Metabolomic Analysis Research Articles

Ketamine attenuates kidney damage and depression-like behaviors in mice with cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is a serious condition characterized by decreased urine output, often accompanied by psychiatric symptoms like depression. However, there are limited pharmacological treatments available for AKI and its associated depressive symptoms. In this study, we investigated whether cisplatin-induced AKI in mice leads to depression-like behaviors and whether ketamine could alleviate both the kidney injury and these behaviors. Mice with cisplatin-induced AKI exhibited elevated levels of creatinine and urea, kidney damage, increased kidney injury molecule-1 protein, and pathological changes in the liver, colon, and spleen. They also showed depression-like behaviors and reduced expression of synaptic proteins in the prefrontal cortex. Remarkably, a single dose of ketamine significantly reduced these symptoms and pathological changes. Interestingly, the beneficial effects of ketamine on the kidneys, other organs, and depression-like behaviors, were reversed by the tropomyosin receptor kinase B (TrkB) inhibitor ANA-12. Western blot analysis revealed the involvement of the TrkB and ERK (extracellular signal-regulated kinase)-CREB (cAMP response element binding protein) signaling pathway. Additionally, metabolomics analysis indicated that blood metabolites, such as C16-ceramide, may contribute to the effects of ketamine in this model. These findings suggest that cisplatin-induced nephrotoxicity in AKI mice contributes to depression-like behaviors, and ketamine can alleviate both kidney damage and depression-like symptoms by modulating the TrkB and ERK-CREB signaling pathways, as well as altering blood metabolites. However, the role of the kidney-brain axis in these depression-like behaviors remains unclear. Furthermore, ketamine may have therapeutic potential for treating kidney diseases such as AKI, along with associated depressive symptoms.

RNF4 mediated degradation of PDHA1 promotes colorectal cancer metabolism and metastasis

This study investigates the role of RNF4-mediated ubiquitination and degradation of PDHA1 in colorectal cancer (CRC) metabolism and metastasis. Integrating (The Cancer Genome Atlas) TCGA and Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases, proteomic, clinical, and metabolomic analyses were performed, revealing PDHA1 as a prognostic marker in CRC. Immunohistochemical staining confirmed lower PDHA1 expression in metastatic CRC tissues. In vitro experiments demonstrated that PDHA1 overexpression inhibited CRC cell proliferation, migration, and invasion. RNF4 was identified as a key mediator in the ubiquitination degradation of PDHA1, influencing glycolytic pathways in CRC cells. Metabolomic analysis of serum samples from metastatic CRC patients further supported these findings. In vivo experiments, including xenograft and metastasis models, validated that RNF4 knockdown stabilized PDHA1, inhibiting tumor formation and metastasis. This study highlights the critical role of RNF4-mediated PDHA1 ubiquitination in promoting glycolytic metabolism, proliferation, and metastasis in CRC.

Intermittent Fasting Improves Insulin Resistance by Modulating the Gut Microbiota and Bile Acid Metabolism in Diet‐Induced Obesity

ScopeAdipose tissue macrophages (ATMs) are crucial in the pathogenesis of insulin resistance (IR). Intermittent fasting (IF) is an effective intervention for obesity. However, the underlying mechanism by which IF improves IR remains unclear.Methods and resultsMale C57BL/6J mice are fed chow‐diet and high‐fat diet (HFD) for 12 weeks, then is randomized into ad libitum feeding or every other day fasting for 8 weeks. Markers of ATMs and expression of uncoupling protein 1 (UCP‐1) are determined. Gut microbiota and bile acids (BAs) are profiled using 16S rRNA sequencing and targeted metabolomics analysis. Results indicate that IF improves IR in HFD‐induced obesity. IF decreases ATM infiltration, pro‐inflammatory M1 gene expression, and promotes white adipose tissue (WAT) browning by elevating UCP‐1 expression. IF restructures microbiota composition, significantly expanding the abundance of Verrucomicrobia particularly Akkermansia muciniphila, with the decrease of that of Firmicutes. IF increases the level of total BAs and alters the composition of BAs with higher proportion of 12α‐hydroxylated (12α‐OH) BAs. The changes in these BAs are correlated with differential bacteria.ConclusionThe findings indicate that IF improves IR partially mediated by the interplay between restructured gut microbiota and BAs metabolism, which has implications for the dietary management in obesity.

