Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.857
Filtrar
1.
Cell ; 186(17): 3593-3605.e12, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37516107

RESUMEN

Animal fertilization relies on hundreds of sperm racing toward the egg, whereas, in angiosperms, only two sperm cells are delivered by a pollen tube to the female gametes (egg cell and central cell) for double fertilization. However, unsuccessful fertilization under this one-pollen-tube design can be detrimental to seed production and plant survival. To mitigate this risk, unfertilized-gamete-controlled extra pollen tube entry has been evolved to bring more sperm cells and salvage fertilization. Despite its importance, the underlying molecular mechanism of this phenomenon remains unclear. In this study, we report that, in Arabidopsis, the central cell secretes peptides SALVAGER1 and SALVAGER2 in a directional manner to attract pollen tubes when the synergid-dependent attraction fails or is terminated by pollen tubes carrying infertile sperm cells. Moreover, loss of SALs impairs the fertilization recovery capacity of the ovules. Therefore, this research uncovers a female gamete-attraction system that salvages seed production for reproductive assurance.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Animales , Arabidopsis/fisiología , Fertilización , Tubo Polínico , Semillas , Células Germinativas de las Plantas
2.
Cell ; 172(4): 797-810.e13, 2018 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-29395326

RESUMEN

Aberrant activation of innate immune receptors can cause a spectrum of immune disorders, such as Aicardi-Goutières syndrome (AGS). One such receptor is MDA5, a viral dsRNA sensor that induces antiviral immune response. Using a newly developed RNase-protection/RNA-seq approach, we demonstrate here that constitutive activation of MDA5 in AGS results from the loss of tolerance to cellular dsRNAs formed by Alu retroelements. While wild-type MDA5 cannot efficiently recognize Alu-dsRNAs because of its limited filament formation on imperfect duplexes, AGS variants of MDA5 display reduced sensitivity to duplex structural irregularities, assembling signaling-competent filaments on Alu-dsRNAs. Moreover, we identified an unexpected role of an RNA-rich cellular environment in suppressing aberrant MDA5 oligomerization, highlighting context dependence of self versus non-self discrimination. Overall, our work demonstrates that the increased efficiency of MDA5 in recognizing dsRNA comes at a cost of self-recognition and implicates a unique role of Alu-dsRNAs as virus-like elements that shape the primate immune system.


Asunto(s)
Elementos Alu/inmunología , Enfermedades Autoinmunes del Sistema Nervioso/inmunología , Helicasa Inducida por Interferón IFIH1/inmunología , Malformaciones del Sistema Nervioso/inmunología , Multimerización de Proteína/inmunología , ARN Bicatenario/inmunología , Autotolerancia , Células A549 , Enfermedades Autoinmunes del Sistema Nervioso/genética , Enfermedades Autoinmunes del Sistema Nervioso/patología , Humanos , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Helicasa Inducida por Interferón IFIH1/genética , Muramidasa , Malformaciones del Sistema Nervioso/genética , Malformaciones del Sistema Nervioso/patología , Fragmentos de Péptidos , Multimerización de Proteína/genética , ARN Bicatenario/genética , Células THP-1
3.
Nature ; 610(7931): 366-372, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36198801

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is a highly desmoplastic, aggressive cancer that frequently progresses and spreads by metastasis to the liver1. Cancer-associated fibroblasts, the extracellular matrix and type I collagen (Col I) support2,3 or restrain the progression of PDAC and may impede blood supply and nutrient availability4. The dichotomous role of the stroma in PDAC, and the mechanisms through which it influences patient survival and enables desmoplastic cancers to escape nutrient limitation, remain poorly understood. Here we show that matrix-metalloprotease-cleaved Col I (cCol I) and intact Col I (iCol I) exert opposing effects on PDAC bioenergetics, macropinocytosis, tumour growth and metastasis. Whereas cCol I activates discoidin domain receptor 1 (DDR1)-NF-κB-p62-NRF2 signalling to promote the growth of PDAC, iCol I triggers the degradation of DDR1 and restrains the growth of PDAC. Patients whose tumours are enriched for iCol I and express low levels of DDR1 and NRF2 have improved median survival compared to those whose tumours have high levels of cCol I, DDR1 and NRF2. Inhibition of the DDR1-stimulated expression of NF-κB or mitochondrial biogenesis blocks tumorigenesis in wild-type mice, but not in mice that express MMP-resistant Col I. The diverse effects of the tumour stroma on the growth and metastasis of PDAC and on the survival of patients are mediated through the Col I-DDR1-NF-κB-NRF2 mitochondrial biogenesis pathway, and targeting components of this pathway could provide therapeutic opportunities.


Asunto(s)
Carcinoma Ductal Pancreático , Colágeno Tipo I , Receptor con Dominio Discoidina 1 , Transducción de Señal , Animales , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Colágeno Tipo I/metabolismo , Receptor con Dominio Discoidina 1/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Ratones , Mitocondrias/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Tasa de Supervivencia
4.
Nature ; 578(7794): 251-255, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32015545

RESUMEN

Solid-state lithium metal batteries require accommodation of electrochemically generated mechanical stress inside the lithium: this stress can be1,2 up to 1 gigapascal for an overpotential of 135 millivolts. Maintaining the mechanical and electrochemical stability of the solid structure despite physical contact with moving corrosive lithium metal is a demanding requirement. Using in situ transmission electron microscopy, we investigated the deposition and stripping of metallic lithium or sodium held within a large number of parallel hollow tubules made of a mixed ionic-electronic conductor (MIEC). Here we show that these alkali metals-as single crystals-can grow out of and retract inside the tubules via mainly diffusional Coble creep along the MIEC/metal phase boundary. Unlike solid electrolytes, many MIECs are electrochemically stable in contact with lithium (that is, there is a direct tie-line to metallic lithium on the equilibrium phase diagram), so this Coble creep mechanism can effectively relieve stress, maintain electronic and ionic contacts, eliminate solid-electrolyte interphase debris, and allow the reversible deposition/stripping of lithium across a distance of 10 micrometres for 100 cycles. A centimetre-wide full cell-consisting of approximately 1010 MIEC cylinders/solid electrolyte/LiFePO4-shows a high capacity of about 164 milliampere hours per gram of LiFePO4, and almost no degradation for over 50 cycles, starting with a 1× excess of Li. Modelling shows that the design is insensitive to MIEC material choice with channels about 100 nanometres wide and 10-100 micrometres deep. The behaviour of lithium metal within the MIEC channels suggests that the chemical and mechanical stability issues with the metal-electrolyte interface in solid-state lithium metal batteries can be overcome using this architecture.

5.
Plant Physiol ; 194(2): 758-773, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-37847103

RESUMEN

Touch induces marked morphological changes in plants, including reduced rosette diameters and delayed flowering, a process called thigmomorphogenesis. Previous studies have revealed that thigmomorphogenesis in Arabidopsis (Arabidopsis thaliana) results from touch-induced accumulation of jasmonic acid (JA) and GIBBERELLIN 2-OXIDASE7 (GA2ox7) transcripts, which encode a gibberellin (GA) catabolism enzyme, leading to reduced levels of active GAs. However, the mechanisms underlying thigmomorphogenesis remain uncharacterized. Here, we showed that touch induces ethylene (ET) production in Arabidopsis. After touch treatment, ET biosynthesis and signaling mutants exhibited even greater thigmomorphogenic changes and more decreased GA4 contents than did wild-type (WT) plants. Biochemical analysis indicated that the transcription factor ETHYLENE INSENSITIVE3 (EIN3) of the ET pathway binds to the promoter of GA2ox8 (encoding another GA 2-oxidase performing the same GA modification as GA2ox7) and represses GA2ox8 transcription. Moreover, MYC2, the master regulator of JA signaling, directly promoted GA2ox7 expression by binding the G-box motif on GA2ox7 promoter. Further genetic analysis suggested that the ET and JA pathways independently control the expression of GA2ox8 and GA2ox7, respectively. This study reveals that the ET pathway is a novel repressor of touch-induced thigmomorphogenesis and highlights that the ET and JA pathways converge on GA catabolism but play opposite roles to fine-tune GA4 content during thigmomorphogenesis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Giberelinas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Etilenos/metabolismo , Regulación de la Expresión Génica de las Plantas
6.
Plant Physiol ; 194(4): 2631-2647, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38206203

RESUMEN

Spontaneous mutations are rare in mitochondria and the lack of mitochondrial transformation methods has hindered genetic analyses. We show that a custom-designed RNA-binding pentatricopeptide repeat (PPR) protein binds and specifically induces cleavage of ATP synthase subunit1 (atp1) mRNA in mitochondria, significantly decreasing the abundance of the Atp1 protein and the assembled F1Fo ATP synthase in Arabidopsis (Arabidopsis thaliana). The transformed plants are characterized by delayed vegetative growth and reduced fertility. Five-fold depletion of Atp1 level was accompanied by a decrease in abundance of other ATP synthase subunits and lowered ATP synthesis rate of isolated mitochondria, but no change to mitochondrial electron transport chain complexes, adenylates, or energy charge in planta. Transcripts for amino acid transport and a variety of stress response processes were differentially expressed in lines containing the PPR protein, indicating changes to achieve cellular homeostasis when ATP synthase was highly depleted. Leaves of ATP synthase-depleted lines showed higher respiratory rates and elevated steady-state levels of numerous amino acids, most notably of the serine family. The results show the value of using custom-designed PPR proteins to influence the expression of specific mitochondrial transcripts to carry out reverse genetic studies on mitochondrial gene functions and the consequences of ATP synthase depletion on cellular functions in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Adenosina Trifosfato/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo
7.
Blood ; 142(12): 1071-1081, 2023 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-37294924

RESUMEN

Rebalance of coagulation and anticoagulation to achieve a hemostatic effect has recently gained attention as an alternative therapeutic strategy for hemophilia. We engineered a humanized chimeric antibody, SR604, based on a previously published murine antibody, HAPC1573, which selectively blocks the anticoagulant activity of human activated protein C (APC). SR604 effectively blocked the anticoagulation activities of APC in human plasma deficient in various coagulation factors in vitro with affinities ∼60 times greater than that of HAPC1573. SR604 exhibited prophylactic and therapeutic efficacy in the tail-bleeding and knee-injury models of hemophilia A and B mice expressing human APC (humanized hemophilic mice). SR604 did not interfere with the cytoprotection and endothelial barrier function of APC, nor were there obvious toxicity effects in humanized hemophilic mice. Pharmacokinetic study showed a high bioavailability (106%) of subcutaneously injected SR604 in cynomolgus monkeys. These results demonstrate that SR604 is expected to be a safe and effective therapeutic and/or prophylactic agent with a prolonged half-life for patients with congenital factor deficiencies including hemophilia A and B.


Asunto(s)
Hemofilia A , Proteína C , Humanos , Ratones , Animales , Proteína C/uso terapéutico , Hemofilia A/tratamiento farmacológico , Modelos Animales de Enfermedad , Coagulación Sanguínea , Anticoagulantes/uso terapéutico
8.
FASEB J ; 38(1): e23390, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38169064

RESUMEN

Lymph node metastasis (LNM) is one of the common features of oral tongue squamous cell carcinoma (OTSCC). LNM is also taken as a sign of advanced OTSCC and poor survival rate. Recently, single-cell RNA sequencing has been applied in investigating the heterogeneity of tumor microenvironment and discovering the potential biomarkers for helping the diagnosis and prognosticating. Pathogenesis of LNM in OTSCC remains unknown. Specifically, cancer-associated fibroblasts (CAFs) and epithelial tumor cells could foster the progression of tumors. Thus, in this study, we aimed to comprehensively analyze the roles of subpopulations of CAFs and epithelial tumor cells in lymph node metastatic OTSCC using the integration of OTSCC single-cell RNA sequencing datasets. Four distinct subtypes of CAFs, namely vascular CAFs, myofibroblast CAFs, inflammatory CAFs, and growth arrest CAFs were successfully discovered in LNM tumor and confirmed the roles of GAS and PTN pathways in the progression of tumor metastasis. In addition, NKAIN2+ epithelial cells and FN1+ epithelial cells specifically exhibited an upregulation of PTN, NRG, MIF, and SPP1 signaling pathways in the metastatic OTSCC. In doing so, we put forth some potential biomarkers that could be utilized for the purpose of diagnosing and prognosticating OTSCC during its metastatic phase and tried to confirm by immunofluorescence assays.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Lengua , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Neoplasias de la Lengua/genética , Neoplasias de la Lengua/patología , Fibroblastos/patología , Células Epiteliales/patología , Biomarcadores , Metástasis Linfática/patología , Neoplasias de Cabeza y Cuello/patología , Análisis de Secuencia de ARN , Microambiente Tumoral
9.
Mol Cell ; 67(6): 907-921.e7, 2017 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-28844862

RESUMEN

The class III phosphoinositide 3-kinase VPS34 plays a key role in the regulation of vesicular trafficking and macroautophagy. So far, we know little about the molecular mechanism of VPS34 activation besides its interaction with regulatory proteins to form complexes. Here, we report that VPS34 is specifically acetylated by the acetyltransferase p300, and p300-mediated acetylation represses VPS34 activity. Acetylation at K771 directly diminishes the affinity of VPS34 for its substrate PI, while acetylation at K29 hinders the VPS34-Beclin 1 core complex formation. Inactivation of p300 induces VPS34 deacetylation, PI3P production, and autophagy, even in AMPK-/-, TSC2-/-, or ULK1-/- cells. In fasting mice, liver autophagy correlates well with p300 inactivation/VPS34 deacetylation, which facilitates the clearance of lipid droplets in hepatocytes. Thus, p300-dependent VPS34 acetylation/deacetylation is the physiological key to VPS34 activation, which controls the initiation of canonical autophagy and of non-canonical autophagy in which the upstream kinases of VPS34 can be bypassed.


Asunto(s)
Autofagia , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Hepatocitos/enzimología , Metabolismo de los Lípidos , Hígado/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Procesamiento Proteico-Postraduccional , Estrés Fisiológico , Factores de Transcripción p300-CBP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Acetilación , Animales , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Beclina-1/metabolismo , Fosfatidilinositol 3-Quinasas Clase III/genética , Activación Enzimática , Femenino , Células HEK293 , Células HeLa , Hepatocitos/patología , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hígado/patología , Ratones Endogámicos C57BL , Fosfatidilinositol 3-Quinasas/genética , Fosfatos de Fosfatidilinositol/metabolismo , Unión Proteica , Interferencia de ARN , Transducción de Señal , Transfección , Proteína 2 del Complejo de la Esclerosis Tuberosa , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Factores de Transcripción p300-CBP/genética
10.
Nucleic Acids Res ; 51(D1): D208-D216, 2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36318250

RESUMEN

DNA methylation, as the most intensively studied epigenetic mark, regulates gene expression in numerous biological processes including development, aging, and disease. With the rapid accumulation of whole-genome bisulfite sequencing data, integrating, archiving, analyzing, and visualizing those data becomes critical. Since its first publication in 2015, MethBank has been continuously updated to include more DNA methylomes across more diverse species. Here, we present MethBank 4.0 (https://ngdc.cncb.ac.cn/methbank/), which reports an increase of 309% in data volume, with 1449 single-base resolution methylomes of 23 species, covering 236 tissues/cell lines and 15 biological contexts. Value-added information, such as more rigorous quality evaluation, more standardized metadata, and comprehensive downstream annotations have been integrated in the new version. Moreover, expert-curated knowledge modules of featured differentially methylated genes associated with biological contexts and methylation analysis tools have been incorporated as new components of MethBank. In addition, MethBank 4.0 is equipped with a series of new web interfaces to browse, search, and visualize DNA methylation profiles and related information. With all these improvements, we believe the updated MethBank 4.0 will serve as a fundamental resource to provide a wide range of data services for the global research community.


Asunto(s)
Metilación de ADN , Bases de Datos Genéticas , Epigenómica , Bases de Datos Factuales , Epigenoma , Análisis de Secuencia de ADN , Secuenciación Completa del Genoma
11.
Proc Natl Acad Sci U S A ; 119(49): e2203071119, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36442132

RESUMEN

Remodeling of the uterine vasculature by invasive extravillous trophoblasts (EVTs) is a critical aspect of human placentation. Insufficient EVT invasion can lead to severe obstetrical complications like preeclampsia, intrauterine growth restriction, and preterm birth. Glial cells missing-1 (GCM1) is a transcription factor that is crucial for proper placentation in mice, and is highly expressed in human syncytiotrophoblast (ST) and EVTs. GCM1 is classically considered a master regulator of ST formation, but little is known about its contribution to the development and function of EVTs. Therefore, in this study we test the hypothesis that GCM1 is a critical regulator of both EVT and ST development and function. We show that GCM1 is highly expressed in human trophoblast stem (TS) cells differentiated into either ST or EVTs. Knockdown of GCM1 in TS cells hindered differentiation into both ST and EVT pathways. When placed in ST media, GCM1-knockdown cells formed small, unstable clusters; when placed in EVT media, cells had altered morphology and transcript profiles resembling cells trapped in an intermediate state between CT and EVT, and invasive capacity through matrix was reduced. RNA sequencing analysis of GCM1-deficient TS cells revealed downregulation of EVT-associated genes and enrichment in transcripts related to WNT signaling, which was linked to decreased expression of the EVT master regulator ASCL2 and the WNT antagonist NOTUM. Our findings reveal an essential role of GCM1 during ST and EVT development, and suggest that GCM1 regulates differentiation of human TS cells into EVTs by inducing expression of ASCL2 and NOTUM.


Asunto(s)
Nacimiento Prematuro , Trofoblastos , Recién Nacido , Femenino , Embarazo , Humanos , Animales , Ratones , Neuroglía , Diferenciación Celular , Células Madre , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Proteínas de Unión al ADN/genética , Factores de Transcripción/genética
12.
J Biol Chem ; 299(11): 105315, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37797700

RESUMEN

A high-fat diet (HFD) plays a critical role in hepatocyte insulin resistance. Numerous models and factors have been proposed to elucidate the mechanism of palmitic acid (PA)-induced insulin resistance. However, proteomic studies of insulin resistance by HFD stimulation are usually performed under insulin conditions, leading to an unclear understanding of how a HFD alone affects hepatocytes. Here, we mapped the phosphorylation rewiring events in PA-stimulated HepG2 cells and found PA decreased the phosphorylation level of the eukaryotic translation initiation factor 4E-binding protein 2 (4EBP2) at S65/T70. Further experiments identified 4EBP2 as a key node of insulin resistance in either HFD mice or PA-treated cells. Reduced 4EBP2 levels increased glucose uptake and insulin sensitivity, whereas the 4EBP2_S65A/T70A mutation exacerbated PA-induced insulin resistance. Additionally, the nascent proteome revealed many glycolysis-related proteins translationally regulated by 4EBP2 such as hexokinase-2, pyruvate kinase PKM, TBC1 domain family member 4, and glucose-6-phosphate 1-dehydrogenase. In summary, we report the critical role of 4EBP2 in regulating HFD-stimulated insulin resistance in hepatocytes.


Asunto(s)
Resistencia a la Insulina , Animales , Masculino , Ratones , Proteínas Portadoras/metabolismo , Línea Celular , Dieta Alta en Grasa/efectos adversos , Hepatocitos/metabolismo , Insulina/metabolismo , Resistencia a la Insulina/fisiología , Ratones Endogámicos C57BL , Ácido Palmítico/metabolismo , Biosíntesis de Proteínas , Proteómica
13.
Br J Cancer ; 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760444

RESUMEN

BACKGROUND: Risk of recurrence and progression of ductal carcinoma in situ (DCIS) to invasive cancer remains uncertain, emphasizing the need for developing predictive biomarkers of aggressive DCIS. METHODS: Human cell lines and mouse models of disease progression were analyzed for candidate risk predictive biomarkers identified and validated in two independent DCIS cohorts. RESULTS: RNA profiling of normal mammary and DCIS tissues (n = 48) revealed that elevated SOX11 expression correlates with MKI67, EZH2, and DCIS recurrence score. The 21T human cell line model of DCIS progression to invasive cancer and two mouse models developing mammary intraepithelial neoplasia confirmed the findings. AKT activation correlated with chromatin accessibility and EZH2 enrichment upregulating SOX11 expression. AKT and HER2 inhibitors decreased SOX11 expression along with diminished mammosphere formation. SOX11 was upregulated in HER2+ and basal-like subtypes (P < 0.001). Longitudinal DCIS cohort (n = 194) revealed shorter recurrence-free survival in SOX11+ than SOX11- patients (P = 0.0056 in all DCIS; P < 0.0001 in HER2+ subtype) associated with increased risk of ipsilateral breast event/IBE (HR = 1.9, 95%CI = 1.2-2.9; P = 0.003). DISCUSSION: Epigenetic activation of SOX11 drives recurrence of DCIS and progression to invasive cancer, suggesting SOX11 as a predictive biomarker of IBE.

14.
Anal Chem ; 96(14): 5527-5536, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38483815

RESUMEN

Dynamic tracing of intracellular telomerase activity plays a crucial role in cancer cell recognition and correspondingly in earlier cancer diagnosis and personalized precision therapy. However, due to the complexity of the required reaction system and insufficient loading of reaction components into cells, achieving a high-fidelity determination of telomerase activity is still a challenge. Herein, an Aptamer-Liposome mediated Telomerase activated poly-Molecular beacon Arborescent Nanoassembly(ALTMAN) approach was described for direct high-fidelity visualization of telomerase activity. Briefly, intracellular telomerase activates molecular beacons, causing their hairpin structures to unfold and produce fluorescent signals. Furthermore, multiple molecular beacons can self-assemble, forming arborescent nanostructures and leading to exponential amplification of fluorescent signals. Integrating the enzyme-free isothermal signal amplification successfully increased the sensitivity and reduced interference by leveraging the skillful design of the molecular beacon and the extension of the telomerase-activated TTAGGG repeat sequence. The proposed approach enabled ultrasensitive visualization of activated telomerase exclusively with a prominent detection limit of 2 cells·µL-1 and realized real-time imaging of telomerase activity in living cancer cells including blood samples from breast cancer patients and urine samples from bladder cancer patients. This approach opens an avenue for establishing a telomerase activity determination and in situ monitoring technique that can facilitate both telomerase fundamental biological studies and cancer diagnostics.


Asunto(s)
Nanoestructuras , Células Neoplásicas Circulantes , Telomerasa , Humanos , Telomerasa/metabolismo , Colorantes Fluorescentes/química , Nanoestructuras/química , Células HeLa
15.
J Neuroinflammation ; 21(1): 138, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802927

RESUMEN

Sepsis-associated encephalopathy (SAE) is a significant cause of mortality in patients with sepsis. Despite extensive research, its exact cause remains unclear. Our previous research indicated a relationship between non-hepatic hyperammonemia (NHH) and SAE. This study aimed to investigate the relationship between NHH and SAE and the potential mechanisms causing cognitive impairment. In the in vivo experimental results, there were no significant abnormalities in the livers of mice with moderate cecal ligation and perforation (CLP); however, ammonia levels were elevated in the hippocampal tissue and serum. The ELISA study suggest that fecal microbiota transplantation in CLP mice can reduce ammonia levels. Reduction in ammonia levels improved cognitive dysfunction and neurological impairment in CLP mice through behavioral, neuroimaging, and molecular biology studies. Further studies have shown that ammonia enters the brain to regulate the expression of aquaporins-4 (AQP4) in astrocytes, which may be the mechanism underlying brain dysfunction in CLP mice. The results of the in vitro experiments showed that ammonia up-regulated AQP4 expression in astrocytes, resulting in astrocyte damage. The results of this study suggest that ammonia up-regulates astrocyte AQP4 expression through the gut-brain axis, which may be a potential mechanism for the occurrence of SAE.


Asunto(s)
Acuaporina 4 , Astrocitos , Eje Cerebro-Intestino , Hiperamonemia , Encefalopatía Asociada a la Sepsis , Animales , Ratones , Acuaporina 4/metabolismo , Acuaporina 4/genética , Acuaporina 4/biosíntesis , Astrocitos/metabolismo , Hiperamonemia/metabolismo , Encefalopatía Asociada a la Sepsis/metabolismo , Masculino , Eje Cerebro-Intestino/fisiología , Ratones Endogámicos C57BL , Amoníaco/metabolismo , Amoníaco/sangre , Encéfalo/metabolismo , Trasplante de Microbiota Fecal
16.
J Transl Med ; 22(1): 507, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802851

RESUMEN

BACKGROUND: Gastric cancer (GC) ranks fifth in global cancer incidence and third in mortality rate among all cancer types. Circular RNAs (circRNAs) have been extensively demonstrated to regulate multiple malignant biological behaviors in GC. Emerging evidence suggests that several circRNAs derived from FNDC3B play pivotal roles in cancer. However, the role of circFNDC3B in GC remains elusive. METHODS: We initially screened circFNDC3B with translation potential via bioinformatics algorithm prediction. Subsequently, Sanger sequencing, qRT-PCR, RNase R, RNA-FISH and nuclear-cytoplasmic fractionation assays were explored to assess the identification and localization of circ0003692, a circRNA derived from FNDC3B. qRT-PCR and ISH were performed to quantify expression of circ0003692 in human GC tissues and adjacent normal tissues. The protein-encoding ability of circ0003692 was investigated through dual-luciferase reporter assay and LC/MS. The biological behavior of circ0003692 in GC was confirmed via in vivo and in vitro experiments. Additionally, Co-IP and rescue experiments were performed to elucidate the interaction between the encoded protein and c-Myc. RESULTS: We found that circ0003692 was significantly downregulated in GC tissues. Circ0003692 had the potential to encode a novel protein FNDC3B-267aa, which was downregulated in GC cells. We verified that FNDC3B-267aa, rather than circ0003692, inhibited GC migration in vitro and in vivo. Mechanistically, FNDC3B-267aa directly interacted with c-Myc and promoted proteasomal degradation of c-Myc, resulting in the downregulation of c-Myc-Snail/Slug axis. CONCLUSIONS: Our study revealed that the novel protein FNDC3B-267aa encoded by circ0003692 suppressed GC metastasis through binding to c-Myc and enhancing proteasome-mediated degradation of c-Myc. The study offers the potential applications of circ0003692 or FNDC3B-267aa as therapeutic targets for GC.


Asunto(s)
Fibronectinas , Metástasis de la Neoplasia , Complejo de la Endopetidasa Proteasomal , Proteínas Proto-Oncogénicas c-myc , ARN Circular , Neoplasias Gástricas , Neoplasias Gástricas/patología , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Humanos , ARN Circular/genética , ARN Circular/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Línea Celular Tumoral , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Animales , Fibronectinas/metabolismo , Regulación Neoplásica de la Expresión Génica , Masculino , Proteolisis , Ratones Desnudos , Secuencia de Bases , Movimiento Celular/genética , Femenino , Ratones
17.
Blood ; 139(8): 1208-1221, 2022 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-34482403

RESUMEN

Inherited predisposition to myeloid malignancies is more common than previously appreciated. We analyzed the whole-exome sequencing data of paired leukemia and skin biopsy samples from 391 adult patients from the Beat AML 1.0 consortium. Using the 2015 American College of Medical Genetics and Genomics (ACMG) guidelines for variant interpretation, we curated 1547 unique variants from 228 genes. The pathogenic/likely pathogenic (P/LP) germline variants were identified in 53 acute myeloid leukemia (AML) patients (13.6%) in 34 genes, including 6.39% (25/391) of patients harboring P/LP variants in genes considered clinically actionable (tier 1). 41.5% of the 53 patients with P/LP variants were in genes associated with the DNA damage response. The most frequently mutated genes were CHEK2 (8 patients) and DDX41 (7 patients). Pathogenic germline variants were also found in new candidate genes (DNAH5, DNAH9, DNMT3A, and SUZ12). No strong correlation was found between the germline mutational rate and age of AML onset. Among 49 patients who have a reported history of at least one family member affected with hematological malignancies, 6 patients harbored known P/LP germline variants and the remaining patients had at least one variant of uncertain significance, suggesting a need for further functional validation studies. Using CHEK2 as an example, we show that three-dimensional protein modeling can be one of the effective methodologies to prioritize variants of unknown significance for functional studies. Further, we evaluated an in silico approach that applies ACMG curation in an automated manner using the tool for assessment and (TAPES) prioritization in exome studies, which can minimize manual curation time for variants. Overall, our findings suggest a need to comprehensively understand the predisposition potential of many germline variants in order to enable closer monitoring for disease management and treatment interventions for affected patients and families.


Asunto(s)
Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
18.
Glob Chang Biol ; 30(1): e17108, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38273551

RESUMEN

Future phosphorus (P) shortages could seriously affect terrestrial productivity and food security. We investigated the changes in topsoil available P (AP) and total P (TP) in China's forests, grasslands, paddy fields, and upland croplands during the 1980s-2010s based on substantial repeated soil P measurements (63,220 samples in the 1980s, 2000s, and 2010s) and machine learning techniques. Between the 1980s and 2010s, total soil AP stock increased with a small but significant rate of 0.13 kg P ha-1 year-1 , but total soil TP stock declined substantially (4.5 kg P ha-1 year-1 ) in the four ecosystems. We quantified the P budgets of soil-plant systems by harmonizing P fluxes from various sources for this period. Matching trends of soil contents over the decades with P budgets and fluxes, we found that the P-surplus in cultivated soils (especially in upland croplands) might be overestimated due to the great soil TP pool compared to fertilization and the substantial soil P losses through plant uptake and water erosion that offset the P additions. Our findings of P-deficit in China raise the alarm on the sustainability of future biomass production (especially in forests), highlight the urgency of P recycling in croplands, and emphasize the critical role of country-level basic data in guiding sound policies to tackle the global P crises.


Asunto(s)
Ecosistema , Suelo , Fósforo/análisis , Bosques , Plantas , China
19.
Strahlenther Onkol ; 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38498173

RESUMEN

OBJECTIVE: This study aims to examine the ability of deep learning (DL)-derived imaging features for the prediction of radiation pneumonitis (RP) in locally advanced non-small-cell lung cancer (LA-NSCLC) patients. MATERIALS AND METHODS: The study cohort consisted of 90 patients from the Fudan University Shanghai Cancer Center and 59 patients from the Affiliated Hospital of Jiangnan University. Occurrences of RP were used as the endpoint event. A total of 512 3D DL-derived features were extracted from two regions of interest (lung-PTV and PTV-GTV) delineated on the pre-radiotherapy planning CT. Feature selection was done using LASSO regression, and the classification models were built using the multilayered perceptron method. Performances of the developed models were evaluated by receiver operating characteristic curve analysis. In addition, the developed models were supplemented with clinical variables and dose-volume metrics of relevance to search for increased predictive value. RESULTS: The predictive model using DL features derived from lung-PTV outperformed the one based on features extracted from PTV-GTV, with AUCs of 0.921 and 0.892, respectively, in the internal test dataset. Furthermore, incorporating the dose-volume metric V30Gy into the predictive model using features from lung-PTV resulted in an improvement of AUCs from 0.835 to 0.881 for the training data and from 0.690 to 0.746 for the validation data, respectively (DeLong p < 0.05). CONCLUSION: Imaging features extracted from pre-radiotherapy planning CT using 3D DL networks could predict radiation pneumonitis and may be of clinical value for risk stratification and toxicity management in LA-NSCLC patients. CLINICAL RELEVANCE STATEMENT: Integrating DL-derived features with dose-volume metrics provides a promising noninvasive method to predict radiation pneumonitis in LA-NSCLC lung cancer radiotherapy, thus improving individualized treatment and patient outcomes.

20.
Cell Commun Signal ; 22(1): 115, 2024 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-38347536

RESUMEN

Phosphorylation proteomics is the basis for the study of abnormally activated kinase signaling pathways in breast cancer, which facilitates the discovery of new oncogenic agents and drives the discovery of potential targets for early diagnosis and therapy of breast cancer. In this study, we have explored the aberrantly active kinases in breast cancer development and to elucidate the role of PRKCD_pY313 in triple negative breast cancer (TNBC) progression. We collected 47 pairs of breast cancer and paired far-cancer normal tissues and analyzed phosphorylated tyrosine (pY) peptides by Superbinder resin and further enriched the phosphorylated serine/threonine (pS/pT) peptides using TiO2 columns. We mapped the kinases activity of different subtypes of breast cancer and identified PRKCD_pY313 was upregulated in TNBC cell lines. Gain-of-function assay revealed that PRKCD_pY313 facilitated the proliferation, enhanced invasion, accelerated metastasis, increased the mitochondrial membrane potential and reduced ROS level of TNBC cell lines, while Y313F mutation and low PRKCD_pY313 reversed these effects. Furthermore, PRKCD_pY313 significantly upregulated Src_pY419 and p38_pT180/pY182, while low PRKCD_pY313 and PRKCD_Y313F had opposite effects. Dasatinib significantly inhibited the growth of PRKCD_pY313 overexpression cells, and this effect could be enhanced by Adezmapimod. In nude mice xenograft model, PRKCD_pY313 significantly promoted tumor progression, accompanied by increased levels of Ki-67, Bcl-xl and Vimentin, and decreased levels of Bad, cleaved caspase 3 and ZO1, which was opposite to the trend of Y313F group. Collectively, the heterogeneity of phosphorylation exists in different molecular subtypes of breast cancer. PRKCD_pY313 activates Src and accelerates TNBC progression, which could be inhibited by Dasatinib.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Animales , Humanos , Ratones , Línea Celular Tumoral , Proliferación Celular , Dasatinib/farmacología , Ratones Desnudos , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Péptidos/farmacología , Proteína Quinasa C-delta/metabolismo , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Familia-src Quinasas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA