). L/EI were analyzed in murine cremasteric venules in vivo and between human umbilical endothelial cells (HUVECs) and peripheral blood mononuclear cells (PBMCs) in vitro. We observed that TNFα increased the expression of SUCNR1 and that the L/EI, the proinflammatory cytokines’ upregulation and the NF-κB activation that induced this cytokine were reduced in Sucnr1^−/− mice in comparison with WT mice. Intrascrotal injection of exogenous succinate did not induce significant proinflammatory effects per se but, combined with TNFα, allowed a Sucnr1-independent upregulation of pro-inflammatory cytokines. In vitro, the SUCNR1 antagonist NF-56-EJ40 prevented the interactions of PBMCs with TNFα-treated HUVECs. HUVECs incubated with exogenous succinate presented higher L/EI but a limited response to TNFα. SUCNR1 contributes to TNFα-induced leukocyte–endothelial interactions. However, exogenous administration of high concentrations of this succinate exerts a complex pattern of effects that may include anti-inflammatory actions. Full article

Efflux pumps are essential components of cellular detoxification mechanisms, regulating the intracellular accumulation of xenobiotics and endogenous compounds. Among them, P-glycoprotein (P-gp) plays a role in protecting the brain from potentially toxic molecules, and alterations in its function have been associated with neurodegenerative disorders, including Parkinson’s disease (PD). Although P-gp inhibitors have been extensively investigated in the context of multidrug resistance, their effects on neuronal cells remain poorly characterized. In the present study, we investigated the biological effects of the pyridoquinoxaline-based efflux pump inhibitor 2,2′-(pyrido[2,3-g]quinoxaline-2,3-diylbis(methylene))bis(oxy)bis(N-phenylbenzamide) (10d) in PC12 cells, a widely used dopaminergic neuronal model. The effects of 10d were evaluated by an MTT-based cell viability assay, while intracellular and extracellular dopamine (DA) levels and DA metabolites were quantified by high-performance liquid chromatography (HPLC). In addition, the ability of 10d to modulate MPTP-induced neurotoxicity was assessed, alone and in combination with amantadine (AMA), a known antiparkinsonian drug. Exposure to 10d (5 and 10 μM) reduced PC12 cell viability and markedly enhanced MPTP-induced cytotoxicity. Furthermore, 10d altered dopaminergic homeostasis by decreasing intracellular DA levels and modifying DA metabolite profiles, with more pronounced effects following co-treatment with MPTP. The combined administration of 10d, MPTP and AMA produced a stronger disruption of DA metabolism compared with individual treatments or 10d/MPTP co-exposure. Full article

Background: Myelodysplastic neoplasms (MDSs) are clonal hematopoietic stem cell disorders associated with ineffective hematopoiesis, chronic inflammation, and increased cardiovascular morbidity. Although metabolic dysregulation has been implicated in MDS pathogenesis, systemic metabolic alterations remain incompletely characterized. Methods: Plasma samples from treatment-naïve patients with MDS or chronic myelomonocytic leukemia (CMML) and age-matched healthy controls were analyzed using quantitative nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Metabolomic profiles were compared using unsupervised and supervised multivariate analyses, validated in an independent external MDS cohort, and integrated with re-analysis of publicly available RNA-sequencing datasets from purified CD14⁺ CMML monocytes. Results: Patients with MDS and CMML exhibited broad reductions in circulating lipoprotein-associated metabolites, including HDL-, LDL-, IDL-, and apolipoprotein-associated fractions, indicating disturbed systemic lipoprotein homeostasis. Within the discovery cohort, CMML samples showed higher concentrations of the ketone bodies 3-hydroxybutyrate and acetoacetate, as well as succinate. LC-MS analysis demonstrated selective increases in C18:1 acylcarnitine, oleic and isopalmitic acids, whereas free carnitine abundance remained unchanged. Elevated 3-hydroxybutyrate levels were not associated with mutational burden, hematologic parameters, disease risk, or immunophenotypic features. Re-analysis of public CMML monocyte transcriptomes demonstrated increased expression of genes involved in lipid uptake and intracellular lipid trafficking, including FABP5, APOE, LPL, and SLC27A2, without coordinated activation of fatty acid oxidation pathways. External cohort analysis confirmed the overall MDS-associated plasma metabolomic profile. Conclusions: MDSs and CMML are associated with reproducible alterations in systemic lipid metabolism characterized by reduced circulating lipoprotein-associated metabolites, while CMML showed more pronounced ketone body- and acylcarnitine-associated metabolic phenotype accompanied by changes in lipid-handling transcriptional programs. These findings support altered systemic lipid metabolism and carnitine-dependent fatty acid handling as characteristic features of myeloid neoplasms and provide a rationale for future functional studies investigating lipid metabolism in disease pathogenesis. Full article

