Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 129
Filtrar
1.
Cell ; 186(10): 2193-2207.e19, 2023 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-37098343

RESUMEN

Somatic hypermutation (SHM), initiated by activation-induced cytidine deaminase (AID), generates mutations in the antibody-coding sequence to allow affinity maturation. Why these mutations intrinsically focus on the three nonconsecutive complementarity-determining regions (CDRs) remains enigmatic. Here, we found that predisposition mutagenesis depends on the single-strand (ss) DNA substrate flexibility determined by the mesoscale sequence surrounding AID deaminase motifs. Mesoscale DNA sequences containing flexible pyrimidine-pyrimidine bases bind effectively to the positively charged surface patches of AID, resulting in preferential deamination activities. The CDR hypermutability is mimicable in in vitro deaminase assays and is evolutionarily conserved among species using SHM as a major diversification strategy. We demonstrated that mesoscale sequence alterations tune the in vivo mutability and promote mutations in an otherwise cold region in mice. Our results show a non-coding role of antibody-coding sequence in directing hypermutation, paving the way for the synthetic design of humanized animal models for optimal antibody discovery and explaining the AID mutagenesis pattern in lymphoma.


Asunto(s)
Citidina Desaminasa , Hipermutación Somática de Inmunoglobulina , Animales , Ratones , Anticuerpos/genética , Citidina Desaminasa/genética , Citidina Desaminasa/metabolismo , ADN/genética , ADN de Cadena Simple , Mutación , Evolución Molecular , Regiones Determinantes de Complementariedad/genética , Motivos de Nucleótidos
2.
BMC Microbiol ; 24(1): 422, 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39438834

RESUMEN

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections poses global challenges, with limited options available for targeted therapy. Polymyxin was been regarded as one of the most important last-resort antimicrobial agents. Many factors could accelerate the resistance evolution of polymyxin. Insertion sequence (IS) inserted into mgrB is the main polymyxin resistance mechanism in K. pneumoniae. In this study, two CRKPs (KP31157 and KP31311) were isolated from the urine of a patient, shifting from susceptible to resistant as the mgrB inserted by ISkpn14. We intended to explore the origin of the IS and underlying mechanisms resulting in polymyxin resistance. METHODS: The within-host evolution relationship and molecular features of both CRKPs were determined by pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). pKP31311_KPC-2 plasmid genome structures contained in the above two CRKPs were aligned with the homologic plasmids, retrieved from the NCBI genome database via comparative genomic analysis. The plasmids encoding ISkpn14 elements flanked by direct repeat (DR) or not were analyzed. The mRNA expression, plasmid curing and in vitro antibiotics inducing experiment were employed to understand the potential mechanism of polymyxin resistance. RESULTS: Both strains, sharing homology, exhibited polymyxin resistance due to the insertion of ISkpn14 into the mgrB gene, influenced by minocycline exposure. Minocycline and tigecycline could accelerate polymyxin resistance (P < 0.05), validated by an in vitro induction experiment. The ISkpn14 without DR flanked expressed about 4 times higher than that with DR. The frequency of the mgrB insertion induced by polymyxin was significantly reduced (0 strain detected) after the blaKPC-2-carrying plasmid was eliminated. CONCLUSIONS: This study provides direct experimental evidence that the ISkpn14 element causing mgrB inactivation and polymyxin resistance in K. pneumoniae originates from blaKPC-2-carrying plasmids. Minocycline exposure will accelerate the evolution of polymyxin resistance. Understanding the dynamics of IS transposition and its association with antibiotic exposure is crucial for developing effective strategies to reduce the emergence of polymyxin resistance in CRKP.


Asunto(s)
Antibacterianos , Carbapenémicos , Infecciones por Klebsiella , Klebsiella pneumoniae , Plásmidos , Polimixinas , beta-Lactamasas , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efectos de los fármacos , Plásmidos/genética , Humanos , Polimixinas/farmacología , Antibacterianos/farmacología , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/tratamiento farmacológico , beta-Lactamasas/genética , Carbapenémicos/farmacología , Pruebas de Sensibilidad Microbiana , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Secuenciación Completa del Genoma , Elementos Transponibles de ADN/genética , Farmacorresistencia Bacteriana/genética
3.
Artículo en Inglés | MEDLINE | ID: mdl-39307849

RESUMEN

PURPOSE: The diagnosis of pulmonary cryptococcosis (PC) remains challenging, particularly in patients presenting with lobar or patchy consolidation on chest radiographs. Biopsies are sometimes performed for histopathologic examination and microbiological culture to differentiate infections, including PC, from lung cancers. However, to date, the clinical value of small biopsy samples and their reasonable processing methods for detecting Cryptococcus are rarely evaluated. Furthermore, the cryptococcal antigen (CrAg) test has been widely used in cryptococcosis diagnosis due to its high specificity. This 6-year retrospective study aimed to assess the efficacy of four tests commonly used for detecting Cryptococcus in the diagnosis of pulmonary cryptococcosis, and reveal that the combination of 2 or 3 methods would raise diagnosis sensitivity. METHODS: The results of CrAg test, histopathologic examination and routine cryptococcal culture of sputum/bronchoalveolar lavage fluid (BALF) were collected from hospitalized patients between June 2019 to May 2024. Additionally, the results of 4 above-mentioned methods were analyzed to compare their effectiveness in PC diagnosis. RESULTS: Among 1508 patients whose biopsy specimens were sent for pathogen detection, 63 PC cases were diagnosed, and 24 C. neoformans strains were cultivated using the Myco/F Lytic culture, which was more than those by sputum/BALF culture (9 strains). CrAg was positive in 82.5% (52/63) PC patients and remained the most sensitive method. The combination of CrAg and biopsy culture will increase the overall diagnostic yield to 95.2% (60/63). CONCLUSIONS: In summary, for those having biopsy tissue collected, the combination of CrAg and biopsy culture using Myco/F could effectively identify most PC cases.

4.
J Chem Phys ; 160(19)2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38752536

RESUMEN

The proton transport in one-dimensional (1D) confined water chains has been extensively studied as a model for ion channels in cell membrane and fuel cell. However, the mechanistic understanding of the proton transfer (PT) process in 1D water chains remains incomplete. In this study, we demonstrate that the two limiting structures of the hydrated excess proton, H5O2+ (Zundel) and H3O+ (linear H7O3+), undergo a change in dominance as the water chain grows, causing two co-existing and opposing PT mechanisms. Specifically, H5O2+ is stable in the middle of the chain, whereas H3O+ serves as a transition state (TS). Except for this region, H3O+ is stabilized while H5O2+ serves as a TS. The interaction analysis shows that the electrostatic interaction plays a crucial role in the difference in PT mechanisms. Our work fills a knowledge gap between the various PT mechanisms reported in bulk water and long 1D water chains, contributing to a deeper understanding of biological ion channels at the atomic level.

5.
J Chem Phys ; 160(16)2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38647312

RESUMEN

Understanding and further regulating the degradation of mandrel materials is a key aspect of target fabrication in inertial confinement fusion (ICF). Here, a quasi-one-dimensional confinement model is developed using a series of single-walled carbon nanotubes with varying diameters (Dm), and the degradation of poly-α-methylstyrene (PAMS) as a typical mandrel material is investigated under such confined conditions by using the combined method of quantum mechanics and molecular mechanics. In comparison to the isolated system, the calculations show that confinement can decrease or increase the energy barriers of PAMS degradation, which directly depends on Dm. Following which a clear exponential relationship between the degradation rate of PAMS and its own density is derived, indicating that the density of PAMS can be used to regulate mandrel degradation. This work highlights the important effects of confinement on degradation and provides a valuable reference for further development of polymer degradation technologies in ICF target fabrication and other fields.