Genome-wide identification and functional analysis of CYP450 genes in eggplant (Solanum melongena L.) with a focus on anthocyanin accumlation

BackgroundIn plants, Cytochrome P450 (CYP450) constitutes the largest family of metabolic enzymes and plays a crucial role in various physiological processes, including plant growth and development. Eggplants are well-known for their peel’s high concentration of anthocyanin compounds that provide significant health benefits to humans. The accumulation of anthocyanins in eggplant peels is an important process during growth and development. Therefore, it is essential to identify the CYP450 genes in eggplant (SmCYPs) and analyze their expression profiles during the period of anthocyanin accumulation in the peel.ResultsA total of 180 SmCYPs were identified in the eggplant genome and classified into eight subfamilies based on phylogenetic analysis. These SmCYPs exhibited highly conserved gene structure (exon/intron) and protein motifs, especially within their respective subgroup. Sixteen pairs of genes with collinearity were identified through gene duplication analysis. Promoter cis-acting element analysis revealed that SmCYPs are involved in various responses, including growth and development, stress responsiveness, and light responsiveness. Transcriptome data analysis revealed that all SmCYPs were expressed in various eggplant tissues, such as roots, stems, leaves, flowers, and fruits; with diverse expression patterns among members. The expression patterns of SmCYPs in eggplant peel also exhibited diversity during different stages of anthocyanin accumulation. qRT-PCR analysis demonstrated similar expression patterns for 15 selected SmCYPs as observed in the transcriptome data. Metabolomics analysis further suggested that SmCYPs are involved in the biosynthesis of secondary metabolites and metabolic pathways related to flavonoid and flavone/flavonol biosynthesis. Notably, three specific SmCYPs (SmCYP73A1/75A/98A1) play a significant role in flavonoid biosynthesis, particularly in anthocyanin synthesis in eggplant.ConclusionGenome-wide identification, phylogenetic analysis, expression profile analysis, and exploration of metabolic pathways related to SmCYPs provide valuable insights into the roles of these genes in anthocyanin accumulation in various tissues and organs, including eggplant peel. The findings from this study lay a foundation for the functional analysis of SmCYPs involvement in anthocyanin accumulation in eggplant peel, providing a molecular basis for breeders to cultivate novel varieties of eggplants with high levels of anthocyanin content.

Impact of thermal seed treatment on spermosphere microbiome, metabolome and viability of winter wheat

Thermal seed treatment can be used as an alternative method to prevent infection by seed-borne diseases, but exposure duration and temperature during thermal treatment are important to maintain high seed viability and emergence whilst decreasing infection rate. A method for predicting suitable treatment parameters to maintain viability and eliminate seed-borne pathogens is therefore needed. Seeds of winter wheat were subjected to thermal treatment at four levels of intensity and pre-treatments with or without imbibition. Treatment impact was measured by metabolome analysis using LC-MS and GC-MS, analysis of spermosphere bacterial and fungal metagenomes using Illumina MiSeq, and detection of presence of Fusarium spp. and Microdochium spp. using ddPCR. The results showed that moderate treatment intensity reduced signs of infection and increased seedling emergence. In imbibed samples, myo-inositol concentration and myo-inositol: glucose ratio were positively correlated with treatment intensity, whereas concentrations of glucose and citric acid were negatively correlated. No correlations were found for non-imbibed samples. Imbibition had a large significant impact on microbial community composition of the wheat spermosphere. Imbibition of wheat seeds prior to thermal treatment altered wheat spermosphere microbiota. The concentration of myo-inositol, potentially in combination with glucose, could be a candidate predictor for suitable thermal treatment intensity of wheat seeds.

