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1.
Theranostics ; 14(10): 3909-3926, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38994036

RESUMEN

Background: Aurora kinase A (AURKA) is a potent oncogene that is often aberrantly expressed during tumorigenesis, and is associated with chemo-resistance in various malignancies. However, the role of AURKA in chemo-resistance remains largely elusive. Methods: The cleavage of AURKA upon viral infection or apoptosis stimuli was assesed by immunoblotting assays in several cancer cells or caspase deficient cell line models. The effect of AURKA cleavage at Asp132 on mitosis was explored by live cell imaging and immunofluorescence staining experiments. The role of Asp132-cleavage of AURKA induced by the chemotherapy drug paclitaxel was investigated using TUNEL, immunohistochemistry assay in mouse tumor xenograft model and patient tissues. Results: The proteolytic cleavage of AURKA at Asp132 commonly occurs in several cancer cell types, regardless of viral infection or apoptosis stimuli. Mechanistically, caspase 3/7/8 cleave AURKA at Asp132, and the Asp132-cleaved forms of AURKA promote cell apoptosis by disrupting centrosome formation and bipolar spindle assembly in metaphase during mitosis. The AURKAD132A mutation blocks the expression of cleaved caspase 3 and EGR1, which leads to reduced therapeutic effects of paclitaxel on colony formation and malignant growth of tumor cells in vitro and in vivo using a murine xenograft model and cancer patients. Conclusions: This study reveals that caspase-mediated AURKAD132 proteolysis is essential for paclitaxel to elicit cell apoptosis and indicates that AURKAD132 is a potential key target for chemotherapy.


Asunto(s)
Apoptosis , Aurora Quinasa A , Paclitaxel , Paclitaxel/farmacología , Aurora Quinasa A/metabolismo , Animales , Humanos , Apoptosis/efectos de los fármacos , Ratones , Línea Celular Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto , Caspasas/metabolismo , Antineoplásicos Fitogénicos/farmacología , Resistencia a Antineoplásicos , Mitosis/efectos de los fármacos , Proteolisis/efectos de los fármacos , Femenino , Ratones Desnudos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología
2.
Nat Commun ; 15(1): 5705, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38977710

RESUMEN

In nature, coenzyme-independent oxidases have evolved in selective catalysis using isolated substrate-binding pockets. Single-atom nanozymes (SAzymes), an emerging type of non-protein artificial enzymes, are promising to simulate enzyme active centers, but owing to the lack of recognition sites, realizing substrate specificity is a formidable task. Here we report a metal-ligand dual-site SAzyme (Ni-DAB) that exhibited selectivity in uric acid (UA) oxidation. Ni-DAB mimics the dual-site catalytic mechanism of urate oxidase, in which the Ni metal center and the C atom in the ligand serve as the specific UA and O2 binding sites, respectively, characterized by synchrotron soft X-ray absorption spectroscopy, in situ near ambient pressure X-ray photoelectron spectroscopy, and isotope labeling. The theoretical calculations reveal the high catalytic specificity is derived from not only the delicate interaction between UA and the Ni center but also the complementary oxygen reduction at the beta C site in the ligand. As a potential application, a Ni-DAB-based biofuel cell using human urine is constructed. This work unlocks an approach of enzyme-like isolated dual sites in boosting the selectivity of non-protein artificial enzymes.


Asunto(s)
Oxidación-Reducción , Urato Oxidasa , Ácido Úrico , Especificidad por Sustrato , Urato Oxidasa/química , Urato Oxidasa/metabolismo , Ácido Úrico/química , Ácido Úrico/metabolismo , Ácido Úrico/orina , Ligandos , Humanos , Níquel/química , Níquel/metabolismo , Sitios de Unión , Dominio Catalítico , Catálisis , Modelos Moleculares , Espectroscopía de Absorción de Rayos X
3.
Mol Cancer Res ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38888574