Androgenetic alopecia (AGA), the most common form of hair loss, is driven by dihydrotestosterone-mediated follicular miniaturization, oxidative stress, and perifollicular inflammation, requiring multi-target intervention. Coffee pulp is an abundant coffee-processing by-product and a potential source of value-added bioactives relevant to AGA. This study investigated whether fermentation with Saccharomyces cerevisiae, Lactobacillus plantarum, or their mixed culture could remodel coffee pulp composition and enhance biological activities relevant to AGA. Untargeted metabolomics revealed treatment-dependent metabolic remodeling. LP-CP showed the largest number of significantly altered metabolite features (1020; 666 increased and 354 decreased), whereas MIX-CP exhibited a predominantly upward pattern, with 238 of 283 significantly altered features (84.10%) showing increased abundance relative to the unfermented control. Targeted polyphenol analysis showed MIX-CP contained the highest levels of rosmarinic acid and quercetin. In human hair follicle dermal papilla cells, MIX-CP stimulated proliferation, increased fibroblast proliferation in a conditioned-medium model, partially rescued cell viability under potassium-channel inhibition, and attenuated intracellular reactive oxygen species and lipid peroxidation more than monoculture-fermented extracts. At the transcriptional level, MIX-CP downregulated androgen metabolism genes SRD5A1 and SRD5A2 alongside pro-regression mediator TGFB1 while upregulating Wnt/β-catenin (CTNNB1), Sonic Hedgehog (SHH, SMO, GLI1), and angiogenic (VEGF) genes, showing transcript-level modulation comparable to standard hair-loss drugs for most targets. These findings position MIX-CP as a promising multi-target cosmeceutical for AGA management, warranting further in vivo validation. Full article

(1) Background: Adipocyte differentiation involves coordinated changes in mitochondrial activity, redox balance, and cellular metabolism. Here, we examined how quercetin affects lipid accumulation and associated mitochondrial-redox and metabolic features during 3T3-L1 adipogenic differentiation by combining functional assays with time-resolved ¹H NMR metabolomics. (2) Materials and methods: 3T3-L1 cells were differentiated for six days in the absence or presence of 20 μM quercetin. Lipid accumulation, mitochondrial membrane potential, intracellular reactive oxygen species (ROS), and intracellular metabolite profiles were assessed at defined stages of differentiation. (3) Results: Quercetin reduced lipid accumulation, mitochondrial membrane potential, and ROS accumulation, particularly at the mid-to-late stages of adipogenic differentiation. ¹H NMR analysis showed lower lipid-associated resonances and changes in metabolites related to energy metabolism, choline metabolism, and amino acid metabolism in quercetin-treated cells. Orthogonal partial least squares-discriminant analysis (OPLS-DA) showed separation of the metabolic profiles of untreated and quercetin-treated cells at each measured stage. The variables contributing to this separation included lipid-associated resonances, lactate, 3-hydroxybutyrate, choline-related metabolites, and selected amino acids. (4) Conclusions: The results indicate that quercetin reduces lipid accumulation during adipogenic differentiation in association with changes in mitochondrial-redox status and intracellular metabolic profiles. Overall, the findings support stage-dependent alterations of metabolic profiles in quercetin-treated 3T3-L1 cells during adipogenic differentiation. Full article