6.
Biochem Genet ; 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38839646

RESUMEN

Thyroid cancer (THCA) is one of the most common malignancies of the endocrine system. Exosomes have significant value in performing molecular treatments, evaluating the diagnosis and determining tumor prognosis. Thus, the identification of exosome-related genes could be valuable for the diagnosis and potential treatment of THCA. In this study, we examined a set of exosome-related differentially expressed genes (DEGs) (BIRC5, POSTN, TGFBR1, DUSP1, BID, and FGFR2) by taking the intersection between the DEGs of the TCGA-THCA and GeneCards datasets. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of the exosome-related DEGs indicated that these genes were involved in certain biological functions and pathways. Protein‒protein interaction (PPI), mRNA‒miRNA, and mRNA-TF interaction networks were constructed using the 6 exosome-related DEGs as hub genes. Furthermore, we analyzed the correlation between the 6 exosome-related DEGs and immune infiltration. The Genomics of Drug Sensitivity in Cancer (GDSC), the Cancer Cell Line Encyclopedia (CCLE), and the CellMiner database were used to elucidate the relationship between the exosome-related DEGs and drug sensitivity. In addition, we verified that both POSTN and BID were upregulated in papillary thyroid cancer (PTC) patients and that their expression was correlated with cancer progression. The POSTN and BID protein expression levels were further examined in THCA cell lines. These findings provide insights into exosome-related clinical trials and drug development.

7.
Vascular ; : 17085381241249288, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38670962

RESUMEN

BACKGROUND: Endovenous interventions and minimally invasive procedures are effective in the management of varicose veins. However, they can cause postoperative discomfort. OBJECTIVE: To evaluate the clinical efficacy of sodium aescinate (SA) in improving edema, pain, vein-specific symptoms, and quality of life in patients following endovenous laser ablation (EVLA) for varicose veins. METHODS: In this single-center randomized controlled trial (RCT), patients were allocated into two groups: in Group A, 60 mg SA was administered twice daily for 20 days, and in Group B (control), no venoactive drug was prescribed. The Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification system for chronic venous disorders was used to assess the varicose veins. The circumferences of the calf and ankle were recorded for evaluating edema. The 10-point Visual Analog Scale (VAS), Venous Clinical Severity Score (VCSS), and Aberdeen Varicose Veins Questionnaire (AVVQ) were used to measure the pain intensity, overall varicose vein severity, and patient's quality of life, respectively. RESULTS: The study included 87 patients (mean age, 59.9 ± 10.7 years; 54 men) with CEAP class C2-C5 varicose veins who underwent EVLA and phlebectomy or foam sclerotherapy. The calf circumference recovered quicker in Group A than in Group B by days 10, 21, and 30 (difference from baseline was 1.04 ± 0.35 vs 2.39 ± 1.15 [p < .001], 0.48 ± 0.42 vs1.73 ± 1.00 [p < .001], and 0.18 ± 0.64 vs 0.82 ± 0.96 [p < .001], respectively). The ankle circumference recovered quicker in Group A than in Group B by days 10 and 21 (the difference from baseline was 1.37 ± 0.52 vs 2.36 ± 0.93 [p < .001] and 0.58 ± 0.60 vs 1.14 ± 0.88 [p = .002], respectively). Pain relief was achieved quicker in Group A than in Group B (0.257 ± 1.097 [p = .0863] vs 0.506 ± 1.250 [p = .0168] by day 21). There were no significant differences in the VCSS and AVVQ scores between both groups. There were no drug-related adverse effects. CONCLUSIONS: SA, in combination with compression therapy, can relieve edema and alleviate pain in patients following EVLA for varicose veins.

