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Although it is known that the centrioles play instructive roles in pericentriolar material (PCM) assembly and that the PCM is essential for proper centriole formation, the mechanism that governs centriole-PCM interaction is poorly understood. Here, we show that ATF5 forms a characteristic 9-fold symmetrical ring structure in the inner layer of the PCM outfitting the proximal end of the mother centriole. ATF5 controls the centriole-PCM interaction in a cell-cycle- and centriole-age-dependent manner. Interaction of ATF5 with polyglutamylated tubulin (PGT) on the mother centriole and with PCNT in the PCM renders ATF5 as a required molecule in mother centriole-directed PCM accumulation and in PCM-dependent centriole formation. ATF5 depletion blocks PCM accumulation at the centrosome and causes fragmentation of centrioles, leading to the formation of multi-polar mitotic spindles and genomic instability. These data show that ATF5 is an essential structural protein that is required for the interaction between the mother centriole and the PCM.
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Factores de Transcripción Activadores/metabolismo , Centriolos/metabolismo , Centrosoma/metabolismo , Citoesqueleto/metabolismo , Regulación hacia Abajo , Inestabilidad Genómica , Células HeLa , Humanos , Huso Acromático/metabolismo , Tubulina (Proteína)/metabolismoRESUMEN
Chiral amines are commonly used in the pharmaceutical and agrochemical industries1. The strong demand for unnatural chiral amines has driven the development of catalytic asymmetric methods1,2. Although the N-alkylation of aliphatic amines with alkyl halides has been widely adopted for over 100 years, catalyst poisoning and unfettered reactivity have been preventing the development of a catalyst-controlled enantioselective version3-5. Here we report the use of chiral tridentate anionic ligands to enable the copper-catalysed chemoselective and enantioconvergent N-alkylation of aliphatic amines with α-carbonyl alkyl chlorides. This method can directly convert feedstock chemicals, including ammonia and pharmaceutically relevant amines, into unnatural chiral α-amino amides under mild and robust conditions. Excellent enantioselectivity and functional-group tolerance were observed. The power of the method is demonstrated in a number of complex settings, including late-stage functionalization and in the expedited synthesis of diverse amine drug molecules. The current method indicates that multidentate anionic ligands are a general solution for overcoming transition-metal-catalyst poisoning.
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Alquilación , Aminas , Catálisis , Cobre , Amidas/química , Aminas/química , Cobre/química , Ligandos , Preparaciones Farmacéuticas/químicaRESUMEN
Mitophagy is essential for cellular homeostasis, but how mitophagy is regulated is largely unknown. Here we found that the kinase Jnk2 was required for stress-induced mitophagy. Jnk2 promoted ubiquitination and proteasomal degradation of the small mitochondrial form of the tumor suppressor ARF (smARF). Loss of Jnk2 led to the accumulation of smARF, which induced excessive autophagy that resulted in lysosomal degradation of the mitophagy adaptor p62 at steady state. Depletion of p62 prevented Jnk2-deficient cells from mounting mitophagy upon stress. Jnk2-deficient mice displayed defective mitophagy, which resulted in tissue damage under hypoxic stress, as well as hyperactivation of inflammasomes and increased mortality in sepsis. Our findings define a unique mechanism of maintaining immunological homeostasis that protects the host from tissue damage and mortality.
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Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Hipoxia/inmunología , Proteína Quinasa 9 Activada por Mitógenos/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Sepsis/inmunología , Animales , Células Cultivadas , Daño del ADN/fisiología , Femenino , Inflamasomas/metabolismo , Lipopolisacáridos/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína Quinasa 9 Activada por Mitógenos/genética , Mitofagia/genética , Proteolisis , Proteínas Proto-Oncogénicas c-myc/metabolismo , Sepsis/inducido químicamente , UbiquitinaciónRESUMEN
The tracheal epithelium is a primary target for pulmonary diseases as it provides a conduit for air flow between the environment and the lung lobes. The cellular and molecular mechanisms underlying airway epithelial cell proliferation and differentiation remain poorly understood. Hedgehog (HH) signaling orchestrates communication between epithelial and mesenchymal cells in the lung, where it modulates stromal cell proliferation, differentiation and signaling back to the epithelium. Here, we reveal a previously unreported autocrine function of HH signaling in airway epithelial cells. Epithelial cell depletion of the ligand sonic hedgehog (SHH) or its effector smoothened (SMO) causes defects in both epithelial cell proliferation and differentiation. In cultured primary human airway epithelial cells, HH signaling inhibition also hampers cell proliferation and differentiation. Epithelial HH function is mediated, at least in part, through transcriptional activation, as HH signaling inhibition leads to downregulation of cell type-specific transcription factor genes in both the mouse trachea and human airway epithelial cells. These results provide new insights into the role of HH signaling in epithelial cell proliferation and differentiation during airway development.