The mycelium of Phallus rubrovolvatus contains abundant metabolites with broad application prospects in functional foods and pharmaceuticals. However, how carbon and nitrogen substrate availability regulate the accumulation dynamics of mycelial metabolites remains under-explored. In this study, the supply levels of carbon (glucose) and nitrogen (peptone) were optimized to select high-biomass mycelia. Integrating nutritional activity assays with metabolomics and redundancy analysis, the regulatory mechanisms governing carbon–nitrogen metabolic flux were deciphered. The results demonstrated that mycelial nutritional content and antioxidant capacity exhibited a progressive upward trend under three distinct modes: carbon-driven, nitrogen-driven, and carbon–nitrogen synergistic-driven regimes. In the optimal carbon–nitrogen synergistic-driven group, the contents of total soluble sugars, reducing sugars, flavonoids, total phenolics, and soluble proteins increased by 72.06%, 160.80%, 52.47%, 113.69%, and 8.21%, respectively, compared with the control group. Meanwhile, the scavenging rates of superoxide anion, hydroxyl, ABTS, and DPPH free radicals increased by 14.12%, 24.09%, 14.77%, and 66.47%, respectively, compared with the control group. Differentially accumulated metabolites were significantly enriched in amino acid metabolism, energy metabolism, and secondary metabolite biosynthesis pathways. Carbon and nitrogen substrates reshaped intracellular metabolic flux, cooperatively regulating nutrient synthesis and intracellular redox equilibrium. This work reveals a cascade-linking relationship in which nutrient supply triggers metabolic remodeling, regulates oxidative balance, and drives pathway response. It provides theoretical support for the precision fermentation and industrial upgrade of P. rubrovolvatus, while offering a valuable reference paradigm for the high-value exploitation of other rare edible and medicinal fungi. Full article

Traditional fermented vegetables are important resources for screening excellent antibacterial lactic acid bacteria (LAB). In this study, a strain of Lactiplantibacillus plantarum JC2211 with broad-spectrum antibacterial activity against Salmonella Typhimurium (S.T), Staphylococcus aureus (S.a), Listeria monocytogenes (L.m), and Pseudomonas aeruginosa (P.a) was isolated from Yangzhou pickles. The minimum inhibitory concentration (MIC) of its cell-free supernatant (CFS) against all four pathogens was 25 μL/mL. The strain exhibited favorable biosafety and strong environmental adaptability, tolerating 8% NaCl, pH 3.0–10.0, and 0.3% bile salt. The CFS exerted synergistic antibacterial effects via multiple pathways, including increasing cell membrane permeability, reducing membrane potential, decreasing intracellular ATP levels, and inducing ROS accumulation. Metabolite identification indicated that organic acids (dominated by D-lactic acid at 9.37%, citric acid at 8.00%, and phenyllactic acid at 4.42%) were the main components. Using chitosan (CS) as the base material, composite preservation films were fabricated by incorporating 10–50% CFS. The composite film containing 40% CFS (CS/CFS40) exhibited the optimal comprehensive performance, with ABTS and DPPH radical scavenging rates of 90.24% and 79.17%, respectively, along with satisfactory tensile strength (18.70 MPa) and elongation at break (22.93%). In chilled pork preservation, the CS/CFS40 film significantly inhibited the proliferation of spoilage microorganisms, and effectively retarded lipid oxidation. Moreover, the film suppressed the colonization of L.m and S.T on meat surfaces, with bacterial loads maintained at 2.07–2.67 lg CFU/g and 2.92–2.99 lg CFU/g, respectively, over 7 days of refrigeration. Collectively, the CS/CFS40 composite film extended the shelf life of chilled pork to approximately 6 days. This study provides a novel natural biological preservative and eco-friendly active packaging material for chilled meat preservation. Full article

Fatty acid-binding proteins (FABPs) are a family of intracellular lipid chaperones that transport fatty acids and other hydrophobic molecules, playing essential roles in cellular lipid metabolism, signaling, and brain function. Within the central nervous system, FABP3, FABP5, and FABP7 facilitate the trafficking of long-chain polyunsaturated fatty acids and endocannabinoids, thereby modulating key regulatory pathways including the endocannabinoid system (ECS), peroxisome proliferator-activated receptor (PPAR) signaling, and dopaminergic neurotransmission. Peripherally, FABP1 and FABP4 contribute to hepatic drug metabolism, kidney excretion, and inflammatory processes in both tissues, with implications for the pharmacokinetics of substances of abuse. This narrative review synthesizes the current literature on FABPs and their involvement in substance use and addiction-related behaviors. Evidence from transgenic knockout models, pharmacological inhibition studies, and adeno-associated virus vector approaches demonstrates that manipulation of FABP subtypes can alter reward-related behaviors across multiple substances, including THC, ethanol, nicotine, and cocaine. Reduction or knockout of FABP7 alters THC metabolite levels in a sex-dependent manner. FABP3 shows involvement with dopamine receptor expression; however, interaction between FABP3 modulation and specific substances has sparsely been investigated. FABP5 has vastly diverging interactions with addictive behavior and appears to be substance dependent, as downregulation reduces cocaine self-administration, but knockout enhances nicotine conditioned place preference (CPP) and increases brain uptake of THC. Combined deletion of FABP5 and 7 additionally reduces cocaine CPP and reinstatement, while showing promising decreases in ethanol consumption paradigms. FABPs may be a potential therapeutic target for treating substance use disorders and underlying reward deficiency mechanisms underlying addiction and further research is required to elucidate specific mechanistic effects and eliminate potential adverse consequences of chronic FABP modulation. Full article

Raspberry ketone (RK) is a valuable natural flavor compound, but its extraction from plants is inefficient because of its low natural abundance. Microbial production of RK offers a promising alternative; however, insufficient availability of malonyl-CoA can limit RK biosynthesis. In this study, we introduced a malonate-dependent malonyl-CoA supply module into an engineered Escherichia coli strain designed for de novo RK production through heterologous expression of malonyl-CoA synthetase MatB and malonate transporter MatC. In the presence of malonate, the introduction of the MatB–MatC module increased RK production by 2.3-fold. To optimize malonate supplementation, RK pathway metabolites, including intracellular acyl-CoA intermediates, were quantified by liquid chromatography–mass spectrometry, and the resulting metabolite profiles were analyzed by principal component analysis, hierarchical clustering, and correlation analysis. This study indicated that 50-mM malonate was optimal, yielding 24 mg/L RK during 96-deep-well plate cultivation. Fed-batch optimization increased RK production to 301 mg/L in a 100-mL jar fermenter, and scale-up cultivation in a 2-L jar fermenter produced 340 mg/L RK. In this study, optimizing MatB–MatC-dependent malonyl-CoA supply, combined with pathway-level metabolic profiling and controlled fed-batch cultivation, enhanced de novo RK production in E. coli. Full article

Marine fungi associated with sponges and brown algae are promising sources of pharmacologically active compounds. This study investigated the cytotoxic potential and metabolomic profiles of fungal strains isolated from the marine environment of Mauritius. Among the twenty extracts screened, the mycelium extracts were more cytotoxic than the broth extracts. Four extracts demonstrated the most potent activity: Aspergillus chevalieri (F2M), Aspergillus ochraceus (F25M) and Biatriospora sp. (F34M, F34B). The algal endophyte Aspergillus chevalieri (F2M) mycelium extract displayed an IC₅₀ of 14.27 ± 1.22 µg/mL after 24 h against HepG2 cells. The sponge-associated fungi Aspergillus ochraceus (F25M) showed promising cytotoxic activities against HepG2 cells (IC₅₀ of 8.775 ± 0.78 µg/mL) after 24 h of treatment, with a selectivity index of 2.27, and had the lowest IC₅₀ (2.49 ± 0.60 µg/mL after 24 h; 7.14 ± 3.14 µg/mL after 48 h) against FLO-1 cells, also reducing tumor spheroid growth and integrity during the first four hours. All four extracts increased the intracellular ROS production, but only the mycelium extract of A. chevalieri (F2M) significantly increased superoxide dismutase (SOD) and catalase (CAT) activity. Metabolomic profiling identified diverse compound classes, including alkaloids, terpenoids, amino acids, anthraquinones and coumarins. The findings revealed that the marine fungi from Mauritius are promising sources of cytotoxic metabolites that require purification and subsequent confirmation and mechanistic studies. Full article

