RESUMO
Low-field magnetic resonance imaging (MRI) has recently experienced a renaissance that is largely attributable to the numerous technological advancements made in MRI, including optimized pulse sequences, parallel receive and compressed sensing, improved calibrations and reconstruction algorithms, and the adoption of machine learning for image postprocessing. This new attention on low-field MRI originates from a lack of accessibility to traditional MRI and the need for affordable imaging. Low-field MRI provides a viable option due to its lack of reliance on radio-frequency shielding rooms, expensive liquid helium, and cryogen quench pipes. Moreover, its relatively small size and weight allow for easy and affordable installation in most settings. Rather than replacing conventional MRI, low-field MRI will provide new opportunities for imaging both in developing and developed countries. This article discusses the history of low-field MRI, low-field MRI hardware and software, current devices on the market, advantages and disadvantages, and low-field MRI's global potential.
Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Sistemas Automatizados de Assistência Junto ao Leito , Software , Imageamento por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Desenho de Equipamento , Aprendizado de Máquina , CalibragemRESUMO
BACKGROUND: Postharvest quality deterioration poses a significant challenge to the commercial value of fresh lotus seeds. Low temperature storage is widely employed as the primary method for preserving postharvest lotus seeds during storage and transportation. RESULTS: This approach effectively extends the storage life of lotus seeds, resulting in distinct physiological changes compared to room temperature storage, including a notable reduction in starch, protein, H2O2, and MDA content. Here, we conducted RNA-sequencing to generate global transcriptome profiles of postharvest lotus seeds stored under room or low temperature conditions. Principal component analysis (PCA) revealed that gene expression in postharvest lotus seeds demonstrated less variability during low temperature storage in comparison to room temperature storage. A total of 14,547 differentially expressed genes (DEGs) associated with various biological processes such as starch and sucrose metabolism, energy metabolism, and plant hormone signaling response were identified. Notably, the expression levels of DEGs involved in ABA signaling were significantly suppressed in contrast to room temperature storage. Additionally, nine weighted gene co-expression network analysis (WGCNA)-based gene molecular modules were identified, providing insights into the co-expression relationship of genes during postharvest storage. CONCLUSION: Our findings illuminate transcriptional differences in postharvest lotus seeds between room and low temperature storage, offering crucial insights into the molecular mechanisms of low temperature preservation in lotus seeds.
Assuntos
Temperatura Baixa , Sementes , Transcriptoma , Sementes/genética , Lotus/genética , Lotus/fisiologia , Lotus/metabolismo , Regulação da Expressão Gênica de Plantas , Perfilação da Expressão GênicaRESUMO
Understanding the signals from the physical microenvironment is critical for deciphering the processes of neurogenesis and neurodevelopment. The discovery of how surrounding physical signals shape human developing neurons is hindered by the bottleneck of conventional cell culture and animal models. Notwithstanding neural organoids provide a promising platform for recapitulating human neurogenesis and neurodevelopment, building neuronal physical microenvironment that accurately mimics the native neurophysical features is largely ignored in current organoid technologies. Here, it is discussed how the physical microenvironment modulates critical events during the periods of neurogenesis and neurodevelopment, such as neural stem cell fates, neural tube closure, neuronal migration, axonal guidance, optic cup formation, and cortical folding. Although animal models are widely used to investigate the impacts of physical factors on neurodevelopment and neuropathy, the important roles of human stem cell-derived neural organoids in this field are particularly highlighted. Considering the great promise of human organoids, building neural organoid microenvironments with mechanical forces, electrophysiological microsystems, and light manipulation will help to fully understand the physical cues in neurodevelopmental processes. Neural organoids combined with cutting-edge techniques, such as advanced atomic force microscopes, microrobots, and structural color biomaterials might promote the development of neural organoid-based research and neuroscience.