Myocardial Posttranscriptional Landscape in Peripartum Cardiomyopathy

BACKGROUND: Pregnancy imposes significant cardiovascular adaptations, including progressive increases in plasma volume and cardiac output. For most women, this physiological adaptation resolves at the end of pregnancy, but some women develop pathological dilatation and ultimately heart failure late in pregnancy or in the postpartum period, manifesting as peripartum cardiomyopathy (PPCM). Despite the mortality risk of this form of heart failure, the molecular mechanisms underlying PPCM have not been extensively examined in human hearts. METHODs: Protein and metabolite profiles from left ventricular tissue of end-stage PPCM patients (N=6–7) were compared with dilated cardiomyopathy (DCM; N=5–6) and nonfailing donors (N=7–18) using unbiased quantitative mass spectrometry. All samples were derived from the Sydney Heart Bank. Data are available via ProteomeXchange with identifier PXD055986. Differential protein expression and metabolite abundance and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed. RESULTS: Proteomic analysis identified 2 proteins, SBSPON (somatomedin B and thrombospondin type 1 domain-containing protein precursor) and TNS3 (tensin 3), that were uniquely downregulated in PPCM. SBSPON, an extracellular matrix protein, and TNS3, involved in actin remodeling and cell signaling, may contribute to impaired tissue remodeling and fibrosis in PPCM. Metabolomic analysis revealed elevated levels of homogentisate and deoxycholate and reduced levels of lactate and alanine in PPCM, indicating disrupted metabolic pathways and glucose utilization. Both PPCM and DCM shared pathways related to inflammation, immune responses, and signal transduction. However, thyroid hormone signaling was notably reduced in PPCM, affecting contractility and calcium handling through altered expression of PLN (phospholamban) and Sarcoendoplasmic Reticulum Calcium ATPase (SERCA). Enhanced endoplasmic reticulum stress and altered endocytosis pathways in PPCM suggested additional mechanisms of energy metabolism disruption. CONCLUSIONS: The present study reveals unique posttranslational molecular features of the PPCM myocardium, which mediates cellular and metabolic remodeling, and holds promise as potential targets for therapeutic intervention.

Proteomics and Metabolomics Study on the Responses of Sertoli Cells Infected With Brucella and Its bvfA‐Deletion Strains

ABSTRACTObjectiveTo investigate the potential effects of BvfA in reproductive system damage caused by Brucella.MethodsBrucella intracellular multiplication ability was determined by a gentamicin protection assay; the LDH method was used to determine the lethal effect of Brucella on TM4 cells. Afterward, Label‐free proteomics and LC‐MS/MS metabolomics assays were combined to reveal differential abundant proteins and metabolites of TM4 cells infected with bvfA‐deletion strains and parental strains. Finally, PRM mass spectrometry and western blot analysis were carried out to confirm differential expression of proteins.ResultsThis report demonstrated that bvfA‐deletion strains failed to invade TM4 cells and reconstitution of invasion when a strain with gene bvfA was reintroduced to the deletion strain in 3 h. The bvfA‐deletion exhibited weakened intracellular multiplication compared with parental strains in TM4 cells in 12 h; however, the death rate of TM4 cells infected with bvfA‐deletion strains was higher than that of TM4 cells infected with parental strains. Combined proteomics and metabolomics analyses revealed that the differential abundant proteins and metabolites in TM4 cells infected with bvfA‐deletion and parental strains mainly involved the mineral absorption‐related pathway, NADH:ubiquinone oxidoreductase subunit‐related mitochondrial respiratory signaling pathway, and sphingolipid signaling pathway of TM4 cells. These three signaling pathways were involved in expression changes of TRPM6/7, STEAP1, Gnaq, Trp53, Pbk, Tns2, Akt2, and the NADH:ubiquinone oxidoreductase subunit, as well as content changes of l‐Valine, l‐Isoleucine, l‐Methionine, PC, PE DG, and SM metabolites.SignificanceThese results indicated that BvfA of Brucella abortus S19 affected the above proteins and metabolites in TM4 cells.

