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1.
Int J Biol Sci ; 20(7): 2640-2657, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38725843

RESUMEN

Esophageal carcinoma is amongst the prevalent malignancies worldwide, characterized by unclear molecular classifications and varying clinical outcomes. The PI3K/AKT/mTOR signaling, one of the frequently perturbed dysregulated pathways in human malignancies, has instigated the development of various inhibitory agents targeting this pathway, but many ESCC patients exhibit intrinsic or adaptive resistance to these inhibitors. Here, we aim to explore the reasons for the insensitivity of ESCC patients to mTOR inhibitors. We assessed the sensitivity to rapamycin in various ESCC cell lines by determining their respective IC50 values and found that cells with a low level of HMGA1 were more tolerant to rapamycin. Subsequent experiments have supported this finding. Through a transcriptome sequencing, we identified a crucial downstream effector of HMGA1, FKBP12, and found that FKBP12 was necessary for HMGA1-induced cell sensitivity to rapamycin. HMGA1 interacted with ETS1, and facilitated the transcription of FKBP12. Finally, we validated this regulatory axis in in vivo experiments, where HMGA1 deficiency in transplanted tumors rendered them resistance to rapamycin. Therefore, we speculate that mTOR inhibitor therapy for individuals exhibiting a reduced level of HMGA1 or FKBP12 may not work. Conversely, individuals exhibiting an elevated level of HMGA1 or FKBP12 are more suitable candidates for mTOR inhibitor treatment.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Proteína HMGA1a , Inhibidores mTOR , Proteína Proto-Oncogénica c-ets-1 , Humanos , Línea Celular Tumoral , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/genética , Proteína Proto-Oncogénica c-ets-1/metabolismo , Proteína Proto-Oncogénica c-ets-1/genética , Carcinoma de Células Escamosas de Esófago/metabolismo , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/patología , Proteína HMGA1a/metabolismo , Proteína HMGA1a/genética , Inhibidores mTOR/farmacología , Inhibidores mTOR/uso terapéutico , Proteína 1A de Unión a Tacrolimus/metabolismo , Proteína 1A de Unión a Tacrolimus/genética , Animales , Sirolimus/farmacología , Sirolimus/uso terapéutico , Transducción de Señal/efectos de los fármacos , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/tratamiento farmacológico , Serina-Treonina Quinasas TOR/metabolismo , Ratones , Ratones Desnudos
2.
J Hypertens ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38690935

RESUMEN

OBJECTIVE: Proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to vascular remodeling. Asprosin, a newly discovered protein hormone, is involved in metabolic diseases. Little is known about the roles of asprosin in cardiovascular diseases. This study focused on the role and mechanism of asprosin on VSMC proliferation and migration, and vascular remodeling in a rat model of hypertension. METHODS AND RESULTS: VSMCs were obtained from the aortic media of 8-week-old male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Asprosin was upregulated in the VSMCs of SHR. For in vitro studies, asprosin promoted VSMC proliferation and migration of WKY and SHR, and increased Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity, NOX1/2/4 protein expressions and superoxide production. Knockdown of asprosin inhibited the proliferation, migration, NOX activity, NOX1/2 expressions and superoxide production in the VSMCs of SHR. The roles of asprosin in promoting VSMC proliferation and migration were not affected by hydrogen peroxide scavenger, but attenuated by superoxide scavenger, selective NOX1 or NOX2 inhibitor. Toll-like receptor 4 (TLR4) was upregulated in SHR, TLR4 knockdown inhibited asprosin overexpression-induced proliferation, migration and oxidative stress in VSMCs of WKY and SHR. Asprosin was upregulated in arteries of SHR, and knockdown of asprosin in vivo not only attenuated oxidative stress and vascular remodeling in aorta and mesentery artery, but also caused a subsequent persistent antihypertensive effect in SHR. CONCLUSIONS: Asprosin promotes VSMC proliferation and migration via NOX-mediated superoxide production. Inhibition of endogenous asprosin expression attenuates VSMC proliferation and migration, and vascular remodeling of SHR.

3.
Curr Med Sci ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748368

RESUMEN

OBJECTIVE: Ferritin, initially acting as an iron-storage protein, was found to be associated with metabolic diseases. Our study was designed to investigate the association between serum ferritin and metabolic-associated fatty liver disease (MAFLD) using data from the National Health and Nutrition Examination Survey (NHANES) of the United State of America. METHODS: A cross-sectional study was conducted, enrolling a total of 2145 participants from the NHANES in the 2017-2018 cycles. Hepatic steatosis and liver fibrosis were assessed by ultrasound images and several non-invasive indexes. Multiple regression analysis was conducted to determine the associations between serum ferritin concentration and MAFLD and liver fibrosis. RESULTS: The analysis revealed that participants with higher serum ferritin levels (Q3 and Q4 groups) had a higher prevalence of MAFLD than those with the lowest serum ferritin levels [Q3 vs. Q1: OR=2.17 (1.33, 3.53), P<0.05 in fatty liver index (FLI); Q4 vs. Q1: OR=3.13 (1.91, 5.13), P<0.05 in FLI]. Additionally, participants with the highest serum ferritin levels (Q4 group) displayed a higher prevalence of liver fibrosis [Q4 vs. Q1: OR=2.59 (1.19, 5.62), P<0.05 in liver stiffness measurement; OR=5.06 (1.12, 22.94), P<0.05 in fibrosis-4 index], with significantly increased risk observed in participants with concomitant diabetes [OR=7.45 (1.55, 35.72), P=0.012]. CONCLUSION: Our study revealed that elevated serum ferritin levels are associated with a higher prevalence of MAFLD and advanced liver fibrosis in patients. Elevated serum ferritin levels combined with diabetes are important risk factors for liver fibrosis.

4.
Nat Chem Biol ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720107

RESUMEN

Whether stem-cell-like cancer cells avert ferroptosis to mediate therapy resistance remains unclear. In this study, using a soft fibrin gel culture system, we found that tumor-repopulating cells (TRCs) with stem-cell-like cancer cell characteristics resist chemotherapy and radiotherapy by decreasing ferroptosis sensitivity. Mechanistically, through quantitative mass spectrometry and lipidomic analysis, we determined that mitochondria metabolic kinase PCK2 phosphorylates and activates ACSL4 to drive ferroptosis-associated phospholipid remodeling. TRCs downregulate the PCK2 expression to confer themselves on a structural ferroptosis-resistant state. Notably, in addition to confirming the role of PCK2-pACSL4(T679) in multiple preclinical models, we discovered that higher PCK2 and pACSL4(T679) levels are correlated with better response to chemotherapy and radiotherapy as well as lower distant metastasis in nasopharyngeal carcinoma cohorts.

5.
Front Bioeng Biotechnol ; 12: 1371851, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38699432

RESUMEN

Purpose: This study investigates the impact of elastic improvements to the artificial ankle joint insert on prosthesis biomechanics to reduce the risk of prosthesis loosening in TAR patients. Methods: CT data of the right ankle was collected from one elderly female volunteer. An original TAR model (Model A) was developed from CT images and the INBONE II implant system. The development of the new inserts adopts an elastic improvement design approach, where different geometric configurations of flexible layers are inserted into the traditional insert. The structure can be divided into continuous flexible layers and intermittent flexible layers. The flexible layers aim to improve the elasticity of the component by absorbing and dispersing more kinetic energy. The newly designed inserts are used to replace the original insert in Model A, resulting in the development of Models B-D. A finite element model of gait analysis was based by gait parameters. Discrepancies in micromotion and contact behaviour were analysed during the gait cycle, along with interface fretting and articular surface stress at 50% of the gait cycle. Results: In terms of micromotion, the improved elastic models showed reduced micromotion at the tibial-implant interfaces compared to the original model. The peak average micromotion decreased by 12.1%, 13.1%, and 14.5% in Models B, C, and D, respectively. The micromotion distribution also improved in the improved models, especially in Model D. Regarding contact areas, all models showed increased contact areas of articular surfaces with axial load, with Models B, C, and D increasing by 26.8%, 23.9%, and 24.4%, respectively. Contact stress on articular surfaces increased with axial load, reaching peak stress during the late stance phase. Models with continuous flexible layer designs exhibited lower stress levels. The insert and the talar prosthetic articular surfaces showed more uniform stress distribution in the improved models. Conclusion: Improving the elasticity of the insert can enhance component flexibility, absorb impact forces, reduce micromotion, and improve contact behavior. The design scheme of continuous flexible layers is more advantageous in transmitting and dispersing stress, providing reference value for insert improvement.

6.
Nature ; 629(8010): 74-79, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38693415

RESUMEN

Within the family of two-dimensional dielectrics, rhombohedral boron nitride (rBN) is considerably promising owing to having not only the superior properties of hexagonal boron nitride1-4-including low permittivity and dissipation, strong electrical insulation, good chemical stability, high thermal conductivity and atomic flatness without dangling bonds-but also useful optical nonlinearity and interfacial ferroelectricity originating from the broken in-plane and out-of-plane centrosymmetry5-23. However, the preparation of large-sized single-crystal rBN layers remains a challenge24-26, owing to the requisite unprecedented growth controls to coordinate the lattice orientation of each layer and the sliding vector of every interface. Here we report a facile methodology using bevel-edge epitaxy to prepare centimetre-sized single-crystal rBN layers with exact interlayer ABC stacking on a vicinal nickel surface. We realized successful accurate fabrication over a single-crystal nickel substrate with bunched step edges of the terrace facet (100) at the bevel facet (110), which simultaneously guided the consistent boron-nitrogen bond orientation in each BN layer and the rhombohedral stacking of BN layers via nucleation near each bevel facet. The pure rhombohedral phase of the as-grown BN layers was verified, and consequently showed robust, homogeneous and switchable ferroelectricity with a high Curie temperature. Our work provides an effective route for accurate stacking-controlled growth of single-crystal two-dimensional layers and presents a foundation for applicable multifunctional devices based on stacked two-dimensional materials.

7.
Research (Wash D C) ; 7: 0359, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38694199

RESUMEN

Porous substrates act as open "interfacial reactors" during the synthesis of polyamide composite membranes via interfacial polymerization. However, achieving a thin and dense polyamide nanofilm with high permeance and selectivity is challenging when using a conventional substrate with uniform wettability. To overcome this limitation, we propose the use of Janus porous substrates as confined interfacial reactors to decouple the local monomer concentration from the total monomer amount during interfacial polymerization. By manipulating the location of the hydrophilic/hydrophobic interface in a Janus porous substrate, we can precisely control the monomer solution confined within the hydrophilic layer without compromising its concentration. The hydrophilic surface ensures the uniform distribution of monomers, preventing the formation of defects. By employing Janus substrates fabricated through single-sided deposition of polydopamine/polyethyleneimine, we significantly reduce the thickness of the polyamide nanofilms from 88.4 to 3.8 nm by decreasing the thickness of the hydrophilic layer. This reduction leads to a remarkable enhancement in water permeance from 7.2 to 52.0 l/m2·h·bar while still maintaining ~96% Na2SO4 rejection. The overall performance of this membrane surpasses that of most reported membranes, including state-of-the-art commercial products. The presented strategy is both simple and effective, bringing ultrapermeable polyamide nanofilms one step closer to practical separation applications.

8.
Biomed Pharmacother ; 175: 116643, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38696988

RESUMEN

Accumulated alterations in metabolic control provide energy and anabolic demands for enhanced cancer cell proliferation. Exemplified by the Warburg effect, changes in glucose metabolism during cancer progression are widely recognized as a characteristic of metabolic disorders. Since telomerases are a vital factor in maintaining DNA integrity and stability, any damage threatening telomerases could have a severe impact on DNA and, subsequently, whole-cell homeostasis. However, it remains unclear whether the regulation of glucose metabolism in cancer is connected to the regulation of telomerase. In this review, we present the latest insights into the crosstalk between telomerase function and glucose metabolism in cancer cells. However, at this moment this subject is not well investigated that the association is mostly indirectly regulations and few explicit regulating pathways were identified between telomerase and glucose metabolism. Therefore, the information presented in this review can provide a scientific basis for further research on the detail mechanism and the clinical application of cancer therapy, which could be valuable in improving the effectiveness of chemotherapy.

9.
Front Neurosci ; 18: 1181670, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38737099

RESUMEN

Given its high morbidity, disability, and mortality rates, ischemic stroke (IS) is a severe disease posing a substantial public health threat. Although early thrombolytic therapy is effective in IS treatment, the limited time frame for its administration presents a formidable challenge. Upon occurrence, IS triggers an ischemic cascade response, inducing the brain to generate endogenous protective mechanisms against excitotoxicity and inflammation, among other pathological processes. Stroke patients often experience limited recovery stages. As a result, activating their innate self-protective capacity [endogenous brain protection (EBP)] is essential for neurological function recovery. Acupuncture has exhibited clinical efficacy in cerebral ischemic stroke (CIS) treatment by promoting the human body's self-preservation and "Zheng Qi" (a term in traditional Chinese medicine (TCM) describing positive capabilities such as self-immunity, self-recovery, and disease prevention). According to research, acupuncture can modulate astrocyte activity, decrease oxidative stress (OS), and protect neurons by inhibiting excitotoxicity, inflammation, and apoptosis via activating endogenous protective mechanisms within the brain. Furthermore, acupuncture was found to modulate microglia transformation, thereby reducing inflammation and autoimmune responses, as well as promoting blood flow restoration by regulating the vasculature or the blood-brain barrier (BBB). However, the precise mechanism underlying these processes remains unclear. Consequently, this review aims to shed light on the potential acupuncture-induced endogenous neuroprotective mechanisms by critically examining experimental evidence on the preventive and therapeutic effects exerted by acupuncture on CIS. This review offers a theoretical foundation for acupuncture-based stroke treatment.

10.
Sci Rep ; 14(1): 9287, 2024 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-38653771

RESUMEN

The Mycobacterium tuberculosis complex (MTBC) comprises nine human-adapted lineages that differ in their geographical distribution. Local adaptation of specific MTBC genotypes to the respective human host population has been invoked in this context. We aimed to assess if bacterial genetics governs MTBC pathogenesis or if local co-adaptation translates into differential susceptibility of human macrophages to infection by different MTBC genotypes. We generated macrophages from cryopreserved blood mononuclear cells of Tanzanian tuberculosis patients, from which the infecting MTBC strains had previously been phylogenetically characterized. We infected these macrophages ex vivo with a phylogenetically similar MTBC strain ("matched infection") or with strains representative of other MTBC lineages ("mismatched infection"). We found that L1 infections resulted in a significantly lower bacterial burden and that the intra-cellular replication rate of L2 strains was significantly higher compared the other MTBC lineages, irrespective of the MTBC lineage originally infecting the patients. Moreover, L4-infected macrophages released significantly greater amounts of TNF-α, IL-6, IL-10, MIP-1ß, and IL-1ß compared to macrophages infected by all other strains. While our results revealed no measurable effect of local adaptation, they further highlight the strong impact of MTBC phylogenetic diversity on the variable outcome of the host-pathogen interaction in human tuberculosis.


Asunto(s)
Macrófagos , Mycobacterium tuberculosis , Filogenia , Tuberculosis , Humanos , Tanzanía , Macrófagos/microbiología , Macrófagos/inmunología , Macrófagos/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/inmunología , Tuberculosis/microbiología , Tuberculosis/inmunología , Citocinas/metabolismo , Interacciones Huésped-Patógeno/inmunología , Interacciones Huésped-Patógeno/genética , Adulto , Masculino , Femenino , Genotipo
11.
Zhongguo Zhong Yao Za Zhi ; 49(3): 789-797, 2024 Feb.
Artículo en Chino | MEDLINE | ID: mdl-38621883

RESUMEN

This study aims to investigate the effect and mechanism of Fuyu Decoction(FYD) in the treatment of myocardial fibrosis in the rat model of heart failure(HF). Sixty Wistar rats were randomized into a modeling group(n=50) and a sham group(n=10). A post-myocardial infarction HF model was established by ligating the left anterior descending coronary artery in rats. The successfully modeled rats were assigned into model, low-dose(2.5 g·kg~(-1)) FYD(FYD-L), high-dose(5.0 g·kg~(-1)) FYD(FYD-H), and FYD+Nrf2 inhibitor(ML385, 30 mg·kg~(-1)) groups(n=10). FYD was administrated by gavage and ML385 by intraperitoneal injection. The rats in the sham and model groups were administrated with equal amounts of normal saline by gavage. After 8 weeks of intervention, the cardiac function indicators were measured, and the myocardial tissue morphology and collagen deposition were observed. The positive expression of collagens Ⅰ and Ⅲ, apoptosis, and oxidative stress were examined, and the levels of Fe~(2+) and reactive oxygen species(ROS) were determined. The protein levels of nuclear factor erythroid 2-related factor 2(Nrf2), solute carrier family 7 member 11(SLC7A11), glutathione peroxidase 4(GPX4), and acyl-coenzyme A synthase long chain family member 4(ACSL4) in the myocardial tissue were determined. Compared with sham group, the model group showed decreased left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), increased left ventricular end internal dimension in systole(LVIDs), left ventricular internal diameter in diastole(LVIDd), and myocardial collagen deposition, positive expression of collagens Ⅰ and Ⅲ, elevated apoptosis rate and malondialdehyde(MDA), Fe~(2+), and ROS levels, lowered superoxide dismutase(SOD) and glutathione peroxidase(GSH) levels, down-regulated protein levels of Nrf2, SLC7A11, and GPX4, and up-regulated protein level of ACSL4. Compared with the model group, the above indicators were restored by FYD. Moreover, ML385 reversed the protective effect of FYD on myocardial fibrosis in HF rats. In conclusion, FYD can inhibit ferroptosis by activating the Nrf2/GPX4 pathway, thereby ameliorating myocardial fibrosis in HF rats.


Asunto(s)
Ferroptosis , Insuficiencia Cardíaca , Ratas , Animales , Ratas Sprague-Dawley , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Volumen Sistólico , Especies Reactivas de Oxígeno , Función Ventricular Izquierda , Ratas Wistar , Insuficiencia Cardíaca/tratamiento farmacológico , Fibrosis , Colágeno/farmacología
12.
Soft Matter ; 20(19): 3987-3995, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38686608

RESUMEN

To elucidate the effect of aromatic side chains on dilational rheological properties of N-acyltaurate amphiphiles at the decane-water interface, the interfacial rheological properties of sodium N-2-(2-naphthoxy)-tetradecanoyltaurinate (12+N-T) and sodium N-2-(p-butylphenoxy)-tetradecanoyltaurinate (12+4B-T) were investigated utilizing the drop shape analysis method. The effects of adsorption time, interfacial pressure, oscillating frequency, and bulk concentration on the interfacial dilational modulus and phase angle were explored. The results show that the 12+4B-T molecule with a longer hydrophobic chain shows a higher ability for reducing the interfacial tension (IFT). In addition, the interfacial films of both 12+N-T and 12+4B-T are dominated by diffusion exchange at high concentrations. The rigidity of molecules controls the diffusion exchange at low concentrations, while the molecular hydrodynamic radius determines the diffusion exchange at high concentrations. Thus, at low concentrations, the stronger intermolecular interaction between 12+4B-T molecules results in higher dilational modulus values than 12+N-T. When approaching the CMC (critical micelle concentration) value, the rapid diffusion exchange of 12+4B-T between the sublayer micelles and the interface causes a significant decrease in the dilational modulus, while the relatively rigid structure of 12+N-T enables a higher dilational modulus than 12+4B-T. What's more, the longer hydrophobic chain allows 12+4B-T molecules to escape from the interface more easily, resulting in a higher phase angle at low concentrations. However, the diffusion exchange of 12+4B-T is slower than that of 12+N-T, which results in lower phase angles for 12+4B-T than 12+N-T at high concentrations. In general, the introduction of a rigid naphthalene ring in the molecular structure gives the interfacial film greater strength at high concentration. The research results in this paper provide a new technique for the strength regulation of interfacial surfactant adsorption films.

13.
World J Gastrointest Oncol ; 16(4): 1281-1295, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38660643

RESUMEN

BACKGROUND: Gastric cancer (GC) is the fifth most common and the fourth most lethal malignant tumour in the world. Most patients are already in the advanced stage when they are diagnosed, which also leads to poor overall survival. The effect of postoperative adjuvant chemotherapy for advanced GC is unsatisfactory with a high rate of distant metastasis and local recurrence. AIM: To investigate the safety and efficacy of a programmed cell death 1 (PD-1) inhibitor combined with oxaliplatin and S-1 (SOX) in the treatment of Borrmann large type III and IV GCs. METHODS: A retrospective analysis (IRB-2022-371) was performed on 89 patients with Borrmann large type III and IV GCs who received neoadjuvant therapy (NAT) from January 2020 to December 2021. According to the different neoadjuvant treatment regimens, the patients were divided into the SOX group (61 patients) and the PD-1 + SOX (P-SOX) group (28 patients). RESULTS: The pathological response (tumor regression grade 0/1) in the P-SOX group was significantly higher than that in the SOX group (42.86% vs 18.03%, P = 0.013). The incidence of ypN0 in the P-SOX group was higher than that in the SOX group (39.29% vs 19.67%, P = 0.05). The use of PD-1 inhibitors was an independent factor affecting tumor regression grade. Meanwhile, the use of PD-1 did not increase postoperative complications or the adverse effects of NAT. CONCLUSION: A PD-1 inhibitor combined with SOX could significantly improve the rate of tumour regression during NAT for patients with Borrmann large type III and IV GCs.

14.
World J Microbiol Biotechnol ; 40(5): 163, 2024 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-38613659

RESUMEN

Biotin, also known as vitamin H or B7, acts as a crucial cofactor in the central metabolism processes of fatty acids, amino acids, and carbohydrates. Biotin has important applications in food additives, biomedicine, and other fields. While the ability to synthesize biotin de novo is confined to microorganisms and plants, humans and animals require substantial daily intake, primarily through dietary sources and intestinal microflora. Currently, chemical synthesis stands as the primary method for commercial biotin production, although microbial biotin production offers an environmentally sustainable alternative with promising prospects. This review presents a comprehensive overview of the pathways involved in de novo biotin synthesis in various species of microbes and insights into its regulatory and transport systems. Furthermore, diverse strategies are discussed to improve the biotin production here, including mutation breeding, rational metabolic engineering design, artificial genetic modification, and process optimization. The review also presents the potential strategies for addressing current challenges for industrial-scale bioproduction of biotin in the future. This review is very helpful for exploring efficient and sustainable strategies for large-scale biotin production.


Asunto(s)
Aminoácidos , Biotina , Animales , Humanos , Biotecnología , Ácidos Grasos , Aditivos Alimentarios
16.
Mol Divers ; 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38647989

RESUMEN

The pyridine moiety is a crucial structural component in various pharmaceuticals. While the direct ortho- and para-functionalization of pyridines is relatively straightforward, the meta-selective C-H functionalization remains a significant challenge. This review highlights dearomatization strategies as a key area of interest in expanding the application of meta-C-H functionalization of pyridines. Dearomatization enables the meta-functionalization through various catalytic methods that directly generate dearomatization products, and some products can be rearomatized back to pyridine derivatives. Furthermore, this article also covers the dearomatization of multiple positions of pyridine in the synthesis of polycyclic compounds. It offers a comprehensive overview of the latest advancements in dearomatization at different positions of pyridine, aiming to provide a valuable resource for researchers in this field. It also highlights the advantages and limitations of existing technologies, aiming to inform a broader audience about this important field and foster its future development.

17.
Front Immunol ; 15: 1325998, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38601166

RESUMEN

Background: The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives. Method: The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined. Results: The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36. Conclusion: This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.


Asunto(s)
Hipersensibilidad , Vacunas , Animales , Humanos , Conejos , Epítopos de Linfocito B , Leucocitos Mononucleares , Inteligencia Artificial , Inmunoglobulina E , Proteínas de Artrópodos , Hipersensibilidad/terapia , Alérgenos , Pyroglyphidae , Dermatophagoides pteronyssinus , Citocinas/metabolismo , Inmunoglobulina G
18.
J Phys Chem B ; 128(15): 3732-3741, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38568211

RESUMEN

Using nanobubbles as geometrical confinements, we create a thin water film (∼10 nm) in a graphene liquid cell and investigate the evolution of its instability at the nanoscale under transmission electron microscopy. The breakdown of the water films, resulting in the subsequent formation and growth of nanodroplets, is visualized and generalized into different modes. We identified distinct droplet formation and growth modes by analyzing the dynamic processes involving 61 droplets and 110 liquid bridges within 31 Graphene Liquid Cells (GLCs). Droplet formation is influenced by their positions in GLCs, taking on a semicircular shape at the edge and a circular shape in the middle. Growth modes include liquid mass transfer driven by Plateau-Rayleigh instability and merging processes in and out-of-plane of the graphene interface. Droplet growth can lead to the formation of liquid bridges for which we obtain multiview projections. Data analysis reveals the general dynamics of liquid bridges, including drawing liquids from neighboring residual water films, merging with surrounding droplets, and merging with other liquid bridges. Our experimental observations provide insights into fluid transport at the nanoscale.

19.
Adv Mater ; : e2400075, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38597782

RESUMEN

Designing nanocomposite hydrogels with oriented nanosheets has emerged as a promising toolkit to achieve preferential performances that go beyond their disordered counterparts. Although current fabrication strategies via electric/magnetic force fields have made remarkable achievements, they necessitate special properties of nanosheets and suffer from an inferior orientation degree of nanosheets. Herein, a facile and universal approach is discovered to elaborate MXene-based nanocomposite hydrogels with highly oriented, heterogeneous architecture by virtue of supergravity to replace conventional force fields. The key to such architecture is to leverage bidirectional, force-tunable attributes of supergravity containing coupled orthogonal shear and centrifugal force field for steering high-efficient movement, pre-orientation, and stacking of MXene nanosheets in the bottom. Such a synergetic effect allows for yielding heterogeneous nanocomposite hydrogels with a high-orientation MXene-rich layer (orientation degree, f = 0.83) and a polymer-rich layer. The authors demonstrate that MXene-based nanocomposite hydrogels leverage their high-orientation, heterogeneous architecture to deliver an extraordinary electromagnetic interference shielding effectiveness of 55.2 dB at 12.4 GHz yet using a super-low MXene of 0.3 wt%, surpassing most hydrogels-based electromagnetic shielding materials. This versatile supergravity-steered strategy can be further extended to arbitrary nanosheets including MoS2, GO, and C3N4, offering a paradigm in the development of oriented nanocomposites.

20.
Nat Prod Res ; : 1-10, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38635344

RESUMEN

Bioassay-guided purification of the xanthine oxidase (XOD) inhibitory extract of the roots of Ampelopsis japonica resulted in the isolation of two new triterpenoids (1-2), designated Ampejaponoside A and B, along with sixteen known compounds (3-18). The structures of Ampejaposide A and B were elucidated by comprehensive analysis of spectroscopic data with the structures of the known compounds 3-18 confirmed by comparison the spectral data with corresponding values reported in literatures. All the isolates were evaluated for their XOD inhibitory activity in vitro. As a result, compounds 2, 8, and 14-16 displayed significant XOD inhibitory effect, particularly 16 being the most potent with an IC50 value of 0.21 µM, superior to positive substance allopurinol (IC50 1.95 µM). Molecular docking uncovered a unique interaction mode of 16 with the active site of XOD. The current study showed that the triterpenoids and polyphenols from A. japonica could serve as new lead compounds with the potential to speed up the development of novel XOD inhibitors with clinical potential to treat hyperuricaemia and gout.

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