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

Using a multiomics approach to unravel a septic shock specific signature in skeletal muscle

Sun, 06/11/2022 - 12:00
Sci Rep. 2022 Nov 5;12(1):18776. doi: 10.1038/s41598-022-23544-8.ABSTRACTSepsis is defined as a dysregulated host response to infection leading to organs failure. Among them, sepsis induces skeletal muscle (SM) alterations that contribute to acquired-weakness in critically ill patients. Proteomics and metabolomics could unravel biological mechanisms in sepsis-related organ dysfunction. Our objective was to characterize a distinctive signature of septic shock in human SM by using an integrative multi-omics approach. Muscle biopsies were obtained as part of a multicenter non-interventional prospective study. Study population included patients in septic shock (S group, with intra-abdominal source of sepsis) and two critically ill control populations: cardiogenic shock (C group) and brain dead (BD group). The proteins and metabolites were extracted and analyzed by High-Performance Liquid Chromatography-coupled to tandem Mass Spectrometry, respectively. Fifty patients were included, 19 for the S group (53% male, 64 ± 17 years, SAPS II 45 ± 14), 12 for the C group (75% male, 63 ± 4 years, SAPS II 43 ± 15), 19 for the BD group (63% male, 58 ± 10 years, SAPS II 58 ± 9). Biopsies were performed in median 3 days [interquartile range 1-4]) after intensive care unit admission. Respectively 31 patients and 40 patients were included in the proteomics and metabolomics analyses of 2264 proteins and 259 annotated metabolites. Enrichment analysis revealed that mitochondrial pathways were significantly decreased in the S group at protein level: oxidative phosphorylation (adjusted p = 0.008); branched chained amino acids degradation (adjusted p = 0.005); citrate cycle (adjusted p = 0.005); ketone body metabolism (adjusted p = 0.003) or fatty acid degradation (adjusted p = 0.008). Metabolic reprogramming was also suggested (i) by the differential abundance of the peroxisome proliferator-activated receptors signaling pathway (adjusted p = 0.007), and (ii) by the accumulation of fatty acids like octanedioic acid dimethyl or hydroxydecanoic. Increased polyamines and depletion of mitochondrial thioredoxin or mitochondrial peroxiredoxin indicated a high level of oxidative stress in the S group. Coordinated alterations in the proteomic and metabolomic profiles reveal a septic shock signature in SM, highlighting a global impairment of mitochondria-related metabolic pathways, the depletion of antioxidant capacities, and a metabolic shift towards lipid accumulation.ClinicalTrial registration: NCT02789995. Date of first registration 03/06/2016.PMID:36335235 | DOI:10.1038/s41598-022-23544-8

RNA-binding proteins of KHDRBS and IGF2BP families control the oncogenic activity of MLL-AF4

Sun, 06/11/2022 - 12:00
Nat Commun. 2022 Nov 5;13(1):6688. doi: 10.1038/s41467-022-34558-1.ABSTRACTChromosomal translocation generates the MLL-AF4 fusion gene, which causes acute leukemia of multiple lineages. MLL-AF4 is a strong oncogenic driver that induces leukemia without additional mutations and is the most common cause of pediatric leukemia. However, establishment of a murine disease model via retroviral transduction has been difficult owning to a lack of understanding of its regulatory mechanisms. Here, we show that MLL-AF4 protein is post-transcriptionally regulated by RNA-binding proteins, including those of KHDRBS and IGF2BP families. MLL-AF4 translation is inhibited by ribosomal stalling, which occurs at regulatory sites containing AU-rich sequences recognized by KHDRBSs. Synonymous mutations disrupting the association of KHDRBSs result in proper translation of MLL-AF4 and leukemic transformation. Consequently, the synonymous MLL-AF4 mutant induces leukemia in vivo. Our results reveal that post-transcriptional regulation critically controls the oncogenic activity of MLL-AF4; these findings might be valuable in developing novel therapies via modulation of the activity of RNA-binding proteins.PMID:36335100 | DOI:10.1038/s41467-022-34558-1

Genetic and environmental circadian disruption induce weight gain through changes in the gut microbiome

