RESUMO
Plant cell wall polysaccharides, including xylan, mannan, xyloglucan, and pectins, are often acetylated and members of the domain of unknown function 231 (DUF231)/trichome birefringence-like (TBL) family have been shown to be O-acetyltransferases mediating the acetylation of xylan, mannan, and xyloglucan. However, little is known about the O-acetyltransferases responsible for pectin acetylation. In this report, we biochemically characterized a suite of Arabidopsis DUF231/TBL proteins for their roles in pectin acetylation. We generated 24 TBL recombinant proteins in mammalian cells and demonstrated that 10 of them were able to transfer acetyl groups from acetyl-CoA onto the pectins homogalacturonan (HG) or rhamnogalacturonan-I (RG-I), and thus were named pectin O-acetyltransferase 1 to 10 (POAT1 to 10). It was found that POAT2,4,9,10 specifically acetylated HG and POAT5,6 acetylated RG-I, whereas POAT1,3,7,8 could act on both HG and RG-I. The acetylation of HG and RG-I by POATs was further corroborated by hydrolysis with pectin acetylesterases and by nuclear magnetic resonance spectroscopy. In addition, mutations of the conserved GDS and DXXH motifs in POAT3 and POAT8 were shown to lead to a loss of their ability to acetylate HG and RG-I. Furthermore, simultaneous RNA interference downregulation of POAT1,3,6,7,8 resulted in reduced cell expansion, impaired plant growth, and decreased pectin acetylation. Together, our findings indicate that these POATs are pectin O-acetyltransferases involved in acetylation of the pectin polysaccharides HG and RG-I.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Xilanos/metabolismo , Ramnogalacturonanos/análise , Ramnogalacturonanos/metabolismo , Mananas/metabolismo , Acetilação , Birrefringência , Tricomas/metabolismo , Pectinas/metabolismo , Polissacarídeos/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Acetiltransferases/genética , Acetiltransferases/metabolismo , Catálise , Parede Celular/metabolismoRESUMO
Xylan is one of the major hemicelluloses in plant cell walls and its xylosyl backbone is often decorated at O-2 with glucuronic acid (GlcA) and/or methylglucuronic acid (MeGlcA) residues. The GlcA/MeGlcA side chains may be further substituted with 2-O-arabinopyranose (Arap) or 2-O-galactopyranose (Gal) residues in some plant species, but the enzymes responsible for these substitutions remain unknown. During our endeavor to investigate the enzymatic activities of Arabidopsis MUR3-clade members of the GT47 glycosyltransferase family, we found that one of them was able to transfer Arap from UDP-Arap onto O-2 of GlcA side chains of xylan, and thus it was named xylan 2-O-arabinopyranosyltransferase 1 (AtXAPT1). The function of AtXAPT1 was verified in planta by its T-DNA knockout mutation showing a loss of the Arap substitution on xylan GlcA side chains. Further biochemical characterization of XAPT close homologs from other plant species demonstrated that while the poplar ones had the same catalytic activity as AtXAPT1, those from Eucalyptus, lemon-scented gum, sea apple, 'Ohi'a lehua, duckweed and purple yam were capable of catalyzing both 2-O-Arap and 2-O-Gal substitutions of xylan GlcA side chains albeit with differential activities. Sequential reactions with XAPTs and glucuronoxylan methyltransferase 3 (GXM3) showed that XAPTs acted poorly on MeGlcA side chains, whereas GXM3 could efficiently methylate arabinosylated or galactosylated GlcA side chains of xylan. Furthermore, molecular docking and site-directed mutagenesis analyses of Eucalyptus XAPT1 revealed critical roles of several amino acid residues at the putative active site in its activity. Together, these findings establish that XAPTs residing in the MUR3 clade of family GT47 are responsible for 2-O-arabinopyranosylation and 2-O-galactosylation of GlcA side chains of xylan.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Glicosiltransferases , Xilanos , Xilanos/metabolismo , Arabidopsis/genética , Arabidopsis/enzimologia , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Glicosiltransferases/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/química , Parede Celular/metabolismo , Parede Celular/enzimologia , Arabinose/metabolismoRESUMO
Zinc (Zn) transporters contribute to the maintenance of intracellular Zn homeostasis in vertebrate, whose activity and function are modulated by post-translational modification. However, the function of small ubiquitin-like modifier (SUMOylation) in Zn metabolism remains elusive. Here, compared with low Zn group, a high-Zn diet significantly increases hepatic Zn content and upregulates the expression of metal-response element-binding transcription factor-1 (MTF-1), Zn transporter 6 (ZnT6) and deSUMOylation enzymes (SENP1, SENP2, and SENP6), but inhibits the expression of SUMO proteins and the E1, E2, and E3 enzymes. Mechanistically, Zn triggers the activation of the MTF-1/SENP1 pathway, resulting in the reduction of ZnT6 SUMOylation at Lys 409 by small ubiquitin-like modifier 1 (SUMO1), and promoting the deSUMOylation process mediated by SENP1. SUMOylation modification of ZnT6 has no influence on its localization but reduces its protein stability. Importantly, deSUMOylation of ZnT6 is crucial for controlling Zn export from the cytosols into the Golgi apparatus. In conclusion, for the first time, we elucidate a novel mechanism by which SUMO1-catalyzed SUMOylation and SENP1-mediated deSUMOylation of ZnT6 orchestrate the regulation of Zn metabolism within the Golgi apparatus.