Dn-OPDA conjugation with amino acids inhibits its phytohormone bioactivity in Marchantia polymorpha

Abstract Jasmonates are important phytohormones that regulate plant tolerance to biotic and abiotic stresses, and developmental processes. Distinct jasmonates in different plant lineages activate a conserved signalling pathway that mediates these responses: dinor-12-oxo-phytodienoic acid (dn-OPDA) isomers in bryophytes and lycophytes, and JA-Ile in most vascular plants. In many cases, the final responses triggered by these phytohormones depend on the accumulation of specialized metabolites. To identify compounds regulated by the dn-OPDA pathway in the liverwort Marchantia polymorpha, untargeted metabolomic analyses were carried out in response to wounding, a stress that activates the dn-OPDA pathway. A previously unreported group of molecules was identified from these analyses: dn-OPDA-amino acid conjugates (dn-OPDA-aas). Their accumulation after wounding and herbivory was confirmed by targeted metabolic profiling in Marchantia and in all species in which we previously detected dn-iso-OPDA. Mutants in GRETCHEN-HAGEN 3A (MpGH3A) failed to accumulate dn-OPDA-aa conjugates and showed a constitutive activation of the OPDA pathway and increased resistance to herbivory. Our results show that dn-iso-OPDA bioactivity is reduced by amino acid conjugation. Therefore, jasmonate conjugation in land plants plays dichotomous roles: jasmonic acid (JA) conjugation with isoleucine (Ile) produces the bioactive JA-Ile in tracheophytes, whereas conjugation of dn-iso-OPDA with different amino acids deactivates the phytohormone in bryophytes and lycophytes.

Metabolomic Analysis of Barley by Gas Chromatography/Mass Spectrometry

Metabolomic Analysis of Barley by Gas Chromatography/Mass Spectrometry

Spatial and Single Cell Analyses Reveal Heterogeneity of DNAM-1 Receptor-Ligand Interactions that Instructs Intratumoral γδT-Cell Activity

Abstract The dynamic interplay between tumor cells and γδT cells within the tumor microenvironment (TME) significantly influences disease progression and immunotherapy outcome. Here, we delved into the modulation of γδT-cell activation by tumor cell ligands CD112 and CD155, which interact with the activating receptor DNAM-1 on γδT cells. Spatial and single cell RNA sequencing (scRNA-seq), as well as spatial metabolome analysis, from neuroblastoma (NB) revealed that the expression levels and localization of CD112 and CD155 varied across and within tumors, correlating with differentiation status, metabolic pathways, and ultimately disease prognosis and patient survival. Both in vivo tumor xenograft experiments and in vitro co-culture experiments demonstrated that a high CD112/CD155 expression ratio in tumors enhanced γδT-cell-mediated cytotoxicity, while a low-ratio fostered tumor resistance. Mechanistically, CD112 sustained DNAM-1-mediated γδT-cell activation, whereas CD155 downregulated DNAM-1 expression via TRIM21-mediated ubiquitin proteasomal degradation. By interacting with tumor cells differentially expressing CD112 and CD155, intratumoral γδT cells exhibited varying degrees of activation and DNAM-1 expression, representing three major functional subsets. This study underscores the complexity of tumor-immune crosstalk, offering insights into how tumor heterogeneity shapes the immune landscape.

Profiling of Metabolome in the Plasma Following a circH19 Knockdown Intervention in Diet-Induced Obese Mice

The circular RNA circH19 has been implicated in the regulation of gene expression and various biological processes, including obesity. Objectives: This study aimed to elucidate the metabolic changes in plasma after circH19 knockdown in a diet-induced obese (DIO) mouse model. Methods: Plasma samples were collected following the intervention and subjected to non-targeted metabolomics analysis using liquid chromatography–mass spectrometry (LC-MS). Metabolic profiling was performed to identify and quantify metabolites, followed by multivariate statistical analysis to discern differential metabolic signatures. Results: A total of 1250 features were quantified, resulting in the upregulation of 564 metabolites and the downregulation of 686 metabolites in the circH19 knockdown group compared to the control mice. Metabolic pathway analysis revealed disruptions in lipid metabolism, amino acid turnover, and energy production pathways. Notably, the intervention led to a substantial decrease in circulating lipids and alterations in the plasma amino acid profile, indicative of an impact on protein catabolism and anabolic processes. The observed shifts in lipid and amino acid metabolism suggest potential therapeutic avenues for obesity and related metabolic disorders. Conclusions: The circH19 knockdown in DIO mice led to significant alterations in plasma metabolites, highlighting its potential role in the regulation of obesity and metabolic disorders.

