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PURPOSE: To investigate dynamical degree centrality (dDC) alteration and its association with metabolic disturbance and cognitive impairment in minimal hepatic encephalopathy (MHE). METHODS: Fifty-eight cirrhotic patients (22 with MHE, 36 without MHE [NHE]) and 25 healthy controls underwent resting-state functional magnetic resonance imaging, 1H-magnetic resonance spectroscopy, and neurocognitive examination based on the Psychometric Hepatic Encephalopathy Score (PHES). We obtained metabolite ratios in the bilateral posterior cingulate cortex and precuneus, including glutamate and glutamine (Glx)/total creatine (tCr), myo-inositol (mI)/tCr, total choline/tCr, and N-acetyl aspartate/tCr. For each voxel, degree centrality was calculated as the sum of its functional connectivity with other voxels in the brain; and sliding-window correlation was used to calculate dDC per voxel. RESULTS: We observed a stepwise increase in Glx/tCr and a decrease in mI/tCr from NHE to MHE. The intergroup dDC differences were observed in the bilateral posterior cingulate cortex and precuneus (region of interest [ROI1]), bilateral superior-medial frontal gyrus and anterior cingulate cortex (ROI2), and left caudate head. The dDC in ROI2 (r = 0.450, P < 0.001) and mI/tCr (r = 0.297, P = 0.024) was correlated with PHES. Significant correlations were found between dDC in ROI1 and Glx/tCr (r = - 0.413, P = 0.001) and mI/tCr (r = 0.554, P < 0.001). The dDC in ROI2, Glx/tCr, and mI/tCr showed potential for distinguishing NHE from MHE (areas under the curve = 0.859, 0.655, and 0.672, respectively). CONCLUSION: Our findings suggested dynamic brain network disorganization in MHE, which was associated with metabolic derangement and neurocognitive impairment.

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Alzheimer's disease (AD) is a neurodegenerative disorder frequently accompanied by neuroinflammation and oxidative stress. The medicine and food homology (MFH) has shown potential for treating neuroinflammation and oxidative stress. This study aimed to provide a safe and efficient therapy for AD based on MFH. In this study, we develop a MFH formula consisting of egg yolk oil, perilla seed oil, raphani seed oil, cinnamon oil, and noni puree (EPRCN). To evaluate the ameliorative effects of EPRCN on AD-related symptoms, a mouse model of AD was constructed using intraperitoneal injection of scopolamine in ICR mice. Experimental results demonstrated that EPRCN supplement restored behavioral deficits and suppressed neuroinflammation and oxidative stress in the hippocampus of scopolamine-induced mice. An in vitro study was then performed using induction of Aß(25-35) in glial (BV-2 and SW-1783) and neuron (SH-SY5Y) cell lines to examine the improvement mechanism of EPRCN on cognitive deficits. Multi-omics and in vitro studies demonstrated that these changes were driven by the anandamide (AEA)-Trpv1-Nrf2 pathway, which was inhibited by AM404 (an AEA inhibitor), AMG9810 (a Trpv1 inhibitor), and BT (an Nrf2 inhibitor). Consequently, EPRCN is an effective therapy on preventing cognitive deficits in mouse models of AD. In contrast to donepezil, EPRCN exhibits a novel modes action for ameliorating neuroinflammation. The mechanism of EPRCN on preventing cognitive deficits is mediated by improving neuroinflammation and oxidative stress via activating the AEA-Trpv1-Nrf2 pathway.