Assuntos
Proteínas de Transporte de Cátions , Cisteína Endopeptidases , Complexo de Golgi , Sumoilação , Zinco , Animais , Humanos , Masculino , Camundongos , Proteínas de Transporte , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Complexo de Golgi/metabolismo , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Processamento de Proteína Pós-Traducional , Proteína SUMO-1/metabolismo , Fator MTF-1 de Transcrição , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Zinco/metabolismoRESUMO
OBJECTIVE: Precancerous metaplasia transition to dysplasia poses a risk for subsequent intestinal-type gastric adenocarcinoma. However, the molecular basis underlying the transformation from metaplastic to cancerous cells remains poorly understood. DESIGN: An integrated analysis of genes associated with metaplasia, dysplasia was conducted, verified and characterised in the gastric tissues of patients by single-cell RNA sequencing and immunostaining. Multiple mouse models, including homozygous conditional knockout Klhl21-floxed mice, were generated to investigate the role of Klhl21 deletion in stemness, DNA damage and tumour formation. Mass-spectrometry-based proteomics and ribosome sequencing were used to elucidate the underlying molecular mechanisms. RESULTS: Kelch-like protein 21 (KLHL21) expression progressively decreased in metaplasia, dysplasia and cancer. Genetic deletion of Klhl21 enhances the rapid proliferation of Mist1+ cells and their descendant cells. Klhl21 loss during metaplasia facilitates the recruitment of damaged cells into the cell cycle via STAT3 signalling. Increased STAT3 activity was confirmed in cancer cells lacking KLHL21, boosting self-renewal and tumourigenicity. Mechanistically, the loss of KLHL21 promotes PIK3CB mRNA translation by stabilising the PABPC1-eIF4G complex, subsequently causing STAT3 activation. Pharmacological STAT3 inhibition by TTI-101 elicited anticancer effects, effectively impeding the transition from metaplasia to dysplasia. In patients with gastric cancer, low levels of KLHL21 had a shorter survival rate and a worse response to adjuvant chemotherapy. CONCLUSIONS: Our findings highlighted that KLHL21 loss triggers STAT3 reactivation through PABPC1-mediated PIK3CB translational activation, and targeting STAT3 can reverse preneoplastic metaplasia in KLHL21-deficient stomachs.
Assuntos
Proteínas de Ciclo Celular , Proteínas do Citoesqueleto , Metaplasia , Fator de Transcrição STAT3 , Transdução de Sinais , Neoplasias Gástricas , Animais , Humanos , Camundongos , Adenocarcinoma/patologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Carcinogênese/genética , Carcinogênese/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Homeostase , Metaplasia/metabolismo , Camundongos Knockout , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/genética , Fator de Transcrição STAT3/metabolismo , Estômago/patologia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genética , Proteínas do Citoesqueleto/genética , Proteínas de Ciclo Celular/genéticaRESUMO
BACKGROUND: Recent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are involved in the occurrence and development of a variety of tumors. The aim of this study was to investigate the effects of circ_PPAPDC1A in Osimertinib resistance in NSCLC. METHODS: Human circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in Osimertinib-acquired resistance tissues of NSCLC. The effect of circ_PPAPDC1A on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_PPAPDC1A/miR-30a-3p/IGF1R axis. RESULTS: The results revealed that circ_PPAPDC1A was significantly upregulated in Osimertinib acquired resistance tissues of NSCLC. circ_PPAPDC1A reduced the sensitivity of PC9 and HCC827 cells to Osimertinib and promoted cell proliferation, invasion, migration, while inhibiting apoptosis in Osimertinib-resistant PC9/OR and HCC829/OR cells, both in vitro and in vivo. Silencing circ_PPAPDC1A partially reversed Osimertinib resistance. Additionally, circ_PPAPDC1A acted as a competing endogenous RNA (ceRNA) by targeting miR-30a-3p, and Insulin-like Growth Factor 1 Receptor (IGF1R) was identified as a functional gene for miR-30a-3p in NSCLC. Furthermore, the results confirmed that circ_PPAPDC1A/miR-30a-3p/IGF1R axis plays a role in activating the PI3K/AKT/mTOR signaling pathway in NSCLC with Osimertinib resistance. CONCLUSIONS: Therefore, for the first time we identified that circ_PPAPDC1A was significantly upregulated and exerts an oncogenic role in NSCLC with Osimertinib resistance by sponging miR-30a-3p to active IGF1R/PI3K/AKT/mTOR pathway. circ_PPAPDC1A may serve as a novel diagnostic biomarker and therapeutic target for NSCLC patients with Osimertinib resistance.
Assuntos
Acrilamidas , Compostos de Anilina , Carcinoma Pulmonar de Células não Pequenas , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , MicroRNAs , RNA Circular , Receptor IGF Tipo 1 , Transdução de Sinais , Humanos , MicroRNAs/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Acrilamidas/farmacologia , RNA Circular/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Compostos de Anilina/farmacologia , Linhagem Celular Tumoral , Animais , Camundongos , Apoptose , Movimento Celular/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Masculino , Feminino , Indóis , PirimidinasRESUMO
Members of the domain of unknown function 231/trichome birefringence-like (TBL) family have been shown to be O-acetyltransferases catalyzing the acetylation of plant cell wall polysaccharides, including pectins, mannan, xyloglucan and xylan. However, little is known about the origin and evolution of plant cell wall polysaccharide acetyltransferases. Here, we investigated the biochemical functions of TBL homologs from Klebsormidium nitens, a representative of an early divergent class of charophyte green algae that are considered to be the closest living relatives of land plants, and Marchantia polymorpha, a liverwort that is an extant representative of an ancient lineage of land plants. The genomes of K. nitens and Marchantia polymorpha harbor two and six TBL homologs, respectively. Biochemical characterization of their recombinant proteins expressed in human embryonic kidney 293 cells demonstrated that the two K. nitens TBLs exhibited acetyltransferase activities acetylating the pectin homogalacturonan (HG) and hence were named KnPOAT1 and KnPOAT2. Among the six M. polymorpha TBLs, five (MpPOAT1 to 5) possessed acetyltransferase activities toward pectins and the remaining one (MpMOAT1) catalyzed 2-O- and 3-O-acetylation of mannan. While MpPOAT1,2 specifically acetylated HG, MpPOAT3,4,5 could acetylate both HG and rhamnogalacturonan-I. Consistent with the acetyltransferase activities of these TBLs, pectins isolated from K. nitens and both pectins and mannan from M. polymorpha were shown to be acetylated. These findings indicate that the TBL genes were recruited as cell wall polysaccharide O-acetyltransferases as early as in charophyte green algae with activities toward pectins and they underwent expansion and functional diversification to acetylate various cell wall polysaccharides during evolution of land plants.
Assuntos
Acetiltransferases , Parede Celular , Pectinas , Polissacarídeos , Parede Celular/metabolismo , Acetilação , Acetiltransferases/metabolismo , Acetiltransferases/genética , Polissacarídeos/metabolismo , Pectinas/metabolismo , Filogenia , Células HEK293 , Humanos , Marchantia/genética , Marchantia/enzimologia , Marchantia/metabolismo , Mananas/metabolismo , Carofíceas/genética , Carofíceas/enzimologia , Carofíceas/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
Grass xylan consists of a linear chain of ß-1,4-linked xylosyl residues that often form domains substituted only with either arabinofuranose (Araf) or glucuronic acid (GlcA)/methylglucuronic acid (MeGlcA) residues, and it lacks the unique reducing end tetrasaccharide sequence found in dicot xylan. The mechanism of how grass xylan backbone elongation is initiated and how its distinctive substitution pattern is determined remains elusive. Here, we performed biochemical characterization of rice xylan biosynthetic enzymes, including xylan synthases, glucuronyltransferases and methyltransferases. Activity assays of rice xylan synthases demonstrated that they required short xylooligomers as acceptors for their activities. While rice xylan glucuronyltransferases effectively glucuronidated unsubstituted xylohexaose acceptors, they transferred little GlcA residues onto (Araf)-substituted xylohexaoses and rice xylan 3-O-arabinosyltransferase could not arabinosylate GlcA-substituted xylohexaoses, indicating that their intrinsic biochemical properties may contribute to the distinctive substitution patterns of rice xylan. In addition, we found that rice xylan methyltransferase exhibited a low substrate binding affinity, which may explain the partial GlcA methylation in rice xylan. Furthermore, immunolocalization of xylan in xylem cells of both rice and Arabidopsis showed that it was deposited together with cellulose in secondary walls without forming xylan-rich nanodomains. Together, our findings provide new insights into the biochemical mechanisms underlying xylan backbone elongation and substitutions in grass species.
Assuntos
Oryza , Proteínas de Plantas , Xilanos , Xilanos/metabolismo , Oryza/genética , Oryza/enzimologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Pentosiltransferases/metabolismo , Pentosiltransferases/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Xilema/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/metabolismo , Glucuronosiltransferase/metabolismo , Glucuronosiltransferase/genéticaRESUMO
The mitochondria, as one of the essential organelles in cells, are closely associated with numerous biological processes. Therefore, the realization of clear and real-time imaging for tracking mitochondria is of profound significance. Here, we present a mitochondria-targeting fluorescent probe, N(CH2)3-PD-NEt, for the real-time fluorescence imaging of mitochondria in living cells. Using the probe, the fluorescence changes of mitochondria stimulated by different drugs were successfully observed by fluorescence imaging. In addition, the dynamic processes of mitochondria and lysosomes during apoptosis were also explored. Importantly, we observed several novel dynamic interaction patterns between mitochondria and lysosomes. Among them, the most prominent pattern involved the noncontact movements of two lysosomes, that is, one lysosome gradually approached the other lysosome over time, eventually coming into contact and merging with it while gradually combining with mitochondria to form new mitochondria. Notably, the protrusions of the mitochondria became increasingly evident during this process. Meanwhile, we successfully observed the dynamic changes of mitochondria with SIM super-resolution imaging. The study provides promising help for the in-depth study of the dynamic processes of mitochondrial physiology and pathology and the study of the interactions between organelles.
Assuntos
Apoptose , Corantes Fluorescentes , Lisossomos , Mitocôndrias , Lisossomos/metabolismo , Lisossomos/química , Mitocôndrias/metabolismo , Corantes Fluorescentes/química , Humanos , Imagem Óptica , Células HeLaRESUMO
The complete structure-functional repair of volumetric muscle loss (VML) remains a giant challenge and biomedical hydrogels to remodel microenvironment and enhance neurogenesis have appeared to be a promising direction. However, the current hydrogels for VML repair hardly achieve these two goals simultaneously due to their insufficient functionality and the challenge in high-cost of bioactive factors. In this study, a facile strategy using Nb2C MXene-functionalized hydrogel (OPTN) as a bioactive scaffold is proposed to promote VML repair with skeletal muscle regeneration and functional restoration. In vitro experiments show that OPTN scaffold can effectively scavenge reactive oxygen species (ROS), guide macrophages polarization toward M2 phenotype, and resist bacterial infection, providing a favorable microenvironment for myoblasts proliferation as well as the endothelial cells proliferation, migration, and tube formation. More importantly, OPTN scaffold with electroactive feature remarkably boosts myoblasts differentiation and mesenchymal stem cells neural differentiation. Animal experiments further confirm that OPTN scaffold can achieve a prominent structure-functional VML repair by attenuating ROS levels, alleviating inflammation, reducing fibrosis, and facilitating angiogenesis, newborn myotube formation, and neurogenesis. Collectively, this study provides a highly promising and effective strategy for the structure-functional VML repair through designing bioactive multifunctional hydrogel with microenvironment remodeling and enhanced neurogenesis.
Assuntos
Hidrogéis , Músculo Esquelético , Neurogênese , Regeneração , Hidrogéis/química , Hidrogéis/farmacologia , Animais , Neurogênese/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Camundongos , Proliferação de Células/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Alicerces Teciduais/química , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Microambiente Celular/efeitos dos fármacosRESUMO
Antimony selenide (Sb2 Se3 ) is a highly promising photovoltaic material thanks to its outstanding optoelectronic properties, as well as its cost-effective and eco-friendly merits. However, toxic CdS is widely used as an electron transport layer (ETL) in efficient Sb2 Se3 solar cells, which largely limit their development toward market commercialization. Herein, an effective green Cd-free ETL of SnOx is introduced and deposited by atomic layer deposition method. Additionally, an important post-annealing treatment is designed to further optimize the functional layers and the heterojunction interface properties. Such engineering strategy can optimize SnOx ETL with higher nano-crystallinity, higher carrier density, and less defect groups, modify Sb2 Se3 /SnOx heterojunction with better interface performance and much desirable "spike-like" band alignment, and also improve the Sb2 Se3 light absorber layer quality with passivated bulk defects and prolonged carrier lifetime, and therefore to enhance carrier separation and transport while suppressing non-radiative recombination. Finally, the as-fabricated Cd-free Mo/Sb2 Se3 /SnOx /ITO/Ag thin-film solar cell exhibits a stimulating efficiency of 7.39%, contributing a record value for Cd-free substrate structured Sb2 Se3 solar cells reported to date. This work provides a viable strategy for developing and broadening practical applications of environmental-friendly Sb2 Se3 photovoltaic devices.
RESUMO
MAIN CONCLUSION: A member of the rice GT61 clade B is capable of transferring both 2-O-xylosyl and 2-O-arabinosyl residues onto xylan and another member specifically catalyses addition of 2-O-xylosyl residue onto xylan. Grass xylan is substituted predominantly with 3-O-arabinofuranose (Araf) as well as with some minor side chains, such as 2-O-Araf and 2-O-(methyl)glucuronic acid [(Me)GlcA]. 3-O-Arabinosylation of grass xylan has been shown to be catalysed by grass-expanded clade A members of the glycosyltransferase family 61. However, glycosyltransferases mediating 2-O-arabinosylation of grass xylan remain elusive. Here, we performed biochemical studies of two rice GT61 clade B members and found that one of them was capable of transferring both xylosyl (Xyl) and Araf residues from UDP-Xyl and UDP-Araf, respectively, onto xylooligomer acceptors, whereas the other specifically catalysed Xyl transfer onto xylooligomers, indicating that the former is a xylan xylosyl/arabinosyl transferase (named OsXXAT1 herein) and the latter is a xylan xylosyltransferase (named OsXYXT2). Structural analysis of the OsXXAT1- and OsXYXT2-catalysed reaction products revealed that the Xyl and Araf residues were transferred onto O-2 positions of xylooligomers. Furthermore, we demonstrated that OsXXAT1 and OsXYXT2 were able to substitute acetylated xylooligomers, but only OsXXAT1 could xylosylate GlcA-substituted xylooligomers. OsXXAT1 and OsXYXT2 were predicted to adopt a GT-B fold structure and molecular docking revealed candidate amino acid residues at the predicted active site involved in binding of the nucleotide sugar donor and the xylohexaose acceptor substrates. Together, our results establish that OsXXAT1 is a xylan 2-O-xylosyl/2-O-arabinosyl transferase and OsXYXT2 is a xylan 2-O-xylosyltransferase, which expands our knowledge of roles of the GT61 family in grass xylan synthesis.
Assuntos
Arabidopsis , Oryza , Glicosiltransferases/análise , Oryza/metabolismo , Xilanos/metabolismo , Arabidopsis/metabolismo , Simulação de Acoplamento Molecular , UDP Xilose-Proteína Xilosiltransferase , Poaceae/metabolismo , Parede Celular/metabolismoRESUMO
Dietary fiber metabolism by gut microorganisms plays important roles in host physiology and health. Alginate, the major dietary fiber of daily diet seaweeds, is drawing more attention because of multiple biological activities. To advance the understanding of alginate assimilation mechanism in the gut, we show the presence of unsaturated alginate oligosaccharides (uAOS)-specific alginate utilization loci (AUL) in human gut microbiome. As a representative example, a working model of the AUL from the gut microorganism Bacteroides clarus was reconstructed from biochemistry and transcriptome data. The fermentation of resulting monosaccharides through Entner-Doudoroff pathway tunes the metabolism of short-chain fatty acids and amino acids. Furthermore, we show that uAOS feeding protects the mice against dextran sulfate sodium-induced acute colitis probably by remodeling gut microbiota and metabolome. IMPORTANCE: Alginate has been included in traditional Chinese medicine and daily diet for centuries. Recently discovered biological activities suggested that alginate-derived alginate oligosaccharides (AOS) might be an active ingredient in traditional Chinese medicine, but how these AOS are metabolized in the gut and how it affects health need more information. The study on the working mechanism of alginate utilization loci (AUL) by the gut microorganism uncovers the role of unsaturated alginate oligosaccharides (uAOS) assimilation in tuning short-chain fatty acids and amino acids metabolism and demonstrates that uAOS metabolism by gut microorganisms results in a variation of cell metabolites, which potentially contributes to the physiology and health of gut.
Assuntos
Alginatos , Microbioma Gastrointestinal , Oligossacarídeos , Alginatos/metabolismo , Oligossacarídeos/metabolismo , Camundongos , Animais , Humanos , Colite/microbiologia , Colite/induzido quimicamente , Camundongos Endogâmicos C57BL , Ácidos Graxos Voláteis/metabolismo , Inflamação/metabolismo , Sulfato de Dextrana , Fibras na Dieta/metabolismoRESUMO
ß-Galactosidases (Bgals) remove terminal ß-D-galactosyl residues from the nonreducing ends of ß-D-galactosidases and oligosaccharides. Bgals are present in bacteria, fungi, animals, and plants and have various functions. Despite the many studies on the evolution of BGALs in plants, their functions remain obscure. Here, we identified rice (Oryza sativa) ß-galactosidase9 (OsBGAL9) as a direct target of the heat stress-induced transcription factor SPOTTED-LEAF7 (OsSPL7), as demonstrated by protoplast transactivation analysis and yeast 1-hybrid and electrophoretic mobility shift assays. Knockout plants for OsBGAL9 (Osbgal9) showed short stature and growth retardation. Histochemical ß-glucuronidase (GUS) analysis of transgenic lines harboring an OsBGAL9pro:GUS reporter construct revealed that OsBGAL9 is mainly expressed in internodes at the mature stage. OsBGAL9 expression was barely detectable in seedlings under normal conditions but increased in response to biotic and abiotic stresses. Ectopic expression of OsBGAL9 enhanced resistance to the rice pathogens Magnaporthe oryzae and Xanthomonas oryzae pv. oryzae, as well as tolerance to cold and heat stress, while Osbgal9 mutant plants showed the opposite phenotypes. OsBGAL9 localized to the cell wall, suggesting that OsBGAL9 and its plant putative orthologs likely evolved functions distinct from those of its closely related animal enzymes. Enzyme activity assays and analysis of the cell wall composition of OsBGAL9 overexpression and mutant plants indicated that OsBGAL9 has activity toward galactose residues of arabinogalactan proteins (AGPs). Our study clearly demonstrates a role for a member of the BGAL family in AGP processing during plant development and stress responses.
Assuntos
Oryza , Xanthomonas , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Genes de Plantas , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo , Xanthomonas/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologiaRESUMO
BACKGROUND: Robotic gastrectomy (RG) has been widely used to treat gastric cancer. However, whether the short-term outcomes of robotic gastrectomy are superior to those of laparoscopic gastrectomy (LG) for elderly patients with advanced gastric cancer has not been reported. METHODS: The study enrolled of 594 elderly patients with advanced gastric cancer who underwent robotic or laparoscopic radical gastrectomy. The RG cohort was matched 1:3 with the LG cohort using propensity score-matching (PSM). RESULTS: After PSM, 121 patients were included in the robot group and 363 patients in the laparoscopic group. Excluding the docking and undocking times, the operation time of the two groups was similar (P = 0.617). The RG group had less intraoperative blood loss than the LG group (P < 0.001). The time to ambulation and first liquid food intake was significantly shorter in the RG group than in the LG group (P < 0.05). The incidence of postoperative complications did not differ significantly between the two groups (P = 0.14). Significantly more lymph nodes were dissected in the RG group than in the LG group (P = 0.001). Postoperative adjuvant chemotherapy was started earlier in the RG group than in the LG group (P = 0.02). CONCLUSIONS: For elderly patients with advanced gastric cancer, RG is safe and feasible. Compared with LG, RG is associated with less intraoperative blood loss; a faster postoperative recovery time, allowing a greater number of lymph nodes to be dissected; and earlier adjuvant chemotherapy.
Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Neoplasias Gástricas , Humanos , Idoso , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Pontuação de Propensão , Perda Sanguínea Cirúrgica , Resultado do Tratamento , Gastrectomia , Complicações Pós-Operatórias/cirurgia , Estudos RetrospectivosRESUMO
In this Letter, we propose and experimentally demonstrate a highly sensitive distributed dynamic pressure sensor based on a dual-linear frequency modulated optical frequency domain reflectometry (OFDR) and a coating thickness-enhanced single-mode fiber (SMF). A dual-sideband linear frequency modulation (LFM) signal is used to interrogate the sensing fiber, which allows us to obtain a dual-sideband Rayleigh backscattering signal. Due to the opposite slopes of the two LFM sidebands, the Rayleigh backscattering spectra of the two sidebands drift in opposite directions when the fiber is disturbed. By subtracting the frequency shifts of the two spectra, we can double the system's sensitivity. We further enhance the sensitivity by using an SMF with a coating thickness of 200â µm. This results in a pressure sensitivity of 3979â MHz/MPa, a measurement accuracy of 0.76â kPa, and a spatial resolution of 35â cm over a 500â m optical fiber. Our system successfully detected a dynamic pressure change at a sampling rate of 1.25â kHz, demonstrating the sensor's excellent dynamic measuring capabilities.
RESUMO
BACKGROUND: Systemic inflammatory factors can predict the survival prognosis of gastric cancer (GC) patients after neoadjuvant chemotherapy (NACT). However, whether longitudinal changes in systemic inflammatory factors are associated with short - and long-term outcomes has not been reported. METHODS: This study is a retrospective analysis of 216 patients with advanced gastric cancer who received NACT between January 2011 and June 2019, comparing receiver operating characteristic (ROC) curves for screening suitable inflammatory markers. Group-based trajectory modeling (GBTM) was used to analyze longitudinal changes in inflammatory markers during NACT to identify different potential subgroups and to compare postoperative complications, recurrence-free survival (RFS), and overall survival (OS) among subgroups. RESULTS: Ultimately, neutrophil-lymphocyte ratio (NLR) had the highest area under the curve (AUC) value in predicting prognosis was included in the GBTM analysis. Three trajectories of NLR were obtained: Stable group (SG) (n = 89), Ascent-descend group (ADG) (n = 80) and Continuous descend group (CDG) (n = 47). Compared with SG, ADG and CDG are associated with an increased risk of postoperative recurrence and death. The median time of RFS and OS of SG was longer than that of ADG and CDG (median RFS 81 vs. 44 and 22 months; median OS 69 vs. 41 and 30 months). In addition, CDG had significantly higher postoperative serious complications than SG and ADG (17 (36.2%) vs. 17 (19.1%) and 12 (15.0%); p = 0.005). CONCLUSION: There were different trajectories of NLR during NACT, and these potential trajectories were significantly associated with severe postoperative complications, recurrence, and mortality in patients with GC.
Assuntos
Neutrófilos , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Estudos Retrospectivos , Terapia Neoadjuvante , Linfócitos , Prognóstico , Complicações Pós-OperatóriasRESUMO
BACKGROUND: Independent and valid prognostic predictors for locally advanced gastric cancer (LAGC) patients with non-elevated serum tumor markers (Triple-negative: CA199 < 37U/ml, CEA < 5 µg/ml and CA125 < 35U/ml) before and after neoadjuvant chemotherapy (NACT) remain unclear. METHODS: A total of 352 LAGC patients treated with NACT(NLAGC) from two centers were included. Of the 156 were Triple-negative patients. CA72-4 trajectory groupings was defined as longitudinal changes in CA72-4 levels before and after NACT to identify different potential subgroups and to compare recurrence-free survival (RFS) and overall survival (OS) among subgroups. The predictive performance of the nomogram-trajectory was evaluated using the area under the receiver operating characteristic curve(AUC), decision curve analysis, and C-index. RESULTS: In the Triple-negative patients, the Stable group had significantly worse 3-year OS than the Normal, Elevated, and Descend groups(3-year OS: 53.9% vs. 77.9% vs. 73.5% vs. 87.7%;P = 0.002). Cox multivariate analysis showed that CA72-4 trajectory groupings (Stable group: HR:3.442, 95%CI[1.574-7.528], P = 0.002) was an independent prognostic risk factor. In addition, the C-index and AUC values based on the nomogram-trajectory were significantly higher than those of ypTNM staging (C-index: 0.788 vs. 0.719,P < 0.001;AUC: 0.800 vs. 0.667,P < 0.001). Furthermore, The survival analysis revealed that the 3-year OS of the Low-Risk group of nomogram scores was significantly better than that of the High-Risk group(3-year OS:84.7% vs. 29.1%). And the Low-Risk group had the lower cumulative risk of recurrence (P < 0.001). CONCLUSION: The CA72-4 trajectory groupings were an independent prognostic factor for NLAGC Triple-negative patients. The predictive efficacy of the Nomogram-trajectory was significantly better than the ypTNM.
Assuntos
Biomarcadores Tumorais , Terapia Neoadjuvante , Nomogramas , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Neoplasias Gástricas/sangue , Feminino , Masculino , Terapia Neoadjuvante/métodos , Pessoa de Meia-Idade , Biomarcadores Tumorais/sangue , Idoso , Prognóstico , Antígenos Glicosídicos Associados a Tumores/sangue , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Estudos Retrospectivos , Quimioterapia Adjuvante/métodos , Curva ROCRESUMO
OBJECTIVE: To build and merge a diagnostic model called multi-input DenseNet fused with clinical features (MI-DenseCFNet) for discriminating between Staphylococcus aureus pneumonia (SAP) and Aspergillus pneumonia (ASP) and to evaluate the significant correlation of each clinical feature in determining these two types of pneumonia using a random forest dichotomous diagnosis model. This will enhance diagnostic accuracy and efficiency in distinguishing between SAP and ASP. METHODS: In this study, 60 patients with clinically confirmed SAP and ASP, who were admitted to four large tertiary hospitals in Kunming, China, were included. Thoracic high-resolution CT lung windows of all patients were extracted from the picture archiving and communication system, and the corresponding clinical data of each patient were collected. RESULTS: The MI-DenseCFNet diagnosis model demonstrates an internal validation set with an area under the curve (AUC) of 0.92. Its external validation set demonstrates an AUC of 0.83. The model requires only 10.24s to generate a categorical diagnosis and produce results from 20 cases of data. Compared with high-, mid-, and low-ranking radiologists, the model achieves accuracies of 78% vs. 75% vs. 60% vs. 40%. Eleven significant clinical features were screened by the random forest dichotomous diagnosis model. CONCLUSION: The MI-DenseCFNet multimodal diagnosis model can effectively diagnose SAP and ASP, and its diagnostic performance significantly exceeds that of junior radiologists. The 11 important clinical features were screened in the constructed random forest dichotomous diagnostic model, providing a reference for clinicians. CLINICAL RELEVANCE STATEMENT: MI-DenseCFNet could provide diagnostic assistance for primary hospitals that do not have advanced radiologists, enabling patients with suspected infections like Staphylococcus aureus pneumonia or Aspergillus pneumonia to receive a quicker diagnosis and cut down on the abuse of antibiotics. KEY POINTS: ⢠MI-DenseCFNet combines deep learning neural networks with crucial clinical features to discern between Staphylococcus aureus pneumonia and Aspergillus pneumonia. ⢠The comprehensive group had an area under the curve of 0.92, surpassing the proficiency of junior radiologists. ⢠This model can enhance a primary radiologist's diagnostic capacity.
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Aprendizado Profundo , Tomografia Computadorizada por Raios X , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Diagnóstico Diferencial , Tomografia Computadorizada por Raios X/métodos , Pneumonia Estafilocócica/diagnóstico por imagem , Pneumonia Estafilocócica/microbiologia , Idoso , Aspergilose Pulmonar/diagnóstico por imagem , Staphylococcus aureus/isolamento & purificação , Adulto , Interpretação de Imagem Radiográfica Assistida por Computador/métodosRESUMO
Choline plays a crucial role in hepatic lipid homeostasis by acting as a major methyl-group donor. However, despite this well-accepted fact, no study has yet explored how choline's methyl-donor function contributes to preventing hepatic lipid dysregulation. Moreover, the potential regulatory role of Ire-1α, an ER-transmembrane transducer for the unfolded protein response (UPRer), in choline-mediated hepatic lipid homeostasis remains unexplored. Thus, this study investigated the mechanism by which choline prevents hepatic lipid dysregulation, focusing on its role as a methyl-donor and the involvement of Ire-1α in this process. To this end, a model animal for lipid metabolism, yellow catfish (Pelteobagrus fulvidraco) were fed two different diets (adequate or deficient choline diets) in vivo for 10 weeks. The key findings of studies are as follows: 1. Dietary choline, upregulated selected lipolytic and fatty acid ß-oxidation transcripts promoting hepatic lipid homeostasis. 2. Dietary choline ameliorated UPRer and prevented hepatic lipid dysregulation mainly through ire-1α signalling, not perk or atf-6α signalling. 3. Choline inhibited the transcriptional expression level of ire-1α by activating site-specific DNA methylations in the promoter of ire-1α. 4. Choline-mediated ire-1α methylations reduced Ire-1α/Fas interactions, thereby further inhibiting Fas activity and reducing lipid droplet deposition. These results offer a novel insight into the direct and indirect regulation of choline on lipid metabolism genes and suggests a potential crosstalk between ire-1α signalling and choline-deficiency-induced hepatic lipid dysregulation, highlighting the critical contribution of choline as a methyl-donor in maintaining hepatic lipid homeostasis.
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Peixes-Gato , Lipotrópicos , Animais , Lipotrópicos/metabolismo , Colina/farmacologia , Colina/metabolismo , Peixes-Gato/metabolismo , Fígado/metabolismo , Metabolismo dos Lipídeos , Homeostase , LipídeosRESUMO
This experiment was conducted to investigate whether dietary chenodeoxycholic acid (CDCA) could attenuate high-fat (HF) diet-induced growth retardation, lipid accumulation and bile acid (BA) metabolism disorder in the liver of yellow catfish Pelteobagrus fulvidraco. Yellow catfish (initial weight: 4·40 (sem 0·08) g) were fed four diets: the control (105·8 g/kg lipid), HF diet (HF group, 159·6 g/kg lipid), the control supplemented with 0·9 g/kg CDCA (CDCA group) and HF diet supplemented with 0·9 g/kg CDCA (HF + CDCA group). CDCA supplemented in the HF diet significantly improved growth performance and feed utilisation of yellow catfish (P < 0·05). CDCA alleviated HF-induced increment of hepatic lipid and cholesterol contents by down-regulating the expressions of lipogenesis-related genes and proteins and up-regulating the expressions of lipololysis-related genes and proteins. Compared with the control group, CDCA group significantly reduced cholesterol level (P < 0·05). CDCA significantly inhibited BA biosynthesis and changed BA profile by activating farnesoid X receptor (P < 0·05). The contents of CDCA, taurochenodeoxycholic acid and glycochenodeoxycholic acid were significantly increased with the supplementation of CDCA (P < 0·05). HF-induced elevation of cholic acid content was significantly attenuated by the supplementation of CDCA (P < 0·05). Supplementation of CDCA in the control and HF groups could improve the liver antioxidant capacity. This study proved that CDCA could improve growth retardation, lipid accumulation and BA metabolism disorder induced by HF diet, which provided new insight into understanding the physiological functions of BA in fish.