Sat, 05/11/2022 - 11:00
Mol Metab. 2022 Nov 2:101628. doi: 10.1016/j.molmet.2022.101628. Online ahead of print.ABSTRACTOBJECTIVE: Internal clocks time behavior and physiology, including the gut microbiome, in a circadian (∼24 h) manner. Mismatch between internal and external time, e.g. during shift work, disrupts circadian system coordination promoting the development of obesity and type 2 diabetes (T2D). Conversely, body weight changes induce microbiota dysbiosis. The relationship between circadian disruption and microbiota dysbiosis in metabolic diseases, however, remains largely unknown.METHODS: Core and accessory clock gene expression in different gastrointestinal (GI) tissues were determined by qPCR in two different models of circadian disruption - mice with Bmal1 deficiency in the circadian pacemaker, the suprachiasmatic nucleus (Bmal1SCNfl/-), and wild-type mice exposed to simulated shift work (SSW). Body composition and energy balance were evaluated by nuclear magnetic resonance (NMR), bomb calorimetry, food intake and running-wheel activity. Intestinal permeability was measured in an Ussing chamber. Microbiota composition and functionality were evaluated by 16S rRNA gene amplicon sequencing, PICRUST2.0 analysis and targeted metabolomics. Finally, microbiota transfer was conducted to evaluate the functional impact of SSW-associated microbiota on the host's physiology.RESULTS: Both chronodisruption models show desynchronization within and between peripheral clocks in GI tissues and reduced microbial rhythmicity, in particular in taxa involved in short-chain fatty acid (SCFA) fermentation and lipid metabolism. In Bmal1SCNfl/- mice, loss of rhythmicity in microbial functioning associates with previously shown increased body weight, dysfunctional glucose homeostasis and adiposity. Similarly, we observe an increase in body weight in SSW mice. Germ-free colonization experiments with SSW-associated microbiota mechanistically link body weight gain to microbial changes. Moreover, alterations in expression of peripheral clock genes as well as clock-controlled genes (CCGs) relevant for metabolic functioning of the host were observed in recipients, indicating a bidirectional relationship between microbiota rhythmicity and peripheral clock regulation.CONCLUSIONS: Collectively, our data suggest that loss of rhythmicity in bacteria taxa and their products, which likely originates in desynchronization of intestinal clocks, promotes metabolic abnormalities during shift work.PMID:36334897 | DOI:10.1016/j.molmet.2022.101628

Dose-effect of polystyrene microplastics on digestive toxicity in chickens (Gallus gallus): Multi-omics reveals critical role of gut-liver axis

Sat, 05/11/2022 - 11:00
J Adv Res. 2022 Nov 2:S2090-1232(22)00244-2. doi: 10.1016/j.jare.2022.10.015. Online ahead of print.ABSTRACTINTRODUCTION: Microplastic pollution seriously threatens the health and safety of humans and wildlife. Avian is one of the main species endangered by microplastics. However, the damage mechanism of microplastics to the digestive system of avian is not clear.OBJECTIVES: The gut-liver axis is a bidirectional channel that regulates the exchange of information between the gut and the liver and is also a key target for tissue damage caused by pollutants. This study aimed to elucidate the digestive toxicity of microplastics in avian and the key role of the gut-liver axis in it.METHODS: We constructed an exposure model for microplastics in environmental concentrations and toxicological concentrations in chickens and reveal the digestive toxicity of polystyrene microplastics (PS-MPs) in avian by 16S rRNA, transcriptomics and metabolomics.RESULTS: PS-MPs changed the death mode from apoptosis to necrosis and pyroptosis by upregulating Caspase 8, disrupting the intestinal vascular barrier, disturbing the intestinal flora and promoting the accumulation of lipopolysaccharide. Harmful flora and metabolites were translocated to the liver through the liver-gut axis, eliciting hepatic immune responses and promoting hepatic lipid metabolism disorders and apoptosis. Liver injury involves multiple molecular effects of mitochondrial dynamics disturbance, oxidative stress, endoplasmic reticulum stress, and cell cycle disturbance. Furthermore, metabolomics suggested that caffeine and melanin metabolites may be potential natural resistance substances for microplastics CONCLUSION: Taken together, our data demonstrate the digestive damage of PS-MPs in avian, revealing a critical role of the liver-gut axis in it. This will provide a reference for protecting the safety of avian populations.PMID:36334886 | DOI:10.1016/j.jare.2022.10.015