Assuntos
Células-Tronco Neurais , Neurogênese , Animais , Humanos , Organoides , Neurônios , Técnicas de Cultura de Células , Encéfalo/fisiologiaRESUMO
PURPOSE: To standardize T 2 $$ {}_2 $$ -weighted images from clinical Turbo Spin Echo (TSE) scans by generating corresponding T 2 $$ {}_2 $$ maps with the goal of removing scanner- and/or protocol-specific heterogeneity. METHODS: The T 2 $$ {}_2 $$ map is estimated by minimizing an objective function containing a data fidelity term in a Virtual Conjugate Coils (VCC) framework, where the signal evolution model is expressed as a linear constraint. The objective function is minimized by Projected Gradient Descent (PGD). RESULTS: The algorithm achieves accuracy comparable to methods with customized sampling schemes for accelerated T 2 $$ {}_2 $$ mapping. The results are insensitive to the tunable parameters, and the relaxed background phase prior produces better T 2 $$ {}_2 $$ maps compared to the strict real-value enforcement. It is worth noting that the algorithm works well with challenging T 2 $$ {}_2 $$ w-TSE data using typical clinical parameters. The observed normalized root mean square error ranges from 6.8% to 12.3% over grey and white matter, a clinically common level of quantitative map error. CONCLUSION: The novel methodological development creates an efficient algorithm that allows for T 2 $$ {}_2 $$ map generated from TSE data with typical clinical parameters, such as high resolution, long echo train length, and low echo spacing. Reconstruction of T 2 $$ {}_2 $$ maps from TSE data with typical clinical parameters has not been previously reported.
RESUMO
Lotus (Nelumbo spp.) is an important aquatic ornamental genus in the family Nelumbonaceae comprising only 2 species: Nelumbo lutea with yellow flowers and Nelumbo nucifera with red or white flowers. The petal color variations between these 2 species have previously been associated with the potential activities of FLAVONOL SYNTHASE (FLS) and MYB5. However, the underlying genetic mechanisms of flower color divergence within the N. nucifera species remain unclear. Here, quantitative trait locus mapping led to the identification of MYB5, a candidate gene controlling petal color in N. nucifera. Genotyping of 213 natural lotus accessions revealed an 80 kb presence/absence variant (PAV) of the NnMYB5 gene that is associated with petal color variation. Transcriptome analysis, dual-luciferase, and yeast 1-hybrid assays showed that NnMYB5 could directly activate the anthocyanin transporter gene GLUTATHIONE S-TRANSFERASE2 (NnGST2). Heterologous expression of NnGST2 in Arabidopsis (Arabidopsis thaliana) and its overexpression in lotus petals induced anthocyanin accumulation. Deletion of the 80 kb PAV within NnMYB5 inactivated NnGST2 expression and blocked anthocyanin accumulation in white N. nucifera petals. In contrast, the anthocyanin deficiency of N. lutea occurred due to pseudogenized NlMYB5 alleles. Our results establish a regulatory link between NnMYB5 and NnGST2 in petal anthocyanin accumulation and demonstrate the independent mechanisms controlling flower coloration in Nelumbo.
Assuntos
Antocianinas , Nelumbo , Antocianinas/metabolismo , Nelumbo/genética , Nelumbo/metabolismo , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Flores/genética , Flores/metabolismo , CorRESUMO
BACKGROUND: Growth hormone-secreted pituitary adenoma (GHPA) is a prominent subtype of pituitary adenoma (PA) associated with progressive somatic disfigurement, various complications, and elevated mortality rates. Existing treatment options have limited efficacy, highlighting the urgent need for novel pharmacological interventions. Previous studies have revealed that sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P)/S1P receptors (S1PRs) signalling have critical roles in the tumour microenvironment, but their role in GHPA remains unclear. METHODS: We performed integrative analyses including bioinformatics analyses, functional studies, and clinical validation to investigate the pathological roles of SPHK1/S1P and evaluated the effectiveness of the S1P receptor 2 (S1PR2) inhibitor JTE-013 in GHPA treatment. RESULTS: SPHK1/S1P signalling is abnormally expressed in patients with GHPA. Knockdown of SPHK1 suppresses S1P-mediated cell proliferation in GH3 Cells. Mechanistically, S1P inhibits apoptosis and autophagy while promoting the secretion of Growth Hormone (GH) by binding to the S1P receptor subtype 2 (S1PR2) in GH3 cells. Moreover, the function of S1PR2 in GH3 cells is mediated by the downstream Akt-Creb pathway. We then identify the S1PR2 as a novel target for therapeutic intervention in GHPA. Systemic administration of the potent and selective S1PR2 antagonist, JTE-013, significantly reduces both tumour size and GH secretion. Importantly, we identify preoperative serum S1P levels as a biomarker predicting poor prognosis in GHPA patients at follow-up. CONCLUSION: Our study shows that blocking SPHK1/S1P/S1PR2 axis can ameliorate the progression of GHPA, providing evidence of a promising therapeutic target for GHPA.
