Integrative Molecular Phenotyping
INTEGRATIVE MOLECULAR
PHENOTYPING
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY

PubMed

Biomarker discovery for tuberculosis using metabolomics

Thu, 09/03/2023 - 12:00
Front Mol Biosci. 2023 Feb 20;10:1099654. doi: 10.3389/fmolb.2023.1099654. eCollection 2023.ABSTRACTTuberculosis (TB) is the leading cause of death among infectious diseases, and the ratio of cases in which its pathogen Mycobacterium tuberculosis (Mtb) is drug resistant has been increasing worldwide, whereas latent tuberculosis infection (LTBI) may develop into active TB. Thus it is important to understand the mechanism of drug resistance, find new drugs, and find biomarkers for TB diagnosis. The rapid progress of metabolomics has enabled quantitative metabolite profiling of both the host and the pathogen. In this context, we provide recent progress in the application of metabolomics toward biomarker discovery for tuberculosis. In particular, we first focus on biomarkers based on blood or other body fluids for diagnosing active TB, identifying LTBI and predicting the risk of developing active TB, as well as monitoring the effectiveness of anti-TB drugs. Then we discuss the pathogen-based biomarker research for identifying drug resistant TB. While there have been many reports of potential candidate biomarkers, validations and clinical testing as well as improved bioinformatics analysis are needed to further substantiate and select key biomarkers before they can be made clinically applicable.PMID:36891238 | PMC:PMC9986447 | DOI:10.3389/fmolb.2023.1099654

Metabolome combined with gut microbiome revealed the lipid-lowering mechanism of Xuezhiping capsule on hyperlipidemic hamster induced by high fat diet

Thu, 09/03/2023 - 12:00
Front Mol Biosci. 2023 Feb 20;10:1147910. doi: 10.3389/fmolb.2023.1147910. eCollection 2023.ABSTRACTIntroduction: Hyperlipidemia is a common metabolic disorder with presence of excess fat or lipids in the blood, may induce liver injury, oxidative stress and inflammatory. Xuezhiping capsule (XZP) is a famous Chinese patent medicine clinically used for anti-hyperlipidemia. However, the regulation mechanism of XZP on hyperlipidemia has not been elucidated so far. Methods: This study aimed to explore the effects of XZP on hypolipidemic, antioxidant and anti-inflammatory effects, and the potential mechanism by a combination of untargeted metabolomics and 16S rRNA sequencing. Results: The results indicated that XZP reduced the level of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), increased the level of high density liptein cholesterol (HDL-C), alleviated excessive accumulation of lipid droplets in liver. Biochemical indexes of liver function including gamma glutamyl transferase (GGT) and glutamic oxaloacetic transaminase (GOT) in liver were remarkably decreased. Meanwhile, XZP increased the level of oxidative stress biochemical indexes including superoxide dismutase (SOD) and glutathione (GSH). In addition, XZP increased the level of peroxisome proliferators-activated receptors α (PPARα), acetyl CoA carboxylase 1 (ACOX1) and cholesterol 7-alpha hydroxylase (CYP7A1) in liver, and improved lipid metabolism in serum, liver and fecal lipid metabolism. XZP increased diversity index and the ratio of Firmicutes and Bacteroidetes, regulated seventeen genera, and illustrated strong correlations with liver lipid metabolism and phenotypic indicators. Discussion: These findings suggest that XZP reduced blood lipid and liver lipid, protected liver function, anti inflammation and anti-oxidation, ameliorate lipid metabolic disorders by modulating alpha linolenic acid and linoleic acid metabolism, bile acid metabolism, arachidonic acid metabolism, and regulated gut microbiota composition of high-fat diet (HFD) hamsters.PMID:36891237 | PMC:PMC9986548 | DOI:10.3389/fmolb.2023.1147910

UPLC-MS based integrated plasma proteomic and metabolomic profiling of TSC-RAML and its relationship with everolimus treatment

