Systems Biology

Gut indigenous <em>Ruminococcus gnavus</em> alleviates constipation and stress-related behaviors in mice with loperamide-induced constipation

Tue, 2023-06-06 06:00

Food Funct. 2023 Jun 6. doi: 10.1039/d2fo03574j. Online ahead of print.

ABSTRACT

Refractory constipation is the most severe form of constipation, and its etiology remains unknown. The symptoms of constipation occur repeatedly, which brings great pain to the patient's body and psychology. Accumulating studies suggest that constipation patients present a significant dysbiosis of the gut microbiota compared with healthy individuals. In this study, we analyzed the gut microbiota composition of fresh feces and accumulated feces (old feces) of patients with refractory constipation and found that there was a significant difference between them. Through a mouse model of loperamide-induced constipation, it was proved that the old feces of patients with refractory constipation could aggravate the constipation symptoms in mice, while the fresh feces could alleviate the symptoms, which is consistent with the effect of feces from healthy volunteers in a mouse model of loperamide-induced constipation. We identified an indigenous strain Ruminococcus gnavus (R. gnavus), which is highly enriched in the fresh feces of patients with refractory constipation, and found that oral administration of R. gnavus could effectively improve the constipation symptoms in mice with constipation induced by loperamide and fecal bacteria transplanted from patients with constipation and significantly improve the stress-related behaviors of mice. This result may be related to the regulation of intestinal muc2, c-kit, sert and other gene expression by R. gnavus and the control of somatostatin (SS) and motilin (MTL) production. Our results suggest that gut microbe intervention with indigenous strains such as R. gnavus is a potential and promising alternative for the treatment of constipation, especially for refractory constipation.

PMID:37278206 | DOI:10.1039/d2fo03574j

Categories: Literature Watch

NALCN-mediated sodium influx confers metastatic prostate cancer cell invasiveness

Tue, 2023-06-06 06:00

EMBO J. 2023 Jun 6:e112198. doi: 10.15252/embj.2022112198. Online ahead of print.

ABSTRACT

There is growing evidence that ion channels are critically involved in cancer cell invasiveness and metastasis. However, the molecular mechanisms of ion signaling promoting cancer behavior are poorly understood and the complexity of the underlying remodeling during metastasis remains to be explored. Here, using a variety of in vitro and in vivo techniques, we show that metastatic prostate cancer cells acquire a specific Na+ /Ca2+ signature required for persistent invasion. We identify the Na+ leak channel, NALCN, which is overexpressed in metastatic prostate cancer, as a major initiator and regulator of Ca2+ oscillations required for invadopodia formation. Indeed, NALCN-mediated Na+ influx into cancer cells maintains intracellular Ca2+ oscillations via a specific chain of ion transport proteins including plasmalemmal and mitochondrial Na+ /Ca2+ exchangers, SERCA and store-operated channels. This signaling cascade promotes activity of the NACLN-colocalized proto-oncogene Src kinase, actin remodeling and secretion of proteolytic enzymes, thus increasing cancer cell invasive potential and metastatic lesions in vivo. Overall, our findings provide new insights into an ion signaling pathway specific for metastatic cells where NALCN acts as persistent invasion controller.

PMID:37278161 | DOI:10.15252/embj.2022112198

Categories: Literature Watch

Increased expression of sodium-glucose cotransporter 2 and O-GlcNAcylation in hepatocytes drives non-alcoholic steatohepatitis

Mon, 2023-06-05 06:00

Metabolism. 2023 Jun 3:155612. doi: 10.1016/j.metabol.2023.155612. Online ahead of print.

ABSTRACT

AIMS: Steatosis reducing effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors in non-alcoholic steatohepatitis (NASH) has been consistently reported in humans, but their mechanism remains uncertain. In this study, we examined the expression of SGLT2 in human livers and investigated the crosstalk between SGLT2 inhibition and hepatic glucose uptake, intracellular O-GlcNAcylation, and autophagic regulation in NASH.

MATERIALS AND METHODS: Human liver samples obtained from subjects with/without NASH were analyzed. For in vitro studies, human normal hepatocytes and hepatoma cells were treated with SGLT2 inhibitor under high-glucose and high-lipid conditions. NASH in vivo was induced by a high-fat, -fructose, and -cholesterol Amylin liver NASH (AMLN) diet for 10 weeks followed by an additional 10 weeks with/without SGLT2 inhibitor (empagliflozin 10 mg/kg/day).