Assuntos
Fosfotransferases (Aceptor do Grupo Álcool) , Neoplasias Hipofisárias , Receptores de Lisoesfingolipídeo , Humanos , Receptores de Esfingosina-1-Fosfato , Receptores de Lisoesfingolipídeo/metabolismo , Hormônio do Crescimento , Neoplasias Hipofisárias/tratamento farmacológico , Esfingosina/metabolismo , Lisofosfolipídeos/metabolismo , Microambiente TumoralRESUMO
PURPOSE: The natural history of congenital scoliosis (CS) caused by hemivertebra varies greatly. This study aimed to explore the association between the morphology of hemivertebra and the severity of CS, since the diagnosis of the hemivertebra. METHODS: Patients with isolated (single fully segmented) hemivertebra were enrolled. The degree and progression of deformity were compared by three morphological parameters of hemivertebra, comprising whether the width of hemivertebra extends across the central vertical line of lower adjacent vertebra (midline); the lateral height ratio (LHR, lateral height of hemivertebra× 2/(lateral height of HV-1 plus HV + 1) with the cut-point being 0.9; and the sagittal position of hemivertebra that was divided into the lateral and posterolateral group. RESULTS: In total, 156 patients (mean age 9.7 ± 6.2 years, 81 males) were enrolled. The number of thoracic, thoracolumbar (T12/13-L1), and lumbar hemivertebrae were 63, 41, and 52, respectively. Hemivertebrae across the midline had larger scoliosis and kyphosis (58.3 ± 20.6° vs. 42.8 ± 15.0°, P < 0.001; 45.1 ± 32.5° vs. 29.5 ± 25.7°, P = 0.013, respectively). Hemivertebrae with LHR ≥0.9 was associated with larger scoliosis (55.7 ± 20.6° vs. 41.4 ± 13.3°, P < 0.001). Larger scoliosis and kyphosis were observed in posterolateral hemivertebrae (54.4 ± 21.0° vs. 44.4 ± 15.6°, P = 0.026; 51.4 ± 31.5° vs. 20.6 ± 17.1°, P < 0.001, respectively). Co-occurrence of more than one of the three positive parameters above indicated higher annual progression (5.0 ± 2.2° vs. 3.3 ± 1.3°, P < 0.001). CONCLUSION: Three positive parameters, width across the midline, LHR ≥0.9, and posterolateral position were associated with a more severe deformity in patients with isolated hemivertebra. Hemivertebrae with more than one positive parameter may cause progressive deformity, and thus need prompt surgery. LEVEL OF EVIDENCE: Prognostic, level IV.