Molecular Mechanisms of Poplar Adaptation to Water–Fertilizer Coupling: Insights from Transcriptomic and Metabolomic Analyses

The aim of this paper was to investigate the transcriptomic and metabolomic differences in Populus cathayana × canadasis ‘Xinlin1’ (P. cathayana × canadasis ‘Xinlin 1’) under varying irrigation and fertilization conditions. Ten-year-old P. cathayana × canadasis ‘Xinlin 1’ was selected as the test subject in this study; different irrigation and fertilization treatments were set up, and DEGs and DAMs in response to water and fertilizer regulation were identified. Transcriptomic and metabolomic profiles were analyzed from both leaves and roots. A total of 22,870 DEGs were identified in response to water and fertilizer treatments, predominantly belonging to 48 transcription factor families, including MYB, ERF, and MYB-related ones. Additionally, 2432 DAMs were detected and categorized into 18 metabolite classes, with flavonoids being the most abundant (342 metabolites), followed by terpenoids, lipids, and others. KEGG enrichment analysis revealed that DEGs and DAMs were significantly associated with pathways such as plant hormone signal transduction and starch and sucrose metabolism pathways. The levels of ABA exhibited an initial decrease followed by an increase, with several key genes, including PYR/PYL, PP2C, SnRK2, and ABF, also differentially expressed in the plant hormone signal transduction pathway. In the starch and sucrose metabolic pathways, sucrose was more hydrolyzed into D-fructose, which gradually translocated from roots to leaves. DEGs were significantly involved in sucrose synthesis and decomposition into D-fructose and 1,3-β-glucose, as well as starch synthesis and starch decomposition into cellulose dextrin, which underwent complete hydrolysis to glucose. In the starch hydrolysis process, 29 DEGs were involved, with 12 down-regulated and 17 up-regulated.

Host-derived Lactobacillus plantarum alleviates hyperuricemia by improving gut microbial community and hydrolase-mediated degradation of purine nucleosides.

The gut microbiota is implicated in the pathogenesis of hyperuricemia (HUA) and gout. However, it remains unclear whether probiotics residing in the host gut, such as Lactobacillus, can prevent HUA development. Herein, we isolated Lactobacillus plantarum SQ001 from the cecum of HUA geese and conducted in vitro assays on uric acid (UA) and nucleoside co-culture. Metabolomics and genome-wide analyses, revealed that this strain may promote nucleoside uptake and hydrolysis through its nucleoside hydrolase gene. The functional role of iunH gene was confirmed via heterologous expression and gene knockout studies. Oral administration of L. plantarum SQ001 resulted in increased abundance of Lactobacillus species and reduced serum UA levels. Furthermore, it downregulated hepatic xanthine oxidase, a key enzyme involved in UA synthesis, as well as renal reabsorption protein GLUT9, while enhancing the expression of renal excretion protein ABCG2. Our findings suggest that L. plantarum has potential to ameliorate gut microbial dysbiosis with HUA, thereby offering insights into its potential application as a probiotic therapy for individuals with HUA or gout.

An Integrated Profiling of Liver Metabolome and Transcriptome of Pigs Fed Diets with Different Starch Sources

