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1.
ChemSusChem ; : e202400050, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898597

RESUMO

Alkaline iron (Fe) batteries are attractive due to the high abundance, low cost, and multiple valent states of Fe but show limited columbic efficiency and storage capacity when forming electrochemically inert Fe3O4 on discharging and parasitic H2 on charging. Herein, sodium silicate is found to promote Fe(OH)2/FeOOH against Fe(OH)2/Fe3O4 conversions. Electrochemical experiments, operando X-ray characterization, and atomistic simulations reveal that improved Fe(OH)2/FeOOH conversion originates from (i) strong interaction between sodium silicate and iron oxide and (ii) silicate-induced strengthening of hydrogen-bond networks in electrolytes that inhibits water transport. Furthermore, the silicate additive suppresses hydrogen evolution by impairing energetics of water dissociation and hydroxyl de-sorption on iron surfaces. This new silicate-assisted redox chemistry mitigates H2 and Fe3O4formation, improving storage capacity (199 mAh g-1 in half-cells) and coulombic efficiency (94% after 400 full-cell cycles), paving a path to realizing green battery systems built from earth-abundant materials.

2.
J Biol Chem ; 300(6): 107311, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657866

RESUMO

The Hippo signaling pathway plays an essential role in organ size control and tumorigenesis. Loss of Hippo signal and hyper-activation of the downstream oncogenic YAP signaling are commonly observed in various types of cancers. We previously identified STRN3-containing PP2A phosphatase as a negative regulator of MST1/2 kinases (i.e., Hippo) in gastric cancer (GC), opening the possibility of selectively targeting the PP2Aa-STRN3-MST1/2 axis to recover Hippo signaling against cancer. Here, we further discovered 1) disulfiram (DSF), an FDA-approved drug, which can similarly block the binding of STRN3 to PP2A core enzyme and 2) CX-6258 (CX), a chemical inhibitor, that can disrupt the interaction between STRN3 and MST1/2, both allowing reactivation of Hippo activity to inhibit GC. More importantly, we found these two compounds, via an MST1/2 kinase-dependent manner, inhibit DNA repair to sensitize GC towards chemotherapy. In addition, we identified thiram, a structural analog of DSF, can function similarly to inhibit cancer cell proliferation or enhance chemotherapy sensitivity. Interestingly, inclusion of copper ion enhanced such effects of DSF and thiram on GC treatment. Overall, this work demonstrated that pharmacological targeting of the PP2Aa-STRN3-MST1/2 axis by drug compounds can potently recover Hippo signal for tumor treatment.


Assuntos
Dissulfiram , Via de Sinalização Hippo , Proteínas Serina-Treonina Quinases , Neoplasias Gástricas , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Dissulfiram/farmacologia , Linhagem Celular Tumoral , Animais , Antineoplásicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Camundongos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fator de Crescimento de Hepatócito/metabolismo , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética
3.
Nat Commun ; 14(1): 6416, 2023 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828059

RESUMO

Alteration of the size and stiffness of the nucleus triggered by environmental cues are thought to be important for eukaryotic cell fate and function. However, it remains unclear how context-dependent nuclear remodeling occurs and reprograms gene expression. Here we identify the nuclear envelope proteins SUN1/2 as mechano-regulators of the nucleus during M1 polarization of the macrophage. Specifically, we show that LPS treatment decreases the protein levels of SUN1/2 in a CK2-ßTrCP-dependent manner to shrink and soften the nucleus, therefore altering the chromatin accessibility for M1-associated gene expression. Notably, the transmembrane helix of SUN1/2 is solely required and sufficient for the nuclear mechano-remodeling. Consistently, SUN1/2 depletion in macrophages facilitates their phagocytosis, tissue infiltration, and proinflammatory cytokine production, thereby boosting the antitumor immunity in mice. Thus, our study demonstrates that, in response to inflammatory cues, SUN1/2 proteins act as mechano-regulators to remodel the nucleus and chromatin for M1 polarization of the macrophage.