Assuntos
Cifose , Anormalidades Musculoesqueléticas , Escoliose , Fusão Vertebral , Masculino , Humanos , Pré-Escolar , Criança , Adolescente , Escoliose/cirurgia , Resultado do Tratamento , Seguimentos , Estudos Retrospectivos , Cifose/diagnóstico por imagem , Cifose/etiologia , Vértebras Torácicas/cirurgia , Vértebras Lombares/cirurgiaRESUMO
Apoptosis signaling controls the cell cycle through the protein-protein interactions (PPIs) of its major B-cell lymphoma 2-associated x protein (BAX) and B-cell lymphoma 2 protein (Bcl-2). Due to the antagonistic function of both proteins, apoptosis depends on a properly tuned balance of the kinetics of BAX and Bcl-2 activities. The utilization of natural polyphenols to regulate the binding process of PPIs is feasible. However, the mechanism of this modulation has not been studied in detail. Here, we utilized atomic force microscopy (AFM) to evaluate the effects of polyphenols (kaempferol, quercetin, dihydromyricetin, baicalin, curcumin, rutin, epigallocatechin gallate, and gossypol) on the BAX/Bcl-2 binding mechanism. We demonstrated at the molecular scale that polyphenols quantitatively affect the interaction forces, kinetics, thermodynamics, and structural properties of BAX/Bcl-2 complex formation. We observed that rutin, epigallocatechin gallate, and baicalin reduced the binding affinity of BAX/Bcl-2 by an order of magnitude. Combined with surface free energy and molecular docking, the results revealed that polyphenols are driven by multiple forces that affect the orientation freedom of PPIs, with hydrogen bonding, hydrophobic interactions, and van der Waals forces being the major contributors. Overall, our work provides valuable insights into how molecules tune PPIs to modulate their function.
Assuntos
Polifenóis , Proteínas Proto-Oncogênicas c-bcl-2 , Polifenóis/farmacologia , Proteína X Associada a bcl-2/metabolismo , Simulação de Acoplamento Molecular , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RutinaRESUMO
The efficacy and safety of Shenshao Capsules in combination with conventional western medicine for the treatment of angina pectoris in coronary heart disease were systematically evaluated. Computer search of seven databases, including CNKI, Wanfang, VIP, SinoMed, PubMed, EMbase, and Cochrane Library, was conducted to identify randomized controlled trial(RCT) on Shenshao Capsules for the treatment of angina pectoris in coronary heart disease up to December 2023. According to inclusion and exclusion criteria, articles were screened, and data was extracted. Cochrane bias risk assessment tool 2.0(RoB 2.0) was used to evaluate the quality of the included articles. Meta-analysis was performed by RevMan 5.4 and Stata/SE 15.1 software, and evidence quality was rated by the GRADE system. TSA 0.9.5.10 beta software was used for the trial sequential analysis(TSA). Twelve RCTs, with a total of 1 128 participants(567 in the experimental group and 561 in the control group), were included. Meta-analysis showed that Shenshao Capsules + conventional western medicine significantly improved clinical efficacy(RR=1.20, 95%CI[1.15, 1.26], P<0.000 01) and electrocardiogram efficacy(RR=1.16, 95%CI[1.04, 1.30], P=0.01), reduced the frequency of weekly angina pectoris attacks(MD=-2.85, 95%CI[-5.27,-0.43], P=0.02), daily angina pectoris attacks(MD=-0.30, 95%CI[-0.57,-0.03], P=0.03) and the duration of angina pectoris attacks(RR=-2.28, 95%CI[-3.44,-1.12], P=0.000 1). There was no statistically significant difference in adverse reactions between the two groups(RR=1.33, 95%CI[0.71, 2.51], P=0.37). TSA indicated that the cumulative evidence for clinical efficacy exceeded the traditional boundary but did not exceed the TSA boundary, suggesting a potential false positive result. According to GRADE assessment, except for clinical efficacy, which was rated as low-quality evidence, the remaining outcomes were rated as very low-quality evidence. The results indicate that Shenshao Capsules + conventional western medicine may have certain advantages in improving clinical efficacy and electrocardiographic efficacy, reducing the frequency and duration of angina pectoris attacks. However, due to the limitations of this study, more rigorous and high-quality RCT is needed to validate its efficacy and safety.
Assuntos
Angina Pectoris , Cápsulas , Doença das Coronárias , Medicamentos de Ervas Chinesas , Ensaios Clínicos Controlados Aleatórios como Assunto , Medicamentos de Ervas Chinesas/administração & dosagem , Humanos , Angina Pectoris/tratamento farmacológico , Doença das Coronárias/tratamento farmacológico , Pessoa de Meia-Idade , Masculino , Idoso , Feminino , Resultado do TratamentoRESUMO
Nelumbo lutea (American lotus), which differs from Nelumbo nucifera (Asian lotus) morphologically, is one of the two remaining species in the basal eudicot family Nelumbonaceae. Here, we assembled the 843-Mb genome of American lotus into eight pseudochromosomes containing 31 382 protein-coding genes. Comparative analyses revealed conserved synteny without large chromosomal rearrangements between the genomes of American and Asian lotus and identified 29 533 structural variants (SVs). Carotenoid and anthocyanin pigments determine the yellow and red petal colors of American and Asian lotus, respectively. The structural genes encoding enzymes of the carotenoid and anthocyanin biosynthesis pathways were conserved between two species but differed in expression. We detected SVs caused by repetitive sequence expansion or contraction among the anthocyanin biosynthesis regulatory MYB genes. Further transient overexpression of candidate NnMYB5 induced anthocyanin accumulation in lotus petals. Alternative oxidase (AOX), uncoupling proteins (UCPs), and sugar metabolism and transportation contributed to carpel thermogenesis. Carpels produce heat with sugars transported from leaves as the main substrates, because there was weak tonoplast sugar transporter (TST) activity, and with SWEETs were highly expressed during thermogenesis. Cell proliferation-related activities were particularly enhanced in the warmer carpels compared with stamens during the cold night before blooming, which suggested that thermogenesis plays an important role in flower protogyny. Population genomic analyses revealed deep divergence between American and Asian lotus, and independent domestication affecting seed, rhizome, and flower traits. Our findings provide a high-quality reference genome of American lotus for exploring the genetic divergence and variation between two species and revealed possible genomic bases for petal color, carpel thermogenesis and domestication in lotus.
Assuntos
Genoma de Planta , Nelumbo , Antocianinas/análise , Carotenoides/análise , Domesticação , Flores/química , Flores/genética , Nelumbo/genética , Nelumbo/metabolismo , Açúcares/metabolismo , TermogêneseRESUMO
The emergence and evolution of antimicrobial resistance (AMR) pose a significant challenge to the current arsenal to fight infection. Antibiotic adjuvants represent an appealing tactic for tackling the AMR of pathogens, however, their practical applications are greatly constrained by the harsh infectious microenvironment. Herein, it is found that silver nanoclusters (Ag NCs) can possess tunable enzymatic activities to modulate infectious microenvironments. Based on this finding, an enzymatic nanoadjuvant (EnzNA) self-assembled from Ag NCs, which is inert under neutral physiological conditions but can readily disassemble into isolated Ag NCs exhibiting biofilm destructive oxidase-mimetic activity in the acidic biofilm microenvironment, is developed. Once internalized into the neutral cytoplasm of bacteria, Ag NCs switch to reveal the thiol oxidase-mimetic activity to suppress ribosomal biogenesis for AMR reversal and evolution inhibition of pathogens. Consequently, EnzNAs revitalize various existing antibiotics against methicillin-resistant Staphylococcus aureus, and potentiate the antibiotic efficacy against biofilm-mediated skin infection and lethal lung infection in mice. These findings highlight the capability of enzyme-mimetic nanomaterials to modulate the infectious microenvironment and potentiate antibiotics, providing a paradigm shift for anti-infection therapy.
Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Animais , Camundongos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Bactérias , Biofilmes , Testes de Sensibilidade MicrobianaRESUMO
The cambium and procambium generate the majority of biomass in vascular plants. These meristems constitute a bifacial stem cell population from which xylem and phloem are specified on opposing sides by positional signals. The PHLOEM INTERCALATED WITH XYLEM (PXY) receptor kinase promotes vascular cell division and organization. However, how these functions are specified and integrated is unknown. Here, we mapped a putative PXY-mediated transcriptional regulatory network comprising 690 transcription factor-promoter interactions in Arabidopsis (Arabidopsis thaliana). Among these interactions was a feedforward loop containing transcription factors WUSCHEL HOMEOBOX RELATED14 (WOX14) and TARGET OF MONOPTEROS6 (TMO6), each of which regulates the expression of the gene encoding a third transcription factor, LATERAL ORGAN BOUNDARIES DOMAIN4 (LBD4). PXY signaling in turn regulates the WOX14, TMO6, and LBD4 feedforward loop to control vascular proliferation. Genetic interaction between LBD4 and PXY suggests that LBD4 marks the phloem-procambium boundary, thus defining the shape of the vascular bundle. These data collectively support a mechanism that influences the recruitment of cells into the phloem lineage, and they define the role of PXY signaling in this context in determining the arrangement of vascular tissue.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Redes Reguladoras de Genes/fisiologia , Proteínas Quinases/metabolismo , Transdução de Sinais/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Divisão Celular , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes/genética , Genes Homeobox , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Floema/metabolismo , Caules de Planta/citologia , Caules de Planta/metabolismo , Proteínas Quinases/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Xilema/metabolismoRESUMO
Dowling-Degos disease (DDD) is an autosomal dominant hereditary skin disease characterized by acquired reticular hyperpigmentation in flexural sites, and one of its causative genes is KRT5 gene. But the effect of KRT5, expressed only in keratinocytes, on melanocytes is unclear. Other pathogenic genes of DDD include POFUT1, POGLUT1 and PSENEN genes, which is involved in posttranslational modification of Notch receptor. In this study, we aim to determine the ablation of keratinocyte KRT5 affect melanogenesis in melanocyte through Notch signalling pathway. Here we found that KRT5 downregulation decreased the expression of the Notch ligand in keratinocytes and Notch1 intracellular domain in melanocytes, by establishing two cell models of ablation of KRT5 in keratinocytes based on CRISPR/Cas9 site-directed mutation and lentivirus-mediated shRNA. Treatment of melanocytes with Notch inhibitors had same effects with ablation of KRT5 on increase of TYR and decrease of Fascin1. Activation of Notch signalling reverses the effect of ablation of KRT5 on melanogenesis. Immunohistochemistry of DDD lesions with KRT5 gene mutation confirmed changes in the expression of relevant molecules in Notch signalling. Our research elucidates molecular mechanism of KRT5-Notch signalling pathway in the regulation of melanocytes by keratinocytes, and preliminary reveal the mechanism of DDD pigment abnormality caused by KRT5 mutation. These findings identify potential therapeutic targets of the Notch signalling pathway for the treatment of skin pigment disorders.
Assuntos
Hiperpigmentação , Melaninas , Humanos , Melaninas/metabolismo , Mutação , Queratinócitos/metabolismo , Hiperpigmentação/genética , Melanócitos/metabolismo , Proteínas de Membrana/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Queratina-5/genética , Glucosiltransferases/genética , Glucosiltransferases/metabolismoRESUMO
Drug combination therapy is a highly effective approach for enhancing the therapeutic efficacy of anti-cancer drugs and overcoming drug resistance. However, the innumerable possible drug combinations make it impractical to screen all synergistic drug pairs. Moreover, biological insights into synergistic drug pairs are still lacking. To address this challenge, we systematically analyzed drug combination datasets curated from multiple databases to identify drug pairs more likely to show synergy. We classified drug pairs based on their MoA and discovered that 110 MoA pairs were significantly enriched in synergy in at least one type of cancer. To improve the accuracy of predicting synergistic effects of drug pairs, we developed a suite of machine learning models that achieve better predictive performance. Unlike most previous methods that were rarely validated by wet-lab experiments, our models were validated using two-dimensional cell lines and three-dimensional tumor slice culture (3D-TSC) models, implying their practical utility. Our prediction and validation results indicated that the combination of the RTK inhibitors Lapatinib and Pazopanib exhibited a strong therapeutic effect in breast cancer by blocking the downstream PI3K/AKT/mTOR signaling pathway. Furthermore, we incorporated molecular features to identify potential biomarkers for synergistic drug pairs, and almost all potential biomarkers found connections between drug targets and corresponding molecular features using protein-protein interaction network. Overall, this study provides valuable insights to complement and guide rational efforts to develop drug combination treatments.
Assuntos
Antineoplásicos , Neoplasias da Mama , Humanos , Feminino , Fosfatidilinositol 3-Quinases , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Transdução de Sinais , Neoplasias da Mama/tratamento farmacológico , Sistemas de Liberação de MedicamentosRESUMO
Cisplatin (DDP) based chemotherapy occurs a reduced therapeutic effect on the later treatment of ovarian cancer (OC) due to DDP resistance. Astragaloside II (ASII), a natural product extracted from Radix Astragali, has shown promising anticancer effects. However, the effects of ASII on OC have not been clarified. In this study, we found that ASII inhibited cell growth and promoted cell apoptosis of DDP-resistant OC cells in vitro and in vivo. Further study showed that ASII downregulated multidrug resistance-related protein MDR1 and cell cycle-related protein Cyclin D1 and PCNA, and also upregulated apoptosis-related protein leaved PRAP and cleaved caspase-3. In addition, ASII induced autophagy, characterized by upregulation of LC3II expression, downregulation of p62 expression, and elevation of LC3 punctuation, may be associated with inhibition of the AKT/mTOR signaling pathway. Moreover, the messenger RNA-sequencing was used to identify potential molecules regulated by ASII. In conclusion, these findings indicated that ASII increased sensitivity of DDP in the treatment of OC.
Assuntos
Antineoplásicos , Neoplasias Ovarianas , Humanos , Feminino , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Apoptose , AutofagiaRESUMO
Proteins are major drug targets, and drug-target interaction identification and analysis are important factors for drug discovery. Atomic force microscopy (AFM) is a powerful tool making it possible to image proteins with nanometric resolution and probe intermolecular forces under physiological conditions. We review recent studies conducted in the field of target protein drug discovery using AFM-based analysis technology, including drug-driven changes in nanomechanical properties of protein morphology and interactions. Underlying mechanisms (including thermodynamic and kinetic parameters) of the drug-target interaction and drug-modulating protein-protein interaction (PPI) on the surfaces of models or living cells are discussed. Furthermore, challenges and the outlook for the field are likewise discussed. Overall, this insight into the mechanical properties of protein-drug interactions provides an unprecedented information framework for rational drug discovery in the pharmaceutical field.
Assuntos
Proteínas , Microscopia de Força Atômica/métodos , Proteínas/metabolismo , Cinética , Termodinâmica , Interações MedicamentosasRESUMO
Callus browning is a major drawback to lotus callus proliferation and regeneration. However, the underlying mechanism of its formation remains largely unknown. Herein, we aimed to explore the metabolic and molecular basis of lotus callus browning by combining histological staining, high-throughput metabolomics, and transcriptomic assays for lotus callus at three browning stages. Histological stained brown callus cross sections displayed severe cell death symptoms, accompanied by an obvious accumulation of polyphenols and lignified materials. Widely targeted metabolomics revealed extensively decreased accumulation of most detected flavonoids and benzylisoquinoline alkaloids (BIAs), as well as a few phenolic acids, amino acids and their derivatives in callus with browning symptoms. Conversely, the contents of most detected tannins were significantly increased. Subsequent comparative transcriptomics identified a set of differentially expressed genes (DEGs) associated with the biosynthesis and regulation of flavonoids and BIAs in lotus. Notably, callus browning was coupled with significantly up-regulated expression of two polyphenol oxidase (PPO) and 17 peroxidase (POD) encoding genes, while the expression of ethylene associated genes remained at marginal levels. These results suggest that lotus callus browning is primarily controlled at the level of metabolism, wherein the oxidation of flavonoids and BIAs is crucially decisive.
Assuntos
Lotus , Nelumbo , Nelumbo/genética , Nelumbo/metabolismo , Lotus/metabolismo , Transcriptoma/genética , Perfilação da Expressão Gênica , Flavonoides/metabolismoRESUMO
Protein-protein interactions (PPIs) between the B-cell lymphoma 2 (Bcl-2) family are considered a major driving force in cell cycle regulation and signaling. However, how this interfacial noncovalent interaction is achieved molecularly remains poorly understood. Herein, anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (BAX) were used as models and their PPIs were explored for the first time using atomic force microscopy-based single-molecule force spectroscopy (SMFS) and in silico approaches. In addition, we used advanced analytical models, including multiple kinetic models, thermodynamic models, Poisson distributions, and contact angle molecular recognition to fully reveal the complexity of the BAX/Bcl-2 interaction interfaces. We propose that the binding kinetics between BAX/Bcl-2 are mainly mediated by specific (hydrogen bonding) and non-specific forces (hydrophobic interactions and electrostatic interactions) and show that the complicated multivalent binding interaction induces stable BAX/Bcl-2 complexes. This study enriches our understanding of the molecular mechanisms by which BAX interacts with Bcl-2. It provides valuable insights into the physical factors that need to be considered when designing PPI inhibitors.
Assuntos
Proteínas Reguladoras de Apoptose , Apoptose , Proteína X Associada a bcl-2/químicaRESUMO
Understanding and memorizing the primary, secondary, and tertiary functions of the vertical recti and oblique extraocular muscles play a decisive role in correctly diagnosing various types of strabismus, determining the location of nervous system lesions, and formulating correct treatment plans. However, for beginners, rapid learning, memorization, and application of these extraocular muscle functions are challenging. To improve the teaching of strabismus in ophthalmology and help students overcome the core learning difficulties, our team developed a gesture method based on a functional diagram of the extraocular muscles and a corresponding rhyme to teach clinical medicine students. The effects of the gesture method were determined by using in-class quizzes and self-confidence levels. Students' evaluations of the gesture method were assessed using a questionnaire survey. The gesture method significantly improved the mean scores on the tests (4.85 ± 1.65 vs. 6.31 ± 1.87 vs. 6.80 ± 1.45, all p < 0.001) and self-confidence scores (20.83 ± 4.06 vs. 27.38 ± 4.88 vs. 28.69 ± 3.53, all p < 0.001) of the students. The evaluations showed that the students were satisfied with the auxiliary memorization learning method. This new method could help students better understand and remember the function of the extraocular muscles, and is a valuable auxiliary teaching strategy.
Assuntos
Oftalmologia , Estrabismo , Humanos , Músculos Oculomotores , Estrabismo/diagnóstico , Cognição , Inquéritos e QuestionáriosRESUMO
Uricase-based therapies are limited for gout partially due to the accumulation of H2O2 in an arthrosis environment with slow metabolism. To tackle this limitation, previous studies adopted a cascade reaction between the degradation of uric acid (UA) and timely elimination of H2O2 using complicated composites of uricase and catalase (CAT)/CAT-like nanozyme. Herein, the self-cascade nanozyme Pt/CeO2 with high efficiency toward simultaneous UA degradation and H2O2 elimination is demonstrated on the basis of both uricase- and CAT-like activities in Pt, Ir, Rh, and Pd platinum-group metals. With an optimized molar ratio of Pt and CeO2, Pt/CeO2 (1/5) not only does better in degrading UA but also has excellent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging activities. In monosodium urate (MSU)-induced acute gout rats, Pt/CeO2 nanozyme markedly alleviates pain along with joint edema, thus improving gait claudication and tissue inflammation. These results provide novel insights into strategies of an efficient enzyme-mimetic treatment for gout.