Diets containing higher-amylose-content starches were proved to have some beneficial effects on monogastric animals, such as promoting the proliferation of intestinal probiotics. However, current research on the effects of diets with different starch sources on animals at the extraintestinal level is still very limited. We hypothesized that diets with different starch sources may affect lipid-related gene expression and metabolism in the liver of pigs. This study aimed to use adult pig models to evaluate the effects of diets with different starch sources (tapioca starch, TS; pea starch, PS) on the liver gene expressions and metabolism. In total, 48 growing pigs were randomly assigned to the TS and PS diets with 8 replicate pens/group and 3 pigs per pen. On day 44 of the experiment, liver samples were collected for metabolome and transcriptome analysis. Metabolome data suggested that different starch sources affected (p < 0.05) the metabolic patterns of liver. Compared with the TS diet, the PS diet increased (p < 0.05) some unsaturated fatty acids and several amino acids or peptide levels in the liver of pigs. Moreover, transcriptome data indicated the PS diets elevated (p < 0.05) fatty acid β-oxidation-related gene expression in the liver of pigs, and reduced (p < 0.05) unsaturated fatty acid metabolism-related gene expression. The results of quantitative real-time PCR confirmed that the PS diet upregulated (p < 0.05) the expression of acyl-CoA dehydrogenase very long chain (ACADVL), carnitine palmitoyl transferase (CPT) 1A, and malonyl-CoA decarboxylase (MLYCD), and downregulated (p < 0.05) the expression level of cytochrome P450 2U1 (CYP2U1) and aldehyde dehydrogenase 1B1 (ALDH1B1) in the liver. In addition, the results of a Mantel test indicated the muscle fatty acids were significantly closely correlated (p < 0.05) with liver gene expressions and metabolites. In summary, these findings suggest that diets containing higher amylose starches improved the lipid degradation and the unsaturated fatty acid levels in pig livers, and thus can generate some potential beneficial effects (such as anti-inflammatory and antioxidant) on pig health.

Transcriptome and metabolome analyses provide crucial insights into the adaptation of chieh-qua to Fusarium oxysporum infection

Transcriptome and metabolome analyses provide crucial insights into the adaptation of chieh-qua to Fusarium oxysporum infection

Anti-Inflammatory Effects and Metabolomic Analysis of Ilex Rotunda Extracted by Supercritical Fluid Extraction

Anti-Inflammatory Effects and Metabolomic Analysis of Ilex Rotunda Extracted by Supercritical Fluid Extraction

The oviposition of cotton bollworms stimulates the defense against its eggs and larvae in tomato plants

AbstractBACKGROUNDHerbivorous insects sustain their populations by oviposition. To reduce the damage caused by herbivores, the host plant triggers a defensive response upon detection of egg deposition. However, the specific impact of the egg deposition time of the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae), on the tomato plant defense remains obscure.RESULTSThis study investigated the effects of tomato plant defenses on cotton bollworm eggs and larvae at different time intervals following egg deposition. The study revealed that tomato plant defense triggered by egg deposition did not directly affect the hatchability of the eggs. Nevertheless, it attracted Trichogramma chilonis 48 h after the egg deposition. Gas chromatography–mass spectrometry analysis of the oviposition‐induced plant volatiles (OIPVs) revealed a considerable increase in the amount of α‐pinene released by tomato plants 48 h after egg deposition. The olfactory results from Y‐tube experiments showed that α‐pinene exhibited a substantial attraction towards T. chilonis. In addition, it was found that the defense response induced by egg deposition for 24 and 48 h significantly inhibited the growth and development of the larvae. Metabolomics analysis revealed that the egg deposition of cotton bollworm altered the metabolite composition and caused significant modifications in the metabolic pathways of tomato plants.CONCLUSIONThese findings provide novel insights into pest management by using egg‐induced plant defenses to reduce egg hatching, and impede larval growth and development in herbivorous insects. © 2024 Society of Chemical Industry.

Deciphering the inhibitory effects of trimetazidine on pulmonary hypertension development via decreasing fatty acid oxidation and promoting glucose oxidation

