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

Transcriptome analysis of differential sugar accumulation in the developing embryo of contrasting two <em>Castanea mollissima</em> cultivars

Wed, 05/07/2023 - 12:00
Front Plant Sci. 2023 Jun 19;14:1206585. doi: 10.3389/fpls.2023.1206585. eCollection 2023.ABSTRACTChinese chestnut (Castanea mollissima) is an important nut tree species, and its embryo is rich in sugar. We combined metabolomic and transcriptomic data to analyze metabolites and genes related to sugar in two Chinese chestnut cultivars at 60, 70, 80, 90 and 100 days after flowering (DAF). The soluble sugar content of high-sugar cultivar at maturity is 1.5 times that of low-sugar cultivar. Thirty sugar metabolites were identified in embryo, with the most dominant being sucrose. Analysis of the gene expression patterns revealed that the high-sugar cultivar promoted the conversion of starch to sucrose by up-regulating genes related to starch degradation and sucrose synthesis at 90-100 DAF. It also strongly increased the enzyme activity of SUS-synthetic, which may promote sucrose synthesis. Gene co-expression network analysis showed that ABA and peroxide were related to starch decomposition during Chinese chestnut ripening. Our study analyzed the composition and molecular synthesis mechanism of sugar in Chinese chestnut embryos, and provided a new insight into the regulation pattern of high sugar accumulation in Chinese chestnut nuts.PMID:37404530 | PMC:PMC10315843 | DOI:10.3389/fpls.2023.1206585

The feline skin microbiome: interrelationship between health and disease

Wed, 05/07/2023 - 12:00
J Feline Med Surg. 2023 Jul;25(7):1098612X231180231. doi: 10.1177/1098612X231180231.ABSTRACTPRACTICAL RELEVANCE: As with other species, the skin microbiome of cats has been assessed over the past few years utilizing modern technologies. This has resulted in the identification of many more bacterial and fungal organisms compared with what had been recorded historically on the skin in various states of health and disease using culture-based studies. This information is expanding the knowledge of how microbial communities are impacted by various changes in the skin health of cats. More specifically, how these microbial communities change in the face of health and disease, and how various therapeutic interventions affect the cutaneous microbiome, lends a greater understanding of disease pathogenesis and provides a growing area of research for correcting dysbiosis and improving feline skin health.EVIDENCE BASE: Most studies on the feline skin microbiome thus far have been descriptive in nature. These provide a framework for the next level of investigations on how various states of health and disease impact the products produced by the cutaneous microbiome (ie, the cutaneous metabolome), as well as how targeted interventions may promote the restoration of balance.AIMS: This review aims to summarize what is currently known about the feline cutaneous microbiome and its clinical implications. The role of the skin microbiome in health and disease, the current state of research in this area and the potential for future studies to produce targeted interventions for cats are a particular focus.PMID:37404049 | DOI:10.1177/1098612X231180231

Integration of Metabolomics, Lipidomics, and Proteomics Reveals the Metabolic Characterization of Nonalcoholic Steatohepatitis

Wed, 05/07/2023 - 12:00
J Proteome Res. 2023 Jul 5. doi: 10.1021/acs.jproteome.3c00009. Online ahead of print.ABSTRACTMetabolic dysfunction is associated with nonalcoholic steatohepatitis (NASH) development. However, omics studies investigating metabolic changes in NASH patients are limited. In this study, metabolomics and lipidomics in plasma, as well as proteomics in the liver, were performed to characterize the metabolic profiles of NASH patients. Moreover, the accumulation of bile acids (BAs) in NASH patients prompted us to investigate the protective effect of cholestyramine on NASH. The liver expression of essential proteins involved in FA transport and lipid droplets was significantly elevated in patients with NASH. Furthermore, we observed a distinct lipidomic remodeling in patients with NASH. We also report a novel finding suggesting an increase in the expression of critical proteins responsible for glycolysis and the level of glycolytic output (pyruvic acid) in patients with NASH. Furthermore, the accumulation of branched chain amino acids, aromatic amino acids, purines, and BAs was observed in NASH patients. Similarly, a dramatic metabolic disorder was also observed in a NASH mouse model. Cholestyramine not only significantly alleviated liver steatosis and fibrosis but also reversed NASH-induced accumulation of BAs and steroid hormones. In conclusion, NASH patients were characterized by perturbations in FA uptake, lipid droplet formation, glycolysis, and accumulation of BAs and other metabolites.PMID:37403919 | DOI:10.1021/acs.jproteome.3c00009