Phytosphingosine-induced cell apoptosis via a mitochondrially mediated pathway

Sat, 05/11/2022 - 11:00
Toxicology. 2022 Nov 2:153370. doi: 10.1016/j.tox.2022.153370. Online ahead of print.ABSTRACTCyanobacterial blooms, usually dominated by Microcystis aeruginosa, pose a serious threat to global freshwater ecosystems owing to their production and release of various harmful secondary metabolites. Detection of the chemicals in M. aeruginosa exudates using metabolomics technology revealed that phytosphingosine (PHS) was one of the most abundant compounds. However, its specific toxicological mechanism remained unclear. CNE-2 cells were selected to illustrate the cytotoxic mechanism of PHS, and it was determined to cause excessive production of reactive oxygen species and subsequently damage the mitochondrial structure. Mitochondrial membrane rupture led to matrix mitochondrial membrane potential disintegration, which induced Ca2+ overload and interrupted ATP synthesis. Furthermore, rupture of the mitochondrial membrane induced the opening of the permeability transition pore, which caused the release of proapoptotic factors into the cytoplasm and the expression of apoptosis-related proteins Bax, Bcl-2, cytochrome-c and cleaved caspase-3 in CNE-2 cells. These events, in turn, activated the mitochondrially mediated intrinsic apoptotic pathway. A mitochondrial repair mechanism, namely, PINK1/Parkin-mediated mitophagy, was then blocked, which further promoted apoptosis. Our findings suggest that more attention should be paid to the ecotoxicity of PHS, which is already listed as a contaminant of emerging concern.PMID:36334778 | DOI:10.1016/j.tox.2022.153370

Physiological and metabolic toxicity of polystyrene microplastics to Dunaliella salina

Sat, 05/11/2022 - 11:00
Environ Pollut. 2022 Nov 2:120544. doi: 10.1016/j.envpol.2022.120544. Online ahead of print.ABSTRACTThe toxicity of microplastics (MPs) to marine microalgae has raised much concern. However, research at metabolic level is quite limited. In this study, the physiological and metabolic effects of polystyrene (PS) and aged polystyrene (A-PS) MPs on Dunaliella salina were investigated. Both PS and A-PS inhibited the growth of microalgae, but promoted the pigment synthesis in algal cells. The oxidative stress analysis indicated that PS and A-PS induced high production of reactive oxygen species (ROS), and caused oxidative damage to algal cells. Particularly, the highest ROS level in PS and A-PS groups were 1.70- and 2.24-fold of that in the control group, respectively. Untargeted metabolomics analysis indicated that PS and A-PS significantly increased the differential metabolites. Compared with the control group, the significant upregulation of glycerophospholipids metabolites illustrated that severe membrane lipid peroxidation occurred in the MPs groups. Metabolic pathways analysis showed that PS and A-PS perturbed the amino acid-related metabolic pathways. In particular, the amino acid biosynthesis and ATP-binding cassette (ABC) transporter pathways were significantly upregulated, thus promoting nitrogen storage and transmembrane transport in Dunaliella salina. Transmembrane transport requires a large amount of ATP; as a result, algal cell division is inhibited. In addition, A-PS stimulated more active glutathione metabolism than PS. These results enrich the understanding of the toxicity of PS MPs to microalgae at the metabolic level, and are helpful for further assessing the ecological impacts of MPs on microalgae.PMID:36334776 | DOI:10.1016/j.envpol.2022.120544

Bacillus amyloliquefaciens modulate sugar metabolism to mitigate arsenic toxicity in Oryza sativa L. var Saryu-52

Sat, 05/11/2022 - 11:00
Chemosphere. 2022 Nov 2:137070. doi: 10.1016/j.chemosphere.2022.137070. Online ahead of print.ABSTRACTIn the current study, plant growth-promoting rhizobacterium Bacillus amyloliquefaciens SN13 (SN13) was evaluated for arsenic (As) toxicity amelioration potential under arsenate (AsV) and arsenite (AsIII) stress exposed to rice (Oryza sativa var Saryu-52) plants for 15 days. The PGPR-mediated alleviation of As toxicity was demonstrated by modulated measures such as proline, total soluble sugar, malondialdehyde content, enzymatic status, relative water content, and electrolytic leakage in treated rice seedlings under arsenic-stressed conditions as compared to the respective control. SN13 inoculation not only improved the agronomic traits but also modulated the micronutrient concentrations (Fe, Mo, Zn, Cu, and Co). The desirable results were obtained due to a significant decrease in the AsIII and AsV accumulation in the shoot (47 and 10 mg kg-1 dw), and the root (62 and 26 mg kg-1 dw) in B. amyloliquefaciens inoculated seedlings as compared to their uninoculated root (98 and 43 mg kg-1 dw) and shoot (57 and 12 mg kg-1 dw), respectively. Further, metabolome (GC-MS) analysis was performed to decipher the underlying PGPR-induced mechanisms under arsenic stress. A total of 67 distinct metabolites were identified, which influence the metabolic and physiological factors to modulate the As stress. The expression analysis of metabolism- and stress-responsive genes further proclaimed the involvement of SN13 through modulating the carbohydrate metabolism in rice seedlings, to enable improved growth and As stress tolerance.PMID:36334743 | DOI:10.1016/j.chemosphere.2022.137070