8.
Ann Hum Biol ; 51(1): 1-6, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38251837

RESUMEN

BACKGROUND: At present, there are no available genetic data on the AGCU EX22 Kit from the Wuhu Han population. AIM: This study investigates the applicability of the AGCU EX22 kit, designed for the Chinese population for forensic analysis and population genetics of the Wuhu Han population. SUBJECTS AND METHODS: Bloodstains from 1565 unrelated healthy individuals in Wuhu city, Anhui Province, were collected for analysis. The AGCU EX22 kit was used for amplification, and capillary electrophoresis was used to separate the amplification products. Allele frequencies and forensic parameters were determined. The Wuhu Han population was compared to 10 reference populations through genetic distance, a phylogenetic neighbor-joining tree and principal component analysis. RESULTS: In total, 281 alleles and 1187 genotypes were observed. No significant deviations from Hardy-Weinberg equilibrium at any locus were found after Bonferroni's correction. The 21 autosomal short tandem repeat (STR) genetic markers exhibited high informativeness and polymorphism. The cumulative power of discrimination and power of exclusion were 0.999999999999999999999999913380 and 0.999999996752339, respectively. Population comparisons revealed a genetic affinity between Wuhu Han and southern Han populations, except for the Guangdong Han population, which aligned with the traditional geographical division in China. CONCLUSION: The AGCU EX22 Kit, containing 21 STR loci, is suitable for forensic application and population genetics studies in the Wuhu Han population.


Asunto(s)
Pueblos del Este de Asia , Repeticiones de Microsatélite , Humanos , Alelos , China , Pueblos del Este de Asia/genética , Genética Forense , Frecuencia de los Genes , Genética de Población , Voluntarios Sanos , Filogenia , Sangre
9.
Nano Lett ; 23(7): 2808-2815, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36961344

RESUMEN

Tuning the ferroelectric domain structure by a combination of elastic and electrostatic engineering provides an effective route for enhanced piezoelectricity. However, for epitaxial thin films, the clamping effect imposed by the substrate does not allow aftergrowth tuning and also limits the electromechanical response. In contrast, freestanding membranes, which are free of substrate constraints, enable the tuning of a subtle balance between elastic and electrostatic energies, giving new platforms for enhanced and tunable functionalities. Here, highly tunable piezoelectricity is demonstrated in freestanding PbTiO3 membranes, by varying the ferroelectric domain structures from c-dominated to c/a and a domains via aftergrowth thermal treatment. Significantly, the piezoelectric coefficient of the c/a domain structure is enhanced by a factor of 2.5 compared with typical c domain PbTiO3. This work presents a new strategy to manipulate the piezoelectricity in ferroelectric membranes, highlighting their great potential for nano actuators, transducers, sensors and other NEMS device applications.

10.
Int J Mol Sci ; 25(5)2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38474182

RESUMEN

Blocking the interaction between the SARS-CoV-2 spike protein and the human angiotensin-converting enzyme II (hACE2) protein serves as a therapeutic strategy for treating COVID-19. Traditional Chinese medicine (TCM) treatments containing bioactive products could alleviate the symptoms of severe COVID-19. However, the emergence of SARS-CoV-2 variants has complicated the process of developing broad-spectrum drugs. As such, the aim of this study was to explore the efficacy of TCM treatments against SARS-CoV-2 variants through targeting the interaction of the viral spike protein with the hACE2 receptor. Antiviral activity was systematically evaluated using a pseudovirus system. Scutellaria baicalensis (S. baicalensis) was found to be effective against SARS-CoV-2 infection, as it mediated the interaction between the viral spike protein and the hACE2 protein. Moreover, the active molecules of S. baicalensis were identified and analyzed. Baicalein and baicalin, a flavone and a flavone glycoside found in S. baicalensis, respectively, exhibited strong inhibitory activities targeting the viral spike protein and the hACE2 protein, respectively. Under optimized conditions, virus infection was inhibited by 98% via baicalein-treated pseudovirus and baicalin-treated hACE2. In summary, we identified the potential SARS-CoV-2 inhibitors from S. baicalensis that mediate the interaction between the Omicron spike protein and the hACE2 receptor. Future studies on the therapeutic application of baicalein and baicalin against SARS-CoV-2 variants are needed.