Determination of volatile profiles of woodland strawberry (Fragaria vesca) during fruit maturation by HS-SPME GC-MS

Wed, 05/07/2023 - 12:00
J Sci Food Agric. 2023 Jul 5. doi: 10.1002/jsfa.12827. Online ahead of print.ABSTRACTBACKGROUND: Aroma is an important agronomic trait for strawberries, and the improvement of fruit flavor is a key goal in current strawberry breeding programs. Fragaria vesca (also known as woodland strawberry) has become an excellent model plant with exquisite flavor, a small genome size, and a short life cycle. Thus, the comprehensive identification of fruit volatiles and their accumulation pattern of F. vesca strawberries are very important and necessary to the fruit aroma study. This study examined the volatile profile changes from the fruits of three F. vesca genotypes during maturation using the headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME GC-MS) with multivariate analysis.RESULTS: A total of 191 putative volatile compounds were identified, while 152, 159, and 175 volatiles were detected in 20-30 dap fruits of Hawaii 4 (HW), Reugen (RG), and Yellow Wonder (YW), respectively. Aldehydes and alcohols predominated in the early time point while esters were predominant during the late time point. Ketones were the dominant compounds from F. vesca strawberries fruits at the ripe stage. Certain genotype-characteristic volatiles were identified, including eugenol, γ-octalactone, and δ-decalactone were only detected in YW, and mesifurane was found in HW.CONCLUSIONS: RG and YW showed very similar volatile compositions, but YW presented a greater number of volatiles and RG yielded a higher content. Differences in the volatile composition may be primarily due to genetic relationships. The metabolic changes that occurred during fruit ripening and characteristic volatiles will be a useful reference for future strawberry volatile studies. This article is protected by copyright. All rights reserved.PMID:37403783 | DOI:10.1002/jsfa.12827

Untargeted-based metabolomics analysis and in vitro/in silico antiviral activity of extracts from Phyllanthus brasiliensis (Aubl.) Poir

Wed, 05/07/2023 - 12:00
Phytochem Anal. 2023 Jul 4. doi: 10.1002/pca.3259. Online ahead of print.ABSTRACTINTRODUCTION: This study describes the molecular profile and the potential antiviral activity of extracts from Phyllanthus brasiliensis, a plant widely found in the Brazilian Amazon. The research aims to shed light on the potential use of this species as a natural antiviral agent.METHODS: The extracts were analysed using liquid chromatography-mass spectrometry (LC-MS) system, a potent analytical technique to discover drug candidates. In the meantime, in vitro antiviral assays were performed against Mayaro, Oropouche, Chikungunya, and Zika viruses. In addition, the antiviral activity of annotated compounds was predicted by in silico methods.RESULTS: Overall, 44 compounds were annotated in this study. The results revealed that P. brasiliensis has a high content of fatty acids, flavones, flavan-3-ols, and lignans. Furthermore, in vitro assays revealed potent antiviral activity against different arboviruses, especially lignan-rich extracts against Zika virus (ZIKV), as follows: methanolic extract from bark (MEB) [effective concentration for 50% of the cells (EC50 ) = 0.80 μg/mL, selectivity index (SI) = 377.59], methanolic extract from the leaf (MEL) (EC50 = 0.84 μg/mL, SI = 297.62), and hydroalcoholic extract from the leaf (HEL) (EC50 = 1.36 μg/mL, SI = 735.29). These results were supported by interesting in silico prediction, where tuberculatin (a lignan) showed a high antiviral activity score.CONCLUSIONS: Phyllanthus brasiliensis extracts contain metabolites that could be a new kick-off point for the discovery of candidates for antiviral drug development, with lignans becoming a promising trend for further virology research.PMID:37403427 | DOI:10.1002/pca.3259

An integrated fecal metabolomic based on <sup>1</sup> H-NMR and UPLC-QTOF-MS revealed the preventive mechanism of Gushudan on glucocorticoid-induced osteoporotic rats

