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1.
J Am Chem Soc ; 146(29): 19782-19791, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39001846

RESUMEN

RAP1 proteins belong to the RAS family of small GTPases that operate as molecular switches by cycling between GDP-bound inactive and GTP-bound active states. The C-terminal anchors of RAP1 proteins are known to direct membrane localization, but how these anchors organize RAP1 on the plasma membrane (PM) has not been investigated. Using high-resolution imaging, we show that RAP1A and RAP1B form spatially segregated nanoclusters on the inner leaflet of the PM, with further lateral segregation between GDP-bound and GTP-bound proteins. The C-terminal polybasic anchors of RAP1A and RAP1B differ in their amino acid sequences and exhibit different lipid binding specificities, which can be modified by single-point mutations in the respective polybasic domains (PBD). Molecular dynamics simulations reveal that single PBD mutations substantially reduce the interactions of the membrane anchors with the PM lipid phosphatidylserine. In summary, we show that aggregate lipid binding specificity encoded within the C-terminal anchor determines PM association and nanoclustering of RAP1A and RAP1B. Taken together with previous observations on RAC1 and KRAS, the study reveals that the PBD sequences of small GTPase membrane anchors can encode distinct lipid binding specificities that govern PM interactions.


Asunto(s)
Secuencia de Aminoácidos , Membrana Celular , Simulación de Dinámica Molecular , Proteínas de Unión al GTP rap , Proteínas de Unión al GTP rap/metabolismo , Proteínas de Unión al GTP rap/química , Proteínas de Unión al GTP rap/genética , Membrana Celular/metabolismo , Membrana Celular/química , Humanos , Proteínas de Unión al GTP rap1/metabolismo , Proteínas de Unión al GTP rap1/química , Proteínas de Unión al GTP rap1/genética , Unión Proteica , Fosfatidilserinas/química , Fosfatidilserinas/metabolismo , Sitios de Unión
2.
Animals (Basel) ; 14(11)2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38891686

RESUMEN

Human-wildlife conflicts are becoming increasingly common worldwide and are a challenge to biodiversity management. Compared with compensatory management, which often focuses on solving emergency conflicts, mitigation management allows decision-makers to better understand where the damage is distributed, how the species are distributed and when the species conduct their activity. Here, we integrated data collected from 90 districts/counties' damage surveys and 1271 camera traps to understand the damage status, abundance, density and activity rhythms of wild boar (Sus scrofa) in Zhejiang, Eastern China, from January 2019 to August 2023. We found that (1) wild boar-human conflicts were mainly distributed in the northwest and southwest mountainous regions of Zhejiang Province; (2) the total abundance of wild boar was 115,156 ± 24,072 individuals, indicating a growing trend over the past decade and a higher density in the western and southern regions; (3) wild boar exhibited different activity patterns across different damage regions, and the periods around 7:00, 11:00 and 16:00 represented activity peaks for wild boar in seriously damaged regions. The damage distribution, density, distribution and activity rhythms provide specific priority regions and activity intensity peaks for conflict mitigation. We believe that these findings based on the damage, distribution and activity could provide a scientific basis for mitigation management at the county level and enrich the framework of human-wildlife conflict mitigation.

3.
bioRxiv ; 2024 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-38853864

RESUMEN

KRAS is frequently mutated in cancer, contributing to 20% of all human cancer especially pancreatic, colorectal and lung cancer. Signaling of the constitutively active KRAS oncogenic mutants is mostly compartmentalized to proteolipid nanoclusters on the plasma membrane (PM). Signaling nanoclusters of many KRAS mutants selectively enrich phosphatidylserine (PS) lipids with unsaturated sn-2 acyl chains, but not the fully saturated PS species. Thus, remodeling PS acyl chains may suppress KRAS oncogenesis. Lysophosphatidylcholine acyltransferases (LPCATs) remodel sn-2 acyl chains of phospholipids, with LPCAT1 preferentially generating the fully saturated lipids. Here, we show that stable expression of LPCAT1 depletes major PS species with unsaturated sn-2 chains while decreasing minor phosphatidylcholine (PC) species with the corresponding acyl chains. LPCAT1 expression more effectively disrupts the nanoclustering of oncogenic GFP-KRASG12V, which is restored by acute addback of exogenous unsaturated PS. LPCAT1 expression compromises signaling and oncogenic activities of the KRAS-dependent pancreatic tumor lines. LPCAT1 expression sensitizes human pancreatic tumor MiaPaCa-2 cells to KRASG12C specific inhibitor, Sotorasib. Statistical analyses of patient data further reveal that pancreatic cancer patients with KRAS mutations express less LPCAT1. Higher LPCAT1 expression also improves survival probability of pancreatic and lung adenocarcinoma patients with KRAS mutations. Thus, PS acyl chain remodeling selectively suppresses KRAS oncogenesis.

