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1.
Proc Natl Acad Sci U S A ; 120(34): e2120771120, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37579137

RESUMEN

The binding of tumor necrosis factor-like cytokine 1A (TL1A) to death receptor 3 (DR3) plays an important role in the interaction between dendritic cells (DCs) and T cells and contributes to intestinal inflammation development. However, the mechanism by which DCs expressing TL1A mediate helper T (Th) cell differentiation in the intestinal lamina propria (LP) during the pathogenesis of inflammatory bowel disease remains unclear. In this study, we found that TL1A/DR3 promoted Th1 and Th17 cell differentiation in T-T and DC-T cell interaction-dependent manners. TL1A-deficient CD4+ T cells failed to polarize into Th1/Th17 cells and did not cause colonic inflammation in a T cell transfer colitis model. Notably, TL1A was located in the cytoplasm and nuclei of DCs, positively regulated the DC-specific ICAM-grabbing nonintegrin/RAF1/nuclear factor κB signaling pathway, enhanced the antigen uptake ability of DCs, and promoted TLR4-mediated DC activation, inducing naive CD4+ T cell differentiation into Th1 and Th17 cells. Our work reveals that TL1A plays a regulatory role in inflammatory bowel disease pathogenesis.


Asunto(s)
Enfermedades Inflamatorias del Intestino , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral , Humanos , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/genética , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/metabolismo , Miembro 25 de Receptores de Factores de Necrosis Tumoral/metabolismo , Enfermedades Inflamatorias del Intestino/metabolismo , Inflamación/metabolismo , Factor de Necrosis Tumoral alfa
2.
Plant Physiol ; 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38696652

RESUMEN

Pear ring rot, caused by Botryosphaeria dothidea, is the most serious disease of pear (Pyrus spp.) trees. However, the molecular mechanisms underlying pear resistance to B. dothidea remain elusive. Herein, we demonstrated that the pear AuTophagy-related Gene 1a (PbrATG1a) plays a key role in autophagic activity and resistance to B. dothidea. Stable overexpression of PbrATG1a enhanced resistance to B. dothidea in pear calli. Autophagy activity was greater in PbrATG1a overexpressing calli than in WT calli. We used yeast one-hybrid screening to identify a transcription factor, Related to ABI3 and VP1 (Pbr3RAV2), that binds the promoter of PbrATG1a and enhances pear resistance to B. dothidea by regulating autophagic activity. Specifically, overexpression of Pbr3RAV2 enhanced resistance to B. dothidea in pear calli, while transient silencing of Pbr3RAV2 resulted in compromised resistance to B. dothidea in Pyrus betulaefolia. In addition, we identified Transparent Testa Glabra 1 (PbrTTG1), which interacts with Pbr3RAV2. Pathogen infection enhanced the interaction between Pbr3RAV2 and PbrTTG1. The Pbr3RAV2-PbrTTG1 complex increased the binding capacity of Pbr3RAV2 and transcription of PbrATG1a. In addition to providing insights into the molecular mechanisms underlying pear disease resistance, these findings suggest potential genetic targets for enhancing disease resistance in pear.

3.
J Am Chem Soc ; 146(1): 532-542, 2024 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-38134439

RESUMEN

Aggregation of transthyretin (TTR) is associated with devastating amyloid diseases. Amyloidosis begins with the dissociation of the native homotetramer (a dimer of dimers) to form a monomeric intermediate that assembles into pathogenic aggregates. This process is accelerated in vitro at low pH, but the process by which TTR dissociates and reassembles at neutral pH remains poorly characterized due to the low population of intermediates. Here, we use 19F-nuclear magnetic resonance (NMR) and a highly sensitive trifluoromethyl probe to determine the relative populations of the species formed by the dissociation of a destabilized variant, A25T. The A25T mutation perturbs both the strong dimer and weak dimer-dimer interfaces. A tetramer ⇌ dimer ⇌ monomer (TDM) equilibrium model is proposed to account for concentration- and temperature-dependent population changes. Thermodynamic and kinetic parameters and activation energetics for dissociation of the native A25T tetramer, as well as a destabilized alternative tetramer (T*) with a mispacked F87 side chain, were extracted by van't Hoff and 19F-NMR line shape analysis, saturation transfer, and transition state theory. Chemical shifts for the dimer and T* species are degenerate for 19F and methyl probes close to the strong dimer interface, implicating interfacial perturbation as a common structural feature of these destabilized species. All-atom molecular dynamics simulations further suggest more frequent F87 ring flipping on the nanosecond time scale in the A25T dimer than in the native A25T tetramer. Our integrated approach offers quantitative insights into the energy landscape of the dissociation pathway of TTR at neutral pH.


Asunto(s)
Prealbúmina , Prealbúmina/genética , Prealbúmina/química , Prealbúmina/metabolismo , Mutación , Espectroscopía de Resonancia Magnética
4.
Breast Cancer Res ; 26(1): 48, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38504374

RESUMEN

BACKGROUND: Breast cancer stem cell (CSC) expansion results in tumor progression and chemoresistance; however, the modulation of CSC pluripotency remains unexplored. Transmembrane protein 120B (TMEM120B) is a newly discovered protein expressed in human tissues, especially in malignant tissues; however, its role in CSC expansion has not been studied. This study aimed to determine the role of TMEM120B in transcriptional coactivator with PDZ-binding motif (TAZ)-mediated CSC expansion and chemotherapy resistance. METHODS: Both bioinformatics analysis and immunohistochemistry assays were performed to examine expression patterns of TMEM120B in lung, breast, gastric, colon, and ovarian cancers. Clinicopathological factors and overall survival were also evaluated. Next, colony formation assay, MTT assay, EdU assay, transwell assay, wound healing assay, flow cytometric analysis, sphere formation assay, western blotting analysis, mouse xenograft model analysis, RNA-sequencing assay, immunofluorescence assay, and reverse transcriptase-polymerase chain reaction were performed to investigate the effect of TMEM120B interaction on proliferation, invasion, stemness, chemotherapy sensitivity, and integrin/FAK/TAZ/mTOR activation. Further, liquid chromatography-tandem mass spectrometry analysis, GST pull-down assay, and immunoprecipitation assays were performed to evaluate the interactions between TMEM120B, myosin heavy chain 9 (MYH9), and CUL9. RESULTS: TMEM120B expression was elevated in lung, breast, gastric, colon, and ovarian cancers. TMEM120B expression positively correlated with advanced TNM stage, lymph node metastasis, and poor prognosis. Overexpression of TMEM120B promoted breast cancer cell proliferation, invasion, and stemness by activating TAZ-mTOR signaling. TMEM120B directly bound to the coil-coil domain of MYH9, which accelerated the assembly of focal adhesions (FAs) and facilitated the translocation of TAZ. Furthermore, TMEM120B stabilized MYH9 by preventing its degradation by CUL9 in a ubiquitin-dependent manner. Overexpression of TMEM120B enhanced resistance to docetaxel and doxorubicin. Conversely, overexpression of TMEM120B-∆CCD delayed the formation of FAs, suppressed TAZ-mTOR signaling, and abrogated chemotherapy resistance. TMEM120B expression was elevated in breast cancer patients with poor treatment outcomes (Miller/Payne grades 1-2) than in those with better outcomes (Miller/Payne grades 3-5). CONCLUSIONS: Our study reveals that TMEM120B bound to and stabilized MYH9 by preventing its degradation. This interaction activated the ß1-integrin/FAK-TAZ-mTOR signaling axis, maintaining stemness and accelerating chemotherapy resistance.


Asunto(s)
Neoplasias de la Mama , Neoplasias Ováricas , Humanos , Animales , Ratones , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Integrina beta1 , Línea Celular Tumoral , Serina-Treonina Quinasas TOR/metabolismo , Proliferación Celular , Cadenas Pesadas de Miosina
5.
Small ; 20(16): e2307366, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38039446

RESUMEN

Restoring immune tolerance is the ultimate goal for rheumatoid arthritis (RA) treatment. The most reported oral or intravenous injection routes for the immunization of autoantigens cause gastrointestinal side effects, low patient compliance, and unsatisfied immune tolerance induction. Herein, the use of a transdermal microneedle patch is for the first time investigated to codeliver CII peptide autoantigen and rapamycin for reversing immune disorders of RA. The immunized microneedles efficiently recruit antigen-presenting cells particularly Langerhans cells, and induce tolerogenic dendritic cells at the administration skin site. The tolerogenic dendritic cells further homing to lymph nodes to activate systemic Treg cell differentiation, which upregulates the expression of anti-inflammatory mediators while inhibiting the polarization of Th1/2 and Th17 T cell phenotypes and the expression of inflammatory profiles. As a result, the optimized microneedles nearly completely eliminate RA symptoms and inflammatory infiltrations. Furthermore, it is demonstrated that a low dose of rapamycin is crucial for the successful induction of immune tolerance. The results indicate that a rationally designed microneedle patch is a promising strategy for immune balance restoration with increased immune tolerance induction efficiency and patient compliance.


Asunto(s)
Artritis Reumatoide , Células de Langerhans , Humanos , Células Th17 , Artritis Reumatoide/terapia , Tolerancia Inmunológica , Sirolimus/farmacología
6.
Opt Express ; 32(5): 8122-8128, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38439477

RESUMEN

In current inertial confinement fusion (ICF) facilities, potassium dihydrogen phosphate (KH2PO4, KDP) type crystals are the only nonlinear optical (NLO) materials that can satisfy the aperture requirement of the ICF laser driver. Ammonium dihydrogen phosphate (NH4H2PO4, ADP) crystal is a typical isomer of KDP crystal, with a large nonlinear optical coefficient, high ultraviolet transmittance, and large growth sizes, which is an important deep ultraviolet (UV) NLO material. In this paper, we investigated the effect of ADP temperature on its fourth-harmonic-generation (FHG) performance. When the temperature of the ADP crystal was elevated to 48.9 °C, the 90° phase-matched FHG of the 1064 nm laser was realized. Compared with the 79° phase-matched FHG at room temperature (23.0 °C), the output energy at 266 nm, conversion efficiency, angular acceptance, and laser-induced damage threshold (LIDT) increased 113%, 71%, 623%, 19.6%, respectively. It shows that elevating ADP temperature is an efficient method to improve its deep UV frequency conversion properties, which may also be available to other NLO crystals. This discovery provides a very valuable technology for the future development of UV, deep UV lasers in ICF facilities.

7.
Dig Dis Sci ; 69(4): 1214-1227, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38376789

RESUMEN

BACKGROUND: HSK3486 (ciprofol), a new candidate drug similar to propofol, exerts sedative and hypnotic effects through gamma-aminobutyric acid type A receptors; however, its potential role in colorectal cancer is currently unknown. AIMS: This study aimed to evaluate the effects of HSK3486 on colorectal cancer cell proliferation. METHODS: Imaging was performed to detect reactive oxygen species and mitochondrial membrane potential. Western blotting was used to determine the expression of target signals. The HSK3486 molecular mechanism was investigated through ATPase inhibitory factor 1 knockdown and xenograft model experiments to assess mitochondrial function in colorectal cancer cells. RESULTS: Cell Counting Kit-8 and Annexin V/propidium iodide double staining assays showed that HSK3486 inhibited colorectal cancer cell proliferation in a concentration-dependent manner. In addition, HSK3486 treatment increased the expression of B-cell lymphoma-2-associated X, cleaved caspase 3, and cleaved poly (ADP-ribose) polymerase, whereas myeloid cell leukemia-1 and B-cell lymphoma 2 expression decreased. HSK3486 promoted mitochondrial dysfunction by inducing ATPase inhibitor factor 1 expression. Furthermore, HSK3486 promoted oxidative stress, as shown by the increase in reactive oxygen species and lactate dehydrogenase levels, along with a decrease in mitochondrial membrane potential and ATP levels. ATPase inhibitor factor 1 small interfering RNA pretreatment dramatically increased the mitochondrial membrane potential and tumor size in a xenograft model following exposure to HSK3486. CONCLUSION: Collectively, our findings revealed that HSK3486 induces oxidative stress, resulting in colorectal cancer cell apoptosis, making it a potential candidate therapeutic strategy for colorectal cancer.


Asunto(s)
Apoptosis , Neoplasias Colorrectales , Humanos , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfatasas/farmacología , Adenosina Trifosfatasas/uso terapéutico , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Potencial de la Membrana Mitocondrial , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Proteína Inhibidora ATPasa/efectos de los fármacos
8.
Int J Med Sci ; 21(5): 965-977, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38616996

RESUMEN

Cardiac hypertrophy is the most prevalent compensatory heart disease that ultimately leads to spontaneous heart failure. Mounting evidence suggests that microRNAs (miRs) and endogenous hydrogen sulfide (H2S) play a crucial role in the regulation of cardiac hypertrophy. In this study, we aimed to investigate whether inhibition of miR-27a could protect against cardiac hypertrophy by modulating H2S signaling. We established a model of cardiac hypertrophy by obtaining hypertrophic tissue from mice subjected to transverse aortic constriction (TAC) and from cells treated with angiotensin-II. Molecular alterations in the myocardium were quantified using quantitative real time PCR (qRT-PCR), Western blotting, and ELISA. Morphological changes were characterized by hematoxylin and eosin (HE) staining and Masson's trichrome staining. Functional myocardial changes were assessed using echocardiography. Our results demonstrated that miR-27a levels were elevated, while H2S levels were reduced in TAC mice and myocardial hypertrophy. Further luciferase and target scan assays confirmed that cystathionine-γ-lyase (CSE) was a direct target of miR-27a and was negatively regulated by it. Notably, enhancement of H2S expression in the heart was observed in mice injected with recombinant adeno-associated virus vector 9 (rAAV9)-anti-miR-27a and in cells transfected with a miR-27a inhibitor during cardiac hypertrophy. However, this effect was abolished by co-transfection with CSE siRNA and the miR-27a inhibitor. Conversely, injecting rAAV9-miR-27a yielded opposite results. Interestingly, our findings demonstrated that glucagon-like peptide-1 (GLP-1) agonists could mitigate myocardial damage by down-regulating miR-27a and up-regulating CSE. In summary, our study suggests that inhibition of miR-27a holds therapeutic promise for the treatment of cardiac hypertrophy by increasing H2S levels. Furthermore, our findings unveil a novel mechanism of GLP-1 agonists involving the miR-27a/H2S pathway in the management of cardiac hypertrophy.


Asunto(s)
Estenosis de la Válvula Aórtica , Insuficiencia Cardíaca , MicroARNs , Animales , Ratones , Cardiomegalia/genética , Péptido 1 Similar al Glucagón , MicroARNs/genética , Cistationina gamma-Liasa
9.
Acta Biochim Biophys Sin (Shanghai) ; 56(6): 866-878, 2024 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-38606479

RESUMEN

Approximately 20% of colorectal cancer (CRC) patients are first diagnosed with metastatic colorectal cancer (mCRC) because they develop symptoms at an advanced stage. Despite advancements in treatment, patients with metastatic disease still experience inferior survival rates. Our objective is to investigate the association between long noncoding RNAs (lncRNAs) and prognosis and to explore their role in mCRC. In this study, we find that elevated expression of PCAT6 is independently linked to unfavourable survival outcomes in The Cancer Genome Atlas (TCGA) data, and this finding is further confirmed in CRC samples obtained from Fudan University Shanghai Cancer Center. Cell lines and xenograft mouse models are used to examine the impact of PCAT6 on tumor metastasis. Knockdown of PCAT6 is observed to impede the metastatic phenotype of CRC, as evidenced by functional assays, demonstrating the suppression of epithelial-mesenchymal transition (EMT) and stemness. Our findings show the significance of PCAT6 in mCRC and its potential use as a prognostic biomarker.


Asunto(s)
Neoplasias Colorrectales , Transición Epitelial-Mesenquimal , Células Madre Neoplásicas , ARN Largo no Codificante , Animales , Femenino , Humanos , Masculino , Ratones , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Ratones Desnudos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Pronóstico , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN no Traducido/genética
10.
Proc Natl Acad Sci U S A ; 118(1)2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-33443163

RESUMEN

The tumor-suppressor p53 is a critical regulator of the cellular response to DNA damage and is tightly regulated by posttranslational modifications. Thr55 in the AD2 interaction motif of the N-terminal transactivation domain functions as a phosphorylation-dependent regulatory switch that modulates p53 activity. Thr55 is constitutively phosphorylated, becomes dephosphorylated upon DNA damage, and is subsequently rephosphorylated to facilitate dissociation of p53 from promoters and inactivate p53-mediated transcription. Using NMR and fluorescence spectroscopy, we show that Thr55 phosphorylation inhibits DNA-binding by enhancing competitive interactions between the disordered AD2 motif and the structured DNA-binding domain (DBD). Nonphosphorylated p53 exhibits positive cooperativity in binding DNA as a tetramer. Upon phosphorylation of Thr55, cooperativity is abolished and p53 binds initially to cognate DNA sites as a dimer. As the concentration of phosphorylated p53 is further increased, a second dimer binds and causes p53 to dissociate from the DNA, resulting in a bell-shaped binding curve. This autoinhibition is driven by favorable interactions between the DNA-binding surface of the DBD and the multiple phosphorylated AD2 motifs within the tetramer. These interactions are augmented by additional phosphorylation of Ser46 and are fine-tuned by the proline-rich domain (PRD). Removal of the PRD strengthens the AD2-DBD interaction and leads to autoinhibition of DNA binding even in the absence of Thr55 phosphorylation. This study reveals the molecular mechanism by which the phosphorylation status of Thr55 modulates DNA binding and controls both activation and termination of p53-mediated transcriptional programs at different stages of the cellular DNA damage response.


Asunto(s)
Proteínas de Unión al ADN/química , Dominios Proteicos Ricos en Prolina , Proteína p53 Supresora de Tumor/química , Sitios de Unión , ADN/química , Proteínas de Unión al ADN/genética , Dimerización , Polarización de Fluorescencia , Expresión Génica , Espectroscopía de Resonancia Magnética , Mutación , Fosforilación , Unión Proteica , Dominios Proteicos , Procesamiento Proteico-Postraduccional , Proteínas Recombinantes , Eliminación de Secuencia , Espectrometría de Fluorescencia , Proteína p53 Supresora de Tumor/genética
11.
Nano Lett ; 23(7): 2733-2742, 2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-36930562

RESUMEN

Dendritic cells (DCs) play an essential role in both the induction of the immune response and the maintenance of immune tolerance, with any malfunction of DCs potentially causing several diseases. While gene-based therapy for DC manipulation is a promising approach, it remains challenging due to the lack of efficient delivery systems for DC targeting. Herein, we describe a novel bacterial nanomedicine (BNM) system for pathogen recognition-mediated DCs-specific gene silencing and gene editing. BNMs contain components from bacterial outer membranes and achieve efficient DC targeting through the recognition of pathogen-associated molecular patterns by pattern recognition receptors on DCs. The targeting efficiency of BNMs is reduced in DCs lacking toll-like receptor 4, which is responsible for recognizing lipopolysaccharide, a major component of the bacterial outer membrane. As a proof-of-concept demonstration, we present gene-based therapy mediated by BNMs for enhancing antigen cross-presentation in DCs, which generates a remarkable antitumor effect.


Asunto(s)
Presentación de Antígeno , Lipopolisacáridos , Células Dendríticas , Silenciador del Gen
12.
Arch Psychiatr Nurs ; 49: 118-125, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38734447

RESUMEN

BACKGROUND: In early 2020, Chinese children started to demonstrate severe depression and post-traumatic stress disorder symptoms (PTSS) caused by lockdown and self-isolation (measures taken at the beginning of the COVID-19 pandemic). OBJECTIVES: Concerning the significant impact of the pandemic on children's physical and mental development, the study aimed to explore children's depression and PTSS during the COVID-19 pandemic and the protective effects of family resilience on the trajectories. METHODS: 883 children participated and completed three waves of online follow-up questionnaires. The latent growth mixture modeling (LGMM) analysis was used to explore the trajectories of children's depression and PTSS based on the individual approach. RESULTS: Two types of depression trajectories were identified and defined as the resilient group (83.01 %) and the recovery group (16.99 %); Two types of PTSS trajectories were identified and defined as the resilient group (71.12 %) and the recovery group (28.88 %); Two types of the joint trajectories of depression and PTSS were identified and defined as the resilient group (83.47 %) and the chronic group (16.53 %). The results indicated that maintaining a positive outlook (a dimension of family resilience) was the potential predictor of PTSS trajectories. CONCLUSION: The trajectories of depression and PTSS among Chinese children during the COVID-19 pandemic were heterogeneous, and there were similar evolving subtypes. Family resilience could be a critical protective factor for children and families.


Asunto(s)
COVID-19 , Depresión , Resiliencia Psicológica , Trastornos por Estrés Postraumático , Niño , Femenino , Humanos , Masculino , China/epidemiología , COVID-19/psicología , Depresión/psicología , Depresión/epidemiología , Pueblos del Este de Asia , Pandemias , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/psicología , Encuestas y Cuestionarios
13.
Angew Chem Int Ed Engl ; : e202408670, 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38943429

RESUMEN

Peptide folding is a dynamic process driven by non-covalent cross-linking leading to functional nanostructures for essential biochemical activities. However, replicating this process in synthetic systems is challenging due to the difficulty in mimicking nature's real-time regulation of non-covalent crosslinking for single-chain polymer folding. Here, we address this by employing anionic dithiol building blocks to create macrocyclic disulfides as non-covalent crosslinkers that adapted to the folding process. Initially, small macrocycles facilitated a low degree folding of a polycation. Then, this preorganized structure catalysed the production of larger macrocycles that enhanced the folding conversely. The self-adaptive synthesis was verified through the encapsulation of an anticancer drug, showing an updated production distribution of non-covalent crosslinkers and maximizing drug-loading efficiency against drug-resistant cancer in vitro. Our research advances the understanding of molecular systems by exploring species evolution via the structural dynamics of polymer folding. Additionally, adaptive synthesis enables controlled, sequential folding of synthetic polymers, with the potential to mimic protein functions.

14.
J Biol Chem ; 298(8): 102162, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35724960

RESUMEN

Transthyretin (TTR) amyloidosis is associated with tissue deposition of TTR aggregates. TTR aggregation is initiated by dissociation of the native tetramer to form a monomeric intermediate, which locally unfolds and assembles into soluble oligomers and higher-order aggregates. However, a detailed mechanistic understanding requires kinetic and structural characterization of the low population intermediates formed. Here, we show that the monomeric intermediate exchanges with an ensemble of oligomers on the millisecond timescale. This transient and reversible exchange causes broadening of the 19F resonance of a trifluoromethyl probe coupled to the monomeric intermediate at S85C. We show the 19F linewidth and R2 relaxation rate increase with increasing concentration of the oligomer. Furthermore, introduction of 19F probes at additional TTR sites yielded distinct 19F chemical shifts for the TTR tetramer and monomer when the trifluoromethyl probe was attached at S100C, located near the same subunit interface as S85C, but not with probes attached at S46C or E63C, which are distant from any interfaces. The 19F probe at E63C shows that part of the DE loop, which is solvent accessible in the tetramer, becomes more buried in the NMR-visible oligomers. Finally, using backbone amides as probes, we show that parts of the EF helix and H-strand become highly flexible in the otherwise structured monomeric intermediate at acidic pH. We further find that TTR aggregation can be reversed by increasing pH. Taken together, this work provides insights into location-dependent conformational changes in the reversible early steps of a kinetically concerted TTR aggregation pathway.


Asunto(s)
Amiloidosis , Prealbúmina , Agregado de Proteínas , Amiloide/química , Cinética , Prealbúmina/química , Agregación Patológica de Proteínas , Conformación Proteica
15.
Biochem Biophys Res Commun ; 639: 62-69, 2023 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-36470073

RESUMEN

It is increasingly recognized that a single protein can have multiple, sometimes paradoxical, roles in cell functions as well as pathological conditions depending on its cellular locations. Here we report that moesins (MSNs) in the intracellular and extracellular domains present opposing roles in pro-tumorigenic signaling in breast cancer cells. Using live cell imaging with fluorescence resonance energy transfer (FRET)- and green fluorescent protein (GFP)-based biosensors, we investigated the molecular mechanism underlying the cellular location-dependent effect of MSN on Src and ß-catenin signaling in MDA-MB-231 breast cancer cells. Inhibition of intracellular MSN decreased the activities of Src and FAK, whereas overexpression of intracellular MSN increased them. By contrast, extracellular MSN decreased the activities of Src, FAK, and RhoA, as well as ß-catenin translocation to the nucleus. Consistently, Western blotting and MTT-based analysis showed that overexpression of intracellular MSN elevated the expression of oncogenic genes, such as p-Src, ß-catenin, Lrp5, MMP9, Runx2, and Snail, as well as cell viability, whereas extracellular MSN suppressed them. Conditioned medium derived from MSN-overexpressing mesenchymal stem cells or osteocytes showed the anti-tumor effects by inhibiting the Src activity and ß-catenin translocation to the nucleus as well as the activities of FAK and RhoA and MTT-based cell viability. Conditioned medium derived from MSN-inhibited cells increased the Src activity, but it did not affect the activities of FAK and RhoA. Silencing CD44 and/or FN1 in MDA-MB-231 cells blocked the suppression of Src activity and ß-catenin accumulation in the nucleus by extracellular MSN. Collectively, the results suggest that cellular location-specific MSN is a strong regulator of Src and ß-catenin signaling in breast cancer cells, and that extracellular MSN exerts tumor-suppressive effects via its interaction with CD44 and FN1.


Asunto(s)
Neoplasias de la Mama , beta Catenina , Humanos , Femenino , beta Catenina/metabolismo , Neoplasias de la Mama/patología , Medios de Cultivo Condicionados , Transducción de Señal , Línea Celular Tumoral
16.
Eur J Nucl Med Mol Imaging ; 50(6): 1665-1670, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36576511

RESUMEN

PURPOSE: This study aimed to assess prognosis of patients with newly diagnosed multiple myeloma (NDMM) by combining [18F]-FDG positron emission tomography (PET)/CT parameters and clinical indices. METHODS: Clinical data and PET/CT parameters of 133 NDMM patients were retrospectively analyzed for associations between clinical indices and PET/CT parameters. Independent predictors of progression-free survival (PFS) and overall survival (OS) were determined. A new prognostic prediction system (NPPS) was constructed based on our findings. Prediction effectiveness was compared among the NPPS, International Staging System (ISS), Revised ISS (R-ISS), and R2-ISS. RESULTS: Prevalence of elevated ß2-microglobulin, serum creatinine (sCr), serum calcium (sCa), and C-reactive protein concentrations was higher in patients with higher SUVmax (≥ 5.3). Prevalence of elevated sCa, sCr, and extramedullary disease (EMD) was higher in patients with a higher number of focal lesions (≥ 10). SUVmax, serum free-light chain (sFLC) ratio, and EMD were independent predictors of PFS and OS. The NPPS used SUVmax, sFLC ratio, and EMD could effectively predict OS and was more effective at prognostication than the ISS, R-ISS, and R2-ISS. CONCLUSIONS: [18F]-FDG PET/CT parameters play a significant role in predicting prognosis in NDMM patients. The NPPS based on SUVmax, sFLC ratio, and EMD outperformed the ISS, R-ISS, and R2-ISS in prognostication.


Asunto(s)
Mieloma Múltiple , Humanos , Mieloma Múltiple/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones , Fluorodesoxiglucosa F18 , Estudios Retrospectivos , Tomografía de Emisión de Positrones , Pronóstico
17.
Eur Radiol ; 33(7): 4567-4579, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37099173

RESUMEN

OBJECTIVES: Quantification of tau accumulation using positron emission tomography (PET) is critical for the diagnosis of Alzheimer's disease (AD). This study aimed to evaluate the feasibility of 18F-florzolotau quantification in patients with AD using a magnetic resonance imaging (MRI)-free tau PET template, since individual high-resolution MRI is costly and not always available in practice. METHODS: 18F-florzolotau PET and MRI scans were obtained in a discovery cohort including (1) patients within the AD continuum (n = 87), (2) cognitively impaired patients with non-AD (n = 32), and (3) cognitively unimpaired subjects (n = 26). The validation cohort comprised 24 patients with AD. Following MRI-dependent spatial normalization (standard approach) in randomly selected subjects (n = 40) to cover the entire spectrum of cognitive function, selected PET images were averaged to create the 18F-florzolotau-specific template. Standardized uptake value ratios (SUVRs) were calculated in five predefined regions of interest (ROIs). MRI-free and MRI-dependent methods were compared in terms of continuous and dichotomous agreement, diagnostic performances, and associations with specific cognitive domains. RESULTS: MRI-free SUVRs had a high continuous and dichotomous agreement with MRI-dependent measures for all ROIs (intraclass correlation coefficient ≥ 0.980; agreement ≥ 94.5%). Similar findings were observed for AD-related effect sizes, diagnostic performances with respect to categorization across the cognitive spectrum, and associations with cognitive domains. The robustness of the MRI-free approach was confirmed in the validation cohort. CONCLUSIONS: The use of an 18F-florzolotau-specific template is a valid alternative to MRI-dependent spatial normalization, improving the clinical generalizability of this second-generation tau tracer. KEY POINTS: • Regional 18F-florzolotau SUVRs reflecting tau accumulation in the living brains are reliable biomarkers for the diagnosis, differential diagnosis, and assessment of disease severity in patients with AD. • The 18F-florzolotau-specific template is a valid alternative to MRI-dependent spatial normalization, improving the clinical generalizability of this second-generation tau tracer.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/patología , Estudios de Factibilidad , Tomografía de Emisión de Positrones/métodos , Imagen por Resonancia Magnética/métodos , Encéfalo/patología , Proteínas tau/metabolismo
18.
J Bone Miner Metab ; 41(3): 365-370, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36040520

RESUMEN

Wnt signaling plays a critical role in loading-driven bone formation and bone homeostasis, whereas its activation in cancer cells promotes their progression. Currently, major research efforts in cancer treatment have been directed to the development of Wnt inhibitors. Recent studies on tumor-bone interactions, however, presented multiple lines of evidence that support a tumor-suppressive role of Lrp5, a Wnt co-receptor, and ß-catenin, in Wnt signaling. This review describes the action of Wnt signaling as a double-edged sword in the bone microenvironment and suggests the possibility of a novel option for protecting bone from cancer.


Asunto(s)
Neoplasias Óseas , Vía de Señalización Wnt , Humanos , Proteína-5 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Huesos , Osteogénesis , Microambiente Tumoral
19.
Bioorg Med Chem Lett ; 82: 129153, 2023 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-36706843

RESUMEN

Triple-negative breast cancer (TNBC) is a highly heterogeneous and aggressive disease that is prone to metastasis and recurrence. It accounts for 15-20% of all breast cancer cases. Surgical resection is effective in removing most of the malignant tissues for non-metastasized tumors; however, some residual tumor tissues would be left, leading to a poor prognosis. Thus, real-time monitoring of surgical resection would be beneficial for the surgical resection of tumors. Although NIR-II fluorescent probe-guided surgical resection has been widely used for other types of diseases, it is not currently used for TNBC in clinical practice. Here, we describe the design and synthesis of a novel NIR-II fluorescent probe, FD-1050@NPs-cRGD, that targets TNBC. We found that it has a high fluorescence quantum efficiency, good stability, and low cytotoxicity. In vivo imaging in mice demonstrated a high tumor signal/normal tissue signal ratio, indicating that FD-1050@NPs-cRGD has great potential to be applied in tumor imaging of TNBC.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Animales , Ratones , Neoplasias de la Mama Triple Negativas/diagnóstico por imagen , Neoplasias de la Mama Triple Negativas/patología , Colorantes Fluorescentes , Imagen Óptica/métodos , Línea Celular Tumoral
20.
Inorg Chem ; 62(43): 17577-17582, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37843583

RESUMEN

Our research demonstrated that novel pentamethylcyclopentadienyl (Cp*) iridium pyridine sulfonamide complex PySO2NPh-Ir (7) could highly specifically catalyze nicotinamide adenine dinucleotide (NAD+) into the corresponding reducing cofactor NADH in cell growth media containing various biomolecules. The structures and catalytic mechanism of 7 were studied by single-crystal X-ray, NMR, electrochemical, and kinetic methods, and the formation of iridium hydride species Ir-H was confirmed to be the plausible hydride-transfer intermediate of 7. Moreover, benefiting from its high hydrogen-transfer activity and selectivity for NADH regeneration, 7 was used as an optimal metal catalyst to establish a chem-enzyme cascade catalytic hydrogen-transfer system, which realized the high-efficiency preparation of l-glutamic acid by combining with l-glutamate dehydrogenase (GLDH).


Asunto(s)
Hidrógeno , NAD , NAD/química , Hidrógeno/química , Iridio/química , Catálisis , Regeneración
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