Transcriptomic and metabolomic investigation of molecular inactivation mechanisms in Escherichia coli triggered by graphene quantum dots

Sat, 05/11/2022 - 11:00
Chemosphere. 2022 Nov 2:137051. doi: 10.1016/j.chemosphere.2022.137051. Online ahead of print.ABSTRACTGraphene quantum dots (GQDs), a novel broad-spectrum antibacterial agent, are considered potential candidates in the field of biomedical and food safety due to their outstanding antimicrobial properties and excellent biocompatibility. To uncover the molecular regulatory mechanisms underlying the phenotypes, the overall regulation of genes and metabolites in Escherichia coli (E. coli) after GQDs stimulation was investigated by RNA-sequencing and LC-MS. Gene transcription and metabolite expression related to a series of crucial biomolecular processes were influenced by the GQDs stimulation, including biofilm formation, bacterial secretion system, sulfur metabolism and nitrogen metabolism, etc. This study could provide profound insights into the GQDs stress response in E. coli, which would be useful for the development and application of GQDs in food safety.PMID:36334733 | DOI:10.1016/j.chemosphere.2022.137051

Systematic Dissection, Preservation, and Multiomics in Whole Human and Bovine Hearts

Sat, 05/11/2022 - 11:00
Cardiovasc Pathol. 2022 Nov 2:107495. doi: 10.1016/j.carpath.2022.107495. Online ahead of print.ABSTRACTOBJECTIVES: We sought to develop a rigorous, systematic protocol for the dissection and preservation of human hearts for biobanking that expands previous success in postmortem transcriptomics to multiomics from paired tissue.BACKGROUND: Existing cardiac biobanks consist largely of biopsy tissue or explanted hearts in select diseases and are insufficient for correlating whole organ phenotype with clinical data.METHODS: We demonstrate optimal conditions for multiomics interrogation (ribonucleic acid (RNA) sequencing, untargeted metabolomics) in hearts by evaluating the effect of technical variables (storage solution, temperature) and simulated postmortem interval (PMI) on RNA and metabolite stability. We used bovine (n=3) and human (n=2) hearts fixed in PAXgene or snap-frozen with liquid nitrogen.RESULTS: Using a paired Wald test, only two of the genes assessed were differentially expressed between left ventricular samples from bovine hearts stored in PAXgene at 0 and 12 hours PMI (FDR q < 0.05). We obtained similar findings in human left ventricular samples, suggesting stability of RNA transcripts at PMIs up to 12 hours. Different library preparation methods (mRNA poly-A capture vs. rRNA depletion) resulted in similar quality metrics with both library preparations achieving >95% of reads properly aligning to the reference genomes across all PMIs for bovine and human hearts. PMI had no effect on RNA Integrity Number or quantity of RNA recovered at the time points evaluated. Of the metabolites identified (855 total) using untargeted metabolomics of human left ventricular tissue, 503 metabolites remained stable across PMIs (0, 4, 8, 12 hours). Most metabolic pathways retained several stable metabolites.CONCLUSIONS: Our data demonstrate a technically rigorous, reproducible protocol that will enhance cardiac biobanking practices and facilitate novel insights into human CVD.CONDENSED ABSTRACT: Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Current biobanking practices insufficiently capture both the diverse array of phenotypes present in CVDs and the spatial heterogeneity across cardiac tissue sites. We have developed a rigorous and systematic protocol for the dissection and preservation of human cardiac biospecimens to enhance the availability of whole organ tissue for multiple applications. When combined with longitudinal clinical phenotyping, our protocol will enable multiomics in hearts to deepen our understanding of CVDs.PMID:36334690 | DOI:10.1016/j.carpath.2022.107495

