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1.
Nat Immunol ; 22(7): 904-913, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34031613

RESUMEN

Antigen-activated B cells diversify variable regions of B cell antigen receptors by somatic hypermutation in germinal centers (GCs). The positive selection of GC B cells that acquire high-affinity mutations enables antibody affinity maturation. In spite of considerable progress, the genomic states underlying this process remain to be elucidated. Single-cell RNA sequencing and topic modeling revealed increased expression of the oxidative phosphorylation (OXPHOS) module in GC B cells undergoing mitoses. Coupled analysis of somatic hypermutation in immunoglobulin heavy chain (Igh) variable gene regions showed that GC B cells acquiring higher-affinity mutations had further elevated expression of OXPHOS genes. Deletion of mitochondrial Cox10 in GC B cells resulted in reduced cell division and impaired positive selection. Correspondingly, augmentation of OXPHOS activity with oltipraz promoted affinity maturation. We propose that elevated OXPHOS activity promotes B cell clonal expansion and also positive selection by tuning cell division times.


Asunto(s)
Linfocitos B/metabolismo , Perfilación de la Expresión Génica , Centro Germinal/metabolismo , Mutación , Fosforilación Oxidativa , Receptores de Antígenos de Linfocitos B/genética , Análisis de la Célula Individual , Transcriptoma , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/metabolismo , Animales , Linfocitos B/inmunología , Proliferación Celular , Células Cultivadas , Análisis Mutacional de ADN , Femenino , Genes de las Cadenas Pesadas de las Inmunoglobulinas , Centro Germinal/inmunología , Región Variable de Inmunoglobulina , Activación de Linfocitos , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/genética , Mitocondrias/metabolismo , RNA-Seq , Receptores de Antígenos de Linfocitos B/metabolismo
2.
Immunity ; 54(12): 2784-2794.e6, 2021 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-34626548

RESUMEN

Self-reactive B cell progenitors are eliminated through central tolerance checkpoints, a process thought to be restricted to the bone marrow in mammals. Here, we identified a consecutive trajectory of B cell development in the meninges of mice and non-human primates. The meningeal B cells were located predominantly at the dural sinuses, where endothelial cells expressed essential niche factors to support B cell development. Parabiosis experiments together with lineage tracing showed that meningeal developing B cells were replenished continuously from hematopoietic stem cell (HSC)-derived progenitors via a circulation-independent route. Autoreactive immature B cells that recognized myelin oligodendrocyte glycoprotein (MOG), a central nervous system-specific antigen, were eliminated specifically from the meninges. Furthermore, genetic deletion of the Mog gene restored the self-reactive B cell population in the meninges. These findings identify the meninges as a distinct reservoir for B cell development, allowing in situ negative selection to ensure a locally non-self-reactive immune repertoire.


Asunto(s)
Células Dendríticas/inmunología , Células Madre Hematopoyéticas/fisiología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Meninges/inmunología , Células Plasmáticas/inmunología , Animales , Anticuerpos Neutralizantes/metabolismo , Antígeno B7-1/metabolismo , Antígenos CD28/metabolismo , Autorrenovación de las Células , Supervivencia Celular , Células Cultivadas , Humanos , Inmunidad Humoral , Memoria Inmunológica , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Ratones , Ratones Endogámicos C57BL
3.
Nature ; 627(8002): 165-173, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38326613

RESUMEN

The arachnoid barrier delineates the border between the central nervous system and dura mater. Although the arachnoid barrier creates a partition, communication between the central nervous system and the dura mater is crucial for waste clearance and immune surveillance1,2. How the arachnoid barrier balances separation and communication is poorly understood. Here, using transcriptomic data, we developed transgenic mice to examine specific anatomical structures that function as routes across the arachnoid barrier. Bridging veins create discontinuities where they cross the arachnoid barrier, forming structures that we termed arachnoid cuff exit (ACE) points. The openings that ACE points create allow the exchange of fluids and molecules between the subarachnoid space and the dura, enabling the drainage of cerebrospinal fluid and limited entry of molecules from the dura to the subarachnoid space. In healthy human volunteers, magnetic resonance imaging tracers transit along bridging veins in a similar manner to access the subarachnoid space. Notably, in neuroinflammatory conditions such as experimental autoimmune encephalomyelitis, ACE points also enable cellular trafficking, representing a route for immune cells to directly enter the subarachnoid space from the dura mater. Collectively, our results indicate that ACE points are a critical part of the anatomy of neuroimmune communication in both mice and humans that link the central nervous system with the dura and its immunological diversity and waste clearance systems.


Asunto(s)
Aracnoides , Encéfalo , Duramadre , Animales , Humanos , Ratones , Aracnoides/anatomía & histología , Aracnoides/irrigación sanguínea , Aracnoides/inmunología , Aracnoides/metabolismo , Transporte Biológico , Encéfalo/anatomía & histología , Encéfalo/irrigación sanguínea , Encéfalo/inmunología , Encéfalo/metabolismo , Duramadre/anatomía & histología , Duramadre/irrigación sanguínea , Duramadre/inmunología , Duramadre/metabolismo , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/metabolismo , Perfilación de la Expresión Génica , Imagen por Resonancia Magnética , Ratones Transgénicos , Espacio Subaracnoideo/anatomía & histología , Espacio Subaracnoideo/irrigación sanguínea , Espacio Subaracnoideo/inmunología , Espacio Subaracnoideo/metabolismo , Líquido Cefalorraquídeo/metabolismo , Venas/metabolismo
4.
Crit Rev Immunol ; 44(6): 49-61, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38848293

RESUMEN

BACKGROUND: Sustained expression of the long noncoding RNA (lncRNA) LINC01106 in tumors is crucial for the malignant phenotype of tumor cells. Nevertheless, the mechanisms and clinical effects of LINC01106 in lung adenocarcinoma (LUAD) are limited. This study shows the effect of vir-like m6A methyltransferase-associated (KIAA1429)-mediated N6-methyladenosine (m6A) modification on steady LINC01106 expression on LUAD progression. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine LINC01106 and KIAA1429 levels in LUAD tissues. Transwell, 5-ethynyl-2'-deoxyuridine (EdU), and cell counting kit-8 (CCK-8) assays were used to analyze the functional roles of LINC01106. A xenograft was constructed to verify the function of silencing LINC01106 in tumor growth. The regulatory role of LINC01106 was investigated using methylated RNA immunoprecipitation (MeRIP), qRT-PCR, and the actinomycin D assay. Western blotting was used to identify key proteins in the JAK/STAT3 (JAK2, STAT3) pathway. RESULTS: LINC01106 and KIAA1429 were highly expressed in LUAD, and LINC01106 was interconnected with high tumor grade, stage, and poor prognosis. Data revealed that LINC01106 inhibition reduced LUAD cell proliferation, invasion, and migration and restrained LUAD cell tumorigenicity. In addition, LINC01106 silencing reduced phosphorylated JAK2 and STAT3 levels. KIAA1429-mediated LINC01106 enhances its m6A modification and expression in LUAD cells. Moreover, KIAA1429 promotion eliminated the malignant phenotypic suppression induced by low expression in LUAD cells. CONCLUSION: This study showed that KIAA1429 enhanced LINC01106 m6A modification to promote LUAD development. These results may lead to a better understanding of the mechanism of KIAA1429-m6A-LINC01106 in LUAD and offer a valuable therapeutic target for LUAD.


Asunto(s)
Adenocarcinoma del Pulmón , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares , ARN Largo no Codificante , Factor de Transcripción STAT3 , Transducción de Señal , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Adenocarcinoma del Pulmón/patología , Animales , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Proliferación Celular/genética , Línea Celular Tumoral , Adenosina/análogos & derivados , Adenosina/metabolismo , Metiltransferasas/metabolismo , Metiltransferasas/genética , Ratones Desnudos , Janus Quinasa 2/metabolismo , Janus Quinasa 2/genética , Movimiento Celular/genética , Femenino , Quinasas Janus/metabolismo , Masculino , Proteínas de Unión al ARN
5.
Neurobiol Dis ; 193: 106457, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38423191