Assuntos
Núcleo Celular , Proteínas Associadas aos Microtúbulos , Animais , Camundongos , Núcleo Celular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Nucleares/metabolismo , Cromatina/metabolismo
4.
BMC Public Health ; 23(1): 2011, 2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37845647

RESUMO

BACKGROUND: There is limited longitudinal evidence on the hypertensive effects of long-term exposure to ambient O3. We investigated the association between long-term O3 exposure at workplace and incident hypertension, diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure (PP), and mean arterial pressure (MAP) in general working adults. METHODS: We conducted a cohort study by recruiting over 30,000 medical examination attendees through multistage stratified cluster sampling. Participants completed a standard questionnaire and comprehensive medical examination. Three-year ambient O3 concentrations at each employed participant's workplace were estimated using a two-stage machine learning model. Mixed-effects Cox proportional hazards models and linear mixed-effects models were used to examine the effect of O3 concentrations on incident hypertension and blood pressure parameters, respectively. Generalized additive mixed models were used to explore non-linear concentration-response relationships. RESULTS: A total of 16,630 hypertension-free working participants at baseline finished the follow-up. The mean (SD) O3 exposure was 45.26 (2.70) ppb. The cumulative incidence of hypertension was 7.11 (95% CI: 6.76, 7.47) per 100 person-years. Long-term O3 exposure was independently, positively and non-linearly associated with incident hypertension (Hazard ratios (95% CI) for Q2, Q3, and Q4 were 1.77 (1.34, 2.36), 2.06 (1.42, 3.00) and 3.43 (2.46, 4.79), respectively, as compared with the first quartile (Q1)), DBP (ß (95% CI) was 0.65 (0.01, 1.30) for Q2, as compared to Q1), SBP (ß (95% CI) was 2.88 (2.00, 3.77), 2.49 (1.36, 3.61) and 2.61 (1.64, 3.58) for Q2, Q3, and Q4, respectively), PP (ß (95% CI) was 2.12 (1.36, 2.87), 2.03 (1.18, 2.87) and 2.14 (1.38, 2.90) for Q2, Q3, and Q4, respectively), and MAP (ß (95% CI) was 1.39 (0.76, 2.02), 1.04 (0.24, 1.84) and 1.12 (0.43, 1.82) for Q2, Q3, and Q4, respectively). The associations were robust across sex, age, BMI, and when considering PM2.5 and NO2. CONCLUSIONS: To our knowledge, this is the first cohort study in the general population that demonstrates the non-linear hypertensive effects of long-term O3 exposure. The findings are particularly relevant for policymakers and researchers involved in ambient pollution and public health, supporting the integration of reduction of ambient O3 into public health interventions.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Hipertensão , Ozônio , Adulto , Humanos , Ozônio/análise , Pressão Sanguínea , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Estudos de Coortes , Material Particulado/análise , Pequim , Hipertensão/epidemiologia , Local de Trabalho , Exposição Ambiental
7.
Mol Biol Rep ; 50(6): 5081-5089, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37101008

RESUMO

BACKGROUND: With an ageing population, the incidence of bone loss and obesity are increasing. Numerous studies emphasized the multidirectional differentiation ability of mesenchymal stem cells (MSCs), and reported betaine modulated the osteogenic differentiation and adipogenic differentiation of MSCs in vitro. We wondered how betaine affected the differentiation of hAD-MSCs and hUC-MSCs. METHODS AND RESULTS: ALP staining and alizarin red S (ARS) staining were proved 10 mM betaine significantly increased the number of ALP-positive cells and plaque calcified extracellular matrices, accompanying by the up-regulation of OPN, Runx-2 and OCN. Oil red O staining demonstrated the number and size of lipid droplets were reduced, the expression of adipogenic master genes such as PPARγ, CEBPα and FASN were down-regulated simultaneously. For further investigating the mechanism of betaine on hAD-MSCs, RNA-seq was performed in none-differentiation medium. The Gene Ontology (GO) analysis showed fat cell differentiation and bone mineralization function terms were enriched, and KEGG showed PI3K-Akt signaling pathway, cytokine-cytokine receptor interaction and ECM-receptor interaction pathways were enriched in betaine treated hAD-MSCs, demonstrated betaine had a positive inducing effect on osteogenic of hAD-MSCs in the non-differentiation medium in vitro, which is opposite to the effect on adipogenic differentiation. CONCLUSIONS: Our study demonstrated that betaine promoted osteogenic and compromised adipogenic differentiation of hUC-MSCs and hAD-MSCs upon low concentration administration. PI3K-Akt signaling pathway, cytokine-cytokine receptor interaction and ECM-receptor interaction were significantly enriched under betaine-treated. We showed hAD-MSCs were more sensitive to betaine stimulation and have a better differentiation ability than hUC-MSCs. Our results contributed to the exploration of betaine as an aiding agent for MSCs therapy.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Osteogênese/genética , Betaína/farmacologia , Betaína/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células-Tronco Mesenquimais/metabolismo , Citocinas/metabolismo , Diferenciação Celular , Células Cultivadas
8.
Protein Cell ; 14(7): 513-531, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-36921037