Wed, 05/07/2023 - 12:00
Biomed Chromatogr. 2023 Jul 4:e5693. doi: 10.1002/bmc.5693. Online ahead of print.ABSTRACTGushudan (GSD) has the effect of strengthening bones and nourishing kidneys. However, its specific intervention mechanism still remains unclear. In this study, to investigate the pathogenesis of glucocorticoid-induced osteoporosis (GIOP) and the preventive mechanism of GSD on GIOP, fecal metabolomics based on 1 H-NMR and ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry method was established. The changes in endogenous metabolites and the relevant metabolic pathways in the control group, model group, and GSD treatment group were investigated via multivariate statistical analysis. As a result, a total of 39 differential metabolites were identified. Of these, 22 metabolites, such as L-methionine, guanine, and sphingosine, were newly discovered as differential metabolites of GIOP. Amino acid metabolism, energy metabolism, intestinal flora metabolism, and lipid metabolism were significantly changed in the fecal profiles of GIOP rats, and GSD could play an anti-osteoporosis role by regulating these metabolic pathways. Finally, compared with our previous study of the GSD to prevent kidney yang deficiency syndrome, this study suggested that there were some identical differential metabolites and metabolic pathways. It showed that there was some correlation among the metabolic profiles of the intestine, kidney, and bone in GIOP rats. Therefore, this study offered new insights into the in-depth understanding of the pathogenesis of GIOP and the intervention mechanism of GSD.PMID:37403411 | DOI:10.1002/bmc.5693

Systemic analysis of metabolome reconfiguration in Arabidopsis after abiotic stressors uncovers metabolites modulating defence against pathogens

Wed, 05/07/2023 - 12:00
Plant Commun. 2023 Jul 4:100645. doi: 10.1016/j.xplc.2023.100645. Online ahead of print.ABSTRACTUnderstanding plant immune responses is complex due to the high interdependence among biological processes in homeostatic networks. Hence, the integration of environmental cues causes network rewiring that interferes with defence responses. Similarly, plants retain molecular signatures configured under abiotic stress periods to rapidly respond to recurrent stress that can alter immunity. Metabolome changes imposed by abiotic stressors are persistent, although the impact on defence is elusive. In this study, we profiled metabolomes of Arabidopsis plants under several abiotic stress treatments applied individually or simultaneously to capture temporal trajectories in metabolite composition during adverse conditions and recovery. Further systemic analysis was conducted to address the relevance of metabolome changes and extract central features to be tested in planta. Our results demonstrate irreversibility in major fractions of metabolome changes as a general pattern in response to abiotic stress periods. Functional analysis of metabolomes and co-abundance networks points to convergences in the reconfiguration of the metabolism of organic acids and secondary metabolites. Arabidopsis mutant lines for components related to these metabolic pathways displayed altered defence capacities against different pathogens. Collectively, our data support that sustained metabolome changes configured during adverse environments can act as modulators of immune responses and provide evidence for a new layer of regulation in plant defence.PMID:37403356 | DOI:10.1016/j.xplc.2023.100645

Ozone-enabled fatty acid discovery reveals unexpected diversity in the human lipidome

Tue, 04/07/2023 - 12:00
Nat Commun. 2023 Jul 4;14(1):3940. doi: 10.1038/s41467-023-39617-9.ABSTRACTFatty acid isomers are responsible for an under-reported lipidome diversity across all kingdoms of life. Isomers of unsaturated fatty acids are often masked in contemporary analysis by incomplete separation and the absence of sufficiently diagnostic methods for structure elucidation. Here, we introduce a comprehensive workflow, to discover unsaturated fatty acids through coupling liquid chromatography and mass spectrometry with gas-phase ozonolysis of double bonds. The workflow encompasses semi-automated data analysis and enables de novo identification in complex media including human plasma, cancer cell lines and vernix caseosa. The targeted analysis including ozonolysis enables structural assignment over a dynamic range of five orders of magnitude, even in instances of incomplete chromatographic separation. Thereby we expand the number of identified plasma fatty acids two-fold, including non-methylene-interrupted fatty acids. Detection, without prior knowledge, allows discovery of non-canonical double bond positions. Changes in relative isomer abundances reflect underlying perturbations in lipid metabolism.PMID:37402773 | PMC:PMC10319862 | DOI:10.1038/s41467-023-39617-9

