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1.
Nature ; 609(7927): 479-484, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36104555

RESUMEN

Studying strong electron correlations has been an essential driving force for pushing the frontiers of condensed matter physics. In particular, in the vicinity of correlation-driven quantum phase transitions (QPTs), quantum critical fluctuations of multiple degrees of freedom facilitate exotic many-body states and quantum critical behaviours beyond Landau's framework1. Recently, moiré heterostructures of van der Waals materials have been demonstrated as highly tunable quantum platforms for exploring fascinating, strongly correlated quantum physics2-22. Here we report the observation of tunable quantum criticalities in an experimental simulator of the extended Hubbard model with spin-valley isospins arising in chiral-stacked twisted double bilayer graphene (cTDBG). Scaling analysis shows a quantum two-stage criticality manifesting two distinct quantum critical points as the generalized Wigner crystal transits to a Fermi liquid by varying the displacement field, suggesting the emergence of a critical intermediate phase. The quantum two-stage criticality evolves into a quantum pseudo criticality as a high parallel magnetic field is applied. In such a pseudo criticality, we find that the quantum critical scaling is only valid above a critical temperature, indicating a weak first-order QPT therein. Our results demonstrate a highly tunable solid-state simulator with intricate interplay of multiple degrees of freedom for exploring exotic quantum critical states and behaviours.

2.
Blood ; 144(6): 657-671, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-38635773

RESUMEN

ABSTRACT: Pseudouridine is the most prevalent RNA modification, and its aberrant function is implicated in various human diseases. However, the specific impact of pseudouridylation on hematopoiesis remains poorly understood. Here, we investigated the role of transfer RNA (tRNA) pseudouridylation in erythropoiesis and its association with mitochondrial myopathy, lactic acidosis, and sideroblastic anemia syndrome (MLASA) pathogenesis. By using patient-specific induced pluripotent stem cells (iPSCs) carrying a genetic pseudouridine synthase 1 (PUS1) mutation and a corresponding mutant mouse model, we demonstrated impaired erythropoiesis in MLASA-iPSCs and anemia in the MLASA mouse model. Both MLASA-iPSCs and mouse erythroblasts exhibited compromised mitochondrial function and impaired protein synthesis. Mechanistically, we revealed that PUS1 deficiency resulted in reduced mitochondrial tRNA levels because of pseudouridylation loss, leading to aberrant mitochondrial translation. Screening of mitochondrial supplements aimed at enhancing respiration or heme synthesis showed limited effect in promoting erythroid differentiation. Interestingly, the mammalian target of rapamycin (mTOR) inhibitor rapamycin facilitated erythroid differentiation in MLASA-iPSCs by suppressing mTOR signaling and protein synthesis, and consistent results were observed in the MLASA mouse model. Importantly, rapamycin treatment partially ameliorated anemia phenotypes in a patient with MLASA. Our findings provide novel insights into the crucial role of mitochondrial tRNA pseudouridylation in governing erythropoiesis and present potential therapeutic strategies for patients with anemia facing challenges related to protein translation.


Asunto(s)
Eritropoyesis , Células Madre Pluripotentes Inducidas , Mitocondrias , ARN de Transferencia , Animales , Ratones , Humanos , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Mitocondrias/metabolismo , Mitocondrias/patología , Células Madre Pluripotentes Inducidas/metabolismo , Seudouridina/metabolismo , Anemia Sideroblástica/genética , Anemia Sideroblástica/metabolismo , Anemia Sideroblástica/patología , ARN Mitocondrial/genética , ARN Mitocondrial/metabolismo , Hidroliasas/metabolismo , Hidroliasas/genética , Síndrome MELAS/genética , Síndrome MELAS/patología , Síndrome MELAS/metabolismo , Modelos Animales de Enfermedad
3.
Circ Res ; 134(7): e17-e33, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38420756

RESUMEN

BACKGROUND: Microvascular complications are the major outcome of type 2 diabetes progression, and the underlying mechanism remains to be determined. METHODS: High-throughput RNA sequencing was performed using human monocyte samples from controls and diabetes. The transgenic mice expressing human CTSD (cathepsin D) in the monocytes was constructed using CD68 promoter. In vivo 2-photon imaging, behavioral tests, immunofluorescence, transmission electron microscopy, Western blot analysis, vascular leakage assay, and single-cell RNA sequencing were performed to clarify the phenotype and elucidate the molecular mechanism. RESULTS: Monocytes expressed high-level CTSD in patients with type 2 diabetes. The transgenic mice expressing human CTSD in the monocytes showed increased brain microvascular permeability resembling the diabetic microvascular phenotype, accompanied by cognitive deficit. Mechanistically, the monocytes release nonenzymatic pro-CTSD to upregulate caveolin expression in brain endothelium triggering caveolae-mediated transcytosis, without affecting the paracellular route of brain microvasculature. The circulating pro-CTSD activated the caveolae-mediated transcytosis in brain endothelial cells via its binding with low-density LRP1 (lipoprotein receptor-related protein 1). Importantly, genetic ablation of CTSD in the monocytes exhibited a protective effect against the diabetes-enhanced brain microvascular transcytosis and the diabetes-induced cognitive impairment. CONCLUSIONS: These findings uncover the novel role of circulatory pro-CTSD from monocytes in the pathogenesis of cerebral microvascular lesions in diabetes. The circulatory pro-CTSD is a potential target for the intervention of microvascular complications in diabetes.


Asunto(s)
Catepsina D , Diabetes Mellitus Tipo 2 , Monocitos , Animales , Humanos , Ratones , Encéfalo/metabolismo , Catepsina D/metabolismo , Catepsina D/farmacología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Precursores Enzimáticos , Ratones Transgénicos , Monocitos/metabolismo , Transcitosis/fisiología
4.
J Neurosci ; 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39060175

RESUMEN

Protein synthesis in response to neuronal activity, known as activity-dependent translation, is critical for synaptic plasticity and memory formation. However, the signaling cascades that couple neuronal activity to the translational events remains elusive. In this study, we identified the role of calmodulin (CaM), a conserved Ca2+-binding protein, in rRNA biogenesis in neurons. We found the CaM-regulated rRNA synthesis is Ca2+-dependent and necessary for nascent protein synthesis and axon growth in hippocampal neurons. Mechanistically, CaM interacts with nucleolar DDX21 in a Ca2+-dependent manner to regulate nascent rRNA transcription within nucleoli. We further found CaM alters the conformation of DDX21 to liberate the DDX21-sequestered RPA194, the catalytic subunit of RNA polymerase I, to facilitate transcription of rDNA. Using high-throughput screening, we identified the small molecules Batefenterol and Indacaterol that attenuate the CaM-DDX21 interaction and suppress nascent rRNA synthesis and axon growth in hippocampal neurons. These results unveiled the previously unrecognized role of CaM as a messenger to link the activity-induced Ca2+ influx to the nucleolar events essential for protein synthesis. We thus identified the ability of CaM to transmit information to the nucleoli of neurons in response to stimulation.Significance statement Protein synthesis in response to neuronal activity, known as activity-dependent translation, is critical for synaptic plasticity and long-term memory formation. In this study, we identify the novel role of calmodulin (CaM), a highly conserved Ca2+-binding protein, which is well-known by regulating myriad vital biological processes, in activity-dependent translation by regulating rRNA synthesis in neurons. We find that CaM can shuttle into the nucleolus upon depolarization and modulate the activity-induced de novo rRNA biogenesis, which is associated with ribosome assembly and protein synthesis in neurons. Mechanistically, CaM interacts with DDX21, an RNA helicase directly associated with Pol I subunit, to regulate the transcription of rDNA. Our study demonstrates CaM as a messenger linking neuronal activity to ribosome-dependent protein biosynthesis.

5.
Nat Mater ; 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664497

RESUMEN

In situ tailoring of two-dimensional materials' phases under external stimulus facilitates the manipulation of their properties for electronic, quantum and energy applications. However, current methods are mainly limited to the transitions among phases with unchanged chemical stoichiometry. Here we propose on-device phase engineering that allows us to realize various lattice phases with distinct chemical stoichiometries. Using palladium and selenide as a model system, we show that a PdSe2 channel with prepatterned Pd electrodes can be transformed into Pd17Se15 and Pd4Se by thermally tailoring the chemical composition ratio of the channel. Different phase configurations can be obtained by precisely controlling the thickness and spacing of the electrodes. The device can be thus engineered to implement versatile functions in situ, such as exhibiting superconducting behaviour and achieving ultralow-contact resistance, as well as customizing the synthesis of electrocatalysts. The proposed on-device phase engineering approach exhibits a universal mechanism and can be expanded to 29 element combinations between a metal and chalcogen. Our work highlights on-device phase engineering as a promising research approach through which to exploit fundamental properties as well as their applications.

6.
Nano Lett ; 24(13): 4044-4053, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38517749

RESUMEN

Fungal keratitis (FK) is an infectious eye disease that poses a significant risk of blindness. However, the effectiveness of conventional antifungal drugs is limited due to the intrinsic ocular barrier that impedes drug absorption. There is an urgent need to develop new therapeutic strategies to effectively combat FK. Herein, we synthesized an ultrasmall positively charged carbon dot using a simple stage-melting method. The carbon dot can penetrate the corneal barrier by opening the tight junctions, allowing them to reach the lesion site and effectively kill the fungi. The results both in vitro and in vivo demonstrated that it exhibited good biocompatibility and antifungal activity, significantly improving the therapeutic effect in a mouse model of FK. Therefore, this biophilic ultrasmall size and positive carbon dot, characterized by its ability to penetrate the corneal barrier and its antifungal properties, may offer valuable insights into the design of effective ocular nanomedicines.


Asunto(s)
Úlcera de la Córnea , Infecciones Fúngicas del Ojo , Queratitis , Animales , Ratones , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Queratitis/tratamiento farmacológico , Queratitis/microbiología , Úlcera de la Córnea/tratamiento farmacológico , Úlcera de la Córnea/microbiología , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/microbiología , Córnea/microbiología
7.
Nano Lett ; 24(1): 140-147, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-37982545

RESUMEN

Optical spatial differentiation is a typical operation of optical analog computing and can single out the edge to accelerate the subsequent image processing, but in some cases, overall information about the object needs to be presented synchronously. Here, we propose a multifunctional optical device based on structured chiral photonic crystals for the simultaneous realization of real-time dual-mode imaging. This optical differentiator is realized by self-organized large-birefringence cholesteric liquid crystals, which are photopatterned to encode with a special integrated geometric phase. Two highly spin-selective modes of second-order spatial differentiation and bright-field imaging are exhibited in the reflected and transmitted directions, respectively. Two-dimensional edges of both amplitude and phase objects have been efficiently enhanced in high contrast and the broadband spectrum. This work extends the ingenious building of hierarchical chiral nanostructures, enriches their applications in the emerging frontiers of optical computing, and boasts considerable potential in machine vision and microscopy.

8.
J Am Chem Soc ; 146(28): 19286-19294, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38956888

RESUMEN

As one of the most powerful trifluoromethylation reagents, (trifluoromethyl)trimethylsilane (TMSCF3) has been widely used for the synthesis of fluorine-containing molecules. However, to the best of our knowledge, the simultaneous incorporation of both TMS- and CF3- groups of this reagent onto the same carbon of the products has not been realized. Herein, we report an unprecedented SmI2/Sm promoted deoxygenative difunctionalization of amides with TMSCF3, in which both silyl and trifluoromethyl groups are incorporated into the final product, yielding α-silyl-α-trifluoromethyl amines with high efficiency. Notably, the silyl group could be further transformed into other functional groups, providing a new method for the synthesis of α-quaternary α-CF3-amines.

9.
Lab Invest ; 104(8): 102094, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38871058

RESUMEN

Accurate assessment of epidermal growth factor receptor (EGFR) mutation status and subtype is critical for the treatment of non-small cell lung cancer patients. Conventional molecular testing methods for detecting EGFR mutations have limitations. In this study, an artificial intelligence-powered deep learning framework was developed for the weakly supervised prediction of EGFR mutations in non-small cell lung cancer from hematoxylin and eosin-stained histopathology whole-slide images. The study cohort was partitioned into training and validation subsets. Foreground regions containing tumor tissue were extracted from whole-slide images. A convolutional neural network employing a contrastive learning paradigm was implemented to extract patch-level morphologic features. These features were aggregated using a vision transformer-based model to predict EGFR mutation status and classify patient cases. The established prediction model was validated on unseen data sets. In internal validation with a cohort from the University of Science and Technology of China (n = 172), the model achieved patient-level areas under the receiver-operating characteristic curve (AUCs) of 0.927 and 0.907, sensitivities of 81.6% and 83.3%, and specificities of 93.0% and 92.3%, for surgical resection and biopsy specimens, respectively, in EGFR mutation subtype prediction. External validation with cohorts from the Second Affiliated Hospital of Anhui Medical University and the First Affiliated Hospital of Wannan Medical College (n = 193) yielded patient-level AUCs of 0.849 and 0.867, sensitivities of 79.2% and 80.7%, and specificities of 91.7% and 90.7% for surgical and biopsy specimens, respectively. Further validation with the Cancer Genome Atlas data set (n = 81) showed an AUC of 0.861, a sensitivity of 84.6%, and a specificity of 90.5%. Deep learning solutions demonstrate potential advantages for automated, noninvasive, fast, cost-effective, and accurate inference of EGFR alterations from histomorphology. Integration of such artificial intelligence frameworks into routine digital pathology workflows could augment existing molecular testing pipelines.

10.
Anal Chem ; 96(17): 6784-6793, 2024 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-38632870

RESUMEN

Hepatitis B virus (HBV) is a major cause of liver cirrhosis and hepatocellular carcinoma, with HBV surface antigen (HBsAg) being a crucial marker in the clinical detection of HBV. Due to the significant harm and ease of transmission associated with HBV, HBsAg testing has become an essential part of preoperative assessments, particularly for emergency surgeries where healthcare professionals face exposure risks. Therefore, a timely and accurate detection method for HBsAg is urgently needed. In this study, a surface-enhanced Raman scattering (SERS) sensor with a sandwich structure was developed for HBsAg detection. Leveraging the ultrasensitive and rapid detection capabilities of SERS, this sensor enables quick detection results, significantly reducing waiting times. By systematically optimizing critical factors in the detection process, such as the composition and concentration of the incubation solution as well as the modification conditions and amount of probe particles, the sensitivity of the SERS immune assay system was improved. Ultimately, the sensor achieved a sensitivity of 0.00576 IU/mL within 12 min, surpassing the clinical requirement of 0.05 IU/mL by an order of magnitude. In clinical serum assay validation, the issue of false positives was effectively addressed by adding a blocker. The final sensor demonstrated 100% specificity and sensitivity at the threshold of 0.05 IU/mL. Therefore, this study not only designed an ultrasensitive SERS sensor for detecting HBsAg in actual clinical serum samples but also provided theoretical support for similar systems, filling the knowledge gap in existing literature.


Asunto(s)
Antígenos de Superficie de la Hepatitis B , Espectrometría Raman , Antígenos de Superficie de la Hepatitis B/sangre , Espectrometría Raman/métodos , Humanos , Virus de la Hepatitis B/aislamiento & purificación , Nanopartículas del Metal/química , Hepatitis B/sangre , Hepatitis B/diagnóstico , Propiedades de Superficie , Límite de Detección
11.
Genome Res ; 31(4): 622-634, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33722936

RESUMEN

Heterosis or hybrid vigor is a common phenomenon in plants and animals; however, the molecular mechanisms underlying heterosis remain elusive, despite extensive studies on the phenomenon for more than a century. Here we constructed a large collection of F1 hybrids of Saccharomyces cerevisiae by spore-to-spore mating between homozygous wild strains of the species with different genetic distances and compared growth performance of the F1 hybrids with their parents. We found that heterosis was prevalent in the F1 hybrids at 40°C. A hump-shaped relationship between heterosis and parental genetic distance was observed. We then analyzed transcriptomes of selected heterotic and depressed F1 hybrids and their parents growing at 40°C and found that genes associated with one-carbon metabolism and related pathways were generally up-regulated in the heterotic F1 hybrids, leading to improved cellular redox homeostasis at high temperature. Consistently, genes related with DNA repair, stress responses, and ion homeostasis were generally down-regulated in the heterotic F1 hybrids. Furthermore, genes associated with protein quality control systems were also generally down-regulated in the heterotic F1 hybrids, suggesting a lower level of protein turnover and thus higher energy use efficiency in these strains. In contrast, the depressed F1 hybrids, which were limited in number and mostly shared a common aneuploid parental strain, showed a largely opposite gene expression pattern to the heterotic F1 hybrids. We provide new insights into molecular mechanisms underlying heterosis and thermotolerance of yeast and new clues for a better understanding of the molecular basis of heterosis in plants and animals.


Asunto(s)
Carbono/metabolismo , Homeostasis , Calor , Vigor Híbrido , Saccharomyces cerevisiae , Homeostasis/genética , Vigor Híbrido/genética , Hibridación Genética , Oxidación-Reducción , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Regulación hacia Arriba
12.
Small ; 20(32): e2312135, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38501794

RESUMEN

Carbon fiber (CF) is a potential microwave absorption (MA) material due to the strong dielectric loss. Nevertheless, owing to the high conductivity, poor impedance matching of carbon-based  materials results in limited MA performance. How to solve this problem and achieve excellent MA performance remains a principal challenge. Herein, taking full advantage of CF and excellent impedance matching of bimetallic metal-organic frameworks (MOF) derivatives layer, an excellent microwave absorber based on micron-scale 1D CF and NiCoMOF (CF@NiCoMOF-800) is developed. After adjusting the oxygen vacancies of the bimetallic MOF, the resultant microwave absorber presented excellent MA properties including the minimum reflection loss (RLmin) of -80.63 dB and wide effective absorption bandwidth (EAB) of 8.01 GHz when its mass percent is only 5 wt.% and the thickness is 2.59 mm. Simultaneously, the mechanical properties of the epoxy resin (EP)-based coating with this microwave absorber are effectively improved. The hardness (H), elastic modulus (E), bending strength, and compressive strength of CF@NiCoMOF-800/EP coating are 334 MPa, 5.56 GPa, 82.2 MPa, and 135.8 MPa, which is 38%, 15%, 106% and 53% higher than EP coating. This work provides a promising solution for carbon materials achieving excellent MA properties and mechanical properties.

13.
Chemistry ; 30(44): e202401293, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-38828487

RESUMEN

Herein, we report a general copper-catalyzed method for the tunable oxygenative rearrangement of tetrahydrocarbazoles to cyclopentyl-bearing spiroindolin-2-ones and spiroindolin-3-ones. The method demonstrates excellent chemoselectivity, regioselectivity, and product control simply by using the H2O and O2 as oxygen source, respectively. This open-flask method is safe and simple to operate, and no other chemical oxidants are required. Besides, inspired from the unique pathway of 1, 2-migration rearrangement, a highly controllable hydroxylation of indoles for the construction of C3a-hydroxyl iminium indolines was also developed. Mechanistic experiments suggest that a single-electron transfer-induced oxidation process is responsible for the tunable selectivity control.

14.
Gastrointest Endosc ; 99(5): 667-675.e1, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38184117

RESUMEN

BACKGROUND AND AIMS: The aim of this study was to determine if utilization of artificial intelligence (AI) in the course of endoscopic procedures can significantly diminish both the adenoma miss rate (AMR) and the polyp miss rate (PMR) compared with standard endoscopy. METHODS: We performed an extensive search of various databases, encompassing PubMed, Embase, Cochrane Library, Web of Science, and Scopus, until June 2023. The search terms used were artificial intelligence, machine learning, deep learning, transfer machine learning, computer-assisted diagnosis, convolutional neural networks, gastrointestinal (GI) endoscopy, endoscopic image analysis, polyp, adenoma, and neoplasms. The main study aim was to explore the impact of AI on the AMR, PMR, and sessile serrated lesion miss rate. RESULTS: A total of 7 randomized controlled trials were included in this meta-analysis. Pooled AMR was markedly lower in the AI group versus the non-AI group (pooled relative risk [RR], .46; 95% confidence interval [CI], .36-.59; P < .001). PMR was also reduced in the AI group in contrast with the non-AI control (pooled RR, .43; 95% CI, .27-.69; P < .001). The results showed that AI decreased the miss rate of sessile serrated lesions (pooled RR, .43; 95% CI, .20 to .92; P < .05) and diminutive adenomas (pooled RR, .49; 95% CI, .26-.93) during endoscopy, but no significant effect was observed for advanced adenomas (pooled RR, .48; 95% CI, .17-1.37; P = .17). The average number of polyps (Hedges' g = -.486; 95% CI, -.697 to -.274; P = .000) and adenomas (Hedges' g = -.312; 95% CI, -.551 to -.074; P = .01) detected during the second procedure also favored AI. However, AI implementation did not lead to a prolonged withdrawal time (P > .05). CONCLUSIONS: This meta-analysis suggests that AI technology leads to significant reduction of miss rates for GI adenomas, polyps, and sessile serrated lesions during endoscopic surveillance. These results underscore the potential of AI to improve the accuracy and efficiency of GI endoscopic procedures.

15.
Langmuir ; 40(22): 11491-11503, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38770578

RESUMEN

Foam flooding is an important tool for reservoir development. This study aims to further investigate the interaction between stimulus-responsive wormlike micelle (WLM)-CO2 foams and crude oil. We performed micromorphology experiments as our major studies and used molecular dynamics simulations as an auxiliary tool for interfacial analysis. We utilized foam generation, liquid separation, and defoaming as the entry points of experimental research and energy as the quantitative assessment index to investigate the dynamic process of the action of different oil contents and oil phase types in a DOAPA@NaSal-H+ foam system. We also examined the role of NaSal in the generation and development of the foam system. Results indicated that the law of crude oil's effect on foam could be summarized as "low contents are beneficial and high contents are harmful." In addition, although the DOAPA@NaSal-H+ foam system has high compatibility for saturated and aromatic hydrocarbons, it is highly suitable for application in reservoir environments with relatively high asphaltene and resin contents. Through combined experimental and simulation approaches, we clarified the law governing the stability of the DOAPA@NaSal-H+ foam system in different oil-containing environments, identified the key role of NaSal, and provided a reference for the targeted application of the DOAPA@NaSal-H+ foam system in different oil reservoirs.

16.
Org Biomol Chem ; 22(4): 741-744, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38170630

RESUMEN

An unexpected isomerization of azomethine ylides generated in situ from isatin with indoline-2-carboxylic acid has been disclosed, providing direct access to N-functionalized indole scaffolds. This protocol has good functional group tolerance and provides various 3-(1H-indol-1-yl)indolin-2-one derivatives in moderate to high yields simply by using alcohol as the solvent, with no additional additive being required.

17.
Mol Biol Rep ; 51(1): 98, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38206538

RESUMEN

BACKGROUND: Mutations in the receptor tyrosine kinase KIT are the main cause of gastrointestinal stromal tumor (GIST), and the KIT mutants mediated PI3 kinase activation plays a key role in the tumorigenesis of GIST. In this study, we aimed to block PI3 kinase activation by cell-permeable peptide and investigate its possible application in the treatment of GIST. METHODS AND RESULTS: We designed cell-permeable peptides based on the binding domain of PI3 kinase subunit p85 to KIT or PI3 kinase subunit p110, respectively, in order to compete for the binding between p85 and KIT or p110 and therefore inhibit the activation of PI3 kinases mediated by KIT. The results showed that the peptide can penetrate the cells, and inhibit the activation of PI3 kinases, leading to reduced cell survival and cell proliferation mediated by KIT mutants in vitro. Treatment of mice carrying germline KIT/V558A mutation, which can develop GIST, with the peptide that can compete for the binding between p85 and p110, led to reduced tumorigenesis of GIST. The peptide can further enhance the inhibition of the tumor growth by imatinib which is used as the first line targeted therapy of GIST. CONCLUSIONS: Our results showed that cell-permeable PI3 kinase competitive peptide can inhibit KIT-mediated PI3 kinase activation and tumorigenesis of GIST, providing a rationale to further test the peptide in the treatment of GIST and even other tumors with over-activation of PI3 kinases.


Asunto(s)
Tumores del Estroma Gastrointestinal , Fosfatidilinositol 3-Quinasas , Animales , Ratones , Fosfatidilinositol 3-Quinasas/genética , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/genética , Carcinogénesis/genética , Transformación Celular Neoplásica , Fosfatidilinositol 3-Quinasa , Péptidos/farmacología
18.
Mol Biol Rep ; 51(1): 159, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38252346

