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The impact of apolipoprotein E ε4 (APOE4), the strongest genetic risk factor for Alzheimer's disease (AD), on human brain cellular function remains unclear. Here, we investigated the effects of APOE4 on brain cell types derived from population and isogenic human induced pluripotent stem cells, post-mortem brain, and APOE targeted replacement mice. Population and isogenic models demonstrate that APOE4 local haplotype, rather than a single risk allele, contributes to risk. Global transcriptomic analyses reveal human-specific, APOE4-driven lipid metabolic dysregulation in astrocytes and microglia. APOE4 enhances de novo cholesterol synthesis despite elevated intracellular cholesterol due to lysosomal cholesterol sequestration in astrocytes. Further, matrisome dysregulation is associated with upregulated chemotaxis, glial activation, and lipid biosynthesis in astrocytes co-cultured with neurons, which recapitulates altered astrocyte matrisome signaling in human brain. Thus, APOE4 initiates glia-specific cell and non-cell autonomous dysregulation that may contribute to increased AD risk.
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Doença de Alzheimer , Células-Tronco Pluripotentes Induzidas , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Astrócitos/metabolismo , Colesterol/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Microglia/metabolismoRESUMO
Despite half a century's advance in the field of transition-metal-catalyzed asymmetric alkene hydrogenation, the enantioselective hydrogenation of purely alkyl-substituted 1,1-dialkylethenes has remained an unmet challenge. Herein, we describe a chiral PCNOx-pincer iridium complex for asymmetric transfer hydrogenation of this alkene class with ethanol, furnishing all-alkyl-substituted tertiary stereocenters. High levels of enantioselectivity can be achieved in the reactions of substrates with secondary/primary and primary/primary alkyl combinations. The catalyst is further applied to the redox isomerization of disubstituted alkenols, producing a tertiary stereocenter remote to the resulting carbonyl group. Mechanistic studies reveal a dihydride species, (PCNOx)Ir(H)2, as the catalytically active intermediate, which can decay to a dimeric species (κ3-PCNOx)IrH(µ-H)2IrH(κ2-PCNOx) via a ligand-remetalation pathway. The catalyst deactivation under the hydrogenation conditions with H2 is much faster than that under the transfer hydrogenation conditions with EtOH, which explains why the (PCNOx)Ir catalyst is effective for the transfer hydrogenation but ineffective for the hydrogenation. The suppression of di-to-trisubstituted alkene isomerization by regioselective 1,2-insertion is partly responsible for the success of this system, underscoring the critical role played by the pincer ligand in enantioselective transfer hydrogenation of 1,1-dialkylethenes. Moreover, computational studies elucidate the significant influence of the London dispersion interaction between the ligand and the substrate on enantioselectivity control, as illustrated by the complete reversal of stereochemistry through cyclohexyl-to-cyclopropyl group substitution in the alkene substrates.
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BACKGROUND: Obesity is well-established as a significant contributor to the development of insulin resistance (IR) and diabetes, partially due to elevated plasma saturated free fatty acids like palmitic acid (PA). Grb10-interacting GYF Protein 2 (GIGYF2), an RNA-binding protein, is widely expressed in various tissues including the liver, and has been implicated in diabetes-induced cognitive impairment. Whereas, its role in obesity-related IR remains uninvestigated. METHODS: In this study, we employed palmitic acid (PA) exposure to establish an in vitro IR model in the human liver cancer cell line HepG2 with high-dose chronic PA treatment. The cells were stained with fluorescent dye 2-NBDG to evaluate cell glucose uptake. The mRNA expression levels of genes were determined by real-time qRT-PCR (RT-qPCR). Western blotting was employed to examine the protein expression levels. The RNA immunoprecipitation (RIP) was used to investigate the binding between protein and mRNA. Lentivirus-mediated gene knockdown and overexpression were employed for gene manipulation. In mice, an IR model induced by a high-fat diet (HFD) was established to validate the role and action mechanisms of GIGYF2 in the modulation of HFD-induced IR in vivo. RESULTS: In hepatocytes, high levels of PA exposure strongly trigger the occurrence of hepatic IR evidenced by reduced glucose uptake and elevated extracellular glucose content, which is remarkably accompanied by up-regulation of GIGYF2. Silencing GIGYF2 ameliorated PA-induced IR and enhanced glucose uptake. Conversely, GIGYF2 overexpression promoted IR, PTEN upregulation, and AKT inactivation. Additionally, PA-induced hepatic IR caused a notable increase in STAU1, which was prevented by depleting GIGYF2. Notably, silencing STAU1 prevented GIGYF2-induced PTEN upregulation, PI3K/AKT pathway inactivation, and IR. STAU1 was found to stabilize PTEN mRNA by binding to its 3'UTR. In liver cells, tocopherol treatment inhibits GIGYF2 expression and mitigates PA-induced IR. In the in vivo mice model, GIGYF2 knockdown and tocopherol administration alleviate high-fat diet (HFD)-induced glucose intolerance and IR, along with the suppression of STAU1/PTEN and restoration of PI3K/AKT signaling. CONCLUSIONS: Our study discloses that GIGYF2 mediates obesity-related IR by disrupting the PI3K/AKT signaling axis through the up-regulation of STAU1/PTEN. Targeting GIGYF2 may offer a potential strategy for treating obesity-related metabolic diseases, including type 2 diabetes.
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Proteínas de Transporte , Resistência à Insulina , Fígado , PTEN Fosfo-Hidrolase , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Proteínas de Ligação a RNA , Transdução de Sinais , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , PTEN Fosfo-Hidrolase/metabolismo , PTEN Fosfo-Hidrolase/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Fosfatidilinositol 3-Quinases/metabolismo , Camundongos , Fígado/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Transporte/genética , Células Hep G2 , Ácido Palmítico , Masculino , Proteínas do Citoesqueleto/metabolismo , Proteínas do Citoesqueleto/genética , Camundongos Endogâmicos C57BL , Dieta Hiperlipídica/efeitos adversosRESUMO
Inherited retinal degenerations (IRDs) are a group of untreatable and commonly blinding diseases characterized by progressive photoreceptor loss. IRD pathology has been linked to an excessive activation of cyclic nucleotide-gated channels (CNGC) leading to Na+- and Ca2+-influx, subsequent activation of voltage-gated Ca2+-channels (VGCC), and further Ca2+ influx. However, a connection between excessive Ca2+ influx and photoreceptor loss has yet to be proven.Here, we used whole-retina and single-cell RNA-sequencing to compare gene expression between the rd1 mouse model for IRD and wild-type (wt) mice. Differentially expressed genes indicated links to several Ca2+-signalling related pathways. To explore these, rd1 and wt organotypic retinal explant cultures were treated with the intracellular Ca2+-chelator BAPTA-AM or inhibitors of different Ca2+-permeable channels, including CNGC, L-type VGCC, T-type VGCC, Ca2+-release-activated channel (CRAC), and Na+/Ca2+ exchanger (NCX). Moreover, we employed the novel compound NA-184 to selectively inhibit the Ca2+-dependent protease calpain-2. Effects on the retinal activity of poly(ADP-ribose) polymerase (PARP), sirtuin-type histone-deacetylase, calpains, as well as on activation of calpain-1, and - 2 were monitored, cell death was assessed via the TUNEL assay.While rd1 photoreceptor cell death was reduced by BAPTA-AM, Ca2+-channel blockers had divergent effects: While inhibition of T-type VGCC and NCX promoted survival, blocking CNGCs and CRACs did not. The treatment-related activity patterns of calpains and PARPs corresponded to the extent of cell death. Remarkably, sirtuin activity and calpain-1 activation were linked to photoreceptor protection, while calpain-2 activity was related to degeneration. In support of this finding, the calpain-2 inhibitor NA-184 protected rd1 photoreceptors.These results suggest that Ca2+ overload in rd1 photoreceptors may be triggered by T-type VGCCs and NCX. High Ca2+-levels likely suppress protective activity of calpain-1 and promote retinal degeneration via activation of calpain-2. Overall, our study details the complexity of Ca2+-signalling in photoreceptors and emphasizes the importance of targeting degenerative processes specifically to achieve a therapeutic benefit for IRDs. Video Abstract.
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Ácido Egtázico/análogos & derivados , Degeneração Retiniana , Sirtuínas , Camundongos , Animais , Degeneração Retiniana/metabolismo , Calpaína/metabolismo , Trocador de Sódio e Cálcio , Células Fotorreceptoras/metabolismo , Células Fotorreceptoras/patologia , Morte Celular , Sirtuínas/metabolismoRESUMO
Hyaluronic acid (HA), a vital glycosaminoglycan in living organisms, possesses remarkable mechanical and viscoelastic properties that have garnered significant attention in therapeutic, biomedical, and cosmetic applications. However, a comprehensive picture of the physicochemical and biocharacterization of HA at the single-molecule level remains elusive. In this work, atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulation were used to investigate the nanomechanics and water retention properties of HA at the single-molecule level. The present study aims to unravel the intricate details of the influence of molecular structure on HA behavior and shed light on its unique attributes. According to the force measurements, the energy used to stretch a HA chain in water is 8.45 kJ/mol, significantly surpassing that of Curdlan (3.45 kJ/mol) and chitin (2.23 kJ/mol), both of which possess molecular structures partially similar to that of HA. Intriguingly, the strength of the intrachain interaction of HA (5.54 kJ/mol) was considerably weaker compared to Curdlan (11.06 kJ/mol) and chitin (or cellulose, 10.76 kJ/mol). This result indicates that HA exhibits a preference for interacting with water rather than with itself, thereby showing enhanced water affinity. Moreover, the force measurements demonstrated that changing the glycosidic bond from ß-(1-3) (Curdlan) or ß-(1-4) (chitin or cellulose) to ß-(1-3) + ß-(1-4) (HA) resulted in polysaccharides displaying improved water affinity and more extended conformation. These conclusions were further verified by molecular dynamics (MD) simulations. Overall, our work sheds new light on the nanomechanics and water retention properties of HA at the single-molecule level, offering valuable insights for future research in this field.
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Celulose , Ácido Hialurônico , Ácido Hialurônico/química , Conformação Molecular , Celulose/química , Água/química , QuitinaRESUMO
Objective: To analyze the intervention effects of targeted nursing based on goal management theory on pregnancy outcomes, blood pressure, postpartum self-efficacy, and quality of life in patients with preeclampsia. Methods: We retrospectively analyzed 90 cases of preeclampsia admitted to Huzhou Maternity & Child Health Care Hospital from January 2022 to June 2023. All patients met the complete inclusion criteria. They were divided into 2 groups based on different nursing interventions: the control group (n = 45) received routine nursing interventions, and the observation group (n = 45) received targeted nursing based on goal management theory. Pregnancy outcomes, blood pressure, postpartum self-efficacy, and quality of life were compared between the 2 groups. Results: The incidence of adverse pregnancy outcomes was 28.89% in the control group and was significantly lower in the observation group at 11.11% (P < .001). Before intervention, there were no significant differences in systolic blood pressure and diastolic blood pressure between the 2 groups (P > .05). After intervention, the systolic blood pressure and diastolic blood pressure were significantly lower in the observation group than in the control group (P < .001). Before intervention, there was no significant difference in Breastfeeding Self-Efficacy Scale scores between the 2 groups (P > .05). After intervention, the Breastfeeding Self-Efficacy Scale scores were significantly higher in the observation group than in the control group (P < .001). Before intervention, there was no significant difference in the Short Form 36 Health Survey scores between the 2 groups (P > .05). After intervention, the Short Form 36 Health Survey scores were significantly higher in the observation group than in the control group (P < .001). Conclusion: Compared with routine nursing, targeted nursing based on goal management theory had superior intervention effects on preeclampsia. It can further alleviate patients' blood pressure, promote postpartum self-efficacy, improve quality of life, and reduce the risk of adverse pregnancy outcomes. It is worthy of clinical application and promotion.
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As indicated by longitudinal observation, autism has difficulty controlling emotions to a certain extent in early childhood, and most children's emotional and behavioral problems are further aggravated with the growth of age. This study aimed at exploring the correlation between white matter and white matter fiber bundle connectivity characteristics and their emotional regulation ability in children with autism using machine learning methods, which can lay an empirical basis for early clinical intervention of autism. Fifty-five high risk of autism spectrum disorder (HR-ASD) children and 52 typical development (TD) children were selected to complete the skull 3D-T1 structure and diffusion tensor imaging (DTI). The emotional regulation ability of the two groups was compared using the still-face paradigm (SFP). The classification and regression models of white matter characteristics and white matter fiber bundle connections of emotion regulation ability in the HR-ASD group were built based on the machine learning method. The volume of the right amygdala (R2 = 0.245) and the volume of the right hippocampus (R2 = 0.197) affected constructive emotion regulation strategies. FA (R2 = 0.32) and MD (R2 = 0.34) had the predictive effect on self-stimulating behaviour. White matter fiber bundle connection predicted constructive regulation strategies (positive edging R2 = 0.333, negative edging R2 = 0.334) and mother-seeking behaviors (positive edging R2 = 0.667, negative edging R2 = 0.363). The emotional regulation ability of HR-ASD children is significantly correlated with the connections of multiple white matter fiber bundles, which is a potential neuro-biomarker of emotional regulation ability.
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BACKGROUND: Craniocerebral interventional surgery is a common and essential treatment for cerebrovascular diseases. Despite continuous progress in interventional diagnosis and treatment technology, there is no effective method to alleviate contrast-induced kidney injuries. In this retrospective cohort study, we investigated the effect of the concurrent use of Dexmedetomidine (DEX) during the perioperative period on the renal function of patients following craniocerebral interventional surgery. METHODS: We identified 228 cases of patients underwent craniocerebral interventional surgery from January 2018 to March 2022. Patients who used DEX during general anesthesia were in the DEX group (DEX group) or that did not use dexmedetomidine as the control group (CON group). The markers of kidney injury were recorded before and within 48 h after surgery. RESULTS: Compared with CON group, the urea nitrogen (BUN) of the DEX group decreased significantly on the first day and the second day after surgery (p < 0.05). The serum cystatin-C and the blood urea nitrogen/creatinine ratio (BUN/Cr) was significantly lower than that in CON group on the second day (p < 0.05). The urine output in the DEX group increased significantly, and the mean arterial pressure (MAP) was higher than the CON group (p < 0.01). There was no difference in postoperative complications, ICU stay time and hospitalization time between the two groups. CONCLUSION: The combined use of dexmedetomidine in general anesthesia for craniocerebral interventional surgery can reduce BUN levels within 48 h after surgery, significantly increase intraoperative urine volume, maintain intraoperative circulation stability.
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The collaborative robot can complete various drilling tasks in complex processing environments thanks to the high flexibility, small size and high load ratio. However, the inherent weaknesses of low rigidity and variable rigidity in robots bring detrimental effects to surface quality and drilling efficiency. Effective online monitoring of the drilling quality is critical to achieve high performance robotic drilling. To this end, an end-to-end drilling-state monitoring framework is developed in this paper, where the drilling quality can be monitored through online-measured vibration signals. To evaluate the drilling effect, a Canny operator-based edge detection method is used to quantify the inclination state of robotic drilling, which provides the data labeling information. Then, a robotic drilling inclination state monitoring model is constructed based on the Resnet network to classify the drilling inclination states. With the aid of the training dataset labeled by different inclination states and the end-to-end training process, the relationship between the inclination states and vibration signals can be established. Finally, the proposed method is verified by collaborative robotic drilling experiments with different workpiece materials. The results show that the proposed method can effectively recognize the drilling inclination state with high accuracy for different workpiece materials, which demonstrates the effectiveness and applicability of this method.
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Ionogels are promising for soft iontronics, with their network structure playing a pivotal role in determining their performance and potential applications. However, simultaneously achieving mechanical toughness, low hysteresis, self-healing, and fluorescence using existing network structures is challenging. Drawing inspiration from jellyfish, we propose a novel hierarchical crosslinking network structure design for in situ formation of hyperbranched cluster aggregates (HCA) to fabricate polyurea ionogels to overcome these challenges. Leveraging the disparate reactivity of isocyanate groups, we induce the in situ formation of HCA through competing reactions, enhancing toughness and imparting the clustering-triggered emission of ionogel. This synergy between supramolecular interactions in the network and plasticizing effect in ionic liquid leads to reduced hysteresis of the ionogel. Furthermore, the incorporation of NCO-terminated prepolymer with dynamic oxime-urethane bonds (NPU) enables self-healing and enhances stretchability. Our investigations highlight the significant influence of HCA on ionogel performance, showcasing mechanical robustness including high strength (3.5 MPa), exceptional toughness (5.5 MJ m-3), resistance to puncture, and low hysteresis, self-healing, as well as fluorescence, surpassing conventional dynamic crosslinking approaches. This network design strategy is versatile and can meet the various demands of flexible electronics applications.
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Hyperinsulinemia is a critical risk factor for the pathogenesis of insulin resistance (IR) in metabolic tissues, including the liver. Ethanolamine phosphate phospholyase (ETNPPL), a newly discovered metabolic enzyme that converts phosphoethanolamine (PEA) to ammonia, inorganic phosphate, and acetaldehyde, is abundantly expressed in liver tissue. Whether it plays a role in the regulation of hyperinsulinemia-induced IR in hepatocytes remains elusive. Here, we established an in vitro hyperinsulinemia-induced IR model in the HepG2 human liver cancer cell line and primary mouse hepatocyte via a high dose of insulin treatment. Next, we overexpressed ETNPPL by using lentivirus-mediated ectopic to investigate the effects of ETNPPL per se on IR without insulin stimulation. To explore the underlying mechanism of ETNPPL mediating hyperinsulinemia-induced IR in HepG2, we performed genome-wide transcriptional analysis using RNA sequencing (RNA-seq) to identify the downstream target gene of ETNPPL. The results showed that ETNPPL expression levels in both mRNA and protein were significantly upregulated in hyperinsulinemia-induced IR in HepG2 and primary mouse hepatocytes. Upon silencing ETNPPL, hyperinsulinemia-induced IR was ameliorated. Under normal conditions without IR in hepatocytes, overexpressing ETNPPL promotes IR, reactive oxygen species (ROS) generation, and AKT inactivation. Transcriptome analysis revealed that salt-inducible kinase 1 (SIK1) is markedly downregulated in the ETNPPL knockdown HepG2 cells. Moreover, disrupting SIK1 prevents ETNPPL-induced ROS accumulation, damage to the PI3K/AKT pathway and IR. Our study reveals that ETNPPL mediates hyperinsulinemia-induced IR through the SIK1/ROS-mediated inactivation of the PI3K/AKT signaling pathway in hepatocyte cells. Targeting ETNPPL may present a potential strategy for hyperinsulinemia-associated metabolic disorders such as type 2 diabetes.
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Diabetes Mellitus Tipo 2 , Hiperinsulinismo , Resistência à Insulina , Animais , Humanos , Camundongos , Diabetes Mellitus Tipo 2/metabolismo , Hepatócitos/metabolismo , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Insulina/metabolismo , Resistência à Insulina/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: Systemic inflammation is closely associated with the development and progression of heart failure (HF), increasing vulnerability to thromboembolic events. This retrospective cohort study assessed the potential of the fibrinogen-to-albumin ratio (FAR), a new inflammatory biomarker, as a prognostic indicator for HF risk. METHODS: One thousand one hundred and sixty six women and 826 men with a mean age of 70.70 ± 13.98 years were extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV v2.0) database. Additionally, a second cohort was obtained, including 309 patients from the Second Affiliated Hospital of Wenzhou Medical University. The relationship between FAR and the prognosis of HF was evaluated using multivariate analysis, propensity score-matched analysis, and subgroup analysis. RESULTS: Fibrinogen-to-albumin ratio was an independent risk factor for 90-day all-cause mortality (hazard ratio: 1.19; 95% confidence interval (CI): 1.01-1.40), 1-year all-cause mortality (hazard ratio: 1.23; 95% confidence interval: 1.06-1.41), and length of hospital stay (LOS) (ß: 1.52; 95% CI: 0.67-2.37) in the MIMIC-IV dataset, even after adjusting for potential covariates. These findings were verified in the second cohort (ß: 1.82; 95% CI: 0.33-3.31) and persisted after propensity score-matching and subgroup analysis. FAR was positively correlated with C-reactive protein, NT-proBNP, and Padua score. The correlation between FAR and NT-proBNP (R = .3026) was higher than with fibrinogen (R = .2576), albumin (R = -.1822), platelet-to-albumin ratio (R = .1170), and platelet-to-lymphocyte ratio (R = .1878) (ps < .05). CONCLUSIONS: Fibrinogen-to-albumin ratio is an independent risk prognostic factor for 90-day, 1-year all-cause mortality and LOS among HF patients. Inflammation and prothrombotic state may underlie the relationship between FAR and poor prognosis in HF.
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Insuficiência Cardíaca , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Prognóstico , Albuminas , Inflamação , FibrinogênioRESUMO
To understand the antimicrobial effect of surfaces fabricated with dead probiotics, we prepared surfaces decorated with dead probiotics Lactobacillus rhamnosus GG (LGG) with varied inactivation methods and explored their inhibitory interactions with Pseudomonas aeruginosa (PAO1). By combining several techniques, i.e., digital holographic microscopy (DHM), atomic force microscopy (AFM), RNA sequencing, and metabolomic analysis, we studied the three-dimensional (3D) swimming behaviors, surface adhesion, biofilm formation, and adaptive responses of PAO1 near such surfaces. The results show that planktonic PAO1 decreases their flick and reverse motions by downregulating the chemotaxis pathway and accelerates with less accumulation near dead LGG surfaces by upregulating the flagellar assembly pathway and decreasing cyclic adenosine monophosphate. Distinct from live siblings, the surfaces decorated with dead LGG show a significant reduction in adhesion strength with PAO1 and inhibit biofilm formation with more downregulated genes in the Pseudomonas quinolone signal and biofilm formation pathway. We demonstrate that the antibacterial ability of such surfaces stems from the gradually released lysate from the dead LGG that is unfavorable to PAO1 in close proximity. The releasing rate and order depend on the cell membrane integrity, which closely relates to the inactivation methods.
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Lacticaseibacillus rhamnosus , Probióticos , Biofilmes , Pseudomonas aeruginosa/fisiologia , Microscopia de Força Atômica , Probióticos/farmacologiaRESUMO
Denitrification is an important process of the global nitrogen cycle as some of its intermediates are environmentally important or related to global warming. However, how the phylogenetic diversity of denitrifying communities affects their denitrification rates and temporal stability remains unclear. Here we selected denitrifiers based on their phylogenetic distance to construct two groups of synthetic denitrifying communities: one closely related (CR) group with all strains from the genus Shewanella and the other distantly related (DR) group with all constituents from different genera. All synthetic denitrifying communities (SDCs) were experimentally evolved for 200 generations. The results showed that high phylogenetic diversity followed by experimental evolution promoted the function and stability of synthetic denitrifying communities. Specifically, the productivity and denitrification rates were significantly (P < 0.05) higher with Paracocus denitrificans as the dominant species (since the 50th generation) in the DR community than those in the CR community. The DR community also showed significantly (t = 7.119, df = 10, P < 0.001) higher stability through overyielding and asynchrony of species fluctuations, and showed more complementarity than the CR group during the experimental evolution. This study has important implications for applying synthetic communities to remediate environmental problems and mitigate greenhouse gas emissions.
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Desnitrificação , FilogeniaRESUMO
Chitin is one of the most common polysaccharides and is abundant in the cell walls of fungi and the shells of insects and aquatic organisms as a skeleton. The mechanism of how chitin responds to pH is essential to the precise control of brewing and the design of smart chitin materials. However, this molecular mechanism remains a mystery. Results from single-molecule studies, including single-molecule force spectroscopy (SMFS), AFM imaging, and molecular dynamic (MD) simulations, have shown that the mechanical and conformational behaviors of chitin molecules show surprising pH responsiveness. This can be compared with how, in natural aqueous solutions, chitin tends to form a more relaxed spreading conformation and show considerable elasticity under low stretching forces in acidic conditions. However, its molecular chain collapses into a rigid globule in alkaline solutions. The results show that the chain state of chitin can be regulated by the proportions of inter- and intramolecular H-bonds, which are determined via the number of water bridges on the chain under different pH values. This basic study may be helpful for understanding the cellular activities of fungi under pH stress and the design of chitin-based drug carriers.
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Quitina , Polissacarídeos , Quitina/química , Polissacarídeos/química , Água/química , Conformação Molecular , Concentração de Íons de HidrogênioRESUMO
Medical genetics, which is a frontier subject in biomedicine, is the clinical core of gene diagnosis and gene therapy. In the training of medical students, medical genetics plays an important role in bridging basic medicine and clinical medicine. In recent years, problem-based learning (PBL) has been widely used in medical education as an important method to cultivate the autonomous learning ability of medical students. In the current study, we designed and shared the research on brachydactyly type A2 (BDA2) as the main case of PBL teaching, in order to guide the students towards autonomous learning, and to cultivate independent analysis and problem solving ability instead of simple knowledge acquisition. Such excellent academic teaching will provide more high quality medical talents and internationally competitiveness for constructing a healthy China.
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Genética Médica , Aprendizagem Baseada em Problemas , Humanos , Aprendizagem Baseada em Problemas/métodos , Aprendizagem , Currículo , EnsinoRESUMO
The effect of P. americana L. on anxiety and depression-behavior after chronic stress (CS) is still unknown. Here, CS were induced by a combined stimulation of chronic restraint stress, excess failure and improper diet in SD rats. At 15 days after CS, except for normal group and model group, all the groups were continuously administrated P. americana L. (i.g., 400, 200, 100 mg/kg) treatment for 14 days. Anxiety and depression-behavior was determined by sucrose preference test, forced swimming and open field. The contents of cortisol (CORT), adrenocorticotropic hormone (ACTH), adrenocorticotropic hormone-releasing hormone (CRH), interleukin (IL)-4, IL-6, IL-17 and interferon (IFN) -γ were detected by ELISA. 16S rRNA analysis was performed to examine the composition of gut microbiota. Our results indicated that P. americana L. improved the anxiety and depression-behavior. P. americana L. reduced the release of IL-6, IL-17 and IFN-γ and increased the release of IL-4. Comparably, remarkably decreased CRH, ACTH and CORT were observed by the treatment of P. americana L. 16S rRNA analysis suggested that Bifidobacterium and sulfate-reducing bacteria may be responsible for improving CS in P. americana L. -treated rats. Collectively, P. americana L. could relieve CS are associated with regulation of intestinal flora.
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Interleucina-17 , Periplaneta , Animais , Ratos , Ratos Sprague-Dawley , RNA Ribossômico 16S , Depressão/tratamento farmacológico , Depressão/prevenção & controle , Interleucina-6 , Ansiedade/tratamento farmacológico , Ansiedade/prevenção & controle , Hormônio Adrenocorticotrópico , HidrocortisonaRESUMO
BACKGROUND: The mRNA levels of C2CD4A and C2CD4B were dysregulation in lung cancer (LC). We aimed to evaluate the role of C2CD4A/B variants in LC susceptibility. METHODS: There were 710 cases with LC and 710 healthy controls enrolled in the study. The genotyping of twelve variants in C2CD4A/B was carried out by Agena MassARRAY system. Odds ratios (ORs) were calculated by logistic regression analysis to assess the relationship between these variants and LC predisposition. RESULTS: Rs8037894 (OR = 0.81, p = 0.005), rs7172432 (OR = 0.83, p = 0.013), rs11856307 (OR = 0.86, p = 0.043), and rs1436953 (OR = 0.79, p = 0.002) were related to the reduced risk of LC. Besides, the relation of rs7172432 with LC risk in subjects aged > 60 years was observed. Rs4502156 conferred to the increased LC risk, while rs1436953 was associated with the lower susceptibility to LC among males. Rs731820, rs4502156, rs11071657, rs7172432, and rs11856307 contributed to the predisposition of LC among subjects with BMI > 24 kg/m2, while rs7495253 was associated with an increased risk of LC in subjects with BMI ≤ 24 kg/m2. The increased LC risk was found in rs4502156, while the protective risk effect of rs8037894, rs7172432, rs11856307, and rs1436953 on the occurrence of LC was observed in smokers and non-drinkers. Moreover, rs7495253 and rs7495931 had a higher risk of lymphatic metastasis. Rs1436953 was related to the reduced risk of lung adenocarcinoma, while rs4502156, rs8037894, rs7172432, rs11856307, and rs1436953 were related to the risk of small cell carcinoma. CONCLUSIONS: Our results first display that C2CD4A/B polymorphisms served as protective factors for LC predisposition in a Chinese Han population. These findings could provide new biological insight into the understanding of C2CD4A/B genes on LC pathogenesis.
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Predisposição Genética para Doença , Neoplasias Pulmonares , Proteínas Nucleares , Fatores de Transcrição , Estudos de Casos e Controles , China , Feminino , Genótipo , Humanos , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/genéticaRESUMO
Heart failure (HF), as the leading cause of death, is continuing to increase along with the aging of the general population all over the world. Identification of diagnostic biomarkers for early detection of HF is considered as the most effective way to reduce the risk and mortality. Herein, we collected plasma samples from HF patients (n = 40) before and after medical therapy to determine the change of circulating miRNAs through a quantitative real-time PCR (QRT-PCR)-based miRNA screening analysis. miR-30a-5p and miR-654-5p were identified as the most significantly changed miRNAs in the plasma of patients upon treatment. In consistence, miR-30a-5p showed upregulation and miR-654-5p showed downregulation in the circulation of 30 HF patients, compared to 15 normal controls in the training phase, from which a two-circulating miRNA model was developed for HF diagnosis. Next, we performed the model validation using an independent cohort including 50 HF patients and 30 controls. As high as 98.75% of sensitivity and 95.00% of specificity were achieved. A comparison between the miRNA model and NT-pro BNP in diagnostic accuracy of HF indicated an upward trend of the miRNA model. Moreover, change of the two miRNAs was further verified in association with the therapeutic effect of HF patients, in which miR-30a-5p showed decrease while miR-654-5p showed increase in the plasma of patients after LVAD implantation. In conclusion, the current study not only identified circulating miR-654-5p for the first time as a novel biomarker of HF, but also developed a novel 2-circulating miRNA model with promising potentials for diagnosis and prognosis of HF patients, and in association with therapeutic effects as well.
Assuntos
MicroRNA Circulante , Insuficiência Cardíaca , MicroRNAs , Biomarcadores , Biomarcadores Tumorais/genética , MicroRNA Circulante/genética , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/terapia , Humanos , MicroRNAs/genética , PrognósticoRESUMO
BACKGROUND AIMS: Sepsis-induced acute respiratory distress syndrome (ARDS) can be mediated by an imbalance in macrophage polarization; however, the underlying mechanisms remain poorly understood. This study aimed to investigate the modulatory role of sirtuin 6 (SIRT6) in macrophage polarization during sepsis-induced ARDS. METHODS: A mouse ARDS model was established using cecal ligation and puncture. Isolated alveolar macrophages (AMs) and lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs) were adopted as in vitro models. Macrophage polarization was evaluated by measuring M1 and M2 macrophage percentages via flow cytometry and expression of specific markers. The expression of microtubule-associated light chain protein 3I/II and beclin-1 was detected for assessing macrophage autophagy. Binding between specificity protein 1 (SP1) and the target gene promoter was evaluated using a chromatin immunoprecipitation assay. RNA expression was analyzed by quantitative reverse transcription polymerase chain reaction and western blotting. RESULTS: Treatment with the SIRT6 activator UBCS039 significantly alleviated lung injury in the mouse ARDS model and enhanced autophagy and M2 polarization in isolated AMs. M2 polarization and autophagy in LPS-challenged BMDMs were also effectively promoted by UBCS039 treatment or SIRT6 overexpression. An adenosine monophosphate-activated protein kinase inhibitor (Compound C) or autophagy inhibitor (3-methyladenine) partially abrogated M2 polarization mediated by SIRT6 overexpression upon LPS exposure. SIRT6 induced autophagy and M2 polarization of BMDMs partially via its deacetylase activity. SIRT6 inhibited mammalian target of rapamycin transcription by modulating SP1 to promote BMDM M2 polarization, which was independent of autophagy. CONCLUSIONS: SIRT6 promotes M2 polarization of macrophages to alleviate sepsis-induced ARDS in an autophagy-dependent and -independent manner.