Abelmoschus manihot (L.) flowers are widely used in traditional Chinese medicine, whereas the roots are often discarded as agricultural waste. The compact cellular and tissue architecture of the roots hinders the release of intracellular metabolites, thus impeding their reutilization. Here, enzyme-assisted ultrasonic extraction was developed to obtain a polysaccharide-rich crude extract from A. manihot roots. Orthogonal optimization identified pH 4.5, a temperature of 60 °C and a cellulase dosage of 6% (w/w) as the optimal extraction conditions, giving an extraction yield of 21.59%. The phenol–sulfuric acid assay indicated a total carbohydrate content of 75.09% (glucose equivalents). Structural analysis by Fourier transform infrared (FT−IR) confirmed the presence of characteristic polysaccharide functional groups, while monosaccharide composition analysis via high-performance liquid chromatography (HPLC) revealed the major components of glucose, glucuronic acid, rhamnose, galacturonic acid, etc. Inspired by the traditional use of A. manihot extract in papermaking, its preliminary hair care-related properties were further evaluated. At a concentration of 30 mg/mL, the extract solution inhibited Malassezia furfur growth by 84%, reduced wet and dry combing work by 16.93% and 30.86%, and increased tensile strength and tensile fracture energy by 13.04% and 14.84%, respectively. Scanning electron microscope (SEM) images suggested smoother hair fiber surfaces after treatment. These results highlight the extract’s great potential for hair care cosmetic products. Full article

Solute Carrier Family 13 Member 5 (SLC13A5) encodes the sodium-dependent citrate cotransporter NaCT, which mediates citrate transport across cell membranes. Pathogenic variants in SLC13A5 cause developmental and epileptic encephalopathy 25 with amelogenesis imperfecta, DEE25; OMIM #615905, a debilitating autosomal recessive disorder. To better define the role of NaCT in ameloblast function and enamel mineralization, we used CRISPR/Cas9 genome editing to generate Slc13a5^R337* knock-in mice that terminate NaCT translation at the Arg337 codon, which is homologous to the human SLC13A5^R333* variant associated with DEE25. We compared enamel phenotypes among wild-type, Slc13a5^+/+; heterozygous, Slc13a5^+/R337*; and homozygous, Slc13a5^R337*/R337* mice using light microscopy, in situ hybridization, immunohistochemistry, backscattered scanning electron microscopy (bSEM); and focused ion beam–scanning electron microscopy (FIB-SEM) with quantitative imaging of organelles and matrix. Citrate bioassays were performed on serum, long bones, such as the femur and tibia, and developing mouse first molars, including enamel organ epithelium, mineralized tooth matrix, and pulp mesenchyme, to assess citrate levels during the presecretory, secretory, and maturation stages of enamel formation. In addition, first molars collected at postnatal days 0, 3, 5, and 12 were analyzed to characterize glycolytic and TCA cycle-related metabolic signatures. Homozygous Slc13a5^R337*/R337* mice exhibited severe defects during the secretory and maturation stages of amelogenesis. Most notably, Slc13a5^R337*/R337* ameloblasts failed to develop a Tomes’ process, detached from the enamel matrix surface, and produced a thin, poorly mineralized crust on the dentin surface rather than organized enamel ribbons. Despite the absence of normal enamel deposition, ameloblasts initially appeared viable and did not become dysplastic until the late secretory stage. Cellular and subcellular analyses revealed increased secondary lysosomes and intracellular accumulation of enamel matrix proteins, consistent with impaired matrix processing or secretion. Citrate concentrations were elevated in serum and long bones at both 7 and 35 weeks of age. Citrate was elevated in secretory-stage Slc13a5^R337*/R337* molars at days 0 and 3, the enamel organ epithelium (including ameloblasts), the pulp mesenchyme (including odontoblasts), and mineralizing dentin and enamel matrices. These levels gradually declined at day 5 and into the enamel maturation stage (day 12). GC-MS-based analysis of central carbon metabolites revealed increased intracellular accumulation of citrate, malate, and pyruvate, suggesting altered energy metabolism and reduced metabolic efficiency in Slc13a5^R337*/R337* mice. Together, these findings indicate that loss of NaCT function in the ameloblasts causes citrate accumulation, which impairs hydroxyapatite formation. Consequently, only a thin, structurally defective mineral crust forms on the dentin surface, while mineral nodules develop ectopically within the maturation-stage enamel organ epithelium. We conclude that regulating citrate concentration is essential for proper appositional growth of enamel. Full article