RESULTS: Liver samples from subjects with NASH were associated with increased SGLT2 and O-GlcNAcylation expression compared with controls. Under NASH condition (in vitro condition with high glucose and lipid), intracellular O-GlcNAcylation and inflammatory markers were increased in hepatocytes and SGLT2 expression was upregulated; SGLT2 inhibitor treatment blocked these changes by directly reducing hepatocellular glucose uptake. In addition, decreased intracellular O-GlcNAcylation by SGLT2 inhibitor promoted autophagic flux through AMPK-TFEB activation. In the AMLN diet-induced NASH mice model, SGLT2 inhibitor alleviated lipid accumulation, inflammation, and fibrosis through autophagy activation related to decreased SGLT2 expression and O-GlcNAcylation in the liver.

CONCLUSIONS: This study firstly demonstrates increased SGLT2 expression in NASH and secondly reveals the novel effect of SGLT2 inhibition on NASH by activating autophagy mediated by inhibition of hepatocellular glucose uptake and consequently decreasing intracellular O-GlcNAcylation.

PMID:37277060 | DOI:10.1016/j.metabol.2023.155612

Categories: Literature Watch

Mechanistic insights into the interactions between cancer drivers and the tumour immune microenvironment

Mon, 2023-06-05 06:00

Genome Med. 2023 Jun 5;15(1):40. doi: 10.1186/s13073-023-01197-0.

ABSTRACT

BACKGROUND: The crosstalk between cancer and the tumour immune microenvironment (TIME) has attracted significant interest in the latest years because of its impact on cancer evolution and response to treatment. Despite this, cancer-specific tumour-TIME interactions and their mechanistic insights are still poorly understood.

METHODS: Here, we compute the significant interactions occurring between cancer-specific genetic drivers and five anti- and pro-tumour TIME features in 32 cancer types using Lasso regularised ordinal regression. Focusing on head and neck squamous cancer (HNSC), we rebuild the functional networks linking specific TIME driver alterations to the TIME state they associate with.

RESULTS: The 477 TIME drivers that we identify are multifunctional genes whose alterations are selected early in cancer evolution and recur across and within cancer types. Tumour suppressors and oncogenes have an opposite effect on the TIME and the overall anti-tumour TIME driver burden is predictive of response to immunotherapy. TIME driver alterations predict the immune profiles of HNSC molecular subtypes, and perturbations in keratinization, apoptosis and interferon signalling underpin specific driver-TIME interactions.

CONCLUSIONS: Overall, our study delivers a comprehensive resource of TIME drivers, gives mechanistic insights into their immune-regulatory role, and provides an additional framework for patient prioritisation to immunotherapy. The full list of TIME drivers and associated properties are available at http://www.network-cancer-genes.org .

PMID:37277866 | DOI:10.1186/s13073-023-01197-0

Categories: Literature Watch

Drivers of heterogeneity in synovial fibroblasts in rheumatoid arthritis

Mon, 2023-06-05 06:00

Nat Immunol. 2023 Jun 5. doi: 10.1038/s41590-023-01527-9. Online ahead of print.

ABSTRACT

Inflammation of non-barrier immunologically quiescent tissues is associated with a massive influx of blood-borne innate and adaptive immune cells. Cues from the latter are likely to alter and expand activated states of the resident cells. However, local communications between immigrant and resident cell types in human inflammatory disease remain poorly understood. Here, we explored drivers of fibroblast-like synoviocyte (FLS) heterogeneity in inflamed joints of patients with rheumatoid arthritis using paired single-cell RNA and ATAC sequencing, multiplexed imaging and spatial transcriptomics along with in vitro modeling of cell-extrinsic factor signaling. These analyses suggest that local exposures to myeloid and T cell-derived cytokines, TNF, IFN-γ, IL-1β or lack thereof, drive four distinct FLS states some of which closely resemble fibroblast states in other disease-affected tissues including skin and colon. Our results highlight a role for concurrent, spatially distributed cytokine signaling within the inflamed synovium.

PMID:37277655 | DOI:10.1038/s41590-023-01527-9

Categories: Literature Watch

Generation of Amber Suppression Cell Lines Using CRISPR-Cas9

Mon, 2023-06-05 06:00

Methods Mol Biol. 2023;2676:169-180. doi: 10.1007/978-1-0716-3251-2_12.