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BACKGROUND: Pathways for intravenously administered gadolinium-based-contrast-agents (GBCAs) entering cerebrospinal-fluid (CSF) circulation in the human brain are not well-understood. The blood-CSF-barrier (BCSFB) in choroid-plexus (CP) has long been hypothesized to be a main entry-point for intravenous-GBCAs into CSF. Most existing studies on this topic were performed in animals and human patients with various diseases. Results in healthy human subjects are limited. Besides, most studies were performed using MRI methods with limited temporal resolution and significant partial-volume effects from blood and CSF. METHODS: This study employs the recently developed dynamic-susceptibility-contrast-in-the-CSF (cDSC) MRI approach to measure GBCA-distribution in the CSF immediately and 4 h after intravenous-GBCA administration in healthy subjects. With a temporal resolution of 10 s, cDSC MRI can track GBCA-induced CSF signal changes during the bolus phase, which has not been investigated previously. It employs a long echo-time (TE = 1347 ms) to suppress tissue and blood signals so that pure CSF signal is detected with minimal partial-volume effects. GBCA concentration in the CSF can be estimated from cDSC MRI. In this study, cDSC and FLAIR MRI were performed immediately and 4 h after intravenous GBCA administration in 25 healthy volunteers (age 48.9 ± 19.5 years; 14 females). Paired t-tests were used to compare pre-GBCA and post-GBCA signal changes, and their correlations with age were evaluated using Pearson-correlation-coefficients. RESULTS: At ~ 20 s post-GBCA, GBCA-induced cDSC signal changes were detected in the CSF around CP (ΔS/S = - 2.40 ± 0.30%; P < .001) but not in the rest of lateral ventricle (LV). At 4 h, significant GBCA-induced cDSC signal changes were observed in the entire LV (ΔS/S = - 7.58 ± 3.90%; P = .002). FLAIR MRI showed a similar trend. GBCA-induced CSF signal changes did not correlate with age. CONCLUSIONS: These results provided direct imaging evidence that GBCAs can pass the BCSFB in the CP and enter ventricular CSF immediately after intravenous administration in healthy human brains. Besides, our results in healthy subjects established a basis for clinical studies in brain diseases exploiting GBCA-enhanced MRI to detect BCSFB dysfunction.

Assuntos

Plexo Corióideo , Meios de Contraste , Imageamento por Ressonância Magnética , Humanos , Meios de Contraste/administração & dosagem , Plexo Corióideo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto , Feminino , Gadolínio/administração & dosagem , Pessoa de Meia-Idade , Voluntários Saudáveis , Adulto Jovem , Administração Intravenosa

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Climate warming and drying has led to a sharp increase in nitrogen (N) emissions from the boreal peatland soils, but the underlying microbial-mediated mechanism is still unclear. We reviewed the responses of soil N transformation and emission in alpine peatland to temperature increases and water table changes, the interaction between soil anaerobic ammonia oxidation (Anammox) and NO3- dissimilatory reduction processes, and soil N2O production pathways and their contributions. There are several knowledge gaps. First, the amount of N loss in peatlands in alpine areas is seriously underestimated because most studies focused only on soil N2O emissions and ignored the release of N2. Second, the contribution of Anammox process to N2 emissions from peatlands is not quantified. Third, there is a lack of quantification of the relative contributions of Anammox, bacterial denitrification, and fungal co-denitrification processes to N2 loss. Finally, the decoupling mechanism of Anammox and NO3- reduction processes under a warming and drying climate scenario is not clear. Considering aforementioned shortages in previous studies, we proposed the directions and contents for future research. Through building an experimental platform with field warming and water level controlling, combining stable isotope, molecular biology, and metagenomics technology, the magnitude, composition ratio and main controlling factors of N emissions (N2O, NO, and N2) in boreal peatlands should be systematically investigated. The interaction among the main N loss processes in soils as well as the relative contributions of nitrification, anaerobic ammonia oxidation, and denitrification to N2O and N2 productions should be investigated and quantified. Furthermore, the sensitive microbial groups and the coupling between soil N transformations and microbial community succession should be clarified to reveal the microbiological mechanism underlying the responses of soil N turnover process to climate warming and drying.