Thu, 09/03/2023 - 12:00
Front Mol Biosci. 2023 Feb 20;10:1000248. doi: 10.3389/fmolb.2023.1000248. eCollection 2023.ABSTRACTAim: To profile the plasma proteomics and metabolomics of patients with renal cysts, sporadic angiomyolipoma (S-AML) and tuberous sclerosis complex related angiomyolipoma (TSC-RAML) before and after everolimus treatment, and to find potential diagnostic and prognostic biomarkers as well as reveal the underlying mechanism of TSC tumorigenesis. Materials and Methods: We retrospectively measured the plasma proteins and metabolites from November 2016 to November 2017 in a cohort of pre-treatment and post-treatment TSC-RAML patients and compared them with renal cyst and S-AML patients by ultra-performance liquid chromatography-mass spectrometer (UPLC-MS). The tumor reduction rates of TSC-RAML were assessed and correlated with the plasma protein and metabolite levels. In addition, functional analysis based on differentially expressed molecules was performed to reveal the underlying mechanisms. Results: Eighty-five patients with one hundred and ten plasma samples were enrolled in our study. Multiple proteins and metabolites, such as pre-melanosome protein (PMEL) and S-adenosylmethionine (SAM), demonstrated both diagnostic and prognostic effects. Functional analysis revealed many dysregulated pathways, including angiogenesis synthesis, smooth muscle proliferation and migration, amino acid metabolism and glycerophospholipid metabolism. Conclusion: The plasma proteomics and metabolomics pattern of TSC-RAML was clearly different from that of other renal tumors, and the differentially expressed plasma molecules could be used as prognostic and diagnostic biomarkers. The dysregulated pathways, such as angiogenesis and amino acid metabolism, may shed new light on the treatment of TSC-RAML.PMID:36891236 | PMC:PMC9986496 | DOI:10.3389/fmolb.2023.1000248

The metabolome of human milk is altered differentially by Holder pasteurization and high hydrostatic pressure processing

Thu, 09/03/2023 - 12:00
Front Nutr. 2023 Feb 20;10:1107054. doi: 10.3389/fnut.2023.1107054. eCollection 2023.ABSTRACTThe milk metabolome is composed of hundreds of molecules that can impact infant development. In preterm infants, sterilized donor milk (DM) is frequently used for their feeding. We aimed to identify differences in the metabolome of DM after two types of milk sterilization: the Holder pasteurization (HoP) and a high hydrostatic pressure (HP) processing. DM samples were sterilized by HoP (62.5°C for 30 min) or processed by HP (350 MPa at 38°C). 595 milk metabolites were analyzed using an untargeted metabolomic analysis. Both treatments differentially altered several classes of compounds. The major changes noted included decreased levels of free fatty acids, phospholipid metabolites, and sphingomyelins. Decreases were more strongly noted in HP samples rather than in HoP ones. Both HoP and HP treatments increased the levels of ceramides and nucleotide compounds. The sterilization of human milk altered its metabolome especially for lipids.PMID:36891163 | PMC:PMC9987212 | DOI:10.3389/fnut.2023.1107054

Pathogen-triggered metabolic adjustments to potato virus Y infection in potato

Thu, 09/03/2023 - 12:00
Front Plant Sci. 2023 Feb 20;13:1031629. doi: 10.3389/fpls.2022.1031629. eCollection 2022.ABSTRACTPotato (Solanum tuberosum L) is affected by several viral pathogens with the most economically damaging being potato virus Y (PVY). At least nine biologically distinct variants of PVY are known to attack potato, with necrotic types named PVYNTN and PVYN-Wi being the most recent additions to the list. So far, the molecular plant-virus interactions underlying this pathogenicity are not fully understood. In this study, gas chromatography coupled with mass spectroscopy (GC-MS) was used for an untargeted investigation of the changes in leaf metabolomes of PVY-resistant cultivar Premier Russet, and a susceptible cultivar, Russet Burbank, following inoculation with three PVY strains, PVYNTN, PVYN-Wi, and PVYO. Analysis of the resulting GC-MS spectra with the online software Metaboanalyst (version 5.0) uncovered several common and strain-specific metabolites that are induced by PVY inoculation. In Premier Russet, the major overlap in differential accumulation was found between PVYN-Wi and PVYO. However, the 14 significant pathways occurred solely due to PVYN-Wi. In contrast, the main overlap in differential metabolite profiles and pathways in Russet Burbank was between PVYNTN and PVYO. Overall, limited overlap was observed between PVYNTN and PVYN-Wi. As a result, PVYN-Wi-induced necrosis may be mechanistically distinguishable from that of PVYNTN. Furthermore, 10 common and seven cultivar-specific metabolites as potential indicators of PVY infection and susceptibility/resistance were identified by using PLS-DA and ANOVA. In Russet Burbank, glucose-6-phosphate and fructose-6-phosphate were particularly affected by strain-time interaction. This highlights the relevance of the regulation of carbohydrate metabolism for defense against PVY. Some strain- and cultivar-dependent metabolite changes were also observed, reflecting the known genetic resistance-susceptibility dichotomy between the two cultivars. Consequently, engineering broad-spectrum resistance may be the most effective breeding strategy for managing these necrotic strains of PVY.PMID:36891131 | PMC:PMC9986423 | DOI:10.3389/fpls.2022.1031629

Integrated transcriptomics and metabolomics analysis provide insight into anthocyanin biosynthesis for sepal color formation in <em>Heptacodium miconioides</em>