ABSTRACT

Genetic code expansion via amber suppression allows cotranslational, site-specific introduction of nonnatural chemical groups into proteins in the living cell. The archaeal pyrrolysine-tRNA/pyrrolysine-tRNA synthetase (PylT/RS) pair from Methanosarcina mazei (Mma) has been established for incorporation of a wide range of noncanonical amino acids (ncAAs) in mammalian cells. Once integrated in an engineered protein, ncAAs allow for simple click-chemistry derivatization, photo-cage control of enzyme activity, and site-specific placement of posttranslational modifications. We previously described a modular amber suppression plasmid system for generating stable cell lines via piggyBac transposition in a range of mammalian cells. Here we detail a general protocol for the generation of CRISPR-Cas9 knock-in cell lines using the same plasmid system. The knock-in strategy relies on CRISPR-Cas9-induced double-strand breaks (DSBs) and nonhomologous end joining (NHEJ) repair to target the PylT/RS expression cassette to the AAVS1 safe harbor locus in human cells. MmaPylRS expression from this single locus is sufficient for efficient amber suppression when the cells are subsequently transfected transiently with a PylT/gene of interest plasmid.

PMID:37277632 | DOI:10.1007/978-1-0716-3251-2_12

Categories: Literature Watch

Scribble mis-localization induces adaptive resistance to KRAS G12C inhibitors through feedback activation of MAPK signaling mediated by YAP-induced MRAS

Mon, 2023-06-05 06:00

Nat Cancer. 2023 Jun 5. doi: 10.1038/s43018-023-00575-2. Online ahead of print.

ABSTRACT

Tumor cells evade targeted drugs by rewiring their genetic and epigenetic networks. Here, we identified that inhibition of MAPK signaling rapidly induces an epithelial-to-mesenchymal transition program by promoting re-localization of an apical-basal polarity protein, Scribble, in oncogene-addicted lung cancer models. Mis-localization of Scribble suppressed Hippo-YAP signaling, leading to YAP nuclear translocation. Furthermore, we discovered that a RAS superfamily protein MRAS is a direct target of YAP. Treatment with KRAS G12C inhibitors induced MRAS expression, which formed a complex with SHOC2, precipitating feedback activation of MAPK signaling. Abrogation of YAP activation or MRAS induction enhanced the efficacy of KRAS G12C inhibitor treatment in vivo. These results highlight a role for protein localization in the induction of a non-genetic mechanism of resistance to targeted therapies in lung cancer. Furthermore, we demonstrate that induced MRAS expression is a key mechanism of adaptive resistance following KRAS G12C inhibitor treatment.

PMID:37277529 | DOI:10.1038/s43018-023-00575-2

Categories: Literature Watch

Pathogen-specific innate immune response patterns are distinctly affected by genetic diversity

Mon, 2023-06-05 06:00

Nat Commun. 2023 Jun 5;14(1):3239. doi: 10.1038/s41467-023-38994-5.

ABSTRACT

Innate immune responses vary by pathogen and host genetics. We analyze quantitative trait loci (eQTLs) and transcriptomes of monocytes from 215 individuals stimulated by fungal, Gram-negative or Gram-positive bacterial pathogens. We identify conserved monocyte responses to bacterial pathogens and a distinct antifungal response. These include 745 response eQTLs (reQTLs) and corresponding genes with pathogen-specific effects, which we find first in samples of male donors and subsequently confirm for selected reQTLs in females. reQTLs affect predominantly upregulated genes that regulate immune response via e.g., NOD-like, C-type lectin, Toll-like and complement receptor-signaling pathways. Hence, reQTLs provide a functional explanation for individual differences in innate response patterns. Our identified reQTLs are also associated with cancer, autoimmunity, inflammatory and infectious diseases as shown by external genome-wide association studies. Thus, reQTLs help to explain interindividual variation in immune response to infection and provide candidate genes for variants associated with a range of diseases.

PMID:37277347 | DOI:10.1038/s41467-023-38994-5

Categories: Literature Watch

Quantitating CD8<sup>+</sup> T cell memory development

Mon, 2023-06-05 06:00

Trends Immunol. 2023 Jun 3:S1471-4906(23)00085-6. doi: 10.1016/j.it.2023.05.004. Online ahead of print.

ABSTRACT

In acute immune responses to infection, memory T cells develop that can spawn recall responses. This process has not been observable directly in vivo. Here we highlight the utility of mathematical inference to derive quantitatively testable models of mammalian CD8+ T cell memory development from complex experimental data. Previous inference studies suggested that precursors of memory T cells arise early during the immune response. Recent work has both validated a crucial prediction of this T cell diversification model and refined the model. While multiple developmental routes to distinct memory subsets might exist, a branch point occurs early in proliferating T cell blasts, from which separate differentiation pathways emerge for slowly dividing precursors of re-expandable memory cells and rapidly dividing effectors.

PMID:37277233 | DOI:10.1016/j.it.2023.05.004

Categories: Literature Watch

Polyvalent immunization elicits a synergistic broadly neutralizing immune response to hypervariable region 1 variants of hepatitis C virus

Mon, 2023-06-05 06:00

Proc Natl Acad Sci U S A. 2023 Jun 13;120(24):e2220294120. doi: 10.1073/pnas.2220294120. Epub 2023 Jun 5.

ABSTRACT

A hepatitis C virus (HCV) vaccine is urgently needed. Vaccine development has been hindered by HCV's genetic diversity, particularly within the immunodominant hypervariable region 1 (HVR1). Here, we developed a strategy to elicit broadly neutralizing antibodies to HVR1, which had previously been considered infeasible. We first applied a unique information theory-based measure of genetic distance to evaluate phenotypic relatedness between HVR1 variants. These distances were used to model the structure of HVR1's sequence space, which was found to have five major clusters. Variants from each cluster were used to immunize mice individually, and as a pentavalent mixture. Sera obtained following immunization neutralized every variant in a diverse HCVpp panel (n = 10), including those resistant to monovalent immunization, and at higher mean titers (1/ID50 = 435) than a glycoprotein E2 (1/ID50 = 205) vaccine. This synergistic immune response offers a unique approach to overcoming antigenic variability and may be applicable to other highly mutable viruses.

PMID:37276424 | DOI:10.1073/pnas.2220294120

Categories: Literature Watch

Schistosoma japonicum Tyrosine Hydroxylase is promising targets for immunodiagnosis and immunoprotection of Schistosomiasis japonica

Mon, 2023-06-05 06:00

PLoS Negl Trop Dis. 2023 Jun 5;17(6):e0011389. doi: 10.1371/journal.pntd.0011389. Online ahead of print.

ABSTRACT

Identification of promising schistosome antigen targets is crucial for the development of anti-schistosomal strategies. Schistosomes rely on their neuromuscular systems to coordinate important locomotory behaviors. Tyrosine hydroxylase (TH) is critical in the initial rate-limiting step in biosynthesis of catecholamine, the important neuroactive agents, which promote the lengthening of the worm through muscular relaxation and are therefore of great importance to the movement of the organism both within and between its hosts. THs from both Schistosoma mansoni and Schistosoma japonicum and their enzyme activities have been discovered; however, the role of these proteins during infection have not been explored. Herein, a recombinant protein of the nonconserved fragment of S. japonicum TH (SjTH) was produced and the corresponding polyclonal antibody was generated. The expression and antigenicity of SjTH were detected by qRT-PCR, western blotting, immunofluorescence assays, and ELISA. Mice immunized with the recombinant SjTH were challenged with cercariae to evaluate the immunoprotective value of this protein. Our results showed SjTH not only distributed in the head associated with the central nervous system, but also expressed along the tegument and the intestinal intima, which are involved in the movement, coupling and digestion of the parasites and associated with the peripheral nervous system. This protein can effectively stimulate humoral immune responses in mammalian hosts and has high potential as a biomarker for schistosomiasis immunodiagnosis. Furthermore, immunization with recombinant SjTH showed to reduce the worm and egg burden of challenged mice, and to contribute to the systemic balance of the Th1/Th2 responses. Taken together, these results suggest that SjTH is an important pathogenic molecule in S. japonicum and may be a possible target for anti-schistosomal approaches.

PMID:37276235 | DOI:10.1371/journal.pntd.0011389

Categories: Literature Watch

Genetic architecture of heart mitochondrial proteome influencing cardiac hypertrophy

Mon, 2023-06-05 06:00

Elife. 2023 Jun 5;12:e82619. doi: 10.7554/eLife.82619.

ABSTRACT

Mitochondria play an important role in both normal heart function and disease etiology. We report analysis of common genetic variations contributing to mitochondrial and heart functions using an integrative proteomics approach in a panel of inbred mouse strains called the Hybrid Mouse Diversity Panel (HMDP). We performed a whole heart proteome study in the HMDP (72 strains, n=2-3 mice) and retrieved 848 mitochondrial proteins (quantified in ≥50 strains). High-resolution association mapping on their relative abundance levels revealed three trans-acting genetic loci on chromosomes (chr) 7, 13 and 17 that regulate distinct classes of mitochondrial proteins as well as cardiac hypertrophy. DAVID enrichment analyses of genes regulated by each of the loci revealed that the chr13 locus was highly enriched for complex-I proteins (24 proteins, P=2.2E-61), the chr17 locus for mitochondrial ribonucleoprotein complex (17 proteins, P=3.1E-25) and the chr7 locus for ubiquinone biosynthesis (3 proteins, P=6.9E-05). Follow-up high resolution regional mapping identified NDUFS4, LRPPRC and COQ7 as the candidate genes for chr13, chr17 and chr7 loci, respectively, and both experimental and statistical analyses supported their causal roles. Furthermore, a large cohort of Diversity Outbred mice was used to corroborate Lrpprc gene as a driver of mitochondrial DNA (mtDNA)-encoded gene regulation, and to show that the chr17 locus is specific to heart. Variations in all three loci were associated with heart mass in at least one of two independent heart stress models, namely, isoproterenol-induced heart failure and diet-induced obesity. These findings suggest that common variations in certain mitochondrial proteins can act in trans to influence tissue-specific mitochondrial functions and contribute to heart hypertrophy, elucidating mechanisms that may underlie genetic susceptibility to heart failure in human populations.

PMID:37276142 | DOI:10.7554/eLife.82619

Categories: Literature Watch

Clinical value of anoikis-related genes and molecular subtypes identification in bladder urothelial carcinoma and <em>in vitro</em> validation

Mon, 2023-06-05 06:00

Front Immunol. 2023 May 18;14:1122570. doi: 10.3389/fimmu.2023.1122570. eCollection 2023.

ABSTRACT

BACKGROUND: Anoikis is a programmed cell death process that was proven to be associated with cancer. Uroepithelial carcinoma of the bladder (BLCA) is a malignant disease of the urinary tract and has a strong metastatic potential. To determine whether anoikis-associated genes can predict the prognosis of BLCA accurately, we evaluated the prognostic value of anoikis-associated genes in BLCA and constructed the best model to predict prognosis.

METHOD: The BLCA transcriptome data were downloaded from TCGA and GEO databases, and genes with differential expression were selected and then clustered using non-negative matrix factorization (NMF). The genes with the most correlation with anoikis were screened and identified using univariate Cox regression, lasso regression, and multivariate Cox regression. The GEO dataset was used for external validation. Nomograms were created based on risk characteristics in combination with clinical variants and the performance of the model was validated with receiver operating characteristic (ROC) curves. The immunotherapeutic significance of this risk score was assessed using the immune phenomenon score (IPS). IC50 values of predictive chemotherapeutic agents were calculated. Finally, we used RT-qPCR to determine the mRNA expression of four genes, CALR, FASN, CASP6, and RAD9A.

RESULT: We screened 406 tumor samples and 19 normal tissue samples from the TCGA database. Based on anoikis-associated genes, we classified patients into two subtypes (C1 and C2) using NMF method. Subsequently, nine core genes were screened by multiple methods after analysis, which were used to construct risk profiles. The design of nomograms based on risk profiles and clinical variables, ROC, and calibration curves confirmed that the model could well have the ability to predict the survival of BLCA patients at 1, 3, and 5 years. By predicting the IC50 values of chemotherapeutic drugs, it was learned that the high-risk group (HRG) was more susceptible to paclitaxel, gemcitabine, and cisplatin, and the low-risk group (LRG) was more susceptible to veriparib and afatinib.

CONCLUSION: In summary, the risk score of anoikis-associated genes can be applied as a predictor to predict the prognosis of BLCA in clinical practice.

