Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 287
Filtrar
1.
Aging Cell ; : e14143, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38482753

RESUMO

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal disease manifested by premature aging and aging-related phenotypes, making it a disease model for aging. The cellular machinery mediating age-associated phenotypes in HGPS remains largely unknown, resulting in limited therapeutic targets for HGPS. In this study, we showed that mitophagy defects impaired mitochondrial function and contributed to cellular markers associated with aging in mesenchymal stem cells derived from HGPS patients (HGPS-MSCs). Mechanistically, we discovered that mitophagy affected the aging-associated phenotypes of HGPS-MSCs by inhibiting the STING-NF-ĸB pathway and the downstream transcription of senescence-associated secretory phenotypes (SASPs). Furthermore, by utilizing UMI-77, an effective mitophagy inducer, we showed that mitophagy induction alleviated aging-associated phenotypes in HGPS and naturally aged mice. Collectively, our results uncovered that mitophagy defects mediated the aging-associated markers in HGPS, highlighted the function of mitochondrial homeostasis in HGPS progression, and suggested mitophagy as an intervention target for HGPS and aging.

2.
J Ethnopharmacol ; 326: 117967, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38431111

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Psoraleae Fructus (PF), the dried fruit of Psoralea corylifolia L., is a commonly used traditional medicine that has contributed to the treatment of orthopedic diseases for thousands of years in China. However, recent PF-related liver injury reports have drawn widespread attention regarding its potential hepatotoxicity risks. AIM OF THE STUDY: This study was aimed to evaluate the long-term efficacy and chronic toxicity of PF using a 26-week administration experiment on rats in order to simulate the clinical usage situation. MATERIALS AND METHODS: The PF aqueous extract was consecutively administrated to rats daily at dosages of 0.7, 2.0, and 5.6 g/kg (equivalent to 1-8 times the clinical doses for humans) for as long as 26 weeks. Samples were collected after 13, 26, and 32 weeks (withdrawal for 6 weeks) since the first administration. The chronic toxicity of PF was evaluated by conventional toxicological methods, and the efficacy of PF was evaluated by osteogenic effects in the natural growth process. RESULTS: In our experiments, only the H group (5.6 g/kg) for 26-week PF treatment demonstrated liver or kidney injury, which the injuries were reversible after 6 weeks of withdrawal. Notably, the PF treatment beyond 13 weeks showed significant benefits for bone growth and development in rats, with a higher benefit-risk ratio in female rats. CONCLUSIONS: PF displayed a promising benefit-risk ratio in the treatment and prevention of osteoporosis, a disease that lacks effective medicine so far. This is the first study to elucidate the benefit-risk balance associated with clinical dosage and long-term use of PF, thereby providing valuable insights for rational clinical use and risk control of PF.


Assuntos
Medicamentos de Ervas Chinesas , Fabaceae , Psoralea , Humanos , Ratos , Feminino , Animais , Frutas , Razão de Chances , Fígado , Medicamentos de Ervas Chinesas/toxicidade
3.
Cell Rep Methods ; 4(3): 100733, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38503288

RESUMO

Here, we present Anchored-fusion, a highly sensitive fusion gene detection tool. It anchors a gene of interest, which often involves driver fusion events, and recovers non-unique matches of short-read sequences that are typically filtered out by conventional algorithms. In addition, Anchored-fusion contains a module based on a deep learning hierarchical structure that incorporates self-distillation learning (hierarchical view learning and distillation [HVLD]), which effectively filters out false positive chimeric fragments generated during sequencing while maintaining true fusion genes. Anchored-fusion enables highly sensitive detection of fusion genes, thus allowing for application in cases with low sequencing depths. We benchmark Anchored-fusion under various conditions and found it outperformed other tools in detecting fusion events in simulated data, bulk RNA sequencing (bRNA-seq) data, and single-cell RNA sequencing (scRNA-seq) data. Our results demonstrate that Anchored-fusion can be a useful tool for fusion detection tasks in clinically relevant RNA-seq data and can be applied to investigate intratumor heterogeneity in scRNA-seq data.


Assuntos
Algoritmos , Software , RNA-Seq , Análise de Sequência de RNA/métodos , RNA/genética
4.
Ren Fail ; 46(1): 2326186, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38466161

RESUMO

BACKGROUND: Immune checkpoint inhibitor-associated acute kidney injury (ICI-AKI) is the most common renal complication and has attracted increasing amounts of attention. However, studies on this topic in Chinese cancer patients are very limited. Therefore, we conducted a retrospective study on the incidence, risk factors, clinical features and renal recovery of ICI-AKI in all patients with malignancies treated with ICIs in Shandong Provincial Hospital Affiliated to Shandong First Medical University. METHODS: In this single-center retrospective cohort study, the data of 904 patients who received immune checkpoint inhibitors (ICIs) treatment were retrospectively analyzed. Multivariable logistic regression was used to identify the predictors of ICI-AKI. RESULTS: A total of 46 of 904 patients receiving ICIs developed ICI-AKI, and the incidence of ICI-AKI was 5.1%. Patients developed ICI-AKI at a median of 9 weeks (IQR 3-23) after ICIs initiation. A lower baseline estimated glomerular filtration rate (eGFR) and use of antibiotics were associated with a higher risk of ICI-AKI. Renal recovery occurred in 17 patients (46%) at a median of 4 weeks (IQR 2-8) after ICI-AKI, including 16 (43%) with complete recovery and 1 (3%) with partial recovery. Of the 14 rechallenged patients, only one developed recurrent ICI-AKI. CONCLUSIONS: Patients with ICI-AKI were more likely to have impaired renal function at baseline and after treatment with antibiotics. Approximately half of the patients achieved renal recovery.


Assuntos
Injúria Renal Aguda , Inibidores de Checkpoint Imunológico , Humanos , Estudos Retrospectivos , Inibidores de Checkpoint Imunológico/efeitos adversos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/epidemiologia , Rim , Antibacterianos
6.
Proc Natl Acad Sci U S A ; 121(12): e2317218121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38483997

RESUMO

Across the animal kingdom, visual predation relies on motion-sensing neurons in the superior colliculus (SC) and its orthologs. These neurons exhibit complex stimulus preferences, including direction selectivity, which is thought to be critical for tracking the unpredictable escape routes of prey. The source of direction selectivity in the SC is contested, and its contributions to predation have not been tested experimentally. Here, we use type-specific cell removal to show that narrow-field (NF) neurons in the mouse SC guide predation. In vivo recordings demonstrate that direction-selective responses of NF cells are independent of recently reported stimulus-edge effects. Monosynaptic retrograde tracing reveals that NF cells receive synaptic input from direction-selective ganglion cells. When we eliminate direction selectivity in the retina of adult mice, direction-selective responses in the SC, including in NF cells, are lost. However, eliminating retinal direction selectivity does not affect the hunting success or strategies of mice, even when direction selectivity is removed after mice have learned to hunt, and despite abolishing the gaze-stabilizing optokinetic reflex. Thus, our results identify the retinal source of direction selectivity in the SC. They show that NF cells in the SC guide predation, an essential spatial orienting task, independent of their direction selectivity, revealing behavioral multiplexing of complex neural feature preferences and highlighting the importance of feature-selective manipulations for neuroethology.


Assuntos
Neurônios , Comportamento Predatório , Camundongos , Animais , Neurônios/fisiologia , Colículos Superiores/fisiologia , Retina , Vias Visuais/fisiologia
7.
BMC Public Health ; 24(1): 807, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38486191

RESUMO

BACKGROUND: The objective of this study was to detect the urinary levels of chlorpyrifos, paraquat, and cyproconazole in residents living in Fuyang City and to analyze the correlation between these urinary pesticides levels and the severity of fatty liver disease (FLD). METHODS: All participants' fat fraction (FF) values were recorded by MRI (Magnetic resonance imaging). First-morning urine samples were collected from 53 participants from Fuyang Peoples'Hospital. The levels of three urinary pesticides were measured using ß-glucuronidase hydrolysis followed by a. The results were analyzed by using Pearson correlation analysis and binary logistic regression analysis to reveal the correlation between three urinary pesticides and the severity of fatty liver. RESULTS: 53 individuals were divided into 3 groups based on the results from MRI, with 20 cases in the normal control group, 16 cases in the mild fatty liver group, and 17 cases in the moderate and severe fatty liver group. Urinary chlorpyrifos level was increased along with the increase of the severity of fatty liver. Urinary paraquat level was significantly higher both in the low-grade fatty liver group and moderate & serve grade fatty liver group compared with the control group. No significant differences in urinary cyproconazole levels were observed among the three groups. Furthermore, urinary chlorpyrifos and paraquat levels were positively correlated with FF value. And chlorpyrifos was the risk factor that may be involved in the development of FLD and Receiver Operating Characteristic curve (ROC curve) analysis showed that chlorpyrifos and paraquat may serve as potential predictors of FLD. CONCLUSION: The present findings indicate urinary chlorpyrifos and paraquat were positively correlated with the severity of fatty liver. Moreover, urinary chlorpyrifos and paraquat have the potential to be considered as the predictors for development of FLD. Thus, this study may provide a new perspective from the environmental factors for the diagnosis, prevention, and treatment of FLD.


Assuntos
Clorpirifos , Hepatopatia Gordurosa não Alcoólica , Praguicidas , Triazóis , Humanos , Clorpirifos/urina , Paraquat , Imageamento por Ressonância Magnética
8.
Nat Commun ; 15(1): 1920, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429280

RESUMO

How sensory systems extract salient features from natural environments and organize them across neural pathways is unclear. Combining single-cell and population two-photon calcium imaging in mice, we discover that retinal ON bipolar cells (second-order neurons of the visual system) are divided into two blocks of four types. The two blocks distribute temporal and spatial information encoding, respectively. ON bipolar cell axons co-stratify within each block, but separate laminarly between them (upper block: diverse temporal, uniform spatial tuning; lower block: diverse spatial, uniform temporal tuning). ON bipolar cells extract temporal and spatial features similarly from artificial and naturalistic stimuli. In addition, they differ in sensitivity to coherent motion in naturalistic movies. Motion information is distributed across ON bipolar cells in the upper and the lower blocks, multiplexed with temporal and spatial contrast, independent features of natural scenes. Comparing the responses of different boutons within the same arbor, we find that axons of all ON bipolar cell types function as computational units. Thus, our results provide insights into the visual feature extraction from naturalistic stimuli and reveal how structural and functional organization cooperate to generate parallel ON pathways for temporal and spatial information in the mammalian retina.


Assuntos
Retina , Células Bipolares da Retina , Animais , Camundongos , Retina/fisiologia , Células Bipolares da Retina/fisiologia , Axônios/fisiologia , Terminações Pré-Sinápticas/fisiologia , Mamíferos
9.
Environ Sci Pollut Res Int ; 31(17): 24913-24935, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460036

RESUMO

High levels of urban green infrastructure (UGI) development can help mitigate the climate, biodiversity, and habitat crises faced by cities and support the achievement of sustainable urban development. Based on the relevant data of 41 cities in the Yangtze River Delta region obtained from 2011 to 2020, this study measured the development level of natural and geographic conditions, economic development, urban construction, social and cultural development, and eco-environment quality and urban green infrastructure (UGI); evaluated the development trend of UGI in the region during the 12th Five-Year Plan and 13th Five-Year Plan by using entropy TOPSIS; and used fs/QCA to explain the high-level development path of each city toward the achievement of a green infrastructure. The results showed that (1) the development level of UGI in the Yangtze River Delta region decreases from southeast to northwest, and gradually decreases from Shanghai, Hangzhou, and other central cities. (2) There were several different configurations of high levels and non-high levels of UGI development drivers across regions, confirming the existence of multiple causality and asymmetry indices in the drivers of UGI. (3) During the "12th Five-Year Plan" and the "13th Five-Year Plan" period, the conditions needed to achieve a high level of UGI gradually became stricter, expanding from nature-social culture and urban construction-eco-environmental drivers to nature-urban construction, nature-social culture-eco-environmental, urban construction-economy-social culture-eco-environmental drivers. Research findings can provide greater guidance and implications for future sustainable urban development.


Assuntos
Anti-Infecciosos , Reforma Urbana , China , Penicilinas , Biodiversidade , Cidades , Desenvolvimento Econômico , Fibrinolíticos
10.
Adv Healthc Mater ; : e2303295, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321619

RESUMO

The emerging antibiotic resistance has been named by the World Health Organization (WHO) as one of the top 10 threats to public health. Notably, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VREF) are designated as serious threats, whereas Clostridioides difficile (C. difficile) is recognized as one of the most urgent threats to human health and unmet medical need. Herein, they report the design and application of novel biodegradable polymers - the lipidated antimicrobial guanidinylate polycarbonates. These polymers showed potent antimicrobial activity against a panel of bacteria with fast-killing kinetics and low resistance development tendency, mainly due to their bacterial membrane disruption mechanism. More importantly, the optimal polymer showed excellent antibacterial activity against C. difficile infection (CDI) in vivo via oral administration. In addition, compared with vancomycin, the polymer demonstrated a much-prolonged therapeutic effect and virtually diminished recurrence rate of CDI. The convenient synthesis, easy scale-up, low cost, as well as biodegradability of this class of polycarbonates, together with their in vitro broad-spectrum antimicrobial activity and orally in vivo efficacy against CDI, suggest the great potential of lipidated guandinylate polycarbonates as a new class of antibacterial biomaterials to treat CDI and combat emerging antibiotic resistance.

11.
Int J Neural Syst ; 34(3): 2450013, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38369905

RESUMO

Automatic sleep staging offers a quick and objective assessment for quantitatively interpreting sleep stages in neonates. However, most of the existing studies either do not encompass any temporal information, or simply apply neural networks to exploit temporal information at the expense of high computational overhead and modeling ambiguity. This limits the application of these methods to multiple scenarios. In this paper, a sequential end-to-end sleep staging model, SeqEESleepNet, which is competent for parallelly processing sequential epochs and has a fast training rate to adapt to different scenarios, is proposed. SeqEESleepNet consists of a sequence epoch generation (SEG) module, a sequential multi-scale convolution neural network (SMSCNN) and squeeze and excitation (SE) blocks. The SEG module expands independent epochs into sequential signals, enabling the model to learn the temporal information between sleep stages. SMSCNN is a multi-scale convolution neural network that can extract both multi-scale features and temporal information from the signal. Subsequently, the followed SE block can reassign the weights of features through mapping and pooling. Experimental results exhibit that in a clinical dataset, the proposed method outperforms the state-of-the-art approaches, achieving an overall accuracy, F1-score, and Kappa coefficient of 71.8%, 71.8%, and 0.684 on a three-class classification task with a single channel EEG signal. Based on our overall results, we believe the proposed method could pave the way for convenient multi-scenario neonatal sleep staging methods.


Assuntos
Eletroencefalografia , Sono , Recém-Nascido , Humanos , Eletroencefalografia/métodos , Redes Neurais de Computação , Fases do Sono , Aprendizado de Máquina
12.
Nat Cell Biol ; 26(2): 278-293, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38302721

RESUMO

Lipids are indispensable for energy storage, membrane structure and cell signalling. However, dynamic changes in various categories of endogenous lipids in mammalian early embryonic development have not been systematically characterized. Here we comprehensively investigated the dynamic lipid landscape during mouse and human early embryo development. Lipid signatures of different developmental stages are distinct, particularly for the phospholipid classes. We highlight that the high degree of phospholipid unsaturation is a conserved feature as embryos develop to the blastocyst stage. Moreover, we show that lipid desaturases such as SCD1 are required for in vitro blastocyst development and blastocyst implantation. One of the mechanisms is through the regulation of unsaturated fatty-acid-mediated fluidity of the plasma membrane and apical proteins and the establishment of apical-basal polarity during development of the eight-cell embryo to the blastocyst. Overall, our study provides an invaluable resource about the remodelling of the endogenous lipidome in mammalian preimplantation embryo development and mechanistic insights into the regulation of embryogenesis and implantation by lipid unsaturation.


Assuntos
Metabolismo dos Lipídeos , Lipidômica , Gravidez , Humanos , Feminino , Camundongos , Animais , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/fisiologia , Blastocisto/metabolismo , Fosfolipídeos/metabolismo , Mamíferos
13.
BMC Microbiol ; 24(1): 56, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347440

RESUMO

BACKGROUND: The occurrence of multidrug-resistant and hypervirulent Klebsiella pneumoniae (MDR-hvKp) worldwide poses a great challenge for public health. Few studies have focused on ST218 MDR-hvKp. METHODS: Retrospective genomic surveillance was conducted at the Peking University Third Hospital from 2017 and clinical information was obtained. To understand genomic and microbiological characteristics, antimicrobial susceptibility testing, plasmid conjugation and stability, biofilm formation, serum killing, growth curves and whole-genome sequencing were performed. We also assessed the clinical and microbiological characteristics of ST218 compared with ST23. RESULTS: A total of eleven ST218 Kp isolates were included. The most common infection type was lower respiratory tract infection (72.7%, 8/11) in our hospital, whereas ST23 hvKp (72.7%, 8/11) was closely associated with bloodstream infection. Notably, nosocomial infections caused by ST218 (54.5%, 6/11) was slightly higher than ST23 (36.4%, 4/11). All of the ST218 and ST23 strains presented with the virulence genes combination of iucA + iroB + peg344 + rmpA + rmpA2. Interestingly, the virulence score of ST218 was lower than ST23, whereas one ST218 strain (pPEKP3107) exhibited resistance to carbapenems, cephalosporins, ß-lactamase/inhibitors and quinolones and harbored an ~ 59-kb IncN type MDR plasmid carrying resistance genes including blaNDM-1, dfrA14 and qnrS1. Importantly, blaNDM-1 and qnrS1 were flanked with IS26 located within the plasmid that could successfully transfer into E. coli J53. Additionally, PEKP2044 harbored an ~ 41-kb resistance plasmid located within tetA indicating resistance to doxycycline. CONCLUSION: The emergence of blaNDM-1 revealed that there is great potential for ST218 Kp to become a high-risk clone for MDR-hvKp, indicating the urgent need for enhanced genomic surveillance.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , beta-Lactamases/genética , Estudos Retrospectivos , Escherichia coli , Resistência a Múltiplos Medicamentos , Infecções por Klebsiella/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
14.
Genome Med ; 16(1): 3, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38185709

RESUMO

Identifying pathogenic variants from the vast majority of nucleotide variation remains a challenge. We present a method named Multimodal Annotation Generated Pathogenic Impact Evaluator (MAGPIE) that predicts the pathogenicity of multi-type variants. MAGPIE uses the ClinVar dataset for training and demonstrates superior performance in both the independent test set and multiple orthogonal validation datasets, accurately predicting variant pathogenicity. Notably, MAGPIE performs best in predicting the pathogenicity of rare variants and highly imbalanced datasets. Overall, results underline the robustness of MAGPIE as a valuable tool for predicting pathogenicity in various types of human genome variations. MAGPIE is available at https://github.com/shenlab-genomics/magpie .


Assuntos
Genoma Humano , Aprendizado de Máquina , Humanos
15.
FASEB J ; 38(2): e23409, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38193628

RESUMO

Diabetic kidney disease (DKD) is one of the severe complications of diabetes mellitus, yet there is no effective treatment. Exploring the development of DKD is essential to treatment. Podocyte injury and inflammation are closely related to the development of DKD. However, the mechanism of podocyte injury and progression in DKD remains largely unclear. Here, we observed that FTO expression was significantly upregulated in high glucose-induced podocytes and that overexpression of FTO promoted podocyte injury and inflammation. By performing RNA-seq and MeRIP-seq with control podocytes and high glucose-induced podocytes with or without FTO knockdown, we revealed that serum amyloid A2 (SAA2) is a target of FTO-mediated m6A modification. Knockdown of FTO markedly increased SAA2 mRNA m6A modification and decreased SAA2 mRNA expression. Mechanistically, we demonstrated that SAA2 might participate in podocyte injury and inflammation through activation of the NF-κB signaling pathway. Furthermore, by generating podocyte-specific adeno-associated virus 9 (AAV9) to knockdown SAA2 in mice, we discovered that the depletion of SAA2 significantly restored podocyte injury and inflammation. Together, our results suggested that upregulation of SAA2 promoted podocyte injury through m6A-dependent regulation, thus suggesting that SAA2 may be a therapeutic target for diabetic kidney disease.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato , Nefropatias Diabéticas , Podócitos , Proteína Amiloide A Sérica , Animais , Camundongos , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Nefropatias Diabéticas/genética , Glucose , Inflamação/genética , NF-kappa B , RNA Mensageiro/genética , Transdução de Sinais , Proteína Amiloide A Sérica/genética
16.
Drug Resist Updat ; 73: 101038, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38181587

RESUMO

AIMS: Although cefiderocol (FDC) is not prescribed in China, FDC-resistant pandrug-resistant hypervirulent Klebsiella pneumoniae (PDR-hvKp) is emerging. In this study, we performed FDC susceptibility testing of clinical Kp isolates to explore the prevalence of FDC-resistant isolates and the mechanism of FDC-resistance. METHODS: We retrospectively selected 151 carbapenem-resistant Kp isolates to assess FDC susceptibility. Seven isolates harboring blaSHV-12 from two patients were enrolled for whole-genome sequencing. The antimicrobial resistance, virulence, blaSHV-12 expression, and fitness costs in different media were examined. The amplification of blaSHV-12 was further investigated by qPCR and long-read sequencing. RESULTS: The 151 isolates showed a low MIC50/MIC90 (1/4 mg/L) of FDC. The seven isolates were ST11 PDR-hvKp, and two represented FDC-resistance (MIC=32 mg/L). The IncR/IncFII plasmids of two FDC-resistant isolates harbored 6 and 15 copies of blaSHV-12, whereas four FDC-susceptible isolates carried one copy and one harbored three copies. These blaSHV-12 genes concatenated together and were located within the same 7.3 kb fragment flanked by IS26, which contributed to the increased expression and FDC resistance without fitness costs. The amplification of blaSHV-12 and FDC resistance could be induced by FDC in vitro and reversed during continuous passage. CONCLUSIONS: The amplification of blaSHV-12 and the consequent dynamic within-host heteroresistance are important concerns for the rational application of antibiotics. Long-read sequencing might be a superior way to detect resistance gene amplification rapidly and accurately.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , Klebsiella pneumoniae/genética , 60607 , Estudos Retrospectivos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
17.
Proc Natl Acad Sci U S A ; 121(6): e2311733121, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38285951