Assuntos

Mudança Climática , Aquecimento Global , Nitrogênio , Microbiologia do Solo , Solo , Solo/química , Nitrogênio/análise , Nitrogênio/metabolismo , Ecossistema , Secas , Óxido Nitroso/análise , Óxido Nitroso/metabolismo

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The Genome in a Bottle Consortium (GIAB), hosted by the National Institute of Standards and Technology (NIST), is developing new matched tumor-normal samples, the first to be explicitly consented for public dissemination of genomic data and cell lines. Here, we describe a comprehensive genomic dataset from the first individual, HG008, including DNA from an adherent, epithelial-like pancreatic ductal adenocarcinoma (PDAC) tumor cell line (HG008-T) and matched normal cells from duodenal tissue (HG008-N-D) and pancreatic tissue (HG008-N-P). The data come from thirteen whole genome measurement technologies: Illumina paired-end, Element standard and long insert, Ultima UG100, PacBio (HiFi and Onso), Oxford Nanopore (standard and ultra-long), Bionano Optical Mapping, Arima and Phase Genomics Hi-C, G-banded karyotyping, directional genomic hybridization, and BioSkryb Genomics single-cell ResolveDNA. Most tumor data is from a large homogenous batch of non-viable cells after 23 passages of the primary tumor cells, along with some data from different passages to enable an initial understanding of genomic instability. These data will be used by the GIAB Consortium to develop matched tumor-normal benchmarks for somatic variant detection. In addition, extensive data from two different normal tissues from the same individual can enable understanding of mosaicism. Long reads also contain methylation tags for epigenetic analyses. We expect these data to facilitate innovation for whole genome measurement technologies, de novo assembly of tumor and normal genomes, and bioinformatic tools to identify small and structural somatic mutations. This first-of-its-kind broadly consented open-access resource will facilitate further understanding of sequencing methods used for cancer biology.

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INTRODUCTION: An early evaluating system for autism spectrum disorder (ASD) severity is crucial. Questionnaire survey is challenging for accurately assessing the severity levels for ASD in children. METHODS: Offspring with ASD-like phenotypes were induced by treating pregnant mice with Poly (I:C) at GD12.5 and the placentae corresponding to the offspring were obtained by caesarean. The autism severity composite score (ASCS) for offspring was calculated through behavioral tests. HE staining and immunohistochemistry were used to observe the morphology of placenta. Candidate biomarkers were identified by weighted protein co-expression network analysis (WPCNA) combined with machine learning and further validated by ELISA. Sperman's was used to analyze the correlation between biomarkers and metabolome. RESULTS: The placental weight and mean vascular area of male offspring with ASD-like phenotypes were significantly decreased compared with typical mice. According to the WPCNA, four modules were identified and significantly correlated with ASCS of offspring. Two biomarkers (ASPG and DAD1) with high correlation with ASCS in offspring were identified. DISCUSSION: VEGF pathway may contribute to sexual dimorphism in placental morphology within mice with ASD-like phenotypes in term. The placental ASPG and DAD1 levels could reflect ASD-like symptom severity levels in male/female mice offspring.

Assuntos

Proteínas Reguladoras de Apoptose , Asparaginase , Transtorno do Espectro Autista , Proteínas de Membrana , Placenta , Animais , Feminino , Masculino , Camundongos , Gravidez , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Transtorno do Espectro Autista/metabolismo , Biomarcadores/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Placenta/metabolismo , Placenta/patologia , Índice de Gravidade de Doença , Asparaginase/genética , Asparaginase/metabolismo

RESUMO

Leptomeningeal metastases (LMs) remain a devastating complication of non-small cell lung cancer (NSCLC), particularly following osimertinib resistance. We conducted single-cell RNA sequencing on cerebrospinal fluid (CSF) from EGFR-mutant NSCLC with central nervous system metastases. We found that macrophages of LMs displayed functional and phenotypic heterogeneity and enhanced immunosuppressive properties. A population of lipid-associated macrophages, namely RNASE1_M, were linked to osimertinib resistance and LM development, which was regulated by Midkine (MDK) from malignant epithelial cells. MDK exhibited significant elevation in both CSF and plasma among patients with LMs, with higher MDK levels correlating to poorer outcomes in an independent cohort. Moreover, MDK could promote macrophage M2 polarization with lipid metabolism and phagocytic function. Furthermore, malignant epithelial cells in CSF, particularly after resistance to osimertinib, potentially achieved immune evasion through CD47-SIRPA interactions with RNASE1_M. In conclusion, we revealed a specific subtype of macrophages linked to osimertinib resistance and LM development, providing a potential target to overcome LMs.