Differentiation of the metabolic profile of actinobacteria isolated from the soil of the caatinga biome by paper spray mass spectrometry

Tue, 04/07/2023 - 12:00
J Mass Spectrom. 2023 Jul;58(7):e4956. doi: 10.1002/jms.4956.ABSTRACTPaper spray mass spectrometry (PS-MS) is an ambient ionization technique that allows for rapid and direct mass spectrometry analysis for a wide range of chemical compounds due to its portability, little to no sample preparation, and cost-effective materials. As applications with this technique continue to expand, the identification and discrimination of bacteria at the strain level remain a promising avenue for researchers. Although studies in the past demonstrated the applicability of PS-MS to discriminate bacteria at the strain level, no one has reported the strain-level differentiation of actinobacteria without using solvent for PS-MS. Hence, this study demonstrates that optimization of PS-MS permits the investigation and differentiation of the metabolic profiles of actinobacteria without the need for solvents, diminishing the potential for sample contamination and consequently increasing the versatility of this technique. In doing so, strains of actinobacteria (CAAT P5-21, CAAT P5-16, CAAT 8-25, CAAT P8-92, and CAAT P11-13) were grown and transferred to produce a crude growth medium. The supernatant was used for the PS-MS analyses using a Thermo Scientific LTQ mass spectrometer. Multivariate statistical analysis, including principal component analysis (PCA) and hierarchal cluster analysis (HCA), was employed to chemically distinguish the strains of bacteria. As a result, each strain of actinobacteria could be visually differentiated based on their metabolic profile. These findings demonstrate the practicability of using a liquid medium as an alternative to many other organic solvents when analyzing bacteria, making PS-MS a crucial addition to a microbiologist's research toolkit.PMID:37401101 | DOI:10.1002/jms.4956

CO<sub>2</sub> enhances low-nitrogen adaption by promoting amino acid metabolism in Brassica napus

Tue, 04/07/2023 - 12:00
Plant Physiol Biochem. 2023 Jun 26;201:107864. doi: 10.1016/j.plaphy.2023.107864. Online ahead of print.ABSTRACTIncreasing concentrations of atmospheric CO2 are driving climate change and negatively impacting the carbon-nitrogen (C/N) balance in crops, which in turn alters fertilizer use efficiency. In this study, Brassica napus was cultivated under different CO2 and NO3--N concentrations to study the impact of C/N ratio on plant growth. Elevated CO2 enhanced biomass and nitrogen assimilation efficiency under low NO3--N conditions, indicating an adaptation by Brassica napus. Transcriptome and metabolome analyses revealed that elevated CO2 promoted amino acid catabolism under low NO3--N conditions. This study provides new insights into how Brassica napus adapts to environmental change.PMID:37402344 | DOI:10.1016/j.plaphy.2023.107864

Rapid and Online Detection of Foodborne Bacteria via a Novel Ultraviolet Photoionization Time-of-Flight Mass Spectrometry

Tue, 04/07/2023 - 12:00
J Agric Food Chem. 2023 Jul 4. doi: 10.1021/acs.jafc.3c01486. Online ahead of print.ABSTRACTFoodborne bacteria are widespread contaminated sources of food; hence, the real-time monitoring of pathogenic bacteria in food production is important for the food industry. In this study, a novel rapid detection method based on microbial volatile organic compounds (MVOCs) emitted from foodborne bacteria was established by using ultraviolet photoionization time-of-flight mass spectrometry (UVP-TOF-MS). The results showed obvious differences of MVOCs among the five species of bacteria, and the characteristic MVOCs for each bacterium were selected by a feature selection algorithm. Online monitoring of MVOCs during bacterial growth displayed distinct metabolomic patterns of the five species. MVOCs were most abundant and varied among species during the logarithmic phase. Finally, MVOC production by bacteria in different food matrixes was explored. The machine learning models for bacteria cultured in different matrixes showed a good classification performance for the five species with an accuracy of over 0.95. This work based on MVOC analysis by online UVP-TOF-MS achieved effective rapid detection of bacteria and showed its great application potential in the food industry for bacterial monitoring.PMID:37402704 | DOI:10.1021/acs.jafc.3c01486