4.
Small ; : e2401939, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38924354

RESUMEN

3D carbon-based porous sponges are recognized for significant potential in oil absorption and electromagnetic interference (EMI). However, their widespread application is hindered by a common compromise between high performance and affordability of mass production. Herein, a novel approach is introduced that involves laser-assisted micro-zone heating melt-blown spinning (LMHMS) to address this challenge by creating pitch-based submicron carbon fibers (PSCFs) sponge with 3D interconnected structures. These structures bestow the resulting sponge exceptional characteristics including low density (≈20 mg cm-3), high porosity (≈99%), remarkable compressibility (80% maximum strain), and superior conductivity (≈628 S m-1). The resultant PSCF sponges realize an oil/organic solvent sorption capacity over 56 g/g and possess remarkable regenerated ability. In addition to their effectiveness in cleaning up oil/organic solvent spills, they also demonstrated strong electromagnetic shielding capabilities, with a total shielding effectiveness (SE) exceeding 60 dB across the X-band GHz range. In virtue of extreme lightweight of ≈20 mg cm-3, the specific SE of the PSCF sponge reaches as high as ≈1466 dB cm3 g-1, surpassing the performance of numerous carbon-based porous structures. Thus, the unique blend of properties renders these sponges promising for transforming strategies in addressing oil/organic solvent contaminations and providing effective protection against EMI.

5.
Ecol Evol ; 14(6): e11533, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38911496

RESUMEN

Dams worldwide have significantly altered the composition of riparian forests. However, research on the functional traits of dominant herbs experiencing flooding stress due to dam impoundment remains limited. Given the high plasticity of leaf traits and their susceptibility to environmental influences, this study focuses on riparian herbs along the Three Gorges Hydro-Fluctuation Zone (TGHFZ). Specifically, it investigates how six leaf physiological traits of leading herbs-carbon, nitrogen, phosphorus, and their stoichiometric ratios-adapt to periodic flooding in the TGHFZ using cluster analysis, one-way analysis of variance (ANOVA), multiple comparisons, Pearson correlation analysis, and principal component analysis (PCA). We categorized 25 dominant herb species into three plant functional types (PFTs), noting that species from the same family tended to fall into the same PFT. Notably, leaf carbon content (LCC) exhibited no significant differences across various PFTs or altitudes. Within riparian forests, different PFTs employ distinct adaptation strategies: PFT-I herbs invest in structural components to enhance stress resistance; PFT-II, mostly comprising gramineous plants, responds to prolonged flooding by rapid growth above the water; and PFT-III, encompassing nearly all Compositae and annual plants, responds to prolonged flooding with vigorous rhizome growth and seed production. Soil water content (SWC) emerges as the primary environmental factor influencing dominant herb growth in the TGHFZ. By studying the response of leaf physiological traits in dominant plants to artificial flooding, we intend to reveal the survival mechanisms of plants under adverse conditions and lay the foundation for vegetation restoration in the TGHFZ.

6.
Front Oncol ; 14: 1332522, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38863624

RESUMEN

Rearrangements involving the neurotrophic-tropomyosin receptor kinase (NTRK) gene family (NTRK1, NTRK2, and NTRK3) have been identified as drivers in a wide variety of human cancers. However, the association between NTRK rearranged thyroid carcinoma and clinicopathological characteristics has not yet been established. In our study, we retrospectively reviewed medical records of thyroid cancer patients and identified 2 cases with NTRK rearrangement, no additional molecular alterations were observed in either of these cases. The fusion of the rearrangement in both cases was ETV6(E4)::NTRK3(E14). By analyzing the clinicopathological features of these two cases, we found that both were characterized by multiple tumor nodules, invasive growth, and central lymph node metastases, indicating the follicular subtype of papillary thyroid carcinoma. Immunohistochemical staining profiles showed CD56-, CK19+, Galectin-3+, HBME1+. These clinicopathological features suggest the possibility of ETV6-NTRK3 rearranged thyroid carcinoma and highlight the importance of performing gene fusion testing by FISH or NGS for these patients.

7.
J Chem Phys ; 160(15)2024 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-38629605

RESUMEN

MnO(001) thin films were grown on commercial MgO(001) substrates at 520 °C by reactive molecular beam epitaxy (MBE) using Mn vapor and O2-seeded supersonic molecular beams (SMBs) both with and without radio frequency (RF) plasma excitation. For comparison, MnO(001) films were grown by reactive MBE using O2 from a leak valve. X-ray photoelectron spectroscopy confirmed the Mn2+ oxidation state and 10%-15% excess oxygen near the growth surface. Reflection high-energy electron diffraction and x-ray diffraction evidenced that the films were rock salt cubic MnO with very strong (001) orientation. High-angle annular dark field scanning transmission electron microscopy with energy-dispersive x-ray spectroscopy demonstrated abrupt MnO/MgO interfaces and indicated [(001)MnO||(001)MgO] epitaxial growth. Ex situ atomic force microscopy of films deposited without RF excitation revealed smooth growth surfaces. An SMB-grown MnO(001) film was converted to Mn3O4 with strong (110) orientation by post-growth exposure to an RF-discharge (RFD) SMB source providing O atoms; the surface of the resultant film contained elongated pits aligned with the MgO110 directions. In contrast, using the RFD-SMB source for growth resulted in MnO(001) films with elongated growth pits and square pyramidal hillocks aligned along the MgO110 and 100 directions, respectively.

8.
BMC Med Genomics ; 17(1): 17, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38200578

RESUMEN

Immunotherapy is a promising treatment for breast cancer (BC). However, due to individual differences and tumor heterogeneity, immunotherapy is only applicable to some BC patients. Glutamine metabolism plays a role in inhibiting immunotherapy, but its role in BC is limitedly studied. Therefore, we aimed to identify different BC subgroups based on glutamine metabolism and characterize the features of different subgroups to provide guidance for personalized immunotherapy for BC patients. Using unsupervised clustering analysis, we classified BC patients in The Cancer Genome Atlas (TCGA) with glutamine metabolism-related genes and obtained low-risk (LR) and high-risk (HR) subgroups. Survival analysis revealed that prognosis of LR subgroup was notably better than HR subgroup. Through ssGSEA and CIBERSORT methods, we disclosed that infiltration levels of B cells, Mast cells, T helper cells, and Th2 cells, and Type II IFN Response immune function were notably higher in LR subgroup than in HR subgroup. The Wilcox algorithm comparison denoted that DEPTH of LR subgroup was significantly lower than HR subgroup. The TIDE of LR subgroup was significantly higher than HR subgroup. Functional annotation of differentially expressed genes revealed that channel activity and the Estrogen signaling pathway may be related to BC prognosis. Ten hub genes were selected between the subgroups through the STRING database and Cytoscape, and their correlation with drugs was predicted on the CellMiner website. This study analyzed the immune characteristics of BC subgroups based on glutamine metabolism and provided reference for prognosis prediction and personalized immunotherapy.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/genética , Glutamina , Transducción de Señal , Inmunoterapia , Algoritmos
9.
ACS Nano ; 17(24): 24487-24513, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38064282

RESUMEN

Brain-computer interfaces (BCIs) have garnered significant attention in recent years due to their potential applications in medical, assistive, and communication technologies. Building on this, noninvasive BCIs stand out as they provide a safe and user-friendly method for interacting with the human brain. In this work, we provide a comprehensive overview of the latest developments and advancements in material, design, and application of noninvasive BCIs electrode technology. We also explore the challenges and limitations currently faced by noninvasive BCI electrode technology and sketch out the technological roadmap from three dimensions: Materials and Design; Performances; Mode and Function. We aim to unite research efforts within the field of noninvasive BCI electrode technology, focusing on the consolidation of shared goals and fostering integrated development strategies among a diverse array of multidisciplinary researchers.


Asunto(s)
Interfaces Cerebro-Computador , Humanos , Electroencefalografía/métodos , Encéfalo , Electrodos
10.
Biomimetics (Basel) ; 8(8)2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-38132497

RESUMEN

Estimating the contact forces and moments (CFMs) between exoskeletons' feet and the ground is a prerequisite for calculating exoskeletons' joint moments. However, comfortable, portable, and high-precision force sensors for CFM detection are difficult to design and manufacture. In addition, there are many unknown CFM components (six force components and six moment components in the double-support phase). These reasons make it challenging to estimate CFMs precisely. In this paper, we propose a novel method for estimating these CFMs based on a proposed dynamic decoupled coordinate system (DDCS) and the minimum energy hypothesis. By decomposing these CFMs into a DDCS, the number of unknowns can be significantly reduced from twelve to two. Meanwhile, the minimum energy hypothesis provides a relatively reliable target for optimizing the remaining two unknown variables. We verify the accuracy of this method using a public data set about human walking. The validation shows that the proposed method is capable of estimating CFMs. This study provides a practical way to estimate the CFMs under the soles, which contributes to reducing the research and development costs of exoskeletons by avoiding the need for expensive plantar sensors. The sensor-free approach also reduces the dependence on high-precision, portable, and comfortable CFM detection sensors, which are usually difficult to design.

11.
Nat Commun ; 14(1): 7749, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38012194

RESUMEN

The oxidative coupling of methane to higher hydrocarbons offers a promising autothermal approach for direct methane conversion, but its progress has been hindered by yield limitations, high temperature requirements, and performance penalties at practical methane partial pressures (~1 atm). In this study, we report a class of Li2CO3-coated mixed rare earth oxides as highly effective redox catalysts for oxidative coupling of methane under a chemical looping scheme. This catalyst achieves a single-pass C2+ yield up to 30.6%, demonstrating stable performance at 700 °C and methane partial pressures up to 1.4 atm. In-situ characterizations and quantum chemistry calculations provide insights into the distinct roles of the mixed oxide core and Li2CO3 shell, as well as the interplay between the Pr oxidation state and active peroxide formation upon Li2CO3 coating. Furthermore, we establish a generalized correlation between Pr4+ content in the mixed lanthanide oxide and hydrocarbons yield, offering a valuable optimization strategy for this class of oxidative coupling of methane redox catalysts.

12.
J Anim Sci ; 1012023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-37583344

RESUMEN

We investigated the effects of different Bacillus subtilis QST713 doses and a B. subtilis QST713 and ß-mannanase mix on growth performance, intestinal barrier function, and gut microbiota in weaned piglets. In total, 320 healthy piglets were randomly assigned to four groups: 1) control group (basal diet), 2) BS100 group (basal diet plus 100 mg/kg B. subtilis QST713), 3) BS200 group (basal diet plus 200 mg/kg B. subtilis QST713), and 4) a BS100XT group (basal diet plus 100 mg/kg B. subtilis QST713 and 150 mg/kg ß-mannanase). The study duration was 42 d. We showed that feed intake in weaned piglets on days 1 to 21 was increased in group BS100 (P < 0.05), and that the feed conversion ratio in group BS100XT animals decreased throughout the study (P < 0.05). In terms of microbial counts, the BS100XT group showed reduced Escherichia coli and Clostridium perfringens numbers on day 21 (P < 0.05). Moreover, no significant α-diversity differences were observed across all groups during the study (P > 0.05). However, principal coordinates analysis indicated clear separations in bacterial community structures across groups (analysis of similarities: P < 0.05) on days 21 and 42. Additionally, E-cadherin, occludin, and zonula occludens-1 (ZO-1) expression in piglet feces increased (P < 0.05) by adding B. subtilis QST713 and ß-mannanase to diets. Notably, this addition decreased short-chain fatty acid concentrations. In conclusion, B. subtilis QST713 addition or combined B. subtilis QST713 plus ß-mannanase effectively improved growth performance, intestinal barrier function, and microbial balance in weaned piglets.


The use of antibiotics in pig farming raises serious concerns in terms of antibiotic resistance. Consequently, alternative approaches such as probiotics, including Bacillus subtilis, and enzymes such as ß-mannanase, have been proposed to improve pig health and performance. In particular, B. subtilis improves gut microbiota and reduces the prevalence of harmful bacteria such as Escherichia coli and Clostridium perfringens. Similarly, ß-mannanase enhances feed digestibility and improves nutrient use in pigs. Thus, combined B. subtilis and ß-mannanase may provide synergistic effects toward pig performance and gut health. In this study, we showed that adding B. subtilis to a weaned piglet diet improved feed intake, while a B. subtilis and ß-mannanase mix reduced feed conversion ratios in weaned piglets.


Asunto(s)
Microbioma Gastrointestinal , Animales , Porcinos , Bacillus subtilis , beta-Manosidasa/farmacología , Dieta/veterinaria , Heces/microbiología , Escherichia coli
13.
Artículo en Inglés | MEDLINE | ID: mdl-37463719

RESUMEN

RAS genes are frequently mutated in cancer. The primary signaling compartment of wild-type and constitutively active oncogenic mutant RAS proteins is the inner leaflet of the plasma membrane (PM). Thus, a better understanding of the unique environment of the PM inner leaflet is important to shed further light on RAS function. Over the past few decades, an integrated approach of superresolution imaging, molecular dynamic simulations, and biophysical assays has yielded new insights into the capacity of RAS proteins to sort lipids with specific headgroups and acyl chains, to assemble signaling nanoclusters on the inner PM. RAS proteins also sense and respond to changes in components of the outer PM leaflet, including glycophosphatidylinositol-anchored proteins, sphingophospholipids, glycosphingolipids, and galectins, as well as cholesterol that translocates between the two leaflets. Such communication between the inner and outer leaflets of the PM, called interleaflet coupling, allows RAS to potentially integrate extracellular mechanical and electrostatic information with intracellular biochemical signaling events, and reciprocally allows mutant RAS-transformed tumor cells to modify tumor microenvironments. Here, we review RAS-lipid interactions and speculate on potential mechanisms that allow communication between the opposing leaflets of the PM.


Asunto(s)
Neoplasias , Proteínas ras , Humanos , Proteínas ras/genética , Proteínas ras/metabolismo , Membrana Celular/metabolismo , Neoplasias/metabolismo , Transducción de Señal , Microambiente Tumoral
14.
Neural Regen Res ; 18(10): 2268-2277, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37056147

RESUMEN

Controlled cortical impingement is a widely accepted method to induce traumatic brain injury to establish a traumatic brain injury animal model. A strike depth of 1 mm at a certain speed is recommended for a moderate brain injury and a depth of > 2 mm is used to induce severe brain injury. However, the different effects and underlying mechanisms of these two model types have not been proven. This study investigated the changes in cerebral blood flow, differences in the degree of cortical damage, and differences in motor function under different injury parameters of 1 and 2 mm at injury speeds of 3, 4, and 5 m/s. We also explored the functional changes and mitochondrial damage between the 1 and 2 mm groups in the acute (7 days) and chronic phases (30 days). The results showed that the cerebral blood flow in the injured area of the 1 mm group was significantly increased, and swelling and bulging of brain tissue, increased vascular permeability, and large-scale exudation occurred. In the 2 mm group, the main pathological changes were decreased cerebral blood flow, brain tissue loss, and cerebral vasospasm occlusion in the injured area. Substantial motor and cognitive impairments were found on day 7 after injury in the 2 mm group; at 30 days after injury, the motor function of the 2 mm group mice recovered significantly while cognitive impairment persisted. Transcriptome sequencing showed that compared with the 1 mm group, the 2 mm group expressed more ferroptosis-related genes. Morphological changes of mitochondria in the two groups on days 7 and 30 using transmission electron microscopy revealed that on day 7, the mitochondria in both groups shrank and the vacuoles became larger; on day 30, the mitochondria in the 1 mm group became larger, and the vacuoles in the 2 mm group remained enlarged. By analyzing the proportion of mitochondrial subgroups in different groups, we found that the model mice had different patterns of mitochondrial composition at different time periods, suggesting that the difference in the degree of damage among traumatic brain injury groups may reflect the mitochondrial changes. Taken together, differences in mitochondrial morphology and function between the 1 and 2 mm groups provide a new direction for the accurate classification of traumatic brain injury. Our results provide reliable data support and evaluation methods for promoting the establishment of standard mouse controlled cortical impingement model guidelines.

15.
Molecules ; 28(5)2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36903661

RESUMEN

Panax notoginseng (Burk) F. H. Chen is a traditional Chinese medicinal and edible plant. However, Panax notoginseng flower (PNF) is rarely used. Therefore, the purpose of this study was to explore the main saponins and the anti-inflammatory bioactivity of PNF saponins (PNFS). We explored the regulation of cyclooxygenase 2 (COX-2), a key mediator of inflammatory pathways, in human keratinocyte cells treated with PNFS. A cell model of UVB-irradiation-induced inflammation was established to determine the influence of PNFS on inflammatory factors and their relationship with LL-37 expression. An enzyme-linked immunosorbent assay and Western blotting analysis were used to detect the production of inflammatory factors and LL37. Finally, liquid chromatography-tandem mass spectrometry was employed to quantify the main active components (ginsenosides Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1, and notoginsenoside R1) in PNF. The results show that PNFS substantially inhibited COX-2 activity and downregulated the production of inflammatory factors, indicating that they can be used to reduce skin inflammation. PNFS also increased the expression of LL-37. The contents of ginsenosides Rb1, Rb2, Rb3, Rc, and Rd in PNF were much higher than those of Rg1, and notoginsenoside R1. This paper provides data in support of the application of PNF in cosmetics.


Asunto(s)
Ginsenósidos , Panax notoginseng , Panax , Saponinas , Humanos , Ginsenósidos/química , Saponinas/química , Panax notoginseng/química , Espectrometría de Masas en Tándem , Ciclooxigenasa 2/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida , Flores/química , Antiinflamatorios/metabolismo , Inflamación , Panax/metabolismo
16.
Pharmgenomics Pers Med ; 16: 29-36, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36714524

RESUMEN

Immune checkpoint inhibitors (ICIs) have been shown to be significant in improving the overall survival rate in certain malignancies with poor prognoses. However, only 20-40% of patients achieve long-term benefits, highlighting the relevance of the factors that influence the treatment, which can help clinicians improve their results and guide the development of new immune checkpoint therapies. In this study, the current pharmacokinetic aspects associated with the ICIs and the factors influencing clinical efficacy were characterised, including in terms of drug metabolism, drug clearance, hormonal effects and immunosuppressive effects.

17.
Nat Commun ; 14(1): 465, 2023 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-36709325

RESUMEN

Oncogenic KRAS expression generates a metabolic dependency on aerobic glycolysis, known as the Warburg effect. We report an effect of increased glycolytic flux that feeds into glycosphingolipid biosynthesis and is directly linked to KRAS oncogenic function. High resolution imaging and genetic approaches show that a defined subset of outer leaflet glycosphingolipids, including GM3 and SM4, is required to maintain KRAS plasma membrane localization, with GM3 engaging in cross-bilayer coupling to maintain inner leaflet phosphatidylserine content. Thus, glycolysis is critical for KRAS plasma membrane localization and nanoscale spatial organization. Reciprocally oncogenic KRAS selectively upregulates cellular content of these same glycosphingolipids, whose depletion in turn abrogates KRAS oncogenesis in pancreatic cancer models. Our findings expand the role of the Warburg effect beyond ATP generation and biomass building to high-level regulation of KRAS function. The positive feedforward loop between oncogenic KRAS signaling and glycosphingolipid synthesis represents a vulnerability with therapeutic potential.


Asunto(s)
Neoplasias Pancreáticas , Proteínas Proto-Oncogénicas p21(ras) , Humanos , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Membrana Celular/metabolismo , Transducción de Señal , Glucólisis , Glicoesfingolípidos/metabolismo
18.
Chem Commun (Camb) ; 59(1): 10-28, 2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36477169

RESUMEN

Over the past two decades, chemical looping combustion (CLC) has been extensively investigated as a promising means to produce electric power while generating a concentrated carbon dioxide stream for sequestration. We note that the chemical looping strategy can be extended well outside of combustion-based carbon capture. In fact, application of the chemical looping strategy in areas beyond combustion can result in somewhat unexpected energy and carbon dioxide savings without producing a concentrated CO2 stream at all. Furthermore, it allows the looping-based technologies to tap into applications such as chemical production - a $4 trillion per year industrial sector with high energy and carbon intensities. The key resides in the design of effective oxygen carriers, also known as redox catalysts in the context of selective chemical conversion through chemical looping catalysis (CLCa). This contribution focuses on the design and applications of mixed oxides as multi-function reaction media in CLCa. Since typical mixed oxide oxygen carriers tend to be nonselective for hydrocarbon conversion, the first part of this article presents generalized design principles for surface modification of mixed oxides to improve their selectivity and catalytic activity. Applications of these redox catalysts in chemical looping - oxidative dehydrogenation (CL-ODH) of a variety of light alkanes and alkyl-benzenes are presented. This is followed with a discussion of computation assisted mixed oxide design based upon thermodynamic criteria. Finally, a few new directions for the chemical looping technologies are introduced.

19.
Cells ; 11(22)2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36429120

RESUMEN

Chimeric antigen receptor (CAR)-expressing macrophages (CAR-M) have a great potential to improve cancer therapy, as shown from several recent preclinical studies. However, unlike CAR-T cell therapy, which has been widely studied, the efficacy and limitations of CAR-M cells remain to be established. To address this issue, in the present study, we compared three intracellular signaling domains (derived from common γ subunit of Fc receptors (FcRγ), multiple EGF-like-domains protein 10 (Megf10), and the CD19 cytoplasmic domain that recruits the p85 subunit of phosphoinositide-3 kinase (PI3K), respectively) for their ability to promote primary CAR-M functions, and investigated the potential synergistic effect between CAR-M and CAR-T cells in their ability to kill tumor cells. We found that CAR-MFcRγ exerted more potent phagocytic and tumor-killing capacity than CAR-MMegf10 and CAR-MPI3K. CAR-M and CAR-T demonstrated synergistic cytotoxicity against tumor cells in vitro. Mechanistically, the inflammatory factors secreted by CAR-T increased the expression of costimulatory ligands (CD86 and CD80) on CAR-M and augmented the cytotoxicity of CAR-M by inducing macrophage M1 polarization. The upregulated costimulatory ligands may promote the fitness and activation of CAR-T cells in turn, achieving significantly enhanced cytotoxicity. Taken together, our study demonstrated for the first time that CAR-M could synergize with CAR-T cells to kill tumor cells, which provides proof-of-concept for a novel combinational immunotherapy.


Asunto(s)
Receptores Quiméricos de Antígenos , Receptores Quiméricos de Antígenos/metabolismo , Ligandos , Linfocitos T , Macrófagos/metabolismo , Recuento de Leucocitos , Fosfatidilinositol 3-Quinasas
20.
Nanoscale ; 14(48): 18094-18105, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36448707

RESUMEN

The current study reports AxA'1-xByB'1-yO3-δ perovskite redox catalysts (RCs) for CO2-splitting and methane partial oxidation (POx) in a cyclic redox scheme. Strontium (Sr) and iron (Fe) were chosen as A and B site elements with A' being lanthanum (La), samarium (Sm) or yttrium (Y), and B' being manganese (Mn) or titanium (Ti) to tailor their equilibrium oxygen partial pressures (PO2s) for CO2-splitting and methane partial oxidation. DFT calculations were performed for predictive optimization of the oxide materials whereas experimental investigation confirmed the DFT-predicted redox performance. The redox kinetics of the RCs improved significantly by 1 wt% ruthenium (Ru) impregnation without affecting their redox thermodynamics. Ru-impregnated LaFe0.375Mn0.625O3 (A = 0, A' = La, B = Fe, and B' = Mn) was the most promising RC in terms of its superior redox performance (CH4/CO2 conversion >90% and CO selectivity ∼95%) at 800 °C. Long-term redox testing over Ru-impregnated LaFe0.375Mn0.625O3 indicated a stable performance during the first 30 cycles followed by an ∼25% decrease in the activity during the last 70 cycles. Air treatment was effective to reactivate the redox catalyst. Detailed characterizations revealed the underlying mechanism of the redox catalyst deactivation and reactivation. This study not only validated a DFT-guided mixed oxide design strategy for CO2 utilization but also provides potentially effective approaches to enhance redox kinetics and long-term redox catalyst performance.

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