Asunto(s)
COVID-19 , Flavonas , Humanos , SARS-CoV-2 , Scutellaria baicalensis , Glicoproteína de la Espiga del Coronavirus , Angiotensinas , Unión Proteica
11.
Molecules ; 29(9)2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38731569

RESUMEN

Skin wounds, leading to infections and death, have a huge negative impact on healthcare systems around the world. Antibacterial therapy and the suppression of excessive inflammation help wounds heal. To date, the application of wound dressings, biologics and biomaterials (hydrogels, epidermal growth factor, stem cells, etc.) is limited due to their difficult and expensive preparation process. Cinnamomum burmannii (Nees & T. Nees) Blume is an herb in traditional medicine, and its essential oil is rich in D-borneol, with antibacterial and anti-inflammatory effects. However, it is not clear whether Cinnamomum burmannii essential oil has the function of promoting wound healing. This study analyzed 32 main components and their relative contents of essential oil using GC-MS. Then, network pharmacology was used to predict the possible targets of this essential oil in wound healing. We first proved this essential oil's effects in vitro and in vivo. Cinnamomum burmannii essential oil could not only promote the proliferation and migration of skin stromal cells, but also promote M2-type polarization of macrophages while inhibiting the expression of pro-inflammatory cytokines. This study explored the possible mechanism by which Cinnamomum burmannii essential oil promotes wound healing, providing a cheap and effective strategy for promoting wound healing.


Asunto(s)
Cinnamomum , Aceites Volátiles , Piel , Cicatrización de Heridas , Cinnamomum/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Cicatrización de Heridas/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Proliferación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Piel/citología , Piel/efectos de los fármacos , Piel/lesiones , Piel/microbiología , Células del Estroma/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Animales , Ratones , Humanos , Células RAW 264.7 , Células HaCaT
12.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(1): 6-12, 2024 Jan 20.
Artículo en Zh | MEDLINE | ID: mdl-38322525

RESUMEN

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Due to the insidious onset and rapid progression and a lack of effective treatments, the prognosis of patients with HCC is extremely poor, with the average 5-year survival rate being less than 10%. The tumor microenvironment (TME), the internal environment in which HCC develops, can regulate the oncogenesis, development, invasion, and metastasis of HCC. During the process of cancer progression, HCC cells can regulate the biological behaviors of tumor cells, cancer-associated fibroblasts, cancer-associated immune cells, and other cells in the TME by releasing exosomes containing specific signals, thereby promoting cancer progression. However, the exact molecular mechanisms and the roles of exosomes in the specific cellular regulation of these processes are not fully understood. Herein, we summarized the TME components of HCC, the sources and the biological traits of exosomes in the TME, and the impact of mechanical factors on exosomes. In addition, special attention was given to the discussion of the effects of HCC-exosomes on different types of cells in the microenvironment. There are still many difficulties to be overcome before exosomes can be applied as carriers in clinical cancer treatment. First of all, the homogeneity of exosomes is difficult to ensure. Secondly, exosomes are mainly administered through subcutaneous injection. Although this method is simple and easy to implement, the absorption efficiency is not ideal. Thirdly, exosome extraction methods are limited in number and inefficient, making it difficult to prepare exosomes in large quantities. It is important to ensure that exosomes are used in sufficient quantities to trigger an effective tumor immune response, especially for exosome-mediated tumor immunotherapy. With the improvement in identification, isolation, and purification technology, exosomes are expected to be successfully used in the clinical diagnosis of early-stage HCC and the clinical treatment of liver cancer.


Asunto(s)
Carcinoma Hepatocelular , Exosomas , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Microambiente Tumoral , Comunicación Celular
13.
J Am Chem Soc ; 145(29): 16026-16036, 2023 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-37458419

RESUMEN

Developing highly sensitive multiplex immunoassays is urgently needed to guide medical research and improve clinical diagnosis. Here, we report the proximity electrochemiluminescence (ECL) generation enabled by gold microbeads (GMBs) for improving the detection sensitivity and multiplexing capacity of ECL immunoassays (ECLIAs). As demonstrated by microscopy and finite element simulation, GMBs can function as spherical ultramicroelectrodes for triggering ECL reactions in solutions. Employing GMBs as solid carriers in the bead-based ECLIA, the electrochemical oxidation of a coreactant can occur at both the GMB surface and the substrate electrode, allowing the coreactant radicals to diffuse only a short distance of ∼100 nm to react with ECL luminophores that are labeled on the GMB surface. The ECL generation via this proximity low oxidation potential (LOP) route results in a 21.7-fold increase in the turnover frequency of ECL generation compared with the non-conductive microbeads that rely exclusively on the conventional LOP route. Moreover, the proximity ECL generation is not restricted by the diffusion distance of short-lived coreactant radicals, which enables the simultaneous determination of multiple acute myocardial infarction biomarkers using size-encoded GMB-based multiplex ECLIAs. This work brings new insight into the understanding of ECL mechanisms and may advance the practical use of multiplex ECLIAs.


Asunto(s)
Técnicas Biosensibles , Mediciones Luminiscentes , Mediciones Luminiscentes/métodos , Oro , Microesferas , Inmunoensayo/métodos , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos
14.
Anal Chem ; 95(9): 4543-4549, 2023 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-36820622

RESUMEN

Cyclometalated Ir(III) complexes with high electrochemiluminescence (ECL) efficiency and appropriate bioconjugation sites are urgently needed in ECL immunoassays (ECLIA). Herein, we report the synthesis, photophysics, electrochemistry, and ECL of six new Ir(III) complexes bearing naphthyl (nap) or adamantane phenyl (adap) substitutions, four of which emit cyan, green, or red light and display 1.7- to 7.5-fold increases in ECL intensity. In combination with DFT/TDDFT calculations, this enhancement is rationalized to the augmented radiative rate that arises from both the strengthened spin-orbit coupling (SOC) and the increased transition dipole moment. In addition, the adap-based Ir(III) complex shows high binding affinity with ß-cyclodextrin (ß-CD) due to the strong hydrophobic interaction, which enables us to develop a modular strategy for the labeling of Ir(III) complexes with biomolecules and to use hydrophobic luminophores in the aqueous-phase detection. As demonstrated, a novel ECLIA is built up and exhibits a wide linear range from 1 ng/mL to 10 µg/mL and a detection limit of 72 pg/mL for the determination of C-reactive protein (CRP). These findings provide new insights into the design, synthesis, and bio-labeling of highly emissive Ir(III) complexes and pave the way for the development of novel ECLIA based on host-guest recognition motifs.

15.
Small ; 19(50): e2207637, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36707417

RESUMEN

The application of reversible deactivation radical polymerization techniques in 3D printing is emerging as a powerful method to build "living" polymer networks, which can be easily postmodified with various functionalities. However, the building speed of these systems is still limited compared to commercial systems. Herein, a digital light processing (DLP)-based 3D printing system via photoinduced free radical-promoted cationic reversible addition-fragmentation chain transfer polymerization of vinyl ethers, which can build "living" objects by a commercial DLP 3D printer at a relatively fast building speed (12.99 cm h-1 ), is reported. The polymerization behavior and printing conditions are studied in detail. The livingness of the printed objects is demonstrated by spatially controlled postmodification with a fluorescent monomer.

16.
Mol Carcinog ; 62(7): 1025-1037, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37042566

RESUMEN

It has been challenging to target mutant KRAS (mKRAS) in colorectal cancer (CRC) and other malignancies. Recent efforts have focused on developing inhibitors blocking molecules essential for KRAS activity. In this regard, SOS1 inhibition has arisen as an attractive approach for mKRAS CRC given its essential role as a guanine nucleotide exchange factor for this GTPase. Here, we demonstrated the translational value of SOS1 blockade in mKRAS CRC. We used CRC patient-derived organoids (PDOs) as preclinical models to evaluate their sensitivity to SOS1 inhibitor BI3406. A combination of in silico analyses and wet lab techniques was utilized to define potential predictive markers for SOS1 sensitivity and potential mechanisms of resistance in CRC. RNA-seq analysis of CRC PDOs revealed two groups of CRC PDOs with differential sensitivities to SOS1 inhibitor BI3406. The resistant group was enriched in gene sets involving cholesterol homeostasis, epithelial-mesenchymal transition, and TNF-α/NFκB signaling. Expression analysis identified a significant correlation between SOS1 and SOS2 mRNA levels (Spearman's ρ 0.56, p < 0.001). SOS1/2 protein expression was universally present with heterogeneous patterns in CRC cells but only minimal to none in surrounding nonmalignant cells. Only SOS1 protein expression was associated with worse survival in patients with RAS/RAF mutant CRC (p = 0.04). We also found that SOS1/SOS2 protein expression ratio >1 by immunohistochemistry (p = 0.03) instead of KRAS mutation (p = 1) was a better predictive marker to BI3406 sensitivity of CRC PDOs, concordant with the significant positive correlation between SOS1/SOS2 protein expression ratio and SOS1 dependency. Finally, we showed that GTP-bound RAS level underwent rebound even in BI3406-sensitive PDOs with no change of KRAS downstream effector genes, thus suggesting upregulation of guanine nucleotide exchange factor as potential cellular adaptation mechanisms to SOS1 inhibition. Taken together, our results show that high SOS1/SOS2 protein expression ratio predicts sensitivity to SOS1 inhibition and support further clinical development of SOS1-targeting agents in CRC.


Asunto(s)
Neoplasias Colorrectales , Proteínas Proto-Oncogénicas p21(ras) , Humanos , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Transducción de Señal , Proteína SOS1/genética , Proteína SOS1/metabolismo , Factores de Intercambio de Guanina Nucleótido/genética , Mutación , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética
17.
Phys Chem Chem Phys ; 25(33): 21957-21963, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37553960

RESUMEN

The donor-acceptor exchange (DAE) is a significant hydrogen bond network rearrangement (HBNR) mechanism because it can lead to the change of the hydrogen bond direction. In this work, we report a new DAE mechanism found in water trimers that is realized by sequential flipping (SF) of all molecules rather than the well-known proton transfer (PT) process. Meanwhile, the SF process has a much smaller potential barrier (0.262 eV) than the previously predicted collective rotation process (about 1.7 eV), implying that the SF process is the main flipping process that can lead to DAE. Importantly, high-precision ab initio calculations show that SF-DAE can make the water ring to show a clear chiral difference from PT-DAE, which brings the prospect of distinguishing the two confusing processes based on circular dichroism spectra. The reaction rate analysis including quantum tunneling indicates an obvious temperature-dependent competitive relationship between the SF and PT processes; specifically, the SF process dominates above 65 K, while the PT process dominates below 65 K. Therefore, in most cases, the contribution for DAE mainly comes from the flipping process, rather than the PT process as previously thought. Our work enriches the understanding of the DAE mechanism in water trimers and provides a piece of the jigsaw that has been sought for the HBNR mechanism.

18.
J Nanobiotechnology ; 21(1): 320, 2023 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-37679841

RESUMEN

The utilization of nanomaterials in the biosensor field has garnered substantial attention in recent years. Initially, the emphasis was on enhancing the sensor current rather than material interactions. However, carbon nanotubes (CNTs) have gained prominence in glucose sensors due to their high aspect ratio, remarkable chemical stability, and notable optical and electronic attributes. The diverse nanostructures and metal surface designs of CNTs, coupled with their exceptional physical and chemical properties, have led to diverse applications in electrochemical glucose sensor research. Substantial progress has been achieved, particularly in constructing flexible interfaces based on CNTs. This review focuses on CNT-based sensor design, manufacturing advancements, material synergy effects, and minimally invasive/noninvasive glucose monitoring devices. The review also discusses the trend toward simultaneous detection of multiple markers in glucose sensors and the pivotal role played by CNTs in this trend. Furthermore, the latest applications of CNTs in electrochemical glucose sensors are explored, accompanied by an overview of the current status, challenges, and future prospects of CNT-based sensors and their potential applications.


Asunto(s)
Nanoestructuras , Nanotubos de Carbono , Glucemia , Automonitorización de la Glucosa Sanguínea , Conductividad Eléctrica
19.
J Med Internet Res ; 25: e44939, 2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-37043273

RESUMEN

BACKGROUND: Elevated low-density lipoprotein cholesterol (LDL-C) is an established risk factor for atherosclerotic cardiovascular disease (ASCVD). However, low adherence to medication and lifestyle management has limited the benefits of lowering lipid levels. Cognitive behavioral therapy (CBT) has been proposed as a promising solution. OBJECTIVE: This trial aimed to evaluate the efficacy of mobile-based CBT interventions in lowering LDL-C levels in patients with ASCVD. METHODS: This multicenter, prospective, randomized controlled trial enrolled 300 patients with ASCVD, who were randomly assigned to the mobile-based CBT intervention group and the control group in a ratio of 1:1. The intervention group received CBT for ASCVD lifestyle interventions delivered by WeChat MiniApp: "CBT ASCVD." The control group only received routine health education during each follow-up. The linear regression and logistic regression analyses were used to determine the effects of a mobile-based CBT intervention on LDL-C, triglyceride, C-reactive protein, the score of General Self-Efficacy Scale (GSE), quality of life index (QL-index), and LDL-C up-to-standard rate (<1.8 mmol/L) at the first, third, and sixth months. RESULTS: Finally, 296 participants completed the 6-month follow-up (CBT group: n=148; control group: n=148). At baseline, the mean LDL-C level was 2.48 (SD 0.90) mmol/L, and the LDL-C up-to-standard rate (<1.8 mmol/L) was 21.3%. Mobile-based CBT intervention significantly increased the reduction of LDL-C change (%) at the 6-month follow-up (ß=-10.026, 95% CI -18.111 to -1.940). In addition, this benefit remained when baseline LDL-C <1.8 mmol/L (ß=-24.103, 95% CI -43.110 to -5.095). Logistic regression analysis showed that mobile-based CBT intervention moderately increased the LDL-C up-to-standard rates (<1.8 mmol/L) in the sixth month (odds ratio 1.579, 95% CI 0.994-2.508). For GSE and QL-index, mobile-based CBT intervention significantly increased the change of scores (%) at the 1-, 3-, and 6-month follow-up (all P values <.05). CONCLUSIONS: In patients with ASCVD, mobile-based CBT is effective in reducing LDL-C levels (even for those who already had a standard LDL-C) and can improve self-efficacy and quality of life. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100046775; https://www.chictr.org.cn/showproj.aspx?proj=127140.


Asunto(s)
Aterosclerosis , Enfermedades Cardiovasculares , Terapia Cognitivo-Conductual , Humanos , LDL-Colesterol/uso terapéutico , Enfermedades Cardiovasculares/prevención & control , Estudios Prospectivos , Calidad de Vida , Colesterol/uso terapéutico , Aterosclerosis/tratamiento farmacológico
20.
Medicina (Kaunas) ; 59(9)2023 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-37763673

RESUMEN

COVID-19 is a highly transmittable respiratory illness caused by SARS-CoV-2, and acute lung injury (ALI) is the major complication of COVID-19. The challenge in studying SARS-CoV-2 pathogenicity is the limited availability of animal models. Therefore, it is necessary to establish animal models that can reproduce multiple characteristics of ALI to study therapeutic applications. The present study established a mouse model that has features of ALI that are similar to COVID-19 syndrome to investigate the role of ACE2 and the administration of the Chinese herbal prescription NRICM101 in ALI. Mice with genetic modifications, including overexpression of human ACE2 (K18-hACE2 TG) and absence of ACE2 (mACE2 KO), were intratracheally instillated with hydrochloric acid. The acid intratracheal instillation induced severe immune cell infiltration, cytokine storms, and pulmonary disease in mice. Compared with K18-hACE2 TG mice, mACE2 KO mice exhibited dramatically increased levels of multiple inflammatory cytokines (IL-6 and TNF-α) in bronchoalveolar lavage fluid, histological evidence of lung injury, and dysregulation of MAPK and MMP activation. In mACE2 KO mice, NRICM101 could ameliorate the disease progression of acid-induced ALI. In conclusion, the established mouse model provided an effective platform for researchers to investigate pathological mechanisms and develop therapeutic strategies for ALI, including COVID-19-related ALI.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda