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1.
Nat Immunol ; 22(9): 1127-1139, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34413521

RESUMEN

Follicular helper T (TFH) cells are a specialized subset of CD4+ T cells that essentially support germinal center responses where high-affinity and long-lived humoral immunity is generated. The regulation of TFH cell survival remains unclear. Here we report that TFH cells show intensified lipid peroxidation and altered mitochondrial morphology, resembling the features of ferroptosis, a form of programmed cell death that is driven by iron-dependent accumulation of lipid peroxidation. Glutathione peroxidase 4 (GPX4) is the major lipid peroxidation scavenger and is necessary for TFH cell survival. The deletion of GPX4 in T cells selectively abrogated TFH cells and germinal center responses in immunized mice. Selenium supplementation enhanced GPX4 expression in T cells, increased TFH cell numbers and promoted antibody responses in immunized mice and young adults after influenza vaccination. Our findings reveal the central role of the selenium-GPX4-ferroptosis axis in regulating TFH homeostasis, which can be targeted to enhance TFH cell function in infection and following vaccination.


Asunto(s)
Ferroptosis/fisiología , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Selenio/farmacología , Células T Auxiliares Foliculares/fisiología , Adolescente , Adulto , Animales , Supervivencia Celular/inmunología , Niño , Femenino , Centro Germinal/citología , Centro Germinal/inmunología , Homeostasis/efectos de los fármacos , Homeostasis/genética , Humanos , Inmunidad Humoral/inmunología , Vacunas contra la Influenza/inmunología , Peroxidación de Lípido/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/fisiología , Ovalbúmina , Células T Auxiliares Foliculares/inmunología , Vacunación , Adulto Joven
4.
Proc Natl Acad Sci U S A ; 121(45): e2406174121, 2024 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-39471219

RESUMEN

Mitochondria play diverse roles in mammalian physiology. The architecture, activity, and physiological functions of mitochondria in oocytes are largely different from those in somatic cells, but the mitochondrial proteins related to oocyte quality and reproductive longevity remain largely unknown. Here, using whole-exome sequencing data from 1,024 women (characterized by oocyte maturation arrest and degenerated or morphologically abnormal oocytes) and 2,868 healthy controls, we performed a population and gene-based burden test for mitochondrial genes and identified a candidate gene, cytochrome c oxidase assembly protein 15 (COX15). We report that biallelic COX15 pathogenic variants cause human oocyte ferroptosis and female infertility in a recessive inheritance pattern. COX15 variants impaired mitochondrial respiration in Saccharomyces cerevisiae and led to reduced protein levels in HeLa cells. Oocyte-specific deletion of Cox15 led to impaired Fe2+ and reactive oxygen species homeostasis that caused mitochondrial dysfunction and ultimately sensitized oocytes to ferroptosis. In addition, ferrostatin-1 (an inhibitor of ferroptosis) could rescue the oocyte ferroptosis phenotype in vitro and ex vivo. Our findings not only provide a genetic diagnostic marker for oocyte development defects but also expand the spectrum of mitochondrial disorders to female infertility and contribute to unique insights into the role of ferroptosis in human oocyte defects.


Asunto(s)
Ferroptosis , Mitocondrias , Oocitos , Humanos , Oocitos/metabolismo , Femenino , Ferroptosis/genética , Mitocondrias/metabolismo , Mitocondrias/genética , Infertilidad Femenina/genética , Infertilidad Femenina/metabolismo , Infertilidad Femenina/patología , Células HeLa , Especies Reactivas de Oxígeno/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Adulto , Secuenciación del Exoma
5.
Development ; 150(10)2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37213079

RESUMEN

Dentin is the major hard tissue of teeth formed by differentiated odontoblasts. How odontoblast differentiation is regulated remains enigmatic. Here, we report that the E3 ubiquitin ligase CHIP is highly expressed in undifferentiated dental mesenchymal cells and downregulated after differentiation of odontoblasts. Ectopic expression of CHIP inhibits odontoblastic differentiation of mouse dental papilla cells, whereas knockdown of endogenous CHIP has opposite effects. Chip (Stub1) knockout mice display increased formation of dentin and enhanced expression of odontoblast differentiation markers. Mechanistically, CHIP interacts with and induces K63 polyubiquitylation of the transcription factor DLX3, leading to its proteasomal degradation. Knockdown of DLX3 reverses the enhanced odontoblastic differentiation caused by knockdown of CHIP. These results suggest that CHIP inhibits odontoblast differentiation by targeting its tooth-specific substrate DLX3. Furthermore, our results indicate that CHIP competes with another E3 ubiquitin ligase, MDM2, that promotes odontoblast differentiation by monoubiquitylating DLX3. Our findings suggest that the two E3 ubiquitin ligases CHIP and MDM2 reciprocally regulate DLX3 activity by catalyzing distinct types of ubiquitylation, and reveal an important mechanism by which differentiation of odontoblasts is delicately regulated by divergent post-translational modifications.