RESUMO

As an important part of tumor microenvironment, neutrophils are poorly understood due to their spatiotemporal heterogeneity in tumorigenesis. Here we defined, at single-cell resolution, CD44-CXCR2- neutrophils as tumor-specific neutrophils (tsNeus) in both mouse and human gastric cancer (GC). We uncovered a Hippo regulon in neutrophils with unique YAP signature genes (e.g., ICAM1, CD14, EGR1) distinct from those identified in epithelial and/or cancer cells. Importantly, knockout of YAP/TAZ in neutrophils impaired their differentiation into CD54+ tsNeus and reduced their antitumor activity, leading to accelerated GC progression. Moreover, the relative amounts of CD54+ tsNeus were found to be negatively associated with GC progression and positively associated with patient survival. Interestingly, GC patients receiving neoadjuvant chemotherapy had increased numbers of CD54+ tsNeus. Furthermore, pharmacologically enhancing YAP activity selectively activated neutrophils to suppress refractory GC, with no significant inflammation-related side effects. Thus, our work characterized tumor-specific neutrophils in GC and revealed an essential role of YAP/TAZ-CD54 axis in tsNeus, opening a new possibility to develop neutrophil-based antitumor therapeutics.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias Gástricas , Humanos , Animais , Camundongos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Fatores de Transcrição/metabolismo , Neoplasias Gástricas/patologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Transdução de Sinais/genética , Proteínas de Sinalização YAP , Microambiente Tumoral , Receptores de Hialuronatos/genética
9.
Front Public Health ; 11: 1053421, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36755902

RESUMO

Purpose: Research on the relationship between sleep duration and obesity defined using multiple anthropometric and bioelectrical indices in women remains scarce. We aimed to explore the association between sleep duration and body mass index (BMI), waist-hip ratio (WHR), body fat percentage (PBF) and visceral fat area (VFA) among females. Methods: We recruited women for medical examination using multistage cluster sampling. Sleep was assessed using Pittsburgh Sleep Quality Index (PSQI) and sleep duration was categorized into short (<7 h), optimal (7 <9 h) and long sleep (≥ 9 h). Weight and height were measured using a calibrated stadiometer. Waist circumference was manually measured. PBF, and VFA were estimated by bioelectrical impedance analysis. Data on sociodemographic characteristics and lifestyle factors were also collected and included in the logistic regression models to explore the independent association between sleep duration and obesity defined by different indices. Results: A total of 7,763 women with a mean age of 42.6 ± 13.5 years were included. The percentage of women reporting short and long sleep was 10.3 and 13.4% respectively. The mean BMI, WHR, PBF and VFA were 23.07 ± 3.30 kg/m2, 0.78 ± 0.06, 32.23 ± 6.08% and 91.64 ± 35.97cm2, respectively. Short sleep was independently associated with 35% (95% CI: 1.05-1.75) increased odds of general obesity (BMI ≥ 28 kg/cm2), and long sleep was associated with 18% (95% CI: 1.01-1.37) increased odds of visceral obesity (VFA > 100 cm2). No association was observed between sleep deprivation or excessive sleep and high WHR or high PBF. Conclusion: In women, short sleep was associated with an increased odds of general obesity, whereas long sleep was associated with an increased odds of visceral obesity. Longitudinal observations are needed to confirm this cross-sectional relationship.


Assuntos
Obesidade Abdominal , Obesidade , Duração do Sono , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , População do Leste Asiático , Obesidade/epidemiologia , Obesidade/complicações , Obesidade Abdominal/epidemiologia , Obesidade Abdominal/complicações , Fatores de Risco , Qualidade do Sono , Transtornos do Sono-Vigília
10.
Front Public Health ; 10: 936717, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35968481

RESUMO

Data on updated hyperuricemia prevalence in Beijing-Tianjin-Hebei (BTH) region in China, which is one of the world-class urban agglomerations, is sparse. Overweight/obesity, alcohol consumption, smoking and sedentary behavior are modifiable risk factors (MRFs) for elevated serum uric acid (SUA), but their population attributable fractions (PAFs) for hyperuricemia is still unclear. Using baseline data from the BTH Physical Examination General Population Cohort, we calculated the crude- and adjusted-prevalence of hyperuricemia based on the 30,158 participants aged 18-80 years. Hyperuricemia was defined as SUA >420 µmol/L in men and >360 µmol/L in women, or currently use of uric acid lowering drugs. Overweight/obesity, alcohol consumption, smoking and sedentary behavior were considered as MRFs and their adjusted PAFs were estimated. The prevalence of hyperuricemia was 19.37%, 27.72% in men and 10.69% in women. The PAFs and 95% confidence intervals for overweight, obesity were 16.25% (14.26-18.25%) and 12.08% (11.40-12.77%) in men, 13.95% (12.31-15.59%) and 6.35% (5.97-6.74%) in women, respectively. Alcohol consumption can explain 4.64% (2.72-6.56%) hyperuricemia cases in men, but with no statistical significance in women. Cigarette smoking contributed to 3.15% (1.09-5.21%) cases in men, but a much lower fraction in women (0.85%, 0.49-1.22%). Compared with sedentary time <2 h per day, the PAFs of 2-4 h, 4-6 h, and more than 6 h per day were 3.14% (1.34-4.93%), 6.72% (4.44-8.99%) and 8.04% (4.95-11.13%) in men, respectively. Sedentary time was not found to be associated with hyperuricemia in women. These findings concluded that hyperuricemia is prevalent in this representative Chinese adult general population with substantial sex difference. Four MRFs (overweight/obesity, alcohol consumption, cigarette smoking and sedentary behavior) accounted for a notable proportion of hyperuricemia cases. The PAF estimations enable the exploration of the expected proportion of hyperuricemia cases that could be prevented if the MRFs were removed, which warrants the public health significance of life-style intervention.


Assuntos
Hiperuricemia , Adulto , China/epidemiologia , Feminino , Humanos , Hiperuricemia/epidemiologia , Hiperuricemia/etiologia , Masculino , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Prevalência , Ácido Úrico
11.
J Am Chem Soc ; 144(27): 11938-11942, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35699519

RESUMO

Iron hydroxides are desirable alkaline battery electrodes for low cost and environmental beneficence. However, hydrogen evolution on charging and Fe3O4 formation on discharging cause low storage capacity and poor cycling life. We report that green rust (GR) (Fe2+4Fe3+2 (HO-)12SO4), formed via sulfate insertion, promotes Fe(OH)2/FeOOH conversion and shows a discharge capacity of ∼211 mAh g-1 in half-cells and Coulombic efficiency of 93% after 300 cycles in full-cells. Theoretical calculations show that Fe(OH)2/FeOOH conversion is facilitated by intercalated sulfate anions. Classical molecular dynamics simulations reveal that electrolyte alkalinity strongly impacts the energetics of sulfate solvation, and low alkalinity ensures fast transport of sulfate ions. Anion-insertion-assisted Fe(OH)2/FeOOH conversion, also achieved with Cl- ion, paves a pathway toward efficient utilization of Fe-based electrodes for sustainable applications.


