PubMed

Front Plant Sci. 2023 Mar 8;14:1142913. doi: 10.3389/fpls.2023.1142913. eCollection 2023.ABSTRACTSeveral physiological changes occur during fruit storage, which include the regulation of genes, metabolisms and transcription factors. In this study, we compared 'JF308' (a normal tomato cultivar) and 'YS006' (a storable tomato cultivar) to determine the difference in accumulated metabolites, gene expression, and accessible chromatin regions through metabolome, transcriptome, and ATAC-seq analysis. A total of 1006 metabolites were identified in two cultivars. During storage time, sugars, alcohols and flavonoids were found to be more abundant in 'YS006' compared to 'JF308' on day 7, 14, and 21, respectively. Differentially expressed genes, which involved in starch and sucrose biosynthesis were observed higher in 'YS006'. 'YS006' had lower expression levels of CesA (cellulose synthase), PL (pectate lyase), EXPA (expansin) and XTH (xyglucan endoglutransglucosylase/hydrolase) than 'JF308'. The results showed that phenylpropanoid pathway, carbohydrate metabolism and cell wall metabolism play important roles in prolonging the shelf life of tomato (Solanum lycopersicum) fruit. The ATAC-seq analysis revealed that the most significantly up-regulated transcription factors during storage were TCP 2,3,4,5, and 24 in 'YS006' compared to 'JF308' on day 21. This information on the molecular regulatory mechanisms and metabolic pathways of post-harvest quality changes in tomato fruit provides a theoretical foundation for slowing post-harvest decay and loss, and has theoretical importance and application value in breeding for longer shelf life cultivars.PMID:36968400 | PMC:PMC10032333 | DOI:10.3389/fpls.2023.1142913

Front Plant Sci. 2023 Mar 9;14:1114172. doi: 10.3389/fpls.2023.1114172. eCollection 2023.ABSTRACTSeaweed extracts are a prominent class of biostimulants that enhance plant health and tolerance to biotic and abiotic stresses due to their unique bioactive components. However, the mechanisms of action of biostimulants are still unknown. Here, we have used a metabolomic approach, a UHPLC-MS method, to uncover the mechanisms induced following application to Arabidopsis thaliana of a seaweed extract derived from Durvillaea potatorum and Ascophyllum nodosum. We have identified, following the application of the extract, key metabolites and systemic responses in roots and leaves across 3 timepoints (0, 3, 5 days). Significant alterations in metabolite accumulation or reduction were found for those belonging to broad groups of compounds such as lipids, amino acids, and phytohormones; and secondary metabolites such as phenylpropanoids, glucosinolates, and organic acids. Strong accumulations of TCA cycle and N-containing and defensive metabolites such as glucosinolates were also found revealing the enhancement of carbon and nitrogen metabolism and defence systems. Our study has demonstrated that application of seaweed extract dramatically altered the metabolomic profiles of Arabidopsis and revealed differences in roots and leaves that varied across the timepoints tested. We also show clear evidence of systemic responses that were initiated in the roots and resulted in metabolic alterations in the leaves. Collectively, our results suggest that this seaweed extract promotes plant growth and activates defence systems by altering various physiological processes at the individual metabolite level.PMID:36968386 | PMC:PMC10035662 | DOI:10.3389/fpls.2023.1114172

Front Plant Sci. 2023 Mar 8;14:1170103. doi: 10.3389/fpls.2023.1170103. eCollection 2023.NO ABSTRACTPMID:36968384 | PMC:PMC10031092 | DOI:10.3389/fpls.2023.1170103