Asunto(s)
Odontoblastos , Diente , Animales , Ratones , Diferenciación Celular/genética , Ratones Noqueados , Diente/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
6.
Plant J ; 120(1): 199-217, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39136690

RESUMEN

Maintaining an optimal redox status is essential for plant growth and development, particularly when the plants are under stress. AT-hook motif nuclear localized (AHL) proteins are evolutionarily conserved transcription factors in plants. Much of our understanding about this gene family has been derived from studies on clade A members. To elucidate the functions of clade B genes, we first analyzed their spatial expression patterns using transgenic plants expressing a nuclear localized GFP under the control of their promoter sequences. AHL1, 2, 6, 7, and 10 were further functionally characterized owing to their high expression in the root apical meristem. Through mutant analyses and transgenic studies, we showed that these genes have the ability to promote root growth. Using yeast one-hybrid and dual luciferase assays, we demonstrated that AHL1, 2, 6, 7, and 10 are transcription regulators and this activity is required for their roles in root growth. Although mutants for these genes did not showed obvious defects in root growth, transgenic plants expressing their fusion proteins with the SRDX repressor motif exhibited a short-root phenotype. Through transcriptome analysis, histochemical staining and molecular genetics experiments, we found that AHL10 maintains redox homeostasis via direct regulation of glutathione transferase (GST) genes. When the transcript level of GSTF2, a top-ranked target of AHL10, was reduced by RNAi, the short-root phenotype in the AHL10-SRDX expressing plant was largely rescued. These results together suggest that AHL genes function redundantly in promoting root growth through direct regulation of redox homeostasis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Homeostasis , Oxidación-Reducción , Raíces de Plantas , Plantas Modificadas Genéticamente , Factores de Transcripción , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Secuencias AT-Hook/genética
7.
Hepatology ; 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38861680

RESUMEN

BACKGROUND AND AIMS: Biliary tract cancers are aggressive gastrointestinal malignancies characterized by a dismal 5-year overall survival rate <20%. Current diagnostic modalities suffer from limitations regarding sensitivity and specificity. This study aimed to develop a bile metabolite-based platform for precise discrimination between malignant and benign biliary diseases. APPROACH AND RESULTS: Samples were collected from 336 patients with biliary tract cancer or benign biliary diseases across 3 independent cohorts. Untargeted metabolic fingerprinting was performed on 300 bile samples using novel nanoparticle-enhanced laser desorption/ionization mass spectrometry. Subsequently, a diagnostic assay was developed based on the exploratory cohort using a selected bile metabolic biomarker panel, with performance evaluated in the validation cohort. Further external validation of disease-specific metabolites from bile samples was conducted in a prospective cohort (n = 36) using quantitative analysis. As a result, we established a novel bile-based assay, BileMet, for the rapid and precise detection of malignancies in the biliary tract system with an AUC of 0.891. We identified 6-metabolite biomarker candidates and discovered the critical role of the chenodeoxycholic acid glycine conjugate as a protective metabolite associated with biliary tract cancer. CONCLUSIONS: Our findings confirmed the improved diagnostic capabilities of BileMet assay in a clinical setting. If applied, the BileMet assay enables intraoperative testing and fast medical decision-making for cases with suspected malignancy where brush cytology detection fails to support malignancy, ultimately reducing the economic burden by over 90%.

8.
Plant Physiol ; 194(4): 2372-2386, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38096479

RESUMEN

Stem cells are essential to plant growth and development. Through data mining, we identified five DEVIL-like (DVL) small peptide genes that are preferentially expressed in the quiescent center of Arabidopsis (Arabidopsis thaliana) root but whose functions are unknown. When overexpressed, these genes caused a dramatic decrease in root length and pleiotropic phenotypes in the shoot. No root-growth defect was observed in the single-gene mutants, but the quintuple mutant exhibited slightly longer roots than the wild type (WT). Through transcriptome analysis with DVL20-overexpressing plants, we found that many genes involved in abscisic acid (ABA) signaling were regulated by these peptides. Consistent with this finding, we demonstrated that, relative to the WT, DVL20-overexpressing plants were more tolerant whereas the quintuple mutant was more sensitive to ABA. Using RT-qPCR, we showed that ABA signaling-associated genes were affected in an opposite manner when the plants were grown in normal or ABA-containing medium. Strikingly, ectopic expression of ABA signaling genes such as PYRABACTIN RESISTANCE 1-LIKE (PYL) 4, 5, or 6 or suppression of HIGHLY ABA-INDUCED 2 (HAI2) and MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE 18 (MAPKKK18) not only largely rescued the root growth defects in DVL20-overexpressing plants in normal growth condition but also conferred tolerance to ABA. Based on these results, we propose that DVL1, 2, 5, 8 and 20 function redundantly in root stem-cell maintenance under abiotic stress, and this role is achieved via ABA signaling.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/farmacología , Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Péptidos/metabolismo , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas , Plantas Modificadas Genéticamente/metabolismo
9.
Gut ; 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39349007

RESUMEN

BACKGROUND: The potency of T cell-mediated responses is a determinant of immunotherapy effectiveness in treating malignancies; however, the clinical efficacy of T-cell therapies has been limited in hepatocellular carcinoma (HCC) owing to the extensive immunosuppressive microenvironment. OBJECTIVE: Here, we aimed to investigate the key genes contributing to immune escape in HCC and raise a new therapeutic strategy for remoulding the HCC microenvironment. DESIGN: The genome-wide in vivo clustered regularly interspaced short palindromic repeats (CRISPR) screen library was conducted to identify the key genes associated with immune tolerance. Single-cell RNA-seq (scRNA-seq), flow cytometry, HCC mouse models, chromatin immunoprecipitation and coimmunoprecipitation were used to explore the function and mechanism of adenylate cyclase 7 (ADCY7) in HCC immune surveillance. RESULTS: Here, a genome-wide in vivo CRISPR screen identified a novel immune modulator-ADCY7. The transmembrane protein ADCY7 undergoes subcellular translocation via caveolae-mediated endocytosis and then translocates to the nucleus with the help of leucine-rich repeat-containing protein 59 (LRRC59) and karyopherin subunit beta 1 (KPNB1). In the nucleus, it functions as a transcription cofactor of CCAAT/enhancer binding protein alpha (CEBPA) to induce CCL5 transcription, thereby increasing CD8+ T cell infiltration to restrain HCC progression. Furthermore, ADCY7 can be secreted as exosomes and enter neighbouring tumour cells to promote CCL5 induction. Exosomes with high ADCY7 levels promote intratumoural infiltration of CD8+ T cells and suppress HCC tumour growth. CONCLUSION: We delineate the unconventional function and subcellular location of ADCY7, highlighting its pivotal role in T cell-mediated immunity in HCC and its potential as a promising treatment target.

10.
J Neurochem ; 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39374168

RESUMEN

High-fat diet (HFD)-induced obesity induces peripheral inflammation and hypothalamic pathogenesis linking the activation of astrocytes and microglia. Clinical evidence indicates a positive correlation between obesity and psychiatric disorders, such as depression. The connectivity of the frontal-striatal (FS) circuit, involving the caudate putamen (CPu) and anterior cingulate cortex (ACC) within the prefrontal cortex (PFC), is known for its role in stress-induced depression. Thus, there is a need for a thorough investigation into whether chronic obesity-induced gliosis, characterized by the activation of astrocytes and microglia, in these brain regions of individuals with chronic obesity. The results revealed increased S100ß+ astrocytes and Iba1+ microglia in the CPu and ACC of male obese mice, along with immune cell accumulation in meningeal lymphatic drainage. Activated GFAP+ astrocytes and Iba1+ microglia were observed in the corpus callosum of obese mice. Gliosis in the CPu and ACC was linked to elevated cleaved caspase-3 levels, indicating potential neural cell death by chronic HFD feeding. There was a loss of myelin and adenomatous polyposis coli (APC)+ oligodendrocytes (OLs) in the corpus callosum, an area known to be linked with injury to the CPu. Additionally, reduced levels of aquaporin-4 (AQP4), a protein associated within the glymphatic systems, were noted in the CPu and ACC, while ciliary neurotrophic factor (CNTF) gene expression was upregulated in these brain regions of obese mice. The in vitro study revealed that high-dose CNTF causing a trend of reduced astrocytic AQP4 expression, but it significantly impaired OL maturation. This pathological evidence highlights that prolonged HFD consumption induces persistent FS gliosis and demyelination in the corpus callosum. An elevated level of CNTF appears to act as a potential regulator, leading to AQP4 downregulation in the FS areas and demyelination in the corpus callosum. This cascade of events might contribute to neural cell damage within these regions and disrupt the glymphatic flow.

11.
Plant Cell Physiol ; 65(8): 1231-1244, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-38757817

RESUMEN

To adapt to a terrestrial habitat, the ancestors of land plants must have made several morphological and physiological modifications, such as a meristem allowing for three-dimensional growth, rhizoids for water and nutrient uptake, air pore complexes or stomata that permit air exchange, and a defense system to cope with oxidative stress that occurs frequently in a terrestrial habitat. To understand how the meristem was determined during land plant evolution, we characterized the function of the closest PLETHORA homolog in the liverwort Marchantia polymorpha, which we named MpPLT. Through a transgenic approach, we showed that MpPLT is expressed not only in the stem cells at the apical notch but also in the proliferation zone of the meristem, as well as in cells that form the air-pore complex and rhizoids. Using the CRISPR method we then created mutants for MpPLT and found that the mutants are not only defective in meristem maintenance but also compromised in air-pore complex and rhizoid development. Strikingly, at later developmental stages, numerous gemma-like structures were formed in Mpplt mutants, suggesting developmental arrest. Further experiments indicated that MpPLT promotes plant growth by regulating MpWOX, which shared a similar expression pattern to MpPLT, and genes involved in auxin and cytokinin signaling pathways. Through transcriptome analyses, we found that MpPLT also has a role in redox homeostasis and that this role is essential for plant growth. Taken together, these results suggest that MpPLT has a crucial role in liverwort growth and development and hence may have played a crucial role in early land plant evolution.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Homeostasis , Marchantia , Meristema , Oxidación-Reducción , Proteínas de Plantas , Marchantia/genética , Marchantia/crecimiento & desarrollo , Marchantia/metabolismo , Meristema/genética , Meristema/crecimiento & desarrollo , Meristema/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Mutación/genética , Ácidos Indolacéticos/metabolismo
12.
J Hepatol ; 80(2): 309-321, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37918568

RESUMEN

BACKGROUND & AIMS: Post-hepatectomy liver failure (PHLF) leads to poor prognosis in patients undergoing hepatectomy, with hepatic vascular reconstitution playing a critical role. However, the regulators of hepatic vascular reconstitution remain unclear. In this study, we aimed to investigate the regulatory mechanisms of hepatic vascular reconstitution and identify biomarkers predicting PHLF in patients undergoing hepatectomy. METHODS: Candidate genes that were associated with hepatic vascular reconstitution were screened using adeno-associated virus vectors in Alb-Cre-CRISPR/Cas9 mice subjected to partial hepatectomy. The biological activities of candidate genes were estimated using endothelial precursor transfusion and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) models. The level of candidates was detected in biopsies from patients undergoing ALPPS. Risk factors for PHLF were also screened using retrospective data. RESULTS: Downregulation of Gata3 and upregulation of Ramp2 in hepatocytes promoted the proliferation of liver sinusoidal endothelial cells and hepatic revascularization. Pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor A (VEGFA) played opposite roles in regulating the migration of endothelial precursors from bone marrow and the formation of new sinusoids after hepatectomy. Gata3 restricted endothelial cell function in patient-derived hepatic organoids, which was abrogated by a Gata3 inhibitor. Moreover, overexpression of Gata3 led to higher mortality in ALPPS mice, which was improved by a PEDF-neutralizing antibody. The expression of Gata3/RAMP and PEDF/VEGFA tended to have a negative correlation in patients undergoing ALPPS. A nomogram incorporating multiple factors, such as serum PEDF/VEGF index, was constructed and could efficiently predict the risk of PHLF. CONCLUSIONS: The balance of Gata3 and Ramp2 in hepatocytes regulates the proliferation of liver sinusoidal endothelial cells and hepatic revascularization via changes in the expression of PEDF and VEGFA, revealing potential targets for the prevention and treatment of PHLF. IMPACT AND IMPLICATIONS: In this study, we show that the balance of Gata3 and Ramp2 in hepatocytes regulates hepatic vascular reconstitution by promoting a shift from pigment epithelium-derived factor (PEDF) to vascular endothelial growth factor A (VEGFA) expression during hepatectomy- or ALLPS (associating liver partition and portal vein ligation for staged hepatectomy)-induced liver regeneration. We also identified serum PEDF/VEGFA index as a potential predictor of post-hepatectomy liver failure in patients who underwent hepatectomy. This study improves our understanding of how hepatocytes contribute to liver regeneration and provides new targets for the prevention and treatment of post-hepatectomy liver failure.


Asunto(s)
Fallo Hepático , Neoplasias Hepáticas , Humanos , Ratones , Animales , Regeneración Hepática/fisiología , Factor A de Crecimiento Endotelial Vascular , Estudios Retrospectivos , Células Endoteliales , Hígado/cirugía , Hepatectomía/efectos adversos , Hepatocitos/fisiología , Vena Porta/cirugía , Fallo Hepático/etiología , Ligadura , Factor de Transcripción GATA3 , Proteína 2 Modificadora de la Actividad de Receptores
13.
Hum Genet ; 143(9-10): 1049-1060, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38252283

RESUMEN

Preimplantation embryonic arrest is an important pathogenesis of female infertility, but little is known about the genetic factors behind this phenotype. MEI4 is an essential protein for DNA double-strand break formation during meiosis, and Mei4 knock-out female mice are viable but sterile, indicating that MEI4 plays a crucial role in reproduction. To date, MEI4 has not been found to be associated with any human reproductive diseases. Here, we identified six compound heterozygous and homozygous MEI4 variants-namely, c.293C > T, p.(Ser98Leu), c.401C > G, p.(Pro134Arg), c.391C > G, p.(Pro131Ala), c.914A > T, p.(Tyr305Phe), c.908C > G, p.(Ala303Gly), and c.899A > T, p.(Gln300Leu)-in four independent families that were responsible for female infertility mainly characterized by preimplantation embryonic arrest. In vitro, we found that these variants reduced the interaction between MEI4 and DNA. In vivo, we generated a knock-in mouse model and demonstrated that female mice were infertile and were characterized by developmental defects during oogenesis. Our findings reveal the important roles of MEI4 in human reproduction and provide a new diagnostic marker for genetic counseling of clinical infertility patients.


Asunto(s)
Infertilidad Femenina , Mutación Missense , Animales , Femenino , Humanos , Masculino , Ratones , Alelos , Blastocisto/metabolismo , Proteínas de Homeodominio/genética , Infertilidad Femenina/genética , Infertilidad Femenina/patología , Meiosis/genética , Ratones Noqueados , Oogénesis/genética , Linaje
14.
N Engl J Med ; 385(22): 2047-2058, 2021 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-34818479

RESUMEN

BACKGROUND: Embryo selection with preimplantation genetic testing for aneuploidy (PGT-A) may improve pregnancy outcomes after initial embryo transfer. However, it remains uncertain whether PGT-A improves the cumulative live-birth rate as compared with conventional in vitro fertilization (IVF). METHODS: In this multicenter, randomized, controlled trial, we randomly assigned subfertile women with three or more good-quality blastocysts to undergo either PGT-A or conventional IVF; all the women were between 20 and 37 years of age. Three blastocysts were screened by next-generation sequencing in the PGT-A group or were chosen by morphologic criteria in the conventional-IVF group and then were successively transferred one by one. The primary outcome was the cumulative live-birth rate after up to three embryo-transfer procedures within 1 year after randomization. We hypothesized that the use of PGT-A would result in a cumulative live-birth rate that was no more than 7 percentage points higher than the rate after conventional IVF, which would constitute the noninferiority margin for conventional IVF as compared with PGT-A. RESULTS: A total of 1212 patients underwent randomization, and 606 were assigned to each trial group. Live births occurred in 468 women (77.2%) in the PGT-A group and in 496 (81.8%) in the conventional-IVF group (absolute difference, -4.6 percentage points; 95% confidence interval [CI], -9.2 to -0.0; P<0.001). The cumulative frequency of clinical pregnancy loss was 8.7% and 12.6%, respectively (absolute difference, -3.9 percentage points; 95% CI, -7.5 to -0.2). The incidences of obstetrical or neonatal complications and other adverse events were similar in the two groups. CONCLUSIONS: Among women with three or more good-quality blastocysts, conventional IVF resulted in a cumulative live-birth rate that was noninferior to the rate with PGT-A. (Funded by the National Natural Science Foundation of China and others; ClinicalTrials.gov number, NCT03118141.).


Asunto(s)
Aneuploidia , Fertilización In Vitro , Pruebas Genéticas , Nacimiento Vivo , Diagnóstico Preimplantación , Adulto , Blastómeros , Trastornos de los Cromosomas/diagnóstico , Transferencia de Embrión , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Análisis de Intención de Tratar , Embarazo , Pronóstico , Adulto Joven
15.
Small ; : e2405946, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39246162

RESUMEN

Under large current densities, the excessive hydroxide ion (OH) consumption hampers alkaline water splitting involving the oxygen evolution reaction (OER). High OH concentration (≈30 wt.%) is often used to enhance the catalytic activity of OER, but it also leads to higher corrosion in practical systems. To achieve higher catalytic activity in low OH concentration, catalysts on magnetic frame (CMF) are built to utilize the local magnetic convection induced from the host frame's magnetic field distributions. This way, a higher reaction rate can be achieved in relatively lower OH concentrations. A CMF model system with catalytically active CoFeOx nanograins grown on the magnetic Ni foam is demonstrated. The OER current of CoFeOx@NF receives ≈90% enhancement under 400 mT (900 mA cm-2 at 1.65 V) compared to that in zero field, and exhibits remarkable durability over 120 h. As a demonstration, the water-splitting performance sees a maximum 45% magnetic enhancement under 400 mT in 1 m KOH (700 mA cm-2 at 2.4 V), equivalent to the concentration enhancement of the same electrode in a more corrosive 2 m KOH electrolyte. Therefore, the catalyst-on-magnetic-frame strategy can make efficient use of the catalysts and achieve higher catalytic activity in low OH concentration by harvesting local magnetic convection.

16.
Plant Physiol ; 192(2): 1115-1131, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-36943300

RESUMEN

Stem cells are the ultimate source of cells for various tissues and organs and thus are essential for postembryonic plant growth and development. SCARECROW (SCR) is a plant-specific transcription regulator well known for its role in stem cell renewal in plant roots, but the mechanism by which SCR exerts this function remains unclear. To address this question, we carried out a genetic screen for mutants that no longer express SCR in the stem cell niche of Arabidopsis (Arabidopsis thaliana) roots and characterized 1 of these mutants. Molecular genetics methods allowed us to pinpoint the causal mutation in this mutant in TELOMERIC PATHWAYS IN ASSOCIATION WITH STN 1 (TEN1), encoding a factor that protects telomere ends. Interestingly, TEN1 expression was dramatically reduced in the scr mutant. Telomerase and STN1 and CONSERVED TELOMERE MAINTENANCE COMPONENT 1 (CTC1), components of the same protein complex as TEN1, were also dramatically downregulated in scr. Loss of STN1, CTC1, and telomerase caused defects in root stem cells. These results together suggest that SCR maintains root stem cells by promoting expression of genes that ensure genome integrity. Supporting this conclusion, we demonstrated that the scr mutant accumulates more DNA damage than wild-type Arabidopsis and that this problem is aggravated after exposure to zeocin, a DNA damage reagent. Finally, we identified 2 previously uncharacterized motifs in TEN1 and provide evidence that a conserved amino acid residue in 1 of the motifs is indispensable for TEN1 function. SCR thus provides a connection between genome integrity and stem cell maintenance in Arabidopsis roots.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Telomerasa , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Nicho de Células Madre/genética , Telomerasa/genética , Telomerasa/metabolismo , Telómero/genética , Telómero/metabolismo
17.
J Cardiovasc Pharmacol ; 84(2): 175-187, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38547523

RESUMEN

ABSTRACT: Sepsis-induced myocardial dysfunction commonly occurs in individuals with sepsis and is a severe complication with high morbidity and mortality rates. This study aimed to investigate the effects and potential mechanisms of the natural steroidal sapogenin ruscogenin (RUS) against lipopolysaccharide (LPS)-induced myocardial injury in septic mice. We found that RUS effectively alleviated myocardial pathological damage, normalized cardiac function, and increased survival in septic mice. RNA sequencing demonstrated that RUS administration significantly inhibited the activation of the NOD-like receptor signaling pathway in the myocardial tissues of septic mice. Subsequent experiments further confirmed that RUS suppressed myocardial inflammation and pyroptosis during sepsis. In addition, cultured HL-1 cardiomyocytes were challenged with LPS, and we observed that RUS could protect these cells against LPS-induced cytotoxicity by suppressing inflammation and pyroptosis. Notably, both the in vivo and in vitro findings indicated that RUS inhibited NOD-like receptor protein-3 (NLRP3) upregulation in cardiomyocytes stimulated with LPS. As expected, knockdown of NLRP3 blocked the LPS-induced activation of inflammation and pyroptosis in HL-1 cells. Furthermore, the cardioprotective effects of RUS on HL-1 cells under LPS stimulation were abolished by the novel NLRP3 agonist BMS-986299. Taken together, our results suggest that RUS can alleviate myocardial injury during sepsis, at least in part by suppressing NLRP3-mediated inflammation and pyroptosis, highlighting the potential of this molecule as a promising candidate for sepsis-induced myocardial dysfunction therapy.


Asunto(s)
Antiinflamatorios , Modelos Animales de Enfermedad , Lipopolisacáridos , Ratones Endogámicos C57BL , Miocitos Cardíacos , Proteína con Dominio Pirina 3 de la Familia NLR , Piroptosis , Sepsis , Transducción de Señal , Espirostanos , Animales , Lipopolisacáridos/toxicidad , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Miocitos Cardíacos/metabolismo , Espirostanos/farmacología , Sepsis/tratamiento farmacológico , Sepsis/complicaciones , Sepsis/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/antagonistas & inhibidores , Piroptosis/efectos de los fármacos , Masculino , Transducción de Señal/efectos de los fármacos , Línea Celular , Antiinflamatorios/farmacología , Ratones , Cardiomiopatías/prevención & control , Cardiomiopatías/patología , Cardiomiopatías/metabolismo , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/inducido químicamente , Mediadores de Inflamación/metabolismo
18.
Dig Dis ; 42(5): 452-460, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38697048

RESUMEN

INTRODUCTION: The Baveno criteria for assessing advanced liver fibrosis were mainly determined by transient elastography (TE), and its pathology-based validation studies in two-dimensional shear wave elastography (2D-SWE) remain limited. We aimed to validate the Baveno criteria through use of 2D-SWE. METHOD: Consecutive patients who underwent liver biopsies for various benign liver diseases were prospectively recruited. Liver stiffness measurement (LSM) was simultaneously evaluated by TE and 2D-SWE. The optimal cutoff value to predict advanced liver fibrosis was determined by the Youden Index, and the diagnostic performance was estimated using area under the receiver operating characteristic (AUROC) analysis. RESULTS: A total of 101 patients were enrolled having a median age of 55.0 (IQR: 46.0-63.5) years, with 53 (52.48%) of them being male. Using <9 and >14 kPa as the optimal dual cutoffs, the AUROC values in TE and 2D-SWE were 0.92 (95% CI: 0.83-0.97) and 0.93 (95% CI: 0.84-0.98), respectively (p = 0.61). The sensitivity and specificity of LSM by TE/2D-SWE achieved rates of 94.44%/94.44% and 86.00%/88.00%, respectively. However, using the Baveno criteria, the AUROC values in TE and 2D-SWE could remain achieving 0.91 (95% CI: 0.82-0.97) and 0.93 (95% CI: 0.84-0.98), respectively (p = 0.36). The sensitivity and specificity in TE/2D-SWE were 88.24%/88.24% and 86.79%/90.57%, respectively. CONCLUSION: This study establishes the compatibility of the Baveno dual cutoff criteria with 2D-SWE, positioning it as an easily used criteria in clinical practice and research.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Cirrosis Hepática , Humanos , Diagnóstico por Imagen de Elasticidad/métodos , Masculino , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/patología , Persona de Mediana Edad , Femenino , Estudios Prospectivos , Curva ROC , Hígado/diagnóstico por imagen , Hígado/patología , Sensibilidad y Especificidad
19.
Acta Pharmacol Sin ; 45(6): 1252-1263, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38360931

RESUMEN

Although ALK tyrosine kinase inhibitors (ALK-TKIs) have shown remarkable benefits in EML4-ALK positive NSCLC patients compared to conventional chemotherapy, the optimal sequence of ALK-TKIs treatment remains unclear due to the emergence of primary and acquired resistance and the lack of potential prognostic biomarkers. In this study, we systematically explored the validity of sequential ALK inhibitors (alectinib, lorlatinib, crizotinib, ceritinib and brigatinib) for a heavy-treated patient with EML4-ALK fusion via developing an in vitro and in vivo drug testing system based on patient-derived models. Based on the patient-derived models and clinical responses of the patient, we found that crizotinib might inhibit proliferation of EML4-ALK positive tumors resistant to alectinib and lorlatinib. In addition, NSCLC patients harboring the G1269A mutation, which was identified in alectinib, lorlatinib and crizotinib-resistant NSCLC, showed responsiveness to brigatinib and ceritinib. Transcriptomic analysis revealed that brigatinib suppressed the activation of multiple inflammatory signaling pathways, potentially contributing to its anti-tumor activity. Moreover, we constructed a prognostic model based on the expression of IL6, CXCL1, and CXCL5, providing novel perspectives for predicting prognosis in EML4-ALK positive NSCLC patients. In summary, our results delineate clinical responses of sequential ALK-TKIs treatments and provide insights into the mechanisms underlying the superior effects of brigatinib in patients harboring ALKG1269A mutation and resistant towards alectinib, lorlatinib and crizotinib. The molecular signatures model based on the combination of IL6, CXCL1 and CXCL5 has the potential to predict prognosis of EML4-ALK positive NSCLC patients.


Asunto(s)
Adenocarcinoma del Pulmón , Antineoplásicos , Neoplasias Pulmonares , Proteínas de Fusión Oncogénica , Compuestos Organofosforados , Inhibidores de Proteínas Quinasas , Pirimidinas , Humanos , Compuestos Organofosforados/uso terapéutico , Compuestos Organofosforados/farmacología , Pirimidinas/uso terapéutico , Pirimidinas/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Animales , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Pronóstico , Antineoplásicos/uso terapéutico , Antineoplásicos/farmacología , Resistencia a Antineoplásicos , Lactamas/uso terapéutico , Carbazoles/uso terapéutico , Carbazoles/farmacología , Sulfonas/uso terapéutico , Sulfonas/farmacología , Crizotinib/uso terapéutico , Crizotinib/farmacología , Línea Celular Tumoral , Piperidinas/uso terapéutico , Piperidinas/farmacología , Femenino , Ratones , Inflamación/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Pirazoles/uso terapéutico , Pirazoles/farmacología , Masculino , Quinasa de Linfoma Anaplásico/genética , Quinasa de Linfoma Anaplásico/antagonistas & inhibidores , Quinasa de Linfoma Anaplásico/metabolismo , Proliferación Celular/efectos de los fármacos , Mutación , Aminopiridinas/uso terapéutico , Aminopiridinas/farmacología
20.
J Nanobiotechnology ; 22(1): 647, 2024 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-39434141

RESUMEN

The clinical efficacy of immunotherapy for hepatocellular carcinoma (HCC) is significantly limited by the low immunogenicity of the tumor. Recent studies have revealed that both pyroptosis and photothermal therapy can effectively induce tumor immunogenic cell death (ICD) in liver cancer cells. Polyphyllin II (PPII), the major active component of Rhizoma Paridis, has been demonstrated for the first time to induce pyroptosis in tumor cells, while IR780 is activated by 808 nm laser to transform light energy into heat energy, effectively eliminating tumor cells. However, both PPII and IR780 are afflicted with challenges such as low solubility and poor targeting, significantly limiting their utilization. To address these problems, the pyroptosis inducer PPII and photosensitizer IR780 were co-loaded in PLGA nanoparticles by precipitation method, and the aptamer AS1411 was modified on the surface of nanoparticles to construct the targeting nanoparticles (Apt/PPII/IR780-NPs). The nanoparticles exhibit a pH/NIR dual-response intelligent release feature, which realizes the targeted and controlled release of drugs in tumor site. Furthermore, it can rapidly release PPII to induce cell pyroptosis under laser irradiation, combining with IR780-based photothermal therapy exert a significant synergistic anti-tumor effect in vitro and in vivo. This process not only promotes maturation of DCs and activates effector T cells, thereby initiating adaptive immunity, but also generates enduring and effective immune memory. In addition, Apt/PPII/IR780-NPs significantly improved the Anti-PD-1 efficacy. In summary, chemo-photothermal therapy based on Apt/PPII/IR780-NPs can significantly enhance tumor ICD, which provides a promising new strategy for HCC immunotherapy.


Asunto(s)
Carcinoma Hepatocelular , Inmunoterapia , Indoles , Neoplasias Hepáticas , Nanopartículas , Terapia Fototérmica , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Piroptosis , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/tratamiento farmacológico , Animales , Inmunoterapia/métodos , Piroptosis/efectos de los fármacos , Ratones , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Humanos , Nanopartículas/química , Indoles/química , Indoles/farmacología , Terapia Fototérmica/métodos , Línea Celular Tumoral , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Ratones Endogámicos BALB C
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