RESUMO

In contrast to prevalent strategies which make use of ß-sheet mimetics to block Aß fibrillar growth, in this study, we designed a series of sulfonyl-γ-AApeptide helices that targeted the crucial α-helix domain of Aß13-26 and stabilized Aß conformation to avoid forming the neurotoxic Aß oligomeric ß-sheets. Biophysical assays such as amyloid kinetics and TEM demonstrated that the Aß oligomerization and fibrillation could be greatly prevented and even reversed in the presence of sulfonyl-γ-AApeptides in a sequence-specific and dose-dependent manner. The studies based on circular dichroism, Two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) spectra unambiguously suggested that the sulfonyl-γ-AApeptide Ab-6 could bind to the central region of Aß42 and induce α-helix conformation in Aß. Additionally, Electrospray ionisation-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS) was employed to rule out a colloidal mechanism of inhibitor and clearly supported the capability of Ab-6 for inhibiting the formation of Aß aggregated forms. Furthermore, Ab-6 could rescue neuroblastoma cells by eradicating Aß-mediated cytotoxicity even in the presence of pre-formed Aß aggregates. The confocal microscopy demonstrated that Ab-6 could still specifically bind Aß42 and colocalize into mitochondria in the cellular environment, suggesting the rescue of cell viability might be due to the protection of mitochondrial function otherwise impaired by Aß42 aggregation. Taken together, our studies indicated that sulfonyl-γ-AApeptides as helical peptidomimetics could direct Aß into the off-pathway helical secondary structure, thereby preventing the formation of Aß oligomerization, fibrillation and rescuing Aß induced cell cytotoxicity.


Assuntos
Amidas , Peptídeos beta-Amiloides , Amiloide , Amiloide/química , Conformação Proteica em alfa-Hélice , Conformação Molecular , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/metabolismo
19.
J Biosci Bioeng ; 137(2): 115-123, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38135638

RESUMO

Tyrosol (4-hydroxyphenylethanol) is a phenolic compound used in the pharmaceutical and chemical industries. However, current supply methods, such as extraction from natural resources and chemical synthesis, have disadvantages from the viewpoint of cost and environmental protection. Here, we developed a tyrosol-producing Escherichia coli cell factory from a high-tyrosine-producing strain by expressing selected tyrosine decarboxylase-, tyramine oxidase (TYO)-, and medium-chain dehydrogenase/reductase (YahK)-encoding genes. The genes were controlled by the strong T7 promoter and integrated into the chromosome because of the advantages over plasmid-based systems. The strain produced a melanin-like pigment as a by-product, which is suggested to be formed from 4-hydroxyphenylacetaldehyde (a TYO product/YahK substrate). By using a culture medium containing a high concentration of glycerol, which was reported to enhance NADH supply required for YahK activity, the final titer of tyrosol reached 2.42 g/L in test tube-scale cultivation with a concomitant decrease in the amount of pigment. These results indicate that chromosomally integrated and T7 promoter-controlled gene expression system in E. coli is useful for high production of heterologous enzymes and might be applied for industrial production of useful compounds including tyrosine and tyrosol.


Assuntos
Escherichia coli , Álcool Feniletílico/análogos & derivados , Tirosina , Escherichia coli/genética , Escherichia coli/metabolismo , Tirosina/metabolismo , Tirosina Descarboxilase/genética , Tirosina Descarboxilase/metabolismo , Monoaminoxidase/genética , Monoaminoxidase/metabolismo , Engenharia Metabólica
20.
Genome Med ; 15(1): 115, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38111063

RESUMO

Identifying expressed somatic mutations from single-cell RNA sequencing data de novo is challenging but highly valuable. We propose RESA - Recurrently Expressed SNV Analysis, a computational framework to identify expressed somatic mutations from scRNA-seq data. RESA achieves an average precision of 0.77 on three in silico spike-in datasets. In extensive benchmarking against existing methods using 19 datasets, RESA consistently outperforms them. Furthermore, we applied RESA to analyze intratumor mutational heterogeneity in a melanoma drug resistance dataset. By enabling high precision detection of expressed somatic mutations, RESA substantially enhances the reliability of mutational analysis in scRNA-seq. RESA is available at https://github.com/ShenLab-Genomics/RESA .


Assuntos
Melanoma , Análise de Célula Única , Humanos , Reprodutibilidade dos Testes , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Mutação , Melanoma/genética , Perfilação da Expressão Gênica/métodos , Análise por Conglomerados , Software
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...