RESUMEN

Epilepsy is a brain disorder affecting up to 1 in 26 individuals. Despite its clinical importance, the molecular mechanisms of epileptogenesis are still far from clarified. Our previous study showed that disruption of Clock in excitatory neurons alters cortical circuits and leads to generation of focal epilepsy. In this study, a GAD-Cre;Clockflox/flox mouse line with conditional Clock gene knockout in inhibitory neurons was established. We observed that seizure latency was prolonged, the severity and mortality of pilocarpine-induced seizure were significantly reduced, and memory was improved in GAD-Cre;Clockflox/flox mice. We hypothesize that mice with CLOCK knockout in inhibitory neurons have increased threshold for seizure, opposite from mice with CLOCK knockout in excitatory neurons. Further investigation showed Clock knockout in inhibitory neurons upregulated the basal protein level of ARC, a synaptic plasticity-associated immediate-early gene product, likely through the BDNF-ERK pathway. Altered basal levels of ARC may play an important role in epileptogenesis after Clock deletion in inhibitory neurons. Although sEPSCs and intrinsic properties of layer 5 pyramidal neurons in the somatosensory cortex exhibit no changes, the spine density increased in apical dendrite of pyramidal neurons in CLOCK knockout group. Our results suggest an underlying mechanism by which the circadian protein CLOCK in inhibitory neurons participates in neuronal activity and regulates the predisposition to epilepsy.


Asunto(s)
Epilepsia , Animales , Ratones , Ansiedad , Susceptibilidad a Enfermedades/metabolismo , Epilepsia/genética , Epilepsia/metabolismo , Ratones Noqueados , Neuronas/metabolismo , Convulsiones/metabolismo
6.
Funct Integr Genomics ; 24(2): 62, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38514486

RESUMEN

Long-wave sensitive (LWS) is a G protein-coupled receptor expressed in the retina, and zebrafish is a better model organism for studying vision, but the role of LWS1 in vision-guided behavior of larvae fish has rarely been reported. In this study, we found that zebrafish lws1 and lws2 are tandemly replicated genes, both with six exons, with lws1 being more evolutionarily conserved. The presence of Y277F in the amino acid sequence of lws2 may have contributed to the shift of λmax to green light. We established a lws1 knockout zebrafish model using CRISPR/Cas9 technology. Lws1-/- larvae showed significantly higher levels of feeding and appetite gene (agrp) expression than WT, and significantly lower levels of anorexia gene (pomc, cart) expression. In addition, green light gene compensation was observed in lws1-/- larvae with significantly increased expression levels of rh2-1. The light-dark movement test showed that lws1-/- larvae were more active under light-dark transitions or vibrational stimuli, and the expression of phototransduction-related genes was significantly up-regulated. This study reveals the important role of lws1 gene in the regulation of vision-guided behavior in larvae.


Asunto(s)
Opsinas de los Conos , Pez Cebra , Animales , Secuencia de Aminoácidos , Pez Cebra/genética , Pez Cebra/metabolismo , Opsinas de los Conos/genética , Conducta Alimentaria , Visión Ocular/genética
7.
Biochem Biophys Res Commun ; 702: 149633, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38341921

RESUMEN

Ribosomal protein 25 (RPS25) has been related to male fertility diseases in humans. However, the role of RPS25 in spermatogenesis has yet to be well understood. RpS25 is evolutionarily highly conserved from flies to humans through sequence alignment and phylogenetic tree construction. In this study, we found that RpS25 plays a critical role in Drosophila spermatogenesis and its knockdown leads to male sterility. Examination of each stage of spermatogenesis from RpS25-knockdown flies showed that RpS25 was not required for initial germline cell divisions, but was required for spermatid elongation and individualization. In RpS25-knockdown testes, the average length of cyst elongation was shortened, the spermatid nuclei bundling was disrupted, and the assembly of individualization complex from actin cones failed, resulting in the failure of mature sperm production. Our data revealed an essential role of RpS25 during Drosophila spermatogenesis through regulating spermatid elongation and individualization.


Asunto(s)
Proteínas de Drosophila , Drosophila , Animales , Humanos , Masculino , Drosophila/genética , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Filogenia , Semen/metabolismo , Espermátides/metabolismo , Espermatogénesis/genética , Espermatozoides/metabolismo , Testículo/metabolismo
8.
BMC Cancer ; 24(1): 353, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38504158

RESUMEN

NUP155 is reported to be correlated with tumor development. However, the role of NUP155 in tumor physiology and the tumor immune microenvironment (TIME) has not been previously examined. This study comprehensively investigated the expression, immunological function, and prognostic significance of NUP155 in different cancer types. Bioinformatics analysis revealed that NUP155 was upregulated in 26 types of cancer. Additionally, NUP155 upregulation was strongly correlated with advanced pathological or clinical stages and poor prognosis in several cancers. Furthermore, NUP155 was significantly and positively correlated with DNA methylation, tumor mutational burden, microsatellite instability, and stemness score in most cancers. Additionally, NUP155 was also found to be involved in TIME and closely associated with tumor infiltrating immune cells and immunoregulation-related genes. Functional enrichment analysis revealed a strong correlation between NUP155 and immunomodulatory pathways, especially antigen processing and presentation. The role of NUP155 in breast cancer has not been examined. This study, for the first time, demonstrated that NUP155 was upregulated in breast invasive carcinoma (BRCA) cells and revealed its oncogenic role in BRCA using molecular biology experiments. Thus, our study highlights the potential value of NUP155 as a biomarker in the assessment of prognostic prediction, tumor microenvironment and immunotherapeutic response in pan-cancer.


Asunto(s)
Neoplasias de la Mama , Carcinoma , Humanos , Femenino , Neoplasias de la Mama/genética , Apoptosis , Mama , Proliferación Celular/genética , Pronóstico , Microambiente Tumoral/genética , Proteínas de Complejo Poro Nuclear/genética
9.
Nature ; 556(7699): 74-79, 2018 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-29590094

RESUMEN

Majorana zero-modes-a type of localized quasiparticle-hold great promise for topological quantum computing. Tunnelling spectroscopy in electrical transport is the primary tool for identifying the presence of Majorana zero-modes, for instance as a zero-bias peak in differential conductance. The height of the Majorana zero-bias peak is predicted to be quantized at the universal conductance value of 2e2/h at zero temperature (where e is the charge of an electron and h is the Planck constant), as a direct consequence of the famous Majorana symmetry in which a particle is its own antiparticle. The Majorana symmetry protects the quantization against disorder, interactions and variations in the tunnel coupling. Previous experiments, however, have mostly shown zero-bias peaks much smaller than 2e2/h, with a recent observation of a peak height close to 2e2/h. Here we report a quantized conductance plateau at 2e2/h in the zero-bias conductance measured in indium antimonide semiconductor nanowires covered with an aluminium superconducting shell. The height of our zero-bias peak remains constant despite changing parameters such as the magnetic field and tunnel coupling, indicating that it is a quantized conductance plateau. We distinguish this quantized Majorana peak from possible non-Majorana origins by investigating its robustness to electric and magnetic fields as well as its temperature dependence. The observation of a quantized conductance plateau strongly supports the existence of Majorana zero-modes in the system, consequently paving the way for future braiding experiments that could lead to topological quantum computing.

10.
Arch Toxicol ; 98(3): 865-881, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38212449

RESUMEN

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is correlated with poor prognosis, the current treatment of which is still based on surgery and adjuvant targeted therapy with monoclonal antibody. Problems of drug resistance hinder the use of monoclonal antibodies. Subsequently, tyrosine kinase inhibitors (TKIs) have been noticed, TKIs have the advantages of multi-targets and reduced drug resistance. However, TKIs that target HER family proteins often cause adverse effects such as liver damage and diarrhea. Thus, TKIs with high selectivity are being developed. TH-4000, a prodrug that generated an active form TH-4000Effector (TH-4000E) under hypoxic condition, was evaluated in this research. We found that TH-4000E ([(E)-4-[[4-(3-bromo-4-chloroanilino)pyrido[3,4-d]pyrimidin-6-yl]amino]-4-oxobut-2-enyl]-dimethyl-[(3-methyl-5-nitroimidazol-4-yl)methyl]azanium) (1-1000 nM) had potent and highly selective toxic effects on HER2+ breast cancer cells and inhibited the phosphorylation of HER family kinases at lower doses than that of Lapatinib and Tucatinib. TH-4000E activated Caspase-3 and induced apoptosis through a reactive oxygen species (ROS)-dependent pathway. The prodrug TH-4000 ([(E)-4-[[4-(3-bromo-4-chloroanilino)pyrido[3,4-d]pyrimidin-6-yl]amino]-4-oxobut-2-enyl]-dimethyl-[(3-methyl-5-nitroimidazol-4-yl)methyl]azanium;bromide) (50 mg/kg) effectively suppressed the tumor growth with less liver damage in mouse tumor models. This hypoxia-targeted strategy has possessed advantage in avoiding drug-induced liver damage, TH-4000 could be a promising drug candidate for the treatment of HER2+ breast cancer.


Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Neoplasias , Profármacos , Humanos , Animales , Ratones , Femenino , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Receptor ErbB-2/metabolismo , Receptor ErbB-2/uso terapéutico , Lapatinib/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral
11.
BMC Urol ; 24(1): 81, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589861

RESUMEN

OBJECTIVE: To observe the safety and short-term outcomes of a new way of laparoscopic trocar placement in pediatric robotic-assisted Lich-Gregoir ureteral reimplantation for vesicoureteral reflux. METHODS: The retrospective study included 32 patients under 14 years diagnosed with primary vesicoureteral reflux (VUR). All these patients underwent robotic-assisted Lich-Gregoir ureteral reimplantation in our department from December 2020 to August 2022. These patients were divided into the following groups according to the different ways of trocar placement: 13 patients in group single-port plus one (SR) and 19 patients in group multiple-port (MR). Patients' characteristics as well as their perioperative and follow-up data were collected and evaluated. RESULTS: There was no significant difference in the data regarding patients' characteristics and preoperative data. These data included the grade of vesicoureteral reflux according to the voiding cystourethrogram (VCUG), and the differential degree of renal function (DRF) at the following time points: preoperative, postoperative, and comparison of preoperative and postoperative. There was no difference between the two groups. During surgery, the time of artificial pneumoperitoneum establishment, ureteral reimplantation time, and total operative time in the SR group were longer than those in the MR group. Yet only the time of artificial pneumoperitoneum establishment shows a statistical difference (P < 0.0001). Also, the peri-operative data, including the volume of blood loss, fasting time, hospitalization, and length of time that a ureteral catheter remained in place, and the number of postoperative complications demonstrate no difference. In addition, the SFU grade and VCUG grade at the following time point also show no difference between the two groups. CONCLUSION: The study demonstrates that SR in robotic-assisted Lich-Gregoir ureteral reimplantation has reached the same surgical effects as MR. In addition, the single-port plus one trocar placement receives a higher cosmetic satisfaction score from parents and did not increase the surgical time and complexity.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Uréter , Reflujo Vesicoureteral , Niño , Humanos , Reflujo Vesicoureteral/cirugía , Estudios Retrospectivos , Procedimientos Quirúrgicos Urológicos , Resultado del Tratamiento , Uréter/cirugía , Reimplantación
12.
Int J Mol Sci ; 25(9)2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38731824

RESUMEN

Agar, as a seaweed polysaccharide mainly extracted from Gracilariopsis lemaneiformis, has been commercially applied in multiple fields. To investigate factors indicating the agar accumulation in G. lemaneiformis, the agar content, soluble polysaccharides content, and expression level of 11 genes involved in the agar biosynthesis were analysed under 4 treatments, namely salinity, temperature, and nitrogen and phosphorus concentrations. The salinity exerted the greatest impact on the agar content. Both high (40‱) and low (10‱, 20‱) salinity promoted agar accumulation in G. lemaneiformis by 4.06%, 2.59%, and 3.00%, respectively. The content of agar as a colloidal polysaccharide was more stable than the soluble polysaccharide content under the treatments. No significant correlation was noted between the two polysaccharides, and between the change in the agar content and the relative growth rate of the algae. The expression of all 11 genes was affected by the 4 treatments. Furthermore, in the cultivar 981 with high agar content (21.30 ± 0.95%) compared to that (16.23 ± 1.59%) of the wild diploid, the transcriptional level of 9 genes related to agar biosynthesis was upregulated. Comprehensive analysis of the correlation between agar accumulation and transcriptional level of genes related to agar biosynthesis in different cultivation conditions and different species of G. lemaneiformis, the change in the relative expression level of glucose-6-phosphate isomerase II (gpiII), mannose-6-phosphate isomerase (mpi), mannose-1-phosphate guanylyltransferase (mpg), and galactosyltransferase II (gatII) genes was highly correlated with the relative agar accumulation. This study lays a basis for selecting high-yield agar strains, as well as for targeted breeding, by using gene editing tools in the future.