Pulmonary hypertension (PH) is a devastating disease characterized by vascular remodeling, resulting in right ventricular failure and death. Dysregulation of energy metabolism is linked to PH pathogenesis. Trimetazidine (TMZ), a selective long-chain 3-ketoacyl coenzyme A thiolase inhibitor, is critical in maintaining energy metabolism. Despite the indicated TMZ’s inhibitory effect on pulmonary vascular remodeling in PH development, the integrated evaluation of the changes in biomolecules, such as metabolites and transcripts, that TMZ induces in the lung and heart tissues is largely unknown in vivo. For an improved understanding of the molecular mechanism involving the effects of TMZ on PH development, we performed a comprehensive analysis of the changes in cardiac metabolites and pulmonary transcripts of SU5416-Hypoxia (Su/Hx) rats treated with TMZ. Metabolomic analysis of the Su/Hx-induced PH hearts demonstrated that TMZ reduced the long-chain fatty acid concentration. Additionally, TMZ alleviated PH degree and excessive strain on the right heart functions in rats with Su/Hx-induced PH. We identified the candidate target genes for TMZ treatment during PH development. Interestingly, the mRNA levels of the fatty acid transporters were substantially downregulated by TMZ administration in the lungs with Su/Hx-induced PH. Notably, TMZ suppressed excessive proliferation of human pulmonary artery smooth muscle cells under hypoxic conditions. Our study suggests that TMZ ameliorates PH development by involving energy metabolism in the lungs and heart.

RNA-seq and metabolomic analyses of beneficial plant phenol biochemical pathways in red alder

RNA-seq and metabolomic analyses of beneficial plant phenol biochemical pathways in red alder

Metabolomics and proteomics insights into hepatic responses of weaned piglets to dietary Spirulina inclusion and lysozyme supplementation

BackgroundStudying the effect of dietary Spirulina and lysozyme supplementation on the metabolome and proteome of liver tissue contributes to understanding potential hepatic adaptations of piglets to these novel diets. This study aimed to understand the influence of including 10% Spirulina on the metabolome and proteome of piglet liver tissue. Three groups of 10 post-weaned piglets, housed in pairs, were fed for 28 days with one of three experimental diets: a cereal and soybean meal-based diet (Control), a base diet with 10% Spirulina (SP), and an SP diet supplemented with 0.01% lysozyme (SP + L). At the end of the trial, animals were sacrificed and liver tissue was collected. Metabolomics analysis (n = 10) was performed using NMR data analysed with PCA and PLS-DA. Proteomics analysis (n = 5) was conducted using a filter aided sample preparation (FASP) protocol and Tandem Mass Tag (TMT)-based quantitative approach with an Orbitrap mass spectrometer.ResultsGrowth performance showed an average daily gain reduction of 9.5% and a feed conversion ratio increase of 10.6% in groups fed Spirulina compared to the control group. Metabolomic analysis revealed no significant differences among the groups and identified 60 metabolites in the liver tissue. Proteomics analysis identified 2,560 proteins, with 132, 11, and 52 differentially expressed in the Control vs. SP, Control vs. SP + L and SP vs. SP + L comparisons, respectively. This study demonstrated that Spirulina enhances liver energy conversion efficiency, detoxification and cellular secretion. It improves hepatic metabolic efficiency through alterations in fatty acid oxidation (e.g., upregulation of enzymes like fatty acid synthase and increased acetyl-CoA levels), carbohydrate catabolism (e.g., increased glucose and glucose-6-phosphate), pyruvate metabolism (e.g., higher levels of pyruvate and phosphoenolpyruvate carboxykinase), and cellular defence mechanisms (e.g., upregulation of glutathione and metallothionein). Lysozyme supplementation mitigates some adverse effects of Spirulina, bringing physiological responses closer to control levels. This includes fewer differentially expressed proteins and improved dry matter, organic matter and energy digestibility. Lysozyme also enhances coenzyme availability, skeletal myofibril assembly, actin-mediated cell contraction, tissue regeneration and development through mesenchymal migration and nucleic acid synthesis pathways.ConclusionsWhile Spirulina inclusion had some adverse effects on growth performance, it also enhanced hepatic metabolic efficiency by improving fatty acid oxidation, carbohydrate catabolism and cellular defence mechanisms. The addition of lysozyme further improved these benefits by reducing some of the negative impacts on growth and enhancing nutrient digestibility, tissue regeneration, and overall metabolic balance. Together, Spirulina and lysozyme demonstrate potential as functional dietary components, but further optimization is needed to fully realize their benefits without compromising growth performance.