Front Plant Sci. 2023 Mar 9;14:1100601. doi: 10.3389/fpls.2023.1100601. eCollection 2023.ABSTRACTINTRODUCTION: Alfalfa (Medicago sativa L.) is a highly nutritious leguminous forage that plays an essential role in animal husbandry. In the middle and high latitudes of the northern hemisphere, there are problems with its low rates of overwintering and production. The application of phosphate (P) is an important measure to improve the cold resistance and production of alfalfa, but little is known about the mechanism of P in improving the cold resistance of alfalfa.METHODS: This study integrated the transcriptome and metabolome to explain the mechanism of alfalfa in response to low-temperature stress under two applications of P (50 and 200 mg kg-1) and a control of none applied.RESULTS: The application of P fertilizer improved the root structure and increased the content of soluble sugar and soluble protein in the root crown. In addition, there were 49 differentially expressed genes (DEGs) with 23 upregulated and 24 metabolites with 12 upregulated when 50 mg kg-1 of P was applied. In contrast, there were 224 DEGs with 173 upregulated and 12 metabolites with 6 upregulated in the plants treated with 200 mg kg-1 of P compared with the Control Check (CK). These genes and metabolites were significantly enriched in the biosynthesis of other secondary metabolites and the metabolic pathways of carbohydrates and amino acids. The integration of the transcriptome and metabolome indicated that P affected the biosynthesis of N-acetyl-L-phenylalanine, L-serine, lactose, and isocitrate during the period of increasing cold. It could also affect the expression of related genes that regulate cold tolerance in alfalfa.DISCUSSION: Our findings could contribute to a deeper understanding of the mechanism that alfalfa uses to tolerate cold and lay a theoretical foundation for breeding alfalfa that is highly efficient at utilizing phosphorus.PMID:36968379 | PMC:PMC10034057 | DOI:10.3389/fpls.2023.1100601

Front Plant Sci. 2023 Mar 9;14:1114840. doi: 10.3389/fpls.2023.1114840. eCollection 2023.ABSTRACTSymbiotic nodules formed on legume roots with rhizobia fix atmospheric N2. Bacteria reduce N2 to NH4 + that is assimilated into amino acids by the plant. In return, the plant provides photosynthates to fuel the symbiotic nitrogen fixation. Symbiosis is tightly adjusted to the whole plant nutritional demand and to the plant photosynthetic capacities, but regulatory circuits behind this control remain poorly understood. The use of split-root systems combined with biochemical, physiological, metabolomic, transcriptomic, and genetic approaches revealed that multiple pathways are acting in parallel. Systemic signaling mechanisms of the plant N demand are required for the control of nodule organogenesis, mature nodule functioning, and nodule senescence. N-satiety/N-deficit systemic signaling correlates with rapid variations of the nodules' sugar levels, tuning symbiosis by C resources allocation. These mechanisms are responsible for the adjustment of plant symbiotic capacities to the mineral N resources. On the one hand, if mineral N can satisfy the plant N demand, nodule formation is inhibited, and nodule senescence is activated. On the other hand, local conditions (abiotic stresses) may impair symbiotic activity resulting in plant N limitation. In these conditions, systemic signaling may compensate the N deficit by stimulating symbiotic root N foraging. In the past decade, several molecular components of the systemic signaling pathways controlling nodule formation have been identified, but a major challenge remains, that is, to understand their specificity as compared to the mechanisms of non-symbiotic plants that control root development and how they contribute to the whole plant phenotypes. Less is known about the control of mature nodule development and functioning by N and C nutritional status of the plant, but a hypothetical model involving the sucrose allocation to the nodule as a systemic signaling process, the oxidative pentose phosphate pathway, and the redox status as potential effectors of this signaling is emerging. This work highlights the importance of organism integration in plant biology.PMID:36968361 | PMC:PMC10033964 | DOI:10.3389/fpls.2023.1114840

Front Plant Sci. 2023 Mar 10;14:1130292. doi: 10.3389/fpls.2023.1130292. eCollection 2023.ABSTRACTSeed development is a crucial phase in the life cycle of seed-propagated plants. As the only group of angiosperms that evolved from terrestrial plants to complete their life cycle submerged in marine environments, the mechanisms underlying seed development in seagrasses are still largely unknown. In the present study, we attempted to combine transcriptomic, metabolomic, and physiological data to comprehensively analyze the molecular mechanism that regulates energy metabolism in Zostera marina seeds at the four major developmental stages. Our results demonstrated that seed metabolism was reprogrammed with significant alteration of starch and sucrose metabolism, glycolysis, the tricarboxylic acid cycle (TCA cycle), and the pentose phosphate pathway during the transition from seed formation to seedling establishment. The interconversion of starch and sugar provided energy storage substances in mature seeds and further acted as energy sources to support seed germination and seedling growth. The glycolysis pathway was active during Z. marina germination and seedling establishment, which provided pyruvate for TCA cycle by decomposing soluble sugar. Notably, the biological processes of glycolysis were severely inhibited during Z. marina seed maturation may have a positive effect on seed germination, maintaining a low level of metabolic activity during seed maturation to preserve seed viability. Increased acetyl-CoA and ATP contents were accompanied with the higher TCA cycle activity during seed germination and seedling establishment, indicating that the accumulations of precursor and intermediates metabolite that can strengthen the TCA cycle and facilitate energy supply for Z. marina seed germination and seedling growth. The large amount of oxidatively generated sugar phosphate promotes fructose 1,6-bisphosphate synthesis to feed back to glycolysis during seed germination, indicating that the pentose phosphate pathway not only provides energy for germination, but also complements the glycolytic pathway. Collectively, our findings suggest these energy metabolism pathways cooperate with each other in the process of seed transformation from maturity to seedling establishment, transforming seed from storage tissue to highly active metabolic tissue to meet the energy requirement seed development. These findings provide insights into the roles of the energy metabolism pathway in the complete developmental process of Z. marina seeds from different perspectives, which could facilitate habitat restoration of Z. marina meadows via seeds.PMID:36968358 | PMC:PMC10036900 | DOI:10.3389/fpls.2023.1130292

Front Plant Sci. 2023 Feb 20;14:1126660. doi: 10.3389/fpls.2023.1126660. eCollection 2023.ABSTRACTINTRODUCTION: The Camellia oleifera (C. oleifera) cultivars 'Huashuo' (HS) and 'Huaxin' (HX) are new high-yielding and economically valuable cultivars that frequently encounter prolonged cold weather during the flowering period, resulting in decreased yields and quality. The flower buds of HS sometimes fail to open or open incompletely under cold stress, whereas the flower buds of HX exhibit delayed opening but the flowers and fruits rarely drop.METHODS: In this study, flower buds at the same development stage of two C. oleifera cultivars were used as test materials for a combination of physiological, transcriptomic and metabolomic analyses, to unravel the different cold regulatory mechanisms between two cultivars of C. oleifera.RESULTS AND DISCUSSION: Key differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) involved in sugar metabolism, phenylpropanoid biosynthesis, and hormone signal transduction were significantly higher in HX than in HS, which is consistent with phenotypic observations from a previous study. The results indicate that the flower buds of HX are less affected by long-term cold stress than those of HS, and that cold resistance in C. oleifera cultivars varies among tissues or organs.This study will provide a basis for molecular markers and molecular breeding of C. oleifera.PMID:36968351 | PMC:PMC10037702 | DOI:10.3389/fpls.2023.1126660

Front Mol Biosci. 2023 Mar 13;10:1140375. doi: 10.3389/fmolb.2023.1140375. eCollection 2023.ABSTRACTIntroduction: In this study estimated genetic and phenotypic correlations between fifteen complete blood count (CBC) traits and thirty-three heritable plasma metabolites in young healthy nursery pigs. In addition, it provided an opportunity to identify candidate genes associated with variation in metabolite concentration and their potential association with immune response, disease resilience, and production traits. Methods: The blood samples were collected from healthy young pigs and Nuclear Magnetic Resonance (NMR) was used to quantify plasma metabolites. CBC was determined using the ADVIA® 2120i Hematology System. Genetic correlations of metabolite with CBC traits and single step genome-wide association study (ssGWAS) were estimated using the BLUPF90 programs. Results: Results showed low phenotypic correlation estimates between plasma metabolites and CBC traits. The highest phenotypic correlation was observed between lactic acid and plasma basophil concentration (0.36 ± 0.04; p < 0.05). Several significant genetic correlations were found between metabolites and CBC traits. The plasma concentration of proline was genetically positively correlated with hemoglobin concentration (0.94 ± 0.03; p < 0.05) and L-tyrosine was negatively correlated with mean corpuscular hemoglobin (MCH; -0.92 ± 0.74; p < 0.05). The genomic regions identified in this study only explained a small percentage of the genetic variance of metabolites levels that were genetically correlated with CBC, resilience, and production traits. Discussion: The results of this systems approach suggest that several plasma metabolite phenotypes are phenotypically and genetically correlated with CBC traits, suggesting that they may be potential genetic indicators of immune response following disease challenge. Genomic analysis revealed genes and pathways that might interact to modulate CBC, resilience, and production traits.PMID:36968283 | PMC:PMC10034349 | DOI:10.3389/fmolb.2023.1140375

Front Mol Biosci. 2023 Mar 10;10:1129602. doi: 10.3389/fmolb.2023.1129602. eCollection 2023.ABSTRACT[This corrects the article DOI: 10.3389/fmolb.2022.1042231.].PMID:36968282 | PMC:PMC10038211 | DOI:10.3389/fmolb.2023.1129602

Front Mol Biosci. 2023 Mar 10;10:1168941. doi: 10.3389/fmolb.2023.1168941. eCollection 2023.NO ABSTRACTPMID:36968280 | PMC:PMC10037091 | DOI:10.3389/fmolb.2023.1168941

Front Mol Biosci. 2023 Mar 10;10:1165720. doi: 10.3389/fmolb.2023.1165720. eCollection 2023.ABSTRACT[This corrects the article DOI: 10.3389/fmolb.2022.1070394.].PMID:36968275 | PMC:PMC10036897 | DOI:10.3389/fmolb.2023.1165720

Front Cell Dev Biol. 2023 Mar 8;11:1129009. doi: 10.3389/fcell.2023.1129009. eCollection 2023.ABSTRACTATP wasting is recognized as an efficient strategy to enhance metabolic activity and productivity of specific metabolites in several microorganisms. However, such strategy has been rarely implemented in Streptomyces species whereas antibiotic production by members of this genus is known to be triggered in condition of phosphate limitation that is correlated with a low ATP content. In consequence, to assess the effects of ATP spilling on the primary and specialized metabolisms of Streptomyces, the gene encoding the small synthetic protein DX, that has high affinity for ATP and dephosphorylates ATP into ADP, was cloned in the integrative vector pOSV10 under the control of the strong ErmE promoter. This construct and the empty vector were introduced into the species Streptomyces albogriseolus/viridodiastaticus yielding A37 and A36, respectively. A37 yielded higher biomass than A36 indicating that the DX-mediated ATP degradation resulted into a stimulation of A37 metabolism, consistently with what was reported in other microorganisms. The comparative analysis of the metabolomes of A36 and A37 revealed that A37 had a lower content in glycolytic and Tricarboxylic Acid Cycle intermediates as well as in amino acids than A36, these metabolites being consumed for biomass generation in A37. In contrast, the abundance of other molecules indicative either of energetic stress (ADP, AMP, UMP, ornithine and thymine), of activation (NAD and threonic acid) or inhibition (citramalic acid, fatty acids, TAG and L-alanine) of the oxidative metabolism, was higher in A37 than in A36. Furthermore, hydroxyl-pyrimidine derivatives and polycyclic aromatic polyketide antibiotics belonging to the angucycline class and thought to have a negative impact on respiration were also more abundantly produced by A37 than by A36. This comparative analysis thus revealed the occurrence in A37 of antagonistic metabolic strategies, namely, activation or slowing down of oxidative metabolism and respiration, to maintain the cellular energetic balance. This study thus demonstrated that DX constitutes an efficient biotechnological tool to enhance the expression of the specialized metabolic pathways present in the Streptomyces genomes that may include cryptic pathways. Its use thus might lead to the discovery of novel bioactive molecules potentially useful to human health.PMID:36968208 | PMC:PMC10030506 | DOI:10.3389/fcell.2023.1129009

iScience. 2023 Mar 7;26(4):106346. doi: 10.1016/j.isci.2023.106346. eCollection 2023 Apr 21.ABSTRACTPeriodontitis may aggravate the development of nonalcoholic fatty liver disease (NAFLD); however, the precise mechanism is unknown. In this study, salivary microbiota collected from patients with periodontitis was transferred intragastrically to obese mice induced by high-fat diet. Microbiomics and metabolomics analysis were performed to assess the influence of periodontitis salivary microbiota on gut microbiome and liver metabolism. Periodontitis salivary microbiota altered gut microbiota composition and exacerbated intestinal barrier dysfunction in obese mice. Subsequently, the bacterial lipopolysaccharide transported to liver may activate the toll-like receptor 4 signaling and cause the release of pro-inflammatory factors. Moreover, the tryptophan-kynurenine-AhR signal axis was upregulated in liver, which may be related to aggravated hepatic steatosis and glucolipid metabolism dysregulation during NAFLD development. This study indicated that in the context of obesity, periodontitis salivary microbiota may aggravate the pathological progression of NAFLD, in which the tryptophan-AhR pathway may play a key role.PMID:36968080 | PMC:PMC10031158 | DOI:10.1016/j.isci.2023.106346

iScience. 2023 Mar 3;26(4):106329. doi: 10.1016/j.isci.2023.106329. eCollection 2023 Apr 21.ABSTRACTRespiratory syncytial virus (RSV) is an important pathogen causing pneumonia in children. Few studies have used multi-omics data to investigate the pathogenies of RSV pneumonia. Here, metabolomics was first used to identify potential biomarkers for RSV diagnosis. In the training cohort, serum from 36 healthy controls (HCs), 45 RSV pneumonia children, and 32 infectious disease controls (IDCs) were recruited. After analyses, six metabolites had potential diagnostic value. Using an independent cohort of 49 subjects, two biomarkers (neuromedin N and histidyl-proline diketopiperazine) were validated. Next, multi-omics analysis were applied to analyze the pathogenies of RSV pneumonia. Accumulation of collagen in the serum of RSVs indicated that RSV infection could lead to increased levels of soluble collage. Activation of the complement system and imbalance in lipid metabolism were also observed in RSV patients. The multi-omics analysis presented here revealed the signature protein and metabolite changes in serum caused by RSV infection.PMID:36968072 | PMC:PMC10034469 | DOI:10.1016/j.isci.2023.106329

iScience. 2023 Mar 5;26(4):106328. doi: 10.1016/j.isci.2023.106328. eCollection 2023 Apr 21.ABSTRACTHypobaric hypoxia (HH) is the primary challenge at highland. Prolonged HH exposure impairs right cardiac function. Mitochondria-associated membrane (MAM) plays a principal role in regulating mitochondrial function under hypoxia, but the mechanism was unclear. In this study, proteomics analysis identified that PACS2, a key protein in MAM, and mitophagy were downregulated in HH. Metabolomics analysis indicated suppression of glucose and fatty acids aerobic oxidation in HH conditions. Cardiomyocyte Pacs2 deficiency disrupted MAM formation and endoplasmic reticulum (ER)-mitochondria calcium flux, further inhibiting mitophagy and energy metabolism in HH. Pacs2 overexpression reversed these effects. Cardiac-specific knockout of Pacs2 exacerbated mitophagy inhibition, cardiomyocyte injury, and right cardiac dysfunction induced by HH. Conditional knock-in of Pacs2 recovered HH-induced right cardiac impairment. Thus, PACS2 is essential for protecting cardiomyocytes through ER-mitochondria calcium flux, mitophagy, and mitochondrial energy metabolism. Our work provides insight into the mechanism of HH-induced cardiomyocyte injury and potential targets for maintaining the right cardiac function at the highland.PMID:36968068 | PMC:PMC10034453 | DOI:10.1016/j.isci.2023.106328

PeerJ. 2023 Mar 20;11:e14539. doi: 10.7717/peerj.14539. eCollection 2023.ABSTRACTPURPOSE: Plant secondary metabolites are used to treat various human diseases. However, it is difficult to produce a large number of specific metabolites, which largely limits their medicinal applications. Many methods, such as drought and nutrient application, have been used to induce the biosynthetic production of secondary metabolites. Among these secondary metabolite-inducing methods, mechanical wounding maintains the composition of secondary metabolites with little potential risk. However, the effects of mechanical stress have not been fully investigated, and thus this method remains widely unused.METHODS: In this study, we used metabolomics to investigate the metabolites produced in the upper and lower leaves of Catharanthus roseus in response to mechanical wounding.RESULTS: In the upper leaves, 13 different secondary metabolites (three terpenoid indole alkaloids and 10 phenolic compounds) were screened using an orthogonal partial least squares discriminant analysis (OPLS-DA) score plot. The mechanical wounding of different plant parts affected the production of secondary metabolites. Specifically, when lower leaves were mechanically wounded, the upper leaves became a strong source of resources. Conversely, when upper leaves were injured, the upper leaves themselves became a resource sink. Changes in the source-sink relationship reflected a new balance between resource tradeoff and the upregulation or downregulation of certain metabolic pathways.CONCLUSION: Our findings suggest that mechanical wounding to specific plant parts is a novel approach to increase the biosynthetic production of specific secondary metabolites. These results indicate the need for a reevaluation of production practices for secondary metabolites from select commercial plants.PMID:36968002 | PMC:PMC10035419 | DOI:10.7717/peerj.14539

Front Endocrinol (Lausanne). 2023 Mar 8;14:1131771. doi: 10.3389/fendo.2023.1131771. eCollection 2023.ABSTRACTTo figure out the differentially changed metabolites and disturbed pathways in follicular fluid (FF) of patients with OHSS in comparison to the control group undergoing in vitro fertilization (IVF), we conducted this metabolomic analysis between two groups, the OHSS group included 30 patients treated with oocyte retrieval and developed OHSS in the next 7-14 days, while another 30 patients without OHSS tendency were selected as the control group. The FF samples were obtained during the process of oocyte retrieval. FF samples were analyzed using ultra-high liquid chromatography-tandem mass spectrometry (UPLC-MS). The results identified a total of 59 differentially changed metabolites, including 33 decreased metabolites (P < 0.01) and 26 increased metabolites (P < 0.01) in FF of OHSS compared with the control group. 12 metabolites could be the most valuable biomarkers for OHSS based on ROC results. Our correlation analyses showed that deoxyinosine levels were found positively correlated with serum estradiol (E2) levels in OHSS patients, while L-isoleucine, pyruvic acid, maleamate, and arachidonic acid were found to be positively correlated with the number of retrieved oocytes. Furthermore, 4-hydroxyphenylacetaldehyde, deoxycorticosterone, creatinine, and creatine were found to be negatively associated with serum E2 levels, while 4-hydroxyphenylacetaldehyde, L-carnitine, isovaleric acid and L-2-hydroxyglutaric acid were negatively related with the number of oocytes retrieved in OHSS patients. Taken together, our study provides better identification of OHSS FF metabolic dynamics, suggesting the metabolic compounds can be used as valuable predictors or treatment targets of OHSS.PMID:36967756 | PMC:PMC10031058 | DOI:10.3389/fendo.2023.1131771

J Environ Manage. 2023 Jun 15;336:117602. doi: 10.1016/j.jenvman.2023.117602. Epub 2023 Mar 10.ABSTRACTBiochar has been shown to affect the nitrogen (N) cycle in soil, however, it is unknown how this occurs. Therefore, we used metabolomics, high-throughput sequencing, and quantitative PCR to explore biochar and nitrogen fertilizer effects on the mitigation mechanisms of adverse environments in acidic soil. In the current research, we used acidic soil and maize straw biochar (pyrolyzed at 400 °C with limited oxygen). Three maize straw biochar levels (B1; 0t ha-1, B2; 45 t ha-1, and B3; 90 t ha-1) along with three N fertilizer (urea) levels (N1; 0 kg ha-1, N2; 225 kg ha-1 mg kg-1, and N3; 450 kg ha-1 mg kg-1) were employed in a sixty-day pot experiment. We found that the formation of NH+ 4-N was faster at 0-10 days, while the formation of NO- 3-N occurred at 20-35 days. Furthermore, the combined application of biochar and N fertilizer most effectively boosted soil inorganic N contents compared to biochar and N fertilizer treatments alone. The B3 treatment increased the total N and total inorganic N by 0.2-24.2% and 55.2-91.7%, respectively. Soil microorganism, N fixation, and nitrification capabilities increased with biochar and N fertilizer addition in terms of N-cycling-functional genes. Biochar-N fertilizer had a greater impact on the soil bacterial community and their diversity and richness. Metabolomics revealed 756 distinct metabolites, including 8 substantially upregulated metabolites and 21 significantly downregulated metabolites. A significant amount of lipids and organic acids were formed by biochar-N fertilizer treatments. Thus, biochar and N fertilizer triggered soil metabolism by affecting bacterial community structure, and N-cycling of the soil micro-ecological environment.PMID:36967687 | DOI:10.1016/j.jenvman.2023.117602

