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1.
Cell ; 149(7): 1565-77, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-22726442

RESUMO

Secreted Wnt morphogens are signaling molecules essential for embryogenesis, pathogenesis, and regeneration and require distinct modifications for secretion, gradient formation, and activity. Whether Wnt proteins can be posttranslationally inactivated during development and homeostasis is unknown. Here we identify, through functional cDNA screening, a transmembrane protein Tiki1 that is expressed specifically in the dorsal Spemann-Mangold Organizer and is required for anterior development during Xenopus embryogenesis. Tiki1 antagonizes Wnt function in embryos and human cells via a TIKI homology domain that is conserved from bacteria to mammals and acts likely as a protease to cleave eight amino-terminal residues of a Wnt protein, resulting in oxidized Wnt oligomers that exhibit normal secretion but minimized receptor-binding capability. Our findings identify a Wnt-specific protease that controls head formation, reveal a mechanism for morphogen inactivation through proteolysis-induced oxidation-oligomerization, and suggest a role of the Wnt amino terminus in evasion of oxidizing inactivation. TIKI proteins may represent potential therapeutic targets.


Assuntos
Padronização Corporal , Cabeça/embriologia , Proteínas de Membrana/metabolismo , Metaloproteases/metabolismo , Via de Sinalização Wnt , Proteínas de Xenopus/metabolismo , Xenopus/embriologia , Sequência de Aminoácidos , Animais , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Células HeLa , Humanos , Proteínas de Membrana/genética , Metaloproteases/genética , Dados de Sequência Molecular , Organizadores Embrionários/metabolismo , Alinhamento de Sequência , Xenopus/metabolismo , Proteínas de Xenopus/genética
2.
Proc Natl Acad Sci U S A ; 120(42): e2220029120, 2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37812700

RESUMO

Voltage-gated potassium channels (Kv) are tetrameric membrane proteins that provide a highly selective pathway for potassium ions (K+) to diffuse across a hydrophobic cell membrane. These unique voltage-gated cation channels detect changes in membrane potential and, upon activation, help to return the depolarized cell to a resting state during the repolarization stage of each action potential. The Kv3 family of potassium channels is characterized by a high activation potential and rapid kinetics, which play a crucial role for the fast-spiking neuronal phenotype. Mutations in the Kv3.1 channel have been shown to have implications in various neurological diseases like epilepsy and Alzheimer's disease. Moreover, disruptions in neuronal circuitry involving Kv3.1 have been correlated with negative symptoms of schizophrenia. Here, we report the discovery of a novel positive modulator of Kv3.1, investigate its biophysical properties, and determine the cryo-EM structure of the compound in complex with Kv3.1. Structural analysis reveals the molecular determinants of positive modulation in Kv3.1 channels by this class of compounds and provides additional opportunities for rational drug design for the treatment of associated neurological disorders.


Assuntos
Neurônios , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Humanos , Neurônios/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Canais de Potássio/metabolismo , Potenciais de Ação/fisiologia , Proteínas de Membrana/metabolismo
3.
EMBO Rep ; 24(6): e55873, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36994853

RESUMO

The membrane-tethered protease Tiki antagonizes Wnt3a signaling by cleaving and inactivating Wnt3a in Wnt-producing cells. Tiki also functions in Wnt-receiving cells to antagonize Wnt signaling by an unknown mechanism. Here, we demonstrate that Tiki inhibition of Wnt signaling at the cell surface requires Frizzled (FZD) receptors. Tiki associates with the Wnt-FZD complex and cleaves the N-terminus of Wnt3a or Wnt5a, preventing the Wnt-FZD complex from recruiting and activating the coreceptor LRP6 or ROR1/2 without affecting Wnt-FZD complex stability. Intriguingly, we demonstrate that the N-terminus of Wnt3a is required for Wnt3a binding to LRP6 and activating ß-catenin signaling, while the N-terminus of Wnt5a is dispensable for recruiting and phosphorylating ROR1/2. Both Tiki enzymatic activity and its association with the Wnt-FZD complex contribute to its inhibitory function on Wnt5a. Our study uncovers the mechanism by which Tiki antagonizes Wnt signaling at the cell surface and reveals a negative role of FZDs in Wnt signaling by acting as Tiki cofactors. Our findings also reveal an unexpected role of the Wnt3a N-terminus in the engagement of the coreceptor LRP6.


Assuntos
Receptores Frizzled , Via de Sinalização Wnt , Receptores Frizzled/metabolismo , Proteína Wnt3A/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Membrana Celular/metabolismo , beta Catenina/metabolismo
4.
Mol Biol Evol ; 40(1)2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36617238

RESUMO

Adaptive introgression (AI) facilitates local adaptation in a wide range of species. Many state-of-the-art methods detect AI with ad-hoc approaches that identify summary statistic outliers or intersect scans for positive selection with scans for introgressed genomic regions. Although widely used, approaches intersecting outliers are vulnerable to a high false-negative rate as the power of different methods varies, especially for complex introgression events. Moreover, population genetic processes unrelated to AI, such as background selection or heterosis, may create similar genomic signals to AI, compromising the reliability of methods that rely on neutral null distributions. In recent years, machine learning (ML) methods have been increasingly applied to population genetic questions. Here, we present a ML-based method called MaLAdapt for identifying AI loci from genome-wide sequencing data. Using an Extra-Trees Classifier algorithm, our method combines information from a large number of biologically meaningful summary statistics to capture a powerful composite signature of AI across the genome. In contrast to existing methods, MaLAdapt is especially well-powered to detect AI with mild beneficial effects, including selection on standing archaic variation, and is robust to non-AI selective sweeps, heterosis from deleterious mutations, and demographic misspecification. Furthermore, MaLAdapt outperforms existing methods for detecting AI based on the analysis of simulated data and the validation of empirical signals through visual inspection of haplotype patterns. We apply MaLAdapt to the 1000 Genomes Project human genomic data and discover novel AI candidate regions in non-African populations, including genes that are enriched in functionally important biological pathways regulating metabolism and immune responses.


Assuntos
Homem de Neandertal , Humanos , Animais , Homem de Neandertal/genética , Reprodutibilidade dos Testes , Genética Populacional , Adaptação Fisiológica , Seleção Genética , Genoma Humano
5.
Brief Bioinform ; 23(3)2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35443027

RESUMO

Predicting the binding of peptide and major histocompatibility complex (MHC) plays a vital role in immunotherapy for cancer. The success of Alphafold of applying natural language processing (NLP) algorithms in protein secondary struction prediction has inspired us to explore the possibility of NLP methods in predicting peptide-MHC class I binding. Based on the above motivations, we propose the MHCRoBERTa method, RoBERTa pre-training approach, for predicting the binding affinity between type I MHC and peptides. Analysis of the results on benchmark dataset demonstrates that MHCRoBERTa can outperform other state-of-art prediction methods with an increase of the Spearman rank correlation coefficient (SRCC) value. Notably, our model gave a significant improvement on IC50 value. Our method has achieved SRCC value and AUC value as 0.785 and 0.817, respectively. Our SRCC value is 14.3% higher than NetMHCpan3.0 (the second highest SRCC value on pan-specific) and is 3% higher than MHCflurry (the second highest SRCC value on all methods). The AUC value is also better than any other pan-specific methods. Moreover, we visualize the multi-head self-attention for the token representation across the layers and heads by this method. Through the analysis of the representation of each layer and head, we can show whether the model has learned the syntax and semantics necessary to perform the prediction task well. All these results demonstrate that our model can accurately predict the peptide-MHC class I binding affinity and that MHCRoBERTa is a powerful tool for screening potential neoantigens for cancer immunotherapy. MHCRoBERTa is available as an open source software at github (https://github.com/FuxuWang/MHCRoBERTa).