PMID:37275895 | PMC:PMC10232821 | DOI:10.3389/fimmu.2023.1122570

Categories: Literature Watch

An <em>in silico</em> approach to identify early damage biomarker candidates in metachromatic leukodystrophy

Mon, 2023-06-05 06:00

Mol Genet Metab Rep. 2023 May 15;35:100974. doi: 10.1016/j.ymgmr.2023.100974. eCollection 2023 Jun.

ABSTRACT

Metachromatic leukodystrophy (MLD) is a rare, autosomal recessive lysosomal storage disease. Deficient activity of arylsulfatase A causes sulfatides to accumulate in cells of different tissues, including those in the central and peripheral nervous systems, leading to progressive demyelination and neurodegeneration. Although there is some association between specific arylsulfatase A alleles and disease severity, genotype-phenotype correlations are not fully understood. We aimed to identify biomarker candidates of early tissue damage in MLD using a modeling approach based on systems biology. A review of the literature was performed in an initial disease characterization step, allowing identification of pathophysiological processes involved in MLD and proteins relating to these processes. Three mathematical models were generated to simulate different stages of MLD at the molecular level: an early pro-inflammatory stage model (including only processes considered to be active in the early stages of disease), a pre-demyelination stage model (including additional processes that are active after some disease progression), and a demyelination stage model (in which all pathophysiological processes are active). The models evaluated 3457 proteins of interest, individually and by pairs through data mining techniques, applying five filters to prioritize biomarkers that could differentiate between the models. Sixteen potential biomarkers were identified, including effectors relating to mitochondrial dysfunction, remyelination, and neurodegeneration. The findings were corroborated in a gene expression data set from T lymphocytes of patients with MLD; all candidates formed combinations that were able to distinguish patients with MLD from controls, and all but one candidate distinguished late-infantile MLD from juvenile MLD as part of a combinatorial biomarker pair. In particular, pro-neuregulin-1 appeared as differential on all comparisons (patients with MLD vs controls and within clinical subtypes); casein kinase II subunit alpha was detected as a potential individual marker within clinical subtypes. These findings provide a panel of biomarker candidates suitable for experimental validation and highlight the utility of mathematical models to identify biomarker candidates of early tissue damage in MLD with a high degree of accuracy and sensitivity.

PMID:37275681 | PMC:PMC10233284 | DOI:10.1016/j.ymgmr.2023.100974

Categories: Literature Watch

Improved multi-trait prediction of wheat end-product quality traits by integrating NIR-predicted phenotypes

Mon, 2023-06-05 06:00

Front Plant Sci. 2023 May 18;14:1167221. doi: 10.3389/fpls.2023.1167221. eCollection 2023.

ABSTRACT

Historically, end-product quality testing has been costly and required large flour samples; therefore, it was generally implemented in the late phases of variety development, imposing a huge cost on the breeding effort and effectiveness. High genetic correlations of end-product quality traits with higher throughput and nondestructive testing technologies, such as near-infrared (NIR), could enable early-stage testing and effective selection of these highly valuable traits in a multi-trait genomic prediction model. We studied the impact on prediction accuracy in genomic best linear unbiased prediction (GBLUP) of adding NIR-predicted secondary traits for six end-product quality traits (crumb yellowness, water absorption, texture hardness, flour yield, grain protein, flour swelling volume). Bread wheat lines (1,400-1,900) were measured across 8 years (2012-2019) for six end-product quality traits with standard laboratory assays and with NIR, which were combined to generate predicted data for approximately 27,000 lines. All lines were genotyped with the Infinium™ Wheat Barley 40K BeadChip and imputed using exome sequence data. End-product and NIR phenotypes were genetically correlated (0.5-0.83, except for flour swelling volume 0.19). Prediction accuracies of end-product traits ranged between 0.28 and 0.64 and increased by 30% through the inclusion of NIR-predicted data compared to single-trait analysis. There was a high correlation between the multi-trait prediction accuracy and genetic correlations between end-product and NIR-predicted data (0.69-0.77). Our forward prediction validation revealed a gradual increase in prediction accuracy when adding more years to the multi-trait model. Overall, we achieved genomic prediction accuracy at a level that enables selection for end-product quality traits early in the breeding cycle.

PMID:37275257 | PMC:PMC10233148 | DOI:10.3389/fpls.2023.1167221

Categories: Literature Watch

Microbiota-dependent influence of prebiotics on the resilience of infant gut microbiota to amoxicillin/clavulanate perturbation in an <em>in vitro</em> colon model

Mon, 2023-06-05 06:00

Front Microbiol. 2023 May 18;14:1131953. doi: 10.3389/fmicb.2023.1131953. eCollection 2023.

ABSTRACT

Antibiotic exposure disturbs the developing infant gut microbiota. The capacity of the gut microbiota to recover from this disturbance (resilience) depends on the type of antibiotic. In this study, infant gut microbiota was exposed to a combination of amoxicillin and clavulanate (amoxicillin/clavulanate) in an in vitro colon model (TIM-2) with fecal-derived microbiota from 1-month-old (1-M; a mixed-taxa community type) as well as 3-month-old (3-M; Bifidobacterium dominated community type) breastfed infants. We investigated the effect of two common infant prebiotics, 2'-fucosyllactose (2'-FL) or galacto-oligosaccharides (GOS), on the resilience of infant gut microbiota to amoxicillin/clavulanate-induced changes in microbiota composition and activity. Amoxicillin/clavulanate treatment decreased alpha diversity and induced a temporary shift of microbiota to a community dominated by enterobacteria. Moreover, antibiotic treatment increased succinate and lactate in both 1- and 3-M colon models, while decreasing the production of short-chain (SCFA) and branched-chain fatty acids (BFCA). The prebiotic effect on the microbiota recovery depended on the fermenting capacity of antibiotic-exposed microbiota. In the 1-M colon model, the supplementation of 2'-FL supported the recovery of microbiota and restored the production of propionate and butyrate. In the 3-M colon model, GOS supplementation supported the recovery of microbiota and increased the production of acetate and butyrate.

PMID:37275167 | PMC:PMC10232780 | DOI:10.3389/fmicb.2023.1131953

Categories: Literature Watch

A lncRNA-disease association prediction tool development based on bridge heterogeneous information network via graph representation learning for family medicine and primary care

Mon, 2023-06-05 06:00

Front Genet. 2023 May 18;14:1084482. doi: 10.3389/fgene.2023.1084482. eCollection 2023.

ABSTRACT

Identification of long non-coding RNAs (lncRNAs) associated with common diseases is crucial for patient self-diagnosis and monitoring of health conditions using artificial intelligence (AI) technology at home. LncRNAs have gained significant attention due to their crucial roles in the pathogenesis of complex human diseases and identifying their associations with diseases can aid in developing diagnostic biomarkers at the molecular level. Computational methods for predicting lncRNA-disease associations (LDAs) have become necessary due to the time-consuming and labor-intensive nature of wet biological experiments in hospitals, enabling patients to access LDAs through their AI terminal devices at any time. Here, we have developed a predictive tool, LDAGRL, for identifying potential LDAs using a bridge heterogeneous information network (BHnet) constructed via Structural Deep Network Embedding (SDNE). The BHnet consists of three types of molecules as bridge nodes to implicitly link the lncRNA with disease nodes and the SDNE is used to learn high-quality node representations and make LDA predictions in a unified graph space. To assess the feasibility and performance of LDAGRL, extensive experiments, including 5-fold cross-validation, comparison with state-of-the-art methods, comparison on different classifiers and comparison of different node feature combinations, were conducted, and the results showed that LDAGRL achieved satisfactory prediction performance, indicating its potential as an effective LDAs prediction tool for family medicine and primary care.

PMID:37274787 | PMC:PMC10234424 | DOI:10.3389/fgene.2023.1084482

Categories: Literature Watch

Editorial: Bioinformatics of genome regulation and systems biology, Volume III

Mon, 2023-06-05 06:00

Front Genet. 2023 May 18;14:1215987. doi: 10.3389/fgene.2023.1215987. eCollection 2023.

NO ABSTRACT

PMID:37274783 | PMC:PMC10233740 | DOI:10.3389/fgene.2023.1215987

Categories: Literature Watch

Engineered Protein-Iron Oxide Hybrid Biomaterial for MRI-traceable Drug Encapsulation

Mon, 2023-06-05 06:00

Mol Syst Des Eng. 2022 Aug 1;7(8):915-932. doi: 10.1039/d2me00002d. Epub 2022 May 6.