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Comunicación Autocrina/fisiología , Diferenciación Celular , Proliferación Celular , Proteínas Hedgehog/metabolismo , Transducción de Señal/genética , Animales , Células Cultivadas , Regulación hacia Abajo , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Células Epiteliales/citología , Células Epiteliales/metabolismo , Proteínas Hedgehog/deficiencia , Proteínas Hedgehog/genética , Humanos , Pulmón/crecimiento & desarrollo , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Noqueados , Receptor Smoothened/deficiencia , Receptor Smoothened/genética , Receptor Smoothened/metabolismo , Tráquea/citología , Tráquea/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
The essential role of plastid translation in embryogenesis has been established in many plants, but a retrograde signal triggered by defective plastid translation machinery that may leads to embryogenesis arrest remains unknown. In this study, we characterized an embryo defective27 (emb27) mutant in maize (Zea mays), and cloning indicates that Emb27 encodes the plastid ribosomal protein S13. The null mutant emb27-1 conditions an emb phenotype with arrested embryogenesis; however, the leaky mutant emb27-2 exhibits normal embryogenesis but an albino seedling-lethal phenotype. The emb27-1/emb27-2 trans-heterozygotes display varying phenotypes from emb to normal seeds but albino seedlings. Analysis of the Emb27 transcription levels in these mutants revealed that the Emb27 expression level in the embryo corresponds with the phenotypic expression of the emb27 mutants. In the W22 genetic background, an Emb27 transcription level higher than 6% of the wild-type level renders normal embryogenesis, whereas lower than that arrests embryogenesis. Mutation of Emb27 reduces the level of plastid 16S rRNA and the accumulation of the plastid-encoded proteins. As a secondary effect, splicing of several plastid introns was impaired in emb27-1 and 2 other plastid translation-defective mutants, emb15 and emb16, suggesting that plastome-encoded factors are required for the splicing of these introns, such as Maturase K (MatK). Our results indicate that EMB27 is essential for plastid protein translation, embryogenesis, and seedling development in maize and reveal an expression threshold of Emb27 for maize embryogenesis.
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Regulación de la Expresión Génica de las Plantas , Mutación , Proteínas de Plantas , Plastidios , Plantones , Semillas , Zea mays , Zea mays/genética , Zea mays/embriología , Plantones/genética , Plantones/crecimiento & desarrollo , Semillas/genética , Semillas/crecimiento & desarrollo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mutación/genética , Plastidios/genética , Plastidios/metabolismo , Fenotipo , Empalme del ARN/genética , Intrones/genética , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismoRESUMEN
Identifying the PPR-E+-NUWA-DYW2 editosome improves our understanding of the C-to-U RNA editing in plant organelles. However, the mechanism of RNA editing remains to be elucidated. Here, we report that GLUTAMINE-RICH PROTEIN23 (GRP23), a previously identified nuclear transcription regulator, plays an essential role in mitochondrial RNA editing through interacting with MORF (multiple organellar RNA-editing factor) proteins and atypical DYW-type pentatricopeptide repeat (PPR) proteins. GRP23 is targeted to mitochondria, plastids, and nuclei. Analysis of the grp23 mutants rescued by embryo-specific complementation shows decreased editing efficiency at 352 sites in mitochondria and 6 sites in plastids, with a predominant specificity for sites edited by the PPR-E and PPR-DYW proteins. GRP23 interacts with atypical PPR-DYW proteins (MEF8, MEF8S, DYW2, and DYW4) and MORF proteins (MORF1 and MORF8), whereas the four PPR-DYWs interact with the two MORFs. These interactions may increase the stability of the GRP23-MORF-atypical PPR-DYW complex. Furthermore, analysis of mef8Nâ³64aamef8s double mutants shows that MEF8/MEF8S are required for the editing of the PPR-E protein-targeted sites in mitochondria. GRP23 could enhance the interaction between PPR-E and MEF8/MEF8S and form a homodimer or heterodimer with NUWA. Genetic complementation analysis shows that the C-terminal domains of GRP23 and NUWA possess a similar function, probably in the interaction with the MORFs. NUWA also interacts with atypical PPR-DYWs in yeast. Both GRP23 and NUWA interact with the atypical PPR-DYWs, suggesting that the PPR-E proteins recruit MEF8/MEF8S, whereas the PPR-E+ proteins specifically recruit DYW2 as the trans deaminase, and then GRP23, NUWA, and MORFs facilitate and/or stabilize the E or E+-type editosome formation.
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Proteínas de Arabidopsis , Arabidopsis , Edición de ARN , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Mitocondrias/metabolismo , Edición de ARN/genética , ARN Mitocondrial/metabolismo , Factores de Transcripción/metabolismoRESUMEN
The 3d transition metal-catalyzed enantioconvergent radical cross-coupling provides a powerful tool for chiral molecule synthesis. In the classic mechanism, the bond formation relies on the interaction between nucleophile-sequestered metal complexes and radicals, limiting the nucleophile scope to sterically uncongested ones. The coupling of sterically congested nucleophiles poses a significant challenge due to difficulties in transmetalation, restricting the reaction generality. Here, we describe a probable outer-sphere nucleophilic attack mechanism that circumvents the challenging transmetalation associated with sterically congested nucleophiles. This strategy enables a general copper-catalyzed enantioconvergent radical N-alkylation of aromatic amines with secondary/tertiary alkyl halides and exhibits catalyst-controlled stereoselectivity. It accommodates diverse aromatic amines, especially bulky secondary and primary ones to deliver value-added chiral amines (>110 examples). It is expected to inspire the coupling of more nucleophiles, particularly challenging sterically congested ones, and accelerate reaction generality.
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Spinocerebellar ataxia type 3 (SCA3) is an inherited movement disorder characterized by a progressive decline in motor coordination. Despite the extensive functional connectivity (FC) alterations reported in previous SCA3 studies in the cerebellum and cerebellar-cerebral pathways, the influence of these FC disturbances on the hierarchical organization of cerebellar functional regions remains unclear. Here, we compared 35 SCA3 patients with 48 age- and sex-matched healthy controls using a combination of voxel-based morphometry and resting-state functional magnetic resonance imaging to investigate whether cerebellar hierarchical organization is altered in SCA3. Utilizing connectome gradients, we identified the gradient axis of cerebellar hierarchical organization, spanning sensorimotor to transmodal (task-unfocused) regions. Compared to healthy controls, SCA3 patients showed a compressed hierarchical organization in the cerebellum at both voxel-level (p < .05, TFCE corrected) and network-level (p < .05, FDR corrected). This pattern was observed in both intra-cerebellar and cerebellar-cerebral gradients. We observed that decreased intra-cerebellar gradient scores in bilateral Crus I/II both negatively correlated with SARA scores (left/right Crus I/II: r = -.48/-.50, p = .04/.04, FDR corrected), while increased cerebellar-cerebral gradients scores in the vermis showed a positive correlation with disease duration (r = .48, p = .04, FDR corrected). Control analyses of cerebellar gray matter atrophy revealed that gradient alterations were associated with cerebellar volume loss. Further FC analysis showed increased functional connectivity in both unimodal and transmodal areas, potentially supporting the disrupted cerebellar functional hierarchy uncovered by the gradients. Our findings provide novel evidence regarding alterations in the cerebellar functional hierarchy in SCA3.
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Conectoma , Enfermedad de Machado-Joseph , Humanos , Enfermedad de Machado-Joseph/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Cerebelo/patología , Corteza CerebelosaRESUMEN
BACKGROUND: Little is known regarding the association between clonal hematopoiesis of indeterminate potential (CHIP) and risk of neurodegenerative diseases. OBJECTIVE: To estimate the risk of neurodegenerative diseases among individuals with CHIP. METHODS: We conducted a community-based cohort study based on UK Biobank and used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of any neurodegenerative disease, subtypes of neurodegenerative diseases (including primary neurodegenerative diseases, vascular neurodegenerative diseases, and other neurodegenerative diseases), and specific diagnoses of neurodegenerative diseases (i.e., amyotrophic lateral sclerosis [ALS], Alzheimer's disease [AD], and Parkinson's disease [PD]) associated with CHIP. RESULTS: We identified 14,440 individuals with CHIP and 450,907 individuals without CHIP. Individuals with CHIP had an increased risk of any neurodegenerative disease (HR 1.10, 95% CI: 1.01-1.19). We also observed a statistically significantly increased risk for vascular neurodegenerative diseases (HR 1.31, 95% CI 1.05-1.63) and ALS (HR 1.50, 95% CI 1.05-2.15). An increased risk was also noted for other neurodegenerative diseases (HR 1.13, 95% CI 0.97-1.32), although not statistically significant. Null association was noted for primary neurodegenerative diseases (HR 1.06, 95% CI 0.96-1.17), AD (HR 1.04, 95% CI 0.88-1.23), and PD (HR 1.02, 95% CI 0.86-1.21). The risk increase in any neurodegenerative disease was mainly observed for DNMT3A-mutant CHIP, ASXL1-mutant CHIP, or SRSF2-mutant CHIP. CONCLUSION: Individuals with CHIP were at an increased risk of neurodegenerative diseases, primarily vascular neurodegenerative diseases and ALS, but potentially also other neurodegenerative diseases. These findings suggest potential shared mechanisms between CHIP and neurodegenerative diseases.
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MOTIVATION: Gene set enrichment analysis (GSEA) is a commonly used algorithm for characterizing gene expression changes. However, the currently available tools used to perform GSEA have a limited ability to analyze large datasets, which is particularly problematic for the analysis of single-cell data. To overcome this limitation, we developed a GSEA package in Python (GSEApy), which could efficiently analyze large single-cell datasets. RESULTS: We present a package (GSEApy) that performs GSEA in either the command line or Python environment. GSEApy uses a Rust implementation to enable it to calculate the same enrichment statistic as GSEA for a collection of pathways. The Rust implementation of GSEApy is 3-fold faster than the Numpy version of GSEApy (v0.10.8) and uses >4-fold less memory. GSEApy also provides an interface between Python and Enrichr web services, as well as for BioMart. The Enrichr application programming interface enables GSEApy to perform over-representation analysis for an input gene list. Furthermore, GSEApy consists of several tools, each designed to facilitate a particular type of enrichment analysis. AVAILABILITY AND IMPLEMENTATION: The new GSEApy with Rust extension is deposited in PyPI: https://pypi.org/project/gseapy/. The GSEApy source code is freely available at https://github.com/zqfang/GSEApy. Also, the documentation website is available at https://gseapy.rtfd.io/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Algoritmos , Programas Informáticos , DocumentaciónRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is not sensitive to immune checkpoint blockade therapy, and negative feedback of tumor immune evasion might be partly responsible. We isolated CD8+ T cells and cultured them in vitro. Proteomics analysis was performed to compare changes in Panc02 cell lines cultured with conditioned medium, and leucine-rich repeat kinase 2 (LRRK2) was identified as a differential gene. LRRK2 expression was related to CD8+ T cell spatial distribution in PDAC clinical samples and upregulated by CD8+ T cells via interferon gamma (IFN-γ) simulation in vitro. Knockdown or pharmacological inhibition of LRRK2 activated an anti-pancreatic cancer immune response in mice, which meant that LRRK2 acted as an immunosuppressive gene. Mechanistically, LRRK2 phosphorylated PD-L1 at T210 to inhibit its ubiquitination-mediated proteasomal degradation. LRRK2 inhibition attenuated PD-1/PD-L1 blockade-mediated, T cell-induced upregulation of LRRK2/PD-L1, thus sensitizing the mice to anti-PD-L1 therapy. In addition, adenosylcobalamin, the activated form of vitamin B12, which was found to be a broad-spectrum inhibitor of LRRK2, could inhibit LRRK2 in vivo and sensitize PDAC to immunotherapy as well, which potentially endows LRRK2 inhibition with clinical translational value. Therefore, PD-L1 blockade combined with LRRK2 inhibition could be a novel therapy strategy for PDAC.
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Heavy metals (HMs) have been widely reported to pose an adverse effect on anaerobic ammonia oxidation (anammox) bacteria, yet the underlying mechanisms remain unclear. This study provides new insights into the potential mechanisms of interaction between HMs and functional enzymes through big date analysis, molecular docking and molecular dynamics simulation. The statistical analysis indicated that 10 mg/L Cu(II) and Cd(II) reduced nitrogen removal rate (NRR) by 85% and 43%, while 5 mg/L Fe(II) enhanced NRR by 29%. Additionally, the results of molecular simulations provided a microscopic interpretation for these macroscopic data. Molecular docking revealed that Hg(II) formed a distinctive binding site on ferritin, while other HMs resided at iron oxidation sites. Furthermore, HMs exhibited distinct binding sites on hydrazine dehydrogenase. Concurrently, the molecular dynamics simulation results further substantiated their capacity to form complexes. Cu(II) displayed the strongest binding affinity with ferritin for -1576 ± 79 kJ/mol in binding free energy calculation. Moreover, Cd(II) bound to ferritin and HDH for -1052.67 ± 58.49 kJ/mol, -290.02 ± 49.68 kJ/mol, respectively. This research addressed a crucial knowledge gap, shedding light on potential applications for remediating heavy metal-laden industrial wastewater.
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Cadmio , Metales Pesados , Simulación del Acoplamiento Molecular , Oxidación Anaeróbica del Amoníaco , Simulación de Dinámica Molecular , Macrodatos , Metales Pesados/química , Iones , Ferritinas , Oxidación-Reducción , Reactores Biológicos/microbiología , Nitrógeno , Aguas del Alcantarillado , Desnitrificación , AnaerobiosisRESUMEN
Developing solid-state hydrogen storage materials is as pressing as ever, which requires a comprehensive understanding of the dehydrogenation chemistry of a solid-state hydride. Transition state search and kinetics calculations are essential to understanding and designing high-performance solid-state hydrogen storage materials by filling in the knowledge gap that current experimental techniques cannot measure. However, the ab initio analysis of these processes is computationally expensive and time-consuming. Searching for descriptors to accurately predict the energy barrier is urgently needed, to accelerate the prediction of hydrogen storage material properties and identify the opportunities and challenges in this field. Herein, we develop a data-driven model to describe and predict the dehydrogenation barriers of a typical solid-state hydrogen storage material, magnesium hydride (MgH2), based on the combination of the crystal Hamilton population orbital of Mg-H bond and the distance between atomic hydrogen. By deriving the distance energy ratio, this model elucidates the key chemistry of the reaction kinetics. All the parameters in this model can be directly calculated with significantly less computational cost than conventional transition state search, so that the dehydrogenation performance of hydrogen storage materials can be predicted efficiently. Finally, we found that this model leads to excellent agreement with typical experimental measurements reported to date and provides clear design guidelines on how to propel the performance of MgH2 closer to the target set by the United States Department of Energy (US-DOE).
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In contrast with the well-established C(sp2 )-SCF3 cross-coupling to forge the Ar-SCF3 bond, the corresponding enantioselective coupling of readily available alkyl electrophiles to forge chiral C(sp3 )-SCF3 bond has remained largely unexplored. We herein disclose a copper-catalyzed enantioselective radical C(sp3 )-SCF3 coupling of a range of secondary/tertiary benzyl radicals with the easily available (Me4 N)SCF3 reagent. The key to the success lies in the utilization of chiral phosphino-oxazoline-derived anionic N,N,P-ligands through tuning electronic and steric effects for the simultaneous control of the reaction initiation and enantioselectivity. This strategy can successfully realize two types of asymmetric radical reactions, including enantioconvergent C(sp3 )-SCF3 cross-coupling of racemic benzyl halides and three-component 1,2-carbotrifluoromethylthiolation of arylated alkenes under mild reaction conditions. It therefore provides a highly flexible platform for the rapid assembly of an array of enantioenriched SCF3 -containing molecules of interest in organic synthesis and medicinal chemistry.