Thu, 09/03/2023 - 12:00
Front Plant Sci. 2023 Feb 20;14:1044581. doi: 10.3389/fpls.2023.1044581. eCollection 2023.ABSTRACTHeptacodium miconioides Rehd., commonly known as "seven-son flower," is an ornamental species with a beautiful flower pattern and persistent sepals. Its sepals are of horticultural value, turning bright red and elongating in the autumn; however, the molecular mechanisms that cause sepal color change remain unclear. We analyzed the dynamic changes in anthocyanin composition in the sepal of H. miconioides at four developmental stages (S1-S4). A total of 41 anthocyanins were detected and classified into 7 major anthocyanin aglycones. High levels of the pigments cyanidin-3,5-O-diglucoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, and pelargonidin-3-O-glucoside were responsible for sepal reddening. Transcriptome analysis revealed 15 differentially expressed genes involved in anthocyanin biosynthesis that were detected between 2 developmental stages. Of these, the high expression of HmANS was considered critical structural gene related to anthocyanin biosynthesis pathway in the sepal through co-expression analysis with anthocyanin content. In addition, a transcription factor (TF)-metabolite correlation analysis revealed that three HmMYB, two HmbHLH, two HmWRKY, and two HmNAC TFs exhibited a strong positive role in the regulation of the anthocyanin structural genes (Pearson's correlation coefficient > 0.90). Luciferase activity assay showed that HmMYB114, HmbHLH130, HmWRKY6, and HmNAC1 could activate the promoters of HmCHS4 and HmDFR1 genes in vitro. These findings increase our understanding of anthocyanin metabolism in the sepal of H. miconioides and provide a guide for studies involving sepal color conversion and regulation.PMID:36890897 | PMC:PMC9987713 | DOI:10.3389/fpls.2023.1044581

The gut microbiota metabolite capsiate regulate SLC2A1 expression by targeting HIF-1α to inhibit knee osteoarthritis-induced ferroptosis

Thu, 09/03/2023 - 12:00
Aging Cell. 2023 Mar 8:e13807. doi: 10.1111/acel.13807. Online ahead of print.ABSTRACTFerroptosis is an iron-dependent cell death that has been found to aggravate the progression of osteoarthritis (OA) and gut microbiota- OA axis refers to the bidirectional information network between the gut microbiota and OA, which may provide a new way to protect the OA. However, the role of gut microbiota-derived metabolites in ferroptosis-relative osteoarthritis remains unclear. The objective of this study was to analyze the protective effect of gut microbiota and its metabolite capsiate (CAT) on ferroptosis-relative osteoarthritis in vivo and in vitro experiments. From June 2021 to February 2022, 78 patients were evaluated retrospectively and divided into two groups: The health group (n = 39) and the OA group (n = 40). Iron and oxidative stress indicators were determined in peripheral blood samples. And then in vivo and in vitro experiments, a surgically destabilized medial meniscus (DMM) mice model was established and treated with CAT or Ferric Inhibitor-1 (Fer-1). Solute Carrier Family 2 Member 1 (SLC2A1) short hairpin RNA (shRNA) was utilized to inhibit SLC2A1 expression. Serum iron was increased significantly but total iron binding capacity was decreased significantly in OA patients than healthy people (p < 0.0001). The least absolute shrinkage and selection operator clinical prediction model suggested that serum iron, total iron binding capacity, transferrin, and superoxide dismutase were all independent predictors of OA (p < 0.001). Bioinformatics results suggested that SLC2A1, Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1), and HIF-1α (Hypoxia Inducible Factor 1 Alpha)-related oxidative stress signaling pathways play an important role in iron homeostasis and OA. In addition, gut microbiota 16s RNA sequencing and untargeted metabolomics were used to find that gut microbiota metabolites CAT in mice with osteoarthritis were negatively correlated with Osteoarthritis Research Society International (OARSI) scores for chondrogenic degeneration (p = 0.0017). Moreover, CAT reduced ferroptosis-dependent osteoarthritis in vivo and in vitro. However, the protective effect of CAT against ferroptosis-dependent osteoarthritis could be eliminated by silencing SLC2A1. SLC2A1 was upregulated but reduced the SLC2A1 and HIF-1α levels in the DMM group. HIF-1α, MALAT1, and apoptosis levels were increased after SLC2A1 knockout in chondrocyte cells (p = 0.0017). Finally, downregulation of SLC2A1 expression by Adeno-associated Virus (AAV) -SLC2A1 shRNA improves osteoarthritis in vivo. Our findings indicated that CAT inhibited HIF-1a expression and reduced ferroptosis-relative osteoarthritis progression by activating SLC2A1.PMID:36890785 | DOI:10.1111/acel.13807