Immunol Cell Biol. 2023 Mar 26. doi: 10.1111/imcb.12642. Online ahead of print.ABSTRACTCO2 is produced during aerobic respiration. Normally, levels of CO2 in the blood are tightly regulated but pCO2 can rise (hypercapnia, pCO2 > 45 mmHg) in patients with lung diseases e.g. Chronic Obstructive Pulmonary Disease (COPD). Hypercapnia is a risk factor in COPD but may be of benefit in the context of destructive inflammation. The effects of CO2 per se, on transcription, independent of pH change are poorly understood and warrant further investigation. Here we elucidate the influence of hypercapnia on monocytes and macrophages through integration of state-of-the-art RNA-sequencing, metabolic and metabolomic approaches. THP-1 monocytes and IL4 polarised primary murine macrophages were exposed to 5% CO2 Vs 10% CO2 for up to 24 h in pH- buffered conditions. In hypercapnia, we identified ~370 differentially expressed genes (DEGs) under basal and ~1889 DEGs under LPS-stimulated conditions in monocytes. Transcripts relating to both mitochondrial and nuclear-encoded gene expression were enhanced in hypercapnia in basal and LPS-stimulated cells. Mitochondrial DNA content was not enhanced, but acylcarnitine species and genes associated with fatty acid metabolism were increased in hypercapnia. Primary macrophages exposed to hypercapnia also increased activation of genes associated with fatty acid metabolism and reduced activation of genes associated with glycolysis. Thus, hypercapnia elicits metabolic shifts in lipid metabolism in monocytes and macrophages under pH buffered conditions. These data indicate that CO2 is an important modulator of monocyte transcription that can influence immunometabolic signalling in immune cells in hypercapnia. These immunometabolic insights may be of benefit in the treatment of patients experiencing hypercapnia.PMID:36967673 | DOI:10.1111/imcb.12642

Int Microbiol. 2023 Mar 27. doi: 10.1007/s10123-023-00349-x. Online ahead of print.ABSTRACTSepsis causes high mortality in intensive care units. Although there have been many studies on the gut microbiota in patients with sepsis, the impact of sepsis on the gut microbiota has not been directly determined because the treatment of sepsis also affects the gut microbiota. Therefore, we designed this animal experiment to explore gut microbiota alterations during sepsis. Mice were divided into two groups, mice that survived less than 3 days and mice that survived more than 3 days. Fecal samples collected on the day of cecal ligation and puncture (CLP), as well as on the 3rd and 7th days after CLP, were subjected to microbial community analysis and nontargeted metabolomics analysis. The results showed significantly lower bacterial diversity in fecal samples after CLP. At the genus level, the fecal samples obtained on the 3rd and 7th days after CLP exhibited significantly increased relative abundances of Bacteroides, Helicobacter, etc., and significantly decreased relative abundances of Alloprevotella, Prevotella, etc. Innate metabolite levels were significantly different in mice that survived less than 3 days and mice that survived more than 3 days. In conclusion, CLP-induced sepsis in mice changes the structure of the gut microbiome, and innate metabolites affect the prognosis of septic mice.PMID:36967434 | DOI:10.1007/s10123-023-00349-x