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Transition-metal-catalyzed enantioselective functionalization of acyl radicals has so far not been realized, probably due to their relatively high reactivity, which renders the chemo- and stereocontrol challenging. Herein, we describe Cu(I)-catalyzed enantioselective desymmetrizing C-O bond coupling of acyl radicals. This reaction is compatible with (hetero)aryl and alkyl aldehydes and, more importantly, displays a very broad scope of challenging alcohol substrates, such as 2,2-disubstituted 1,3-diols, 2-substituted-2-chloro-1,3-diols, 2-substituted 1,2,3-triols, 2-substituted serinols, and meso primary 1,4-diols, providing enantioenriched esters characterized by challenging acyclic tetrasubstituted carbon stereocenters. Partnered by one- or two-step follow-up transformations, this reaction provides a convenient and practical strategy for the rapid preparation of chiral C3 building blocks from readily available alcohols, particularly the industrially relevant glycerol. Mechanistic studies supported the proposed C-O bond coupling of acyl radicals.
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The enantioconvergent C(sp3)-N cross-coupling of racemic alkyl halides with (hetero)aromatic amines represents an ideal means to afford enantioenriched N-alkyl (hetero)aromatic amines yet has remained unexplored due to the catalyst poisoning specifically for strong-coordinating heteroaromatic amines. Here, we demonstrate a copper-catalyzed enantioconvergent radical C(sp3)-N cross-coupling of activated racemic alkyl halides with (hetero)aromatic amines under ambient conditions. The key to success is the judicious selection of appropriate multidentate anionic ligands through readily fine-tuning both electronic and steric properties for the formation of a stable and rigid chelating Cu complex. Thus, this kind of ligand could not only enhance the reducing capability of a copper catalyst to provide an enantioconvergent radical pathway but also avoid the coordination with other coordinating heteroatoms, thereby overcoming catalyst poisoning and/or chiral ligand displacement. This protocol covers a wide range of coupling partners (89 examples for activated racemic secondary/tertiary alkyl bromides/chlorides and (hetero)aromatic amines) with high functional group compatibility. When allied with follow-up transformations, it provides a highly flexible platform to access synthetically useful enantioenriched amine building blocks.
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BACKGROUND & AIMS: The progression of non-alcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS: C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH-inducing diets or standard chow for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and µMT mice (containing B cells only in the gastrointestinal tract) were fed a choline-deficient high-fat diet, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with simple steatosis, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and single-cell RNA-sequencing analysis were performed in liver and gastrointestinal tissue to characterise immune cells in mice and humans. RESULTS: Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B cells; additionally, we observed a positive correlation between IgA levels and activated FcRg+ hepatic myeloid cells, as well the extent of liver fibrosis. CONCLUSIONS: Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for the treatment of NASH. IMPACT AND IMPLICATIONS: There is currently no effective treatment for non-alcoholic steatohepatitis (NASH), which is associated with a substantial healthcare burden and is a growing risk factor for hepatocellular carcinoma (HCC). We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we show that the absence of B cells prevented HCC development. B cell-intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets for combinatorial NASH therapies against inflammation and fibrosis.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Microbiota , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/genética , Ratones Endogámicos C57BL , Hígado/patología , Fibrosis , Cirrosis Hepática/complicaciones , Ratones Transgénicos , Inmunoglobulina A/metabolismo , Inmunoglobulina A/farmacología , Modelos Animales de Enfermedad , Dieta Alta en Grasa/efectos adversosRESUMEN
BACKGROUND: Recent findings elucidated hepatic PPARγ functions as a steatogenic-inducer gene that activates de novo lipogenesis, and is involved in regulation of glucose homeostasis, lipid accumulation, and inflammation response. This study delved into a comprehensive analysis of how PPARγ signaling affects the exercise-induced improvement of insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD), along with its underlying mechanism. METHODS: Chronic and acute swimming exercise intervention were conducted in each group mice. IR status was assessed by GTT and ITT assays. Serum inflammatory cytokines were detected by Elisa assays. PPARγ and its target genes expression were detected by qPCR assay. Relative protein levels were quantified via Western blotting. ChIP-qPCR assays were used to detect the enrichment of PPARγ on its target genes promoter. RESULTS: Through an exploration of a high-fat diet (HFD)-induced IR and NAFLD model, both chronic and acute swimming exercise training led to significant reductions in body weight and visceral fat mass, as well as hepatic lipid accumulation. The exercise interventions also demonstrated a significant amelioration in IR and the inflammatory response. Meanwhile, swimming exercise significantly inhibited PPARγ and its target genes expression induced by HFD, containing CD36, SCD1 and PLIN2. Furthermore, swimming exercise presented significant modulation on regulatory factors of PPARγ expression and transcriptional activity. CONCLUSION: The findings suggest that swimming exercise can improve lipid metabolism in IR and NAFLD, possibly through PPARγ signaling in the liver of mice.
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Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Dieta Alta en Grasa/efectos adversos , Redes Reguladoras de Genes , Resistencia a la Insulina/genética , Metabolismo de los Lípidos/genética , Lípidos , Hígado/metabolismo , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , PPAR gamma/genética , PPAR gamma/metabolismo , NataciónRESUMEN
Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disorder characterized by progressive motor and nonmotor deficits concomitant with degenerative pathophysiological changes within the cerebellum. The cerebellum is topographically organized into cerebello-cerebral circuits that create distinct functional networks regulating movement, cognition, and affect. SCA3-associated motor and nonmotor symptoms are possibly related not only to intracerebellar changes but also to disruption of the connectivity within these cerebello-cerebral circuits. However, to date, no comprehensive investigation of cerebello-cerebral connectivity in SCA3 has been conducted. The present study aimed to identify cerebello-cerebral functional connectivity alterations and associations with downstream clinical phenotypes and upstream topographic markers of cerebellar neurodegeneration in patients with SCA3. This study included 45 patients with SCA3 and 49 healthy controls. Voxel-based morphometry and resting-state functional magnetic resonance imaging (MRI) were performed to characterize the cerebellar atrophy and to examine the cerebello-cerebral functional connectivity patterns. Structural MRI confirmed widespread gray matter atrophy in the motor and cognitive cerebellum of patients with SCA3. We found reduced functional connectivity between the cerebellum and the cerebral cortical networks, including the somatomotor, frontoparietal, and default networks; however, increased connectivity was observed between the cerebellum and the dorsal attention network. These abnormal patterns correlated with the CAG repeat expansion and deficits in global cognition. Our results indicate the contribution of cerebello-cerebral networks to the motor and cognitive impairments in patients with SCA3 and reveal that such alterations occur in association with cerebellar atrophy. These findings add important insights into our understanding of the role of the cerebellum in SCA3.
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Enfermedades Cerebelosas , Enfermedad de Machado-Joseph , Humanos , Enfermedad de Machado-Joseph/diagnóstico por imagen , Cerebelo , Corteza Cerebral , Enfermedades Cerebelosas/patología , Imagen por Resonancia Magnética/métodos , Atrofia/patologíaRESUMEN
The therapeutic effects of existing drug regimens against pancreatic neuroendocrine neoplasms (pNENs) remain limited, and identifying ideal therapeutic targets is warranted. PDZ binding kinase (PBK) may play an oncogenic role in most solid tumors. However, its function in pNEN remains unclear. In this study, pNEN samples and International Cancer Genome Consortium data were used to determine the clinical significance of PBK. Cell counting and CCK8 assays were used to assess cell proliferation. Flow cytometry was used to assess drug-induced apoptosis and cell cycle arrest. An in vivo PBK-targeting experiment was performed in mice bearing pNENs. Western blotting, quantitative PCR, and immunohistochemistry were performed to assess the molecular mechanisms. PBK was significantly upregulated in pNEN tissues compared with paracancerous tissues. Additionally, PBK was a poor prognostic factor for pNEN patients. PBK was found to promote the proliferation of pNEN cells by activating the AKT/mTOR pathway. Furthermore, PBK inhibition combined with everolimus treatment had enhanced antitumour effects on pNEN via inhibiting AKT/mTOR pathway and inducing G0/G1 phase cell cycle arrest. This study highlights that PBK plays an oncogenic role in and is a promising therapeutic target for pNEN.