Sanghuangporus baumii, a medicinal macrofungus, remains unexplored in its response to aluminum stress, despite the widespread environmental relevance of this metal. This study investigated the dose-dependent effects of Al³⁺ on mycelial growth and metabolic regulation. Exposure to 1 mM Al³⁺ moderately stimulated growth (1.11-fold of control) and induced mild oxidative stress, which activated an effective antioxidant response—including increased SOD, CAT, and POD activities and elevated reduced glutathione content—thereby maintaining redox balance and increasing soluble sugar content. In contrast, 10 mM Al³⁺ led to pronounced intracellular Al³⁺ accumulation, severe growth inhibition, and marked oxidative damage, accompanied by impairment of the antioxidant system, yet a marked increase in total triterpenoid content (1.72-fold). Transcriptomic analysis identified 642 and 3019 differentially expressed genes (DEGs) in the 1 and 10 mM Al³⁺ treatments, respectively. KEGG enrichment analysis revealed concentration-dependent alterations in pathways related to peroxisome function, glutathione metabolism, starch and sucrose metabolism, and terpenoid backbone biosynthesis. Collectively, these findings suggest that Al³⁺ modulates S. baumii growth and metabolism in a dose-dependent manner, with redox remodeling as a potential mechanism, offering novel insights into fungal metal adaptation and the targeted modulation of medicinal metabolite production. Full article

Industrial bioprocesses remain constrained by their limited ability to monitor intracellular events in real time. Most rely on external measurements—nutrient or metabolite levels in the culture medium—that provide only delayed and indirect information about the cell’s internal state. Riboswitches, RNA elements that respond to specific small molecules, offer a complementary route to direct intracellular sensing. Acting as genetically encoded biosensors, they bind metabolites with nanomolar-to-micromolar affinity, and ligand binding drives rapid conformational changes in the RNA. When coupled to gene regulatory outputs, riboswitches can, in principle, support dynamic feedback control that allows cells to sense metabolic imbalances and adjust their own metabolism. This Commentary argues that the central opportunity is conceptual: reframing intracellular biosensing as a foundational layer for adaptive, self-regulating cell factories. It distinguishes what riboswitch technology already demonstrates at laboratory scale from what remains a forward-looking vision, and outlines the engineering barriers, specificity, dynamic range, context-dependence, metabolic burden, evolutionary stability, and validation in production settings that must be addressed before autonomous bioprocess control becomes routine. Importantly, the functional response time of such systems is governed not by binding kinetics alone but by transcription, translation and mRNA turnover, a distinction that matters for feedback stability. Full article

Plant specialized metabolites are valuable sources of pharmaceuticals, nutraceuticals, and industrial compounds. Transferring their biosynthetic pathways into microbial hosts remains a major challenge, particularly in photosynthetic microalgae. Here, we investigated the ability of the green microalga Chlamydomonas reinhardtii to functionally express Cannabis sativa polyketide biosynthetic enzymes involved in olivetolic acid synthesis, a key intermediate in cannabinoid biosynthesis. Nuclear transformants carrying the C. sativa tetraketide synthase (CsTKS) and olivetolic acid cyclase (CsOAC) genes were generated. Functional enzyme activity was confirmed by in vitro enzymatic assays using total protein extracts. In vitro olivetolic acid production was detected, verified, and quantified by high-performance liquid chromatography and liquid chromatography–tandem mass spectrometry using authentic standards. However, in vivo olivetolic acid and downstream metabolites were not detected in algal biomass. This indicated that functional enzyme expression did not result in productive intracellular pathway flux. Untargeted metabolomic profiling revealed extensive metabolic rewiring and strain-specific metabolic perturbations following pathway introduction. These findings suggest that heterologous pathway expression triggered broad physiological responses. This study demonstrates that plant polyketide enzymes remain catalytically active in C. reinhardtii; however, intrinsic metabolic and cellular constraints limit in vivo metabolite accumulation. These findings provide important insights into the biological barriers that limit the functional implementation of plant polyketide pathways in photosynthetic microalgae C. reinhardtii and identify key targets for future metabolic and cellular engineering. Full article