Assuntos

Acrilamidas , Compostos de Anilina , Carcinoma Pulmonar de Células não Pequenas , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares , Macrófagos , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/tratamento farmacológico , Compostos de Anilina/farmacologia , Compostos de Anilina/uso terapêutico , Acrilamidas/farmacologia , Acrilamidas/uso terapêutico , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Animais , Camundongos , Linhagem Celular Tumoral , Feminino , Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/patologia , Carcinomatose Meníngea/secundário , Metabolismo dos Lipídeos/efeitos dos fármacos , Antígeno CD47/metabolismo , Antígeno CD47/genética , Masculino , Fagocitose/efeitos dos fármacos , Receptores ErbB/metabolismo , Receptores ErbB/genética , Indóis , Pirimidinas

RESUMO

OBJECTIVES: Non-small cell lung cancer (NSCLC) patients with exon 20 insertion mutations (ex20ins) of the epidermal growth factor receptor (EGFR) were resistant to monotherapy of immune checkpoint inhibitor (ICI). However, recent reports have shown that the combination of ICI and chemotherapy (ICI-combined regimen) exhibited certain efficacy for NSCLC with EGFR ex20ins. The mechanisms behind this phenomenon have not been thoroughly clarified. Hence, we conducted this study tofind correlations between the tumor immune microenvironment of EGFR ex20ins and the efficacy of ICI-combined regimen. METHODS: We performed single-cell transcriptome sequencing and multiplex immunofluorescence staining (mIF) to investigate the immune microenvironment of NSCLC patients with EGFR ex20ins, L858R, and EGFR wild-type. We analyzed 15 treatment-naïve NSCLC samples utilizing single-cell RNA sequencing (scRNA-seq). Another 30 cases of EGFR L858R and 4 cases of wild-type were recruited to compare the immune microenvironment with that of EGFR ex20ins (28 cases) by mIF. RESULTS: We observed that cell components, function and interactions varied between EGFR ex20ins, L858R, and wild-type NSCLC.We discovered similar T cell and CD8+ T cell distributions among groups but found noninferior or even better T cell activation in ex20ins patients. Infiltrating CD8+ FOXP3- T cells were significantly lower in the tumor region of EGFR ex20ins compared to wild-type. T cells from the ex20ins group had a greater tendency to promote cancer cell inflammation and epithelial-mesenchymal transition (EMT) compared to wild-type group. For macrophages, there were more M2-like macrophages in ex20ins patients. M1-like macrophages in ex20ins group produced fewer antitumor cytokines than in other groups. CONCLUSIONS: The immune microenvironment of EGFR ex20ins is more suppressive than that of L858R and wild-type, suggesting that ICI monotherapy may not be sufficient for these patients. ICI-combined regimen might be a treatment option for EGFR ex20ins due to tumor-promoting inflammation and noninferior T cell functions in the immune microenvironment.

Assuntos

Carcinoma Pulmonar de Células não Pequenas , Receptores ErbB , Éxons , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares , Microambiente Tumoral , Humanos , Microambiente Tumoral/imunologia , Microambiente Tumoral/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/imunologia , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/imunologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Éxons/genética , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mutagênese Insercional , Prognóstico

RESUMO

Hyperoxia-induced acute lung injury (HALI) is a complication of oxygen therapy. Ferroptosis is a vital factor in HALI. This paper was anticipated to investigate the underlying mechanism of Wedelolactone (WED) on ferroptosis in HALI. The current study used hyperoxia to injure two models, one HALI mouse model and one MLE-12 cell injury model. We found that WED treatment attenuated HALI by decreasing the lung injury score and lung wet/dry weight ratio and alleviating pathomorphological changes. Then, the inflammatory reaction and apoptosis in HALI mice and hyperoxia-mediated MLE-12 cells were inhibited by WED treatment. Moreover, WED alleviated ferroptosis with less iron accumulation and reversed expression alterations of ferroptosis markers, including MDA, GSH, GPX4, SLC7A11, FTH1, and TFR1 in hyperoxia-induced MLE-12 cells in vitro and in vivo. Nrf2-KO mice and Nrf2 inhibitor (ML385) decreased WED's ability to protect against apoptosis, inflammatory response, and ferroptosis in hyperoxia-induced MLE-12 cells. Collectively, our data highlighted the alleviatory role of WED in HALI by activating the Nrf2/HO-1 pathway.

RESUMO

Iron Dextran is a widely used iron oxide compound to treat iron-deficiency anemia patients in the clinic. Similar to other iron oxide compounds such as Ferumoxytol, it can also be used off-label as an intravascular magnetic resonance imaging (MRI) contrast agent due to its strong iron-induced T2 and T2* shortening effects. In this study, we seek to evaluate the feasibility of using Iron Dextran enhanced multi-echo susceptibility weighted imaging (SWI) MRI at 7T to image arterial and venous blood vessels in the human brain. Phantom experiments were performed to measure the r2* relaxivity for Iron Dextran in blood, based on which the SWI sequence was optimized. Pre- and post-infusion MR images were acquired in human subjects from which maps of arteries and veins were extracted. The post-contrast SWI images showed enhanced susceptibility difference between blood and the surrounding tissue in both arteries and veins. Our results showed that the proposed Iron Dextran enhanced multi-echo SWI approach allowed the visualization of blood vessels with diameters down to ~100 µm, including small blood vessels supplying and draining small brain structures such as the hippocampus. We conclude that Iron Dextran can be an alternative iron-based MRI contrast agent for blood vessel imaging in the human brain.

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Background: Amyotrophic lateral sclerosis (ALS)-related white-matter microstructural abnormalities have received considerable attention; however, gray-matter structural abnormalities have not been fully elucidated. This study aimed to evaluate cortical microstructural abnormalities in ALS and determine their association with disease severity. Methods: This study included 34 patients with ALS and 30 healthy controls. Diffusion-weighted data were used to estimate neurite orientation dispersion and density imaging (NODDI) parameters, including neurite density index (NDI) and orientation dispersion index (ODI). We performed gray matter-based spatial statistics (GBSS) in a voxel-wise manner to determine the cortical microstructure difference. We used the revised ALS Functional Rating Scale (ALSFRS-R) to assess disease severity and conducted a correlation analysis between NODDI parameters and ALSFRS-R. Results: In patients with ALS, the NDI reduction involved several cortical regions [primarily the precentral gyrus, postcentral gyrus, temporal cortex, prefrontal cortex, occipital cortex, and posterior parietal cortex; family-wise error (FWE)-corrected P<0.05]. ODI decreased in relatively few cortical regions (including the precentral gyrus, postcentral gyrus, prefrontal cortex, and inferior parietal lobule; FWE-corrected P<0.05). The NDI value in the left precentral and postcentral gyrus was positively correlated with the ALS disease severity (FWE-corrected P<0.05). Conclusions: The decreases in NDI and ODI involved both motor-related and extra-motor regions and indicated the presence of gray-matter microstructural impairment in ALS. NODDI parameters are potential imaging biomarkers for evaluating disease severity in vivo. Our results showed that GBSS is a feasible method for identifying abnormalities in the cortical microstructure of patients with ALS.

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BACKGROUND: Osteoporotic vertebral compression fractures (OVCFs) of the lumbar region may be accompanied by thoracic fractures. Treating only the lumbar fractures can lead to worsening of the thoracic fractures or unresolved postoperative symptoms. This study aims to investigate the need to perform thoracic MRI before vertebral augmentation (including percutaneous vertebroplasty and percutaneous kyphoplasty) in patients with lumbar OVCF. METHODS: This study retrospectively analyzed patients with lumbar OVCF who were scheduled for surgical treatment. All patients underwent thoracic and lumbar MRI before surgery. We evaluated the proportion of thoracic fractures accompanying lumbar fractures at each segment and identified the common locations of these accompanying fractures. Univariate and multivariate analyses were conducted to determine the risk factors and optimal thresholds for predicting accompanying thoracic fractures. RESULTS: The study recruited 700 patients, of whom 96 (13.71%) had new thoracic fractures along with lumbar fractures. The most common thoracic segments affected were T10 (22.50%), T9 (19.17%), T8 (26.67%), and T7 (20.83%). Univariate analysis showed significant differences in age and cause of injury between the thoracic fracture group and the control group. The bone density of the thoracic fracture group was significantly lower than that of the control group. Multivariate logistic regression analysis indicated that lifting heavy objects, sprains, and low bone density are risk factors for thoracic fractures in patients with lumbar OVCF. CONCLUSION: It is crucial to perform thoracic MRI before surgery in patients with lumbar OVCF. This helps to avoid missing thoracic fractures, prevent the worsening of injuries, and ensure better postoperative outcomes.

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Triple-negative breast cancer (TNBC) is a highly lethal malignancy, and its clinical management encounters severe challenges due to its high metastatic propensity and the absence of effective therapeutic targets. To improve druggability of aurovertin B (AVB), a natural polyketide with a significant antiproliferative effect on TNBC, a series of NO donor/AVB hybrids were synthesized and tested for bioactivities. Among them, compound 4d significantly inhibited the proliferation and metastasis of TNBC in vitro and in vivo with better safety than that of AVB. The structure-activity relationship analysis suggested that the types of NO donor and the linkers had considerable effects on the activities. Mechanistic investigations unveiled that 4d induced apoptosis and ferroptosis by the reduction of mitochondrial membrane potential and the down-regulation of GPX4, respectively. The antimetastatic effect of 4d was associated with the upregulation of DUSP1. Overall, these compelling results underscore the tremendous potential of 4d for treating TNBC.

Assuntos

Antineoplásicos , Apoptose , Ferroptose , Doadores de Óxido Nítrico , Neoplasias de Mama Triplo Negativas , Animais , Feminino , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Ferroptose/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Doadores de Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/uso terapêutico , Doadores de Óxido Nítrico/síntese química , Relação Estrutura-Atividade , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/metabolismo , Oxidiazóis/química , Oxidiazóis/farmacologia , Piranos/química , Piranos/farmacologia

RESUMO

The conformational properties of Alanine (Ala) residue have been investigated to understand protein folding and develop force fields. In this work, we examined the neighbor effect on the conformational spaces of Ala residue using model azapeptides, Ac-Ala-azaGly-NHMe (3, AaG), and Ac-azaGly-Ala-NHMe (4, aGA1). Ramachandran energy maps were generated by scanning (φ, ψ) dihedral angles of the Ala residues in models with the fixed dihedral angles (φ = ±90°, ψ = ±0° or ±180°) of azaGly residue using LCgau-BOP and LCgau-BOP + LRD functionals in the gas and water phases. The integral-equation-formalism polarizable continuum model (IEF-PCM) and a solvation model density (SMD) were employed to mimic the solvation effect. The most favorable conformation of Ala residue in azapeptide models is found as the polyproline II (ßP), inverse γ-turn (γ'), ß-sheet (ßS), right-handed helix (αR), or left-handed helix (αL) depending on the conformation of neighbor azaGly residue in isolated form. Solvation methods exhibit that the Ala residue favors the ßP, δR, and αR conformations regardless of its position in azapeptides 3 and 4 in water. Azapeptide 5, Ac-azaGly-Ala-NH2 (aGA2), was synthesized to evaluate the theoretical results. The X-ray structure showed that azaGly residue adopts the polyproline II (ßP) and Ala residue adopts the right-handed helical (αR) structure in aGA2. The conformational preferences of aGA2 and the dimer structure of aGA2 based on the X-ray structure were examined to assess the performance of DFT functionals. In addition, the local minima of azapeptide 6, Ac-Phe-azaGly-NH2 (FaG), were compared with the previous experimental results. SMD/LCgau-BOP + LRD methods agreed well with the reported experimental results. The results suggest the importance of weak dispersion interactions, neighbor effect, and solvent influence in the conformational preferences of Ala residue in model azapeptides.

RESUMO

H5, H7, and H9 are pivotal avian influenza virus (AIV) subtypes that cause substantial economic losses and pose potential threats to public health worldwide. In this study, a novel triplex fluorescence reverse transcription-loop-mediated isothermal amplification (TLAMP) assay was developed in which traditional LAMP techniques were combined with probes for detection. Through this innovative approach, H5, H7, and H9 subtypes of AIV can be simultaneously identified and differentiated, thereby offering crucial technical support for prevention and control efforts. Three primer sets and composite probes were designed based on conserved regions of the haemagglutinin gene for each subtype. The probes were labelled with distinct fluorophores at their 3' ends, which were detached to release the fluorescence signal during the amplification process. The detection results were interpreted based on the colour of the TLAMP products. Then, the reaction conditions were optimized, and three primer sets and probes were combined in the same reaction system, resulting in a TLAMP detection assay for the differential diagnosis of AIV subtypes. Sensitivity testing with in vitro-transcribed RNA revealed that the detection limit of the TLAMP assay was 205 copies per reaction for H5, 360 copies for H7, and 545 copies for H9. The TLAMP assay demonstrated excellent specificity, no cross-reactivity with related avian viruses, and 100% consistency with a previously published quantitative polymerase chain reaction (qPCR) assay. Therefore, due to its simplicity, rapidity, sensitivity, and specificity, this TLAMP assay is suitable for epidemiological investigations and is a valuable tool for detecting and distinguishing H5, H7, and H9 subtypes of AIV in clinical samples.

RESUMO

Resistance to chemotherapy has been a major hurdle that limits therapeutic benefits for many types of cancer. Here we systematically identify genetic drivers underlying chemoresistance by performing 30 genome-scale CRISPR knockout screens for seven chemotherapeutic agents in multiple cancer cells. Chemoresistance genes vary between conditions primarily due to distinct genetic background and mechanism of action of drugs, manifesting heterogeneous and multiplexed routes towards chemoresistance. By focusing on oxaliplatin and irinotecan resistance in colorectal cancer, we unravel that evolutionarily distinct chemoresistance can share consensus vulnerabilities identified by 26 second-round CRISPR screens with druggable gene library. We further pinpoint PLK4 as a therapeutic target to overcome oxaliplatin resistance in various models via genetic ablation or pharmacological inhibition, highlighting a single-agent strategy to antagonize evolutionarily distinct chemoresistance. Our study not only provides resources and insights into the molecular basis of chemoresistance, but also proposes potential biomarkers and therapeutic strategies against such resistance.

Assuntos

Antineoplásicos , Sistemas CRISPR-Cas , Resistencia a Medicamentos Antineoplásicos , Irinotecano , Oxaliplatina , Proteínas Serina-Treonina Quinases , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Oxaliplatina/farmacologia , Irinotecano/farmacologia , Sistemas CRISPR-Cas/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Neoplasias Colorretais/genética , Neoplasias Colorretais/tratamento farmacológico , Animais , Neoplasias/genética , Neoplasias/tratamento farmacológico , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Camundongos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos

RESUMO

Colorectal cancer (CRC) is one of the most common tumors of the digestive system worldwide. KRAS mutations limit the use of anti-EGFR antibodies in combination with chemotherapy for the treatment of CRC. Therefore, novel targeted therapies are needed to overcome the KRAS-induced oncogenesis. Recent evidence suggests that inhibition of PI3K led to ferroptosis, a nonapoptotic cell death closely related to KRAS-mutant cells. Here, we showed that a selective PI3Kδ inhibitor TYM-3-98 can suppress the AKT/mTOR signaling and activate the ferroptosis pathway in KRAS-mutant CRC cells in a concentration-dependent manner. This was evidenced by the lipid peroxidation, iron accumulation, and depletion of GSH. Moreover, the overexpression of the sterol regulatory element-binding protein 1 (SREBP1), a downstream transcription factor regulating lipid metabolism, conferred CRC cells greater resistance to ferroptosis induced by TYM-3-98. In addition, the effect of TYM-3-98 was confirmed in a xenograft mouse model, which demonstrated significant tumor suppression without obvious hepatoxicity or renal toxicity. Taken together, our work demonstrated that the induction of ferroptosis contributed to the PI3Kδ inhibitor-induced cell death via the suppression of AKT/mTOR/SREBP1-mediated lipogenesis, thus displaying a promising therapeutic effect of TYM-3-98 in CRC treatment.

Assuntos

Neoplasias Colorretais , Ferroptose , Lipogênese , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas p21(ras) , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1 , Serina-Treonina Quinases TOR , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Humanos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Serina-Treonina Quinases TOR/metabolismo , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Lipogênese/efeitos dos fármacos , Lipogênese/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Camundongos , Transdução de Sinais/efeitos dos fármacos , Camundongos Nus , Linhagem Celular Tumoral , Mutação/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Endogâmicos BALB C , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Classe I de Fosfatidilinositol 3-Quinases/genética , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia

RESUMO

Developing electrocatalysts with excellent activity and stability for water splitting in acidic media remains a formidable challenge due to the sluggish kinetics and severe dissolution. As a solution, a multi-component doped RuO2 prepared through a process of dealloying-annealing is presented. The resulting multi-doped RuO2 possesses a nanoporous structure, ensuring a high utilization efficiency of Ru. Furthermore, the dopants can regulate the electronic structure, causing electron aggregation around unsaturated Ru sites, which mitigates Ru dissolution and significantly enhances the catalytic stability/activity. The representative catalyst (FeCoNiCrTi-RuO2) shows an overpotential of 167 mV at 10 mA cm-2 for oxygen evolution reaction (OER) in 0.5 m H2SO4 solution with a Tafel slope of 53.1 mV dec-1, which is among the highest performance reported. Moreover, it remains stable for over 200 h at a current density of 10 mA cm-2. This work presents a promising approach for improving RuO2-based electrocatalysts, offering a crucial advancement for electrochemical water splitting.

RESUMO

Objective: The objective of this study is to examine the risk factors associated with apnea in hospitalized patients diagnosed with bronchiolitis and to develop a nomogram prediction model for the early identification of patients who are at risk of developing apnea. Methods: The clinical data of patients diagnosed with acute bronchiolitis and hospitalized at the Children's Hospital of Nanjing Medical University between February 2018 and May 2021 were retrospectively analyzed. LASSO regression and logistic regression analysis were used to determine the risk factors for apnea in these patients. A nomogram was constructed based on variables selected through multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve and calibration curve were used to assess the accuracy and discriminative ability of the nomogram model, and decision curve analysis (DCA) was performed to evaluate the model's performance and clinical effectiveness. Results: A retrospective analysis was conducted on 613 children hospitalized with bronchiolitis, among whom 53 (8.6%) experienced apnea. The results of Lasso regression and Logistic regression analyses showed that underlying diseases, feeding difficulties, tachypnea, WBC count, and lung consolidation were independent risk factors for apnea. A nomogram prediction model was constructed based on the five predictors mentioned above. After internal validation, the nomogram model demonstrated an AUC of 0.969 (95% CI 0.951-0.987), indicating strong predictive performance for apnea in bronchiolitis. Calibration curve analysis confirmed that the nomogram prediction model had good calibration, and the clinical decision curve analysis (DCA) indicated that the nomogram was clinically useful in estimating the net benefit to patients. Conclusion: In this study, a nomogram model was developed to predict the risk of apnea in hospitalized children with bronchiolitis. The model showed good predictive performance and clinical applicability, allowing for timely identification and intensified monitoring and treatment of high-risk patients to improve overall clinical prognosis.