Assuntos
Antígenos de Histocompatibilidade Classe I , Peptídeos , Algoritmos , Sequência de Aminoácidos , Antígenos de Histocompatibilidade Classe I/metabolismo , Aprendizado de Máquina , Peptídeos/metabolismo , Ligação Proteica
6.
Physiol Plant ; 176(4): e14422, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962815

RESUMO

Low temperatures pose a common challenge in the production of cucumbers and tomatoes, hindering plant growth and, in severe cases, leading to plant death. In our investigation, we observed a substantial improvement in the growth of cucumber and tomato seedlings through the application of corn steep liquor (CSL), myo-inositol (MI), and their combinations. When subjected to low-temperature stress, these treatments resulted in heightened levels of photosynthetic pigments, thereby fostering enhanced photosynthesis in both tomato and cucumber plants. Furthermore, it contributed to a decrease in malondialdehyde (MDA) levels and electrolyte leakage (REP). The effectiveness of the treatment was further validated through the analysis of key gene expressions (CBF1, COR, MIOX4, and MIPS1) in cucumber. Particularly, noteworthy positive outcomes were noted in the treatment involving 0.6 mL L-1 CSL combined with 72 mg L-1 MI. This study provides valuable technical insights into leveraging the synergistic effects of inositol and maize leachate to promote early crop growth and bolster resistance to low temperatures.


Assuntos
Temperatura Baixa , Cucumis sativus , Inositol , Plântula , Solanum lycopersicum , Zea mays , Inositol/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Zea mays/genética , Zea mays/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/genética , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Solanum lycopersicum/fisiologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/metabolismo , Cucumis sativus/genética , Cucumis sativus/fisiologia , Fotossíntese/efeitos dos fármacos , Malondialdeído/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos
7.
BMC Geriatr ; 24(1): 478, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822230

RESUMO

BACKGROUND: Evidence of the optimal blood pressure (BP) target for older adults with disability in long-term care is limited. We aim to analyze the associations of BP with mortality in older adults in long-term care setting with different levels of disability. METHODS: This prospective cohort study was based on the government-led long-term care programme in Chengdu, China, including 41,004 consecutive disabled adults aged ≥ 60 years. BP was measured during the baseline survey by trained medical personnel using electronic sphygmomanometers. Disability profile was assessed using the Barthel index. The association between blood pressure and mortality was analyzed with doubly robust estimation, which combined exposure model by inverse probability weighting and outcome model fitted with Cox regression. The non-linearity was examined by restricted cubic spline. The primary endpoint was all-cause mortality, and the secondary endpoints were cardiovascular and non-cardiovascular mortality. RESULTS: The associations between systolic blood pressure (SBP) and all-cause mortality were close to a U-shaped curve in mild-moderate disability group (Barthel index ≥ 40), and a reversed J-shaped in severe disability group (Barthel index < 40). In mild-moderate disability group, SBP < 135 mmHg was associated with elevated all-cause mortality risks (HR 1.21, 95% CI, 1.10-1.33), compared to SBP between 135 and 150 mmHg. In severe disability group, SBP < 150 mmHg increased all-cause mortality risks (HR 1.21, 95% CI, 1.16-1.27), compared to SBP between 150 and 170 mmHg. The associations were robust in subgroup analyses in terms of age, gender, cardiovascular comorbidity and antihypertensive treatment. Diastolic blood pressure (DBP) < 67 mmHg (HR 1.29, 95% CI, 1.18-1.42) in mild-moderate disability group and < 79 mmHg (HR 1.15, 95% CI, 1.11-1.20) in severe disability group both demonstrated an increased all-cause mortality risk. CONCLUSION: The optimal SBP range was found to be higher in older individuals in long-term care with severe disability (150-170mmHg) compared to those with mild to moderate disability (135-150mmHg). This study provides new evidence that antihypertensive treatment should be administered cautiously in severe disability group in long-term care setting. Additionally, assessment of disability using the Barthel index can serve as a valuable tool in customizing the optimal BP management strategy. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registration Number: ChiCTR2100049973).


Assuntos
Pressão Sanguínea , Pessoas com Deficiência , Assistência de Longa Duração , Humanos , Masculino , Feminino , Idoso , China/epidemiologia , Estudos Prospectivos , Assistência de Longa Duração/métodos , Assistência de Longa Duração/tendências , Pressão Sanguínea/fisiologia , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Estudos de Coortes , Hipertensão/mortalidade , Hipertensão/fisiopatologia , Hipertensão/epidemiologia , Mortalidade/tendências , População do Leste Asiático
8.
PLoS Genet ; 17(9): e1009493, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34570765

RESUMO

Ancient human migrations led to the settlement of population groups in varied environmental contexts worldwide. The extent to which adaptation to local environments has shaped human genetic diversity is a longstanding question in human evolution. Recent studies have suggested that introgression of archaic alleles in the genome of modern humans may have contributed to adaptation to environmental pressures such as pathogen exposure. Functional genomic studies have demonstrated that variation in gene expression across individuals and in response to environmental perturbations is a main mechanism underlying complex trait variation. We considered gene expression response to in vitro treatments as a molecular phenotype to identify genes and regulatory variants that may have played an important role in adaptations to local environments. We investigated if Neanderthal introgression in the human genome may contribute to the transcriptional response to environmental perturbations. To this end we used eQTLs for genes differentially expressed in a panel of 52 cellular environments, resulting from 5 cell types and 26 treatments, including hormones, vitamins, drugs, and environmental contaminants. We found that SNPs with introgressed Neanderthal alleles (N-SNPs) disrupt binding of transcription factors important for environmental responses, including ionizing radiation and hypoxia, and for glucose metabolism. We identified an enrichment for N-SNPs among eQTLs for genes differentially expressed in response to 8 treatments, including glucocorticoids, caffeine, and vitamin D. Using Massively Parallel Reporter Assays (MPRA) data, we validated the regulatory function of 21 introgressed Neanderthal variants in the human genome, corresponding to 8 eQTLs regulating 15 genes that respond to environmental perturbations. These findings expand the set of environments where archaic introgression may have contributed to adaptations to local environments in modern humans and provide experimental validation for the regulatory function of introgressed variants.


Assuntos
Exposição Ambiental , Genoma Humano , Homem de Neandertal/genética , Adaptação Fisiológica/genética , Alelos , Animais , Regulação da Expressão Gênica , Migração Humana , Humanos , Polimorfismo de Nucleotídeo Único , Ligação Proteica , Locos de Características Quantitativas , Fatores de Transcrição/metabolismo
9.
Proc Natl Acad Sci U S A ; 118(22)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34050022

RESUMO

Recent studies suggest that admixture with archaic hominins played an important role in facilitating biological adaptations to new environments. For example, interbreeding with Denisovans facilitated the adaptation to high-altitude environments on the Tibetan Plateau. Specifically, the EPAS1 gene, a transcription factor that regulates the response to hypoxia, exhibits strong signatures of both positive selection and introgression from Denisovans in Tibetan individuals. Interestingly, despite being geographically closer to the Denisova Cave, East Asian populations do not harbor as much Denisovan ancestry as populations from Melanesia. Recently, two studies have suggested two independent waves of Denisovan admixture into East Asians, one of which is shared with South Asians and Oceanians. Here, we leverage data from EPAS1 in 78 Tibetan individuals to interrogate which of these two introgression events introduced the EPAS1 beneficial sequence into the ancestral population of Tibetans, and we use the distribution of introgressed segment lengths at this locus to infer the timing of the introgression and selection event. We find that the introgression event unique to East Asians most likely introduced the beneficial haplotype into the ancestral population of Tibetans around 48,700 (16,000-59,500) y ago, and selection started around 9,000 (2,500-42,000) y ago. Our estimates suggest that one of the most convincing examples of adaptive introgression is in fact selection acting on standing archaic variation.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Evolução Molecular , Haplótipos , Adaptação Fisiológica/genética , Altitude , Humanos , Tibet
10.
BMC Musculoskelet Disord ; 24(1): 733, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37710203

RESUMO

OBJECTIVE: To introduce a new type of simple adjustable bilateral bidirectional polyvinyl chloride (PVC) tube traction device and discuss the value of using this device before surgery in patients with lower limb fractures. METHODS: To introduce the manufacturing process of an adjustable bilateral traction device made of PVC pipes. From August 2018 to November 2019, the data of 36 patients with lower limb fractures who were treated with this traction device were retrospectively analysed. The treatment outcomes were analysed, including length of both lower limbs, fracture reduction, lower limb mobility, visual analogue scale (VAS) score, incidence of complications, and patient satisfaction. RESULTS: All patients were able to move the affected limb immediately after using the device. The patient's pain was significantly reduced, they were able to turn over freely during bed rest, and the length of the affected limb was restored to that of the healthy limb. Thirty-four (94.5%) patients were satisfied with the reduction of the fracture end, 2 (5.5%) patients with tibiofibular fractures showed angular displacement of the fractured end and satisfactory reduction after the position of the bone traction needle was adjusted; 7 (19.5%) patients developed deep vein thrombosis of the affected lower limb during traction; there was no decubitus or vascular nerve injury, and the overall complication rate was 25% (9/36). All the patients and their families were satisfied with the results of this treatment. CONCLUSION: The aim of this study is to introduce a new type of traction device. It is advantageous in that it is light weight, low cost, easy to assemble, promotes immediate movement of the affected limb after assembly, improves patient comfort and can be used with a titanium steel needle for MRI examination under traction. In the clinical setting, it has been shown to be suitable for the temporary treatment of patients with lower leg fractures prior to surgery, particularly patients who, for various reasons, require nonsurgical treatment in the short term.


Assuntos
Fraturas Ósseas , Tração , Humanos , Estudos Retrospectivos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Extremidade Inferior , Perna (Membro)
11.
BMC Oral Health ; 23(1): 173, 2023 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-36966303

RESUMO

BACKGROUND: There is a lack of consensus regarding the best treatment option, including physical exercise, available for temporomandibular degenerative joint disease (DJD) that affect the older patients. Herein, we aimed to study and compare the efficacy of a combined approach using injection and home physical exercise with physical therapy alone as well as explored an optimal treatment strategy for older patients with DJD. METHODS: We included 213 older patients with DJD treated at our medical centre from June 2020 to June 2021, 64 of whom were selected for analysis. Of these 64 patients, 32 received injections combined with home physical exercise, and the other 32 received physical therapy alone. Propensity score matching was used to ensure that the two groups did not differ significantly in categorical and continuous variables. Measurements included pain intensity, maximum mouth opening, joint crepitus, jaw functional limitation scale (JFLS) scores, treatment times, and treatment durations. Improvement in each measurement was compared between the two groups 2, 4, and 12 weeks after the treatment commenced, as were the final treatment times and durations. RESULTS: Pain intensity, maximum mouth opening, and JFLS scores in the two groups improved 2, 4, and 12 weeks after treatment (all p < 0.05). The crepitus ratio improved significantly only in the combined treatment group after 12 weeks. Compared with the physical therapy group, pain while opening the mouth improved after 2, 4, and 12 weeks in the combined treatment group. Furthermore, 2 weeks after treatment, the physical therapy group showed significant improvement in maximal mouth opening compared with the combined treatment group. No significant between-group differences were observed regarding improvement in joint crepitus and JFLS scores at each observation point. The combined treatment group had a significantly lower number of visits than the physical therapy group; however, the treatment duration was longer. CONCLUSION: Compared with physical therapy, pain while opening the mouth is significantly improved by the combined treatment within 12 weeks, and the number of required visits is fewer. Physical therapy improves the patients' mouth-opening capabilities in a short time (2 weeks), and the treatment cycle is short.


Assuntos
Transtornos da Articulação Temporomandibular , Humanos , Transtornos da Articulação Temporomandibular/terapia , Estudos Prospectivos , Dor , Modalidades de Fisioterapia , Arcada Osseodentária , Resultado do Tratamento , Articulação Temporomandibular
12.
Entropy (Basel) ; 25(2)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36832642

RESUMO

The detection of infusion containers is highly conducive to reducing the workload of medical staff. However, when applied in complex environments, the current detection solutions cannot satisfy the high demands for clinical requirements. In this paper, we address this problem by proposing a novel method for the detection of infusion containers that is based on the conventional method, You Only Look Once version 4 (YOLOv4). First, the coordinate attention module is added after the backbone to improve the perception of direction and location information by the network. Then, we build the cross stage partial-spatial pyramid pooling (CSP-SPP) module to replace the spatial pyramid pooling (SPP) module, which allows the input information features to be reused. In addition, the adaptively spatial feature fusion (ASFF) module is added after the original feature fusion module, path aggregation network (PANet), to facilitate the fusion of feature maps at different scales for more complete feature information. Finally, EIoU is used as a loss function to solve the anchor frame aspect ratio problem, and this improvement allows for more stable and accurate information of the anchor aspect when calculating losses. The experimental results demonstrate the advantages of our method in terms of recall, timeliness, and mean average precision (mAP).

13.
Opt Express ; 30(2): 3101-3112, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35209436

RESUMO

The microlens array (MLA) with a small geometric footprint and unique performances, is the key enabler to push the development of photonic devices toward miniaturization, multi-function and large-scale integration. However, the realization of 100% fill-factor (FF) MLAs with high controllability and its mass manufacturing without complex steps has always been a difficult issue. Here, we propose an efficient, highly flexible and low-cost manufacturing approach for MLAs with a high FF via snapshot polarization patterning. The digitalized linear polarization pattern was distributed across the photo-alignment layer with both high efficiency and accuracy, enabling large-area liquid crystal MLA with parameter controllability from element to element. The MLA manufacturing process does not involve developing, etching and deposition steps and is suitable for industry up-scaling. We further proposed a novel compact compound-eye imaging system for biometrics with the obtained MLAs. The 100% FF MLA enables high light utilization efficiency and low background crosstalk, yielding compact biometrics indentation with high recognition accuracy. The realization of such planar optics would lead to a plethora of different miniaturized multiaperture imaging systems in the future.

14.
Opt Express ; 30(25): 44864-44877, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36522900

RESUMO

To compensate for the inability for polarization imaging by conventional methods, metasurface optics with compactness and multi-function emerge as an approach to provide images with different linear and circular polarizations. Here, we propose a liquid crystal (LC) geometric phase-based chiral imaging lens (CIL) that simultaneously forms images of objects with opposite helicity. The CIL (Diameter 2.3 cm) was optimized by a spatial multiplexing algorithm and realized using the digital holography technique, where the LC domains were regulated by pixelated nanogratings with varied orientation. We investigated the potential of the patterning technique toward high order LC alignment by balancing the periodicity and depth of the nanogratings. The CIL exhibited a wide field of view of ±20°, which is attributed to the self- assembling effects of LC molecules. The compactness, lightness, and ability to produce chiral images of the LC CIL even at large angles have significant potential for practical polarization imaging.

15.
Nature ; 538(7625): 350-355, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27680706

RESUMO

Clostridium difficile toxin B (TcdB) is a critical virulence factor that causes diseases associated with C. difficile infection. Here we carried out CRISPR-Cas9-mediated genome-wide screens and identified the members of the Wnt receptor frizzled family (FZDs) as TcdB receptors. TcdB binds to the conserved Wnt-binding site known as the cysteine-rich domain (CRD), with the highest affinity towards FZD1, 2 and 7. TcdB competes with Wnt for binding to FZDs, and its binding blocks Wnt signalling. FZD1/2/7 triple-knockout cells are highly resistant to TcdB, and recombinant FZD2-CRD prevented TcdB binding to the colonic epithelium. Colonic organoids cultured from FZD7-knockout mice, combined with knockdown of FZD1 and 2, showed increased resistance to TcdB. The colonic epithelium in FZD7-knockout mice was less susceptible to TcdB-induced tissue damage in vivo. These findings establish FZDs as physiologically relevant receptors for TcdB in the colonic epithelium.


Assuntos
Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Colo/metabolismo , Epitélio/metabolismo , Receptores Frizzled/metabolismo , Animais , Antígenos/metabolismo , Proteínas de Bactérias/química , Toxinas Bacterianas/química , Sítios de Ligação , Células CHO , Sistemas CRISPR-Cas , Linhagem Celular , Clostridioides difficile/patogenicidade , Cricetulus , Feminino , Receptores Frizzled/química , Receptores Frizzled/deficiência , Receptores Frizzled/genética , Técnicas de Inativação de Genes , Humanos , Masculino , Camundongos , Camundongos Knockout , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Organoides/metabolismo , Domínios Proteicos , Proteoglicanas/metabolismo , Fatores de Virulência/metabolismo , Proteínas Wnt/metabolismo
16.
Pharmacology ; 107(9-10): 486-494, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35732157

RESUMO

INTRODUCTION: Abundant studies have disclosed that proteins can function as pivotal tumor promoters or suppressors in cancers' progression. This work was planned to investigate the regulatory function of N-myristoyltransferase-1 (NMT1) on non-small cell lung cancer (NSCLC) and the underlying molecular mechanisms. METHODS: The self-renewal abilities were assessed through a spheroid-formation assay. The tumorigenic abilities were examined through nude mice in vivo assay. The proteins' expression was measured through Western blot. The NMT1 protein expression in tumor tissues was measured through an IHC assay. The cell migration and invasion was confirmed through a transwell assay. The IC50 was verified through a CCK-8 assay. The NMT1 mRNA expression in NSCLC tissues was detected through RT-qPCR. RESULTS: It was demonstrated that NMT1 exhibited higher expression in spheroid cells. Additionally, NMT1 facilitated the stemness in NSCLC. It was also found that NMT1 accelerated NSCLC tumor metastasis and the resistance to cisplatin. Moreover, NMT1 activated the PI3K/AKT pathway to facilitate stemness in NSCLC. NMT1 was also higher in tumor tissues of NSCLC patients and resulted in a poor survival rate. CONCLUSION: NMT1 enhanced the stemness of NSCLC cells by activating the PI3K/AKT pathway. This discovery suggested that NMT1 may be a valid therapeutic biomarker for NSCLC.


Assuntos
Aciltransferases , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Aciltransferases/genética , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
17.
Mol Cell ; 52(2): 157-8, 2013 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-24210173

RESUMO

In this issue of Molecular Cell, Park and colleagues (Jung et al., 2013) show that PAF (PCNA-associated factor) binds to and hyperactivates transcriptional function of ß-catenin in colon cancer cells by recruiting EZH2 to the coactivator complex. PAF-ß-catenin and PAF-PCNA interactions are competitive, raising the question of whether ß-catenin might regulate PCNA-dependent DNA replication and repair.


Assuntos
Proteínas de Transporte/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Animais , Proteínas de Ligação a DNA , Proteína Potenciadora do Homólogo 2 de Zeste , Humanos
18.
Cancer Cell Int ; 20: 439, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32943987

RESUMO

BACKGROUND: KLF5 is a member of the Kruppel-like factor, subfamily of zinc finger proteins that are involved in cancers. KLF5 functions as a transcription factor and regulates the diverse protein-coding genes (PCGs) in colorectal cancer (CRC). However, the long non-coding RNAs (lncRNAs) regulated by KLF5 in CRC are currently unknown. METHODS: In this study, we first designed a computational pipeline to determine the PCG and lncRNA targets of KLF5 in CRC. Then we analyzed the motif pattern of the binding regions for the lncRNA targets. The regulatory co-factors of KLF5 were then searched for through bioinformatics analysis. We also constructed a regulatory network for KLF5 and annotated its functions. Finally, one of the KLF5 lncRNA targets, SNHG12, was selected to further explore its expression pattern and functions in CRC. RESULTS: We were able to identify 19 lncRNA targets of KLF5 and found that the motifs of the lncRNA binding sites were GC-enriched. Next, we pinpointed the transcription factors AR and HSF1 as the regulatory co-factors of KLF5 through bioinformatics analysis. Then, through the analysis of the regulatory network, we found that KLF5 may be involved in DNA replication, DNA repair, and the cell cycle. Furthermore, in the cell cycle module, the SNHG12 up-regulating expression pattern was verified in the CRC cell lines and tissues, associating it to CRC invasion and distal metastasis. This indicates that SNHG12 may play a critical part in CRC tumorigenesis and progression. Additionally, expression of SNHG12 was found to be down-regulated in CRC cell lines when KLF5 expression was knocked-down by siRNA; and a strong correlation was observed between the expression levels of SNHG12 and KLF5, further alluding to their regulatory relationship. CONCLUSIONS: In conclusion, the network analysis of KLF5 targets indicates that SNHG12 may be a significant lncRNA in CRC.

19.
Lipids Health Dis ; 18(1): 229, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881889

RESUMO

BACKGROUND: Hypertension is a highly prevalent disease and the leading cause of chronic kidney disease (CKD). Metabolic syndrome could also be the risk factor for CKD. We sought to study the association between metabolic syndrome components and the prevalence of CKD in patients with hypertension. METHODS: We carried out a multi-center cross-sectional study from Apr. 2017- Apr. 2018 in 15 cities in China. RESULTS: A total of 2484 patients with hypertension were enrolled. Among them, 56% were male and the average age was 65.12 ± 12.71 years. The systolic BP/diastolic BP was 142 ± 18/83 ± 12 mmHg. Metabolic syndrome components turned out to be highly prevalent in patients with hypertension, ranging from 40 to 58%. The prevalence of chronic kidney disease reached 22.0%. Multi-variate logistic analysis revealed that elevated triglyceride (TG) (OR = 1.81, 95% CI 1.28-2.57, p < 0.01), elevated fasting blood glucose (FBG) (OR = 1.43, 95% CI 1.00-2.07, p = 0.05) and hypertension grades (OR = 1.20, 95% CI 1.00-1.44, p = 0.05) were associated with the prevalence of CKD. In sub-group analysis, elevated TG remained strongly associated with CKD in both diabetes (OR = 2.10, 95%CI 1.22-3.61, p < 0.01) and non-diabetes (OR = 1.53, 95% CI 1.09-2.16, p = 0.01). In sub-group analysis of hypertension grades, there was also a graded trend between elevated TG and CKD from controlled blood pressure (BP) to hypertension grade 2 (OR = 1.81, 95%CI 1.06-3.11, p = 0.03; OR = 1.85, 95%CI 1.00-3.43, p = 0.05; OR = 2.81, 95% CI 1.09-7.28, p = 0.03, respectively). CONCLUSION: Elevated TG, elevated FBG and hypertension grades were significantly associated with the prevalence of CKD in patients with hypertension. Particularly, elevated TG was strongly associated with CKD, independent of diabetes and hypertension grades.


Assuntos
Hipertensão/sangue , Síndrome Metabólica/sangue , Insuficiência Renal Crônica/sangue , Triglicerídeos/sangue , Idoso , Glicemia , Pressão Sanguínea , Complicações do Diabetes/sangue , Complicações do Diabetes/patologia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , Hipertensão/patologia , Modelos Logísticos , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/patologia , Pessoa de Meia-Idade , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/patologia , Fatores de Risco
20.
BMC Geriatr ; 19(1): 222, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416442

RESUMO

BACKGROUND: Frailty is common and associated with poorer outcomes in the elderly, but its prognostic value in acute coronary syndromes (ACS) requires clarification. We thus undertook a systematic review and meta-analysis to evaluate the relationship between frailty and poor prognosis in patients with ACS. METHODS: We systematically searched PubMed, Embase to find literatures which studied the prognostic value of frailty in elderly patients with ACS. Our main endpoints were the all-cause mortality, cardiovascular disease (CVD), major bleeding and readmissions. We pooled studies using random-effect generic inverse variance method, and conducted three pre-specified subgroup analyses. RESULTS: Of 1216 identified studies, 15 studies were included in our analysis. Compared with the normal group, frailty (HR = 2.65; 95%CI: 1.81-3.89, I2 = 60.2%) and pre-frailty (HR = 1.41; 95%CI: 1.19-1.66, I2 = 0%) were characterized by a higher risk of mortality after adjustment. Frailty also was associated with increased risk of any-type CVD, major bleeding and hospital readmissions in elderly patients with ACS. The pooled effect sizes in frail patients were 1.54 (95%CI: 1.32-1.79), 1.51 (95%CI: 1.14-1.99) and 1.51 (95%CI: 1.09-2.10). CONCLUSIONS: Frailty provides quantifiable and significant prognostic value for mortality and adverse events in elderly ACS patients, helping doctors to appraise the comprehensive prognosis risk and to applicate appropriate management strategies.


Assuntos
Síndrome Coronariana Aguda/diagnóstico , Idoso Fragilizado , Fragilidade/diagnóstico , Síndrome Coronariana Aguda/mortalidade , Idoso , Idoso de 80 Anos ou mais , Fragilidade/mortalidade , Humanos , Readmissão do Paciente/tendências , Prognóstico
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