Assuntos
Fontes de Energia Elétrica , Ferro , Hidróxidos , Oxirredução , Sulfatos
12.
J Neuroimaging ; 31(6): 1082-1098, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34128556

RESUMO

BACKGROUND AND PURPOSE: Diffusion MRI of the brain enables to quantify white matter fiber orientations noninvasively. Several approaches have been proposed to estimate such characteristics from diffusion MRI data with spherical deconvolution being one of the most widely used methods. Spherical deconvolution requires to define--or derive from the data--a response function, which is used to compute the fiber orientation distribution (FOD). Different characteristics of the response function are expected to affect the FOD computation and the subsequent fiber tracking. METHODS: In this work, we explored the effects of inaccuracies in the shape factors of the response function on the FOD characteristics. RESULTS: With simulations, we show that the apparent fiber density could be doubled in the presence of underestimated shape factors in the response functions, whereas the overestimation of the shape factor will cause more spurious peaks in the FOD, especially when the signal-to-noise ratio is below 15. Moreover, crossing fiber populations with a separation angle smaller than 60° were more sensitive to inaccuracies in the response function than fiber populations with more orthogonal separation angles. Results with in vivo data demonstrate angular deviations in the FODs and spurious peaks as a result of modified shape factors of the response function, while the reconstruction of the main parts of fiber bundles is well preserved. CONCLUSIONS: This work sheds light on how specific aspects of the response function shape can affect the estimated FODs, and highlights the importance of a proper calibration/definition of the response function.


Assuntos
Imagem de Tensor de Difusão , Substância Branca , Algoritmos , Encéfalo/diagnóstico por imagem , Calibragem , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Substância Branca/diagnóstico por imagem
13.
Infect Dis Poverty ; 10(1): 27, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33795011

RESUMO

BACKGROUND: Sexual transmission among men who have sex with men (MSM) is the dominant route of HIV transmission in China. Extensive use of geosocial networking (GSN) smartphone application (app) has dramatically changed the pattern of sexual behaviors and HIV risk among MSM, but data on HIV incidence and the changing risk behaviors of GSN app-using MSM are limited. We aims to assess the HIV incidence and its correlates among gay GSN app-using MSM in China. METHODS: We constructed an open cohort which was initiated and maintained using a GSN app to assess the HIV incidence among app-using MSM, recruited from June 2017 to December 2018. MSM completed an online questionnaire on their sociodemographic characteristics, sexual behaviors, recreational drug use and sexually transmitted infections status. Then each man had an HIV test, and those tested negatives were enrolled into the cohort. Participants completed follow-ups with additional HIV tests though the app during the study period, and were censored at HIV seroconversion or study end date. HIV incidence was calculated by dividing the sum of observed HIV seroconversions by the observed person-time. Univariate (Chi-square test and Fisher's exact test) and multivariate (proportional hazards regression) analyses were used to examine correlates of HIV incidence. RESULTS: A total of 6957 HIV negative MSM were enrolled in the open cohort, 37 seroconversions occurred among 1937 men contributing 1065 observed person-years: HIV incidence was 3.47 per 100 person-years [95% confidence interval (CI): 2.37-4.57]. More than five sexual partners [hazard ratio (HR) = 2.65, 95% CI: 1.04-6.67], and sex with HIV positive partners (HR = 3.82, 95% CI: 1.16-12.64) in the preceding six months were positively associated with HIV seroconversion. Consistent condom use for anal sex (HR = 0.27, 95% CI: 0.07-0.96), and reporting insertive anal sex only (HR = 0.23, 95% CI: 0.08-0.62) in the preceding six months were protective factors for HIV seroconversion. CONCLUSIONS: Tailored interventions targeting app-using MSM are urgently needed given their high risk of HIV. As a new tool for accessing MSM at higher HIV risk, GSN smartphone app could play an important role in HIV research among MSM.


Assuntos
Infecções por HIV , Aplicativos Móveis , Minorias Sexuais e de Gênero , Pequim , China/epidemiologia , Estudos de Coortes , Infecções por HIV/epidemiologia , Homossexualidade Masculina , Humanos , Incidência , Masculino , Comportamento Sexual , Smartphone , Rede Social
14.
Gastroenterol Res Pract ; 2021: 6610737, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33574839

RESUMO

We propose a modification to the reconstruction method of natural orifice specimen extraction surgery (NOSES) during laparoscopic anterior resection (LAR) for rectal cancer (RC) and evaluated its feasibility and short-term safety by comparing surgical and postoperative outcomes with those of conventional LAR. Twenty patients with RC underwent "double-purse" NOSES-LAR from October 2017 to June 2018. Data of clinicopathological characteristics, surgical and postoperative outcomes, and follow-up findings in NOSES-LAR cases were collected and retrospectively compared with those of conventional LAR to clarify the clinical benefits. The median postoperative hospital stay was lower in the double-purse NOSES group than the conventional group (6.6 vs. 7.1 days, respectively). In the conventional group, anastomotic leakage and incision site infection occurred in one patient each. In contrast, there were no complications in the double-purse group. There were no significant differences in blood loss, surgical duration, and time of the first flatus between the two groups. Additionally, "double-purse" NOSES-LAR was more economical than the conventional LAR. "Double-purse" NOSES-LAR is a safe, feasible, and minimally invasive promising procedure for LAR of RC with faster recovery, while requiring less surgical skills and lower clinical costs.

15.
Hum Brain Mapp ; 42(2): 367-383, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33035372

RESUMO

Gradient nonlinearities in magnetic resonance imaging (MRI) cause spatially varying mismatches between the imposed and the effective gradients and can cause significant biases in rotationally invariant diffusion MRI measures derived from, for example, diffusion tensor imaging. The estimation of the orientational organization of fibrous tissue, which is nowadays frequently performed with spherical deconvolution techniques ideally using higher diffusion weightings, can likewise be biased by gradient nonlinearities. We explore the sensitivity of two established spherical deconvolution approaches to gradient nonlinearities, namely constrained spherical deconvolution (CSD) and damped Richardson-Lucy (dRL). Additionally, we propose an extension of dRL to take into account gradient imperfections, without the need of data interpolation. Simulations show that using the effective b-matrix can improve dRL fiber orientation estimation and reduces angular deviations, while CSD can be more robust to gradient nonlinearity depending on the implementation. Angular errors depend on a complex interplay of many factors, including the direction and magnitude of gradient deviations, underlying microstructure, SNR, anisotropy of the effective response function, and diffusion weighting. Notably, angular deviations can also be observed at lower b-values in contrast to the perhaps common assumption that only high b-value data are affected. In in vivo Human Connectome Project data and acquisitions from an ultrastrong gradient (300 mT/m) scanner, angular differences are observed between applying and not applying the effective gradients in dRL estimation. As even small angular differences can lead to error propagation during tractography and as such impact connectivity analyses, incorporating gradient deviations into the estimation of fiber orientations should make such analyses more reliable.


Assuntos
Encéfalo/diagnóstico por imagem , Bases de Dados Factuais , Imagem de Difusão por Ressonância Magnética/métodos , Fibras Nervosas Mielinizadas , Dinâmica não Linear , Substância Branca/diagnóstico por imagem , Anisotropia , Bases de Dados Factuais/normas , Imagem de Difusão por Ressonância Magnética/normas , Humanos
16.
Neuroimage ; 222: 117206, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32745681

RESUMO

In diffusion MRI, spherical deconvolution approaches can estimate local white matter (WM) fiber orientation distributions (FOD) which can be used to produce fiber tractography reconstructions. The applicability of spherical deconvolution to gray matter (GM), however, is still limited, despite its critical role as start/endpoint of WM fiber pathways. The advent of multi-shell diffusion MRI data offers additional contrast to model the GM signal but, to date, only isotropic models have been applied to GM. Evidence from both histology and high-resolution diffusion MRI studies suggests a marked anisotropic character of the diffusion process in GM, which could be exploited to improve the description of the cortical organization. In this study, we investigated whether performing spherical deconvolution with tissue specific models of both WM and GM can improve the characterization of the latter while retaining state-of-the-art performances in WM. To this end, we developed a framework able to simultaneously accommodate multiple anisotropic response functions to estimate multiple, tissue-specific, fiber orientation distributions (mFODs). As proof of principle, we used the diffusion kurtosis imaging model to represent the WM signal, and the neurite orientation dispersion and density imaging (NODDI) model to represent the GM signal. The feasibility of the proposed approach is shown with numerical simulations and with data from the Human Connectome Project (HCP). The performance of our method is compared to the current state of the art, multi-shell constrained spherical deconvolution (MSCSD). The simulations show that with our new method we can accurately estimate a mixture of two FODs at SNR≥50. With HCP data, the proposed method was able to reconstruct both tangentially and radially oriented FODs in GM, and performed comparably well to MSCSD in computing FODs in WM. When performing fiber tractography, the trajectories reconstructed with mFODs reached the cortex with more spatial continuity and for a longer distance as compared to MSCSD and allowed to reconstruct short trajectories tangential to the cortical folding. In conclusion, we demonstrated that our proposed method allows to perform spherical deconvolution of multiple anisotropic response functions, specifically improving the performances of spherical deconvolution in GM tissue.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Substância Cinzenta/diagnóstico por imagem , Fibras Nervosas/ultraestrutura , Substância Branca/diagnóstico por imagem , Adulto , Simulação por Computador , Estudos de Viabilidade , Humanos
17.
PeerJ ; 8: e9458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32704448

RESUMO

Although much progress has been made to improve treatment, colon cancer remains a leading cause of cancer death worldwide. Metabolic reprogramming is a significant ability of cancer cells to ensure the necessary energy supply in uncontrolled proliferation. Since reprogramming energy metabolism has emerged as a new hallmark of cancer cells, accumulating evidences have suggested that metabolism-related genes may serve as key regulators of tumorigenesis and potential biomarkers. In this study, we analyzed a set of reprogramming energy metabolism-related genes by transcriptome analysis in colon cancer and revealed a five-gene signature that could significantly predict the overall survival. The reprogramming energy metabolism-related signature could distinguish patients into high-risk and low-risk groups with significantly different survival times (P = 0.0011; HR = 1.92; 95% CI [1.29-2.87]). Its prognostic value was confirmed in another two independent colon cancer cohorts (P = 5.2e-04; HR = 2.09, 95%; CI [1.37-3.2] for GSE17538 and P = 3.8e-04; HR = 2.08, 95% CI [1.37-3.16] for GSE41258). By multivariable analysis, we found that the signature was independent of clinicopathological features. Its power in promoting risk stratification of the current clinical stage was then evaluated by stratified analysis. Moreover, the signature could improve the power of the TNM stage for the prediction of overall survival and could be used in patients who received adjuvant chemotherapy. Overall, our results demonstrated the important role of the reprogramming energy metabolism-related signature in promoting stratification of high-risk patients, which could be diagnostic of adjuvant therapy benefit.

18.
Cancer Cell ; 38(1): 115-128.e9, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32589942

RESUMO

Loss of Hippo tumor-suppressor activity and hyperactivation of YAP are commonly observed in cancers. Inactivating mutations of Hippo kinases MST1/2 are uncommon, and it remains unclear how their activity is turned off during tumorigenesis. We identified STRN3 as an essential regulatory subunit of protein phosphatase 2A (PP2A) that recruits MST1/2 and promotes its dephosphorylation, which results in YAP activation. We also identified STRN3 upregulation in gastric cancer correlated with YAP activation and poor prognosis. Based on this mechanistic understanding and aided by structure-guided medicinal chemistry, we developed a highly selective peptide inhibitor, STRN3-derived Hippo-activating peptide, or SHAP, which disrupts the STRN3-PP2Aa interaction and reactivates the Hippo tumor suppressor, inhibits YAP activation, and has antitumor effects in vivo.


Assuntos
Autoantígenos/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Peptídeos/farmacologia , Proteína Fosfatase 2/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias Gástricas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Sequência de Aminoácidos , Animais , Autoantígenos/genética , Proteínas de Ligação a Calmodulina/genética , Linhagem Celular Tumoral , Feminino , Via de Sinalização Hippo , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/prevenção & controle , Proteínas Supressoras de Tumor/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
19.
Neuroimage ; 218: 116948, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32428705

RESUMO

Spherical deconvolution is a widely used approach to quantify the fiber orientation distribution (FOD) from diffusion MRI data of the brain. The damped Richardson-Lucy (dRL) is an algorithm developed to perform robust spherical deconvolution on single-shell diffusion MRI data while suppressing spurious FOD peaks due to noise or partial volume effects. Due to recent progress in acquisition hardware and scanning protocols, it is becoming increasingly common to acquire multi-shell diffusion MRI data, which allows for the modelling of multiple tissue types beyond white matter. While the dRL algorithm could, in theory, be directly applied to multi-shell data, it is not optimised to exploit its information content to model the signal from multiple tissue types. In this work, we introduce a new framework based on dRL - dubbed generalized Richardson-Lucy (GRL) - that uses multi-shell data in combination with user-chosen tissue models to disentangle partial volume effects and increase the accuracy in FOD estimation. Further, GRL estimates signal fraction maps associated to each user-selected model, which can be used during fiber tractography to dissect and terminate the tracking without need for additional structural data. The optimal weighting of multi-shell data in the fit and the robustness to noise and to partial volume effects of GRL was studied with synthetic data. Subsequently, we investigated the performance of GRL in comparison to dRL and to multi-shell constrained spherical deconvolution (MSCSD) on a high-resolution diffusion MRI dataset from the Human Connectome Project and on an MRI dataset acquired at 3T on a clinical scanner. In line with previous studies, we described the signal of the cerebrospinal-fluid and of the grey matter with isotropic diffusion models, whereas four diffusion models were considered to describe the white matter. With a third dataset including small diffusion weightings, we studied the feasibility of including intra-voxel incoherent motion effects due to blood pseudo-diffusion in the modelling. Further, the reliability of GRL was demonstrated with a test-retest scan of a subject acquired at 3T. Results of simulations show that GRL can robustly disentangle different tissue types at SNR above 20 with respect to the non-weighted image, and that it improves the angular accuracy of the FOD estimation as compared to dRL. On real data, GRL provides signal fraction maps that are physiologically plausible and consistent with those obtained with MSCSD, with correlation coefficients between the two methods up to 0.96. When considering IVIM effects, a high blood pseudo-diffusion fraction is observed in the medial temporal lobe and in the sagittal sinus. In comparison to dRL and MSCSD, GRL provided sharper FODs and less spurious peaks in presence of partial volume effects, but the FOD reconstructions are also highly dependent on the chosen modelling of white matter. When performing fiber tractography, GRL allows to terminate fiber tractography using the signal fraction maps, which results in a better tract termination at the grey-white matter interface or at the outer cortical surface. In terms of inter-scan reliability, GRL performed similarly to or better than compared methods. In conclusion, GRL offers a new modular and flexible framework to perform spherical deconvolution of multi-shell data.


Assuntos
Algoritmos , Imagem de Difusão por Ressonância Magnética/métodos , Processamento de Imagem Assistida por Computador/métodos , Mapeamento Encefálico , Líquido Cefalorraquidiano , Simulação por Computador , Conectoma , Imagem de Difusão por Ressonância Magnética/estatística & dados numéricos , Estudos de Viabilidade , Humanos , Reprodutibilidade dos Testes , Seio Sagital Superior/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
20.
Nat Commun ; 10(1): 4975, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31672984

RESUMO

Birnessite is a low-cost and environmentally friendly layered material for aqueous electrochemical energy storage; however, its storage capacity is poor due to its narrow potential window in aqueous electrolyte and low redox activity. Herein we report a sodium rich disordered birnessite (Na0.27MnO2) for aqueous sodium-ion electrochemical storage with a much-enhanced capacity and cycling life (83 mAh g-1 after 5000 cycles in full-cell). Neutron total scattering and in situ X-ray diffraction measurements show that both structural water and the Na-rich disordered structure contribute to the improved electrochemical performance of current cathode material. Particularly, the co-deintercalation of the hydrated water and sodium-ion during the high potential charging process results in the shrinkage of interlayer distance and thus stabilizes the layered structure. Our results provide a genuine insight into how structural disordering and structural water improve sodium-ion storage in a layered electrode and open up an exciting direction for improving aqueous batteries.

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