Antimicrobial peptides act on the rumen microbiome and metabolome affecting the performance of castrated bulls

Wed, 08/03/2023 - 12:00
J Anim Sci Biotechnol. 2023 Mar 9;14(1):31. doi: 10.1186/s40104-023-00832-5.ABSTRACTBACKGROUND: Many countries have already banned the use of antibiotics in animal husbandry, making it extremely difficult to maintain animal health in livestock breeding. In the livestock industry, there is an urgent need to develop alternatives to antibiotics which will not lead to drug resistance on prolonged use. In this study, eighteen castrated bulls were randomly divided into two groups. The control group (CK) was fed the basal diet, while the antimicrobial peptide group (AP) was fed the basal diet supplemented with 8 g of antimicrobial peptides in the basal diet for the experimental period of 270 d. They were then slaughtered to measure production performance, and the ruminal contents were isolated for metagenomic and metabolome sequencing analysis.RESULT: The results showed that antimicrobial peptides could improve the daily weight, carcass weight, and net meat weight of the experimental animals. Additionally, the rumen papillae diameter and the micropapillary density in the AP were significantly greater than those in the CK. Furthermore, the determination of digestive enzymes and fermentation parameters showed that the contents of protease, xylanase, and β-glucoside in the AP were greater than those in the CK. However, lipase content in the CK was greater than that in the AP. Moreover, the content of acetate, propionate, butyrate, and valerate was found to be greater in AP than those in CK. The metagenomic analysis annotated 1993 differential microorganisms at the species level. The KEGG enrichment of these microorganisms revealed that the enrichment of drug resistance-related pathways was dramatically decreased in the AP, whereas the enrichment of immune-related pathways was significantly increased. There was also a significant reduction in the types of viruses in the AP. 187 probiotics with significant differences were found, 135 of which were higher in AP than in CK. It was also found that the antimicrobial mechanism of the antimicrobial peptides was quite specific. Seven low-abundance microorganisms (Acinetobacter_sp._Ac_1271, Aequorivita soesokkakensis, Bacillus lacisalsi, Haloferax larsenii, Lysinibacillus_sp._3DF0063, Parabacteroides_sp._2_1_7, Streptomyces_sp._So13.3) were found to regulate growth performance of the bull negatively. Metabolome analysis identified 45 differentially differential metabolites that significantly different between the CK and the AP groups. Seven upregulated metabolites (4-pyridoxic acid, Ala-Phe, 3-ureidopropionate, hippuric acid, terephthalic acid, L-alanine, uridine 5-monophosphate) improve the growth performance of the experimental animals. To detect the interactions between the rumen microbiome and metabolism, we associated the rumen microbiome with the metabolome and found that negative regulation between the above 7 microorganisms and 7 metabolites.CONCLUSIONS: This study shows that antimicrobial peptides can improve the growth performance of animals while resisting viruses and harmful bacteria and are expected to become healthy alternatives to antibiotics. We demonstrated a new antimicrobial peptides pharmacological model. We demonstrated low-abundance microorganisms may play a role by regulating the content of metabolites.PMID:36890581 | DOI:10.1186/s40104-023-00832-5

Cannabinoids modulate the microbiota-gut-brain axis in HIV/SIV infection by reducing neuroinflammation and dysbiosis while concurrently elevating endocannabinoid and indole-3-propionate levels

Wed, 08/03/2023 - 12:00
J Neuroinflammation. 2023 Mar 8;20(1):62. doi: 10.1186/s12974-023-02729-6.ABSTRACTBACKGROUND: Although the advent of combination anti-retroviral therapy (cART) has transformed HIV into a manageable chronic disease, an estimated 30-50% of people living with HIV (PLWH) exhibit cognitive and motor deficits collectively known as HIV-associated neurocognitive disorders (HAND). A key driver of HAND neuropathology is chronic neuroinflammation, where proinflammatory mediators produced by activated microglia and macrophages are thought to inflict neuronal injury and loss. Moreover, the dysregulation of the microbiota-gut-brain axis (MGBA) in PLWH, consequent to gastrointestinal dysfunction and dysbiosis, can lead to neuroinflammation and persistent cognitive impairment, which underscores the need for new interventions.METHODS: We performed RNA-seq and microRNA profiling in basal ganglia (BG), metabolomics (plasma) and shotgun metagenomic sequencing (colon contents) in uninfected and SIV-infected rhesus macaques (RMs) administered vehicle (VEH/SIV) or delta-9-tetrahydrocannabinol (THC) (THC/SIV).RESULTS: Long-term, low-dose THC reduced neuroinflammation and dysbiosis and significantly increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid and indole-3-propionate levels in chronically SIV-infected RMs. Chronic THC potently blocked the upregulation of genes associated with type-I interferon responses (NLRC5, CCL2, CXCL10, IRF1, IRF7, STAT2, BST2), excitotoxicity (SLC7A11), and enhanced protein expression of WFS1 (endoplasmic reticulum stress) and CRYM (oxidative stress) in BG. Additionally, THC successfully countered miR-142-3p-mediated suppression of WFS1 protein expression via a cannabinoid receptor-1-mediated mechanism in HCN2 neuronal cells. Most importantly, THC significantly increased the relative abundance of Firmicutes and Clostridia including indole-3-propionate (C. botulinum, C. paraputrificum, and C. cadaveris) and butyrate (C. butyricum, Faecalibacterium prausnitzii and Butyricicoccus pullicaecorum) producers in colonic contents.CONCLUSION: This study demonstrates the potential of long-term, low-dose THC to positively modulate the MGBA by reducing neuroinflammation, enhancing endocannabinoid levels and promoting the growth of gut bacterial species that produce neuroprotective metabolites, like indole-3-propionate. The findings from this study may benefit not only PLWH on cART, but also those with no access to cART and more importantly, those who fail to suppress the virus under cART.PMID:36890518 | DOI:10.1186/s12974-023-02729-6