Asunto(s)
Agar , Rhodophyta , Rhodophyta/genética , Rhodophyta/metabolismo , Rhodophyta/crecimiento & desarrollo , Salinidad , Regulación de la Expresión Génica de las Plantas , Polisacáridos/metabolismo , Polisacáridos/biosíntesis , Temperatura , Nitrógeno/metabolismo
13.
Molecules ; 29(5)2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38474480

RESUMEN

Since the discovery of classical chiral oxazoline ferrocene ligands in 1995, they have become pivotal in transition metal-catalyzed asymmetric transformations. Over the past decade, a notable evolution has been observed with the emergence of siloxane-substituted oxazoline ferrocenes, demonstrating significant potential as chiral ligands and catalysts. These compounds have consistently delivered exceptional results in diverse and mechanistically distinct transformations, surpassing the capabilities of classical oxazoline ferrocene ligands. This review meticulously delineates the research progress on siloxane-substituted oxazoline ferrocene compounds. It encompasses the synthesis of crucial precursors and desired products, highlights their achievements in asymmetric catalysis reactions, and delves into the exploration of the derivatization of these compounds, emphasizing the introduction of ionophilic groups and their impact on the recovery of transition metal catalysts. In addition to presenting the current state of knowledge, this review propels future research directions by identifying potential topics for further investigation concerning the siloxane-tagged derivatives. These derivatives are poised to be promising candidates for the next generation of highly efficient ligands and catalysts.

14.
J Integr Plant Biol ; 66(5): 973-985, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38391049

RESUMEN

Starch is a major storage carbohydrate in plants and is critical in crop yield and quality. Starch synthesis is intricately regulated by internal metabolic processes and external environmental cues; however, the precise molecular mechanisms governing this process remain largely unknown. In this study, we revealed that high red to far-red (high R:FR) light significantly induces the synthesis of leaf starch and the expression of synthesis-related genes, whereas low R:FR light suppress these processes. Arabidopsis phytochrome B (phyB), the primary R and FR photoreceptor, was identified as a critical positive regulator in this process. Downstream of phyB, basic leucine zipper transcription factor ELONGATED HYPOCOTYL5 (HY5) was found to enhance starch synthesis, whereas the basic helix-loop-helix transcription factors PHYTOCHROME INTERACTING FACTORs (PIF3, PIF4, and PIF5) inhibit starch synthesis in Arabidopsis leaves. Notably, HY5 and PIFs directly compete for binding to a shared G-box cis-element in the promoter region of genes encoding starch synthases GBSS, SS3, and SS4, which leads to antagonistic regulation of their expression and, consequently, starch synthesis. Our findings highlight the vital role of phyB in enhancing starch synthesis by stabilizing HY5 and facilitating PIFs degradation under high R:FR light conditions. Conversely, under low R:FR light, PIFs predominantly inhibit starch synthesis. This study provides insight into the physiological and molecular functions of phyB and its downstream transcription factors HY5 and PIFs in starch synthesis regulation, shedding light on the regulatory mechanism by which plants synchronize dynamic light signals with metabolic cues to module starch synthesis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Fitocromo B , Almidón , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Luz , Fototransducción , Fitocromo B/metabolismo , Fitocromo B/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/efectos de la radiación , Almidón/metabolismo , Almidón/biosíntesis
15.
Angew Chem Int Ed Engl ; 63(19): e202402053, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38494439

RESUMEN

Direct synthesis of dimethyl carbonate (DMC) from CO2 plays an important role in carbon neutrality, but its efficiency is still far from the practical application, due to the limited understanding of the reaction mechanism and rational design of efficient catalyst. Herein, abundant electron-enriched lattice oxygen species were introduced into CeO2 catalyst by constructing the point defects and crystal-terminated phases in the crystal reconstruction process. Benefitting from the acid-base properties modulated by the electron-enriched lattice oxygen, the optimized CeO2 catalyst exhibited a much higher DMC yield of 22.2 mmol g-1 than the reported metal-oxide-based catalysts at the similar conditions. Mechanistic investigations illustrated that the electron-enriched lattice oxygen can provide abundant sites for CO2 adsorption and activation, and was advantageous of the formation of the weakly adsorbed active methoxy species. These were facilitating to the coupling of methoxy and CO2 for the key *CH3OCOO intermediate formation. More importantly, the weakened adsorption of *CH3OCOO on the electron-enriched lattice oxygen can switch the rate-determining-step (RDS) of DMC synthesis from *CH3OCOO formation to *CH3OCOO dissociation, and lower the corresponding activation barriers, thus giving rise to a high performance. This work provides insights into the underlying reaction mechanism for DMC synthesis from CO2 and methanol and the design of highly efficient catalysts.

16.
Angew Chem Int Ed Engl ; 63(21): e202401973, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38520059

RESUMEN

The inherently huge volume expansion during Li uptake has hindered the use of Si-based anodes in high-energy lithium-ion batteries. While some pore-forming and nano-architecting strategies show promises to effectively buffer the volume change, other parameters essential for practical electrode fabrication, such as compaction density, are often compromised. Here we propose a new in situ Mg doping strategy to form closed-nanopore structure into a micron-sized SiOx particle at a high bulk density. The doped Mg atoms promote the segregation of O, so that high-density magnesium silicates form to generate closed nanopores. By altering the mass content of Mg dopant, the average radii (ranged from 5.4 to 9.7 nm) and porosities (ranged from 1.4 % to 15.9 %) of the closed pores are precisely adjustable, which accounts for volume expansion of SiOx from 77.8 % to 22.2 % at the minimum. Benefited from the small volume variation, the Mg-doped micron-SiOx anode demonstrates improved Li storage performance towards realization of a 700-(dis)charge-cycle, 11-Ah-pouch-type cell at a capacity retention of >80 %. This work offers insights into reasonable design of the internal structure of micron-sized SiOx and other materials that undergo conversion or alloying reactions with drastic volume change, to enable high-energy batteries with stable electrochemistry.

17.
BMC Bioinformatics ; 24(1): 270, 2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37386390

RESUMEN

PURPOSE: Most Hepatocellular carcinoma (HCC) patients are in advanced or metastatic stage at the time of diagnosis. Prognosis for advanced HCC patients is dismal. This study was based on our previous microarray results, and aimed to explore the promising diagnostic and prognostic markers for advanced HCC by focusing on the important function of KLF2. METHODS: The Cancer Genome Atlas (TCGA), Cancer Genome Consortium database (ICGC), and the Gene Expression Comprehensive Database (GEO) provided the raw data of this study research. The cBioPortal platform, CeDR Atlas platform, and the Human Protein Atlas (HPA) website were applied to analyze the mutational landscape and single-cell sequencing data of KLF2. Basing on the results of single-cell sequencing analyses, we further explored the molecular mechanism of KLF2 regulation in the fibrosis and immune infiltration of HCC. RESULTS: Decreased KLF2 expression was discovered to be mainly regulated by hypermethylation, and indicated a poor prognosis of HCC. Single-cell level expression analyses revealed KLF2 was highly expressed in immune cells and fibroblasts. The function enrichment analysis of KLF2 targets indicated the crucial association between KLF2 and tumor matrix. 33-genes related with cancer associated fibroblasts (CAFs) were collected to identify the significant association of KLF2 with fibrosis. And SPP1 was validated as a promising prognostic and diagnostic marker for advanced HCC patients. CXCR6 CD8+ T cells were noted as a predominant proportion in the immune microenvironment, and T cell receptor CD3D was discovered to be a potential therapeutic biomarker for HCC immunotherapy. CONCLUSION: This study identified that KLF2 is an important factor promoting HCC progression by affecting the fibrosis and immune infiltration, highlighting its great potential as a novel prognostic biomarker for advanced HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Linfocitos T CD8-positivos , Pronóstico , Neoplasias Hepáticas/genética , Fibrosis , Microambiente Tumoral/genética , Factores de Transcripción de Tipo Kruppel/genética
18.
J Cell Physiol ; 238(12): 2867-2878, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37850660

RESUMEN

The melanocortin 4 receptor (MC4R) is a G protein-coupled transporter that mediates the regulation of thyroid hormones and leptin on energy balance and food intake. However, the mechanisms of transcriptional regulation of Mc4r by thyroid hormone and leptin in fish have been rarely reported. The messenger RNA expression of Mc4r gene was significantly higher in brain than those in other tissues of mandarin fish. We analyzed the structure and function of a 2029 bp sequence of Mc4r promoter. Meanwhile, overexpression of NKX2.1 and incubation with leptin significantly increased Mc4r promoter activity, but triiodothyronine showed the opposite effect. In addition, mutations in the NKX2.1 binding site abolished not only the activation of Mc4r promoter activity by leptin but also the inhibitory effect of thyroid hormones on Mc4r promoter activity. In summary, these results suggested that thyroid hormones and leptin might regulate the transcriptional expression of Mc4r through NKX2.1.