The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis

Sat, 05/11/2022 - 11:00
Phytomedicine. 2022 Oct 22;108:154520. doi: 10.1016/j.phymed.2022.154520. Online ahead of print.ABSTRACTBACKGROUND: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools.METHODS: In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST.RESULTS AND CONCLUSION: The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events.PMID:36334386 | DOI:10.1016/j.phymed.2022.154520

Mefunidone ameliorates lipopolysaccharide-induced acute lung injury through inhibiting MAPK signaling pathway and enhancing Nrf2 pathway

Sat, 05/11/2022 - 11:00
Int Immunopharmacol. 2022 Nov 2;113(Pt A):109263. doi: 10.1016/j.intimp.2022.109263. Online ahead of print.ABSTRACTBACKGROUND AND OBJECTIVE: Acute lung injury (ALI) is a life-threatening disease which has high mortality and lacks effective pharmacological treatments. Excessive inflammation and oxidative stress are the key pathogenesis of ALI. Mefunidone (MFD), a novel small molecule compound, displayed anti-inflammation and anti-oxidative stress effects on streptozocin (STZ) and db/db mice in our previous studies. In this study, we aimed to investigate the effects of MFD on lipopolysaccharide (LPS)-induced ALI and explore the potential molecular mechanisms.METHODS: We investigated the effects of MFD on LPS-induced ALI mouse model and LPS-stimulated immortalized mouse bone marrow-derived macrophages (iBMDMs).RESULTS: MFD could alleviate pulmonary structure disorder and attenuate pulmonary neutrophils infiltration induced by LPS. MFD could also decreased proinflammatory cytokines release and reduce reactive oxygen species (ROS) generation stimulated by LPS. Further, MFD could significantly reduce LPS-induced phosphorylation levels of mitogen-activated protein kinase (MAPK), increase expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) and restore the expressions of antioxidant enzymes.CONCLUSION: Our results firstly supported that MFD effectively protected LPS-induced ALI against inflammation and oxidative stress through inhibiting MAPK signaling pathway and activating Nrf2 pathway.PMID:36334370 | DOI:10.1016/j.intimp.2022.109263

Multi-omics analysis on seasonal variations of the biofilm microbial community in a full-scale pre-denitrification biofilter

Sat, 05/11/2022 - 11:00
Environ Sci Pollut Res Int. 2022 Nov 5. doi: 10.1007/s11356-022-23539-y. Online ahead of print.ABSTRACTThe seasonal variations of biofilm communities in a municipal wastewater treatment plant were investigated using multi-omics techniques. The abundance of the main phyla of microorganisms varied with summer (July 2019) and winter (January 2019) samples considerably, the Bacteroidetes enriched in winter and Chloroflexi in summer. The results of metaproteomic and metagenomic showed that most of the functional microorganisms belonged to the Betaproteobacteria class, and the enrichment of Flavobacteria class in winter guaranteed the stability of denitrification performance to some extent. Seasonal variations affected the proteomic expression profiling, a total of 2835 differentially expressed proteins identified were significantly enriched in quorum sensing, two-component system, ribosome, benzoate degradation, butanoate metabolism, tricarboxylic acid cycle (TCA cycle), and cysteine and methionine metabolism pathways. With the expression of nitrogen metabolic proteins decreases in winter, the overall expression of denitrification-related enzymes in winter was much lower than that in summer, the nitrogen metabolism pathway varied significantly. Seasonal variations also induced the alteration of the biofilm metabolite profile; a total of 66 differential metabolites, 8 potential biomarkers, and 8 perturbed metabolic pathways such as TCA cycle were detected. It was found that most of the perturbed pathways are directly related to nitrogen metabolism, and several amino acids and organic acids associated with the TCA cycle were significantly perturbed, the accumulation of TCA cycle intermediates, ornithine, and L-histidine in winter might be conducive to resisting cold temperatures. Furthermore, the correlation between biofilm microbial communities and metabolites was identified by the combined analysis of metabolomic and metaproteomic. The differences of microbial community structure, function, and metabolism between winter and summer in a full-scale pre-denitrification biofilter were revealed for the first time, strengthening our understanding of the microbial ecology of biofilm communities.PMID:36334202 | DOI:10.1007/s11356-022-23539-y

Metabolite profiling of tubers of an early- and a late-maturing potato line and their grafts

Sat, 05/11/2022 - 11:00
Metabolomics. 2022 Nov 5;18(11):88. doi: 10.1007/s11306-022-01950-3.ABSTRACTINTRODUCTION: Earliness of tuberisation and the quality of potato tubers are important traits in potato breeding. The qualitative traits rely on the metabolite profile of tubers, which are storage organs and net importers of assimilates. Thus, the quality of tubers largely depends on the metabolites transported from leaves to developing tubers.OBJECTIVES: To test the influence of canopy on the quality of tubers by metabolite profiling of tubers of an early- and a late-maturing potato line and their grafts.METHODS: Potatoes were grown under greenhouse conditions, grafted and the tubers harvested at the end of the scions' vegetation period. Metabolite profiling of freshly harvested tubers was performed using gas chromatography coupled with mass spectrometry. Statistical analyses were applied to determine the significant differences between the different tubers.RESULTS: 99 metabolites were identified and an additional 181 peaks detected in chromatograms, out of which 186 were polar and 94 non-polar compounds. The concentrations of 113 metabolites were significantly different in the tubers from the early-maturing CE3130 and the late-maturing CE3027 line. Hetero-grafting resulted in considerable changes in the metabolite content of tubers. Especially, the effect of CE3027 on the metabolite composition of tubers formed on CE3130 rootstocks was readily apparent. Nevertheless, many compounds were present at similar levels in the tubers of hetero-grafted plants as was found in the tubers of their scion counterparts.CONCLUSION: Hetero-grafting resulted in many compounds at similar concentrations in rootstock tubers as in scion tubers suggesting that these are transported from the source leaves to tubers.PMID:36334159 | DOI:10.1007/s11306-022-01950-3

Retinal regions shape human and murine Müller cell proteome profile and functionality

Sat, 05/11/2022 - 11:00
Glia. 2022 Nov 5. doi: 10.1002/glia.24283. Online ahead of print.ABSTRACTThe human macula is a highly specialized retinal region with pit-like morphology and rich in cones. How Müller cells, the principal glial cell type in the retina, are adapted to this environment is still poorly understood. We compared proteomic data from cone- and rod-rich retinae from human and mice and identified different expression profiles of cone- and rod-associated Müller cells that converged on pathways representing extracellular matrix and cell adhesion. In particular, epiplakin (EPPK1), which is thought to play a role in intermediate filament organization, was highly expressed in macular Müller cells. Furthermore, EPPK1 knockout in a human Müller cell-derived cell line led to a decrease in traction forces as well as to changes in cell size, shape, and filopodia characteristics. We here identified EPPK1 as a central molecular player in the region-specific architecture of the human retina, which likely enables specific functions under the immense mechanical loads in vivo.PMID:36334068 | DOI:10.1002/glia.24283

Deciphering interactions between the marine dinoflagellate Prorocentrum lima and the fungus Aspergillus pseudoglaucus

Sat, 05/11/2022 - 11:00
Environ Microbiol. 2022 Nov 4. doi: 10.1111/1462-2920.16271. Online ahead of print.ABSTRACTThe comprehension of microbial interactions is one of the key challenges in marine microbial ecology. This study focused on exploring chemical interactions between the toxic dinoflagellate Prorocentrum lima and a filamentous fungal species, Aspergillus pseudoglaucus, which has been isolated from the microalgal culture. Such interspecies interactions are expected to occur even though they were rarely studied. Here, a co-culture system was designed in a dedicated microscale marine-like condition. This system allowed to explore microalgal-fungal physical and metabolic interactions in presence and absence of the bacterial consortium. Microscopic observation showed an unusual physical contact between the fungal mycelium and dinoflagellate cells. To delineate specialized metabolome alterations during microalgal-fungal co-culture metabolomes were monitored by high-performance liquid chromatography coupled to high-resolution mass spectrometry. In-depth multivariate statistical analysis using dedicated approaches highlighted (1) the metabolic alterations associated with microalgal-fungal co-culture, and (2) the impact of associated bacteria in microalgal metabolome response to fungal interaction. Unfortunately, only a very low number of highlighted features were fully characterised. However, an up-regulation of the dinoflagellate toxins okadaic acid and dinophysistoxin 1 was observed during co-culture in supernatants. Such results highlight the importance to consider microalgal-fungal interactions in the study of parameters regulating toxin production. This article is protected by copyright. All rights reserved.PMID:36333915 | DOI:10.1111/1462-2920.16271

Metabolomics profiling in acute liver transplant rejection in a pediatric population

Sat, 05/11/2022 - 11:00
Sci Rep. 2022 Nov 4;12(1):18663. doi: 10.1038/s41598-022-18957-4.ABSTRACTPediatric liver transplantation rejection affects 20% of children. Currently, liver biopsy, expensive and invasive, is the best method of diagnosis. Discovery and validation of clinical biomarkers from blood or other biospecimens would improve clinical care. For this study, stored plasma samples were utilized from two cross-sectional cohorts of liver transplant patients at Children's Healthcare of Atlanta. High resolution metabolic profiling was completed using established methods. Children with (n = 18) or without (n = 25) acute cellular rejection were included in the analysis (n = 43 total). The mean age of these racially diverse cohorts ranged from 12.6 years in the rejection group and 13.6 years in the no rejection group. Linear regression provided 510 significantly differentiating metabolites between groups, and OPLS-DA showed 145 metabolites with VIP > 2. A total of 95 overlapping significant metabolites between OPLS-DA and linear regression analyses were detected. Pathway analysis (p < 0.05) showed bile acid biosynthesis and tryptophan metabolism as the top two differentiating pathways. Network analysis also identified tryptophan and clustered with liver enzymes and steroid use. We conclude metabolic profiling of plasma from children with acute liver transplant rejection demonstrates > 500 significant metabolites. This result suggests that development of a non-invasive biomarker-based test is possible for rejection screening.PMID:36333377 | DOI:10.1038/s41598-022-18957-4

Metabolite annotation from knowns to unknowns through knowledge-guided multi-layer metabolic networking

Sat, 05/11/2022 - 11:00
Nat Commun. 2022 Nov 4;13(1):6656. doi: 10.1038/s41467-022-34537-6.ABSTRACTLiquid chromatography - mass spectrometry (LC-MS) based untargeted metabolomics allows to measure both known and unknown metabolites in the metabolome. However, unknown metabolite annotation is a major challenge in untargeted metabolomics. Here, we develop an approach, namely, knowledge-guided multi-layer network (KGMN), to enable global metabolite annotation from knowns to unknowns in untargeted metabolomics. The KGMN approach integrates three-layer networks, including knowledge-based metabolic reaction network, knowledge-guided MS/MS similarity network, and global peak correlation network. To demonstrate the principle, we apply KGMN in an in vitro enzymatic reaction system and different biological samples, with ~100-300 putative unknowns annotated in each data set. Among them, >80% unknown metabolites are corroborated with in silico MS/MS tools. Finally, we validate 5 metabolites that are absent in common MS/MS libraries through repository mining and synthesis of chemical standards. Together, the KGMN approach enables efficient unknown annotations, and substantially advances the discovery of recurrent unknown metabolites for common biological samples from model organisms, towards deciphering dark matter in untargeted metabolomics.PMID:36333358 | DOI:10.1038/s41467-022-34537-6

Radiofrequency-assisted transection of the pancreas versus stapler in distal pancreatectomy: study protocol for a multicentric randomised clinical trial (TRANSPAIRE)

Fri, 04/11/2022 - 11:00
BMJ Open. 2022 Nov 4;12(11):e062873. doi: 10.1136/bmjopen-2022-062873.ABSTRACTINTRODUCTION: To date, no pancreatic stump closure technique has been shown to be superior to any other in distal pancreatectomy. Although several studies have shown a trend towards better results in transection using a radiofrequency device (radiofrequency-assisted transection (RFT)), no randomised trial for this purpose has been performed to date. Therefore, we designed a randomised clinical trial, with the hypothesis that this technique used in distal pancreatectomies is superior in reducing clinically relevant postoperative pancreatic fistula (CR-POPF) than mechanical closures.METHODS AND ANALYSIS: TRANSPAIRE is a multicentre randomised controlled trial conducted in seven Spanish pancreatic centres that includes 112 patients undergoing elective distal pancreatectomy for any indication who will be randomly assigned to RFT or classic stapler transections (control group) in a ratio of 1:1. The primary outcome is the CR-POPF percentage. Sample size is calculated with the following assumptions: 5% one-sided significance level (α), 80% power (1-β), expected POPF in control group of 32%, expected POPF in RFT group of 10% and a clinically relevant difference of 22%. Secondary outcomes include postoperative results, complications, radiological evaluation of the pancreatic stump, metabolomic profile of postoperative peritoneal fluid, survival and quality of life. Follow-ups will be carried out in the external consultation at 1, 6 and 12 months postoperatively.ETHICS AND DISSEMINATION: TRANSPAIRE has been approved by the CEIM-PSMAR Ethics Committee. This project is being carried out in accordance with national and international guidelines, the basic principles of protection of human rights and dignity established in the Declaration of Helsinki (64th General Assembly, Fortaleza, Brazil, October 2013), and in accordance with regulations in studies with biological samples, Law 14/2007 on Biomedical Research will be followed. We have defined a dissemination strategy, whose main objective is the participation of stakeholders and the transfer of knowledge to support the exploitation of activities.REGISTRATION DETAILS: ClinicalTrials.gov Registry (NCT04402346).PMID:36332946 | DOI:10.1136/bmjopen-2022-062873

A comparative proteomics analysis identified differentially expressed proteins in pancreatic cancer-associated stellate cell small extracellular vesicles

Fri, 04/11/2022 - 11:00
Mol Cell Proteomics. 2022 Nov 1:100438. doi: 10.1016/j.mcpro.2022.100438. Online ahead of print.ABSTRACTHuman pancreatic stellate cells (HPSCs) are an essential stromal component and mediators of pancreatic ductal adenocarcinoma (PDAC) progression. Small extracellular vesicles (sEVs) are membrane-enclosed nanoparticles involved in cell-to-cell communications and are released from stromal cells within PDAC. A detailed comparison of sEVs from normal pancreatic stellate cells (HPaStec) and from PDAC-associated stellate cells (HPSCs) remains a gap in our current knowledge regarding stellate cells and PDAC. We hypothesized there would be differences in sEVs secretion and protein expression that might contribute to PDAC biology. To test this hypothesis, we isolated sEVs using ultracentrifugation followed by characterization by electron microscopy and Nanoparticle Tracking Analysis. We report here our initial observations. First, HPSC cells derived from PDAC tumors secrete a higher volume of sEVs when compared to normal pancreatic stellate cells (HPaStec). Although our data revealed that both normal and tumor derived sEVs demonstrated no significant biological effect on cancer cells, we observed efficient uptake of sEVs by both normal and cancer epithelial cells. Additionally, intact membrane-associated proteins on sEVs were essential for efficient uptake. We then compared sEV proteins isolated from HPSCs and HPaStecs cells using liquid chromatography-tandem mass spectrometry. Most of the 1,481 protein groups identified were shared with the exosome database, ExoCarta. Eighty-seven protein groups were differentially expressed (selected by 2-fold difference and adjusted p value ≤ 0.05) between HPSC and HPaStec sEVs. Of note, HPSC sEVs contained dramatically more CSE1L (chromosome segregation 1-like protein), a described marker of poor prognosis in patients with pancreatic cancer. Based on our results, we have demonstrated unique populations of sEVs originating from stromal cells with PDAC and suggest that these are significant to cancer biology. Further studies should be undertaken to gain a deeper understanding that could drive novel therapy.PMID:36332889 | DOI:10.1016/j.mcpro.2022.100438

Determination of the variations in the metabolic profile and sensory quality of Liupao tea during fermentation through UHPLC-HR-MS metabolomics

Fri, 04/11/2022 - 11:00
Food Chem. 2022 Oct 29;404(Pt B):134773. doi: 10.1016/j.foodchem.2022.134773. Online ahead of print.ABSTRACTLiupao tea is a dark tea with unique quality. Semi-finished Liupao tea with two different fermentation processes (traditional/tank) was analyzed to explain the chemical characteristics and taste quality. The content change rate of polyphenols, flavonoids, and theabrownin in traditional fermentation was approximately twice that in tank fermentation. Electronic tongue revealed that bitterness and astringency increased, whereas aftertaste-astringency decreased after fermentation. 36 compounds were identified as the biomarkers responsible for the metabolic changes caused by fermentation with significant decrements in catechins, catechin gallate, and α, α-trehalose, and significant increments in gallic acid content (VIP > 3; P < 0.05). In addition, 26 metabolites were identified to distinguish between tank and traditional fermentation, with correlation analysis indicating that catechin gallate, epicatechin and gallic acid accounting for the differences in taste between the two processes. This study provides a comprehensive insight into the chemical composition and sensory quality of different Liupao tea fermentations.PMID:36332583 | DOI:10.1016/j.foodchem.2022.134773

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