COVRECON: Automated Integration of Genome- and Metabolome- Scale Network Reconstruction and Data-driven Inverse Modeling of Metabolic Interaction Neworks

Tue, 04/07/2023 - 12:00
Bioinformatics. 2023 Jul 4:btad397. doi: 10.1093/bioinformatics/btad397. Online ahead of print.ABSTRACTMOTIVATION: One central goal of systems biology is to infer biochemical regulations from large-scale OMICS data. Many aspects of cellular physiology and organismal phenotypes can be understood as results of metabolic interaction network dynamics. Previously, we have proposed a convenient mathematical method which addresses this problem using metabolomics data for the inverse calculation of biochemical Jacobian matrices revealing regulatory checkpoints of biochemical regulations. The proposed algorithms for this inference are limited by two issues: they rely on structural network information that needs to be assembled manually, and they are numerically unstable due to ill-conditioned regression problems for large-scale metabolic networks.RESULTS: To address these problems we developed a novel regression-loss based inverse Jacobian algorithm, combining metabolomics COVariance and genome-scale metabolic RECONstruction, which allows for a fully automated, algorithmic implementation of the COVRECON workflow. It consists of two parts: a, Sim-Network and b, Inverse differential Jacobian evaluation. Sim-Network automatically generates an organism-specific enzyme and reaction dataset from Bigg and KEGG databases, which is then used to reconstruct the Jacobian's structure for a specific metabolomics dataset. Instead of directly solving a regression problem as in the previous workflow, the new inverse differential Jacobian is based on a substantially more robust approach and rates the biochemical interactions according to their relevance from large-scale metabolomics data.The approach is illustrated by in silico stochastic analysis with differently-sized metabolic networks from the BioModels database and applied to a real-world example. The characteristics of the COVRECON implementation are that i) it automatically reconstructs a data-driven superpathway model; ii) more general network structures can be investigated and iii) the new inverse algorithm improves stability, decreases computation time, and extends to large-scale models.AVAILABILITY: The code is available in the website https://bitbucket.org/mosys-univie/covrecon.SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.PMID:37402625 | DOI:10.1093/bioinformatics/btad397

Casein as protein and hydrolysate: biostimulant or nitrogen source for Nicotiana tabacum plants grown in vitro?

Tue, 04/07/2023 - 12:00
Physiol Plant. 2023 Jul 4:e13973. doi: 10.1111/ppl.13973. Online ahead of print.ABSTRACTIn contrast to inorganic nitrogen (N) assimilation, the role of organic N forms, such as proteins and peptides, as sources of N and their impact on plant metabolism remains unclear. Simultaneously, organic biostimulants are used as priming agents to improve plant defense response. Here, we analyzed the metabolic response of tobacco plants grown in vitro with casein hydrolysate or protein. As the sole source of N, casein hydrolysate enabled tobacco growth, while protein casein was used only to a limited extent. Free amino acids were detected in the roots of tobacco plants grown with protein casein but not in the plants grown with no source of N. Combining hydrolysate with inorganic N had beneficial effects on growth, root N uptake and protein content. The metabolism of casein-supplemented plants shifted to aromatic (Trp), branched-chain (Ile, Leu, Val) and basic (Arg, His, Lys) amino acids, suggesting their preferential uptake and/or alterations in their metabolic pathways. Complementarily, proteomic analysis of tobacco roots identified peptidase C1A and peptidase S10 families as potential key players in casein degradation and response to N starvation. Moreover, amidases were significantly upregulated, most likely for their role in ammonia release and impact on auxin synthesis. In phytohormonal analysis, both forms of casein influenced phenylacetic acid and cytokinin contents, suggesting a root system response to scarce N availability. In turn, metabolomics highlighted the stimulation of some plant defense mechanisms under such growth conditions, i.e., the high concentrations of secondary metabolites (e.g. ferulic acid) and heat shock proteins. This article is protected by copyright. All rights reserved.PMID:37402155 | DOI:10.1111/ppl.13973

Recent advances in understanding brain cancer metabolomics: a review

Tue, 04/07/2023 - 12:00
Med Oncol. 2023 Jul 4;40(8):220. doi: 10.1007/s12032-023-02109-3.ABSTRACTRegardless of the significant progress made in surgical techniques and adjuvant therapies, brain tumors are a major contributor to cancer-related morbidity and mortality in both pediatric and adult populations. Gliomas represent a significant proportion of cerebral neoplasms, exhibiting diverse levels of malignancy. The etiology and mechanisms of resistance of this malignancy are inadequately comprehended, and the optimization of patient diagnosis and prognosis is a challenge due to the diversity of the disease and the restricted availability of therapeutic options. Metabolomics refers to the comprehensive analysis of endogenous and exogenous small molecules, both in a targeted and untargeted manner, that enables the characterization of an individual's phenotype and offers valuable insights into cellular activity, particularly in the context of cancer biology, including brain tumor biology. Metabolomics has garnered attention in current years due to its potential to facilitate comprehension of the dynamic spatiotemporal regulatory network of enzymes and metabolites that enables cancer cells to adapt to their environment and foster the development of tumors. Metabolic changes are widely acknowledged as a significant characteristic for tracking the advancement of diseases, treatment efficacy, and identifying novel molecular targets for successful medical management. Metabolomics has emerged as an exciting area for personalized medicine and drug discovery, utilizing advanced analytical techniques such as nuclear magnetic resonance spectroscopy (MRS) and mass spectrometry (MS) to achieve high-throughput analysis. This review examines and highlights the latest developments in MRS, MS, and other technologies in studying human brain tumor metabolomics.PMID:37402029 | DOI:10.1007/s12032-023-02109-3

Metabolomics investigation of post-mortem human pericardial fluid

Tue, 04/07/2023 - 12:00
Int J Legal Med. 2023 Jul 4. doi: 10.1007/s00414-023-03050-w. Online ahead of print.ABSTRACTINTRODUCTION: Due to its peculiar anatomy and physiology, the pericardial fluid is a biological matrix of particular interest in the forensic field. Despite this, the available literature has mainly focused on post-mortem biochemistry and forensic toxicology, while to the best of authors' knowledge post-mortem metabolomics has never been applied. Similarly, estimation of the time since death or post-mortem interval based on pericardial fluids has still rarely been attempted.OBJECTIVES: We applied a metabolomic approach based on 1H nuclear magnetic resonance spectroscopy to ascertain the feasibility of monitoring post-mortem metabolite changes on human pericardial fluids with the aim of building a multivariate regression model for post-mortem interval estimation.METHODS: Pericardial fluid samples were collected in 24 consecutive judicial autopsies, in a time frame ranging from 16 to 170 h after death. The only exclusion criterion was the quantitative and/or qualitative alteration of the sample. Two different extraction protocols were applied for low molecular weight metabolites selection, namely ultrafiltration and liquid-liquid extraction. Our metabolomic approach was based on the use of 1H nuclear magnetic resonance and multivariate statistical data analysis.RESULTS: The pericardial fluid samples treated with the two experimental protocols did not show significant differences in the distribution of the metabolites detected. A post-mortem interval estimation model based on 18 pericardial fluid samples was validated with an independent set of 6 samples, giving a prediction error of 33-34 h depending on the experimental protocol used. By narrowing the window to post-mortem intervals below 100 h, the prediction power of the model was significantly improved with an error of 13-15 h depending on the extraction protocol. Choline, glycine, ethanolamine, and hypoxanthine were the most relevant metabolites in the prediction model.CONCLUSION: The present study, although preliminary, shows that PF samples collected from a real forensic scenario represent a biofluid of interest for post-mortem metabolomics, with particular regard to the estimation of the time since death.PMID:37402012 | DOI:10.1007/s00414-023-03050-w

ER-mitochondria contacts and cholesterol metabolism are disrupted by disease-associated tau protein

Tue, 04/07/2023 - 12:00
EMBO Rep. 2023 Jul 4:e57499. doi: 10.15252/embr.202357499. Online ahead of print.ABSTRACTAbnormal tau protein impairs mitochondrial function, including transport, dynamics, and bioenergetics. Mitochondria interact with the endoplasmic reticulum (ER) via mitochondria-associated ER membranes (MAMs), which coordinate and modulate many cellular functions, including mitochondrial cholesterol metabolism. Here, we show that abnormal tau loosens the association between the ER and mitochondria in vivo and in vitro. Especially, ER-mitochondria interactions via vesicle-associated membrane protein-associated protein (VAPB)-protein tyrosine phosphatase-interacting protein 51 (PTPIP51) are decreased in the presence of abnormal tau. Disruption of MAMs in cells with abnormal tau alters the levels of mitochondrial cholesterol and pregnenolone, indicating that conversion of cholesterol into pregnenolone is impaired. Opposite effects are observed in the absence of tau. Besides, targeted metabolomics reveals overall alterations in cholesterol-related metabolites by tau. The inhibition of GSK3β decreases abnormal tau hyperphosphorylation and increases VAPB-PTPIP51 interactions, restoring mitochondrial cholesterol and pregnenolone levels. This study is the first to highlight a link between tau-induced impairments in the ER-mitochondria interaction and cholesterol metabolism.PMID:37401859 | DOI:10.15252/embr.202357499

MFN2 deficiency promotes cardiac response to hypobaric hypoxia by reprogramming cardiomyocyte metabolism

Tue, 04/07/2023 - 12:00
Acta Physiol (Oxf). 2023 Jul 4:e14018. doi: 10.1111/apha.14018. Online ahead of print.ABSTRACTAIM: Under hypobaric hypoxia (HH), the heart triggers various defense mechanisms including metabolic remodeling against lack of oxygen. Mitofusin 2 (MFN2), located at the mitochondrial outer membrane, is closely involved in the regulation of mitochondrial fusion and cell metabolism. To date, however, the role of MFN2 in cardiac response to HH has not been explored.METHODS: Loss- and gain-of-function approaches were used to investigate the role of MFN2 in cardiac response to HH. In vitro, the function of MFN2 in the contraction of primary neonatal rat cardiomyocytes under hypoxia was examined. Non-targeted metabolomics and mitochondrial respiration analyses, as well as functional experiments were performed to explore underlying molecular mechanisms.RESULTS: Our data demonstrated that, following 4 weeks of HH, cardiac-specific MFN2 knockout (MFN2 cKO) mice exhibited significantly better cardiac function than control mice. Moreover, restoring the expression of MFN2 clearly inhibited the cardiac response to HH in MFN2 cKO mice. Importantly, MFN2 knockout significantly improved cardiac metabolic reprogramming during HH, resulting in reduced capacity for fatty acid oxidation (FAO) and oxidative phosphorylation, and increased glycolysis and ATP production. In vitro data showed that down-regulation of MFN2 promoted cardiomyocyte contractility under hypoxia. Interestingly, increased FAO through palmitate treatment decreased contractility of cardiomyocyte with MFN2 knockdown under hypoxia. Furthermore, treatment with mdivi-1, an inhibitor of mitochondrial fission, disrupted HH-induced metabolic reprogramming and subsequently promoted cardiac dysfunction in MFN2-knockout hearts.CONCLUSION: Our findings provide the first evidence that down-regulation of MFN2 preserves cardiac function in chronic HH by promoting cardiac metabolic reprogramming.PMID:37401731 | DOI:10.1111/apha.14018

High-fat diet alters the radiation tolerance of female mice and the modulatory effect of melatonin

Tue, 04/07/2023 - 12:00
Food Funct. 2023 Jul 4. doi: 10.1039/d3fo01831h. Online ahead of print.ABSTRACTHigh-fat diet (HFD) increases the risk of developing malignant tumors. Ionizing radiation (IR) is used as an adjuvant treatment in oncology. In this study, we investigated the effects of an 8-week 35% fat HFD on the tolerance to IR and the modulatory effect of melatonin (MLT). The results of lethal dose irradiation survival experiments revealed that the 8-week HFD altered the radiation tolerance of female mice and increased their radiosensitivity, whereas it had no comparable effects on males. Pre-treatment with MLT was, however, found to attenuate the radiation-induced hematopoietic damage in mice, promote intestinal structural repair after whole abdominal irradiation (WAI), and enhance the regeneration of Lgr5+ intestinal stem cells. 16S rRNA high-throughput sequencing and untargeted metabolome analyses revealed that HFD consumption and WAI sex-specifically altered the composition of intestinal microbiota and fecal metabolites and that MLT supplementation differentially modulated the composition of the intestinal microflora in mice. However, in both males and females, different bacteria were associated with the modulation of the metabolite 5-methoxytryptamine. Collectively, the findings indicate that MLT ameliorates the radiation-induced damage and sex-specifically shapes the composition of the gut microbiota and metabolites, protecting mice from the adverse side effects associated with HFD and IR.PMID:37401725 | DOI:10.1039/d3fo01831h

Time-Dependent Changes in the Bladder Muscle Metabolome After Traumatic Spinal Cord Injury in Rats Using Metabolomics

Tue, 04/07/2023 - 12:00
Int Neurourol J. 2023 Jun;27(2):88-98. doi: 10.5213/inj.2346068.034. Epub 2023 Jun 30.ABSTRACTPURPOSE: The main treatment options of neurogenic bladder remains catheterization and long-term oral medications. Metabolic interventions have shown good therapeutic results in many diseases. To date, no studies have characterized the metabolites of the detrusor muscle during neurogenic bladder. Using metabolomics, new muscle metabolomic signatures were identified to reveal the temporal metabolic profile of muscle during disease progression.METHODS: We used 42 Sprague-Dawley rats (200±20 g, males) for T10 segmental spinal cord injury modeling and collected detrusor tissue and performed nontargeted metabolomics after sham surgery, 30-minute, 6-hour, 12-hour, 24-hour, 5-day, and 2-week postmodelling, to identify the dysregulated metabolic pathways and key metabolites.RESULTS: By comparing mzCloud, mzVault, MassList, we identified a total of 1,271 metabolites and enriched a total of 12 metabolism-related pathways with significant differences (P<0.05) based on Kyoto Encyclopedia of Genes and Genomes analysis. Metabolites in several differential metabolic pathways such as ascorbate and aldarate metabolism, Steroid hormone biosynthesis, and carbon metabolism are altered in a regular manner before and after ridge shock.CONCLUSION: Our study is the first time-based metabolomic study of rat forced urinary muscle after traumatic spinal cord injury, and we identified multiple differential metabolic pathways during injury that may improve long-term management strategies for neurogenic bladder and reduce costs in long-term treatment.PMID:37401019 | DOI:10.5213/inj.2346068.034

Diet high in linoleic acid dysregulates the intestinal endocannabinoid system and increases susceptibility to colitis in Mice

Tue, 04/07/2023 - 12:00
Gut Microbes. 2023 Jan-Dec;15(1):2229945. doi: 10.1080/19490976.2023.2229945.ABSTRACTInflammatory bowel disease (IBD) is a multifactorial disease with increasing incidence in the U.S. suggesting that environmental factors, including diet, are involved. It has been suggested that excessive consumption of linoleic acid (LA, C18:2 omega-6), which must be obtained from the diet, may promote the development of IBD in humans. To demonstrate a causal link between LA and IBD, we show that a high fat diet (HFD) based on soybean oil (SO), which is comprised of ~55% LA, increases susceptibility to colitis in several models, including IBD-susceptible IL10 knockout mice. This effect was not observed with low-LA HFDs derived from genetically modified soybean oil or olive oil. The conventional SO HFD causes classical IBD symptoms including immune dysfunction, increased intestinal epithelial barrier permeability, and disruption of the balance of isoforms from the IBD susceptibility gene Hepatocyte Nuclear Factor 4α (HNF4α). The SO HFD causes gut dysbiosis, including increased abundance of an endogenous adherent invasive Escherichia coli (AIEC), which can use LA as a carbon source. Metabolomic analysis shows that in the mouse gut, even in the absence of bacteria, the presence of soybean oil increases levels of LA, oxylipins and prostaglandins. Many compounds in the endocannabinoid system, which are protective against IBD, are decreased by SO both in vivo and in vitro. These results indicate that a high LA diet increases susceptibility to colitis via microbial and host-initiated pathways involving alterations in the balance of bioactive metabolites of omega-6 and omega-3 polyunsaturated fatty acids, as well as HNF4α isoforms.PMID:37400966 | DOI:10.1080/19490976.2023.2229945

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