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1.
Cell ; 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39270656

RESUMO

In a rigorous 40-month study, we evaluated the geroprotective effects of metformin on adult male cynomolgus monkeys, addressing a gap in primate aging research. The study encompassed a comprehensive suite of physiological, imaging, histological, and molecular evaluations, substantiating metformin's influence on delaying age-related phenotypes at the organismal level. Specifically, we leveraged pan-tissue transcriptomics, DNA methylomics, plasma proteomics, and metabolomics to develop innovative monkey aging clocks and applied these to gauge metformin's effects on aging. The results highlighted a significant slowing of aging indicators, notably a roughly 6-year regression in brain aging. Metformin exerts a substantial neuroprotective effect, preserving brain structure and enhancing cognitive ability. The geroprotective effects on primate neurons were partially mediated by the activation of Nrf2, a transcription factor with anti-oxidative capabilities. Our research pioneers the systemic reduction of multi-dimensional biological age in primates through metformin, paving the way for advancing pharmaceutical strategies against human aging.

2.
Cell ; 186(2): 287-304.e26, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36610399

RESUMO

Whether and how certain transposable elements with viral origins, such as endogenous retroviruses (ERVs) dormant in our genomes, can become awakened and contribute to the aging process is largely unknown. In human senescent cells, we found that HERVK (HML-2), the most recently integrated human ERVs, are unlocked to transcribe viral genes and produce retrovirus-like particles (RVLPs). These HERVK RVLPs constitute a transmissible message to elicit senescence phenotypes in young cells, which can be blocked by neutralizing antibodies. The activation of ERVs was also observed in organs of aged primates and mice as well as in human tissues and serum from the elderly. Their repression alleviates cellular senescence and tissue degeneration and, to some extent, organismal aging. These findings indicate that the resurrection of ERVs is a hallmark and driving force of cellular senescence and tissue aging.


Assuntos
Envelhecimento , Retrovirus Endógenos , Idoso , Animais , Humanos , Camundongos , Envelhecimento/genética , Envelhecimento/patologia , Senescência Celular , Retrovirus Endógenos/genética , Primatas
3.
Nucleic Acids Res ; 52(19): 11481-11499, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39258545

RESUMO

Dysfunction of the ribosome manifests during cellular senescence and contributes to tissue aging, functional decline, and development of aging-related disorders in ways that have remained enigmatic. Here, we conducted a comprehensive CRISPR-based loss-of-function (LOF) screen of ribosome-associated genes (RAGs) in human mesenchymal progenitor cells (hMPCs). Through this approach, we identified ribosomal protein L22 (RPL22) as the foremost RAG whose deficiency mitigates the effects of cellular senescence. Consequently, absence of RPL22 delays hMPCs from becoming senescent, while an excess of RPL22 accelerates the senescence process. Mechanistically, we found in senescent hMPCs, RPL22 accumulates within the nucleolus. This accumulation triggers a cascade of events, including heterochromatin decompaction with concomitant degradation of key heterochromatin proteins, specifically heterochromatin protein 1γ (HP1γ) and heterochromatin protein KRAB-associated protein 1 (KAP1). Subsequently, RPL22-dependent breakdown of heterochromatin stimulates the transcription of ribosomal RNAs (rRNAs), triggering cellular senescence. In summary, our findings unveil a novel role for nucleolar RPL22 as a destabilizer of heterochromatin and a driver of cellular senescence, shedding new light on the intricate mechanisms underlying the aging process.


Assuntos
Sistemas CRISPR-Cas , Nucléolo Celular , Senescência Celular , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona , Heterocromatina , Proteínas Ribossômicas , Heterocromatina/metabolismo , Heterocromatina/genética , Humanos , Senescência Celular/genética , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Nucléolo Celular/metabolismo , Nucléolo Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Cromossômicas não Histona/genética , Células-Tronco Mesenquimais/metabolismo , RNA Ribossômico/metabolismo , RNA Ribossômico/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética
4.
Proc Natl Acad Sci U S A ; 119(29): e2117054119, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858343

RESUMO

The G protein-coupled bile acid receptor (GPBAR) is the membrane receptor for bile acids and a driving force of the liver-bile acid-microbiota-organ axis to regulate metabolism and other pathophysiological processes. Although GPBAR is an important therapeutic target for a spectrum of metabolic and neurodegenerative diseases, its activation has also been found to be linked to carcinogenesis, leading to potential side effects. Here, via functional screening, we found that two specific GPBAR agonists, R399 and INT-777, demonstrated strikingly different regulatory effects on the growth and apoptosis of non-small cell lung cancer (NSCLC) cells both in vitro and in vivo. Further mechanistic investigation showed that R399-induced GPBAR activation displayed an obvious bias for ß-arrestin 1 signaling, thus promoting YAP signaling activation to stimulate cell proliferation. Conversely, INT-777 preferentially activated GPBAR-Gs signaling, thus inactivating YAP to inhibit cell proliferation and induce apoptosis. Phosphorylation of GPBAR by GRK2 at S310/S321/S323/S324 sites contributed to R399-induced GPBAR-ß-arrestin 1 association. The cryoelectron microscopy (cryo-EM) structure of the R399-bound GPBAR-Gs complex enabled us to identify key interaction residues and pivotal conformational changes in GPBAR responsible for the arrestin signaling bias and cancer cell proliferation. In summary, we demonstrate that different agonists can regulate distinct functions of cell growth and apoptosis through biased GPBAR signaling and control of YAP activity in a NSCLC cell model. The delineated mechanism and structural basis may facilitate the rational design of GPBAR-targeting drugs with both metabolic and anticancer benefits.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Proteínas de Ciclo Celular , Neoplasias Pulmonares , Receptores Acoplados a Proteínas G , Fatores de Transcrição , Ácidos e Sais Biliares/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Ciclo Celular/metabolismo , Ácidos Cólicos/farmacologia , Microscopia Crioeletrônica , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Fatores de Transcrição/metabolismo , beta-Arrestina 1/metabolismo
5.
Breast Cancer Res ; 26(1): 37, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454442

RESUMO

Increasing evidence shows the oncogenic function of FAM83D in human cancer, but how FAM83D exerts its oncogenic function remains largely unclear. Here, we investigated the importance of FAM83D/FBXW7 interaction in breast cancer (BC). We systematically mapped the FBXW7-binding sites on FAM83D through a comprehensive mutational analysis together with co-immunoprecipitation assay. Mutations at the FBXW7-binding sites on FAM83D led to that FAM83D lost its capability to promote the ubiquitination and proteasomal degradation of FBXW7; cell proliferation, migration, and invasion in vitro; and tumor growth and metastasis in vivo, indicating that the FBXW7-binding sites on FAM83D are essential for its oncogenic functions. A meta-evaluation of FAM83D revealed that the prognostic impact of FAM83D was independent on molecular subtypes. The higher expression of FAM83D has poorer prognosis. Moreover, high expression of FAM83D confers resistance to chemotherapy in BCs, which is experimentally validated in vitro. We conclude that identification of FBXW7-binding sites on FAM83D not only reveals the importance for FAM83D oncogenic function, but also provides valuable insights for drug target.


Assuntos
Neoplasias da Mama , Proteínas de Ciclo Celular , Humanos , Feminino , Proteína 7 com Repetições F-Box-WD/genética , Proteína 7 com Repetições F-Box-WD/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Prognóstico , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo
6.
N Engl J Med ; 384(14): 1323-1334, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33826820

RESUMO

BACKGROUND: Cold agglutinin disease is a rare autoimmune hemolytic anemia characterized by hemolysis that is caused by activation of the classic complement pathway. Sutimlimab, a humanized monoclonal antibody, selectively targets the C1s protein, a C1 complex serine protease responsible for activating this pathway. METHODS: We conducted a 26-week multicenter, open-label, single-group study to assess the efficacy and safety of intravenous sutimlimab in patients with cold agglutinin disease and a recent history of transfusion. The composite primary end point was a normalization of the hemoglobin level to 12 g or more per deciliter or an increase in the hemoglobin level of 2 g or more per deciliter from baseline, without red-cell transfusion or medications prohibited by the protocol. RESULTS: A total of 24 patients were enrolled and received at least one dose of sutimlimab; 13 patients (54%) met the criteria for the composite primary end point. The least-squares mean increase in hemoglobin level was 2.6 g per deciliter at the time of treatment assessment (weeks 23, 25, and 26). A mean hemoglobin level of more than 11 g per deciliter was maintained in patients from week 3 through the end of the study period. The mean bilirubin levels normalized by week 3. A total of 17 patients (71%) did not receive a transfusion from week 5 through week 26. Clinically meaningful reductions in fatigue were observed by week 1 and were maintained throughout the study. Activity in the classic complement pathway was rapidly inhibited, as assessed by a functional assay. Increased hemoglobin levels, reduced bilirubin levels, and reduced fatigue coincided with inhibition of the classic complement pathway. At least one adverse event occurred during the treatment period in 22 patients (92%). Seven patients (29%) had at least one serious adverse event, none of which were determined by the investigators to be related to sutimlimab. No meningococcal infections occurred. CONCLUSIONS: In patients with cold agglutinin disease who received sutimlimab, selective upstream inhibition of activity in the classic complement pathway rapidly halted hemolysis, increased hemoglobin levels, and reduced fatigue. (Funded by Sanofi; CARDINAL ClinicalTrials.gov number, NCT03347396.).


Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Complemento C1s/antagonistas & inibidores , Idoso , Idoso de 80 Anos ou mais , Anemia Hemolítica Autoimune/sangue , Anemia Hemolítica Autoimune/complicações , Anemia Hemolítica Autoimune/terapia , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/farmacologia , Transfusão de Sangue , Fadiga/tratamento farmacológico , Fadiga/etiologia , Feminino , Hemoglobinas/análise , Hemólise/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida
7.
Blood ; 140(9): 980-991, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35687757

RESUMO

Sutimlimab, a first-in-class humanized immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits the classical complement pathway at C1s, rapidly halted hemolysis in the single-arm CARDINAL study in recently transfused patients with cold agglutinin disease (CAD). CADENZA was a 26-week randomized, placebo-controlled phase 3 study to assess safety and efficacy of sutimlimab in patients with CAD without recent (within 6 months prior to enrollment) transfusion history. Forty-two patients with screening hemoglobin ≤10 g/dL, elevated bilirubin, and ≥1 CAD symptom received sutimlimab (n = 22) or placebo (n = 20) on days 0 and 7 and then biweekly. Composite primary endpoint criteria (hemoglobin increase ≥1.5 g/dL at treatment assessment timepoint [mean of weeks 23, 25, 26], avoidance of transfusion, and study-prohibited CAD therapy [weeks 5-26]) were met by 16 patients (73%) on sutimlimab, and 3 patients (15%) on placebo (odds ratio, 15.9 [95% confidence interval, 2.9, 88.0; P < .001]). Sutimlimab, but not placebo, significantly increased mean hemoglobin and FACIT-Fatigue scores at treatment assessment timepoint. Sutimlimab normalized mean bilirubin by week 1. Improvements correlated with near-complete inhibition of the classical complement pathway (2.3% mean activity at week 1) and C4 normalization. Twenty-one (96%) sutimlimab patients and 20 (100%) placebo patients experienced ≥1 treatment-emergent adverse event. Headache, hypertension, rhinitis, Raynaud phenomenon, and acrocyanosis were more frequent with sutimlimab vs placebo, with a difference of ≥3 patients between groups. Three sutimlimab patients discontinued owing to adverse events; no placebo patients discontinued. These data demonstrate that sutimlimab has potential to be an important advancement in the treatment of CAD. This trial was registered at www.clinicaltrials.gov as #NCT03347422.


Assuntos
Anemia Hemolítica Autoimune , Anticorpos Monoclonais Humanizados , Anemia Hemolítica Autoimune/sangue , Anemia Hemolítica Autoimune/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Bilirrubina/sangue , Método Duplo-Cego , Hemoglobinas/análise , Humanos , Resultado do Tratamento
8.
J Magn Reson Imaging ; 59(2): 575-584, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37218596

RESUMO

BACKGROUND: Breast cancer treatment response evaluation using the response evaluation criteria in solid tumors (RECIST) guidelines, based on tumor volume changes, has limitations, prompting interest in novel imaging markers for accurate therapeutic effect determination. PURPOSE: To use MRI-measured cell size as a new imaging biomarker for assessing chemotherapy response in breast cancer. STUDY TYPE: Longitudinal; animal model. STUDY POPULATION: Triple-negative human breast cancer cell (MDA-MB-231) pellets (4 groups, n = 7) treated with dimethyl sulfoxide (DMSO) or 10 nM of paclitaxel for 24, 48, and 96 hours, and 29 mice with MDA-MB-231 tumors in right hind limbs treated with paclitaxel (n = 16) or DMSO (n = 13) twice weekly for 3 weeks. FIELD STRENGTH/SEQUENCE: Oscillating gradient spin echo and pulsed gradient spin echo sequences at 4.7 T. ASSESSMENT: MDA-MB-231 cells were analyzed using flowcytometry and light microscopy to assess cell cycle phases and cell size distribution. MDA-MB-231 cell pellets were MR imaged. Mice were imaged weekly, with 9, 6, and 14 being sacrificed for histology after MRI at weeks 1, 2, and 3, respectively. Microstructural parameters of tumors/cell pellets were derived by fitting diffusion MRI data to a biophysical model. STATISTICAL TESTS: One-way ANOVA compared cell sizes and MR-derived parameters between treated and control samples. Repeated measures 2-way ANOVA with Bonferroni post-tests compared temporal changes in MR-derived parameters. A P-value <0.05 was considered statistically significant. RESULTS: In vitro experiments showed that the mean MR-derived cell sizes of paclitaxel-treated cells increased significantly with a 24-hours treatment and decreased (P = 0.06) with a 96-hour treatment. For in vivo xenograft experiments, the paclitaxel-treated tumors showed significant decreases in cell size at later weeks. MRI observations were supported by flowcytometry, light microscopy, and histology. DATA CONCLUSIONS: MR-derived cell size may characterize the cell shrinkage during treatment-induced apoptosis, and may potentially provide new insights into the assessment of therapeutic response. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 4.


Assuntos
Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Feminino , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Neoplasias de Mama Triplo Negativas/diagnóstico por imagem , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Dimetil Sulfóxido/uso terapêutico , Linhagem Celular Tumoral , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Imageamento por Ressonância Magnética/métodos , Tamanho Celular
9.
Mol Pharm ; 21(5): 2148-2162, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38536949

RESUMO

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer for which effective therapies are lacking. Targeted remodeling of the immunosuppressive tumor microenvironment (TME) and activation of the body's immune system to fight tumors with well-designed nanoparticles have emerged as pivotal breakthroughs in tumor treatment. To simultaneously remodel the immunosuppressive TME and trigger immune responses, we designed two potential therapeutic nanodelivery systems to inhibit TNBC. First, the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 and the cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) were coloaded into chondroitin sulfate (CS) to obtain CS@JQ1/CXB nanoparticles (NPs). Then, the biomimetic nanosystem MM@P3 was prepared by coating branched polymer poly(ß-amino ester) self-assembled NPs with melittin embedded macrophage membranes (MM). Both in vitro and in vivo, the CS@JQ1/CXB and MM@P3 NPs showed excellent immune activation efficiencies. Combination treatment exhibited synergistic cytotoxicity, antimigration ability, and apoptosis-inducing and immune activation effects on TNBC cells and effectively suppressed tumor growth and metastasis in TNBC tumor-bearing mice by activating the tumor immune response and inhibiting angiogenesis. In summary, this study offers a novel combinatorial immunotherapeutic strategy for the clinical TNBC treatment.


Assuntos
Azepinas , Celecoxib , Triazóis , Neoplasias de Mama Triplo Negativas , Microambiente Tumoral , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/imunologia , Neoplasias de Mama Triplo Negativas/patologia , Microambiente Tumoral/efeitos dos fármacos , Animais , Feminino , Camundongos , Humanos , Celecoxib/administração & dosagem , Linhagem Celular Tumoral , Sulfatos de Condroitina/química , Sulfatos de Condroitina/administração & dosagem , Nanopartículas/química , Nanopartículas/administração & dosagem , Meliteno/administração & dosagem , Meliteno/química , Apoptose/efeitos dos fármacos , Sistemas de Liberação de Fármacos por Nanopartículas/química , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Endogâmicos BALB C , Inibidores de Ciclo-Oxigenase 2/administração & dosagem , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Polímeros/química , Camundongos Nus , Sistemas de Liberação de Medicamentos/métodos
10.
Nucleic Acids Res ; 50(6): 3323-3347, 2022 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-35286396

RESUMO

Aging in humans is intricately linked with alterations in circadian rhythms concomitant with physiological decline and stem cell exhaustion. However, whether the circadian machinery directly regulates stem cell aging, especially in primates, remains poorly understood. In this study, we found that deficiency of BMAL1, the only non-redundant circadian clock component, results in an accelerated aging phenotype in both human and cynomolgus monkey mesenchymal progenitor cells (MPCs). Unexpectedly, this phenotype was mainly attributed to a transcription-independent role of BMAL1 in stabilizing heterochromatin and thus preventing activation of the LINE1-cGAS-STING pathway. In senescent primate MPCs, we observed decreased capacity of BMAL1 to bind to LINE1 and synergistic activation of LINE1 expression. Likewise, in the skin and muscle tissues from the BMAL1-deficient cynomolgus monkey, we observed destabilized heterochromatin and aberrant LINE1 transcription. Altogether, these findings uncovered a noncanonical role of BMAL1 in stabilizing heterochromatin to inactivate LINE1 that drives aging in primate cells.


Assuntos
Fatores de Transcrição ARNTL , Senescência Celular , Relógios Circadianos , Macaca fascicularis/metabolismo , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Animais , Relógios Circadianos/genética , Ritmo Circadiano , Heterocromatina , Macaca fascicularis/genética
11.
Chem Soc Rev ; 52(14): 4603-4631, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37341718

RESUMO

Amyloid fibrillar assemblies, originally identified as pathological entities in neurodegenerative diseases, have been widely adopted by various proteins to fulfill diverse biological functions in living organisms. Due to their unique features, such as hierarchical assembly, exceptional mechanical properties, environmental stability, and self-healing properties, amyloid fibrillar assemblies have been employed as functional materials in numerous applications. Recently, with the rapid advancement in synthetic biology and structural biology tools, new trends in the functional design of amyloid fibrillar assemblies have begun to emerge. In this review, we provide a comprehensive overview of the design principles for functional amyloid fibrillar assemblies from an engineering perspective, as well as through the lens of structural insights. Initially, we introduce the fundamental structural configurations of amyloid assemblies and highlight the functions of representative examples. We then focus on the underlying design principles of two prevalent strategies for the design of functional amyloid fibrillar assemblies: (1) introducing new functions via protein modular design and/or hybridization, with typical applications encompassing catalysis, virus disinfection, biomimetic mineralization, bio-imaging, and biotherapy; and (2) dynamically regulating living amyloid fibrillar assemblies using synthetic gene circuits, with typical applications in pattern formation, leakage repair, and pressure sensing. Next, we summarize how breakthroughs in characterization techniques have contributed to unveiling the structural polymorphism of amyloid fibrils at the atomic level, and further clarifying the highly diverse regulation mechanisms of amyloid fibrillar assembly and disassembly fine-tuned by various factors. The structural knowledge may significantly aid in the structure-guided design of amyloid fibrillar assemblies with diverse bio-activities and adjustable regulatory properties. Finally, we envision that a new trend in functional amyloid design may emerge by integrating structural tunability, synthetic biology and artificial intelligence.


Assuntos
Amiloide , Inteligência Artificial , Amiloide/química , Proteínas Amiloidogênicas
12.
Molecules ; 29(19)2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39407496

RESUMO

The adsorption of common anions found in water can have a considerable impact on the surface state and optical characteristics of titanium dioxide (TiO2), which has an important impact on the photocatalytic nitrogen reduction reaction (NRR). This work utilizes density functional theory (DFT) computations to examine the electronic and optical characteristics of the TiO2 (001) surface under various anion adsorptions in order to clarify their influence on the photocatalytic NRR of TiO2. The modifications in the structure, optical, and electronic properties of TiO2 before and after anion adsorption are investigated. In addition, the routes of Gibbs free energy for the NRR are also evaluated. The results indicate that the adsorption of anions modifies the surface characteristics of TiO2 to a certain degree, hence impacting the separating and recombining charge carriers by affecting the energy gap of TiO2. More importantly, the adsorption of anions can increase the energy barriers for the NRR, thereby exerting a detrimental effect on its photocatalytic activity. These findings provide a valuable theoretical contribution to understanding the photocatalytic reaction process of TiO2 and its potential application of NRR in the actual complex water phase.

13.
Magn Reson Med ; 89(6): 2432-2440, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36740894

RESUMO

PURPOSE: To quantify the variations of the power-law dependences on diffusion time t or gradient frequency f $$ f $$ of extracellular water diffusion measured by diffusion MRI (dMRI). METHODS: Model cellular systems containing only extracellular water were used to investigate the t / f $$ t/f $$ dependence of D ex $$ {D}_{ex} $$ , the extracellular diffusion coefficient. Computer simulations used a randomly packed tissue model with realistic intracellular volume fractions and cell sizes. DMRI measurements were performed on samples consisting of liposomes containing heavy water(D2 O, deuterium oxide) dispersed in regular water (H2 O). D ex $$ {D}_{ex} $$ was obtained over a broad t $$ t $$ range (∼1-1000 ms) and then fit power-law equations D ex ( t ) = D const + const · t - ϑ t $$ {D}_{ex}(t)={D}_{\mathrm{const}}+\mathrm{const}\cdotp {t}^{-{\vartheta}_t} $$ and D ex ( f ) = D const + const · f ϑ f $$ {D}_{ex}(f)={D}_{\mathrm{const}}+\mathrm{const}\cdotp {f}^{\vartheta_f} $$ . RESULTS: Both simulated and experimental results suggest that no single power-law adequately describes the behavior of D ex $$ {D}_{ex} $$ over the range of diffusion times of most interest in practical dMRI. Previous theoretical predictions are accurate over only limited t $$ t $$ ranges; for example, θ t = θ f = - 1 2 $$ {\theta}_t={\theta}_f=-\frac{1}{2} $$ is valid only for short times, whereas θ t = 1 $$ {\theta}_t=1 $$ or θ f = 3 2 $$ {\theta}_f=\frac{3}{2} $$ is valid only for long times but cannot describe other ranges simultaneously. For the specific t $$ t $$ range of 5-70 ms used in typical human dMRI measurements, θ t = θ f = 1 $$ {\theta}_t={\theta}_f=1 $$ matches the data well empirically. CONCLUSION: The optimal power-law fit of extracellular diffusion varies with diffusion time. The dependency obtained at short or long t $$ t $$ limits cannot be applied to typical dMRI measurements in human cancer or liver. It is essential to determine the appropriate diffusion time range when modeling extracellular diffusion in dMRI-based quantitative microstructural imaging.


Assuntos
Imagem de Difusão por Ressonância Magnética , Neoplasias , Humanos , Imagem de Difusão por Ressonância Magnética/métodos , Difusão , Modelos Biológicos , Simulação por Computador
14.
Blood ; 137(13): 1741-1753, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33024996

RESUMO

Diffuse large B-cell lymphomas (DLBCLs) are clinically and genetically heterogeneous tumors. Deregulation of diverse biological processes specific to B cells, such as B-cell receptor (BCR) signaling and motility regulation, contribute to lymphomagenesis. Human germinal center associated lymphoma (HGAL) is a B-cell-specific adaptor protein controlling BCR signaling and B lymphocyte motility. In normal B cells, it is expressed in germinal center (GC) B lymphocytes and promptly downregulated upon further differentiation. The majority of DLBCL tumors, primarily GC B-cell types, but also activated types, express HGAL. To investigate the consequences of constitutive expression of HGAL in vivo, we generated mice that conditionally express human HGAL at different stages of hematopoietic development using 3 restricted Cre-mediated approaches to initiate expression of HGAL in hematopoietic stem cells, pro-B cells, or GC B cells. Following immune stimulation, we observed larger GCs in mice in which HGAL expression was initiated in GC B cells. All 3 mouse strains developed DLBCL at a frequency of 12% to 30% starting at age 13 months, leading to shorter survival. Immunohistochemical studies showed that all analyzed tumors were of the GC B-cell type. Exon sequencing revealed mutations reported in human DLBCL. Our data demonstrate that constitutive enforced expression of HGAL leads to DLBCL development.


Assuntos
Carcinogênese/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Linfoma Difuso de Grandes Células B/genética , Proteínas dos Microfilamentos/genética , Animais , Carcinogênese/patologia , Linhagem Celular , Feminino , Mutação com Ganho de Função , Regulação Neoplásica da Expressão Gênica , Centro Germinativo/metabolismo , Centro Germinativo/patologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Camundongos Endogâmicos C57BL
15.
Eur J Haematol ; 110(3): 280-288, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36403132

RESUMO

Cold agglutinin disease (CAD) is a rare chronic autoimmune haemolytic anaemia, driven mainly by classical complement pathway activation, leading to profound fatigue and poor quality of life. In the Phase 3 CADENZA trial, sutimlimab-a C1s complement inhibitor-rapidly halted haemolysis, increased haemoglobin levels and improved fatigue versus placebo in patients with CAD without a recent history of transfusion. Patient-reported outcomes (PROs) included Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), 12-Item Short Form Health Survey (SF-12), EuroQol visual analogue scale (EQ-VAS), Patient Global Impression of Change (PGIC) and Patient Global Impression of (fatigue) Severity (PGIS). Sutimlimab resulted in significant rapid and meaningful improvements versus placebo in PROs. From Week 1, the FACIT-Fatigue mean score increased >5 points above baseline (considered a clinically important change [CIC]). Least-squares (LS) mean change in FACIT-Fatigue score from baseline to treatment assessment timepoint was 10.8 vs. 1.9 points (sutimlimab vs. placebo; p < 0.001). Improvements in physical (PCS) and mental (MCS) component scores of the SF-12 were also considered CICs (LS mean changes from baseline to Week 26: PCS 5.54 vs. 1.57 [p = 0.064]; MCS 5.65 vs. -0.48 [p = 0.065]). These findings demonstrate that in addition to improving haematologic parameters, sutimlimab treatment demonstrates significant patient-reported benefits. Study registered at www.clinicaltrials.gov: NCT03347422.


Assuntos
Anemia Hemolítica Autoimune , Anemia Hemolítica , Humanos , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/tratamento farmacológico , Qualidade de Vida , Resultado do Tratamento , Medidas de Resultados Relatados pelo Paciente , Fadiga/diagnóstico , Fadiga/tratamento farmacológico , Fadiga/etiologia , Método Duplo-Cego
16.
Nanotechnology ; 34(21)2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36780669

RESUMO

Successful construction of heterojunction can improve the utilization efficiency of solar light by broadening the absorption range, facilitating charge-carrier separation, promoting carrier transportation and influencing surface-interface reaction. Herein, visible-light-driven AgBr was deposited on the surface of lamellar BiVO4which was prepared by a facile hydrothermal process to improve charge carrier separation, and subsequent photocatalytic effectiveness. The catalyst with an optimal AgBr/BiVO4ratio exhibited a superbly enhanced photocatalytic decolorization ability (about 6.85 times higher than that of pure BiVO4) and high stability after four cycles. The unique photocatalytic mechanism of S-scheme carrier migration was investigated on the bases of radical trapping tests and photo/electrochemical characterizations. Results showed that the enhanced migration strategy and intimately interfacial collaboration guaranteed the effective charge carriers separation/transfer, leading to magnificent photocatalytic performance as well as excellent stability.

17.
Mol Ther ; 30(6): 2163-2175, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35283272

RESUMO

Presynaptic syntaxin binding protein 1 (STXBP1) is essential for neurotransmitter release. Heterozygous mutations in this protein cause STXBP1 encephalopathy (STXBP1-E), which is characterized by intellectual disabilities and epilepsies. Since nonhuman primates closely resemble humans, monkey models may advance studies on the pathogenesis and therapeutic treatments of STXBP1-E. We generated cynomolgus monkeys carrying STXBP1 (R292H) mutation through base editing of in vitro fertilized embryos to mimic a clinical condition. The newborn STXBP1-edited monkeys exhibited focal epilepsy, and the animal that survived beyond the first week postpartum presented typical EEG phenotypes. Biochemical analysis of brain biopsy samples showed reduced levels of STXBP1 (MUNC18-1) and SNARE complex proteins. Single-cell sequencing identified one specific cell cluster that may contribute to encephalopathy. Thus, our case report shows that base-edited STXBP1 mutant monkeys are a good animal model for STXBP1-E, and that a base-editing approach is useful for generating primate models of human genetic disorders.


Assuntos
Encefalopatias , Epilepsia , Animais , Encéfalo/metabolismo , Epilepsia/tratamento farmacológico , Epilepsia/genética , Feminino , Macaca fascicularis/metabolismo , Proteínas Munc18/genética , Proteínas Munc18/metabolismo , Mutação
18.
Sci Technol Adv Mater ; 24(1): 2157682, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36620090

RESUMO

Architected cellular materials are a class of artificial materials with cellular architecture-dependent properties. Typically, designing cellular architectures paves the way to generate architected cellular materials with specific properties. However, most previous studies have primarily focused on a forward design strategy, wherein a geometry is generated using computer-aided design modeling, and its properties are investigated experimentally or via simulations. In this study, we developed an inverse design framework for a disordered architected cellular material (Voronoi lattices) using deep learning. This inverse design framework is a three-dimensional conditional generative adversarial network (3D-CGAN) trained based on supervised learning using a dataset consisting of voxelized Voronoi lattices and their corresponding relative densities and Young's moduli. A well-trained 3D-CGAN adopts variational sampling to generate multiple distinct Voronoi lattices with the target relative density and Young's modulus. Consequently, the mechanical properties of the 3D-CGAN generated Voronoi lattices are validated through uniaxial compression tests and finite element simulations. The inverse design framework demonstrates potential for use in bone implants, where scaffold implants can be automatically generated with the target relative density and Young's modulus.

19.
Int J Mol Sci ; 24(11)2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37298330

RESUMO

In this work, the MnFe2O4/BGA (boron-doped graphene aerogel) composite prepared via the solvothermal method is applied as a photocatalyst to the degradation of tetracycline in the presence of peroxymonosulfate. The composite's phase composition, morphology, valence state of elements, defect and pore structure were analyzed by XRD, SEM/TEM, XPS, Raman scattering and N2 adsorption-desorption isotherms, respectively. Under the radiation of visible light, the experimental parameters, including the ratio of BGA to MnFe2O4, the dosages of MnFe2O4/BGA and PMS, and the initial pH and tetracycline concentration were optimized in line with the degradation of tetracycline. Under the optimized conditions, the degradation rate of tetracycline reached 92.15% within 60 min, whereas the degradation rate constant on MnFe2O4/BGA remained 4.1 × 10-2 min-1, which was 1.93 and 1.56 times of those on BGA and MnFe2O4, respectively. The largely enhanced photocatalytic activity of the MnFe2O4/BGA composite over MnFe2O4 and BGA could be ascribed to the formation of type I heterojunction on the interfaces of BGA and MnFe2O4, which leads to the efficient transfer and separation of photogenerated charge carriers. Transient photocurrent response and electrochemical impedance spectroscopy tests offered solid support to this assumption. In line with the active species trapping experiments, SO4•- and O2•- radicals are confirmed to play crucial roles in the rapid and efficient degradation of tetracycline, and accordingly, a photodegradation mechanism for the degradation of tetracycline on MnFe2O4/BGA is proposed.


Assuntos
Antibacterianos , Tetraciclina , Catálise , Antibacterianos/química , Tetraciclina/química , Fotólise , Luz
20.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615627

RESUMO

Radiotherapy (RT) is one of the main clinical therapeutic strategies against cancer. Currently, multiple radiosensitizers aimed at enhancing X-ray absorption in cancer tissues have been developed, while limitations still exist for their further applications, such as poor cellular uptake, hypoxia-induced radioresistance, and unavoidable damage to adjacent normal body tissues. In order to address these problems, a cell-penetrating TAT peptide (YGRKKRRQRRRC)-modified nanohybrid was constructed by doping high-Z element Au in hollow semiconductor Cu2-xSe nanoparticles for combined RT and photothermal therapy (PTT) against breast cancer. The obtained Cu2-xSe nanoparticles possessed excellent radiosensitizing properties based on their particular band structures, and high photothermal conversion efficiency beneficial for tumor ablation and promoting RT efficacy. Further doping high-Z element Au deposited more high-energy radiation for better radiosensitizing performance. Conjugation of TAT peptides outside the constructed Cu2-xSe/Au nanoparticles facilitated their cellular uptake, thus reducing overdosage-induced side effects. This prepared multifunctional nanohybrid showed powerful suppression effects towards breast cancer, both in vitro and in vivo via integrating enhanced cell penetration and uptake, and combined RT/PTT strategies.


Assuntos
Neoplasias da Mama , Peptídeos Penetradores de Células , Nanopartículas Metálicas , Neoplasias , Humanos , Feminino , Terapia Fototérmica , Nanopartículas Metálicas/uso terapêutico , Nanopartículas Metálicas/química , Ouro/farmacologia , Ouro/química , Neoplasias da Mama/terapia , Linhagem Celular Tumoral
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