Caffeine ameliorates the metabolic syndrome in diet-induced obese mice through regulating the gut microbiota and serum metabolism

Wed, 08/03/2023 - 12:00
Diabetol Metab Syndr. 2023 Mar 8;15(1):37. doi: 10.1186/s13098-023-00993-3.ABSTRACTOBJECTIVE: Obesity is associated with gut microbiota disorders, which has been related to developing metabolic syndromes. The research aims to investigate the effects of caffeine treatment on insulin resistance, intestinal microbiota composition and serum metabolomic changes in high-fat diet (HFD)-induced obesity mice.METHODS: Eight-week-old male C57BL/6 J mice were fed a normal chow diet (NCD) or HFD with or without different concentrations of caffeine. After 12 weeks of treatment, body weight, insulin resistance, serum lipid profiles, gut microbiota and serum metabolomic profiles were assessed.RESULTS: Caffeine intervention improved the metabolic syndrome in HFD-fed mice, such as serum lipid disorders and insulin resistance. 16S rRNA Sequencing analysis revealed that caffeine increased the relative abundance of Dubosiella, Bifidobacterium and Desulfovibrio and decreased that of Bacteroides, Lactobacillus and Lactococcus to reverse HFD-fed obesity in mice. Additionally, Caffeine Supplementation also altered serum metabolomics, mainly focusing on lipid metabolism, bile acid metabolism and energy metabolism. Caffeine increased its metabolite 1,7-Dimethylxanthine, which was positively correlated with Dubosiella.CONCLUSIONS: Caffeine exerts a beneficial effect on insulin resistance in HFD-mice, and the underlying mechanism may be partly related to altered gut microbiota and bile acid metabolism.PMID:36890514 | DOI:10.1186/s13098-023-00993-3

Metabolic reprogramming by Acly inhibition using SB-204990 alters glucoregulation and modulates molecular mechanisms associated with aging

Wed, 08/03/2023 - 12:00
Commun Biol. 2023 Mar 8;6(1):250. doi: 10.1038/s42003-023-04625-4.ABSTRACTATP-citrate lyase is a central integrator of cellular metabolism in the interface of protein, carbohydrate, and lipid metabolism. The physiological consequences as well as the molecular mechanisms orchestrating the response to long-term pharmacologically induced Acly inhibition are unknown. We report here that the Acly inhibitor SB-204990 improves metabolic health and physical strength in wild-type mice when fed with a high-fat diet, while in mice fed with healthy diet results in metabolic imbalance and moderated insulin resistance. By applying a multiomic approach using untargeted metabolomics, transcriptomics, and proteomics, we determined that, in vivo, SB-204990 plays a role in the regulation of molecular mechanisms associated with aging, such as energy metabolism, mitochondrial function, mTOR signaling, and folate cycle, while global alterations on histone acetylation are absent. Our findings indicate a mechanism for regulating molecular pathways of aging that prevents the development of metabolic abnormalities associated with unhealthy dieting. This strategy might be explored for devising therapeutic approaches to prevent metabolic diseases.PMID:36890357 | DOI:10.1038/s42003-023-04625-4

Towards a Rosetta stone for metabolomics: recommendations to overcome inconsistent metabolite nomenclature

Wed, 08/03/2023 - 12:00
Nat Metab. 2023 Mar 8. doi: 10.1038/s42255-023-00757-3. Online ahead of print.NO ABSTRACTPMID:36890347 | DOI:10.1038/s42255-023-00757-3

Structural basis for bacterial energy extraction from atmospheric hydrogen

Wed, 08/03/2023 - 12:00
Nature. 2023 Mar 8. doi: 10.1038/s41586-023-05781-7. Online ahead of print.ABSTRACTDiverse aerobic bacteria use atmospheric H2 as an energy source for growth and survival1. This globally significant process regulates the composition of the atmosphere, enhances soil biodiversity and drives primary production in extreme environments2,3. Atmospheric H2 oxidation is attributed to uncharacterized members of the [NiFe] hydrogenase superfamily4,5. However, it remains unresolved how these enzymes overcome the extraordinary catalytic challenge of oxidizing picomolar levels of H2 amid ambient levels of the catalytic poison O2 and how the derived electrons are transferred to the respiratory chain1. Here we determined the cryo-electron microscopy structure of the Mycobacterium smegmatis hydrogenase Huc and investigated its mechanism. Huc is a highly efficient oxygen-insensitive enzyme that couples oxidation of atmospheric H2 to the hydrogenation of the respiratory electron carrier menaquinone. Huc uses narrow hydrophobic gas channels to selectively bind atmospheric H2 at the expense of O2, and 3 [3Fe-4S] clusters modulate the properties of the enzyme so that atmospheric H2 oxidation is energetically feasible. The Huc catalytic subunits form an octameric 833 kDa complex around a membrane-associated stalk, which transports and reduces menaquinone 94 Å from the membrane. These findings provide a mechanistic basis for the biogeochemically and ecologically important process of atmospheric H2 oxidation, uncover a mode of energy coupling dependent on long-range quinone transport, and pave the way for the development of catalysts that oxidize H2 in ambient air.PMID:36890228 | DOI:10.1038/s41586-023-05781-7

Macrophage fumarate hydratase restrains mtRNA-mediated interferon production

Wed, 08/03/2023 - 12:00
Nature. 2023 Mar 8. doi: 10.1038/s41586-023-05720-6. Online ahead of print.ABSTRACTMetabolic rewiring underlies the effector functions of macrophages1-3, but the mechanisms involved remain incompletely defined. Here, using unbiased metabolomics and stable isotope-assisted tracing, we show that an inflammatory aspartate-argininosuccinate shunt is induced following lipopolysaccharide stimulation. The shunt, supported by increased argininosuccinate synthase (ASS1) expression, also leads to increased cytosolic fumarate levels and fumarate-mediated protein succination. Pharmacological inhibition and genetic ablation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) further increases intracellular fumarate levels. Mitochondrial respiration is also suppressed and mitochondrial membrane potential increased. RNA sequencing and proteomics analyses demonstrate that there are strong inflammatory effects resulting from FH inhibition. Notably, acute FH inhibition suppresses interleukin-10 expression, which leads to increased tumour necrosis factor secretion, an effect recapitulated by fumarate esters. Moreover, FH inhibition, but not fumarate esters, increases interferon-β production through mechanisms that are driven by mitochondrial RNA (mtRNA) release and activation of the RNA sensors TLR7, RIG-I and MDA5. This effect is recapitulated endogenously when FH is suppressed following prolonged lipopolysaccharide stimulation. Furthermore, cells from patients with systemic lupus erythematosus also exhibit FH suppression, which indicates a potential pathogenic role for this process in human disease. We therefore identify a protective role for FH in maintaining appropriate macrophage cytokine and interferon responses.PMID:36890227 | DOI:10.1038/s41586-023-05720-6

Skeletal muscle atrophy is exacerbated by steatotic and fibrotic liver-derived TNF-alpha in senescence-accelerated mice

Wed, 08/03/2023 - 12:00
J Gastroenterol Hepatol. 2023 Mar 8. doi: 10.1111/jgh.16171. Online ahead of print.ABSTRACTBACKGROUND AND AIM: Although liver diseases, including non-alcoholic steatohepatitis, are associated with skeletal muscle atrophy, the mechanism behind their association has not been fully elucidated. In this study, the effects of aging and non-alcoholic steatohepatitis on the skeletal muscle and the interaction between the liver and muscle were investigated using a diet-induced non-alcoholic steatohepatitis model in senescence-accelerated mice.METHODS: A total of four groups of senescence-accelerated mice and the control mice were fed either a non-alcoholic steatohepatitis-inducing or control diet, and their livers and skeletal muscles were removed for examinations.RESULTS: In the senescence-accelerated/non-alcoholic steatohepatitis group, serum level of alanine aminotransferase was markedly elevated and histopathology of non-alcoholic steatohepatitis was significant. Skeletal muscles were also markedly atrophied. The expression of the ubiquitin ligase Murf1 in the muscle was significantly increased with muscle atrophy, while that of Tnfa was not significantly different. In contrast, the hepatic Tnfa expression and serum TNF-α levels were significantly increased in the senescence-accelerated/non-alcoholic steatohepatitis group. These results suggest that liver-derived TNF-α might promote muscle atrophy associated with steatohepatitis and aging through Murf-1. The metabolomic analysis of skeletal muscle indicated higher spermidine and lower tryptophan levels in the steatohepatitis-diet group.CONCLUSIONS: The findings of this study revealed an aspect of liver-muscle interaction, which might be important in developing treatments for sarcopenia associated with liver diseases.PMID:36890117 | DOI:10.1111/jgh.16171

Microcosm-omics centric investigation reveals elevated bacterial degradation of imidacloprid

Wed, 08/03/2023 - 12:00
Environ Pollut. 2023 Mar 6:121402. doi: 10.1016/j.envpol.2023.121402. Online ahead of print.ABSTRACTImidacloprid, a broad-spectrum insecticide, is widely used against aphids and other sucking insects. As a result, its toxic effect is becoming apparent in non-targeted organisms. In-situ bioremediation of residual insecticide from the environment utilizing efficient microbes would be helpful in reducing its load. In the present work, in-depth genomics, proteomics, bioinformatics, and metabolomics analyses were employed to reveal the potential of Sphingobacterium sp. InxBP1 for in-situ degradation of imidacloprid. The microcosm study revealed ∼79% degradation with first-order kinetics (k = 0.0726 day-1). Genes capable of mediating oxidative degradation of imidacloprid and subsequent decarboxylation of intermediates were identified in the bacterial genome. Proteome analysis demonstrated significant overexpression of the enzymes coded by these genes. Bioinformatic analysis revealed significant affinity and binding of the identified enzymes for their respective substrates (the degradation pathway intermediates). The nitronate monooxygenase (K7A41 01745), amidohydrolase (K7A41 03835 and K7A41 07535), FAD-dependent monooxygenase (K7A41 12,275), and ABC transporter enzymes (K7A41 05325, and K7A41 05605) were found to be effective in facilitating the transport and intracellular degradation of imidacloprid. The metabolomic study identified the pathway intermediates and validated the proposed mechanism and functional role of the identified enzymes in degradation. Thus, the present investigation provides an efficient imidacloprid degrading bacterial species as evidenced by its genetic attributes which can be utilized or further improved to develop technologies for in-situ remediation.PMID:36889658 | DOI:10.1016/j.envpol.2023.121402

Severely-ill COVID-19 patients have altered circulating levels of proteins controlling the epitranscriptome

Wed, 08/03/2023 - 12:00
J Infect. 2023 Mar 6:S0163-4453(23)00132-9. doi: 10.1016/j.jinf.2023.03.002. Online ahead of print.NO ABSTRACTPMID:36889510 | DOI:10.1016/j.jinf.2023.03.002

Prostaglandin I<sub>2</sub> suppresses the development of gut-brain axis disorder in irritable bowel syndrome in rats

Wed, 08/03/2023 - 12:00
Biochim Biophys Acta Gen Subj. 2023 Mar 6:130344. doi: 10.1016/j.bbagen.2023.130344. Online ahead of print.ABSTRACTIn this study, we attempted to clarify a role of prostaglandin (PG) I2 and its specific receptor, IP in the pathogenesis of irritable bowel syndrome (IBS) using a maternal separation (MS)-induced IBS model. Administration of beraprost (BPS), a specific IP agonist, improved visceral hypersensitivity and depressive state with decreased serum CRF level in the IBS rats. To clarify the mechanism of the effect of BPS, we performed serum metabolome analysis and 1-methylnicotinamide (1-MNA) was identified as a possible candidate for a clue metabolite of pathogenesis of IBS. The serum 1-MNA levels revealed inverse correlation to the level of visceral sensitivity, and positive correlation to a depression marker, immobilizing time. Administration of 1-MNA induced visceral hypersensitivity and depression with increased levels of serum CRF. Since fecal 1-MNA is known for a marker of dysbiosis, we examined the composition of fecal microbiota by T-RFLP analysis. The proportion of clostridium cluster XI, XIVa and XVIII was significantly changed in MS-induced IBS rats treated with BPS. Fecal microbiota transplant of BPS-treated rats improved visceral hypersensitivity and depression in IBS rats. These results suggest for the first time that PGI2-IP signaling plays an important role in IBS phenotypes such as visceral hypersensitivity and depressive state. BPS modified microbiota, thereby inhibition of 1-MNA-CRF pathway, followed by improvement of MS-induced IBS phenotype. These results suggest that the PGI2-IP signaling could be considered to be a therapeutic option for IBS.PMID:36889449 | DOI:10.1016/j.bbagen.2023.130344

Mass spectrometry-based metabolomics reveal Dendrobium huoshanense polysaccharide effects and potential mechanism of N-methyl-N'- nitro-N-nitrosoguanidine -induced damage in GES-1 cells

Wed, 08/03/2023 - 12:00
J Ethnopharmacol. 2023 Mar 6:116342. doi: 10.1016/j.jep.2023.116342. Online ahead of print.ABSTRACTETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium huoshanense C. Z. Tang et S. J. Cheng is an important edible medicinal plant that thickens the stomach and intestines, and its active ingredient, polysaccharide, can have anti-inflammatory, immunoregulatory, and antitumor effects. However, the gastroprotective effects and potential mechanisms of Dendrobium huoshanense polysaccharides (DHP) remain unclear.AIM OF THE STUDY: An N-methyl-N'- nitro-N-nitrosoguanidine (MNNG) induced human gastric mucosal epithelial cells (GES-1) damage model was used in this research, aiming to investigate whether DHP has a protective effect on MNNG-induced GES-1 cell injury and its underlying mechanism based on the combination of multiple methods.MATERIALS AND METHODS: DHP was extracted using water extraction and alcohol precipitation methods, and the proteins were removed using the Sevag method. The morphology was observed using scanning electron microscopy. A MNNG-induced GES-1 cell damage model was developed. Cell viability and proliferation of the experimental cells were investigated using a cell counting kit-8 (CCK-8). Cell nuclear morphology was detected using the fluorescent dye Hoechst 33342. Cell scratch wounds and migration were detected using a Transwell chamber. The expression levels of apoptosis proteins (Bcl-2, Bax, Caspase-3) in the experimental cells were detected by Western blotting. Ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was performed to investigate the potential mechanism of action of DHP.RESULTS: The CCK-8 kit analysis showed that DHP increased GES-1 cell viability and ameliorated GES-1 cell injury by MNNG. In addition, scratch assay and Transwell chambers results suggested that DHP improved the MNNG-induced motility and migration ability of GES-1 cells. Likewise, the results of the apoptotic protein assay indicated that DHP had a protective effect against gastric mucosal epithelial cell injury. To further investigate the potential mechanism of action of DHP, we analyzed the metabolite differences between GES-1 cells, GES-1 cells with MNNG-induced injury, and DHP + MMNG-treated cells using UHPLC-HRMS. The results indicated that DHP upregulated 1-methylnicotinamide, famotidine, N4-acetylsulfamethoxazole, acetyl-L-carnitine, choline and cer (d18:1/19:0) metabolites and significantly down-regulated 6-O-desmethyldonepezil, valet hamate, L-cystine, propoxur, and oleic acid.CONCLUSIONS: DHP may protect against gastric mucosal cell injury through nicotinamide and energy metabolism-related pathways. This research may provide a useful reference for further in-depth studies on the treatment of gastric cancer, precancerous lesions, and other gastric diseases.PMID:36889419 | DOI:10.1016/j.jep.2023.116342

Contribution of plastic and microplastic to global climate change and their conjoining impacts on the environment - A review

Wed, 08/03/2023 - 12:00
Sci Total Environ. 2023 Mar 6:162627. doi: 10.1016/j.scitotenv.2023.162627. Online ahead of print.ABSTRACTPlastics are fossil fuel-derived products. The emissions of greenhouse gases (GHG) during different processes involved in the lifecycle of plastic-related products are a significant threat to the environment as it contributes to global temperature rise. By 2050, a high volume of plastic production will be responsible for up to 13 % of our planet's total carbon budget. The global emissions of GHG and their persistence in the environment have depleted Earth's residual carbon resources and have generated an alarming feedback loop. Each year at least 8 million tonnes of discarded plastics are entering our oceans, creating concerns regarding plastic toxicity on marine biota as they end up in the food chain and ultimately affect human health. The unsuccessful management of plastic waste and its presence on the riverbanks, coastlines, and landscapes leads to the emission of a higher percentage of GHG in the atmosphere. The persistence of microplastics is also a significant threat to the fragile and extreme ecosystem containing diverse life forms with low genetic variation, making them vulnerable to climatic change. In this review, we have categorically discussed the contribution of plastic and plastic waste to global climate change covering the current plastic production and future trends, the types of plastics and plastic materials used globally, plastic lifecycle and GHG emission, and how microplastics become a major threat to ocean carbon sequestration and marine health. The conjoining impact of plastic pollution and climate change on the environment and human health has also been discussed in detail. In the end, we have also discussed some strategies to reduce the climate impact of plastics.PMID:36889403 | DOI:10.1016/j.scitotenv.2023.162627

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