RESUMEN

Metabolic reprogramming of aerobic glycolysis contributes to tumorigenesis. High plasma lactate is a critical regulator in the development of many human malignancies; however, the underlying molecular mechanisms of cancer progression in the response to lactate (LA) remain elusive. Here we show that reduction of Yin-Yang 1 (YY1) expression correlated with high LA commonly occurs in various cancer cell types, including B-lymphoma and cervical cancer. Mechanistically, LA induces YY1 nuclear export and degradation via HSP70-mediated autophagy adjacent to mitochondria in a Histidine-rich LAR (LA-responsive) motif-dependent manner. Mutation of the LAR motif blocks LA-mediated YY1 cytoplasmic accumulation and in turn enhances cell apoptosis. Furthermore, low expression of YY1 promotes the colony formation, invasion, angiogenesis and growth of cancer cells in response to LA in vitro and in vivo using a murine xenograft model. Taken together, our findings reveal that a key lactate-responsive` element and may serve as therapeutic target for intervening cancer progression. Implications: We have shown lactate can induce YY1 degradation via its Histidine-rich LAR motif, and low expression of YY1 promotes cancer cell progression in response to lactate, leading to better prediction of YY1-targeting therapy.

4.
J Virol ; 98(6): e0000524, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38717113

RESUMEN

TRIM32 is often aberrantly expressed in many types of cancers. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked with several human malignancies, including Kaposi's sarcoma and primary effusion lymphomas (PELs). Increasing evidence has demonstrated the crucial role of KSHV lytic replication in viral tumorigenesis. However, the role of TRIM32 in herpesvirus lytic replication remains unclear. Here, we reveal that the expression of TRIM32 is upregulated by KSHV in latency, and reactivation of KSHV lytic replication leads to the inhibition of TRIM32 in PEL cells. Strikingly, RTA, the master regulator of lytic replication, interacts with TRIM32 and dramatically promotes TRIM32 for degradation via the proteasome systems. Inhibition of TRIM32 induces cell apoptosis and in turn inhibits the proliferation and colony formation of KSHV-infected PEL cells and facilitates the reactivation of KSHV lytic replication and virion production. Thus, our data imply that the degradation of TRIM32 is vital for the lytic activation of KSHV and is a potential therapeutic target for KSHV-associated cancers. IMPORTANCE: TRIM32 is associated with many cancers and viral infections; however, the role of TRIM32 in viral oncogenesis remains largely unknown. In this study, we found that the expression of TRIM32 is elevated by Kaposi's sarcoma-associated herpesvirus (KSHV) in latency, and RTA (the master regulator of lytic replication) induces TRIM32 for proteasome degradation upon viral lytic reactivation. This finding provides a potential therapeutic target for KSHV-associated cancers.


Asunto(s)
Herpesvirus Humano 8 , Proteínas Inmediatas-Precoces , Transactivadores , Factores de Transcripción , Proteínas de Motivos Tripartitos , Ubiquitina-Proteína Ligasas , Replicación Viral , Humanos , Herpesvirus Humano 8/fisiología , Herpesvirus Humano 8/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Transactivadores/metabolismo , Transactivadores/genética , Proteínas de Motivos Tripartitos/metabolismo , Proteínas de Motivos Tripartitos/genética , Proteínas Inmediatas-Precoces/metabolismo , Proteínas Inmediatas-Precoces/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteolisis , Latencia del Virus , Apoptosis , Activación Viral , Sarcoma de Kaposi/virología , Sarcoma de Kaposi/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Línea Celular , Linfoma de Efusión Primaria/virología , Linfoma de Efusión Primaria/metabolismo
5.
Biomark Res ; 12(1): 33, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38481347

RESUMEN

BACKGROUND: Helicobacter pylori (H pylori) infection is the primary cause of gastric cancer (GC). The role of Disabled-2 (DAB2) in GC remains largely unclear. This study aimed to investigate the role of DAB2 in H pylori-mediated gastric tumorigenesis. METHODS: We screened various datasets of GC to analyze DAB2 expression and cell signaling pathways. DAB2 expression was assessed in human GC tissue microarrays. H pylori infection in vivo and in vitro models were further explored. Immunostaining, immunofluorescence, chromatin immunoprecipitation, co-immunoprecipitation, Western blot, quantitative polymerase chain reaction, and luciferase reporter assays were performed in the current study. RESULTS: The bioinformatic analysis verified that DAB2 was 1 of the 8 genes contributed to tumorigenesis and associated with poor prognosis in GC. The median overall survival and disease-free survival rates in DAB2high group were significantly less than those in DAB2low group. These findings demonstrated that H pylori transcriptionally activated DAB2 expression via signal transducer and activator of transcription 3 (STAT3)-dependent pathway. By bioinformatics analysis and knockdown or overexpression of DAB2, we found that DAB2 upregulated Yes-associated protein 1 (YAP1) transcriptional activity. Mechanistically, DAB2 served as a scaffold protein for integrin beta 3 (ITGB3) and SRC proto-oncogene non-receptor tyrosine kinase (SRC), facilitated the phosphorylation of SRC, promoted the small GTPase ras homolog family member A (RHOA) activation and phosphorylation of YAP1, and ultimately enhanced the YAP1 transcriptional activity. CONCLUSIONS: Altogether, these findings indicated that DAB2 is a key mediator in STAT3-regulated translation of YAP1 and plays crucial roles in H pylori-mediated GC development. DAB2 might serve as a novel therapeutic target for GC.

6.
BMC Pregnancy Childbirth ; 24(1): 166, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38408929

RESUMEN

BACKGROUND: To date, there are no clinical guidelines for dichorionic diamniotic (DCDA) twins complicated with previable premature rupture of membrane (PV-ROM) before 24 weeks of gestation. The typical management options including expectant management and/or pregnant termination, induce the risks of fetal mortality and morbidity. OBJECTIVE: To explore the feasibility selective feticide in DCDA twins complicated with PV-ROM. STUDY DESIGN: A Retrospective cohort study, enrolling 28 DCDA twins suffering from PV-ROM in a tertiary medical center from Jan 01 2012 to Jan 01 2022. The obstetric outcome was compared between selective feticide group and expectant management group. RESULTS: There were 12 cases managed expectantly and 16 underwent selective feticide. More cases suffered from oligohydramnios in expectant management group compared to selective feticide group (P = 0.008). Among 13 cases with ROM of upper sac, the mean gestational age at delivery was (33.9 ± 4.9) weeks in the selective feticide group, which was significantly higher than that in the expectant management (P = 0.038). Five fetuses (83.3%) with selective feticide delivered after 32 weeks, whereas only one (14.3%) case in expectant management group (P = 0.029). However, in the subgroup with ROM of lower sac, no significant difference of the mean gestation age at delivery between groups and none of cases delivered after 32 weeks. CONCLUSION: There was a trend towards an increase in latency interval in DCDA twins with PV-ROM following selective feticide, compared to that with expectant management. Furthermore, selective feticide in cases with PV-ROM of upper sac has a favorable outcome.


Asunto(s)
Aborto Inducido , Rotura Prematura de Membranas Fetales , Femenino , Embarazo , Humanos , Lactante , Resultado del Embarazo , Estudios Retrospectivos , Reducción de Embarazo Multifetal , Gemelos Dicigóticos , Embarazo Gemelar
7.
BMC Public Health ; 24(1): 336, 2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38297279

RESUMEN

BACKGROUND: In 2016, the "universal two-child" policy, allowing each couple to have two children, was introduced in China. The characteristic change of the long-term period after the implementation of the universal two-child policy was unclear. We studied trends in the obstetric characteristics and their potential impact on the rates of cesarean section and preterm birth in the era of China's universal two-child policy. METHODS: A tertiary center-based study (2010-2021) retrospectively focused single high-risk pregnancies who delivered from the one-child policy period (OCP, 2010-2015) to the universal two-child policy period (TCP, 2016-2021). A total of 39, 016 pregnancies were enrolled. Maternal demographics, complications, delivery mode and obstetric outcomes were analyzed. Furthermore, logistic regression analysis was used to explore the association between the cesarean section rate, preterm birth and implementation of the universal two-child policy, adjusting maternal age, parity, and fetal distress. RESULTS: Ultimately a total of 39,016 pregnant women met the criteria and were included in this analysis. The proportion of women with advanced maternal age (AMA) increased from 14.6% in the OCP to 31.6% in the TCP. The number of multiparous women increased 2-fold in the TCP. In addition, the overall rate of cesarean section significantly decreased over the policy change, regardless of maternal age, whereas the risk of preterm birth significantly increased in the TCP. Adjusting for maternal age, parity and fetal distress, the universal two-child policy showed a significantly favorable impact on the cesarean section rate (RR 0.745, 95%CI (0.714-0.777), P < 0.001). Compared to the OCP group, a higher increase in fetal distress and premature rupture of membranes (PROM) were observed in the TCP group. In pregnancies with AMA, there was no increase in the risk of postpartum hemorrhage, whereas more women who younger than 35 years old suffered from postpartum hemorrhage in TCP. The logistic regression model showed that the universal two-child policy was positively associated with the risk of postpartum hemorrhage (RR: 1.135, 95%CI: 1.025-1.257, P = 0.015). CONCLUSIONS: After the implementation of the universal two-child policy in China, the rate of the cesarean section significantly decreased, especially for women under 35 years old. However, the overall risk of postpartum hemorrhage increased in women under 35 years old, while there was no change in women with AMA. Under the new population policy, the prevention of postpartum hemorrhage in the young women should not be neglected.


Asunto(s)
Política de Planificación Familiar , Hemorragia Posparto , Nacimiento Prematuro , Embarazo , Femenino , Recién Nacido , Humanos , Adulto , Cesárea , Estudios Retrospectivos , Mujeres Embarazadas , Nacimiento Prematuro/epidemiología , Sufrimiento Fetal , Paridad , China/epidemiología
8.
Anal Chem ; 95(44): 16407-16417, 2023 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-37883696

RESUMEN

Regulation of the reaction pathways is a perennial theme in the field of chemistry. As a typical chromogenic substrate, 3,3',5,5'-tetramethylbenzidine (TMB) generally undertakes one-electron oxidation, but the product (TMBox1) is essentially a confused complex and is unstable, which significantly hampers the clinic chromogenic bioassays for more than 50 years. Herein, we report that sodium dodecyl sulfate (SDS)-based micelles could drive the direct two-electron oxidation of TMB to the final stable TMBox2. Rather than activation of H2O2 oxidant in the one-electron TMB oxidation by common natural peroxidase, activation of the TMB substrate by SDS micelles decoupled the thermodynamically favorable complex between TMBox2 with unreacted TMB, leading to an unusual direct two-electron oxidation pathway. Mechanism studies demonstrated that the complementary spatial and electrostatic isolation effects, caused by the confined hydrophobic cavities and negatively charged outer surfaces of SDS micelles, were crucial. Further cascading with glucose oxidase, as a proof-of-concept application, allowed glucose to be more reliably measured, even in a broader range of concentrations without any conventional strong acid termination.


Asunto(s)
Peróxido de Hidrógeno , Micelas , Oxidación-Reducción , Peroxidasa/metabolismo , Bencidinas/química , Colorimetría , Compuestos Cromogénicos/química
9.
BMC Pregnancy Childbirth ; 23(1): 715, 2023 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-37805457

RESUMEN

BACKGROUND: Compared to traditional fetal heart rate monitoring (FHR) for the outpatients in clinic, remote FHR monitoring shows real-time assessment of fetal wellbeing at home. The clinical function of remote FHR monitoring in pregnant wome in outpatient is still unclear. OBJECTIVE: To explore the feasibility of remote FHR self-monitoring in singleton pregnant women from southern China. STUDY DESIGN: This prospective cohort study was conducted at one tertiary center in southern China. Pregnant women used a mobile cardiotocogram device to measure the FHR at least once a week until delivery in the remote group. For the control group, pregnant women underwent traditional FHR monitoring once a week in the outpatient clinic. The rate of cesarean section, risk of postpartum hemorrhage and adverse neonatal outcomes were compared between the two groups. All the pregnant women completed a questionnaire survey to evaluate their acquisition of remote FHR self-monitoring. RESULTS: Approximately 500 women were recruited in the remote FHR self-monitoring group (remote group), and 567 women were recruited in the traditional FHR monitoring group (control group). The women in the remote FHR monitoring group were more likely to be nulliparous (P < 0.001), more likely to have a higher education level (P < 0.001) and more likely to be at high risk (P = 0.003). There was no significant difference in the risk of cesarean section (P = 0.068) or postpartum hemorrhage (P = 0.836) between the two groups. No difference in fetal complications was observed across groups, with the exception of the incidence of NICU stays, which was higher in the remote group (12.0% vs. 8.3%, P = 0.044). The questionnaire survey showed that the interval time (P = 0.001) and cost (P = 0.010) of fetal heart rate monitoring were lower in the remote group. Regarding age, prepregnancy BMI, risk factors, education level, maternal risk and household income, senior high school (OR 2.86, 95% CI 1.67-4.90, P < 0.001), undergraduate (OR 2.96, 95% CI 1.73-5.06, P < 0.001), advanced maternal age (OR 1.42, 95% CI 1.07-1.89, P = 0.015) and high-risk pregnancy (OR 1.61, 95% CI 1.11-2.35, P = 0.013) were independent factors for pregnant women to choose remote fetal monitoring. Multiparty (OR 0.33, 95% CI 0.21-0.51, P < 0.001), full-time motherhood (OR 0.47, 95% CI 0.33-0.678, P < 0.001) and high household income (OR 0.67, 95% CI 0.50-0.88, P = 0.004) were negatively correlated with the choice of remote FHR self-monitoring. CONCLUSION: Remote FHR self-monitoring technology has a lower cost and shows potential clinical efficacy for the outpatient setting in southern China. This approach does not increase the risk of cesarean section or adverse neonatal outcomes. It is acceptable among nulliparous pregnant women with a high education level, high household income or high risk. Further research is needed to assess the impact of this technology on obstetric outcomes in different health settings.


Asunto(s)
Cesárea , Hemorragia Posparto , Femenino , Humanos , Recién Nacido , Embarazo , Frecuencia Cardíaca Fetal/fisiología , Estudios Prospectivos , Resultado del Tratamiento , Consulta Remota
10.
Lasers Surg Med ; 55(10): 880-885, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37750246

RESUMEN

BACKGROUND: The detection and continuous monitoring of low-grade squamous intraepithelial lesions (LSIL) within the endocervical canal pose considerable challenges, and the effectiveness of ablation treatment is also constrained. In this context, the potential efficacy of 5-aminolevulinic acid photodynamic therapy (5-ALA PDT) in targeting these concealed lesions merits exploration. The present study undertakes a comprehensive analysis of the clinical effectiveness and safety aspects associated with the utilization of 5-ALA PDT. METHODS: A retrospective analysis was conducted on a cohort of 13 patients who were diagnosed with LSIL within the endocervical canal, concomitant with high-risk human papillomavirus (hrHPV) infection. These patients were subjected to treatment with 5-ALA PDT and subsequently monitored over a period of 3-6 months following the intervention. RESULTS: The study cohort comprised 13 patients, among whom 4 presented with isolated lesions within the endocervical canal, 5 exhibited LSIL involving both the endocervical canal and the cervix vaginal portion, 3 displayed LSIL within the endocervical canal in conjunction with vaginal involvement, and 1 patient demonstrated lesions across all three of these anatomical sites. All identified lesions underwent therapeutic intervention via 5-ALA PDT. Before treatment initiation, 9 patients returned positive results in the liquid-based cytologic test (LBC), 4 displayed concurrent multiple hrHPV infections, and 5 manifested infections specifically with HPV 16/18. Subsequent to the application of 5-ALA PDT, regression was observed in the LBC results of all patients, with only 3 individuals retaining a singular type of hrHPV infection. Adverse reactions following treatment encompassed mild aberrant vaginal secretions and mild to moderately pronounced distending abdominal discomfort, all of which were remitted within a span of 7 days. CONCLUSIONS: Within the context of LSIL within the endocervical canal in association with hrHPV infection, the findings affirm the efficacy and safety of 5-ALA PDT as a viable therapeutic modality.


Asunto(s)
Infecciones por Papillomavirus , Fotoquimioterapia , Lesiones Intraepiteliales Escamosas , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Femenino , Humanos , Cuello del Útero/patología , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/patología , Ácido Aminolevulínico/uso terapéutico , Neoplasias del Cuello Uterino/patología , Estudios Retrospectivos , Frotis Vaginal , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/tratamiento farmacológico , Infecciones por Papillomavirus/diagnóstico , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Lesiones Intraepiteliales Escamosas/complicaciones , Lesiones Intraepiteliales Escamosas/patología , Fármacos Fotosensibilizantes/uso terapéutico
11.
Chem Sci ; 14(24): 6780-6791, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37350812

RESUMEN

A single stimulus leading to multiple responses is an essential function of many biological networks, which enable complex life activities. However, it is challenging to duplicate a similar chemical reaction network (CRN) using non-living chemicals, aiming at the disclosure of the origin of life. Herein, we report a nanozyme-based CRN with feedback and feedforward functions for the first time. It demonstrates multiple responses at different modes and intensities upon a single H2O2 stimulus. In the two-electron cascade oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), the endogenous product H2O2 competitively inhibited substrates in the first one-electron oxidation reaction on a single-atom nanozyme (Co-N-CNTs) and strikingly accelerated the second one-electron oxidation reaction under a micellar nanozyme. As a proof-of-concept, we further confined the nanozymatic network to a microfluidic chip as a simplified artificial cell. It exhibited remarkable selectivity and linearity in the perception of H2O2 stimulus against more than 20 interferences in a wide range of concentrations (0.01-100 mM) and offered an instructive platform for studying primordial life-like processes.

12.
Theranostics ; 13(7): 2368-2383, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37153736

RESUMEN

Background: Lactate is associated with the poor prognosis of many human malignancies. Cervical cancer, one of main causes of women mortality worldwide, is aggressive and absent of effective pharmacological treatment, and its underlying mechanisms of progression remain elusive. Methods: The regulation of ß-catenin to fascin protrusion formation upon acidic lactate (Lactic acid [LA]) stimulation was evaluated through in ß-catenin or fascin deficiency cell line models by immunofluorescence assays, and subcellular fractionation. The effect of ß-catenin and fascin relocation by LA and its antagonist were evaluated by immunohistochemistry assay in patient tissues and mouse tumor xenograft model. Trypsin digestion, Transwell assay, cell proliferation in vitro was performed to explore the role of LA in the cell growth, adhesion and migration. Results: Low concentration of LA significantly promotes cytoskeleton remodeling via `protrusion formation to increase cell adhesion and migration. Mechanistically, upon LA stimulation, ß-catenin diffuses from the cytoplasmic membrane into the nucleus, which in turn induces fascin nuclear-cytoplasm redistribution to the protrusion compartment. Moreover, the antagonist of LA sufficiently blocks the LA-mediated ß-catenin nuclear import, fascin nuclear export, and the growth and invasion of cervical cancer cells in vitro and in vivo using a murine xenograft model. Conclusions: This study uncovers ß-catenin-fascin axis as a key signal in response to extracellular lactate and indicates that antagonist of LA may serve as a potential clinical intervention for cancer development.


Asunto(s)
Neoplasias del Cuello Uterino , beta Catenina , Humanos , Femenino , Ratones , Animales , beta Catenina/metabolismo , Adhesión Celular , Movimiento Celular , Ácido Láctico/farmacología , Línea Celular Tumoral , Proliferación Celular
13.
Nat Commun ; 14(1): 2780, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37188673

RESUMEN

Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. For this goal, seeking catalysts with multiple and modulable reaction pathways is promising but generally hampered by inconsistent reaction conditions and negative internal interferences. Herein, we report an adaptable graphitic C6N6-based copper single-atom catalyst. It drives the basic oxidation of peroxidase substrates by a bound copper-oxo pathway, and undertakes a second gain reaction triggered by light via a free hydroxyl radical pathway. Such multiformity of reactive oxygen-related intermediates for the same oxidation reaction makes the reaction conditions capable to be the same. Moreover, the unique topological structure of CuSAC6N6 along with the specialized donor-π-acceptor linker promotes intramolecular charge separation and migration, thus inhibiting negative interferences of the above two reaction pathways. As a result, a sound basic activity and a superb gain of up to 3.6 times under household lights are observed, superior to that of the controls, including peroxidase-like catalysts, photocatalysts, or their mixtures. CuSAC6N6 is further applied to a glucose biosensor, which can intelligently switch sensitivity and linear detection range in vitro.


Asunto(s)
Cobre , Grafito , Cobre/química , Oxidación-Reducción , Catálisis , Peroxidasa , Peroxidasas , Radicales Libres , Grafito/química , Especies Reactivas de Oxígeno
14.
Angew Chem Int Ed Engl ; 62(27): e202302463, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37144706

RESUMEN

Ascorbate (H2 A) is a well-known antioxidant to protect cellular components from free radical damage and has also emerged as a pro-oxidant in cancer therapies. However, such "contradictory" mechanisms underlying H2 A oxidation are not well understood. Herein, we report Fe leaching during catalytic H2 A oxidation using an Fe-N-C nanozyme as a ferritin mimic and its influence on the selectivity of the oxygen reduction reaction (ORR). Owing to the heterogeneity, the Fe-Nx sites in Fe-N-C primarily catalyzed H2 A oxidation and 4 e- ORR via an iron-oxo intermediate. Nonetheless, trace O2 ⋅- produced by marginal N-C sites through 2 e- ORR accumulated and attacked Fe-Nx sites, leading to the linear leakage of unstable Fe ions up to 420 ppb when the H2 A concentration increased to 2 mM. As a result, a substantial fraction (ca. 40 %) of the N-C sites on Fe-N-C were activated, and a new 2+2 e- ORR path was finally enabled, along with Fenton-type H2 A oxidation. Consequently, after Fe ions diffused into the bulk solution, the ORR at the N-C sites stopped at H2 O2 production, which was the origin of the pro-oxidant effect of H2 A.

15.
Foods ; 12(5)2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36900592

RESUMEN

Mesenchymal stem cells (MSCs) can be used as a cell source for cultivated meat production due to their adipose differentiation potential, but MSCs lose their stemness and undergo replicative senescence during expansion in vitro. Autophagy is an important mechanism for senescent cells to remove toxic substances. However, the role of autophagy in the replicative senescence of MSCs is controversial. Here, we evaluated the changes in autophagy in porcine MSCs (pMSCs) during long-term culture in vitro and identified a natural phytochemical, ginsenoside Rg2, that could stimulate pMSC proliferation. First, some typical senescence characteristics were observed in aged pMSCs, including decreased EdU-positive cells, increased senescence-associated beta-galactosidase activity, declined stemness-associated marker OCT4 expression, and enhanced P53 expression. Importantly, autophagic flux was impaired in aged pMSCs, suggesting deficient substrate clearance in aged pMSCs. Rg2 was found to promote the proliferation of pMSCs using MTT assay and EdU staining. In addition, Rg2 inhibited D-galactose-induced senescence and oxidative stress in pMSCs. Rg2 increased autophagic activity via the AMPK signaling pathway. Furthermore, long-term culture with Rg2 promoted the proliferation, inhibited the replicative senescence, and maintained the stemness of pMSCs. These results provide a potential strategy for porcine MSC expansion in vitro.

16.
Mater Horiz ; 10(5): 1719-1725, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-36857668

RESUMEN

Rechargeable magnesium-ion batteries (MIBs) have received much attention in recent years, but their development remains limited due to a lack of anode materials with high capacity and fast diffusion kinetics. Herein, for the first time, hierarchical BiOX (X = Cl, Br, I) flowerlike microspheres composed of interleaved nanosheets are constructed via a simple room-temperature solid-state chemical reaction as the anode for MIBs. Among them, BiOCl flowerlike microspheres deliver good cycling stability (110 mA h g-1 after 100 cycles) and a superior rate capacity (134 mA h g-1 at 500 mA g-1). This is attributed to their unique flowerlike microsphere structure that not only accommodates a volume change to maintain their structural integrity but also shortens the ion-transport path to improve the diffusion rate. Importantly, ex situ tests were carried out to clarify the phase and structure evolution of the BiOCl flowerlike microspheres during cycling. The results show that BiOCl is first transformed to Bi and then alloyed to Mg3Bi2 in the discharging process, and Mg3Bi2 is turned back to Bi in the charging process. Besides, the initial microsphere structure is essentially maintained during the discharging/charging process, indicating the better stability of the structure. The current study demonstrates that the structural design of flowerlike microspheres is an effective strategy to develop promising anode materials for MIBs.

17.
Sci China Chem ; 66(5): 1318-1335, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36817323

RESUMEN

Emerging as cost-effective potential alternatives to natural enzymes, nanozymes have attracted increasing interest in broad fields. To exploit the in-depth potential of nanozymes, rational structural engineering and explicit catalytic mechanisms at the molecular scale are required. Recently, impressive progress has been made in mimicking the characteristics of natural enzymes by constructing metal active sites, binding pockets, scaffolds, and delicate allosteric regulation. Ingenious in-depth studies have been conducted with advances in structural characterization and theoretical calculations, unveiling the "black box" of nanozyme-catalytic mechanisms. This review introduces the state-of-art synthesis strategies by learning from the natural enzyme counterparts and summarizes the general overview of the nanozyme mechanism with a particular emphasis on the adsorbed intermediates and descriptors that predict the nanozyme activity The emerging activity assessment methodology that illustrates the relationship between electrochemical oxygen reduction and enzymatic oxygen reduction is discussed with up-to-date advances Future opportunities and challenges are presented in the end to spark more profound work and attract more researchers from various backgrounds to the flourishing field of nanozymes.

18.
Nutrients ; 14(18)2022 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36145205

RESUMEN

Exposure to probiotics in early life contributes to host intestinal development and prevention of necrotizing enterocolitis (NEC). Cronobacter sakazakii (C. sakazakii), an opportunistic pathogen, can cause NEC, bacteremia, and meningitis in neonates, but the research of probiotics against C. sakazakii is limited relative to other enteropathogens. Here, the protective effect and mechanism of a novel probiotic Ligilactobacillus salivarius (L. salivarius) YL20 isolated from breast milk on C. sakazakii-induced intestinal injury were explored by using two in vitro models, including an C. sakazakii-infected intestinal organoid model and intestinal barrier model, as well as an in vivo experimental animal model. Our results revealed that L. salivarius YL20 could promote epithelial cell proliferation in intestinal organoids, rescue budding-impaired organoids, prevent the decrease of mRNA levels of leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5), zonula occludens-1 (Zo-1) and Occludin, and reverse C. sakazakii-induced low level of Mucin 2 (MUC2) in intestinal organoids. Additionally, YL20 could inhibit C. sakazakii invasion, increase the expression of ZO-1 and occludin in C. sakazakii-infected HT-29 cells, and reverse TEER decrease and corresponding permeability increase across C. sakazakii-infected Caco-2 monolayers. Furthermore, YL20 administration could alleviate NEC in C. sakazakii-infected neonatal mice by increasing the mice survival ratio, decreasing pathology scores, and downregulating pro-inflammatory cytokines. Meanwhile, YL20 could also enhance intestinal barrier function in vivo by increasing the number of goblet cells, the level of MUC-2 and the expression of ZO-1. Our overall findings demonstrated for the first time the beneficial effects of L. salivarius YL20 against C. sakazakii-induced NEC by improving intestinal stem cell function and enhancing intestinal barrier integrity.


Asunto(s)
Cronobacter sakazakii , Enterocolitis Necrotizante , Enfermedades del Recién Nacido , Ligilactobacillus salivarius , Probióticos , Animales , Células CACO-2 , Citocinas/metabolismo , Modelos Animales de Enfermedad , Enterocolitis Necrotizante/tratamiento farmacológico , Enterocolitis Necrotizante/metabolismo , Enterocolitis Necrotizante/prevención & control , Humanos , Recién Nacido , Mucosa Intestinal/metabolismo , Ligilactobacillus salivarius/genética , Leucina/metabolismo , Ratones , Mucina 2/genética , Mucina 2/metabolismo , Ocludina/metabolismo , Probióticos/farmacología , ARN Mensajero/metabolismo
19.
Science ; 377(6603): 276-284, 2022 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-35857588

RESUMEN

γδ T cells represent a substantial fraction of intestinal lymphocytes at homeostasis, but they also constitute a major lymphocyte population infiltrating colorectal cancers (CRCs); however, their temporal contribution to CRC development or progression remains unclear. Using human CRC samples and murine CRC models, we found that most γδ T cells in premalignant or nontumor colons exhibit cytotoxic markers, whereas tumor-infiltrating γδ T cells express a protumorigenic profile. These contrasting T cell profiles were associated with distinct T cell receptor (TCR)-Vγδ gene usage in both humans and mice. Longitudinal intersectional genetics and antibody-dependent strategies targeting murine γδ T cells enriched in the epithelium at steady state led to heightened tumor development, whereas targeting γδ subsets that accumulate during CRC resulted in reduced tumor growth. Our results uncover temporal pro- and antitumor roles for γδ T cell subsets.


Asunto(s)
Neoplasias Colorrectales , Citotoxicidad Inmunológica , Intestinos , Linfocitos Intraepiteliales , Receptores de Antígenos de Linfocitos T gamma-delta , Animales , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Humanos , Intestinos/inmunología , Linfocitos Intraepiteliales/inmunología , Ratones , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Receptores de Antígenos de Linfocitos T gamma-delta/fisiología
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