Asunto(s)
Peces , Genes Homeobox , Leptina , Animales , Proteínas de Unión al ADN/genética , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Peces/genética , Peces/metabolismo , Leptina/genética , Leptina/farmacología , Regiones Promotoras Genéticas/genética , Receptor de Melanocortina Tipo 4/genética , Receptor de Melanocortina Tipo 4/metabolismo , Hormonas Tiroideas , Factor Nuclear Tiroideo 1/genética , Factor Nuclear Tiroideo 1/metabolismo , Humanos , Células HEK293
19.
Ann Surg ; 277(2): e439-e448, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33630430

RESUMEN

OBJECTIVE: To investigate the effectiveness of a CTC-based classifier in stratifying stage IB LUAD. SUMMARY OF BACKGROUND DATA: Stage IB LUADs have an approximately 70% 5-year survival rate. The clinical application of ACT is controversial due to inconsistent results in a series of trials and few useful guide biomarkers. Thus, there is a pressing need for robust biomarkers to stratify stage IB patients to define which group would most likely benefit from ACT. Methods: Two hundred twelve stage IB LUAD patients were enrolled and were divided into 3 independent cohorts. The aptamer-modified NanoVelcro system was used to enrich the CTCs. RESULTS: A cutoff of <4 or >4 CTCs as the optimal prognostic threshold for stage IB LUAD was generated to stratify the patients in a 70-patient cohort into low-risk and high-risk groups. Patients with ≥ 4 CTCs in the training cohort had shorter progression-free survival ( P < 0.0001) and overall survival ( P < 0.0001) than patients with <4 CTCs. CTC number remained the strongest predictor of progression-free survival and overall survival even in a multivariate analysis including other clinicopathological parameters. Furthermore, a nomogram based on the CTC count was developed to predict the 3-year and 5-year survival in the training cohort and performed well in the other 2 validation cohorts (C-index: 0.862, 0.853, and 0.877). CONCLUSION: The presence of >4 CTCs can define a high-risk subgroup, providing a new strategy to make optimal clinical decisions for stage IB LUAD.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Células Neoplásicas Circulantes , Humanos , Relevancia Clínica , Estudios de Cohortes
20.
Plant Cell ; 32(5): 1574-1588, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32152188

RESUMEN

Leaf senescence is tightly regulated by numerous internal cues and external environmental signals. The process of leaf senescence is promoted by a low ratio of red to far-red (R:FR) light, FR light, or extended darkness and is repressed by a high ratio of R:FR light or R light. However, the precise regulatory mechanisms by which plants assess external light signals and their internal cues to initiate and control the process of leaf senescence remain largely unknown. In this study, we discovered that the light-signaling protein FAR-RED ELONGATED HYPOCOTYL3 (FHY3) negatively regulates age-induced and light-mediated leaf senescence in Arabidopsis (Arabidopsis thaliana). FHY3 directly binds to the promoter region of transcription factor gene WRKY28 to repress its expression, thus negatively regulating salicylic acid biosynthesis and senescence. Both the fhy3 loss-of-function mutant and WRKY28-overexpressing Arabidopsis plants exhibited early senescence under high R:FR light conditions, indicating that the FHY3-WRKY28 transcriptional module specifically prevents leaf senescence under high R:FR light conditions. This study reveals the physiological and molecular functions of FHY3 and WRKY28 in leaf senescence and provides insight into the regulatory mechanism by which plants integrate dynamic environmental light signals and internal cues to initiate and control leaf senescence.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Fototransducción , Fitocromo/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/efectos de la radiación , Arabidopsis/efectos de los fármacos , Secuencia de Bases , Luz , Fototransducción/efectos de los fármacos , Fototransducción/efectos de la radiación , Mutación/genética , Hojas de la Planta/efectos de los fármacos , Regiones Promotoras Genéticas , Unión Proteica/efectos de los fármacos , Unión Proteica/efectos de la radiación , Ácido Salicílico/farmacología , Transcripción Genética/efectos de los fármacos , Transcripción Genética/efectos de la radiación
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