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1.
Proc Natl Acad Sci U S A ; 121(20): e2321260121, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38722807

RESUMO

Protein capsids are a widespread form of compartmentalization in nature. Icosahedral symmetry is ubiquitous in capsids derived from spherical viruses, as this geometry maximizes the internal volume that can be enclosed within. Despite the strong preference for icosahedral symmetry, we show that simple point mutations in a virus-like capsid can drive the assembly of unique symmetry-reduced structures. Starting with the encapsulin from Myxococcus xanthus, a 180-mer bacterial capsid that adopts the well-studied viral HK97 fold, we use mass photometry and native charge detection mass spectrometry to identify a triple histidine point mutant that forms smaller dimorphic assemblies. Using cryoelectron microscopy, we determine the structures of a precedented 60-mer icosahedral assembly and an unexpected 36-mer tetrahedron that features significant geometric rearrangements around a new interaction surface between capsid protomers. We subsequently find that the tetrahedral assembly can be generated by triple-point mutation to various amino acids and that even a single histidine point mutation is sufficient to form tetrahedra. These findings represent a unique example of tetrahedral geometry when surveying all characterized encapsulins, HK97-like capsids, or indeed any virus-derived capsids reported in the Protein Data Bank, revealing the surprising plasticity of capsid self-assembly that can be accessed through minimal changes in the protein sequence.


Assuntos
Proteínas do Capsídeo , Capsídeo , Microscopia Crioeletrônica , Mutação Puntual , Capsídeo/metabolismo , Capsídeo/química , Capsídeo/ultraestrutura , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Myxococcus xanthus/genética , Myxococcus xanthus/metabolismo , Modelos Moleculares
2.
Proc Natl Acad Sci U S A ; 121(19): e2313590121, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38683978

RESUMO

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Exossomos , Músculo Esquelético , Exossomos/metabolismo , Animais , Músculo Esquelético/metabolismo , Músculo Esquelético/inervação , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Camundongos , Fibronectinas/metabolismo , Neurônios Motores/metabolismo , Interleucina-6/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Neurônios/metabolismo , Fatores de Crescimento Neural/metabolismo , Miocinas
3.
Plant Physiol ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39028839

RESUMO

The involvement of nuclear factor Y (NF-Y) in transcriptional reprogramming during arbuscular mycorrhizal symbiosis has been demonstrated in several plant species. However, a comprehensive picture is lacking. We showed that the spatial expression of NF-YC3 was observed in cortical cells containing arbuscules via the cis-regulatory element GCC boxes. Moreover, the NF-YC3 promoter was transactivated by the combination of CYCLOPS and autoactive calcium and calmodulin-dependent kinase (CCaMK) via GCC boxes. Knockdown of NF-YC3 significantly reduced the abundance of all intraradical fungal structures and affected arbuscule size. BCP1, SbtM1, and WRI5a, whose expression associated with NF-YC3 levels, might be downstream of NF-YC3. NF-YC3 interacted with NF-YB3a, NF-YB5c, or NF-YB3b, in yeast (Saccharomyces cerevisiae) and in planta, and interacted with NF-YA3a in yeast. Spatial expression of three NF-YBs was observed in all cell layers of roots under both mock and mycorrhizal conditions. Simultaneous knockdown of three NF-YBs, but not individually, reduced the fungal colonization level, suggesting that there might be functional redundancy of NF-YBs to regulate AM symbiosis. Collectively, our data suggest that NF-YC3 and NF-YBs positively regulate AM symbiosis in tomato, and arbuscule-related NF-YC3 may be an important downstream gene of the common symbiosis signaling pathway.

4.
Nano Lett ; 24(5): 1808-1815, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38198566

RESUMO

The novel depth-sensing system presented here revolutionizes structured light (SL) technology by employing metasurfaces and photonic crystal surface-emitting lasers (PCSELs) for efficient facial recognition in monocular depth-sensing. Unlike conventional dot projectors relying on diffractive optical elements (DOEs) and collimators, our system projects approximately 45,700 infrared dots from a compact 297-µm-dimention metasurface, drastically more spots (1.43 times) and smaller (233 times) than the DOE-based dot projector in an iPhone. With a measured field-of-view (FOV) of 158° and a 0.611° dot sampling angle, the system is lens-free and lightweight and boasts lower power consumption than vertical-cavity surface-emitting laser (VCSEL) arrays, resulting in a 5-10 times reduction in power. Utilizing a GaAs-based metasurface and a simplified optical architecture, this innovation not only addresses the drawbacks of traditional SL depth-sensing but also opens avenues for compact integration into wearable devices, offering remarkable advantages in size, power efficiency, and potential for widespread adoption.

5.
Biophys J ; 123(8): 931-939, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38454599

RESUMO

Guanosine monophosphate (GMP) is a nucleotide that can self-assemble in aqueous solution under certain conditions. An understanding of the process at the molecular level is an essential step to comprehend the involvement of DNA substructures in transcription and replication, as well as their relationship to genetic diseases such as cancer. We present the temperature-dependent terahertz (1.5-12 THz, 50-400 cm-1) absorptivity spectra of aqueous Na2 GMP solution in comparison with the aqueous solutions of other RNA nucleotides. Distinct absorption features were observed in the spectrum of GMP, which we attribute to the intramolecular modes of the self-assemblies (i.e., G-complexes) that, at 1 M, start to form at 313 K and below. Changes in broad-band features of the terahertz spectrum were also observed, which we associate with the release of hydration water in the temperature-dependent formation of guanine quadruplexes. Using a state-of-the-art THz calorimetry approach correlating spectroscopic to thermodynamic changes, we propose a molecular mechanism of hydrophilic hydration driving GMP self-assembly as a function of temperature. The free energy contribution of hydrophilic hydration is shown as a decisive factor in guanine-quadruplex formation. Our findings spotlight the role of hydration in the formation of macromolecular structures and suggest the potential of hydration tuning for regulating DNA transcription and replication.


Assuntos
Quadruplex G , Guanosina Monofosfato , Guanosina Monofosfato/química , Água/química , Nucleotídeos , DNA/química
6.
BMC Bioinformatics ; 25(1): 95, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438950

RESUMO

BACKGROUND: Dynamical compensation (DC) provides robustness to parameter fluctuations. As an example, DC enables control of the functional mass of endocrine or neuronal tissue essential for controlling blood glucose by insulin through a nonlinear feedback loop. Researchers have shown that DC is related to the structural unidentifiability and the P -invariance property. The P -invariance property is a sufficient and necessary condition for the DC property. DC has been seen in systems with at least three dimensions. In this article, we discuss DC and P -invariance from an adaptive control perspective. An adaptive controller automatically adjusts its parameters to optimise performance, maintain stability, and deal with uncertainties in a system. RESULTS: We initiate our analysis by introducing a simplified two-dimensional dynamical model with DC, fostering experimentation and understanding of the system's behavior. We explore the system's behavior with time-varying input and disturbance signals, with a focus on illustrating the system's P -invariance properties in phase portraits and step-like response graphs. CONCLUSIONS: We show that DC can be seen as a case of ideal adaptive control since the system is invariant to the compensated parameter.


Assuntos
Insulina , Projetos de Pesquisa , Pesquisa Empírica , Incerteza
7.
Eur J Neurosci ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992988

RESUMO

The involvement of inwardly rectifying potassium channel 4.1 (Kir4.1) in neuropathic pain has been established. However, there is limited understanding of the downstream mechanism through which Kir4.1 contributes to orofacial neuropathic pain. The objective of this study was to examine the regulation of Kir4.1 on the expression of pannexin 3 (Panx3) in the trigeminal ganglion (TG) and the underlying mechanism in the context of orofacial neuropathic pain caused by chronic constriction injury of the infraorbital nerve (CCI-ION). The study observed a significant increase in Panx3 expression in the TG of mice with CCI-ION. Inhibition of Panx3 in the TG of CCI-ION mice resulted in alleviation of orofacial mechanical allodynia. Furthermore, conditional knockdown (CKD) of Kir4.1 in the TG of both male and female mice led to mechanical allodynia and upregulation of Panx3 expression. Conversely, overexpression of Kir4.1 decreased Panx3 levels in the TG and relieved mechanical allodynia in CCI-ION mice. In addition, silencing Kir4.1 in satellite glial cells (SGCs) decreased Panx3 expression and increased the phosphorylation of P38 MAPK. Moreover, silencing Kir4.1 in SGCs increased the levels of reactive oxygen species (ROS). The elevated phosphorylation of P38 MAPK resulting from Kir4.1 silencing was inhibited by using a superoxide scavenger known as the tempol. Silencing Panx3 in the TG in vivo attenuated the mechanical allodynia caused by Kir4.1 CKD. In conclusion, these findings suggest that the reduction of Kir4.1 promotes the expression of Panx3 by activating the ROS-P38 MAPK signalling pathway, thus contributing to the development of orofacial neuropathic pain.

8.
Opt Lett ; 49(5): 1305-1308, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426999

RESUMO

Temperature characteristics of GaN-based laser diodes are investigated. It is noted that the characteristic temperature of the threshold current (T0) decreases with decreasing lasing wavelength for GaN-based LDs. The performance deteriorates seriously for UV LDs at high temperature. It is ascribed to the increase of carriers escaping from quantum wells due to the lower potential barrier height. In this Letter, AlGaN is used as the barrier layer in UV LDs instead of GaN to improve the temperature characteristic of the threshold current and slope efficiency by increasing the potential barrier height of quantum wells. Based on this structure, a high output power of 4.6 W is obtained at the injection current of 3.8 A; its lasing wavelength is 386.8 nm.

9.
Cancer Cell Int ; 24(1): 262, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048994

RESUMO

BACKGROUND: This study investigated the molecular mechanism of long intergenic non-protein coding RNA 1605 (LINC01605) in the process of tumor growth and liver metastasis of pancreatic ductal adenocarcinoma (PDAC). METHODS: LINC01605 was filtered out with specificity through TCGA datasets (related to DFS) and our RNA-sequencing data of PDAC tissue samples from Renji Hospital. The expression level and clinical relevance of LINC01605 were then verified in clinical cohorts and samples by immunohistochemical staining assay and survival analysis. Loss- and gain-of-function experiments were performed to estimate the regulatory effects of LINC01605 in vitro. RNA-seq of LINC01605-knockdown PDAC cells and subsequent inhibitor-based cellular function, western blotting, immunofluorescence and rescue experiments were conducted to explore the mechanisms by which LINC01605 regulates the behaviors of PDAC tumor cells. Subcutaneous xenograft models and intrasplenic liver metastasis models were employed to study its role in PDAC tumor growth and liver metastasis in vivo. RESULTS: LINC01605 expression is upregulated in both PDAC primary tumor and liver metastasis tissues and correlates with poor clinical prognosis. Loss and gain of function experiments in cells demonstrated that LINC01605 promotes the proliferation and migration of PDAC cells in vitro. In subsequent verification experiments, we found that LINC01605 contributes to PDAC progression through cholesterol metabolism regulation in a LIN28B-interacting manner by activating the mTOR signaling pathway. Furthermore, the animal models showed that LINC01605 facilitates the proliferation and metastatic invasion of PDAC cells in vivo. CONCLUSIONS: Our results indicate that the upregulated lncRNA LINC01605 promotes PDAC tumor cell proliferation and migration by regulating cholesterol metabolism via activation of the mTOR signaling pathway in a LIN28B-interacting manner. These findings provide new insight into the role of LINC01605 in PDAC tumor growth and liver metastasis as well as its value for clinical approaches as a metabolic therapeutic target in PDAC.

10.
Reprod Biol Endocrinol ; 22(1): 78, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987797

RESUMO

OBJECTIVE: To explore the optimal models for predicting the formation of high-quality embryos in Poor Ovarian Response (POR) Patients with Progestin-Primed Ovarian Stimulation (PPOS) using machine learning algorithms. METHODS: A retrospective analysis was conducted on the clinical data of 4,216 POR cycles who underwent in vitro fertilization (IVF) / intracytoplasmic sperm injection (ICSI) at Sichuan Jinxin Xinan Women and Children's Hospital from January 2015 to December 2021. Based on the presence of high-quality cleavage embryos 72 h post-fertilization, the samples were divided into the high-quality cleavage embryo group (N = 1950) and the non-high-quality cleavage embryo group (N = 2266). Additionally, based on whether high-quality blastocysts were observed following full blastocyst culture, the samples were categorized into the high-quality blastocyst group (N = 124) and the non-high-quality blastocyst group (N = 1800). The factors influencing the formation of high-quality embryos were analyzed using logistic regression. The predictive models based on machine learning methods were constructed and evaluated accordingly. RESULTS: Differential analysis revealed that there are statistically significant differences in 14 factors between high-quality and non-high-quality cleavage embryos. Logistic regression analysis identified 14 factors as influential in forming high-quality cleavage embryos. In models excluding three variables (retrieved oocytes, MII oocytes, and 2PN fertilized oocytes), the XGBoost model performed slightly better (AUC = 0.672, 95% CI = 0.636-0.708). Conversely, in models including these three variables, the Random Forest model exhibited the best performance (AUC = 0.788, 95% CI = 0.759-0.818). In the analysis of high-quality blastocysts, significant differences were found in 17 factors. Logistic regression analysis indicated that 13 factors influence the formation of high-quality blastocysts. Including these variables in the predictive model, the XGBoost model showed the highest performance (AUC = 0.813, 95% CI = 0.741-0.884). CONCLUSION: We developed a predictive model for the formation of high-quality embryos using machine learning methods for patients with POR undergoing treatment with the PPOS protocol. This model can help infertility patients better understand the likelihood of forming high-quality embryos following treatment and help clinicians better understand and predict treatment outcomes, thus facilitating more targeted and effective interventions.


Assuntos
Aprendizado de Máquina , Indução da Ovulação , Progestinas , Humanos , Feminino , Indução da Ovulação/métodos , Estudos Retrospectivos , Adulto , Gravidez , Progestinas/farmacologia , Fertilização in vitro/métodos , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/fisiologia , Injeções de Esperma Intracitoplásmicas/métodos , Blastocisto/efeitos dos fármacos , Blastocisto/fisiologia , Transferência Embrionária/métodos , Taxa de Gravidez
11.
BMC Cancer ; 24(1): 925, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39085796

RESUMO

BACKGROUND: Lung adenocarcinoma is a high-mortality rate cancer. Within this category, Lung mucinous adenocarcinoma (LMAC) is a rare and distinct subtype of lung adenocarcinoma necessitating further investigation. The study was launched to compare the difference of survival features between LMAC and lung non-mucinous adenocarcinoma (LNMAC) and to investigate the significance and demand for developing a new staging system tailored to LMAC. METHODS: This retrospective study assessed the suitableness of the current staging system for LMAC. It compared the overall survival (OS) between LMAC and LNMAC from 2004 to 2020 (LNMAC: 160,387; LMAC: 6,341) and instituted a novel classification framework for LMAC based on US population. Verification group consisting of patients from two Chinese medical centers from 2010 to 2018 (n = 392) was set to ascertain the applicability of this novel system. The primary endpoint was OS. To minimize the bias, propensity score match (PSM) was employed. Survival analysis and Log-rank test were executed to explore the survival features of LMAC. RESULTS: The results indicated that the existed staging system was not suitable for LMAC. Patients diagnosed with LMAC exhibited a superior OS compared to those with LNMAC in stage IA2 (P < 0.0001), IA3 (P < 0.0001), IB (P = 0.0062), IIA (P = 0.0090), IIB (P = 0.0005). In contrast, a worse OS in stage IVA (P = 0.0103) was found in LMAC patients. The novel classification system proposed for LMAC proved to be highly applicable and demonstrated substantial efficacy, as confirmed by the verification group. CONCLUSION: The newly established classification system was more effective for LMAC, but it necessitates large-scale verification to confirm its applicability and reliability.


Assuntos
Adenocarcinoma de Pulmão , Adenocarcinoma Mucinoso , Neoplasias Pulmonares , Estadiamento de Neoplasias , Humanos , Estadiamento de Neoplasias/métodos , Masculino , Feminino , Estudos Retrospectivos , Adenocarcinoma Mucinoso/patologia , Adenocarcinoma Mucinoso/mortalidade , Pessoa de Meia-Idade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/mortalidade , Idoso , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/mortalidade , Adulto , Prognóstico , Análise de Sobrevida
12.
Int J Legal Med ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39060444

RESUMO

In Chinese criminal law, the ages of 12, 14, 16, and 18 years old play a significant role in the determination of criminal responsibility. In this study, we developed an epiphyseal grading system based on magnetic resonance image (MRI) of the hand and wrist for the Chinese Han population and explored the feasibility of employing deep learning techniques for bone age assessment based on MRI of the hand and wrist. This study selected 282 Chinese Han Chinese males aged 6.0-21.0 years old. In the course of our study, we proposed a novel deep learning model for extracting and enhancing MRI hand and wrist bone features to enhance the prediction of target MRI hand and wrist bone age and achieve precise classification of the target MRI and regression of bone age. The evaluation metric for the classification model including precision, specificity, sensitivity, and accuracy, while the evaluation metrics chosen for the regression model are MAE. The epiphyseal grading was used as a supervised method, which effectively solved the problem of unbalanced sample distribution, and the two experts showed strong consistency in the epiphyseal plate grading process. In the classification results, the accuracy in distinguishing between adults and minors was 91.1%, and the lowest accuracy in the three minor classifications (12, 14, and 16 years of age) was 94.6%, 91.1% and 96.4%, respectively. The MAE of the regression results was 1.24 years. In conclusion, the deep learning model proposed enabled the age assessment of hand and wrist bones based on MRI.

13.
Org Biomol Chem ; 22(30): 6095-6102, 2024 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-39007293

RESUMO

Bicyclic peptides are a powerful modality for engaging challenging drug targets such as protein-protein interactions. Here, we use 1,2,3-tris(bromomethyl)benzene (1,2,3-TBMB) to access bicyclic peptides with diverse conformations that differ from conventional bicyclisation products formed with 1,3,5-TBMB. Bicyclisation at cysteine residues under aqueous buffer conditions proceeds efficiently, with broad substrate scope, compatibility with high-throughput screening, and clean conversion (>90%) for 96 of the 115 peptides tested. We envisage that the 1,2,3-TBMB linker will be applicable to a variety of peptide screening techniques in drug discovery.


Assuntos
Peptídeos Cíclicos , Peptídeos Cíclicos/química , Peptídeos Cíclicos/síntese química , Conformação Proteica , Derivados de Benzeno/química , Ciclização
14.
J Pept Sci ; 30(5): e3562, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38148630

RESUMO

The non-POU domain-containing octamer-binding protein (NONO) is a nucleic acid-binding protein with diverse functions that has been identified as a potential cancer target in cell biology studies. Little is known about structural motifs that mediate binding to NONO apart from its ability to form homodimers, as well as heterodimers and oligomers with related homologues. We report a stapling approach to macrocyclise helical peptides derived from the insulin-like growth factor binding protein (IGFBP-3) that NONO interacts with, and also from the dimerisation domain of NONO itself. Using a range of chemistries including Pd-catalysed cross-coupling, cysteine arylation and cysteine alkylation, we successfully improved the helicity and observed modest peptide binding to the NONO dimer, although binding could not be saturated at micromolar concentrations. Unexpectedly, we observed cell permeability and preferential nuclear localisation of various dye-labelled peptides in live confocal microscopy, indicating the potential for developing peptide-based tools to study NONO in a cellular context.


Assuntos
Proteínas de Ligação a DNA , Proteínas de Ligação a RNA , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Cisteína , Peptídeos/metabolismo , Permeabilidade
15.
Bioorg Chem ; 142: 106925, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37890213

RESUMO

Thirty new tricyclicmatrinic derivatives were successively synthesized and evaluated for their inhibitory activity on the accumulation of triglycerides (TG) in AML12 cells, using 12 N-m-trifluoromethylbenzenesulfonyl matrine (1) as the hit compound. Among the analogues, compound 7n possessing 11-trimethylbutylamine quaternary exerted the highest in vitro TG-lowering potency, as well as a good safety profile. 7n significantly attenuated the hepatic injury and steatosis, and ameliorated dyslipidemia and dysglycemia in the mice with non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet. Primary mechanism study revealed that upregulation of peroxisome proliferator-activated receptors α (PPARα)-carnitine palmitoyltransferase 1A (CPT1A) pathway mediated the efficacy of 7n. Our study provides powerful information for developing this kind of compound into a new class of anti-NAFLD candidates, and compound 7n is worthy of further investigation as an ideal lead compound.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Matrinas , Triglicerídeos/metabolismo , Fígado/metabolismo , PPAR alfa/metabolismo , Camundongos Endogâmicos C57BL
16.
Acta Pharmacol Sin ; 45(4): 844-856, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38057506

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy prone to recurrence and metastasis. Studies show that tumor cells with increased invasive and metastatic potential are more likely to undergo ferroptosis. SMAD4 is a critical molecule in the transforming growth factor ß (TGF-ß) pathway, which affects the TGF-ß-induced epithelial-mesenchymal transition (EMT) status. SMAD4 loss is observed in more than half of patients with PDAC. In this study, we investigated whether SMAD4-positive PDAC cells were prone to ferroptosis because of their high invasiveness. We showed that SMAD4 status almost determined the orientation of transforming growth factor ß1 (TGF-ß1)-induced EMT via the SMAD4-dependent canonical pathway in PDAC, which altered ferroptosis vulnerability. We identified glutathione peroxidase 4 (GPX4), which inhibited ferroptosis, as a SMAD4 down-regulated gene by RNA sequencing. We found that SMAD4 bound to the promoter of GPX4 and decreased GPX4 transcription in PDAC. Furthermore, TGF-ß1-induced high invasiveness enhanced sensitivity of SMAD4-positive organoids and pancreas xenograft models to the ferroptosis inducer RAS-selective lethal 3 (RSL3). Moreover, SMAD4 enhanced the cytotoxic effect of gemcitabine combined with RSL3 in highly invasive PDAC cells. This study provides new ideas for the treatment of PDAC, especially SMAD4-positive PDAC.


Assuntos
Carcinoma Ductal Pancreático , Ferroptose , Neoplasias Pancreáticas , Proteína Smad4 , Fator de Crescimento Transformador beta1 , Humanos , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteína Smad4/genética , Proteína Smad4/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
17.
J Chem Phys ; 160(21)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38828818

RESUMO

Here, we report the frequency-dependent spectrum of ice Ih in the range of 0.2-2 THz. We confirm the presence of a feature that blue-shifts from around 1.55-1.65 THz with a decreasing temperature from 260 to 160 K. There is also a change in the trend of the refractive index of ice corresponding to a dispersion, which is also around 1.6 THz. The features are reproduced in data acquired with three commercial terahertz time-domain spectrometers. Computer-simulated spectra assign the feature to lattice translations perpendicular to the 110 and 1̄10 planes of the ice Ih crystal. The feature's existence should be recognized in the terahertz measurements of frozen aqueous solution samples to avoid false interpretations.

18.
Proc Natl Acad Sci U S A ; 118(37)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34493676

RESUMO

Body-centered cubic metals including steels and refractory metals suffer from an abrupt ductile-to-brittle transition (DBT) at a critical temperature, hampering their performance and applications. Temperature-dependent dislocation mobility and dislocation nucleation have been proposed as the potential factors responsible for the DBT. However, the origin of this sudden switch from toughness to brittleness still remains a mystery. Here, we discover that the ratio of screw dislocation velocity to edge dislocation velocity is a controlling factor responsible for the DBT. A physical model was conceived to correlate the efficiency of Frank-Read dislocation source with the relative mobility of screw versus edge dislocations. A sufficiently high relative mobility is a prerequisite for the coordinated movement of screw and edge segments to sustain dislocation multiplication. Nanoindentation experiments found that DBT in chromium requires a critical mobility ratio of 0.7, above which the dislocation sources transition from disposable to regeneratable ones. The proposed model is also supported by the experimental results of iron, tungsten, and aluminum.

19.
Am J Otolaryngol ; 45(2): 104206, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38141564

RESUMO

PURPOSE: There has been mounting evidence that inflammation is a key risk factor towards the development of certain cancers. Past studies have shown associations between nasopharyngeal carcinoma (NPC) and sinonasal tract inflammation. We aim to conduct a review and meta-analysis on the association between NPC and chronic sinus inflammation. MATERIALS AND METHODS: We conducted a meta-analysis, searching 4 international databases from 1 January 1973 to 28 March 2022 for studies reporting on sinonasal inflammation and NPC in adult patients (>18 years old). We included cohort, case-control or cross-sectional studies. These studies must examine the association between a prior history of sinonasal inflammation and the risk of developing NPC. The outcome is the incidence of NPC in patients who had prior sinonasal inflammation. RESULTS: 8 studies (8245 NPC; 1,036,087 non-NPC) were included. The overall odds ratio (OR) of patients having NPC after reporting sinonasal inflammation was 1.81 (95 % CI 1.73-1.89). Of note, chronic rhinosinusitis (CRS) (OR of 1.78 (95 %-CI: 1.68-1.90)) was more closely associated with an increased risk of NPC, as compared to allergic rhinitis (AR) (OR of 1.60 (95 %-CI: 1.52-1.68)). CONCLUSION: Chronic sinonasal inflammation is significantly associated with NPC in this systemic review and meta-analysis. The true cause-effect relationship and the potential effects of targeted screening need to be explored thoroughly with large scale prospective studies.

20.
Hu Li Za Zhi ; 71(1): 99-104, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38253858

RESUMO

Empowerment not only benefits patients but also provides support and assistance to their family members, especially in cases when patients are subject to custodial protection sentences. The positive effects of empowerment on patients' family members may be summarized into three main aspects, including: enhancing their engagement in healthcare, alleviating their anxiety, and enhancing their caregiving skills. With regard to enhancing engagement in healthcare, family members receive health education that provides an overview of the illness, treatment options, prognosis, and key nursing points and allows them to better understand the patient's condition and actively participate in decision-making. With regard to alleviating anxiety, patients under custodial protection sentences are involved in legal problems, which results in higher levels of stress for family members compared to their peers caring for general patients. Through emotional support and active listening, nurses provide opportunities for family members to express their concerns and offer comfort and encouragement, helping them cope with difficulties and pressures. With regard to enhancing caregiving skills, the purpose of custodial protection sentences is to prevent recidivism, and family members bear significant responsibility for caregiving after discharge. Nurses can share similar caregiving experiences from their ward, educate family members about observing symptoms, and provide guidance, thereby strengthening their caregiving capabilities. In addition, with regard to the disposition of patients, nurses assist family members to understand the medical process and provide necessary guidance, ensuring family members have a clear understanding and are respected during the preparations for discharge. Based on related theoretical frameworks and practical experiences, this research highlights the positive role of empowerment in enhancing the caregiving abilities and satisfaction of the family members of patients, particularly those subject to custodial protection sentences.


Assuntos
Ansiedade , Família , Humanos , Educação em Saúde , Hospitais , Alta do Paciente
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