RESUMEN

BACKGROUND: Due to the global increase in aging populations and changes in modern lifestyles, the prevalence of neurodegenerative diseases, cerebrovascular disorders, neuropsychiatrcic conditions, and related ailments is rising, placing an increasing burden on the global public health system. MATERIALS AND METHODS: All studies on tetramethylpyrazine (TMP) and its derivatives were obtained from reputable sources such as PubMed, Elsevier, Library Genesis, and Google Scholar. Comprehensive data on TMP and its derivatives was meticulously compiled. RESULTS: This comprehensive analysis explains the neuroprotective effects demonstrated by TMP and its derivatives in diseases of the central nervous system. These compounds exert their influence on various targets and signaling pathways, playing crucial roles in the development of various central nervous system diseases. Their multifaceted mechanisms include inhibiting oxidative damage, inflammation, cell apoptosis, calcium overload, glutamate excitotoxicity, and acetylcholinesterase activity. CONCLUSION: This review provides a brief summary of the most recent advancements in research on TMP and its derivatives in the context of central nervous system diseases. It involves synthesizing analogs of TMP and evaluating their effectiveness in models of central nervous system diseases. The ultimate goal is to facilitate the practical application of TMP and its derivatives in the future treatment of central nervous system diseases.


Asunto(s)
Enfermedades del Sistema Nervioso Central , Neuroprotección , Humanos , Acetilcolinesterasa , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Pirazinas/farmacología , Pirazinas/uso terapéutico
19.
J Biochem Mol Toxicol ; 38(4): e23686, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38549433

RESUMEN

Part of human long noncoding RNAs (lncRNAs) has been elucidated to play an essential role in the carcinogenesis and progression of hepatocellular carcinoma (HCC), a type of malignant tumor with poor outcomes. Tumor-derived exosomes harboring lncRNAs have also been implicated as crucial mediators to orchestrate biological functions among neighbor tumor cells. The recruitment of tumor-associated macrophages (TAMs) exerting M2-like phenotype usually indicates the poor prognosis. Yet, the precise involvement of tumor-derived lncRNAs in cross-talk with environmental macrophages has not been fully identified. In this study, we reported the aberrantly overexpressed HCC upregulated EZH2-associated lncRNA (HEIH) in tumor tissues and cell lines was positively correlated with poor prognosis, as well as enriched exosomal HEIH levels in blood plasma and cell supernatants. Besides, HCC cell-derived exosomes transported HEIH into macrophages for triggering macrophage M2 polarization, thereby in turn promoting the proliferation, migration, and invasion of HCC cells. Mechanistically, HEIH acted as a miRNA sponge for miR-98-5p to up-regulate STAT3, which was then further verified in the tumor xenograft models. Collectively, our study provides the evidence for recognizing tumor-derived exosomal lncRNA HEIH as a novel regulatory function through targeting miR-98-5p/STAT3 axis in environmental macrophages, which may shed light on the complicated tumor microenvironment among tumor and immune cells for HCC treatment.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroARNs , ARN Largo no Codificante , Humanos , Carcinoma Hepatocelular/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neoplasias Hepáticas/metabolismo , Línea Celular Tumoral , Macrófagos/metabolismo , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Microambiente Tumoral , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo
20.
J Phys Chem A ; 128(27): 5298-5306, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38917472

RESUMEN

The identification of the non-noble metal constituted TaO cluster as a potential analogue to the noble metal Au is significant for the development of tailored materials. It leverages the superatom concept to engineer properties with precision. However, the impact of incrementally integrating TaO units on the electronic configurations and properties within larger TaO-based clusters remains to be elucidated. By employing the density functional theory calculations, the global minima and low-lying isomers of the TanOn (n = 2-5) clusters were determined, and their structural evolution was disclosed. In the cluster series, Ta5O5 was found to possess the highest electron affinity (EA) with a value of 2.14 eV, based on which a dual external field (DEF) strategy was applied to regulate the electronic property of the cluster. Initially, the electron-withdrawing CO ligand was affixed to Ta5O5, followed by the application of an oriented external electric field (OEEF). The CO ligation was found to be able to enhance the Ta5O5 cluster's electron capture capability by adjusting its electron energy levels, with the EA of Ta5O5(CO)4 peaking at 2.58 eV. Subsequently, the introduction of OEEF further elevated the EA of the CO-ligated cluster. Notably, OEEF, when applied along the +x axis, was observed to sharply increase the EA to 3.26 eV, meeting the criteria for superhalogens. The enhancement of EA in response to OEEF intensity can be quantified as a functional relationship. This finding highlights the advantage of OEEF over conventional methods, demonstrating its capacity for precise and continuous modulation of cluster EAs. Consequently, this research has adeptly transformed tantalum oxide clusters into superhalogen structures, underscoring the effectiveness of the DEF strategy in augmenting cluster EAs and its promise as a viable tool for the creation of superhalogens.

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