ABSTRACT

Labeled protein-based biomaterials have become a popular for various biomedical applications such as tissue-engineered, therapeutic, or diagnostic scaffolds. Labeling of protein biomaterials, including with ultrasmall super-paramagnetic iron oxide (USPIO) nanoparticles, has enabled a wide variety of imaging techniques. These USPIO-based biomaterials are widely studied in magnetic resonance imaging (MRI), thermotherapy, and magnetically-driven drug delivery which provide a method for direct and non-invasive monitoring of implants or drug delivery agents. Where most developments have been made using polymers or collagen hydrogels, shown here is the use of a rationally designed protein as the building block for a meso-scale fiber. While USPIOs have been chemically conjugated to antibodies, glycoproteins, and tissue-engineered scaffolds for targeting or improved biocompatibility and stability, these constructs have predominantly served as diagnostic agents and often involve harsh conditions for USPIO synthesis. Here, we present an engineered protein-iron oxide hybrid material comprised of an azide-functionalized coiled-coil protein with small molecule binding capacity conjugated via bioorthogonal azide-alkyne cycloaddition to an alkyne-bearing iron oxide templating peptide, CMms6, for USPIO biomineralization under mild conditions. The coiled-coil protein, dubbed Q, has been previously shown to form nanofibers and, upon small molecule binding, further assembles into mesofibers via encapsulation and aggregation. The resulting hybrid material is capable of doxorubicin encapsulation as well as sensitive T2*-weighted MRI darkening for strong imaging capability that is uniquely derived from a coiled-coil protein.

PMID:37274761 | PMC:PMC10237276 | DOI:10.1039/d2me00002d

Categories: Literature Watch

Core and auxiliary functions of one-carbon metabolism in <em>Pseudomonas putida</em> exposed by a systems-level analysis of transcriptional and physiological responses

Mon, 2023-06-05 06:00

mSystems. 2023 Jun 5:e0000423. doi: 10.1128/msystems.00004-23. Online ahead of print.

ABSTRACT

The soil bacterium Pseudomonas putida is a robust biomanufacturing host that assimilates a broad range of substrates while efficiently coping with adverse environmental conditions. P. putida is equipped with functions related to one-carbon (C1) compounds (e.g. methanol, formaldehyde, and formate) oxidation-yet pathways to assimilate these carbon sources are largely absent. In this work, we adopted a systems-level approach to study the genetic and molecular basis of C1 metabolism in P. putida. RNA sequencing identified two oxidoreductases, encoded by PP_0256 and PP_4596, transcriptionally active in the presence of formate. Quantitative physiology of deletion mutants revealed growth defects at high formate concentrations, pointing to an important role of these oxidoreductases in C1 tolerance. Moreover, we describe a concerted detoxification process for methanol and formaldehyde, the C1 intermediates upstream formate. Alcohol oxidation to highly-reactive formaldehyde by PedEH and other broad-substrate-range dehydrogenases underpinned the (apparent) suboptimal methanol tolerance of P. putida. Formaldehyde was mostly processed by a glutathione-dependent mechanism encoded in the frmAC operon, and thiol-independent FdhAB and AldB-II overtook detoxification at high aldehyde concentrations. Deletion strains were constructed and characterized towards unveiling these biochemical mechanisms, underscoring the worth of P. putida for emergent biotechnological applications-e.g. engineering synthetic formatotrophy and methylotrophy.IMPORTANCEC1 substrates continue to attract interest in biotechnology, as their use is both cost-effective and ultimately expected to mitigate the impact of greenhouse gas emissions. However, our current understanding of bacterial C1 metabolism remains relatively limited in species that cannot grow on (i.e., assimilate) these substrates. Pseudomonas putida, a model Gram-negative environmental bacterium, constitutes a prime example of this sort. The biochemical pathways active in response to methanol, formaldehyde, and formate have been largely overlooked-although the ability of P. putida to process C1 molecules has been previously alluded to in the literature. By using a systems-level strategy, this study bridges such knowledge gap through the identification and characterization of mechanisms underlying methanol, formaldehyde, and formate detoxification-including hitherto unknown enzymes that act on these substrates. The results reported herein both expand our understanding of microbial metabolism and lay a solid foundation for engineering efforts toward valorizing C1 feedstocks.

PMID:37273222 | DOI:10.1128/msystems.00004-23

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